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2011-01-18O3: Fixes the way prefetches are handled inside the iew unit.Matt Horsnell
This patch prevents the prefetch being added to the instCommit queue twice.
2011-01-18O3: Support timing translations for O3 CPU fetch.Ali Saidi
2011-01-18ARM: Add support for moving predicated false dest operands from sources.Ali Saidi
2011-01-18O3: Fixes fetch deadlock when the interrupt clears before CPU handles it.Min Kyu Jeong
When this condition occurs the cpu should restart the fetch stage to fetch from the original execution path. Fault handling in the commit stage is cleaned up a little bit so the control flow is simplier. Finally, if an instruction is being used to carry a fault it isn't executed, so the fault propagates appropriately.
2011-01-07Replace curTick global variable with accessor functions.Steve Reinhardt
This step makes it easy to replace the accessor functions (which still access a global variable) with ones that access per-thread curTick values.
2011-01-03Move sched_list.hh and timebuf.hh from src/base to src/cpu.Steve Reinhardt
These files really aren't general enough to belong in src/base. This patch doesn't reorder include lines, leaving them unsorted in many cases, but Nate's magic script will fix that up shortly. --HG-- rename : src/base/sched_list.hh => src/cpu/sched_list.hh rename : src/base/timebuf.hh => src/cpu/timebuf.hh
2010-12-07O3: Allow a store entry to store up to 16 bytes (instead of TheISA::IntReg).Ali Saidi
The store queue doesn't need to be ISA specific and architectures can frequently store more than an int registers worth of data. A 128 bits seems more common, but even 256 bits may be appropriate. Pretty much anything less than a cache line size is buildable.
2010-12-07O3: Support squashing all state after special instructionAli Saidi
For SPARC ASIs are added to the ExtMachInst. If the ASI is changed simply marking the instruction as Serializing isn't enough beacuse that only stops rename. This provides a mechanism to squash all the instructions and refetch them
2010-12-07O3: Make all instructions that write a misc. register not perform the write ↵Giacomo Gabrielli
until commit. ARM instructions updating cumulative flags (ARM FP exceptions and saturation flags) are not serialized. Added aliases for ARM FP exceptions and saturation flags in FPSCR. Removed write accesses to the FP condition codes for most ARM VFP instructions: only VCMP and VCMPE instructions update the FP condition codes. Removed a potential cause of seg. faults in the O3 model for NEON memory macro-ops (ARM).
2010-12-07O3: Support SWAP and predicated loads/store in ARM.Min Kyu Jeong
2010-11-18O3: Fix fp destination register flattening, and index offset adjusting.Gabe Black
This change makes O3 flatten floating point destination registers, and also fixes misc register flattening so that it's correctly repositioned relative to the resized regions for integer and floating point indices. It also fixes some overly long lines.
2010-11-15O3: Make O3 support variably lengthed instructions.Gabe Black
2010-11-15O3: reset architetural state by calling clear()Ali Saidi
2010-11-15CPU/ARM: Add SIMD op classes to CPU models and ARM ISA.Giacomo Gabrielli
2010-11-15O3: prevent a squash when completeAcc() modifies misc reg through TC.Min Kyu Jeong
This happens on ARM instructions when they update the IT state bits. Code and associated comment was copied from execute() and initiateAcc() methods
2010-10-31ISA,CPU,etc: Create an ISA defined PC type that abstracts out ISA behaviors.Gabe Black
This change is a low level and pervasive reorganization of how PCs are managed in M5. Back when Alpha was the only ISA, there were only 2 PCs to worry about, the PC and the NPC, and the lsb of the PC signaled whether or not you were in PAL mode. As other ISAs were added, we had to add an NNPC, micro PC and next micropc, x86 and ARM introduced variable length instruction sets, and ARM started to keep track of mode bits in the PC. Each CPU model handled PCs in its own custom way that needed to be updated individually to handle the new dimensions of variability, or, in the case of ARMs mode-bit-in-the-pc hack, the complexity could be hidden in the ISA at the ISA implementation's expense. Areas like the branch predictor hadn't been updated to handle branch delay slots or micropcs, and it turns out that had introduced a significant (10s of percent) performance bug in SPARC and to a lesser extend MIPS. Rather than perpetuate the problem by reworking O3 again to handle the PC features needed by x86, this change was introduced to rework PC handling in a more modular, transparent, and hopefully efficient way. PC type: Rather than having the superset of all possible elements of PC state declared in each of the CPU models, each ISA defines its own PCState type which has exactly the elements it needs. A cross product of canned PCState classes are defined in the new "generic" ISA directory for ISAs with/without delay slots and microcode. These are either typedef-ed or subclassed by each ISA. To read or write this structure through a *Context, you use the new pcState() accessor which reads or writes depending on whether it has an argument. If you just want the address of the current or next instruction or the current micro PC, you can get those through read-only accessors on either the PCState type or the *Contexts. These are instAddr(), nextInstAddr(), and microPC(). Note the move away from readPC. That name is ambiguous since it's not clear whether or not it should be the actual address to fetch from, or if it