| Age | Commit message (Collapse) | Author | |
|---|---|---|---|
| 2011-09-19 | Syscall: Make the syscall function available in both SE and FS modes. | Gabe Black | |
| In FS mode the syscall function will panic, but the interface will be consistent and code which calls syscall can be compiled in. This will allow, for instance, instructions that use syscall to be built unconditionally but then not returned by the decoder. | |||
| 2011-08-14 | O3: Add a pointer to the macroop for a microop in the dyninst. | Gabe Black | |
| 2011-08-02 | O3: Get rid of the raw ExtMachInst constructor on DynInsts. | Gabe Black | |
| This constructor assumes that the ExtMachInst can be decoded directly into a StaticInst that's useful to execute. With the advent of microcoded instructions that's no longer true. | |||
| 2011-07-15 | O3: Create a pipeline activity viewer for the O3 CPU model. | Giacomo Gabrielli | |
| Implemented a pipeline activity viewer as a python script (util/o3-pipeview.py) and modified O3 code base to support an extra trace flag (O3PipeView) for generating traces to be used as inputs by the tool. | |||
| 2011-04-15 | includes: sort all includes | Nathan Binkert | |
| 2011-01-18 | ARM: Add support for moving predicated false dest operands from sources. | Ali Saidi | |
| 2010-12-07 | O3: 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). | |||
| 2010-10-31 | ISA,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. | |||
| 2009-09-23 | arch: nuke arch/isa_specific.hh and move stuff to generated config/the_isa.hh | Nathan Binkert | |
| 2009-07-08 | Registers: Get rid of the float register width parameter. | Gabe Black | |
| 2008-10-20 | O3CPU: Undo Gabe's changes to remove hwrei and simpalcheck from O3 CPU. ↵ | Ali Saidi | |
| Removing hwrei causes the instruction after the hwrei to be fetched before the ITB/DTB_CM register is updated in a call pal call sys and thus the translation fails because the user is attempting to access a super page address. Minimally, it seems as though some sort of fetch stall or refetch after a hwrei is required. I think this works currently because the hwrei uses the exec context interface, and the o3 stalls when that occurs. Additionally, these changes don't update the LOCK register and probably break ll/sc. Both o3 changes were removed since a great deal of manual patching would be required to only remove the hwrei change. | |||
| 2008-10-11 | CPU: Eliminate the simPalCheck funciton. | Gabe Black | |
| 2008-10-11 | CPU: Eliminate the hwrei function. | Gabe Black | |
| 2008-10-09 | O3: Generaize the O3 dynamic instruction class so it isn't split out by ISA. | Gabe Black | |
| --HG-- rename : src/cpu/o3/dyn_inst.hh => src/cpu/o3/dyn_inst_decl.hh rename : src/cpu/o3/alpha/dyn_inst_impl.hh => src/cpu/o3/dyn_inst_impl.hh | |||
| 2008-02-05 | Add base ARM code to M5 | Stephen Hines | |
| --HG-- extra : convert_revision : d811bf87d1a0bfc712942ecd3db1b48fc75257af | |||
| 2007-03-05 | Added an x86 dyninst | Gabe Black | |
| --HG-- extra : convert_revision : 2317e9bb0bcf8010ab5d02019f7a14eeb7b1459c | |||
| 2006-08-11 | Started to add support for O3 for sparc. | Gabe Black | |
| --HG-- extra : convert_revision : 3f94bda14024a09b9fbd7a5d13284d4987349ddf | |||
| 2006-07-23 | This changeset gets the MIPS ISA pretty much working in the O3CPU. It ↵ | Korey Sewell | |
