gem5/src/cpu/o3/comm.hh

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/*
* Copyright (c) 2011 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* 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
*/
#ifndef __CPU_O3_COMM_HH__
#define __CPU_O3_COMM_HH__
Update to make multiple instruction issue and different latencies work. Also change to ref counted DynInst. SConscript: Add branch predictor, BTB, load store queue, and storesets. arch/isa_parser.py: Specify the template parameter for AlphaDynInst base/traceflags.py: Add load store queue, store set, and mem dependence unit to the list of trace flags. cpu/base_dyn_inst.cc: Change formating, add in debug statement. cpu/base_dyn_inst.hh: Change DynInst to be RefCounted, add flag to clear whether or not this instruction can commit. This is likely to be removed in the future. cpu/beta_cpu/alpha_dyn_inst.cc: AlphaDynInst has been changed to be templated, so now this CC file is just used to force instantiations of AlphaDynInst. cpu/beta_cpu/alpha_dyn_inst.hh: Changed AlphaDynInst to be templated on Impl. Removed some unnecessary functions. cpu/beta_cpu/alpha_full_cpu.cc: AlphaFullCPU has been changed to be templated, so this CC file is now just used to force instantation of AlphaFullCPU. cpu/beta_cpu/alpha_full_cpu.hh: Change AlphaFullCPU to be templated on Impl. cpu/beta_cpu/alpha_impl.hh: Update it to reflect AlphaDynInst and AlphaFullCPU being templated on Impl. Also removed time buffers from here, as they are really a part of the CPU and are thus in the CPU policy now. cpu/beta_cpu/alpha_params.hh: Make AlphaSimpleParams inherit from the BaseFullCPU so that it doesn't need to specifically declare any parameters that are already in the BaseFullCPU. cpu/beta_cpu/comm.hh: Changed the structure of the time buffer communication structs. Now they include the size of the packet of instructions it is sending. Added some parameters to the backwards communication struct, mainly for squashing. cpu/beta_cpu/commit.hh: Update typenames to reflect change in location of time buffer structs. Update DynInst to DynInstPtr (it is refcounted now). cpu/beta_cpu/commit_impl.hh: Formatting changes mainly. Also sends back proper information on branch mispredicts so that the bpred unit can update itself. Updated behavior for non-speculative instructions (stores, any other non-spec instructions): once they reach the head of the ROB, the ROB signals back to the IQ that it can go ahead and issue the non-speculative instruction. The instruction itself is updated so that commit won't try to commit it again until it is done executing. cpu/beta_cpu/cpu_policy.hh: Added branch prediction unit, mem dependence prediction unit, load store queue. Moved time buffer structs from AlphaSimpleImpl to here. cpu/beta_cpu/decode.hh: Changed typedefs to reflect change in location of time buffer structs and also the change from DynInst to ref counted DynInstPtr. cpu/beta_cpu/decode_impl.hh: Continues to buffer instructions even while unblocking now. Changed how it loops through groups of instructions so it can properly block during the middle of a group of instructions. cpu/beta_cpu/fetch.hh: Changed typedefs to reflect change in location of time buffer structs and the change to ref counted DynInsts. Also added in branch brediction unit. cpu/beta_cpu/fetch_impl.hh: Add in branch prediction. Changed how fetch checks inputs and its current state to make for easier logic. cpu/beta_cpu/free_list.cc: Changed int regs and float regs to logically use one flat namespace. Future change will be moving them to a single scoreboard to conserve space. cpu/beta_cpu/free_list.hh: Mostly debugging statements. Might be removed for performance in future. cpu/beta_cpu/full_cpu.cc: Added in some debugging statements. Updated BaseFullCPU to take a params object. cpu/beta_cpu/full_cpu.hh: Added params class within BaseCPU that other param classes will be able to inherit from. Updated typedefs to reflect change in location of time buffer structs and ref counted DynInst. cpu/beta_cpu/iew.hh: Updated typedefs to reflect change in location of time buffer structs and use of ref counted DynInsts. cpu/beta_cpu/iew_impl.hh: Added in load store queue, updated iew to be able to execute non- speculative instructions, instead of having them execute in commit. cpu/beta_cpu/inst_queue.hh: Updated change to ref counted DynInsts. Changed inst queue to hold non-speculative instructions as well, which are issued only when commit signals backwards that a nonspeculative instruction is at the head of the ROB. cpu/beta_cpu/inst_queue_impl.hh: Updated to allow for non-speculative instructions to be in the inst queue. Also added some debug functions. cpu/beta_cpu/regfile.hh: Added debugging statements, changed formatting. cpu/beta_cpu/rename.hh: Updated typedefs, added some functions to clean up code. cpu/beta_cpu/rename_impl.hh: Moved some code into functions to make it easier to read. cpu/beta_cpu/rename_map.cc: Changed int and float reg behavior to use a single flat namespace. In the future, the rename maps can be combined to a single rename map to save space. cpu/beta_cpu/rename_map.hh: Added destructor. cpu/beta_cpu/rob.hh: Updated it with change from DynInst to ref counted DynInst. cpu/beta_cpu/rob_impl.hh: Formatting, updated to use ref counted DynInst. cpu/static_inst.hh: Updated forward declaration for AlphaDynInst now that it is templated. --HG-- extra : convert_revision : 1045f240ee9b6a4bd368e1806aca029ebbdc6dd3