should have extra bits in it like the PAL mode bit. Each class is free to define its own functions to get at whatever values it needs however it needs to to be used in ISA specific code. Eventually Alpha's PAL mode bit could be moved out of the PC and into a separate field like ARM. These types can be reset to a particular pc (where npc = pc + sizeof(MachInst), nnpc = npc + sizeof(MachInst), upc = 0, nupc = 1 as appropriate), printed, serialized, and compared. There is a branching() function which encapsulates code in the CPU models that checked if an instruction branched or not. Exactly what that means in the context of branch delay slots which can skip an instruction when not taken is ambiguous, and ideally this function and its uses can be eliminated. PCStates also generally know how to advance themselves in various ways depending on if they point at an instruction, a microop, or the last microop of a macroop. More on that later. Ideally, accessing all the PCs at once when setting them will improve performance of M5 even though more data needs to be moved around. This is because often all the PCs need to be manipulated together, and by getting them all at once you avoid multiple function calls. Also, the PCs of a particular thread will have spatial locality in the cache. Previously they were grouped by element in arrays which spread out accesses. Advancing the PC: The PCs were previously managed entirely by the CPU which had to know about PC semantics, try to figure out which dimension to increment the PC in, what to set NPC/NNPC, etc. These decisions are best left to the ISA in conjunction with the PC type itself. Because most of the information about how to increment the PC (mainly what type of instruction it refers to) is contained in the instruction object, a new advancePC virtual function was added to the StaticInst class. Subclasses provide an implementation that moves around the right element of the PC with a minimal amount of decision making. In ISAs like Alpha, the instructions always simply assign NPC to PC without having to worry about micropcs, nnpcs, etc. The added cost of a virtual function call should be outweighed by not having to figure out as much about what to do with the PCs and mucking around with the extra elements. One drawback of making the StaticInsts advance the PC is that you have to actually have one to advance the PC. This would, superficially, seem to require decoding an instruction before fetch could advance. This is, as far as I can tell, realistic. fetch would advance through memory addresses, not PCs, perhaps predicting new memory addresses using existing ones. More sophisticated decisions about control flow would be made later on, after the instruction was decoded, and handed back to fetch. If branching needs to happen, some amount of decoding needs to happen to see that it's a branch, what the target is, etc. This could get a little more complicated if that gets done by the predecoder, but I'm choosing to ignore that for now. Variable length instructions: To handle variable length instructions in x86 and ARM, the predecoder now takes in the current PC by reference to the getExtMachInst function. It can modify the PC however it needs to (by setting NPC to be the PC + instruction length, for instance). This could be improved since the CPU doesn't know if the PC was modified and always has to write it back. ISA parser: To support the new API, all PC related operand types were removed from the parser and replaced with a PCState type. There are two warts on this implementation. First, as with all the other operand types, the PCState still has to have a valid operand type even though it doesn't use it. Second, using syntax like PCS.npc(target) doesn't work for two reasons, this looks like the syntax for operand type overriding, and the parser can't figure out if you're reading or writing. Instructions that use the PCS operand (which I've consistently called it) need to first read it into a local variable, manipulate it, and then write it back out. Return address stack: The return address stack needed a little extra help because, in the presence of branch delay slots, it has to merge together elements of the return PC and the call PC. To handle that, a buildRetPC utility function was added. There are basically only two versions in all the ISAs, but it didn't seem short enough to put into the generic ISA directory. Also, the branch predictor code in O3 and InOrder were adjusted so that they always store the PC of the actual call instruction in the RAS, not the next PC. If the call instruction is a microop, the next PC refers to the next microop in the same macroop which is probably not desirable. The buildRetPC function advances the PC intelligently to the next macroop (in an ISA specific way) so that that case works. Change in stats: There were no change in stats except in MIPS and SPARC in the O3 model. MIPS runs in about 9% fewer ticks. SPARC runs with 30%-50% fewer ticks, which could likely be improved further by setting call/return instruction flags and taking advantage of the RAS. TODO: Add != operators to the PCState classes, defined trivially to be !(a==b). Smooth out places where PCs are split apart, passed around, and put back together later. I think this might happen in SPARC's fault code. Add ISA specific constructors that allow setting PC elements without calling a bunch of accessors. Try to eliminate the need for the branching() function. Factor out Alpha's PAL mode pc bit into a separate flag field, and eliminate places where it's blindly masked out or tested in the PC.
