diff options
Diffstat (limited to 'src/cpu/o3')
66 files changed, 15949 insertions, 4765 deletions
diff --git a/src/cpu/o3/2bit_local_pred.cc b/src/cpu/o3/2bit_local_pred.cc index 2ed2de1f9..77a45ea26 100644 --- a/src/cpu/o3/2bit_local_pred.cc +++ b/src/cpu/o3/2bit_local_pred.cc @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,27 +28,37 @@ * Authors: Kevin Lim */ +#include "base/intmath.hh" +#include "base/misc.hh" #include "base/trace.hh" #include "cpu/o3/2bit_local_pred.hh" -DefaultBP::DefaultBP(unsigned _localPredictorSize, - unsigned _localCtrBits, - unsigned _instShiftAmt) +LocalBP::LocalBP(unsigned _localPredictorSize, + unsigned _localCtrBits, + unsigned _instShiftAmt) : localPredictorSize(_localPredictorSize), localCtrBits(_localCtrBits), instShiftAmt(_instShiftAmt) { - // Should do checks here to make sure sizes are correct (powers of 2). + if (!isPowerOf2(localPredictorSize)) { + fatal("Invalid local predictor size!\n"); + } + + localPredictorSets = localPredictorSize / localCtrBits; + + if (!isPowerOf2(localPredictorSets)) { + fatal("Invalid number of local predictor sets! Check localCtrBits.\n"); + } // Setup the index mask. - indexMask = localPredictorSize - 1; + indexMask = localPredictorSets - 1; DPRINTF(Fetch, "Branch predictor: index mask: %#x\n", indexMask); // Setup the array of counters for the local predictor. - localCtrs = new SatCounter[localPredictorSize]; + localCtrs.resize(localPredictorSets); - for (int i = 0; i < localPredictorSize; ++i) + for (int i = 0; i < localPredictorSets; ++i) localCtrs[i].setBits(_localCtrBits); DPRINTF(Fetch, "Branch predictor: local predictor size: %i\n", @@ -60,24 +70,30 @@ DefaultBP::DefaultBP(unsigned _localPredictorSize, instShiftAmt); } +void +LocalBP::reset() +{ + for (int i = 0; i < localPredictorSets; ++i) { + localCtrs[i].reset(); + } +} + bool -DefaultBP::lookup(Addr &branch_addr) +LocalBP::lookup(Addr &branch_addr, void * &bp_history) { bool taken; - uint8_t local_prediction; + uint8_t counter_val; unsigned local_predictor_idx = getLocalIndex(branch_addr); DPRINTF(Fetch, "Branch predictor: Looking up index %#x\n", local_predictor_idx); - assert(local_predictor_idx < localPredictorSize); - - local_prediction = localCtrs[local_predictor_idx].read(); + counter_val = localCtrs[local_predictor_idx].read(); DPRINTF(Fetch, "Branch predictor: prediction is %i.\n", - (int)local_prediction); + (int)counter_val); - taken = getPrediction(local_prediction); + taken = getPrediction(counter_val); #if 0 // Speculative update. @@ -94,8 +110,9 @@ DefaultBP::lookup(Addr &branch_addr) } void -DefaultBP::update(Addr &branch_addr, bool taken) +LocalBP::update(Addr &branch_addr, bool taken, void *bp_history) { + assert(bp_history == NULL); unsigned local_predictor_idx; // Update the local predictor. @@ -104,8 +121,6 @@ DefaultBP::update(Addr &branch_addr, bool taken) DPRINTF(Fetch, "Branch predictor: Looking up index %#x\n", local_predictor_idx); - assert(local_predictor_idx < localPredictorSize); - if (taken) { DPRINTF(Fetch, "Branch predictor: Branch updated as taken.\n"); localCtrs[local_predictor_idx].increment(); @@ -117,7 +132,7 @@ DefaultBP::update(Addr &branch_addr, bool taken) inline bool -DefaultBP::getPrediction(uint8_t &count) +LocalBP::getPrediction(uint8_t &count) { // Get the MSB of the count return (count >> (localCtrBits - 1)); @@ -125,7 +140,7 @@ DefaultBP::getPrediction(uint8_t &count) inline unsigned -DefaultBP::getLocalIndex(Addr &branch_addr) +LocalBP::getLocalIndex(Addr &branch_addr) { return (branch_addr >> instShiftAmt) & indexMask; } diff --git a/src/cpu/o3/2bit_local_pred.hh b/src/cpu/o3/2bit_local_pred.hh index 808f3e96e..0a2a71d3e 100644 --- a/src/cpu/o3/2bit_local_pred.hh +++ b/src/cpu/o3/2bit_local_pred.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,41 +28,61 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_2BIT_LOCAL_PRED_HH__ -#define __CPU_O3_CPU_2BIT_LOCAL_PRED_HH__ +#ifndef __CPU_O3_2BIT_LOCAL_PRED_HH__ +#define __CPU_O3_2BIT_LOCAL_PRED_HH__ // For Addr type. #include "arch/isa_traits.hh" #include "cpu/o3/sat_counter.hh" -class DefaultBP +#include <vector> + +/** + * Implements a local predictor that uses the PC to index into a table of + * counters. Note that any time a pointer to the bp_history is given, it + * should be NULL using this predictor because it does not have any branch + * predictor state that needs to be recorded or updated; the update can be + * determined solely by the branch being taken or not taken. + */ +class LocalBP { public: /** * Default branch predictor constructor. + * @param localPredictorSize Size of the local predictor. + * @param localCtrBits Number of bits per counter. + * @param instShiftAmt Offset amount for instructions to ignore alignment. */ - DefaultBP(unsigned localPredictorSize, unsigned localCtrBits, - unsigned instShiftAmt); + LocalBP(unsigned localPredictorSize, unsigned localCtrBits, + unsigned instShiftAmt); /** * Looks up the given address in the branch predictor and returns * a true/false value as to whether it is taken. * @param branch_addr The address of the branch to look up. + * @param bp_history Pointer to any bp history state. * @return Whether or not the branch is taken. */ - bool lookup(Addr &branch_addr); + bool lookup(Addr &branch_addr, void * &bp_history); /** * Updates the branch predictor with the actual result of a branch. * @param branch_addr The address of the branch to update. * @param taken Whether or not the branch was taken. */ - void update(Addr &branch_addr, bool taken); + void update(Addr &branch_addr, bool taken, void *bp_history); - private: + void squash(void *bp_history) + { assert(bp_history == NULL); } + + void reset(); - /** Returns the taken/not taken prediction given the value of the + private: + /** + * Returns the taken/not taken prediction given the value of the * counter. + * @param count The value of the counter. + * @return The prediction based on the counter value. */ inline bool getPrediction(uint8_t &count); @@ -70,11 +90,14 @@ class DefaultBP inline unsigned getLocalIndex(Addr &PC); /** Array of counters that make up the local predictor. */ - SatCounter *localCtrs; + std::vector<SatCounter> localCtrs; /** Size of the local predictor. */ unsigned localPredictorSize; + /** Number of sets. */ + unsigned localPredictorSets; + /** Number of bits of the local predictor's counters. */ unsigned localCtrBits; @@ -85,4 +108,4 @@ class DefaultBP unsigned indexMask; }; -#endif // __CPU_O3_CPU_2BIT_LOCAL_PRED_HH__ +#endif // __CPU_O3_2BIT_LOCAL_PRED_HH__ diff --git a/src/cpu/o3/alpha_cpu.hh b/src/cpu/o3/alpha_cpu.hh index 04d923ce4..f81837f3c 100644 --- a/src/cpu/o3/alpha_cpu.hh +++ b/src/cpu/o3/alpha_cpu.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,266 +28,407 @@ * Authors: Kevin Lim */ -// Todo: Find all the stuff in ExecContext and ev5 that needs to be -// specifically designed for this CPU. +#ifndef __CPU_O3_ALPHA_FULL_CPU_HH__ +#define __CPU_O3_ALPHA_FULL_CPU_HH__ -#ifndef __CPU_O3_CPU_ALPHA_FULL_CPU_HH__ -#define __CPU_O3_CPU_ALPHA_FULL_CPU_HH__ - -#include "cpu/o3/cpu.hh" #include "arch/isa_traits.hh" +#include "cpu/thread_context.hh" +#include "cpu/o3/cpu.hh" #include "sim/byteswap.hh" +class EndQuiesceEvent; +namespace Kernel { + class Statistics; +}; + +class TranslatingPort; + +/** + * AlphaFullCPU class. Derives from the FullO3CPU class, and + * implements all ISA and implementation specific functions of the + * CPU. This is the CPU class that is used for the SimObjects, and is + * what is given to the DynInsts. Most of its state exists in the + * FullO3CPU; the state is has is mainly for ISA specific + * functionality. + */ template <class Impl> class AlphaFullCPU : public FullO3CPU<Impl> { protected: typedef TheISA::IntReg IntReg; + typedef TheISA::FloatReg FloatReg; + typedef TheISA::FloatRegBits FloatRegBits; typedef TheISA::MiscReg MiscReg; typedef TheISA::RegFile RegFile; typedef TheISA::MiscRegFile MiscRegFile; public: + typedef O3ThreadState<Impl> ImplState; + typedef O3ThreadState<Impl> Thread; typedef typename Impl::Params Params; - public: - AlphaFullCPU(Params ¶ms); + /** Constructs an AlphaFullCPU with the given parameters. */ + AlphaFullCPU(Params *params); + + /** + * Derived ThreadContext class for use with the AlphaFullCPU. It + * provides the interface for any external objects to access a + * single thread's state and some general CPU state. Any time + * external objects try to update state through this interface, + * the CPU will create an event to squash all in-flight + * instructions in order to ensure state is maintained correctly. + * It must be defined specifically for the AlphaFullCPU because + * not all architectural state is located within the O3ThreadState + * (such as the commit PC, and registers), and specific actions + * must be taken when using this interface (such as squashing all + * in-flight instructions when doing a write to this interface). + */ + class AlphaTC : public ThreadContext + { + public: + /** Pointer to the CPU. */ + AlphaFullCPU<Impl> *cpu; + + /** Pointer to the thread state that this TC corrseponds to. */ + O3ThreadState<Impl> *thread; + + /** Returns a pointer to this CPU. */ + virtual BaseCPU *getCpuPtr() { return cpu; } + + /** Sets this CPU's ID. */ + virtual void setCpuId(int id) { cpu->cpu_id = id; } + + /** Reads this CPU's ID. */ + virtual int readCpuId() { return cpu->cpu_id; } + +#if FULL_SYSTEM + /** Returns a pointer to the system. */ + virtual System *getSystemPtr() { return cpu->system; } + + /** Returns a pointer to physical memory. */ + virtual PhysicalMemory *getPhysMemPtr() { return cpu->physmem; } + + /** Returns a pointer to the ITB. */ + virtual AlphaITB *getITBPtr() { return cpu->itb; } + + /** Returns a pointer to the DTB. */ + virtual AlphaDTB *getDTBPtr() { return cpu->dtb; } + + /** Returns a pointer to this thread's kernel statistics. */ + virtual Kernel::Statistics *getKernelStats() + { return thread->kernelStats; } + + virtual FunctionalPort *getPhysPort() { return thread->getPhysPort(); } + + virtual VirtualPort *getVirtPort(ThreadContext *src_tc = NULL); + + void delVirtPort(VirtualPort *vp); +#else + virtual TranslatingPort *getMemPort() { return thread->getMemPort(); } + + /** Returns a pointer to this thread's process. */ + virtual Process *getProcessPtr() { return thread->getProcessPtr(); } +#endif + /** Returns this thread's status. */ + virtual Status status() const { return thread->status(); } + + /** Sets this thread's status. */ + virtual void setStatus(Status new_status) + { thread->setStatus(new_status); } + + /** Set the status to Active. Optional delay indicates number of + * cycles to wait before beginning execution. */ + virtual void activate(int delay = 1); + + /** Set the status to Suspended. */ + virtual void suspend(); + + /** Set the status to Unallocated. */ + virtual void deallocate(); + + /** Set the status to Halted. */ + virtual void halt(); + +#if FULL_SYSTEM + /** Dumps the function profiling information. + * @todo: Implement. + */ + virtual void dumpFuncProfile(); +#endif + /** Takes over execution of a thread from another CPU. */ + virtual void takeOverFrom(ThreadContext *old_context); + + /** Registers statistics associated with this TC. */ + virtual void regStats(const std::string &name); + + /** Serializes state. */ + virtual void serialize(std::ostream &os); + /** Unserializes state. */ + virtual void unserialize(Checkpoint *cp, const std::string §ion); + +#if FULL_SYSTEM + /** Returns pointer to the quiesce event. */ + virtual EndQuiesceEvent *getQuiesceEvent(); + + /** Reads the last tick that this thread was activated on. */ + virtual Tick readLastActivate(); + /** Reads the last tick that this thread was suspended on. */ + virtual Tick readLastSuspend(); + + /** Clears the function profiling information. */ + virtual void profileClear(); + /** Samples the function profiling information. */ + virtual void profileSample(); +#endif + /** Returns this thread's ID number. */ + virtual int getThreadNum() { return thread->readTid(); } + + /** Returns the instruction this thread is currently committing. + * Only used when an instruction faults. + */ + virtual TheISA::MachInst getInst(); + + /** Copies the architectural registers from another TC into this TC. */ + virtual void copyArchRegs(ThreadContext *tc); + + /** Resets all architectural registers to 0. */ + virtual void clearArchRegs(); + + /** Reads an integer register. */ + virtual uint64_t readIntReg(int reg_idx); + + virtual FloatReg readFloatReg(int reg_idx, int width); + + virtual FloatReg readFloatReg(int reg_idx); + + virtual FloatRegBits readFloatRegBits(int reg_idx, int width); + + virtual FloatRegBits readFloatRegBits(int reg_idx); + + /** Sets an integer register to a value. */ + virtual void setIntReg(int reg_idx, uint64_t val); + + virtual void setFloatReg(int reg_idx, FloatReg val, int width); + + virtual void setFloatReg(int reg_idx, FloatReg val); + + virtual void setFloatRegBits(int reg_idx, FloatRegBits val, int width); + + virtual void setFloatRegBits(int reg_idx, FloatRegBits val); + + /** Reads this thread's PC. */ + virtual uint64_t readPC() + { return cpu->readPC(thread->readTid()); } + + /** Sets this thread's PC. */ + virtual void setPC(uint64_t val); + + /** Reads this thread's next PC. */ + virtual uint64_t readNextPC() + { return cpu->readNextPC(thread->readTid()); } + + /** Sets this thread's next PC. */ + virtual void setNextPC(uint64_t val); + + virtual uint64_t readNextNPC() + { + panic("Alpha has no NextNPC!"); + return 0; + } + + virtual void setNextNPC(uint64_t val) + { } + + /** Reads a miscellaneous register. */ + virtual MiscReg readMiscReg(int misc_reg) + { return cpu->readMiscReg(misc_reg, thread->readTid()); } + + /** Reads a misc. register, including any side-effects the + * read might have as defined by the architecture. */ + virtual MiscReg readMiscRegWithEffect(int misc_reg, Fault &fault) + { return cpu->readMiscRegWithEffect(misc_reg, fault, thread->readTid()); } + + /** Sets a misc. register. */ + virtual Fault setMiscReg(int misc_reg, const MiscReg &val); + + /** Sets a misc. register, including any side-effects the + * write might have as defined by the architecture. */ + virtual Fault setMiscRegWithEffect(int misc_reg, const MiscReg &val); + + /** Returns the number of consecutive store conditional failures. */ + // @todo: Figure out where these store cond failures should go. + virtual unsigned readStCondFailures() + { return thread->storeCondFailures; } + + /** Sets the number of consecutive store conditional failures. */ + virtual void setStCondFailures(unsigned sc_failures) + { thread->storeCondFailures = sc_failures; } + +#if FULL_SYSTEM + /** Returns if the thread is currently in PAL mode, based on + * the PC's value. */ + virtual bool inPalMode() + { return TheISA::PcPAL(cpu->readPC(thread->readTid())); } +#endif + // Only really makes sense for old CPU model. Lots of code + // outside the CPU still checks this function, so it will + // always return false to keep everything working. + /** Checks if the thread is misspeculating. Because it is + * very difficult to determine if the thread is + * misspeculating, this is set as false. */ + virtual bool misspeculating() { return false; } + +#if !FULL_SYSTEM + /** Gets a syscall argument by index. */ + virtual IntReg getSyscallArg(int i); + + /** Sets a syscall argument. */ + virtual void setSyscallArg(int i, IntReg val); + + /** Sets the syscall return value. */ + virtual void setSyscallReturn(SyscallReturn return_value); + + /** Executes a syscall in SE mode. */ + virtual void syscall(int64_t callnum) + { return cpu->syscall(callnum, thread->readTid()); } + + /** Reads the funcExeInst counter. */ + virtual Counter readFuncExeInst() { return thread->funcExeInst; } +#endif + virtual void changeRegFileContext(TheISA::RegFile::ContextParam param, + TheISA::RegFile::ContextVal val) + { panic("Not supported on Alpha!"); } + }; #if FULL_SYSTEM + /** ITB pointer. */ AlphaITB *itb; + /** DTB pointer. */ AlphaDTB *dtb; #endif - public: + /** Registers statistics. */ void regStats(); #if FULL_SYSTEM - //Note that the interrupt stuff from the base CPU might be somewhat - //ISA specific (ie NumInterruptLevels). These functions might not - //be needed in FullCPU though. -// void post_interrupt(int int_num, int index); -// void clear_interrupt(int int_num, int index); -// void clear_interrupts(); - - Fault translateInstReq(MemReqPtr &req) + /** Translates instruction requestion. */ + Fault translateInstReq(RequestPtr &req, Thread *thread) { - return itb->translate(req); + return itb->translate(req, thread->getTC()); } - Fault translateDataReadReq(MemReqPtr &req) + /** Translates data read request. */ + Fault translateDataReadReq(RequestPtr &req, Thread *thread) { - return dtb->translate(req, false); + return dtb->translate(req, thread->getTC(), false); } - Fault translateDataWriteReq(MemReqPtr &req) + /** Translates data write request. */ + Fault translateDataWriteReq(RequestPtr &req, Thread *thread) { - return dtb->translate(req, true); + return dtb->translate(req, thread->getTC(), true); } #else - Fault dummyTranslation(MemReqPtr &req) + /** Translates instruction requestion in syscall emulation mode. */ + Fault translateInstReq(RequestPtr &req, Thread *thread) { -#if 0 - assert((req->vaddr >> 48 & 0xffff) == 0); -#endif - - // put the asid in the upper 16 bits of the paddr - req->paddr = req->vaddr & ~((Addr)0xffff << sizeof(Addr) * 8 - 16); - req->paddr = req->paddr | (Addr)req->asid << sizeof(Addr) * 8 - 16; - return NoFault; + return thread->getProcessPtr()->pTable->translate(req); } - Fault translateInstReq(MemReqPtr &req) + /** Translates data read request in syscall emulation mode. */ + Fault translateDataReadReq(RequestPtr &req, Thread *thread) { - return dummyTranslation(req); + return thread->getProcessPtr()->pTable->translate(req); } - Fault translateDataReadReq(MemReqPtr &req) + /** Translates data write request in syscall emulation mode. */ + Fault translateDataWriteReq(RequestPtr &req, Thread *thread) { - return dummyTranslation(req); - } - - Fault translateDataWriteReq(MemReqPtr &req) - { - return dummyTranslation(req); + return thread->getProcessPtr()->pTable->translate(req); } #endif + /** Reads a miscellaneous register. */ + MiscReg readMiscReg(int misc_reg, unsigned tid); - // Later on may want to remove this misc stuff from the regfile and - // have it handled at this level. Might prove to be an issue when - // trying to rename source/destination registers... - MiscReg readMiscReg(int misc_reg) - { - // Dummy function for now. - // @todo: Fix this once reg file gets fixed. - return 0; - } + /** Reads a misc. register, including any side effects the read + * might have as defined by the architecture. + */ + MiscReg readMiscRegWithEffect(int misc_reg, Fault &fault, unsigned tid); - Fault setMiscReg(int misc_reg, const MiscReg &val) - { - // Dummy function for now. - // @todo: Fix this once reg file gets fixed. - return NoFault; - } + /** Sets a miscellaneous register. */ + Fault setMiscReg(int misc_reg, const MiscReg &val, unsigned tid); + + /** Sets a misc. register, including any side effects the write + * might have as defined by the architecture. + */ + Fault setMiscRegWithEffect(int misc_reg, const MiscReg &val, unsigned tid); + + /** Initiates a squash of all in-flight instructions for a given + * thread. The source of the squash is an external update of + * state through the TC. + */ + void squashFromTC(unsigned tid); - // Most of the full system code and syscall emulation is not yet - // implemented. These functions do show what the final interface will - // look like. #if FULL_SYSTEM + /** Posts an interrupt. */ + void post_interrupt(int int_num, int index); + /** Reads the interrupt flag. */ int readIntrFlag(); + /** Sets the interrupt flags. */ void setIntrFlag(int val); - Fault hwrei(); - bool inPalMode() { return AlphaISA::PcPAL(this->regFile.readPC()); } + /** HW return from error interrupt. */ + Fault hwrei(unsigned tid); + /** Returns if a specific PC is a PAL mode PC. */ bool inPalMode(uint64_t PC) { return AlphaISA::PcPAL(PC); } - void trap(Fault fault); - bool simPalCheck(int palFunc); + /** Traps to handle given fault. */ + void trap(Fault fault, unsigned tid); + bool simPalCheck(int palFunc, unsigned tid); + /** Processes any interrupts. */ void processInterrupts(); -#endif - - -#if !FULL_SYSTEM - // Need to change these into regfile calls that directly set a certain - // register. Actually, these functions should handle most of this - // functionality by themselves; should look up the rename and then - // set the register. - IntReg getSyscallArg(int i) - { - return this->cpuXC->readIntReg(AlphaISA::ArgumentReg0 + i); - } - - // used to shift args for indirect syscall - void setSyscallArg(int i, IntReg val) - { - this->cpuXC->setIntReg(AlphaISA::ArgumentReg0 + i, val); - } - - void setSyscallReturn(int64_t return_value) - { - // check for error condition. Alpha syscall convention is to - // indicate success/failure in reg a3 (r19) and put the - // return value itself in the standard return value reg (v0). - const int RegA3 = 19; // only place this is used - if (return_value >= 0) { - // no error - this->cpuXC->setIntReg(RegA3, 0); - this->cpuXC->setIntReg(AlphaISA::ReturnValueReg, return_value); - } else { - // got an error, return details - this->cpuXC->setIntReg(RegA3, (IntReg) -1); - this->cpuXC->setIntReg(AlphaISA::ReturnValueReg, -return_value); - } - } - - void syscall(short thread_num); - void squashStages(); - -#endif - - void copyToXC(); - void copyFromXC(); - - public: -#if FULL_SYSTEM - bool palShadowEnabled; - - // Not sure this is used anywhere. - void intr_post(RegFile *regs, Fault fault, Addr pc); - // Actually used within exec files. Implement properly. - void swapPALShadow(bool use_shadow); - // Called by CPU constructor. Can implement as I please. - void initCPU(RegFile *regs); - // Called by initCPU. Implement as I please. - void initIPRs(RegFile *regs); + /** Halts the CPU. */ void halt() { panic("Halt not implemented!\n"); } #endif - template <class T> - Fault read(MemReqPtr &req, T &data) - { -#if FULL_SYSTEM && THE_ISA == ALPHA_ISA - if (req->flags & LOCKED) { - req->xc->setMiscReg(TheISA::Lock_Addr_DepTag, req->paddr); - req->xc->setMiscReg(TheISA::Lock_Flag_DepTag, true); - } +#if !FULL_SYSTEM + /** Executes a syscall. + * @todo: Determine if this needs to be virtual. + */ + void syscall(int64_t callnum, int tid); + /** Gets a syscall argument. */ + IntReg getSyscallArg(int i, int tid); + + /** Used to shift args for indirect syscall. */ + void setSyscallArg(int i, IntReg val, int tid); + + /** Sets the return value of a syscall. */ + void setSyscallReturn(SyscallReturn return_value, int tid); #endif - Fault error; - error = this->mem->read(req, data); - data = gtoh(data); - return error; - } - + /** CPU read function, forwards read to LSQ. */ template <class T> - Fault read(MemReqPtr &req, T &data, int load_idx) + Fault read(RequestPtr &req, T &data, int load_idx) { return this->iew.ldstQueue.read(req, data, load_idx); } + /** CPU write function, forwards write to LSQ. */ template <class T> - Fault write(MemReqPtr &req, T &data) - { -#if FULL_SYSTEM && THE_ISA == ALPHA_ISA - ExecContext *xc; - - // If this is a store conditional, act appropriately - if (req->flags & LOCKED) { - xc = req->xc; - - if (req->flags & UNCACHEABLE) { - // Don't update result register (see stq_c in isa_desc) - req->result = 2; - xc->setStCondFailures(0);//Needed? [RGD] - } else { - bool lock_flag = xc->readMiscReg(TheISA::Lock_Flag_DepTag); - Addr lock_addr = xc->readMiscReg(TheISA::Lock_Addr_DepTag); - req->result = lock_flag; - if (!lock_flag || - ((lock_addr & ~0xf) != (req->paddr & ~0xf))) { - xc->setMiscReg(TheISA::Lock_Flag_DepTag, false); - xc->setStCondFailures(xc->readStCondFailures() + 1); - if (((xc->readStCondFailures()) % 100000) == 0) { - std::cerr << "Warning: " - << xc->readStCondFailures() - << " consecutive store conditional failures " - << "on cpu " << req->xc->readCpuId() - << std::endl; - } - return NoFault; - } - else xc->setStCondFailures(0); - } - } - - // Need to clear any locked flags on other proccessors for - // this address. Only do this for succsful Store Conditionals - // and all other stores (WH64?). Unsuccessful Store - // Conditionals would have returned above, and wouldn't fall - // through. - for (int i = 0; i < this->system->execContexts.size(); i++){ - xc = this->system->execContexts[i]; - if ((xc->readMiscReg(TheISA::Lock_Addr_DepTag) & ~0xf) == - (req->paddr & ~0xf)) { - xc->setMiscReg(TheISA::Lock_Flag_DepTag, false); - } - } - -#endif - - return this->mem->write(req, (T)htog(data)); - } - - template <class T> - Fault write(MemReqPtr &req, T &data, int store_idx) + Fault write(RequestPtr &req, T &data, int store_idx) { return this->iew.ldstQueue.write(req, data, store_idx); } + Addr lockAddr; + + /** Temporary fix for the lock flag, works in the UP case. */ + bool lockFlag; }; -#endif // __CPU_O3_CPU_ALPHA_FULL_CPU_HH__ +#endif // __CPU_O3_ALPHA_FULL_CPU_HH__ diff --git a/src/cpu/o3/alpha_cpu_builder.cc b/src/cpu/o3/alpha_cpu_builder.cc index 8c7bea003..828977ccb 100644 --- a/src/cpu/o3/alpha_cpu_builder.cc +++ b/src/cpu/o3/alpha_cpu_builder.cc @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,39 +28,19 @@ * Authors: Kevin Lim */ -#include "base/inifile.hh" -#include "base/loader/symtab.hh" -#include "base/misc.hh" +#include <string> + #include "cpu/base.hh" -#include "cpu/exetrace.hh" #include "cpu/o3/alpha_cpu.hh" #include "cpu/o3/alpha_impl.hh" -#include "mem/base_mem.hh" -#include "mem/cache/base_cache.hh" -#include "mem/mem_interface.hh" +#include "cpu/o3/alpha_params.hh" +#include "cpu/o3/fu_pool.hh" #include "sim/builder.hh" -#include "sim/debug.hh" -#include "sim/host.hh" -#include "sim/process.hh" -#include "sim/sim_events.hh" -#include "sim/sim_object.hh" -#include "sim/stats.hh" - -#if FULL_SYSTEM -#include "base/remote_gdb.hh" -#include "mem/functional/memory_control.hh" -#include "mem/functional/physical.hh" -#include "sim/system.hh" -#include "arch/tlb.hh" -#include "arch/vtophys.hh" -#else // !FULL_SYSTEM -#include "mem/functional/functional.hh" -#endif // FULL_SYSTEM class DerivAlphaFullCPU : public AlphaFullCPU<AlphaSimpleImpl> { public: - DerivAlphaFullCPU(AlphaSimpleParams p) + DerivAlphaFullCPU(AlphaSimpleParams *p) : AlphaFullCPU<AlphaSimpleImpl>(p) { } }; @@ -69,6 +49,7 @@ BEGIN_DECLARE_SIM_OBJECT_PARAMS(DerivAlphaFullCPU) Param<int> clock; Param<int> numThreads; +Param<int> activity; #if FULL_SYSTEM SimObjectParam<System *> system; @@ -78,15 +59,17 @@ SimObjectParam<AlphaDTB *> dtb; #else SimObjectVectorParam<Process *> workload; #endif // FULL_SYSTEM -SimObjectParam<FunctionalMemory *> mem; + +SimObjectParam<MemObject *> mem; + +SimObjectParam<BaseCPU *> checker; Param<Counter> max_insts_any_thread; Param<Counter> max_insts_all_threads; Param<Counter> max_loads_any_thread; Param<Counter> max_loads_all_threads; -SimObjectParam<BaseCache *> icache; -SimObjectParam<BaseCache *> dcache; +Param<unsigned> cachePorts; Param<unsigned> decodeToFetchDelay; Param<unsigned> renameToFetchDelay; @@ -114,25 +97,25 @@ Param<unsigned> executeIntWidth; Param<unsigned> executeFloatWidth; Param<unsigned> executeBranchWidth; Param<unsigned> executeMemoryWidth; +SimObjectParam<FUPool *> fuPool; Param<unsigned> iewToCommitDelay; Param<unsigned> renameToROBDelay; Param<unsigned> commitWidth; Param<unsigned> squashWidth; +Param<Tick> trapLatency; +Param<Tick> fetchTrapLatency; -#if 0 +Param<std::string> predType; Param<unsigned> localPredictorSize; -Param<unsigned> localPredictorCtrBits; -#endif -Param<unsigned> local_predictor_size; -Param<unsigned> local_ctr_bits; -Param<unsigned> local_history_table_size; -Param<unsigned> local_history_bits; -Param<unsigned> global_predictor_size; -Param<unsigned> global_ctr_bits; -Param<unsigned> global_history_bits; -Param<unsigned> choice_predictor_size; -Param<unsigned> choice_ctr_bits; +Param<unsigned> localCtrBits; +Param<unsigned> localHistoryTableSize; +Param<unsigned> localHistoryBits; +Param<unsigned> globalPredictorSize; +Param<unsigned> globalCtrBits; +Param<unsigned> globalHistoryBits; +Param<unsigned> choicePredictorSize; +Param<unsigned> choiceCtrBits; Param<unsigned> BTBEntries; Param<unsigned> BTBTagSize; @@ -149,6 +132,16 @@ Param<unsigned> numPhysFloatRegs; Param<unsigned> numIQEntries; Param<unsigned> numROBEntries; +Param<unsigned> smtNumFetchingThreads; +Param<std::string> smtFetchPolicy; +Param<std::string> smtLSQPolicy; +Param<unsigned> smtLSQThreshold; +Param<std::string> smtIQPolicy; +Param<unsigned> smtIQThreshold; +Param<std::string> smtROBPolicy; +Param<unsigned> smtROBThreshold; +Param<std::string> smtCommitPolicy; + Param<unsigned> instShiftAmt; Param<bool> defer_registration; @@ -162,6 +155,7 @@ BEGIN_INIT_SIM_OBJECT_PARAMS(DerivAlphaFullCPU) INIT_PARAM(clock, "clock speed"), INIT_PARAM(numThreads, "number of HW thread contexts"), + INIT_PARAM_DFLT(activity, "Initial activity count", 0), #if FULL_SYSTEM INIT_PARAM(system, "System object"), @@ -172,7 +166,9 @@ BEGIN_INIT_SIM_OBJECT_PARAMS(DerivAlphaFullCPU) INIT_PARAM(workload, "Processes to run"), #endif // FULL_SYSTEM - INIT_PARAM_DFLT(mem, "Memory", NULL), + INIT_PARAM(mem, "Memory"), + + INIT_PARAM_DFLT(checker, "Checker CPU", NULL), INIT_PARAM_DFLT(max_insts_any_thread, "Terminate when any thread reaches this inst count", @@ -189,8 +185,7 @@ BEGIN_INIT_SIM_OBJECT_PARAMS(DerivAlphaFullCPU) "count", 0), - INIT_PARAM_DFLT(icache, "L1 instruction cache", NULL), - INIT_PARAM_DFLT(dcache, "L1 data cache", NULL), + INIT_PARAM_DFLT(cachePorts, "Cache Ports", 200), INIT_PARAM(decodeToFetchDelay, "Decode to fetch delay"), INIT_PARAM(renameToFetchDelay, "Rename to fetch delay"), @@ -198,7 +193,6 @@ BEGIN_INIT_SIM_OBJECT_PARAMS(DerivAlphaFullCPU) "delay"), INIT_PARAM(commitToFetchDelay, "Commit to fetch delay"), INIT_PARAM(fetchWidth, "Fetch width"), - INIT_PARAM(renameToDecodeDelay, "Rename to decode delay"), INIT_PARAM(iewToDecodeDelay, "Issue/Execute/Writeback to decode" "delay"), @@ -224,27 +218,26 @@ BEGIN_INIT_SIM_OBJECT_PARAMS(DerivAlphaFullCPU) INIT_PARAM(executeFloatWidth, "Floating point execute width"), INIT_PARAM(executeBranchWidth, "Branch execute width"), INIT_PARAM(executeMemoryWidth, "Memory execute width"), + INIT_PARAM_DFLT(fuPool, "Functional unit pool", NULL), INIT_PARAM(iewToCommitDelay, "Issue/Execute/Writeback to commit " "delay"), INIT_PARAM(renameToROBDelay, "Rename to reorder buffer delay"), INIT_PARAM(commitWidth, "Commit width"), INIT_PARAM(squashWidth, "Squash width"), - -#if 0 - INIT_PARAM(localPredictorSize, "Size of the local predictor in entries. " - "Must be a power of 2."), - INIT_PARAM(localPredictorCtrBits, "Number of bits per counter for bpred"), -#endif - INIT_PARAM(local_predictor_size, "Size of local predictor"), - INIT_PARAM(local_ctr_bits, "Bits per counter"), - INIT_PARAM(local_history_table_size, "Size of local history table"), - INIT_PARAM(local_history_bits, "Bits for the local history"), - INIT_PARAM(global_predictor_size, "Size of global predictor"), - INIT_PARAM(global_ctr_bits, "Bits per counter"), - INIT_PARAM(global_history_bits, "Bits of history"), - INIT_PARAM(choice_predictor_size, "Size of choice predictor"), - INIT_PARAM(choice_ctr_bits, "Bits of choice counters"), + INIT_PARAM_DFLT(trapLatency, "Number of cycles before the trap is handled", 6), + INIT_PARAM_DFLT(fetchTrapLatency, "Number of cycles before the fetch trap is handled", 12), + + INIT_PARAM(predType, "Type of branch predictor ('local', 'tournament')"), + INIT_PARAM(localPredictorSize, "Size of local predictor"), + INIT_PARAM(localCtrBits, "Bits per counter"), + INIT_PARAM(localHistoryTableSize, "Size of local history table"), + INIT_PARAM(localHistoryBits, "Bits for the local history"), + INIT_PARAM(globalPredictorSize, "Size of global predictor"), + INIT_PARAM(globalCtrBits, "Bits per counter"), + INIT_PARAM(globalHistoryBits, "Bits of history"), + INIT_PARAM(choicePredictorSize, "Size of choice predictor"), + INIT_PARAM(choiceCtrBits, "Bits of choice counters"), INIT_PARAM(BTBEntries, "Number of BTB entries"), INIT_PARAM(BTBTagSize, "Size of the BTB tags, in bits"), @@ -262,6 +255,16 @@ BEGIN_INIT_SIM_OBJECT_PARAMS(DerivAlphaFullCPU) INIT_PARAM(numIQEntries, "Number of instruction queue entries"), INIT_PARAM(numROBEntries, "Number of reorder buffer entries"), + INIT_PARAM_DFLT(smtNumFetchingThreads, "SMT Number of Fetching Threads", 1), + INIT_PARAM_DFLT(smtFetchPolicy, "SMT Fetch Policy", "SingleThread"), + INIT_PARAM_DFLT(smtLSQPolicy, "SMT LSQ Sharing Policy", "Partitioned"), + INIT_PARAM_DFLT(smtLSQThreshold,"SMT LSQ Threshold", 100), + INIT_PARAM_DFLT(smtIQPolicy, "SMT IQ Policy", "Partitioned"), + INIT_PARAM_DFLT(smtIQThreshold, "SMT IQ Threshold", 100), + INIT_PARAM_DFLT(smtROBPolicy, "SMT ROB Sharing Policy", "Partitioned"), + INIT_PARAM_DFLT(smtROBThreshold,"SMT ROB Threshold", 100), + INIT_PARAM_DFLT(smtCommitPolicy,"SMT Commit Fetch Policy", "RoundRobin"), + INIT_PARAM(instShiftAmt, "Number of bits to shift instructions by"), INIT_PARAM(defer_registration, "defer system registration (for sampling)"), @@ -289,101 +292,114 @@ CREATE_SIM_OBJECT(DerivAlphaFullCPU) #endif - AlphaSimpleParams params; + AlphaSimpleParams *params = new AlphaSimpleParams; - params.clock = clock; + params->clock = clock; - params.name = getInstanceName(); - params.numberOfThreads = actual_num_threads; + params->name = getInstanceName(); + params->numberOfThreads = actual_num_threads; + params->activity = activity; #if FULL_SYSTEM - params.system = system; - params.cpu_id = cpu_id; - params.itb = itb; - params.dtb = dtb; + params->system = system; + params->cpu_id = cpu_id; + params->itb = itb; + params->dtb = dtb; #else - params.workload = workload; + params->workload = workload; #endif // FULL_SYSTEM - params.mem = mem; + params->mem = mem; + + params->checker = checker; - params.max_insts_any_thread = max_insts_any_thread; - params.max_insts_all_threads = max_insts_all_threads; - params.max_loads_any_thread = max_loads_any_thread; - params.max_loads_all_threads = max_loads_all_threads; + params->max_insts_any_thread = max_insts_any_thread; + params->max_insts_all_threads = max_insts_all_threads; + params->max_loads_any_thread = max_loads_any_thread; + params->max_loads_all_threads = max_loads_all_threads; // // Caches // - params.icacheInterface = icache ? icache->getInterface() : NULL; - params.dcacheInterface = dcache ? dcache->getInterface() : NULL; - - params.decodeToFetchDelay = decodeToFetchDelay; - params.renameToFetchDelay = renameToFetchDelay; - params.iewToFetchDelay = iewToFetchDelay; - params.commitToFetchDelay = commitToFetchDelay; - params.fetchWidth = fetchWidth; - - params.renameToDecodeDelay = renameToDecodeDelay; - params.iewToDecodeDelay = iewToDecodeDelay; - params.commitToDecodeDelay = commitToDecodeDelay; - params.fetchToDecodeDelay = fetchToDecodeDelay; - params.decodeWidth = decodeWidth; - - params.iewToRenameDelay = iewToRenameDelay; - params.commitToRenameDelay = commitToRenameDelay; - params.decodeToRenameDelay = decodeToRenameDelay; - params.renameWidth = renameWidth; - - params.commitToIEWDelay = commitToIEWDelay; - params.renameToIEWDelay = renameToIEWDelay; - params.issueToExecuteDelay = issueToExecuteDelay; - params.issueWidth = issueWidth; - params.executeWidth = executeWidth; - params.executeIntWidth = executeIntWidth; - params.executeFloatWidth = executeFloatWidth; - params.executeBranchWidth = executeBranchWidth; - params.executeMemoryWidth = executeMemoryWidth; - - params.iewToCommitDelay = iewToCommitDelay; - params.renameToROBDelay = renameToROBDelay; - params.commitWidth = commitWidth; - params.squashWidth = squashWidth; -#if 0 - params.localPredictorSize = localPredictorSize; - params.localPredictorCtrBits = localPredictorCtrBits; -#endif - params.local_predictor_size = local_predictor_size; - params.local_ctr_bits = local_ctr_bits; - params.local_history_table_size = local_history_table_size; - params.local_history_bits = local_history_bits; - params.global_predictor_size = global_predictor_size; - params.global_ctr_bits = global_ctr_bits; - params.global_history_bits = global_history_bits; - params.choice_predictor_size = choice_predictor_size; - params.choice_ctr_bits = choice_ctr_bits; - - params.BTBEntries = BTBEntries; - params.BTBTagSize = BTBTagSize; - - params.RASSize = RASSize; - - params.LQEntries = LQEntries; - params.SQEntries = SQEntries; - params.SSITSize = SSITSize; - params.LFSTSize = LFSTSize; - - params.numPhysIntRegs = numPhysIntRegs; - params.numPhysFloatRegs = numPhysFloatRegs; - params.numIQEntries = numIQEntries; - params.numROBEntries = numROBEntries; - - params.instShiftAmt = 2; - - params.defReg = defer_registration; - - params.functionTrace = function_trace; - params.functionTraceStart = function_trace_start; + params->cachePorts = cachePorts; + + params->decodeToFetchDelay = decodeToFetchDelay; + params->renameToFetchDelay = renameToFetchDelay; + params->iewToFetchDelay = iewToFetchDelay; + params->commitToFetchDelay = commitToFetchDelay; + params->fetchWidth = fetchWidth; + + params->renameToDecodeDelay = renameToDecodeDelay; + params->iewToDecodeDelay = iewToDecodeDelay; + params->commitToDecodeDelay = commitToDecodeDelay; + params->fetchToDecodeDelay = fetchToDecodeDelay; + params->decodeWidth = decodeWidth; + + params->iewToRenameDelay = iewToRenameDelay; + params->commitToRenameDelay = commitToRenameDelay; + params->decodeToRenameDelay = decodeToRenameDelay; + params->renameWidth = renameWidth; + + params->commitToIEWDelay = commitToIEWDelay; + params->renameToIEWDelay = renameToIEWDelay; + params->issueToExecuteDelay = issueToExecuteDelay; + params->issueWidth = issueWidth; + params->executeWidth = executeWidth; + params->executeIntWidth = executeIntWidth; + params->executeFloatWidth = executeFloatWidth; + params->executeBranchWidth = executeBranchWidth; + params->executeMemoryWidth = executeMemoryWidth; + params->fuPool = fuPool; + + params->iewToCommitDelay = iewToCommitDelay; + params->renameToROBDelay = renameToROBDelay; + params->commitWidth = commitWidth; + params->squashWidth = squashWidth; + params->trapLatency = trapLatency; + params->fetchTrapLatency = fetchTrapLatency; + + params->predType = predType; + params->localPredictorSize = localPredictorSize; + params->localCtrBits = localCtrBits; + params->localHistoryTableSize = localHistoryTableSize; + params->localHistoryBits = localHistoryBits; + params->globalPredictorSize = globalPredictorSize; + params->globalCtrBits = globalCtrBits; + params->globalHistoryBits = globalHistoryBits; + params->choicePredictorSize = choicePredictorSize; + params->choiceCtrBits = choiceCtrBits; + + params->BTBEntries = BTBEntries; + params->BTBTagSize = BTBTagSize; + + params->RASSize = RASSize; + + params->LQEntries = LQEntries; + params->SQEntries = SQEntries; + + params->SSITSize = SSITSize; + params->LFSTSize = LFSTSize; + + params->numPhysIntRegs = numPhysIntRegs; + params->numPhysFloatRegs = numPhysFloatRegs; + params->numIQEntries = numIQEntries; + params->numROBEntries = numROBEntries; + + params->smtNumFetchingThreads = smtNumFetchingThreads; + params->smtFetchPolicy = smtFetchPolicy; + params->smtIQPolicy = smtIQPolicy; + params->smtLSQPolicy = smtLSQPolicy; + params->smtLSQThreshold = smtLSQThreshold; + params->smtROBPolicy = smtROBPolicy; + params->smtROBThreshold = smtROBThreshold; + params->smtCommitPolicy = smtCommitPolicy; + + params->instShiftAmt = 2; + + params->deferRegistration = defer_registration; + + params->functionTrace = function_trace; + params->functionTraceStart = function_trace_start; cpu = new DerivAlphaFullCPU(params); diff --git a/src/cpu/o3/alpha_cpu_impl.hh b/src/cpu/o3/alpha_cpu_impl.hh index 624fe8594..98290e57f 100644 --- a/src/cpu/o3/alpha_cpu_impl.hh +++ b/src/cpu/o3/alpha_cpu_impl.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -32,27 +32,130 @@ #include "base/cprintf.hh" #include "base/statistics.hh" #include "base/timebuf.hh" -#include "mem/cache/cache.hh" // for dynamic cast -#include "mem/mem_interface.hh" -#include "sim/builder.hh" +#include "cpu/checker/thread_context.hh" #include "sim/sim_events.hh" #include "sim/stats.hh" #include "cpu/o3/alpha_cpu.hh" #include "cpu/o3/alpha_params.hh" #include "cpu/o3/comm.hh" +#include "cpu/o3/thread_state.hh" #if FULL_SYSTEM #include "arch/alpha/osfpal.hh" -#include "arch/alpha/isa_traits.hh" +#include "arch/isa_traits.hh" +#include "cpu/quiesce_event.hh" +#include "kern/kernel_stats.hh" +#include "sim/system.hh" #endif +using namespace TheISA; + template <class Impl> -AlphaFullCPU<Impl>::AlphaFullCPU(Params ¶ms) +AlphaFullCPU<Impl>::AlphaFullCPU(Params *params) +#if FULL_SYSTEM + : FullO3CPU<Impl>(params), itb(params->itb), dtb(params->dtb) +#else : FullO3CPU<Impl>(params) +#endif { DPRINTF(FullCPU, "AlphaFullCPU: Creating AlphaFullCPU object.\n"); + // Setup any thread state. + this->thread.resize(this->numThreads); + + for (int i = 0; i < this->numThreads; ++i) { +#if FULL_SYSTEM + // SMT is not supported in FS mode yet. + assert(this->numThreads == 1); + this->thread[i] = new Thread(this, 0); + this->thread[i]->setStatus(ThreadContext::Suspended); +#else + if (i < params->workload.size()) { + DPRINTF(FullCPU, "FullCPU: Workload[%i] process is %#x", + i, this->thread[i]); + this->thread[i] = new Thread(this, i, params->workload[i], + i, params->mem); + + this->thread[i]->setStatus(ThreadContext::Suspended); + +#if !FULL_SYSTEM + /* Use this port to for syscall emulation writes to memory. */ + Port *mem_port; + TranslatingPort *trans_port; + trans_port = new TranslatingPort(csprintf("%s-%d-funcport", + name(), i), + params->workload[i]->pTable, + false); + mem_port = params->mem->getPort("functional"); + mem_port->setPeer(trans_port); + trans_port->setPeer(mem_port); + this->thread[i]->setMemPort(trans_port); +#endif + //usedTids[i] = true; + //threadMap[i] = i; + } else { + //Allocate Empty thread so M5 can use later + //when scheduling threads to CPU + Process* dummy_proc = NULL; + + this->thread[i] = new Thread(this, i, dummy_proc, i, params->mem); + //usedTids[i] = false; + } +#endif // !FULL_SYSTEM + + ThreadContext *tc; + + // Setup the TC that will serve as the interface to the threads/CPU. + AlphaTC *alpha_tc = new AlphaTC; + + // If we're using a checker, then the TC should be the + // CheckerThreadContext. + if (params->checker) { + tc = new CheckerThreadContext<AlphaTC>( + alpha_tc, this->checker); + } else { + tc = alpha_tc; + } + + alpha_tc->cpu = this; + alpha_tc->thread = this->thread[i]; + +#if FULL_SYSTEM + // Setup quiesce event. + this->thread[i]->quiesceEvent = new EndQuiesceEvent(tc); + + Port *mem_port; + FunctionalPort *phys_port; + VirtualPort *virt_port; + phys_port = new FunctionalPort(csprintf("%s-%d-funcport", + name(), i)); + mem_port = this->system->physmem->getPort("functional"); + mem_port->setPeer(phys_port); + phys_port->setPeer(mem_port); + + virt_port = new VirtualPort(csprintf("%s-%d-vport", + name(), i)); + mem_port = this->system->physmem->getPort("functional"); + mem_port->setPeer(virt_port); + virt_port->setPeer(mem_port); + + this->thread[i]->setPhysPort(phys_port); + this->thread[i]->setVirtPort(virt_port); +#endif + // Give the thread the TC. + this->thread[i]->tc = tc; + + // Add the TC to the CPU's list of TC's. + this->threadContexts.push_back(tc); + } + + for (int i=0; i < this->numThreads; i++) { + this->thread[i]->setFuncExeInst(0); + } + + // Sets CPU pointers. These must be set at this level because the CPU + // pointers are defined to be the highest level of CPU class. this->fetch.setCPU(this); this->decode.setCPU(this); this->rename.setCPU(this); @@ -60,6 +163,10 @@ AlphaFullCPU<Impl>::AlphaFullCPU(Params ¶ms) this->commit.setCPU(this); this->rob.setCPU(this); + this->regFile.setCPU(this); + + lockAddr = 0; + lockFlag = false; } template <class Impl> @@ -75,179 +182,519 @@ AlphaFullCPU<Impl>::regStats() this->commit.regStats(); } -#if !FULL_SYSTEM +#if FULL_SYSTEM +template <class Impl> +VirtualPort * +AlphaFullCPU<Impl>::AlphaTC::getVirtPort(ThreadContext *src_tc) +{ + if (!src_tc) + return thread->getVirtPort(); + + VirtualPort *vp; + Port *mem_port; + + vp = new VirtualPort("tc-vport", src_tc); + mem_port = cpu->system->physmem->getPort("functional"); + mem_port->setPeer(vp); + vp->setPeer(mem_port); + return vp; +} -// Will probably need to know which thread is calling syscall -// Will need to pass that information in to the DynInst when it is constructed, -// so that this call can be made with the proper thread number. template <class Impl> void -AlphaFullCPU<Impl>::syscall(short thread_num) +AlphaFullCPU<Impl>::AlphaTC::dumpFuncProfile() { - DPRINTF(FullCPU, "AlphaFullCPU: Syscall() called.\n\n"); + // Currently not supported +} +#endif - // Commit stage needs to run as well. - this->commit.tick(); +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::takeOverFrom(ThreadContext *old_context) +{ + // some things should already be set up +#if FULL_SYSTEM + assert(getSystemPtr() == old_context->getSystemPtr()); +#else + assert(getProcessPtr() == old_context->getProcessPtr()); +#endif - squashStages(); + // copy over functional state + setStatus(old_context->status()); + copyArchRegs(old_context); + setCpuId(old_context->readCpuId()); - // Temporarily increase this by one to account for the syscall - // instruction. - ++(this->funcExeInst); +#if !FULL_SYSTEM + thread->funcExeInst = old_context->readFuncExeInst(); +#else + EndQuiesceEvent *other_quiesce = old_context->getQuiesceEvent(); + if (other_quiesce) { + // Point the quiesce event's TC at this TC so that it wakes up + // the proper CPU. + other_quiesce->tc = this; + } + if (thread->quiesceEvent) { + thread->quiesceEvent->tc = this; + } - // Copy over all important state to xc once all the unrolling is done. - copyToXC(); + // Transfer kernel stats from one CPU to the other. + thread->kernelStats = old_context->getKernelStats(); +// storeCondFailures = 0; + cpu->lockFlag = false; +#endif - // This is hardcoded to thread 0 while the CPU is only single threaded. - this->thread[0]->syscall(); + old_context->setStatus(ThreadContext::Unallocated); - // Copy over all important state back to CPU. - copyFromXC(); + thread->inSyscall = false; + thread->trapPending = false; +} - // Decrease funcExeInst by one as the normal commit will handle - // incrememnting it. - --(this->funcExeInst); +#if FULL_SYSTEM +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::delVirtPort(VirtualPort *vp) +{ + delete vp->getPeer(); + delete vp; } +#endif -// This is not a pretty function, and should only be used if it is necessary -// to fake having everything squash all at once (ie for non-full system -// syscalls). Maybe put this at the FullCPU level? template <class Impl> void -AlphaFullCPU<Impl>::squashStages() +AlphaFullCPU<Impl>::AlphaTC::activate(int delay) { - InstSeqNum rob_head = this->rob.readHeadSeqNum(); + DPRINTF(FullCPU, "Calling activate on AlphaTC\n"); + + if (thread->status() == ThreadContext::Active) + return; + +#if FULL_SYSTEM + thread->lastActivate = curTick; +#endif - // Now hack the time buffer to put this sequence number in the places - // where the stages might read it. - for (int i = 0; i < 5; ++i) - { - this->timeBuffer.access(-i)->commitInfo.doneSeqNum = rob_head; + if (thread->status() == ThreadContext::Unallocated) { + cpu->activateWhenReady(thread->readTid()); + return; } - this->fetch.squash(this->rob.readHeadNextPC()); - this->fetchQueue.advance(); - - this->decode.squash(); - this->decodeQueue.advance(); - - this->rename.squash(); - this->renameQueue.advance(); - this->renameQueue.advance(); - - // Be sure to advance the IEW queues so that the commit stage doesn't - // try to set an instruction as completed at the same time that it - // might be deleting it. - this->iew.squash(); - this->iewQueue.advance(); - this->iewQueue.advance(); - // Needs to tell the LSQ to write back all of its data - this->iew.lsqWriteback(); - - this->rob.squash(rob_head); - this->commit.setSquashing(); - - // Now hack the time buffer to clear the sequence numbers in the places - // where the stages might read it.? - for (int i = 0; i < 5; ++i) - { - this->timeBuffer.access(-i)->commitInfo.doneSeqNum = 0; + thread->setStatus(ThreadContext::Active); + + // status() == Suspended + cpu->activateContext(thread->readTid(), delay); +} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::suspend() +{ + DPRINTF(FullCPU, "Calling suspend on AlphaTC\n"); + + if (thread->status() == ThreadContext::Suspended) + return; + +#if FULL_SYSTEM + thread->lastActivate = curTick; + thread->lastSuspend = curTick; +#endif +/* +#if FULL_SYSTEM + // Don't change the status from active if there are pending interrupts + if (cpu->check_interrupts()) { + assert(status() == ThreadContext::Active); + return; } +#endif +*/ + thread->setStatus(ThreadContext::Suspended); + cpu->suspendContext(thread->readTid()); +} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::deallocate() +{ + DPRINTF(FullCPU, "Calling deallocate on AlphaTC\n"); + + if (thread->status() == ThreadContext::Unallocated) + return; + thread->setStatus(ThreadContext::Unallocated); + cpu->deallocateContext(thread->readTid()); } -#endif // FULL_SYSTEM +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::halt() +{ + DPRINTF(FullCPU, "Calling halt on AlphaTC\n"); + + if (thread->status() == ThreadContext::Halted) + return; + + thread->setStatus(ThreadContext::Halted); + cpu->haltContext(thread->readTid()); +} template <class Impl> void -AlphaFullCPU<Impl>::copyToXC() +AlphaFullCPU<Impl>::AlphaTC::regStats(const std::string &name) { - PhysRegIndex renamed_reg; +#if FULL_SYSTEM + thread->kernelStats = new Kernel::Statistics(cpu->system); + thread->kernelStats->regStats(name + ".kern"); +#endif +} - // First loop through the integer registers. - for (int i = 0; i < AlphaISA::NumIntRegs; ++i) - { - renamed_reg = this->renameMap.lookup(i); - this->cpuXC->setIntReg(i, this->regFile.readIntReg(renamed_reg)); - DPRINTF(FullCPU, "FullCPU: Copying register %i, has data %lli.\n", - renamed_reg, this->regFile.intRegFile[renamed_reg]); - } +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::serialize(std::ostream &os) +{ +#if FULL_SYSTEM + if (thread->kernelStats) + thread->kernelStats->serialize(os); +#endif - // Then loop through the floating point registers. - for (int i = 0; i < AlphaISA::NumFloatRegs; ++i) - { - renamed_reg = this->renameMap.lookup(i + AlphaISA::FP_Base_DepTag); - this->cpuXC->setFloatRegBits(i, - this->regFile.readFloatRegBits(renamed_reg)); - } +} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::unserialize(Checkpoint *cp, const std::string §ion) +{ +#if FULL_SYSTEM + if (thread->kernelStats) + thread->kernelStats->unserialize(cp, section); +#endif - this->cpuXC->setMiscReg(AlphaISA::Fpcr_DepTag, - this->regFile.readMiscReg(AlphaISA::Fpcr_DepTag)); - this->cpuXC->setMiscReg(AlphaISA::Uniq_DepTag, - this->regFile.readMiscReg(AlphaISA::Uniq_DepTag)); - this->cpuXC->setMiscReg(AlphaISA::Lock_Flag_DepTag, - this->regFile.readMiscReg(AlphaISA::Lock_Flag_DepTag)); - this->cpuXC->setMiscReg(AlphaISA::Lock_Addr_DepTag, - this->regFile.readMiscReg(AlphaISA::Lock_Addr_DepTag)); +} - this->cpuXC->setPC(this->rob.readHeadPC()); - this->cpuXC->setNextPC(this->cpuXC->readPC()+4); +#if FULL_SYSTEM +template <class Impl> +EndQuiesceEvent * +AlphaFullCPU<Impl>::AlphaTC::getQuiesceEvent() +{ + return thread->quiesceEvent; +} -#if !FULL_SYSTEM - this->cpuXC->setFuncExeInst(this->funcExeInst); +template <class Impl> +Tick +AlphaFullCPU<Impl>::AlphaTC::readLastActivate() +{ + return thread->lastActivate; +} + +template <class Impl> +Tick +AlphaFullCPU<Impl>::AlphaTC::readLastSuspend() +{ + return thread->lastSuspend; +} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::profileClear() +{} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::profileSample() +{} #endif + +template <class Impl> +TheISA::MachInst +AlphaFullCPU<Impl>::AlphaTC:: getInst() +{ + return thread->getInst(); } -// This function will probably mess things up unless the ROB is empty and -// there are no instructions in the pipeline. template <class Impl> void -AlphaFullCPU<Impl>::copyFromXC() +AlphaFullCPU<Impl>::AlphaTC::copyArchRegs(ThreadContext *tc) { + // This function will mess things up unless the ROB is empty and + // there are no instructions in the pipeline. + unsigned tid = thread->readTid(); PhysRegIndex renamed_reg; // First loop through the integer registers. - for (int i = 0; i < AlphaISA::NumIntRegs; ++i) - { - renamed_reg = this->renameMap.lookup(i); + for (int i = 0; i < AlphaISA::NumIntRegs; ++i) { + renamed_reg = cpu->renameMap[tid].lookup(i); DPRINTF(FullCPU, "FullCPU: Copying over register %i, had data %lli, " "now has data %lli.\n", - renamed_reg, this->regFile.intRegFile[renamed_reg], - this->cpuXC->readIntReg(i)); + renamed_reg, cpu->readIntReg(renamed_reg), + tc->readIntReg(i)); - this->regFile.setIntReg(renamed_reg, this->cpuXC->readIntReg(i)); + cpu->setIntReg(renamed_reg, tc->readIntReg(i)); } // Then loop through the floating point registers. - for (int i = 0; i < AlphaISA::NumFloatRegs; ++i) - { - renamed_reg = this->renameMap.lookup(i + AlphaISA::FP_Base_DepTag); - this->regFile.setFloatRegBits(renamed_reg, - this->cpuXC->readFloatRegBits(i)); + for (int i = 0; i < AlphaISA::NumFloatRegs; ++i) { + renamed_reg = cpu->renameMap[tid].lookup(i + AlphaISA::FP_Base_DepTag); + cpu->setFloatRegBits(renamed_reg, + tc->readFloatRegBits(i)); } - // Then loop through the misc registers. - this->regFile.setMiscReg(AlphaISA::Fpcr_DepTag, - this->cpuXC->readMiscReg(AlphaISA::Fpcr_DepTag)); - this->regFile.setMiscReg(AlphaISA::Uniq_DepTag, - this->cpuXC->readMiscReg(AlphaISA::Uniq_DepTag)); - this->regFile.setMiscReg(AlphaISA::Lock_Flag_DepTag, - this->cpuXC->readMiscReg(AlphaISA::Lock_Flag_DepTag)); - this->regFile.setMiscReg(AlphaISA::Lock_Addr_DepTag, - this->cpuXC->readMiscReg(AlphaISA::Lock_Addr_DepTag)); + // Copy the misc regs. + copyMiscRegs(tc, this); // Then finally set the PC and the next PC. -// regFile.pc = cpuXC->regs.pc; -// regFile.npc = cpuXC->regs.npc; + cpu->setPC(tc->readPC(), tid); + cpu->setNextPC(tc->readNextPC(), tid); #if !FULL_SYSTEM - this->funcExeInst = this->cpuXC->readFuncExeInst(); + this->thread->funcExeInst = tc->readFuncExeInst(); #endif } +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::clearArchRegs() +{} + +template <class Impl> +uint64_t +AlphaFullCPU<Impl>::AlphaTC::readIntReg(int reg_idx) +{ + return cpu->readArchIntReg(reg_idx, thread->readTid()); +} + +template <class Impl> +FloatReg +AlphaFullCPU<Impl>::AlphaTC::readFloatReg(int reg_idx, int width) +{ + switch(width) { + case 32: + return cpu->readArchFloatRegSingle(reg_idx, thread->readTid()); + case 64: + return cpu->readArchFloatRegDouble(reg_idx, thread->readTid()); + default: + panic("Unsupported width!"); + return 0; + } +} + +template <class Impl> +FloatReg +AlphaFullCPU<Impl>::AlphaTC::readFloatReg(int reg_idx) +{ + return cpu->readArchFloatRegSingle(reg_idx, thread->readTid()); +} + +template <class Impl> +FloatRegBits +AlphaFullCPU<Impl>::AlphaTC::readFloatRegBits(int reg_idx, int width) +{ + DPRINTF(Fault, "Reading floatint register through the TC!\n"); + return cpu->readArchFloatRegInt(reg_idx, thread->readTid()); +} + +template <class Impl> +FloatRegBits +AlphaFullCPU<Impl>::AlphaTC::readFloatRegBits(int reg_idx) +{ + return cpu->readArchFloatRegInt(reg_idx, thread->readTid()); +} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::setIntReg(int reg_idx, uint64_t val) +{ + cpu->setArchIntReg(reg_idx, val, thread->readTid()); + + // Squash if we're not already in a state update mode. + if (!thread->trapPending && !thread->inSyscall) { + cpu->squashFromTC(thread->readTid()); + } +} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::setFloatReg(int reg_idx, FloatReg val, int width) +{ + switch(width) { + case 32: + cpu->setArchFloatRegSingle(reg_idx, val, thread->readTid()); + break; + case 64: + cpu->setArchFloatRegDouble(reg_idx, val, thread->readTid()); + break; + } + + // Squash if we're not already in a state update mode. + if (!thread->trapPending && !thread->inSyscall) { + cpu->squashFromTC(thread->readTid()); + } +} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::setFloatReg(int reg_idx, FloatReg val) +{ + cpu->setArchFloatRegSingle(reg_idx, val, thread->readTid()); + + if (!thread->trapPending && !thread->inSyscall) { + cpu->squashFromTC(thread->readTid()); + } +} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::setFloatRegBits(int reg_idx, FloatRegBits val, + int width) +{ + DPRINTF(Fault, "Setting floatint register through the TC!\n"); + cpu->setArchFloatRegInt(reg_idx, val, thread->readTid()); + + // Squash if we're not already in a state update mode. + if (!thread->trapPending && !thread->inSyscall) { + cpu->squashFromTC(thread->readTid()); + } +} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::setFloatRegBits(int reg_idx, FloatRegBits val) +{ + cpu->setArchFloatRegInt(reg_idx, val, thread->readTid()); + + // Squash if we're not already in a state update mode. + if (!thread->trapPending && !thread->inSyscall) { + cpu->squashFromTC(thread->readTid()); + } +} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::setPC(uint64_t val) +{ + cpu->setPC(val, thread->readTid()); + + // Squash if we're not already in a state update mode. + if (!thread->trapPending && !thread->inSyscall) { + cpu->squashFromTC(thread->readTid()); + } +} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::setNextPC(uint64_t val) +{ + cpu->setNextPC(val, thread->readTid()); + + // Squash if we're not already in a state update mode. + if (!thread->trapPending && !thread->inSyscall) { + cpu->squashFromTC(thread->readTid()); + } +} + +template <class Impl> +Fault +AlphaFullCPU<Impl>::AlphaTC::setMiscReg(int misc_reg, const MiscReg &val) +{ + Fault ret_fault = cpu->setMiscReg(misc_reg, val, thread->readTid()); + + // Squash if we're not already in a state update mode. + if (!thread->trapPending && !thread->inSyscall) { + cpu->squashFromTC(thread->readTid()); + } + + return ret_fault; +} + +template <class Impl> +Fault +AlphaFullCPU<Impl>::AlphaTC::setMiscRegWithEffect(int misc_reg, + const MiscReg &val) +{ + Fault ret_fault = cpu->setMiscRegWithEffect(misc_reg, val, + thread->readTid()); + + // Squash if we're not already in a state update mode. + if (!thread->trapPending && !thread->inSyscall) { + cpu->squashFromTC(thread->readTid()); + } + + return ret_fault; +} + +#if !FULL_SYSTEM + +template <class Impl> +TheISA::IntReg +AlphaFullCPU<Impl>::AlphaTC::getSyscallArg(int i) +{ + return cpu->getSyscallArg(i, thread->readTid()); +} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::setSyscallArg(int i, IntReg val) +{ + cpu->setSyscallArg(i, val, thread->readTid()); +} + +template <class Impl> +void +AlphaFullCPU<Impl>::AlphaTC::setSyscallReturn(SyscallReturn return_value) +{ + cpu->setSyscallReturn(return_value, thread->readTid()); +} + +#endif // FULL_SYSTEM + +template <class Impl> +MiscReg +AlphaFullCPU<Impl>::readMiscReg(int misc_reg, unsigned tid) +{ + return this->regFile.readMiscReg(misc_reg, tid); +} + +template <class Impl> +MiscReg +AlphaFullCPU<Impl>::readMiscRegWithEffect(int misc_reg, Fault &fault, + unsigned tid) +{ + return this->regFile.readMiscRegWithEffect(misc_reg, fault, tid); +} + +template <class Impl> +Fault +AlphaFullCPU<Impl>::setMiscReg(int misc_reg, const MiscReg &val, unsigned tid) +{ + return this->regFile.setMiscReg(misc_reg, val, tid); +} + +template <class Impl> +Fault +AlphaFullCPU<Impl>::setMiscRegWithEffect(int misc_reg, const MiscReg &val, + unsigned tid) +{ + return this->regFile.setMiscRegWithEffect(misc_reg, val, tid); +} + +template <class Impl> +void +AlphaFullCPU<Impl>::squashFromTC(unsigned tid) +{ + this->thread[tid]->inSyscall = true; + this->commit.generateTCEvent(tid); +} + #if FULL_SYSTEM template <class Impl> +void +AlphaFullCPU<Impl>::post_interrupt(int int_num, int index) +{ + BaseCPU::post_interrupt(int_num, index); + + if (this->thread[0]->status() == ThreadContext::Suspended) { + DPRINTF(IPI,"Suspended Processor awoke\n"); + this->threadContexts[0]->activate(); + } +} + +template <class Impl> int AlphaFullCPU<Impl>::readIntrFlag() { @@ -261,20 +708,14 @@ AlphaFullCPU<Impl>::setIntrFlag(int val) this->regFile.setIntrFlag(val); } -// Can force commit stage to squash and stuff. template <class Impl> Fault -AlphaFullCPU<Impl>::hwrei() +AlphaFullCPU<Impl>::hwrei(unsigned tid) { - if (!inPalMode()) - return new AlphaISA::UnimplementedOpcodeFault; - - this->setNextPC(this->regFile.miscRegs.readReg(AlphaISA::IPR_EXC_ADDR)); + // Need to clear the lock flag upon returning from an interrupt. + this->lockFlag = false; -// kernelStats.hwrei(); - - if ((this->regFile.miscRegs.readReg(AlphaISA::IPR_EXC_ADDR) & 1) == 0) -// AlphaISA::swap_palshadow(®s, false); + this->thread[tid]->kernelStats->hwrei(); this->checkInterrupts = true; @@ -284,9 +725,11 @@ AlphaFullCPU<Impl>::hwrei() template <class Impl> bool -AlphaFullCPU<Impl>::simPalCheck(int palFunc) +AlphaFullCPU<Impl>::simPalCheck(int palFunc, unsigned tid) { -// kernelStats.callpal(palFunc); + if (this->thread[tid]->kernelStats) + this->thread[tid]->kernelStats->callpal(palFunc, + this->threadContexts[tid]); switch (palFunc) { case PAL::halt: @@ -305,69 +748,125 @@ AlphaFullCPU<Impl>::simPalCheck(int palFunc) return true; } -// Probably shouldn't be able to switch to the trap handler as quickly as -// this. Also needs to get the exception restart address from the commit -// stage. template <class Impl> void -AlphaFullCPU<Impl>::trap(Fault fault) +AlphaFullCPU<Impl>::trap(Fault fault, unsigned tid) +{ + // Pass the thread's TC into the invoke method. + fault->invoke(this->threadContexts[tid]); +} + +template <class Impl> +void +AlphaFullCPU<Impl>::processInterrupts() { -/* // Keep in mind that a trap may be initiated by fetch if there's a TLB - // miss - uint64_t PC = this->commit.readCommitPC(); + // Check for interrupts here. For now can copy the code that + // exists within isa_fullsys_traits.hh. Also assume that thread 0 + // is the one that handles the interrupts. + // @todo: Possibly consolidate the interrupt checking code. + // @todo: Allow other threads to handle interrupts. + + // Check if there are any outstanding interrupts + //Handle the interrupts + int ipl = 0; + int summary = 0; + + this->checkInterrupts = false; + + if (this->readMiscReg(IPR_ASTRR, 0)) + panic("asynchronous traps not implemented\n"); + + if (this->readMiscReg(IPR_SIRR, 0)) { + for (int i = INTLEVEL_SOFTWARE_MIN; + i < INTLEVEL_SOFTWARE_MAX; i++) { + if (this->readMiscReg(IPR_SIRR, 0) & (ULL(1) << i)) { + // See table 4-19 of the 21164 hardware reference + ipl = (i - INTLEVEL_SOFTWARE_MIN) + 1; + summary |= (ULL(1) << i); + } + } + } - DPRINTF(Fault, "Fault %s\n", fault->name()); - this->recordEvent(csprintf("Fault %s", fault->name())); + uint64_t interrupts = this->intr_status(); + + if (interrupts) { + for (int i = INTLEVEL_EXTERNAL_MIN; + i < INTLEVEL_EXTERNAL_MAX; i++) { + if (interrupts & (ULL(1) << i)) { + // See table 4-19 of the 21164 hardware reference + ipl = i; + summary |= (ULL(1) << i); + } + } + } - //kernelStats.fault(fault); + if (ipl && ipl > this->readMiscReg(IPR_IPLR, 0)) { + this->setMiscReg(IPR_ISR, summary, 0); + this->setMiscReg(IPR_INTID, ipl, 0); + // Checker needs to know these two registers were updated. + if (this->checker) { + this->checker->threadBase()->setMiscReg(IPR_ISR, summary); + this->checker->threadBase()->setMiscReg(IPR_INTID, ipl); + } + this->trap(Fault(new InterruptFault), 0); + DPRINTF(Flow, "Interrupt! IPLR=%d ipl=%d summary=%x\n", + this->readMiscReg(IPR_IPLR, 0), ipl, summary); + } +} - if (fault->isA<ArithmeticFault>()) - panic("Arithmetic traps are unimplemented!"); +#endif // FULL_SYSTEM - // exception restart address - Get the commit PC - if (!fault->isA<InterruptFault>() || !inPalMode(PC)) - this->regFile.miscRegs.setReg(AlphaISA::IPR_EXC_ADDR, PC); +#if !FULL_SYSTEM - if (fault->isA<PalFault>() || fault->isA<ArithmeticFault>()) - // || fault == InterruptFault && !PC_PAL(regs.pc) - { - // traps... skip faulting instruction - AlphaISA::MiscReg ipr_exc_addr = - this->regFile.miscRegs.readReg(AlphaISA::IPR_EXC_ADDR); - this->regFile.miscRegs.setReg(AlphaISA::IPR_EXC_ADDR, - ipr_exc_addr + 4); - } +template <class Impl> +void +AlphaFullCPU<Impl>::syscall(int64_t callnum, int tid) +{ + DPRINTF(FullCPU, "AlphaFullCPU: [tid:%i] Executing syscall().\n\n", tid); + + DPRINTF(Activity,"Activity: syscall() called.\n"); - if (!inPalMode(PC)) - swapPALShadow(true); + // Temporarily increase this by one to account for the syscall + // instruction. + ++(this->thread[tid]->funcExeInst); - this->regFile.setPC(this->regFile.miscRegs.readReg(AlphaISA::IPR_PAL_BASE) + - (dynamic_cast<AlphaFault *>(fault.get()))->vect()); - this->regFile.setNextPC(PC + sizeof(MachInst));*/ + // Execute the actual syscall. + this->thread[tid]->syscall(callnum); + + // Decrease funcExeInst by one as the normal commit will handle + // incrementing it. + --(this->thread[tid]->funcExeInst); } template <class Impl> -void -AlphaFullCPU<Impl>::processInterrupts() +TheISA::IntReg +AlphaFullCPU<Impl>::getSyscallArg(int i, int tid) { - // Check for interrupts here. For now can copy the code that exists - // within isa_fullsys_traits.hh. + return this->readArchIntReg(AlphaISA::ArgumentReg0 + i, tid); } -// swap_palshadow swaps in the values of the shadow registers and -// swaps them with the values of the physical registers that map to the -// same logical index. template <class Impl> void -AlphaFullCPU<Impl>::swapPALShadow(bool use_shadow) +AlphaFullCPU<Impl>::setSyscallArg(int i, IntReg val, int tid) { - if (palShadowEnabled == use_shadow) - panic("swap_palshadow: wrong PAL shadow state"); - - palShadowEnabled = use_shadow; - - // Will have to lookup in rename map to get physical registers, then - // swap. + this->setArchIntReg(AlphaISA::ArgumentReg0 + i, val, tid); } -#endif // FULL_SYSTEM +template <class Impl> +void +AlphaFullCPU<Impl>::setSyscallReturn(SyscallReturn return_value, int tid) +{ + // check for error condition. Alpha syscall convention is to + // indicate success/failure in reg a3 (r19) and put the + // return value itself in the standard return value reg (v0). + if (return_value.successful()) { + // no error + this->setArchIntReg(SyscallSuccessReg, 0, tid); + this->setArchIntReg(ReturnValueReg, return_value.value(), tid); + } else { + // got an error, return details + this->setArchIntReg(SyscallSuccessReg, (IntReg) -1, tid); + this->setArchIntReg(ReturnValueReg, -return_value.value(), tid); + } +} +#endif diff --git a/src/cpu/o3/alpha_dyn_inst.hh b/src/cpu/o3/alpha_dyn_inst.hh index a5453567a..36a08c4a7 100644 --- a/src/cpu/o3/alpha_dyn_inst.hh +++ b/src/cpu/o3/alpha_dyn_inst.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,21 +28,24 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_ALPHA_DYN_INST_HH__ -#define __CPU_O3_CPU_ALPHA_DYN_INST_HH__ +#ifndef __CPU_O3_ALPHA_DYN_INST_HH__ +#define __CPU_O3_ALPHA_DYN_INST_HH__ +#include "arch/isa_traits.hh" #include "cpu/base_dyn_inst.hh" +#include "cpu/inst_seq.hh" #include "cpu/o3/alpha_cpu.hh" #include "cpu/o3/alpha_impl.hh" -#include "cpu/inst_seq.hh" + +class Packet; /** - * Mostly implementation specific AlphaDynInst. It is templated in case there - * are other implementations that are similar enough to be able to use this - * class without changes. This is mainly useful if there are multiple similar - * CPU implementations of the same ISA. + * Mostly implementation & ISA specific AlphaDynInst. As with most + * other classes in the new CPU model, it is templated on the Impl to + * allow for passing in of all types, such as the CPU type and the ISA + * type. The AlphaDynInst serves as the primary interface to the CPU + * for instructions that are executing. */ - template <class Impl> class AlphaDynInst : public BaseDynInst<Impl> { @@ -52,10 +55,14 @@ class AlphaDynInst : public BaseDynInst<Impl> /** Binary machine instruction type. */ typedef TheISA::MachInst MachInst; + /** Extended machine instruction type. */ + typedef TheISA::ExtMachInst ExtMachInst; /** Logical register index type. */ typedef TheISA::RegIndex RegIndex; /** Integer register index type. */ typedef TheISA::IntReg IntReg; + typedef TheISA::FloatReg FloatReg; + typedef TheISA::FloatRegBits FloatRegBits; /** Misc register index type. */ typedef TheISA::MiscReg MiscReg; @@ -66,60 +73,74 @@ class AlphaDynInst : public BaseDynInst<Impl> public: /** BaseDynInst constructor given a binary instruction. */ - AlphaDynInst(MachInst inst, Addr PC, Addr Pred_PC, InstSeqNum seq_num, + AlphaDynInst(ExtMachInst inst, Addr PC, Addr Pred_PC, InstSeqNum seq_num, FullCPU *cpu); /** BaseDynInst constructor given a static inst pointer. */ AlphaDynInst(StaticInstPtr &_staticInst); /** Executes the instruction.*/ - Fault execute() - { - return this->fault = this->staticInst->execute(this, this->traceData); - } + Fault execute(); + + /** Initiates the access. Only valid for memory operations. */ + Fault initiateAcc(); + + /** Completes the access. Only valid for memory operations. */ + Fault completeAcc(Packet *pkt); + + private: + /** Initializes variables. */ + void initVars(); public: + /** Reads a miscellaneous register. */ MiscReg readMiscReg(int misc_reg) { - // Dummy function for now. - // @todo: Fix this once reg file gets fixed. - return 0; + return this->cpu->readMiscReg(misc_reg, this->threadNumber); } + /** Reads a misc. register, including any side-effects the read + * might have as defined by the architecture. + */ MiscReg readMiscRegWithEffect(int misc_reg, Fault &fault) { - // Dummy function for now. - // @todo: Fix this once reg file gets fixed. - return 0; + return this->cpu->readMiscRegWithEffect(misc_reg, fault, + this->threadNumber); } + /** Sets a misc. register. */ Fault setMiscReg(int misc_reg, const MiscReg &val) { - // Dummy function for now. - // @todo: Fix this once reg file gets fixed. - return NoFault; + this->instResult.integer = val; + return this->cpu->setMiscReg(misc_reg, val, this->threadNumber); } + /** Sets a misc. register, including any side-effects the write + * might have as defined by the architecture. + */ Fault setMiscRegWithEffect(int misc_reg, const MiscReg &val) { - // Dummy function for now. - // @todo: Fix this once reg file gets fixed. - return NoFault; + return this->cpu->setMiscRegWithEffect(misc_reg, val, + this->threadNumber); } #if FULL_SYSTEM + /** Calls hardware return from error interrupt. */ Fault hwrei(); + /** Reads interrupt flag. */ int readIntrFlag(); + /** Sets interrupt flag. */ void setIntrFlag(int val); + /** Checks if system is in PAL mode. */ bool inPalMode(); + /** Traps to handle specified fault. */ void trap(Fault fault); bool simPalCheck(int palFunc); #else - void syscall(); + /** Calls a syscall. */ + void syscall(int64_t callnum); #endif - - private: /** Physical register index of the destination registers of this * instruction. @@ -180,32 +201,32 @@ class AlphaDynInst : public BaseDynInst<Impl> void setIntReg(const StaticInst *si, int idx, uint64_t val) { this->cpu->setIntReg(_destRegIdx[idx], val); - this->instResult.integer = val; + BaseDynInst<Impl>::setIntReg(si, idx, val); } void setFloatReg(const StaticInst *si, int idx, FloatReg val, int width) { this->cpu->setFloatReg(_destRegIdx[idx], val, width); - this->instResult.fp = val; + BaseDynInst<Impl>::setFloatReg(si, idx, val, width); } void setFloatReg(const StaticInst *si, int idx, FloatReg val) { this->cpu->setFloatReg(_destRegIdx[idx], val); - this->instResult.dbl = val; + BaseDynInst<Impl>::setFloatReg(si, idx, val); } void setFloatRegBits(const StaticInst *si, int idx, FloatRegBits val, int width) { this->cpu->setFloatRegBits(_destRegIdx[idx], val, width); - this->instResult.integer = val; + BaseDynInst<Impl>::setFloatRegBits(si, idx, val); } void setFloatRegBits(const StaticInst *si, int idx, FloatRegBits val) { this->cpu->setFloatRegBits(_destRegIdx[idx], val); - this->instResult.integer = val; + BaseDynInst<Impl>::setFloatRegBits(si, idx, val); } /** Returns the physical register index of the i'th destination @@ -251,16 +272,24 @@ class AlphaDynInst : public BaseDynInst<Impl> } public: + /** Calculates EA part of a memory instruction. Currently unused, + * though it may be useful in the future if we want to split + * memory operations into EA calculation and memory access parts. + */ Fault calcEA() { return this->staticInst->eaCompInst()->execute(this, this->traceData); } + /** Does the memory access part of a memory instruction. Currently unused, + * though it may be useful in the future if we want to split + * memory operations into EA calculation and memory access parts. + */ Fault memAccess() { return this->staticInst->memAccInst()->execute(this, this->traceData); } }; -#endif // __CPU_O3_CPU_ALPHA_DYN_INST_HH__ +#endif // __CPU_O3_ALPHA_DYN_INST_HH__ diff --git a/src/cpu/o3/alpha_dyn_inst_impl.hh b/src/cpu/o3/alpha_dyn_inst_impl.hh index fdb83379e..a73cf4a7d 100644 --- a/src/cpu/o3/alpha_dyn_inst_impl.hh +++ b/src/cpu/o3/alpha_dyn_inst_impl.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -31,42 +31,88 @@ #include "cpu/o3/alpha_dyn_inst.hh" template <class Impl> -AlphaDynInst<Impl>::AlphaDynInst(MachInst inst, Addr PC, Addr Pred_PC, +AlphaDynInst<Impl>::AlphaDynInst(ExtMachInst inst, Addr PC, Addr Pred_PC, InstSeqNum seq_num, FullCPU *cpu) : BaseDynInst<Impl>(inst, PC, Pred_PC, seq_num, cpu) { + initVars(); +} + +template <class Impl> +AlphaDynInst<Impl>::AlphaDynInst(StaticInstPtr &_staticInst) + : BaseDynInst<Impl>(_staticInst) +{ + initVars(); +} + +template <class Impl> +void +AlphaDynInst<Impl>::initVars() +{ // Make sure to have the renamed register entries set to the same // as the normal register entries. It will allow the IQ to work // without any modifications. - for (int i = 0; i < this->staticInst->numDestRegs(); i++) - { + for (int i = 0; i < this->staticInst->numDestRegs(); i++) { _destRegIdx[i] = this->staticInst->destRegIdx(i); } - for (int i = 0; i < this->staticInst->numSrcRegs(); i++) - { + for (int i = 0; i < this->staticInst->numSrcRegs(); i++) { _srcRegIdx[i] = this->staticInst->srcRegIdx(i); this->_readySrcRegIdx[i] = 0; } +} + +template <class Impl> +Fault +AlphaDynInst<Impl>::execute() +{ + // @todo: Pretty convoluted way to avoid squashing from happening + // when using the TC during an instruction's execution + // (specifically for instructions that have side-effects that use + // the TC). Fix this. + bool in_syscall = this->thread->inSyscall; + this->thread->inSyscall = true; + + this->fault = this->staticInst->execute(this, this->traceData); + + this->thread->inSyscall = in_syscall; + return this->fault; } template <class Impl> -AlphaDynInst<Impl>::AlphaDynInst(StaticInstPtr &_staticInst) - : BaseDynInst<Impl>(_staticInst) +Fault +AlphaDynInst<Impl>::initiateAcc() { - // Make sure to have the renamed register entries set to the same - // as the normal register entries. It will allow the IQ to work - // without any modifications. - for (int i = 0; i < _staticInst->numDestRegs(); i++) - { - _destRegIdx[i] = _staticInst->destRegIdx(i); - } + // @todo: Pretty convoluted way to avoid squashing from happening + // when using the TC during an instruction's execution + // (specifically for instructions that have side-effects that use + // the TC). Fix this. + bool in_syscall = this->thread->inSyscall; + this->thread->inSyscall = true; + + this->fault = this->staticInst->initiateAcc(this, this->traceData); + + this->thread->inSyscall = in_syscall; - for (int i = 0; i < _staticInst->numSrcRegs(); i++) - { - _srcRegIdx[i] = _staticInst->srcRegIdx(i); + return this->fault; +} + +template <class Impl> +Fault +AlphaDynInst<Impl>::completeAcc(Packet *pkt) +{ + if (this->isLoad()) { + this->fault = this->staticInst->completeAcc(pkt, this, + this->traceData); + } else if (this->isStore()) { + this->fault = this->staticInst->completeAcc(pkt, this, + this->traceData); + } else { + panic("Unknown type!"); } + + return this->fault; } #if FULL_SYSTEM @@ -74,14 +120,26 @@ template <class Impl> Fault AlphaDynInst<Impl>::hwrei() { - return this->cpu->hwrei(); + // Can only do a hwrei when in pal mode. + if (!this->cpu->inPalMode(this->readPC())) + return new AlphaISA::UnimplementedOpcodeFault; + + // Set the next PC based on the value of the EXC_ADDR IPR. + this->setNextPC(this->cpu->readMiscReg(AlphaISA::IPR_EXC_ADDR, + this->threadNumber)); + + // Tell CPU to clear any state it needs to if a hwrei is taken. + this->cpu->hwrei(this->threadNumber); + + // FIXME: XXX check for interrupts? XXX + return NoFault; } template <class Impl> int AlphaDynInst<Impl>::readIntrFlag() { -return this->cpu->readIntrFlag(); + return this->cpu->readIntrFlag(); } template <class Impl> @@ -95,28 +153,28 @@ template <class Impl> bool AlphaDynInst<Impl>::inPalMode() { - return this->cpu->inPalMode(); + return this->cpu->inPalMode(this->PC); } template <class Impl> void AlphaDynInst<Impl>::trap(Fault fault) { - this->cpu->trap(fault); + this->cpu->trap(fault, this->threadNumber); } template <class Impl> bool AlphaDynInst<Impl>::simPalCheck(int palFunc) { - return this->cpu->simPalCheck(palFunc); + return this->cpu->simPalCheck(palFunc, this->threadNumber); } #else template <class Impl> void -AlphaDynInst<Impl>::syscall() +AlphaDynInst<Impl>::syscall(int64_t callnum) { - this->cpu->syscall(this->threadNumber); + this->cpu->syscall(callnum, this->threadNumber); } #endif diff --git a/src/cpu/o3/alpha_impl.hh b/src/cpu/o3/alpha_impl.hh index cd9f6afc4..52f7c2394 100644 --- a/src/cpu/o3/alpha_impl.hh +++ b/src/cpu/o3/alpha_impl.hh @@ -28,8 +28,8 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_ALPHA_IMPL_HH__ -#define __CPU_O3_CPU_ALPHA_IMPL_HH__ +#ifndef __CPU_O3_ALPHA_IMPL_HH__ +#define __CPU_O3_ALPHA_IMPL_HH__ #include "arch/alpha/isa_traits.hh" @@ -43,7 +43,7 @@ class AlphaDynInst; template <class Impl> class AlphaFullCPU; -/** Implementation specific struct that defines several key things to the +/** Implementation specific struct that defines several key types to the * CPU, the stages within the CPU, the time buffers, and the DynInst. * The struct defines the ISA, the CPU policy, the specific DynInst, the * specific FullCPU, and all of the structs from the time buffers to do @@ -56,10 +56,10 @@ struct AlphaSimpleImpl /** The type of MachInst. */ typedef TheISA::MachInst MachInst; - /** The CPU policy to be used (ie fetch, decode, etc.). */ + /** The CPU policy to be used, which defines all of the CPU stages. */ typedef SimpleCPUPolicy<AlphaSimpleImpl> CPUPol; - /** The DynInst to be used. */ + /** The DynInst type to be used. */ typedef AlphaDynInst<AlphaSimpleImpl> DynInst; /** The refcounted DynInst pointer to be used. In most cases this is @@ -67,15 +67,16 @@ struct AlphaSimpleImpl */ typedef RefCountingPtr<DynInst> DynInstPtr; - /** The FullCPU to be used. */ + /** The FullCPU type to be used. */ typedef AlphaFullCPU<AlphaSimpleImpl> FullCPU; /** The Params to be passed to each stage. */ typedef AlphaSimpleParams Params; enum { - MaxWidth = 8 + MaxWidth = 8, + MaxThreads = 4 }; }; -#endif // __CPU_O3_CPU_ALPHA_IMPL_HH__ +#endif // __CPU_O3_ALPHA_IMPL_HH__ diff --git a/src/cpu/o3/alpha_params.hh b/src/cpu/o3/alpha_params.hh index bc48e0908..f3cf36887 100644 --- a/src/cpu/o3/alpha_params.hh +++ b/src/cpu/o3/alpha_params.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,18 +28,18 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_ALPHA_SIMPLE_PARAMS_HH__ -#define __CPU_O3_CPU_ALPHA_SIMPLE_PARAMS_HH__ +#ifndef __CPU_O3_ALPHA_PARAMS_HH__ +#define __CPU_O3_ALPHA_PARAMS_HH__ #include "cpu/o3/cpu.hh" //Forward declarations -class System; -class AlphaITB; class AlphaDTB; -class FunctionalMemory; +class AlphaITB; +class FUPool; +class MemObject; class Process; -class MemInterface; +class System; /** * This file defines the parameters that will be used for the AlphaFullCPU. @@ -58,13 +58,19 @@ class AlphaSimpleParams : public BaseFullCPU::Params Process *process; #endif // FULL_SYSTEM - FunctionalMemory *mem; + MemObject *mem; + + BaseCPU *checker; + + unsigned activity; // // Caches // - MemInterface *icacheInterface; - MemInterface *dcacheInterface; +// MemInterface *icacheInterface; +// MemInterface *dcacheInterface; + + unsigned cachePorts; // // Fetch @@ -104,6 +110,7 @@ class AlphaSimpleParams : public BaseFullCPU::Params unsigned executeFloatWidth; unsigned executeBranchWidth; unsigned executeMemoryWidth; + FUPool *fuPool; // // Commit @@ -112,24 +119,22 @@ class AlphaSimpleParams : public BaseFullCPU::Params unsigned renameToROBDelay; unsigned commitWidth; unsigned squashWidth; + Tick trapLatency; + Tick fetchTrapLatency; // - // Branch predictor (BP & BTB) + // Branch predictor (BP, BTB, RAS) // -/* + std::string predType; unsigned localPredictorSize; - unsigned localPredictorCtrBits; -*/ - - unsigned local_predictor_size; - unsigned local_ctr_bits; - unsigned local_history_table_size; - unsigned local_history_bits; - unsigned global_predictor_size; - unsigned global_ctr_bits; - unsigned global_history_bits; - unsigned choice_predictor_size; - unsigned choice_ctr_bits; + unsigned localCtrBits; + unsigned localHistoryTableSize; + unsigned localHistoryBits; + unsigned globalPredictorSize; + unsigned globalCtrBits; + unsigned globalHistoryBits; + unsigned choicePredictorSize; + unsigned choiceCtrBits; unsigned BTBEntries; unsigned BTBTagSize; @@ -156,10 +161,24 @@ class AlphaSimpleParams : public BaseFullCPU::Params unsigned numIQEntries; unsigned numROBEntries; + //SMT Parameters + unsigned smtNumFetchingThreads; + + std::string smtFetchPolicy; + + std::string smtIQPolicy; + unsigned smtIQThreshold; + + std::string smtLSQPolicy; + unsigned smtLSQThreshold; + + std::string smtCommitPolicy; + + std::string smtROBPolicy; + unsigned smtROBThreshold; + // Probably can get this from somewhere. unsigned instShiftAmt; - - bool defReg; }; -#endif // __CPU_O3_CPU_ALPHA_PARAMS_HH__ +#endif // __CPU_O3_ALPHA_PARAMS_HH__ diff --git a/src/cpu/o3/bpred_unit.cc b/src/cpu/o3/bpred_unit.cc index 3d0636a28..b33543bdc 100644 --- a/src/cpu/o3/bpred_unit.cc +++ b/src/cpu/o3/bpred_unit.cc @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -31,5 +31,9 @@ #include "cpu/o3/bpred_unit_impl.hh" #include "cpu/o3/alpha_impl.hh" #include "cpu/o3/alpha_dyn_inst.hh" +#include "cpu/ozone/ozone_impl.hh" +//#include "cpu/ozone/simple_impl.hh" -template class TwobitBPredUnit<AlphaSimpleImpl>; +template class BPredUnit<AlphaSimpleImpl>; +template class BPredUnit<OzoneImpl>; +//template class BPredUnit<SimpleImpl>; diff --git a/src/cpu/o3/bpred_unit.hh b/src/cpu/o3/bpred_unit.hh index e298f51ad..2c0a39565 100644 --- a/src/cpu/o3/bpred_unit.hh +++ b/src/cpu/o3/bpred_unit.hh @@ -28,8 +28,8 @@ * Authors: Kevin Lim */ -#ifndef __BPRED_UNIT_HH__ -#define __BPRED_UNIT_HH__ +#ifndef __CPU_O3_BPRED_UNIT_HH__ +#define __CPU_O3_BPRED_UNIT_HH__ // For Addr type. #include "arch/isa_traits.hh" @@ -37,99 +37,220 @@ #include "cpu/inst_seq.hh" #include "cpu/o3/2bit_local_pred.hh" -#include "cpu/o3/tournament_pred.hh" #include "cpu/o3/btb.hh" #include "cpu/o3/ras.hh" +#include "cpu/o3/tournament_pred.hh" #include <list> /** * Basically a wrapper class to hold both the branch predictor - * and the BTB. Right now I'm unsure of the implementation; it would - * be nicer to have something closer to the CPUPolicy or the Impl where - * this is just typedefs, but it forces the upper level stages to be - * aware of the constructors of the BP and the BTB. The nicer thing - * to do is have this templated on the Impl, accept the usual Params - * object, and be able to call the constructors on the BP and BTB. + * and the BTB. */ template<class Impl> -class TwobitBPredUnit +class BPredUnit { - public: + private: typedef typename Impl::Params Params; typedef typename Impl::DynInstPtr DynInstPtr; - TwobitBPredUnit(Params ¶ms); + enum PredType { + Local, + Tournament + }; + + PredType predictor; + public: + + /** + * @param params The params object, that has the size of the BP and BTB. + */ + BPredUnit(Params *params); + + /** + * Registers statistics. + */ void regStats(); - bool predict(DynInstPtr &inst, Addr &PC); + void switchOut(); + + void takeOverFrom(); - void update(const InstSeqNum &done_sn); + /** + * Predicts whether or not the instruction is a taken branch, and the + * target of the branch if it is taken. + * @param inst The branch instruction. + * @param PC The predicted PC is passed back through this parameter. + * @param tid The thread id. + * @return Returns if the branch is taken or not. + */ + bool predict(DynInstPtr &inst, Addr &PC, unsigned tid); - void squash(const InstSeqNum &squashed_sn); + // @todo: Rename this function. + void BPUncond(void * &bp_history); + /** + * Tells the branch predictor to commit any updates until the given + * sequence number. + * @param done_sn The sequence number to commit any older updates up until. + * @param tid The thread id. + */ + void update(const InstSeqNum &done_sn, unsigned tid); + + /** + * Squashes all outstanding updates until a given sequence number. + * @param squashed_sn The sequence number to squash any younger updates up + * until. + * @param tid The thread id. + */ + void squash(const InstSeqNum &squashed_sn, unsigned tid); + + /** + * Squashes all outstanding updates until a given sequence number, and + * corrects that sn's update with the proper address and taken/not taken. + * @param squashed_sn The sequence number to squash any younger updates up + * until. + * @param corr_target The correct branch target. + * @param actually_taken The correct branch direction. + * @param tid The thread id. + */ void squash(const InstSeqNum &squashed_sn, const Addr &corr_target, - bool actually_taken); + bool actually_taken, unsigned tid); + + /** + * @param bp_history Pointer to the history object. The predictor + * will need to update any state and delete the object. + */ + void BPSquash(void *bp_history); - bool BPLookup(Addr &inst_PC) - { return BP.lookup(inst_PC); } + /** + * Looks up a given PC in the BP to see if it is taken or not taken. + * @param inst_PC The PC to look up. + * @param bp_history Pointer that will be set to an object that + * has the branch predictor state associated with the lookup. + * @return Whether the branch is taken or not taken. + */ + bool BPLookup(Addr &inst_PC, void * &bp_history); + /** + * Looks up a given PC in the BTB to see if a matching entry exists. + * @param inst_PC The PC to look up. + * @return Whether the BTB contains the given PC. + */ bool BTBValid(Addr &inst_PC) - { return BTB.valid(inst_PC); } + { return BTB.valid(inst_PC, 0); } + /** + * Looks up a given PC in the BTB to get the predicted target. + * @param inst_PC The PC to look up. + * @return The address of the target of the branch. + */ Addr BTBLookup(Addr &inst_PC) - { return BTB.lookup(inst_PC); } + { return BTB.lookup(inst_PC, 0); } - // Will want to include global history. - void BPUpdate(Addr &inst_PC, bool taken) - { BP.update(inst_PC, taken); } + /** + * Updates the BP with taken/not taken information. + * @param inst_PC The branch's PC that will be updated. + * @param taken Whether the branch was taken or not taken. + * @param bp_history Pointer to the branch predictor state that is + * associated with the branch lookup that is being updated. + * @todo Make this update flexible enough to handle a global predictor. + */ + void BPUpdate(Addr &inst_PC, bool taken, void *bp_history); + /** + * Updates the BTB with the target of a branch. + * @param inst_PC The branch's PC that will be updated. + * @param target_PC The branch's target that will be added to the BTB. + */ void BTBUpdate(Addr &inst_PC, Addr &target_PC) - { BTB.update(inst_PC, target_PC); } + { BTB.update(inst_PC, target_PC,0); } + + void dump(); private: struct PredictorHistory { + /** + * Makes a predictor history struct that contains any + * information needed to update the predictor, BTB, and RAS. + */ PredictorHistory(const InstSeqNum &seq_num, const Addr &inst_PC, - const bool pred_taken) - : seqNum(seq_num), PC(inst_PC), predTaken(pred_taken), - globalHistory(0), usedRAS(0), wasCall(0), RASIndex(0), - RASTarget(0) + const bool pred_taken, void *bp_history, + const unsigned _tid) + : seqNum(seq_num), PC(inst_PC), RASTarget(0), + RASIndex(0), tid(_tid), predTaken(pred_taken), usedRAS(0), + wasCall(0), bpHistory(bp_history) { } + /** The sequence number for the predictor history entry. */ InstSeqNum seqNum; + /** The PC associated with the sequence number. */ Addr PC; - bool predTaken; + /** The RAS target (only valid if a return). */ + Addr RASTarget; + + /** The RAS index of the instruction (only valid if a call). */ + unsigned RASIndex; + + /** The thread id. */ + unsigned tid; - unsigned globalHistory; + /** Whether or not it was predicted taken. */ + bool predTaken; + /** Whether or not the RAS was used. */ bool usedRAS; + /** Whether or not the instruction was a call. */ bool wasCall; - unsigned RASIndex; - - Addr RASTarget; + /** Pointer to the history object passed back from the branch + * predictor. It is used to update or restore state of the + * branch predictor. + */ + void *bpHistory; }; - std::list<PredictorHistory> predHist; + typedef std::list<PredictorHistory> History; + + /** + * The per-thread predictor history. This is used to update the predictor + * as instructions are committed, or restore it to the proper state after + * a squash. + */ + History predHist[Impl::MaxThreads]; + + /** The local branch predictor. */ + LocalBP *localBP; - DefaultBP BP; + /** The tournament branch predictor. */ + TournamentBP *tournamentBP; + /** The BTB. */ DefaultBTB BTB; - ReturnAddrStack RAS; + /** The per-thread return address stack. */ + ReturnAddrStack RAS[Impl::MaxThreads]; + /** Stat for number of BP lookups. */ Stats::Scalar<> lookups; + /** Stat for number of conditional branches predicted. */ Stats::Scalar<> condPredicted; + /** Stat for number of conditional branches predicted incorrectly. */ Stats::Scalar<> condIncorrect; + /** Stat for number of BTB lookups. */ Stats::Scalar<> BTBLookups; + /** Stat for number of BTB hits. */ Stats::Scalar<> BTBHits; + /** Stat for number of times the BTB is correct. */ Stats::Scalar<> BTBCorrect; + /** Stat for number of times the RAS is used to get a target. */ Stats::Scalar<> usedRAS; + /** Stat for number of times the RAS is incorrect. */ Stats::Scalar<> RASIncorrect; }; -#endif // __BPRED_UNIT_HH__ +#endif // __CPU_O3_BPRED_UNIT_HH__ diff --git a/src/cpu/o3/bpred_unit_impl.hh b/src/cpu/o3/bpred_unit_impl.hh index a6311527b..0da02145b 100644 --- a/src/cpu/o3/bpred_unit_impl.hh +++ b/src/cpu/o3/bpred_unit_impl.hh @@ -28,25 +28,50 @@ * Authors: Kevin Lim */ +#include <list> +#include <vector> + #include "base/trace.hh" #include "base/traceflags.hh" #include "cpu/o3/bpred_unit.hh" +using namespace std; + template<class Impl> -TwobitBPredUnit<Impl>::TwobitBPredUnit(Params ¶ms) - : BP(params.local_predictor_size, - params.local_ctr_bits, - params.instShiftAmt), - BTB(params.BTBEntries, - params.BTBTagSize, - params.instShiftAmt), - RAS(params.RASSize) +BPredUnit<Impl>::BPredUnit(Params *params) + : BTB(params->BTBEntries, + params->BTBTagSize, + params->instShiftAmt) { + // Setup the selected predictor. + if (params->predType == "local") { + localBP = new LocalBP(params->localPredictorSize, + params->localCtrBits, + params->instShiftAmt); + predictor = Local; + } else if (params->predType == "tournament") { + tournamentBP = new TournamentBP(params->localPredictorSize, + params->localCtrBits, + params->localHistoryTableSize, + params->localHistoryBits, + params->globalPredictorSize, + params->globalHistoryBits, + params->globalCtrBits, + params->choicePredictorSize, + params->choiceCtrBits, + params->instShiftAmt); + predictor = Tournament; + } else { + fatal("Invalid BP selected!"); + } + + for (int i=0; i < Impl::MaxThreads; i++) + RAS[i].init(params->RASSize); } template <class Impl> void -TwobitBPredUnit<Impl>::regStats() +BPredUnit<Impl>::regStats() { lookups .name(name() + ".BPredUnit.lookups") @@ -81,7 +106,7 @@ TwobitBPredUnit<Impl>::regStats() usedRAS .name(name() + ".BPredUnit.usedRAS") - .desc("Number of times the RAS was used.") + .desc("Number of times the RAS was used to get a target.") ; RASIncorrect @@ -91,12 +116,36 @@ TwobitBPredUnit<Impl>::regStats() } template <class Impl> +void +BPredUnit<Impl>::switchOut() +{ + // Clear any state upon switch out. + for (int i = 0; i < Impl::MaxThreads; ++i) { + squash(0, i); + } +} + +template <class Impl> +void +BPredUnit<Impl>::takeOverFrom() +{ + // Can reset all predictor state, but it's not necessarily better + // than leaving it be. +/* + for (int i = 0; i < Impl::MaxThreads; ++i) + RAS[i].reset(); + + BP.reset(); + BTB.reset(); +*/ +} + +template <class Impl> bool -TwobitBPredUnit<Impl>::predict(DynInstPtr &inst, Addr &PC) +BPredUnit<Impl>::predict(DynInstPtr &inst, Addr &PC, unsigned tid) { // See if branch predictor predicts taken. // If so, get its target addr either from the BTB or the RAS. - // Once that's done, speculatively update the predictor? // Save off record of branch stuff so the RAS can be fixed // up once it's done. @@ -107,19 +156,25 @@ TwobitBPredUnit<Impl>::predict(DynInstPtr &inst, Addr &PC) ++lookups; + void *bp_history = NULL; + if (inst->isUncondCtrl()) { - DPRINTF(Fetch, "BranchPred: Unconditional control.