| builds, runs, and gets very very close to completing the hello world succesfully but there are some minor quirks to iron out. Who would've known a DELAY SLOT introduces that much complexity?! arrgh! Anyways, a lot of this stuff had to do with my project at MIPS and me needing to know how I was going to get this working for the MIPS ISA. So I figured I would try to touch it up and throw it in here (I hate to introduce non-completely working components... ) src/arch/alpha/isa/mem.isa: spacing src/arch/mips/faults.cc: src/arch/mips/faults.hh: Gabe really authored this src/arch/mips/isa/decoder.isa: add StoreConditional Flag to instruction src/arch/mips/isa/formats/basic.isa: Steven really did this file src/arch/mips/isa/formats/branch.isa: fix bug for uncond/cond control src/arch/mips/isa/formats/mem.isa: Adjust O3CPU memory access to use new memory model interface. src/arch/mips/isa/formats/util.isa: update LoadStoreBase template src/arch/mips/isa_traits.cc: update SERIALIZE partially src/arch/mips/process.cc: src/arch/mips/process.hh: no need for this for NOW. ASID/Virtual addressing handles it src/arch/mips/regfile/misc_regfile.hh: add in clear() function and comments for future usage of special misc. regs src/cpu/base_dyn_inst.hh: add in nextNPC variable and supporting functions. add isCondDelaySlot function Update predTaken and mispredicted functions src/cpu/base_dyn_inst_impl.hh: init nextNPC src/cpu/o3/SConscript: add MIPS files to compile src/cpu/o3/alpha/thread_context.hh: no need for my name on this file src/cpu/o3/bpred_unit_impl.hh: Update RAS appropriately for MIPS src/cpu/o3/comm.hh: add some extra communication variables to aid in handling the delay slots src/cpu/o3/commit.hh: minor name fix for nextNPC functions. src/cpu/o3/commit_impl.hh: src/cpu/o3/decode_impl.hh: src/cpu/o3/fetch_impl.hh: src/cpu/o3/iew_impl.hh: src/cpu/o3/inst_queue_impl.hh: src/cpu/o3/rename_impl.hh: Fix necessary variables and functions for squashes with delay slots src/cpu/o3/cpu.cc: Update function interface ... adjust removeInstsNotInROB function to recognize delay slots insts src/cpu/o3/cpu.hh: update removeInstsNotInROB src/cpu/o3/decode.hh: declare necessary variables for handling delay slot src/cpu/o3/dyn_inst.hh: Add in MipsDynInst src/cpu/o3/fetch.hh: src/cpu/o3/iew.hh: src/cpu/o3/rename.hh: declare necessary variables and adjust functions for handling delay slot src/cpu/o3/inst_queue.hh: src/cpu/simple/base.cc: no need for my name here src/cpu/o3/isa_specific.hh: add in MIPS files src/cpu/o3/scoreboard.hh: dont include alpha specific isa traits! src/cpu/o3/thread_context.hh: no need for my name here, i just rearranged where the file goes src/cpu/static_inst.hh: add isCondDelaySlot function src/cpu/o3/mips/cpu.cc: src/cpu/o3/mips/cpu.hh: src/cpu/o3/mips/cpu_builder.cc: src/cpu/o3/mips/cpu_impl.hh: src/cpu/o3/mips/dyn_inst.cc: src/cpu/o3/mips/dyn_inst.hh: src/cpu/o3/mips/dyn_inst_impl.hh: src/cpu/o3/mips/impl.hh: src/cpu/o3/mips/params.hh: src/cpu/o3/mips/thread_context.cc: src/cpu/o3/mips/thread_context.hh: MIPS file for O3CPU...mirrors ALPHA definition --HG-- extra : convert_revision : 9bb199b4085903e49ffd5a4c8ac44d11460d988c | |||
| 2006-07-06 | Had to add this because for some reason gcc wasnt recognizing "THE_ISA == ↵ | Korey Sewell | |
| ALPHA_ISA"... wierd but OK --HG-- extra : convert_revision : f847d6c01212e32200a319c16596b8e1c1d15c7d | |||
| 2006-07-06 | Use O3DynInst in cpu_models.py and in static_inst_exec_sigs.hh instead of a ↵ | Korey Sewell | |
| specific ISA dyn. inst. src/cpu/cpu_models.py: Use O3DynInst src/cpu/o3/dyn_inst.hh: declare O3DynInst here based off of ISA ... this must be updated for each ISA. src/cpu/static_inst.hh: take out O3 forward declarations here and include header file to keep this file clean --HG-- extra : convert_revision : 0d65463479c3cfc2d1154935b1032dae32c5efd0 | |||
| 2006-07-06 | more steps toward O3 SMT | Korey Sewell | |
| src/arch/mips/isa/formats/fp.isa: Adjust for newmem src/cpu/cpu_models.py: Use O3DynInst instead of convoluted way src/cpu/o3/alpha/impl.hh: take out O3DynInst typedef here ... src/cpu/o3/cpu.cc: open up the SMT functions in the O3CPU src/cpu/static_inst.hh: Add O3DynInst src/cpu/o3/dyn_inst.hh: Use to get ISA-specific O3DynInst --HG-- extra : convert_revision : 3713187ead93e336e80889e23a1f1d2f36d664fe | |||
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