2010-10-24O3: Get rid of a bunch of commented out lines.Gabe Black
2010-10-04Alpha: Fix Alpha NumMiscArchRegs constant.Gabe Black
Also add asserts in O3's Scoreboard class to catch bad indexes.
2010-09-20CPU: Fix O3 and possible InOrder segfaults in FS.Gabe Black
2010-09-13CPU: Get rid of the now unnecessary getInst/setInst family of functions.Gabe Black
This code is no longer needed because of the preceeding change which adds a StaticInstPtr parameter to the fault's invoke method, obviating the only use for this pair of functions.
2010-09-13Faults: Pass the StaticInst involved, if any, to a Fault's invoke method.Gabe Black
Also move the "Fault" reference counted pointer type into a separate file, sim/fault.hh. It would be better to name this less similarly to sim/faults.hh to reduce confusion, but fault.hh matches the name of the type. We could change Fault to FaultPtr to match other pointer types, and then changing the name of the file would make more sense.
2010-09-10style: fix sorting of includes and whitespace in some filesNathan Binkert
2010-08-25ARM: Fixed register flattening logic (FP_Base_DepTag was set too low)Min Kyu Jeong
When decoding a srs instruction, invalid mode encoding returns invalid instruction. This can happen when garbage instructions are fetched from mispredicted path
2010-08-23ISA: Get rid of old, unused utility functions cluttering up the ISAs.Gabe Black
2010-08-23O3: Skipping mem-order violation check for uncachable loads.Min Kyu Jeong
Uncachable load is not executed until it reaches the head of the ROB, hence cannot cause one.
2010-08-23ARM: Improve printing of uop disassembly.Min Kyu Jeong
2010-08-23CPU: Make Exec trace to print predication result (if false) for memory ↵Min Kyu Jeong
instructions
2010-08-23ARM: mark msr/mrs instructions as SerializeBefore/AfterMin Kyu Jeong
Since miscellaneous registers bypass wakeup logic, force serialization to resolve data dependencies through them * * * ARM: adding non-speculative/serialize flags for instructions change CPSR
2010-08-23O3: Handle loads when the destination is the PC.Min Kyu Jeong
For loads that PC is the destination, check if the load was mispredicted again when the value being loaded returns from memory
2010-08-23ARM/O3: store the result of the predicate evaluation in DynInst or Threadstate.Min Kyu Jeong
THis allows the CPU to handle predicated-false instructions accordingly. This particular patch makes loads that are predicated-false to be sent straight to the commit stage directly, not waiting for return of the data that was never requested since it was predicated-false.
2010-08-13CPU: Add readBytes and writeBytes functions to the exec contexts.Gabe Black
2010-07-22LSQ Unit: After deleting part of a split request, set it to NULL so that itTimothy M. Jones
isn't accidentally deleted again later (causing a segmentation fault).
2010-07-22O3CPU: Fix a bug where stores in the cpu where never marked as split.Timothy M. Jones
2010-07-22O3CPU: O3's tick event gets squashed when it is switched out. When repeatedlyTimothy M. Jones
switching between O3 and another CPU, O3's tick event might still be scheduled in the event queue (as squashed). Therefore, check for a squashed tick event as well as a non-scheduled event when taking over from another CPU and deal with it accordingly.
2010-06-23O3ThreadContext: When taking over from a previous context, only assert thatTimothy M. Jones
the system pointers match in Full System mode.