2004-09-23 20:06:03 +02:00
#include <vector>
Fix up code for initial release. The main bug that remains is properly forwarding data from stores to loads, specifically when they are of differing sizes. cpu/base_dyn_inst.cc: Remove unused commented out code. cpu/base_dyn_inst.hh: Fix up comments. cpu/beta_cpu/2bit_local_pred.cc: Reorder code to match header file. cpu/beta_cpu/2bit_local_pred.hh: Update comments. cpu/beta_cpu/alpha_dyn_inst.hh: Remove useless comments. cpu/beta_cpu/alpha_dyn_inst_impl.hh: cpu/beta_cpu/alpha_full_cpu_impl.hh: cpu/beta_cpu/comm.hh: cpu/beta_cpu/iew_impl.hh: Remove unused commented code. cpu/beta_cpu/alpha_full_cpu.hh: Remove obsolete comment. cpu/beta_cpu/alpha_impl.hh: cpu/beta_cpu/full_cpu.hh: Alphabetize includes. cpu/beta_cpu/bpred_unit.hh: Remove unused global history code. cpu/beta_cpu/btb.hh: cpu/beta_cpu/free_list.hh: Use full path in #defines. cpu/beta_cpu/commit.hh: cpu/beta_cpu/decode.hh: Reorder functions. cpu/beta_cpu/commit_impl.hh: Remove obsolete commented code. cpu/beta_cpu/fetch.hh: Remove obsolete comments. cpu/beta_cpu/fetch_impl.hh: cpu/beta_cpu/rename_impl.hh: Remove commented code. cpu/beta_cpu/full_cpu.cc: Remove useless defines. cpu/beta_cpu/inst_queue.hh: Use full path for #defines. cpu/beta_cpu/inst_queue_impl.hh: Reorder functions to match header file. cpu/beta_cpu/mem_dep_unit.hh: Use full path name for #defines. cpu/beta_cpu/ras.hh: Use full path names for #defines. Remove mod operation. cpu/beta_cpu/regfile.hh: Remove unused commented code, fix up current comments. cpu/beta_cpu/tournament_pred.cc: cpu/beta_cpu/tournament_pred.hh: Update programming style. --HG-- extra : convert_revision : fb9d18a853f58a1108ff827e3c123d5b52a0608a
2005-05-19 07:28:25 +02:00
ISA,CPU,etc: Create an ISA defined PC type that abstracts out ISA behaviors. 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.
2010-10-31 08:07:20 +01:00
#include "arch/types.hh"
#include "base/types.hh"
2009-05-17 23:34:52 +02:00
#include "cpu/inst_seq.hh"
#include "sim/faults.hh"
// 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 DefaultFetchDefaultDecode {
Update to make multiple instruction issue and different latencies work. Also change to ref counted DynInst. SConscript: Add branch predictor, BTB, load store queue, and storesets. arch/isa_parser.py: Specify the template parameter for AlphaDynInst base/traceflags.py: Add load store queue, store set, and mem dependence unit to the list of trace flags. cpu/base_dyn_inst.cc: Change formating, add in debug statement. cpu/base_dyn_inst.hh: Change DynInst to be RefCounted, add flag to clear whether or not this instruction can commit. This is likely to be removed in the future. cpu/beta_cpu/alpha_dyn_inst.cc: AlphaDynInst has been changed to be templated, so now this CC file is just used to force instantiations of AlphaDynInst. cpu/beta_cpu/alpha_dyn_inst.hh: Changed AlphaDynInst to be templated on Impl. Removed some unnecessary functions. cpu/beta_cpu/alpha_full_cpu.cc: AlphaFullCPU has been changed to be templated, so this CC file is now just used to force instantation of AlphaFullCPU. cpu/beta_cpu/alpha_full_cpu.hh: Change AlphaFullCPU to be templated on Impl. cpu/beta_cpu/alpha_impl.hh: Update it to reflect AlphaDynInst and AlphaFullCPU being templated on Impl. Also removed time buffers from here, as they are really a part of the CPU and are thus in the CPU policy now. cpu/beta_cpu/alpha_params.hh: Make AlphaSimpleParams inherit from the BaseFullCPU so that it doesn't need to specifically declare any parameters that are already in the BaseFullCPU. cpu/beta_cpu/comm.hh: Changed the structure of the time buffer communication structs. Now they include the size of the packet of instructions it is sending. Added some parameters to the backwards communication struct, mainly for squashing. cpu/beta_cpu/commit.hh: Update typenames to reflect change in location of time buffer structs. Update DynInst to DynInstPtr (it is refcounted now). cpu/beta_cpu/commit_impl.hh: Formatting changes mainly. Also sends back proper information on branch mispredicts so that the bpred unit can update itself. Updated behavior for non-speculative