\n"); + DPRINTF(Fetch, "BranchPred: [tid:%i] Unconditional control.\n", tid); pred_taken = true; + // Tell the BP there was an unconditional branch. + BPUncond(bp_history); } else { ++condPredicted; - pred_taken = BPLookup(PC); + pred_taken = BPLookup(PC, bp_history); - DPRINTF(Fetch, "BranchPred: Branch predictor predicted %i for PC %#x" - "\n", pred_taken, inst->readPC()); + DPRINTF(Fetch, "BranchPred: [tid:%i]: Branch predictor predicted %i " + "for PC %#x\n", + tid, pred_taken, inst->readPC()); } - PredictorHistory predict_record(inst->seqNum, PC, pred_taken); + PredictorHistory predict_record(inst->seqNum, PC, pred_taken, + bp_history, tid); // Now lookup in the BTB or RAS. if (pred_taken) { @@ -128,45 +183,48 @@ TwobitBPredUnit<Impl>::predict(DynInstPtr &inst, Addr &PC) // If it's a function return call, then look up the address // in the RAS. - target = RAS.top(); + target = RAS[tid].top(); // Record the top entry of the RAS, and its index. predict_record.usedRAS = true; - predict_record.RASIndex = RAS.topIdx(); + predict_record.RASIndex = RAS[tid].topIdx(); predict_record.RASTarget = target; - RAS.pop(); + assert(predict_record.RASIndex < 16); + + RAS[tid].pop(); - DPRINTF(Fetch, "BranchPred: Instruction %#x is a return, RAS " - "predicted target: %#x, RAS index: %i.\n", - inst->readPC(), target, predict_record.RASIndex); + DPRINTF(Fetch, "BranchPred: [tid:%i]: Instruction %#x is a return, " + "RAS predicted target: %#x, RAS index: %i.\n", + tid, inst->readPC(), target, predict_record.RASIndex); } else { ++BTBLookups; if (inst->isCall()) { - RAS.push(PC+sizeof(MachInst)); + RAS[tid].push(PC + sizeof(MachInst)); // Record that it was a call so that the top RAS entry can // be popped off if the speculation is incorrect. predict_record.wasCall = true; - DPRINTF(Fetch, "BranchPred: Instruction %#x was a call, " - "adding %#x to the RAS.\n", - inst->readPC(), PC+sizeof(MachInst)); + DPRINTF(Fetch, "BranchPred: [tid:%i] Instruction %#x was a call" + ", adding %#x to the RAS.\n", + tid, inst->readPC(), PC + sizeof(MachInst)); } - if (BTB.valid(PC)) { + if (BTB.valid(PC, tid)) { ++BTBHits; - //If it's anything else, use the BTB to get the target addr. - target = BTB.lookup(PC); + // If it's not a return, use the BTB to get the target addr. + target = BTB.lookup(PC, tid); - DPRINTF(Fetch, "BranchPred: Instruction %#x predicted target " - "is %#x.\n", inst->readPC(), target); + DPRINTF(Fetch, "BranchPred: [tid:%i]: Instruction %#x predicted" + " target is %#x.\n", + tid, inst->readPC(), target); } else { - DPRINTF(Fetch, "BranchPred: BTB doesn't have a valid entry." - "\n"); + DPRINTF(Fetch, "BranchPred: [tid:%i]: BTB doesn't have a " + "valid entry.\n",tid); pred_taken = false; } @@ -182,97 +240,173 @@ TwobitBPredUnit<Impl>::predict(DynInstPtr &inst, Addr &PC) inst->setPredTarg(PC); } - predHist.push_front(predict_record); + predHist[tid].push_front(predict_record); - assert(!predHist.empty()); + DPRINTF(Fetch, "[tid:%i] predHist.size(): %i\n", tid, predHist[tid].size()); return pred_taken; } template <class Impl> void -TwobitBPredUnit<Impl>::update(const InstSeqNum &done_sn) +BPredUnit<Impl>::update(const InstSeqNum &done_sn, unsigned tid) { - DPRINTF(Fetch, "BranchPred: Commiting branches until sequence number " - "%i.\n", done_sn); + DPRINTF(Fetch, "BranchPred: [tid:%i]: Commiting branches until sequence" + "number %lli.\n", tid, done_sn); - while (!predHist.empty() && predHist.back().seqNum <= done_sn) { - assert(!predHist.empty()); + while (!predHist[tid].empty() && + predHist[tid].back().seqNum <= done_sn) { + // Update the branch predictor with the correct results. + BPUpdate(predHist[tid].back().PC, + predHist[tid].back().predTaken, + predHist[tid].back().bpHistory); - // Update the branch predictor with the correct results of branches. - BP.update(predHist.back().PC, predHist.back().predTaken); - - predHist.pop_back(); + predHist[tid].pop_back(); } } template <class Impl> void -TwobitBPredUnit<Impl>::squash(const InstSeqNum &squashed_sn) +BPredUnit<Impl>::squash(const InstSeqNum &squashed_sn, unsigned tid) { - while (!predHist.empty() && predHist.front().seqNum > squashed_sn) { - if (predHist.front().usedRAS) { - DPRINTF(Fetch, "BranchPred: Restoring top of RAS to: %i, " - "target: %#x.\n", - predHist.front().RASIndex, - predHist.front().RASTarget); - - RAS.restore(predHist.front().RASIndex, - predHist.front().RASTarget); - } else if (predHist.front().wasCall) { - DPRINTF(Fetch, "BranchPred: Removing speculative entry added " - "to the RAS.\n"); - - RAS.pop(); + History &pred_hist = predHist[tid]; + + while (!pred_hist.empty() && + pred_hist.front().seqNum > squashed_sn) { + if (pred_hist.front().usedRAS) { + DPRINTF(Fetch, "BranchPred: [tid:%i]: Restoring top of RAS to: %i," + " target: %#x.\n", + tid, + pred_hist.front().RASIndex, + pred_hist.front().RASTarget); + + RAS[tid].restore(pred_hist.front().RASIndex, + pred_hist.front().RASTarget); + + } else if (pred_hist.front().wasCall) { + DPRINTF(Fetch, "BranchPred: [tid:%i]: Removing speculative entry " + "added to the RAS.\n",tid); + + RAS[tid].pop(); } - predHist.pop_front(); + // This call should delete the bpHistory. + BPSquash(pred_hist.front().bpHistory); + + pred_hist.pop_front(); } + } template <class Impl> void -TwobitBPredUnit<Impl>::squash(const InstSeqNum &squashed_sn, - const Addr &corr_target, - const bool actually_taken) +BPredUnit<Impl>::squash(const InstSeqNum &squashed_sn, + const Addr &corr_target, + const bool actually_taken, + unsigned tid) { // Now that we know that a branch was mispredicted, we need to undo // all the branches that have been seen up until this branch and // fix up everything. + History &pred_hist = predHist[tid]; + ++condIncorrect; - DPRINTF(Fetch, "BranchPred: Squashing from sequence number %i, " + DPRINTF(Fetch, "BranchPred: [tid:%i]: Squashing from sequence number %i, " "setting target to %#x.\n", - squashed_sn, corr_target); + tid, squashed_sn, corr_target); - while (!predHist.empty() && predHist.front().seqNum > squashed_sn) { + squash(squashed_sn, tid); - if (predHist.front().usedRAS) { - DPRINTF(Fetch, "BranchPred: Restoring top of RAS to: %i, " - "target: %#x.\n", - predHist.front().RASIndex, - predHist.front().RASTarget); + // If there's a squash due to a syscall, there may not be an entry + // corresponding to the squash. In that case, don't bother trying to + // fix up the entry. + if (!pred_hist.empty()) { + assert(pred_hist.front().seqNum == squashed_sn); + if (pred_hist.front().usedRAS) { + ++RASIncorrect; + } - RAS.restore(predHist.front().RASIndex, - predHist.front().RASTarget); - } else if (predHist.front().wasCall) { - DPRINTF(Fetch, "BranchPred: Removing speculative entry added " - "to the RAS.\n"); + BPUpdate(pred_hist.front().PC, actually_taken, + pred_hist.front().bpHistory); - RAS.pop(); - } + BTB.update(pred_hist.front().PC, corr_target, tid); + pred_hist.pop_front(); + } +} - predHist.pop_front(); +template <class Impl> +void +BPredUnit<Impl>::BPUncond(void * &bp_history) +{ + // Only the tournament predictor cares about unconditional branches. + if (predictor == Tournament) { + tournamentBP->uncondBr(bp_history); } +} - predHist.front().predTaken = actually_taken; +template <class Impl> +void +BPredUnit<Impl>::BPSquash(void *bp_history) +{ + if (predictor == Local) { + localBP->squash(bp_history); + } else if (predictor == Tournament) { + tournamentBP->squash(bp_history); + } else { + panic("Predictor type is unexpected value!"); + } +} - if (predHist.front().usedRAS) { - ++RASIncorrect; +template <class Impl> +bool +BPredUnit<Impl>::BPLookup(Addr &inst_PC, void * &bp_history) +{ + if (predictor == Local) { + return localBP->lookup(inst_PC, bp_history); + } else if (predictor == Tournament) { + return tournamentBP->lookup(inst_PC, bp_history); + } else { + panic("Predictor type is unexpected value!"); } +} - BP.update(predHist.front().PC, actually_taken); +template <class Impl> +void +BPredUnit<Impl>::BPUpdate(Addr &inst_PC, bool taken, void *bp_history) +{ + if (predictor == Local) { + localBP->update(inst_PC, taken, bp_history); + } else if (predictor == Tournament) { + tournamentBP->update(inst_PC, taken, bp_history); + } else { + panic("Predictor type is unexpected value!"); + } +} - BTB.update(predHist.front().PC, corr_target); +template <class Impl> +void +BPredUnit<Impl>::dump() +{ + typename History::iterator pred_hist_it; + + for (int i = 0; i < Impl::MaxThreads; ++i) { + if (!predHist[i].empty()) { + pred_hist_it = predHist[i].begin(); + + cprintf("predHist[%i].size(): %i\n", i, predHist[i].size()); + + while (pred_hist_it != predHist[i].end()) { + cprintf("[sn:%lli], PC:%#x, tid:%i, predTaken:%i, " + "bpHistory:%#x\n", + (*pred_hist_it).seqNum, (*pred_hist_it).PC, + (*pred_hist_it).tid, (*pred_hist_it).predTaken, + (*pred_hist_it).bpHistory); + pred_hist_it++; + } + + cprintf("\n"); + } + } } diff --git a/src/cpu/o3/btb.cc b/src/cpu/o3/btb.cc index 8acd33cae..01640f4d1 100644 --- a/src/cpu/o3/btb.cc +++ b/src/cpu/o3/btb.cc @@ -41,14 +41,15 @@ DefaultBTB::DefaultBTB(unsigned _numEntries, tagBits(_tagBits), instShiftAmt(_instShiftAmt) { - // @todo Check to make sure num_entries is valid (a power of 2) - DPRINTF(Fetch, "BTB: Creating BTB object.\n"); - btb = new BTBEntry[numEntries]; + if (!isPowerOf2(numEntries)) { + fatal("BTB entries is not a power of 2!"); + } + + btb.resize(numEntries); - for (int i = 0; i < numEntries; ++i) - { + for (int i = 0; i < numEntries; ++i) { btb[i].valid = false; } @@ -59,6 +60,14 @@ DefaultBTB::DefaultBTB(unsigned _numEntries, tagShiftAmt = instShiftAmt + floorLog2(numEntries); } +void +DefaultBTB::reset() +{ + for (int i = 0; i < numEntries; ++i) { + btb[i].valid = false; + } +} + inline unsigned DefaultBTB::getIndex(const Addr &inst_PC) @@ -75,7 +84,7 @@ DefaultBTB::getTag(const Addr &inst_PC) } bool -DefaultBTB::valid(const Addr &inst_PC) +DefaultBTB::valid(const Addr &inst_PC, unsigned tid) { unsigned btb_idx = getIndex(inst_PC); @@ -83,7 +92,9 @@ DefaultBTB::valid(const Addr &inst_PC) assert(btb_idx < numEntries); - if (btb[btb_idx].valid && inst_tag == btb[btb_idx].tag) { + if (btb[btb_idx].valid + && inst_tag == btb[btb_idx].tag + && btb[btb_idx].tid == tid) { return true; } else { return false; @@ -94,7 +105,7 @@ DefaultBTB::valid(const Addr &inst_PC) // address is valid, and also the address. For now will just use addr = 0 to // represent invalid entry. Addr -DefaultBTB::lookup(const Addr &inst_PC) +DefaultBTB::lookup(const Addr &inst_PC, unsigned tid) { unsigned btb_idx = getIndex(inst_PC); @@ -102,7 +113,9 @@ DefaultBTB::lookup(const Addr &inst_PC) assert(btb_idx < numEntries); - if (btb[btb_idx].valid && inst_tag == btb[btb_idx].tag) { + if (btb[btb_idx].valid + && inst_tag == btb[btb_idx].tag + && btb[btb_idx].tid == tid) { return btb[btb_idx].target; } else { return 0; @@ -110,12 +123,13 @@ DefaultBTB::lookup(const Addr &inst_PC) } void -DefaultBTB::update(const Addr &inst_PC, const Addr &target) +DefaultBTB::update(const Addr &inst_PC, const Addr &target, unsigned tid) { unsigned btb_idx = getIndex(inst_PC); assert(btb_idx < numEntries); + btb[btb_idx].tid = tid; btb[btb_idx].valid = true; btb[btb_idx].target = target; btb[btb_idx].tag = getTag(inst_PC); diff --git a/src/cpu/o3/btb.hh b/src/cpu/o3/btb.hh index 006fa4666..dfa3b7b06 100644 --- a/src/cpu/o3/btb.hh +++ b/src/cpu/o3/btb.hh @@ -28,11 +28,12 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_BTB_HH__ -#define __CPU_O3_CPU_BTB_HH__ +#ifndef __CPU_O3_BTB_HH__ +#define __CPU_O3_BTB_HH__ // For Addr type. #include "arch/isa_traits.hh" +#include "base/misc.hh" class DefaultBTB { @@ -44,39 +45,86 @@ class DefaultBTB { } + /** The entry's tag. */ Addr tag; + + /** The entry's target. */ Addr target; + + /** The entry's thread id. */ + unsigned tid; + + /** Whether or not the entry is valid. */ bool valid; }; public: + /** Creates a BTB with the given number of entries, number of bits per + * tag, and instruction offset amount. + * @param numEntries Number of entries for the BTB. + * @param tagBits Number of bits for each tag in the BTB. + * @param instShiftAmt Offset amount for instructions to ignore alignment. + */ DefaultBTB(unsigned numEntries, unsigned tagBits, unsigned instShiftAmt); - Addr lookup(const Addr &inst_PC); - - bool valid(const Addr &inst_PC); - - void update(const Addr &inst_PC, const Addr &target_PC); + void reset(); + + /** Looks up an address in the BTB. Must call valid() first on the address. + * @param inst_PC The address of the branch to look up. + * @param tid The thread id. + * @return Returns the target of the branch. + */ + Addr lookup(const Addr &inst_PC, unsigned tid); + + /** Checks if a branch is in the BTB. + * @param inst_PC The address of the branch to look up. + * @param tid The thread id. + * @return Whether or not the branch exists in the BTB. + */ + bool valid(const Addr &inst_PC, unsigned tid); + + /** Updates the BTB with the target of a branch. + * @param inst_PC The address of the branch being updated. + * @param target_PC The target address of the branch. + * @param tid The thread id. + */ + void update(const Addr &inst_PC, const Addr &target_PC, + unsigned tid); private: + /** Returns the index into the BTB, based on the branch's PC. + * @param inst_PC The branch to look up. + * @return Returns the index into the BTB. + */ inline unsigned getIndex(const Addr &inst_PC); + /** Returns the tag bits of a given address. + * @param inst_PC The branch's address. + * @return Returns the tag bits. + */ inline Addr getTag(const Addr &inst_PC); - BTBEntry *btb; + /** The actual BTB. */ + std::vector<BTBEntry> btb; + /** The number of entries in the BTB. */ unsigned numEntries; + /** The index mask. */ unsigned idxMask; + /** The number of tag bits per entry. */ unsigned tagBits; + /** The tag mask. */ unsigned tagMask; + /** Number of bits to shift PC when calculating index. */ unsigned instShiftAmt; + /** Number of bits to shift PC when calculating tag. */ unsigned tagShiftAmt; }; -#endif // __CPU_O3_CPU_BTB_HH__ +#endif // __CPU_O3_BTB_HH__ diff --git a/src/cpu/o3/comm.hh b/src/cpu/o3/comm.hh index 7ed92f5d7..bf1bd08e8 100644 --- a/src/cpu/o3/comm.hh +++ b/src/cpu/o3/comm.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,30 +28,37 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_COMM_HH__ -#define __CPU_O3_CPU_COMM_HH__ +#ifndef __CPU_O3_COMM_HH__ +#define __CPU_O3_COMM_HH__ #include <vector> +#include "arch/faults.hh" #include "arch/isa_traits.hh" #include "cpu/inst_seq.hh" #include "sim/host.hh" -// Find better place to put this typedef. -// The impl might be the best place for this. +// Typedef for physical register index type. Although the Impl would be the +// most likely location for this, there are a few classes that need this +// typedef yet are not templated on the Impl. For now it will be defined here. typedef short int PhysRegIndex; +/** Struct that defines the information passed from fetch to decode. */ template<class Impl> -struct SimpleFetchSimpleDecode { +struct DefaultFetchDefaultDecode { typedef typename Impl::DynInstPtr DynInstPtr; int size; DynInstPtr insts[Impl::MaxWidth]; + Fault fetchFault; + InstSeqNum fetchFaultSN; + bool clearFetchFault; }; +/** Struct that defines the information passed from decode to rename. */ template<class Impl> -struct SimpleDecodeSimpleRename { +struct DefaultDecodeDefaultRename { typedef typename Impl::DynInstPtr DynInstPtr; int size; @@ -59,8 +66,9 @@ struct SimpleDecodeSimpleRename { DynInstPtr insts[Impl::MaxWidth]; }; +/** Struct that defines the information passed from rename to IEW. */ template<class Impl> -struct SimpleRenameSimpleIEW { +struct DefaultRenameDefaultIEW { typedef typename Impl::DynInstPtr DynInstPtr; int size; @@ -68,20 +76,23 @@ struct SimpleRenameSimpleIEW { DynInstPtr insts[Impl::MaxWidth]; }; +/** Struct that defines the information passed from IEW to commit. */ template<class Impl> -struct SimpleIEWSimpleCommit { +struct DefaultIEWDefaultCommit { typedef typename Impl::DynInstPtr DynInstPtr; int size; DynInstPtr insts[Impl::MaxWidth]; - bool squash; - bool branchMispredict; - bool branchTaken; - uint64_t mispredPC; - uint64_t nextPC; - InstSeqNum squashedSeqNum; + bool squash[Impl::MaxThreads]; + bool branchMispredict[Impl::MaxThreads]; + bool branchTaken[Impl::MaxThreads]; + uint64_t mispredPC[Impl::MaxThreads]; + uint64_t nextPC[Impl::MaxThreads]; + InstSeqNum squashedSeqNum[Impl::MaxThreads]; + + bool includeSquashInst[Impl::MaxThreads]; }; template<class Impl> @@ -93,73 +104,95 @@ struct IssueStruct { DynInstPtr insts[Impl::MaxWidth]; }; +/** Struct that defines all backwards communication. */ +template<class Impl> struct TimeBufStruct { struct decodeComm { bool squash; - bool stall; bool predIncorrect; uint64_t branchAddr; InstSeqNum doneSeqNum; - // Might want to package this kind of branch stuff into a single + // @todo: Might want to package this kind of branch stuff into a single // struct as it is used pretty frequently. bool branchMispredict; bool branchTaken; uint64_t mispredPC; uint64_t nextPC; + + unsigned branchCount; }; - decodeComm decodeInfo; + decodeComm decodeInfo[Impl::MaxThreads]; - // Rename can't actually tell anything to squash or send a new PC back - // because it doesn't do anything along those lines. But maybe leave - // these fields in here to keep the stages mostly orthagonal. struct renameComm { - bool squash; - bool stall; - - uint64_t nextPC; }; - renameComm renameInfo; + renameComm renameInfo[Impl::MaxThreads]; struct iewComm { - bool stall; - // Also eventually include skid buffer space. + bool usedIQ; unsigned freeIQEntries; + bool usedLSQ; + unsigned freeLSQEntries; + + unsigned iqCount; + unsigned ldstqCount; + + unsigned dispatched; + unsigned dispatchedToLSQ; }; - iewComm iewInfo; + iewComm iewInfo[Impl::MaxThreads]; struct commitComm { - bool squash; - bool stall; + bool usedROB; unsigned freeROBEntries; + bool emptyROB; + + bool squash; + bool robSquashing; bool branchMispredict; bool branchTaken; uint64_t mispredPC; uint64_t nextPC; - bool robSquashing; - // Represents the instruction that has either been retired or // squashed. Similar to having a single bus that broadcasts the // retired or squashed sequence number. InstSeqNum doneSeqNum; - // Extra bit of information so that the LDSTQ only updates when it - // needs to. - bool commitIsLoad; + //Just in case we want to do a commit/squash on a cycle + //(necessary for multiple ROBs?) + bool commitInsts; + InstSeqNum squashSeqNum; // Communication specifically to the IQ to tell the IQ that it can // schedule a non-speculative instruction. InstSeqNum nonSpecSeqNum; + + // Hack for now to send back an uncached access to the IEW stage. + typedef typename Impl::DynInstPtr DynInstPtr; + bool uncached; + DynInstPtr uncachedLoad; + + bool interruptPending; + bool clearInterrupt; }; - commitComm commitInfo; + commitComm commitInfo[Impl::MaxThreads]; + + bool decodeBlock[Impl::MaxThreads]; + bool decodeUnblock[Impl::MaxThreads]; + bool renameBlock[Impl::MaxThreads]; + bool renameUnblock[Impl::MaxThreads]; + bool iewBlock[Impl::MaxThreads]; + bool iewUnblock[Impl::MaxThreads]; + bool commitBlock[Impl::MaxThreads]; + bool commitUnblock[Impl::MaxThreads]; }; -#endif //__CPU_O3_CPU_COMM_HH__ +#endif //__CPU_O3_COMM_HH__ diff --git a/src/cpu/o3/commit.cc b/src/cpu/o3/commit.cc index e5288761d..770008a33 100644 --- a/src/cpu/o3/commit.cc +++ b/src/cpu/o3/commit.cc @@ -32,4 +32,4 @@ #include "cpu/o3/alpha_impl.hh" #include "cpu/o3/commit_impl.hh" -template class SimpleCommit<AlphaSimpleImpl>; +template class DefaultCommit<AlphaSimpleImpl>; diff --git a/src/cpu/o3/commit.hh b/src/cpu/o3/commit.hh index 847459231..b7404c488 100644 --- a/src/cpu/o3/commit.hh +++ b/src/cpu/o3/commit.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,29 +28,42 @@ * Authors: Kevin Lim */ -// Todo: Maybe have a special method for handling interrupts/traps. -// -// Traps: Have IEW send a signal to commit saying that there's a trap to -// be handled. Have commit send the PC back to the fetch stage, along -// with the current commit PC. Fetch will directly access the IPR and save -// off all the proper stuff. Commit can send out a squash, or something -// close to it. -// Do the same for hwrei(). However, requires that commit be specifically -// built to support that kind of stuff. Probably not horrible to have -// commit support having the CPU tell it to squash the other stages and -// restart at a given address. The IPR register does become an issue. -// Probably not a big deal if the IPR stuff isn't cycle accurate. Can just -// have the original function handle writing to the IPR register. - -#ifndef __CPU_O3_CPU_SIMPLE_COMMIT_HH__ -#define __CPU_O3_CPU_SIMPLE_COMMIT_HH__ +#ifndef __CPU_O3_COMMIT_HH__ +#define __CPU_O3_COMMIT_HH__ +#include "arch/faults.hh" #include "base/statistics.hh" #include "base/timebuf.hh" -#include "mem/memory_interface.hh" - +#include "cpu/exetrace.hh" +#include "cpu/inst_seq.hh" + +template <class> +class O3ThreadState; + +/** + * DefaultCommit handles single threaded and SMT commit. Its width is + * specified by the parameters; each cycle it tries to commit that + * many instructions. The SMT policy decides which thread it tries to + * commit instructions from. Non- speculative instructions must reach + * the head of the ROB before they are ready to execute; once they + * reach the head, commit will broadcast the instruction's sequence + * number to the previous stages so that they can issue/ execute the + * instruction. Only one non-speculative instruction is handled per + * cycle. Commit is responsible for handling all back-end initiated + * redirects. It receives the redirect, and then broadcasts it to all + * stages, indicating the sequence number they should squash until, + * and any necessary branch misprediction information as well. It + * priortizes redirects by instruction's age, only broadcasting a + * redirect if it corresponds to an instruction that should currently + * be in the ROB. This is done by tracking the sequence number of the + * youngest instruction in the ROB, which gets updated to any + * squashing instruction's sequence number, and only broadcasting a + * redirect if it corresponds to an older instruction. Commit also + * supports multiple cycle squashing, to model a ROB that can only + * remove a certain number of instructions per cycle. + */ template<class Impl> -class SimpleCommit +class DefaultCommit { public: // Typedefs from the Impl. @@ -59,62 +72,219 @@ class SimpleCommit typedef typename Impl::Params Params; typedef typename Impl::CPUPol CPUPol; + typedef typename CPUPol::RenameMap RenameMap; typedef typename CPUPol::ROB ROB; typedef typename CPUPol::TimeStruct TimeStruct; + typedef typename CPUPol::FetchStruct FetchStruct; typedef typename CPUPol::IEWStruct IEWStruct; typedef typename CPUPol::RenameStruct RenameStruct; - public: - // I don't believe commit can block, so it will only have two - // statuses for now. - // Actually if there's a cache access that needs to block (ie - // uncachable load or just a mem access in commit) then the stage - // may have to wait. - enum Status { + typedef typename CPUPol::Fetch Fetch; + typedef typename CPUPol::IEW IEW; + + typedef O3ThreadState<Impl> Thread; + + /** Event class used to schedule a squash due to a trap (fault or + * interrupt) to happen on a specific cycle. + */ + class TrapEvent : public Event { + private: + DefaultCommit<Impl> *commit; + unsigned tid; + + public: + TrapEvent(DefaultCommit<Impl> *_commit, unsigned _tid); + + void process(); + const char *description(); + }; + + /** Overall commit status. Used to determine if the CPU can deschedule + * itself due to a lack of activity. + */ + enum CommitStatus{ + Active, + Inactive + }; + + /** Individual thread status. */ + enum ThreadStatus { Running, Idle, ROBSquashing, - DcacheMissStall, - DcacheMissComplete + TrapPending, + FetchTrapPending + }; + + /** Commit policy for SMT mode. */ + enum CommitPolicy { + Aggressive, + RoundRobin, + OldestReady }; private: - Status _status; + /** Overall commit status. */ + CommitStatus _status; + /** Next commit status, to be set at the end of the cycle. */ + CommitStatus _nextStatus; + /** Per-thread status. */ + ThreadStatus commitStatus[Impl::MaxThreads]; + /** Commit policy used in SMT mode. */ + CommitPolicy commitPolicy; public: - SimpleCommit(Params ¶ms); + /** Construct a DefaultCommit with the given parameters. */ + DefaultCommit(Params *params); + + /** Returns the name of the DefaultCommit. */ + std::string name() const; + /** Registers statistics. */ void regStats(); + /** Sets the CPU pointer. */ void setCPU(FullCPU *cpu_ptr); + /** Sets the list of threads. */ + void setThreads(std::vector<Thread *> &threads); + + /** Sets the main time buffer pointer, used for backwards communication. */ void setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr); + void setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr); + + /** Sets the pointer to the queue coming from rename. */ void setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr); + /** Sets the pointer to the queue coming from IEW. */ void setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr); + void setFetchStage(Fetch *fetch_stage); + + Fetch *fetchStage; + + /** Sets the pointer to the IEW stage. */ + void setIEWStage(IEW *iew_stage); + + /** The pointer to the IEW stage. Used solely to ensure that + * various events (traps, interrupts, syscalls) do not occur until + * all stores have written back. + */ + IEW *iewStage; + + /** Sets pointer to list of active threads. */ + void setActiveThreads(std::list<unsigned> *at_ptr); + + /** Sets pointer to the commited state rename map. */ + void setRenameMap(RenameMap rm_ptr[Impl::MaxThreads]); + + /** Sets pointer to the ROB. */ void setROB(ROB *rob_ptr); + /** Initializes stage by sending back the number of free entries. */ + void initStage(); + + /** Initializes the switching out of commit. */ + void switchOut(); + + /** Completes the switch out of commit. */ + void doSwitchOut(); + + /** Takes over from another CPU's thread. */ + void takeOverFrom(); + + /** Ticks the commit stage, which tries to commit instructions. */ void tick(); + /** Handles any squashes that are sent from IEW, and adds instructions + * to the ROB and tries to commit instructions. + */ void commit(); + /** Returns the number of free ROB entries for a specific thread. */ + unsigned numROBFreeEntries(unsigned tid); + + /** Generates an event to schedule a squash due to a trap. */ + void generateTrapEvent(unsigned tid); + + /** Records that commit needs to initiate a squash due to an + * external state update through the TC. + */ + void generateTCEvent(unsigned tid); + private: + /** Updates the overall status of commit with the nextStatus, and + * tell the CPU if commit is active/inactive. + */ + void updateStatus(); + + /** Sets the next status based on threads' statuses, which becomes the + * current status at the end of the cycle. + */ + void setNextStatus(); + + /** Checks if the ROB is completed with squashing. This is for the case + * where the ROB can take multiple cycles to complete squashing. + */ + bool robDoneSquashing(); + + /** Returns if any of the threads have the number of ROB entries changed + * on this cycle. Used to determine if the number of free ROB entries needs + * to be sent back to previous stages. + */ + bool changedROBEntries(); + + /** Squashes all in flight instructions. */ + void squashAll(unsigned tid); + + /** Handles squashing due to a trap. */ + void squashFromTrap(unsigned tid); + + /** Handles squashing due to an TC write. */ + void squashFromTC(unsigned tid); + /** Commits as many instructions as possible. */ void commitInsts(); + /** Tries to commit the head ROB instruction passed in. + * @param head_inst The instruction to be committed. + */ bool commitHead(DynInstPtr &head_inst, unsigned inst_num); + /** Gets instructions from rename and inserts them into the ROB. */ void getInsts(); + /** Marks completed instructions using information sent from IEW. */ void markCompletedInsts(); + /** Gets the thread to commit, based on the SMT policy. */ + int getCommittingThread(); + + /** Returns the thread ID to use based on a round robin policy. */ + int roundRobin(); + + /** Returns the thread ID to use based on an oldest instruction policy. */ + int oldestReady(); + public: - uint64_t readCommitPC(); + /** Returns the PC of the head instruction of the ROB. + * @todo: Probably remove this function as it returns only thread 0. + */ + uint64_t readPC() { return PC[0]; } + + /** Returns the PC of a specific thread. */ + uint64_t readPC(unsigned tid) { return PC[tid]; } - void setSquashing() { _status = ROBSquashing; } + /** Sets the PC of a specific thread. */ + void setPC(uint64_t val, unsigned tid) { PC[tid] = val; } + + /** Reads the PC of a specific thread. */ + uint64_t readNextPC(unsigned tid) { return nextPC[tid]; } + + /** Sets the next PC of a specific thread. */ + void setNextPC(uint64_t val, unsigned tid) { nextPC[tid] = val; } private: /** Time buffer interface. */ @@ -126,6 +296,10 @@ class SimpleCommit /** Wire to read information from IEW (for ROB). */ typename TimeBuffer<TimeStruct>::wire robInfoFromIEW; + TimeBuffer<FetchStruct> *fetchQueue; + + typename TimeBuffer<FetchStruct>::wire fromFetch; + /** IEW instruction queue interface. */ TimeBuffer<IEWStruct> *iewQueue; @@ -138,22 +312,54 @@ class SimpleCommit /** Wire to read information from rename queue. */ typename TimeBuffer<RenameStruct>::wire fromRename; + public: /** ROB interface. */ ROB *rob; + private: /** Pointer to FullCPU. */ FullCPU *cpu; - /** Memory interface. Used for d-cache accesses. */ - MemInterface *dcacheInterface; + /** Vector of all of the threads. */ + std::vector<Thread *> thread; + + Fault fetchFault; + + int fetchTrapWait; + + /** Records that commit has written to the time buffer this cycle. Used for + * the CPU to determine if it can deschedule itself if there is no activity. + */ + bool wroteToTimeBuffer; + + /** Records if the number of ROB entries has changed this cycle. If it has, + * then the number of free entries must be re-broadcast. + */ + bool changedROBNumEntries[Impl::MaxThreads]; + + /** A counter of how many threads are currently squashing. */ + int squashCounter; + + /** Records if a thread has to squash this cycle due to a trap. */ + bool trapSquash[Impl::MaxThreads]; + + /** Records if a thread has to squash this cycle due to an XC write. */ + bool tcSquash[Impl::MaxThreads]; + + /** Priority List used for Commit Policy */ + std::list<unsigned> priority_list; - private: /** IEW to Commit delay, in ticks. */ unsigned iewToCommitDelay; + /** Commit to IEW delay, in ticks. */ + unsigned commitToIEWDelay; + /** Rename to ROB delay, in ticks. */ unsigned renameToROBDelay; + unsigned fetchToCommitDelay; + /** Rename width, in instructions. Used so ROB knows how many * instructions to get from the rename instruction queue. */ @@ -167,16 +373,82 @@ class SimpleCommit /** Commit width, in instructions. */ unsigned commitWidth; + /** Number of Reorder Buffers */ + unsigned numRobs; + + /** Number of Active Threads */ + unsigned numThreads; + + /** Is a switch out pending. */ + bool switchPending; + + /** Is commit switched out. */ + bool switchedOut; + + /** The latency to handle a trap. Used when scheduling trap + * squash event. + */ + Tick trapLatency; + + Tick fetchTrapLatency; + + Tick fetchFaultTick; + + /** The commit PC of each thread. Refers to the instruction that + * is currently being processed/committed. + */ + Addr PC[Impl::MaxThreads]; + + /** The next PC of each thread. */ + Addr nextPC[Impl::MaxThreads]; + + /** The sequence number of the youngest valid instruction in the ROB. */ + InstSeqNum youngestSeqNum[Impl::MaxThreads]; + + /** Pointer to the list of active threads. */ + std::list<unsigned> *activeThreads; + + /** Rename map interface. */ + RenameMap *renameMap[Impl::MaxThreads]; + + /** Updates commit stats based on this instruction. */ + void updateComInstStats(DynInstPtr &inst); + + /** Stat for the total number of committed instructions. */ Stats::Scalar<> commitCommittedInsts; + /** Stat for the total number of squashed instructions discarded by commit. + */ Stats::Scalar<> commitSquashedInsts; + /** Stat for the total number of times commit is told to squash. + * @todo: Actually increment this stat. + */ Stats::Scalar<> commitSquashEvents; + /** Stat for the total number of times commit has had to stall due to a non- + * speculative instruction reaching the head of the ROB. + */ Stats::Scalar<> commitNonSpecStalls; - Stats::Scalar<> commitCommittedBranches; - Stats::Scalar<> commitCommittedLoads; - Stats::Scalar<> commitCommittedMemRefs; + /** Stat for the total number of branch mispredicts that caused a squash. */ Stats::Scalar<> branchMispredicts; - - Stats::Distribution<> n_committed_dist; + /** Distribution of the number of committed instructions each cycle. */ + Stats::Distribution<> numCommittedDist; + + /** Total number of instructions committed. */ + Stats::Vector<> statComInst; + /** Total number of software prefetches committed. */ + Stats::Vector<> statComSwp; + /** Stat for the total number of committed memory references. */ + Stats::Vector<> statComRefs; + /** Stat for the total number of committed loads. */ + Stats::Vector<> statComLoads; + /** Total number of committed memory barriers. */ + Stats::Vector<> statComMembars; + /** Total number of committed branches. */ + Stats::Vector<> statComBranches; + + /** Number of cycles where the commit bandwidth limit is reached. */ + Stats::Scalar<> commitEligibleSamples; + /** Number of instructions not committed due to bandwidth limits. */ + Stats::Vector<> commitEligible; }; -#endif // __CPU_O3_CPU_SIMPLE_COMMIT_HH__ +#endif // __CPU_O3_COMMIT_HH__ diff --git a/src/cpu/o3/commit_impl.hh b/src/cpu/o3/commit_impl.hh index f315c9494..ceb2918e0 100644 --- a/src/cpu/o3/commit_impl.hh +++ b/src/cpu/o3/commit_impl.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,26 +28,113 @@ * Authors: Kevin Lim */ +#include <algorithm> +#include <string> + +#include "base/loader/symtab.hh" #include "base/timebuf.hh" -#include "cpu/o3/commit.hh" +#include "cpu/checker/cpu.hh" #include "cpu/exetrace.hh" +#include "cpu/o3/commit.hh" +#include "cpu/o3/thread_state.hh" + +using namespace std; template <class Impl> -SimpleCommit<Impl>::SimpleCommit(Params ¶ms) - : dcacheInterface(params.dcacheInterface), - iewToCommitDelay(params.iewToCommitDelay), - renameToROBDelay(params.renameToROBDelay), - renameWidth(params.renameWidth), - iewWidth(params.executeWidth), - commitWidth(params.commitWidth) +DefaultCommit<Impl>::TrapEvent::TrapEvent(DefaultCommit<Impl> *_commit, + unsigned _tid) + : Event(&mainEventQueue, CPU_Tick_Pri), commit(_commit), tid(_tid) { - _status = Idle; + this->setFlags(Event::AutoDelete); } template <class Impl> void -SimpleCommit<Impl>::regStats() +DefaultCommit<Impl>::TrapEvent::process() +{ + // This will get reset by commit if it was switched out at the + // time of this event processing. + commit->trapSquash[tid] = true; +} + +template <class Impl> +const char * +DefaultCommit<Impl>::TrapEvent::description() +{ + return "Trap event"; +} + +template <class Impl> +DefaultCommit<Impl>::DefaultCommit(Params *params) + : squashCounter(0), + iewToCommitDelay(params->iewToCommitDelay), + commitToIEWDelay(params->commitToIEWDelay), + renameToROBDelay(params->renameToROBDelay), + fetchToCommitDelay(params->commitToFetchDelay), + renameWidth(params->renameWidth), + iewWidth(params->executeWidth), + commitWidth(params->commitWidth), + numThreads(params->numberOfThreads), + switchPending(false), + switchedOut(false), + trapLatency(params->trapLatency), + fetchTrapLatency(params->fetchTrapLatency) { + _status = Active; + _nextStatus = Inactive; + string policy = params->smtCommitPolicy; + + //Convert string to lowercase + std::transform(policy.begin(), policy.end(), policy.begin(), + (int(*)(int)) tolower); + + //Assign commit policy + if (policy == "aggressive"){ + commitPolicy = Aggressive; + + DPRINTF(Commit,"Commit Policy set to Aggressive."); + } else if (policy == "roundrobin"){ + commitPolicy = RoundRobin; + + //Set-Up Priority List + for (int tid=0; tid < numThreads; tid++) { + priority_list.push_back(tid); + } + + DPRINTF(Commit,"Commit Policy set to Round Robin."); + } else if (policy == "oldestready"){ + commitPolicy = OldestReady; + + DPRINTF(Commit,"Commit Policy set to Oldest Ready."); + } else { + assert(0 && "Invalid SMT Commit Policy. Options Are: {Aggressive," + "RoundRobin,OldestReady}"); + } + + for (int i=0; i < numThreads; i++) { + commitStatus[i] = Idle; + changedROBNumEntries[i] = false; + trapSquash[i] = false; + tcSquash[i] = false; + PC[i] = nextPC[i] = 0; + } + + fetchFaultTick = 0; + fetchTrapWait = 0; +} + +template <class Impl> +std::string +DefaultCommit<Impl>::name() const +{ + return cpu->name() + ".commit"; +} + +template <class Impl> +void +DefaultCommit<Impl>::regStats() +{ + using namespace Stats; commitCommittedInsts .name(name() + ".commitCommittedInsts") .desc("The number of committed instructions") @@ -65,41 +152,110 @@ SimpleCommit<Impl>::regStats() .desc("The number of times commit has been forced to stall to " "communicate backwards") .prereq(commitNonSpecStalls); - commitCommittedBranches - .name(name() + ".commitCommittedBranches") - .desc("The number of committed branches") - .prereq(commitCommittedBranches); - commitCommittedLoads - .name(name() + ".commitCommittedLoads") - .desc("The number of committed loads") - .prereq(commitCommittedLoads); - commitCommittedMemRefs - .name(name() + ".commitCommittedMemRefs") - .desc("The number of committed memory references") - .prereq(commitCommittedMemRefs); branchMispredicts .name(name() + ".branchMispredicts") .desc("The number of times a branch was mispredicted") .prereq(branchMispredicts); - n_committed_dist + numCommittedDist .init(0,commitWidth,1) .name(name() + ".COM:committed_per_cycle") .desc("Number of insts commited each cycle") .flags(Stats::pdf) ; + + statComInst + .init(cpu->number_of_threads) + .name(name() + ".COM:count") + .desc("Number of instructions committed") + .flags(total) + ; + + statComSwp + .init(cpu->number_of_threads) + .name(name() + ".COM:swp_count") + .desc("Number of s/w prefetches committed") + .flags(total) + ; + + statComRefs + .init(cpu->number_of_threads) + .name(name() + ".COM:refs") + .desc("Number of memory references committed") + .flags(total) + ; + + statComLoads + .init(cpu->number_of_threads) + .name(name() + ".COM:loads") + .desc("Number of loads committed") + .flags(total) + ; + + statComMembars + .init(cpu->number_of_threads) + .name(name() + ".COM:membars") + .desc("Number of memory barriers committed") + .flags(total) + ; + + statComBranches + .init(cpu->number_of_threads) + .name(name() + ".COM:branches") + .desc("Number of branches committed") + .flags(total) + ; + + // + // Commit-Eligible instructions... + // + // -> The number of instructions eligible to commit in those + // cycles where we reached our commit BW limit (less the number + // actually committed) + // + // -> The average value is computed over ALL CYCLES... not just + // the BW limited cycles + // + // -> The standard deviation is computed only over cycles where + // we reached the BW limit + // + commitEligible + .init(cpu->number_of_threads) + .name(name() + ".COM:bw_limited") + .desc("number of insts not committed due to BW limits") + .flags(total) + ; + + commitEligibleSamples + .name(name() + ".COM:bw_lim_events") + .desc("number cycles where commit BW limit reached") + ; } template <class Impl> void -SimpleCommit<Impl>::setCPU(FullCPU *cpu_ptr) +DefaultCommit<Impl>::setCPU(FullCPU *cpu_ptr) { DPRINTF(Commit, "Commit: Setting CPU pointer.\n"); cpu = cpu_ptr; + + // Commit must broadcast the number of free entries it has at the start of + // the simulation, so it starts as active. + cpu->activateStage(FullCPU::CommitIdx); + + trapLatency = cpu->cycles(trapLatency); + fetchTrapLatency = cpu->cycles(fetchTrapLatency); +} + +template <class Impl> +void +DefaultCommit<Impl>::setThreads(vector<Thread *> &threads) +{ + thread = threads; } template <class Impl> void -SimpleCommit<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) +DefaultCommit<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) { DPRINTF(Commit, "Commit: Setting time buffer pointer.\n"); timeBuffer = tb_ptr; @@ -113,7 +269,18 @@ SimpleCommit<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) template <class Impl> void -SimpleCommit<Impl>::setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr) +DefaultCommit<Impl>::setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr) +{ + DPRINTF(Commit, "Commit: Setting fetch queue pointer.\n"); + fetchQueue = fq_ptr; + + // Setup wire to get instructions from rename (for the ROB). + fromFetch = fetchQueue->getWire(-fetchToCommitDelay); +} + +template <class Impl> +void +DefaultCommit<Impl>::setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr) { DPRINTF(Commit, "Commit: Setting rename queue pointer.\n"); renameQueue = rq_ptr; @@ -124,7 +291,7 @@ SimpleCommit<Impl>::setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr) template <class Impl> void -SimpleCommit<Impl>::setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr) +DefaultCommit<Impl>::setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr) { DPRINTF(Commit, "Commit: Setting IEW queue pointer.\n"); iewQueue = iq_ptr; @@ -135,7 +302,40 @@ SimpleCommit<Impl>::setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr) template <class Impl> void -SimpleCommit<Impl>::setROB(ROB *rob_ptr) +DefaultCommit<Impl>::setFetchStage(Fetch *fetch_stage) +{ + fetchStage = fetch_stage; +} + +template <class Impl> +void +DefaultCommit<Impl>::setIEWStage(IEW *iew_stage) +{ + iewStage = iew_stage; +} + +template<class Impl> +void +DefaultCommit<Impl>::setActiveThreads(list<unsigned> *at_ptr) +{ + DPRINTF(Commit, "Commit: Setting active threads list pointer.\n"); + activeThreads = at_ptr; +} + +template <class Impl> +void +DefaultCommit<Impl>::setRenameMap(RenameMap rm_ptr[]) +{ + DPRINTF(Commit, "Setting rename map pointers.\n"); + + for (int i=0; i < numThreads; i++) { + renameMap[i] = &rm_ptr[i]; + } +} + +template <class Impl> +void +DefaultCommit<Impl>::setROB(ROB *rob_ptr) { DPRINTF(Commit, "Commit: Setting ROB pointer.\n"); rob = rob_ptr; @@ -143,107 +343,451 @@ SimpleCommit<Impl>::setROB(ROB *rob_ptr) template <class Impl> void -SimpleCommit<Impl>::tick() -{ - // If the ROB is currently in its squash sequence, then continue - // to squash. In this case, commit does not do anything. Otherwise - // run commit. - if (_status == ROBSquashing) { - if (rob->isDoneSquashing()) { - _status = Running; - } else { - rob->doSquash(); - - // Send back sequence number of tail of ROB, so other stages - // can squash younger instructions. Note that really the only - // stage that this is important for is the IEW stage; other - // stages can just clear all their state as long as selective - // replay isn't used. - toIEW->commitInfo.doneSeqNum = rob->readTailSeqNum(); - toIEW->commitInfo.robSquashing = true; +DefaultCommit<Impl>::initStage() +{ + rob->setActiveThreads(activeThreads); + rob->resetEntries(); + + // Broadcast the number of free entries. + for (int i=0; i < numThreads; i++) { + toIEW->commitInfo[i].usedROB = true; + toIEW->commitInfo[i].freeROBEntries = rob->numFreeEntries(i); + } + + cpu->activityThisCycle(); +} + +template <class Impl> +void +DefaultCommit<Impl>::switchOut() +{ + switchPending = true; +} + +template <class Impl> +void +DefaultCommit<Impl>::doSwitchOut() +{ + switchedOut = true; + switchPending = false; + rob->switchOut(); +} + +template <class Impl> +void +DefaultCommit<Impl>::takeOverFrom() +{ + switchedOut = false; + _status = Active; + _nextStatus = Inactive; + for (int i=0; i < numThreads; i++) { + commitStatus[i] = Idle; + changedROBNumEntries[i] = false; + trapSquash[i] = false; + tcSquash[i] = false; + } + squashCounter = 0; + rob->takeOverFrom(); +} + +template <class Impl> +void +DefaultCommit<Impl>::updateStatus() +{ + // reset ROB changed variable + list<unsigned>::iterator threads = (*activeThreads).begin(); + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + changedROBNumEntries[tid] = false; + + // Also check if any of the threads has a trap pending + if (commitStatus[tid] == TrapPending || + commitStatus[tid] == FetchTrapPending) { + _nextStatus = Active; + } + } + + if (_nextStatus == Inactive && _status == Active) { + DPRINTF(Activity, "Deactivating stage.\n"); + cpu->deactivateStage(FullCPU::CommitIdx); + } else if (_nextStatus == Active && _status == Inactive) { + DPRINTF(Activity, "Activating stage.\n"); + cpu->activateStage(FullCPU::CommitIdx); + } + + _status = _nextStatus; +} + +template <class Impl> +void +DefaultCommit<Impl>::setNextStatus() +{ + int squashes = 0; + + list<unsigned>::iterator threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + if (commitStatus[tid] == ROBSquashing) { + squashes++; + } + } + + assert(squashes == squashCounter); + + // If commit is currently squashing, then it will have activity for the + // next cycle. Set its next status as active. + if (squashCounter) { + _nextStatus = Active; + } +} + +template <class Impl> +bool +DefaultCommit<Impl>::changedROBEntries() +{ + list<unsigned>::iterator threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + if (changedROBNumEntries[tid]) { + return true; + } + } + + return false; +} + +template <class Impl> +unsigned +DefaultCommit<Impl>::numROBFreeEntries(unsigned tid) +{ + return rob->numFreeEntries(tid); +} + +template <class Impl> +void +DefaultCommit<Impl>::generateTrapEvent(unsigned tid) +{ + DPRINTF(Commit, "Generating trap event for [tid:%i]\n", tid); + + TrapEvent *trap = new TrapEvent(this, tid); + + trap->schedule(curTick + trapLatency); + + thread[tid]->trapPending = true; +} + +template <class Impl> +void +DefaultCommit<Impl>::generateTCEvent(unsigned tid) +{ + DPRINTF(Commit, "Generating TC squash event for [tid:%i]\n", tid); + + tcSquash[tid] = true; +} + +template <class Impl> +void +DefaultCommit<Impl>::squashAll(unsigned tid) +{ + // If we want to include the squashing instruction in the squash, + // then use one older sequence number. + // Hopefully this doesn't mess things up. Basically I want to squash + // all instructions of this thread. + InstSeqNum squashed_inst = rob->isEmpty() ? + 0 : rob->readHeadInst(tid)->seqNum - 1;; + + // All younger instructions will be squashed. Set the sequence + // number as the youngest instruction in the ROB (0 in this case. + // Hopefully nothing breaks.) + youngestSeqNum[tid] = 0; + + rob->squash(squashed_inst, tid); + changedROBNumEntries[tid] = true; + + // Send back the sequence number of the squashed instruction. + toIEW->commitInfo[tid].doneSeqNum = squashed_inst; + + // Send back the squash signal to tell stages that they should + // squash. + toIEW->commitInfo[tid].squash = true; + + // Send back the rob squashing signal so other stages know that + // the ROB is in the process of squashing. + toIEW->commitInfo[tid].robSquashing = true; + + toIEW->commitInfo[tid].branchMispredict = false; + + toIEW->commitInfo[tid].nextPC = PC[tid]; +} + +template <class Impl> +void +DefaultCommit<Impl>::squashFromTrap(unsigned tid) +{ + squashAll(tid); + + DPRINTF(Commit, "Squashing from trap, restarting at PC %#x\n", PC[tid]); + + thread[tid]->trapPending = false; + thread[tid]->inSyscall = false; + + trapSquash[tid] = false; + + commitStatus[tid] = ROBSquashing; + cpu->activityThisCycle(); + + ++squashCounter; +} + +template <class Impl> +void +DefaultCommit<Impl>::squashFromTC(unsigned tid) +{ + squashAll(tid); + + DPRINTF(Commit, "Squashing from TC, restarting at PC %#x\n", PC[tid]); + + thread[tid]->inSyscall = false; + assert(!thread[tid]->trapPending); + + commitStatus[tid] = ROBSquashing; + cpu->activityThisCycle(); + + tcSquash[tid] = false; + + ++squashCounter; +} + +template <class Impl> +void +DefaultCommit<Impl>::tick() +{ + wroteToTimeBuffer = false; + _nextStatus = Inactive; + + if (switchPending && rob->isEmpty() && !iewStage->hasStoresToWB()) { + cpu->signalSwitched(); + return; + } + + list<unsigned>::iterator threads = (*activeThreads).begin(); + + // Check if any of the threads are done squashing. Change the + // status if they are done. + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + if (commitStatus[tid] == ROBSquashing) { + + if (rob->isDoneSquashing(tid)) { + commitStatus[tid] = Running; + --squashCounter; + } else { + DPRINTF(Commit,"[tid:%u]: Still Squashing, cannot commit any" + "insts this cycle.\n", tid); + } } - } else { - commit(); } + commit(); + markCompletedInsts(); - // Writeback number of free ROB entries here. - DPRINTF(Commit, "Commit: ROB has %d free entries.\n", - rob->numFreeEntries()); - toIEW->commitInfo.freeROBEntries = rob->numFreeEntries(); + threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + if (!rob->isEmpty(tid) && rob->readHeadInst(tid)->readyToCommit()) { + // The ROB has more instructions it can commit. Its next status + // will be active. + _nextStatus = Active; + + DynInstPtr inst = rob->readHeadInst(tid); + + DPRINTF(Commit,"[tid:%i]: Instruction [sn:%lli] PC %#x is head of" + " ROB and ready to commit\n", + tid, inst->seqNum, inst->readPC()); + + } else if (!rob->isEmpty(tid)) { + DynInstPtr inst = rob->readHeadInst(tid); + + DPRINTF(Commit,"[tid:%i]: Can't commit, Instruction [sn:%lli] PC " + "%#x is head of ROB and not ready\n", + tid, inst->seqNum, inst->readPC()); + } + + DPRINTF(Commit, "[tid:%i]: ROB has %d insts & %d free entries.\n", + tid, rob->countInsts(tid), rob->numFreeEntries(tid)); + } + + + if (wroteToTimeBuffer) { + DPRINTF(Activity, "Activity This Cycle.\n"); + cpu->activityThisCycle(); + } + + updateStatus(); } template <class Impl> void -SimpleCommit<Impl>::commit() +DefaultCommit<Impl>::commit() { + ////////////////////////////////////// // Check for interrupts ////////////////////////////////////// - // Process interrupts if interrupts are enabled and not in PAL mode. - // Take the PC from commit and write it to the IPR, then squash. The - // interrupt completing will take care of restoring the PC from that value - // in the IPR. Look at IPR[EXC_ADDR]; - // hwrei() is what resets the PC to the place where instruction execution - // beings again. #if FULL_SYSTEM - if (//checkInterrupts && + // Process interrupts if interrupts are enabled, not in PAL mode, + // and no other traps or external squashes are currently pending. + // @todo: Allow other threads to handle interrupts. + if (cpu->checkInterrupts && cpu->check_interrupts() && - !cpu->inPalMode(readCommitPC())) { - // Will need to squash all instructions currently in flight and have - // the interrupt handler restart at the last non-committed inst. - // Most of that can be handled through the trap() function. The - // processInterrupts() function really just checks for interrupts - // and then calls trap() if there is an interrupt present. + !cpu->inPalMode(readPC()) && + !trapSquash[0] && + !tcSquash[0]) { + // Tell fetch that there is an interrupt pending. This will + // make fetch wait until it sees a non PAL-mode PC, at which + // point it stops fetching instructions. + toIEW->commitInfo[0].interruptPending = true; + + // Wait until the ROB is empty and all stores have drained in + // order to enter the interrupt. + if (rob->isEmpty() && !iewStage->hasStoresToWB()) { + // Not sure which thread should be the one to interrupt. For now + // always do thread 0. + assert(!thread[0]->inSyscall); + thread[0]->inSyscall = true; + + // CPU will handle implementation of the interrupt. + cpu->processInterrupts(); + + // Now squash or record that I need to squash this cycle. + commitStatus[0] = TrapPending; + + // Exit state update mode to avoid accidental updating. + thread[0]->inSyscall = false; + + // Generate trap squash event. + generateTrapEvent(0); - // CPU will handle implementation of the interrupt. - cpu->processInterrupts(); + toIEW->commitInfo[0].clearInterrupt = true; + + DPRINTF(Commit, "Interrupt detected.\n"); + } else { + DPRINTF(Commit, "Interrupt pending, waiting for ROB to empty.\n"); + } } #endif // FULL_SYSTEM //////////////////////////////////// - // Check for squash signal, handle that first + // Check for any possible squashes, handle them first //////////////////////////////////// - // Want to mainly check if the IEW stage is telling the ROB to squash. - // Should I also check if the commit stage is telling the ROB to squah? - // This might be necessary to keep the same timing between the IQ and - // the ROB... - if (fromIEW->squash) { - DPRINTF(Commit, "Commit: Squashing instructions in the ROB.\n"); + list<unsigned>::iterator threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; +/* + if (fromFetch->fetchFault && commitStatus[0] != TrapPending) { + // Record the fault. Wait until it's empty in the ROB. + // Then handle the trap. Ignore it if there's already a + // trap pending as fetch will be redirected. + fetchFault = fromFetch->fetchFault; + fetchFaultTick = curTick + fetchTrapLatency; + commitStatus[0] = FetchTrapPending; + DPRINTF(Commit, "Fault from fetch recorded. Will trap if the " + "ROB empties without squashing the fault.\n"); + fetchTrapWait = 0; + } + + // Fetch may tell commit to clear the trap if it's been squashed. + if (fromFetch->clearFetchFault) { + DPRINTF(Commit, "Received clear fetch fault signal\n"); + fetchTrapWait = 0; + if (commitStatus[0] == FetchTrapPending) { + DPRINTF(Commit, "Clearing fault from fetch\n"); + commitStatus[0] = Running; + } + } +*/ + // Not sure which one takes priority. I think if we have + // both, that's a bad sign. + if (trapSquash[tid] == true) { + assert(!tcSquash[tid]); + squashFromTrap(tid); + } else if (tcSquash[tid] == true) { + squashFromTC(tid); + } + + // Squashed sequence number must be older than youngest valid + // instruction in the ROB. This prevents squashes from younger + // instructions overriding squashes from older instructions. + if (fromIEW->squash[tid] && + commitStatus[tid] != TrapPending && + fromIEW->squashedSeqNum[tid] <= youngestSeqNum[tid]) { - _status = ROBSquashing; + DPRINTF(Commit, "[tid:%i]: Squashing due to PC %#x [sn:%i]\n", + tid, + fromIEW->mispredPC[tid], + fromIEW->squashedSeqNum[tid]); - InstSeqNum squashed_inst = fromIEW->squashedSeqNum; + DPRINTF(Commit, "[tid:%i]: Redirecting to PC %#x\n", + tid, + fromIEW->nextPC[tid]); - rob->squash(squashed_inst); + commitStatus[tid] = ROBSquashing; - // Send back the sequence number of the squashed instruction. - toIEW->commitInfo.doneSeqNum = squashed_inst; + ++squashCounter; - // Send back the squash signal to tell stages that they should squash. - toIEW->commitInfo.squash = true; + // If we want to include the squashing instruction in the squash, + // then use one older sequence number. + InstSeqNum squashed_inst = fromIEW->squashedSeqNum[tid]; - // Send back the rob squashing signal so other stages know that the - // ROB is in the process of squashing. - toIEW->commitInfo.robSquashing = true; + if (fromIEW->includeSquashInst[tid] == true) + squashed_inst--; - toIEW->commitInfo.branchMispredict = fromIEW->branchMispredict; + // All younger instructions will be squashed. Set the sequence + // number as the youngest instruction in the ROB. + youngestSeqNum[tid] = squashed_inst; - toIEW->commitInfo.branchTaken = fromIEW->branchTaken; + rob->squash(squashed_inst, tid); + changedROBNumEntries[tid] = true; - toIEW->commitInfo.nextPC = fromIEW->nextPC; + toIEW->commitInfo[tid].doneSeqNum = squashed_inst; - toIEW->commitInfo.mispredPC = fromIEW->mispredPC; + toIEW->commitInfo[tid].squash = true; - if (toIEW->commitInfo.branchMispredict) { - ++branchMispredicts; + // Send back the rob squashing signal so other stages know that + // the ROB is in the process of squashing. + toIEW->commitInfo[tid].robSquashing = true; + + toIEW->commitInfo[tid].branchMispredict = + fromIEW->branchMispredict[tid]; + + toIEW->commitInfo[tid].branchTaken = + fromIEW->branchTaken[tid]; + + toIEW->commitInfo[tid].nextPC = fromIEW->nextPC[tid]; + + toIEW->commitInfo[tid].mispredPC = fromIEW->mispredPC[tid]; + + if (toIEW->commitInfo[tid].branchMispredict) { + ++branchMispredicts; + } } + } - if (_status != ROBSquashing) { + setNextStatus(); + + if (squashCounter != numThreads) { // If we're not currently squashing, then get instructions. getInsts(); @@ -251,121 +795,186 @@ SimpleCommit<Impl>::commit() commitInsts(); } - // If the ROB is empty, we can set this stage to idle. Use this - // in the future when the Idle status will actually be utilized. -#if 0 - if (rob->isEmpty()) { - DPRINTF(Commit, "Commit: ROB is empty. Status changed to idle.\n"); - _status = Idle; - // Schedule an event so that commit will actually wake up - // once something gets put in the ROB. + //Check for any activity + threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + if (changedROBNumEntries[tid]) { + toIEW->commitInfo[tid].usedROB = true; + toIEW->commitInfo[tid].freeROBEntries = rob->numFreeEntries(tid); + + if (rob->isEmpty(tid)) { + toIEW->commitInfo[tid].emptyROB = true; + } + + wroteToTimeBuffer = true; + changedROBNumEntries[tid] = false; + } } -#endif } -// Loop that goes through as many instructions in the ROB as possible and -// tries to commit them. The actual work for committing is done by the -// commitHead() function. template <class Impl> void -SimpleCommit<Impl>::commitInsts() +DefaultCommit<Impl>::commitInsts() { //////////////////////////////////// // Handle commit - // Note that commit will be handled prior to the ROB so that the ROB - // only tries to commit instructions it has in this current cycle, and - // not instructions it is writing in during this cycle. - // Can't commit and squash things at the same time... + // Note that commit will be handled prior to putting new + // instructions in the ROB so that the ROB only tries to commit + // instructions it has in this current cycle, and not instructions + // it is writing in during this cycle. Can't commit and squash + // things at the same time... //////////////////////////////////// - if (rob->isEmpty()) - return; - - DynInstPtr head_inst = rob->readHeadInst(); + DPRINTF(Commit, "Trying to commit instructions in the ROB.\n"); unsigned num_committed = 0; + DynInstPtr head_inst; + // Commit as many instructions as possible until the commit bandwidth // limit is reached, or it becomes impossible to commit any more. - while (!rob->isEmpty() && - head_inst->readyToCommit() && - num_committed < commitWidth) - { - DPRINTF(Commit, "Commit: Trying to commit head instruction.\n"); + while (num_committed < commitWidth) { + int commit_thread = getCommittingThread(); + + if (commit_thread == -1 || !rob->isHeadReady(commit_thread)) + break; + + head_inst = rob->readHeadInst(commit_thread); + + int tid = head_inst->threadNumber; + + assert(tid == commit_thread); + + DPRINTF(Commit, "Trying to commit head instruction, [sn:%i] [tid:%i]\n", + head_inst->seqNum, tid); - // If the head instruction is squashed, it is ready to retire at any - // time. However, we need to avoid updating any other state - // incorrectly if it's already been squashed. + // If the head instruction is squashed, it is ready to retire + // (be removed from the ROB) at any time. if (head_inst->isSquashed()) { - DPRINTF(Commit, "Commit: Retiring squashed instruction from " + DPRINTF(Commit, "Retiring squashed instruction from " "ROB.\n"); - // Tell ROB to retire head instruction. This retires the head - // inst in the ROB without affecting any other stages. - rob->retireHead(); + rob->retireHead(commit_thread); ++commitSquashedInsts; + // Record that the number of ROB entries has changed. + changedROBNumEntries[tid] = true; } else { + PC[tid] = head_inst->readPC(); + nextPC[tid] = head_inst->readNextPC(); + // Increment the total number of non-speculative instructions // executed. // Hack for now: it really shouldn't happen until after the // commit is deemed to be successful, but this count is needed // for syscalls. - cpu->funcExeInst++; + thread[tid]->funcExeInst++; // Try to commit the head instruction. bool commit_success = commitHead(head_inst, num_committed); - // Update what instruction we are looking at if the commit worked. if (commit_success) { ++num_committed; - // Send back which instruction has been committed. - // @todo: Update this later when a wider pipeline is used. - // Hmm, can't really give a pointer here...perhaps the - // sequence number instead (copy). - toIEW->commitInfo.doneSeqNum = head_inst->seqNum; + changedROBNumEntries[tid] = true; + + // Set the doneSeqNum to the youngest committed instruction. + toIEW->commitInfo[tid].doneSeqNum = head_inst->seqNum; ++commitCommittedInsts; - if (!head_inst->isNop()) { - cpu->instDone(); + // To match the old model, don't count nops and instruction + // prefetches towards the total commit count. + if (!head_inst->isNop() && !head_inst->isInstPrefetch()) { + cpu->instDone(tid); + } + + PC[tid] = nextPC[tid]; + nextPC[tid] = nextPC[tid] + sizeof(TheISA::MachInst); +#if FULL_SYSTEM + int count = 0; + Addr oldpc; + do { + // Debug statement. Checks to make sure we're not + // currently updating state while handling PC events. + if (count == 0) + assert(!thread[tid]->inSyscall && + !thread[tid]->trapPending); + oldpc = PC[tid]; + cpu->system->pcEventQueue.service( + thread[tid]->getTC()); + count++; + } while (oldpc != PC[tid]); + if (count > 1) { + DPRINTF(Commit, "PC skip function event, stopping commit\n"); + break; } +#endif } else { + DPRINTF(Commit, "Unable to commit head instruction PC:%#x " + "[tid:%i] [sn:%i].\n", + head_inst->readPC(), tid ,head_inst->seqNum); break; } } - - // Update the pointer to read the next instruction in the ROB. - head_inst = rob->readHeadInst(); } DPRINTF(CommitRate, "%i\n", num_committed); - n_committed_dist.sample(num_committed); + numCommittedDist.sample(num_committed); + + if (num_committed == commitWidth) { + commitEligibleSamples++; + } } template <class Impl> bool -SimpleCommit<Impl>::commitHead(DynInstPtr &head_inst, unsigned inst_num) +DefaultCommit<Impl>::commitHead(DynInstPtr &head_inst, unsigned inst_num) { - // Make sure instruction is valid assert(head_inst); - // If the instruction is not executed yet, then it is a non-speculative - // or store inst. Signal backwards that it should be executed. + int tid = head_inst->threadNumber; + + // If the instruction is not executed yet, then it will need extra + // handling. Signal backwards that it should be executed. if (!head_inst->isExecuted()) { // Keep this number correct. We have not yet actually executed // and committed this instruction. - cpu->funcExeInst--; - - if (head_inst->isNonSpeculative()) { - DPRINTF(Commit, "Commit: Encountered a store or non-speculative " - "instruction at the head of the ROB, PC %#x.\n", - head_inst->readPC()); + thread[tid]->funcExeInst--; + + head_inst->reachedCommit = true; + + if (head_inst->isNonSpeculative() || + head_inst->isStoreConditional() || + head_inst->isMemBarrier() || + head_inst->isWriteBarrier()) { + + DPRINTF(Commit, "Encountered a barrier or non-speculative " + "instruction [sn:%lli] at the head of the ROB, PC %#x.\n", + head_inst->seqNum, head_inst->readPC()); + +#if !FULL_SYSTEM + // Hack to make sure syscalls/memory barriers/quiesces + // aren't executed until all stores write back their data. + // This direct communication shouldn't be used for + // anything other than this. + if (inst_num > 0 || iewStage->hasStoresToWB()) +#else + if ((head_inst->isMemBarrier() || head_inst->isWriteBarrier() || + head_inst->isQuiesce()) && + iewStage->hasStoresToWB()) +#endif + { + DPRINTF(Commit, "Waiting for all stores to writeback.\n"); + return false; + } - toIEW->commitInfo.nonSpecSeqNum = head_inst->seqNum; + toIEW->commitInfo[tid].nonSpecSeqNum = head_inst->seqNum; // Change the instruction so it won't try to commit again until // it is executed. @@ -374,74 +983,111 @@ SimpleCommit<Impl>::commitHead(DynInstPtr &head_inst, unsigned inst_num) ++commitNonSpecStalls; return false; + } else if (head_inst->isLoad()) { + DPRINTF(Commit, "[sn:%lli]: Uncached load, PC %#x.\n", + head_inst->seqNum, head_inst->readPC()); + + // Send back the non-speculative instruction's sequence + // number. Tell the lsq to re-execute the load. + toIEW->commitInfo[tid].nonSpecSeqNum = head_inst->seqNum; + toIEW->commitInfo[tid].uncached = true; + toIEW->commitInfo[tid].uncachedLoad = head_inst; + + head_inst->clearCanCommit(); + + return false; } else { - panic("Commit: Trying to commit un-executed instruction " + panic("Trying to commit un-executed instruction " "of unknown type!\n"); } } - // Now check if it's one of the special trap or barrier or - // serializing instructions. - if (head_inst->isThreadSync() || - head_inst->isSerializing() || - head_inst->isMemBarrier() || - head_inst->isWriteBarrier() ) - { - // Not handled for now. Mem barriers and write barriers are safe - // to simply let commit as memory accesses only happen once they - // reach the head of commit. Not sure about the other two. - panic("Serializing or barrier instructions" - " are not handled yet.\n"); + if (head_inst->isThreadSync()) { + // Not handled for now. + panic("Thread sync instructions are not handled yet.\n"); + } + + // Stores mark themselves as completed. + if (!head_inst->isStore()) { + head_inst->setCompleted(); + } + + // Use checker prior to updating anything due to traps or PC + // based events. + if (cpu->checker) { + cpu->checker->tick(head_inst); } // Check if the instruction caused a fault. If so, trap. Fault inst_fault = head_inst->getFault(); if (inst_fault != NoFault) { - if (!head_inst->isNop()) { + head_inst->setCompleted(); #if FULL_SYSTEM - cpu->trap(inst_fault); -#else // !FULL_SYSTEM - panic("fault (%d) detected @ PC %08p", inst_fault, - head_inst->PC); -#endif // FULL_SYSTEM + DPRINTF(Commit, "Inst [sn:%lli] PC %#x has a fault\n", + head_inst->seqNum, head_inst->readPC()); + + if (iewStage->hasStoresToWB() || inst_num > 0) { + DPRINTF(Commit, "Stores outstanding, fault must wait.\n"); + return false; } - } - // Check if we're really ready to commit. If not then return false. - // I'm pretty sure all instructions should be able to commit if they've - // reached this far. For now leave this in as a check. - if (!rob->isHeadReady()) { - panic("Commit: Unable to commit head instruction!\n"); - return false; - } + if (cpu->checker && head_inst->isStore()) { + cpu->checker->tick(head_inst); + } - // If it's a branch, then send back branch prediction update info - // to the fetch stage. - // This should be handled in the iew stage if a mispredict happens... + assert(!thread[tid]->inSyscall); - if (head_inst->isControl()) { + // Mark that we're in state update mode so that the trap's + // execution doesn't generate extra squashes. + thread[tid]->inSyscall = true; -#if 0 - toIEW->nextPC = head_inst->readPC(); - //Maybe switch over to BTB incorrect. - toIEW->btbMissed = head_inst->btbMiss(); - toIEW->target = head_inst->nextPC; - //Maybe also include global history information. - //This simple version will have no branch prediction however. -#endif + // DTB will sometimes need the machine instruction for when + // faults happen. So we will set it here, prior to the DTB + // possibly needing it for its fault. + thread[tid]->setInst( + static_cast<TheISA::MachInst>(head_inst->staticInst->machInst)); + + // Execute the trap. Although it's slightly unrealistic in + // terms of timing (as it doesn't wait for the full timing of + // the trap event to complete before updating state), it's + // needed to update the state as soon as possible. This + // prevents external agents from changing any specific state + // that the trap need. + cpu->trap(inst_fault, tid); + + // Exit state update mode to avoid accidental updating. + thread[tid]->inSyscall = false; + + commitStatus[tid] = TrapPending; - ++commitCommittedBranches; + // Generate trap squash event. + generateTrapEvent(tid); + + return false; +#else // !FULL_SYSTEM + panic("fault (%d) detected @ PC %08p", inst_fault, + head_inst->PC); +#endif // FULL_SYSTEM } - // Now that the instruction is going to be committed, finalize its - // trace data. + updateComInstStats(head_inst); + if (head_inst->traceData) { + head_inst->traceData->setFetchSeq(head_inst->seqNum); + head_inst->traceData->setCPSeq(thread[tid]->numInst); head_inst->traceData->finalize(); + head_inst->traceData = NULL; + } + + // Update the commit rename map + for (int i = 0; i < head_inst->numDestRegs(); i++) { + renameMap[tid]->setEntry(head_inst->destRegIdx(i), + head_inst->renamedDestRegIdx(i)); } - //Finally clear the head ROB entry. - rob->retireHead(); + // Finally clear the head ROB entry. + rob->retireHead(tid); // Return true to indicate that we have committed an instruction. return true; @@ -449,37 +1095,39 @@ SimpleCommit<Impl>::commitHead(DynInstPtr &head_inst, unsigned inst_num) template <class Impl> void -SimpleCommit<Impl>::getInsts() +DefaultCommit<Impl>::getInsts() { - ////////////////////////////////////// - // Handle ROB functions - ////////////////////////////////////// - - // Read any issued instructions and place them into the ROB. Do this - // prior to squashing to avoid having instructions in the ROB that - // don't get squashed properly. + // Read any renamed instructions and place them into the ROB. int insts_to_process = min((int)renameWidth, fromRename->size); - for (int inst_num = 0; - inst_num < insts_to_process; - ++inst_num) + for (int inst_num = 0; inst_num < insts_to_process; ++inst_num) { - if (!fromRename->insts[inst_num]->isSquashed()) { - DPRINTF(Commit, "Commit: Inserting PC %#x into ROB.\n", - fromRename->insts[inst_num]->readPC()); - rob->insertInst(fromRename->insts[inst_num]); + DynInstPtr inst = fromRename->insts[inst_num]; + int tid = inst->threadNumber; + + if (!inst->isSquashed() && + commitStatus[tid] != ROBSquashing) { + changedROBNumEntries[tid] = true; + + DPRINTF(Commit, "Inserting PC %#x [sn:%i] [tid:%i] into ROB.\n", + inst->readPC(), inst->seqNum, tid); + + rob->insertInst(inst); + + assert(rob->getThreadEntries(tid) <= rob->getMaxEntries(tid)); + + youngestSeqNum[tid] = inst->seqNum; } else { - DPRINTF(Commit, "Commit: Instruction %i PC %#x was " + DPRINTF(Commit, "Instruction PC %#x [sn:%i] [tid:%i] was " "squashed, skipping.\n", - fromRename->insts[inst_num]->seqNum, - fromRename->insts[inst_num]->readPC()); + inst->readPC(), inst->seqNum, tid); } } } template <class Impl> void -SimpleCommit<Impl>::markCompletedInsts() +DefaultCommit<Impl>::markCompletedInsts() { // Grab completed insts out of the IEW instruction queue, and mark // instructions completed within the ROB. @@ -487,18 +1135,177 @@ SimpleCommit<Impl>::markCompletedInsts() inst_num < fromIEW->size && fromIEW->insts[inst_num]; ++inst_num) { - DPRINTF(Commit, "Commit: Marking PC %#x, SN %i ready within ROB.\n", - fromIEW->insts[inst_num]->readPC(), - fromIEW->insts[inst_num]->seqNum); + if (!fromIEW->insts[inst_num]->isSquashed()) { + DPRINTF(Commit, "[tid:%i]: Marking PC %#x, [sn:%lli] ready " + "within ROB.\n", + fromIEW->insts[inst_num]->threadNumber, + fromIEW->insts[inst_num]->readPC(), + fromIEW->insts[inst_num]->seqNum); + + // Mark the instruction as ready to commit. + fromIEW->insts[inst_num]->setCanCommit(); + } + } +} + +template <class Impl> +bool +DefaultCommit<Impl>::robDoneSquashing() +{ + list<unsigned>::iterator threads = (*activeThreads).begin(); - // Mark the instruction as ready to commit. - fromIEW->insts[inst_num]->setCanCommit(); + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + if (!rob->isDoneSquashing(tid)) + return false; } + + return true; } template <class Impl> -uint64_t -SimpleCommit<Impl>::readCommitPC() +void +DefaultCommit<Impl>::updateComInstStats(DynInstPtr &inst) { - return rob->readHeadPC(); + unsigned thread = inst->threadNumber; + + // + // Pick off the software prefetches + // +#ifdef TARGET_ALPHA + if (inst->isDataPrefetch()) { + statComSwp[thread]++; + } else { + statComInst[thread]++; + } +#else + statComInst[thread]++; +#endif + + // + // Control Instructions + // + if (inst->isControl()) + statComBranches[thread]++; + + // + // Memory references + // + if (inst->isMemRef()) { + statComRefs[thread]++; + + if (inst->isLoad()) { + statComLoads[thread]++; + } + } + + if (inst->isMemBarrier()) { + statComMembars[thread]++; + } +} + +//////////////////////////////////////// +// // +// SMT COMMIT POLICY MAINTAINED HERE // +// // +//////////////////////////////////////// +template <class Impl> +int +DefaultCommit<Impl>::getCommittingThread() +{ + if (numThreads > 1) { + switch (commitPolicy) { + + case Aggressive: + //If Policy is Aggressive, commit will call + //this function multiple times per + //cycle + return oldestReady(); + + case RoundRobin: + return roundRobin(); + + case OldestReady: + return oldestReady(); + + default: + return -1; + } + } else { + int tid = (*activeThreads).front(); + + if (commitStatus[tid] == Running || + commitStatus[tid] == Idle || + commitStatus[tid] == FetchTrapPending) { + return tid; + } else { + return -1; + } + } +} + +template<class Impl> +int +DefaultCommit<Impl>::roundRobin() +{ + list<unsigned>::iterator pri_iter = priority_list.begin(); + list<unsigned>::iterator end = priority_list.end(); + + while (pri_iter != end) { + unsigned tid = *pri_iter; + + if (commitStatus[tid] == Running || + commitStatus[tid] == Idle) { + + if (rob->isHeadReady(tid)) { + priority_list.erase(pri_iter); + priority_list.push_back(tid); + + return tid; + } + } + + pri_iter++; + } + + return -1; +} + +template<class Impl> +int +DefaultCommit<Impl>::oldestReady() +{ + unsigned oldest = 0; + bool first = true; + + list<unsigned>::iterator threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + if (!rob->isEmpty(tid) && + (commitStatus[tid] == Running || + commitStatus[tid] == Idle || + commitStatus[tid] == FetchTrapPending)) { + + if (rob->isHeadReady(tid)) { + + DynInstPtr head_inst = rob->readHeadInst(tid); + + if (first) { + oldest = tid; + first = false; + } else if (head_inst->seqNum < oldest) { + oldest = tid; + } + } + } + } + + if (!first) { + return oldest; + } else { + return -1; + } } diff --git a/src/cpu/o3/cpu.cc b/src/cpu/o3/cpu.cc index b1a54ce74..788c6b164 100644 --- a/src/cpu/o3/cpu.cc +++ b/src/cpu/o3/cpu.cc @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -35,19 +35,30 @@ #else #include "sim/process.hh" #endif -#include "sim/root.hh" -#include "cpu/cpu_exec_context.hh" -#include "cpu/exec_context.hh" +#include "cpu/activity.hh" +#include "cpu/checker/cpu.hh" +#include "cpu/simple_thread.hh" +#include "cpu/thread_context.hh" #include "cpu/o3/alpha_dyn_inst.hh" #include "cpu/o3/alpha_impl.hh" #include "cpu/o3/cpu.hh" +#include "sim/root.hh" +#include "sim/stat_control.hh" + using namespace std; +using namespace TheISA; + +BaseFullCPU::BaseFullCPU(Params *params) + : BaseCPU(params), cpu_id(0) +{ +} -BaseFullCPU::BaseFullCPU(Params ¶ms) - : BaseCPU(¶ms), cpu_id(0) +void +BaseFullCPU::regStats() { + BaseCPU::regStats(); } template <class Impl> @@ -70,97 +81,82 @@ FullO3CPU<Impl>::TickEvent::description() return "FullO3CPU tick event"; } -//Call constructor to all the pipeline stages here template <class Impl> -FullO3CPU<Impl>::FullO3CPU(Params ¶ms) -#if FULL_SYSTEM - : BaseFullCPU(params), -#else +FullO3CPU<Impl>::FullO3CPU(Params *params) : BaseFullCPU(params), -#endif // FULL_SYSTEM tickEvent(this), + removeInstsThisCycle(false), fetch(params), decode(params), rename(params), iew(params), commit(params), - regFile(params.numPhysIntRegs, params.numPhysFloatRegs), + regFile(params->numPhysIntRegs, params->numPhysFloatRegs), - freeList(TheISA::NumIntRegs, params.numPhysIntRegs, - TheISA::NumFloatRegs, params.numPhysFloatRegs), + freeList(params->numberOfThreads,//number of activeThreads + TheISA::NumIntRegs, params->numPhysIntRegs, + TheISA::NumFloatRegs, params->numPhysFloatRegs), - renameMap(TheISA::NumIntRegs, params.numPhysIntRegs, - TheISA::NumFloatRegs, params.numPhysFloatRegs, - TheISA::NumMiscRegs, - TheISA::ZeroReg, - TheISA::ZeroReg + TheISA::NumIntRegs), + rob(params->numROBEntries, params->squashWidth, + params->smtROBPolicy, params->smtROBThreshold, + params->numberOfThreads), - rob(params.numROBEntries, params.squashWidth), + scoreboard(params->numberOfThreads,//number of activeThreads + TheISA::NumIntRegs, params->numPhysIntRegs, + TheISA::NumFloatRegs, params->numPhysFloatRegs, + TheISA::NumMiscRegs * number_of_threads, + TheISA::ZeroReg), - // What to pass to these time buffers? // For now just have these time buffers be pretty big. + // @todo: Make these time buffer sizes parameters or derived + // from latencies timeBuffer(5, 5), fetchQueue(5, 5), decodeQueue(5, 5), renameQueue(5, 5), iewQueue(5, 5), - - cpuXC(NULL), + activityRec(NumStages, 10, params->activity), globalSeqNum(1), #if FULL_SYSTEM - system(params.system), - memCtrl(system->memctrl), + system(params->system), physmem(system->physmem), - itb(params.itb), - dtb(params.dtb), - mem(params.mem), -#else - // Hardcoded for a single thread!! - mem(params.workload[0]->getMemory()), #endif // FULL_SYSTEM - - icacheInterface(params.icacheInterface), - dcacheInterface(params.dcacheInterface), - deferRegistration(params.defReg), - numInsts(0), - funcExeInst(0) + mem(params->mem), + switchCount(0), + deferRegistration(params->deferRegistration), + numThreads(number_of_threads) { _status = Idle; -#if !FULL_SYSTEM - thread.resize(this->number_of_threads); -#endif - - for (int i = 0; i < this->number_of_threads; ++i) { + if (params->checker) { + BaseCPU *temp_checker = params->checker; + checker = dynamic_cast<Checker<DynInstPtr> *>(temp_checker); + checker->setMemory(mem); #if FULL_SYSTEM - assert(i == 0); - thread[i] = new CPUExecContext(this, 0, system, itb, dtb, mem); - system->execContexts[i] = thread[i]->getProxy(); - - execContexts.push_back(system->execContexts[i]); -#else - if (i < params.workload.size()) { - DPRINTF(FullCPU, "FullCPU: Workload[%i]'s starting PC is %#x, " - "process is %#x", - i, params.workload[i]->prog_entry, thread[i]); - thread[i] = new CPUExecContext(this, i, params.workload[i], i); - } - assert(params.workload[i]->getMemory() != NULL); - assert(mem != NULL); - execContexts.push_back(thread[i]->getProxy()); -#endif // !FULL_SYSTEM + checker->setSystem(params->system); +#endif + } else { + checker = NULL; } - // Note that this is a hack so that my code which still uses xc-> will - // still work. I should remove this eventually - cpuXC = thread[0]; +#if !FULL_SYSTEM + thread.resize(number_of_threads); + tids.resize(number_of_threads); +#endif + + // The stages also need their CPU pointer setup. However this + // must be done at the upper level CPU because they have pointers + // to the upper level CPU, and not this FullO3CPU. - // The stages also need their CPU pointer setup. However this must be - // done at the upper level CPU because they have pointers to the upper - // level CPU, and not this FullO3CPU. + // Set up Pointers to the activeThreads list for each stage + fetch.setActiveThreads(&activeThreads); + decode.setActiveThreads(&activeThreads); + rename.setActiveThreads(&activeThreads); + iew.setActiveThreads(&activeThreads); + commit.setActiveThreads(&activeThreads); // Give each of the stages the time buffer they will use. fetch.setTimeBuffer(&timeBuffer); @@ -172,6 +168,7 @@ FullO3CPU<Impl>::FullO3CPU(Params ¶ms) // Also setup each of the stages' queues. fetch.setFetchQueue(&fetchQueue); decode.setFetchQueue(&fetchQueue); + commit.setFetchQueue(&fetchQueue); decode.setDecodeQueue(&decodeQueue); rename.setDecodeQueue(&decodeQueue); rename.setRenameQueue(&renameQueue); @@ -180,16 +177,79 @@ FullO3CPU<Impl>::FullO3CPU(Params ¶ms) commit.setIEWQueue(&iewQueue); commit.setRenameQueue(&renameQueue); + commit.setFetchStage(&fetch); + commit.setIEWStage(&iew); + rename.setIEWStage(&iew); + rename.setCommitStage(&commit); + +#if !FULL_SYSTEM + int active_threads = params->workload.size(); +#else + int active_threads = 1; +#endif + + //Make Sure That this a Valid Architeture + assert(params->numPhysIntRegs >= numThreads * TheISA::NumIntRegs); + assert(params->numPhysFloatRegs >= numThreads * TheISA::NumFloatRegs); + + rename.setScoreboard(&scoreboard); + iew.setScoreboard(&scoreboard); + // Setup the rename map for whichever stages need it. - rename.setRenameMap(&renameMap); - iew.setRenameMap(&renameMap); + PhysRegIndex lreg_idx = 0; + PhysRegIndex freg_idx = params->numPhysIntRegs; //Index to 1 after int regs + + for (int tid=0; tid < numThreads; tid++) { + bool bindRegs = (tid <= active_threads - 1); + + commitRenameMap[tid].init(TheISA::NumIntRegs, + params->numPhysIntRegs, + lreg_idx, //Index for Logical. Regs + + TheISA::NumFloatRegs, + params->numPhysFloatRegs, + freg_idx, //Index for Float Regs + + TheISA::NumMiscRegs, + + TheISA::ZeroReg, + TheISA::ZeroReg, + + tid, + false); + + renameMap[tid].init(TheISA::NumIntRegs, + params->numPhysIntRegs, + lreg_idx, //Index for Logical. Regs - // Setup the free list for whichever stages need it. + TheISA::NumFloatRegs, + params->numPhysFloatRegs, + freg_idx, //Index for Float Regs + + TheISA::NumMiscRegs, + + TheISA::ZeroReg, + TheISA::ZeroReg, + + tid, + bindRegs); + } + + rename.setRenameMap(renameMap); + commit.setRenameMap(commitRenameMap); + + // Give renameMap & rename stage access to the freeList; + for (int i=0; i < numThreads; i++) { + renameMap[i].setFreeList(&freeList); + } rename.setFreeList(&freeList); - renameMap.setFreeList(&freeList); // Setup the ROB for whichever stages need it. commit.setROB(&rob); + + lastRunningCycle = curTick; + + contextSwitch = false; } template <class Impl> @@ -201,7 +261,58 @@ template <class Impl> void FullO3CPU<Impl>::fullCPURegStats() { + BaseFullCPU::regStats(); + // Register any of the FullCPU's stats here. + timesIdled + .name(name() + ".timesIdled") + .desc("Number of times that the entire CPU went into an idle state and" + " unscheduled itself") + .prereq(timesIdled); + + idleCycles + .name(name() + ".idleCycles") + .desc("Total number of cycles that the CPU has spent unscheduled due " + "to idling") + .prereq(idleCycles); + + // Number of Instructions simulated + // -------------------------------- + // Should probably be in Base CPU but need templated + // MaxThreads so put in here instead + committedInsts + .init(numThreads) + .name(name() + ".committedInsts") + .desc("Number of Instructions Simulated"); + + totalCommittedInsts + .name(name() + ".committedInsts_total") + .desc("Number of Instructions Simulated"); + + cpi + .name(name() + ".cpi") + .desc("CPI: Cycles Per Instruction") + .precision(6); + cpi = simTicks / committedInsts; + + totalCpi + .name(name() + ".cpi_total") + .desc("CPI: Total CPI of All Threads") + .precision(6); + totalCpi = simTicks / totalCommittedInsts; + + ipc + .name(name() + ".ipc") + .desc("IPC: Instructions Per Cycle") + .precision(6); + ipc = committedInsts / simTicks; + + totalIpc + .name(name() + ".ipc_total") + .desc("IPC: Total IPC of All Threads") + .precision(6); + totalIpc = totalCommittedInsts / simTicks; + } template <class Impl> @@ -210,9 +321,11 @@ FullO3CPU<Impl>::tick() { DPRINTF(FullCPU, "\n\nFullCPU: Ticking main, FullO3CPU.