2010-02-26cpu_models: get rid of cpu_models.py and move the stuff into SConsNathan Binkert
2010-02-12O3PCU: Split loads and stores that cross cache line boundaries.Timothy M. Jones
When each load or store is sent to the LSQ, we check whether it will cross a cache line boundary and, if so, split it in two. This creates two TLB translations and two memory requests. Care has to be taken if the first packet of a split load is sent but the second blocks the cache. Similarly, for a store, if the first packet cannot be sent, we must store the second one somewhere to retry later. This modifies the LSQSenderState class to record both packets in a split load or store. Finally, a new const variable, HasUnalignedMemAcc, is added to each ISA to indicate whether unaligned memory accesses are allowed. This is used throughout the changed code so that compiler can optimise away code dealing with split requests for ISAs that don't need them.
2009-11-04o3: get rid of unused physmem pointerSteve Reinhardt
2009-09-26O3: Add flag to control whether faulting instructions are traced.Steve Reinhardt
When enabled, faulting instructions appear in the trace twice (once when they fault and again when they're re-executed). This flag is set by the Exec compound flag for backwards compatibility.
2009-09-26O3: Mark fetch stage as active if it faults.Steve Reinhardt
Otherwise if the rest of the pipeline is idle then fault will never propagate to commit to be handled, causing CPU to deadlock.
2009-09-23arch: nuke arch/isa_specific.hh and move stuff to generated config/the_isa.hhNathan Binkert
2009-09-22python: Move more code into m5.util allow SCons to use that code.Nathan Binkert
Get rid of misc.py and just stick misc things in __init__.py Move utility functions out of SCons files and into m5.util Move utility type stuff from m5/__init__.py to m5/util/__init__.py Remove buildEnv from m5 and allow access only from m5.defines Rename AddToPath to addToPath while we're moving it to m5.util Rename read_command to readCommand while we're moving it Rename compare_versions to compareVersions while we're moving it. --HG-- rename : src/python/m5/convert.py => src/python/m5/util/convert.py rename : src/python/m5/smartdict.py => src/python/m5/util/smartdict.py
2009-08-01Fix setting of INST_FETCH flag for O3 CPU.Steve Reinhardt
It's still broken in inorder. Also enhance DPRINTFs in cache and physical memory so we can see more easily whether it's getting set or not.
2009-07-25o3-smt: enforce numThreads parameter for SMT SE modeKorey Sewell
2009-07-08Get rid of the unused get(Data|Inst)Asid and (inst|data)Asid functions.Gabe Black
2009-07-08Registers: Add a registers.hh file as an ISA switched header.Gabe Black
This file is for register indices, Num* constants, and register types. copyRegs and copyMiscRegs were moved to utility.hh and utility.cc. --HG-- rename : src/arch/alpha/regfile.hh => src/arch/alpha/registers.hh rename : src/arch/arm/regfile.hh => src/arch/arm/registers.hh rename : src/arch/mips/regfile.hh => src/arch/mips/registers.hh rename : src/arch/sparc/regfile.hh => src/arch/sparc/registers.hh rename : src/arch/x86/regfile.hh => src/arch/x86/registers.hh
2009-07-08Registers: Get rid of the float register width parameter.Gabe Black
2009-07-08Registers: Add an ISA object which replaces the MiscRegFile.Gabe Black
This object encapsulates (or will eventually) the identity and characteristics of the ISA in the CPU.
2009-06-04move: put predictor includes and cc files into the same placeNathan Binkert
--HG-- rename : src/cpu/2bit_local_pred.cc => src/cpu/pred/2bit_local.cc rename : src/cpu/o3/2bit_local_pred.hh => src/cpu/pred/2bit_local.hh rename : src/cpu/btb.cc => src/cpu/pred/btb.cc rename : src/cpu/o3/btb.hh => src/cpu/pred/btb.hh rename : src/cpu/ras.cc => src/cpu/pred/ras.cc rename : src/cpu/o3/ras.hh => src/cpu/pred/ras.hh rename : src/cpu/tournament_pred.cc => src/cpu/pred/tournament.cc rename : src/cpu/o3/tournament_pred.hh => src/cpu/pred/tournament.hh
2009-05-26types: add a type for thread IDs and try to use it everywhereNathan Binkert