instructions (stores, any other non-spec instructions): once they reach the head of the ROB, the ROB signals back to the IQ that it can go ahead and issue the non-speculative instruction. The instruction itself is updated so that commit won't try to commit it again until it is done executing. cpu/beta_cpu/cpu_policy.hh: Added branch prediction unit, mem dependence prediction unit, load store queue. Moved time buffer structs from AlphaSimpleImpl to here. cpu/beta_cpu/decode.hh: Changed typedefs to reflect change in location of time buffer structs and also the change from DynInst to ref counted DynInstPtr. cpu/beta_cpu/decode_impl.hh: Continues to buffer instructions even while unblocking now. Changed how it loops through groups of instructions so it can properly block during the middle of a group of instructions. cpu/beta_cpu/fetch.hh: Changed typedefs to reflect change in location of time buffer structs and the change to ref counted DynInsts. Also added in branch brediction unit. cpu/beta_cpu/fetch_impl.hh: Add in branch prediction. Changed how fetch checks inputs and its current state to make for easier logic. cpu/beta_cpu/free_list.cc: Changed int regs and float regs to logically use one flat namespace. Future change will be moving them to a single scoreboard to conserve space. cpu/beta_cpu/free_list.hh: Mostly debugging statements. Might be removed for performance in future. cpu/beta_cpu/full_cpu.cc: Added in some debugging statements. Updated BaseFullCPU to take a params object. cpu/beta_cpu/full_cpu.hh: Added params class within BaseCPU that other param classes will be able to inherit from. Updated typedefs to reflect change in location of time buffer structs and ref counted DynInst. cpu/beta_cpu/iew.hh: Updated typedefs to reflect change in location of time buffer structs and use of ref counted DynInsts. cpu/beta_cpu/iew_impl.hh: Added in load store queue, updated iew to be able to execute non- speculative instructions, instead of having them execute in commit. cpu/beta_cpu/inst_queue.hh: Updated change to ref counted DynInsts. Changed inst queue to hold non-speculative instructions as well, which are issued only when commit signals backwards that a nonspeculative instruction is at the head of the ROB. cpu/beta_cpu/inst_queue_impl.hh: Updated to allow for non-speculative instructions to be in the inst queue. Also added some debug functions. cpu/beta_cpu/regfile.hh: Added debugging statements, changed formatting. cpu/beta_cpu/rename.hh: Updated typedefs, added some functions to clean up code. cpu/beta_cpu/rename_impl.hh: Moved some code into functions to make it easier to read. cpu/beta_cpu/rename_map.cc: Changed int and float reg behavior to use a single flat namespace. In the future, the rename maps can be combined to a single rename map to save space. cpu/beta_cpu/rename_map.hh: Added destructor. cpu/beta_cpu/rob.hh: Updated it with change from DynInst to ref counted DynInst. cpu/beta_cpu/rob_impl.hh: Formatting, updated to use ref counted DynInst. cpu/static_inst.hh: Updated forward declaration for AlphaDynInst now that it is templated. --HG-- extra : convert_revision : 1045f240ee9b6a4bd368e1806aca029ebbdc6dd3
2004-09-23 20:06:03 +02:00
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 DefaultDecodeDefaultRename {
Update to make multiple instruction issue and different latencies work. Also change to ref counted DynInst. SConscript: Add branch predictor, BTB, load store queue, and storesets. arch/isa_parser.py: Specify the template parameter for AlphaDynInst base/traceflags.py: Add load store queue, store set, and mem dependence unit to the list of trace flags. cpu/base_dyn_inst.cc: Change formating, add in debug statement. cpu/base_dyn_inst.hh: Change DynInst to be RefCounted, add flag to clear whether or not this instruction can commit. This is likely to be removed in the future. cpu/beta_cpu/alpha_dyn_inst.cc: AlphaDynInst has been changed to be templated, so now this CC file is just used to force instantiations of AlphaDynInst. cpu/beta_cpu/alpha_dyn_inst.hh: Changed AlphaDynInst to be templated on Impl. Removed some unnecessary functions. cpu/beta_cpu/alpha_full_cpu.cc: AlphaFullCPU has been changed to be templated, so this CC file is now just used to force instantation of AlphaFullCPU. cpu/beta_cpu/alpha_full_cpu.hh: Change AlphaFullCPU to be templated on Impl. cpu/beta_cpu/alpha_impl.hh: Update it to reflect AlphaDynInst and AlphaFullCPU being templated on Impl. Also removed time buffers from here, as they are really a part of the CPU and are thus in the CPU policy now. cpu/beta_cpu/alpha_params.hh: Make AlphaSimpleParams inherit from the BaseFullCPU so that it doesn't need to specifically declare any parameters that are already in the BaseFullCPU. cpu/beta_cpu/comm.hh: Changed the structure of the time buffer communication structs. Now