\n"); - //Tick each of the stages if they're actually running. - //Will want to figure out a way to unschedule itself if they're all - //going to be idle for a long time. + ++numCycles; + +// activity = false; + + //Tick each of the stages fetch.tick(); decode.tick(); @@ -223,7 +336,11 @@ FullO3CPU<Impl>::tick() commit.tick(); - // Now advance the time buffers, unless the stage is stalled. +#if !FULL_SYSTEM + doContextSwitch(); +#endif + + // Now advance the time buffers timeBuffer.advance(); fetchQueue.advance(); @@ -231,114 +348,405 @@ FullO3CPU<Impl>::tick() renameQueue.advance(); iewQueue.advance(); - if (_status == Running && !tickEvent.scheduled()) - tickEvent.schedule(curTick + 1); + activityRec.advance(); + + if (removeInstsThisCycle) { + cleanUpRemovedInsts(); + } + + if (!tickEvent.scheduled()) { + if (_status == SwitchedOut) { + // increment stat + lastRunningCycle = curTick; + } else if (!activityRec.active()) { + lastRunningCycle = curTick; + timesIdled++; + } else { + tickEvent.schedule(curTick + cycles(1)); + } + } + +#if !FULL_SYSTEM + updateThreadPriority(); +#endif + } template <class Impl> void FullO3CPU<Impl>::init() { - if(!deferRegistration) - { - this->registerExecContexts(); + if (!deferRegistration) { + registerThreadContexts(); + } + + // Set inSyscall so that the CPU doesn't squash when initially + // setting up registers. + for (int i = 0; i < number_of_threads; ++i) + thread[i]->inSyscall = true; - // Need to do a copy of the xc->regs into the CPU's regfile so - // that it can start properly. + for (int tid=0; tid < number_of_threads; tid++) { #if FULL_SYSTEM - ExecContext *src_xc = system->execContexts[0]; - TheISA::initCPU(src_xc, src_xc->readCpuId()); + ThreadContext *src_tc = threadContexts[tid]; #else - ExecContext *src_xc = thread[0]->getProxy(); + ThreadContext *src_tc = thread[tid]->getTC(); #endif - // First loop through the integer registers. - for (int i = 0; i < TheISA::NumIntRegs; ++i) - { - regFile.intRegFile[i] = src_xc->readIntReg(i); + // Threads start in the Suspended State + if (src_tc->status() != ThreadContext::Suspended) { + continue; } - // Then loop through the floating point registers. - for (int i = 0; i < TheISA::NumFloatRegs; ++i) - { - regFile.floatRegFile.setRegBits(i, src_xc->readRegBits(i)) - } -/* - // Then loop through the misc registers. - regFile.miscRegs.fpcr = src_xc->regs.miscRegs.fpcr; - regFile.miscRegs.uniq = src_xc->regs.miscRegs.uniq; - regFile.miscRegs.lock_flag = src_xc->regs.miscRegs.lock_flag; - regFile.miscRegs.lock_addr = src_xc->regs.miscRegs.lock_addr; -*/ - // Then finally set the PC and the next PC. - regFile.pc = src_xc->readPC(); - regFile.npc = src_xc->readNextPC(); +#if FULL_SYSTEM + TheISA::initCPU(src_tc, src_tc->readCpuId()); +#endif + } + + // Clear inSyscall. + for (int i = 0; i < number_of_threads; ++i) + thread[i]->inSyscall = false; + + // Initialize stages. + fetch.initStage(); + iew.initStage(); + rename.initStage(); + commit.initStage(); + + commit.setThreads(thread); +} + +template <class Impl> +void +FullO3CPU<Impl>::insertThread(unsigned tid) +{ + DPRINTF(FullCPU,"[tid:%i] Initializing thread data"); + // Will change now that the PC and thread state is internal to the CPU + // and not in the ThreadContext. +#if 0 +#if FULL_SYSTEM + ThreadContext *src_tc = system->threadContexts[tid]; +#else + ThreadContext *src_tc = thread[tid]; +#endif + + //Bind Int Regs to Rename Map + for (int ireg = 0; ireg < TheISA::NumIntRegs; ireg++) { + PhysRegIndex phys_reg = freeList.getIntReg(); + + renameMap[tid].setEntry(ireg,phys_reg); + scoreboard.setReg(phys_reg); + } + + //Bind Float Regs to Rename Map + for (int freg = 0; freg < TheISA::NumFloatRegs; freg++) { + PhysRegIndex phys_reg = freeList.getFloatReg(); + + renameMap[tid].setEntry(freg,phys_reg); + scoreboard.setReg(phys_reg); + } + + //Copy Thread Data Into RegFile + this->copyFromTC(tid); + + //Set PC/NPC + regFile.pc[tid] = src_tc->readPC(); + regFile.npc[tid] = src_tc->readNextPC(); + + src_tc->setStatus(ThreadContext::Active); + + activateContext(tid,1); + + //Reset ROB/IQ/LSQ Entries + commit.rob->resetEntries(); + iew.resetEntries(); +#endif +} + +template <class Impl> +void +FullO3CPU<Impl>::removeThread(unsigned tid) +{ + DPRINTF(FullCPU,"[tid:%i] Removing thread data"); +#if 0 + //Unbind Int Regs from Rename Map + for (int ireg = 0; ireg < TheISA::NumIntRegs; ireg++) { + PhysRegIndex phys_reg = renameMap[tid].lookup(ireg); + + scoreboard.unsetReg(phys_reg); + freeList.addReg(phys_reg); } + + //Unbind Float Regs from Rename Map + for (int freg = 0; freg < TheISA::NumFloatRegs; freg++) { + PhysRegIndex phys_reg = renameMap[tid].lookup(freg); + + scoreboard.unsetReg(phys_reg); + freeList.addReg(phys_reg); + } + + //Copy Thread Data From RegFile + /* Fix Me: + * Do we really need to do this if we are removing a thread + * in the sense that it's finished (exiting)? If the thread is just + * being suspended we might... + */ +// this->copyToTC(tid); + + //Squash Throughout Pipeline + fetch.squash(0,tid); + decode.squash(tid); + rename.squash(tid); + + assert(iew.ldstQueue.getCount(tid) == 0); + + //Reset ROB/IQ/LSQ Entries + if (activeThreads.size() >= 1) { + commit.rob->resetEntries(); + iew.resetEntries(); + } +#endif } + template <class Impl> void -FullO3CPU<Impl>::activateContext(int thread_num, int delay) +FullO3CPU<Impl>::activateWhenReady(int tid) +{ + DPRINTF(FullCPU,"[tid:%i]: Checking if resources are available for incoming" + "(e.g. PhysRegs/ROB/IQ/LSQ) \n", + tid); + + bool ready = true; + + if (freeList.numFreeIntRegs() >= TheISA::NumIntRegs) { + DPRINTF(FullCPU,"[tid:%i] Suspending thread due to not enough " + "Phys. Int. Regs.\n", + tid); + ready = false; + } else if (freeList.numFreeFloatRegs() >= TheISA::NumFloatRegs) { + DPRINTF(FullCPU,"[tid:%i] Suspending thread due to not enough " + "Phys. Float. Regs.\n", + tid); + ready = false; + } else if (commit.rob->numFreeEntries() >= + commit.rob->entryAmount(activeThreads.size() + 1)) { + DPRINTF(FullCPU,"[tid:%i] Suspending thread due to not enough " + "ROB entries.\n", + tid); + ready = false; + } else if (iew.instQueue.numFreeEntries() >= + iew.instQueue.entryAmount(activeThreads.size() + 1)) { + DPRINTF(FullCPU,"[tid:%i] Suspending thread due to not enough " + "IQ entries.\n", + tid); + ready = false; + } else if (iew.ldstQueue.numFreeEntries() >= + iew.ldstQueue.entryAmount(activeThreads.size() + 1)) { + DPRINTF(FullCPU,"[tid:%i] Suspending thread due to not enough " + "LSQ entries.\n", + tid); + ready = false; + } + + if (ready) { + insertThread(tid); + + contextSwitch = false; + + cpuWaitList.remove(tid); + } else { + suspendContext(tid); + + //blocks fetch + contextSwitch = true; + + //do waitlist + cpuWaitList.push_back(tid); + } +} + +template <class Impl> +void +FullO3CPU<Impl>::activateContext(int tid, int delay) { // Needs to set each stage to running as well. + list<unsigned>::iterator isActive = find( + activeThreads.begin(), activeThreads.end(), tid); + + if (isActive == activeThreads.end()) { + //May Need to Re-code this if the delay variable is the + //delay needed for thread to activate + DPRINTF(FullCPU, "Adding Thread %i to active threads list\n", + tid); + + activeThreads.push_back(tid); + } + + assert(_status == Idle || _status == SwitchedOut); scheduleTickEvent(delay); + // Be sure to signal that there's some activity so the CPU doesn't + // deschedule itself. + activityRec.activity(); + fetch.wakeFromQuiesce(); + _status = Running; } template <class Impl> void -FullO3CPU<Impl>::suspendContext(int thread_num) +FullO3CPU<Impl>::suspendContext(int tid) { - panic("suspendContext unimplemented!"); + DPRINTF(FullCPU,"[tid: %i]: Suspended ...\n", tid); + unscheduleTickEvent(); + _status = Idle; +/* + //Remove From Active List, if Active + list<unsigned>::iterator isActive = find( + activeThreads.begin(), activeThreads.end(), tid); + + if (isActive != activeThreads.end()) { + DPRINTF(FullCPU,"[tid:%i]: Removing from active threads list\n", + tid); + activeThreads.erase(isActive); + } +*/ } template <class Impl> void -FullO3CPU<Impl>::deallocateContext(int thread_num) +FullO3CPU<Impl>::deallocateContext(int tid) { - panic("deallocateContext unimplemented!"); + DPRINTF(FullCPU,"[tid:%i]: Deallocating ...", tid); +/* + //Remove From Active List, if Active + list<unsigned>::iterator isActive = find( + activeThreads.begin(), activeThreads.end(), tid); + + if (isActive != activeThreads.end()) { + DPRINTF(FullCPU,"[tid:%i]: Removing from active threads list\n", + tid); + activeThreads.erase(isActive); + + removeThread(tid); + } +*/ +} + +template <class Impl> +void +FullO3CPU<Impl>::haltContext(int tid) +{ + DPRINTF(FullCPU,"[tid:%i]: Halted ...", tid); +/* + //Remove From Active List, if Active + list<unsigned>::iterator isActive = find( + activeThreads.begin(), activeThreads.end(), tid); + + if (isActive != activeThreads.end()) { + DPRINTF(FullCPU,"[tid:%i]: Removing from active threads list\n", + tid); + activeThreads.erase(isActive); + + removeThread(tid); + } +*/ } template <class Impl> void -FullO3CPU<Impl>::haltContext(int thread_num) +FullO3CPU<Impl>::switchOut(Sampler *_sampler) { - panic("haltContext unimplemented!"); + sampler = _sampler; + switchCount = 0; + fetch.switchOut(); + decode.switchOut(); + rename.switchOut(); + iew.switchOut(); + commit.switchOut(); + + // Wake the CPU and record activity so everything can drain out if + // the CPU is currently idle. + wakeCPU(); + activityRec.activity(); } template <class Impl> void -FullO3CPU<Impl>::switchOut() +FullO3CPU<Impl>::signalSwitched() { - panic("FullO3CPU does not have a switch out function.\n"); + if (++switchCount == NumStages) { + fetch.doSwitchOut(); + rename.doSwitchOut(); + commit.doSwitchOut(); + instList.clear(); + while (!removeList.empty()) { + removeList.pop(); + } + + if (checker) + checker->switchOut(sampler); + + if (tickEvent.scheduled()) + tickEvent.squash(); + sampler->signalSwitched(); + _status = SwitchedOut; + } + assert(switchCount <= 5); } template <class Impl> void FullO3CPU<Impl>::takeOverFrom(BaseCPU *oldCPU) { + // Flush out any old data from the time buffers. + for (int i = 0; i < 10; ++i) { + timeBuffer.advance(); + fetchQueue.advance(); + decodeQueue.advance(); + renameQueue.advance(); + iewQueue.advance(); + } + + activityRec.reset(); + BaseCPU::takeOverFrom(oldCPU); + fetch.takeOverFrom(); + decode.takeOverFrom(); + rename.takeOverFrom(); + iew.takeOverFrom(); + commit.takeOverFrom(); + assert(!tickEvent.scheduled()); - // Set all status's to active, schedule the - // CPU's tick event. - for (int i = 0; i < execContexts.size(); ++i) { - ExecContext *xc = execContexts[i]; - if (xc->status() == ExecContext::Active && _status != Running) { + // @todo: Figure out how to properly select the tid to put onto + // the active threads list. + int tid = 0; + + list<unsigned>::iterator isActive = find( + activeThreads.begin(), activeThreads.end(), tid); + + if (isActive == activeThreads.end()) { + //May Need to Re-code this if the delay variable is the delay + //needed for thread to activate + DPRINTF(FullCPU, "Adding Thread %i to active threads list\n", + tid); + + activeThreads.push_back(tid); + } + + // Set all statuses to active, schedule the CPU's tick event. + // @todo: Fix up statuses so this is handled properly + for (int i = 0; i < threadContexts.size(); ++i) { + ThreadContext *tc = threadContexts[i]; + if (tc->status() == ThreadContext::Active && _status != Running) { _status = Running; tickEvent.schedule(curTick); } } -} - -template <class Impl> -InstSeqNum -FullO3CPU<Impl>::getAndIncrementInstSeq() -{ - // Hopefully this works right. - return globalSeqNum++; + if (!tickEvent.scheduled()) + tickEvent.schedule(curTick); } template <class Impl> @@ -413,156 +821,368 @@ FullO3CPU<Impl>::setFloatRegBits(int reg_idx, FloatRegBits val) template <class Impl> uint64_t -FullO3CPU<Impl>::readPC() +FullO3CPU<Impl>::readArchIntReg(int reg_idx, unsigned tid) +{ + PhysRegIndex phys_reg = commitRenameMap[tid].lookup(reg_idx); + + return regFile.readIntReg(phys_reg); +} + +template <class Impl> +float +FullO3CPU<Impl>::readArchFloatRegSingle(int reg_idx, unsigned tid) +{ + int idx = reg_idx + TheISA::FP_Base_DepTag; + PhysRegIndex phys_reg = commitRenameMap[tid].lookup(idx); + + return regFile.readFloatReg(phys_reg); +} + +template <class Impl> +double +FullO3CPU<Impl>::readArchFloatRegDouble(int reg_idx, unsigned tid) +{ + int idx = reg_idx + TheISA::FP_Base_DepTag; + PhysRegIndex phys_reg = commitRenameMap[tid].lookup(idx); + + return regFile.readFloatReg(phys_reg, 64); +} + +template <class Impl> +uint64_t +FullO3CPU<Impl>::readArchFloatRegInt(int reg_idx, unsigned tid) { - return regFile.readPC(); + int idx = reg_idx + TheISA::FP_Base_DepTag; + PhysRegIndex phys_reg = commitRenameMap[tid].lookup(idx); + + return regFile.readFloatRegBits(phys_reg); } template <class Impl> void -FullO3CPU<Impl>::setNextPC(uint64_t val) +FullO3CPU<Impl>::setArchIntReg(int reg_idx, uint64_t val, unsigned tid) { - regFile.setNextPC(val); + PhysRegIndex phys_reg = commitRenameMap[tid].lookup(reg_idx); + + regFile.setIntReg(phys_reg, val); } template <class Impl> void -FullO3CPU<Impl>::setPC(Addr new_PC) +FullO3CPU<Impl>::setArchFloatRegSingle(int reg_idx, float val, unsigned tid) { - regFile.setPC(new_PC); + PhysRegIndex phys_reg = commitRenameMap[tid].lookup(reg_idx); + + regFile.setFloatReg(phys_reg, val); } template <class Impl> void -FullO3CPU<Impl>::addInst(DynInstPtr &inst) +FullO3CPU<Impl>::setArchFloatRegDouble(int reg_idx, double val, unsigned tid) { - instList.push_back(inst); + PhysRegIndex phys_reg = commitRenameMap[tid].lookup(reg_idx); + + regFile.setFloatReg(phys_reg, val, 64); } template <class Impl> void -FullO3CPU<Impl>::instDone() +FullO3CPU<Impl>::setArchFloatRegInt(int reg_idx, uint64_t val, unsigned tid) { - // Keep an instruction count. - numInsts++; + PhysRegIndex phys_reg = commitRenameMap[tid].lookup(reg_idx); - // Check for instruction-count-based events. - comInstEventQueue[0]->serviceEvents(numInsts); + regFile.setFloatRegBits(phys_reg, val); +} + +template <class Impl> +uint64_t +FullO3CPU<Impl>::readPC(unsigned tid) +{ + return commit.readPC(tid); } template <class Impl> void -FullO3CPU<Impl>::removeBackInst(DynInstPtr &inst) +FullO3CPU<Impl>::setPC(Addr new_PC,unsigned tid) { - DynInstPtr inst_to_delete; + commit.setPC(new_PC, tid); +} - // Walk through the instruction list, removing any instructions - // that were inserted after the given instruction, inst. - while (instList.back() != inst) - { - assert(!instList.empty()); +template <class Impl> +uint64_t +FullO3CPU<Impl>::readNextPC(unsigned tid) +{ + return commit.readNextPC(tid); +} - // Obtain the pointer to the instruction. - inst_to_delete = instList.back(); +template <class Impl> +void +FullO3CPU<Impl>::setNextPC(uint64_t val,unsigned tid) +{ + commit.setNextPC(val, tid); +} - DPRINTF(FullCPU, "FullCPU: Removing instruction %i, PC %#x\n", - inst_to_delete->seqNum, inst_to_delete->readPC()); +template <class Impl> +typename FullO3CPU<Impl>::ListIt +FullO3CPU<Impl>::addInst(DynInstPtr &inst) +{ + instList.push_back(inst); - // Remove the instruction from the list. - instList.pop_back(); + return --(instList.end()); +} - // Mark it as squashed. - inst_to_delete->setSquashed(); - } +template <class Impl> +void +FullO3CPU<Impl>::instDone(unsigned tid) +{ + // Keep an instruction count. + thread[tid]->numInst++; + thread[tid]->numInsts++; + committedInsts[tid]++; + totalCommittedInsts++; + + // Check for instruction-count-based events. + comInstEventQueue[tid]->serviceEvents(thread[tid]->numInst); +} + +template <class Impl> +void +FullO3CPU<Impl>::addToRemoveList(DynInstPtr &inst) +{ + removeInstsThisCycle = true; + + removeList.push(inst->getInstListIt()); } template <class Impl> void FullO3CPU<Impl>::removeFrontInst(DynInstPtr &inst) { - DynInstPtr inst_to_remove; + DPRINTF(FullCPU, "FullCPU: Removing committed instruction [tid:%i] PC %#x " + "[sn:%lli]\n", + inst->threadNumber, inst->readPC(), inst->seqNum); - // The front instruction should be the same one being asked to be removed. - assert(instList.front() == inst); + removeInstsThisCycle = true; // Remove the front instruction. - inst_to_remove = inst; - instList.pop_front(); - - DPRINTF(FullCPU, "FullCPU: Removing committed instruction %#x, PC %#x\n", - inst_to_remove, inst_to_remove->readPC()); + removeList.push(inst->getInstListIt()); } template <class Impl> void -FullO3CPU<Impl>::removeInstsNotInROB() +FullO3CPU<Impl>::removeInstsNotInROB(unsigned tid) { - DPRINTF(FullCPU, "FullCPU: Deleting instructions from instruction " - "list.\n"); + DPRINTF(FullCPU, "FullCPU: Thread %i: Deleting instructions from instruction" + " list.\n", tid); + + ListIt end_it; + + bool rob_empty = false; + + if (instList.empty()) { + return; + } else if (rob.isEmpty(/*tid*/)) { + DPRINTF(FullCPU, "FullCPU: ROB is empty, squashing all insts.\n"); + end_it = instList.begin(); + rob_empty = true; + } else { + end_it = (rob.readTailInst(tid))->getInstListIt(); + DPRINTF(FullCPU, "FullCPU: ROB is not empty, squashing insts not in ROB.\n"); + } + + removeInstsThisCycle = true; - DynInstPtr rob_tail = rob.readTailInst(); + ListIt inst_it = instList.end(); - removeBackInst(rob_tail); + inst_it--; + + // Walk through the instruction list, removing any instructions + // that were inserted after the given instruction iterator, end_it. + while (inst_it != end_it) { + assert(!instList.empty()); + + squashInstIt(inst_it, tid); + + inst_it--; + } + + // If the ROB was empty, then we actually need to remove the first + // instruction as well. + if (rob_empty) { + squashInstIt(inst_it, tid); + } } template <class Impl> void -FullO3CPU<Impl>::removeInstsUntil(const InstSeqNum &seq_num) +FullO3CPU<Impl>::removeInstsUntil(const InstSeqNum &seq_num, + unsigned tid) { + assert(!instList.empty()); + + removeInstsThisCycle = true; + + ListIt inst_iter = instList.end(); + + inst_iter--; + DPRINTF(FullCPU, "FullCPU: Deleting instructions from instruction " - "list.\n"); + "list that are from [tid:%i] and above [sn:%lli] (end=%lli).\n", + tid, seq_num, (*inst_iter)->seqNum); - DynInstPtr inst_to_delete; + while ((*inst_iter)->seqNum > seq_num) { - while (instList.back()->seqNum > seq_num) { - assert(!instList.empty()); + bool break_loop = (inst_iter == instList.begin()); - // Obtain the pointer to the instruction. - inst_to_delete = instList.back(); + squashInstIt(inst_iter, tid); - DPRINTF(FullCPU, "FullCPU: Removing instruction %i, PC %#x\n", - inst_to_delete->seqNum, inst_to_delete->readPC()); + inst_iter--; - // Remove the instruction from the list. - instList.back() = NULL; - instList.pop_back(); + if (break_loop) + break; + } +} + +template <class Impl> +inline void +FullO3CPU<Impl>::squashInstIt(const ListIt &instIt, const unsigned &tid) +{ + if ((*instIt)->threadNumber == tid) { + DPRINTF(FullCPU, "FullCPU: Squashing instruction, " + "[tid:%i] [sn:%lli] PC %#x\n", + (*instIt)->threadNumber, + (*instIt)->seqNum, + (*instIt)->readPC()); // Mark it as squashed. - inst_to_delete->setSquashed(); - } + (*instIt)->setSquashed(); + // @todo: Formulate a consistent method for deleting + // instructions from the instruction list + // Remove the instruction from the list. + removeList.push(instIt); + } } template <class Impl> void +FullO3CPU<Impl>::cleanUpRemovedInsts() +{ + while (!removeList.empty()) { + DPRINTF(FullCPU, "FullCPU: Removing instruction, " + "[tid:%i] [sn:%lli] PC %#x\n", + (*removeList.front())->threadNumber, + (*removeList.front())->seqNum, + (*removeList.front())->readPC()); + + instList.erase(removeList.front()); + + removeList.pop(); + } + + removeInstsThisCycle = false; +} +/* +template <class Impl> +void FullO3CPU<Impl>::removeAllInsts() { instList.clear(); } - +*/ template <class Impl> void FullO3CPU<Impl>::dumpInsts() { int num = 0; - typename list<DynInstPtr>::iterator inst_list_it = instList.begin(); - while (inst_list_it != instList.end()) - { - cprintf("Instruction:%i\nPC:%#x\nSN:%lli\nIssued:%i\nSquashed:%i\n\n", - num, (*inst_list_it)->readPC(), (*inst_list_it)->seqNum, - (*inst_list_it)->isIssued(), (*inst_list_it)->isSquashed()); + ListIt inst_list_it = instList.begin(); + + cprintf("Dumping Instruction List\n"); + + while (inst_list_it != instList.end()) { + cprintf("Instruction:%i\nPC:%#x\n[tid:%i]\n[sn:%lli]\nIssued:%i\n" + "Squashed:%i\n\n", + num, (*inst_list_it)->readPC(), (*inst_list_it)->threadNumber, + (*inst_list_it)->seqNum, (*inst_list_it)->isIssued(), + (*inst_list_it)->isSquashed()); inst_list_it++; ++num; } } - +/* template <class Impl> void FullO3CPU<Impl>::wakeDependents(DynInstPtr &inst) { iew.wakeDependents(inst); } +*/ +template <class Impl> +void +FullO3CPU<Impl>::wakeCPU() +{ + if (activityRec.active() || tickEvent.scheduled()) { + DPRINTF(Activity, "CPU already running.\n"); + return; + } + + DPRINTF(Activity, "Waking up CPU\n"); + + idleCycles += (curTick - 1) - lastRunningCycle; + + tickEvent.schedule(curTick); +} + +template <class Impl> +int +FullO3CPU<Impl>::getFreeTid() +{ + for (int i=0; i < numThreads; i++) { + if (!tids[i]) { + tids[i] = true; + return i; + } + } + + return -1; +} + +template <class Impl> +void +FullO3CPU<Impl>::doContextSwitch() +{ + if (contextSwitch) { + + //ADD CODE TO DEACTIVE THREAD HERE (???) + + for (int tid=0; tid < cpuWaitList.size(); tid++) { + activateWhenReady(tid); + } + + if (cpuWaitList.size() == 0) + contextSwitch = true; + } +} + +template <class Impl> +void +FullO3CPU<Impl>::updateThreadPriority() +{ + if (activeThreads.size() > 1) + { + //DEFAULT TO ROUND ROBIN SCHEME + //e.g. Move highest priority to end of thread list + list<unsigned>::iterator list_begin = activeThreads.begin(); + list<unsigned>::iterator list_end = activeThreads.end(); + + unsigned high_thread = *list_begin; + + activeThreads.erase(list_begin); + + activeThreads.push_back(high_thread); + } +} // Forward declaration of FullO3CPU. template class FullO3CPU<AlphaSimpleImpl>; diff --git a/src/cpu/o3/cpu.hh b/src/cpu/o3/cpu.hh index fbb5f32d5..ff41a3306 100644 --- a/src/cpu/o3/cpu.hh +++ b/src/cpu/o3/cpu.hh @@ -28,31 +28,32 @@ * Authors: Kevin Lim */ -//Todo: Add in a lot of the functions that are ISA specific. Also define -//the functions that currently exist within the base cpu class. Define -//everything for the simobject stuff so it can be serialized and -//instantiated, add in debugging statements everywhere. Have CPU schedule -//itself properly. Threads! -// Avoid running stages and advancing queues if idle/stalled. - -#ifndef __CPU_O3_CPU_FULL_CPU_HH__ -#define __CPU_O3_CPU_FULL_CPU_HH__ +#ifndef __CPU_O3_CPU_HH__ +#define __CPU_O3_CPU_HH__ #include <iostream> #include <list> +#include <queue> +#include <set> #include <vector> +#include "arch/isa_traits.hh" #include "base/statistics.hh" #include "base/timebuf.hh" #include "config/full_system.hh" +#include "cpu/activity.hh" #include "cpu/base.hh" -#include "cpu/cpu_exec_context.hh" +#include "cpu/simple_thread.hh" #include "cpu/o3/comm.hh" #include "cpu/o3/cpu_policy.hh" +#include "cpu/o3/scoreboard.hh" +#include "cpu/o3/thread_state.hh" #include "sim/process.hh" -class ExecContext; -class FunctionalMemory; +template <class> +class Checker; +class ThreadContext; +class MemObject; class Process; class BaseFullCPU : public BaseCPU @@ -61,59 +62,79 @@ class BaseFullCPU : public BaseCPU public: typedef BaseCPU::Params Params; -#if FULL_SYSTEM - BaseFullCPU(Params ¶ms); -#else - BaseFullCPU(Params ¶ms); -#endif // FULL_SYSTEM + BaseFullCPU(Params *params); + + void regStats(); + + int readCpuId() { return cpu_id; } protected: int cpu_id; }; +/** + * FullO3CPU class, has each of the stages (fetch through commit) + * within it, as well as all of the time buffers between stages. The + * tick() function for the CPU is defined here. + */ template <class Impl> class FullO3CPU : public BaseFullCPU { public: - //Put typedefs from the Impl here. + typedef TheISA::FloatReg FloatReg; + typedef TheISA::FloatRegBits FloatRegBits; + + // Typedefs from the Impl here. typedef typename Impl::CPUPol CPUPolicy; typedef typename Impl::Params Params; typedef typename Impl::DynInstPtr DynInstPtr; + typedef O3ThreadState<Impl> Thread; + + typedef typename std::list<DynInstPtr>::iterator ListIt; + public: enum Status { Running, Idle, Halted, - Blocked // ? + Blocked, + SwitchedOut }; + /** Overall CPU status. */ Status _status; private: class TickEvent : public Event { private: + /** Pointer to the CPU. */ FullO3CPU<Impl> *cpu; public: + /** Constructs a tick event. */ TickEvent(FullO3CPU<Impl> *c); + + /** Processes a tick event, calling tick() on the CPU. */ void process(); + /** Returns the description of the tick event. */ const char *description(); }; + /** The tick event used for scheduling CPU ticks. */ TickEvent tickEvent; - /// Schedule tick event, regardless of its current state. + /** Schedule tick event, regardless of its current state. */ void scheduleTickEvent(int delay) { if (tickEvent.squashed()) - tickEvent.reschedule(curTick + delay); + tickEvent.reschedule(curTick + cycles(delay)); else if (!tickEvent.scheduled()) - tickEvent.schedule(curTick + delay); + tickEvent.schedule(curTick + cycles(delay)); } - /// Unschedule tick event, regardless of its current state. + /** Unschedule tick event, regardless of its current state. */ void unscheduleTickEvent() { if (tickEvent.scheduled()) @@ -121,25 +142,83 @@ class FullO3CPU : public BaseFullCPU } public: - FullO3CPU(Params ¶ms); + /** Constructs a CPU with the given parameters. */ + FullO3CPU(Params *params); + /** Destructor. */ ~FullO3CPU(); + /** Registers statistics. */ void fullCPURegStats(); + /** Ticks CPU, calling tick() on each stage, and checking the overall + * activity to see if the CPU should deschedule itself. + */ void tick(); + /** Initialize the CPU */ void init(); - void activateContext(int thread_num, int delay); - void suspendContext(int thread_num); - void deallocateContext(int thread_num); - void haltContext(int thread_num); + /** Setup CPU to insert a thread's context */ + void insertThread(unsigned tid); + + /** Remove all of a thread's context from CPU */ + void removeThread(unsigned tid); + + /** Count the Total Instructions Committed in the CPU. */ + virtual Counter totalInstructions() const + { + Counter total(0); + + for (int i=0; i < thread.size(); i++) + total += thread[i]->numInst; + + return total; + } + + /** Add Thread to Active Threads List. */ + void activateContext(int tid, int delay); + + /** Remove Thread from Active Threads List */ + void suspendContext(int tid); + + /** Remove Thread from Active Threads List && + * Remove Thread Context from CPU. + */ + void deallocateContext(int tid); + + /** Remove Thread from Active Threads List && + * Remove Thread Context from CPU. + */ + void haltContext(int tid); + + /** Activate a Thread When CPU Resources are Available. */ + void activateWhenReady(int tid); - void switchOut(); + /** Add or Remove a Thread Context in the CPU. */ + void doContextSwitch(); + + /** Update The Order In Which We Process Threads. */ + void updateThreadPriority(); + + /** Executes a syscall on this cycle. + * --------------------------------------- + * Note: this is a virtual function. CPU-Specific + * functionality defined in derived classes + */ + virtual void syscall(int tid) { panic("Unimplemented!"); } + + /** Switches out this CPU. */ + void switchOut(Sampler *sampler); + + /** Signals to this CPU that a stage has completed switching out. */ + void signalSwitched(); + + /** Takes over from another CPU. */ void takeOverFrom(BaseCPU *oldCPU); /** Get the current instruction sequence number, and increment it. */ - InstSeqNum getAndIncrementInstSeq(); + InstSeqNum getAndIncrementInstSeq() + { return globalSeqNum++; } #if FULL_SYSTEM /** Check if this address is a valid instruction address. */ @@ -149,27 +228,24 @@ class FullO3CPU : public BaseFullCPU bool validDataAddr(Addr addr) { return true; } /** Get instruction asid. */ - int getInstAsid() - { return regFile.miscRegs.getInstAsid(); } + int getInstAsid(unsigned tid) + { return regFile.miscRegs[tid].getInstAsid(); } /** Get data asid. */ - int getDataAsid() - { return regFile.miscRegs.getDataAsid(); } + int getDataAsid(unsigned tid) + { return regFile.miscRegs[tid].getDataAsid(); } #else - bool validInstAddr(Addr addr) - { return thread[0]->validInstAddr(addr); } - - bool validDataAddr(Addr addr) - { return thread[0]->validDataAddr(addr); } + /** Get instruction asid. */ + int getInstAsid(unsigned tid) + { return thread[tid]->getInstAsid(); } - int getInstAsid() { return thread[0]->getInstAsid(); } - int getDataAsid() { return thread[0]->getDataAsid(); } + /** Get data asid. */ + int getDataAsid(unsigned tid) + { return thread[tid]->getDataAsid(); } #endif - // - // New accessors for new decoder. - // + /** Register accessors. Index refers to the physical register index. */ uint64_t readIntReg(int reg_idx); FloatReg readFloatReg(int reg_idx); @@ -182,103 +258,115 @@ class FullO3CPU : public BaseFullCPU void setIntReg(int reg_idx, uint64_t val); - void setFloatReg(int reg_idx, FloatReg val, int width); + void setFloatReg(int reg_idx, FloatReg val); void setFloatReg(int reg_idx, FloatReg val, int width); void setFloatRegBits(int reg_idx, FloatRegBits val); - void setFloatRegBits(int reg_idx, FloatRegBits val); + void setFloatRegBits(int reg_idx, FloatRegBits val, int width); + + uint64_t readArchIntReg(int reg_idx, unsigned tid); + + float readArchFloatRegSingle(int reg_idx, unsigned tid); + + double readArchFloatRegDouble(int reg_idx, unsigned tid); + + uint64_t readArchFloatRegInt(int reg_idx, unsigned tid); + + /** Architectural register accessors. Looks up in the commit + * rename table to obtain the true physical index of the + * architected register first, then accesses that physical + * register. + */ + void setArchIntReg(int reg_idx, uint64_t val, unsigned tid); + + void setArchFloatRegSingle(int reg_idx, float val, unsigned tid); - uint64_t readPC(); + void setArchFloatRegDouble(int reg_idx, double val, unsigned tid); - void setNextPC(uint64_t val); + void setArchFloatRegInt(int reg_idx, uint64_t val, unsigned tid); - void setPC(Addr new_PC); + /** Reads the commit PC of a specific thread. */ + uint64_t readPC(unsigned tid); + + /** Sets the commit PC of a specific thread. */ + void setPC(Addr new_PC, unsigned tid); + + /** Reads the next PC of a specific thread. */ + uint64_t readNextPC(unsigned tid); + + /** Sets the next PC of a specific thread. */ + void setNextPC(uint64_t val, unsigned tid); /** Function to add instruction onto the head of the list of the * instructions. Used when new instructions are fetched. */ - void addInst(DynInstPtr &inst); + ListIt addInst(DynInstPtr &inst); /** Function to tell the CPU that an instruction has completed. */ - void instDone(); - - /** Remove all instructions in back of the given instruction, but leave - * that instruction in the list. This is useful in a squash, when there - * are instructions in this list that don't exist in structures such as - * the ROB. The instruction doesn't have to be the last instruction in - * the list, but will be once this function completes. - * @todo: Remove only up until that inst? Squashed inst is most likely - * valid. - */ - void removeBackInst(DynInstPtr &inst); - - /** Remove an instruction from the front of the list. It is expected - * that there are no instructions in front of it (that is, none are older - * than the instruction being removed). Used when retiring instructions. - * @todo: Remove the argument to this function, and just have it remove - * last instruction once it's verified that commit has the same ordering - * as the instruction list. + void instDone(unsigned tid); + + /** Add Instructions to the CPU Remove List*/ + void addToRemoveList(DynInstPtr &inst); + + /** Remove an instruction from the front end of the list. There's + * no restriction on location of the instruction. */ void removeFrontInst(DynInstPtr &inst); /** Remove all instructions that are not currently in the ROB. */ - void removeInstsNotInROB(); + void removeInstsNotInROB(unsigned tid); /** Remove all instructions younger than the given sequence number. */ - void removeInstsUntil(const InstSeqNum &seq_num); + void removeInstsUntil(const InstSeqNum &seq_num,unsigned tid); - /** Remove all instructions from the list. */ - void removeAllInsts(); + /** Removes the instruction pointed to by the iterator. */ + inline void squashInstIt(const ListIt &instIt, const unsigned &tid); - void dumpInsts(); + /** Cleans up all instructions on the remove list. */ + void cleanUpRemovedInsts(); - /** Basically a wrapper function so that instructions executed at - * commit can tell the instruction queue that they have completed. - * Eventually this hack should be removed. - */ - void wakeDependents(DynInstPtr &inst); + /** Debug function to print all instructions on the list. */ + void dumpInsts(); public: /** List of all the instructions in flight. */ - list<DynInstPtr> instList; + std::list<DynInstPtr> instList; + + /** List of all the instructions that will be removed at the end of this + * cycle. + */ + std::queue<ListIt> removeList; + +#ifdef DEBUG + /** Debug structure to keep track of the sequence numbers still in + * flight. + */ + std::set<InstSeqNum> snList; +#endif + + /** Records if instructions need to be removed this cycle due to + * being retired or squashed. + */ + bool removeInstsThisCycle; - //not sure these should be private. protected: /** The fetch stage. */ typename CPUPolicy::Fetch fetch; - /** The fetch stage's status. */ - typename CPUPolicy::Fetch::Status fetchStatus; - /** The decode stage. */ typename CPUPolicy::Decode decode; - /** The decode stage's status. */ - typename CPUPolicy::Decode::Status decodeStatus; - /** The dispatch stage. */ typename CPUPolicy::Rename rename; - /** The dispatch stage's status. */ - typename CPUPolicy::Rename::Status renameStatus; - /** The issue/execute/writeback stages. */ typename CPUPolicy::IEW iew; - /** The issue/execute/writeback stage's status. */ - typename CPUPolicy::IEW::Status iewStatus; - /** The commit stage. */ typename CPUPolicy::Commit commit; - /** The fetch stage's status. */ - typename CPUPolicy::Commit::Status commitStatus; - - //Might want to just pass these objects in to the constructors of the - //appropriate stage. regFile is in iew, freeList in dispatch, renameMap - //in dispatch, and the rob in commit. /** The register file. */ typename CPUPolicy::RegFile regFile; @@ -286,12 +374,33 @@ class FullO3CPU : public BaseFullCPU typename CPUPolicy::FreeList freeList; /** The rename map. */ - typename CPUPolicy::RenameMap renameMap; + typename CPUPolicy::RenameMap renameMap[Impl::MaxThreads]; + + /** The commit rename map. */ + typename CPUPolicy::RenameMap commitRenameMap[Impl::MaxThreads]; /** The re-order buffer. */ typename CPUPolicy::ROB rob; + /** Active Threads List */ + std::list<unsigned> activeThreads; + + /** Integer Register Scoreboard */ + Scoreboard scoreboard; + public: + /** Enum to give each stage a specific index, so when calling + * activateStage() or deactivateStage(), they can specify which stage + * is being activated/deactivated. + */ + enum StageIdx { + FetchIdx, + DecodeIdx, + RenameIdx, + IEWIdx, + CommitIdx, + NumStages }; + /** Typedefs from the Impl to get the structs that each of the * time buffers should use. */ @@ -320,46 +429,109 @@ class FullO3CPU : public BaseFullCPU /** The IEW stage's instruction queue. */ TimeBuffer<IEWStruct> iewQueue; + private: + /** The activity recorder; used to tell if the CPU has any + * activity remaining or if it can go to idle and deschedule + * itself. + */ + ActivityRecorder activityRec; + public: - /** The temporary exec context to support older accessors. */ - CPUExecContext *cpuXC; + /** Records that there was time buffer activity this cycle. */ + void activityThisCycle() { activityRec.activity(); } - /** Temporary function to get pointer to exec context. */ - ExecContext *xcBase() - { - return thread[0]->getProxy(); - } + /** Changes a stage's status to active within the activity recorder. */ + void activateStage(const StageIdx idx) + { activityRec.activateStage(idx); } + + /** Changes a stage's status to inactive within the activity recorder. */ + void deactivateStage(const StageIdx idx) + { activityRec.deactivateStage(idx); } - CPUExecContext *cpuXCBase() + /** Wakes the CPU, rescheduling the CPU if it's not already active. */ + void wakeCPU(); + + /** Gets a free thread id. Use if thread ids change across system. */ + int getFreeTid(); + + public: + /** Returns a pointer to a thread context. */ + ThreadContext *tcBase(unsigned tid) { - return thread[0]; + return thread[tid]->getTC(); } + /** The global sequence number counter. */ InstSeqNum globalSeqNum; + /** Pointer to the checker, which can dynamically verify + * instruction results at run time. This can be set to NULL if it + * is not being used. + */ + Checker<DynInstPtr> *checker; + #if FULL_SYSTEM + /** Pointer to the system. */ System *system; - MemoryController *memCtrl; + /** Pointer to physical memory. */ PhysicalMemory *physmem; +#endif - AlphaITB *itb; - AlphaDTB *dtb; + /** Pointer to memory. */ + MemObject *mem; -// SWContext *swCtx; -#endif - std::vector<CPUExecContext *> thread; + /** Pointer to the sampler */ + Sampler *sampler; + + /** Counter of how many stages have completed switching out. */ + int switchCount; - FunctionalMemory *mem; + /** Pointers to all of the threads in the CPU. */ + std::vector<Thread *> thread; + /** Pointer to the icache interface. */ MemInterface *icacheInterface; + /** Pointer to the dcache interface. */ MemInterface *dcacheInterface; + /** Whether or not the CPU should defer its registration. */ bool deferRegistration; - Counter numInsts; - - Counter funcExeInst; + /** Is there a context switch pending? */ + bool contextSwitch; + + /** Threads Scheduled to Enter CPU */ + std::list<int> cpuWaitList; + + /** The cycle that the CPU was last running, used for statistics. */ + Tick lastRunningCycle; + + /** Number of Threads CPU can process */ + unsigned numThreads; + + /** Mapping for system thread id to cpu id */ + std::map<unsigned,unsigned> threadMap; + + /** Available thread ids in the cpu*/ + std::vector<unsigned> tids; + + /** Stat for total number of times the CPU is descheduled. */ + Stats::Scalar<> timesIdled; + /** Stat for total number of cycles the CPU spends descheduled. */ + Stats::Scalar<> idleCycles; + /** Stat for the number of committed instructions per thread. */ + Stats::Vector<> committedInsts; + /** Stat for the total number of committed instructions. */ + Stats::Scalar<> totalCommittedInsts; + /** Stat for the CPI per thread. */ + Stats::Formula cpi; + /** Stat for the total CPI. */ + Stats::Formula totalCpi; + /** Stat for the IPC per thread. */ + Stats::Formula ipc; + /** Stat for the total IPC. */ + Stats::Formula totalIpc; }; -#endif +#endif // __CPU_O3_CPU_HH__ diff --git a/src/cpu/o3/cpu_policy.hh b/src/cpu/o3/cpu_policy.hh index a90cdcde0..32a0adcf1 100644 --- a/src/cpu/o3/cpu_policy.hh +++ b/src/cpu/o3/cpu_policy.hh @@ -28,13 +28,14 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_CPU_POLICY_HH__ -#define __CPU_O3_CPU_CPU_POLICY_HH__ +#ifndef __CPU_O3_CPU_POLICY_HH__ +#define __CPU_O3_CPU_POLICY_HH__ #include "cpu/o3/bpred_unit.hh" #include "cpu/o3/free_list.hh" #include "cpu/o3/inst_queue.hh" -#include "cpu/o3/ldstq.hh" +#include "cpu/o3/lsq.hh" +#include "cpu/o3/lsq_unit.hh" #include "cpu/o3/mem_dep_unit.hh" #include "cpu/o3/regfile.hh" #include "cpu/o3/rename_map.hh" @@ -49,42 +50,70 @@ #include "cpu/o3/comm.hh" +/** + * Struct that defines the key classes to be used by the CPU. All + * classes use the typedefs defined here to determine what are the + * classes of the other stages and communication buffers. In order to + * change a structure such as the IQ, simply change the typedef here + * to use the desired class instead, and recompile. In order to + * create a different CPU to be used simultaneously with this one, see + * the alpha_impl.hh file for instructions. + */ template<class Impl> struct SimpleCPUPolicy { - typedef TwobitBPredUnit<Impl> BPredUnit; + /** Typedef for the branch prediction unit (which includes the BP, + * RAS, and BTB). + */ + typedef BPredUnit<Impl> BPredUnit; + /** Typedef for the register file. Most classes assume a unified + * physical register file. + */ typedef PhysRegFile<Impl> RegFile; + /** Typedef for the freelist of registers. */ typedef SimpleFreeList FreeList; + /** Typedef for the rename map. */ typedef SimpleRenameMap RenameMap; + /** Typedef for the ROB. */ typedef ROB<Impl> ROB; + /** Typedef for the instruction queue/scheduler. */ typedef InstructionQueue<Impl> IQ; + /** Typedef for the memory dependence unit. */ typedef MemDepUnit<StoreSet, Impl> MemDepUnit; - typedef LDSTQ<Impl> LDSTQ; + /** Typedef for the LSQ. */ + typedef LSQ<Impl> LSQ; + /** Typedef for the thread-specific LSQ units. */ + typedef LSQUnit<Impl> LSQUnit; - typedef SimpleFetch<Impl> Fetch; - typedef SimpleDecode<Impl> Decode; - typedef SimpleRename<Impl> Rename; - typedef SimpleIEW<Impl> IEW; - typedef SimpleCommit<Impl> Commit; + /** Typedef for fetch. */ + typedef DefaultFetch<Impl> Fetch; + /** Typedef for decode. */ + typedef DefaultDecode<Impl> Decode; + /** Typedef for rename. */ + typedef DefaultRename<Impl> Rename; + /** Typedef for Issue/Execute/Writeback. */ + typedef DefaultIEW<Impl> IEW; + /** Typedef for commit. */ + typedef DefaultCommit<Impl> Commit; /** The struct for communication between fetch and decode. */ - typedef SimpleFetchSimpleDecode<Impl> FetchStruct; + typedef DefaultFetchDefaultDecode<Impl> FetchStruct; /** The struct for communication between decode and rename. */ - typedef SimpleDecodeSimpleRename<Impl> DecodeStruct; + typedef DefaultDecodeDefaultRename<Impl> DecodeStruct; /** The struct for communication between rename and IEW. */ - typedef SimpleRenameSimpleIEW<Impl> RenameStruct; + typedef DefaultRenameDefaultIEW<Impl> RenameStruct; /** The struct for communication between IEW and commit. */ - typedef SimpleIEWSimpleCommit<Impl> IEWStruct; + typedef DefaultIEWDefaultCommit<Impl> IEWStruct; /** The struct for communication within the IEW stage. */ typedef IssueStruct<Impl> IssueStruct; /** The struct for all backwards communication. */ - typedef TimeBufStruct TimeStruct; + typedef TimeBufStruct<Impl> TimeStruct; }; -#endif //__CPU_O3_CPU_CPU_POLICY_HH__ +#endif //__CPU_O3_CPU_POLICY_HH__ diff --git a/src/cpu/o3/decode.cc b/src/cpu/o3/decode.cc index 8301e6655..4924f018a 100644 --- a/src/cpu/o3/decode.cc +++ b/src/cpu/o3/decode.cc @@ -32,4 +32,4 @@ #include "cpu/o3/alpha_impl.hh" #include "cpu/o3/decode_impl.hh" -template class SimpleDecode<AlphaSimpleImpl>; +template class DefaultDecode<AlphaSimpleImpl>; diff --git a/src/cpu/o3/decode.hh b/src/cpu/o3/decode.hh index 1bea47045..ff88358d6 100644 --- a/src/cpu/o3/decode.hh +++ b/src/cpu/o3/decode.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,16 +28,23 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_SIMPLE_DECODE_HH__ -#define __CPU_O3_CPU_SIMPLE_DECODE_HH__ +#ifndef __CPU_O3_DECODE_HH__ +#define __CPU_O3_DECODE_HH__ #include <queue> #include "base/statistics.hh" #include "base/timebuf.hh" +/** + * DefaultDecode class handles both single threaded and SMT + * decode. Its width is specified by the parameters; each cycles it + * tries to decode that many instructions. Because instructions are + * actually decoded when the StaticInst is created, this stage does + * not do much other than check any PC-relative branches. + */ template<class Impl> -class SimpleDecode +class DefaultDecode { private: // Typedefs from the Impl. @@ -52,49 +59,132 @@ class SimpleDecode typedef typename CPUPol::TimeStruct TimeStruct; public: - // The only time decode will become blocked is if dispatch becomes - // blocked, which means IQ or ROB is probably full. - enum Status { + /** Overall decode stage status. Used to determine if the CPU can + * deschedule itself due to a lack of activity. + */ + enum DecodeStatus { + Active, + Inactive + }; + + /** Individual thread status. */ + enum ThreadStatus { Running, Idle, + StartSquash, Squashing, Blocked, Unblocking }; private: - // May eventually need statuses on a per thread basis. - Status _status; + /** Decode status. */ + DecodeStatus _status; + + /** Per-thread status. */ + ThreadStatus decodeStatus[Impl::MaxThreads]; public: - SimpleDecode(Params ¶ms); + /** DefaultDecode constructor. */ + DefaultDecode(Params *params); + /** Returns the name of decode. */ + std::string name() const; + + /** Registers statistics. */ void regStats(); + /** Sets CPU pointer. */ void setCPU(FullCPU *cpu_ptr); + /** Sets the main backwards communication time buffer pointer. */ void setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr); + /** Sets pointer to time buffer used to communicate to the next stage. */ void setDecodeQueue(TimeBuffer<DecodeStruct> *dq_ptr); + /** Sets pointer to time buffer coming from fetch. */ void setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr); + /** Sets pointer to list of active threads. */ + void setActiveThreads(std::list<unsigned> *at_ptr); + + /** Switches out the decode stage. */ + void switchOut(); + + /** Takes over from another CPU's thread. */ + void takeOverFrom(); + + /** Ticks decode, processing all input signals and decoding as many + * instructions as possible. + */ void tick(); - void decode(); + /** Determines what to do based on decode's current status. + * @param status_change decode() sets this variable if there was a status + * change (ie switching from from blocking to unblocking). + * @param tid Thread id to decode instructions from. + */ + void decode(bool &status_change, unsigned tid); + + /** Processes instructions from fetch and passes them on to rename. + * Decoding of instructions actually happens when they are created in + * fetch, so this function mostly checks if PC-relative branches are + * correct. + */ + void decodeInsts(unsigned tid); private: + /** Inserts a thread's instructions into the skid buffer, to be decoded + * once decode unblocks. + */ + void skidInsert(unsigned tid); + + /** Returns if all of the skid buffers are empty. */ + bool skidsEmpty(); + + /** Updates overall decode status based on all of the threads' statuses. */ + void updateStatus(); + + /** Separates instructions from fetch into individual lists of instructions + * sorted by thread. + */ + void sortInsts(); + + /** Reads all stall signals from the backwards communication timebuffer. */ + void readStallSignals(unsigned tid); + + /** Checks all input signals and updates decode's status appropriately. */ + bool checkSignalsAndUpdate(unsigned tid); + + /** Checks all stall signals, and returns if any are true. */ + bool checkStall(unsigned tid) const; + + /** Returns if there any instructions from fetch on this cycle. */ inline bool fetchInstsValid(); - void block(); + /** Switches decode to blocking, and signals back that decode has + * become blocked. + * @return Returns true if there is a status change. + */ + bool block(unsigned tid); - inline void unblock(); + /** Switches decode to unblocking if the skid buffer is empty, and + * signals back that decode has unblocked. + * @return Returns true if there is a status change. + */ + bool unblock(unsigned tid); - void squash(DynInstPtr &inst); + /** Squashes if there is a PC-relative branch that was predicted + * incorrectly. Sends squash information back to fetch. + */ + void squash(DynInstPtr &inst, unsigned tid); public: - // Might want to make squash a friend function. - void squash(); + /** Squashes due to commit signalling a squash. Changes status to + * squashing and clears block/unblock signals as needed. + */ + unsigned squash(unsigned tid); private: // Interfaces to objects outside of decode. @@ -129,10 +219,27 @@ class SimpleDecode /** Wire to get fetch's output from fetch queue. */ typename TimeBuffer<FetchStruct>::wire fromFetch; + /** Queue of all instructions coming from fetch this cycle. */ + std::queue<DynInstPtr> insts[Impl::MaxThreads]; + /** Skid buffer between fetch and decode. */ - std::queue<FetchStruct> skidBuffer; + std::queue<DynInstPtr> skidBuffer[Impl::MaxThreads]; + + /** Variable that tracks if decode has written to the time buffer this + * cycle. Used to tell CPU if there is activity this cycle. + */ + bool wroteToTimeBuffer; + + /** Source of possible stalls. */ + struct Stalls { + bool rename; + bool iew; + bool commit; + }; + + /** Tracks which stages are telling decode to stall. */ + Stalls stalls[Impl::MaxThreads]; - //Consider making these unsigned to avoid any confusion. /** Rename to decode delay, in ticks. */ unsigned renameToDecodeDelay; @@ -148,20 +255,43 @@ class SimpleDecode /** The width of decode, in instructions. */ unsigned decodeWidth; - /** The instruction that decode is currently on. It needs to have - * persistent state so that when a stall occurs in the middle of a - * group of instructions, it can restart at the proper instruction. - */ - unsigned numInst; + /** Index of instructions being sent to rename. */ + unsigned toRenameIndex; + + /** number of Active Threads*/ + unsigned numThreads; + /** List of active thread ids */ + std::list<unsigned> *activeThreads; + + /** Number of branches in flight. */ + unsigned branchCount[Impl::MaxThreads]; + + /** Maximum size of the skid buffer. */ + unsigned skidBufferMax; + + /** Stat for total number of idle cycles. */ Stats::Scalar<> decodeIdleCycles; + /** Stat for total number of blocked cycles. */ Stats::Scalar<> decodeBlockedCycles; + /** Stat for total number of normal running cycles. */ + Stats::Scalar<> decodeRunCycles; + /** Stat for total number of unblocking cycles. */ Stats::Scalar<> decodeUnblockCycles; + /** Stat for total number of squashing cycles. */ Stats::Scalar<> decodeSquashCycles; + /** Stat for number of times a branch is resolved at decode. */ + Stats::Scalar<> decodeBranchResolved; + /** Stat for number of times a branch mispredict is detected. */ Stats::Scalar<> decodeBranchMispred; + /** Stat for number of times decode detected a non-control instruction + * incorrectly predicted as a branch. + */ Stats::Scalar<> decodeControlMispred; + /** Stat for total number of decoded instructions. */ Stats::Scalar<> decodeDecodedInsts; + /** Stat for total number of squashed instructions. */ Stats::Scalar<> decodeSquashedInsts; }; -#endif // __CPU_O3_CPU_SIMPLE_DECODE_HH__ +#endif // __CPU_O3_DECODE_HH__ diff --git a/src/cpu/o3/decode_impl.hh b/src/cpu/o3/decode_impl.hh index 7f0d98643..8a6ea6626 100644 --- a/src/cpu/o3/decode_impl.hh +++ b/src/cpu/o3/decode_impl.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -30,71 +30,99 @@ #include "cpu/o3/decode.hh" +using namespace std; + template<class Impl> -SimpleDecode<Impl>::SimpleDecode(Params ¶ms) - : renameToDecodeDelay(params.renameToDecodeDelay), - iewToDecodeDelay(params.iewToDecodeDelay), - commitToDecodeDelay(params.commitToDecodeDelay), - fetchToDecodeDelay(params.fetchToDecodeDelay), - decodeWidth(params.decodeWidth), - numInst(0) +DefaultDecode<Impl>::DefaultDecode(Params *params) + : renameToDecodeDelay(params->renameToDecodeDelay), + iewToDecodeDelay(params->iewToDecodeDelay), + commitToDecodeDelay(params->commitToDecodeDelay), + fetchToDecodeDelay(params->fetchToDecodeDelay), + decodeWidth(params->decodeWidth), + numThreads(params->numberOfThreads) { - DPRINTF(Decode, "Decode: decodeWidth=%i.\n", decodeWidth); - _status = Idle; + _status = Inactive; + + // Setup status, make sure stall signals are clear. + for (int i = 0; i < numThreads; ++i) { + decodeStatus[i] = Idle; + + stalls[i].rename = false; + stalls[i].iew = false; + stalls[i].commit = false; + } + + // @todo: Make into a parameter + skidBufferMax = (fetchToDecodeDelay * params->fetchWidth) + decodeWidth; +} + +template <class Impl> +std::string +DefaultDecode<Impl>::name() const +{ + return cpu->name() + ".decode"; } template <class Impl> void -SimpleDecode<Impl>::regStats() +DefaultDecode<Impl>::regStats() { decodeIdleCycles - .name(name() + ".decodeIdleCycles") + .name(name() + ".DECODE:IdleCycles") .desc("Number of cycles decode is idle") .prereq(decodeIdleCycles); decodeBlockedCycles - .name(name() + ".decodeBlockedCycles") + .name(name() + ".DECODE:BlockedCycles") .desc("Number of cycles decode is blocked") .prereq(decodeBlockedCycles); + decodeRunCycles + .name(name() + ".DECODE:RunCycles") + .desc("Number of cycles decode is running") + .prereq(decodeRunCycles); decodeUnblockCycles - .name(name() + ".decodeUnblockCycles") + .name(name() + ".DECODE:UnblockCycles") .desc("Number of cycles decode is unblocking") .prereq(decodeUnblockCycles); decodeSquashCycles - .name(name() + ".decodeSquashCycles") + .name(name() + ".DECODE:SquashCycles") .desc("Number of cycles decode is squashing") .prereq(decodeSquashCycles); + decodeBranchResolved + .name(name() + ".DECODE:BranchResolved") + .desc("Number of times decode resolved a branch") + .prereq(decodeBranchResolved); decodeBranchMispred - .name(name() + ".decodeBranchMispred") + .name(name() + ".DECODE:BranchMispred") .desc("Number of times decode detected a branch misprediction") .prereq(decodeBranchMispred); decodeControlMispred - .name(name() + ".decodeControlMispred") + .name(name() + ".DECODE:ControlMispred") .desc("Number of times decode detected an instruction incorrectly" " predicted as a control") .prereq(decodeControlMispred); decodeDecodedInsts - .name(name() + ".decodeDecodedInsts") + .name(name() + ".DECODE:DecodedInsts") .desc("Number of instructions handled by decode") .prereq(decodeDecodedInsts); decodeSquashedInsts - .name(name() + ".decodeSquashedInsts") + .name(name() + ".DECODE:SquashedInsts") .desc("Number of squashed instructions handled by decode") .prereq(decodeSquashedInsts); } template<class Impl> void -SimpleDecode<Impl>::setCPU(FullCPU *cpu_ptr) +DefaultDecode<Impl>::setCPU(FullCPU *cpu_ptr) { - DPRINTF(Decode, "Decode: Setting CPU pointer.\n"); + DPRINTF(Decode, "Setting CPU pointer.\n"); cpu = cpu_ptr; } template<class Impl> void -SimpleDecode<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) +DefaultDecode<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) { - DPRINTF(Decode, "Decode: Setting time buffer pointer.\n"); + DPRINTF(Decode, "Setting time buffer pointer.\n"); timeBuffer = tb_ptr; // Setup wire to write information back to fetch. @@ -108,9 +136,9 @@ SimpleDecode<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) template<class Impl> void -SimpleDecode<Impl>::setDecodeQueue(TimeBuffer<DecodeStruct> *dq_ptr) +DefaultDecode<Impl>::setDecodeQueue(TimeBuffer<DecodeStruct> *dq_ptr) { - DPRINTF(Decode, "Decode: Setting decode queue pointer.\n"); + DPRINTF(Decode, "Setting decode queue pointer.\n"); decodeQueue = dq_ptr; // Setup wire to write information to proper place in decode queue. @@ -119,9 +147,9 @@ SimpleDecode<Impl>::setDecodeQueue(TimeBuffer<DecodeStruct> *dq_ptr) template<class Impl> void -SimpleDecode<Impl>::setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr) +DefaultDecode<Impl>::setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr) { - DPRINTF(Decode, "Decode: Setting fetch queue pointer.\n"); + DPRINTF(Decode, "Setting fetch queue pointer.\n"); fetchQueue = fq_ptr; // Setup wire to read information from fetch queue. @@ -129,250 +157,541 @@ SimpleDecode<Impl>::setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr) } template<class Impl> +void +DefaultDecode<Impl>::setActiveThreads(list<unsigned> *at_ptr) +{ + DPRINTF(Decode, "Setting active threads list pointer.\n"); + activeThreads = at_ptr; +} + +template <class Impl> +void +DefaultDecode<Impl>::switchOut() +{ + // Decode can immediately switch out. + cpu->signalSwitched(); +} + +template <class Impl> +void +DefaultDecode<Impl>::takeOverFrom() +{ + _status = Inactive; + + // Be sure to reset state and clear out any old instructions. + for (int i = 0; i < numThreads; ++i) { + decodeStatus[i] = Idle; + + stalls[i].rename = false; + stalls[i].iew = false; + stalls[i].commit = false; + while (!insts[i].empty()) + insts[i].pop(); + while (!skidBuffer[i].empty()) + skidBuffer[i].pop(); + branchCount[i] = 0; + } + wroteToTimeBuffer = false; +} + +template<class Impl> +bool +DefaultDecode<Impl>::checkStall(unsigned tid) const +{ + bool ret_val = false; + + if (stalls[tid].rename) { + DPRINTF(Decode,"[tid:%i]: Stall fom Rename stage detected.\n", tid); + ret_val = true; + } else if (stalls[tid].iew) { + DPRINTF(Decode,"[tid:%i]: Stall fom IEW stage detected.\n", tid); + ret_val = true; + } else if (stalls[tid].commit) { + DPRINTF(Decode,"[tid:%i]: Stall fom Commit stage detected.\n", tid); + ret_val = true; + } + + return ret_val; +} + +template<class Impl> inline bool -SimpleDecode<Impl>::fetchInstsValid() +DefaultDecode<Impl>::fetchInstsValid() { return fromFetch->size > 0; } template<class Impl> -void -SimpleDecode<Impl>::block() +bool +DefaultDecode<Impl>::block(unsigned tid) { - DPRINTF(Decode, "Decode: Blocking.\n"); - - // Set the status to Blocked. - _status = Blocked; + DPRINTF(Decode, "[tid:%u]: Blocking.\n", tid); // Add the current inputs to the skid buffer so they can be // reprocessed when this stage unblocks. - skidBuffer.push(*fromFetch); + skidInsert(tid); + + // If the decode status is blocked or unblocking then decode has not yet + // signalled fetch to unblock. In that case, there is no need to tell + // fetch to block. + if (decodeStatus[tid] != Blocked) { + // Set the status to Blocked. + decodeStatus[tid] = Blocked; + + if (decodeStatus[tid] != Unblocking) { + toFetch->decodeBlock[tid] = true; + wroteToTimeBuffer = true; + } + + return true; + } - // Note that this stage only signals previous stages to stall when - // it is the cause of the stall originates at this stage. Otherwise - // the previous stages are expected to check all possible stall signals. + return false; } template<class Impl> -inline void -SimpleDecode<Impl>::unblock() +bool +DefaultDecode<Impl>::unblock(unsigned tid) { - DPRINTF(Decode, "Decode: Unblocking, going to remove " - "instructions from skid buffer.\n"); - // Remove the now processed instructions from the skid buffer. - skidBuffer.pop(); - - // If there's still information in the skid buffer, then - // continue to tell previous stages to stall. They will be - // able to restart once the skid buffer is empty. - if (!skidBuffer.empty()) { - toFetch->decodeInfo.stall = true; - } else { - DPRINTF(Decode, "Decode: Finished unblocking.\n"); - _status = Running; + // Decode is done unblocking only if the skid buffer is empty. + if (skidBuffer[tid].empty()) { + DPRINTF(Decode, "[tid:%u]: Done unblocking.\n", tid); + toFetch->decodeUnblock[tid] = true; + wroteToTimeBuffer = true; + + decodeStatus[tid] = Running; + return true; } + + DPRINTF(Decode, "[tid:%u]: Currently unblocking.\n", tid); + + return false; } -// This squash is specifically for when Decode detects a PC-relative branch -// was predicted incorrectly. template<class Impl> void -SimpleDecode<Impl>::squash(DynInstPtr &inst) +DefaultDecode<Impl>::squash(DynInstPtr &inst, unsigned tid) { - DPRINTF(Decode, "Decode: Squashing due to incorrect branch prediction " - "detected at decode.\n"); - Addr new_PC = inst->readNextPC(); - - toFetch->decodeInfo.branchMispredict = true; - toFetch->decodeInfo.doneSeqNum = inst->seqNum; - toFetch->decodeInfo.predIncorrect = true; - toFetch->decodeInfo.squash = true; - toFetch->decodeInfo.nextPC = new_PC; - toFetch->decodeInfo.branchTaken = true; + DPRINTF(Decode, "[tid:%i]: Squashing due to incorrect branch prediction " + "detected at decode.\n", tid); + + // Send back mispredict information. + toFetch->decodeInfo[tid].branchMispredict = true; + toFetch->decodeInfo[tid].doneSeqNum = inst->seqNum; + toFetch->decodeInfo[tid].predIncorrect = true; + toFetch->decodeInfo[tid].squash = true; + toFetch->decodeInfo[tid].nextPC = inst->branchTarget(); + toFetch->decodeInfo[tid].branchTaken = + inst->readNextPC() != (inst->readPC() + sizeof(TheISA::MachInst)); + + // Might have to tell fetch to unblock. + if (decodeStatus[tid] == Blocked || + decodeStatus[tid] == Unblocking) { + toFetch->decodeUnblock[tid] = 1; + } // Set status to squashing. - _status = Squashing; + decodeStatus[tid] = Squashing; + + for (int i=0; i<fromFetch->size; i++) { + if (fromFetch->insts[i]->threadNumber == tid && + fromFetch->insts[i]->seqNum > inst->seqNum) { + fromFetch->insts[i]->squashed = true; + } + } - // Clear the skid buffer in case it has any data in it. - while (!skidBuffer.empty()) { - skidBuffer.pop(); + // Clear the instruction list and skid buffer in case they have any + // insts in them. + while (!insts[tid].empty()) { + insts[tid].pop(); + } + + while (!skidBuffer[tid].empty()) { + skidBuffer[tid].pop(); } // Squash instructions up until this one - // Slightly unrealistic! - cpu->removeInstsUntil(inst->seqNum); + cpu->removeInstsUntil(inst->seqNum, tid); } template<class Impl> -void -SimpleDecode<Impl>::squash() +unsigned +DefaultDecode<Impl>::squash(unsigned tid) { - DPRINTF(Decode, "Decode: Squashing.\n"); + DPRINTF(Decode, "[tid:%i]: Squashing.\n",tid); + + if (decodeStatus[tid] == Blocked || + decodeStatus[tid] == Unblocking) { +#if !FULL_SYSTEM + // In syscall emulation, we can have both a block and a squash due + // to a syscall in the same cycle. This would cause both signals to + // be high. This shouldn't happen in full system. + // @todo: Determine if this still happens. + if (toFetch->decodeBlock[tid]) { + toFetch->decodeBlock[tid] = 0; + } else { + toFetch->decodeUnblock[tid] = 1; + } +#else + toFetch->decodeUnblock[tid] = 1; +#endif + } + // Set status to squashing. - _status = Squashing; + decodeStatus[tid] = Squashing; - // Maybe advance the time buffer? Not sure what to do in the normal - // case. + // Go through incoming instructions from fetch and squash them. + unsigned squash_count = 0; + + for (int i=0; i<fromFetch->size; i++) { + if (fromFetch->insts[i]->threadNumber == tid) { + fromFetch->insts[i]->squashed = true; + squash_count++; + } + } + + // Clear the instruction list and skid buffer in case they have any + // insts in them. + while (!insts[tid].empty()) { + insts[tid].pop(); + } - // Clear the skid buffer in case it has any data in it. - while (!skidBuffer.empty()) - { - skidBuffer.pop(); + while (!skidBuffer[tid].empty()) { + skidBuffer[tid].pop(); } + + return squash_count; } template<class Impl> void -SimpleDecode<Impl>::tick() +DefaultDecode<Impl>::skidInsert(unsigned tid) { - // Decode should try to execute as many instructions as its bandwidth - // will allow, as long as it is not currently blocked. - if (_status != Blocked && _status != Squashing) { - DPRINTF(Decode, "Decode: Not blocked, so attempting to run " - "stage.\n"); - // Make sure that the skid buffer has something in it if the - // status is unblocking. - assert(_status == Unblocking ? !skidBuffer.empty() : 1); + DynInstPtr inst = NULL; - decode(); + while (!insts[tid].empty()) { + inst = insts[tid].front(); - // If the status was unblocking, then instructions from the skid - // buffer were used. Remove those instructions and handle - // the rest of unblocking. - if (_status == Unblocking) { - ++decodeUnblockCycles; + insts[tid].pop(); - if (fetchInstsValid()) { - // Add the current inputs to the skid buffer so they can be - // reprocessed when this stage unblocks. - skidBuffer.push(*fromFetch); - } + assert(tid == inst->threadNumber); - unblock(); - } - } else if (_status == Blocked) { - ++decodeBlockedCycles; + DPRINTF(Decode,"Inserting [sn:%lli] PC:%#x into decode skidBuffer %i\n", + inst->seqNum, inst->readPC(), inst->threadNumber); - if (fetchInstsValid()) { - block(); - } + skidBuffer[tid].push(inst); + } - if (!fromRename->renameInfo.stall && - !fromIEW->iewInfo.stall && - !fromCommit->commitInfo.stall) { - DPRINTF(Decode, "Decode: Stall signals cleared, going to " - "unblock.\n"); - _status = Unblocking; + // @todo: Eventually need to enforce this by not letting a thread + // fetch past its skidbuffer + assert(skidBuffer[tid].size() <= skidBufferMax); +} - // Continue to tell previous stage to block until this - // stage is done unblocking. - toFetch->decodeInfo.stall = true; - } else { - DPRINTF(Decode, "Decode: Still blocked.\n"); - toFetch->decodeInfo.stall = true; +template<class Impl> +bool +DefaultDecode<Impl>::skidsEmpty() +{ + list<unsigned>::iterator threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + if (!skidBuffer[*threads++].empty()) + return false; + } + + return true; +} + +template<class Impl> +void +DefaultDecode<Impl>::updateStatus() +{ + bool any_unblocking = false; + + list<unsigned>::iterator threads = (*activeThreads).begin(); + + threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + if (decodeStatus[tid] == Unblocking) { + any_unblocking = true; + break; } + } + + // Decode will have activity if it's unblocking. + if (any_unblocking) { + if (_status == Inactive) { + _status = Active; + + DPRINTF(Activity, "Activating stage.\n"); - if (fromCommit->commitInfo.squash || - fromCommit->commitInfo.robSquashing) { - squash(); + cpu->activateStage(FullCPU::DecodeIdx); } - } else if (_status == Squashing) { - if (!fromCommit->commitInfo.squash && - !fromCommit->commitInfo.robSquashing) { - _status = Running; - } else if (fromCommit->commitInfo.squash) { - ++decodeSquashCycles; - - squash(); + } else { + // If it's not unblocking, then decode will not have any internal + // activity. Switch it to inactive. + if (_status == Active) { + _status = Inactive; + DPRINTF(Activity, "Deactivating stage.\n"); + + cpu->deactivateStage(FullCPU::DecodeIdx); } } } +template <class Impl> +void +DefaultDecode<Impl>::sortInsts() +{ + int insts_from_fetch = fromFetch->size; +#ifdef DEBUG + for (int i=0; i < numThreads; i++) + assert(insts[i].empty()); +#endif + for (int i = 0; i < insts_from_fetch; ++i) { + insts[fromFetch->insts[i]->threadNumber].push(fromFetch->insts[i]); + } +} + template<class Impl> void -SimpleDecode<Impl>::decode() +DefaultDecode<Impl>::readStallSignals(unsigned tid) { - // Check time buffer if being told to squash. - if (fromCommit->commitInfo.squash) { - squash(); - return; + if (fromRename->renameBlock[tid]) { + stalls[tid].rename = true; } - // Check time buffer if being told to stall. - if (fromRename->renameInfo.stall || - fromIEW->iewInfo.stall || - fromCommit->commitInfo.stall) { - block(); - return; + if (fromRename->renameUnblock[tid]) { + assert(stalls[tid].rename); + stalls[tid].rename = false; + } + + if (fromIEW->iewBlock[tid]) { + stalls[tid].iew = true; + } + + if (fromIEW->iewUnblock[tid]) { + assert(stalls[tid].iew); + stalls[tid].iew = false; + } + + if (fromCommit->commitBlock[tid]) { + stalls[tid].commit = true; + } + + if (fromCommit->commitUnblock[tid]) { + assert(stalls[tid].commit); + stalls[tid].commit = false; + } +} + +template <class Impl> +bool +DefaultDecode<Impl>::checkSignalsAndUpdate(unsigned tid) +{ + // Check if there's a squash signal, squash if there is. + // Check stall signals, block if necessary. + // If status was blocked + // Check if stall conditions have passed + // if so then go to unblocking + // If status was Squashing + // check if squashing is not high. Switch to running this cycle. + + // Update the per thread stall statuses. + readStallSignals(tid); + + // Check squash signals from commit. + if (fromCommit->commitInfo[tid].squash) { + + DPRINTF(Decode, "[tid:%u]: Squashing instructions due to squash " + "from commit.\n", tid); + + squash(tid); + + return true; + } + + // Check ROB squash signals from commit. + if (fromCommit->commitInfo[tid].robSquashing) { + DPRINTF(Decode, "[tid:%]: ROB is still squashing.\n",tid); + + // Continue to squash. + decodeStatus[tid] = Squashing; + + return true; + } + + if (checkStall(tid)) { + return block(tid); } - // Check fetch queue to see if instructions are available. - // If no available instructions, do nothing, unless this stage is - // currently unblocking. - if (!fetchInstsValid() && _status != Unblocking) { - DPRINTF(Decode, "Decode: Nothing to do, breaking out early.\n"); + if (decodeStatus[tid] == Blocked) { + DPRINTF(Decode, "[tid:%u]: Done blocking, switching to unblocking.\n", + tid); + + decodeStatus[tid] = Unblocking; + + unblock(tid); + + return true; + } + + if (decodeStatus[tid] == Squashing) { + // Switch status to running if decode isn't being told to block or + // squash this cycle. + DPRINTF(Decode, "[tid:%u]: Done squashing, switching to running.\n", + tid); + + decodeStatus[tid] = Running; + + return false; + } + + // If we've reached this point, we have not gotten any signals that + // cause decode to change its status. Decode remains the same as before. + return false; +} + +template<class Impl> +void +DefaultDecode<Impl>::tick() +{ + wroteToTimeBuffer = false; + + bool status_change = false; + + toRenameIndex = 0; + + list<unsigned>::iterator threads = (*activeThreads).begin(); + + sortInsts(); + + //Check stall and squash signals. + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + DPRINTF(Decode,"Processing [tid:%i]\n",tid); + status_change = checkSignalsAndUpdate(tid) || status_change; + + decode(status_change, tid); + } + + if (status_change) { + updateStatus(); + } + + if (wroteToTimeBuffer) { + DPRINTF(Activity, "Activity this cycle.\n"); + + cpu->activityThisCycle(); + } +} + +template<class Impl> +void +DefaultDecode<Impl>::decode(bool &status_change, unsigned tid) +{ + // If status is Running or idle, + // call decodeInsts() + // If status is Unblocking, + // buffer any instructions coming from fetch + // continue trying to empty skid buffer + // check if stall conditions have passed + + if (decodeStatus[tid] == Blocked) { + ++decodeBlockedCycles; + } else if (decodeStatus[tid] == Squashing) { + ++decodeSquashCycles; + } + + // Decode should try to decode as many instructions as its bandwidth + // will allow, as long as it is not currently blocked. + if (decodeStatus[tid] == Running || + decodeStatus[tid] == Idle) { + DPRINTF(Decode, "[tid:%u] Not blocked, so attempting to run " + "stage.\n",tid); + + decodeInsts(tid); + } else if (decodeStatus[tid] == Unblocking) { + // Make sure that the skid buffer has something in it if the + // status is unblocking. + assert(!skidsEmpty()); + + // If the status was unblocking, then instructions from the skid + // buffer were used. Remove those instructions and handle + // the rest of unblocking. + decodeInsts(tid); + + if (fetchInstsValid()) { + // Add the current inputs to the skid buffer so they can be + // reprocessed when this stage unblocks. + skidInsert(tid); + } + + status_change = unblock(tid) || status_change; + } +} + +template <class Impl> +void +DefaultDecode<Impl>::decodeInsts(unsigned tid) +{ + // Instructions can come either from the skid buffer or the list of + // instructions coming from fetch, depending on decode's status. + int insts_available = decodeStatus[tid] == Unblocking ? + skidBuffer[tid].size() : insts[tid].size(); + + if (insts_available == 0) { + DPRINTF(Decode, "[tid:%u] Nothing to do, breaking out" + " early.\n",tid); // Should I change the status to idle? ++decodeIdleCycles; return; + } else if (decodeStatus[tid] == Unblocking) { + DPRINTF(Decode, "[tid:%u] Unblocking, removing insts from skid " + "buffer.\n",tid); + ++decodeUnblockCycles; + } else if (decodeStatus[tid] == Running) { + ++decodeRunCycles; } - // Might be better to use a base DynInst * instead? DynInstPtr inst; - unsigned to_rename_index = 0; + std::queue<DynInstPtr> + &insts_to_decode = decodeStatus[tid] == Unblocking ? + skidBuffer[tid] : insts[tid]; - int insts_available = _status == Unblocking ? - skidBuffer.front().size - numInst : - fromFetch->size; + DPRINTF(Decode, "[tid:%u]: Sending instruction to rename.\n",tid); - // Debug block... -#if 0 - if (insts_available) { - DPRINTF(Decode, "Decode: Instructions available.\n"); - } else { - if (_status == Unblocking && skidBuffer.empty()) { - DPRINTF(Decode, "Decode: No instructions available, skid buffer " - "empty.\n"); - } else if (_status != Unblocking && - !fromFetch->insts[0]) { - DPRINTF(Decode, "Decode: No instructions available, fetch queue " - "empty.\n"); - } else { - panic("Decode: No instructions available, unexpected condition!" - "\n"); - } - } -#endif + while (insts_available > 0 && toRenameIndex < decodeWidth) { + assert(!insts_to_decode.empty()); - while (insts_available > 0) - { - DPRINTF(Decode, "Decode: Sending instruction to rename.\n"); + inst = insts_to_decode.front(); - inst = _status == Unblocking ? skidBuffer.front().insts[numInst] : - fromFetch->insts[numInst]; + insts_to_decode.pop(); - DPRINTF(Decode, "Decode: Processing instruction %i with PC %#x\n", - inst->seqNum, inst->readPC()); + DPRINTF(Decode, "[tid:%u]: Processing instruction [sn:%lli] with " + "PC %#x\n", + tid, inst->seqNum, inst->readPC()); if (inst->isSquashed()) { - DPRINTF(Decode, "Decode: Instruction %i with PC %#x is " + DPRINTF(Decode, "[tid:%u]: Instruction %i with PC %#x is " "squashed, skipping.\n", - inst->seqNum, inst->readPC()); + tid, inst->seqNum, inst->readPC()); ++decodeSquashedInsts; - ++numInst; --insts_available; continue; } - // Also check if instructions have no source registers. Mark // them as ready to issue at any time. Not sure if this check // should exist here or at a later stage; however it doesn't matter // too much for function correctness. - // Isn't this handled by the inst queue? if (inst->numSrcRegs() == 0) { inst->setCanIssue(); } @@ -380,9 +699,12 @@ SimpleDecode<Impl>::decode() // This current instruction is valid, so add it into the decode // queue. The next instruction may not be valid, so check to // see if branches were predicted correctly. - toRename->insts[to_rename_index] = inst; + toRename->insts[toRenameIndex] = inst; ++(toRename->size); + ++toRenameIndex; + ++decodeDecodedInsts; + --insts_available; // Ensure that if it was predicted as a branch, it really is a // branch. @@ -390,38 +712,40 @@ SimpleDecode<Impl>::decode() panic("Instruction predicted as a branch!"); ++decodeControlMispred; + // Might want to set some sort of boolean and just do // a check at the end - squash(inst); + squash(inst, inst->threadNumber); + break; } // Go ahead and compute any PC-relative branches. - if (inst->isDirectCtrl() && inst->isUncondCtrl()) { + ++decodeBranchResolved; - inst->setNextPC(inst->branchTarget()); - - if (inst->mispredicted()) { + if (inst->branchTarget() != inst->readPredTarg()) { ++decodeBranchMispred; + // Might want to set some sort of boolean and just do // a check at the end - squash(inst); + squash(inst, inst->threadNumber); + inst->setPredTarg(inst->branchTarget()); + break; } } + } - // Normally can check if a direct branch has the right target - // addr (either the immediate, or the branch PC + 4) and redirect - // fetch if it's incorrect. - - // Increment which instruction we're looking at. - ++numInst; - ++to_rename_index; - ++decodeDecodedInsts; - - --insts_available; + // If we didn't process all instructions, then we will need to block + // and put all those instructions into the skid buffer. + if (!insts_to_decode.empty()) { + block(tid); } - numInst = 0; + // Record that decode has written to the time buffer for activity + // tracking. + if (toRenameIndex) { + wroteToTimeBuffer = true; + } } diff --git a/src/cpu/o3/dep_graph.hh b/src/cpu/o3/dep_graph.hh new file mode 100644 index 000000000..3659b1a37 --- /dev/null +++ b/src/cpu/o3/dep_graph.hh @@ -0,0 +1,264 @@ +/* + * Copyright (c) 2006 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Kevin Lim + */ + +#ifndef __CPU_O3_DEP_GRAPH_HH__ +#define __CPU_O3_DEP_GRAPH_HH__ + +#include "cpu/o3/comm.hh" + +/** Node in a linked list. */ +template <class DynInstPtr> +class DependencyEntry +{ + public: + DependencyEntry() + : inst(NULL), next(NULL) + { } + + DynInstPtr inst; + //Might want to include data about what arch. register the + //dependence is waiting on. + DependencyEntry<DynInstPtr> *next; +}; + +/** Array of linked list that maintains the dependencies between + * producing instructions and consuming instructions. Each linked + * list represents a single physical register, having the future + * producer of the register's value, and all consumers waiting on that + * value on the list. The head node of each linked list represents + * the producing instruction of that register. Instructions are put + * on the list upon reaching the IQ, and are removed from the list + * either when the producer completes, or the instruction is squashed. +*/ +template <class DynInstPtr> +class DependencyGraph +{ + public: + typedef DependencyEntry<DynInstPtr> DepEntry; + + /** Default construction. Must call resize() prior to use. */ + DependencyGraph() + : numEntries(0), memAllocCounter(0), nodesTraversed(0), nodesRemoved(0) + { } + + /** Resize the dependency graph to have num_entries registers. */ + void resize(int num_entries); + + /** Clears all of the linked lists. */ + void reset(); + + /** Inserts an instruction to be dependent on the given index. */ + void insert(PhysRegIndex idx, DynInstPtr &new_inst); + + /** Sets the producing instruction of a given register. */ + void setInst(PhysRegIndex idx, DynInstPtr &new_inst) + { dependGraph[idx].inst = new_inst; } + + /** Clears the producing instruction. */ + void clearInst(PhysRegIndex idx) + { dependGraph[idx].inst = NULL; } + + /** Removes an instruction from a single linked list. */ + void remove(PhysRegIndex idx, DynInstPtr &inst_to_remove); + + /** Removes and returns the newest dependent of a specific register. */ + DynInstPtr pop(PhysRegIndex idx); + + /** Checks if there are any dependents on a specific register. */ + bool empty(PhysRegIndex idx) { return !dependGraph[idx].next; } + + /** Debugging function to dump out the dependency graph. + */ + void dump(); + + private: + /** Array of linked lists. Each linked list is a list of all the + * instructions that depend upon a given register. The actual + * register's index is used to index into the graph; ie all + * instructions in flight that are dependent upon r34 will be + * in the linked list of dependGraph[34]. + */ + DepEntry *dependGraph; + + /** Number of linked lists; identical to the number of registers. */ + int numEntries; + + // Debug variable, remove when done testing. + unsigned memAllocCounter; + + public: + // Debug variable, remove when done testing. + uint64_t nodesTraversed; + // Debug variable, remove when done testing. + uint64_t nodesRemoved; +}; + +template <class DynInstPtr> +void +DependencyGraph<DynInstPtr>::resize(int num_entries) +{ + numEntries = num_entries; + dependGraph = new DepEntry[numEntries]; +} + +template <class DynInstPtr> +void +DependencyGraph<DynInstPtr>::reset() +{ + // Clear the dependency graph + DepEntry *curr; + DepEntry *prev; + + for (int i = 0; i < numEntries; ++i) { + curr = dependGraph[i].next; + + while (curr) { + memAllocCounter--; + + prev = curr; + curr = prev->next; + prev->inst = NULL; + + delete prev; + } + + if (dependGraph[i].inst) { + dependGraph[i].inst = NULL; + } + + dependGraph[i].next = NULL; + } +} + +template <class DynInstPtr> +void +DependencyGraph<DynInstPtr>::insert(PhysRegIndex idx, DynInstPtr &new_inst) +{ + //Add this new, dependent instruction at the head of the dependency + //chain. + + // First create the entry that will be added to the head of the + // dependency chain. + DepEntry *new_entry = new DepEntry; + new_entry->next = dependGraph[idx].next; + new_entry->inst = new_inst; + + // Then actually add it to the chain. + dependGraph[idx].next = new_entry; + + ++memAllocCounter; +} + + +template <class DynInstPtr> +void +DependencyGraph<DynInstPtr>::remove(PhysRegIndex idx, + DynInstPtr &inst_to_remove) +{ + DepEntry *prev = &dependGraph[idx]; + DepEntry *curr = dependGraph[idx].next; + + // Make sure curr isn't NULL. Because this instruction is being + // removed from a dependency list, it must have been placed there at + // an earlier time. The dependency chain should not be empty, + // unless the instruction dependent upon it is already ready. + if (curr == NULL) { + return; + } + + nodesRemoved++; + + // Find the instruction to remove within the dependency linked list. + while (curr->inst != inst_to_remove) { + prev = curr; + curr = curr->next; + nodesTraversed++; + + assert(curr != NULL); + } + + // Now remove this instruction from the list. + prev->next = curr->next; + + --memAllocCounter; + + // Could push this off to the destructor of DependencyEntry + curr->inst = NULL; + + delete curr; +} + +template <class DynInstPtr> +DynInstPtr +DependencyGraph<DynInstPtr>::pop(PhysRegIndex idx) +{ + DepEntry *node; + node = dependGraph[idx].next; + DynInstPtr inst = NULL; + if (node) { + inst = node->inst; + dependGraph[idx].next = node->next; + node->inst = NULL; + memAllocCounter--; + delete node; + } + return inst; +} + +template <class DynInstPtr> +void +DependencyGraph<DynInstPtr>::dump() +{ + DepEntry *curr; + + for (int i = 0; i < numEntries; ++i) + { + curr = &dependGraph[i]; + + if (curr->inst) { + cprintf("dependGraph[%i]: producer: %#x [sn:%lli] consumer: ", + i, curr->inst->readPC(), curr->inst->seqNum); + } else { + cprintf("dependGraph[%i]: No producer. consumer: ", i); + } + + while (curr->next != NULL) { + curr = curr->next; + + cprintf("%#x [sn:%lli] ", + curr->inst->readPC(), curr->inst->seqNum); + } + + cprintf("\n"); + } + cprintf("memAllocCounter: %i\n", memAllocCounter); +} + +#endif // __CPU_O3_DEP_GRAPH_HH__ diff --git a/src/cpu/o3/fetch.cc b/src/cpu/o3/fetch.cc index ea7cd2811..5f52d0fca 100644 --- a/src/cpu/o3/fetch.cc +++ b/src/cpu/o3/fetch.cc @@ -32,4 +32,4 @@ #include "cpu/o3/alpha_impl.hh" #include "cpu/o3/fetch_impl.hh" -template class SimpleFetch<AlphaSimpleImpl>; +template class DefaultFetch<AlphaSimpleImpl>; diff --git a/src/cpu/o3/fetch.hh b/src/cpu/o3/fetch.hh index dd4a52d07..76b32de68 100644 --- a/src/cpu/o3/fetch.hh +++ b/src/cpu/o3/fetch.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,26 +28,29 @@ * Authors: Kevin Lim */ -// Todo: SMT fetch, -// Add a way to get a stage's current status. - -#ifndef __CPU_O3_CPU_SIMPLE_FETCH_HH__ -#define __CPU_O3_CPU_SIMPLE_FETCH_HH__ +#ifndef __CPU_O3_FETCH_HH__ +#define __CPU_O3_FETCH_HH__ +#include "arch/utility.hh" #include "base/statistics.hh" #include "base/timebuf.hh" #include "cpu/pc_event.hh" -#include "mem/mem_interface.hh" +#include "mem/packet.hh" +#include "mem/port.hh" #include "sim/eventq.hh" +class Sampler; + /** - * SimpleFetch class to fetch a single instruction each cycle. SimpleFetch - * will stall if there's an Icache miss, but otherwise assumes a one cycle - * Icache hit. + * DefaultFetch class handles both single threaded and SMT fetch. Its + * width is specified by the parameters; each cycle it tries to fetch + * that many instructions. It supports using a branch predictor to + * predict direction and targets. + * It supports the idling functionality of the CPU by indicating to + * the CPU when it is active and inactive. */ - template <class Impl> -class SimpleFetch +class DefaultFetch { public: /** Typedefs from Impl. */ @@ -57,56 +60,153 @@ class SimpleFetch typedef typename Impl::FullCPU FullCPU; typedef typename Impl::Params Params; + /** Typedefs from the CPU policy. */ typedef typename CPUPol::BPredUnit BPredUnit; typedef typename CPUPol::FetchStruct FetchStruct; typedef typename CPUPol::TimeStruct TimeStruct; /** Typedefs from ISA. */ typedef TheISA::MachInst MachInst; + typedef TheISA::ExtMachInst ExtMachInst; + + /** IcachePort class for DefaultFetch. Handles doing the + * communication with the cache/memory. + */ + class IcachePort : public Port + { + protected: + /** Pointer to fetch. */ + DefaultFetch<Impl> *fetch; + + public: + /** Default constructor. */ + IcachePort(DefaultFetch<Impl> *_fetch) + : Port(_fetch->name() + "-iport"), fetch(_fetch) + { } + + protected: + /** Atomic version of receive. Panics. */ + virtual Tick recvAtomic(PacketPtr pkt); + + /** Functional version of receive. Panics. */ + virtual void recvFunctional(PacketPtr pkt); + + /** Receives status change. Other than range changing, panics. */ + virtual void recvStatusChange(Status status); + + /** Returns the address ranges of this device. */ + virtual void getDeviceAddressRanges(AddrRangeList &resp, + AddrRangeList &snoop) + { resp.clear(); snoop.clear(); } + + /** Timing version of receive. Handles setting fetch to the + * proper status to start fetching. */ + virtual bool recvTiming(PacketPtr pkt); + + /** Handles doing a retry of a failed fetch. */ + virtual void recvRetry(); + }; public: - enum Status { + /** Overall fetch status. Used to determine if the CPU can + * deschedule itsef due to a lack of activity. + */ + enum FetchStatus { + Active, + Inactive + }; + + /** Individual thread status. */ + enum ThreadStatus { Running, Idle, Squashing, Blocked, - IcacheMissStall, - IcacheMissComplete + Fetching, + TrapPending, + QuiescePending, + SwitchOut, + IcacheWaitResponse, + IcacheWaitRetry, + IcacheAccessComplete }; - // May eventually need statuses on a per thread basis. - Status _status; + /** Fetching Policy, Add new policies here.*/ + enum FetchPriority { + SingleThread, + RoundRobin, + Branch, + IQ, + LSQ + }; - bool stalled; + private: + /** Fetch status. */ + FetchStatus _status; - public: - class CacheCompletionEvent : public Event - { - private: - SimpleFetch *fetch; + /** Per-thread status. */ + ThreadStatus fetchStatus[Impl::MaxThreads]; - public: - CacheCompletionEvent(SimpleFetch *_fetch); + /** Fetch policy. */ + FetchPriority fetchPolicy; - virtual void process(); - virtual const char *description(); - }; + /** List that has the threads organized by priority. */ + std::list<unsigned> priorityList; public: - /** SimpleFetch constructor. */ - SimpleFetch(Params ¶ms); + /** DefaultFetch constructor. */ + DefaultFetch(Params *params); + /** Returns the name of fetch. */ + std::string name() const; + + /** Registers statistics. */ void regStats(); + /** Sets CPU pointer. */ void setCPU(FullCPU *cpu_ptr); + /** Sets the main backwards communication time buffer pointer. */ void setTimeBuffer(TimeBuffer<TimeStruct> *time_buffer); + /** Sets pointer to list of active threads. */ + void setActiveThreads(std::list<unsigned> *at_ptr); + + /** Sets pointer to time buffer used to communicate to the next stage. */ void setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr); - void processCacheCompletion(); + /** Initialize stage. */ + void initStage(); + + /** Processes cache completion event. */ + void processCacheCompletion(PacketPtr pkt); + + /** Begins the switch out of the fetch stage. */ + void switchOut(); + + /** Completes the switch out of the fetch stage. */ + void doSwitchOut(); + + /** Takes over from another CPU's thread. */ + void takeOverFrom(); + + /** Checks if the fetch stage is switched out. */ + bool isSwitchedOut() { return switchedOut; } + + /** Tells fetch to wake up from a quiesce instruction. */ + void wakeFromQuiesce(); private: + /** Changes the status of this stage to active, and indicates this + * to the CPU. + */ + inline void switchToActive(); + + /** Changes the status of this stage to inactive, and indicates + * this to the CPU. + */ + inline void switchToInactive(); + /** * Looks up in the branch predictor to see if the next PC should be * either next PC+=MachInst or a branch target. @@ -122,24 +222,54 @@ class SimpleFetch * fault that happened. Puts the data into the class variable * cacheData. * @param fetch_PC The PC address that is being fetched from. + * @param ret_fault The fault reference that will be set to the result of + * the icache access. + * @param tid Thread id. * @return Any fault that occured. */ - Fault fetchCacheLine(Addr fetch_PC); + bool fetchCacheLine(Addr fetch_PC, Fault &ret_fault, unsigned tid); - inline void doSquash(const Addr &new_PC); + /** Squashes a specific thread and resets the PC. */ + inline void doSquash(const Addr &new_PC, unsigned tid); - void squashFromDecode(const Addr &new_PC, const InstSeqNum &seq_num); + /** Squashes a specific thread and resets the PC. Also tells the CPU to + * remove any instructions between fetch and decode that should be sqaushed. + */ + void squashFromDecode(const Addr &new_PC, const InstSeqNum &seq_num, + unsigned tid); + + /** Checks if a thread is stalled. */ + bool checkStall(unsigned tid) const; + + /** Updates overall fetch stage status; to be called at the end of each + * cycle. */ + FetchStatus updateFetchStatus(); public: - // Figure out PC vs next PC and how it should be updated - void squash(const Addr &new_PC); + /** Squashes a specific thread and resets the PC. Also tells the CPU to + * remove any instructions that are not in the ROB. The source of this + * squash should be the commit stage. + */ + void squash(const Addr &new_PC, unsigned tid); + /** Ticks the fetch stage, processing all inputs signals and fetching + * as many instructions as possible. + */ void tick(); - void fetch(); + /** Checks all input signals and updates the status as necessary. + * @return: Returns if the status has changed due to input signals. + */ + bool checkSignalsAndUpdate(unsigned tid); - // Align an address (typically a PC) to the start of an I-cache block. - // We fold in the PISA 64- to 32-bit conversion here as well. + /** Does the actual fetching of instructions and passing them on to the + * next stage. + * @param status_change fetch() sets this variable if there was a status + * change (ie switching to IcacheMissStall). + */ + void fetch(bool &status_change); + + /** Align a PC to the start of an I-cache block. */ Addr icacheBlockAlignPC(Addr addr) { addr = TheISA::realPCToFetchPC(addr); @@ -147,6 +277,25 @@ class SimpleFetch } private: + /** Handles retrying the fetch access. */ + void recvRetry(); + + /** Returns the appropriate thread to fetch, given the fetch policy. */ + int getFetchingThread(FetchPriority &fetch_priority); + + /** Returns the appropriate thread to fetch using a round robin policy. */ + int roundRobin(); + + /** Returns the appropriate thread to fetch using the IQ count policy. */ + int iqCount(); + + /** Returns the appropriate thread to fetch using the LSQ count policy. */ + int lsqCount(); + + /** Returns the appropriate thread to fetch using the branch count policy. */ + int branchCount(); + + private: /** Pointer to the FullCPU. */ FullCPU *cpu; @@ -172,14 +321,41 @@ class SimpleFetch /** Wire used to write any information heading to decode. */ typename TimeBuffer<FetchStruct>::wire toDecode; + MemObject *mem; + /** Icache interface. */ - MemInterface *icacheInterface; + IcachePort *icachePort; /** BPredUnit. */ BPredUnit branchPred; + /** Per-thread fetch PC. */ + Addr PC[Impl::MaxThreads]; + + /** Per-thread next PC. */ + Addr nextPC[Impl::MaxThreads]; + /** Memory request used to access cache. */ - MemReqPtr memReq; + RequestPtr memReq[Impl::MaxThreads]; + + /** Variable that tracks if fetch has written to the time buffer this + * cycle. Used to tell CPU if there is activity this cycle. + */ + bool wroteToTimeBuffer; + + /** Tracks how many instructions has been fetched this cycle. */ + int numInst; + + /** Source of possible stalls. */ + struct Stalls { + bool decode; + bool rename; + bool iew; + bool commit; + }; + + /** Tracks which stages are telling fetch to stall. */ + Stalls stalls[Impl::MaxThreads]; /** Decode to fetch delay, in ticks. */ unsigned decodeToFetchDelay; @@ -196,6 +372,15 @@ class SimpleFetch /** The width of fetch in instructions. */ unsigned fetchWidth; + /** Is the cache blocked? If so no threads can access it. */ + bool cacheBlocked; + + /** The packet that is waiting to be retried. */ + PacketPtr retryPkt; + + /** The thread that is waiting on the cache to tell fetch to retry. */ + int retryTid; + /** Cache block size. */ int cacheBlkSize; @@ -203,23 +388,68 @@ class SimpleFetch Addr cacheBlkMask; /** The cache line being fetched. */ - uint8_t *cacheData; + uint8_t *cacheData[Impl::MaxThreads]; /** Size of instructions. */ int instSize; /** Icache stall statistics. */ - Counter lastIcacheStall; + Counter lastIcacheStall[Impl::MaxThreads]; + + /** List of Active Threads */ + std::list<unsigned> *activeThreads; + /** Number of threads. */ + unsigned numThreads; + + /** Number of threads that are actively fetching. */ + unsigned numFetchingThreads; + + /** Thread ID being fetched. */ + int threadFetched; + + /** Checks if there is an interrupt pending. If there is, fetch + * must stop once it is not fetching PAL instructions. + */ + bool interruptPending; + + /** Records if fetch is switched out. */ + bool switchedOut; + + // @todo: Consider making these vectors and tracking on a per thread basis. + /** Stat for total number of cycles stalled due to an icache miss. */ Stats::Scalar<> icacheStallCycles; + /** Stat for total number of fetched instructions. */ Stats::Scalar<> fetchedInsts; + Stats::Scalar<> fetchedBranches; + /** Stat for total number of predicted branches. */ Stats::Scalar<> predictedBranches; + /** Stat for total number of cycles spent fetching. */ Stats::Scalar<> fetchCycles; + /** Stat for total number of cycles spent squashing. */ Stats::Scalar<> fetchSquashCycles; + /** Stat for total number of cycles spent blocked due to other stages in + * the pipeline. + */ + Stats::Scalar<> fetchIdleCycles; + /** Total number of cycles spent blocked. */ Stats::Scalar<> fetchBlockedCycles; + /** Total number of cycles spent in any other state. */ + Stats::Scalar<> fetchMiscStallCycles; + /** Stat for total number of fetched cache lines. */ Stats::Scalar<> fetchedCacheLines; - - Stats::Distribution<> fetch_nisn_dist; + /** Total number of outstanding icache accesses that were dropped + * due to a squash. + */ + Stats::Scalar<> fetchIcacheSquashes; + /** Distribution of number of instructions fetched each cycle. */ + Stats::Distribution<> fetchNisnDist; + /** Rate of how often fetch was idle. */ + Stats::Formula idleRate; + /** Number of branch fetches per cycle. */ + Stats::Formula branchRate; + /** Number of instruction fetched per cycle. */ + Stats::Formula fetchRate; }; -#endif //__CPU_O3_CPU_SIMPLE_FETCH_HH__ +#endif //__CPU_O3_FETCH_HH__ diff --git a/src/cpu/o3/fetch_impl.hh b/src/cpu/o3/fetch_impl.hh index fb5748c97..c0a2a5d09 100644 --- a/src/cpu/o3/fetch_impl.hh +++ b/src/cpu/o3/fetch_impl.