diff options
Diffstat (limited to 'src/cpu/o3/rob.hh')
| -rw-r--r-- | src/cpu/o3/rob.hh | 232 |
1 files changed, 191 insertions, 41 deletions
diff --git a/src/cpu/o3/rob.hh b/src/cpu/o3/rob.hh index 1185564ad..e05eebe5a 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 @@ -26,23 +26,15 @@ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ -// 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 @@ -54,16 +46,43 @@ 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. @@ -71,12 +90,19 @@ 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); + + void switchOut(); + + 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); @@ -84,40 +110,134 @@ 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 @@ -125,23 +245,46 @@ 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 @@ -149,16 +292,23 @@ 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; + 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__ |