they include the size of the packet of instructions it is sending. Added some parameters to the backwards communication struct, mainly for squashing. cpu/beta_cpu/commit.hh: Update typenames to reflect change in location of time buffer structs. Update DynInst to DynInstPtr (it is refcounted now). cpu/beta_cpu/commit_impl.hh: Formatting changes mainly. Also sends back proper information on branch mispredicts so that the bpred unit can update itself. Updated behavior for non-speculative instructions (stores, any other non-spec instructions): once they reach the head of the ROB, the ROB signals back to the IQ that it can go ahead and issue the non-speculative instruction. The instruction itself is updated so that commit won't try to commit it again until it is done executing. cpu/beta_cpu/cpu_policy.hh: Added branch prediction unit, mem dependence prediction unit, load store queue. Moved time buffer structs from AlphaSimpleImpl to here. cpu/beta_cpu/decode.hh: Changed typedefs to reflect change in location of time buffer structs and also the change from DynInst to ref counted DynInstPtr. cpu/beta_cpu/decode_impl.hh: Continues to buffer instructions even while unblocking now. Changed how it loops through groups of instructions so it can properly block during the middle of a group of instructions. cpu/beta_cpu/fetch.hh: Changed typedefs to reflect change in location of time buffer structs and the change to ref counted DynInsts. Also added in branch brediction unit. cpu/beta_cpu/fetch_impl.hh: Add in branch prediction. Changed how fetch checks inputs and its current state to make for easier logic. cpu/beta_cpu/free_list.cc: Changed int regs and float regs to logically use one flat namespace. Future change will be moving them to a single scoreboard to conserve space. cpu/beta_cpu/free_list.hh: Mostly debugging statements. Might be removed for performance in future. cpu/beta_cpu/full_cpu.cc: Added in some debugging statements. Updated BaseFullCPU to take a params object. cpu/beta_cpu/full_cpu.hh: Added params class within BaseCPU that other param classes will be able to inherit from. Updated typedefs to reflect change in location of time buffer structs and ref counted DynInst. cpu/beta_cpu/iew.hh: Updated typedefs to reflect change in location of time buffer structs and use of ref counted DynInsts. cpu/beta_cpu/iew_impl.hh: Added in load store queue, updated iew to be able to execute non- speculative instructions, instead of having them execute in commit. cpu/beta_cpu/inst_queue.hh: Updated change to ref counted DynInsts. Changed inst queue to hold non-speculative instructions as well, which are issued only when commit signals backwards that a nonspeculative instruction is at the head of the ROB. cpu/beta_cpu/inst_queue_impl.hh: Updated to allow for non-speculative instructions to be in the inst queue. Also added some debug functions. cpu/beta_cpu/regfile.hh: Added debugging statements, changed formatting. cpu/beta_cpu/rename.hh: Updated typedefs, added some functions to clean up code. cpu/beta_cpu/rename_impl.hh: Moved some code into functions to make it easier to read. cpu/beta_cpu/rename_map.cc: Changed int and float reg behavior to use a single flat namespace. In the future, the rename maps can be combined to a single rename map to save space. cpu/beta_cpu/rename_map.hh: Added destructor. cpu/beta_cpu/rob.hh: Updated it with change from DynInst to ref counted DynInst. cpu/beta_cpu/rob_impl.hh: Formatting, updated to use ref counted DynInst. cpu/static_inst.hh: Updated forward declaration for AlphaDynInst now that it is templated. --HG-- extra : convert_revision : 1045f240ee9b6a4bd368e1806aca029ebbdc6dd3
2004-09-23 20:06:03 +02:00
typedef typename Impl::DynInstPtr DynInstPtr;
int size;
DynInstPtr insts[Impl::MaxWidth];
};
/** Struct that defines the information passed from rename to IEW. */
template<class Impl>
struct DefaultRenameDefaultIEW {
Update to make multiple instruction issue and different latencies work. Also change to ref counted DynInst. SConscript: Add branch predictor, BTB, load store queue, and storesets. arch/isa_parser.py: Specify the template parameter for AlphaDynInst base/traceflags.py: Add load store queue, store set, and mem dependence unit to the list of trace flags. cpu/base_dyn_inst.cc: Change formating, add in debug statement. cpu/base_dyn_inst.hh: Change DynInst to be RefCounted, add flag to clear whether or not this instruction can commit. This is likely to be removed in the future. cpu/beta_cpu/alpha_dyn_inst.cc: AlphaDynInst has been changed to be templated, so now this CC file is just used to force instantiations of AlphaDynInst. cpu/beta_cpu/alpha_dyn_inst.hh: Changed AlphaDynInst to be templated on Impl. Removed some unnecessary functions. cpu/beta_cpu/alpha_full_cpu.cc: AlphaFullCPU has been changed to be