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,83 +28,157 @@ * Authors: Kevin Lim */ -// Remove this later; used only for debugging. -#define OPCODE(X) (X >> 26) & 0x3f - #include "arch/isa_traits.hh" -#include "sim/byteswap.hh" +#include "arch/utility.hh" +#include "cpu/checker/cpu.hh" #include "cpu/exetrace.hh" -#include "mem/base_mem.hh" -#include "mem/mem_interface.hh" -#include "mem/mem_req.hh" #include "cpu/o3/fetch.hh" - +#include "mem/packet.hh" +#include "mem/request.hh" +#include "sim/byteswap.hh" +#include "sim/host.hh" #include "sim/root.hh" +#if FULL_SYSTEM +#include "arch/tlb.hh" +#include "arch/vtophys.hh" +#include "base/remote_gdb.hh" +#include "sim/system.hh" +#endif // FULL_SYSTEM + +#include <algorithm> + +using namespace std; +using namespace TheISA; + +template<class Impl> +Tick +DefaultFetch<Impl>::IcachePort::recvAtomic(PacketPtr pkt) +{ + panic("DefaultFetch doesn't expect recvAtomic callback!"); + return curTick; +} + template<class Impl> -SimpleFetch<Impl>::CacheCompletionEvent -::CacheCompletionEvent(SimpleFetch *_fetch) - : Event(&mainEventQueue), - fetch(_fetch) +void +DefaultFetch<Impl>::IcachePort::recvFunctional(PacketPtr pkt) { + panic("DefaultFetch doesn't expect recvFunctional callback!"); } template<class Impl> void -SimpleFetch<Impl>::CacheCompletionEvent::process() +DefaultFetch<Impl>::IcachePort::recvStatusChange(Status status) { - fetch->processCacheCompletion(); + if (status == RangeChange) + return; + + panic("DefaultFetch doesn't expect recvStatusChange callback!"); } template<class Impl> -const char * -SimpleFetch<Impl>::CacheCompletionEvent::description() +bool +DefaultFetch<Impl>::IcachePort::recvTiming(Packet *pkt) { - return "SimpleFetch cache completion event"; + fetch->processCacheCompletion(pkt); + return true; } template<class Impl> -SimpleFetch<Impl>::SimpleFetch(Params ¶ms) - : icacheInterface(params.icacheInterface), +void +DefaultFetch<Impl>::IcachePort::recvRetry() +{ + fetch->recvRetry(); +} + +template<class Impl> +DefaultFetch<Impl>::DefaultFetch(Params *params) + : mem(params->mem), branchPred(params), - decodeToFetchDelay(params.decodeToFetchDelay), - renameToFetchDelay(params.renameToFetchDelay), - iewToFetchDelay(params.iewToFetchDelay), - commitToFetchDelay(params.commitToFetchDelay), - fetchWidth(params.fetchWidth) -{ - DPRINTF(Fetch, "Fetch: Fetch constructor called\n"); - - // Set status to idle. - _status = Idle; - - // Create a new memory request. - memReq = new MemReq(); - // Not sure of this parameter. I think it should be based on the - // thread number. -#if !FULL_SYSTEM - memReq->asid = 0; -#else - memReq->asid = 0; -#endif // FULL_SYSTEM - memReq->data = new uint8_t[64]; + decodeToFetchDelay(params->decodeToFetchDelay), + renameToFetchDelay(params->renameToFetchDelay), + iewToFetchDelay(params->iewToFetchDelay), + commitToFetchDelay(params->commitToFetchDelay), + fetchWidth(params->fetchWidth), + cacheBlocked(false), + retryPkt(NULL), + retryTid(-1), + numThreads(params->numberOfThreads), + numFetchingThreads(params->smtNumFetchingThreads), + interruptPending(false), + switchedOut(false) +{ + if (numThreads > Impl::MaxThreads) + fatal("numThreads is not a valid value\n"); + + DPRINTF(Fetch, "Fetch constructor called\n"); + + // Set fetch stage's status to inactive. + _status = Inactive; + + string policy = params->smtFetchPolicy; + + // Convert string to lowercase + std::transform(policy.begin(), policy.end(), policy.begin(), + (int(*)(int)) tolower); + + // Figure out fetch policy + if (policy == "singlethread") { + fetchPolicy = SingleThread; + } else if (policy == "roundrobin") { + fetchPolicy = RoundRobin; + DPRINTF(Fetch, "Fetch policy set to Round Robin\n"); + } else if (policy == "branch") { + fetchPolicy = Branch; + DPRINTF(Fetch, "Fetch policy set to Branch Count\n"); + } else if (policy == "iqcount") { + fetchPolicy = IQ; + DPRINTF(Fetch, "Fetch policy set to IQ count\n"); + } else if (policy == "lsqcount") { + fetchPolicy = LSQ; + DPRINTF(Fetch, "Fetch policy set to LSQ count\n"); + } else { + fatal("Invalid Fetch Policy. Options Are: {SingleThread," + " RoundRobin,LSQcount,IQcount}\n"); + } // Size of cache block. - cacheBlkSize = icacheInterface ? icacheInterface->getBlockSize() : 64; + cacheBlkSize = 64; // Create mask to get rid of offset bits. cacheBlkMask = (cacheBlkSize - 1); + for (int tid=0; tid < numThreads; tid++) { + + fetchStatus[tid] = Running; + + priorityList.push_back(tid); + + memReq[tid] = NULL; + + // Create space to store a cache line. + cacheData[tid] = new uint8_t[cacheBlkSize]; + + stalls[tid].decode = 0; + stalls[tid].rename = 0; + stalls[tid].iew = 0; + stalls[tid].commit = 0; + } + // Get the size of an instruction. instSize = sizeof(MachInst); +} - // Create space to store a cache line. - cacheData = new uint8_t[cacheBlkSize]; +template <class Impl> +std::string +DefaultFetch<Impl>::name() const +{ + return cpu->name() + ".fetch"; } template <class Impl> void -SimpleFetch<Impl>::regStats() +DefaultFetch<Impl>::regStats() { icacheStallCycles .name(name() + ".icacheStallCycles") @@ -112,58 +186,114 @@ SimpleFetch<Impl>::regStats() .prereq(icacheStallCycles); fetchedInsts - .name(name() + ".fetchedInsts") + .name(name() + ".Insts") .desc("Number of instructions fetch has processed") .prereq(fetchedInsts); + + fetchedBranches + .name(name() + ".Branches") + .desc("Number of branches that fetch encountered") + .prereq(fetchedBranches); + predictedBranches .name(name() + ".predictedBranches") .desc("Number of branches that fetch has predicted taken") .prereq(predictedBranches); + fetchCycles - .name(name() + ".fetchCycles") + .name(name() + ".Cycles") .desc("Number of cycles fetch has run and was not squashing or" " blocked") .prereq(fetchCycles); + fetchSquashCycles - .name(name() + ".fetchSquashCycles") + .name(name() + ".SquashCycles") .desc("Number of cycles fetch has spent squashing") .prereq(fetchSquashCycles); + + fetchIdleCycles + .name(name() + ".IdleCycles") + .desc("Number of cycles fetch was idle") + .prereq(fetchIdleCycles); + fetchBlockedCycles - .name(name() + ".fetchBlockedCycles") + .name(name() + ".BlockedCycles") .desc("Number of cycles fetch has spent blocked") .prereq(fetchBlockedCycles); + fetchedCacheLines - .name(name() + ".fetchedCacheLines") + .name(name() + ".CacheLines") .desc("Number of cache lines fetched") .prereq(fetchedCacheLines); - fetch_nisn_dist + fetchMiscStallCycles + .name(name() + ".MiscStallCycles") + .desc("Number of cycles fetch has spent waiting on interrupts, or " + "bad addresses, or out of MSHRs") + .prereq(fetchMiscStallCycles); + + fetchIcacheSquashes + .name(name() + ".IcacheSquashes") + .desc("Number of outstanding Icache misses that were squashed") + .prereq(fetchIcacheSquashes); + + fetchNisnDist .init(/* base value */ 0, /* last value */ fetchWidth, /* bucket size */ 1) - .name(name() + ".FETCH:rate_dist") + .name(name() + ".rateDist") .desc("Number of instructions fetched each cycle (Total)") - .flags(Stats::pdf) - ; + .flags(Stats::pdf); + + idleRate + .name(name() + ".idleRate") + .desc("Percent of cycles fetch was idle") + .prereq(idleRate); + idleRate = fetchIdleCycles * 100 / cpu->numCycles; + + branchRate + .name(name() + ".branchRate") + .desc("Number of branch fetches per cycle") + .flags(Stats::total); + branchRate = fetchedBranches / cpu->numCycles; + + fetchRate + .name(name() + ".rate") + .desc("Number of inst fetches per cycle") + .flags(Stats::total); + fetchRate = fetchedInsts / cpu->numCycles; branchPred.regStats(); } template<class Impl> void -SimpleFetch<Impl>::setCPU(FullCPU *cpu_ptr) +DefaultFetch<Impl>::setCPU(FullCPU *cpu_ptr) { - DPRINTF(Fetch, "Fetch: Setting the CPU pointer.\n"); + DPRINTF(Fetch, "Setting the CPU pointer.\n"); cpu = cpu_ptr; - // This line will be removed eventually. - memReq->xc = cpu->xcBase(); + + // Name is finally available, so create the port. + icachePort = new IcachePort(this); + + Port *mem_dport = mem->getPort(""); + icachePort->setPeer(mem_dport); + mem_dport->setPeer(icachePort); + + if (cpu->checker) { + cpu->checker->setIcachePort(icachePort); + } + + // Fetch needs to start fetching instructions at the very beginning, + // so it must start up in active state. + switchToActive(); } template<class Impl> void -SimpleFetch<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *time_buffer) +DefaultFetch<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *time_buffer) { - DPRINTF(Fetch, "Fetch: Setting the time buffer pointer.\n"); + DPRINTF(Fetch, "Setting the time buffer pointer.\n"); timeBuffer = time_buffer; // Create wires to get information from proper places in time buffer. @@ -175,9 +305,17 @@ SimpleFetch<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *time_buffer) template<class Impl> void -SimpleFetch<Impl>::setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr) +DefaultFetch<Impl>::setActiveThreads(list<unsigned> *at_ptr) { - DPRINTF(Fetch, "Fetch: Setting the fetch queue pointer.\n"); + DPRINTF(Fetch, "Setting active threads list pointer.\n"); + activeThreads = at_ptr; +} + +template<class Impl> +void +DefaultFetch<Impl>::setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr) +{ + DPRINTF(Fetch, "Setting the fetch queue pointer.\n"); fetchQueue = fq_ptr; // Create wire to write information to proper place in fetch queue. @@ -186,21 +324,134 @@ SimpleFetch<Impl>::setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr) template<class Impl> void -SimpleFetch<Impl>::processCacheCompletion() +DefaultFetch<Impl>::initStage() +{ + // Setup PC and nextPC with initial state. + for (int tid = 0; tid < numThreads; tid++) { + PC[tid] = cpu->readPC(tid); + nextPC[tid] = cpu->readNextPC(tid); + } +} + +template<class Impl> +void +DefaultFetch<Impl>::processCacheCompletion(PacketPtr pkt) { - DPRINTF(Fetch, "Fetch: Waking up from cache miss.\n"); + unsigned tid = pkt->req->getThreadNum(); + + DPRINTF(Fetch, "[tid:%u] Waking up from cache miss.\n",tid); // Only change the status if it's still waiting on the icache access // to return. - // Can keep track of how many cache accesses go unused due to - // misspeculation here. - if (_status == IcacheMissStall) - _status = IcacheMissComplete; + if (fetchStatus[tid] != IcacheWaitResponse || + pkt->req != memReq[tid] || + isSwitchedOut()) { + ++fetchIcacheSquashes; + delete pkt->req; + delete pkt; + memReq[tid] = NULL; + return; + } + + // Wake up the CPU (if it went to sleep and was waiting on this completion + // event). + cpu->wakeCPU(); + + DPRINTF(Activity, "[tid:%u] Activating fetch due to cache completion\n", + tid); + + switchToActive(); + + // Only switch to IcacheAccessComplete if we're not stalled as well. + if (checkStall(tid)) { + fetchStatus[tid] = Blocked; + } else { + fetchStatus[tid] = IcacheAccessComplete; + } + + // Reset the mem req to NULL. + delete pkt->req; + delete pkt; + memReq[tid] = NULL; +} + +template <class Impl> +void +DefaultFetch<Impl>::switchOut() +{ + // Fetch is ready to switch out at any time. + switchedOut = true; + cpu->signalSwitched(); +} + +template <class Impl> +void +DefaultFetch<Impl>::doSwitchOut() +{ + // Branch predictor needs to have its state cleared. + branchPred.switchOut(); +} + +template <class Impl> +void +DefaultFetch<Impl>::takeOverFrom() +{ + // Reset all state + for (int i = 0; i < Impl::MaxThreads; ++i) { + stalls[i].decode = 0; + stalls[i].rename = 0; + stalls[i].iew = 0; + stalls[i].commit = 0; + PC[i] = cpu->readPC(i); + nextPC[i] = cpu->readNextPC(i); + fetchStatus[i] = Running; + } + numInst = 0; + wroteToTimeBuffer = false; + _status = Inactive; + switchedOut = false; + branchPred.takeOverFrom(); +} + +template <class Impl> +void +DefaultFetch<Impl>::wakeFromQuiesce() +{ + DPRINTF(Fetch, "Waking up from quiesce\n"); + // Hopefully this is safe + // @todo: Allow other threads to wake from quiesce. + fetchStatus[0] = Running; +} + +template <class Impl> +inline void +DefaultFetch<Impl>::switchToActive() +{ + if (_status == Inactive) { + DPRINTF(Activity, "Activating stage.\n"); + + cpu->activateStage(FullCPU::FetchIdx); + + _status = Active; + } +} + +template <class Impl> +inline void +DefaultFetch<Impl>::switchToInactive() +{ + if (_status == Active) { + DPRINTF(Activity, "Deactivating stage.\n"); + + cpu->deactivateStage(FullCPU::FetchIdx); + + _status = Inactive; + } } template <class Impl> bool -SimpleFetch<Impl>::lookupAndUpdateNextPC(DynInstPtr &inst, Addr &next_PC) +DefaultFetch<Impl>::lookupAndUpdateNextPC(DynInstPtr &inst, Addr &next_PC) { // Do branch prediction check here. // A bit of a misnomer...next_PC is actually the current PC until @@ -213,7 +464,9 @@ SimpleFetch<Impl>::lookupAndUpdateNextPC(DynInstPtr &inst, Addr &next_PC) return false; } - predict_taken = branchPred.predict(inst, next_PC); + predict_taken = branchPred.predict(inst, next_PC, inst->threadNumber); + + ++fetchedBranches; if (predict_taken) { ++predictedBranches; @@ -223,251 +476,425 @@ SimpleFetch<Impl>::lookupAndUpdateNextPC(DynInstPtr &inst, Addr &next_PC) } template <class Impl> -Fault -SimpleFetch<Impl>::fetchCacheLine(Addr fetch_PC) +bool +DefaultFetch<Impl>::fetchCacheLine(Addr fetch_PC, Fault &ret_fault, unsigned tid) { - // Check if the instruction exists within the cache. - // If it does, then proceed on to read the instruction and the rest - // of the instructions in the cache line until either the end of the - // cache line or a predicted taken branch is encountered. + Fault fault = NoFault; #if FULL_SYSTEM // Flag to say whether or not address is physical addr. - unsigned flags = cpu->inPalMode() ? PHYSICAL : 0; + unsigned flags = cpu->inPalMode(fetch_PC) ? PHYSICAL : 0; #else unsigned flags = 0; #endif // FULL_SYSTEM - Fault fault = NoFault; + if (cacheBlocked || (interruptPending && flags == 0) || switchedOut) { + // Hold off fetch from getting new instructions when: + // Cache is blocked, or + // while an interrupt is pending and we're not in PAL mode, or + // fetch is switched out. + return false; + } // Align the fetch PC so it's at the start of a cache block. fetch_PC = icacheBlockAlignPC(fetch_PC); - // Setup the memReq to do a read of the first isntruction's address. + // Setup the memReq to do a read of the first instruction's address. // Set the appropriate read size and flags as well. - memReq->cmd = Read; - memReq->reset(fetch_PC, cacheBlkSize, flags); + // Build request here. + RequestPtr mem_req = new Request(tid, fetch_PC, cacheBlkSize, flags, + fetch_PC, cpu->readCpuId(), tid); - // Translate the instruction request. - // Should this function be - // in the CPU class ? Probably...ITB/DTB should exist within the - // CPU. + memReq[tid] = mem_req; - fault = cpu->translateInstReq(memReq); + // Translate the instruction request. + fault = cpu->translateInstReq(mem_req, cpu->thread[tid]); // In the case of faults, the fetch stage may need to stall and wait - // on what caused the fetch (ITB or Icache miss). + // for the ITB miss to be handled. // If translation was successful, attempt to read the first // instruction. if (fault == NoFault) { +#if 0 + if (cpu->system->memctrl->badaddr(memReq[tid]->paddr) || + memReq[tid]->flags & UNCACHEABLE) { + DPRINTF(Fetch, "Fetch: Bad address %#x (hopefully on a " + "misspeculating path)!", + memReq[tid]->paddr); + ret_fault = TheISA::genMachineCheckFault(); + return false; + } +#endif + + // Build packet here. + PacketPtr data_pkt = new Packet(mem_req, + Packet::ReadReq, Packet::Broadcast); + data_pkt->dataStatic(cacheData[tid]); + DPRINTF(Fetch, "Fetch: Doing instruction read.\n"); - fault = cpu->mem->read(memReq, cacheData); - // This read may change when the mem interface changes. fetchedCacheLines++; - } - // Now do the timing access to see whether or not the instruction - // exists within the cache. - if (icacheInterface && fault == NoFault) { - DPRINTF(Fetch, "Fetch: Doing timing memory access.\n"); - memReq->completionEvent = NULL; - - memReq->time = curTick; + // Now do the timing access to see whether or not the instruction + // exists within the cache. + if (!icachePort->sendTiming(data_pkt)) { + assert(retryPkt == NULL); + assert(retryTid == -1); + DPRINTF(Fetch, "[tid:%i] Out of MSHRs!\n", tid); + fetchStatus[tid] = IcacheWaitRetry; + retryPkt = data_pkt; + retryTid = tid; + cacheBlocked = true; + return false; + } - MemAccessResult result = icacheInterface->access(memReq); + DPRINTF(Fetch, "Doing cache access.\n"); - // If the cache missed (in this model functional and timing - // memories are different), then schedule an event to wake - // up this stage once the cache miss completes. - if (result != MA_HIT && icacheInterface->doEvents()) { - memReq->completionEvent = new CacheCompletionEvent(this); + lastIcacheStall[tid] = curTick; - // How does current model work as far as individual - // stages scheduling/unscheduling? - // Perhaps have only the main CPU scheduled/unscheduled, - // and have it choose what stages to run appropriately. + DPRINTF(Activity, "[tid:%i]: Activity: Waiting on I-cache " + "response.\n", tid); - DPRINTF(Fetch, "Fetch: Stalling due to icache miss.\n"); - _status = IcacheMissStall; - } + fetchStatus[tid] = IcacheWaitResponse; + } else { + delete mem_req; + memReq[tid] = NULL; } - return fault; + ret_fault = fault; + return true; } template <class Impl> inline void -SimpleFetch<Impl>::doSquash(const Addr &new_PC) +DefaultFetch<Impl>::doSquash(const Addr &new_PC, unsigned tid) { - DPRINTF(Fetch, "Fetch: Squashing, setting PC to: %#x.\n", new_PC); + DPRINTF(Fetch, "[tid:%i]: Squashing, setting PC to: %#x.\n", + tid, new_PC); - cpu->setNextPC(new_PC + instSize); - cpu->setPC(new_PC); + PC[tid] = new_PC; + nextPC[tid] = new_PC + instSize; // Clear the icache miss if it's outstanding. - if (_status == IcacheMissStall && icacheInterface) { - DPRINTF(Fetch, "Fetch: Squashing outstanding Icache miss.\n"); - // @todo: Use an actual thread number here. - icacheInterface->squash(0); + if (fetchStatus[tid] == IcacheWaitResponse) { + DPRINTF(Fetch, "[tid:%i]: Squashing outstanding Icache miss.\n", + tid); + memReq[tid] = NULL; } - _status = Squashing; + // Get rid of the retrying packet if it was from this thread. + if (retryTid == tid) { + assert(cacheBlocked); + cacheBlocked = false; + retryTid = -1; + retryPkt = NULL; + delete retryPkt->req; + delete retryPkt; + } + + fetchStatus[tid] = Squashing; ++fetchSquashCycles; } template<class Impl> void -SimpleFetch<Impl>::squashFromDecode(const Addr &new_PC, - const InstSeqNum &seq_num) +DefaultFetch<Impl>::squashFromDecode(const Addr &new_PC, + const InstSeqNum &seq_num, + unsigned tid) { - DPRINTF(Fetch, "Fetch: Squashing from decode.\n"); + DPRINTF(Fetch, "[tid:%i]: Squashing from decode.\n",tid); - doSquash(new_PC); + doSquash(new_PC, tid); // Tell the CPU to remove any instructions that are in flight between // fetch and decode. - cpu->removeInstsUntil(seq_num); + cpu->removeInstsUntil(seq_num, tid); +} + +template<class Impl> +bool +DefaultFetch<Impl>::checkStall(unsigned tid) const +{ + bool ret_val = false; + + if (cpu->contextSwitch) { + DPRINTF(Fetch,"[tid:%i]: Stalling for a context switch.\n",tid); + ret_val = true; + } else if (stalls[tid].decode) { + DPRINTF(Fetch,"[tid:%i]: Stall from Decode stage detected.\n",tid); + ret_val = true; + } else if (stalls[tid].rename) { + DPRINTF(Fetch,"[tid:%i]: Stall from Rename stage detected.\n",tid); + ret_val = true; + } else if (stalls[tid].iew) { + DPRINTF(Fetch,"[tid:%i]: Stall from IEW stage detected.\n",tid); + ret_val = true; + } else if (stalls[tid].commit) { + DPRINTF(Fetch,"[tid:%i]: Stall from Commit stage detected.\n",tid); + ret_val = true; + } + + return ret_val; +} + +template<class Impl> +typename DefaultFetch<Impl>::FetchStatus +DefaultFetch<Impl>::updateFetchStatus() +{ + //Check Running + list<unsigned>::iterator threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + + unsigned tid = *threads++; + + if (fetchStatus[tid] == Running || + fetchStatus[tid] == Squashing || + fetchStatus[tid] == IcacheAccessComplete) { + + if (_status == Inactive) { + DPRINTF(Activity, "[tid:%i]: Activating stage.\n",tid); + + if (fetchStatus[tid] == IcacheAccessComplete) { + DPRINTF(Activity, "[tid:%i]: Activating fetch due to cache" + "completion\n",tid); + } + + cpu->activateStage(FullCPU::FetchIdx); + } + + return Active; + } + } + + // Stage is switching from active to inactive, notify CPU of it. + if (_status == Active) { + DPRINTF(Activity, "Deactivating stage.\n"); + + cpu->deactivateStage(FullCPU::FetchIdx); + } + + return Inactive; } template <class Impl> void -SimpleFetch<Impl>::squash(const Addr &new_PC) +DefaultFetch<Impl>::squash(const Addr &new_PC, unsigned tid) { - DPRINTF(Fetch, "Fetch: Squash from commit.\n"); + DPRINTF(Fetch, "[tid:%u]: Squash from commit.\n",tid); - doSquash(new_PC); + doSquash(new_PC, tid); // Tell the CPU to remove any instructions that are not in the ROB. - cpu->removeInstsNotInROB(); + cpu->removeInstsNotInROB(tid); } -template<class Impl> +template <class Impl> void -SimpleFetch<Impl>::tick() +DefaultFetch<Impl>::tick() +{ + list<unsigned>::iterator threads = (*activeThreads).begin(); + bool status_change = false; + + wroteToTimeBuffer = false; + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + // Check the signals for each thread to determine the proper status + // for each thread. + bool updated_status = checkSignalsAndUpdate(tid); + status_change = status_change || updated_status; + } + + DPRINTF(Fetch, "Running stage.\n"); + + // Reset the number of the instruction we're fetching. + numInst = 0; + + if (fromCommit->commitInfo[0].interruptPending) { + interruptPending = true; + } + if (fromCommit->commitInfo[0].clearInterrupt) { + interruptPending = false; + } + + for (threadFetched = 0; threadFetched < numFetchingThreads; + threadFetched++) { + // Fetch each of the actively fetching threads. + fetch(status_change); + } + + // Record number of instructions fetched this cycle for distribution. + fetchNisnDist.sample(numInst); + + if (status_change) { + // Change the fetch stage status if there was a status change. + _status = updateFetchStatus(); + } + + // If there was activity this cycle, inform the CPU of it. + if (wroteToTimeBuffer || cpu->contextSwitch) { + DPRINTF(Activity, "Activity this cycle.\n"); + + cpu->activityThisCycle(); + } +} + +template <class Impl> +bool +DefaultFetch<Impl>::checkSignalsAndUpdate(unsigned tid) { + // Update the per thread stall statuses. + if (fromDecode->decodeBlock[tid]) { + stalls[tid].decode = true; + } + + if (fromDecode->decodeUnblock[tid]) { + assert(stalls[tid].decode); + assert(!fromDecode->decodeBlock[tid]); + stalls[tid].decode = false; + } + + if (fromRename->renameBlock[tid]) { + stalls[tid].rename = true; + } + + if (fromRename->renameUnblock[tid]) { + assert(stalls[tid].rename); + assert(!fromRename->renameBlock[tid]); + stalls[tid].rename = false; + } + + if (fromIEW->iewBlock[tid]) { + stalls[tid].iew = true; + } + + if (fromIEW->iewUnblock[tid]) { + assert(stalls[tid].iew); + assert(!fromIEW->iewBlock[tid]); + stalls[tid].iew = false; + } + + if (fromCommit->commitBlock[tid]) { + stalls[tid].commit = true; + } + + if (fromCommit->commitUnblock[tid]) { + assert(stalls[tid].commit); + assert(!fromCommit->commitBlock[tid]); + stalls[tid].commit = false; + } + // Check squash signals from commit. - if (fromCommit->commitInfo.squash) { - DPRINTF(Fetch, "Fetch: Squashing instructions due to squash " - "from commit.\n"); + if (fromCommit->commitInfo[tid].squash) { + + DPRINTF(Fetch, "[tid:%u]: Squashing instructions due to squash " + "from commit.\n",tid); // In any case, squash. - squash(fromCommit->commitInfo.nextPC); + squash(fromCommit->commitInfo[tid].nextPC,tid); // Also check if there's a mispredict that happened. - if (fromCommit->commitInfo.branchMispredict) { - branchPred.squash(fromCommit->commitInfo.doneSeqNum, - fromCommit->commitInfo.nextPC, - fromCommit->commitInfo.branchTaken); + if (fromCommit->commitInfo[tid].branchMispredict) { + branchPred.squash(fromCommit->commitInfo[tid].doneSeqNum, + fromCommit->commitInfo[tid].nextPC, + fromCommit->commitInfo[tid].branchTaken, + tid); } else { - branchPred.squash(fromCommit->commitInfo.doneSeqNum); + branchPred.squash(fromCommit->commitInfo[tid].doneSeqNum, + tid); } - return; - } else if (fromCommit->commitInfo.doneSeqNum) { + return true; + } else if (fromCommit->commitInfo[tid].doneSeqNum) { // Update the branch predictor if it wasn't a squashed instruction - // that was braodcasted. - branchPred.update(fromCommit->commitInfo.doneSeqNum); + // that was broadcasted. + branchPred.update(fromCommit->commitInfo[tid].doneSeqNum, tid); } // Check ROB squash signals from commit. - if (fromCommit->commitInfo.robSquashing) { - DPRINTF(Fetch, "Fetch: ROB is still squashing.\n"); + if (fromCommit->commitInfo[tid].robSquashing) { + DPRINTF(Fetch, "[tid:%u]: ROB is still squashing Thread %u.\n", tid); // Continue to squash. - _status = Squashing; + fetchStatus[tid] = Squashing; - ++fetchSquashCycles; - return; + return true; } // Check squash signals from decode. - if (fromDecode->decodeInfo.squash) { - DPRINTF(Fetch, "Fetch: Squashing instructions due to squash " - "from decode.\n"); + if (fromDecode->decodeInfo[tid].squash) { + DPRINTF(Fetch, "[tid:%u]: Squashing instructions due to squash " + "from decode.\n",tid); // Update the branch predictor. - if (fromDecode->decodeInfo.branchMispredict) { - branchPred.squash(fromDecode->decodeInfo.doneSeqNum, - fromDecode->decodeInfo.nextPC, - fromDecode->decodeInfo.branchTaken); + if (fromDecode->decodeInfo[tid].branchMispredict) { + branchPred.squash(fromDecode->decodeInfo[tid].doneSeqNum, + fromDecode->decodeInfo[tid].nextPC, + fromDecode->decodeInfo[tid].branchTaken, + tid); } else { - branchPred.squash(fromDecode->decodeInfo.doneSeqNum); + branchPred.squash(fromDecode->decodeInfo[tid].doneSeqNum, + tid); } - if (_status != Squashing) { - // Squash unless we're already squashing? - squashFromDecode(fromDecode->decodeInfo.nextPC, - fromDecode->decodeInfo.doneSeqNum); - return; + if (fetchStatus[tid] != Squashing) { + // Squash unless we're already squashing + squashFromDecode(fromDecode->decodeInfo[tid].nextPC, + fromDecode->decodeInfo[tid].doneSeqNum, + tid); + + return true; } } - // Check if any of the stall signals are high. - if (fromDecode->decodeInfo.stall || - fromRename->renameInfo.stall || - fromIEW->iewInfo.stall || - fromCommit->commitInfo.stall) - { - // Block stage, regardless of current status. - - DPRINTF(Fetch, "Fetch: Stalling stage.\n"); - DPRINTF(Fetch, "Fetch: Statuses: Decode: %i Rename: %i IEW: %i " - "Commit: %i\n", - fromDecode->decodeInfo.stall, - fromRename->renameInfo.stall, - fromIEW->iewInfo.stall, - fromCommit->commitInfo.stall); - - _status = Blocked; + if (checkStall(tid) && fetchStatus[tid] != IcacheWaitResponse) { + DPRINTF(Fetch, "[tid:%i]: Setting to blocked\n",tid); - ++fetchBlockedCycles; - return; - } else if (_status == Blocked) { - // Unblock stage if status is currently blocked and none of the - // stall signals are being held high. - _status = Running; + fetchStatus[tid] = Blocked; - ++fetchBlockedCycles; - return; + return true; } - // If fetch has reached this point, then there are no squash signals - // still being held high. Check if fetch is in the squashing state; - // if so, fetch can switch to running. - // Similarly, there are no blocked signals still being held high. - // Check if fetch is in the blocked state; if so, fetch can switch to - // running. - if (_status == Squashing) { - DPRINTF(Fetch, "Fetch: Done squashing, switching to running.\n"); - - // Switch status to running - _status = Running; - - ++fetchCycles; - - fetch(); - } else if (_status != IcacheMissStall) { - DPRINTF(Fetch, "Fetch: Running stage.\n"); + if (fetchStatus[tid] == Blocked || + fetchStatus[tid] == Squashing) { + // Switch status to running if fetch isn't being told to block or + // squash this cycle. + DPRINTF(Fetch, "[tid:%i]: Done squashing, switching to running.\n", + tid); - ++fetchCycles; + fetchStatus[tid] = Running; - fetch(); + return true; } + + // If we've reached this point, we have not gotten any signals that + // cause fetch to change its status. Fetch remains the same as before. + return false; } template<class Impl> void -SimpleFetch<Impl>::fetch() +DefaultFetch<Impl>::fetch(bool &status_change) { ////////////////////////////////////////// // Start actual fetch ////////////////////////////////////////// + int tid = getFetchingThread(fetchPolicy); + + if (tid == -1) { + DPRINTF(Fetch,"There are no more threads available to fetch from.\n"); + + // Breaks looping condition in tick() + threadFetched = numFetchingThreads; + return; + } // The current PC. - Addr fetch_PC = cpu->readPC(); + Addr &fetch_PC = PC[tid]; // Fault code for memory access. Fault fault = NoFault; @@ -475,60 +902,71 @@ SimpleFetch<Impl>::fetch() // If returning from the delay of a cache miss, then update the status // to running, otherwise do the cache access. Possibly move this up // to tick() function. - if (_status == IcacheMissComplete) { - DPRINTF(Fetch, "Fetch: Icache miss is complete.\n"); - - // Reset the completion event to NULL. - memReq->completionEvent = NULL; - - _status = Running; + if (fetchStatus[tid] == IcacheAccessComplete) { + DPRINTF(Fetch, "[tid:%i]: Icache miss is complete.\n", + tid); + + fetchStatus[tid] = Running; + status_change = true; + } else if (fetchStatus[tid] == Running) { + DPRINTF(Fetch, "[tid:%i]: Attempting to translate and read " + "instruction, starting at PC %08p.\n", + tid, fetch_PC); + + bool fetch_success = fetchCacheLine(fetch_PC, fault, tid); + if (!fetch_success) { + ++fetchMiscStallCycles; + return; + } } else { - DPRINTF(Fetch, "Fetch: Attempting to translate and read " - "instruction, starting at PC %08p.\n", - fetch_PC); + if (fetchStatus[tid] == Idle) { + ++fetchIdleCycles; + } else if (fetchStatus[tid] == Blocked) { + ++fetchBlockedCycles; + } else if (fetchStatus[tid] == Squashing) { + ++fetchSquashCycles; + } else if (fetchStatus[tid] == IcacheWaitResponse) { + ++icacheStallCycles; + } - fault = fetchCacheLine(fetch_PC); + // Status is Idle, Squashing, Blocked, or IcacheWaitResponse, so + // fetch should do nothing. + return; } - // If we had a stall due to an icache miss, then return. It'd - // be nicer if this were handled through the kind of fault that - // is returned by the function. - if (_status == IcacheMissStall) { + ++fetchCycles; + + // If we had a stall due to an icache miss, then return. + if (fetchStatus[tid] == IcacheWaitResponse) { + ++icacheStallCycles; + status_change = true; return; } - // As far as timing goes, the CPU will need to send an event through - // the MemReq in order to be woken up once the memory access completes. - // Probably have a status on a per thread basis so each thread can - // block independently and be woken up independently. - Addr next_PC = fetch_PC; InstSeqNum inst_seq; MachInst inst; - unsigned offset = fetch_PC & cacheBlkMask; - unsigned fetched; + ExtMachInst ext_inst; + // @todo: Fix this hack. + unsigned offset = (fetch_PC & cacheBlkMask) & ~3; if (fault == NoFault) { // If the read of the first instruction was successful, then grab the // instructions from the rest of the cache line and put them into the // queue heading to decode. - DPRINTF(Fetch, "Fetch: Adding instructions to queue to decode.\n"); - - ////////////////////////// - // Fetch first instruction - ////////////////////////// + DPRINTF(Fetch, "[tid:%i]: Adding instructions to queue to " + "decode.\n",tid); // Need to keep track of whether or not a predicted branch // ended this fetch block. bool predicted_branch = false; - for (fetched = 0; + for (; offset < cacheBlkSize && - fetched < fetchWidth && + numInst < fetchWidth && !predicted_branch; - ++fetched) - { + ++numInst) { // Get a sequence number. inst_seq = cpu->getAndIncrementInstSeq(); @@ -538,31 +976,40 @@ SimpleFetch<Impl>::fetch() // Get the instruction from the array of the cache line. inst = gtoh(*reinterpret_cast<MachInst *> - (&cacheData[offset])); + (&cacheData[tid][offset])); + + ext_inst = TheISA::makeExtMI(inst, fetch_PC); // Create a new DynInst from the instruction fetched. - DynInstPtr instruction = new DynInst(inst, fetch_PC, next_PC, + DynInstPtr instruction = new DynInst(ext_inst, fetch_PC, + next_PC, inst_seq, cpu); + instruction->setThread(tid); + + instruction->setASID(tid); + + instruction->setState(cpu->thread[tid]); - DPRINTF(Fetch, "Fetch: Instruction %i created, with PC %#x\n", - inst_seq, instruction->readPC()); + DPRINTF(Fetch, "[tid:%i]: Instruction PC %#x created " + "[sn:%lli]\n", + tid, instruction->readPC(), inst_seq); - DPRINTF(Fetch, "Fetch: Instruction opcode is: %03p\n", - OPCODE(inst)); + DPRINTF(Fetch, "[tid:%i]: Instruction is: %s\n", + tid, instruction->staticInst->disassemble(fetch_PC)); instruction->traceData = - Trace::getInstRecord(curTick, cpu->xcBase(), cpu, + Trace::getInstRecord(curTick, cpu->tcBase(tid), cpu, instruction->staticInst, - instruction->readPC(), 0); + instruction->readPC(),tid); predicted_branch = lookupAndUpdateNextPC(instruction, next_PC); // Add instruction to the CPU's list of instructions. - cpu->addInst(instruction); + instruction->setInstListIt(cpu->addInst(instruction)); // Write the instruction to the first slot in the queue // that heads to decode. - toDecode->insts[fetched] = instruction; + toDecode->insts[numInst] = instruction; toDecode->size++; @@ -572,48 +1019,243 @@ SimpleFetch<Impl>::fetch() // Move to the next instruction, unless we have a branch. fetch_PC = next_PC; + if (instruction->isQuiesce()) { + warn("%lli: Quiesce instruction encountered, halting fetch!", + curTick); + fetchStatus[tid] = QuiescePending; + ++numInst; + status_change = true; + break; + } + offset+= instSize; } + } - fetch_nisn_dist.sample(fetched); + if (numInst > 0) { + wroteToTimeBuffer = true; } // Now that fetching is completed, update the PC to signify what the next - // cycle will be. Might want to move this to the beginning of this - // function so that the PC updates at the beginning of everything. - // Or might want to leave setting the PC to the main CPU, with fetch - // only changing the nextPC (will require correct determination of - // next PC). + // cycle will be. if (fault == NoFault) { - DPRINTF(Fetch, "Fetch: Setting PC to %08p.\n", next_PC); - cpu->setPC(next_PC); - cpu->setNextPC(next_PC + instSize); + DPRINTF(Fetch, "[tid:%i]: Setting PC to %08p.\n",tid, next_PC); + + PC[tid] = next_PC; + nextPC[tid] = next_PC + instSize; } else { - // If the issue was an icache miss, then we can just return and - // wait until it is handled. - if (_status == IcacheMissStall) { - return; + // We shouldn't be in an icache miss and also have a fault (an ITB + // miss) + if (fetchStatus[tid] == IcacheWaitResponse) { + panic("Fetch should have exited prior to this!"); } - // Handle the fault. - // This stage will not be able to continue until all the ROB - // slots are empty, at which point the fault can be handled. - // The only other way it can wake up is if a squash comes along - // and changes the PC. Not sure how to handle that case...perhaps - // have it handled by the upper level CPU class which peeks into the - // time buffer and sees if a squash comes along, in which case it - // changes the status. + // Send the fault to commit. This thread will not do anything + // until commit handles the fault. The only other way it can + // wake up is if a squash comes along and changes the PC. +#if FULL_SYSTEM + assert(numInst != fetchWidth); + // Get a sequence number. + inst_seq = cpu->getAndIncrementInstSeq(); + // We will use a nop in order to carry the fault. + ext_inst = TheISA::NoopMachInst; - DPRINTF(Fetch, "Fetch: Blocked, need to handle the trap.\n"); + // Create a new DynInst from the dummy nop. + DynInstPtr instruction = new DynInst(ext_inst, fetch_PC, + next_PC, + inst_seq, cpu); + instruction->setPredTarg(next_PC + instSize); + instruction->setThread(tid); - _status = Blocked; -#if FULL_SYSTEM -// cpu->trap(fault); - // Send a signal to the ROB indicating that there's a trap from the - // fetch stage that needs to be handled. Need to indicate that - // there's a fault, and the fault type. + instruction->setASID(tid); + + instruction->setState(cpu->thread[tid]); + + instruction->traceData = NULL; + + instruction->setInstListIt(cpu->addInst(instruction)); + + instruction->fault = fault; + + toDecode->insts[numInst] = instruction; + toDecode->size++; + + DPRINTF(Fetch, "[tid:%i]: Blocked, need to handle the trap.\n",tid); + + fetchStatus[tid] = TrapPending; + status_change = true; + + warn("%lli fault (%d) detected @ PC %08p", curTick, fault, PC[tid]); #else // !FULL_SYSTEM - fatal("fault (%d) detected @ PC %08p", fault, cpu->readPC()); + warn("%lli fault (%d) detected @ PC %08p", curTick, fault, PC[tid]); #endif // FULL_SYSTEM } } + +template<class Impl> +void +DefaultFetch<Impl>::recvRetry() +{ + assert(cacheBlocked); + if (retryPkt != NULL) { + assert(retryTid != -1); + assert(fetchStatus[retryTid] == IcacheWaitRetry); + + if (icachePort->sendTiming(retryPkt)) { + fetchStatus[retryTid] = IcacheWaitResponse; + retryPkt = NULL; + retryTid = -1; + cacheBlocked = false; + } + } else { + assert(retryTid == -1); + // Access has been squashed since it was sent out. Just clear + // the cache being blocked. + cacheBlocked = false; + } +} + +/////////////////////////////////////// +// // +// SMT FETCH POLICY MAINTAINED HERE // +// // +/////////////////////////////////////// +template<class Impl> +int +DefaultFetch<Impl>::getFetchingThread(FetchPriority &fetch_priority) +{ + if (numThreads > 1) { + switch (fetch_priority) { + + case SingleThread: + return 0; + + case RoundRobin: + return roundRobin(); + + case IQ: + return iqCount(); + + case LSQ: + return lsqCount(); + + case Branch: + return branchCount(); + + default: + return -1; + } + } else { + int tid = *((*activeThreads).begin()); + + if (fetchStatus[tid] == Running || + fetchStatus[tid] == IcacheAccessComplete || + fetchStatus[tid] == Idle) { + return tid; + } else { + return -1; + } + } + +} + + +template<class Impl> +int +DefaultFetch<Impl>::roundRobin() +{ + list<unsigned>::iterator pri_iter = priorityList.begin(); + list<unsigned>::iterator end = priorityList.end(); + + int high_pri; + + while (pri_iter != end) { + high_pri = *pri_iter; + + assert(high_pri <= numThreads); + + if (fetchStatus[high_pri] == Running || + fetchStatus[high_pri] == IcacheAccessComplete || + fetchStatus[high_pri] == Idle) { + + priorityList.erase(pri_iter); + priorityList.push_back(high_pri); + + return high_pri; + } + + pri_iter++; + } + + return -1; +} + +template<class Impl> +int +DefaultFetch<Impl>::iqCount() +{ + priority_queue<unsigned> PQ; + + list<unsigned>::iterator threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + PQ.push(fromIEW->iewInfo[tid].iqCount); + } + + while (!PQ.empty()) { + + unsigned high_pri = PQ.top(); + + if (fetchStatus[high_pri] == Running || + fetchStatus[high_pri] == IcacheAccessComplete || + fetchStatus[high_pri] == Idle) + return high_pri; + else + PQ.pop(); + + } + + return -1; +} + +template<class Impl> +int +DefaultFetch<Impl>::lsqCount() +{ + priority_queue<unsigned> PQ; + + + list<unsigned>::iterator threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + PQ.push(fromIEW->iewInfo[tid].ldstqCount); + } + + while (!PQ.empty()) { + + unsigned high_pri = PQ.top(); + + if (fetchStatus[high_pri] == Running || + fetchStatus[high_pri] == IcacheAccessComplete || + fetchStatus[high_pri] == Idle) + return high_pri; + else + PQ.pop(); + + } + + return -1; +} + +template<class Impl> +int +DefaultFetch<Impl>::branchCount() +{ + list<unsigned>::iterator threads = (*activeThreads).begin(); + + return *threads; +} diff --git a/src/cpu/o3/free_list.cc b/src/cpu/o3/free_list.cc index cd707d772..ae651398b 100644 --- a/src/cpu/o3/free_list.cc +++ b/src/cpu/o3/free_list.cc @@ -32,7 +32,8 @@ #include "cpu/o3/free_list.hh" -SimpleFreeList::SimpleFreeList(unsigned _numLogicalIntRegs, +SimpleFreeList::SimpleFreeList(unsigned activeThreads, + unsigned _numLogicalIntRegs, unsigned _numPhysicalIntRegs, unsigned _numLogicalFloatRegs, unsigned _numPhysicalFloatRegs) @@ -42,43 +43,30 @@ SimpleFreeList::SimpleFreeList(unsigned _numLogicalIntRegs, numPhysicalFloatRegs(_numPhysicalFloatRegs), numPhysicalRegs(numPhysicalIntRegs + numPhysicalFloatRegs) { - DPRINTF(FreeList, "FreeList: Creating new free list object.\n"); - - // DEBUG stuff. - freeIntRegsScoreboard.resize(numPhysicalIntRegs); - - freeFloatRegsScoreboard.resize(numPhysicalRegs); - - for (PhysRegIndex i = 0; i < numLogicalIntRegs; ++i) { - freeIntRegsScoreboard[i] = 0; - } + DPRINTF(FreeList, "Creating new free list object.\n"); // Put all of the extra physical registers onto the free list. This // means excluding all of the base logical registers. - for (PhysRegIndex i = numLogicalIntRegs; + for (PhysRegIndex i = numLogicalIntRegs * activeThreads; i < numPhysicalIntRegs; ++i) { freeIntRegs.push(i); - - freeIntRegsScoreboard[i] = 1; - } - - for (PhysRegIndex i = 0; i < numPhysicalIntRegs + numLogicalFloatRegs; - ++i) - { - freeFloatRegsScoreboard[i] = 0; } // Put all of the extra physical registers onto the free list. This // means excluding all of the base logical registers. Because the // float registers' indices start where the physical registers end, // some math must be done to determine where the free registers start. - for (PhysRegIndex i = numPhysicalIntRegs + numLogicalFloatRegs; - i < numPhysicalRegs; ++i) + PhysRegIndex i = numPhysicalIntRegs + (numLogicalFloatRegs * activeThreads); + + for ( ; i < numPhysicalRegs; ++i) { freeFloatRegs.push(i); - - freeFloatRegsScoreboard[i] = 1; } } +std::string +SimpleFreeList::name() const +{ + return "cpu.freelist"; +} diff --git a/src/cpu/o3/free_list.hh b/src/cpu/o3/free_list.hh index 9aa1f08f6..c669b0b34 100644 --- a/src/cpu/o3/free_list.hh +++ b/src/cpu/o3/free_list.hh @@ -28,13 +28,14 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_FREE_LIST_HH__ -#define __CPU_O3_CPU_FREE_LIST_HH__ +#ifndef __CPU_O3_FREE_LIST_HH__ +#define __CPU_O3_FREE_LIST_HH__ #include <iostream> #include <queue> #include "arch/isa_traits.hh" +#include "base/misc.hh" #include "base/trace.hh" #include "base/traceflags.hh" #include "cpu/o3/comm.hh" @@ -47,10 +48,9 @@ * other classes, it assumes that the indices for the floating point * registers starts after the integer registers end. Hence the variable * numPhysicalIntRegs is logically equivalent to the baseFP dependency. - * Note that - * while this most likely should be called FreeList, the name "FreeList" - * is used in a typedef within the CPU Policy, and therefore no class - * can be named simply "FreeList". + * Note that while this most likely should be called FreeList, the name + * "FreeList" is used in a typedef within the CPU Policy, and therefore no + * class can be named simply "FreeList". * @todo: Give a better name to the base FP dependency. */ class SimpleFreeList @@ -77,36 +77,51 @@ class SimpleFreeList /** Total number of physical registers. */ int numPhysicalRegs; - /** DEBUG stuff below. */ - std::vector<int> freeIntRegsScoreboard; - - std::vector<bool> freeFloatRegsScoreboard; - public: - SimpleFreeList(unsigned _numLogicalIntRegs, + /** Constructs a free list. + * @param activeThreads Number of active threads. + * @param _numLogicalIntRegs Number of logical integer registers. + * @param _numPhysicalIntRegs Number of physical integer registers. + * @param _numLogicalFloatRegs Number of logical fp registers. + * @param _numPhysicalFloatRegs Number of physical fp registers. + */ + SimpleFreeList(unsigned activeThreads, + unsigned _numLogicalIntRegs, unsigned _numPhysicalIntRegs, unsigned _numLogicalFloatRegs, unsigned _numPhysicalFloatRegs); + /** Gives the name of the freelist. */ + std::string name() const; + + /** Gets a free integer register. */ inline PhysRegIndex getIntReg(); + /** Gets a free fp register. */ inline PhysRegIndex getFloatReg(); + /** Adds a register back to the free list. */ inline void addReg(PhysRegIndex freed_reg); + /** Adds an integer register back to the free list. */ inline void addIntReg(PhysRegIndex freed_reg); + /** Adds a fp register back to the free list. */ inline void addFloatReg(PhysRegIndex freed_reg); + /** Checks if there are any free integer registers. */ bool hasFreeIntRegs() { return !freeIntRegs.empty(); } + /** Checks if there are any free fp registers. */ bool hasFreeFloatRegs() { return !freeFloatRegs.empty(); } + /** Returns the number of free integer registers. */ int numFreeIntRegs() { return freeIntRegs.size(); } + /** Returns the number of free fp registers. */ int numFreeFloatRegs() { return freeFloatRegs.size(); } }; @@ -114,7 +129,8 @@ class SimpleFreeList inline PhysRegIndex SimpleFreeList::getIntReg() { - DPRINTF(Rename, "FreeList: Trying to get free integer register.\n"); + DPRINTF(FreeList, "Trying to get free integer register.\n"); + if (freeIntRegs.empty()) { panic("No free integer registers!"); } @@ -123,17 +139,14 @@ SimpleFreeList::getIntReg() freeIntRegs.pop(); - // DEBUG - assert(freeIntRegsScoreboard[free_reg]); - freeIntRegsScoreboard[free_reg] = 0; - return(free_reg); } inline PhysRegIndex SimpleFreeList::getFloatReg() { - DPRINTF(Rename, "FreeList: Trying to get free float register.\n"); + DPRINTF(FreeList, "Trying to get free float register.\n"); + if (freeFloatRegs.empty()) { panic("No free integer registers!"); } @@ -142,42 +155,28 @@ SimpleFreeList::getFloatReg() freeFloatRegs.pop(); - // DEBUG - assert(freeFloatRegsScoreboard[free_reg]); - freeFloatRegsScoreboard[free_reg] = 0; - return(free_reg); } inline void SimpleFreeList::addReg(PhysRegIndex freed_reg) { - DPRINTF(Rename, "Freelist: Freeing register %i.\n", freed_reg); + DPRINTF(FreeList,"Freeing register %i.\n", freed_reg); //Might want to add in a check for whether or not this register is //already in there. A bit vector or something similar would be useful. if (freed_reg < numPhysicalIntRegs) { - freeIntRegs.push(freed_reg); - - // DEBUG - assert(freeIntRegsScoreboard[freed_reg] == false); - freeIntRegsScoreboard[freed_reg] = 1; + if (freed_reg != TheISA::ZeroReg) + freeIntRegs.push(freed_reg); } else if (freed_reg < numPhysicalRegs) { - freeFloatRegs.push(freed_reg); - - // DEBUG - assert(freeFloatRegsScoreboard[freed_reg] == false); - freeFloatRegsScoreboard[freed_reg] = 1; + if (freed_reg != (TheISA::ZeroReg + numPhysicalIntRegs)) + freeFloatRegs.push(freed_reg); } } inline void SimpleFreeList::addIntReg(PhysRegIndex freed_reg) { - DPRINTF(Rename, "Freelist: Freeing int register %i.\n", freed_reg); - - // DEBUG - assert(!freeIntRegsScoreboard[freed_reg]); - freeIntRegsScoreboard[freed_reg] = 1; + DPRINTF(FreeList,"Freeing int register %i.\n", freed_reg); freeIntRegs.push(freed_reg); } @@ -185,13 +184,9 @@ SimpleFreeList::addIntReg(PhysRegIndex freed_reg) inline void SimpleFreeList::addFloatReg(PhysRegIndex freed_reg) { - DPRINTF(Rename, "Freelist: Freeing float register %i.\n", freed_reg); - - // DEBUG - assert(!freeFloatRegsScoreboard[freed_reg]); - freeFloatRegsScoreboard[freed_reg] = 1; + DPRINTF(FreeList,"Freeing float register %i.\n", freed_reg); freeFloatRegs.push(freed_reg); } -#endif // __CPU_O3_CPU_FREE_LIST_HH__ +#endif // __CPU_O3_FREE_LIST_HH__ diff --git a/src/cpu/o3/fu_pool.cc b/src/cpu/o3/fu_pool.cc new file mode 100644 index 000000000..545deea9b --- /dev/null +++ b/src/cpu/o3/fu_pool.cc @@ -0,0 +1,299 @@ +/* + * Copyright (c) 2006 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Kevin Lim + */ + +#include <sstream> + +#include "cpu/o3/fu_pool.hh" +#include "encumbered/cpu/full/fu_pool.hh" +#include "sim/builder.hh" + +using namespace std; + +//////////////////////////////////////////////////////////////////////////// +// +// A pool of function units +// + +inline void +FUPool::FUIdxQueue::addFU(int fu_idx) +{ + funcUnitsIdx.push_back(fu_idx); + ++size; +} + +inline int +FUPool::FUIdxQueue::getFU() +{ + int retval = funcUnitsIdx[idx++]; + + if (idx == size) + idx = 0; + + return retval; +} + +FUPool::~FUPool() +{ + fuListIterator i = funcUnits.begin(); + fuListIterator end = funcUnits.end(); + for (; i != end; ++i) + delete *i; +} + + +// Constructor +FUPool::FUPool(string name, vector<FUDesc *> paramList) + : SimObject(name) +{ + numFU = 0; + + funcUnits.clear(); + + for (int i = 0; i < Num_OpClasses; ++i) { + maxOpLatencies[i] = 0; + maxIssueLatencies[i] = 0; + } + + // + // Iterate through the list of FUDescData structures + // + for (FUDDiterator i = paramList.begin(); i != paramList.end(); ++i) { + + // + // Don't bother with this if we're not going to create any FU's + // + if ((*i)->number) { + // + // Create the FuncUnit object from this structure + // - add the capabilities listed in the FU's operation + // description + // + // We create the first unit, then duplicate it as needed + // + FuncUnit *fu = new FuncUnit; + + OPDDiterator j = (*i)->opDescList.begin(); + OPDDiterator end = (*i)->opDescList.end(); + for (; j != end; ++j) { + // indicate that this pool has this capability + capabilityList.set((*j)->opClass); + + // Add each of the FU's that will have this capability to the + // appropriate queue. + for (int k = 0; k < (*i)->number; ++k) + fuPerCapList[(*j)->opClass].addFU(numFU + k); + + // indicate that this FU has the capability + fu->addCapability((*j)->opClass, (*j)->opLat, (*j)->issueLat); + + if ((*j)->opLat > maxOpLatencies[(*j)->opClass]) + maxOpLatencies[(*j)->opClass] = (*j)->opLat; + + if ((*j)->issueLat > maxIssueLatencies[(*j)->opClass]) + maxIssueLatencies[(*j)->opClass] = (*j)->issueLat; + } + + numFU++; + + // Add the appropriate number of copies of this FU to the list + ostringstream s; + + s << (*i)->name() << "(0)"; + fu->name = s.str(); + funcUnits.push_back(fu); + + for (int c = 1; c < (*i)->number; ++c) { + ostringstream s; + numFU++; + FuncUnit *fu2 = new FuncUnit(*fu); + + s << (*i)->name() << "(" << c << ")"; + fu2->name = s.str(); + funcUnits.push_back(fu2); + } + } + } + + unitBusy.resize(numFU); + + for (int i = 0; i < numFU; i++) { + unitBusy[i] = false; + } +} + +void +FUPool::annotateMemoryUnits(unsigned hit_latency) +{ + maxOpLatencies[MemReadOp] = hit_latency; + + fuListIterator i = funcUnits.begin(); + fuListIterator iend = funcUnits.end(); + for (; i != iend; ++i) { + if ((*i)->provides(MemReadOp)) + (*i)->opLatency(MemReadOp) = hit_latency; + + if ((*i)->provides(MemWriteOp)) + (*i)->opLatency(MemWriteOp) = hit_latency; + } +} + +int +FUPool::getUnit(OpClass capability) +{ + // If this pool doesn't have the specified capability, + // return this information to the caller + if (!capabilityList[capability]) + return -2; + + int fu_idx = fuPerCapList[capability].getFU(); + int start_idx = fu_idx; + + // Iterate through the circular queue if needed, stopping if we've reached + // the first element again. + while (unitBusy[fu_idx]) { + fu_idx = fuPerCapList[capability].getFU(); + if (fu_idx == start_idx) { + // No FU available + return -1; + } + } + + assert(fu_idx < numFU); + + unitBusy[fu_idx] = true; + + return fu_idx; +} + +void +FUPool::freeUnitNextCycle(int fu_idx) +{ + assert(unitBusy[fu_idx]); + unitsToBeFreed.push_back(fu_idx); +} + +void +FUPool::processFreeUnits() +{ + while (!unitsToBeFreed.empty()) { + int fu_idx = unitsToBeFreed.back(); + unitsToBeFreed.pop_back(); + + assert(unitBusy[fu_idx]); + + unitBusy[fu_idx] = false; + } +} + +void +FUPool::dump() +{ + cout << "Function Unit Pool (" << name() << ")\n"; + cout << "======================================\n"; + cout << "Free List:\n"; + + for (int i = 0; i < numFU; ++i) { + if (unitBusy[i]) { + continue; + } + + cout << " [" << i << "] : "; + + cout << funcUnits[i]->name << " "; + + cout << "\n"; + } + + cout << "======================================\n"; + cout << "Busy List:\n"; + for (int i = 0; i < numFU; ++i) { + if (!unitBusy[i]) { + continue; + } + + cout << " [" << i << "] : "; + + cout << funcUnits[i]->name << " "; + + cout << "\n"; + } +} + +void +FUPool::switchOut() +{ +} + +void +FUPool::takeOverFrom() +{ + for (int i = 0; i < numFU; i++) { + unitBusy[i] = false; + } + unitsToBeFreed.clear(); +} + +// + +//////////////////////////////////////////////////////////////////////////// +// +// The SimObjects we use to get the FU information into the simulator +// +//////////////////////////////////////////////////////////////////////////// + +// +// FUPool - Contails a list of FUDesc objects to make available +// + +// +// The FuPool object +// + +BEGIN_DECLARE_SIM_OBJECT_PARAMS(FUPool) + + SimObjectVectorParam<FUDesc *> FUList; + +END_DECLARE_SIM_OBJECT_PARAMS(FUPool) + + +BEGIN_INIT_SIM_OBJECT_PARAMS(FUPool) + + INIT_PARAM(FUList, "list of FU's for this pool") + +END_INIT_SIM_OBJECT_PARAMS(FUPool) + + +CREATE_SIM_OBJECT(FUPool) +{ + return new FUPool(getInstanceName(), FUList); +} + +REGISTER_SIM_OBJECT("FUPool", FUPool) + diff --git a/src/cpu/o3/fu_pool.hh b/src/cpu/o3/fu_pool.hh new file mode 100644 index 000000000..52d83f056 --- /dev/null +++ b/src/cpu/o3/fu_pool.hh @@ -0,0 +1,167 @@ +/* + * Copyright (c) 2006 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Kevin Lim + */ + +#ifndef __CPU_O3_FU_POOL_HH__ +#define __CPU_O3_FU_POOL_HH__ + +#include <bitset> +#include <list> +#include <string> +#include <vector> + +#include "base/sched_list.hh" +#include "cpu/op_class.hh" +#include "sim/sim_object.hh" + +class FUDesc; +class FuncUnit; + +/** + * Pool of FU's, specific to the new CPU model. The old FU pool had lists of + * free units and busy units, and whenever a FU was needed it would iterate + * through the free units to find a FU that provided the capability. This pool + * has lists of units specific to each of the capabilities, and whenever a FU + * is needed, it iterates through that list to find a free unit. The previous + * FU pool would have to be ticked each cycle to update which units became + * free. This FU pool lets the IEW stage handle freeing units, which frees + * them as their scheduled execution events complete. This limits units in this + * model to either have identical issue and op latencies, or 1 cycle issue + * latencies. + */ +class FUPool : public SimObject +{ + private: + /** Maximum op execution latencies, per op class. */ + unsigned maxOpLatencies[Num_OpClasses]; + /** Maximum issue latencies, per op class. */ + unsigned maxIssueLatencies[Num_OpClasses]; + + /** Bitvector listing capabilities of this FU pool. */ + std::bitset<Num_OpClasses> capabilityList; + + /** Bitvector listing which FUs are busy. */ + std::vector<bool> unitBusy; + + /** List of units to be freed at the end of this cycle. */ + std::vector<int> unitsToBeFreed; + + /** + * Class that implements a circular queue to hold FU indices. The hope is + * that FUs that have been just used will be moved to the end of the queue + * by iterating through it, thus leaving free units at the head of the + * queue. + */ + class FUIdxQueue { + public: + /** Constructs a circular queue of FU indices. */ + FUIdxQueue() + : idx(0), size(0) + { } + + /** Adds a FU to the queue. */ + inline void addFU(int fu_idx); + + /** Returns the index of the FU at the head of the queue, and changes + * the index to the next element. + */ + inline int getFU(); + + private: + /** Circular queue index. */ + int idx; + + /** Size of the queue. */ + int size; + + /** Queue of FU indices. */ + std::vector<int> funcUnitsIdx; + }; + + /** Per op class queues of FUs that provide that capability. */ + FUIdxQueue fuPerCapList[Num_OpClasses]; + + /** Number of FUs. */ + int numFU; + + /** Functional units. */ + std::vector<FuncUnit *> funcUnits; + + typedef std::vector<FuncUnit *>::iterator fuListIterator; + + public: + + /** Constructs a FU pool. */ + FUPool(std::string name, std::vector<FUDesc *> l); + ~FUPool(); + + /** Annotates units that provide memory operations. Included only because + * old FU pool provided this function. + */ + void annotateMemoryUnits(unsigned hit_latency); + + /** + * Gets a FU providing the requested capability. Will mark the unit as busy, + * but leaves the freeing of the unit up to the IEW stage. + * @param capability The capability requested. + * @return Returns -2 if the FU pool does not have the capability, -1 if + * there is no free FU, and the FU's index otherwise. + */ + int getUnit(OpClass capability); + + /** Frees a FU at the end of this cycle. */ + void freeUnitNextCycle(int fu_idx); + + /** Frees all FUs on the list. */ + void processFreeUnits(); + + /** Returns the total number of FUs. */ + int size() { return numFU; } + + /** Debugging function used to dump FU information. */ + void dump(); + + /** Returns the operation execution latency of the given capability. */ + unsigned getOpLatency(OpClass capability) { + return maxOpLatencies[capability]; + } + + /** Returns the issue latency of the given capability. */ + unsigned getIssueLatency(OpClass capability) { + return maxIssueLatencies[capability]; + } + + /** Switches out functional unit pool. */ + void switchOut(); + + /** Takes over from another CPU's thread. */ + void takeOverFrom(); +}; + +#endif // __CPU_O3_FU_POOL_HH__ diff --git a/src/cpu/o3/iew.cc b/src/cpu/o3/iew.cc index 8293477fa..8145f4cc7 100644 --- a/src/cpu/o3/iew.cc +++ b/src/cpu/o3/iew.cc @@ -33,4 +33,4 @@ #include "cpu/o3/iew_impl.hh" #include "cpu/o3/inst_queue.hh" -template class SimpleIEW<AlphaSimpleImpl>; +template class DefaultIEW<AlphaSimpleImpl>; diff --git a/src/cpu/o3/iew.hh b/src/cpu/o3/iew.hh index 88451f3cf..2e61af5fc 100644 --- a/src/cpu/o3/iew.hh +++ b/src/cpu/o3/iew.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,22 +28,41 @@ * Authors: Kevin Lim */ -//Todo: Update with statuses. -//Need to handle delaying writes to the writeback bus if it's full at the -//given time. - -#ifndef __CPU_O3_CPU_SIMPLE_IEW_HH__ -#define __CPU_O3_CPU_SIMPLE_IEW_HH__ +#ifndef __CPU_O3_IEW_HH__ +#define __CPU_O3_IEW_HH__ #include <queue> -#include "config/full_system.hh" #include "base/statistics.hh" #include "base/timebuf.hh" +#include "config/full_system.hh" #include "cpu/o3/comm.hh" - +#include "cpu/o3/scoreboard.hh" +#include "cpu/o3/lsq.hh" + +class FUPool; + +/** + * DefaultIEW handles both single threaded and SMT IEW + * (issue/execute/writeback). It handles the dispatching of + * instructions to the LSQ/IQ as part of the issue stage, and has the + * IQ try to issue instructions each cycle. The execute latency is + * actually tied into the issue latency to allow the IQ to be able to + * do back-to-back scheduling without having to speculatively schedule + * instructions. This happens by having the IQ have access to the + * functional units, and the IQ gets the execution latencies from the + * FUs when it issues instructions. Instructions reach the execute + * stage on the last cycle of their execution, which is when the IQ + * knows to wake up any dependent instructions, allowing back to back + * scheduling. The execute portion of IEW separates memory + * instructions from non-memory instructions, either telling the LSQ + * to execute the instruction, or executing the instruction directly. + * The writeback portion of IEW completes the instructions by waking + * up any dependents, and marking the register ready on the + * scoreboard. + */ template<class Impl> -class SimpleIEW +class DefaultIEW { private: //Typedefs from Impl @@ -54,7 +73,7 @@ class SimpleIEW typedef typename CPUPol::IQ IQ; typedef typename CPUPol::RenameMap RenameMap; - typedef typename CPUPol::LDSTQ LDSTQ; + typedef typename CPUPol::LSQ LSQ; typedef typename CPUPol::TimeStruct TimeStruct; typedef typename CPUPol::IEWStruct IEWStruct; @@ -62,77 +81,205 @@ class SimpleIEW typedef typename CPUPol::IssueStruct IssueStruct; friend class Impl::FullCPU; + friend class CPUPol::IQ; + public: + /** Overall IEW stage status. Used to determine if the CPU can + * deschedule itself due to a lack of activity. + */ enum Status { + Active, + Inactive + }; + + /** Status for Issue, Execute, and Writeback stages. */ + enum StageStatus { Running, Blocked, Idle, + StartSquash, Squashing, Unblocking }; private: + /** Overall stage status. */ Status _status; - Status _issueStatus; - Status _exeStatus; - Status _wbStatus; + /** Dispatch status. */ + StageStatus dispatchStatus[Impl::MaxThreads]; + /** Execute status. */ + StageStatus exeStatus; + /** Writeback status. */ + StageStatus wbStatus; public: - class WritebackEvent : public Event { - private: - DynInstPtr inst; - SimpleIEW<Impl> *iewStage; - - public: - WritebackEvent(DynInstPtr &_inst, SimpleIEW<Impl> *_iew); + /** Constructs a DefaultIEW with the given parameters. */ + DefaultIEW(Params *params); - virtual void process(); - virtual const char *description(); - }; - - public: - SimpleIEW(Params ¶ms); + /** Returns the name of the DefaultIEW stage. */ + std::string name() const; + /** Registers statistics. */ void regStats(); + /** Initializes stage; sends back the number of free IQ and LSQ entries. */ + void initStage(); + + /** Sets CPU pointer for IEW, IQ, and LSQ. */ void setCPU(FullCPU *cpu_ptr); + /** Sets main time buffer used for backwards communication. */ void setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr); + /** Sets time buffer for getting instructions coming from rename. */ void setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr); + /** Sets time buffer to pass on instructions to commit. */ void setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr); - void setRenameMap(RenameMap *rm_ptr); + /** Sets pointer to list of active threads. */ + void setActiveThreads(std::list<unsigned> *at_ptr); + + /** Sets pointer to the scoreboard. */ + void setScoreboard(Scoreboard *sb_ptr); - void squash(); + /** Starts switch out of IEW stage. */ + void switchOut(); - void squashDueToBranch(DynInstPtr &inst); + /** Completes switch out of IEW stage. */ + void doSwitchOut(); - void squashDueToMem(DynInstPtr &inst); + /** Takes over from another CPU's thread. */ + void takeOverFrom(); - void block(); + /** Returns if IEW is switched out. */ + bool isSwitchedOut() { return switchedOut; } - inline void unblock(); + /** Squashes instructions in IEW for a specific thread. */ + void squash(unsigned tid); + /** Wakes all dependents of a completed instruction. */ void wakeDependents(DynInstPtr &inst); + /** Tells memory dependence unit that a memory instruction needs to be + * rescheduled. It will re-execute once replayMemInst() is called. + */ + void rescheduleMemInst(DynInstPtr &inst); + + /** Re-executes all rescheduled memory instructions. */ + void replayMemInst(DynInstPtr &inst); + + /** Sends an instruction to commit through the time buffer. */ void instToCommit(DynInstPtr &inst); + /** Inserts unused instructions of a thread into the skid buffer. */ + void skidInsert(unsigned tid); + + /** Returns the max of the number of entries in all of the skid buffers. */ + int skidCount(); + + /** Returns if all of the skid buffers are empty. */ + bool skidsEmpty(); + + /** Updates overall IEW status based on all of the stages' statuses. */ + void updateStatus(); + + /** Resets entries of the IQ and the LSQ. */ + void resetEntries(); + + /** Tells the CPU to wakeup if it has descheduled itself due to no + * activity. Used mainly by the LdWritebackEvent. + */ + void wakeCPU(); + + /** Reports to the CPU that there is activity this cycle. */ + void activityThisCycle(); + + /** Tells CPU that the IEW stage is active and running. */ + inline void activateStage(); + + /** Tells CPU that the IEW stage is inactive and idle. */ + inline void deactivateStage(); + + /** Returns if the LSQ has any stores to writeback. */ + bool hasStoresToWB() { return ldstQueue.hasStoresToWB(); } + private: - void dispatchInsts(); + /** Sends commit proper information for a squash due to a branch + * mispredict. + */ + void squashDueToBranch(DynInstPtr &inst, unsigned thread_id); + + /** Sends commit proper information for a squash due to a memory order + * violation. + */ + void squashDueToMemOrder(DynInstPtr &inst, unsigned thread_id); + + /** Sends commit proper information for a squash due to memory becoming + * blocked (younger issued instructions must be retried). + */ + void squashDueToMemBlocked(DynInstPtr &inst, unsigned thread_id); + + /** Sets Dispatch to blocked, and signals back to other stages to block. */ + void block(unsigned thread_id); + + /** Unblocks Dispatch if the skid buffer is empty, and signals back to + * other stages to unblock. + */ + void unblock(unsigned thread_id); + + /** Determines proper actions to take given Dispatch's status. */ + void dispatch(unsigned tid); + + /** Dispatches instructions to IQ and LSQ. */ + void dispatchInsts(unsigned tid); + /** Executes instructions. In the case of memory operations, it informs the + * LSQ to execute the instructions. Also handles any redirects that occur + * due to the executed instructions. + */ void executeInsts(); + /** Writebacks instructions. In our model, the instruction's execute() + * function atomically reads registers, executes, and writes registers. + * Thus this writeback only wakes up dependent instructions, and informs + * the scoreboard of registers becoming ready. + */ + void writebackInsts(); + + /** Returns the number of valid, non-squashed instructions coming from + * rename to dispatch. + */ + unsigned validInstsFromRename(); + + /** Reads the stall signals. */ + void readStallSignals(unsigned tid); + + /** Checks if any of the stall conditions are currently true. */ + bool checkStall(unsigned tid); + + /** Processes inputs and changes state accordingly. */ + void checkSignalsAndUpdate(unsigned tid); + + /** Sorts instructions coming from rename into lists separated by thread. */ + void sortInsts(); + public: + /** Ticks IEW stage, causing Dispatch, the IQ, the LSQ, Execute, and + * Writeback to run for one cycle. + */ void tick(); - void iew(); + private: + /** Updates execution stats based on the instruction. */ + void updateExeInstStats(DynInstPtr &inst); - //Interfaces to objects inside and outside of IEW. - /** Time buffer interface. */ + /** Pointer to main time buffer used for backwards communication. */ TimeBuffer<TimeStruct> *timeBuffer; + /** Wire to write information heading to previous stages. */ + typename TimeBuffer<TimeStruct>::wire toFetch; + /** Wire to get commit's output from backwards time buffer. */ typename TimeBuffer<TimeStruct>::wire fromCommit; @@ -160,32 +307,67 @@ class SimpleIEW /** Wire to write infromation heading to commit. */ typename TimeBuffer<IEWStruct>::wire toCommit; - //Will need internal queue to hold onto instructions coming from - //the rename stage in case of a stall. + /** Queue of all instructions coming from rename this cycle. */ + std::queue<DynInstPtr> insts[Impl::MaxThreads]; + /** Skid buffer between rename and IEW. */ - std::queue<RenameStruct> skidBuffer; + std::queue<DynInstPtr> skidBuffer[Impl::MaxThreads]; + + /** Scoreboard pointer. */ + Scoreboard* scoreboard; - protected: + public: /** Instruction queue. */ IQ instQueue; - LDSTQ ldstQueue; + /** Load / store queue. */ + LSQ ldstQueue; -#if !FULL_SYSTEM - public: - void lsqWriteback(); -#endif + /** Pointer to the functional unit pool. */ + FUPool *fuPool; private: - /** Pointer to rename map. Might not want this stage to directly - * access this though... + /** CPU pointer. */ + FullCPU *cpu; + + /** Records if IEW has written to the time buffer this cycle, so that the + * CPU can deschedule itself if there is no activity. */ - RenameMap *renameMap; + bool wroteToTimeBuffer; - /** CPU interface. */ - FullCPU *cpu; + /** Source of possible stalls. */ + struct Stalls { + bool commit; + }; + + /** Stages that are telling IEW to stall. */ + Stalls stalls[Impl::MaxThreads]; + + /** Debug function to print instructions that are issued this cycle. */ + void printAvailableInsts(); + + public: + /** Records if the LSQ needs to be updated on the next cycle, so that + * IEW knows if there will be activity on the next cycle. + */ + bool updateLSQNextCycle; private: + /** Records if there is a fetch redirect on this cycle for each thread. */ + bool fetchRedirect[Impl::MaxThreads]; + + /** Used to track if all instructions have been dispatched this cycle. + * If they have not, then blocking must have occurred, and the instructions + * would already be added to the skid buffer. + * @todo: Fix this hack. + */ + bool dispatchedAllInsts; + + /** Records if the queues have been changed (inserted or issued insts), + * so that IEW knows to broadcast the updated amount of free entries. + */ + bool updatedQueues; + /** Commit to IEW delay, in ticks. */ unsigned commitToIEWDelay; @@ -213,29 +395,108 @@ class SimpleIEW */ unsigned executeWidth; - /** Number of cycles stage has been squashing. Used so that the stage - * knows when it can start unblocking, which is when the previous stage - * has received the stall signal and clears up its outputs. + /** Index into queue of instructions being written back. */ + unsigned wbNumInst; + + /** Cycle number within the queue of instructions being written back. + * Used in case there are too many instructions writing back at the current + * cycle and writesbacks need to be scheduled for the future. See comments + * in instToCommit(). */ - unsigned cyclesSquashing; + unsigned wbCycle; + + /** Number of active threads. */ + unsigned numThreads; + + /** Pointer to list of active threads. */ + std::list<unsigned> *activeThreads; + /** Maximum size of the skid buffer. */ + unsigned skidBufferMax; + + /** Is this stage switched out. */ + bool switchedOut; + + /** Stat for total number of idle cycles. */ Stats::Scalar<> iewIdleCycles; + /** Stat for total number of squashing cycles. */ Stats::Scalar<> iewSquashCycles; + /** Stat for total number of blocking cycles. */ Stats::Scalar<> iewBlockCycles; + /** Stat for total number of unblocking cycles. */ Stats::Scalar<> iewUnblockCycles; -// Stats::Scalar<> iewWBInsts; + /** Stat for total number of instructions dispatched. */ Stats::Scalar<> iewDispatchedInsts; + /** Stat for total number of squashed instructions dispatch skips. */ Stats::Scalar<> iewDispSquashedInsts; + /** Stat for total number of dispatched load instructions. */ Stats::Scalar<> iewDispLoadInsts; + /** Stat for total number of dispatched store instructions. */ Stats::Scalar<> iewDispStoreInsts; + /** Stat for total number of dispatched non speculative instructions. */ Stats::Scalar<> iewDispNonSpecInsts; + /** Stat for number of times the IQ becomes full. */ Stats::Scalar<> iewIQFullEvents; + /** Stat for number of times the LSQ becomes full. */ + Stats::Scalar<> iewLSQFullEvents; + /** Stat for total number of executed instructions. */ Stats::Scalar<> iewExecutedInsts; - Stats::Scalar<> iewExecLoadInsts; - Stats::Scalar<> iewExecStoreInsts; + /** Stat for total number of executed load instructions. */ + Stats::Vector<> iewExecLoadInsts; + /** Stat for total number of executed store instructions. */ +// Stats::Scalar<> iewExecStoreInsts; + /** Stat for total number of squashed instructions skipped at execute. */ Stats::Scalar<> iewExecSquashedInsts; + /** Stat for total number of memory ordering violation events. */ Stats::Scalar<> memOrderViolationEvents; + /** Stat for total number of incorrect predicted taken branches. */ Stats::Scalar<> predictedTakenIncorrect; + /** Stat for total number of incorrect predicted not taken branches. */ + Stats::Scalar<> predictedNotTakenIncorrect; + /** Stat for total number of mispredicted branches detected at execute. */ + Stats::Formula branchMispredicts; + + /** Number of executed software prefetches. */ + Stats::Vector<> exeSwp; + /** Number of executed nops. */ + Stats::Vector<> exeNop; + /** Number of executed meomory references. */ + Stats::Vector<> exeRefs; + /** Number of executed branches. */ + Stats::Vector<> exeBranches; + +// Stats::Vector<> issued_ops; +/* + Stats::Vector<> stat_fu_busy; + Stats::Vector2d<> stat_fuBusy; + Stats::Vector<> dist_unissued; + Stats::Vector2d<> stat_issued_inst_type; +*/ + /** Number of instructions issued per cycle. */ + Stats::Formula issueRate; + /** Number of executed store instructions. */ + Stats::Formula iewExecStoreInsts; +// Stats::Formula issue_op_rate; +// Stats::Formula fu_busy_rate; + /** Number of instructions sent to commit. */ + Stats::Vector<> iewInstsToCommit; + /** Number of instructions that writeback. */ + Stats::Vector<> writebackCount; + /** Number of instructions that wake consumers. */ + Stats::Vector<> producerInst; + /** Number of instructions that wake up from producers. */ + Stats::Vector<> consumerInst; + /** Number of instructions that were delayed in writing back due + * to resource contention. + */ + Stats::Vector<> wbPenalized; + + /** Number of instructions per cycle written back. */ + Stats::Formula wbRate; + /** Average number of woken instructions per writeback. */ + Stats::Formula wbFanout; + /** Number of instructions per cycle delayed in writing back . */ + Stats::Formula wbPenalizedRate; }; -#endif // __CPU_O3_CPU_IEW_HH__ +#endif // __CPU_O3_IEW_HH__ diff --git a/src/cpu/o3/iew_impl.hh b/src/cpu/o3/iew_impl.hh index 35a5bbcb5..3929f2e19 100644 --- a/src/cpu/o3/iew_impl.hh +++ b/src/cpu/o3/iew_impl.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -31,59 +31,34 @@ // @todo: Fix the instantaneous communication among all the stages within // iew. There's a clear delay between issue and execute, yet backwards // communication happens simultaneously. -// Update the statuses for each stage. #include <queue> #include "base/timebuf.hh" +#include "cpu/o3/fu_pool.hh" #include "cpu/o3/iew.hh" -template<class Impl> -SimpleIEW<Impl>::WritebackEvent::WritebackEvent(DynInstPtr &_inst, - SimpleIEW<Impl> *_iew) - : Event(&mainEventQueue, CPU_Tick_Pri), inst(_inst), iewStage(_iew) -{ - this->setFlags(Event::AutoDelete); -} - -template<class Impl> -void -SimpleIEW<Impl>::WritebackEvent::process() -{ - DPRINTF(IEW, "IEW: WRITEBACK EVENT!!!!\n"); - - // Need to insert instruction into queue to commit - iewStage->instToCommit(inst); - // Need to execute second half of the instruction, do actual writing to - // registers and such - inst->execute(); -} - -template<class Impl> -const char * -SimpleIEW<Impl>::WritebackEvent::description() -{ - return "LSQ writeback event"; -} +using namespace std; template<class Impl> -SimpleIEW<Impl>::SimpleIEW(Params ¶ms) - : // Just make this time buffer really big for now +DefaultIEW<Impl>::DefaultIEW(Params *params) + : // @todo: Make this into a parameter. issueToExecQueue(5, 5), instQueue(params), ldstQueue(params), - commitToIEWDelay(params.commitToIEWDelay), - renameToIEWDelay(params.renameToIEWDelay), - issueToExecuteDelay(params.issueToExecuteDelay), - issueReadWidth(params.issueWidth), - issueWidth(params.issueWidth), - executeWidth(params.executeWidth) -{ - DPRINTF(IEW, "IEW: executeIntWidth: %i.\n", params.executeIntWidth); - _status = Idle; - _issueStatus = Idle; - _exeStatus = Idle; - _wbStatus = Idle; + fuPool(params->fuPool), + commitToIEWDelay(params->commitToIEWDelay), + renameToIEWDelay(params->renameToIEWDelay), + issueToExecuteDelay(params->issueToExecuteDelay), + issueReadWidth(params->issueWidth), + issueWidth(params->issueWidth), + executeWidth(params->executeWidth), + numThreads(params->numberOfThreads), + switchedOut(false) +{ + _status = Active; + exeStatus = Running; + wbStatus = Idle; // Setup wire to read instructions coming from issue. fromIssue = issueToExecQueue.getWire(-issueToExecuteDelay); @@ -91,13 +66,33 @@ SimpleIEW<Impl>::SimpleIEW(Params ¶ms) // Instruction queue needs the queue between issue and execute. instQueue.setIssueToExecuteQueue(&issueToExecQueue); + instQueue.setIEW(this); ldstQueue.setIEW(this); + + for (int i=0; i < numThreads; i++) { + dispatchStatus[i] = Running; + stalls[i].commit = false; + fetchRedirect[i] = false; + } + + updateLSQNextCycle = false; + + skidBufferMax = (3 * (renameToIEWDelay * params->renameWidth)) + issueWidth; +} + +template <class Impl> +std::string +DefaultIEW<Impl>::name() const +{ + return cpu->name() + ".iew"; } template <class Impl> void -SimpleIEW<Impl>::regStats() +DefaultIEW<Impl>::regStats() { + using namespace Stats; + instQueue.regStats(); iewIdleCycles @@ -116,8 +111,6 @@ SimpleIEW<Impl>::regStats() .name(name() + ".iewUnblockCycles") .desc("Number of cycles IEW is unblocking"); -// iewWBInsts; - iewDispatchedInsts .name(name() + ".iewDispatchedInsts") .desc("Number of instructions dispatched to IQ"); @@ -142,17 +135,19 @@ SimpleIEW<Impl>::regStats() .name(name() + ".iewIQFullEvents") .desc("Number of times the IQ has become full, causing a stall"); + iewLSQFullEvents + .name(name() + ".iewLSQFullEvents") + .desc("Number of times the LSQ has become full, causing a stall"); + iewExecutedInsts .name(name() + ".iewExecutedInsts") .desc("Number of executed instructions"); iewExecLoadInsts + .init(cpu->number_of_threads) .name(name() + ".iewExecLoadInsts") - .desc("Number of load instructions executed"); - - iewExecStoreInsts - .name(name() + ".iewExecStoreInsts") - .desc("Number of store instructions executed"); + .desc("Number of load instructions executed") + .flags(total); iewExecSquashedInsts .name(name() + ".iewExecSquashedInsts") @@ -165,24 +160,161 @@ SimpleIEW<Impl>::regStats() predictedTakenIncorrect .name(name() + ".predictedTakenIncorrect") .desc("Number of branches that were predicted taken incorrectly"); + + predictedNotTakenIncorrect + .name(name() + ".predictedNotTakenIncorrect") + .desc("Number of branches that were predicted not taken incorrectly"); + + branchMispredicts + .name(name() + ".branchMispredicts") + .desc("Number of branch mispredicts detected at execute"); + + branchMispredicts = predictedTakenIncorrect + predictedNotTakenIncorrect; + + exeSwp + .init(cpu->number_of_threads) + .name(name() + ".EXEC:swp") + .desc("number of swp insts executed") + .flags(total) + ; + + exeNop + .init(cpu->number_of_threads) + .name(name() + ".EXEC:nop") + .desc("number of nop insts executed") + .flags(total) + ; + + exeRefs + .init(cpu->number_of_threads) + .name(name() + ".EXEC:refs") + .desc("number of memory reference insts executed") + .flags(total) + ; + + exeBranches + .init(cpu->number_of_threads) + .name(name() + ".EXEC:branches") + .desc("Number of branches executed") + .flags(total) + ; + + issueRate + .name(name() + ".EXEC:rate") + .desc("Inst execution rate") + .flags(total) + ; + issueRate = iewExecutedInsts / cpu->numCycles; + + iewExecStoreInsts + .name(name() + ".EXEC:stores") + .desc("Number of stores executed") + .flags(total) + ; + iewExecStoreInsts = exeRefs - iewExecLoadInsts; +/* + for (int i=0; i<Num_OpClasses; ++i) { + stringstream subname; + subname << opClassStrings[i] << "_delay"; + issue_delay_dist.subname(i, subname.str()); + } +*/ + // + // Other stats + // + + iewInstsToCommit + .init(cpu->number_of_threads) + .name(name() + ".WB:sent") + .desc("cumulative count of insts sent to commit") + .flags(total) + ; + + writebackCount + .init(cpu->number_of_threads) + .name(name() + ".WB:count") + .desc("cumulative count of insts written-back") + .flags(total) + ; + + producerInst + .init(cpu->number_of_threads) + .name(name() + ".WB:producers") + .desc("num instructions producing a value") + .flags(total) + ; + + consumerInst + .init(cpu->number_of_threads) + .name(name() + ".WB:consumers") + .desc("num instructions consuming a value") + .flags(total) + ; + + wbPenalized + .init(cpu->number_of_threads) + .name(name() + ".WB:penalized") + .desc("number of instrctions required to write to 'other' IQ") + .flags(total) + ; + + wbPenalizedRate + .name(name() + ".WB:penalized_rate") + .desc ("fraction of instructions written-back that wrote to 'other' IQ") + .flags(total) + ; + + wbPenalizedRate = wbPenalized / writebackCount; + + wbFanout + .name(name() + ".WB:fanout") + .desc("average fanout of values written-back") + .flags(total) + ; + + wbFanout = producerInst / consumerInst; + + wbRate + .name(name() + ".WB:rate") + .desc("insts written-back per cycle") + .flags(total) + ; + wbRate = writebackCount / cpu->numCycles; } template<class Impl> void -SimpleIEW<Impl>::setCPU(FullCPU *cpu_ptr) +DefaultIEW<Impl>::initStage() { - DPRINTF(IEW, "IEW: Setting CPU pointer.\n"); + for (int tid=0; tid < numThreads; tid++) { + toRename->iewInfo[tid].usedIQ = true; + toRename->iewInfo[tid].freeIQEntries = + instQueue.numFreeEntries(tid); + + toRename->iewInfo[tid].usedLSQ = true; + toRename->iewInfo[tid].freeLSQEntries = + ldstQueue.numFreeEntries(tid); + } +} + +template<class Impl> +void +DefaultIEW<Impl>::setCPU(FullCPU *cpu_ptr) +{ + DPRINTF(IEW, "Setting CPU pointer.\n"); cpu = cpu_ptr; instQueue.setCPU(cpu_ptr); ldstQueue.setCPU(cpu_ptr); + + cpu->activateStage(FullCPU::IEWIdx); } template<class Impl> void -SimpleIEW<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) +DefaultIEW<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) { - DPRINTF(IEW, "IEW: Setting time buffer pointer.\n"); + DPRINTF(IEW, "Setting time buffer pointer.\n"); timeBuffer = tb_ptr; // Setup wire to read information from time buffer, from commit. @@ -191,15 +323,17 @@ SimpleIEW<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) // Setup wire to write information back to previous stages. toRename = timeBuffer->getWire(0); + toFetch = timeBuffer->getWire(0); + // Instruction queue also needs main time buffer. instQueue.setTimeBuffer(tb_ptr); } template<class Impl> void -SimpleIEW<Impl>::setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr) +DefaultIEW<Impl>::setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr) { - DPRINTF(IEW, "IEW: Setting rename queue pointer.\n"); + DPRINTF(IEW, "Setting rename queue pointer.\n"); renameQueue = rq_ptr; // Setup wire to read information from rename queue. @@ -208,9 +342,9 @@ SimpleIEW<Impl>::setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr) template<class Impl> void -SimpleIEW<Impl>::setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr) +DefaultIEW<Impl>::setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr) { - DPRINTF(IEW, "IEW: Setting IEW queue pointer.\n"); + DPRINTF(IEW, "Setting IEW queue pointer.\n"); iewQueue = iq_ptr; // Setup wire to write instructions to commit. @@ -219,355 +353,938 @@ SimpleIEW<Impl>::setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr) template<class Impl> void -SimpleIEW<Impl>::setRenameMap(RenameMap *rm_ptr) +DefaultIEW<Impl>::setActiveThreads(list<unsigned> *at_ptr) +{ + DPRINTF(IEW, "Setting active threads list pointer.\n"); + activeThreads = at_ptr; + + ldstQueue.setActiveThreads(at_ptr); + instQueue.setActiveThreads(at_ptr); +} + +template<class Impl> +void +DefaultIEW<Impl>::setScoreboard(Scoreboard *sb_ptr) +{ + DPRINTF(IEW, "Setting scoreboard pointer.\n"); + scoreboard = sb_ptr; +} + +template <class Impl> +void +DefaultIEW<Impl>::switchOut() { - DPRINTF(IEW, "IEW: Setting rename map pointer.\n"); - renameMap = rm_ptr; + // IEW is ready to switch out at any time. + cpu->signalSwitched(); +} + +template <class Impl> +void +DefaultIEW<Impl>::doSwitchOut() +{ + // Clear any state. + switchedOut = true; + + instQueue.switchOut(); + ldstQueue.switchOut(); + fuPool->switchOut(); + + for (int i = 0; i < numThreads; i++) { + while (!insts[i].empty()) + insts[i].pop(); + while (!skidBuffer[i].empty()) + skidBuffer[i].pop(); + } +} + +template <class Impl> +void +DefaultIEW<Impl>::takeOverFrom() +{ + // Reset all state. + _status = Active; + exeStatus = Running; + wbStatus = Idle; + switchedOut = false; + + instQueue.takeOverFrom(); + ldstQueue.takeOverFrom(); + fuPool->takeOverFrom(); + + initStage(); + cpu->activityThisCycle(); + + for (int i=0; i < numThreads; i++) { + dispatchStatus[i] = Running; + stalls[i].commit = false; + fetchRedirect[i] = false; + } + + updateLSQNextCycle = false; + + // @todo: Fix hardcoded number + for (int i = 0; i < 6; ++i) { + issueToExecQueue.advance(); + } } template<class Impl> void -SimpleIEW<Impl>::squash() +DefaultIEW<Impl>::squash(unsigned tid) { - DPRINTF(IEW, "IEW: Squashing all instructions.\n"); - _status = Squashing; + DPRINTF(IEW, "[tid:%i]: Squashing all instructions.\n", + tid); // Tell the IQ to start squashing. - instQueue.squash(); + instQueue.squash(tid); // Tell the LDSTQ to start squashing. - ldstQueue.squash(fromCommit->commitInfo.doneSeqNum); + ldstQueue.squash(fromCommit->commitInfo[tid].doneSeqNum, tid); + + updatedQueues = true; + + // Clear the skid buffer in case it has any data in it. + while (!skidBuffer[tid].empty()) { + + if (skidBuffer[tid].front()->isLoad() || + skidBuffer[tid].front()->isStore() ) { + toRename->iewInfo[tid].dispatchedToLSQ++; + } + + toRename->iewInfo[tid].dispatched++; + + skidBuffer[tid].pop(); + } + + while (!insts[tid].empty()) { + if (insts[tid].front()->isLoad() || + insts[tid].front()->isStore() ) { + toRename->iewInfo[tid].dispatchedToLSQ++; + } + + toRename->iewInfo[tid].dispatched++; + + insts[tid].pop(); + } } template<class Impl> void -SimpleIEW<Impl>::squashDueToBranch(DynInstPtr &inst) -{ - DPRINTF(IEW, "IEW: Squashing from a specific instruction, PC: %#x.\n", - inst->PC); - // Perhaps leave the squashing up to the ROB stage to tell it when to - // squash? - _status = Squashing; - - // Tell rename to squash through the time buffer. - toCommit->squash = true; - // Also send PC update information back to prior stages. - toCommit->squashedSeqNum = inst->seqNum; - toCommit->mispredPC = inst->readPC(); - toCommit->nextPC = inst->readNextPC(); - toCommit->branchMispredict = true; - // Prediction was incorrect, so send back inverse. - toCommit->branchTaken = inst->readNextPC() != +DefaultIEW<Impl>::squashDueToBranch(DynInstPtr &inst, unsigned tid) +{ + DPRINTF(IEW, "[tid:%i]: Squashing from a specific instruction, PC: %#x " + "[sn:%i].\n", tid, inst->readPC(), inst->seqNum); + + toCommit->squash[tid] = true; + toCommit->squashedSeqNum[tid] = inst->seqNum; + toCommit->mispredPC[tid] = inst->readPC(); + toCommit->nextPC[tid] = inst->readNextPC(); + toCommit->branchMispredict[tid] = true; + toCommit->branchTaken[tid] = inst->readNextPC() != (inst->readPC() + sizeof(TheISA::MachInst)); + + toCommit->includeSquashInst[tid] = false; + + wroteToTimeBuffer = true; } template<class Impl> void -SimpleIEW<Impl>::squashDueToMem(DynInstPtr &inst) +DefaultIEW<Impl>::squashDueToMemOrder(DynInstPtr &inst, unsigned tid) { - DPRINTF(IEW, "IEW: Squashing from a specific instruction, PC: %#x.\n", - inst->PC); - // Perhaps leave the squashing up to the ROB stage to tell it when to - // squash? - _status = Squashing; + DPRINTF(IEW, "[tid:%i]: Squashing from a specific instruction, " + "PC: %#x [sn:%i].\n", tid, inst->readPC(), inst->seqNum); - // Tell rename to squash through the time buffer. - toCommit->squash = true; - // Also send PC update information back to prior stages. - toCommit->squashedSeqNum = inst->seqNum; - toCommit->nextPC = inst->readNextPC(); + toCommit->squash[tid] = true; + toCommit->squashedSeqNum[tid] = inst->seqNum; + toCommit->nextPC[tid] = inst->readNextPC(); + + toCommit->includeSquashInst[tid] = false; + + wroteToTimeBuffer = true; } template<class Impl> void -SimpleIEW<Impl>::block() +DefaultIEW<Impl>::squashDueToMemBlocked(DynInstPtr &inst, unsigned tid) { - DPRINTF(IEW, "IEW: Blocking.\n"); - // Set the status to Blocked. - _status = Blocked; + DPRINTF(IEW, "[tid:%i]: Memory blocked, squashing load and younger insts, " + "PC: %#x [sn:%i].\n", tid, inst->readPC(), inst->seqNum); + + toCommit->squash[tid] = true; + toCommit->squashedSeqNum[tid] = inst->seqNum; + toCommit->nextPC[tid] = inst->readPC(); + + // Must include the broadcasted SN in the squash. + toCommit->includeSquashInst[tid] = true; + + ldstQueue.setLoadBlockedHandled(tid); + + wroteToTimeBuffer = true; +} + +template<class Impl> +void +DefaultIEW<Impl>::block(unsigned tid) +{ + DPRINTF(IEW, "[tid:%u]: Blocking.\n", tid); + + if (dispatchStatus[tid] != Blocked && + dispatchStatus[tid] != Unblocking) { + toRename->iewBlock[tid] = true; + wroteToTimeBuffer = true; + } // Add the current inputs to the skid buffer so they can be // reprocessed when this stage unblocks. - skidBuffer.push(*fromRename); + skidInsert(tid); - // Note that this stage only signals previous stages to stall when - // it is the cause of the stall originates at this stage. Otherwise - // the previous stages are expected to check all possible stall signals. + dispatchStatus[tid] = Blocked; } template<class Impl> -inline void -SimpleIEW<Impl>::unblock() +void +DefaultIEW<Impl>::unblock(unsigned tid) { - // Check if there's information in the skid buffer. If there is, then - // set status to unblocking, otherwise set it directly to running. - DPRINTF(IEW, "IEW: Reading instructions out of the skid " - "buffer.\n"); - // Remove the now processed instructions from the skid buffer. - skidBuffer.pop(); - - // If there's still information in the skid buffer, then - // continue to tell previous stages to stall. They will be - // able to restart once the skid buffer is empty. - if (!skidBuffer.empty()) { - toRename->iewInfo.stall = true; - } else { - DPRINTF(IEW, "IEW: Stage is done unblocking.\n"); - _status = Running; + DPRINTF(IEW, "[tid:%i]: Reading instructions out of the skid " + "buffer %u.\n",tid, tid); + + // If the skid bufffer is empty, signal back to previous stages to unblock. + // Also switch status to running. + if (skidBuffer[tid].empty()) { + toRename->iewUnblock[tid] = true; + wroteToTimeBuffer = true; + DPRINTF(IEW, "[tid:%i]: Done unblocking.\n",tid); + dispatchStatus[tid] = Running; } } template<class Impl> void -SimpleIEW<Impl>::wakeDependents(DynInstPtr &inst) +DefaultIEW<Impl>::wakeDependents(DynInstPtr &inst) { instQueue.wakeDependents(inst); } +template<class Impl> +void +DefaultIEW<Impl>::rescheduleMemInst(DynInstPtr &inst) +{ + instQueue.rescheduleMemInst(inst); +} + +template<class Impl> +void +DefaultIEW<Impl>::replayMemInst(DynInstPtr &inst) +{ + instQueue.replayMemInst(inst); +} template<class Impl> void -SimpleIEW<Impl>::instToCommit(DynInstPtr &inst) +DefaultIEW<Impl>::instToCommit(DynInstPtr &inst) { + // First check the time slot that this instruction will write + // to. If there are free write ports at the time, then go ahead + // and write the instruction to that time. If there are not, + // keep looking back to see where's the first time there's a + // free slot. + while ((*iewQueue)[wbCycle].insts[wbNumInst]) { + ++wbNumInst; + if (wbNumInst == issueWidth) { + ++wbCycle; + wbNumInst = 0; + } + + assert(wbCycle < 5); + } + // Add finished instruction to queue to commit. + (*iewQueue)[wbCycle].insts[wbNumInst] = inst; + (*iewQueue)[wbCycle].size++; } template <class Impl> +unsigned +DefaultIEW<Impl>::validInstsFromRename() +{ + unsigned inst_count = 0; + + for (int i=0; i<fromRename->size; i++) { + if (!fromRename->insts[i]->squashed) + inst_count++; + } + + return inst_count; +} + +template<class Impl> void -SimpleIEW<Impl>::dispatchInsts() -{ - //////////////////////////////////////// - // DISPATCH/ISSUE stage - //////////////////////////////////////// - - //Put into its own function? - //Add instructions to IQ if there are any instructions there - - // Check if there are any instructions coming from rename, and we're. - // not squashing. - if (fromRename->size > 0) { - int insts_to_add = fromRename->size; - - // Loop through the instructions, putting them in the instruction - // queue. - for (int inst_num = 0; inst_num < insts_to_add; ++inst_num) - { - DynInstPtr inst = fromRename->insts[inst_num]; - - // Make sure there's a valid instruction there. - assert(inst); - - DPRINTF(IEW, "IEW: Issue: Adding PC %#x to IQ.\n", - inst->readPC()); - - // Be sure to mark these instructions as ready so that the - // commit stage can go ahead and execute them, and mark - // them as issued so the IQ doesn't reprocess them. - if (inst->isSquashed()) { - ++iewDispSquashedInsts; - continue; - } else if (instQueue.isFull()) { - DPRINTF(IEW, "IEW: Issue: IQ has become full.\n"); - // Call function to start blocking. - block(); - // Tell previous stage to stall. - toRename->iewInfo.stall = true; - - ++iewIQFullEvents; - break; - } else if (inst->isLoad()) { - DPRINTF(IEW, "IEW: Issue: Memory instruction " - "encountered, adding to LDSTQ.\n"); - - // Reserve a spot in the load store queue for this - // memory access. - ldstQueue.insertLoad(inst); - - ++iewDispLoadInsts; - } else if (inst->isStore()) { - ldstQueue.insertStore(inst); +DefaultIEW<Impl>::skidInsert(unsigned tid) +{ + DynInstPtr inst = NULL; - ++iewDispStoreInsts; - } else if (inst->isNonSpeculative()) { - DPRINTF(IEW, "IEW: Issue: Nonspeculative instruction " - "encountered, skipping.\n"); + while (!insts[tid].empty()) { + inst = insts[tid].front(); - // Same hack as with stores. - inst->setCanCommit(); + insts[tid].pop(); + + DPRINTF(Decode,"[tid:%i]: Inserting [sn:%lli] PC:%#x into " + "dispatch skidBuffer %i\n",tid, inst->seqNum, + inst->readPC(),tid); + + skidBuffer[tid].push(inst); + } + + assert(skidBuffer[tid].size() <= skidBufferMax && + "Skidbuffer Exceeded Max Size"); +} + +template<class Impl> +int +DefaultIEW<Impl>::skidCount() +{ + int max=0; + + list<unsigned>::iterator threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned thread_count = skidBuffer[*threads++].size(); + if (max < thread_count) + max = thread_count; + } + + return max; +} + +template<class Impl> +bool +DefaultIEW<Impl>::skidsEmpty() +{ + list<unsigned>::iterator threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + if (!skidBuffer[*threads++].empty()) + return false; + } + + return true; +} + +template <class Impl> +void +DefaultIEW<Impl>::updateStatus() +{ + bool any_unblocking = false; + + list<unsigned>::iterator threads = (*activeThreads).begin(); + + threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + if (dispatchStatus[tid] == Unblocking) { + any_unblocking = true; + break; + } + } + + // If there are no ready instructions waiting to be scheduled by the IQ, + // and there's no stores waiting to write back, and dispatch is not + // unblocking, then there is no internal activity for the IEW stage. + if (_status == Active && !instQueue.hasReadyInsts() && + !ldstQueue.willWB() && !any_unblocking) { + DPRINTF(IEW, "IEW switching to idle\n"); + + deactivateStage(); + + _status = Inactive; + } else if (_status == Inactive && (instQueue.hasReadyInsts() || + ldstQueue.willWB() || + any_unblocking)) { + // Otherwise there is internal activity. Set to active. + DPRINTF(IEW, "IEW switching to active\n"); + + activateStage(); - // Specificall insert it as nonspeculative. + _status = Active; + } +} + +template <class Impl> +void +DefaultIEW<Impl>::resetEntries() +{ + instQueue.resetEntries(); + ldstQueue.resetEntries(); +} + +template <class Impl> +void +DefaultIEW<Impl>::readStallSignals(unsigned tid) +{ + if (fromCommit->commitBlock[tid]) { + stalls[tid].commit = true; + } + + if (fromCommit->commitUnblock[tid]) { + assert(stalls[tid].commit); + stalls[tid].commit = false; + } +} + +template <class Impl> +bool +DefaultIEW<Impl>::checkStall(unsigned tid) +{ + bool ret_val(false); + + if (stalls[tid].commit) { + DPRINTF(IEW,"[tid:%i]: Stall from Commit stage detected.\n",tid); + ret_val = true; + } else if (instQueue.isFull(tid)) { + DPRINTF(IEW,"[tid:%i]: Stall: IQ is full.\n",tid); + ret_val = true; + } else if (ldstQueue.isFull(tid)) { + DPRINTF(IEW,"[tid:%i]: Stall: LSQ is full\n",tid); + + if (ldstQueue.numLoads(tid) > 0 ) { + + DPRINTF(IEW,"[tid:%i]: LSQ oldest load: [sn:%i] \n", + tid,ldstQueue.getLoadHeadSeqNum(tid)); + } + + if (ldstQueue.numStores(tid) > 0) { + + DPRINTF(IEW,"[tid:%i]: LSQ oldest store: [sn:%i] \n", + tid,ldstQueue.getStoreHeadSeqNum(tid)); + } + + ret_val = true; + } else if (ldstQueue.isStalled(tid)) { + DPRINTF(IEW,"[tid:%i]: Stall: LSQ stall detected.\n",tid); + ret_val = true; + } + + return ret_val; +} + +template <class Impl> +void +DefaultIEW<Impl>::checkSignalsAndUpdate(unsigned tid) +{ + // Check if there's a squash signal, squash if there is + // Check stall signals, block if there is. + // If status was Blocked + // if so then go to unblocking + // If status was Squashing + // check if squashing is not high. Switch to running this cycle. + + readStallSignals(tid); + + if (fromCommit->commitInfo[tid].squash) { + squash(tid); + + if (dispatchStatus[tid] == Blocked || + dispatchStatus[tid] == Unblocking) { + toRename->iewUnblock[tid] = true; + wroteToTimeBuffer = true; + } + + dispatchStatus[tid] = Squashing; + + fetchRedirect[tid] = false; + return; + } + + if (fromCommit->commitInfo[tid].robSquashing) { + DPRINTF(IEW, "[tid:%i]: ROB is still squashing.\n"); + + dispatchStatus[tid] = Squashing; + + return; + } + + if (checkStall(tid)) { + block(tid); + dispatchStatus[tid] = Blocked; + return; + } + + if (dispatchStatus[tid] == Blocked) { + // Status from previous cycle was blocked, but there are no more stall + // conditions. Switch over to unblocking. + DPRINTF(IEW, "[tid:%i]: Done blocking, switching to unblocking.\n", + tid); + + dispatchStatus[tid] = Unblocking; + + unblock(tid); + + return; + } + + if (dispatchStatus[tid] == Squashing) { + // Switch status to running if rename isn't being told to block or + // squash this cycle. + DPRINTF(IEW, "[tid:%i]: Done squashing, switching to running.\n", + tid); + + dispatchStatus[tid] = Running; + + return; + } +} + +template <class Impl> +void +DefaultIEW<Impl>::sortInsts() +{ + int insts_from_rename = fromRename->size; +#ifdef DEBUG + for (int i = 0; i < numThreads; i++) + assert(insts[i].empty()); +#endif + for (int i = 0; i < insts_from_rename; ++i) { + insts[fromRename->insts[i]->threadNumber].push(fromRename->insts[i]); + } +} + +template <class Impl> +void +DefaultIEW<Impl>::wakeCPU() +{ + cpu->wakeCPU(); +} + +template <class Impl> +void +DefaultIEW<Impl>::activityThisCycle() +{ + DPRINTF(Activity, "Activity this cycle.\n"); + cpu->activityThisCycle(); +} + +template <class Impl> +inline void +DefaultIEW<Impl>::activateStage() +{ + DPRINTF(Activity, "Activating stage.\n"); + cpu->activateStage(FullCPU::IEWIdx); +} + +template <class Impl> +inline void +DefaultIEW<Impl>::deactivateStage() +{ + DPRINTF(Activity, "Deactivating stage.\n"); + cpu->deactivateStage(FullCPU::IEWIdx); +} + +template<class Impl> +void +DefaultIEW<Impl>::dispatch(unsigned tid) +{ + // If status is Running or idle, + // call dispatchInsts() + // If status is Unblocking, + // buffer any instructions coming from rename + // continue trying to empty skid buffer + // check if stall conditions have passed + + if (dispatchStatus[tid] == Blocked) { + ++iewBlockCycles; + + } else if (dispatchStatus[tid] == Squashing) { + ++iewSquashCycles; + } + + // Dispatch should try to dispatch as many instructions as its bandwidth + // will allow, as long as it is not currently blocked. + if (dispatchStatus[tid] == Running || + dispatchStatus[tid] == Idle) { + DPRINTF(IEW, "[tid:%i] Not blocked, so attempting to run " + "dispatch.\n", tid); + + dispatchInsts(tid); + } else if (dispatchStatus[tid] == Unblocking) { + // Make sure that the skid buffer has something in it if the + // status is unblocking. + assert(!skidsEmpty()); + + // If the status was unblocking, then instructions from the skid + // buffer were used. Remove those instructions and handle + // the rest of unblocking. + dispatchInsts(tid); + + ++iewUnblockCycles; + + if (validInstsFromRename() && dispatchedAllInsts) { + // Add the current inputs to the skid buffer so they can be + // reprocessed when this stage unblocks. + skidInsert(tid); + } + + unblock(tid); + } +} + +template <class Impl> +void +DefaultIEW<Impl>::dispatchInsts(unsigned tid) +{ + dispatchedAllInsts = true; + + // Obtain instructions from skid buffer if unblocking, or queue from rename + // otherwise. + std::queue<DynInstPtr> &insts_to_dispatch = + dispatchStatus[tid] == Unblocking ? + skidBuffer[tid] : insts[tid]; + + int insts_to_add = insts_to_dispatch.size(); + + DynInstPtr inst; + bool add_to_iq = false; + int dis_num_inst = 0; + + // Loop through the instructions, putting them in the instruction + // queue. + for ( ; dis_num_inst < insts_to_add && + dis_num_inst < issueReadWidth; + ++dis_num_inst) + { + inst = insts_to_dispatch.front(); + + if (dispatchStatus[tid] == Unblocking) { + DPRINTF(IEW, "[tid:%i]: Issue: Examining instruction from skid " + "buffer\n", tid); + } + + // Make sure there's a valid instruction there. + assert(inst); + + DPRINTF(IEW, "[tid:%i]: Issue: Adding PC %#x [sn:%lli] [tid:%i] to " + "IQ.\n", + tid, inst->readPC(), inst->seqNum, inst->threadNumber); + + // Be sure to mark these instructions as ready so that the + // commit stage can go ahead and execute them, and mark + // them as issued so the IQ doesn't reprocess them. + + // Check for squashed instructions. + if (inst->isSquashed()) { + DPRINTF(IEW, "[tid:%i]: Issue: Squashed instruction encountered, " + "not adding to IQ.\n", tid); + + ++iewDispSquashedInsts; + + insts_to_dispatch.pop(); + + //Tell Rename That An Instruction has been processed + if (inst->isLoad() || inst->isStore()) { + toRename->iewInfo[tid].dispatchedToLSQ++; + } + toRename->iewInfo[tid].dispatched++; + + continue; + } + + // Check for full conditions. + if (instQueue.isFull(tid)) { + DPRINTF(IEW, "[tid:%i]: Issue: IQ has become full.\n", tid); + + // Call function to start blocking. + block(tid); + + // Set unblock to false. Special case where we are using + // skidbuffer (unblocking) instructions but then we still + // get full in the IQ. + toRename->iewUnblock[tid] = false; + + dispatchedAllInsts = false; + + ++iewIQFullEvents; + break; + } else if (ldstQueue.isFull(tid)) { + DPRINTF(IEW, "[tid:%i]: Issue: LSQ has become full.\n",tid); + + // Call function to start blocking. + block(tid); + + // Set unblock to false. Special case where we are using + // skidbuffer (unblocking) instructions but then we still + // get full in the IQ. + toRename->iewUnblock[tid] = false; + + dispatchedAllInsts = false; + + ++iewLSQFullEvents; + break; + } + + // Otherwise issue the instruction just fine. + if (inst->isLoad()) { + DPRINTF(IEW, "[tid:%i]: Issue: Memory instruction " + "encountered, adding to LSQ.\n", tid); + + // Reserve a spot in the load store queue for this + // memory access. + ldstQueue.insertLoad(inst); + + ++iewDispLoadInsts; + + add_to_iq = true; + + toRename->iewInfo[tid].dispatchedToLSQ++; + } else if (inst->isStore()) { + DPRINTF(IEW, "[tid:%i]: Issue: Memory instruction " + "encountered, adding to LSQ.\n", tid); + + ldstQueue.insertStore(inst); + + ++iewDispStoreInsts; + + if (inst->isStoreConditional()) { + // Store conditionals need to be set as "canCommit()" + // so that commit can process them when they reach the + // head of commit. + // @todo: This is somewhat specific to Alpha. + inst->setCanCommit(); instQueue.insertNonSpec(inst); + add_to_iq = false; ++iewDispNonSpecInsts; + } else { + add_to_iq = true; + } + + toRename->iewInfo[tid].dispatchedToLSQ++; +#if FULL_SYSTEM + } else if (inst->isMemBarrier() || inst->isWriteBarrier()) { + // Same as non-speculative stores. + inst->setCanCommit(); + instQueue.insertBarrier(inst); + add_to_iq = false; +#endif + } else if (inst->isNonSpeculative()) { + DPRINTF(IEW, "[tid:%i]: Issue: Nonspeculative instruction " + "encountered, skipping.\n", tid); - continue; - } else if (inst->isNop()) { - DPRINTF(IEW, "IEW: Issue: Nop instruction encountered " - ", skipping.\n"); + // Same as non-speculative stores. + inst->setCanCommit(); - inst->setIssued(); - inst->setExecuted(); - inst->setCanCommit(); + // Specifically insert it as nonspeculative. + instQueue.insertNonSpec(inst); - instQueue.advanceTail(inst); + ++iewDispNonSpecInsts; - continue; - } else if (inst->isExecuted()) { - assert(0 && "Instruction shouldn't be executed.\n"); - DPRINTF(IEW, "IEW: Issue: Executed branch encountered, " - "skipping.\n"); + add_to_iq = false; + } else if (inst->isNop()) { + DPRINTF(IEW, "[tid:%i]: Issue: Nop instruction encountered, " + "skipping.\n", tid); - inst->setIssued(); - inst->setCanCommit(); + inst->setIssued(); + inst->setExecuted(); + inst->setCanCommit(); - instQueue.advanceTail(inst); + instQueue.recordProducer(inst); - continue; - } + exeNop[tid]++; + + add_to_iq = false; + } else if (inst->isExecuted()) { + assert(0 && "Instruction shouldn't be executed.\n"); + DPRINTF(IEW, "Issue: Executed branch encountered, " + "skipping.\n"); - // If the instruction queue is not full, then add the - // instruction. - instQueue.insert(fromRename->insts[inst_num]); + inst->setIssued(); + inst->setCanCommit(); - ++iewDispatchedInsts; + instQueue.recordProducer(inst); + + add_to_iq = false; + } else { + add_to_iq = true; } + + // If the instruction queue is not full, then add the + // instruction. + if (add_to_iq) { + instQueue.insert(inst); + } + + insts_to_dispatch.pop(); + + toRename->iewInfo[tid].dispatched++; + + ++iewDispatchedInsts; + } + + if (!insts_to_dispatch.empty()) { + DPRINTF(IEW,"[tid:%i]: Issue: Bandwidth Full. Blocking.\n"); + block(tid); + toRename->iewUnblock[tid] = false; + } + + if (dispatchStatus[tid] == Idle && dis_num_inst) { + dispatchStatus[tid] = Running; + + updatedQueues = true; + } + + dis_num_inst = 0; +} + +template <class Impl> +void +DefaultIEW<Impl>::printAvailableInsts() +{ + int inst = 0; + + cout << "Available Instructions: "; + + while (fromIssue->insts[inst]) { + + if (inst%3==0) cout << "\n\t"; + + cout << "PC: " << fromIssue->insts[inst]->readPC() + << " TN: " << fromIssue->insts[inst]->threadNumber + << " SN: " << fromIssue->insts[inst]->seqNum << " | "; + + inst++; + } + + cout << "\n"; } template <class Impl> void -SimpleIEW<Impl>::executeInsts() +DefaultIEW<Impl>::executeInsts() { - //////////////////////////////////////// - //EXECUTE/WRITEBACK stage - //////////////////////////////////////// + wbNumInst = 0; + wbCycle = 0; - //Put into its own function? - //Similarly should probably have separate execution for int vs FP. - // Above comment is handled by the issue queue only issuing a valid - // mix of int/fp instructions. - //Actually okay to just have one execution, buuuuuut will need - //somewhere that defines the execution latency of all instructions. - // @todo: Move to the FU pool used in the current full cpu. + list<unsigned>::iterator threads = (*activeThreads).begin(); - int fu_usage = 0; - bool fetch_redirect = false; - int inst_slot = 0; - int time_slot = 0; + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + fetchRedirect[tid] = false; + } + + // Uncomment this if you want to see all available instructions. +// printAvailableInsts(); // Execute/writeback any instructions that are available. - for (int inst_num = 0; - fu_usage < executeWidth && /* Haven't exceeded available FU's. */ - inst_num < issueWidth && - fromIssue->insts[inst_num]; - ++inst_num) { + int insts_to_execute = fromIssue->size; + int inst_num = 0; + for (; inst_num < insts_to_execute; + ++inst_num) { - DPRINTF(IEW, "IEW: Execute: Executing instructions from IQ.\n"); + DPRINTF(IEW, "Execute: Executing instructions from IQ.\n"); - // Get instruction from issue's queue. - DynInstPtr inst = fromIssue->insts[inst_num]; + DynInstPtr inst = instQueue.getInstToExecute(); - DPRINTF(IEW, "IEW: Execute: Processing PC %#x.\n", inst->readPC()); + DPRINTF(IEW, "Execute: Processing PC %#x, [tid:%i] [sn:%i].\n", + inst->readPC(), inst->threadNumber,inst->seqNum); // Check if the instruction is squashed; if so then skip it - // and don't count it towards the FU usage. if (inst->isSquashed()) { - DPRINTF(IEW, "IEW: Execute: Instruction was squashed.\n"); + DPRINTF(IEW, "Execute: Instruction was squashed.\n"); // Consider this instruction executed so that commit can go // ahead and retire the instruction. inst->setExecuted(); - toCommit->insts[inst_num] = inst; + // Not sure if I should set this here or just let commit try to + // commit any squashed instructions. I like the latter a bit more. + inst->setCanCommit(); ++iewExecSquashedInsts; continue; } - inst->setExecuted(); - - // If an instruction is executed, then count it towards FU usage. - ++fu_usage; + Fault fault = NoFault; // Execute instruction. // Note that if the instruction faults, it will be handled // at the commit stage. - if (inst->isMemRef()) { - DPRINTF(IEW, "IEW: Execute: Calculating address for memory " + if (inst->isMemRef() && + (!inst->isDataPrefetch() && !inst->isInstPrefetch())) { + DPRINTF(IEW, "Execute: Calculating address for memory " "reference.\n"); // Tell the LDSTQ to execute this instruction (if it is a load). if (inst->isLoad()) { - ldstQueue.executeLoad(inst); - - ++iewExecLoadInsts; + // Loads will mark themselves as executed, and their writeback + // event adds the instruction to the queue to commit + fault = ldstQueue.executeLoad(inst); } else if (inst->isStore()) { ldstQueue.executeStore(inst); - ++iewExecStoreInsts; + // If the store had a fault then it may not have a mem req + if (inst->req && !(inst->req->getFlags() & LOCKED)) { + inst->setExecuted(); + + instToCommit(inst); + } + + // Store conditionals will mark themselves as + // executed, and their writeback event will add the + // instruction to the queue to commit. } else { - panic("IEW: Unexpected memory type!\n"); + panic("Unexpected memory type!\n"); } } else { inst->execute(); - ++iewExecutedInsts; + inst->setExecuted(); + + instToCommit(inst); } - // First check the time slot that this instruction will write - // to. If there are free write ports at the time, then go ahead - // and write the instruction to that time. If there are not, - // keep looking back to see where's the first time there's a - // free slot. What happens if you run out of free spaces? - // For now naively assume that all instructions take one cycle. - // Otherwise would have to look into the time buffer based on the - // latency of the instruction. - (*iewQueue)[time_slot].insts[inst_slot]; - while ((*iewQueue)[time_slot].insts[inst_slot]) { - if (inst_slot < issueWidth) { - ++inst_slot; - } else { - ++time_slot; - inst_slot = 0; - } + updateExeInstStats(inst); - assert(time_slot < 5); - } + // Check if branch prediction was correct, if not then we need + // to tell commit to squash in flight instructions. Only + // handle this if there hasn't already been something that + // redirects fetch in this group of instructions. - // May actually have to work this out, especially with loads and stores + // This probably needs to prioritize the redirects if a different + // scheduler is used. Currently the scheduler schedules the oldest + // instruction first, so the branch resolution order will be correct. + unsigned tid = inst->threadNumber; - // Add finished instruction to queue to commit. - (*iewQueue)[time_slot].insts[inst_slot] = inst; - (*iewQueue)[time_slot].size++; + if (!fetchRedirect[tid]) { - // Check if branch was correct. This check happens after the - // instruction is added to the queue because even if the branch - // is mispredicted, the branch instruction itself is still valid. - // Only handle this if there hasn't already been something that - // redirects fetch in this group of instructions. - if (!fetch_redirect) { if (inst->mispredicted()) { - fetch_redirect = true; + fetchRedirect[tid] = true; - DPRINTF(IEW, "IEW: Execute: Branch mispredict detected.\n"); - DPRINTF(IEW, "IEW: Execute: Redirecting fetch to PC: %#x.\n", + DPRINTF(IEW, "Execute: Branch mispredict detected.\n"); + DPRINTF(IEW, "Execute: Redirecting fetch to PC: %#x.\n", inst->nextPC); // If incorrect, then signal the ROB that it must be squashed. - squashDueToBranch(inst); + squashDueToBranch(inst, tid); if (inst->predTaken()) { predictedTakenIncorrect++; + } else { + predictedNotTakenIncorrect++; } - } else if (ldstQueue.violation()) { - fetch_redirect = true; + } else if (ldstQueue.violation(tid)) { + fetchRedirect[tid] = true; - // Get the DynInst that caused the violation. - DynInstPtr violator = ldstQueue.getMemDepViolator(); + // If there was an ordering violation, then get the + // DynInst that caused the violation. Note that this + // clears the violation signal. + DynInstPtr violator; + violator = ldstQueue.getMemDepViolator(tid); - DPRINTF(IEW, "IEW: LDSTQ detected a violation. Violator PC: " + DPRINTF(IEW, "LDSTQ detected a violation. Violator PC: " "%#x, inst PC: %#x. Addr is: %#x.\n", violator->readPC(), inst->readPC(), inst->physEffAddr); @@ -575,164 +1292,236 @@ SimpleIEW<Impl>::executeInsts() instQueue.violation(inst, violator); // Squash. - squashDueToMem(inst); + squashDueToMemOrder(inst,tid); ++memOrderViolationEvents; + } else if (ldstQueue.loadBlocked(tid) && + !ldstQueue.isLoadBlockedHandled(tid)) { + fetchRedirect[tid] = true; + + DPRINTF(IEW, "Load operation couldn't execute because the " + "memory system is blocked. PC: %#x [sn:%lli]\n", + inst->readPC(), inst->seqNum); + + squashDueToMemBlocked(inst, tid); } } } + + // Update and record activity if we processed any instructions. + if (inst_num) { + if (exeStatus == Idle) { + exeStatus = Running; + } + + updatedQueues = true; + + cpu->activityThisCycle(); + } + + // Need to reset this in case a writeback event needs to write into the + // iew queue. That way the writeback event will write into the correct + // spot in the queue. + wbNumInst = 0; +} + +template <class Impl> +void +DefaultIEW<Impl>::writebackInsts() +{ + // Loop through the head of the time buffer and wake any + // dependents. These instructions are about to write back. Also + // mark scoreboard that this instruction is finally complete. + // Either have IEW have direct access to scoreboard, or have this + // as part of backwards communication. + for (int inst_num = 0; inst_num < issueWidth && + toCommit->insts[inst_num]; inst_num++) { + DynInstPtr inst = toCommit->insts[inst_num]; + int tid = inst->threadNumber; + + DPRINTF(IEW, "Sending instructions to commit, [sn:%lli] PC %#x.\n", + inst->seqNum, inst->readPC()); + + iewInstsToCommit[tid]++; + + // Some instructions will be sent to commit without having + // executed because they need commit to handle them. + // E.g. Uncached loads have not actually executed when they + // are first sent to commit. Instead commit must tell the LSQ + // when it's ready to execute the uncached load. + if (!inst->isSquashed() && inst->isExecuted()) { + int dependents = instQueue.wakeDependents(inst); + + for (int i = 0; i < inst->numDestRegs(); i++) { + //mark as Ready + DPRINTF(IEW,"Setting Destination Register %i\n", + inst->renamedDestRegIdx(i)); + scoreboard->setReg(inst->renamedDestRegIdx(i)); + } + + if (dependents) { + producerInst[tid]++; + consumerInst[tid]+= dependents; + } + writebackCount[tid]++; + } + } } template<class Impl> void -SimpleIEW<Impl>::tick() +DefaultIEW<Impl>::tick() { - // Considering putting all the state-determining stuff in this section. + wbNumInst = 0; + wbCycle = 0; - // Try to fill up issue queue with as many instructions as bandwidth - // allows. - // Decode should try to execute as many instructions as its bandwidth - // will allow, as long as it is not currently blocked. + wroteToTimeBuffer = false; + updatedQueues = false; - // Check if the stage is in a running status. - if (_status != Blocked && _status != Squashing) { - DPRINTF(IEW, "IEW: Status is not blocked, attempting to run " - "stage.\n"); - iew(); + sortInsts(); - // If it's currently unblocking, check to see if it should switch - // to running. - if (_status == Unblocking) { - unblock(); + // Free function units marked as being freed this cycle. + fuPool->processFreeUnits(); - ++iewUnblockCycles; - } - } else if (_status == Squashing) { + list<unsigned>::iterator threads = (*activeThreads).begin(); - DPRINTF(IEW, "IEW: Still squashing.\n"); + // Check stall and squash signals, dispatch any instructions. + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; - // Check if stage should remain squashing. Stop squashing if the - // squash signal clears. - if (!fromCommit->commitInfo.squash && - !fromCommit->commitInfo.robSquashing) { - DPRINTF(IEW, "IEW: Done squashing, changing status to " - "running.\n"); + DPRINTF(IEW,"Issue: Processing [tid:%i]\n",tid); - _status = Running; - instQueue.stopSquash(); - } else { - instQueue.doSquash(); - } + checkSignalsAndUpdate(tid); + dispatch(tid); + } - ++iewSquashCycles; - } else if (_status == Blocked) { - // Continue to tell previous stage to stall. - toRename->iewInfo.stall = true; - - // Check if possible stall conditions have cleared. - if (!fromCommit->commitInfo.stall && - !instQueue.isFull()) { - DPRINTF(IEW, "IEW: Stall signals cleared, going to unblock.\n"); - _status = Unblocking; - } + if (exeStatus != Squashing) { + executeInsts(); - // If there's still instructions coming from rename, continue to - // put them on the skid buffer. - if (fromRename->size == 0) { - block(); - } + writebackInsts(); - if (fromCommit->commitInfo.squash || - fromCommit->commitInfo.robSquashing) { - squash(); - } + // Have the instruction queue try to schedule any ready instructions. + // (In actuality, this scheduling is for instructions that will + // be executed next cycle.) + instQueue.scheduleReadyInsts(); - ++iewBlockCycles; + // Also should advance its own time buffers if the stage ran. + // Not the best place for it, but this works (hopefully). + issueToExecQueue.advance(); } - // @todo: Maybe put these at the beginning, so if it's idle it can - // return early. - // Write back number of free IQ entries here. - toRename->iewInfo.freeIQEntries = instQueue.numFreeEntries(); + bool broadcast_free_entries = false; + + if (updatedQueues || exeStatus == Running || updateLSQNextCycle) { + exeStatus = Idle; + updateLSQNextCycle = false; + + broadcast_free_entries = true; + } + // Writeback any stores using any leftover bandwidth. ldstQueue.writebackStores(); // Check the committed load/store signals to see if there's a load // or store to commit. Also check if it's being told to execute a // nonspeculative instruction. // This is pretty inefficient... - if (!fromCommit->commitInfo.squash && - !fromCommit->commitInfo.robSquashing) { - ldstQueue.commitStores(fromCommit->commitInfo.doneSeqNum); - ldstQueue.commitLoads(fromCommit->commitInfo.doneSeqNum); - } - if (fromCommit->commitInfo.nonSpecSeqNum != 0) { - instQueue.scheduleNonSpec(fromCommit->commitInfo.nonSpecSeqNum); - } + threads = (*activeThreads).begin(); + while (threads != (*activeThreads).end()) { + unsigned tid = (*threads++); - DPRINTF(IEW, "IEW: IQ has %i free entries.\n", - instQueue.numFreeEntries()); -} + DPRINTF(IEW,"Processing [tid:%i]\n",tid); -template<class Impl> -void -SimpleIEW<Impl>::iew() -{ - // Might want to put all state checks in the tick() function. - // Check if being told to stall from commit. - if (fromCommit->commitInfo.stall) { - block(); - return; - } else if (fromCommit->commitInfo.squash || - fromCommit->commitInfo.robSquashing) { - // Also check if commit is telling this stage to squash. - squash(); - return; - } + // Update structures based on instructions committed. + if (fromCommit->commitInfo[tid].doneSeqNum != 0 && + !fromCommit->commitInfo[tid].squash && + !fromCommit->commitInfo[tid].robSquashing) { - dispatchInsts(); + ldstQueue.commitStores(fromCommit->commitInfo[tid].doneSeqNum,tid); - // Have the instruction queue try to schedule any ready instructions. - instQueue.scheduleReadyInsts(); + ldstQueue.commitLoads(fromCommit->commitInfo[tid].doneSeqNum,tid); - executeInsts(); + updateLSQNextCycle = true; + instQueue.commit(fromCommit->commitInfo[tid].doneSeqNum,tid); + } - // Loop through the head of the time buffer and wake any dependents. - // These instructions are about to write back. In the simple model - // this loop can really happen within the previous loop, but when - // instructions have actual latencies, this loop must be separate. - // Also mark scoreboard that this instruction is finally complete. - // Either have IEW have direct access to rename map, or have this as - // part of backwards communication. - for (int inst_num = 0; inst_num < issueWidth && - toCommit->insts[inst_num]; inst_num++) - { - DynInstPtr inst = toCommit->insts[inst_num]; + if (fromCommit->commitInfo[tid].nonSpecSeqNum != 0) { - DPRINTF(IEW, "IEW: Sending instructions to commit, PC %#x.\n", - inst->readPC()); + //DPRINTF(IEW,"NonspecInst from thread %i",tid); + if (fromCommit->commitInfo[tid].uncached) { + instQueue.replayMemInst(fromCommit->commitInfo[tid].uncachedLoad); + } else { + instQueue.scheduleNonSpec( + fromCommit->commitInfo[tid].nonSpecSeqNum); + } + } - if(!inst->isSquashed()) { - instQueue.wakeDependents(inst); + if (broadcast_free_entries) { + toFetch->iewInfo[tid].iqCount = + instQueue.getCount(tid); + toFetch->iewInfo[tid].ldstqCount = + ldstQueue.getCount(tid); - for (int i = 0; i < inst->numDestRegs(); i++) - { - renameMap->markAsReady(inst->renamedDestRegIdx(i)); - } + toRename->iewInfo[tid].usedIQ = true; + toRename->iewInfo[tid].freeIQEntries = + instQueue.numFreeEntries(); + toRename->iewInfo[tid].usedLSQ = true; + toRename->iewInfo[tid].freeLSQEntries = + ldstQueue.numFreeEntries(tid); + + wroteToTimeBuffer = true; } + + DPRINTF(IEW, "[tid:%i], Dispatch dispatched %i instructions.\n", + tid, toRename->iewInfo[tid].dispatched); } - // Also should advance its own time buffers if the stage ran. - // Not the best place for it, but this works (hopefully). - issueToExecQueue.advance(); + DPRINTF(IEW, "IQ has %i free entries (Can schedule: %i). " + "LSQ has %i free entries.\n", + instQueue.numFreeEntries(), instQueue.hasReadyInsts(), + ldstQueue.numFreeEntries()); + + updateStatus(); + + if (wroteToTimeBuffer) { + DPRINTF(Activity, "Activity this cycle.\n"); + cpu->activityThisCycle(); + } } -#if !FULL_SYSTEM -template<class Impl> +template <class Impl> void -SimpleIEW<Impl>::lsqWriteback() +DefaultIEW<Impl>::updateExeInstStats(DynInstPtr &inst) { - ldstQueue.writebackAllInsts(); -} + int thread_number = inst->threadNumber; + + // + // Pick off the software prefetches + // +#ifdef TARGET_ALPHA + if (inst->isDataPrefetch()) + exeSwp[thread_number]++; + else + iewExecutedInsts++; +#else + iewExecutedInsts++; #endif + + // + // Control operations + // + if (inst->isControl()) + exeBranches[thread_number]++; + + // + // Memory operations + // + if (inst->isMemRef()) { + exeRefs[thread_number]++; + + if (inst->isLoad()) { + iewExecLoadInsts[thread_number]++; + } + } +} diff --git a/src/cpu/o3/inst_queue.cc b/src/cpu/o3/inst_queue.cc index 18f2dc646..f2c6b8213 100644 --- a/src/cpu/o3/inst_queue.cc +++ b/src/cpu/o3/inst_queue.cc @@ -34,7 +34,3 @@ // Force instantiation of InstructionQueue. template class InstructionQueue<AlphaSimpleImpl>; - -template<> -unsigned -InstructionQueue<AlphaSimpleImpl>::DependencyEntry::mem_alloc_counter = 0; diff --git a/src/cpu/o3/inst_queue.hh b/src/cpu/o3/inst_queue.hh index 3de3cac27..60a713020 100644 --- a/src/cpu/o3/inst_queue.hh +++ b/src/cpu/o3/inst_queue.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,8 +28,8 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_INST_QUEUE_HH__ -#define __CPU_O3_CPU_INST_QUEUE_HH__ +#ifndef __CPU_O3_INST_QUEUE_HH__ +#define __CPU_O3_INST_QUEUE_HH__ #include <list> #include <map> @@ -39,8 +39,13 @@ #include "base/statistics.hh" #include "base/timebuf.hh" #include "cpu/inst_seq.hh" +#include "cpu/o3/dep_graph.hh" +#include "cpu/op_class.hh" #include "sim/host.hh" +class FUPool; +class MemInterface; + /** * A standard instruction queue class. It holds ready instructions, in * order, in seperate priority queues to facilitate the scheduling of @@ -49,7 +54,14 @@ * floating point registers have their indices start after the integer * registers (ie with 96 int and 96 fp registers, regs 0-95 are integer * and 96-191 are fp). This remains true even for both logical and - * physical register indices. + * physical register indices. The IQ depends on the memory dependence unit to + * track when memory operations are ready in terms of ordering; register + * dependencies are tracked normally. Right now the IQ also handles the + * execution timing; this is mainly to allow back-to-back scheduling without + * requiring IEW to be able to peek into the IQ. At the end of the execution + * latency, the instruction is put into the queue to execute, where it will + * have the execute() function called on it. + * @todo: Make IQ able to handle multiple FU pools. */ template <class Impl> class InstructionQueue @@ -60,87 +72,198 @@ class InstructionQueue typedef typename Impl::DynInstPtr DynInstPtr; typedef typename Impl::Params Params; + typedef typename Impl::CPUPol::IEW IEW; typedef typename Impl::CPUPol::MemDepUnit MemDepUnit; typedef typename Impl::CPUPol::IssueStruct IssueStruct; typedef typename Impl::CPUPol::TimeStruct TimeStruct; - // Typedef of iterator through the list of instructions. Might be - // better to untie this from the FullCPU or pass its information to - // the stages. + // Typedef of iterator through the list of instructions. typedef typename std::list<DynInstPtr>::iterator ListIt; - /** - * Struct for comparing entries to be added to the priority queue. This - * gives reverse ordering to the instructions in terms of sequence - * numbers: the instructions with smaller sequence numbers (and hence - * are older) will be at the top of the priority queue. - */ - struct pqCompare - { - bool operator() (const DynInstPtr &lhs, const DynInstPtr &rhs) const - { - return lhs->seqNum > rhs->seqNum; - } - }; + friend class Impl::FullCPU; - /** - * Struct for comparing entries to be added to the set. This gives - * standard ordering in terms of sequence numbers. - */ - struct setCompare - { - bool operator() (const DynInstPtr &lhs, const DynInstPtr &rhs) const - { - return lhs->seqNum < rhs->seqNum; - } + /** FU completion event class. */ + class FUCompletion : public Event { + private: + /** Executing instruction. */ + DynInstPtr inst; + + /** Index of the FU used for executing. */ + int fuIdx; + + /** Pointer back to the instruction queue. */ + InstructionQueue<Impl> *iqPtr; + + /** Should the FU be added to the list to be freed upon + * completing this event. + */ + bool freeFU; + + public: + /** Construct a FU completion event. */ + FUCompletion(DynInstPtr &_inst, int fu_idx, + InstructionQueue<Impl> *iq_ptr); + + virtual void process(); + virtual const char *description(); + void setFreeFU() { freeFU = true; } }; - typedef std::priority_queue<DynInstPtr, vector<DynInstPtr>, pqCompare> - ReadyInstQueue; + /** Constructs an IQ. */ + InstructionQueue(Params *params); - InstructionQueue(Params ¶ms); + /** Destructs the IQ. */ + ~InstructionQueue(); + /** Returns the name of the IQ. */ + std::string name() const; + + /** Registers statistics. */ void regStats(); - void setCPU(FullCPU *cpu); + /** Resets all instruction queue state. */ + void resetState(); + + /** Sets CPU pointer. */ + void setCPU(FullCPU *_cpu) { cpu = _cpu; } + + /** Sets active threads list. */ + void setActiveThreads(std::list<unsigned> *at_ptr); + + /** Sets the IEW pointer. */ + void setIEW(IEW *iew_ptr) { iewStage = iew_ptr; } + /** Sets the timer buffer between issue and execute. */ void setIssueToExecuteQueue(TimeBuffer<IssueStruct> *i2eQueue); + /** Sets the global time buffer. */ void setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr); + /** Switches out the instruction queue. */ + void switchOut(); + + /** Takes over execution from another CPU's thread. */ + void takeOverFrom(); + + /** Returns if the IQ is switched out. */ + bool isSwitchedOut() { return switchedOut; } + + /** Number of entries needed for given amount of threads. */ + int entryAmount(int num_threads); + + /** Resets max entries for all threads. */ + void resetEntries(); + + /** Returns total number of free entries. */ unsigned numFreeEntries(); + /** Returns number of free entries for a thread. */ + unsigned numFreeEntries(unsigned tid); + + /** Returns whether or not the IQ is full. */ bool isFull(); + /** Returns whether or not the IQ is full for a specific thread. */ + bool isFull(unsigned tid); + + /** Returns if there are any ready instructions in the IQ. */ + bool hasReadyInsts(); + + /** Inserts a new instruction into the IQ. */ void insert(DynInstPtr &new_inst); + /** Inserts a new, non-speculative instruction into the IQ. */ void insertNonSpec(DynInstPtr &new_inst); - void advanceTail(DynInstPtr &inst); + /** Inserts a memory or write barrier into the IQ to make sure + * loads and stores are ordered properly. + */ + void insertBarrier(DynInstPtr &barr_inst); + + /** Returns the oldest scheduled instruction, and removes it from + * the list of instructions waiting to execute. + */ + DynInstPtr getInstToExecute(); + + /** + * Records the instruction as the producer of a register without + * adding it to the rest of the IQ. + */ + void recordProducer(DynInstPtr &inst) + { addToProducers(inst); } + /** Process FU completion event. */ + void processFUCompletion(DynInstPtr &inst, int fu_idx); + + /** + * Schedules ready instructions, adding the ready ones (oldest first) to + * the queue to execute. + */ void scheduleReadyInsts(); + /** Schedules a single specific non-speculative instruction. */ void scheduleNonSpec(const InstSeqNum &inst); - void wakeDependents(DynInstPtr &completed_inst); + /** + * Commits all instructions up to and including the given sequence number, + * for a specific thread. + */ + void commit(const InstSeqNum &inst, unsigned tid = 0); + + /** Wakes all dependents of a completed instruction. */ + int wakeDependents(DynInstPtr &completed_inst); + + /** Adds a ready memory instruction to the ready list. */ + void addReadyMemInst(DynInstPtr &ready_inst); + + /** + * Reschedules a memory instruction. It will be ready to issue once + * replayMemInst() is called. + */ + void rescheduleMemInst(DynInstPtr &resched_inst); + /** Replays a memory instruction. It must be rescheduled first. */ + void replayMemInst(DynInstPtr &replay_inst); + + /** Completes a memory operation. */ + void completeMemInst(DynInstPtr &completed_inst); + + /** Indicates an ordering violation between a store and a load. */ void violation(DynInstPtr &store, DynInstPtr &faulting_load); - // Change this to take in the sequence number - void squash(); + /** + * Squashes instructions for a thread. Squashing information is obtained + * from the time buffer. + */ + void squash(unsigned tid); - void doSquash(); + /** Returns the number of used entries for a thread. */ + unsigned getCount(unsigned tid) { return count[tid]; }; - void stopSquash(); + /** Debug function to print all instructions. */ + void printInsts(); private: + /** Does the actual squashing. */ + void doSquash(unsigned tid); + + ///////////////////////// + // Various pointers + ///////////////////////// + /** Pointer to the CPU. */ FullCPU *cpu; + /** Cache interface. */ + MemInterface *dcacheInterface; + + /** Pointer to IEW stage. */ + IEW *iewStage; + /** The memory dependence unit, which tracks/predicts memory dependences * between instructions. */ - MemDepUnit memDepUnit; + MemDepUnit memDepUnit[Impl::MaxThreads]; /** The queue to the execute stage. Issued instructions will be written * into it. @@ -153,36 +276,40 @@ class InstructionQueue /** Wire to read information from timebuffer. */ typename TimeBuffer<TimeStruct>::wire fromCommit; - enum InstList { - Int, - Float, - Branch, - Memory, - Misc, - Squashed, - None - }; + /** Function unit pool. */ + FUPool *fuPool; - /** List of ready int instructions. Used to keep track of the order in - * which instructions should issue. - */ - ReadyInstQueue readyIntInsts; + ////////////////////////////////////// + // Instruction lists, ready queues, and ordering + ////////////////////////////////////// + + /** List of all the instructions in the IQ (some of which may be issued). */ + std::list<DynInstPtr> instList[Impl::MaxThreads]; - /** List of ready floating point instructions. */ - ReadyInstQueue readyFloatInsts; + /** List of instructions that are ready to be executed. */ + std::list<DynInstPtr> instsToExecute; - /** List of ready branch instructions. */ - ReadyInstQueue readyBranchInsts; + /** + * Struct for comparing entries to be added to the priority queue. + * This gives reverse ordering to the instructions in terms of + * sequence numbers: the instructions with smaller sequence + * numbers (and hence are older) will be at the top of the + * priority queue. + */ + struct pqCompare { + bool operator() (const DynInstPtr &lhs, const DynInstPtr &rhs) const + { + return lhs->seqNum > rhs->seqNum; + } + }; - /** List of ready miscellaneous instructions. */ - ReadyInstQueue readyMiscInsts; + typedef std::priority_queue<DynInstPtr, std::vector<DynInstPtr>, pqCompare> + ReadyInstQueue; - /** List of squashed instructions (which are still valid and in IQ). - * Implemented using a priority queue; the entries must contain both - * the IQ index and sequence number of each instruction so that - * ordering based on sequence numbers can be used. + /** List of ready instructions, per op class. They are separated by op + * class to allow for easy mapping to FUs. */ - ReadyInstQueue squashedInsts; + ReadyInstQueue readyInsts[Num_OpClasses]; /** List of non-speculative instructions that will be scheduled * once the IQ gets a signal from commit. While it's redundant to @@ -193,34 +320,80 @@ class InstructionQueue */ std::map<InstSeqNum, DynInstPtr> nonSpecInsts; - typedef typename std::map<InstSeqNum, DynInstPtr>::iterator non_spec_it_t; + typedef typename std::map<InstSeqNum, DynInstPtr>::iterator NonSpecMapIt; - /** Number of free IQ entries left. */ - unsigned freeEntries; + /** Entry for the list age ordering by op class. */ + struct ListOrderEntry { + OpClass queueType; + InstSeqNum oldestInst; + }; - /** The number of entries in the instruction queue. */ - unsigned numEntries; + /** List that contains the age order of the oldest instruction of each + * ready queue. Used to select the oldest instruction available + * among op classes. + * @todo: Might be better to just move these entries around instead + * of creating new ones every time the position changes due to an + * instruction issuing. Not sure std::list supports this. + */ + std::list<ListOrderEntry> listOrder; - /** The number of integer instructions that can be issued in one - * cycle. + typedef typename std::list<ListOrderEntry>::iterator ListOrderIt; + + /** Tracks if each ready queue is on the age order list. */ + bool queueOnList[Num_OpClasses]; + + /** Iterators of each ready queue. Points to their spot in the age order + * list. */ - unsigned intWidth; + ListOrderIt readyIt[Num_OpClasses]; + + /** Add an op class to the age order list. */ + void addToOrderList(OpClass op_class); - /** The number of floating point instructions that can be issued - * in one cycle. + /** + * Called when the oldest instruction has been removed from a ready queue; + * this places that ready queue into the proper spot in the age order list. */ - unsigned floatWidth; + void moveToYoungerInst(ListOrderIt age_order_it); + + DependencyGraph<DynInstPtr> dependGraph; + + ////////////////////////////////////// + // Various parameters + ////////////////////////////////////// + + /** IQ Resource Sharing Policy */ + enum IQPolicy { + Dynamic, + Partitioned, + Threshold + }; + + /** IQ sharing policy for SMT. */ + IQPolicy iqPolicy; + + /** Number of Total Threads*/ + unsigned numThreads; - /** The number of branches that can be issued in one cycle. */ - unsigned branchWidth; + /** Pointer to list of active threads. */ + std::list<unsigned> *activeThreads; - /** The number of memory instructions that can be issued in one cycle. */ - unsigned memoryWidth; + /** Per Thread IQ count */ + unsigned count[Impl::MaxThreads]; + + /** Max IQ Entries Per Thread */ + unsigned maxEntries[Impl::MaxThreads]; + + /** Number of free IQ entries left. */ + unsigned freeEntries; + + /** The number of entries in the instruction queue. */ + unsigned numEntries; /** The total number of instructions that can be issued in one cycle. */ unsigned totalWidth; - //The number of physical registers in the CPU. + /** The number of physical registers in the CPU. */ unsigned numPhysRegs; /** The number of physical integer registers in the CPU. */ @@ -234,55 +407,11 @@ class InstructionQueue */ unsigned commitToIEWDelay; - ////////////////////////////////// - // Variables needed for squashing - ////////////////////////////////// + /** Is the IQ switched out. */ + bool switchedOut; /** The sequence number of the squashed instruction. */ - InstSeqNum squashedSeqNum; - - /** Iterator that points to the youngest instruction in the IQ. */ - ListIt tail; - - /** Iterator that points to the last instruction that has been squashed. - * This will not be valid unless the IQ is in the process of squashing. - */ - ListIt squashIt; - - /////////////////////////////////// - // Dependency graph stuff - /////////////////////////////////// - - class DependencyEntry - { - public: - DynInstPtr inst; - //Might want to include data about what arch. register the - //dependence is waiting on. - DependencyEntry *next; - - //This function, and perhaps this whole class, stand out a little - //bit as they don't fit a classification well. I want access - //to the underlying structure of the linked list, yet at - //the same time it feels like this should be something abstracted - //away. So for now it will sit here, within the IQ, until - //a better implementation is decided upon. - // This function probably shouldn't be within the entry... - void insert(DynInstPtr &new_inst); - - void remove(DynInstPtr &inst_to_remove); - - // Debug variable, remove when done testing. - static unsigned mem_alloc_counter; - }; - - /** Array of linked lists. Each linked list is a list of all the - * instructions that depend upon a given register. The actual - * register's index is used to index into the graph; ie all - * instructions in flight that are dependent upon r34 will be - * in the linked list of dependGraph[34]. - */ - DependencyEntry *dependGraph; + InstSeqNum squashedSeqNum[Impl::MaxThreads]; /** A cache of the recently woken registers. It is 1 if the register * has been woken up recently, and 0 if the register has been added @@ -290,49 +419,85 @@ class InstructionQueue * is basically a secondary scoreboard, and should pretty much mirror * the scoreboard that exists in the rename map. */ - vector<bool> regScoreboard; + std::vector<bool> regScoreboard; + /** Adds an instruction to the dependency graph, as a consumer. */ bool addToDependents(DynInstPtr &new_inst); - void insertDependency(DynInstPtr &new_inst); - void createDependency(DynInstPtr &new_inst); + /** Adds an instruction to the dependency graph, as a producer. */ + void addToProducers(DynInstPtr &new_inst); + + /** Moves an instruction to the ready queue if it is ready. */ void addIfReady(DynInstPtr &inst); - private: /** Debugging function to count how many entries are in the IQ. It does * a linear walk through the instructions, so do not call this function * during normal execution. */ int countInsts(); - /** Debugging function to dump out the dependency graph. - */ - void dumpDependGraph(); - /** Debugging function to dump all the list sizes, as well as print * out the list of nonspeculative instructions. Should not be used * in any other capacity, but it has no harmful sideaffects. */ void dumpLists(); + /** Debugging function to dump out all instructions that are in the + * IQ. + */ + void dumpInsts(); + + /** Stat for number of instructions added. */ Stats::Scalar<> iqInstsAdded; + /** Stat for number of non-speculative instructions added. */ Stats::Scalar<> iqNonSpecInstsAdded; -// Stats::Scalar<> iqIntInstsAdded; + + Stats::Scalar<> iqInstsIssued; + /** Stat for number of integer instructions issued. */ Stats::Scalar<> iqIntInstsIssued; -// Stats::Scalar<> iqFloatInstsAdded; + /** Stat for number of floating point instructions issued. */ Stats::Scalar<> iqFloatInstsIssued; -// Stats::Scalar<> iqBranchInstsAdded; + /** Stat for number of branch instructions issued. */ Stats::Scalar<> iqBranchInstsIssued; -// Stats::Scalar<> iqMemInstsAdded; + /** Stat for number of memory instructions issued. */ Stats::Scalar<> iqMemInstsIssued; -// Stats::Scalar<> iqMiscInstsAdded; + /** Stat for number of miscellaneous instructions issued. */ Stats::Scalar<> iqMiscInstsIssued; + /** Stat for number of squashed instructions that were ready to issue. */ Stats::Scalar<> iqSquashedInstsIssued; - Stats::Scalar<> iqLoopSquashStalls; + /** Stat for number of squashed instructions examined when squashing. */ Stats::Scalar<> iqSquashedInstsExamined; + /** Stat for number of squashed instruction operands examined when + * squashing. + */ Stats::Scalar<> iqSquashedOperandsExamined; + /** Stat for number of non-speculative instructions removed due to a squash. + */ Stats::Scalar<> iqSquashedNonSpecRemoved; + /** Distribution of number of instructions in the queue. */ + Stats::VectorDistribution<> queueResDist; + /** Distribution of the number of instructions issued. */ + Stats::Distribution<> numIssuedDist; + /** Distribution of the cycles it takes to issue an instruction. */ + Stats::VectorDistribution<> issueDelayDist; + + /** Number of times an instruction could not be issued because a + * FU was busy. + */ + Stats::Vector<> statFuBusy; +// Stats::Vector<> dist_unissued; + /** Stat for total number issued for each instruction type. */ + Stats::Vector2d<> statIssuedInstType; + + /** Number of instructions issued per cycle. */ + Stats::Formula issueRate; +// Stats::Formula issue_stores; +// Stats::Formula issue_op_rate; + /** Number of times the FU was busy. */ + Stats::Vector<> fuBusy; + /** Number of times the FU was busy per instruction issued. */ + Stats::Formula fuBusyRate; }; -#endif //__CPU_O3_CPU_INST_QUEUE_HH__ +#endif //__CPU_O3_INST_QUEUE_HH__ diff --git a/src/cpu/o3/inst_queue_impl.hh b/src/cpu/o3/inst_queue_impl.hh index 3a9db4788..06a052c6f 100644 --- a/src/cpu/o3/inst_queue_impl.hh +++ b/src/cpu/o3/inst_queue_impl.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,73 +28,148 @@ * Authors: Kevin Lim */ -// Todo: -// Current ordering allows for 0 cycle added-to-scheduled. Could maybe fake -// it; either do in reverse order, or have added instructions put into a -// different ready queue that, in scheduleRreadyInsts(), gets put onto the -// normal ready queue. This would however give only a one cycle delay, -// but probably is more flexible to actually add in a delay parameter than -// just running it backwards. - #include <limits> #include <vector> #include "sim/root.hh" +#include "cpu/o3/fu_pool.hh" #include "cpu/o3/inst_queue.hh" -// Either compile error or max int due to sign extension. -// Hack to avoid compile warnings. -const InstSeqNum MaxInstSeqNum = std::numeric_limits<InstSeqNum>::max(); +using namespace std; template <class Impl> -InstructionQueue<Impl>::InstructionQueue(Params ¶ms) - : memDepUnit(params), - numEntries(params.numIQEntries), - intWidth(params.executeIntWidth), - floatWidth(params.executeFloatWidth), - branchWidth(params.executeBranchWidth), - memoryWidth(params.executeMemoryWidth), - totalWidth(params.issueWidth), - numPhysIntRegs(params.numPhysIntRegs), - numPhysFloatRegs(params.numPhysFloatRegs), - commitToIEWDelay(params.commitToIEWDelay) +InstructionQueue<Impl>::FUCompletion::FUCompletion(DynInstPtr &_inst, + int fu_idx, + InstructionQueue<Impl> *iq_ptr) + : Event(&mainEventQueue, Stat_Event_Pri), + inst(_inst), fuIdx(fu_idx), iqPtr(iq_ptr), freeFU(false) { - // Initialize the number of free IQ entries. - freeEntries = numEntries; + this->setFlags(Event::AutoDelete); +} + +template <class Impl> +void +InstructionQueue<Impl>::FUCompletion::process() +{ + iqPtr->processFUCompletion(inst, freeFU ? fuIdx : -1); + inst = NULL; +} + + +template <class Impl> +const char * +InstructionQueue<Impl>::FUCompletion::description() +{ + return "Functional unit completion event"; +} + +template <class Impl> +InstructionQueue<Impl>::InstructionQueue(Params *params) + : fuPool(params->fuPool), + numEntries(params->numIQEntries), + totalWidth(params->issueWidth), + numPhysIntRegs(params->numPhysIntRegs), + numPhysFloatRegs(params->numPhysFloatRegs), + commitToIEWDelay(params->commitToIEWDelay) +{ + assert(fuPool); + + switchedOut = false; + + numThreads = params->numberOfThreads; // Set the number of physical registers as the number of int + float numPhysRegs = numPhysIntRegs + numPhysFloatRegs; - DPRINTF(IQ, "IQ: There are %i physical registers.\n", numPhysRegs); + DPRINTF(IQ, "There are %i physical registers.\n", numPhysRegs); //Create an entry for each physical register within the //dependency graph. - dependGraph = new DependencyEntry[numPhysRegs]; + dependGraph.resize(numPhysRegs); // Resize the register scoreboard. regScoreboard.resize(numPhysRegs); - // Initialize all the head pointers to point to NULL, and all the - // entries as unready. - // Note that in actuality, the registers corresponding to the logical - // registers start off as ready. However this doesn't matter for the - // IQ as the instruction should have been correctly told if those - // registers are ready in rename. Thus it can all be initialized as - // unready. - for (int i = 0; i < numPhysRegs; ++i) - { - dependGraph[i].next = NULL; - dependGraph[i].inst = NULL; - regScoreboard[i] = false; + //Initialize Mem Dependence Units + for (int i = 0; i < numThreads; i++) { + memDepUnit[i].init(params,i); + memDepUnit[i].setIQ(this); } + resetState(); + + string policy = params->smtIQPolicy; + + //Convert string to lowercase + std::transform(policy.begin(), policy.end(), policy.begin(), + (int(*)(int)) tolower); + + //Figure out resource sharing policy + if (policy == "dynamic") { + iqPolicy = Dynamic; + + //Set Max Entries to Total ROB Capacity + for (int i = 0; i < numThreads; i++) { + maxEntries[i] = numEntries; + } + + } else if (policy == "partitioned") { + iqPolicy = Partitioned; + + //@todo:make work if part_amt doesnt divide evenly. + int part_amt = numEntries / numThreads; + + //Divide ROB up evenly + for (int i = 0; i < numThreads; i++) { + maxEntries[i] = part_amt; + } + + DPRINTF(Fetch, "IQ sharing policy set to Partitioned:" + "%i entries per thread.\n",part_amt); + + } else if (policy == "threshold") { + iqPolicy = Threshold; + + double threshold = (double)params->smtIQThreshold / 100; + + int thresholdIQ = (int)((double)threshold * numEntries); + + //Divide up by threshold amount + for (int i = 0; i < numThreads; i++) { + maxEntries[i] = thresholdIQ; + } + + DPRINTF(Fetch, "IQ sharing policy set to Threshold:" + "%i entries per thread.\n",thresholdIQ); + } else { + assert(0 && "Invalid IQ Sharing Policy.Options Are:{Dynamic," + "Partitioned, Threshold}"); + } +} + +template <class Impl> +InstructionQueue<Impl>::~InstructionQueue() +{ + dependGraph.reset(); +#ifdef DEBUG + cprintf("Nodes traversed: %i, removed: %i\n", + dependGraph.nodesTraversed, dependGraph.nodesRemoved); +#endif +} + +template <class Impl> +std::string +InstructionQueue<Impl>::name() const +{ + return cpu->name() + ".iq"; } template <class Impl> void InstructionQueue<Impl>::regStats() { + using namespace Stats; iqInstsAdded .name(name() + ".iqInstsAdded") .desc("Number of instructions added to the IQ (excludes non-spec)") @@ -105,36 +180,31 @@ InstructionQueue<Impl>::regStats() .desc("Number of non-speculative instructions added to the IQ") .prereq(iqNonSpecInstsAdded); -// iqIntInstsAdded; + iqInstsIssued + .name(name() + ".iqInstsIssued") + .desc("Number of instructions issued") + .prereq(iqInstsIssued); iqIntInstsIssued .name(name() + ".iqIntInstsIssued") .desc("Number of integer instructions issued") .prereq(iqIntInstsIssued); -// iqFloatInstsAdded; - iqFloatInstsIssued .name(name() + ".iqFloatInstsIssued") .desc("Number of float instructions issued") .prereq(iqFloatInstsIssued); -// iqBranchInstsAdded; - iqBranchInstsIssued .name(name() + ".iqBranchInstsIssued") .desc("Number of branch instructions issued") .prereq(iqBranchInstsIssued); -// iqMemInstsAdded; - iqMemInstsIssued .name(name() + ".iqMemInstsIssued") .desc("Number of memory instructions issued") .prereq(iqMemInstsIssued); -// iqMiscInstsAdded; - iqMiscInstsIssued .name(name() + ".iqMiscInstsIssued") .desc("Number of miscellaneous instructions issued") @@ -145,12 +215,6 @@ InstructionQueue<Impl>::regStats() .desc("Number of squashed instructions issued") .prereq(iqSquashedInstsIssued); - iqLoopSquashStalls - .name(name() + ".iqLoopSquashStalls") - .desc("Number of times issue loop had to restart due to squashed " - "inst; mainly for profiling") - .prereq(iqLoopSquashStalls); - iqSquashedInstsExamined .name(name() + ".iqSquashedInstsExamined") .desc("Number of squashed instructions iterated over during squash;" @@ -168,25 +232,158 @@ InstructionQueue<Impl>::regStats() .desc("Number of squashed non-spec instructions that were removed") .prereq(iqSquashedNonSpecRemoved); - // Tell mem dependence unit to reg stats as well. - memDepUnit.regStats(); + queueResDist + .init(Num_OpClasses, 0, 99, 2) + .name(name() + ".IQ:residence:") + .desc("cycles from dispatch to issue") + .flags(total | pdf | cdf ) + ; + for (int i = 0; i < Num_OpClasses; ++i) { + queueResDist.subname(i, opClassStrings[i]); + } + numIssuedDist + .init(0,totalWidth,1) + .name(name() + ".ISSUE:issued_per_cycle") + .desc("Number of insts issued each cycle") + .flags(pdf) + ; +/* + dist_unissued + .init(Num_OpClasses+2) + .name(name() + ".ISSUE:unissued_cause") + .desc("Reason ready instruction not issued") + .flags(pdf | dist) + ; + for (int i=0; i < (Num_OpClasses + 2); ++i) { + dist_unissued.subname(i, unissued_names[i]); + } +*/ + statIssuedInstType + .init(numThreads,Num_OpClasses) + .name(name() + ".ISSUE:FU_type") + .desc("Type of FU issued") + .flags(total | pdf | dist) + ; + statIssuedInstType.ysubnames(opClassStrings); + + // + // How long did instructions for a particular FU type wait prior to issue + // + + issueDelayDist + .init(Num_OpClasses,0,99,2) + .name(name() + ".ISSUE:") + .desc("cycles from operands ready to issue") + .flags(pdf | cdf) + ; + + for (int i=0; i<Num_OpClasses; ++i) { + stringstream subname; + subname << opClassStrings[i] << "_delay"; + issueDelayDist.subname(i, subname.str()); + } + + issueRate + .name(name() + ".ISSUE:rate") + .desc("Inst issue rate") + .flags(total) + ; + issueRate = iqInstsIssued / cpu->numCycles; +/* + issue_stores + .name(name() + ".ISSUE:stores") + .desc("Number of stores issued") + .flags(total) + ; + issue_stores = exe_refs - exe_loads; +*/ +/* + issue_op_rate + .name(name() + ".ISSUE:op_rate") + .desc("Operation issue rate") + .flags(total) + ; + issue_op_rate = issued_ops / numCycles; +*/ + statFuBusy + .init(Num_OpClasses) + .name(name() + ".ISSUE:fu_full") + .desc("attempts to use FU when none available") + .flags(pdf | dist) + ; + for (int i=0; i < Num_OpClasses; ++i) { + statFuBusy.subname(i, opClassStrings[i]); + } + + fuBusy + .init(numThreads) + .name(name() + ".ISSUE:fu_busy_cnt") + .desc("FU busy when requested") + .flags(total) + ; + + fuBusyRate + .name(name() + ".ISSUE:fu_busy_rate") + .desc("FU busy rate (busy events/executed inst)") + .flags(total) + ; + fuBusyRate = fuBusy / iqInstsIssued; + + for ( int i=0; i < numThreads; i++) { + // Tell mem dependence unit to reg stats as well. + memDepUnit[i].regStats(); + } } template <class Impl> void -InstructionQueue<Impl>::setCPU(FullCPU *cpu_ptr) +InstructionQueue<Impl>::resetState() { - cpu = cpu_ptr; + //Initialize thread IQ counts + for (int i = 0; i <numThreads; i++) { + count[i] = 0; + instList[i].clear(); + } + + // Initialize the number of free IQ entries. + freeEntries = numEntries; + + // Note that in actuality, the registers corresponding to the logical + // registers start off as ready. However this doesn't matter for the + // IQ as the instruction should have been correctly told if those + // registers are ready in rename. Thus it can all be initialized as + // unready. + for (int i = 0; i < numPhysRegs; ++i) { + regScoreboard[i] = false; + } + + for (int i = 0; i < numThreads; ++i) { + squashedSeqNum[i] = 0; + } - tail = cpu->instList.begin(); + for (int i = 0; i < Num_OpClasses; ++i) { + while (!readyInsts[i].empty()) + readyInsts[i].pop(); + queueOnList[i] = false; + readyIt[i] = listOrder.end(); + } + nonSpecInsts.clear(); + listOrder.clear(); } template <class Impl> void -InstructionQueue<Impl>::setIssueToExecuteQueue( - TimeBuffer<IssueStruct> *i2e_ptr) +InstructionQueue<Impl>::setActiveThreads(list<unsigned> *at_ptr) { - DPRINTF(IQ, "IQ: Set the issue to execute queue.\n"); + DPRINTF(IQ, "Setting active threads list pointer.\n"); + activeThreads = at_ptr; +} + +template <class Impl> +void +InstructionQueue<Impl>::setIssueToExecuteQueue(TimeBuffer<IssueStruct> *i2e_ptr) +{ + DPRINTF(IQ, "Set the issue to execute queue.\n"); issueToExecuteQueue = i2e_ptr; } @@ -194,19 +391,77 @@ template <class Impl> void InstructionQueue<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) { - DPRINTF(IQ, "IQ: Set the time buffer.\n"); + DPRINTF(IQ, "Set the time buffer.\n"); timeBuffer = tb_ptr; fromCommit = timeBuffer->getWire(-commitToIEWDelay); } template <class Impl> +void +InstructionQueue<Impl>::switchOut() +{ + resetState(); + dependGraph.reset(); + switchedOut = true; + for (int i = 0; i < numThreads; ++i) { + memDepUnit[i].switchOut(); + } +} + +template <class Impl> +void +InstructionQueue<Impl>::takeOverFrom() +{ + switchedOut = false; +} + +template <class Impl> +int +InstructionQueue<Impl>::entryAmount(int num_threads) +{ + if (iqPolicy == Partitioned) { + return numEntries / num_threads; + } else { + return 0; + } +} + + +template <class Impl> +void +InstructionQueue<Impl>::resetEntries() +{ + if (iqPolicy != Dynamic || numThreads > 1) { + int active_threads = (*activeThreads).size(); + + list<unsigned>::iterator threads = (*activeThreads).begin(); + list<unsigned>::iterator list_end = (*activeThreads).end(); + + while (threads != list_end) { + if (iqPolicy == Partitioned) { + maxEntries[*threads++] = numEntries / active_threads; + } else if(iqPolicy == Threshold && active_threads == 1) { + maxEntries[*threads++] = numEntries; + } + } + } +} + +template <class Impl> unsigned InstructionQueue<Impl>::numFreeEntries() { return freeEntries; } +template <class Impl> +unsigned +InstructionQueue<Impl>::numFreeEntries(unsigned tid) +{ + return maxEntries[tid] - count[tid]; +} + // Might want to do something more complex if it knows how many instructions // will be issued this cycle. template <class Impl> @@ -221,447 +476,412 @@ InstructionQueue<Impl>::isFull() } template <class Impl> +bool +InstructionQueue<Impl>::isFull(unsigned tid) +{ + if (numFreeEntries(tid) == 0) { + return(true); + } else { + return(false); + } +} + +template <class Impl> +bool +InstructionQueue<Impl>::hasReadyInsts() +{ + if (!listOrder.empty()) { + return true; + } + + for (int i = 0; i < Num_OpClasses; ++i) { + if (!readyInsts[i].empty()) { + return true; + } + } + + return false; +} + +template <class Impl> void InstructionQueue<Impl>::insert(DynInstPtr &new_inst) { // Make sure the instruction is valid assert(new_inst); - DPRINTF(IQ, "IQ: Adding instruction PC %#x to the IQ.\n", - new_inst->readPC()); + DPRINTF(IQ, "Adding instruction [sn:%lli] PC %#x to the IQ.\n", + new_inst->seqNum, new_inst->readPC()); - // Check if there are any free entries. Panic if there are none. - // Might want to have this return a fault in the future instead of - // panicing. assert(freeEntries != 0); - // If the IQ currently has nothing in it, then there's a possibility - // that the tail iterator is invalid (might have been pointing at an - // instruction that was retired). Reset the tail iterator. - if (freeEntries == numEntries) { - tail = cpu->instList.begin(); - } - - // Move the tail iterator. Instructions may not have been issued - // to the IQ, so we may have to increment the iterator more than once. - while ((*tail) != new_inst) { - tail++; - - // Make sure the tail iterator points at something legal. - assert(tail != cpu->instList.end()); - } - + instList[new_inst->threadNumber].push_back(new_inst); - // Decrease the number of free entries. --freeEntries; + new_inst->setInIQ(); + // Look through its source registers (physical regs), and mark any // dependencies. addToDependents(new_inst); // Have this instruction set itself as the producer of its destination // register(s). - createDependency(new_inst); + addToProducers(new_inst); - // If it's a memory instruction, add it to the memory dependency - // unit. if (new_inst->isMemRef()) { - memDepUnit.insert(new_inst); - // Uh..forgot to look it up and put it on the proper dependency list - // if the instruction should not go yet. + memDepUnit[new_inst->threadNumber].insert(new_inst); } else { - // If the instruction is ready then add it to the ready list. addIfReady(new_inst); } ++iqInstsAdded; + count[new_inst->threadNumber]++; + assert(freeEntries == (numEntries - countInsts())); } template <class Impl> void -InstructionQueue<Impl>::insertNonSpec(DynInstPtr &inst) +InstructionQueue<Impl>::insertNonSpec(DynInstPtr &new_inst) { - nonSpecInsts[inst->seqNum] = inst; - // @todo: Clean up this code; can do it by setting inst as unable // to issue, then calling normal insert on the inst. - // Make sure the instruction is valid - assert(inst); + assert(new_inst); - DPRINTF(IQ, "IQ: Adding instruction PC %#x to the IQ.\n", - inst->readPC()); + nonSpecInsts[new_inst->seqNum] = new_inst; - // Check if there are any free entries. Panic if there are none. - // Might want to have this return a fault in the future instead of - // panicing. - assert(freeEntries != 0); + DPRINTF(IQ, "Adding non-speculative instruction [sn:%lli] PC %#x " + "to the IQ.\n", + new_inst->seqNum, new_inst->readPC()); - // If the IQ currently has nothing in it, then there's a possibility - // that the tail iterator is invalid (might have been pointing at an - // instruction that was retired). Reset the tail iterator. - if (freeEntries == numEntries) { - tail = cpu->instList.begin(); - } - - // Move the tail iterator. Instructions may not have been issued - // to the IQ, so we may have to increment the iterator more than once. - while ((*tail) != inst) { - tail++; + assert(freeEntries != 0); - // Make sure the tail iterator points at something legal. - assert(tail != cpu->instList.end()); - } + instList[new_inst->threadNumber].push_back(new_inst); - // Decrease the number of free entries. --freeEntries; + new_inst->setInIQ(); + // Have this instruction set itself as the producer of its destination // register(s). - createDependency(inst); + addToProducers(new_inst); // If it's a memory instruction, add it to the memory dependency // unit. - if (inst->isMemRef()) { - memDepUnit.insertNonSpec(inst); + if (new_inst->isMemRef()) { + memDepUnit[new_inst->threadNumber].insertNonSpec(new_inst); } ++iqNonSpecInstsAdded; + + count[new_inst->threadNumber]++; + + assert(freeEntries == (numEntries - countInsts())); } -// Slightly hack function to advance the tail iterator in the case that -// the IEW stage issues an instruction that is not added to the IQ. This -// is needed in case a long chain of such instructions occurs. -// I don't think this is used anymore. template <class Impl> void -InstructionQueue<Impl>::advanceTail(DynInstPtr &inst) +InstructionQueue<Impl>::insertBarrier(DynInstPtr &barr_inst) { - // Make sure the instruction is valid - assert(inst); - - DPRINTF(IQ, "IQ: Adding instruction PC %#x to the IQ.\n", - inst->readPC()); - - // Check if there are any free entries. Panic if there are none. - // Might want to have this return a fault in the future instead of - // panicing. - assert(freeEntries != 0); + memDepUnit[barr_inst->threadNumber].insertBarrier(barr_inst); - // If the IQ currently has nothing in it, then there's a possibility - // that the tail iterator is invalid (might have been pointing at an - // instruction that was retired). Reset the tail iterator. - if (freeEntries == numEntries) { - tail = cpu->instList.begin(); - } - - // Move the tail iterator. Instructions may not have been issued - // to the IQ, so we may have to increment the iterator more than once. - while ((*tail) != inst) { - tail++; - - // Make sure the tail iterator points at something legal. - assert(tail != cpu->instList.end()); - } - - assert(freeEntries <= numEntries); + insertNonSpec(barr_inst); +} - // Have this instruction set itself as the producer of its destination - // register(s). - createDependency(inst); +template <class Impl> +typename Impl::DynInstPtr +InstructionQueue<Impl>::getInstToExecute() +{ + assert(!instsToExecute.empty()); + DynInstPtr inst = instsToExecute.front(); + instsToExecute.pop_front(); + return inst; } -// Need to make sure the number of float and integer instructions -// issued does not exceed the total issue bandwidth. -// @todo: Figure out a better way to remove the squashed items from the -// lists. Checking the top item of each list to see if it's squashed -// wastes time and forces jumps. template <class Impl> void -InstructionQueue<Impl>::scheduleReadyInsts() +InstructionQueue<Impl>::addToOrderList(OpClass op_class) { - DPRINTF(IQ, "IQ: Attempting to schedule ready instructions from " - "the IQ.\n"); - - int int_issued = 0; - int float_issued = 0; - int branch_issued = 0; - int memory_issued = 0; - int squashed_issued = 0; - int total_issued = 0; - - IssueStruct *i2e_info = issueToExecuteQueue->access(0); - - bool insts_available = !readyBranchInsts.empty() || - !readyIntInsts.empty() || - !readyFloatInsts.empty() || - !memDepUnit.empty() || - !readyMiscInsts.empty() || - !squashedInsts.empty(); - - // Note: Requires a globally defined constant. - InstSeqNum oldest_inst = MaxInstSeqNum; - InstList list_with_oldest = None; - - // Temporary values. - DynInstPtr int_head_inst; - DynInstPtr float_head_inst; - DynInstPtr branch_head_inst; - DynInstPtr mem_head_inst; - DynInstPtr misc_head_inst; - DynInstPtr squashed_head_inst; - - // Somewhat nasty code to look at all of the lists where issuable - // instructions are located, and choose the oldest instruction among - // those lists. Consider a rewrite in the future. - while (insts_available && total_issued < totalWidth) - { - // Set this to false. Each if-block is required to set it to true - // if there were instructions available this check. This will cause - // this loop to run once more than necessary, but avoids extra calls. - insts_available = false; + assert(!readyInsts[op_class].empty()); - oldest_inst = MaxInstSeqNum; + ListOrderEntry queue_entry; - list_with_oldest = None; + queue_entry.queueType = op_class; - if (!readyIntInsts.empty() && - int_issued < intWidth) { + queue_entry.oldestInst = readyInsts[op_class].top()->seqNum; - insts_available = true; + ListOrderIt list_it = listOrder.begin(); + ListOrderIt list_end_it = listOrder.end(); - int_head_inst = readyIntInsts.top(); - - if (int_head_inst->isSquashed()) { - readyIntInsts.pop(); - - ++iqLoopSquashStalls; - - continue; - } - - oldest_inst = int_head_inst->seqNum; - - list_with_oldest = Int; + while (list_it != list_end_it) { + if ((*list_it).oldestInst > queue_entry.oldestInst) { + break; } - if (!readyFloatInsts.empty() && - float_issued < floatWidth) { - - insts_available = true; - - float_head_inst = readyFloatInsts.top(); - - if (float_head_inst->isSquashed()) { - readyFloatInsts.pop(); - - ++iqLoopSquashStalls; - - continue; - } else if (float_head_inst->seqNum < oldest_inst) { - oldest_inst = float_head_inst->seqNum; + list_it++; + } - list_with_oldest = Float; - } - } + readyIt[op_class] = listOrder.insert(list_it, queue_entry); + queueOnList[op_class] = true; +} - if (!readyBranchInsts.empty() && - branch_issued < branchWidth) { +template <class Impl> +void +InstructionQueue<Impl>::moveToYoungerInst(ListOrderIt list_order_it) +{ + // Get iterator of next item on the list + // Delete the original iterator + // Determine if the next item is either the end of the list or younger + // than the new instruction. If so, then add in a new iterator right here. + // If not, then move along. + ListOrderEntry queue_entry; + OpClass op_class = (*list_order_it).queueType; + ListOrderIt next_it = list_order_it; + + ++next_it; + + queue_entry.queueType = op_class; + queue_entry.oldestInst = readyInsts[op_class].top()->seqNum; + + while (next_it != listOrder.end() && + (*next_it).oldestInst < queue_entry.oldestInst) { + ++next_it; + } - insts_available = true; + readyIt[op_class] = listOrder.insert(next_it, queue_entry); +} - branch_head_inst = readyBranchInsts.top(); +template <class Impl> +void +InstructionQueue<Impl>::processFUCompletion(DynInstPtr &inst, int fu_idx) +{ + // The CPU could have been sleeping until this op completed (*extremely* + // long latency op). Wake it if it was. This may be overkill. + if (isSwitchedOut()) { + return; + } - if (branch_head_inst->isSquashed()) { - readyBranchInsts.pop(); + iewStage->wakeCPU(); - ++iqLoopSquashStalls; + if (fu_idx > -1) + fuPool->freeUnitNextCycle(fu_idx); - continue; - } else if (branch_head_inst->seqNum < oldest_inst) { - oldest_inst = branch_head_inst->seqNum; + // @todo: Ensure that these FU Completions happen at the beginning + // of a cycle, otherwise they could add too many instructions to + // the queue. + issueToExecuteQueue->access(0)->size++; + instsToExecute.push_back(inst); +} - list_with_oldest = Branch; - } +// @todo: Figure out a better way to remove the squashed items from the +// lists. Checking the top item of each list to see if it's squashed +// wastes time and forces jumps. +template <class Impl> +void +InstructionQueue<Impl>::scheduleReadyInsts() +{ + DPRINTF(IQ, "Attempting to schedule ready instructions from " + "the IQ.\n"); - } + IssueStruct *i2e_info = issueToExecuteQueue->access(0); - if (!memDepUnit.empty() && - memory_issued < memoryWidth) { + // Have iterator to head of the list + // While I haven't exceeded bandwidth or reached the end of the list, + // Try to get a FU that can do what this op needs. + // If successful, change the oldestInst to the new top of the list, put + // the queue in the proper place in the list. + // Increment the iterator. + // This will avoid trying to schedule a certain op class if there are no + // FUs that handle it. + ListOrderIt order_it = listOrder.begin(); + ListOrderIt order_end_it = listOrder.end(); + int total_issued = 0; - insts_available = true; + while (total_issued < totalWidth && + order_it != order_end_it) { + OpClass op_class = (*order_it).queueType; - mem_head_inst = memDepUnit.top(); + assert(!readyInsts[op_class].empty()); - if (mem_head_inst->isSquashed()) { - memDepUnit.pop(); + DynInstPtr issuing_inst = readyInsts[op_class].top(); - ++iqLoopSquashStalls; + assert(issuing_inst->seqNum == (*order_it).oldestInst); - continue; - } else if (mem_head_inst->seqNum < oldest_inst) { - oldest_inst = mem_head_inst->seqNum; + if (issuing_inst->isSquashed()) { + readyInsts[op_class].pop(); - list_with_oldest = Memory; + if (!readyInsts[op_class].empty()) { + moveToYoungerInst(order_it); + } else { + readyIt[op_class] = listOrder.end(); + queueOnList[op_class] = false; } - } - - if (!readyMiscInsts.empty()) { - - insts_available = true; - - misc_head_inst = readyMiscInsts.top(); - if (misc_head_inst->isSquashed()) { - readyMiscInsts.pop(); + listOrder.erase(order_it++); - ++iqLoopSquashStalls; + ++iqSquashedInstsIssued; - continue; - } else if (misc_head_inst->seqNum < oldest_inst) { - oldest_inst = misc_head_inst->seqNum; - - list_with_oldest = Misc; - } + continue; } - if (!squashedInsts.empty()) { - - insts_available = true; + int idx = -2; + int op_latency = 1; + int tid = issuing_inst->threadNumber; - squashed_head_inst = squashedInsts.top(); + if (op_class != No_OpClass) { + idx = fuPool->getUnit(op_class); - if (squashed_head_inst->seqNum < oldest_inst) { - list_with_oldest = Squashed; + if (idx > -1) { + op_latency = fuPool->getOpLatency(op_class); } - } - DynInstPtr issuing_inst = NULL; - - switch (list_with_oldest) { - case None: - DPRINTF(IQ, "IQ: Not able to schedule any instructions. Issuing " - "inst is %#x.\n", issuing_inst); - break; - - case Int: - issuing_inst = int_head_inst; - readyIntInsts.pop(); - ++int_issued; - DPRINTF(IQ, "IQ: Issuing integer instruction PC %#x.\n", - issuing_inst->readPC()); - break; - - case Float: - issuing_inst = float_head_inst; - readyFloatInsts.pop(); - ++float_issued; - DPRINTF(IQ, "IQ: Issuing float instruction PC %#x.\n", - issuing_inst->readPC()); - break; - - case Branch: - issuing_inst = branch_head_inst; - readyBranchInsts.pop(); - ++branch_issued; - DPRINTF(IQ, "IQ: Issuing branch instruction PC %#x.\n", - issuing_inst->readPC()); - break; - - case Memory: - issuing_inst = mem_head_inst; + // If we have an instruction that doesn't require a FU, or a + // valid FU, then schedule for execution. + if (idx == -2 || idx != -1) { + if (op_latency == 1) { + i2e_info->size++; + instsToExecute.push_back(issuing_inst); + + // Add the FU onto the list of FU's to be freed next + // cycle if we used one. + if (idx >= 0) + fuPool->freeUnitNextCycle(idx); + } else { + int issue_latency = fuPool->getIssueLatency(op_class); + // Generate completion event for the FU + FUCompletion *execution = new FUCompletion(issuing_inst, + idx, this); + + execution->schedule(curTick + cpu->cycles(issue_latency - 1)); + + // @todo: Enforce that issue_latency == 1 or op_latency + if (issue_latency > 1) { + // If FU isn't pipelined, then it must be freed + // upon the execution completing. + execution->setFreeFU(); + } else { + // Add the FU onto the list of FU's to be freed next cycle. + fuPool->freeUnitNextCycle(idx); + } + } - memDepUnit.pop(); - ++memory_issued; - DPRINTF(IQ, "IQ: Issuing memory instruction PC %#x.\n", - issuing_inst->readPC()); - break; + DPRINTF(IQ, "Thread %i: Issuing instruction PC %#x " + "[sn:%lli]\n", + tid, issuing_inst->readPC(), + issuing_inst->seqNum); - case Misc: - issuing_inst = misc_head_inst; - readyMiscInsts.pop(); + readyInsts[op_class].pop(); - ++iqMiscInstsIssued; + if (!readyInsts[op_class].empty()) { + moveToYoungerInst(order_it); + } else { + readyIt[op_class] = listOrder.end(); + queueOnList[op_class] = false; + } - DPRINTF(IQ, "IQ: Issuing a miscellaneous instruction PC %#x.\n", - issuing_inst->readPC()); - break; + issuing_inst->setIssued(); + ++total_issued; - case Squashed: - assert(0 && "Squashed insts should not issue any more!"); - squashedInsts.pop(); - // Set the squashed instruction as able to commit so that commit - // can just drop it from the ROB. This is a bit faked. - ++squashed_issued; - ++freeEntries; + if (!issuing_inst->isMemRef()) { + // Memory instructions can not be freed from the IQ until they + // complete. + ++freeEntries; + count[tid]--; + issuing_inst->removeInIQ(); + } else { + memDepUnit[tid].issue(issuing_inst); + } - DPRINTF(IQ, "IQ: Issuing squashed instruction PC %#x.\n", - squashed_head_inst->readPC()); - break; + listOrder.erase(order_it++); + statIssuedInstType[tid][op_class]++; + } else { + statFuBusy[op_class]++; + fuBusy[tid]++; + ++order_it; } + } - if (list_with_oldest != None && list_with_oldest != Squashed) { - i2e_info->insts[total_issued] = issuing_inst; - i2e_info->size++; - - issuing_inst->setIssued(); - - ++freeEntries; - ++total_issued; - } + numIssuedDist.sample(total_issued); + iqInstsIssued+= total_issued; - assert(freeEntries == (numEntries - countInsts())); + // If we issued any instructions, tell the CPU we had activity. + if (total_issued) { + cpu->activityThisCycle(); + } else { + DPRINTF(IQ, "Not able to schedule any instructions.\n"); } - - iqIntInstsIssued += int_issued; - iqFloatInstsIssued += float_issued; - iqBranchInstsIssued += branch_issued; - iqMemInstsIssued += memory_issued; - iqSquashedInstsIssued += squashed_issued; } template <class Impl> void InstructionQueue<Impl>::scheduleNonSpec(const InstSeqNum &inst) { - DPRINTF(IQ, "IQ: Marking nonspeculative instruction with sequence " - "number %i as ready to execute.\n", inst); + DPRINTF(IQ, "Marking nonspeculative instruction [sn:%lli] as ready " + "to execute.\n", inst); - non_spec_it_t inst_it = nonSpecInsts.find(inst); + NonSpecMapIt inst_it = nonSpecInsts.find(inst); assert(inst_it != nonSpecInsts.end()); - // Mark this instruction as ready to issue. + unsigned tid = (*inst_it).second->threadNumber; + (*inst_it).second->setCanIssue(); - // Now schedule the instruction. if (!(*inst_it).second->isMemRef()) { addIfReady((*inst_it).second); } else { - memDepUnit.nonSpecInstReady((*inst_it).second); + memDepUnit[tid].nonSpecInstReady((*inst_it).second); } + (*inst_it).second = NULL; + nonSpecInsts.erase(inst_it); } template <class Impl> void +InstructionQueue<Impl>::commit(const InstSeqNum &inst, unsigned tid) +{ + DPRINTF(IQ, "[tid:%i]: Committing instructions older than [sn:%i]\n", + tid,inst); + + ListIt iq_it = instList[tid].begin(); + + while (iq_it != instList[tid].end() && + (*iq_it)->seqNum <= inst) { + ++iq_it; + instList[tid].pop_front(); + } + + assert(freeEntries == (numEntries - countInsts())); +} + +template <class Impl> +int InstructionQueue<Impl>::wakeDependents(DynInstPtr &completed_inst) { - DPRINTF(IQ, "IQ: Waking dependents of completed instruction.\n"); - //Look at the physical destination register of the DynInst - //and look it up on the dependency graph. Then mark as ready - //any instructions within the instruction queue. - DependencyEntry *curr; + int dependents = 0; - // Tell the memory dependence unit to wake any dependents on this - // instruction if it is a memory instruction. + DPRINTF(IQ, "Waking dependents of completed instruction.\n"); + + assert(!completed_inst->isSquashed()); + // Tell the memory dependence unit to wake any dependents on this + // instruction if it is a memory instruction. Also complete the memory + // instruction at this point since we know it executed without issues. + // @todo: Might want to rename "completeMemInst" to something that + // indicates that it won't need to be replayed, and call this + // earlier. Might not be a big deal. if (completed_inst->isMemRef()) { - memDepUnit.wakeDependents(completed_inst); + memDepUnit[completed_inst->threadNumber].wakeDependents(completed_inst); + completeMemInst(completed_inst); + } else if (completed_inst->isMemBarrier() || + completed_inst->isWriteBarrier()) { + memDepUnit[completed_inst->threadNumber].completeBarrier(completed_inst); } for (int dest_reg_idx = 0; @@ -678,44 +898,94 @@ InstructionQueue<Impl>::wakeDependents(DynInstPtr &completed_inst) continue; } - DPRINTF(IQ, "IQ: Waking any dependents on register %i.\n", + DPRINTF(IQ, "Waking any dependents on register %i.\n", (int) dest_reg); - //Maybe abstract this part into a function. - //Go through the dependency chain, marking the registers as ready - //within the waiting instructions. - while (dependGraph[dest_reg].next) { + //Go through the dependency chain, marking the registers as + //ready within the waiting instructions. + DynInstPtr dep_inst = dependGraph.pop(dest_reg); - curr = dependGraph[dest_reg].next; - - DPRINTF(IQ, "IQ: Waking up a dependent instruction, PC%#x.\n", - curr->inst->readPC()); + while (dep_inst) { + DPRINTF(IQ, "Waking up a dependent instruction, PC%#x.\n", + dep_inst->readPC()); // Might want to give more information to the instruction - // so that it knows which of its source registers is ready. - // However that would mean that the dependency graph entries - // would need to hold the src_reg_idx. - curr->inst->markSrcRegReady(); - - addIfReady(curr->inst); - - dependGraph[dest_reg].next = curr->next; + // so that it knows which of its source registers is + // ready. However that would mean that the dependency + // graph entries would need to hold the src_reg_idx. + dep_inst->markSrcRegReady(); - DependencyEntry::mem_alloc_counter--; + addIfReady(dep_inst); - curr->inst = NULL; + dep_inst = dependGraph.pop(dest_reg); - delete curr; + ++dependents; } - // Reset the head node now that all of its dependents have been woken - // up. - dependGraph[dest_reg].next = NULL; - dependGraph[dest_reg].inst = NULL; + // Reset the head node now that all of its dependents have + // been woken up. + assert(dependGraph.empty(dest_reg)); + dependGraph.clearInst(dest_reg); // Mark the scoreboard as having that register ready. regScoreboard[dest_reg] = true; } + return dependents; +} + +template <class Impl> +void +InstructionQueue<Impl>::addReadyMemInst(DynInstPtr &ready_inst) +{ + OpClass op_class = ready_inst->opClass(); + + readyInsts[op_class].push(ready_inst); + + // Will need to reorder the list if either a queue is not on the list, + // or it has an older instruction than last time. + if (!queueOnList[op_class]) { + addToOrderList(op_class); + } else if (readyInsts[op_class].top()->seqNum < + (*readyIt[op_class]).oldestInst) { + listOrder.erase(readyIt[op_class]); + addToOrderList(op_class); + } + + DPRINTF(IQ, "Instruction is ready to issue, putting it onto " + "the ready list, PC %#x opclass:%i [sn:%lli].