templated, so this CC file is now just used to force instantation of AlphaFullCPU. cpu/beta_cpu/alpha_full_cpu.hh: Change AlphaFullCPU to be templated on Impl. cpu/beta_cpu/alpha_impl.hh: Update it to reflect AlphaDynInst and AlphaFullCPU being templated on Impl. Also removed time buffers from here, as they are really a part of the CPU and are thus in the CPU policy now. cpu/beta_cpu/alpha_params.hh: Make AlphaSimpleParams inherit from the BaseFullCPU so that it doesn't need to specifically declare any parameters that are already in the BaseFullCPU. cpu/beta_cpu/comm.hh: Changed the structure of the time buffer communication structs. Now they include the size of the packet of instructions it is sending. Added some parameters to the backwards communication struct, mainly for squashing. cpu/beta_cpu/commit.hh: Update typenames to reflect change in location of time buffer structs. Update DynInst to DynInstPtr (it is refcounted now). cpu/beta_cpu/commit_impl.hh: Formatting changes mainly. Also sends back proper information on branch mispredicts so that the bpred unit can update itself. Updated behavior for non-speculative instructions (stores, any other non-spec instructions): once they reach the head of the ROB, the ROB signals back to the IQ that it can go ahead and issue the non-speculative instruction. The instruction itself is updated so that commit won't try to commit it again until it is done executing. cpu/beta_cpu/cpu_policy.hh: Added branch prediction unit, mem dependence prediction unit, load store queue. Moved time buffer structs from AlphaSimpleImpl to here. cpu/beta_cpu/decode.hh: Changed typedefs to reflect change in location of time buffer structs and also the change from DynInst to ref counted DynInstPtr. cpu/beta_cpu/decode_impl.hh: Continues to buffer instructions even while unblocking now. Changed how it loops through groups of instructions so it can properly block during the middle of a group of instructions. cpu/beta_cpu/fetch.hh: Changed typedefs to reflect change in location of time buffer structs and the change to ref counted DynInsts. Also added in branch brediction unit. cpu/beta_cpu/fetch_impl.hh: Add in branch prediction. Changed how fetch checks inputs and its current state to make for easier logic. cpu/beta_cpu/free_list.cc: Changed int regs and float regs to logically use one flat namespace. Future change will be moving them to a single scoreboard to conserve space. cpu/beta_cpu/free_list.hh: Mostly debugging statements. Might be removed for performance in future. cpu/beta_cpu/full_cpu.cc: Added in some debugging statements. Updated BaseFullCPU to take a params object. cpu/beta_cpu/full_cpu.hh: Added params class within BaseCPU that other param classes will be able to inherit from. Updated typedefs to reflect change in location of time buffer structs and ref counted DynInst. cpu/beta_cpu/iew.hh: Updated typedefs to reflect change in location of time buffer structs and use of ref counted DynInsts. cpu/beta_cpu/iew_impl.hh: Added in load store queue, updated iew to be able to execute non- speculative instructions, instead of having them execute in commit. cpu/beta_cpu/inst_queue.hh: Updated change to ref counted DynInsts. Changed inst queue to hold non-speculative instructions as well, which are issued only when commit signals backwards that a nonspeculative instruction is at the head of the ROB. cpu/beta_cpu/inst_queue_impl.hh: Updated to allow for non-speculative instructions to be in the inst queue. Also added some debug functions. cpu/beta_cpu/regfile.hh: Added debugging statements, changed formatting. cpu/beta_cpu/rename.hh: Updated typedefs, added some functions to clean up code. cpu/beta_cpu/rename_impl.hh: Moved some code into functions to make it easier to read. cpu/beta_cpu/rename_map.cc: Changed int and float reg behavior to use a single flat namespace. In the future, the rename maps can be combined to a single rename map to save space. cpu/beta_cpu/rename_map.hh: Added destructor. cpu/beta_cpu/rob.hh: Updated it with change from DynInst to ref counted DynInst. cpu/beta_cpu/rob_impl.hh: Formatting, updated to use ref counted DynInst. cpu/static_inst.hh: Updated forward declaration for AlphaDynInst now that it is templated. --HG-- extra : convert_revision : 1045f240ee9b6a4bd368e1806aca029ebbdc6dd3
2004-09-23 20:06:03 +02:00
typedef typename Impl::DynInstPtr DynInstPtr;
int size;
DynInstPtr insts[Impl::MaxWidth];
};
/** Struct that defines the information passed from IEW to commit. */
template<class Impl>
struct DefaultIEWDefaultCommit {