\n", + ready_inst->readPC(), op_class, ready_inst->seqNum); +} + +template <class Impl> +void +InstructionQueue<Impl>::rescheduleMemInst(DynInstPtr &resched_inst) +{ + memDepUnit[resched_inst->threadNumber].reschedule(resched_inst); +} + +template <class Impl> +void +InstructionQueue<Impl>::replayMemInst(DynInstPtr &replay_inst) +{ + memDepUnit[replay_inst->threadNumber].replay(replay_inst); +} + +template <class Impl> +void +InstructionQueue<Impl>::completeMemInst(DynInstPtr &completed_inst) +{ + int tid = completed_inst->threadNumber; + + DPRINTF(IQ, "Completing mem instruction PC:%#x [sn:%lli]\n", + completed_inst->readPC(), completed_inst->seqNum); + + ++freeEntries; + + completed_inst->memOpDone = true; + + memDepUnit[tid].completed(completed_inst); + + count[tid]--; } template <class Impl> @@ -723,58 +993,64 @@ void InstructionQueue<Impl>::violation(DynInstPtr &store, DynInstPtr &faulting_load) { - memDepUnit.violation(store, faulting_load); + memDepUnit[store->threadNumber].violation(store, faulting_load); } template <class Impl> void -InstructionQueue<Impl>::squash() +InstructionQueue<Impl>::squash(unsigned tid) { - DPRINTF(IQ, "IQ: Starting to squash instructions in the IQ.\n"); + DPRINTF(IQ, "[tid:%i]: Starting to squash instructions in " + "the IQ.\n", tid); // Read instruction sequence number of last instruction out of the // time buffer. - squashedSeqNum = fromCommit->commitInfo.doneSeqNum; - - // Setup the squash iterator to point to the tail. - squashIt = tail; + squashedSeqNum[tid] = fromCommit->commitInfo[tid].doneSeqNum; // Call doSquash if there are insts in the IQ - if (freeEntries != numEntries) { - doSquash(); + if (count[tid] > 0) { + doSquash(tid); } // Also tell the memory dependence unit to squash. - memDepUnit.squash(squashedSeqNum); + memDepUnit[tid].squash(squashedSeqNum[tid], tid); } template <class Impl> void -InstructionQueue<Impl>::doSquash() +InstructionQueue<Impl>::doSquash(unsigned tid) { - // Make sure the squash iterator isn't pointing to nothing. - assert(squashIt != cpu->instList.end()); - // Make sure the squashed sequence number is valid. - assert(squashedSeqNum != 0); + // Start at the tail. + ListIt squash_it = instList[tid].end(); + --squash_it; - DPRINTF(IQ, "IQ: Squashing instructions in the IQ.\n"); + DPRINTF(IQ, "[tid:%i]: Squashing until sequence number %i!\n", + tid, squashedSeqNum[tid]); // Squash any instructions younger than the squashed sequence number // given. - while ((*squashIt)->seqNum > squashedSeqNum) { - DynInstPtr squashed_inst = (*squashIt); + while (squash_it != instList[tid].end() && + (*squash_it)->seqNum > squashedSeqNum[tid]) { + + DynInstPtr squashed_inst = (*squash_it); // Only handle the instruction if it actually is in the IQ and // hasn't already been squashed in the IQ. - if (!squashed_inst->isIssued() && - !squashed_inst->isSquashedInIQ()) { + if (squashed_inst->threadNumber != tid || + squashed_inst->isSquashedInIQ()) { + --squash_it; + continue; + } + + if (!squashed_inst->isIssued() || + (squashed_inst->isMemRef() && + !squashed_inst->memOpDone)) { // Remove the instruction from the dependency list. - // Hack for now: These below don't add themselves to the - // dependency list, so don't try to remove them. - if (!squashed_inst->isNonSpeculative()/* && - !squashed_inst->isStore()*/ - ) { + if (!squashed_inst->isNonSpeculative() && + !squashed_inst->isStoreConditional() && + !squashed_inst->isMemBarrier() && + !squashed_inst->isWriteBarrier()) { for (int src_reg_idx = 0; src_reg_idx < squashed_inst->numSrcRegs(); @@ -783,25 +1059,31 @@ InstructionQueue<Impl>::doSquash() PhysRegIndex src_reg = squashed_inst->renamedSrcRegIdx(src_reg_idx); - // Only remove it from the dependency graph if it was - // placed there in the first place. - // HACK: This assumes that instructions woken up from the - // dependency chain aren't informed that a specific src - // register has become ready. This may not always be true - // in the future. + // Only remove it from the dependency graph if it + // was placed there in the first place. + + // Instead of doing a linked list traversal, we + // can just remove these squashed instructions + // either at issue time, or when the register is + // overwritten. The only downside to this is it + // leaves more room for error. + if (!squashed_inst->isReadySrcRegIdx(src_reg_idx) && src_reg < numPhysRegs) { - dependGraph[src_reg].remove(squashed_inst); + dependGraph.remove(src_reg, squashed_inst); } + ++iqSquashedOperandsExamined; } - - // Might want to remove producers as well. } else { - nonSpecInsts[squashed_inst->seqNum] = NULL; + NonSpecMapIt ns_inst_it = + nonSpecInsts.find(squashed_inst->seqNum); + assert(ns_inst_it != nonSpecInsts.end()); - nonSpecInsts.erase(squashed_inst->seqNum); + (*ns_inst_it).second = NULL; + + nonSpecInsts.erase(ns_inst_it); ++iqSquashedNonSpecRemoved; } @@ -811,91 +1093,25 @@ InstructionQueue<Impl>::doSquash() // Mark it as squashed within the IQ. squashed_inst->setSquashedInIQ(); -// squashedInsts.push(squashed_inst); + // @todo: Remove this hack where several statuses are set so the + // inst will flow through the rest of the pipeline. squashed_inst->setIssued(); squashed_inst->setCanCommit(); + squashed_inst->removeInIQ(); + + //Update Thread IQ Count + count[squashed_inst->threadNumber]--; ++freeEntries; - DPRINTF(IQ, "IQ: Instruction PC %#x squashed.\n", - squashed_inst->readPC()); + DPRINTF(IQ, "[tid:%i]: Instruction [sn:%lli] PC %#x " + "squashed.\n", + tid, squashed_inst->seqNum, squashed_inst->readPC()); } - --squashIt; + instList[tid].erase(squash_it--); ++iqSquashedInstsExamined; } - - assert(freeEntries <= numEntries); - - if (freeEntries == numEntries) { - tail = cpu->instList.end(); - } - -} - -template <class Impl> -void -InstructionQueue<Impl>::stopSquash() -{ - // Clear up the squash variables to ensure that squashing doesn't - // get called improperly. - squashedSeqNum = 0; - - squashIt = cpu->instList.end(); -} - -template <class Impl> -void -InstructionQueue<Impl>::DependencyEntry::insert(DynInstPtr &new_inst) -{ - //Add this new, dependent instruction at the head of the dependency - //chain. - - // First create the entry that will be added to the head of the - // dependency chain. - DependencyEntry *new_entry = new DependencyEntry; - new_entry->next = this->next; - new_entry->inst = new_inst; - - // Then actually add it to the chain. - this->next = new_entry; - - ++mem_alloc_counter; -} - -template <class Impl> -void -InstructionQueue<Impl>::DependencyEntry::remove(DynInstPtr &inst_to_remove) -{ - DependencyEntry *prev = this; - DependencyEntry *curr = this->next; - - // Make sure curr isn't NULL. Because this instruction is being - // removed from a dependency list, it must have been placed there at - // an earlier time. The dependency chain should not be empty, - // unless the instruction dependent upon it is already ready. - if (curr == NULL) { - return; - } - - // Find the instruction to remove within the dependency linked list. - while(curr->inst != inst_to_remove) - { - prev = curr; - curr = curr->next; - - assert(curr != NULL); - } - - // Now remove this instruction from the list. - prev->next = curr->next; - - --mem_alloc_counter; - - // Could push this off to the destructor of DependencyEntry - curr->inst = NULL; - - delete curr; } template <class Impl> @@ -922,21 +1138,21 @@ InstructionQueue<Impl>::addToDependents(DynInstPtr &new_inst) if (src_reg >= numPhysRegs) { continue; } else if (regScoreboard[src_reg] == false) { - DPRINTF(IQ, "IQ: Instruction PC %#x has src reg %i that " + DPRINTF(IQ, "Instruction PC %#x has src reg %i that " "is being added to the dependency chain.\n", new_inst->readPC(), src_reg); - dependGraph[src_reg].insert(new_inst); + dependGraph.insert(src_reg, new_inst); // Change the return value to indicate that something // was added to the dependency graph. return_val = true; } else { - DPRINTF(IQ, "IQ: Instruction PC %#x has src reg %i that " + DPRINTF(IQ, "Instruction PC %#x has src reg %i that " "became ready before it reached the IQ.\n", new_inst->readPC(), src_reg); // Mark a register ready within the instruction. - new_inst->markSrcRegReady(); + new_inst->markSrcRegReady(src_reg_idx); } } } @@ -946,12 +1162,12 @@ InstructionQueue<Impl>::addToDependents(DynInstPtr &new_inst) template <class Impl> void -InstructionQueue<Impl>::createDependency(DynInstPtr &new_inst) +InstructionQueue<Impl>::addToProducers(DynInstPtr &new_inst) { - //Actually nothing really needs to be marked when an - //instruction becomes the producer of a register's value, - //but for convenience a ptr to the producing instruction will - //be placed in the head node of the dependency links. + // Nothing really needs to be marked when an instruction becomes + // the producer of a register's value, but for convenience a ptr + // to the producing instruction will be placed in the head node of + // the dependency links. int8_t total_dest_regs = new_inst->numDestRegs(); for (int dest_reg_idx = 0; @@ -968,13 +1184,13 @@ InstructionQueue<Impl>::createDependency(DynInstPtr &new_inst) continue; } - dependGraph[dest_reg].inst = new_inst; - - if (dependGraph[dest_reg].next) { - dumpDependGraph(); - panic("IQ: Dependency graph not empty!"); + if (!dependGraph.empty(dest_reg)) { + dependGraph.dump(); + panic("Dependency graph %i not empty!", dest_reg); } + dependGraph.setInst(dest_reg, new_inst); + // Mark the scoreboard to say it's not yet ready. regScoreboard[dest_reg] = false; } @@ -984,155 +1200,204 @@ template <class Impl> void InstructionQueue<Impl>::addIfReady(DynInstPtr &inst) { - //If the instruction now has all of its source registers + // If the instruction now has all of its source registers // available, then add it to the list of ready instructions. if (inst->readyToIssue()) { //Add the instruction to the proper ready list. - if (inst->isControl()) { + if (inst->isMemRef()) { - DPRINTF(IQ, "IQ: Branch instruction is ready to issue, " - "putting it onto the ready list, PC %#x.\n", - inst->readPC()); - readyBranchInsts.push(inst); - - } else if (inst->isMemRef()) { - - DPRINTF(IQ, "IQ: Checking if memory instruction can issue.\n"); + DPRINTF(IQ, "Checking if memory instruction can issue.\n"); // Message to the mem dependence unit that this instruction has // its registers ready. + memDepUnit[inst->threadNumber].regsReady(inst); - memDepUnit.regsReady(inst); - -#if 0 - if (memDepUnit.readyToIssue(inst)) { - DPRINTF(IQ, "IQ: Memory instruction is ready to issue, " - "putting it onto the ready list, PC %#x.\n", - inst->readPC()); - readyMemInsts.push(inst); - } else { - // Make dependent on the store. - // Will need some way to get the store instruction it should - // be dependent upon; then when the store issues it can - // put the instruction on the ready list. - // Yet another tree? - assert(0 && "Instruction has no way to actually issue"); - } -#endif - - } else if (inst->isInteger()) { - - DPRINTF(IQ, "IQ: Integer instruction is ready to issue, " - "putting it onto the ready list, PC %#x.\n", - inst->readPC()); - readyIntInsts.push(inst); + return; + } - } else if (inst->isFloating()) { + OpClass op_class = inst->opClass(); - DPRINTF(IQ, "IQ: Floating instruction is ready to issue, " - "putting it onto the ready list, PC %#x.\n", - inst->readPC()); - readyFloatInsts.push(inst); + DPRINTF(IQ, "Instruction is ready to issue, putting it onto " + "the ready list, PC %#x opclass:%i [sn:%lli].\n", + inst->readPC(), op_class, inst->seqNum); - } else { - DPRINTF(IQ, "IQ: Miscellaneous instruction is ready to issue, " - "putting it onto the ready list, PC %#x..\n", - inst->readPC()); + readyInsts[op_class].push(inst); - readyMiscInsts.push(inst); + // Will need to reorder the list if either a queue is not on the list, + // or it has an older instruction than last time. + if (!queueOnList[op_class]) { + addToOrderList(op_class); + } else if (readyInsts[op_class].top()->seqNum < + (*readyIt[op_class]).oldestInst) { + listOrder.erase(readyIt[op_class]); + addToOrderList(op_class); } } } -/* - * Caution, this function must not be called prior to tail being updated at - * least once, otherwise it will fail the assertion. This is because - * instList.begin() actually changes upon the insertion of an element into the - * list when the list is empty. - */ template <class Impl> int InstructionQueue<Impl>::countInsts() { - ListIt count_it = cpu->instList.begin(); +#if 0 + //ksewell:This works but definitely could use a cleaner write + //with a more intuitive way of counting. Right now it's + //just brute force .... + // Change the #if if you want to use this method. int total_insts = 0; - if (tail == cpu->instList.end()) - return 0; + for (int i = 0; i < numThreads; ++i) { + ListIt count_it = instList[i].begin(); + + while (count_it != instList[i].end()) { + if (!(*count_it)->isSquashed() && !(*count_it)->isSquashedInIQ()) { + if (!(*count_it)->isIssued()) { + ++total_insts; + } else if ((*count_it)->isMemRef() && + !(*count_it)->memOpDone) { + // Loads that have not been marked as executed still count + // towards the total instructions. + ++total_insts; + } + } - while (count_it != tail) { - if (!(*count_it)->isIssued()) { - ++total_insts; + ++count_it; } - - ++count_it; - - assert(count_it != cpu->instList.end()); - } - - // Need to count the tail iterator as well. - if (count_it != cpu->instList.end() && - (*count_it) && - !(*count_it)->isIssued()) { - ++total_insts; } return total_insts; +#else + return numEntries - freeEntries; +#endif } template <class Impl> void -InstructionQueue<Impl>::dumpDependGraph() +InstructionQueue<Impl>::dumpLists() { - DependencyEntry *curr; + for (int i = 0; i < Num_OpClasses; ++i) { + cprintf("Ready list %i size: %i\n", i, readyInsts[i].size()); - for (int i = 0; i < numPhysRegs; ++i) - { - curr = &dependGraph[i]; + cprintf("\n"); + } - if (curr->inst) { - cprintf("dependGraph[%i]: producer: %#x consumer: ", i, - curr->inst->readPC()); - } else { - cprintf("dependGraph[%i]: No producer. consumer: ", i); - } + cprintf("Non speculative list size: %i\n", nonSpecInsts.size()); - while (curr->next != NULL) { - curr = curr->next; + NonSpecMapIt non_spec_it = nonSpecInsts.begin(); + NonSpecMapIt non_spec_end_it = nonSpecInsts.end(); - cprintf("%#x ", curr->inst->readPC()); - } + cprintf("Non speculative list: "); - cprintf("\n"); + while (non_spec_it != non_spec_end_it) { + cprintf("%#x [sn:%lli]", (*non_spec_it).second->readPC(), + (*non_spec_it).second->seqNum); + ++non_spec_it; + } + + cprintf("\n"); + + ListOrderIt list_order_it = listOrder.begin(); + ListOrderIt list_order_end_it = listOrder.end(); + int i = 1; + + cprintf("List order: "); + + while (list_order_it != list_order_end_it) { + cprintf("%i OpClass:%i [sn:%lli] ", i, (*list_order_it).queueType, + (*list_order_it).oldestInst); + + ++list_order_it; + ++i; } + + cprintf("\n"); } + template <class Impl> void -InstructionQueue<Impl>::dumpLists() +InstructionQueue<Impl>::dumpInsts() { - cprintf("Ready integer list size: %i\n", readyIntInsts.size()); + for (int i = 0; i < numThreads; ++i) { + int num = 0; + int valid_num = 0; + ListIt inst_list_it = instList[i].begin(); + + while (inst_list_it != instList[i].end()) + { + cprintf("Instruction:%i\n", + num); + if (!(*inst_list_it)->isSquashed()) { + if (!(*inst_list_it)->isIssued()) { + ++valid_num; + cprintf("Count:%i\n", valid_num); + } else if ((*inst_list_it)->isMemRef() && + !(*inst_list_it)->memOpDone) { + // Loads that have not been marked as executed + // still count towards the total instructions. + ++valid_num; + cprintf("Count:%i\n", valid_num); + } + } + + cprintf("PC:%#x\n[sn:%lli]\n[tid:%i]\n" + "Issued:%i\nSquashed:%i\n", + (*inst_list_it)->readPC(), + (*inst_list_it)->seqNum, + (*inst_list_it)->threadNumber, + (*inst_list_it)->isIssued(), + (*inst_list_it)->isSquashed()); - cprintf("Ready float list size: %i\n", readyFloatInsts.size()); + if ((*inst_list_it)->isMemRef()) { + cprintf("MemOpDone:%i\n", (*inst_list_it)->memOpDone); + } - cprintf("Ready branch list size: %i\n", readyBranchInsts.size()); + cprintf("\n"); - cprintf("Ready misc list size: %i\n", readyMiscInsts.size()); + inst_list_it++; + ++num; + } + } - cprintf("Squashed list size: %i\n", squashedInsts.size()); + cprintf("Insts to Execute list:\n"); - cprintf("Non speculative list size: %i\n", nonSpecInsts.size()); + int num = 0; + int valid_num = 0; + ListIt inst_list_it = instsToExecute.begin(); - non_spec_it_t non_spec_it = nonSpecInsts.begin(); + while (inst_list_it != instsToExecute.end()) + { + cprintf("Instruction:%i\n", + num); + if (!(*inst_list_it)->isSquashed()) { + if (!(*inst_list_it)->isIssued()) { + ++valid_num; + cprintf("Count:%i\n", valid_num); + } else if ((*inst_list_it)->isMemRef() && + !(*inst_list_it)->memOpDone) { + // Loads that have not been marked as executed + // still count towards the total instructions. + ++valid_num; + cprintf("Count:%i\n", valid_num); + } + } - cprintf("Non speculative list: "); + cprintf("PC:%#x\n[sn:%lli]\n[tid:%i]\n" + "Issued:%i\nSquashed:%i\n", + (*inst_list_it)->readPC(), + (*inst_list_it)->seqNum, + (*inst_list_it)->threadNumber, + (*inst_list_it)->isIssued(), + (*inst_list_it)->isSquashed()); - while (non_spec_it != nonSpecInsts.end()) { - cprintf("%#x ", (*non_spec_it).second->readPC()); - ++non_spec_it; - } + if ((*inst_list_it)->isMemRef()) { + cprintf("MemOpDone:%i\n", (*inst_list_it)->memOpDone); + } - cprintf("\n"); + cprintf("\n"); + inst_list_it++; + ++num; + } } diff --git a/src/cpu/o3/lsq.cc b/src/cpu/o3/lsq.cc new file mode 100644 index 000000000..de0325920 --- /dev/null +++ b/src/cpu/o3/lsq.cc @@ -0,0 +1,38 @@ +/* + * Copyright (c) 2004-2005 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Korey Sewell + */ + +#include "cpu/o3/alpha_dyn_inst.hh" +#include "cpu/o3/alpha_cpu.hh" +#include "cpu/o3/alpha_impl.hh" +#include "cpu/o3/lsq_impl.hh" + +// Force the instantiation of LDSTQ for all the implementations we care about. +template class LSQ<AlphaSimpleImpl>; + diff --git a/src/cpu/o3/lsq.hh b/src/cpu/o3/lsq.hh new file mode 100644 index 000000000..bc4154c85 --- /dev/null +++ b/src/cpu/o3/lsq.hh @@ -0,0 +1,318 @@ +/* + * Copyright (c) 2004-2006 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Korey Sewell + */ + +#ifndef __CPU_O3_LSQ_HH__ +#define __CPU_O3_LSQ_HH__ + +#include <map> +#include <queue> + +#include "config/full_system.hh" +#include "cpu/inst_seq.hh" +#include "cpu/o3/lsq_unit.hh" +#include "mem/port.hh" +#include "sim/sim_object.hh" + +template <class Impl> +class LSQ { + public: + typedef typename Impl::Params Params; + typedef typename Impl::FullCPU FullCPU; + typedef typename Impl::DynInstPtr DynInstPtr; + typedef typename Impl::CPUPol::IEW IEW; + typedef typename Impl::CPUPol::LSQUnit LSQUnit; + + /** SMT policy. */ + enum LSQPolicy { + Dynamic, + Partitioned, + Threshold + }; + + /** Constructs an LSQ with the given parameters. */ + LSQ(Params *params); + + /** Returns the name of the LSQ. */ + std::string name() const; + + /** Sets the pointer to the list of active threads. */ + void setActiveThreads(std::list<unsigned> *at_ptr); + /** Sets the CPU pointer. */ + void setCPU(FullCPU *cpu_ptr); + /** Sets the IEW stage pointer. */ + void setIEW(IEW *iew_ptr); + /** Switches out the LSQ. */ + void switchOut(); + /** Takes over execution from another CPU's thread. */ + void takeOverFrom(); + + /** Number of entries needed for the given amount of threads.*/ + int entryAmount(int num_threads); + void removeEntries(unsigned tid); + /** Reset the max entries for each thread. */ + void resetEntries(); + /** Resize the max entries for a thread. */ + void resizeEntries(unsigned size, unsigned tid); + + /** Ticks the LSQ. */ + void tick(); + /** Ticks a specific LSQ Unit. */ + void tick(unsigned tid) + { thread[tid].tick(); } + + /** Inserts a load into the LSQ. */ + void insertLoad(DynInstPtr &load_inst); + /** Inserts a store into the LSQ. */ + void insertStore(DynInstPtr &store_inst); + + /** Executes a load. */ + Fault executeLoad(DynInstPtr &inst); + + /** Executes a store. */ + Fault executeStore(DynInstPtr &inst); + + /** + * Commits loads up until the given sequence number for a specific thread. + */ + void commitLoads(InstSeqNum &youngest_inst, unsigned tid) + { thread[tid].commitLoads(youngest_inst); } + + /** + * Commits stores up until the given sequence number for a specific thread. + */ + void commitStores(InstSeqNum &youngest_inst, unsigned tid) + { thread[tid].commitStores(youngest_inst); } + + /** + * Attempts to write back stores until all cache ports are used or the + * interface becomes blocked. + */ + void writebackStores(); + /** Same as above, but only for one thread. */ + void writebackStores(unsigned tid); + + /** + * Squash instructions from a thread until the specified sequence number. + */ + void squash(const InstSeqNum &squashed_num, unsigned tid) + { thread[tid].squash(squashed_num); } + + /** Returns whether or not there was a memory ordering violation. */ + bool violation(); + /** + * Returns whether or not there was a memory ordering violation for a + * specific thread. + */ + bool violation(unsigned tid) + { return thread[tid].violation(); } + + /** Returns if a load is blocked due to the memory system for a specific + * thread. + */ + bool loadBlocked(unsigned tid) + { return thread[tid].loadBlocked(); } + + bool isLoadBlockedHandled(unsigned tid) + { return thread[tid].isLoadBlockedHandled(); } + + void setLoadBlockedHandled(unsigned tid) + { thread[tid].setLoadBlockedHandled(); } + + /** Gets the instruction that caused the memory ordering violation. */ + DynInstPtr getMemDepViolator(unsigned tid) + { return thread[tid].getMemDepViolator(); } + + /** Returns the head index of the load queue for a specific thread. */ + int getLoadHead(unsigned tid) + { return thread[tid].getLoadHead(); } + + /** Returns the sequence number of the head of the load queue. */ + InstSeqNum getLoadHeadSeqNum(unsigned tid) + { + return thread[tid].getLoadHeadSeqNum(); + } + + /** Returns the head index of the store queue. */ + int getStoreHead(unsigned tid) + { return thread[tid].getStoreHead(); } + + /** Returns the sequence number of the head of the store queue. */ + InstSeqNum getStoreHeadSeqNum(unsigned tid) + { + return thread[tid].getStoreHeadSeqNum(); + } + + /** Returns the number of instructions in all of the queues. */ + int getCount(); + /** Returns the number of instructions in the queues of one thread. */ + int getCount(unsigned tid) + { return thread[tid].getCount(); } + + /** Returns the total number of loads in the load queue. */ + int numLoads(); + /** Returns the total number of loads for a single thread. */ + int numLoads(unsigned tid) + { return thread[tid].numLoads(); } + + /** Returns the total number of stores in the store queue. */ + int numStores(); + /** Returns the total number of stores for a single thread. */ + int numStores(unsigned tid) + { return thread[tid].numStores(); } + + /** Returns the total number of loads that are ready. */ + int numLoadsReady(); + /** Returns the number of loads that are ready for a single thread. */ + int numLoadsReady(unsigned tid) + { return thread[tid].numLoadsReady(); } + + /** Returns the number of free entries. */ + unsigned numFreeEntries(); + /** Returns the number of free entries for a specific thread. */ + unsigned numFreeEntries(unsigned tid); + + /** Returns if the LSQ is full (either LQ or SQ is full). */ + bool isFull(); + /** + * Returns if the LSQ is full for a specific thread (either LQ or SQ is + * full). + */ + bool isFull(unsigned tid); + + /** Returns if any of the LQs are full. */ + bool lqFull(); + /** Returns if the LQ of a given thread is full. */ + bool lqFull(unsigned tid); + + /** Returns if any of the SQs are full. */ + bool sqFull(); + /** Returns if the SQ of a given thread is full. */ + bool sqFull(unsigned tid); + + /** + * Returns if the LSQ is stalled due to a memory operation that must be + * replayed. + */ + bool isStalled(); + /** + * Returns if the LSQ of a specific thread is stalled due to a memory + * operation that must be replayed. + */ + bool isStalled(unsigned tid); + + /** Returns whether or not there are any stores to write back to memory. */ + bool hasStoresToWB(); + + /** Returns whether or not a specific thread has any stores to write back + * to memory. + */ + bool hasStoresToWB(unsigned tid) + { return thread[tid].hasStoresToWB(); } + + /** Returns the number of stores a specific thread has to write back. */ + int numStoresToWB(unsigned tid) + { return thread[tid].numStoresToWB(); } + + /** Returns if the LSQ will write back to memory this cycle. */ + bool willWB(); + /** Returns if the LSQ of a specific thread will write back to memory this + * cycle. + */ + bool willWB(unsigned tid) + { return thread[tid].willWB(); } + + /** Debugging function to print out all instructions. */ + void dumpInsts(); + /** Debugging function to print out instructions from a specific thread. */ + void dumpInsts(unsigned tid) + { thread[tid].dumpInsts(); } + + /** Executes a read operation, using the load specified at the load index. */ + template <class T> + Fault read(RequestPtr req, T &data, int load_idx); + + /** Executes a store operation, using the store specified at the store + * index. + */ + template <class T> + Fault write(RequestPtr req, T &data, int store_idx); + + private: + /** The LSQ policy for SMT mode. */ + LSQPolicy lsqPolicy; + + /** The LSQ units for individual threads. */ + LSQUnit thread[Impl::MaxThreads]; + + /** The CPU pointer. */ + FullCPU *cpu; + + /** The IEW stage pointer. */ + IEW *iewStage; + + /** List of Active Threads in System. */ + std::list<unsigned> *activeThreads; + + /** Total Size of LQ Entries. */ + unsigned LQEntries; + /** Total Size of SQ Entries. */ + unsigned SQEntries; + + /** Max LQ Size - Used to Enforce Sharing Policies. */ + unsigned maxLQEntries; + + /** Max SQ Size - Used to Enforce Sharing Policies. */ + unsigned maxSQEntries; + + /** Number of Threads. */ + unsigned numThreads; +}; + +template <class Impl> +template <class T> +Fault +LSQ<Impl>::read(RequestPtr req, T &data, int load_idx) +{ + unsigned tid = req->getThreadNum(); + + return thread[tid].read(req, data, load_idx); +} + +template <class Impl> +template <class T> +Fault +LSQ<Impl>::write(RequestPtr req, T &data, int store_idx) +{ + unsigned tid = req->getThreadNum(); + + return thread[tid].write(req, data, store_idx); +} + +#endif // __CPU_O3_LSQ_HH__ diff --git a/src/cpu/o3/lsq_impl.hh b/src/cpu/o3/lsq_impl.hh new file mode 100644 index 000000000..27aa0dc3c --- /dev/null +++ b/src/cpu/o3/lsq_impl.hh @@ -0,0 +1,529 @@ +/* + * Copyright (c) 2004-2006 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Korey Sewell + */ + +#include <algorithm> +#include <string> + +#include "cpu/o3/lsq.hh" + +using namespace std; + +template <class Impl> +LSQ<Impl>::LSQ(Params *params) + : LQEntries(params->LQEntries), SQEntries(params->SQEntries), + numThreads(params->numberOfThreads) +{ + DPRINTF(LSQ, "Creating LSQ object.\n"); + + //**********************************************/ + //************ Handle SMT Parameters ***********/ + //**********************************************/ + string policy = params->smtLSQPolicy; + + //Convert string to lowercase + std::transform(policy.begin(), policy.end(), policy.begin(), + (int(*)(int)) tolower); + + //Figure out fetch policy + if (policy == "dynamic") { + lsqPolicy = Dynamic; + + maxLQEntries = LQEntries; + maxSQEntries = SQEntries; + + DPRINTF(LSQ, "LSQ sharing policy set to Dynamic\n"); + + } else if (policy == "partitioned") { + lsqPolicy = Partitioned; + + //@todo:make work if part_amt doesnt divide evenly. + maxLQEntries = LQEntries / numThreads; + maxSQEntries = SQEntries / numThreads; + + DPRINTF(Fetch, "LSQ sharing policy set to Partitioned: " + "%i entries per LQ | %i entries per SQ", + maxLQEntries,maxSQEntries); + + } else if (policy == "threshold") { + lsqPolicy = Threshold; + + assert(params->smtLSQThreshold > LQEntries); + assert(params->smtLSQThreshold > SQEntries); + + //Divide up by threshold amount + //@todo: Should threads check the max and the total + //amount of the LSQ + maxLQEntries = params->smtLSQThreshold; + maxSQEntries = params->smtLSQThreshold; + + DPRINTF(LSQ, "LSQ sharing policy set to Threshold: " + "%i entries per LQ | %i entries per SQ", + maxLQEntries,maxSQEntries); + + } else { + assert(0 && "Invalid LSQ Sharing Policy.Options Are:{Dynamic," + "Partitioned, Threshold}"); + } + + //Initialize LSQs + for (int tid=0; tid < numThreads; tid++) { + thread[tid].init(params, maxLQEntries, maxSQEntries, tid); + } +} + + +template<class Impl> +std::string +LSQ<Impl>::name() const +{ + return iewStage->name() + ".lsq"; +} + +template<class Impl> +void +LSQ<Impl>::setActiveThreads(list<unsigned> *at_ptr) +{ + activeThreads = at_ptr; + assert(activeThreads != 0); +} + +template<class Impl> +void +LSQ<Impl>::setCPU(FullCPU *cpu_ptr) +{ + cpu = cpu_ptr; + + for (int tid=0; tid < numThreads; tid++) { + thread[tid].setCPU(cpu_ptr); + } +} + +template<class Impl> +void +LSQ<Impl>::setIEW(IEW *iew_ptr) +{ + iewStage = iew_ptr; + + for (int tid=0; tid < numThreads; tid++) { + thread[tid].setIEW(iew_ptr); + } +} + +template <class Impl> +void +LSQ<Impl>::switchOut() +{ + for (int tid = 0; tid < numThreads; tid++) { + thread[tid].switchOut(); + } +} + +template <class Impl> +void +LSQ<Impl>::takeOverFrom() +{ + for (int tid = 0; tid < numThreads; tid++) { + thread[tid].takeOverFrom(); + } +} + +template <class Impl> +int +LSQ<Impl>::entryAmount(int num_threads) +{ + if (lsqPolicy == Partitioned) { + return LQEntries / num_threads; + } else { + return 0; + } +} + +template <class Impl> +void +LSQ<Impl>::resetEntries() +{ + if (lsqPolicy != Dynamic || numThreads > 1) { + int active_threads = (*activeThreads).size(); + + list<unsigned>::iterator threads = (*activeThreads).begin(); + list<unsigned>::iterator list_end = (*activeThreads).end(); + + int maxEntries; + + if (lsqPolicy == Partitioned) { + maxEntries = LQEntries / active_threads; + } else if (lsqPolicy == Threshold && active_threads == 1) { + maxEntries = LQEntries; + } else { + maxEntries = LQEntries; + } + + while (threads != list_end) { + resizeEntries(maxEntries,*threads++); + } + } +} + +template<class Impl> +void +LSQ<Impl>::removeEntries(unsigned tid) +{ + thread[tid].clearLQ(); + thread[tid].clearSQ(); +} + +template<class Impl> +void +LSQ<Impl>::resizeEntries(unsigned size,unsigned tid) +{ + thread[tid].resizeLQ(size); + thread[tid].resizeSQ(size); +} + +template<class Impl> +void +LSQ<Impl>::tick() +{ + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + + thread[tid].tick(); + } +} + +template<class Impl> +void +LSQ<Impl>::insertLoad(DynInstPtr &load_inst) +{ + unsigned tid = load_inst->threadNumber; + + thread[tid].insertLoad(load_inst); +} + +template<class Impl> +void +LSQ<Impl>::insertStore(DynInstPtr &store_inst) +{ + unsigned tid = store_inst->threadNumber; + + thread[tid].insertStore(store_inst); +} + +template<class Impl> +Fault +LSQ<Impl>::executeLoad(DynInstPtr &inst) +{ + unsigned tid = inst->threadNumber; + + return thread[tid].executeLoad(inst); +} + +template<class Impl> +Fault +LSQ<Impl>::executeStore(DynInstPtr &inst) +{ + unsigned tid = inst->threadNumber; + + return thread[tid].executeStore(inst); +} + +template<class Impl> +void +LSQ<Impl>::writebackStores() +{ + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + + if (numStoresToWB(tid) > 0) { + DPRINTF(Writeback,"[tid:%i] Writing back stores. %i stores " + "available for Writeback.\n", tid, numStoresToWB(tid)); + } + + thread[tid].writebackStores(); + } +} + +template<class Impl> +bool +LSQ<Impl>::violation() +{ + /* Answers: Does Anybody Have a Violation?*/ + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + if (thread[tid].violation()) + return true; + } + + return false; +} + +template<class Impl> +int +LSQ<Impl>::getCount() +{ + unsigned total = 0; + + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + total += getCount(tid); + } + + return total; +} + +template<class Impl> +int +LSQ<Impl>::numLoads() +{ + unsigned total = 0; + + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + total += numLoads(tid); + } + + return total; +} + +template<class Impl> +int +LSQ<Impl>::numStores() +{ + unsigned total = 0; + + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + total += thread[tid].numStores(); + } + + return total; +} + +template<class Impl> +int +LSQ<Impl>::numLoadsReady() +{ + unsigned total = 0; + + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + total += thread[tid].numLoadsReady(); + } + + return total; +} + +template<class Impl> +unsigned +LSQ<Impl>::numFreeEntries() +{ + unsigned total = 0; + + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + total += thread[tid].numFreeEntries(); + } + + return total; +} + +template<class Impl> +unsigned +LSQ<Impl>::numFreeEntries(unsigned tid) +{ + //if( lsqPolicy == Dynamic ) + //return numFreeEntries(); + //else + return thread[tid].numFreeEntries(); +} + +template<class Impl> +bool +LSQ<Impl>::isFull() +{ + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + if (! (thread[tid].lqFull() || thread[tid].sqFull()) ) + return false; + } + + return true; +} + +template<class Impl> +bool +LSQ<Impl>::isFull(unsigned tid) +{ + //@todo: Change to Calculate All Entries for + //Dynamic Policy + if( lsqPolicy == Dynamic ) + return isFull(); + else + return thread[tid].lqFull() || thread[tid].sqFull(); +} + +template<class Impl> +bool +LSQ<Impl>::lqFull() +{ + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + if (!thread[tid].lqFull()) + return false; + } + + return true; +} + +template<class Impl> +bool +LSQ<Impl>::lqFull(unsigned tid) +{ + //@todo: Change to Calculate All Entries for + //Dynamic Policy + if( lsqPolicy == Dynamic ) + return lqFull(); + else + return thread[tid].lqFull(); +} + +template<class Impl> +bool +LSQ<Impl>::sqFull() +{ + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + if (!sqFull(tid)) + return false; + } + + return true; +} + +template<class Impl> +bool +LSQ<Impl>::sqFull(unsigned tid) +{ + //@todo: Change to Calculate All Entries for + //Dynamic Policy + if( lsqPolicy == Dynamic ) + return sqFull(); + else + return thread[tid].sqFull(); +} + +template<class Impl> +bool +LSQ<Impl>::isStalled() +{ + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + if (!thread[tid].isStalled()) + return false; + } + + return true; +} + +template<class Impl> +bool +LSQ<Impl>::isStalled(unsigned tid) +{ + if( lsqPolicy == Dynamic ) + return isStalled(); + else + return thread[tid].isStalled(); +} + +template<class Impl> +bool +LSQ<Impl>::hasStoresToWB() +{ + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + if (!hasStoresToWB(tid)) + return false; + } + + return true; +} + +template<class Impl> +bool +LSQ<Impl>::willWB() +{ + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + if (!willWB(tid)) + return false; + } + + return true; +} + +template<class Impl> +void +LSQ<Impl>::dumpInsts() +{ + list<unsigned>::iterator active_threads = (*activeThreads).begin(); + + while (active_threads != (*activeThreads).end()) { + unsigned tid = *active_threads++; + thread[tid].dumpInsts(); + } +} diff --git a/src/cpu/o3/lsq_unit.cc b/src/cpu/o3/lsq_unit.cc new file mode 100644 index 000000000..e935ffa5c --- /dev/null +++ b/src/cpu/o3/lsq_unit.cc @@ -0,0 +1,39 @@ +/* + * Copyright (c) 2004-2006 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Kevin Lim + * Korey Sewell + */ + +#include "cpu/o3/alpha_dyn_inst.hh" +#include "cpu/o3/alpha_cpu.hh" +#include "cpu/o3/alpha_impl.hh" +#include "cpu/o3/lsq_unit_impl.hh" + +// Force the instantiation of LDSTQ for all the implementations we care about. +template class LSQUnit<AlphaSimpleImpl>; + diff --git a/src/cpu/o3/lsq_unit.hh b/src/cpu/o3/lsq_unit.hh new file mode 100644 index 000000000..ce0cdd36f --- /dev/null +++ b/src/cpu/o3/lsq_unit.hh @@ -0,0 +1,711 @@ +/* + * Copyright (c) 2004-2006 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Kevin Lim + * Korey Sewell + */ + +#ifndef __CPU_O3_LSQ_UNIT_HH__ +#define __CPU_O3_LSQ_UNIT_HH__ + +#include <algorithm> +#include <map> +#include <queue> + +#include "arch/faults.hh" +#include "config/full_system.hh" +#include "base/hashmap.hh" +#include "cpu/inst_seq.hh" +#include "mem/packet.hh" +#include "mem/port.hh" + +/** + * Class that implements the actual LQ and SQ for each specific + * thread. Both are circular queues; load entries are freed upon + * committing, while store entries are freed once they writeback. The + * LSQUnit tracks if there are memory ordering violations, and also + * detects partial load to store forwarding cases (a store only has + * part of a load's data) that requires the load to wait until the + * store writes back. In the former case it holds onto the instruction + * until the dependence unit looks at it, and in the latter it stalls + * the LSQ until the store writes back. At that point the load is + * replayed. + */ +template <class Impl> +class LSQUnit { + protected: + typedef TheISA::IntReg IntReg; + public: + typedef typename Impl::Params Params; + typedef typename Impl::FullCPU FullCPU; + typedef typename Impl::DynInstPtr DynInstPtr; + typedef typename Impl::CPUPol::IEW IEW; + typedef typename Impl::CPUPol::IssueStruct IssueStruct; + + public: + /** Constructs an LSQ unit. init() must be called prior to use. */ + LSQUnit(); + + /** Initializes the LSQ unit with the specified number of entries. */ + void init(Params *params, unsigned maxLQEntries, + unsigned maxSQEntries, unsigned id); + + /** Returns the name of the LSQ unit. */ + std::string name() const; + + /** Sets the CPU pointer. */ + void setCPU(FullCPU *cpu_ptr); + + /** Sets the IEW stage pointer. */ + void setIEW(IEW *iew_ptr) + { iewStage = iew_ptr; } + + /** Switches out LSQ unit. */ + void switchOut(); + + /** Takes over from another CPU's thread. */ + void takeOverFrom(); + + /** Returns if the LSQ is switched out. */ + bool isSwitchedOut() { return switchedOut; } + + /** Ticks the LSQ unit, which in this case only resets the number of + * used cache ports. + * @todo: Move the number of used ports up to the LSQ level so it can + * be shared by all LSQ units. + */ + void tick() { usedPorts = 0; } + + /** Inserts an instruction. */ + void insert(DynInstPtr &inst); + /** Inserts a load instruction. */ + void insertLoad(DynInstPtr &load_inst); + /** Inserts a store instruction. */ + void insertStore(DynInstPtr &store_inst); + + /** Executes a load instruction. */ + Fault executeLoad(DynInstPtr &inst); + + Fault executeLoad(int lq_idx) { panic("Not implemented"); return NoFault; } + /** Executes a store instruction. */ + Fault executeStore(DynInstPtr &inst); + + /** Commits the head load. */ + void commitLoad(); + /** Commits loads older than a specific sequence number. */ + void commitLoads(InstSeqNum &youngest_inst); + + /** Commits stores older than a specific sequence number. */ + void commitStores(InstSeqNum &youngest_inst); + + /** Writes back stores. */ + void writebackStores(); + + void completeDataAccess(PacketPtr pkt); + + // @todo: Include stats in the LSQ unit. + //void regStats(); + + /** Clears all the entries in the LQ. */ + void clearLQ(); + + /** Clears all the entries in the SQ. */ + void clearSQ(); + + /** Resizes the LQ to a given size. */ + void resizeLQ(unsigned size); + + /** Resizes the SQ to a given size. */ + void resizeSQ(unsigned size); + + /** Squashes all instructions younger than a specific sequence number. */ + void squash(const InstSeqNum &squashed_num); + + /** Returns if there is a memory ordering violation. Value is reset upon + * call to getMemDepViolator(). + */ + bool violation() { return memDepViolator; } + + /** Returns the memory ordering violator. */ + DynInstPtr getMemDepViolator(); + + /** Returns if a load became blocked due to the memory system. */ + bool loadBlocked() + { return isLoadBlocked; } + + /** Clears the signal that a load became blocked. */ + void clearLoadBlocked() + { isLoadBlocked = false; } + + /** Returns if the blocked load was handled. */ + bool isLoadBlockedHandled() + { return loadBlockedHandled; } + + /** Records the blocked load as being handled. */ + void setLoadBlockedHandled() + { loadBlockedHandled = true; } + + /** Returns the number of free entries (min of free LQ and SQ entries). */ + unsigned numFreeEntries(); + + /** Returns the number of loads ready to execute. */ + int numLoadsReady(); + + /** Returns the number of loads in the LQ. */ + int numLoads() { return loads; } + + /** Returns the number of stores in the SQ. */ + int numStores() { return stores; } + + /** Returns if either the LQ or SQ is full. */ + bool isFull() { return lqFull() || sqFull(); } + + /** Returns if the LQ is full. */ + bool lqFull() { return loads >= (LQEntries - 1); } + + /** Returns if the SQ is full. */ + bool sqFull() { return stores >= (SQEntries - 1); } + + /** Returns the number of instructions in the LSQ. */ + unsigned getCount() { return loads + stores; } + + /** Returns if there are any stores to writeback. */ + bool hasStoresToWB() { return storesToWB; } + + /** Returns the number of stores to writeback. */ + int numStoresToWB() { return storesToWB; } + + /** Returns if the LSQ unit will writeback on this cycle. */ + bool willWB() { return storeQueue[storeWBIdx].canWB && + !storeQueue[storeWBIdx].completed && + !isStoreBlocked; } + + private: + /** Writes back the instruction, sending it to IEW. */ + void writeback(DynInstPtr &inst, PacketPtr pkt); + + /** Handles completing the send of a store to memory. */ + void storePostSend(Packet *pkt); + + /** Completes the store at the specified index. */ + void completeStore(int store_idx); + + /** Handles doing the retry. */ + void recvRetry(); + + /** Increments the given store index (circular queue). */ + inline void incrStIdx(int &store_idx); + /** Decrements the given store index (circular queue). */ + inline void decrStIdx(int &store_idx); + /** Increments the given load index (circular queue). */ + inline void incrLdIdx(int &load_idx); + /** Decrements the given load index (circular queue). */ + inline void decrLdIdx(int &load_idx); + + public: + /** Debugging function to dump instructions in the LSQ. */ + void dumpInsts(); + + private: + /** Pointer to the CPU. */ + FullCPU *cpu; + + /** Pointer to the IEW stage. */ + IEW *iewStage; + + /** Pointer to memory object. */ + MemObject *mem; + + /** DcachePort class for this LSQ Unit. Handles doing the + * communication with the cache/memory. + * @todo: Needs to be moved to the LSQ level and have some sort + * of arbitration. + */ + class DcachePort : public Port + { + protected: + /** Pointer to CPU. */ + FullCPU *cpu; + /** Pointer to LSQ. */ + LSQUnit *lsq; + + public: + /** Default constructor. */ + DcachePort(FullCPU *_cpu, LSQUnit *_lsq) + : Port(_lsq->name() + "-dport"), cpu(_cpu), lsq(_lsq) + { } + + protected: + /** Atomic version of receive. Panics. */ + virtual Tick recvAtomic(PacketPtr pkt); + + /** Functional version of receive. Panics. */ + virtual void recvFunctional(PacketPtr pkt); + + /** Receives status change. Other than range changing, panics. */ + virtual void recvStatusChange(Status status); + + /** Returns the address ranges of this device. */ + virtual void getDeviceAddressRanges(AddrRangeList &resp, + AddrRangeList &snoop) + { resp.clear(); snoop.clear(); } + + /** Timing version of receive. Handles writing back and + * completing the load or store that has returned from + * memory. */ + virtual bool recvTiming(PacketPtr pkt); + + /** Handles doing a retry of the previous send. */ + virtual void recvRetry(); + }; + + /** Pointer to the D-cache. */ + DcachePort *dcachePort; + + /** Derived class to hold any sender state the LSQ needs. */ + class LSQSenderState : public Packet::SenderState + { + public: + /** Default constructor. */ + LSQSenderState() + : noWB(false) + { } + + /** Instruction who initiated the access to memory. */ + DynInstPtr inst; + /** Whether or not it is a load. */ + bool isLoad; + /** The LQ/SQ index of the instruction. */ + int idx; + /** Whether or not the instruction will need to writeback. */ + bool noWB; + }; + + /** Writeback event, specifically for when stores forward data to loads. */ + class WritebackEvent : public Event { + public: + /** Constructs a writeback event. */ + WritebackEvent(DynInstPtr &_inst, PacketPtr pkt, LSQUnit *lsq_ptr); + + /** Processes the writeback event. */ + void process(); + + /** Returns the description of this event. */ + const char *description(); + + private: + /** Instruction whose results are being written back. */ + DynInstPtr inst; + + /** The packet that would have been sent to memory. */ + PacketPtr pkt; + + /** The pointer to the LSQ unit that issued the store. */ + LSQUnit<Impl> *lsqPtr; + }; + + public: + struct SQEntry { + /** Constructs an empty store queue entry. */ + SQEntry() + : inst(NULL), req(NULL), size(0), data(0), + canWB(0), committed(0), completed(0) + { } + + /** Constructs a store queue entry for a given instruction. */ + SQEntry(DynInstPtr &_inst) + : inst(_inst), req(NULL), size(0), data(0), + canWB(0), committed(0), completed(0) + { } + + /** The store instruction. */ + DynInstPtr inst; + /** The request for the store. */ + RequestPtr req; + /** The size of the store. */ + int size; + /** The store data. */ + IntReg data; + /** Whether or not the store can writeback. */ + bool canWB; + /** Whether or not the store is committed. */ + bool committed; + /** Whether or not the store is completed. */ + bool completed; + }; + + private: + /** The LSQUnit thread id. */ + unsigned lsqID; + + /** The store queue. */ + std::vector<SQEntry> storeQueue; + + /** The load queue. */ + std::vector<DynInstPtr> loadQueue; + + /** The number of LQ entries, plus a sentinel entry (circular queue). + * @todo: Consider having var that records the true number of LQ entries. + */ + unsigned LQEntries; + /** The number of SQ entries, plus a sentinel entry (circular queue). + * @todo: Consider having var that records the true number of SQ entries. + */ + unsigned SQEntries; + + /** The number of load instructions in the LQ. */ + int loads; + /** The number of store instructions in the SQ. */ + int stores; + /** The number of store instructions in the SQ waiting to writeback. */ + int storesToWB; + + /** The index of the head instruction in the LQ. */ + int loadHead; + /** The index of the tail instruction in the LQ. */ + int loadTail; + + /** The index of the head instruction in the SQ. */ + int storeHead; + /** The index of the first instruction that may be ready to be + * written back, and has not yet been written back. + */ + int storeWBIdx; + /** The index of the tail instruction in the SQ. */ + int storeTail; + + /// @todo Consider moving to a more advanced model with write vs read ports + /** The number of cache ports available each cycle. */ + int cachePorts; + + /** The number of used cache ports in this cycle. */ + int usedPorts; + + /** Is the LSQ switched out. */ + bool switchedOut; + + //list<InstSeqNum> mshrSeqNums; + + /** Wire to read information from the issue stage time queue. */ + typename TimeBuffer<IssueStruct>::wire fromIssue; + + /** Whether or not the LSQ is stalled. */ + bool stalled; + /** The store that causes the stall due to partial store to load + * forwarding. + */ + InstSeqNum stallingStoreIsn; + /** The index of the above store. */ + int stallingLoadIdx; + + /** The packet that needs to be retried. */ + PacketPtr retryPkt; + + /** Whehter or not a store is blocked due to the memory system. */ + bool isStoreBlocked; + + /** Whether or not a load is blocked due to the memory system. */ + bool isLoadBlocked; + + /** Has the blocked load been handled. */ + bool loadBlockedHandled; + + /** The sequence number of the blocked load. */ + InstSeqNum blockedLoadSeqNum; + + /** The oldest load that caused a memory ordering violation. */ + DynInstPtr memDepViolator; + + // Will also need how many read/write ports the Dcache has. Or keep track + // of that in stage that is one level up, and only call executeLoad/Store + // the appropriate number of times. +/* + // total number of loads forwaded from LSQ stores + Stats::Vector<> lsq_forw_loads; + + // total number of loads ignored due to invalid addresses + Stats::Vector<> inv_addr_loads; + + // total number of software prefetches ignored due to invalid addresses + Stats::Vector<> inv_addr_swpfs; + + // total non-speculative bogus addresses seen (debug var) + Counter sim_invalid_addrs; + Stats::Vector<> fu_busy; //cumulative fu busy + + // ready loads blocked due to memory disambiguation + Stats::Vector<> lsq_blocked_loads; + + Stats::Scalar<> lsqInversion; +*/ + public: + /** Executes the load at the given index. */ + template <class T> + Fault read(Request *req, T &data, int load_idx); + + /** Executes the store at the given index. */ + template <class T> + Fault write(Request *req, T &data, int store_idx); + + /** Returns the index of the head load instruction. */ + int getLoadHead() { return loadHead; } + /** Returns the sequence number of the head load instruction. */ + InstSeqNum getLoadHeadSeqNum() + { + if (loadQueue[loadHead]) { + return loadQueue[loadHead]->seqNum; + } else { + return 0; + } + + } + + /** Returns the index of the head store instruction. */ + int getStoreHead() { return storeHead; } + /** Returns the sequence number of the head store instruction. */ + InstSeqNum getStoreHeadSeqNum() + { + if (storeQueue[storeHead].inst) { + return storeQueue[storeHead].inst->seqNum; + } else { + return 0; + } + + } + + /** Returns whether or not the LSQ unit is stalled. */ + bool isStalled() { return stalled; } +}; + +template <class Impl> +template <class T> +Fault +LSQUnit<Impl>::read(Request *req, T &data, int load_idx) +{ + DynInstPtr load_inst = loadQueue[load_idx]; + + assert(load_inst); + + assert(!load_inst->isExecuted()); + + // Make sure this isn't an uncacheable access + // A bit of a hackish way to get uncached accesses to work only if they're + // at the head of the LSQ and are ready to commit (at the head of the ROB + // too). + if (req->getFlags() & UNCACHEABLE && + (load_idx != loadHead || !load_inst->reachedCommit)) { + iewStage->rescheduleMemInst(load_inst); + return TheISA::genMachineCheckFault(); + } + + // Check the SQ for any previous stores that might lead to forwarding + int store_idx = load_inst->sqIdx; + + int store_size = 0; + + DPRINTF(LSQUnit, "Read called, load idx: %i, store idx: %i, " + "storeHead: %i addr: %#x\n", + load_idx, store_idx, storeHead, req->getPaddr()); + +#if FULL_SYSTEM + if (req->getFlags() & LOCKED) { + cpu->lockAddr = req->getPaddr(); + cpu->lockFlag = true; + } +#endif + + while (store_idx != -1) { + // End once we've reached the top of the LSQ + if (store_idx == storeWBIdx) { + break; + } + + // Move the index to one younger + if (--store_idx < 0) + store_idx += SQEntries; + + assert(storeQueue[store_idx].inst); + + store_size = storeQueue[store_idx].size; + + if (store_size == 0) + continue; + + // Check if the store data is within the lower and upper bounds of + // addresses that the request needs. + bool store_has_lower_limit = + req->getVaddr() >= storeQueue[store_idx].inst->effAddr; + bool store_has_upper_limit = + (req->getVaddr() + req->getSize()) <= + (storeQueue[store_idx].inst->effAddr + store_size); + bool lower_load_has_store_part = + req->getVaddr() < (storeQueue[store_idx].inst->effAddr + + store_size); + bool upper_load_has_store_part = + (req->getVaddr() + req->getSize()) > + storeQueue[store_idx].inst->effAddr; + + // If the store's data has all of the data needed, we can forward. + if (store_has_lower_limit && store_has_upper_limit) { + // Get shift amount for offset into the store's data. + int shift_amt = req->getVaddr() & (store_size - 1); + // @todo: Magic number, assumes byte addressing + shift_amt = shift_amt << 3; + + // Cast this to type T? + data = storeQueue[store_idx].data >> shift_amt; + + assert(!load_inst->memData); + load_inst->memData = new uint8_t[64]; + + memcpy(load_inst->memData, &data, req->getSize()); + + DPRINTF(LSQUnit, "Forwarding from store idx %i to load to " + "addr %#x, data %#x\n", + store_idx, req->getVaddr(), data); + + PacketPtr data_pkt = new Packet(req, Packet::ReadReq, Packet::Broadcast); + data_pkt->dataStatic(load_inst->memData); + + WritebackEvent *wb = new WritebackEvent(load_inst, data_pkt, this); + + // We'll say this has a 1 cycle load-store forwarding latency + // for now. + // @todo: Need to make this a parameter. + wb->schedule(curTick); + + // Should keep track of stat for forwarded data + return NoFault; + } else if ((store_has_lower_limit && lower_load_has_store_part) || + (store_has_upper_limit && upper_load_has_store_part) || + (lower_load_has_store_part && upper_load_has_store_part)) { + // This is the partial store-load forwarding case where a store + // has only part of the load's data. + + // If it's already been written back, then don't worry about + // stalling on it. + if (storeQueue[store_idx].completed) { + continue; + } + + // Must stall load and force it to retry, so long as it's the oldest + // load that needs to do so. + if (!stalled || + (stalled && + load_inst->seqNum < + loadQueue[stallingLoadIdx]->seqNum)) { + stalled = true; + stallingStoreIsn = storeQueue[store_idx].inst->seqNum; + stallingLoadIdx = load_idx; + } + + // Tell IQ/mem dep unit that this instruction will need to be + // rescheduled eventually + iewStage->rescheduleMemInst(load_inst); + + // Do not generate a writeback event as this instruction is not + // complete. + DPRINTF(LSQUnit, "Load-store forwarding mis-match. " + "Store idx %i to load addr %#x\n", + store_idx, req->getVaddr()); + + return NoFault; + } + } + + // If there's no forwarding case, then go access memory + DPRINTF(LSQUnit, "Doing functional access for inst [sn:%lli] PC %#x\n", + load_inst->seqNum, load_inst->readPC()); + + assert(!load_inst->memData); + load_inst->memData = new uint8_t[64]; + + ++usedPorts; + + DPRINTF(LSQUnit, "Doing timing access for inst PC %#x\n", + load_inst->readPC()); + + PacketPtr data_pkt = new Packet(req, Packet::ReadReq, Packet::Broadcast); + data_pkt->dataStatic(load_inst->memData); + + LSQSenderState *state = new LSQSenderState; + state->isLoad = true; + state->idx = load_idx; + state->inst = load_inst; + data_pkt->senderState = state; + + // if we have a cache, do cache access too + if (!dcachePort->sendTiming(data_pkt)) { + // There's an older load that's already going to squash. + if (isLoadBlocked && blockedLoadSeqNum < load_inst->seqNum) + return NoFault; + + // Record that the load was blocked due to memory. This + // load will squash all instructions after it, be + // refetched, and re-executed. + isLoadBlocked = true; + loadBlockedHandled = false; + blockedLoadSeqNum = load_inst->seqNum; + // No fault occurred, even though the interface is blocked. + return NoFault; + } + + if (data_pkt->result != Packet::Success) { + DPRINTF(LSQUnit, "LSQUnit: D-cache miss!\n"); + DPRINTF(Activity, "Activity: ld accessing mem miss [sn:%lli]\n", + load_inst->seqNum); + } else { + DPRINTF(LSQUnit, "LSQUnit: D-cache hit!\n"); + DPRINTF(Activity, "Activity: ld accessing mem hit [sn:%lli]\n", + load_inst->seqNum); + } + + return NoFault; +} + +template <class Impl> +template <class T> +Fault +LSQUnit<Impl>::write(Request *req, T &data, int store_idx) +{ + assert(storeQueue[store_idx].inst); + + DPRINTF(LSQUnit, "Doing write to store idx %i, addr %#x data %#x" + " | storeHead:%i [sn:%i]\n", + store_idx, req->getPaddr(), data, storeHead, + storeQueue[store_idx].inst->seqNum); + + storeQueue[store_idx].req = req; + storeQueue[store_idx].size = sizeof(T); + storeQueue[store_idx].data = data; + + // This function only writes the data to the store queue, so no fault + // can happen here. + return NoFault; +} + +#endif // __CPU_O3_LSQ_UNIT_HH__ diff --git a/src/cpu/o3/lsq_unit_impl.hh b/src/cpu/o3/lsq_unit_impl.hh new file mode 100644 index 000000000..6f32ec304 --- /dev/null +++ b/src/cpu/o3/lsq_unit_impl.hh @@ -0,0 +1,929 @@ +/* + * Copyright (c) 2004-2005 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Kevin Lim + * Korey Sewell + */ + +#include "cpu/checker/cpu.hh" +#include "cpu/o3/lsq_unit.hh" +#include "base/str.hh" +#include "mem/request.hh" + +template<class Impl> +LSQUnit<Impl>::WritebackEvent::WritebackEvent(DynInstPtr &_inst, PacketPtr _pkt, + LSQUnit *lsq_ptr) + : Event(&mainEventQueue), inst(_inst), pkt(_pkt), lsqPtr(lsq_ptr) +{ + this->setFlags(Event::AutoDelete); +} + +template<class Impl> +void +LSQUnit<Impl>::WritebackEvent::process() +{ + if (!lsqPtr->isSwitchedOut()) { + lsqPtr->writeback(inst, pkt); + } + delete pkt; +} + +template<class Impl> +const char * +LSQUnit<Impl>::WritebackEvent::description() +{ + return "Store writeback event"; +} + +template<class Impl> +void +LSQUnit<Impl>::completeDataAccess(PacketPtr pkt) +{ + LSQSenderState *state = dynamic_cast<LSQSenderState *>(pkt->senderState); + DynInstPtr inst = state->inst; + DPRINTF(IEW, "Writeback event [sn:%lli]\n", inst->seqNum); + DPRINTF(Activity, "Activity: Writeback event [sn:%lli]\n", inst->seqNum); + + //iewStage->ldstQueue.removeMSHR(inst->threadNumber,inst->seqNum); + + if (isSwitchedOut() || inst->isSquashed()) { + delete state; + delete pkt; + return; + } else { + if (!state->noWB) { + writeback(inst, pkt); + } + + if (inst->isStore()) { + completeStore(state->idx); + } + } + + delete state; + delete pkt; +} + +template <class Impl> +Tick +LSQUnit<Impl>::DcachePort::recvAtomic(PacketPtr pkt) +{ + panic("O3CPU model does not work with atomic mode!"); + return curTick; +} + +template <class Impl> +void +LSQUnit<Impl>::DcachePort::recvFunctional(PacketPtr pkt) +{ + panic("O3CPU doesn't expect recvFunctional callback!"); +} + +template <class Impl> +void +LSQUnit<Impl>::DcachePort::recvStatusChange(Status status) +{ + if (status == RangeChange) + return; + + panic("O3CPU doesn't expect recvStatusChange callback!"); +} + +template <class Impl> +bool +LSQUnit<Impl>::DcachePort::recvTiming(PacketPtr pkt) +{ + lsq->completeDataAccess(pkt); + return true; +} + +template <class Impl> +void +LSQUnit<Impl>::DcachePort::recvRetry() +{ + lsq->recvRetry(); +} + +template <class Impl> +LSQUnit<Impl>::LSQUnit() + : loads(0), stores(0), storesToWB(0), stalled(false), + isStoreBlocked(false), isLoadBlocked(false), + loadBlockedHandled(false) +{ +} + +template<class Impl> +void +LSQUnit<Impl>::init(Params *params, unsigned maxLQEntries, + unsigned maxSQEntries, unsigned id) +{ + DPRINTF(LSQUnit, "Creating LSQUnit%i object.\n",id); + + switchedOut = false; + + lsqID = id; + + // Add 1 for the sentinel entry (they are circular queues). + LQEntries = maxLQEntries + 1; + SQEntries = maxSQEntries + 1; + + loadQueue.resize(LQEntries); + storeQueue.resize(SQEntries); + + loadHead = loadTail = 0; + + storeHead = storeWBIdx = storeTail = 0; + + usedPorts = 0; + cachePorts = params->cachePorts; + + mem = params->mem; + + memDepViolator = NULL; + + blockedLoadSeqNum = 0; +} + +template<class Impl> +void +LSQUnit<Impl>::setCPU(FullCPU *cpu_ptr) +{ + cpu = cpu_ptr; + dcachePort = new DcachePort(cpu, this); + + Port *mem_dport = mem->getPort(""); + dcachePort->setPeer(mem_dport); + mem_dport->setPeer(dcachePort); + + if (cpu->checker) { + cpu->checker->setDcachePort(dcachePort); + } +} + +template<class Impl> +std::string +LSQUnit<Impl>::name() const +{ + if (Impl::MaxThreads == 1) { + return iewStage->name() + ".lsq"; + } else { + return iewStage->name() + ".lsq.thread." + to_string(lsqID); + } +} + +template<class Impl> +void +LSQUnit<Impl>::clearLQ() +{ + loadQueue.clear(); +} + +template<class Impl> +void +LSQUnit<Impl>::clearSQ() +{ + storeQueue.clear(); +} + +template<class Impl> +void +LSQUnit<Impl>::switchOut() +{ + switchedOut = true; + for (int i = 0; i < loadQueue.size(); ++i) + loadQueue[i] = NULL; + + assert(storesToWB == 0); +} + +template<class Impl> +void +LSQUnit<Impl>::takeOverFrom() +{ + switchedOut = false; + loads = stores = storesToWB = 0; + + loadHead = loadTail = 0; + + storeHead = storeWBIdx = storeTail = 0; + + usedPorts = 0; + + memDepViolator = NULL; + + blockedLoadSeqNum = 0; + + stalled = false; + isLoadBlocked = false; + loadBlockedHandled = false; +} + +template<class Impl> +void +LSQUnit<Impl>::resizeLQ(unsigned size) +{ + unsigned size_plus_sentinel = size + 1; + assert(size_plus_sentinel >= LQEntries); + + if (size_plus_sentinel > LQEntries) { + while (size_plus_sentinel > loadQueue.size()) { + DynInstPtr dummy; + loadQueue.push_back(dummy); + LQEntries++; + } + } else { + LQEntries = size_plus_sentinel; + } + +} + +template<class Impl> +void +LSQUnit<Impl>::resizeSQ(unsigned size) +{ + unsigned size_plus_sentinel = size + 1; + if (size_plus_sentinel > SQEntries) { + while (size_plus_sentinel > storeQueue.size()) { + SQEntry dummy; + storeQueue.push_back(dummy); + SQEntries++; + } + } else { + SQEntries = size_plus_sentinel; + } +} + +template <class Impl> +void +LSQUnit<Impl>::insert(DynInstPtr &inst) +{ + assert(inst->isMemRef()); + + assert(inst->isLoad() || inst->isStore()); + + if (inst->isLoad()) { + insertLoad(inst); + } else { + insertStore(inst); + } + + inst->setInLSQ(); +} + +template <class Impl> +void +LSQUnit<Impl>::insertLoad(DynInstPtr &load_inst) +{ + assert((loadTail + 1) % LQEntries != loadHead); + assert(loads < LQEntries); + + DPRINTF(LSQUnit, "Inserting load PC %#x, idx:%i [sn:%lli]\n", + load_inst->readPC(), loadTail, load_inst->seqNum); + + load_inst->lqIdx = loadTail; + + if (stores == 0) { + load_inst->sqIdx = -1; + } else { + load_inst->sqIdx = storeTail; + } + + loadQueue[loadTail] = load_inst; + + incrLdIdx(loadTail); + + ++loads; +} + +template <class Impl> +void +LSQUnit<Impl>::insertStore(DynInstPtr &store_inst) +{ + // Make sure it is not full before inserting an instruction. + assert((storeTail + 1) % SQEntries != storeHead); + assert(stores < SQEntries); + + DPRINTF(LSQUnit, "Inserting store PC %#x, idx:%i [sn:%lli]\n", + store_inst->readPC(), storeTail, store_inst->seqNum); + + store_inst->sqIdx = storeTail; + store_inst->lqIdx = loadTail; + + storeQueue[storeTail] = SQEntry(store_inst); + + incrStIdx(storeTail); + + ++stores; +} + +template <class Impl> +typename Impl::DynInstPtr +LSQUnit<Impl>::getMemDepViolator() +{ + DynInstPtr temp = memDepViolator; + + memDepViolator = NULL; + + return temp; +} + +template <class Impl> +unsigned +LSQUnit<Impl>::numFreeEntries() +{ + unsigned free_lq_entries = LQEntries - loads; + unsigned free_sq_entries = SQEntries - stores; + + // Both the LQ and SQ entries have an extra dummy entry to differentiate + // empty/full conditions. Subtract 1 from the free entries. + if (free_lq_entries < free_sq_entries) { + return free_lq_entries - 1; + } else { + return free_sq_entries - 1; + } +} + +template <class Impl> +int +LSQUnit<Impl>::numLoadsReady() +{ + int load_idx = loadHead; + int retval = 0; + + while (load_idx != loadTail) { + assert(loadQueue[load_idx]); + + if (loadQueue[load_idx]->readyToIssue()) { + ++retval; + } + } + + return retval; +} + +template <class Impl> +Fault +LSQUnit<Impl>::executeLoad(DynInstPtr &inst) +{ + // Execute a specific load. + Fault load_fault = NoFault; + + DPRINTF(LSQUnit, "Executing load PC %#x, [sn:%lli]\n", + inst->readPC(),inst->seqNum); + + load_fault = inst->initiateAcc(); + + // If the instruction faulted, then we need to send it along to commit + // without the instruction completing. + if (load_fault != NoFault) { + // Send this instruction to commit, also make sure iew stage + // realizes there is activity. + iewStage->instToCommit(inst); + iewStage->activityThisCycle(); + } + + return load_fault; +} + +template <class Impl> +Fault +LSQUnit<Impl>::executeStore(DynInstPtr &store_inst) +{ + using namespace TheISA; + // Make sure that a store exists. + assert(stores != 0); + + int store_idx = store_inst->sqIdx; + + DPRINTF(LSQUnit, "Executing store PC %#x [sn:%lli]\n", + store_inst->readPC(), store_inst->seqNum); + + // Check the recently completed loads to see if any match this store's + // address. If so, then we have a memory ordering violation. + int load_idx = store_inst->lqIdx; + + Fault store_fault = store_inst->initiateAcc(); + + if (storeQueue[store_idx].size == 0) { + DPRINTF(LSQUnit,"Fault on Store PC %#x, [sn:%lli],Size = 0\n", + store_inst->readPC(),store_inst->seqNum); + + return store_fault; + } + + assert(store_fault == NoFault); + + if (store_inst->isStoreConditional()) { + // Store conditionals need to set themselves as able to + // writeback if we haven't had a fault by here. + storeQueue[store_idx].canWB = true; + + ++storesToWB; + } + + if (!memDepViolator) { + while (load_idx != loadTail) { + // Really only need to check loads that have actually executed + // It's safe to check all loads because effAddr is set to + // InvalAddr when the dyn inst is created. + + // @todo: For now this is extra conservative, detecting a + // violation if the addresses match assuming all accesses + // are quad word accesses. + + // @todo: Fix this, magic number being used here + if ((loadQueue[load_idx]->effAddr >> 8) == + (store_inst->effAddr >> 8)) { + // A load incorrectly passed this store. Squash and refetch. + // For now return a fault to show that it was unsuccessful. + memDepViolator = loadQueue[load_idx]; + + return genMachineCheckFault(); + } + + incrLdIdx(load_idx); + } + + // If we've reached this point, there was no violation. + memDepViolator = NULL; + } + + return store_fault; +} + +template <class Impl> +void +LSQUnit<Impl>::commitLoad() +{ + assert(loadQueue[loadHead]); + + DPRINTF(LSQUnit, "Committing head load instruction, PC %#x\n", + loadQueue[loadHead]->readPC()); + + loadQueue[loadHead] = NULL; + + incrLdIdx(loadHead); + + --loads; +} + +template <class Impl> +void +LSQUnit<Impl>::commitLoads(InstSeqNum &youngest_inst) +{ + assert(loads == 0 || loadQueue[loadHead]); + + while (loads != 0 && loadQueue[loadHead]->seqNum <= youngest_inst) { + commitLoad(); + } +} + +template <class Impl> +void +LSQUnit<Impl>::commitStores(InstSeqNum &youngest_inst) +{ + assert(stores == 0 || storeQueue[storeHead].inst); + + int store_idx = storeHead; + + while (store_idx != storeTail) { + assert(storeQueue[store_idx].inst); + // Mark any stores that are now committed and have not yet + // been marked as able to write back. + if (!storeQueue[store_idx].canWB) { + if (storeQueue[store_idx].inst->seqNum > youngest_inst) { + break; + } + DPRINTF(LSQUnit, "Marking store as able to write back, PC " + "%#x [sn:%lli]\n", + storeQueue[store_idx].inst->readPC(), + storeQueue[store_idx].inst->seqNum); + + storeQueue[store_idx].canWB = true; + + ++storesToWB; + } + + incrStIdx(store_idx); + } +} + +template <class Impl> +void +LSQUnit<Impl>::writebackStores() +{ + while (storesToWB > 0 && + storeWBIdx != storeTail && + storeQueue[storeWBIdx].inst && + storeQueue[storeWBIdx].canWB && + usedPorts < cachePorts) { + + if (isStoreBlocked) { + DPRINTF(LSQUnit, "Unable to write back any more stores, cache" + " is blocked!\n"); + break; + } + + // Store didn't write any data so no need to write it back to + // memory. + if (storeQueue[storeWBIdx].size == 0) { + completeStore(storeWBIdx); + + incrStIdx(storeWBIdx); + + continue; + } + + ++usedPorts; + + if (storeQueue[storeWBIdx].inst->isDataPrefetch()) { + incrStIdx(storeWBIdx); + + continue; + } + + assert(storeQueue[storeWBIdx].req); + assert(!storeQueue[storeWBIdx].committed); + + DynInstPtr inst = storeQueue[storeWBIdx].inst; + + Request *req = storeQueue[storeWBIdx].req; + storeQueue[storeWBIdx].committed = true; + + assert(!inst->memData); + inst->memData = new uint8_t[64]; + memcpy(inst->memData, (uint8_t *)&storeQueue[storeWBIdx].data, + req->getSize()); + + PacketPtr data_pkt = new Packet(req, Packet::WriteReq, Packet::Broadcast); + data_pkt->dataStatic(inst->memData); + + LSQSenderState *state = new LSQSenderState; + state->isLoad = false; + state->idx = storeWBIdx; + state->inst = inst; + data_pkt->senderState = state; + + DPRINTF(LSQUnit, "D-Cache: Writing back store idx:%i PC:%#x " + "to Addr:%#x, data:%#x [sn:%lli]\n", + storeWBIdx, storeQueue[storeWBIdx].inst->readPC(), + req->getPaddr(), *(inst->memData), + storeQueue[storeWBIdx].inst->seqNum); + + // @todo: Remove this SC hack once the memory system handles it. + if (req->getFlags() & LOCKED) { + if (req->getFlags() & UNCACHEABLE) { + req->setScResult(2); + } else { + if (cpu->lockFlag) { + req->setScResult(1); + } else { + req->setScResult(0); + // Hack: Instantly complete this store. + completeDataAccess(data_pkt); + incrStIdx(storeWBIdx); + continue; + } + } + } else { + // Non-store conditionals do not need a writeback. + state->noWB = true; + } + + if (!dcachePort->sendTiming(data_pkt)) { + // Need to handle becoming blocked on a store. + isStoreBlocked = true; + + assert(retryPkt == NULL); + retryPkt = data_pkt; + } else { + storePostSend(data_pkt); + } + } + + // Not sure this should set it to 0. + usedPorts = 0; + + assert(stores >= 0 && storesToWB >= 0); +} + +/*template <class Impl> +void +LSQUnit<Impl>::removeMSHR(InstSeqNum seqNum) +{ + list<InstSeqNum>::iterator mshr_it = find(mshrSeqNums.begin(), + mshrSeqNums.end(), + seqNum); + + if (mshr_it != mshrSeqNums.end()) { + mshrSeqNums.erase(mshr_it); + DPRINTF(LSQUnit, "Removing MSHR. count = %i\n",mshrSeqNums.size()); + } +}*/ + +template <class Impl> +void +LSQUnit<Impl>::squash(const InstSeqNum &squashed_num) +{ + DPRINTF(LSQUnit, "Squashing until [sn:%lli]!" + "(Loads:%i Stores:%i)\n", squashed_num, loads, stores); + + int load_idx = loadTail; + decrLdIdx(load_idx); + + while (loads != 0 && loadQueue[load_idx]->seqNum > squashed_num) { + DPRINTF(LSQUnit,"Load Instruction PC %#x squashed, " + "[sn:%lli]\n", + loadQueue[load_idx]->readPC(), + loadQueue[load_idx]->seqNum); + + if (isStalled() && load_idx == stallingLoadIdx) { + stalled = false; + stallingStoreIsn = 0; + stallingLoadIdx = 0; + } + + // Clear the smart pointer to make sure it is decremented. + loadQueue[load_idx]->squashed = true; + loadQueue[load_idx] = NULL; + --loads; + + // Inefficient! + loadTail = load_idx; + + decrLdIdx(load_idx); + } + + if (isLoadBlocked) { + if (squashed_num < blockedLoadSeqNum) { + isLoadBlocked = false; + loadBlockedHandled = false; + blockedLoadSeqNum = 0; + } + } + + int store_idx = storeTail; + decrStIdx(store_idx); + + while (stores != 0 && + storeQueue[store_idx].inst->seqNum > squashed_num) { + // Instructions marked as can WB are already committed. + if (storeQueue[store_idx].canWB) { + break; + } + + DPRINTF(LSQUnit,"Store Instruction PC %#x squashed, " + "idx:%i [sn:%lli]\n", + storeQueue[store_idx].inst->readPC(), + store_idx, storeQueue[store_idx].inst->seqNum); + + // I don't think this can happen. It should have been cleared + // by the stalling load. + if (isStalled() && + storeQueue[store_idx].inst->seqNum == stallingStoreIsn) { + panic("Is stalled should have been cleared by stalling load!\n"); + stalled = false; + stallingStoreIsn = 0; + } + + // Clear the smart pointer to make sure it is decremented. + storeQueue[store_idx].inst->squashed = true; + storeQueue[store_idx].inst = NULL; + storeQueue[store_idx].canWB = 0; + + storeQueue[store_idx].req = NULL; + --stores; + + // Inefficient! + storeTail = store_idx; + + decrStIdx(store_idx); + } +} + +template <class Impl> +void +LSQUnit<Impl>::storePostSend(Packet *pkt) +{ + if (isStalled() && + storeQueue[storeWBIdx].inst->seqNum == stallingStoreIsn) { + DPRINTF(LSQUnit, "Unstalling, stalling store [sn:%lli] " + "load idx:%i\n", + stallingStoreIsn, stallingLoadIdx); + stalled = false; + stallingStoreIsn = 0; + iewStage->replayMemInst(loadQueue[stallingLoadIdx]); + } + + if (!storeQueue[storeWBIdx].inst->isStoreConditional()) { + // The store is basically completed at this time. This + // only works so long as the checker doesn't try to + // verify the value in memory for stores. + storeQueue[storeWBIdx].inst->setCompleted(); + if (cpu->checker) { + cpu->checker->tick(storeQueue[storeWBIdx].inst); + } + } + + if (pkt->result != Packet::Success) { + DPRINTF(LSQUnit,"D-Cache Write Miss on idx:%i!\n", + storeWBIdx); + + DPRINTF(Activity, "Active st accessing mem miss [sn:%lli]\n", + storeQueue[storeWBIdx].inst->seqNum); + + //mshrSeqNums.push_back(storeQueue[storeWBIdx].inst->seqNum); + + //DPRINTF(LSQUnit, "Added MSHR. count = %i\n",mshrSeqNums.size()); + + // @todo: Increment stat here. + } else { + DPRINTF(LSQUnit,"D-Cache: Write Hit on idx:%i !\n", + storeWBIdx); + + DPRINTF(Activity, "Active st accessing mem hit [sn:%lli]\n", + storeQueue[storeWBIdx].inst->seqNum); + } + + incrStIdx(storeWBIdx); +} + +template <class Impl> +void +LSQUnit<Impl>::writeback(DynInstPtr &inst, PacketPtr pkt) +{ + iewStage->wakeCPU(); + + // Squashed instructions do not need to complete their access. + if (inst->isSquashed()) { + assert(!inst->isStore()); + return; + } + + if (!inst->isExecuted()) { + inst->setExecuted(); + + // Complete access to copy data to proper place. + inst->completeAcc(pkt); + } + + // Need to insert instruction into queue to commit + iewStage->instToCommit(inst); + + iewStage->activityThisCycle(); +} + +template <class Impl> +void +LSQUnit<Impl>::completeStore(int store_idx) +{ + assert(storeQueue[store_idx].inst); + storeQueue[store_idx].completed = true; + --storesToWB; + // A bit conservative because a store completion may not free up entries, + // but hopefully avoids two store completions in one cycle from making + // the CPU tick twice. + cpu->activityThisCycle(); + + if (store_idx == storeHead) { + do { + incrStIdx(storeHead); + + --stores; + } while (storeQueue[storeHead].completed && + storeHead != storeTail); + + iewStage->updateLSQNextCycle = true; + } + + DPRINTF(LSQUnit, "Completing store [sn:%lli], idx:%i, store head " + "idx:%i\n", + storeQueue[store_idx].inst->seqNum, store_idx, storeHead); + + if (isStalled() && + storeQueue[store_idx].inst->seqNum == stallingStoreIsn) { + DPRINTF(LSQUnit, "Unstalling, stalling store [sn:%lli] " + "load idx:%i\n", + stallingStoreIsn, stallingLoadIdx); + stalled = false; + stallingStoreIsn = 0; + iewStage->replayMemInst(loadQueue[stallingLoadIdx]); + } + + storeQueue[store_idx].inst->setCompleted(); + + // Tell the checker we've completed this instruction. Some stores + // may get reported twice to the checker, but the checker can + // handle that case. + if (cpu->checker) { + cpu->checker->tick(storeQueue[store_idx].inst); + } +} + +template <class Impl> +void +LSQUnit<Impl>::recvRetry() +{ + if (isStoreBlocked) { + assert(retryPkt != NULL); + + if (dcachePort->sendTiming(retryPkt)) { + storePostSend(retryPkt); + retryPkt = NULL; + isStoreBlocked = false; + } else { + // Still blocked! + } + } else if (isLoadBlocked) { + DPRINTF(LSQUnit, "Loads squash themselves and all younger insts, " + "no need to resend packet.\n"); + } else { + DPRINTF(LSQUnit, "Retry received but LSQ is no longer blocked.\n"); + } +} + +template <class Impl> +inline void +LSQUnit<Impl>::incrStIdx(int &store_idx) +{ + if (++store_idx >= SQEntries) + store_idx = 0; +} + +template <class Impl> +inline void +LSQUnit<Impl>::decrStIdx(int &store_idx) +{ + if (--store_idx < 0) + store_idx += SQEntries; +} + +template <class Impl> +inline void +LSQUnit<Impl>::incrLdIdx(int &load_idx) +{ + if (++load_idx >= LQEntries) + load_idx = 0; +} + +template <class Impl> +inline void +LSQUnit<Impl>::decrLdIdx(int &load_idx) +{ + if (--load_idx < 0) + load_idx += LQEntries; +} + +template <class Impl> +void +LSQUnit<Impl>::dumpInsts() +{ + cprintf("Load store queue: Dumping instructions.\n"); + cprintf("Load queue size: %i\n", loads); + cprintf("Load queue: "); + + int load_idx = loadHead; + + while (load_idx != loadTail && loadQueue[load_idx]) { + cprintf("%#x ", loadQueue[load_idx]->readPC()); + + incrLdIdx(load_idx); + } + + cprintf("Store queue size: %i\n", stores); + cprintf("Store queue: "); + + int store_idx = storeHead; + + while (store_idx != storeTail && storeQueue[store_idx].inst) { + cprintf("%#x ", storeQueue[store_idx].inst->readPC()); + + incrStIdx(store_idx); + } + + cprintf("\n"); +} diff --git a/src/cpu/o3/mem_dep_unit.cc b/src/cpu/o3/mem_dep_unit.cc index 84693d002..a95103266 100644 --- a/src/cpu/o3/mem_dep_unit.cc +++ b/src/cpu/o3/mem_dep_unit.cc @@ -36,3 +36,15 @@ // Force instantation of memory dependency unit using store sets and // AlphaSimpleImpl. template class MemDepUnit<StoreSet, AlphaSimpleImpl>; + +#ifdef DEBUG +template <> +int +MemDepUnit<StoreSet, AlphaSimpleImpl>::MemDepEntry::memdep_count = 0; +template <> +int +MemDepUnit<StoreSet, AlphaSimpleImpl>::MemDepEntry::memdep_insert = 0; +template <> +int +MemDepUnit<StoreSet, AlphaSimpleImpl>::MemDepEntry::memdep_erase = 0; +#endif diff --git a/src/cpu/o3/mem_dep_unit.hh b/src/cpu/o3/mem_dep_unit.hh index 2c269b205..e399f0133 100644 --- a/src/cpu/o3/mem_dep_unit.hh +++ b/src/cpu/o3/mem_dep_unit.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,15 +28,29 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_MEM_DEP_UNIT_HH__ -#define __CPU_O3_CPU_MEM_DEP_UNIT_HH__ +#ifndef __CPU_O3_MEM_DEP_UNIT_HH__ +#define __CPU_O3_MEM_DEP_UNIT_HH__ -#include <map> +#include <list> #include <set> +#include "base/hashmap.hh" +#include "base/refcnt.hh" #include "base/statistics.hh" #include "cpu/inst_seq.hh" +struct SNHash { + size_t operator() (const InstSeqNum &seq_num) const { + unsigned a = (unsigned)seq_num; + unsigned hash = (((a >> 14) ^ ((a >> 2) & 0xffff))) & 0x7FFFFFFF; + + return hash; + } +}; + +template <class Impl> +class InstructionQueue; + /** * Memory dependency unit class. This holds the memory dependence predictor. * As memory operations are issued to the IQ, they are also issued to this @@ -54,101 +68,166 @@ class MemDepUnit { typedef typename Impl::Params Params; typedef typename Impl::DynInstPtr DynInstPtr; - public: - MemDepUnit(Params ¶ms); + /** Empty constructor. Must call init() prior to using in this case. */ + MemDepUnit() {} + /** Constructs a MemDepUnit with given parameters. */ + MemDepUnit(Params *params); + + /** Frees up any memory allocated. */ + ~MemDepUnit(); + + /** Returns the name of the memory dependence unit. */ + std::string name() const; + + /** Initializes the unit with parameters and a thread id. */ + void init(Params *params, int tid); + + /** Registers statistics. */ void regStats(); + /** Switches out the memory dependence predictor. */ + void switchOut(); + + /** Takes over from another CPU's thread. */ + void takeOverFrom(); + + /** Sets the pointer to the IQ. */ + void setIQ(InstructionQueue<Impl> *iq_ptr); + + /** Inserts a memory instruction. */ void insert(DynInstPtr &inst); + /** Inserts a non-speculative memory instruction. */ void insertNonSpec(DynInstPtr &inst); - // Will want to make this operation relatively fast. Right now it - // is somewhat slow. - DynInstPtr &top(); - - void pop(); + /** Inserts a barrier instruction. */ + void insertBarrier(DynInstPtr &barr_inst); + /** Indicate that an instruction has its registers ready. */ void regsReady(DynInstPtr &inst); + /** Indicate that a non-speculative instruction is ready. */ void nonSpecInstReady(DynInstPtr &inst); - void issue(DynInstPtr &inst); + /** Reschedules an instruction to be re-executed. */ + void reschedule(DynInstPtr &inst); + /** Replays all instructions that have been rescheduled by moving them to + * the ready list. + */ + void replay(DynInstPtr &inst); + + /** Completes a memory instruction. */ + void completed(DynInstPtr &inst); + + /** Completes a barrier instruction. */ + void completeBarrier(DynInstPtr &inst); + + /** Wakes any dependents of a memory instruction. */ void wakeDependents(DynInstPtr &inst); - void squash(const InstSeqNum &squashed_num); + /** Squashes all instructions up until a given sequence number for a + * specific thread. + */ + void squash(const InstSeqNum &squashed_num, unsigned tid); + /** Indicates an ordering violation between a store and a younger load. */ void violation(DynInstPtr &store_inst, DynInstPtr &violating_load); - inline bool empty() - { return readyInsts.empty(); } + /** Issues the given instruction */ + void issue(DynInstPtr &inst); + + /** Debugging function to dump the lists of instructions. */ + void dumpLists(); private: - typedef typename std::set<InstSeqNum>::iterator sn_it_t; - typedef typename std::map<InstSeqNum, DynInstPtr>::iterator dyn_it_t; - - // Forward declarations so that the following two typedefs work. - class Dependency; - class ltDependency; - - typedef typename std::set<Dependency, ltDependency>::iterator dep_it_t; - typedef typename std::map<InstSeqNum, vector<dep_it_t> >::iterator - sd_it_t; - - struct Dependency { - Dependency(const InstSeqNum &_seqNum) - : seqNum(_seqNum), regsReady(0), memDepReady(0) - { } - - Dependency(const InstSeqNum &_seqNum, bool _regsReady, - bool _memDepReady) - : seqNum(_seqNum), regsReady(_regsReady), - memDepReady(_memDepReady) - { } - - InstSeqNum seqNum; - mutable bool regsReady; - mutable bool memDepReady; - mutable sd_it_t storeDep; - }; + typedef typename std::list<DynInstPtr>::iterator ListIt; + + class MemDepEntry; + + typedef RefCountingPtr<MemDepEntry> MemDepEntryPtr; + + /** Memory dependence entries that track memory operations, marking + * when the instruction is ready to execute and what instructions depend + * upon it. + */ + class MemDepEntry : public RefCounted { + public: + /** Constructs a memory dependence entry. */ + MemDepEntry(DynInstPtr &new_inst) + : inst(new_inst), regsReady(false), memDepReady(false), + completed(false), squashed(false) + { +#ifdef DEBUG + ++memdep_count; + + DPRINTF(MemDepUnit, "Memory dependency entry created. " + "memdep_count=%i\n", memdep_count); +#endif + } - struct ltDependency { - bool operator() (const Dependency &lhs, const Dependency &rhs) + /** Frees any pointers. */ + ~MemDepEntry() { - return lhs.seqNum < rhs.seqNum; + for (int i = 0; i < dependInsts.size(); ++i) { + dependInsts[i] = NULL; + } +#ifdef DEBUG + --memdep_count; + + DPRINTF(MemDepUnit, "Memory dependency entry deleted. " + "memdep_count=%i\n", memdep_count); +#endif } + + /** Returns the name of the memory dependence entry. */ + std::string name() const { return "memdepentry"; } + + /** The instruction being tracked. */ + DynInstPtr inst; + + /** The iterator to the instruction's location inside the list. */ + ListIt listIt; + + /** A vector of any dependent instructions. */ + std::vector<MemDepEntryPtr> dependInsts; + + /** If the registers are ready or not. */ + bool regsReady; + /** If all memory dependencies have been satisfied. */ + bool memDepReady; + /** If the instruction is completed. */ + bool completed; + /** If the instruction is squashed. */ + bool squashed; + + /** For debugging. */ +#ifdef DEBUG + static int memdep_count; + static int memdep_insert; + static int memdep_erase; +#endif }; - inline void moveToReady(dep_it_t &woken_inst); + /** Finds the memory dependence entry in the hash map. */ + inline MemDepEntryPtr &findInHash(const DynInstPtr &inst); - /** List of instructions that have passed through rename, yet are still - * waiting on either a memory dependence to resolve or source registers to - * become available before they can issue. - */ - std::set<Dependency, ltDependency> waitingInsts; + /** Moves an entry to the ready list. */ + inline void moveToReady(MemDepEntryPtr &ready_inst_entry); - /** List of instructions that have all their predicted memory dependences - * resolved and their source registers ready. - */ - std::set<InstSeqNum> readyInsts; + typedef m5::hash_map<InstSeqNum, MemDepEntryPtr, SNHash> MemDepHash; - // Change this to hold a vector of iterators, which will point to the - // entry of the waiting instructions. - /** List of stores' sequence numbers, each of which has a vector of - * iterators. The iterators point to the appropriate node within - * waitingInsts that has the depenendent instruction. - */ - std::map<InstSeqNum, vector<dep_it_t> > storeDependents; + typedef typename MemDepHash::iterator MemDepHashIt; - // For now will implement this as a map...hash table might not be too - // bad, or could move to something that mimics the current dependency - // graph. - std::map<InstSeqNum, DynInstPtr> memInsts; + /** A hash map of all memory dependence entries. */ + MemDepHash memDepHash; - // Iterator pointer to the top instruction which has is ready. - // Is set by the top() call. - dyn_it_t topInst; + /** A list of all instructions in the memory dependence unit. */ + std::list<DynInstPtr> instList[Impl::MaxThreads]; + + /** A list of all instructions that are going to be replayed. */ + std::list<DynInstPtr> instsToReplay; /** The memory dependence predictor. It is accessed upon new * instructions being added to the IQ, and responds by telling @@ -157,10 +236,29 @@ class MemDepUnit { */ MemDepPred depPred; + /** Is there an outstanding load barrier that loads must wait on. */ + bool loadBarrier; + /** The sequence number of the load barrier. */ + InstSeqNum loadBarrierSN; + /** Is there an outstanding store barrier that loads must wait on. */ + bool storeBarrier; + /** The sequence number of the store barrier. */ + InstSeqNum storeBarrierSN; + + /** Pointer to the IQ. */ + InstructionQueue<Impl> *iqPtr; + + /** The thread id of this memory dependence unit. */ + int id; + + /** Stat for number of inserted loads. */ Stats::Scalar<> insertedLoads; + /** Stat for number of inserted stores. */ Stats::Scalar<> insertedStores; + /** Stat for number of conflicting loads that had to wait for a store. */ Stats::Scalar<> conflictingLoads; + /** Stat for number of conflicting stores that had to wait for a store. */ Stats::Scalar<> conflictingStores; }; -#endif // __CPU_O3_CPU_MEM_DEP_UNIT_HH__ +#endif // __CPU_O3_MEM_DEP_UNIT_HH__ diff --git a/src/cpu/o3/mem_dep_unit_impl.hh b/src/cpu/o3/mem_dep_unit_impl.hh index 6b93538be..16f67a4e0 100644 --- a/src/cpu/o3/mem_dep_unit_impl.hh +++ b/src/cpu/o3/mem_dep_unit_impl.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -30,13 +30,58 @@ #include <map> +#include "cpu/o3/inst_queue.hh" #include "cpu/o3/mem_dep_unit.hh" template <class MemDepPred, class Impl> -MemDepUnit<MemDepPred, Impl>::MemDepUnit(Params ¶ms) - : depPred(params.SSITSize, params.LFSTSize) +MemDepUnit<MemDepPred, Impl>::MemDepUnit(Params *params) + : depPred(params->SSITSize, params->LFSTSize), loadBarrier(false), + loadBarrierSN(0), storeBarrier(false), storeBarrierSN(0), iqPtr(NULL) { - DPRINTF(MemDepUnit, "MemDepUnit: Creating MemDepUnit object.\n"); + DPRINTF(MemDepUnit, "Creating MemDepUnit object.\n"); +} + +template <class MemDepPred, class Impl> +MemDepUnit<MemDepPred, Impl>::~MemDepUnit() +{ + for (int tid=0; tid < Impl::MaxThreads; tid++) { + + ListIt inst_list_it = instList[tid].begin(); + + MemDepHashIt hash_it; + + while (!instList[tid].empty()) { + hash_it = memDepHash.find((*inst_list_it)->seqNum); + + assert(hash_it != memDepHash.end()); + + memDepHash.erase(hash_it); + + instList[tid].erase(inst_list_it++); + } + } + +#ifdef DEBUG + assert(MemDepEntry::memdep_count == 0); +#endif +} + +template <class MemDepPred, class Impl> +std::string +MemDepUnit<MemDepPred, Impl>::name() const +{ + return "memdepunit"; +} + +template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::init(Params *params, int tid) +{ + DPRINTF(MemDepUnit, "Creating MemDepUnit %i object.\n",tid); + + id = tid; + + depPred.init(params->SSITSize, params->LFSTSize); } template <class MemDepPred, class Impl> @@ -62,56 +107,99 @@ MemDepUnit<MemDepPred, Impl>::regStats() template <class MemDepPred, class Impl> void +MemDepUnit<MemDepPred, Impl>::switchOut() +{ + // Clear any state. + for (int i = 0; i < Impl::MaxThreads; ++i) { + instList[i].clear(); + } + instsToReplay.clear(); + memDepHash.clear(); +} + +template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::takeOverFrom() +{ + // Be sure to reset all state. + loadBarrier = storeBarrier = false; + loadBarrierSN = storeBarrierSN = 0; + depPred.clear(); +} + +template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::setIQ(InstructionQueue<Impl> *iq_ptr) +{ + iqPtr = iq_ptr; +} + +template <class MemDepPred, class Impl> +void MemDepUnit<MemDepPred, Impl>::insert(DynInstPtr &inst) { - InstSeqNum inst_seq_num = inst->seqNum; + unsigned tid = inst->threadNumber; + + MemDepEntryPtr inst_entry = new MemDepEntry(inst); + + // Add the MemDepEntry to the hash. + memDepHash.insert( + std::pair<InstSeqNum, MemDepEntryPtr>(inst->seqNum, inst_entry)); +#ifdef DEBUG + MemDepEntry::memdep_insert++; +#endif - Dependency unresolved_dependencies(inst_seq_num); + instList[tid].push_back(inst); - InstSeqNum producing_store = depPred.checkInst(inst->readPC()); + inst_entry->listIt = --(instList[tid].end()); - if (producing_store == 0 || - storeDependents.find(producing_store) == storeDependents.end()) { + // Check any barriers and the dependence predictor for any + // producing memrefs/stores. + InstSeqNum producing_store; + if (inst->isLoad() && loadBarrier) { + producing_store = loadBarrierSN; + } else if (inst->isStore() && storeBarrier) { + producing_store = storeBarrierSN; + } else { + producing_store = depPred.checkInst(inst->readPC()); + } + + MemDepEntryPtr store_entry = NULL; - DPRINTF(MemDepUnit, "MemDepUnit: No dependency for inst PC " - "%#x.\n", inst->readPC()); + // If there is a producing store, try to find the entry. + if (producing_store != 0) { + MemDepHashIt hash_it = memDepHash.find(producing_store); - unresolved_dependencies.storeDep = storeDependents.end(); + if (hash_it != memDepHash.end()) { + store_entry = (*hash_it).second; + } + } + + // If no store entry, then instruction can issue as soon as the registers + // are ready. + if (!store_entry) { + DPRINTF(MemDepUnit, "No dependency for inst PC " + "%#x [sn:%lli].\n", inst->readPC(), inst->seqNum); + + inst_entry->memDepReady = true; if (inst->readyToIssue()) { - readyInsts.insert(inst_seq_num); - } else { - unresolved_dependencies.memDepReady = true; + inst_entry->regsReady = true; - waitingInsts.insert(unresolved_dependencies); + moveToReady(inst_entry); } } else { - DPRINTF(MemDepUnit, "MemDepUnit: Adding to dependency list; " - "inst PC %#x is dependent on seq num %i.\n", + // Otherwise make the instruction dependent on the store/barrier. + DPRINTF(MemDepUnit, "Adding to dependency list; " + "inst PC %#x is dependent on [sn:%lli].\n", inst->readPC(), producing_store); if (inst->readyToIssue()) { - unresolved_dependencies.regsReady = true; + inst_entry->regsReady = true; } - // Find the store that this instruction is dependent on. - sd_it_t store_loc = storeDependents.find(producing_store); - - assert(store_loc != storeDependents.end()); - - // Record the location of the store that this instruction is - // dependent on. - unresolved_dependencies.storeDep = store_loc; - - // If it's not already ready, then add it to the renamed - // list and the dependencies. - dep_it_t inst_loc = - (waitingInsts.insert(unresolved_dependencies)).first; - // Add this instruction to the list of dependents. - (*store_loc).second.push_back(inst_loc); - - assert(!(*store_loc).second.empty()); + store_entry->dependInsts.push_back(inst_entry); if (inst->isLoad()) { ++conflictingLoads; @@ -121,277 +209,288 @@ MemDepUnit<MemDepPred, Impl>::insert(DynInstPtr &inst) } if (inst->isStore()) { - DPRINTF(MemDepUnit, "MemDepUnit: Inserting store PC %#x.\n", - inst->readPC()); - - depPred.insertStore(inst->readPC(), inst_seq_num); - - // Make sure this store isn't already in this list. - assert(storeDependents.find(inst_seq_num) == storeDependents.end()); - - // Put a dependency entry in at the store's sequence number. - // Uh, not sure how this works...I want to create an entry but - // I don't have anything to put into the value yet. - storeDependents[inst_seq_num]; + DPRINTF(MemDepUnit, "Inserting store PC %#x [sn:%lli].\n", + inst->readPC(), inst->seqNum); - assert(storeDependents.size() != 0); + depPred.insertStore(inst->readPC(), inst->seqNum, inst->threadNumber); ++insertedStores; - } else if (inst->isLoad()) { ++insertedLoads; } else { - panic("MemDepUnit: Unknown type! (most likely a barrier)."); + panic("Unknown type! (most likely a barrier)."); } - - memInsts[inst_seq_num] = inst; } template <class MemDepPred, class Impl> void MemDepUnit<MemDepPred, Impl>::insertNonSpec(DynInstPtr &inst) { - InstSeqNum inst_seq_num = inst->seqNum; + unsigned tid = inst->threadNumber; - Dependency non_spec_inst(inst_seq_num); + MemDepEntryPtr inst_entry = new MemDepEntry(inst); - non_spec_inst.storeDep = storeDependents.end(); + // Insert the MemDepEntry into the hash. + memDepHash.insert( + std::pair<InstSeqNum, MemDepEntryPtr>(inst->seqNum, inst_entry)); +#ifdef DEBUG + MemDepEntry::memdep_insert++; +#endif + + // Add the instruction to the list. + instList[tid].push_back(inst); - waitingInsts.insert(non_spec_inst); + inst_entry->listIt = --(instList[tid].end()); // Might want to turn this part into an inline function or something. // It's shared between both insert functions. if (inst->isStore()) { - DPRINTF(MemDepUnit, "MemDepUnit: Inserting store PC %#x.\n", - inst->readPC()); - - depPred.insertStore(inst->readPC(), inst_seq_num); - - // Make sure this store isn't already in this list. - assert(storeDependents.find(inst_seq_num) == storeDependents.end()); - - // Put a dependency entry in at the store's sequence number. - // Uh, not sure how this works...I want to create an entry but - // I don't have anything to put into the value yet. - storeDependents[inst_seq_num]; + DPRINTF(MemDepUnit, "Inserting store PC %#x [sn:%lli].\n", + inst->readPC(), inst->seqNum); - assert(storeDependents.size() != 0); + depPred.insertStore(inst->readPC(), inst->seqNum, inst->threadNumber); ++insertedStores; - } else if (inst->isLoad()) { ++insertedLoads; } else { - panic("MemDepUnit: Unknown type! (most likely a barrier)."); + panic("Unknown type! (most likely a barrier)."); } - - memInsts[inst_seq_num] = inst; } template <class MemDepPred, class Impl> -typename Impl::DynInstPtr & -MemDepUnit<MemDepPred, Impl>::top() +void +MemDepUnit<MemDepPred, Impl>::insertBarrier(DynInstPtr &barr_inst) { - topInst = memInsts.find( (*readyInsts.begin()) ); + InstSeqNum barr_sn = barr_inst->seqNum; + // Memory barriers block loads and stores, write barriers only stores. + if (barr_inst->isMemBarrier()) { + loadBarrier = true; + loadBarrierSN = barr_sn; + storeBarrier = true; + storeBarrierSN = barr_sn; + DPRINTF(MemDepUnit, "Inserted a memory barrier\n"); + } else if (barr_inst->isWriteBarrier()) { + storeBarrier = true; + storeBarrierSN = barr_sn; + DPRINTF(MemDepUnit, "Inserted a write barrier\n"); + } + + unsigned tid = barr_inst->threadNumber; + + MemDepEntryPtr inst_entry = new MemDepEntry(barr_inst); + + // Add the MemDepEntry to the hash. + memDepHash.insert( + std::pair<InstSeqNum, MemDepEntryPtr>(barr_sn, inst_entry)); +#ifdef DEBUG + MemDepEntry::memdep_insert++; +#endif - DPRINTF(MemDepUnit, "MemDepUnit: Top instruction is PC %#x.\n", - (*topInst).second->readPC()); + // Add the instruction to the instruction list. + instList[tid].push_back(barr_inst); - return (*topInst).second; + inst_entry->listIt = --(instList[tid].end()); } template <class MemDepPred, class Impl> void -MemDepUnit<MemDepPred, Impl>::pop() +MemDepUnit<MemDepPred, Impl>::regsReady(DynInstPtr &inst) { - DPRINTF(MemDepUnit, "MemDepUnit: Removing instruction PC %#x.\n", - (*topInst).second->readPC()); + DPRINTF(MemDepUnit, "Marking registers as ready for " + "instruction PC %#x [sn:%lli].\n", + inst->readPC(), inst->seqNum); - wakeDependents((*topInst).second); + MemDepEntryPtr inst_entry = findInHash(inst); - issue((*topInst).second); + inst_entry->regsReady = true; - memInsts.erase(topInst); + if (inst_entry->memDepReady) { + DPRINTF(MemDepUnit, "Instruction has its memory " + "dependencies resolved, adding it to the ready list.\n"); - topInst = memInsts.end(); + moveToReady(inst_entry); + } else { + DPRINTF(MemDepUnit, "Instruction still waiting on " + "memory dependency.\n"); + } } template <class MemDepPred, class Impl> void -MemDepUnit<MemDepPred, Impl>::regsReady(DynInstPtr &inst) +MemDepUnit<MemDepPred, Impl>::nonSpecInstReady(DynInstPtr &inst) { - DPRINTF(MemDepUnit, "MemDepUnit: Marking registers as ready for " - "instruction PC %#x.\n", - inst->readPC()); + DPRINTF(MemDepUnit, "Marking non speculative " + "instruction PC %#x as ready [sn:%lli].\n", + inst->readPC(), inst->seqNum); - InstSeqNum inst_seq_num = inst->seqNum; + MemDepEntryPtr inst_entry = findInHash(inst); - Dependency inst_to_find(inst_seq_num); + moveToReady(inst_entry); +} - dep_it_t waiting_inst = waitingInsts.find(inst_to_find); +template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::reschedule(DynInstPtr &inst) +{ + instsToReplay.push_back(inst); +} - assert(waiting_inst != waitingInsts.end()); +template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::replay(DynInstPtr &inst) +{ + DynInstPtr temp_inst; + bool found_inst = false; - if ((*waiting_inst).memDepReady) { - DPRINTF(MemDepUnit, "MemDepUnit: Instruction has its memory " - "dependencies resolved, adding it to the ready list.\n"); + // For now this replay function replays all waiting memory ops. + while (!instsToReplay.empty()) { + temp_inst = instsToReplay.front(); - moveToReady(waiting_inst); - } else { - DPRINTF(MemDepUnit, "MemDepUnit: Instruction still waiting on " - "memory dependency.\n"); + MemDepEntryPtr inst_entry = findInHash(temp_inst); + + DPRINTF(MemDepUnit, "Replaying mem instruction PC %#x " + "[sn:%lli].\n", + temp_inst->readPC(), temp_inst->seqNum); - (*waiting_inst).regsReady = true; + moveToReady(inst_entry); + + if (temp_inst == inst) { + found_inst = true; + } + + instsToReplay.pop_front(); } + + assert(found_inst); } template <class MemDepPred, class Impl> void -MemDepUnit<MemDepPred, Impl>::nonSpecInstReady(DynInstPtr &inst) +MemDepUnit<MemDepPred, Impl>::completed(DynInstPtr &inst) { - DPRINTF(MemDepUnit, "MemDepUnit: Marking non speculative " - "instruction PC %#x as ready.\n", - inst->readPC()); + DPRINTF(MemDepUnit, "Completed mem instruction PC %#x " + "[sn:%lli].\n", + inst->readPC(), inst->seqNum); - InstSeqNum inst_seq_num = inst->seqNum; + unsigned tid = inst->threadNumber; - Dependency inst_to_find(inst_seq_num); + // Remove the instruction from the hash and the list. + MemDepHashIt hash_it = memDepHash.find(inst->seqNum); - dep_it_t waiting_inst = waitingInsts.find(inst_to_find); + assert(hash_it != memDepHash.end()); - assert(waiting_inst != waitingInsts.end()); + instList[tid].erase((*hash_it).second->listIt); - moveToReady(waiting_inst); + (*hash_it).second = NULL; + + memDepHash.erase(hash_it); +#ifdef DEBUG + MemDepEntry::memdep_erase++; +#endif } template <class MemDepPred, class Impl> void -MemDepUnit<MemDepPred, Impl>::issue(DynInstPtr &inst) +MemDepUnit<MemDepPred, Impl>::completeBarrier(DynInstPtr &inst) { - assert(readyInsts.find(inst->seqNum) != readyInsts.end()); - - DPRINTF(MemDepUnit, "MemDepUnit: Issuing instruction PC %#x.\n", - inst->readPC()); - - // Remove the instruction from the ready list. - readyInsts.erase(inst->seqNum); - - depPred.issued(inst->readPC(), inst->seqNum, inst->isStore()); + wakeDependents(inst); + completed(inst); + + InstSeqNum barr_sn = inst->seqNum; + + if (inst->isMemBarrier()) { + assert(loadBarrier && storeBarrier); + if (loadBarrierSN == barr_sn) + loadBarrier = false; + if (storeBarrierSN == barr_sn) + storeBarrier = false; + } else if (inst->isWriteBarrier()) { + assert(storeBarrier); + if (storeBarrierSN == barr_sn) + storeBarrier = false; + } } template <class MemDepPred, class Impl> void MemDepUnit<MemDepPred, Impl>::wakeDependents(DynInstPtr &inst) { - // Only stores have dependents. - if (!inst->isStore()) { + // Only stores and barriers have dependents. + if (!inst->isStore() && !inst->isMemBarrier() && !inst->isWriteBarrier()) { return; } - // Wake any dependencies. - sd_it_t sd_it = storeDependents.find(inst->seqNum); + MemDepEntryPtr inst_entry = findInHash(inst); - // If there's no entry, then return. Really there should only be - // no entry if the instruction is a load. - if (sd_it == storeDependents.end()) { - DPRINTF(MemDepUnit, "MemDepUnit: Instruction PC %#x, sequence " - "number %i has no dependents.\n", - inst->readPC(), inst->seqNum); + for (int i = 0; i < inst_entry->dependInsts.size(); ++i ) { + MemDepEntryPtr woken_inst = inst_entry->dependInsts[i]; - return; - } - - for (int i = 0; i < (*sd_it).second.size(); ++i ) { - dep_it_t woken_inst = (*sd_it).second[i]; - - DPRINTF(MemDepUnit, "MemDepUnit: Waking up a dependent inst, " - "sequence number %i.\n", - (*woken_inst).seqNum); -#if 0 - // Should we have reached instructions that are actually squashed, - // there will be no more useful instructions in this dependency - // list. Break out early. - if (waitingInsts.find(woken_inst) == waitingInsts.end()) { - DPRINTF(MemDepUnit, "MemDepUnit: Dependents on inst PC %#x " - "are squashed, starting at SN %i. Breaking early.\n", - inst->readPC(), woken_inst); - break; + if (!woken_inst->inst) { + // Potentially removed mem dep entries could be on this list + continue; } -#endif - if ((*woken_inst).regsReady) { + DPRINTF(MemDepUnit, "Waking up a dependent inst, " + "[sn:%lli].\n", + woken_inst->inst->seqNum); + + if (woken_inst->regsReady && !woken_inst->squashed) { moveToReady(woken_inst); } else { - (*woken_inst).memDepReady = true; + woken_inst->memDepReady = true; } } - storeDependents.erase(sd_it); + inst_entry->dependInsts.clear(); } template <class MemDepPred, class Impl> void -MemDepUnit<MemDepPred, Impl>::squash(const InstSeqNum &squashed_num) +MemDepUnit<MemDepPred, Impl>::squash(const InstSeqNum &squashed_num, + unsigned tid) { - - if (!waitingInsts.empty()) { - dep_it_t waiting_it = waitingInsts.end(); - - --waiting_it; - - // Remove entries from the renamed list as long as we haven't reached - // the end and the entries continue to be younger than the squashed. - while (!waitingInsts.empty() && - (*waiting_it).seqNum > squashed_num) - { - if (!(*waiting_it).memDepReady && - (*waiting_it).storeDep != storeDependents.end()) { - sd_it_t sd_it = (*waiting_it).storeDep; - - // Make sure the iterator that the store has pointing - // back is actually to this instruction. - assert((*sd_it).second.back() == waiting_it); - - // Now remove this from the store's list of dependent - // instructions. - (*sd_it).second.pop_back(); + if (!instsToReplay.empty()) { + ListIt replay_it = instsToReplay.begin(); + while (replay_it != instsToReplay.end()) { + if ((*replay_it)->threadNumber == tid && + (*replay_it)->seqNum > squashed_num) { + instsToReplay.erase(replay_it++); + } else { + ++replay_it; } - - waitingInsts.erase(waiting_it--); } } - if (!readyInsts.empty()) { - sn_it_t ready_it = readyInsts.end(); + ListIt squash_it = instList[tid].end(); + --squash_it; - --ready_it; + MemDepHashIt hash_it; - // Same for the ready list. - while (!readyInsts.empty() && - (*ready_it) > squashed_num) - { - readyInsts.erase(ready_it--); - } - } + while (!instList[tid].empty() && + (*squash_it)->seqNum > squashed_num) { - if (!storeDependents.empty()) { - sd_it_t dep_it = storeDependents.end(); + DPRINTF(MemDepUnit, "Squashing inst [sn:%lli]\n", + (*squash_it)->seqNum); - --dep_it; + hash_it = memDepHash.find((*squash_it)->seqNum); - // Same for the dependencies list. - while (!storeDependents.empty() && - (*dep_it).first > squashed_num) - { - // This store's list of dependent instructions should be empty. - assert((*dep_it).second.empty()); + assert(hash_it != memDepHash.end()); - storeDependents.erase(dep_it--); - } + (*hash_it).second->squashed = true; + + (*hash_it).second = NULL; + + memDepHash.erase(hash_it); +#ifdef DEBUG + MemDepEntry::memdep_erase++; +#endif + + instList[tid].erase(squash_it--); } // Tell the dependency predictor to squash as well. - depPred.squash(squashed_num); + depPred.squash(squashed_num, tid); } template <class MemDepPred, class Impl> @@ -399,7 +498,7 @@ void MemDepUnit<MemDepPred, Impl>::violation(DynInstPtr &store_inst, DynInstPtr &violating_load) { - DPRINTF(MemDepUnit, "MemDepUnit: Passing violating PCs to store sets," + DPRINTF(MemDepUnit, "Passing violating PCs to store sets," " load: %#x, store: %#x\n", violating_load->readPC(), store_inst->readPC()); // Tell the memory dependence unit of the violation. @@ -407,15 +506,66 @@ MemDepUnit<MemDepPred, Impl>::violation(DynInstPtr &store_inst, } template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::issue(DynInstPtr &inst) +{ + DPRINTF(MemDepUnit, "Issuing instruction PC %#x [sn:%lli].\n", + inst->readPC(), inst->seqNum); + + depPred.issued(inst->readPC(), inst->seqNum, inst->isStore()); +} + +template <class MemDepPred, class Impl> +inline typename MemDepUnit<MemDepPred,Impl>::MemDepEntryPtr & +MemDepUnit<MemDepPred, Impl>::findInHash(const DynInstPtr &inst) +{ + MemDepHashIt hash_it = memDepHash.find(inst->seqNum); + + assert(hash_it != memDepHash.end()); + + return (*hash_it).second; +} + +template <class MemDepPred, class Impl> inline void -MemDepUnit<MemDepPred, Impl>::moveToReady(dep_it_t &woken_inst) +MemDepUnit<MemDepPred, Impl>::moveToReady(MemDepEntryPtr &woken_inst_entry) { - DPRINTF(MemDepUnit, "MemDepUnit: Adding instruction sequence number %i " - "to the ready list.\n", (*woken_inst).seqNum); + DPRINTF(MemDepUnit, "Adding instruction [sn:%lli] " + "to the ready list.\n", woken_inst_entry->inst->seqNum); - // Add it to the ready list. - readyInsts.insert((*woken_inst).seqNum); + assert(!woken_inst_entry->squashed); + + iqPtr->addReadyMemInst(woken_inst_entry->inst); +} - // Remove it from the waiting instructions. - waitingInsts.erase(woken_inst); + +template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::dumpLists() +{ + for (unsigned tid=0; tid < Impl::MaxThreads; tid++) { + cprintf("Instruction list %i size: %i\n", + tid, instList[tid].size()); + + ListIt inst_list_it = instList[tid].begin(); + int num = 0; + + while (inst_list_it != instList[tid].end()) { + cprintf("Instruction:%i\nPC:%#x\n[sn:%i]\n[tid:%i]\nIssued:%i\n" + "Squashed:%i\n\n", + num, (*inst_list_it)->readPC(), + (*inst_list_it)->seqNum, + (*inst_list_it)->threadNumber, + (*inst_list_it)->isIssued(), + (*inst_list_it)->isSquashed()); + inst_list_it++; + ++num; + } + } + + cprintf("Memory dependence hash size: %i\n", memDepHash.size()); + +#ifdef DEBUG + cprintf("Memory dependence entries: %i\n", MemDepEntry::memdep_count); +#endif } diff --git a/src/cpu/o3/ras.cc b/src/cpu/o3/ras.cc index 453544b0f..f9939259a 100644 --- a/src/cpu/o3/ras.cc +++ b/src/cpu/o3/ras.cc @@ -30,12 +30,24 @@ #include "cpu/o3/ras.hh" -ReturnAddrStack::ReturnAddrStack(unsigned _numEntries) - : numEntries(_numEntries), usedEntries(0), - tos(0) +void +ReturnAddrStack::init(unsigned _numEntries) { - addrStack = new Addr[numEntries]; + numEntries = _numEntries; + usedEntries = 0; + tos = 0; + + addrStack.resize(numEntries); + + for (int i = 0; i < numEntries; ++i) + addrStack[i] = 0; +} +void +ReturnAddrStack::reset() +{ + usedEntries = 0; + tos = 0; for (int i = 0; i < numEntries; ++i) addrStack[i] = 0; } @@ -55,9 +67,6 @@ ReturnAddrStack::push(const Addr &return_addr) void ReturnAddrStack::pop() { - // Not sure it's possible to really track usedEntries properly. -// assert(usedEntries > 0); - if (usedEntries > 0) { --usedEntries; } diff --git a/src/cpu/o3/ras.hh b/src/cpu/o3/ras.hh index 4e7dec8f3..5c8a93285 100644 --- a/src/cpu/o3/ras.hh +++ b/src/cpu/o3/ras.hh @@ -28,43 +28,70 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_RAS_HH__ -#define __CPU_O3_CPU_RAS_HH__ +#ifndef __CPU_O3_RAS_HH__ +#define __CPU_O3_RAS_HH__ // For Addr type. #include "arch/isa_traits.hh" +#include <vector> +/** Return address stack class, implements a simple RAS. */ class ReturnAddrStack { public: - ReturnAddrStack(unsigned numEntries); + /** Creates a return address stack, but init() must be called prior to + * use. + */ + ReturnAddrStack() {} + /** Initializes RAS with a specified number of entries. + * @param numEntries Number of entries in the RAS. + */ + void init(unsigned numEntries); + + void reset(); + + /** Returns the top address on the RAS. */ Addr top() { return addrStack[tos]; } + /** Returns the index of the top of the RAS. */ unsigned topIdx() { return tos; } + /** Pushes an address onto the RAS. */ void push(const Addr &return_addr); + /** Pops the top address from the RAS. */ void pop(); + /** Changes index to the top of the RAS, and replaces the top address with + * a new target. + * @param top_entry_idx The index of the RAS that will now be the top. + * @param restored_target The new target address of the new top of the RAS. + */ void restore(unsigned top_entry_idx, const Addr &restored_target); private: + /** Increments the top of stack index. */ inline void incrTos() { if (++tos == numEntries) tos = 0; } + /** Decrements the top of stack index. */ inline void decrTos() { tos = (tos == 0 ? numEntries - 1 : tos - 1); } - Addr *addrStack; + /** The RAS itself. */ + std::vector<Addr> addrStack; + /** The number of entries in the RAS. */ unsigned numEntries; + /** The number of used entries in the RAS. */ unsigned usedEntries; + /** The top of stack index. */ unsigned tos; }; -#endif // __CPU_O3_CPU_RAS_HH__ +#endif // __CPU_O3_RAS_HH__ diff --git a/src/cpu/o3/regfile.hh b/src/cpu/o3/regfile.hh index f1f4880e0..ade5e4e56 100644 --- a/src/cpu/o3/regfile.hh +++ b/src/cpu/o3/regfile.hh @@ -29,13 +29,12 @@ * Gabe Black */ -#ifndef __CPU_O3_CPU_REGFILE_HH__ -#define __CPU_O3_CPU_REGFILE_HH__ - -// @todo: Destructor +#ifndef __CPU_O3_REGFILE_HH__ +#define __CPU_O3_REGFILE_HH__ #include "arch/isa_traits.hh" #include "arch/faults.hh" +#include "arch/types.hh" #include "base/trace.hh" #include "config/full_system.hh" #include "cpu/o3/comm.hh" @@ -45,32 +44,40 @@ #endif -// This really only depends on the ISA, and not the Impl. It might be nicer -// to see if I can make it depend on nothing... -// Things that are in the ifdef FULL_SYSTEM are pretty dependent on the ISA, -// and should go in the AlphaFullCPU. +#include <vector> +/** + * Simple physical register file class. + * Right now this is specific to Alpha until we decide if/how to make things + * generic enough to support other ISAs. + */ template <class Impl> class PhysRegFile { protected: typedef TheISA::IntReg IntReg; typedef TheISA::FloatReg FloatReg; + typedef TheISA::FloatRegBits FloatRegBits; typedef TheISA::MiscRegFile MiscRegFile; typedef TheISA::MiscReg MiscReg; - //Note that most of the definitions of the IntReg, FloatReg, etc. exist - //within the Impl/ISA class and not within this PhysRegFile class. + typedef union { + FloatReg d; + FloatRegBits q; + } PhysFloatReg; - //Will need some way to allow stuff like swap_palshadow to access the - //correct registers. Might require code changes to swap_palshadow and - //other execution contexts. + // Note that most of the definitions of the IntReg, FloatReg, etc. exist + // within the Impl/ISA class and not within this PhysRegFile class. - //Will make these registers public for now, but they probably should - //be private eventually with some accessor functions. + // Will make these registers public for now, but they probably should + // be private eventually with some accessor functions. public: typedef typename Impl::FullCPU FullCPU; + /** + * Constructs a physical register file with the specified amount of + * integer and floating point registers. + */ PhysRegFile(unsigned _numPhysicalIntRegs, unsigned _numPhysicalFloatRegs); @@ -83,12 +90,13 @@ class PhysRegFile // void serialize(std::ostream &os); // void unserialize(Checkpoint *cp, const std::string §ion); + /** Reads an integer register. */ uint64_t readIntReg(PhysRegIndex reg_idx) { assert(reg_idx < numPhysicalIntRegs); DPRINTF(IEW, "RegFile: Access to int register %i, has data " - "%i\n", int(reg_idx), intRegFile[reg_idx]); + "%#x\n", int(reg_idx), intRegFile[reg_idx]); return intRegFile[reg_idx]; } @@ -99,14 +107,15 @@ class PhysRegFile assert(reg_idx < numPhysicalFloatRegs + numPhysicalIntRegs); - FloatReg floatReg = floatRegFile.readReg(reg_idx, width); + FloatReg floatReg = floatRegFile[reg_idx].d; DPRINTF(IEW, "RegFile: Access to %d byte float register %i, has " - "data %8.8d\n", int(reg_idx), (double)floatReg); + "data %#x\n", int(reg_idx), floatRegFile[reg_idx].q); return floatReg; } + /** Reads a floating point register (double precision). */ FloatReg readFloatReg(PhysRegIndex reg_idx) { // Remove the base Float reg dependency. @@ -114,14 +123,15 @@ class PhysRegFile assert(reg_idx < numPhysicalFloatRegs + numPhysicalIntRegs); - FloatReg floatReg = floatRegFile.readReg(reg_idx); + FloatReg floatReg = floatRegFile[reg_idx].d; DPRINTF(IEW, "RegFile: Access to float register %i, has " - "data %8.8d\n", int(reg_idx), (double)floatReg); + "data %#x\n", int(reg_idx), floatRegFile[reg_idx].q); return floatReg; } + /** Reads a floating point register as an integer. */ FloatRegBits readFloatRegBits(PhysRegIndex reg_idx, int width) { // Remove the base Float reg dependency. @@ -129,10 +139,10 @@ class PhysRegFile assert(reg_idx < numPhysicalFloatRegs + numPhysicalIntRegs); - FloatRegBits floatRegBits = floatRegFile.readRegBits(reg_idx, width); + FloatRegBits floatRegBits = floatRegFile[reg_idx].q; - DPRINTF(IEW, "RegFile: Access to %d byte float register %i as int, " - "has data %lli\n", int(reg_idx), (uint64_t)floatRegBits); + DPRINTF(IEW, "RegFile: Access to float register %i as int, " + "has data %#x\n", int(reg_idx), (uint64_t)floatRegBits); return floatRegBits; } @@ -144,24 +154,27 @@ class PhysRegFile assert(reg_idx < numPhysicalFloatRegs + numPhysicalIntRegs); - FloatRegBits floatRegBits = floatRegFile.readRegBits(reg_idx); + FloatRegBits floatRegBits = floatRegFile[reg_idx].q; DPRINTF(IEW, "RegFile: Access to float register %i as int, " - "has data %lli\n", int(reg_idx), (uint64_t)floatRegBits); + "has data %#x\n", int(reg_idx), (uint64_t)floatRegBits); return floatRegBits; } + /** Sets an integer register to the given value. */ void setIntReg(PhysRegIndex reg_idx, uint64_t val) { assert(reg_idx < numPhysicalIntRegs); - DPRINTF(IEW, "RegFile: Setting int register %i to %lli\n", + DPRINTF(IEW, "RegFile: Setting int register %i to %#x\n", int(reg_idx), val); - intRegFile[reg_idx] = val; + if (reg_idx != TheISA::ZeroReg) + intRegFile[reg_idx] = val; } + /** Sets a single precision floating point register to the given value. */ void setFloatReg(PhysRegIndex reg_idx, FloatReg val, int width) { // Remove the base Float reg dependency. @@ -169,12 +182,14 @@ class PhysRegFile assert(reg_idx < numPhysicalFloatRegs + numPhysicalIntRegs); - DPRINTF(IEW, "RegFile: Setting float register %i to %8.8d\n", - int(reg_idx), (double)val); + DPRINTF(IEW, "RegFile: Setting float register %i to %#x\n", + int(reg_idx), (uint64_t)val); - floatRegFile.setReg(reg_idx, val, width); + if (reg_idx != TheISA::ZeroReg) + floatRegFile[reg_idx].d = val; } + /** Sets a double precision floating point register to the given value. */ void setFloatReg(PhysRegIndex reg_idx, FloatReg val) { // Remove the base Float reg dependency. @@ -182,12 +197,14 @@ class PhysRegFile assert(reg_idx < numPhysicalFloatRegs + numPhysicalIntRegs); - DPRINTF(IEW, "RegFile: Setting float register %i to %8.8d\n", - int(reg_idx), (double)val); + DPRINTF(IEW, "RegFile: Setting float register %i to %#x\n", + int(reg_idx), (uint64_t)val); - floatRegFile.setReg(reg_idx, val); + if (reg_idx != TheISA::ZeroReg) + floatRegFile[reg_idx].d = val; } + /** Sets a floating point register to the given integer value. */ void setFloatRegBits(PhysRegIndex reg_idx, FloatRegBits val, int width) { // Remove the base Float reg dependency. @@ -195,10 +212,10 @@ class PhysRegFile assert(reg_idx < numPhysicalFloatRegs + numPhysicalIntRegs); - DPRINTF(IEW, "RegFile: Setting float register %i to %lli\n", + DPRINTF(IEW, "RegFile: Setting float register %i to %#x\n", int(reg_idx), (uint64_t)val); - floatRegFile.setRegBits(reg_idx, val, width); + floatRegFile[reg_idx].q = val; } void setFloatRegBits(PhysRegIndex reg_idx, FloatRegBits val) @@ -208,81 +225,68 @@ class PhysRegFile assert(reg_idx < numPhysicalFloatRegs + numPhysicalIntRegs); - DPRINTF(IEW, "RegFile: Setting float register %i to %lli\n", + DPRINTF(IEW, "RegFile: Setting float register %i to %#x\n", int(reg_idx), (uint64_t)val); - floatRegFile.setRegBits(reg_idx, val); + floatRegFile[reg_idx].q = val; } - uint64_t readPC() + MiscReg readMiscReg(int misc_reg, unsigned thread_id) { - return pc; + return miscRegs[thread_id].readReg(misc_reg); } - void setPC(uint64_t val) + MiscReg readMiscRegWithEffect(int misc_reg, Fault &fault, + unsigned thread_id) { - pc = val; + return miscRegs[thread_id].readRegWithEffect(misc_reg, fault, + cpu->tcBase(thread_id)); } - void setNextPC(uint64_t val) + Fault setMiscReg(int misc_reg, const MiscReg &val, unsigned thread_id) { - npc = val; + return miscRegs[thread_id].setReg(misc_reg, val); } - //Consider leaving this stuff and below in some implementation specific - //file as opposed to the general register file. Or have a derived class. - MiscReg readMiscReg(int misc_reg) + Fault setMiscRegWithEffect(int misc_reg, const MiscReg &val, + unsigned thread_id) { - // Dummy function for now. - // @todo: Fix this once proxy XC is used. - return 0; - } - - Fault setMiscReg(int misc_reg, const MiscReg &val) - { - // Dummy function for now. - // @todo: Fix this once proxy XC is used. - return NoFault; + return miscRegs[thread_id].setRegWithEffect(misc_reg, val, + cpu->tcBase(thread_id)); } #if FULL_SYSTEM int readIntrFlag() { return intrflag; } + /** Sets an interrupt flag. */ void setIntrFlag(int val) { intrflag = val; } #endif - // These should be private eventually, but will be public for now - // so that I can hack around the initregs issue. public: /** (signed) integer register file. */ IntReg *intRegFile; /** Floating point register file. */ - FloatReg *floatRegFile; + PhysFloatReg *floatRegFile; /** Miscellaneous register file. */ - MiscRegFile miscRegs; - - /** Program counter. */ - Addr pc; - - /** Next-cycle program counter. */ - Addr npc; + MiscRegFile miscRegs[Impl::MaxThreads]; #if FULL_SYSTEM private: - // This is ISA specifc stuff; remove it eventually once ISAImpl is used -// IntReg palregs[NumIntRegs]; // PAL shadow registers int intrflag; // interrupt flag - bool pal_shadow; // using pal_shadow registers #endif private: + /** CPU pointer. */ FullCPU *cpu; public: + /** Sets the CPU pointer. */ void setCPU(FullCPU *cpu_ptr) { cpu = cpu_ptr; } + /** Number of physical integer registers. */ unsigned numPhysicalIntRegs; + /** Number of physical floating point registers. */ unsigned numPhysicalFloatRegs; }; @@ -293,10 +297,14 @@ PhysRegFile<Impl>::PhysRegFile(unsigned _numPhysicalIntRegs, numPhysicalFloatRegs(_numPhysicalFloatRegs) { intRegFile = new IntReg[numPhysicalIntRegs]; - floatRegFile = new FloatReg[numPhysicalFloatRegs]; + floatRegFile = new PhysFloatReg[numPhysicalFloatRegs]; - memset(intRegFile, 0, sizeof(*intRegFile)); - memset(floatRegFile, 0, sizeof(*floatRegFile)); + for (int i = 0; i < Impl::MaxThreads; ++i) { + miscRegs[i].clear(); + } + + memset(intRegFile, 0, sizeof(IntReg) * numPhysicalIntRegs); + memset(floatRegFile, 0, sizeof(PhysFloatReg) * numPhysicalFloatRegs); } -#endif // __CPU_O3_CPU_REGFILE_HH__ +#endif diff --git a/src/cpu/o3/rename.cc b/src/cpu/o3/rename.cc index 94254625e..9ca8e82c6 100644 --- a/src/cpu/o3/rename.cc +++ b/src/cpu/o3/rename.cc @@ -32,4 +32,4 @@ #include "cpu/o3/alpha_impl.hh" #include "cpu/o3/rename_impl.hh" -template class SimpleRename<AlphaSimpleImpl>; +template class DefaultRename<AlphaSimpleImpl>; diff --git a/src/cpu/o3/rename.hh b/src/cpu/o3/rename.hh index f81e9b2d7..42fdf6bf5 100644 --- a/src/cpu/o3/rename.hh +++ b/src/cpu/o3/rename.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,23 +28,28 @@ * Authors: Kevin Lim */ -// Todo: -// Fix up trap and barrier handling. -// May want to have different statuses to differentiate the different stall -// conditions. - -#ifndef __CPU_O3_CPU_SIMPLE_RENAME_HH__ -#define __CPU_O3_CPU_SIMPLE_RENAME_HH__ +#ifndef __CPU_O3_RENAME_HH__ +#define __CPU_O3_RENAME_HH__ #include <list> #include "base/statistics.hh" #include "base/timebuf.hh" -// Will need rename maps for both the int reg file and fp reg file. -// Or change rename map class to handle both. (RegFile handles both.) +/** + * DefaultRename handles both single threaded and SMT rename. Its + * width is specified by the parameters; each cycle it tries to rename + * that many instructions. It holds onto the rename history of all + * instructions with destination registers, storing the + * arch. register, the new physical register, and the old physical + * register, to allow for undoing of mappings if squashing happens, or + * freeing up registers upon commit. Rename handles blocking if the + * ROB, IQ, or LSQ is going to be full. Rename also handles barriers, + * and does so by stalling on the instruction until the ROB is empty + * and there are no instructions in flight to the ROB. + */ template<class Impl> -class SimpleRename +class DefaultRename { public: // Typedefs from the Impl. @@ -53,112 +58,242 @@ class SimpleRename typedef typename Impl::FullCPU FullCPU; typedef typename Impl::Params Params; - typedef typename CPUPol::FetchStruct FetchStruct; + // Typedefs from the CPUPol typedef typename CPUPol::DecodeStruct DecodeStruct; typedef typename CPUPol::RenameStruct RenameStruct; typedef typename CPUPol::TimeStruct TimeStruct; - - // Typedefs from the CPUPol typedef typename CPUPol::FreeList FreeList; typedef typename CPUPol::RenameMap RenameMap; + // These are used only for initialization. + typedef typename CPUPol::IEW IEW; + typedef typename CPUPol::Commit Commit; // Typedefs from the ISA. typedef TheISA::RegIndex RegIndex; + // A list is used to queue the instructions. Barrier insts must + // be added to the front of the list, which is the only reason for + // using a list instead of a queue. (Most other stages use a + // queue) + typedef std::list<DynInstPtr> InstQueue; + public: - // Rename will block if ROB becomes full or issue queue becomes full, - // or there are no free registers to rename to. - // Only case where rename squashes is if IEW squashes. - enum Status { + /** Overall rename status. Used to determine if the CPU can + * deschedule itself due to a lack of activity. + */ + enum RenameStatus { + Active, + Inactive + }; + + /** Individual thread status. */ + enum ThreadStatus { Running, Idle, + StartSquash, Squashing, Blocked, Unblocking, - BarrierStall + SerializeStall }; private: - Status _status; + /** Rename status. */ + RenameStatus _status; + + /** Per-thread status. */ + ThreadStatus renameStatus[Impl::MaxThreads]; public: - SimpleRename(Params ¶ms); + /** DefaultRename constructor. */ + DefaultRename(Params *params); + /** Returns the name of rename. */ + std::string name() const; + + /** Registers statistics. */ void regStats(); + /** Sets CPU pointer. */ void setCPU(FullCPU *cpu_ptr); + /** Sets the main backwards communication time buffer pointer. */ void setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr); + /** Sets pointer to time buffer used to communicate to the next stage. */ void setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr); + /** Sets pointer to time buffer coming from decode. */ void setDecodeQueue(TimeBuffer<DecodeStruct> *dq_ptr); - void setRenameMap(RenameMap *rm_ptr); + /** Sets pointer to IEW stage. Used only for initialization. */ + void setIEWStage(IEW *iew_stage) + { iew_ptr = iew_stage; } + + /** Sets pointer to commit stage. Used only for initialization. */ + void setCommitStage(Commit *commit_stage) + { commit_ptr = commit_stage; } + + private: + /** Pointer to IEW stage. Used only for initialization. */ + IEW *iew_ptr; + + /** Pointer to commit stage. Used only for initialization. */ + Commit *commit_ptr; + public: + /** Initializes variables for the stage. */ + void initStage(); + + /** Sets pointer to list of active threads. */ + void setActiveThreads(std::list<unsigned> *at_ptr); + + /** Sets pointer to rename maps (per-thread structures). */ + void setRenameMap(RenameMap rm_ptr[Impl::MaxThreads]); + + /** Sets pointer to the free list. */ void setFreeList(FreeList *fl_ptr); - void dumpHistory(); + /** Sets pointer to the scoreboard. */ + void setScoreboard(Scoreboard *_scoreboard); - void tick(); + /** Switches out the rename stage. */ + void switchOut(); + + /** Completes the switch out. */ + void doSwitchOut(); + + /** Takes over from another CPU's thread. */ + void takeOverFrom(); - void rename(); + /** Squashes all instructions in a thread. */ + void squash(unsigned tid); + + /** Ticks rename, which processes all input signals and attempts to rename + * as many instructions as possible. + */ + void tick(); - void squash(); + /** Debugging function used to dump history buffer of renamings. */ + void dumpHistory(); private: - void block(); + /** Determines what to do based on rename's current status. + * @param status_change rename() sets this variable if there was a status + * change (ie switching from blocking to unblocking). + * @param tid Thread id to rename instructions from. + */ + void rename(bool &status_change, unsigned tid); + + /** Renames instructions for the given thread. Also handles serializing + * instructions. + */ + void renameInsts(unsigned tid); + + /** Inserts unused instructions from a given thread into the skid buffer, + * to be renamed once rename unblocks. + */ + void skidInsert(unsigned tid); + + /** Separates instructions from decode into individual lists of instructions + * sorted by thread. + */ + void sortInsts(); + + /** Returns if all of the skid buffers are empty. */ + bool skidsEmpty(); + + /** Updates overall rename status based on all of the threads' statuses. */ + void updateStatus(); + + /** Switches rename to blocking, and signals back that rename has become + * blocked. + * @return Returns true if there is a status change. + */ + bool block(unsigned tid); + + /** Switches rename to unblocking if the skid buffer is empty, and signals + * back that rename has unblocked. + * @return Returns true if there is a status change. + */ + bool unblock(unsigned tid); - inline void unblock(); + /** Executes actual squash, removing squashed instructions. */ + void doSquash(unsigned tid); - void doSquash(); + /** Removes a committed instruction's rename history. */ + void removeFromHistory(InstSeqNum inst_seq_num, unsigned tid); - void removeFromHistory(InstSeqNum inst_seq_num); + /** Renames the source registers of an instruction. */ + inline void renameSrcRegs(DynInstPtr &inst, unsigned tid); - inline void renameSrcRegs(DynInstPtr &inst); + /** Renames the destination registers of an instruction. */ + inline void renameDestRegs(DynInstPtr &inst, unsigned tid); - inline void renameDestRegs(DynInstPtr &inst); + /** Calculates the number of free ROB entries for a specific thread. */ + inline int calcFreeROBEntries(unsigned tid); - inline int calcFreeROBEntries(); + /** Calculates the number of free IQ entries for a specific thread. */ + inline int calcFreeIQEntries(unsigned tid); - inline int calcFreeIQEntries(); + /** Calculates the number of free LSQ entries for a specific thread. */ + inline int calcFreeLSQEntries(unsigned tid); - /** Holds the previous information for each rename. - * Note that often times the inst may have been deleted, so only access - * the pointer for the address and do not dereference it. + /** Returns the number of valid instructions coming from decode. */ + unsigned validInsts(); + + /** Reads signals telling rename to block/unblock. */ + void readStallSignals(unsigned tid); + + /** Checks if any stages are telling rename to block. */ + bool checkStall(unsigned tid); + + /** Gets the number of free entries for a specific thread. */ + void readFreeEntries(unsigned tid); + + /** Checks the signals and updates the status. */ + bool checkSignalsAndUpdate(unsigned tid); + + /** Either serializes on the next instruction available in the InstQueue, + * or records that it must serialize on the next instruction to enter + * rename. + * @param inst_list The list of younger, unprocessed instructions for the + * thread that has the serializeAfter instruction. + * @param tid The thread id. + */ + void serializeAfter(InstQueue &inst_list, unsigned tid); + + /** Holds the information for each destination register rename. It holds + * the instruction's sequence number, the arch register, the old physical + * register for that arch. register, and the new physical register. */ struct RenameHistory { RenameHistory(InstSeqNum _instSeqNum, RegIndex _archReg, PhysRegIndex _newPhysReg, PhysRegIndex _prevPhysReg) : instSeqNum(_instSeqNum), archReg(_archReg), - newPhysReg(_newPhysReg), prevPhysReg(_prevPhysReg), - placeHolder(false) - { - } - - /** Constructor used specifically for cases where a place holder - * rename history entry is being made. - */ - RenameHistory(InstSeqNum _instSeqNum) - : instSeqNum(_instSeqNum), archReg(0), newPhysReg(0), - prevPhysReg(0), placeHolder(true) + newPhysReg(_newPhysReg), prevPhysReg(_prevPhysReg) { } + /** The sequence number of the instruction that renamed. */ InstSeqNum instSeqNum; + /** The architectural register index that was renamed. */ RegIndex archReg; + /** The new physical register that the arch. register is renamed to. */ PhysRegIndex newPhysReg; + /** The old physical register that the arch. register was renamed to. */ PhysRegIndex prevPhysReg; - bool placeHolder; }; - std::list<RenameHistory> historyBuffer; + /** A per-thread list of all destination register renames, used to either + * undo rename mappings or free old physical registers. + */ + std::list<RenameHistory> historyBuffer[Impl::MaxThreads]; - /** CPU interface. */ + /** Pointer to CPU. */ FullCPU *cpu; - // Interfaces to objects outside of rename. - /** Time buffer interface. */ + /** Pointer to main time buffer used for backwards communication. */ TimeBuffer<TimeStruct> *timeBuffer; /** Wire to get IEW's output from backwards time buffer. */ @@ -168,7 +303,6 @@ class SimpleRename typename TimeBuffer<TimeStruct>::wire fromCommit; /** Wire to write infromation heading to previous stages. */ - // Might not be the best name as not only decode will read it. typename TimeBuffer<TimeStruct>::wire toDecode; /** Rename instruction queue. */ @@ -183,15 +317,71 @@ class SimpleRename /** Wire to get decode's output from decode queue. */ typename TimeBuffer<DecodeStruct>::wire fromDecode; + /** Queue of all instructions coming from decode this cycle. */ + InstQueue insts[Impl::MaxThreads]; + /** Skid buffer between rename and decode. */ - std::queue<DecodeStruct> skidBuffer; + InstQueue skidBuffer[Impl::MaxThreads]; /** Rename map interface. */ - SimpleRenameMap *renameMap; + RenameMap *renameMap[Impl::MaxThreads]; /** Free list interface. */ FreeList *freeList; + /** Pointer to the list of active threads. */ + std::list<unsigned> *activeThreads; + + /** Pointer to the scoreboard. */ + Scoreboard *scoreboard; + + /** Count of instructions in progress that have been sent off to the IQ + * and ROB, but are not yet included in their occupancy counts. + */ + int instsInProgress[Impl::MaxThreads]; + + /** Variable that tracks if decode has written to the time buffer this + * cycle. Used to tell CPU if there is activity this cycle. + */ + bool wroteToTimeBuffer; + + /** Structures whose free entries impact the amount of instructions that + * can be renamed. + */ + struct FreeEntries { + unsigned iqEntries; + unsigned lsqEntries; + unsigned robEntries; + }; + + /** Per-thread tracking of the number of free entries of back-end + * structures. + */ + FreeEntries freeEntries[Impl::MaxThreads]; + + /** Records if the ROB is empty. In SMT mode the ROB may be dynamically + * partitioned between threads, so the ROB must tell rename when it is + * empty. + */ + bool emptyROB[Impl::MaxThreads]; + + /** Source of possible stalls. */ + struct Stalls { + bool iew; + bool commit; + }; + + /** Tracks which stages are telling decode to stall. */ + Stalls stalls[Impl::MaxThreads]; + + /** The serialize instruction that rename has stalled on. */ + DynInstPtr serializeInst[Impl::MaxThreads]; + + /** Records if rename needs to serialize on the next instruction for any + * thread. + */ + bool serializeOnNextInst[Impl::MaxThreads]; + /** Delay between iew and rename, in ticks. */ int iewToRenameDelay; @@ -209,27 +399,74 @@ class SimpleRename */ unsigned commitWidth; - /** The instruction that rename is currently on. It needs to have - * persistent state so that when a stall occurs in the middle of a - * group of instructions, it can restart at the proper instruction. + /** The index of the instruction in the time buffer to IEW that rename is + * currently using. + */ + unsigned toIEWIndex; + + /** Whether or not rename needs to block this cycle. */ + bool blockThisCycle; + + /** The number of threads active in rename. */ + unsigned numThreads; + + /** The maximum skid buffer size. */ + unsigned skidBufferMax; + + /** Enum to record the source of a structure full stall. Can come from + * either ROB, IQ, LSQ, and it is priortized in that order. + */ + enum FullSource { + ROB, + IQ, + LSQ, + NONE + }; + + /** Function used to increment the stat that corresponds to the source of + * the stall. */ - unsigned numInst; + inline void incrFullStat(const FullSource &source); + /** Stat for total number of cycles spent squashing. */ Stats::Scalar<> renameSquashCycles; + /** Stat for total number of cycles spent idle. */ Stats::Scalar<> renameIdleCycles; + /** Stat for total number of cycles spent blocking. */ Stats::Scalar<> renameBlockCycles; + /** Stat for total number of cycles spent stalling for a serializing inst. */ + Stats::Scalar<> renameSerializeStallCycles; + /** Stat for total number of cycles spent running normally. */ + Stats::Scalar<> renameRunCycles; + /** Stat for total number of cycles spent unblocking. */ Stats::Scalar<> renameUnblockCycles; + /** Stat for total number of renamed instructions. */ Stats::Scalar<> renameRenamedInsts; + /** Stat for total number of squashed instructions that rename discards. */ Stats::Scalar<> renameSquashedInsts; + /** Stat for total number of times that the ROB starts a stall in rename. */ Stats::Scalar<> renameROBFullEvents; + /** Stat for total number of times that the IQ starts a stall in rename. */ Stats::Scalar<> renameIQFullEvents; + /** Stat for total number of times that the LSQ starts a stall in rename. */ + Stats::Scalar<> renameLSQFullEvents; + /** Stat for total number of times that rename runs out of free registers + * to use to rename. */ Stats::Scalar<> renameFullRegistersEvents; + /** Stat for total number of renamed destination registers. */ Stats::Scalar<> renameRenamedOperands; + /** Stat for total number of source register rename lookups. */ Stats::Scalar<> renameRenameLookups; - Stats::Scalar<> renameHBPlaceHolders; + /** Stat for total number of committed renaming mappings. */ Stats::Scalar<> renameCommittedMaps; + /** Stat for total number of mappings that were undone due to a squash. */ Stats::Scalar<> renameUndoneMaps; - Stats::Scalar<> renameValidUndoneMaps; + /** Number of serialize instructions handled. */ + Stats::Scalar<> renamedSerializing; + /** Number of instructions marked as temporarily serializing. */ + Stats::Scalar<> renamedTempSerializing; + /** Number of instructions inserted into skid buffers. */ + Stats::Scalar<> renameSkidInsts; }; -#endif // __CPU_O3_CPU_SIMPLE_RENAME_HH__ +#endif // __CPU_O3_RENAME_HH__ diff --git a/src/cpu/o3/rename_impl.hh b/src/cpu/o3/rename_impl.hh index 5c470e3d7..df33b98ee 100644 --- a/src/cpu/o3/rename_impl.hh +++ b/src/cpu/o3/rename_impl.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -33,97 +33,146 @@ #include "config/full_system.hh" #include "cpu/o3/rename.hh" +using namespace std; + +template <class Impl> +DefaultRename<Impl>::DefaultRename(Params *params) + : iewToRenameDelay(params->iewToRenameDelay), + decodeToRenameDelay(params->decodeToRenameDelay), + commitToRenameDelay(params->commitToRenameDelay), + renameWidth(params->renameWidth), + commitWidth(params->commitWidth), + numThreads(params->numberOfThreads) +{ + _status = Inactive; + + for (int i=0; i< numThreads; i++) { + renameStatus[i] = Idle; + + freeEntries[i].iqEntries = 0; + freeEntries[i].lsqEntries = 0; + freeEntries[i].robEntries = 0; + + stalls[i].iew = false; + stalls[i].commit = false; + serializeInst[i] = NULL; + + instsInProgress[i] = 0; + + emptyROB[i] = true; + + serializeOnNextInst[i] = false; + } + + // @todo: Make into a parameter. + skidBufferMax = (2 * (iewToRenameDelay * params->decodeWidth)) + renameWidth; +} + template <class Impl> -SimpleRename<Impl>::SimpleRename(Params ¶ms) - : iewToRenameDelay(params.iewToRenameDelay), - decodeToRenameDelay(params.decodeToRenameDelay), - commitToRenameDelay(params.commitToRenameDelay), - renameWidth(params.renameWidth), - commitWidth(params.commitWidth), - numInst(0) +std::string +DefaultRename<Impl>::name() const { - _status = Idle; + return cpu->name() + ".rename"; } template <class Impl> void -SimpleRename<Impl>::regStats() +DefaultRename<Impl>::regStats() { renameSquashCycles - .name(name() + ".renameSquashCycles") + .name(name() + ".RENAME:SquashCycles") .desc("Number of cycles rename is squashing") .prereq(renameSquashCycles); renameIdleCycles - .name(name() + ".renameIdleCycles") + .name(name() + ".RENAME:IdleCycles") .desc("Number of cycles rename is idle") .prereq(renameIdleCycles); renameBlockCycles - .name(name() + ".renameBlockCycles") + .name(name() + ".RENAME:BlockCycles") .desc("Number of cycles rename is blocking") .prereq(renameBlockCycles); + renameSerializeStallCycles + .name(name() + ".RENAME:serializeStallCycles") + .desc("count of cycles rename stalled for serializing inst") + .flags(Stats::total); + renameRunCycles + .name(name() + ".RENAME:RunCycles") + .desc("Number of cycles rename is running") + .prereq(renameIdleCycles); renameUnblockCycles - .name(name() + ".renameUnblockCycles") + .name(name() + ".RENAME:UnblockCycles") .desc("Number of cycles rename is unblocking") .prereq(renameUnblockCycles); renameRenamedInsts - .name(name() + ".renameRenamedInsts") + .name(name() + ".RENAME:RenamedInsts") .desc("Number of instructions processed by rename") .prereq(renameRenamedInsts); renameSquashedInsts - .name(name() + ".renameSquashedInsts") + .name(name() + ".RENAME:SquashedInsts") .desc("Number of squashed instructions processed by rename") .prereq(renameSquashedInsts); renameROBFullEvents - .name(name() + ".renameROBFullEvents") - .desc("Number of times rename has considered the ROB 'full'") + .name(name() + ".RENAME:ROBFullEvents") + .desc("Number of times rename has blocked due to ROB full") .prereq(renameROBFullEvents); renameIQFullEvents - .name(name() + ".renameIQFullEvents") - .desc("Number of times rename has considered the IQ 'full'") + .name(name() + ".RENAME:IQFullEvents") + .desc("Number of times rename has blocked due to IQ full") .prereq(renameIQFullEvents); + renameLSQFullEvents + .name(name() + ".RENAME:LSQFullEvents") + .desc("Number of times rename has blocked due to LSQ full") + .prereq(renameLSQFullEvents); renameFullRegistersEvents - .name(name() + ".renameFullRegisterEvents") + .name(name() + ".RENAME:FullRegisterEvents") .desc("Number of times there has been no free registers") .prereq(renameFullRegistersEvents); renameRenamedOperands - .name(name() + ".renameRenamedOperands") + .name(name() + ".RENAME:RenamedOperands") .desc("Number of destination operands rename has renamed") .prereq(renameRenamedOperands); renameRenameLookups - .name(name() + ".renameRenameLookups") + .name(name() + ".RENAME:RenameLookups") .desc("Number of register rename lookups that rename has made") .prereq(renameRenameLookups); - renameHBPlaceHolders - .name(name() + ".renameHBPlaceHolders") - .desc("Number of place holders added to the history buffer") - .prereq(renameHBPlaceHolders); renameCommittedMaps - .name(name() + ".renameCommittedMaps") + .name(name() + ".RENAME:CommittedMaps") .desc("Number of HB maps that are committed") .prereq(renameCommittedMaps); renameUndoneMaps - .name(name() + ".renameUndoneMaps") + .name(name() + ".RENAME:UndoneMaps") .desc("Number of HB maps that are undone due to squashing") .prereq(renameUndoneMaps); - renameValidUndoneMaps - .name(name() + ".renameValidUndoneMaps") - .desc("Number of HB maps that are undone, and are not place holders") - .prereq(renameValidUndoneMaps); + renamedSerializing + .name(name() + ".RENAME:serializingInsts") + .desc("count of serializing insts renamed") + .flags(Stats::total) + ; + renamedTempSerializing + .name(name() + ".RENAME:tempSerializingInsts") + .desc("count of temporary serializing insts renamed") + .flags(Stats::total) + ; + renameSkidInsts + .name(name() + ".RENAME:skidInsts") + .desc("count of insts added to the skid buffer") + .flags(Stats::total) + ; } template <class Impl> void -SimpleRename<Impl>::setCPU(FullCPU *cpu_ptr) +DefaultRename<Impl>::setCPU(FullCPU *cpu_ptr) { - DPRINTF(Rename, "Rename: Setting CPU pointer.\n"); + DPRINTF(Rename, "Setting CPU pointer.\n"); cpu = cpu_ptr; } template <class Impl> void -SimpleRename<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) +DefaultRename<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) { - DPRINTF(Rename, "Rename: Setting time buffer pointer.\n"); + DPRINTF(Rename, "Setting time buffer pointer.\n"); timeBuffer = tb_ptr; // Setup wire to read information from time buffer, from IEW stage. @@ -138,9 +187,9 @@ SimpleRename<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) template <class Impl> void -SimpleRename<Impl>::setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr) +DefaultRename<Impl>::setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr) { - DPRINTF(Rename, "Rename: Setting rename queue pointer.\n"); + DPRINTF(Rename, "Setting rename queue pointer.\n"); renameQueue = rq_ptr; // Setup wire to write information to future stages. @@ -149,9 +198,9 @@ SimpleRename<Impl>::setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr) template <class Impl> void -SimpleRename<Impl>::setDecodeQueue(TimeBuffer<DecodeStruct> *dq_ptr) +DefaultRename<Impl>::setDecodeQueue(TimeBuffer<DecodeStruct> *dq_ptr) { - DPRINTF(Rename, "Rename: Setting decode queue pointer.\n"); + DPRINTF(Rename, "Setting decode queue pointer.\n"); decodeQueue = dq_ptr; // Setup wire to get information from decode. @@ -160,214 +209,721 @@ SimpleRename<Impl>::setDecodeQueue(TimeBuffer<DecodeStruct> *dq_ptr) template <class Impl> void -SimpleRename<Impl>::setRenameMap(RenameMap *rm_ptr) +DefaultRename<Impl>::initStage() +{ + // Grab the number of free entries directly from the stages. + for (int tid=0; tid < numThreads; tid++) { + freeEntries[tid].iqEntries = iew_ptr->instQueue.numFreeEntries(tid); + freeEntries[tid].lsqEntries = iew_ptr->ldstQueue.numFreeEntries(tid); + freeEntries[tid].robEntries = commit_ptr->numROBFreeEntries(tid); + emptyROB[tid] = true; + } +} + +template<class Impl> +void +DefaultRename<Impl>::setActiveThreads(list<unsigned> *at_ptr) { - DPRINTF(Rename, "Rename: Setting rename map pointer.\n"); - renameMap = rm_ptr; + DPRINTF(Rename, "Setting active threads list pointer.\n"); + activeThreads = at_ptr; } + template <class Impl> void -SimpleRename<Impl>::setFreeList(FreeList *fl_ptr) +DefaultRename<Impl>::setRenameMap(RenameMap rm_ptr[]) { - DPRINTF(Rename, "Rename: Setting free list pointer.\n"); + DPRINTF(Rename, "Setting rename map pointers.\n"); + + for (int i=0; i<numThreads; i++) { + renameMap[i] = &rm_ptr[i]; + } +} + +template <class Impl> +void +DefaultRename<Impl>::setFreeList(FreeList *fl_ptr) +{ + DPRINTF(Rename, "Setting free list pointer.\n"); freeList = fl_ptr; } +template<class Impl> +void +DefaultRename<Impl>::setScoreboard(Scoreboard *_scoreboard) +{ + DPRINTF(Rename, "Setting scoreboard pointer.\n"); + scoreboard = _scoreboard; +} + template <class Impl> void -SimpleRename<Impl>::dumpHistory() +DefaultRename<Impl>::switchOut() { - typename list<RenameHistory>::iterator buf_it = historyBuffer.begin(); + // Rename is ready to switch out at any time. + cpu->signalSwitched(); +} + +template <class Impl> +void +DefaultRename<Impl>::doSwitchOut() +{ + // Clear any state, fix up the rename map. + for (int i = 0; i < numThreads; i++) { + typename list<RenameHistory>::iterator hb_it = historyBuffer[i].begin(); + + while (!historyBuffer[i].empty()) { + assert(hb_it != historyBuffer[i].end()); - while (buf_it != historyBuffer.end()) - { - cprintf("Seq num: %i\nArch reg: %i New phys reg: %i Old phys " - "reg: %i\n", (*buf_it).instSeqNum, (int)(*buf_it).archReg, - (int)(*buf_it).newPhysReg, (int)(*buf_it).prevPhysReg); + DPRINTF(Rename, "[tid:%u]: Removing history entry with sequence " + "number %i.\n", i, (*hb_it).instSeqNum); - buf_it++; + // Tell the rename map to set the architected register to the + // previous physical register that it was renamed to. + renameMap[i]->setEntry(hb_it->archReg, hb_it->prevPhysReg); + + // Put the renamed physical register back on the free list. + freeList->addReg(hb_it->newPhysReg); + + historyBuffer[i].erase(hb_it++); + } + insts[i].clear(); + skidBuffer[i].clear(); } } template <class Impl> void -SimpleRename<Impl>::block() +DefaultRename<Impl>::takeOverFrom() { - DPRINTF(Rename, "Rename: Blocking.\n"); - // Set status to Blocked. - _status = Blocked; + _status = Inactive; + initStage(); - // Add the current inputs onto the skid buffer, so they can be - // reprocessed when this stage unblocks. - skidBuffer.push(*fromDecode); + // Reset all state prior to taking over from the other CPU. + for (int i=0; i< numThreads; i++) { + renameStatus[i] = Idle; + + stalls[i].iew = false; + stalls[i].commit = false; + serializeInst[i] = NULL; + + instsInProgress[i] = 0; + + emptyROB[i] = true; - // Note that this stage only signals previous stages to stall when - // it is the cause of the stall originates at this stage. Otherwise - // the previous stages are expected to check all possible stall signals. + serializeOnNextInst[i] = false; + } } template <class Impl> -inline void -SimpleRename<Impl>::unblock() -{ - DPRINTF(Rename, "Rename: Read instructions out of skid buffer this " - "cycle.\n"); - // Remove the now processed instructions from the skid buffer. - skidBuffer.pop(); - - // If there's still information in the skid buffer, then - // continue to tell previous stages to stall. They will be - // able to restart once the skid buffer is empty. - if (!skidBuffer.empty()) { - toDecode->renameInfo.stall = true; - } else { - DPRINTF(Rename, "Rename: Done unblocking.\n"); - _status = Running; +void +DefaultRename<Impl>::squash(unsigned tid) +{ + DPRINTF(Rename, "[tid:%u]: Squashing instructions.\n",tid); + + // Clear the stall signal if rename was blocked or unblocking before. + // If it still needs to block, the blocking should happen the next + // cycle and there should be space to hold everything due to the squash. + if (renameStatus[tid] == Blocked || + renameStatus[tid] == Unblocking || + renameStatus[tid] == SerializeStall) { + + toDecode->renameUnblock[tid] = 1; + + serializeInst[tid] = NULL; } + + // Set the status to Squashing. + renameStatus[tid] = Squashing; + + // Squash any instructions from decode. + unsigned squashCount = 0; + + for (int i=0; i<fromDecode->size; i++) { + if (fromDecode->insts[i]->threadNumber == tid) { + fromDecode->insts[i]->squashed = true; + wroteToTimeBuffer = true; + squashCount++; + } + } + + insts[tid].clear(); + + // Clear the skid buffer in case it has any data in it. + skidBuffer[tid].clear(); + + doSquash(tid); } template <class Impl> void -SimpleRename<Impl>::doSquash() +DefaultRename<Impl>::tick() { - typename list<RenameHistory>::iterator hb_it = historyBuffer.begin(); + wroteToTimeBuffer = false; - InstSeqNum squashed_seq_num = fromCommit->commitInfo.doneSeqNum; + blockThisCycle = false; -#if FULL_SYSTEM - assert(!historyBuffer.empty()); -#else - // After a syscall squashes everything, the history buffer may be empty - // but the ROB may still be squashing instructions. - if (historyBuffer.empty()) { + bool status_change = false; + + toIEWIndex = 0; + + sortInsts(); + + list<unsigned>::iterator threads = (*activeThreads).begin(); + + // Check stall and squash signals. + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + DPRINTF(Rename, "Processing [tid:%i]\n", tid); + + status_change = checkSignalsAndUpdate(tid) || status_change; + + rename(status_change, tid); + } + + if (status_change) { + updateStatus(); + } + + if (wroteToTimeBuffer) { + DPRINTF(Activity, "Activity this cycle.\n"); + cpu->activityThisCycle(); + } + + threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + // If we committed this cycle then doneSeqNum will be > 0 + if (fromCommit->commitInfo[tid].doneSeqNum != 0 && + !fromCommit->commitInfo[tid].squash && + renameStatus[tid] != Squashing) { + + removeFromHistory(fromCommit->commitInfo[tid].doneSeqNum, + tid); + } + } + + // @todo: make into updateProgress function + for (int tid=0; tid < numThreads; tid++) { + instsInProgress[tid] -= fromIEW->iewInfo[tid].dispatched; + + assert(instsInProgress[tid] >=0); + } + +} + +template<class Impl> +void +DefaultRename<Impl>::rename(bool &status_change, unsigned tid) +{ + // If status is Running or idle, + // call renameInsts() + // If status is Unblocking, + // buffer any instructions coming from decode + // continue trying to empty skid buffer + // check if stall conditions have passed + + if (renameStatus[tid] == Blocked) { + ++renameBlockCycles; + } else if (renameStatus[tid] == Squashing) { + ++renameSquashCycles; + } else if (renameStatus[tid] == SerializeStall) { + ++renameSerializeStallCycles; + } + + if (renameStatus[tid] == Running || + renameStatus[tid] == Idle) { + DPRINTF(Rename, "[tid:%u]: Not blocked, so attempting to run " + "stage.\n", tid); + + renameInsts(tid); + } else if (renameStatus[tid] == Unblocking) { + renameInsts(tid); + + if (validInsts()) { + // Add the current inputs to the skid buffer so they can be + // reprocessed when this stage unblocks. + skidInsert(tid); + } + + // If we switched over to blocking, then there's a potential for + // an overall status change. + status_change = unblock(tid) || status_change || blockThisCycle; + } +} + +template <class Impl> +void +DefaultRename<Impl>::renameInsts(unsigned tid) +{ + // Instructions can be either in the skid buffer or the queue of + // instructions coming from decode, depending on the status. + int insts_available = renameStatus[tid] == Unblocking ? + skidBuffer[tid].size() : insts[tid].size(); + + // Check the decode queue to see if instructions are available. + // If there are no available instructions to rename, then do nothing. + if (insts_available == 0) { + DPRINTF(Rename, "[tid:%u]: Nothing to do, breaking out early.\n", + tid); + // Should I change status to idle? + ++renameIdleCycles; return; + } else if (renameStatus[tid] == Unblocking) { + ++renameUnblockCycles; + } else if (renameStatus[tid] == Running) { + ++renameRunCycles; } -#endif // FULL_SYSTEM - // Go through the most recent instructions, undoing the mappings - // they did and freeing up the registers. - while ((*hb_it).instSeqNum > squashed_seq_num) - { - assert(hb_it != historyBuffer.end()); + DynInstPtr inst; + + // Will have to do a different calculation for the number of free + // entries. + int free_rob_entries = calcFreeROBEntries(tid); + int free_iq_entries = calcFreeIQEntries(tid); + int free_lsq_entries = calcFreeLSQEntries(tid); + int min_free_entries = free_rob_entries; - DPRINTF(Rename, "Rename: Removing history entry with sequence " - "number %i.\n", (*hb_it).instSeqNum); + FullSource source = ROB; - // If it's not simply a place holder, then add the registers. - if (!(*hb_it).placeHolder) { - // Tell the rename map to set the architected register to the - // previous physical register that it was renamed to. - renameMap->setEntry(hb_it->archReg, hb_it->prevPhysReg); + if (free_iq_entries < min_free_entries) { + min_free_entries = free_iq_entries; + source = IQ; + } - // Put the renamed physical register back on the free list. - freeList->addReg(hb_it->newPhysReg); + if (free_lsq_entries < min_free_entries) { + min_free_entries = free_lsq_entries; + source = LSQ; + } + + // Check if there's any space left. + if (min_free_entries <= 0) { + DPRINTF(Rename, "[tid:%u]: Blocking due to no free ROB/IQ/LSQ " + "entries.\n" + "ROB has %i free entries.\n" + "IQ has %i free entries.\n" + "LSQ has %i free entries.\n", + tid, + free_rob_entries, + free_iq_entries, + free_lsq_entries); + + blockThisCycle = true; + + block(tid); - ++renameValidUndoneMaps; + incrFullStat(source); + + return; + } else if (min_free_entries < insts_available) { + DPRINTF(Rename, "[tid:%u]: Will have to block this cycle." + "%i insts available, but only %i insts can be " + "renamed due to ROB/IQ/LSQ limits.\n", + tid, insts_available, min_free_entries); + + insts_available = min_free_entries; + + blockThisCycle = true; + + incrFullStat(source); + } + + InstQueue &insts_to_rename = renameStatus[tid] == Unblocking ? + skidBuffer[tid] : insts[tid]; + + DPRINTF(Rename, "[tid:%u]: %i available instructions to " + "send iew.\n", tid, insts_available); + + DPRINTF(Rename, "[tid:%u]: %i insts pipelining from Rename | %i insts " + "dispatched to IQ last cycle.\n", + tid, instsInProgress[tid], fromIEW->iewInfo[tid].dispatched); + + // Handle serializing the next instruction if necessary. + if (serializeOnNextInst[tid]) { + if (emptyROB[tid] && instsInProgress[tid] == 0) { + // ROB already empty; no need to serialize. + serializeOnNextInst[tid] = false; + } else if (!insts_to_rename.empty()) { + insts_to_rename.front()->setSerializeBefore(); } + } - historyBuffer.erase(hb_it++); + int renamed_insts = 0; - ++renameUndoneMaps; + while (insts_available > 0 && toIEWIndex < renameWidth) { + DPRINTF(Rename, "[tid:%u]: Sending instructions to IEW.\n", tid); + + assert(!insts_to_rename.empty()); + + inst = insts_to_rename.front(); + + insts_to_rename.pop_front(); + + if (renameStatus[tid] == Unblocking) { + DPRINTF(Rename,"[tid:%u]: Removing [sn:%lli] PC:%#x from rename " + "skidBuffer\n", + tid, inst->seqNum, inst->readPC()); + } + + if (inst->isSquashed()) { + DPRINTF(Rename, "[tid:%u]: instruction %i with PC %#x is " + "squashed, skipping.\n", + tid, inst->seqNum, inst->threadNumber,inst->readPC()); + + ++renameSquashedInsts; + + // Decrement how many instructions are available. + --insts_available; + + continue; + } + + DPRINTF(Rename, "[tid:%u]: Processing instruction [sn:%lli] with " + "PC %#x.\n", + tid, inst->seqNum, inst->readPC()); + + // Handle serializeAfter/serializeBefore instructions. + // serializeAfter marks the next instruction as serializeBefore. + // serializeBefore makes the instruction wait in rename until the ROB + // is empty. + + // In this model, IPR accesses are serialize before + // instructions, and store conditionals are serialize after + // instructions. This is mainly due to lack of support for + // out-of-order operations of either of those classes of + // instructions. + if ((inst->isIprAccess() || inst->isSerializeBefore()) && + !inst->isSerializeHandled()) { + DPRINTF(Rename, "Serialize before instruction encountered.\n"); + + if (!inst->isTempSerializeBefore()) { + renamedSerializing++; + inst->setSerializeHandled(); + } else { + renamedTempSerializing++; + } + + // Change status over to SerializeStall so that other stages know + // what this is blocked on. + renameStatus[tid] = SerializeStall; + + serializeInst[tid] = inst; + + blockThisCycle = true; + + break; + } else if ((inst->isStoreConditional() || inst->isSerializeAfter()) && + !inst->isSerializeHandled()) { + DPRINTF(Rename, "Serialize after instruction encountered.\n"); + + renamedSerializing++; + + inst->setSerializeHandled(); + + serializeAfter(insts_to_rename, tid); + } + + // Check here to make sure there are enough destination registers + // to rename to. Otherwise block. + if (renameMap[tid]->numFreeEntries() < inst->numDestRegs()) { + DPRINTF(Rename, "Blocking due to lack of free " + "physical registers to rename to.\n"); + blockThisCycle = true; + + ++renameFullRegistersEvents; + + break; + } + + renameSrcRegs(inst, inst->threadNumber); + + renameDestRegs(inst, inst->threadNumber); + + ++renamed_insts; + + // Put instruction in rename queue. + toIEW->insts[toIEWIndex] = inst; + ++(toIEW->size); + + // Increment which instruction we're on. + ++toIEWIndex; + + // Decrement how many instructions are available. + --insts_available; + } + + instsInProgress[tid] += renamed_insts; + renameRenamedInsts += renamed_insts; + + // If we wrote to the time buffer, record this. + if (toIEWIndex) { + wroteToTimeBuffer = true; + } + + // Check if there's any instructions left that haven't yet been renamed. + // If so then block. + if (insts_available) { + blockThisCycle = true; + } + + if (blockThisCycle) { + block(tid); + toDecode->renameUnblock[tid] = false; } } +template<class Impl> +void +DefaultRename<Impl>::skidInsert(unsigned tid) +{ + DynInstPtr inst = NULL; + + while (!insts[tid].empty()) { + inst = insts[tid].front(); + + insts[tid].pop_front(); + + assert(tid == inst->threadNumber); + + DPRINTF(Rename, "[tid:%u]: Inserting [sn:%lli] PC:%#x into Rename " + "skidBuffer\n", tid, inst->seqNum, inst->readPC()); + + ++renameSkidInsts; + + skidBuffer[tid].push_back(inst); + } + + if (skidBuffer[tid].size() > skidBufferMax) + panic("Skidbuffer Exceeded Max Size"); +} + template <class Impl> void -SimpleRename<Impl>::squash() +DefaultRename<Impl>::sortInsts() { - DPRINTF(Rename, "Rename: Squashing instructions.\n"); - // Set the status to Squashing. - _status = Squashing; + int insts_from_decode = fromDecode->size; +#ifdef DEBUG + for (int i=0; i < numThreads; i++) + assert(insts[i].empty()); +#endif + for (int i = 0; i < insts_from_decode; ++i) { + DynInstPtr inst = fromDecode->insts[i]; + insts[inst->threadNumber].push_back(inst); + } +} - numInst = 0; +template<class Impl> +bool +DefaultRename<Impl>::skidsEmpty() +{ + list<unsigned>::iterator threads = (*activeThreads).begin(); - // Clear the skid buffer in case it has any data in it. - while (!skidBuffer.empty()) - { - skidBuffer.pop(); + while (threads != (*activeThreads).end()) { + if (!skidBuffer[*threads++].empty()) + return false; } - doSquash(); + return true; } template<class Impl> void -SimpleRename<Impl>::removeFromHistory(InstSeqNum inst_seq_num) +DefaultRename<Impl>::updateStatus() { - DPRINTF(Rename, "Rename: Removing a committed instruction from the " - "history buffer, until sequence number %lli.\n", inst_seq_num); - typename list<RenameHistory>::iterator hb_it = historyBuffer.end(); + bool any_unblocking = false; - --hb_it; + list<unsigned>::iterator threads = (*activeThreads).begin(); - if (hb_it->instSeqNum > inst_seq_num) { - DPRINTF(Rename, "Rename: Old sequence number encountered. Ensure " - "that a syscall happened recently.\n"); - return; + threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + if (renameStatus[tid] == Unblocking) { + any_unblocking = true; + break; + } } - while ((*hb_it).instSeqNum != inst_seq_num) - { - // Make sure we haven't gone off the end of the list. - assert(hb_it != historyBuffer.end()); - - // In theory instructions at the end of the history buffer - // should be older than the instruction being removed, which - // means they will have a lower sequence number. Also the - // instruction being removed from the history really should - // be the last instruction in the list, as it is the instruction - // that was just committed that is being removed. - assert(hb_it->instSeqNum < inst_seq_num); - DPRINTF(Rename, "Rename: Freeing up older rename of reg %i, sequence" - " number %i.\n", - (*hb_it).prevPhysReg, (*hb_it).instSeqNum); - - if (!(*hb_it).placeHolder) { - freeList->addReg((*hb_it).prevPhysReg); - ++renameCommittedMaps; + // Rename will have activity if it's unblocking. + if (any_unblocking) { + if (_status == Inactive) { + _status = Active; + + DPRINTF(Activity, "Activating stage.\n"); + + cpu->activateStage(FullCPU::RenameIdx); } + } else { + // If it's not unblocking, then rename will not have any internal + // activity. Switch it to inactive. + if (_status == Active) { + _status = Inactive; + DPRINTF(Activity, "Deactivating stage.\n"); - historyBuffer.erase(hb_it--); + cpu->deactivateStage(FullCPU::RenameIdx); + } } +} - // Finally free up the previous register of the finished instruction - // itself. - if (!(*hb_it).placeHolder) { - freeList->addReg(hb_it->prevPhysReg); - ++renameCommittedMaps; +template <class Impl> +bool +DefaultRename<Impl>::block(unsigned tid) +{ + DPRINTF(Rename, "[tid:%u]: Blocking.\n", tid); + + // Add the current inputs onto the skid buffer, so they can be + // reprocessed when this stage unblocks. + skidInsert(tid); + + // Only signal backwards to block if the previous stages do not think + // rename is already blocked. + if (renameStatus[tid] != Blocked) { + if (renameStatus[tid] != Unblocking) { + toDecode->renameBlock[tid] = true; + toDecode->renameUnblock[tid] = false; + wroteToTimeBuffer = true; + } + + // Rename can not go from SerializeStall to Blocked, otherwise + // it would not know to complete the serialize stall. + if (renameStatus[tid] != SerializeStall) { + // Set status to Blocked. + renameStatus[tid] = Blocked; + return true; + } + } + + return false; +} + +template <class Impl> +bool +DefaultRename<Impl>::unblock(unsigned tid) +{ + DPRINTF(Rename, "[tid:%u]: Trying to unblock.\n", tid); + + // Rename is done unblocking if the skid buffer is empty. + if (skidBuffer[tid].empty() && renameStatus[tid] != SerializeStall) { + + DPRINTF(Rename, "[tid:%u]: Done unblocking.\n", tid); + + toDecode->renameUnblock[tid] = true; + wroteToTimeBuffer = true; + + renameStatus[tid] = Running; + return true; } - historyBuffer.erase(hb_it); + return false; +} + +template <class Impl> +void +DefaultRename<Impl>::doSquash(unsigned tid) +{ + typename list<RenameHistory>::iterator hb_it = historyBuffer[tid].begin(); + + InstSeqNum squashed_seq_num = fromCommit->commitInfo[tid].doneSeqNum; + + // After a syscall squashes everything, the history buffer may be empty + // but the ROB may still be squashing instructions. + if (historyBuffer[tid].empty()) { + return; + } + + // Go through the most recent instructions, undoing the mappings + // they did and freeing up the registers. + while (!historyBuffer[tid].empty() && + (*hb_it).instSeqNum > squashed_seq_num) { + assert(hb_it != historyBuffer[tid].end()); + + DPRINTF(Rename, "[tid:%u]: Removing history entry with sequence " + "number %i.\n", tid, (*hb_it).instSeqNum); + + // Tell the rename map to set the architected register to the + // previous physical register that it was renamed to. + renameMap[tid]->setEntry(hb_it->archReg, hb_it->prevPhysReg); + + // Put the renamed physical register back on the free list. + freeList->addReg(hb_it->newPhysReg); + + historyBuffer[tid].erase(hb_it++); + + ++renameUndoneMaps; + } +} + +template<class Impl> +void +DefaultRename<Impl>::removeFromHistory(InstSeqNum inst_seq_num, unsigned tid) +{ + DPRINTF(Rename, "[tid:%u]: Removing a committed instruction from the " + "history buffer %u (size=%i), until [sn:%lli].\n", + tid, tid, historyBuffer[tid].size(), inst_seq_num); + + typename list<RenameHistory>::iterator hb_it = historyBuffer[tid].end(); + + --hb_it; + + if (historyBuffer[tid].empty()) { + DPRINTF(Rename, "[tid:%u]: History buffer is empty.\n", tid); + return; + } else if (hb_it->instSeqNum > inst_seq_num) { + DPRINTF(Rename, "[tid:%u]: Old sequence number encountered. Ensure " + "that a syscall happened recently.\n", tid); + return; + } + + // Commit all the renames up until (and including) the committed sequence + // number. Some or even all of the committed instructions may not have + // rename histories if they did not have destination registers that were + // renamed. + while (!historyBuffer[tid].empty() && + hb_it != historyBuffer[tid].end() && + (*hb_it).instSeqNum <= inst_seq_num) { + + DPRINTF(Rename, "[tid:%u]: Freeing up older rename of reg %i, " + "[sn:%lli].\n", + tid, (*hb_it).prevPhysReg, (*hb_it).instSeqNum); + + freeList->addReg((*hb_it).prevPhysReg); + ++renameCommittedMaps; + + historyBuffer[tid].erase(hb_it--); + } } template <class Impl> inline void -SimpleRename<Impl>::renameSrcRegs(DynInstPtr &inst) +DefaultRename<Impl>::renameSrcRegs(DynInstPtr &inst,unsigned tid) { + assert(renameMap[tid] != 0); + unsigned num_src_regs = inst->numSrcRegs(); // Get the architectual register numbers from the source and // destination operands, and redirect them to the right register. // Will need to mark dependencies though. - for (int src_idx = 0; src_idx < num_src_regs; src_idx++) - { + for (int src_idx = 0; src_idx < num_src_regs; src_idx++) { RegIndex src_reg = inst->srcRegIdx(src_idx); // Look up the source registers to get the phys. register they've // been renamed to, and set the sources to those registers. - PhysRegIndex renamed_reg = renameMap->lookup(src_reg); + PhysRegIndex renamed_reg = renameMap[tid]->lookup(src_reg); - DPRINTF(Rename, "Rename: Looking up arch reg %i, got " - "physical reg %i.\n", (int)src_reg, (int)renamed_reg); + DPRINTF(Rename, "[tid:%u]: Looking up arch reg %i, got " + "physical reg %i.\n", tid, (int)src_reg, + (int)renamed_reg); inst->renameSrcReg(src_idx, renamed_reg); - // Either incorporate it into the info passed back, - // or make another function call to see if that register is - // ready or not. - if (renameMap->isReady(renamed_reg)) { - DPRINTF(Rename, "Rename: Register is ready.\n"); + // See if the register is ready or not. + if (scoreboard->getReg(renamed_reg) == true) { + DPRINTF(Rename, "[tid:%u]: Register is ready.\n", tid); inst->markSrcRegReady(src_idx); } @@ -378,379 +934,341 @@ SimpleRename<Impl>::renameSrcRegs(DynInstPtr &inst) template <class Impl> inline void -SimpleRename<Impl>::renameDestRegs(DynInstPtr &inst) +DefaultRename<Impl>::renameDestRegs(DynInstPtr &inst,unsigned tid) { - typename SimpleRenameMap::RenameInfo rename_result; + typename RenameMap::RenameInfo rename_result; unsigned num_dest_regs = inst->numDestRegs(); - // If it's an instruction with no destination registers, then put - // a placeholder within the history buffer. It might be better - // to not put it in the history buffer at all (other than branches, - // which always need at least a place holder), and differentiate - // between instructions with and without destination registers - // when getting from commit the instructions that committed. - if (num_dest_regs == 0) { - RenameHistory hb_entry(inst->seqNum); + // Rename the destination registers. + for (int dest_idx = 0; dest_idx < num_dest_regs; dest_idx++) { + RegIndex dest_reg = inst->destRegIdx(dest_idx); - historyBuffer.push_front(hb_entry); + // Get the physical register that the destination will be + // renamed to. + rename_result = renameMap[tid]->rename(dest_reg); - DPRINTF(Rename, "Rename: Adding placeholder instruction to " - "history buffer, sequence number %lli.\n", - inst->seqNum); + //Mark Scoreboard entry as not ready + scoreboard->unsetReg(rename_result.first); - ++renameHBPlaceHolders; - } else { + DPRINTF(Rename, "[tid:%u]: Renaming arch reg %i to physical " + "reg %i.\n", tid, (int)dest_reg, + (int)rename_result.first); - // Rename the destination registers. - for (int dest_idx = 0; dest_idx < num_dest_regs; dest_idx++) - { - RegIndex dest_reg = inst->destRegIdx(dest_idx); + // Record the rename information so that a history can be kept. + RenameHistory hb_entry(inst->seqNum, dest_reg, + rename_result.first, + rename_result.second); - // Get the physical register that the destination will be - // renamed to. - rename_result = renameMap->rename(dest_reg); + historyBuffer[tid].push_front(hb_entry); - DPRINTF(Rename, "Rename: Renaming arch reg %i to physical " - "reg %i.\n", (int)dest_reg, - (int)rename_result.first); + DPRINTF(Rename, "[tid:%u]: Adding instruction to history buffer, " + "[sn:%lli].\n",tid, + (*historyBuffer[tid].begin()).instSeqNum); - // Record the rename information so that a history can be kept. - RenameHistory hb_entry(inst->seqNum, dest_reg, - rename_result.first, - rename_result.second); + // Tell the instruction to rename the appropriate destination + // register (dest_idx) to the new physical register + // (rename_result.first), and record the previous physical + // register that the same logical register was renamed to + // (rename_result.second). + inst->renameDestReg(dest_idx, + rename_result.first, + rename_result.second); - historyBuffer.push_front(hb_entry); + ++renameRenamedOperands; + } +} - DPRINTF(Rename, "Rename: Adding instruction to history buffer, " - "sequence number %lli.\n", - (*historyBuffer.begin()).instSeqNum); +template <class Impl> +inline int +DefaultRename<Impl>::calcFreeROBEntries(unsigned tid) +{ + int num_free = freeEntries[tid].robEntries - + (instsInProgress[tid] - fromIEW->iewInfo[tid].dispatched); - // Tell the instruction to rename the appropriate destination - // register (dest_idx) to the new physical register - // (rename_result.first), and record the previous physical - // register that the same logical register was renamed to - // (rename_result.second). - inst->renameDestReg(dest_idx, - rename_result.first, - rename_result.second); + //DPRINTF(Rename,"[tid:%i]: %i rob free\n",tid,num_free); - ++renameRenamedOperands; - } - } + return num_free; } template <class Impl> inline int -SimpleRename<Impl>::calcFreeROBEntries() +DefaultRename<Impl>::calcFreeIQEntries(unsigned tid) { - return fromCommit->commitInfo.freeROBEntries - - renameWidth * iewToRenameDelay; + int num_free = freeEntries[tid].iqEntries - + (instsInProgress[tid] - fromIEW->iewInfo[tid].dispatched); + + //DPRINTF(Rename,"[tid:%i]: %i iq free\n",tid,num_free); + + return num_free; } template <class Impl> inline int -SimpleRename<Impl>::calcFreeIQEntries() +DefaultRename<Impl>::calcFreeLSQEntries(unsigned tid) { - return fromIEW->iewInfo.freeIQEntries - renameWidth * iewToRenameDelay; -} + int num_free = freeEntries[tid].lsqEntries - + (instsInProgress[tid] - fromIEW->iewInfo[tid].dispatchedToLSQ); -template<class Impl> -void -SimpleRename<Impl>::tick() -{ - // Rename will need to try to rename as many instructions as it - // has bandwidth, unless it is blocked. - - // Check if _status is BarrierStall. If so, then check if the number - // of free ROB entries is equal to the number of total ROB entries. - // Once equal then wake this stage up. Set status to unblocking maybe. - - if (_status != Blocked && _status != Squashing) { - DPRINTF(Rename, "Rename: Status is not blocked, will attempt to " - "run stage.\n"); - // Make sure that the skid buffer has something in it if the - // status is unblocking. - assert(_status == Unblocking ? !skidBuffer.empty() : 1); - - rename(); - - // If the status was unblocking, then instructions from the skid - // buffer were used. Remove those instructions and handle - // the rest of unblocking. - if (_status == Unblocking) { - ++renameUnblockCycles; - - if (fromDecode->size > 0) { - // Add the current inputs onto the skid buffer, so they can be - // reprocessed when this stage unblocks. - skidBuffer.push(*fromDecode); - } + //DPRINTF(Rename,"[tid:%i]: %i lsq free\n",tid,num_free); - unblock(); - } - } else if (_status == Blocked) { - ++renameBlockCycles; + return num_free; +} - // If stage is blocked and still receiving valid instructions, - // make sure to store them in the skid buffer. - if (fromDecode->size > 0) { +template <class Impl> +unsigned +DefaultRename<Impl>::validInsts() +{ + unsigned inst_count = 0; - block(); + for (int i=0; i<fromDecode->size; i++) { + if (!fromDecode->insts[i]->squashed) + inst_count++; + } - // Continue to tell previous stage to stall. - toDecode->renameInfo.stall = true; - } + return inst_count; +} - if (!fromIEW->iewInfo.stall && - !fromCommit->commitInfo.stall && - calcFreeROBEntries() > 0 && - calcFreeIQEntries() > 0 && - renameMap->numFreeEntries() > 0) { - - // Need to be sure to check all blocking conditions above. - // If they have cleared, then start unblocking. - DPRINTF(Rename, "Rename: Stall signals cleared, going to " - "unblock.\n"); - _status = Unblocking; - - // Continue to tell previous stage to block until this stage - // is done unblocking. - toDecode->renameInfo.stall = true; - } else { - // Otherwise no conditions have changed. Tell previous - // stage to continue blocking. - toDecode->renameInfo.stall = true; - } +template <class Impl> +void +DefaultRename<Impl>::readStallSignals(unsigned tid) +{ + if (fromIEW->iewBlock[tid]) { + stalls[tid].iew = true; + } - if (fromCommit->commitInfo.squash || - fromCommit->commitInfo.robSquashing) { - squash(); - return; - } - } else if (_status == Squashing) { - ++renameSquashCycles; + if (fromIEW->iewUnblock[tid]) { + assert(stalls[tid].iew); + stalls[tid].iew = false; + } - if (fromCommit->commitInfo.squash) { - squash(); - } else if (!fromCommit->commitInfo.squash && - !fromCommit->commitInfo.robSquashing) { + if (fromCommit->commitBlock[tid]) { + stalls[tid].commit = true; + } - DPRINTF(Rename, "Rename: Done squashing, going to running.\n"); - _status = Running; - rename(); - } else { - doSquash(); - } + if (fromCommit->commitUnblock[tid]) { + assert(stalls[tid].commit); + stalls[tid].commit = false; } +} - // Ugly code, revamp all of the tick() functions eventually. - if (fromCommit->commitInfo.doneSeqNum != 0 && _status != Squashing) { -#if !FULL_SYSTEM - if (!fromCommit->commitInfo.squash) { - removeFromHistory(fromCommit->commitInfo.doneSeqNum); - } -#else - removeFromHistory(fromCommit->commitInfo.doneSeqNum); -#endif +template <class Impl> +bool +DefaultRename<Impl>::checkStall(unsigned tid) +{ + bool ret_val = false; + + if (stalls[tid].iew) { + DPRINTF(Rename,"[tid:%i]: Stall from IEW stage detected.\n", tid); + ret_val = true; + } else if (stalls[tid].commit) { + DPRINTF(Rename,"[tid:%i]: Stall from Commit stage detected.\n", tid); + ret_val = true; + } else if (calcFreeROBEntries(tid) <= 0) { + DPRINTF(Rename,"[tid:%i]: Stall: ROB has 0 free entries.\n", tid); + ret_val = true; + } else if (calcFreeIQEntries(tid) <= 0) { + DPRINTF(Rename,"[tid:%i]: Stall: IQ has 0 free entries.\n", tid); + ret_val = true; + } else if (calcFreeLSQEntries(tid) <= 0) { + DPRINTF(Rename,"[tid:%i]: Stall: LSQ has 0 free entries.\n", tid); + ret_val = true; + } else if (renameMap[tid]->numFreeEntries() <= 0) { + DPRINTF(Rename,"[tid:%i]: Stall: RenameMap has 0 free entries.\n", tid); + ret_val = true; + } else if (renameStatus[tid] == SerializeStall && + (!emptyROB[tid] || instsInProgress[tid])) { + DPRINTF(Rename,"[tid:%i]: Stall: Serialize stall and ROB is not " + "empty.\n", + tid); + ret_val = true; } + return ret_val; } -template<class Impl> +template <class Impl> void -SimpleRename<Impl>::rename() -{ - // Check if any of the stages ahead of rename are telling rename - // to squash. The squash() function will also take care of fixing up - // the rename map and the free list. - if (fromCommit->commitInfo.squash || - fromCommit->commitInfo.robSquashing) { - DPRINTF(Rename, "Rename: Receiving signal from Commit to squash.\n"); - squash(); - return; +DefaultRename<Impl>::readFreeEntries(unsigned tid) +{ + bool updated = false; + if (fromIEW->iewInfo[tid].usedIQ) { + freeEntries[tid].iqEntries = + fromIEW->iewInfo[tid].freeIQEntries; + updated = true; } - // Check if time buffer is telling this stage to stall. - if (fromIEW->iewInfo.stall || - fromCommit->commitInfo.stall) { - DPRINTF(Rename, "Rename: Receiving signal from IEW/Commit to " - "stall.\n"); - block(); - return; + if (fromIEW->iewInfo[tid].usedLSQ) { + freeEntries[tid].lsqEntries = + fromIEW->iewInfo[tid].freeLSQEntries; + updated = true; } - // Check if the current status is squashing. If so, set its status - // to running and resume execution the next cycle. - if (_status == Squashing) { - DPRINTF(Rename, "Rename: Done squashing.\n"); - _status = Running; - return; + if (fromCommit->commitInfo[tid].usedROB) { + freeEntries[tid].robEntries = + fromCommit->commitInfo[tid].freeROBEntries; + emptyROB[tid] = fromCommit->commitInfo[tid].emptyROB; + updated = true; } - // Check the decode queue to see if instructions are available. - // If there are no available instructions to rename, then do nothing. - // Or, if the stage is currently unblocking, then go ahead and run it. - if (fromDecode->size == 0 && _status != Unblocking) { - DPRINTF(Rename, "Rename: Nothing to do, breaking out early.\n"); - // Should I change status to idle? - return; - } - - //////////////////////////////////// - // Actual rename part. - //////////////////////////////////// - - DynInstPtr inst; + DPRINTF(Rename, "[tid:%i]: Free IQ: %i, Free ROB: %i, Free LSQ: %i\n", + tid, + freeEntries[tid].iqEntries, + freeEntries[tid].robEntries, + freeEntries[tid].lsqEntries); - // If we're unblocking, then we may be in the middle of an instruction - // group. Subtract off numInst to get the proper number of instructions - // left. - int insts_available = _status == Unblocking ? - skidBuffer.front().size - numInst : - fromDecode->size; + DPRINTF(Rename, "[tid:%i]: %i instructions not yet in ROB\n", + tid, instsInProgress[tid]); +} - bool block_this_cycle = false; +template <class Impl> +bool +DefaultRename<Impl>::checkSignalsAndUpdate(unsigned tid) +{ + // Check if there's a squash signal, squash if there is + // Check stall signals, block if necessary. + // If status was blocked + // check if stall conditions have passed + // if so then go to unblocking + // If status was Squashing + // check if squashing is not high. Switch to running this cycle. + // If status was serialize stall + // check if ROB is empty and no insts are in flight to the ROB + + readFreeEntries(tid); + readStallSignals(tid); + + if (fromCommit->commitInfo[tid].squash) { + DPRINTF(Rename, "[tid:%u]: Squashing instructions due to squash from " + "commit.\n", tid); + + squash(tid); + + return true; + } - // Will have to do a different calculation for the number of free - // entries. Number of free entries recorded on this cycle - - // renameWidth * renameToDecodeDelay - int free_rob_entries = calcFreeROBEntries(); - int free_iq_entries = calcFreeIQEntries(); - int min_iq_rob = min(free_rob_entries, free_iq_entries); + if (fromCommit->commitInfo[tid].robSquashing) { + DPRINTF(Rename, "[tid:%u]: ROB is still squashing.\n", tid); - unsigned to_iew_index = 0; + renameStatus[tid] = Squashing; - // Check if there's any space left. - if (min_iq_rob <= 0) { - DPRINTF(Rename, "Rename: Blocking due to no free ROB or IQ " - "entries.\n" - "Rename: ROB has %d free entries.\n" - "Rename: IQ has %d free entries.\n", - free_rob_entries, - free_iq_entries); - block(); - // Tell previous stage to stall. - toDecode->renameInfo.stall = true; + return true; + } - if (free_rob_entries <= 0) { - ++renameROBFullEvents; - } else { - ++renameIQFullEvents; - } + if (checkStall(tid)) { + return block(tid); + } - return; - } else if (min_iq_rob < insts_available) { - DPRINTF(Rename, "Rename: Will have to block this cycle. Only " - "%i insts can be renamed due to IQ/ROB limits.