Update to make multiple instruction issue and different latencies work. Also change to ref counted DynInst. SConscript: Add branch predictor, BTB, load store queue, and storesets. arch/isa_parser.py: Specify the template parameter for AlphaDynInst base/traceflags.py: Add load store queue, store set, and mem dependence unit to the list of trace flags. cpu/base_dyn_inst.cc: Change formating, add in debug statement. cpu/base_dyn_inst.hh: Change DynInst to be RefCounted, add flag to clear whether or not this instruction can commit. This is likely to be removed in the future. cpu/beta_cpu/alpha_dyn_inst.cc: AlphaDynInst has been changed to be templated, so now this CC file is just used to force instantiations of AlphaDynInst. cpu/beta_cpu/alpha_dyn_inst.hh: Changed AlphaDynInst to be templated on Impl. Removed some unnecessary functions. cpu/beta_cpu/alpha_full_cpu.cc: AlphaFullCPU has been changed to be templated, so this CC file is now just used to force instantation of AlphaFullCPU. cpu/beta_cpu/alpha_full_cpu.hh: Change AlphaFullCPU to be templated on Impl. cpu/beta_cpu/alpha_impl.hh: Update it to reflect AlphaDynInst and AlphaFullCPU being templated on Impl. Also removed time buffers from here, as they are really a part of the CPU and are thus in the CPU policy now. cpu/beta_cpu/alpha_params.hh: Make AlphaSimpleParams inherit from the BaseFullCPU so that it doesn't need to specifically declare any parameters that are already in the BaseFullCPU. cpu/beta_cpu/comm.hh: Changed the structure of the time buffer communication structs. Now they include the size of the packet of instructions it is sending. Added some parameters to the backwards communication struct, mainly for squashing. cpu/beta_cpu/commit.hh: Update typenames to reflect change in location of time buffer structs. Update DynInst to DynInstPtr (it is refcounted now). cpu/beta_cpu/commit_impl.hh: Formatting changes mainly. Also sends back proper information on branch mispredicts so that the bpred unit can update itself. Updated behavior for non-speculative instructions (stores, any other non-spec instructions): once they reach the head of the ROB, the ROB signals back to the IQ that it can go ahead and issue the non-speculative instruction. The instruction itself is updated so that commit won't try to commit it again until it is done executing. cpu/beta_cpu/cpu_policy.hh: Added branch prediction unit, mem dependence prediction unit, load store queue. Moved time buffer structs from AlphaSimpleImpl to here. cpu/beta_cpu/decode.hh: Changed typedefs to reflect change in location of time buffer structs and also the change from DynInst to ref counted DynInstPtr. cpu/beta_cpu/decode_impl.hh: Continues to buffer instructions even while unblocking now. Changed how it loops through groups of instructions so it can properly block during the middle of a group of instructions. cpu/beta_cpu/fetch.hh: Changed typedefs to reflect change in location of time buffer structs and the change to ref counted DynInsts. Also added in branch brediction unit. cpu/beta_cpu/fetch_impl.hh: Add in branch prediction. Changed how fetch checks inputs and its current state to make for easier logic. cpu/beta_cpu/free_list.cc: Changed int regs and float regs to logically use one flat namespace. Future change will be moving them to a single scoreboard to conserve space. cpu/beta_cpu/free_list.hh: Mostly debugging statements. Might be removed for performance in future. cpu/beta_cpu/full_cpu.cc: Added in some debugging statements. Updated BaseFullCPU to take a params object. cpu/beta_cpu/full_cpu.hh: Added params class within BaseCPU that other param classes will be able to inherit from. Updated typedefs to reflect change in location of time buffer structs and ref counted DynInst. cpu/beta_cpu/iew.hh: Updated typedefs to reflect change in location of time buffer structs and use of ref counted DynInsts. cpu/beta_cpu/iew_impl.hh: Added in load store queue, updated iew to be able to execute non- speculative instructions, instead of having them execute in commit. cpu/beta_cpu/inst_queue.hh: Updated change to ref counted DynInsts. Changed inst queue to hold non-speculative instructions as well, which are issued only when commit signals backwards that a nonspeculative instruction is at the head of the ROB. cpu/beta_cpu/inst_queue_impl.hh: Updated to allow for non-speculative instructions to be in the inst queue. Also added some debug functions. cpu/beta_cpu/regfile.hh: Added debugging statements, changed formatting. cpu/beta_cpu/rename.hh: Updated typedefs, added some functions to clean up code. cpu/beta_cpu/rename_impl.hh: Moved some code into functions to make it easier to read. cpu/beta_cpu/rename_map.cc: Changed int and float reg behavior to use a single flat namespace. In the future, the rename maps can be combined to a single rename map to save space. cpu/beta_cpu/rename_map.hh: Added destructor. cpu/beta_cpu/rob.hh: Updated it with change from DynInst to ref counted DynInst. cpu/beta_cpu/rob_impl.hh: Formatting, updated to use ref counted DynInst. cpu/static_inst.hh: Updated forward declaration for AlphaDynInst now that it is templated. --HG-- extra : convert_revision : 1045f240ee9b6a4bd368e1806aca029ebbdc6dd3
2004-09-23 20:06:03 +02:00
typedef typename Impl::DynInstPtr DynInstPtr;
int size;
DynInstPtr insts[Impl::MaxWidth];
DynInstPtr mispredictInst[Impl::MaxThreads];
Addr mispredPC[Impl::MaxThreads];
InstSeqNum squashedSeqNum[Impl::MaxThreads];
TheISA::PCState pc[Impl::MaxThreads];
bool squash[Impl::MaxThreads];
bool branchMispredict[Impl::MaxThreads];
bool branchTaken[Impl::MaxThreads];
bool includeSquashInst[Impl::MaxThreads];
};
template<class Impl>
struct IssueStruct {
Update to make multiple instruction issue and different latencies work. Also change to ref counted DynInst. SConscript: Add branch predictor, BTB, load store queue, and storesets. arch/isa_parser.py: Specify the template parameter for AlphaDynInst base/traceflags.py: Add load store queue, store set, and mem dependence unit to the list of trace flags. cpu/base_dyn_inst.cc: Change formating, add in debug statement. cpu/base_dyn_inst.hh: Change DynInst to be RefCounted, add flag to clear whether or not this instruction can commit. This is likely to be removed in the future. cpu/beta_cpu/alpha_dyn_inst.cc: AlphaDynInst has been changed to be templated, so now this CC file is just used to force instantiations of AlphaDynInst. cpu/beta_cpu/alpha_dyn_inst.hh: Changed AlphaDynInst to be templated on Impl. Removed some unnecessary functions. cpu/beta_cpu/alpha_full_cpu.cc: AlphaFullCPU has been changed to be templated, so this CC file is now just used to force instantation of AlphaFullCPU. cpu/beta_cpu/alpha_full_cpu.hh: Change AlphaFullCPU to be templated on Impl. cpu/beta_cpu/alpha_impl.hh: Update it to reflect AlphaDynInst and AlphaFullCPU being templated on Impl. Also removed time buffers from here, as they are really a part of the CPU and are thus in the CPU policy now. cpu/beta_cpu/alpha_params.hh: Make AlphaSimpleParams inherit from the BaseFullCPU so that it doesn't need to specifically declare any parameters that are already in the BaseFullCPU. cpu/beta_cpu/comm.hh: Changed the structure of the time buffer communication structs. Now they include the size of the packet of instructions it is sending. Added some parameters to the backwards communication struct, mainly for squashing. cpu/beta_cpu/commit.hh: Update typenames to reflect change in location of time buffer structs. Update DynInst to DynInstPtr (it is refcounted now). cpu/beta_cpu/commit_impl.hh: Formatting changes mainly. Also sends back proper information on branch mispredicts so that the bpred unit can update itself. Updated behavior for non-speculative instructions (stores, any other non-spec instructions): once they reach the head of the ROB, the ROB signals back to the IQ that it can go ahead and issue the non-speculative instruction. The instruction itself is updated so that commit won't try to commit it again until it is done executing. cpu/beta_cpu/cpu_policy.hh: Added branch prediction unit, mem dependence prediction unit, load store queue. Moved time buffer structs from AlphaSimpleImpl to here. cpu/beta_cpu/decode.hh: Changed typedefs to reflect change in location of time buffer structs and also the change from DynInst to ref counted DynInstPtr. cpu/beta_cpu/decode_impl.hh: Continues to buffer instructions even while unblocking now. Changed how it loops through groups of instructions so it can properly block during the middle of a group of instructions. cpu/beta_cpu/fetch.hh: Changed typedefs to reflect change in location of time buffer structs and the change to ref counted DynInsts. Also added in branch brediction unit. cpu/beta_cpu/fetch_impl.hh: Add in branch prediction. Changed how fetch checks inputs and its current state to make for easier logic. cpu/beta_cpu/free_list.cc: Changed int regs and float regs to logically use one flat namespace. Future change will be moving them to a single scoreboard to conserve space. cpu/beta_cpu/free_list.hh: Mostly debugging statements. Might be removed for performance in future. cpu/beta_cpu/full_cpu.cc: Added in some debugging statements. Updated BaseFullCPU to take a params object. cpu/beta_cpu/full_cpu.hh: Added params class within BaseCPU that other param classes will be able to inherit from. Updated typedefs to reflect change in location of time buffer structs and ref counted DynInst. cpu/beta_cpu/iew.hh: Updated typedefs to reflect change in location of time buffer structs and use of ref counted DynInsts. cpu/beta_cpu/iew_impl.hh: Added in load store queue, updated iew to be able to execute non- speculative instructions, instead of having them execute in commit. cpu/beta_cpu/inst_queue.hh: Updated change to ref counted DynInsts. Changed inst queue to hold non-speculative instructions as well, which are issued only when commit signals backwards that a