\n", - min_iq_rob); + if (renameStatus[tid] == Blocked) { + DPRINTF(Rename, "[tid:%u]: Done blocking, switching to unblocking.\n", + tid); - insts_available = min_iq_rob; + renameStatus[tid] = Unblocking; - block_this_cycle = true; + unblock(tid); - if (free_rob_entries < free_iq_entries) { - ++renameROBFullEvents; - } else { - ++renameIQFullEvents; - } + return true; } - while (insts_available > 0) { - DPRINTF(Rename, "Rename: Sending instructions to iew.\n"); + if (renameStatus[tid] == Squashing) { + // Switch status to running if rename isn't being told to block or + // squash this cycle. + DPRINTF(Rename, "[tid:%u]: Done squashing, switching to running.\n", + tid); - // Get the next instruction either from the skid buffer or the - // decode queue. - inst = _status == Unblocking ? skidBuffer.front().insts[numInst] : - fromDecode->insts[numInst]; + renameStatus[tid] = Running; - if (inst->isSquashed()) { - DPRINTF(Rename, "Rename: instruction %i with PC %#x is " - "squashed, skipping.\n", - inst->seqNum, inst->readPC()); + return false; + } - // Go to the next instruction. - ++numInst; + if (renameStatus[tid] == SerializeStall) { + // Stall ends once the ROB is free. + DPRINTF(Rename, "[tid:%u]: Done with serialize stall, switching to " + "unblocking.\n", tid); - ++renameSquashedInsts; + DynInstPtr serial_inst = serializeInst[tid]; - // Decrement how many instructions are available. - --insts_available; + renameStatus[tid] = Unblocking; - continue; - } + unblock(tid); - DPRINTF(Rename, "Rename: Processing instruction %i with PC %#x.\n", - inst->seqNum, inst->readPC()); - - // If it's a trap instruction, then it needs to wait here within - // rename until the ROB is empty. Needs a way to detect that the - // ROB is empty. Maybe an event? - // Would be nice if it could be avoided putting this into a - // specific stage and instead just put it into the AlphaFullCPU. - // Might not really be feasible though... - // (EXCB, TRAPB) - if (inst->isSerializing()) { - panic("Rename: Serializing instruction encountered.\n"); - DPRINTF(Rename, "Rename: Serializing instruction " - "encountered.\n"); - - // Change status over to BarrierStall so that other stages know - // what this is blocked on. - _status = BarrierStall; + DPRINTF(Rename, "[tid:%u]: Processing instruction [%lli] with " + "PC %#x.\n", + tid, serial_inst->seqNum, serial_inst->readPC()); - block_this_cycle = true; + // Put instruction into queue here. + serial_inst->clearSerializeBefore(); - break; + if (!skidBuffer[tid].empty()) { + skidBuffer[tid].push_front(serial_inst); + } else { + insts[tid].push_front(serial_inst); } - // Check here to make sure there are enough destination registers - // to rename to. Otherwise block. - if (renameMap->numFreeEntries() < inst->numDestRegs()) - { - DPRINTF(Rename, "Rename: Blocking due to lack of free " - "physical registers to rename to.\n"); - // Need some sort of event based on a register being freed. - - block_this_cycle = true; + DPRINTF(Rename, "[tid:%u]: Instruction must be processed by rename." + " Adding to front of list.", tid); - ++renameFullRegistersEvents; + serializeInst[tid] = NULL; - break; - } + return true; + } - renameSrcRegs(inst); + // If we've reached this point, we have not gotten any signals that + // cause rename to change its status. Rename remains the same as before. + return false; +} - renameDestRegs(inst); +template<class Impl> +void +DefaultRename<Impl>::serializeAfter(InstQueue &inst_list, + unsigned tid) +{ + if (inst_list.empty()) { + // Mark a bit to say that I must serialize on the next instruction. + serializeOnNextInst[tid] = true; + return; + } - // Put instruction in rename queue. - toIEW->insts[to_iew_index] = inst; - ++(toIEW->size); + // Set the next instruction as serializing. + inst_list.front()->setSerializeBefore(); +} - // Decrease the number of free ROB and IQ entries. - --free_rob_entries; - --free_iq_entries; +template <class Impl> +inline void +DefaultRename<Impl>::incrFullStat(const FullSource &source) +{ + switch (source) { + case ROB: + ++renameROBFullEvents; + break; + case IQ: + ++renameIQFullEvents; + break; + case LSQ: + ++renameLSQFullEvents; + break; + default: + panic("Rename full stall stat should be incremented for a reason!"); + break; + } +} - // Increment which instruction we're on. - ++to_iew_index; - ++numInst; +template <class Impl> +void +DefaultRename<Impl>::dumpHistory() +{ + typename list<RenameHistory>::iterator buf_it; - ++renameRenamedInsts; + for (int i = 0; i < numThreads; i++) { - // Decrement how many instructions are available. - --insts_available; - } + buf_it = historyBuffer[i].begin(); - // Check if there's any instructions left that haven't yet been renamed. - // If so then block. - if (block_this_cycle) { - block(); + while (buf_it != historyBuffer[i].end()) { + cprintf("Seq num: %i\nArch reg: %i New phys reg: %i Old phys " + "reg: %i\n", (*buf_it).instSeqNum, (int)(*buf_it).archReg, + (int)(*buf_it).newPhysReg, (int)(*buf_it).prevPhysReg); - toDecode->renameInfo.stall = true; - } else { - // If we had a successful rename and didn't have to exit early, then - // reset numInst so it will refer to the correct instruction on next - // run. - numInst = 0; + buf_it++; + } } } diff --git a/src/cpu/o3/rename_map.cc b/src/cpu/o3/rename_map.cc index 2a6db9012..befbc3e8a 100644 --- a/src/cpu/o3/rename_map.cc +++ b/src/cpu/o3/rename_map.cc @@ -34,118 +34,105 @@ using namespace std; -// Todo: Consider making functions inline. Avoid having things that are -// using the zero register or misc registers from adding on the registers -// to the free list. Possibly remove the direct communication between -// this and the freelist. Considering making inline bool functions that -// determine if the register is a logical int, logical fp, physical int, -// physical fp, etc. - -SimpleRenameMap::SimpleRenameMap(unsigned _numLogicalIntRegs, - unsigned _numPhysicalIntRegs, - unsigned _numLogicalFloatRegs, - unsigned _numPhysicalFloatRegs, - unsigned _numMiscRegs, - RegIndex _intZeroReg, - RegIndex _floatZeroReg) - : numLogicalIntRegs(_numLogicalIntRegs), - numPhysicalIntRegs(_numPhysicalIntRegs), - numLogicalFloatRegs(_numLogicalFloatRegs), - numPhysicalFloatRegs(_numPhysicalFloatRegs), - numMiscRegs(_numMiscRegs), - intZeroReg(_intZeroReg), - floatZeroReg(_floatZeroReg) +// @todo: Consider making inline bool functions that determine if the +// register is a logical int, logical fp, physical int, physical fp, +// etc. + +SimpleRenameMap::~SimpleRenameMap() +{ +} + +void +SimpleRenameMap::init(unsigned _numLogicalIntRegs, + unsigned _numPhysicalIntRegs, + PhysRegIndex &ireg_idx, + + unsigned _numLogicalFloatRegs, + unsigned _numPhysicalFloatRegs, + PhysRegIndex &freg_idx, + + unsigned _numMiscRegs, + + RegIndex _intZeroReg, + RegIndex _floatZeroReg, + + int map_id, + bool bindRegs) { - DPRINTF(Rename, "Rename: Creating rename map. Phys: %i / %i, Float: " - "%i / %i.\n", numLogicalIntRegs, numPhysicalIntRegs, + id = map_id; + + numLogicalIntRegs = _numLogicalIntRegs; + + numLogicalFloatRegs = _numLogicalFloatRegs; + + numPhysicalIntRegs = _numPhysicalIntRegs; + + numPhysicalFloatRegs = _numPhysicalFloatRegs; + + numMiscRegs = _numMiscRegs; + + intZeroReg = _intZeroReg; + floatZeroReg = _floatZeroReg; + + DPRINTF(Rename, "Creating rename map %i. Phys: %i / %i, Float: " + "%i / %i.\n", id, numLogicalIntRegs, numPhysicalIntRegs, numLogicalFloatRegs, numPhysicalFloatRegs); numLogicalRegs = numLogicalIntRegs + numLogicalFloatRegs; numPhysicalRegs = numPhysicalIntRegs + numPhysicalFloatRegs; - //Create the rename maps, and their scoreboards. - intRenameMap = new RenameEntry[numLogicalIntRegs]; - floatRenameMap = new RenameEntry[numLogicalRegs]; - - // Should combine this into one scoreboard. - intScoreboard.resize(numPhysicalIntRegs); - floatScoreboard.resize(numPhysicalRegs); - miscScoreboard.resize(numPhysicalRegs + numMiscRegs); - - // Initialize the entries in the integer rename map to point to the - // physical registers of the same index, and consider each register - // ready until the first rename occurs. - for (RegIndex index = 0; index < numLogicalIntRegs; ++index) - { - intRenameMap[index].physical_reg = index; - intScoreboard[index] = 1; - } + //Create the rename maps + intRenameMap.resize(numLogicalIntRegs); + floatRenameMap.resize(numLogicalRegs); - // Initialize the rest of the physical registers (the ones that don't - // directly map to a logical register) as unready. - for (PhysRegIndex index = numLogicalIntRegs; - index < numPhysicalIntRegs; - ++index) - { - intScoreboard[index] = 0; - } + if (bindRegs) { + DPRINTF(Rename, "Binding registers into rename map %i",id); - int float_reg_idx = numPhysicalIntRegs; - - // Initialize the entries in the floating point rename map to point to - // the physical registers of the same index, and consider each register - // ready until the first rename occurs. - // Although the index refers purely to architected registers, because - // the floating reg indices come after the integer reg indices, they - // may exceed the size of a normal RegIndex (short). - for (PhysRegIndex index = numLogicalIntRegs; - index < numLogicalRegs; ++index) - { - floatRenameMap[index].physical_reg = float_reg_idx++; - } + // Initialize the entries in the integer rename map to point to the + // physical registers of the same index + for (RegIndex index = 0; index < numLogicalIntRegs; ++index) + { + intRenameMap[index].physical_reg = ireg_idx++; + } - for (PhysRegIndex index = numPhysicalIntRegs; - index < numPhysicalIntRegs + numLogicalFloatRegs; ++index) - { - floatScoreboard[index] = 1; - } + // Initialize the entries in the floating point rename map to point to + // the physical registers of the same index + // Although the index refers purely to architected registers, because + // the floating reg indices come after the integer reg indices, they + // may exceed the size of a normal RegIndex (short). + for (PhysRegIndex index = numLogicalIntRegs; + index < numLogicalRegs; ++index) + { + floatRenameMap[index].physical_reg = freg_idx++; + } + } else { + DPRINTF(Rename, "Binding registers into rename map %i",id); - // Initialize the rest of the physical registers (the ones that don't - // directly map to a logical register) as unready. - for (PhysRegIndex index = numPhysicalIntRegs + numLogicalFloatRegs; - index < numPhysicalRegs; - ++index) - { - floatScoreboard[index] = 0; - } + PhysRegIndex temp_ireg = ireg_idx; - // Initialize the entries in the misc register scoreboard to be ready. - for (PhysRegIndex index = numPhysicalRegs; - index < numPhysicalRegs + numMiscRegs; ++index) - { - miscScoreboard[index] = 1; - } -} + for (RegIndex index = 0; index < numLogicalIntRegs; ++index) + { + intRenameMap[index].physical_reg = temp_ireg++; + } -SimpleRenameMap::~SimpleRenameMap() -{ - // Delete the rename maps as they were allocated with new. - delete [] intRenameMap; - delete [] floatRenameMap; + PhysRegIndex temp_freg = freg_idx; + + for (PhysRegIndex index = numLogicalIntRegs; + index < numLogicalRegs; ++index) + { + floatRenameMap[index].physical_reg = temp_freg++; + } + } } void SimpleRenameMap::setFreeList(SimpleFreeList *fl_ptr) { - //Setup the interface to the freelist. freeList = fl_ptr; } -// Don't allow this stage to fault; force that check to the rename stage. -// Simply ask to rename a logical register and get back a new physical -// register index. SimpleRenameMap::RenameInfo SimpleRenameMap::rename(RegIndex arch_reg) { @@ -158,45 +145,33 @@ SimpleRenameMap::rename(RegIndex arch_reg) // requested architected register. prev_reg = intRenameMap[arch_reg].physical_reg; - // If it's not referencing the zero register, then mark the register - // as not ready. + // If it's not referencing the zero register, then rename the + // register. if (arch_reg != intZeroReg) { - // Get a free physical register to rename to. renamed_reg = freeList->getIntReg(); - // Update the integer rename map. intRenameMap[arch_reg].physical_reg = renamed_reg; assert(renamed_reg >= 0 && renamed_reg < numPhysicalIntRegs); - // Mark register as not ready. - intScoreboard[renamed_reg] = false; } else { // Otherwise return the zero register so nothing bad happens. renamed_reg = intZeroReg; } } else if (arch_reg < numLogicalRegs) { - // Subtract off the base offset for floating point registers. -// arch_reg = arch_reg - numLogicalIntRegs; - // Record the current physical register that is renamed to the // requested architected register. prev_reg = floatRenameMap[arch_reg].physical_reg; - // If it's not referencing the zero register, then mark the register - // as not ready. + // If it's not referencing the zero register, then rename the + // register. if (arch_reg != floatZeroReg) { - // Get a free floating point register to rename to. renamed_reg = freeList->getFloatReg(); - // Update the floating point rename map. floatRenameMap[arch_reg].physical_reg = renamed_reg; assert(renamed_reg < numPhysicalRegs && renamed_reg >= numPhysicalIntRegs); - - // Mark register as not ready. - floatScoreboard[renamed_reg] = false; } else { // Otherwise return the zero register so nothing bad happens. renamed_reg = floatZeroReg; @@ -205,10 +180,10 @@ SimpleRenameMap::rename(RegIndex arch_reg) // Subtract off the base offset for miscellaneous registers. arch_reg = arch_reg - numLogicalRegs; - // No renaming happens to the misc. registers. They are simply the - // registers that come after all the physical registers; thus - // take the base architected register and add the physical registers - // to it. + // No renaming happens to the misc. registers. They are + // simply the registers that come after all the physical + // registers; thus take the base architected register and add + // the physical registers to it. renamed_reg = arch_reg + numPhysicalRegs; // Set the previous register to the same register; mainly it must be @@ -217,24 +192,17 @@ SimpleRenameMap::rename(RegIndex arch_reg) prev_reg = renamed_reg; assert(renamed_reg < numPhysicalRegs + numMiscRegs); - - miscScoreboard[renamed_reg] = false; } return RenameInfo(renamed_reg, prev_reg); } -//Perhaps give this a pair as a return value, of the physical register -//and whether or not it's ready. PhysRegIndex SimpleRenameMap::lookup(RegIndex arch_reg) { if (arch_reg < numLogicalIntRegs) { return intRenameMap[arch_reg].physical_reg; } else if (arch_reg < numLogicalRegs) { - // Subtract off the base FP offset. -// arch_reg = arch_reg - numLogicalIntRegs; - return floatRenameMap[arch_reg].physical_reg; } else { // Subtract off the misc registers offset. @@ -246,38 +214,18 @@ SimpleRenameMap::lookup(RegIndex arch_reg) } } -bool -SimpleRenameMap::isReady(PhysRegIndex phys_reg) -{ - if (phys_reg < numPhysicalIntRegs) { - return intScoreboard[phys_reg]; - } else if (phys_reg < numPhysicalRegs) { - - // Subtract off the base FP offset. -// phys_reg = phys_reg - numPhysicalIntRegs; - - return floatScoreboard[phys_reg]; - } else { - // Subtract off the misc registers offset. -// phys_reg = phys_reg - numPhysicalRegs; - - return miscScoreboard[phys_reg]; - } -} - -// In this implementation the miscellaneous registers do not actually rename, -// so this function does not allow you to try to change their mappings. void SimpleRenameMap::setEntry(RegIndex arch_reg, PhysRegIndex renamed_reg) { + // In this implementation the miscellaneous registers do not + // actually rename, so this function does not allow you to try to + // change their mappings. if (arch_reg < numLogicalIntRegs) { DPRINTF(Rename, "Rename Map: Integer register %i being set to %i.\n", (int)arch_reg, renamed_reg); intRenameMap[arch_reg].physical_reg = renamed_reg; - } else { - assert(arch_reg < (numLogicalIntRegs + numLogicalFloatRegs)); - + } else if (arch_reg < numLogicalIntRegs + numLogicalFloatRegs) { DPRINTF(Rename, "Rename Map: Float register %i being set to %i.\n", (int)arch_reg - numLogicalIntRegs, renamed_reg); @@ -285,55 +233,6 @@ SimpleRenameMap::setEntry(RegIndex arch_reg, PhysRegIndex renamed_reg) } } -void -SimpleRenameMap::squash(vector<RegIndex> freed_regs, - vector<UnmapInfo> unmaps) -{ - panic("Not sure this function should be called."); - - // Not sure the rename map should be able to access the free list - // like this. - while (!freed_regs.empty()) { - RegIndex free_register = freed_regs.back(); - - if (free_register < numPhysicalIntRegs) { - freeList->addIntReg(free_register); - } else { - // Subtract off the base FP dependence tag. - free_register = free_register - numPhysicalIntRegs; - freeList->addFloatReg(free_register); - } - - freed_regs.pop_back(); - } - - // Take unmap info and roll back the rename map. -} - -void -SimpleRenameMap::markAsReady(PhysRegIndex ready_reg) -{ - DPRINTF(Rename, "Rename map: Marking register %i as ready.\n", - (int)ready_reg); - - if (ready_reg < numPhysicalIntRegs) { - assert(ready_reg >= 0); - - intScoreboard[ready_reg] = 1; - } else if (ready_reg < numPhysicalRegs) { - - // Subtract off the base FP offset. -// ready_reg = ready_reg - numPhysicalIntRegs; - - floatScoreboard[ready_reg] = 1; - } else { - //Subtract off the misc registers offset. -// ready_reg = ready_reg - numPhysicalRegs; - - miscScoreboard[ready_reg] = 1; - } -} - int SimpleRenameMap::numFreeEntries() { diff --git a/src/cpu/o3/rename_map.hh b/src/cpu/o3/rename_map.hh index a48cfb408..c4c90c99a 100644 --- a/src/cpu/o3/rename_map.hh +++ b/src/cpu/o3/rename_map.hh @@ -32,8 +32,8 @@ // Have it so that there's a more meaningful name given to the variable // that marks the beginning of the FP registers. -#ifndef __CPU_O3_CPU_RENAME_MAP_HH__ -#define __CPU_O3_CPU_RENAME_MAP_HH__ +#ifndef __CPU_O3_RENAME_MAP_HH__ +#define __CPU_O3_RENAME_MAP_HH__ #include <iostream> #include <utility> @@ -64,18 +64,30 @@ class SimpleRenameMap typedef std::pair<PhysRegIndex, PhysRegIndex> RenameInfo; public: - //Constructor - SimpleRenameMap(unsigned _numLogicalIntRegs, - unsigned _numPhysicalIntRegs, - unsigned _numLogicalFloatRegs, - unsigned _numPhysicalFloatRegs, - unsigned _numMiscRegs, - RegIndex _intZeroReg, - RegIndex _floatZeroReg); + /** Default constructor. init() must be called prior to use. */ + SimpleRenameMap() {}; /** Destructor. */ ~SimpleRenameMap(); + /** Initializes rename map with given parameters. */ + void init(unsigned _numLogicalIntRegs, + unsigned _numPhysicalIntRegs, + PhysRegIndex &_int_reg_start, + + unsigned _numLogicalFloatRegs, + unsigned _numPhysicalFloatRegs, + PhysRegIndex &_float_reg_start, + + unsigned _numMiscRegs, + + RegIndex _intZeroReg, + RegIndex _floatZeroReg, + + int id, + bool bindRegs); + + /** Sets the free list used with this rename map. */ void setFreeList(SimpleFreeList *fl_ptr); //Tell rename map to get a free physical register for a given @@ -86,23 +98,19 @@ class SimpleRenameMap PhysRegIndex lookup(RegIndex phys_reg); - bool isReady(PhysRegIndex arch_reg); - /** * Marks the given register as ready, meaning that its value has been * calculated and written to the register file. * @param ready_reg The index of the physical register that is now ready. */ - void markAsReady(PhysRegIndex ready_reg); - void setEntry(RegIndex arch_reg, PhysRegIndex renamed_reg); - void squash(std::vector<RegIndex> freed_regs, - std::vector<UnmapInfo> unmaps); - int numFreeEntries(); private: + /** Rename Map ID */ + int id; + /** Number of logical integer registers. */ int numLogicalIntRegs; @@ -145,31 +153,16 @@ class SimpleRenameMap { } }; + private: /** Integer rename map. */ - RenameEntry *intRenameMap; + std::vector<RenameEntry> intRenameMap; /** Floating point rename map. */ - RenameEntry *floatRenameMap; + std::vector<RenameEntry> floatRenameMap; + private: /** Free list interface. */ SimpleFreeList *freeList; - - // Might want to make all these scoreboards into one large scoreboard. - - /** Scoreboard of physical integer registers, saying whether or not they - * are ready. - */ - std::vector<bool> intScoreboard; - - /** Scoreboard of physical floating registers, saying whether or not they - * are ready. - */ - std::vector<bool> floatScoreboard; - - /** Scoreboard of miscellaneous registers, saying whether or not they - * are ready. - */ - std::vector<bool> miscScoreboard; }; -#endif //__CPU_O3_CPU_RENAME_MAP_HH__ +#endif //__CPU_O3_RENAME_MAP_HH__ diff --git a/src/cpu/o3/rob.hh b/src/cpu/o3/rob.hh index 43ab66b97..6d1402531 100644 --- a/src/cpu/o3/rob.hh +++ b/src/cpu/o3/rob.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,23 +28,15 @@ * Authors: Kevin Lim */ -// Todo: Probably add in support for scheduling events (more than one as -// well) on the case of the ROB being empty or full. Considering tracking -// free entries instead of insts in ROB. Differentiate between squashing -// all instructions after the instruction, and all instructions after *and* -// including that instruction. - -#ifndef __CPU_O3_CPU_ROB_HH__ -#define __CPU_O3_CPU_ROB_HH__ +#ifndef __CPU_O3_ROB_HH__ +#define __CPU_O3_ROB_HH__ +#include <string> #include <utility> #include <vector> /** - * ROB class. Uses the instruction list that exists within the CPU to - * represent the ROB. This class doesn't contain that list, but instead - * a pointer to the CPU to get access to the list. The ROB, in this first - * implementation, is largely what drives squashing. + * ROB class. The ROB is largely what drives squashing. */ template <class Impl> class ROB @@ -56,16 +48,43 @@ class ROB typedef typename Impl::FullCPU FullCPU; typedef typename Impl::DynInstPtr DynInstPtr; - typedef std::pair<RegIndex, PhysRegIndex> UnmapInfo_t; - typedef typename list<DynInstPtr>::iterator InstIt_t; + typedef std::pair<RegIndex, PhysRegIndex> UnmapInfo; + typedef typename std::list<DynInstPtr>::iterator InstIt; + + /** Possible ROB statuses. */ + enum Status { + Running, + Idle, + ROBSquashing + }; + + /** SMT ROB Sharing Policy */ + enum ROBPolicy{ + Dynamic, + Partitioned, + Threshold + }; + + private: + /** Per-thread ROB status. */ + Status robStatus[Impl::MaxThreads]; + + /** ROB resource sharing policy for SMT mode. */ + ROBPolicy robPolicy; public: /** ROB constructor. - * @param _numEntries Number of entries in ROB. - * @param _squashWidth Number of instructions that can be squashed in a - * single cycle. + * @param _numEntries Number of entries in ROB. + * @param _squashWidth Number of instructions that can be squashed in a + * single cycle. + * @param _smtROBPolicy ROB Partitioning Scheme for SMT. + * @param _smtROBThreshold Max Resources(by %) a thread can have in the ROB. + * @param _numThreads The number of active threads. */ - ROB(unsigned _numEntries, unsigned _squashWidth); + ROB(unsigned _numEntries, unsigned _squashWidth, std::string smtROBPolicy, + unsigned _smtROBThreshold, unsigned _numThreads); + + std::string name() const; /** Function to set the CPU pointer, necessary due to which object the ROB * is created within. @@ -73,12 +92,21 @@ class ROB */ void setCPU(FullCPU *cpu_ptr); - /** Function to insert an instruction into the ROB. The parameter inst is - * not truly required, but is useful for checking correctness. Note - * that whatever calls this function must ensure that there is enough - * space within the ROB for the new instruction. + /** Sets pointer to the list of active threads. + * @param at_ptr Pointer to the list of active threads. + */ + void setActiveThreads(std::list<unsigned>* at_ptr); + + /** Switches out the ROB. */ + void switchOut(); + + /** Takes over another CPU's thread. */ + void takeOverFrom(); + + /** Function to insert an instruction into the ROB. Note that whatever + * calls this function must ensure that there is enough space within the + * ROB for the new instruction. * @param inst The instruction being inserted into the ROB. - * @todo Remove the parameter once correctness is ensured. */ void insertInst(DynInstPtr &inst); @@ -86,40 +114,134 @@ class ROB * no guarantee as to the return value if the ROB is empty. * @retval Pointer to the DynInst that is at the head of the ROB. */ - DynInstPtr readHeadInst() { return cpu->instList.front(); } +// DynInstPtr readHeadInst(); + + /** Returns a pointer to the head instruction of a specific thread within + * the ROB. + * @return Pointer to the DynInst that is at the head of the ROB. + */ + DynInstPtr readHeadInst(unsigned tid); + + /** Returns pointer to the tail instruction within the ROB. There is + * no guarantee as to the return value if the ROB is empty. + * @retval Pointer to the DynInst that is at the tail of the ROB. + */ +// DynInstPtr readTailInst(); + + /** Returns a pointer to the tail instruction of a specific thread within + * the ROB. + * @return Pointer to the DynInst that is at the tail of the ROB. + */ + DynInstPtr readTailInst(unsigned tid); + + /** Retires the head instruction, removing it from the ROB. */ +// void retireHead(); + + /** Retires the head instruction of a specific thread, removing it from the + * ROB. + */ + void retireHead(unsigned tid); - DynInstPtr readTailInst() { return (*tail); } + /** Is the oldest instruction across all threads ready. */ +// bool isHeadReady(); - void retireHead(); + /** Is the oldest instruction across a particular thread ready. */ + bool isHeadReady(unsigned tid); - bool isHeadReady(); + /** Is there any commitable head instruction across all threads ready. */ + bool canCommit(); + /** Re-adjust ROB partitioning. */ + void resetEntries(); + + /** Number of entries needed For 'num_threads' amount of threads. */ + int entryAmount(int num_threads); + + /** Returns the number of total free entries in the ROB. */ unsigned numFreeEntries(); + /** Returns the number of free entries in a specific ROB paritition. */ + unsigned numFreeEntries(unsigned tid); + + /** Returns the maximum number of entries for a specific thread. */ + unsigned getMaxEntries(unsigned tid) + { return maxEntries[tid]; } + + /** Returns the number of entries being used by a specific thread. */ + unsigned getThreadEntries(unsigned tid) + { return threadEntries[tid]; } + + /** Returns if the ROB is full. */ bool isFull() { return numInstsInROB == numEntries; } + /** Returns if a specific thread's partition is full. */ + bool isFull(unsigned tid) + { return threadEntries[tid] == numEntries; } + + /** Returns if the ROB is empty. */ bool isEmpty() { return numInstsInROB == 0; } - void doSquash(); + /** Returns if a specific thread's partition is empty. */ + bool isEmpty(unsigned tid) + { return threadEntries[tid] == 0; } - void squash(InstSeqNum squash_num); + /** Executes the squash, marking squashed instructions. */ + void doSquash(unsigned tid); - uint64_t readHeadPC(); + /** Squashes all instructions younger than the given sequence number for + * the specific thread. + */ + void squash(InstSeqNum squash_num, unsigned tid); - uint64_t readHeadNextPC(); + /** Updates the head instruction with the new oldest instruction. */ + void updateHead(); - InstSeqNum readHeadSeqNum(); + /** Updates the tail instruction with the new youngest instruction. */ + void updateTail(); - uint64_t readTailPC(); + /** Reads the PC of the oldest head instruction. */ +// uint64_t readHeadPC(); - InstSeqNum readTailSeqNum(); + /** Reads the PC of the head instruction of a specific thread. */ +// uint64_t readHeadPC(unsigned tid); + + /** Reads the next PC of the oldest head instruction. */ +// uint64_t readHeadNextPC(); + + /** Reads the next PC of the head instruction of a specific thread. */ +// uint64_t readHeadNextPC(unsigned tid); + + /** Reads the sequence number of the oldest head instruction. */ +// InstSeqNum readHeadSeqNum(); + + /** Reads the sequence number of the head instruction of a specific thread. + */ +// InstSeqNum readHeadSeqNum(unsigned tid); + + /** Reads the PC of the youngest tail instruction. */ +// uint64_t readTailPC(); + + /** Reads the PC of the tail instruction of a specific thread. */ +// uint64_t readTailPC(unsigned tid); + + /** Reads the sequence number of the youngest tail instruction. */ +// InstSeqNum readTailSeqNum(); + + /** Reads the sequence number of tail instruction of a specific thread. */ +// InstSeqNum readTailSeqNum(unsigned tid); /** Checks if the ROB is still in the process of squashing instructions. * @retval Whether or not the ROB is done squashing. */ - bool isDoneSquashing() const { return doneSquashing; } + bool isDoneSquashing(unsigned tid) const + { return doneSquashing[tid]; } + + /** Checks if the ROB is still in the process of squashing instructions for + * any thread. + */ + bool isDoneSquashing(); /** This is more of a debugging function than anything. Use * numInstsInROB to get the instructions in the ROB unless you are @@ -127,23 +249,46 @@ class ROB */ int countInsts(); - private: + /** This is more of a debugging function than anything. Use + * threadEntries to get the instructions in the ROB unless you are + * double checking that variable. + */ + int countInsts(unsigned tid); + private: /** Pointer to the CPU. */ FullCPU *cpu; + /** Active Threads in CPU */ + std::list<unsigned>* activeThreads; + /** Number of instructions in the ROB. */ unsigned numEntries; + /** Entries Per Thread */ + unsigned threadEntries[Impl::MaxThreads]; + + /** Max Insts a Thread Can Have in the ROB */ + unsigned maxEntries[Impl::MaxThreads]; + + /** ROB List of Instructions */ + std::list<DynInstPtr> instList[Impl::MaxThreads]; + /** Number of instructions that can be squashed in a single cycle. */ unsigned squashWidth; + public: /** Iterator pointing to the instruction which is the last instruction * in the ROB. This may at times be invalid (ie when the ROB is empty), * however it should never be incorrect. */ - InstIt_t tail; + InstIt tail; + /** Iterator pointing to the instruction which is the first instruction in + * in the ROB*/ + InstIt head; + + private: /** Iterator used for walking through the list of instructions when * squashing. Used so that there is persistent state between cycles; * when squashing, the instructions are marked as squashed but not @@ -151,16 +296,24 @@ class ROB * and after a squash. * This will always be set to cpu->instList.end() if it is invalid. */ - InstIt_t squashIt; + InstIt squashIt[Impl::MaxThreads]; + public: /** Number of instructions in the ROB. */ int numInstsInROB; + /** Dummy instruction returned if there are no insts left. */ + DynInstPtr dummyInst; + + private: /** The sequence number of the squashed instruction. */ InstSeqNum squashedSeqNum; /** Is the ROB done squashing. */ - bool doneSquashing; + bool doneSquashing[Impl::MaxThreads]; + + /** Number of active threads. */ + unsigned numThreads; }; -#endif //__CPU_O3_CPU_ROB_HH__ +#endif //__CPU_O3_ROB_HH__ diff --git a/src/cpu/o3/rob_impl.hh b/src/cpu/o3/rob_impl.hh index 5e7d57352..97694e371 100644 --- a/src/cpu/o3/rob_impl.hh +++ b/src/cpu/o3/rob_impl.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,20 +28,74 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_ROB_IMPL_HH__ -#define __CPU_O3_CPU_ROB_IMPL_HH__ - #include "config/full_system.hh" #include "cpu/o3/rob.hh" +using namespace std; + template <class Impl> -ROB<Impl>::ROB(unsigned _numEntries, unsigned _squashWidth) +ROB<Impl>::ROB(unsigned _numEntries, unsigned _squashWidth, + string _smtROBPolicy, unsigned _smtROBThreshold, + unsigned _numThreads) : numEntries(_numEntries), squashWidth(_squashWidth), numInstsInROB(0), - squashedSeqNum(0) + squashedSeqNum(0), + numThreads(_numThreads) +{ + for (int tid=0; tid < numThreads; tid++) { + doneSquashing[tid] = true; + threadEntries[tid] = 0; + } + + string policy = _smtROBPolicy; + + //Convert string to lowercase + std::transform(policy.begin(), policy.end(), policy.begin(), + (int(*)(int)) tolower); + + //Figure out rob policy + if (policy == "dynamic") { + robPolicy = Dynamic; + + //Set Max Entries to Total ROB Capacity + for (int i = 0; i < numThreads; i++) { + maxEntries[i]=numEntries; + } + + } else if (policy == "partitioned") { + robPolicy = Partitioned; + DPRINTF(Fetch, "ROB sharing policy set to Partitioned\n"); + + //@todo:make work if part_amt doesnt divide evenly. + int part_amt = numEntries / numThreads; + + //Divide ROB up evenly + for (int i = 0; i < numThreads; i++) { + maxEntries[i]=part_amt; + } + + } else if (policy == "threshold") { + robPolicy = Threshold; + DPRINTF(Fetch, "ROB sharing policy set to Threshold\n"); + + int threshold = _smtROBThreshold;; + + //Divide up by threshold amount + for (int i = 0; i < numThreads; i++) { + maxEntries[i]=threshold; + } + } else { + assert(0 && "Invalid ROB Sharing Policy.Options Are:{Dynamic," + "Partitioned, Threshold}"); + } +} + +template <class Impl> +std::string +ROB<Impl>::name() const { - doneSquashing = true; + return cpu->name() + ".rob"; } template <class Impl> @@ -50,124 +104,227 @@ ROB<Impl>::setCPU(FullCPU *cpu_ptr) { cpu = cpu_ptr; - // Set the tail to the beginning of the CPU instruction list so that - // upon the first instruction being inserted into the ROB, the tail - // iterator can simply be incremented. - tail = cpu->instList.begin(); + // Set the per-thread iterators to the end of the instruction list. + for (int i=0; i < numThreads;i++) { + squashIt[i] = instList[i].end(); + } - // Set the squash iterator to the end of the instruction list. - squashIt = cpu->instList.end(); + // Initialize the "universal" ROB head & tail point to invalid + // pointers + head = instList[0].end(); + tail = instList[0].end(); } template <class Impl> -int -ROB<Impl>::countInsts() +void +ROB<Impl>::setActiveThreads(list<unsigned> *at_ptr) { - // Start at 1; if the tail matches cpu->instList.begin(), then there is - // one inst in the ROB. - int return_val = 1; + DPRINTF(ROB, "Setting active threads list pointer.\n"); + activeThreads = at_ptr; +} - // There are quite a few special cases. Do not use this function other - // than for debugging purposes. - if (cpu->instList.begin() == cpu->instList.end()) { - // In this case there are no instructions in the list. The ROB - // must be empty. - return 0; - } else if (tail == cpu->instList.end()) { - // In this case, the tail is not yet pointing to anything valid. - // The ROB must be empty. - return 0; +template <class Impl> +void +ROB<Impl>::switchOut() +{ + for (int tid = 0; tid < numThreads; tid++) { + instList[tid].clear(); } +} - // Iterate through the ROB from the head to the tail, counting the - // entries. - for (InstIt_t i = cpu->instList.begin(); i != tail; ++i) - { - assert(i != cpu->instList.end()); - ++return_val; +template <class Impl> +void +ROB<Impl>::takeOverFrom() +{ + for (int tid=0; tid < numThreads; tid++) { + doneSquashing[tid] = true; + threadEntries[tid] = 0; + squashIt[tid] = instList[tid].end(); + } + numInstsInROB = 0; + + // Initialize the "universal" ROB head & tail point to invalid + // pointers + head = instList[0].end(); + tail = instList[0].end(); +} + +template <class Impl> +void +ROB<Impl>::resetEntries() +{ + if (robPolicy != Dynamic || numThreads > 1) { + int active_threads = (*activeThreads).size(); + + list<unsigned>::iterator threads = (*activeThreads).begin(); + list<unsigned>::iterator list_end = (*activeThreads).end(); + + while (threads != list_end) { + if (robPolicy == Partitioned) { + maxEntries[*threads++] = numEntries / active_threads; + } else if (robPolicy == Threshold && active_threads == 1) { + maxEntries[*threads++] = numEntries; + } + } } +} + +template <class Impl> +int +ROB<Impl>::entryAmount(int num_threads) +{ + if (robPolicy == Partitioned) { + return numEntries / num_threads; + } else { + return 0; + } +} + +template <class Impl> +int +ROB<Impl>::countInsts() +{ + int total=0; - return return_val; + for (int i=0;i < numThreads;i++) + total += countInsts(i); - // Because the head won't be tracked properly until the ROB gets the - // first instruction, and any time that the ROB is empty and has not - // yet gotten the instruction, this function doesn't work. -// return numInstsInROB; + return total; +} + +template <class Impl> +int +ROB<Impl>::countInsts(unsigned tid) +{ + return instList[tid].size(); } template <class Impl> void ROB<Impl>::insertInst(DynInstPtr &inst) { - // Make sure we have the right number of instructions. - assert(numInstsInROB == countInsts()); - // Make sure the instruction is valid. + //assert(numInstsInROB == countInsts()); assert(inst); - DPRINTF(ROB, "ROB: Adding inst PC %#x to the ROB.\n", inst->readPC()); + DPRINTF(ROB, "Adding inst PC %#x to the ROB.\n", inst->readPC()); - // If the ROB is full then exit. assert(numInstsInROB != numEntries); - ++numInstsInROB; + int tid = inst->threadNumber; - // Increment the tail iterator, moving it one instruction back. - // There is a special case if the ROB was empty prior to this insertion, - // in which case the tail will be pointing at instList.end(). If that - // happens, then reset the tail to the beginning of the list. - if (tail != cpu->instList.end()) { - ++tail; - } else { - tail = cpu->instList.begin(); + instList[tid].push_back(inst); + + //Set Up head iterator if this is the 1st instruction in the ROB + if (numInstsInROB == 0) { + head = instList[tid].begin(); + assert((*head) == inst); } - // Make sure the tail iterator is actually pointing at the instruction - // added. - assert((*tail) == inst); + //Must Decrement for iterator to actually be valid since __.end() + //actually points to 1 after the last inst + tail = instList[tid].end(); + tail--; - DPRINTF(ROB, "ROB: Now has %d instructions.\n", numInstsInROB); + inst->setInROB(); + + ++numInstsInROB; + ++threadEntries[tid]; + assert((*tail) == inst); + + DPRINTF(ROB, "[tid:%i] Now has %d instructions.\n", tid, threadEntries[tid]); } // Whatever calls this function needs to ensure that it properly frees up // registers prior to this function. +/* template <class Impl> void ROB<Impl>::retireHead() { - assert(numInstsInROB == countInsts()); + //assert(numInstsInROB == countInsts()); + assert(numInstsInROB > 0); + + int tid = (*head)->threadNumber; + + retireHead(tid); + + if (numInstsInROB == 0) { + tail = instList[tid].end(); + } +} +*/ + +template <class Impl> +void +ROB<Impl>::retireHead(unsigned tid) +{ + //assert(numInstsInROB == countInsts()); assert(numInstsInROB > 0); // Get the head ROB instruction. - DynInstPtr head_inst = cpu->instList.front(); + InstIt head_it = instList[tid].begin(); + + DynInstPtr head_inst = (*head_it); - // Make certain this can retire. assert(head_inst->readyToCommit()); - DPRINTF(ROB, "ROB: Retiring head instruction of the ROB, " - "instruction PC %#x, seq num %i\n", head_inst->readPC(), + DPRINTF(ROB, "[tid:%u]: Retiring head instruction, " + "instruction PC %#x,[sn:%lli]\n", tid, head_inst->readPC(), head_inst->seqNum); - // Keep track of how many instructions are in the ROB. --numInstsInROB; + --threadEntries[tid]; + + head_inst->removeInROB(); + head_inst->setCommitted(); + + instList[tid].erase(head_it); - // Tell CPU to remove the instruction from the list of instructions. - // A special case is needed if the instruction being retired is the - // only instruction in the ROB; otherwise the tail iterator will become - // invalidated. + //Update "Global" Head of ROB + updateHead(); + + // @todo: A special case is needed if the instruction being + // retired is the only instruction in the ROB; otherwise the tail + // iterator will become invalidated. cpu->removeFrontInst(head_inst); +} +/* +template <class Impl> +bool +ROB<Impl>::isHeadReady() +{ + if (numInstsInROB != 0) { + return (*head)->readyToCommit(); + } - if (numInstsInROB == 0) { - tail = cpu->instList.end(); + return false; +} +*/ +template <class Impl> +bool +ROB<Impl>::isHeadReady(unsigned tid) +{ + if (threadEntries[tid] != 0) { + return instList[tid].front()->readyToCommit(); } + + return false; } template <class Impl> bool -ROB<Impl>::isHeadReady() +ROB<Impl>::canCommit() { - if (numInstsInROB != 0) { - return cpu->instList.front()->readyToCommit(); + //@todo: set ActiveThreads through ROB or CPU + list<unsigned>::iterator threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + if (isHeadReady(tid)) { + return true; + } } return false; @@ -177,131 +334,339 @@ template <class Impl> unsigned ROB<Impl>::numFreeEntries() { - assert(numInstsInROB == countInsts()); + //assert(numInstsInROB == countInsts()); return numEntries - numInstsInROB; } template <class Impl> +unsigned +ROB<Impl>::numFreeEntries(unsigned tid) +{ + return maxEntries[tid] - threadEntries[tid]; +} + +template <class Impl> void -ROB<Impl>::doSquash() +ROB<Impl>::doSquash(unsigned tid) { - DPRINTF(ROB, "ROB: Squashing instructions.\n"); + DPRINTF(ROB, "[tid:%u]: Squashing instructions until [sn:%i].\n", + tid, squashedSeqNum); + + assert(squashIt[tid] != instList[tid].end()); + + if ((*squashIt[tid])->seqNum < squashedSeqNum) { + DPRINTF(ROB, "[tid:%u]: Done squashing instructions.\n", + tid); - assert(squashIt != cpu->instList.end()); + squashIt[tid] = instList[tid].end(); + + doneSquashing[tid] = true; + return; + } + + bool robTailUpdate = false; for (int numSquashed = 0; - numSquashed < squashWidth && (*squashIt)->seqNum != squashedSeqNum; + numSquashed < squashWidth && + squashIt[tid] != instList[tid].end() && + (*squashIt[tid])->seqNum > squashedSeqNum; ++numSquashed) { - // Ensure that the instruction is younger. - assert((*squashIt)->seqNum > squashedSeqNum); - - DPRINTF(ROB, "ROB: Squashing instruction PC %#x, seq num %i.\n", - (*squashIt)->readPC(), (*squashIt)->seqNum); + DPRINTF(ROB, "[tid:%u]: Squashing instruction PC %#x, seq num %i.\n", + (*squashIt[tid])->threadNumber, + (*squashIt[tid])->readPC(), + (*squashIt[tid])->seqNum); // Mark the instruction as squashed, and ready to commit so that // it can drain out of the pipeline. - (*squashIt)->setSquashed(); - - (*squashIt)->setCanCommit(); - - // Special case for when squashing due to a syscall. It's possible - // that the squash happened after the head instruction was already - // committed, meaning that (*squashIt)->seqNum != squashedSeqNum - // will never be false. Normally the squash would never be able - // to go past the head of the ROB; in this case it might, so it - // must be handled otherwise it will segfault. -#if !FULL_SYSTEM - if (squashIt == cpu->instList.begin()) { - DPRINTF(ROB, "ROB: Reached head of instruction list while " + (*squashIt[tid])->setSquashed(); + + (*squashIt[tid])->setCanCommit(); + + + if (squashIt[tid] == instList[tid].begin()) { + DPRINTF(ROB, "Reached head of instruction list while " "squashing.\n"); - squashIt = cpu->instList.end(); + squashIt[tid] = instList[tid].end(); - doneSquashing = true; + doneSquashing[tid] = true; return; } -#endif - // Move the tail iterator to the next instruction. - squashIt--; + InstIt tail_thread = instList[tid].end(); + tail_thread--; + + if ((*squashIt[tid]) == (*tail_thread)) + robTailUpdate = true; + + squashIt[tid]--; } // Check if ROB is done squashing. - if ((*squashIt)->seqNum == squashedSeqNum) { - DPRINTF(ROB, "ROB: Done squashing instructions.\n"); + if ((*squashIt[tid])->seqNum <= squashedSeqNum) { + DPRINTF(ROB, "[tid:%u]: Done squashing instructions.\n", + tid); + + squashIt[tid] = instList[tid].end(); + + doneSquashing[tid] = true; + } + + if (robTailUpdate) { + updateTail(); + } +} + + +template <class Impl> +void +ROB<Impl>::updateHead() +{ + DynInstPtr head_inst; + InstSeqNum lowest_num = 0; + bool first_valid = true; + + // @todo: set ActiveThreads through ROB or CPU + list<unsigned>::iterator threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned thread_num = *threads++; + + if (instList[thread_num].empty()) + continue; + + if (first_valid) { + head = instList[thread_num].begin(); + lowest_num = (*head)->seqNum; + first_valid = false; + continue; + } + + InstIt head_thread = instList[thread_num].begin(); + + DynInstPtr head_inst = (*head_thread); + + assert(head_inst != 0); + + if (head_inst->seqNum < lowest_num) { + head = head_thread; + lowest_num = head_inst->seqNum; + } + } + + if (first_valid) { + head = instList[0].end(); + } - squashIt = cpu->instList.end(); +} + +template <class Impl> +void +ROB<Impl>::updateTail() +{ + tail = instList[0].end(); + bool first_valid = true; + + list<unsigned>::iterator threads = (*activeThreads).begin(); + + while (threads != (*activeThreads).end()) { + unsigned tid = *threads++; + + if (instList[tid].empty()) { + continue; + } + + // If this is the first valid then assign w/out + // comparison + if (first_valid) { + tail = instList[tid].end(); + tail--; + first_valid = false; + continue; + } - doneSquashing = true; + // Assign new tail if this thread's tail is younger + // than our current "tail high" + InstIt tail_thread = instList[tid].end(); + tail_thread--; + + if ((*tail_thread)->seqNum > (*tail)->seqNum) { + tail = tail_thread; + } } } + template <class Impl> void -ROB<Impl>::squash(InstSeqNum squash_num) +ROB<Impl>::squash(InstSeqNum squash_num,unsigned tid) { - DPRINTF(ROB, "ROB: Starting to squash within the ROB.\n"); - doneSquashing = false; + if (isEmpty()) { + DPRINTF(ROB, "Does not need to squash due to being empty " + "[sn:%i]\n", + squash_num); + + return; + } + + DPRINTF(ROB, "Starting to squash within the ROB.\n"); + + robStatus[tid] = ROBSquashing; + + doneSquashing[tid] = false; squashedSeqNum = squash_num; - assert(tail != cpu->instList.end()); + if (!instList[tid].empty()) { + InstIt tail_thread = instList[tid].end(); + tail_thread--; - squashIt = tail; + squashIt[tid] = tail_thread; - doSquash(); + doSquash(tid); + } +} +/* +template <class Impl> +typename Impl::DynInstPtr +ROB<Impl>::readHeadInst() +{ + if (numInstsInROB != 0) { + assert((*head)->isInROB()==true); + return *head; + } else { + return dummyInst; + } } +*/ +template <class Impl> +typename Impl::DynInstPtr +ROB<Impl>::readHeadInst(unsigned tid) +{ + if (threadEntries[tid] != 0) { + InstIt head_thread = instList[tid].begin(); + assert((*head_thread)->isInROB()==true); + + return *head_thread; + } else { + return dummyInst; + } +} +/* template <class Impl> uint64_t ROB<Impl>::readHeadPC() { - assert(numInstsInROB == countInsts()); + //assert(numInstsInROB == countInsts()); - DynInstPtr head_inst = cpu->instList.front(); + DynInstPtr head_inst = *head; return head_inst->readPC(); } template <class Impl> uint64_t +ROB<Impl>::readHeadPC(unsigned tid) +{ + //assert(numInstsInROB == countInsts()); + InstIt head_thread = instList[tid].begin(); + + return (*head_thread)->readPC(); +} + + +template <class Impl> +uint64_t ROB<Impl>::readHeadNextPC() { - assert(numInstsInROB == countInsts()); + //assert(numInstsInROB == countInsts()); - DynInstPtr head_inst = cpu->instList.front(); + DynInstPtr head_inst = *head; return head_inst->readNextPC(); } template <class Impl> +uint64_t +ROB<Impl>::readHeadNextPC(unsigned tid) +{ + //assert(numInstsInROB == countInsts()); + InstIt head_thread = instList[tid].begin(); + + return (*head_thread)->readNextPC(); +} + +template <class Impl> InstSeqNum ROB<Impl>::readHeadSeqNum() { - // Return the last sequence number that has not been squashed. Other - // stages can use it to squash any instructions younger than the current - // tail. - DynInstPtr head_inst = cpu->instList.front(); + //assert(numInstsInROB == countInsts()); + DynInstPtr head_inst = *head; return head_inst->seqNum; } template <class Impl> +InstSeqNum +ROB<Impl>::readHeadSeqNum(unsigned tid) +{ + InstIt head_thread = instList[tid].begin(); + + return ((*head_thread)->seqNum); +} + +template <class Impl> +typename Impl::DynInstPtr +ROB<Impl>::readTailInst() +{ + //assert(numInstsInROB == countInsts()); + //assert(tail != instList[0].end()); + + return (*tail); +} +*/ +template <class Impl> +typename Impl::DynInstPtr +ROB<Impl>::readTailInst(unsigned tid) +{ + //assert(tail_thread[tid] != instList[tid].end()); + + InstIt tail_thread = instList[tid].end(); + tail_thread--; + + return *tail_thread; +} + +/* +template <class Impl> uint64_t ROB<Impl>::readTailPC() { - assert(numInstsInROB == countInsts()); + //assert(numInstsInROB == countInsts()); - assert(tail != cpu->instList.end()); + //assert(tail != instList[0].end()); return (*tail)->readPC(); } template <class Impl> +uint64_t +ROB<Impl>::readTailPC(unsigned tid) +{ + //assert(tail_thread[tid] != instList[tid].end()); + + InstIt tail_thread = instList[tid].end(); + tail_thread--; + + return (*tail_thread)->readPC(); +} + +template <class Impl> InstSeqNum ROB<Impl>::readTailSeqNum() { @@ -311,4 +676,18 @@ ROB<Impl>::readTailSeqNum() return (*tail)->seqNum; } -#endif // __CPU_O3_CPU_ROB_IMPL_HH__ +template <class Impl> +InstSeqNum +ROB<Impl>::readTailSeqNum(unsigned tid) +{ + // Return the last sequence number that has not been squashed. Other + // stages can use it to squash any instructions younger than the current + // tail. + // assert(tail_thread[tid] != instList[tid].end()); + + InstIt tail_thread = instList[tid].end(); + tail_thread--; + + return (*tail_thread)->seqNum; +} +*/ diff --git a/src/cpu/o3/sat_counter.cc b/src/cpu/o3/sat_counter.cc index 038a8cf32..68d3ef627 100644 --- a/src/cpu/o3/sat_counter.cc +++ b/src/cpu/o3/sat_counter.cc @@ -32,21 +32,21 @@ #include "cpu/o3/sat_counter.hh" SatCounter::SatCounter() - : maxVal(0), counter(0) + : initialVal(0), counter(0) { } SatCounter::SatCounter(unsigned bits) - : maxVal((1 << bits) - 1), counter(0) + : initialVal(0), maxVal((1 << bits) - 1), counter(0) { } -SatCounter::SatCounter(unsigned bits, unsigned initial_val) - : maxVal((1 << bits) - 1), counter(initial_val) +SatCounter::SatCounter(unsigned bits, uint8_t initial_val) + : initialVal(initialVal), maxVal((1 << bits) - 1), counter(initial_val) { // Check to make sure initial value doesn't exceed the max counter value. if (initial_val > maxVal) { - panic("BP: Initial counter value exceeds max size."); + fatal("BP: Initial counter value exceeds max size."); } } @@ -55,19 +55,3 @@ SatCounter::setBits(unsigned bits) { maxVal = (1 << bits) - 1; } - -void -SatCounter::increment() -{ - if(counter < maxVal) { - ++counter; - } -} - -void -SatCounter::decrement() -{ - if(counter > 0) { - --counter; - } -} diff --git a/src/cpu/o3/sat_counter.hh b/src/cpu/o3/sat_counter.hh index fdc20562c..7e15119b0 100644 --- a/src/cpu/o3/sat_counter.hh +++ b/src/cpu/o3/sat_counter.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2005 The Regents of The University of Michigan + * Copyright (c) 2005-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,9 +28,10 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_SAT_COUNTER_HH__ -#define __CPU_O3_CPU_SAT_COUNTER_HH__ +#ifndef __CPU_O3_SAT_COUNTER_HH__ +#define __CPU_O3_SAT_COUNTER_HH__ +#include "base/misc.hh" #include "sim/host.hh" /** @@ -46,47 +47,70 @@ class SatCounter /** * Constructor for the counter. */ - SatCounter(); + SatCounter() + : initialVal(0), counter(0) + { } /** * Constructor for the counter. * @param bits How many bits the counter will have. */ - SatCounter(unsigned bits); + SatCounter(unsigned bits) + : initialVal(0), maxVal((1 << bits) - 1), counter(0) + { } /** * Constructor for the counter. * @param bits How many bits the counter will have. * @param initial_val Starting value for each counter. */ - SatCounter(unsigned bits, unsigned initial_val); + SatCounter(unsigned bits, uint8_t initial_val) + : initialVal(initialVal), maxVal((1 << bits) - 1), counter(initial_val) + { + // Check to make sure initial value doesn't exceed the max + // counter value. + if (initial_val > maxVal) { + fatal("BP: Initial counter value exceeds max size."); + } + } /** * Sets the number of bits. */ - void setBits(unsigned bits); + void setBits(unsigned bits) { maxVal = (1 << bits) - 1; } + + void reset() { counter = initialVal; } /** * Increments the counter's current value. */ - void increment(); + void increment() + { + if (counter < maxVal) { + ++counter; + } + } /** * Decrements the counter's current value. */ - void decrement(); + void decrement() + { + if (counter > 0) { + --counter; + } + } /** * Read the counter's value. */ const uint8_t read() const - { - return counter; - } + { return counter; } private: + uint8_t initialVal; uint8_t maxVal; uint8_t counter; }; -#endif // __CPU_O3_CPU_SAT_COUNTER_HH__ +#endif // __CPU_O3_SAT_COUNTER_HH__ diff --git a/src/cpu/o3/scoreboard.cc b/src/cpu/o3/scoreboard.cc new file mode 100644 index 000000000..1859b35a4 --- /dev/null +++ b/src/cpu/o3/scoreboard.cc @@ -0,0 +1,109 @@ +/* + * Copyright (c) 2005-2006 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Korey Sewell + * Kevin Lim + */ + +#include "cpu/o3/scoreboard.hh" + +Scoreboard::Scoreboard(unsigned activeThreads, + unsigned _numLogicalIntRegs, + unsigned _numPhysicalIntRegs, + unsigned _numLogicalFloatRegs, + unsigned _numPhysicalFloatRegs, + unsigned _numMiscRegs, + unsigned _zeroRegIdx) + : numLogicalIntRegs(_numLogicalIntRegs), + numPhysicalIntRegs(_numPhysicalIntRegs), + numLogicalFloatRegs(_numLogicalFloatRegs), + numPhysicalFloatRegs(_numPhysicalFloatRegs), + numMiscRegs(_numMiscRegs), + zeroRegIdx(_zeroRegIdx) +{ + //Get Register Sizes + numLogicalRegs = numLogicalIntRegs + numLogicalFloatRegs; + numPhysicalRegs = numPhysicalIntRegs + numPhysicalFloatRegs; + + //Resize scoreboard appropriately + regScoreBoard.resize(numPhysicalRegs + (numMiscRegs * activeThreads)); + + //Initialize values + for (int i=0; i < numLogicalIntRegs * activeThreads; i++) { + regScoreBoard[i] = 1; + } + + for (int i= numPhysicalIntRegs; + i < numPhysicalIntRegs + (numLogicalFloatRegs * activeThreads); + i++) { + regScoreBoard[i] = 1; + } + + for (int i = numPhysicalRegs; + i < numPhysicalRegs + (numMiscRegs * activeThreads); + i++) { + regScoreBoard[i] = 1; + } +} + +std::string +Scoreboard::name() const +{ + return "cpu.scoreboard"; +} + +bool +Scoreboard::getReg(PhysRegIndex phys_reg) +{ + // Always ready if int or fp zero reg. + if (phys_reg == zeroRegIdx || + phys_reg == (zeroRegIdx + numPhysicalIntRegs)) { + return 1; + } + + return regScoreBoard[phys_reg]; +} + +void +Scoreboard::setReg(PhysRegIndex phys_reg) +{ + DPRINTF(Scoreboard, "Setting reg %i as ready\n", phys_reg); + + regScoreBoard[phys_reg] = 1; +} + +void +Scoreboard::unsetReg(PhysRegIndex ready_reg) +{ + if (ready_reg == zeroRegIdx || + ready_reg == (zeroRegIdx + numPhysicalIntRegs)) { + // Don't do anything if int or fp zero reg. + return; + } + + regScoreBoard[ready_reg] = 0; +} diff --git a/src/cpu/o3/scoreboard.hh b/src/cpu/o3/scoreboard.hh new file mode 100644 index 000000000..f8e4df3b7 --- /dev/null +++ b/src/cpu/o3/scoreboard.hh @@ -0,0 +1,117 @@ +/* + * Copyright (c) 2005-2006 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Korey Sewell + * Kevin Lim + */ + +#ifndef __CPU_O3_SCOREBOARD_HH__ +#define __CPU_O3_SCOREBOARD_HH__ + +#include <iostream> +#include <utility> +#include <vector> +#include "arch/alpha/isa_traits.hh" +#include "base/trace.hh" +#include "base/traceflags.hh" +#include "cpu/o3/comm.hh" + +/** + * Implements a simple scoreboard to track which registers are ready. + * This class assumes that the fp registers start, index wise, right after + * the integer registers. The misc. registers start, index wise, right after + * the fp registers. + * @todo: Fix up handling of the zero register in case the decoder does not + * automatically make insts that write the zero register into nops. + */ +class Scoreboard +{ + public: + /** Constructs a scoreboard. + * @param activeThreads The number of active threads. + * @param _numLogicalIntRegs Number of logical integer registers. + * @param _numPhysicalIntRegs Number of physical integer registers. + * @param _numLogicalFloatRegs Number of logical fp registers. + * @param _numPhysicalFloatRegs Number of physical fp registers. + * @param _numMiscRegs Number of miscellaneous registers. + * @param _zeroRegIdx Index of the zero register. + */ + Scoreboard(unsigned activeThreads, + unsigned _numLogicalIntRegs, + unsigned _numPhysicalIntRegs, + unsigned _numLogicalFloatRegs, + unsigned _numPhysicalFloatRegs, + unsigned _numMiscRegs, + unsigned _zeroRegIdx); + + /** Destructor. */ + ~Scoreboard() {} + + /** Returns the name of the scoreboard. */ + std::string name() const; + + /** Checks if the register is ready. */ + bool getReg(PhysRegIndex ready_reg); + + /** Sets the register as ready. */ + void setReg(PhysRegIndex phys_reg); + + /** Sets the register as not ready. */ + void unsetReg(PhysRegIndex ready_reg); + + private: + /** Scoreboard of physical integer registers, saying whether or not they + * are ready. + */ + std::vector<bool> regScoreBoard; + + /** Number of logical integer registers. */ + int numLogicalIntRegs; + + /** Number of physical integer registers. */ + int numPhysicalIntRegs; + + /** Number of logical floating point registers. */ + int numLogicalFloatRegs; + + /** Number of physical floating point registers. */ + int numPhysicalFloatRegs; + + /** Number of miscellaneous registers. */ + int numMiscRegs; + + /** Number of logical integer + float registers. */ + int numLogicalRegs; + + /** Number of physical integer + float registers. */ + int numPhysicalRegs; + + /** The logical index of the zero register. */ + int zeroRegIdx; +}; + +#endif diff --git a/src/cpu/o3/store_set.cc b/src/cpu/o3/store_set.cc index 577a9fdc2..2d28b617f 100644 --- a/src/cpu/o3/store_set.cc +++ b/src/cpu/o3/store_set.cc @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,47 +28,90 @@ * Authors: Kevin Lim */ +#include "base/intmath.hh" +#include "base/misc.hh" #include "base/trace.hh" #include "cpu/o3/store_set.hh" StoreSet::StoreSet(int _SSIT_size, int _LFST_size) - : SSIT_size(_SSIT_size), LFST_size(_LFST_size) + : SSITSize(_SSIT_size), LFSTSize(_LFST_size) { DPRINTF(StoreSet, "StoreSet: Creating store set object.\n"); DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n", - SSIT_size, LFST_size); + SSITSize, LFSTSize); - SSIT = new SSID[SSIT_size]; + if (!isPowerOf2(SSITSize)) { + fatal("Invalid SSIT size!\n"); + } + + SSIT.resize(SSITSize); - validSSIT.resize(SSIT_size); + validSSIT.resize(SSITSize); - for (int i = 0; i < SSIT_size; ++i) + for (int i = 0; i < SSITSize; ++i) validSSIT[i] = false; - LFST = new InstSeqNum[LFST_size]; + if (!isPowerOf2(LFSTSize)) { + fatal("Invalid LFST size!\n"); + } - validLFST.resize(LFST_size); + LFST.resize(LFSTSize); - SSCounters = new int[LFST_size]; + validLFST.resize(LFSTSize); - for (int i = 0; i < LFST_size; ++i) - { + for (int i = 0; i < LFSTSize; ++i) { validLFST[i] = false; - SSCounters[i] = 0; + LFST[i] = 0; } - index_mask = SSIT_size - 1; + indexMask = SSITSize - 1; - offset_bits = 2; + offsetBits = 2; } +StoreSet::~StoreSet() +{ +} + +void +StoreSet::init(int _SSIT_size, int _LFST_size) +{ + SSITSize = _SSIT_size; + LFSTSize = _LFST_size; + + DPRINTF(StoreSet, "StoreSet: Creating store set object.\n"); + DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n", + SSITSize, LFSTSize); + + SSIT.resize(SSITSize); + + validSSIT.resize(SSITSize); + + for (int i = 0; i < SSITSize; ++i) + validSSIT[i] = false; + + LFST.resize(LFSTSize); + + validLFST.resize(LFSTSize); + + for (int i = 0; i < LFSTSize; ++i) { + validLFST[i] = false; + LFST[i] = 0; + } + + indexMask = SSITSize - 1; + + offsetBits = 2; +} + + void StoreSet::violation(Addr store_PC, Addr load_PC) { int load_index = calcIndex(load_PC); int store_index = calcIndex(store_PC); - assert(load_index < SSIT_size && store_index < SSIT_size); + assert(load_index < SSITSize && store_index < SSITSize); bool valid_load_SSID = validSSIT[load_index]; bool valid_store_SSID = validSSIT[store_index]; @@ -85,10 +128,7 @@ StoreSet::violation(Addr store_PC, Addr load_PC) SSIT[store_index] = new_set; - assert(new_set < LFST_size); - - SSCounters[new_set]++; - + assert(new_set < LFSTSize); DPRINTF(StoreSet, "StoreSet: Neither load nor store had a valid " "storeset, creating a new one: %i for load %#x, store %#x\n", @@ -100,9 +140,7 @@ StoreSet::violation(Addr store_PC, Addr load_PC) SSIT[store_index] = load_SSID; - assert(load_SSID < LFST_size); - - SSCounters[load_SSID]++; + assert(load_SSID < LFSTSize); DPRINTF(StoreSet, "StoreSet: Load had a valid store set. Adding " "store to that set: %i for load %#x, store %#x\n", @@ -114,9 +152,6 @@ StoreSet::violation(Addr store_PC, Addr load_PC) SSIT[load_index] = store_SSID; - // Because we are having a load point to an already existing set, - // the size of the store set is not incremented. - DPRINTF(StoreSet, "StoreSet: Store had a valid store set: %i for " "load %#x, store %#x\n", store_SSID, load_PC, store_PC); @@ -124,29 +159,19 @@ StoreSet::violation(Addr store_PC, Addr load_PC) SSID load_SSID = SSIT[load_index]; SSID store_SSID = SSIT[store_index]; - assert(load_SSID < LFST_size && store_SSID < LFST_size); + assert(load_SSID < LFSTSize && store_SSID < LFSTSize); - int load_SS_size = SSCounters[load_SSID]; - int store_SS_size = SSCounters[store_SSID]; - - // If the load has the bigger store set, then assign the store - // to the same store set as the load. Otherwise vice-versa. - if (load_SS_size > store_SS_size) { + // The store set with the lower number wins + if (store_SSID > load_SSID) { SSIT[store_index] = load_SSID; - SSCounters[load_SSID]++; - SSCounters[store_SSID]--; - - DPRINTF(StoreSet, "StoreSet: Load had bigger store set: %i; " + DPRINTF(StoreSet, "StoreSet: Load had smaller store set: %i; " "for load %#x, store %#x\n", load_SSID, load_PC, store_PC); } else { SSIT[load_index] = store_SSID; - SSCounters[store_SSID]++; - SSCounters[load_SSID]--; - - DPRINTF(StoreSet, "StoreSet: Store had bigger store set: %i; " + DPRINTF(StoreSet, "StoreSet: Store had smaller store set: %i; " "for load %#x, store %#x\n", store_SSID, load_PC, store_PC); } @@ -161,13 +186,14 @@ StoreSet::insertLoad(Addr load_PC, InstSeqNum load_seq_num) } void -StoreSet::insertStore(Addr store_PC, InstSeqNum store_seq_num) +StoreSet::insertStore(Addr store_PC, InstSeqNum store_seq_num, + unsigned tid) { int index = calcIndex(store_PC); int store_SSID; - assert(index < SSIT_size); + assert(index < SSITSize); if (!validSSIT[index]) { // Do nothing if there's no valid entry. @@ -175,13 +201,15 @@ StoreSet::insertStore(Addr store_PC, InstSeqNum store_seq_num) } else { store_SSID = SSIT[index]; - assert(store_SSID < LFST_size); + assert(store_SSID < LFSTSize); // Update the last store that was fetched with the current one. LFST[store_SSID] = store_seq_num; validLFST[store_SSID] = 1; + storeList[store_seq_num] = store_SSID; + DPRINTF(StoreSet, "Store %#x updated the LFST, SSID: %i\n", store_PC, store_SSID); } @@ -194,7 +222,7 @@ StoreSet::checkInst(Addr PC) int inst_SSID; - assert(index < SSIT_size); + assert(index < SSITSize); if (!validSSIT[index]) { DPRINTF(StoreSet, "Inst %#x with index %i had no SSID\n", @@ -205,7 +233,7 @@ StoreSet::checkInst(Addr PC) } else { inst_SSID = SSIT[index]; - assert(inst_SSID < LFST_size); + assert(inst_SSID < LFSTSize); if (!validLFST[inst_SSID]) { @@ -234,7 +262,13 @@ StoreSet::issued(Addr issued_PC, InstSeqNum issued_seq_num, bool is_store) int store_SSID; - assert(index < SSIT_size); + assert(index < SSITSize); + + SeqNumMapIt store_list_it = storeList.find(issued_seq_num); + + if (store_list_it != storeList.end()) { + storeList.erase(store_list_it); + } // Make sure the SSIT still has a valid entry for the issued store. if (!validSSIT[index]) { @@ -243,7 +277,7 @@ StoreSet::issued(Addr issued_PC, InstSeqNum issued_seq_num, bool is_store) store_SSID = SSIT[index]; - assert(store_SSID < LFST_size); + assert(store_SSID < LFSTSize); // If the last fetched store in the store set refers to the store that // was just issued, then invalidate the entry. @@ -254,18 +288,31 @@ StoreSet::issued(Addr issued_PC, InstSeqNum issued_seq_num, bool is_store) } void -StoreSet::squash(InstSeqNum squashed_num) +StoreSet::squash(InstSeqNum squashed_num, unsigned tid) { - // Not really sure how to do this well. - // Generally this is small enough that it should be okay; short circuit - // evaluation should take care of invalid entries. - DPRINTF(StoreSet, "StoreSet: Squashing until inum %i\n", squashed_num); - for (int i = 0; i < LFST_size; ++i) { - if (validLFST[i] && LFST[i] < squashed_num) { - validLFST[i] = false; + int idx; + SeqNumMapIt store_list_it = storeList.begin(); + + //@todo:Fix to only delete from correct thread + while (!storeList.empty()) { + idx = (*store_list_it).second; + + if ((*store_list_it).first <= squashed_num) { + break; + } + + bool younger = LFST[idx] > squashed_num; + + if (validLFST[idx] && younger) { + DPRINTF(StoreSet, "Squashed [sn:%lli]\n", LFST[idx]); + validLFST[idx] = false; + + storeList.erase(store_list_it++); + } else if (!validLFST[idx] && younger) { + storeList.erase(store_list_it++); } } } @@ -273,12 +320,29 @@ StoreSet::squash(InstSeqNum squashed_num) void StoreSet::clear() { - for (int i = 0; i < SSIT_size; ++i) { + for (int i = 0; i < SSITSize; ++i) { validSSIT[i] = false; } - for (int i = 0; i < LFST_size; ++i) { + for (int i = 0; i < LFSTSize; ++i) { validLFST[i] = false; } + + storeList.clear(); } +void +StoreSet::dump() +{ + cprintf("storeList.size(): %i\n", storeList.size()); + SeqNumMapIt store_list_it = storeList.begin(); + + int num = 0; + + while (store_list_it != storeList.end()) { + cprintf("%i: [sn:%lli] SSID:%i\n", + num, (*store_list_it).first, (*store_list_it).second); + num++; + store_list_it++; + } +} diff --git a/src/cpu/o3/store_set.hh b/src/cpu/o3/store_set.hh index ef869fa0f..f5a44a1ac 100644 --- a/src/cpu/o3/store_set.hh +++ b/src/cpu/o3/store_set.hh @@ -28,61 +28,120 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_STORE_SET_HH__ -#define __CPU_O3_CPU_STORE_SET_HH__ +#ifndef __CPU_O3_STORE_SET_HH__ +#define __CPU_O3_STORE_SET_HH__ +#include <list> +#include <map> +#include <utility> #include <vector> #include "arch/isa_traits.hh" #include "cpu/inst_seq.hh" +struct ltseqnum { + bool operator()(const InstSeqNum &lhs, const InstSeqNum &rhs) const + { + return lhs > rhs; + } +}; + +/** + * Implements a store set predictor for determining if memory + * instructions are dependent upon each other. See paper "Memory + * Dependence Prediction using Store Sets" by Chrysos and Emer. SSID + * stands for Store Set ID, SSIT stands for Store Set ID Table, and + * LFST is Last Fetched Store Table. + */ class StoreSet { public: typedef unsigned SSID; public: + /** Default constructor. init() must be called prior to use. */ + StoreSet() { }; + + /** Creates store set predictor with given table sizes. */ StoreSet(int SSIT_size, int LFST_size); + /** Default destructor. */ + ~StoreSet(); + + /** Initializes the store set predictor with the given table sizes. */ + void init(int SSIT_size, int LFST_size); + + /** Records a memory ordering violation between the younger load + * and the older store. */ void violation(Addr store_PC, Addr load_PC); + /** Inserts a load into the store set predictor. This does nothing but + * is included in case other predictors require a similar function. + */ void insertLoad(Addr load_PC, InstSeqNum load_seq_num); - void insertStore(Addr store_PC, InstSeqNum store_seq_num); + /** Inserts a store into the store set predictor. Updates the + * LFST if the store has a valid SSID. */ + void insertStore(Addr store_PC, InstSeqNum store_seq_num, + unsigned tid); + /** Checks if the instruction with the given PC is dependent upon + * any store. @return Returns the sequence number of the store + * instruction this PC is dependent upon. Returns 0 if none. + */ InstSeqNum checkInst(Addr PC); + /** Records this PC/sequence number as issued. */ void issued(Addr issued_PC, InstSeqNum issued_seq_num, bool is_store); - void squash(InstSeqNum squashed_num); + /** Squashes for a specific thread until the given sequence number. */ + void squash(InstSeqNum squashed_num, unsigned tid); + /** Resets all tables. */ void clear(); + /** Debug function to dump the contents of the store list. */ + void dump(); + private: + /** Calculates the index into the SSIT based on the PC. */ inline int calcIndex(Addr PC) - { return (PC >> offset_bits) & index_mask; } + { return (PC >> offsetBits) & indexMask; } + /** Calculates a Store Set ID based on the PC. */ inline SSID calcSSID(Addr PC) - { return ((PC ^ (PC >> 10)) % LFST_size); } + { return ((PC ^ (PC >> 10)) % LFSTSize); } - SSID *SSIT; + /** The Store Set ID Table. */ + std::vector<SSID> SSIT; + /** Bit vector to tell if the SSIT has a valid entry. */ std::vector<bool> validSSIT; - InstSeqNum *LFST; + /** Last Fetched Store Table. */ + std::vector<InstSeqNum> LFST; + /** Bit vector to tell if the LFST has a valid entry. */ std::vector<bool> validLFST; - int *SSCounters; + /** Map of stores that have been inserted into the store set, but + * not yet issued or squashed. + */ + std::map<InstSeqNum, int, ltseqnum> storeList; + + typedef std::map<InstSeqNum, int, ltseqnum>::iterator SeqNumMapIt; - int SSIT_size; + /** Store Set ID Table size, in entries. */ + int SSITSize; - int LFST_size; + /** Last Fetched Store Table size, in entries. */ + int LFSTSize; - int index_mask; + /** Mask to obtain the index. */ + int indexMask; // HACK: Hardcoded for now. - int offset_bits; + int offsetBits; }; -#endif // __CPU_O3_CPU_STORE_SET_HH__ +#endif // __CPU_O3_STORE_SET_HH__ diff --git a/src/cpu/o3/thread_state.hh b/src/cpu/o3/thread_state.hh new file mode 100644 index 000000000..b6535baa1 --- /dev/null +++ b/src/cpu/o3/thread_state.hh @@ -0,0 +1,102 @@ +/* + * Copyright (c) 2006 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Kevin Lim + */ + +#ifndef __CPU_O3_THREAD_STATE_HH__ +#define __CPU_O3_THREAD_STATE_HH__ + +#include "arch/faults.hh" +#include "arch/isa_traits.hh" +#include "cpu/thread_context.hh" +#include "cpu/thread_state.hh" + +class Event; +class Process; + +#if FULL_SYSTEM +class EndQuiesceEvent; +class FunctionProfile; +class ProfileNode; +#else +class FunctionalMemory; +class Process; +#endif + +/** + * Class that has various thread state, such as the status, the + * current instruction being processed, whether or not the thread has + * a trap pending or is being externally updated, the ThreadContext + * pointer, etc. It also handles anything related to a specific + * thread's process, such as syscalls and checking valid addresses. + */ +template <class Impl> +struct O3ThreadState : public ThreadState { + typedef ThreadContext::Status Status; + typedef typename Impl::FullCPU FullCPU; + + private: + /** Pointer to the CPU. */ + FullCPU *cpu; + public: + /** Whether or not the thread is currently in syscall mode, and + * thus able to be externally updated without squashing. + */ + bool inSyscall; + + /** Whether or not the thread is currently waiting on a trap, and + * thus able to be externally updated without squashing. + */ + bool trapPending; + +#if FULL_SYSTEM + O3ThreadState(FullCPU *_cpu, int _thread_num) + : ThreadState(-1, _thread_num), + inSyscall(0), trapPending(0) + { } +#else + O3ThreadState(FullCPU *_cpu, int _thread_num, Process *_process, int _asid, + MemObject *mem) + : ThreadState(-1, _thread_num, mem, _process, _asid), + cpu(_cpu), inSyscall(0), trapPending(0) + { } +#endif + + /** Pointer to the ThreadContext of this thread. */ + ThreadContext *tc; + + /** Returns a pointer to the TC of this thread. */ + ThreadContext *getTC() { return tc; } + +#if !FULL_SYSTEM + /** Handles the syscall. */ + void syscall(int64_t callnum) { process->syscall(callnum, tc); } +#endif +}; + +#endif // __CPU_O3_THREAD_STATE_HH__ diff --git a/src/cpu/o3/tournament_pred.cc b/src/cpu/o3/tournament_pred.cc index 27c179504..7cf78dcb1 100644 --- a/src/cpu/o3/tournament_pred.cc +++ b/src/cpu/o3/tournament_pred.cc @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,39 +28,46 @@ * Authors: Kevin Lim */ +#include "base/intmath.hh" #include "cpu/o3/tournament_pred.hh" -TournamentBP::TournamentBP(unsigned _local_predictor_size, - unsigned _local_ctr_bits, - unsigned _local_history_table_size, - unsigned _local_history_bits, - unsigned _global_predictor_size, - unsigned _global_ctr_bits, - unsigned _global_history_bits, - unsigned _choice_predictor_size, - unsigned _choice_ctr_bits, +TournamentBP::TournamentBP(unsigned _localPredictorSize, + unsigned _localCtrBits, + unsigned _localHistoryTableSize, + unsigned _localHistoryBits, + unsigned _globalPredictorSize, + unsigned _globalCtrBits, + unsigned _globalHistoryBits, + unsigned _choicePredictorSize, + unsigned _choiceCtrBits, unsigned _instShiftAmt) - : localPredictorSize(_local_predictor_size), - localCtrBits(_local_ctr_bits), - localHistoryTableSize(_local_history_table_size), - localHistoryBits(_local_history_bits), - globalPredictorSize(_global_predictor_size), - globalCtrBits(_global_ctr_bits), - globalHistoryBits(_global_history_bits), - choicePredictorSize(_global_predictor_size), - choiceCtrBits(_choice_ctr_bits), + : localPredictorSize(_localPredictorSize), + localCtrBits(_localCtrBits), + localHistoryTableSize(_localHistoryTableSize), + localHistoryBits(_localHistoryBits), + globalPredictorSize(_globalPredictorSize), + globalCtrBits(_globalCtrBits), + globalHistoryBits(_globalHistoryBits), + choicePredictorSize(_globalPredictorSize), + choiceCtrBits(_choiceCtrBits), instShiftAmt(_instShiftAmt) { - //Should do checks here to make sure sizes are correct (powers of 2) + if (!isPowerOf2(localPredictorSize)) { + fatal("Invalid local predictor size!\n"); + } //Setup the array of counters for the local predictor - localCtrs = new SatCounter[localPredictorSize]; + localCtrs.resize(localPredictorSize); for (int i = 0; i < localPredictorSize; ++i) localCtrs[i].setBits(localCtrBits); + if (!isPowerOf2(localHistoryTableSize)) { + fatal("Invalid local history table size!\n"); + } + //Setup the history table for the local table - localHistoryTable = new unsigned[localHistoryTableSize]; + localHistoryTable.resize(localHistoryTableSize); for (int i = 0; i < localHistoryTableSize; ++i) localHistoryTable[i] = 0; @@ -68,8 +75,12 @@ TournamentBP::TournamentBP(unsigned _local_predictor_size, // Setup the local history mask localHistoryMask = (1 << localHistoryBits) - 1; + if (!isPowerOf2(globalPredictorSize)) { + fatal("Invalid global predictor size!\n"); + } + //Setup the array of counters for the global predictor - globalCtrs = new SatCounter[globalPredictorSize]; + globalCtrs.resize(globalPredictorSize); for (int i = 0; i < globalPredictorSize; ++i) globalCtrs[i].setBits(globalCtrBits); @@ -79,12 +90,17 @@ TournamentBP::TournamentBP(unsigned _local_predictor_size, // Setup the global history mask globalHistoryMask = (1 << globalHistoryBits) - 1; + if (!isPowerOf2(choicePredictorSize)) { + fatal("Invalid choice predictor size!\n"); + } + //Setup the array of counters for the choice predictor - choiceCtrs = new SatCounter[choicePredictorSize]; + choiceCtrs.resize(choicePredictorSize); for (int i = 0; i < choicePredictorSize; ++i) choiceCtrs[i].setBits(choiceCtrBits); + // @todo: Allow for different thresholds between the predictors. threshold = (1 << (localCtrBits - 1)) - 1; threshold = threshold / 2; } @@ -93,166 +109,185 @@ inline unsigned TournamentBP::calcLocHistIdx(Addr &branch_addr) { + // Get low order bits after removing instruction offset. return (branch_addr >> instShiftAmt) & (localHistoryTableSize - 1); } inline void -TournamentBP::updateHistoriesTaken(unsigned local_history_idx) +TournamentBP::updateGlobalHistTaken() { globalHistory = (globalHistory << 1) | 1; globalHistory = globalHistory & globalHistoryMask; - - localHistoryTable[local_history_idx] = - (localHistoryTable[local_history_idx] << 1) | 1; } inline void -TournamentBP::updateHistoriesNotTaken(unsigned local_history_idx) +TournamentBP::updateGlobalHistNotTaken() { globalHistory = (globalHistory << 1); globalHistory = globalHistory & globalHistoryMask; +} +inline +void +TournamentBP::updateLocalHistTaken(unsigned local_history_idx) +{ + localHistoryTable[local_history_idx] = + (localHistoryTable[local_history_idx] << 1) | 1; +} + +inline +void +TournamentBP::updateLocalHistNotTaken(unsigned local_history_idx) +{ localHistoryTable[local_history_idx] = (localHistoryTable[local_history_idx] << 1); } bool -TournamentBP::lookup(Addr &branch_addr) +TournamentBP::lookup(Addr &branch_addr, void * &bp_history) { - uint8_t local_prediction; + bool local_prediction; unsigned local_history_idx; unsigned local_predictor_idx; - uint8_t global_prediction; - uint8_t choice_prediction; + bool global_prediction; + bool choice_prediction; //Lookup in the local predictor to get its branch prediction local_history_idx = calcLocHistIdx(branch_addr); local_predictor_idx = localHistoryTable[local_history_idx] & localHistoryMask; - local_prediction = localCtrs[local_predictor_idx].read(); + local_prediction = localCtrs[local_predictor_idx].read() > threshold; //Lookup in the global predictor to get its branch prediction - global_prediction = globalCtrs[globalHistory].read(); + global_prediction = globalCtrs[globalHistory].read() > threshold; //Lookup in the choice predictor to see which one to use - choice_prediction = choiceCtrs[globalHistory].read(); - - //@todo Put a threshold value in for the three predictors that can - // be set through the constructor (so this isn't hard coded). - //Also should put some of this code into functions. - if (choice_prediction > threshold) { - if (global_prediction > threshold) { - updateHistoriesTaken(local_history_idx); - - assert(globalHistory < globalPredictorSize && - local_history_idx < localPredictorSize); - - globalCtrs[globalHistory].increment(); - localCtrs[local_history_idx].increment(); - + choice_prediction = choiceCtrs[globalHistory].read() > threshold; + + // Create BPHistory and pass it back to be recorded. + BPHistory *history = new BPHistory; + history->globalHistory = globalHistory; + history->localPredTaken = local_prediction; + history->globalPredTaken = global_prediction; + history->globalUsed = choice_prediction; + bp_history = (void *)history; + + assert(globalHistory < globalPredictorSize && + local_history_idx < localPredictorSize); + + // Commented code is for doing speculative update of counters and + // all histories. + if (choice_prediction) { + if (global_prediction) { +// updateHistoriesTaken(local_history_idx); +// globalCtrs[globalHistory].increment(); +// localCtrs[local_history_idx].increment(); + updateGlobalHistTaken(); return true; } else { - updateHistoriesNotTaken(local_history_idx); - - assert(globalHistory < globalPredictorSize && - local_history_idx < localPredictorSize); - - globalCtrs[globalHistory].decrement(); - localCtrs[local_history_idx].decrement(); - +// updateHistoriesNotTaken(local_history_idx); +// globalCtrs[globalHistory].decrement(); +// localCtrs[local_history_idx].decrement(); + updateGlobalHistNotTaken(); return false; } } else { - if (local_prediction > threshold) { - updateHistoriesTaken(local_history_idx); - - assert(globalHistory < globalPredictorSize && - local_history_idx < localPredictorSize); - - globalCtrs[globalHistory].increment(); - localCtrs[local_history_idx].increment(); - + if (local_prediction) { +// updateHistoriesTaken(local_history_idx); +// globalCtrs[globalHistory].increment(); +// localCtrs[local_history_idx].increment(); + updateGlobalHistTaken(); return true; } else { - updateHistoriesNotTaken(local_history_idx); - - assert(globalHistory < globalPredictorSize && - local_history_idx < localPredictorSize); - - globalCtrs[globalHistory].decrement(); - localCtrs[local_history_idx].decrement(); - +// updateHistoriesNotTaken(local_history_idx); +// globalCtrs[globalHistory].decrement(); +// localCtrs[local_history_idx].decrement(); + updateGlobalHistNotTaken(); return false; } } } -// Update the branch predictor if it predicted a branch wrong. void -TournamentBP::update(Addr &branch_addr, unsigned correct_gh, bool taken) +TournamentBP::uncondBr(void * &bp_history) { + // Create BPHistory and pass it back to be recorded. + BPHistory *history = new BPHistory; + history->globalHistory = globalHistory; + history->localPredTaken = true; + history->globalPredTaken = true; + bp_history = static_cast<void *>(history); + + updateGlobalHistTaken(); +} - uint8_t local_prediction; +void +TournamentBP::update(Addr &branch_addr, bool taken, void *bp_history) +{ unsigned local_history_idx; unsigned local_predictor_idx; - bool local_pred_taken; + unsigned local_predictor_hist; - uint8_t global_prediction; - bool global_pred_taken; - - // Load the correct global history into the register. - globalHistory = correct_gh; - - // Get the local predictor's current prediction, remove the incorrect - // update, and update the local predictor + // Get the local predictor's current prediction local_history_idx = calcLocHistIdx(branch_addr); - local_predictor_idx = localHistoryTable[local_history_idx]; - local_predictor_idx = (local_predictor_idx >> 1) & localHistoryMask; - - local_prediction = localCtrs[local_predictor_idx].read(); - local_pred_taken = local_prediction > threshold; - - //Get the global predictor's current prediction, and update the - //global predictor - global_prediction = globalCtrs[globalHistory].read(); - global_pred_taken = global_prediction > threshold; - - //Update the choice predictor to tell it which one was correct - if (local_pred_taken != global_pred_taken) { - //If the local prediction matches the actual outcome, decerement - //the counter. Otherwise increment the counter. - if (local_pred_taken == taken) { - choiceCtrs[globalHistory].decrement(); - } else { - choiceCtrs[globalHistory].increment(); + local_predictor_hist = localHistoryTable[local_history_idx]; + local_predictor_idx = local_predictor_hist & localHistoryMask; + + // Update the choice predictor to tell it which one was correct if + // there was a prediction. + if (bp_history) { + BPHistory *history = static_cast<BPHistory *>(bp_history); + if (history->localPredTaken != history->globalPredTaken) { + // If the local prediction matches the actual outcome, + // decerement the counter. Otherwise increment the + // counter. + if (history->localPredTaken == taken) { + choiceCtrs[globalHistory].decrement(); + } else if (history->globalPredTaken == taken){ + choiceCtrs[globalHistory].increment(); + } } + + // We're done with this history, now delete it. + delete history; } - if (taken) { - assert(globalHistory < globalPredictorSize && - local_predictor_idx < localPredictorSize); + assert(globalHistory < globalPredictorSize && + local_predictor_idx < localPredictorSize); + // Update the counters and local history with the proper + // resolution of the branch. Global history is updated + // speculatively and restored upon squash() calls, so it does not + // need to be updated. + if (taken) { localCtrs[local_predictor_idx].increment(); globalCtrs[globalHistory].increment(); - globalHistory = (globalHistory << 1) | 1; - globalHistory = globalHistory & globalHistoryMask; + updateLocalHistTaken(local_history_idx); + } else { + localCtrs[local_predictor_idx].decrement(); + globalCtrs[globalHistory].decrement(); - localHistoryTable[local_history_idx] |= 1; + updateLocalHistNotTaken(local_history_idx); } - else { - assert(globalHistory < globalPredictorSize && - local_predictor_idx < localPredictorSize); +} - localCtrs[local_predictor_idx].decrement(); - globalCtrs[globalHistory].decrement(); +void +TournamentBP::squash(void *bp_history) +{ + BPHistory *history = static_cast<BPHistory *>(bp_history); - globalHistory = (globalHistory << 1); - globalHistory = globalHistory & globalHistoryMask; + // Restore global history to state prior to this branch. + globalHistory = history->globalHistory; - localHistoryTable[local_history_idx] &= ~1; - } + // Delete this BPHistory now that we're done with it. + delete history; } + +#ifdef DEBUG +int +TournamentBP::BPHistory::newCount = 0; +#endif diff --git a/src/cpu/o3/tournament_pred.hh b/src/cpu/o3/tournament_pred.hh index d23142c70..92402adc6 100644 --- a/src/cpu/o3/tournament_pred.hh +++ b/src/cpu/o3/tournament_pred.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,59 +28,134 @@ * Authors: Kevin Lim */ -#ifndef __CPU_O3_CPU_TOURNAMENT_PRED_HH__ -#define __CPU_O3_CPU_TOURNAMENT_PRED_HH__ +#ifndef __CPU_O3_TOURNAMENT_PRED_HH__ +#define __CPU_O3_TOURNAMENT_PRED_HH__ // For Addr type. #include "arch/isa_traits.hh" #include "cpu/o3/sat_counter.hh" - +#include <vector> + +/** + * Implements a tournament branch predictor, hopefully identical to the one + * used in the 21264. It has a local predictor, which uses a local history + * table to index into a table of counters, and a global predictor, which + * uses a global history to index into a table of counters. A choice + * predictor chooses between the two. Only the global history register + * is speculatively updated, the rest are updated upon branches committing + * or misspeculating. + */ class TournamentBP { public: /** * Default branch predictor constructor. */ - TournamentBP(unsigned local_predictor_size, - unsigned local_ctr_bits, - unsigned local_history_table_size, - unsigned local_history_bits, - unsigned global_predictor_size, - unsigned global_history_bits, - unsigned global_ctr_bits, - unsigned choice_predictor_size, - unsigned choice_ctr_bits, + TournamentBP(unsigned localPredictorSize, + unsigned localCtrBits, + unsigned localHistoryTableSize, + unsigned localHistoryBits, + unsigned globalPredictorSize, + unsigned globalHistoryBits, + unsigned globalCtrBits, + unsigned choicePredictorSize, + unsigned choiceCtrBits, unsigned instShiftAmt); /** * Looks up the given address in the branch predictor and returns - * a true/false value as to whether it is taken. + * a true/false value as to whether it is taken. Also creates a + * BPHistory object to store any state it will need on squash/update. * @param branch_addr The address of the branch to look up. + * @param bp_history Pointer that will be set to the BPHistory object. * @return Whether or not the branch is taken. */ - bool lookup(Addr &branch_addr); + bool lookup(Addr &branch_addr, void * &bp_history); + + /** + * Records that there was an unconditional branch, and modifies + * the bp history to point to an object that has the previous + * global history stored in it. + * @param bp_history Pointer that will be set to the BPHistory object. + */ + void uncondBr(void * &bp_history); /** * Updates the branch predictor with the actual result of a branch. * @param branch_addr The address of the branch to update. * @param taken Whether or not the branch was taken. + * @param bp_history Pointer to the BPHistory object that was created + * when the branch was predicted. + */ + void update(Addr &branch_addr, bool taken, void *bp_history); + + /** + * Restores the global branch history on a squash. + * @param bp_history Pointer to the BPHistory object that has the + * previous global branch history in it. */ - void update(Addr &branch_addr, unsigned global_history, bool taken); + void squash(void *bp_history); + /** Returns the global history. */ inline unsigned readGlobalHist() { return globalHistory; } private: - + /** + * Returns if the branch should be taken or not, given a counter + * value. + * @param count The counter value. + */ inline bool getPrediction(uint8_t &count); + /** + * Returns the local history index, given a branch address. + * @param branch_addr The branch's PC address. + */ inline unsigned calcLocHistIdx(Addr &branch_addr); - inline void updateHistoriesTaken(unsigned local_history_idx); + /** Updates global history as taken. */ + inline void updateGlobalHistTaken(); + + /** Updates global history as not taken. */ + inline void updateGlobalHistNotTaken(); + + /** + * Updates local histories as taken. + * @param local_history_idx The local history table entry that + * will be updated. + */ + inline void updateLocalHistTaken(unsigned local_history_idx); + + /** + * Updates local histories as not taken. + * @param local_history_idx The local history table entry that + * will be updated. + */ + inline void updateLocalHistNotTaken(unsigned local_history_idx); - inline void updateHistoriesNotTaken(unsigned local_history_idx); + /** + * The branch history information that is created upon predicting + * a branch. It will be passed back upon updating and squashing, + * when the BP can use this information to update/restore its + * state properly. + */ + struct BPHistory { +#ifdef DEBUG + BPHistory() + { newCount++; } + ~BPHistory() + { newCount--; } + + static int newCount; +#endif + unsigned globalHistory; + bool localPredTaken; + bool globalPredTaken; + bool globalUsed; + }; /** Local counters. */ - SatCounter *localCtrs; + std::vector<SatCounter> localCtrs; /** Size of the local predictor. */ unsigned localPredictorSize; @@ -89,7 +164,7 @@ class TournamentBP unsigned localCtrBits; /** Array of local history table entries. */ - unsigned *localHistoryTable; + std::vector<unsigned> localHistoryTable; /** Size of the local history table. */ unsigned localHistoryTableSize; @@ -102,9 +177,8 @@ class TournamentBP /** Mask to get the proper local history. */ unsigned localHistoryMask; - /** Array of counters that make up the global predictor. */ - SatCounter *globalCtrs; + std::vector<SatCounter> globalCtrs; /** Size of the global predictor. */ unsigned globalPredictorSize; @@ -121,9 +195,8 @@ class TournamentBP /** Mask to get the proper global history. */ unsigned globalHistoryMask; - /** Array of counters that make up the choice predictor. */ - SatCounter *choiceCtrs; + std::vector<SatCounter> choiceCtrs; /** Size of the choice predictor (identical to the global predictor). */ unsigned choicePredictorSize; @@ -142,4 +215,4 @@ class TournamentBP unsigned threshold; }; -#endif // __CPU_O3_CPU_TOURNAMENT_PRED_HH__ +#endif // __CPU_O3_TOURNAMENT_PRED_HH__ |