nonspeculative instruction is at the head of the ROB. cpu/beta_cpu/inst_queue_impl.hh: Updated to allow for non-speculative instructions to be in the inst queue. Also added some debug functions. cpu/beta_cpu/regfile.hh: Added debugging statements, changed formatting. cpu/beta_cpu/rename.hh: Updated typedefs, added some functions to clean up code. cpu/beta_cpu/rename_impl.hh: Moved some code into functions to make it easier to read. cpu/beta_cpu/rename_map.cc: Changed int and float reg behavior to use a single flat namespace. In the future, the rename maps can be combined to a single rename map to save space. cpu/beta_cpu/rename_map.hh: Added destructor. cpu/beta_cpu/rob.hh: Updated it with change from DynInst to ref counted DynInst. cpu/beta_cpu/rob_impl.hh: Formatting, updated to use ref counted DynInst. cpu/static_inst.hh: Updated forward declaration for AlphaDynInst now that it is templated. --HG-- extra : convert_revision : 1045f240ee9b6a4bd368e1806aca029ebbdc6dd3
2004-09-23 20:06:03 +02:00
typedef typename Impl::DynInstPtr DynInstPtr;
int size;
DynInstPtr insts[Impl::MaxWidth];
};
/** Struct that defines all backwards communication. */
template<class Impl>
struct TimeBufStruct {
typedef typename Impl::DynInstPtr DynInstPtr;
struct decodeComm {
uint64_t branchAddr;
Check in of various updates to the CPU. Mainly adds in stats, improves branch prediction, and makes memory dependence work properly. SConscript: Added return address stack, tournament predictor. cpu/base_cpu.cc: Added debug break and print statements. cpu/base_dyn_inst.cc: cpu/base_dyn_inst.hh: Comment out possibly unneeded variables. cpu/beta_cpu/2bit_local_pred.cc: 2bit predictor no longer speculatively updates itself. cpu/beta_cpu/alpha_dyn_inst.hh: Comment formatting. cpu/beta_cpu/alpha_full_cpu.hh: Formatting cpu/beta_cpu/alpha_full_cpu_builder.cc: Added new parameters for branch predictors, and IQ parameters. cpu/beta_cpu/alpha_full_cpu_impl.hh: Register stats. cpu/beta_cpu/alpha_params.hh: Added parameters for IQ, branch predictors, and store sets. cpu/beta_cpu/bpred_unit.cc: Removed one class. cpu/beta_cpu/bpred_unit.hh: Add in RAS, stats. Changed branch predictor unit functionality so that it holds a history of past branches so it can update, and also hold a proper history of the RAS so it can be restored on branch mispredicts. cpu/beta_cpu/bpred_unit_impl.hh: Added in stats, history of branches, RAS. Now bpred unit actually modifies the instruction's predicted next PC. cpu/beta_cpu/btb.cc: Add in sanity checks. cpu/beta_cpu/comm.hh: Add in communication where needed, remove it where it's not. cpu/beta_cpu/commit.hh: cpu/beta_cpu/rename.hh: cpu/beta_cpu/rename_impl.hh: Add in stats. cpu/beta_cpu/commit_impl.hh: Stats, update what is sent back on branch mispredict. cpu/beta_cpu/cpu_policy.hh: Change the bpred unit being used. cpu/beta_cpu/decode.hh: cpu/beta_cpu/decode_impl.hh: Stats. cpu/beta_cpu/fetch.hh: Stats, change squash so it can handle squashes from decode differently than squashes from commit. cpu/beta_cpu/fetch_impl.hh: Add in stats. Change how a cache line is fetched. Update to work with caches. Also have separate functions for different behavior if squash is coming from decode vs commit. cpu/beta_cpu/free_list.hh: Remove some old comments. cpu/beta_cpu/full_cpu.cc: cpu/beta_cpu/full_cpu.hh: Added function to remove instructions from back of instruction list until a certain sequence number. cpu/beta_cpu/iew.hh: Stats, separate squashing behavior due to branches vs memory. cpu/beta_cpu/iew_impl.hh: Stats, separate squashing behavior for branches vs memory. cpu/beta_cpu/inst_queue.cc: Debug stuff cpu/beta_cpu/inst_queue.hh: Stats, change how mem dep unit works, debug stuff cpu/beta_cpu/inst_queue_impl.hh: Stats, change how mem dep unit works, debug stuff. Also add in parameters that used to be hardcoded. cpu/beta_cpu/mem_dep_unit.hh: cpu/beta_cpu/mem_dep_unit_impl.hh: Add in stats, change how memory dependence unit works. It now holds the memory instructions that are waiting for their memory dependences to resolve. It provides which instructions are ready directly to the IQ. cpu/beta_cpu/regfile.hh: Fix up sanity checks. cpu/beta_cpu/rename_map.cc: Fix loop variable type. cpu/beta_cpu/rob_impl.hh: Remove intermediate DynInstPtr cpu/beta_cpu/store_set.cc: Add in debugging statements. cpu/beta_cpu/store_set.hh: Reorder function arguments to match the rest of the calls. --HG-- extra : convert_revision : aabf9b1fecd1d743265dfc3b174d6159937c6f44
2004-10-22 00:02:36 +02:00
InstSeqNum doneSeqNum;
DynInstPtr mispredictInst;
DynInstPtr squashInst;
Addr mispredPC;
ISA,CPU,etc: Create an ISA defined PC type that abstracts out ISA behaviors. 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.
2010-10-31 08:07:20 +01:00
TheISA::PCState nextPC;
unsigned branchCount;
bool squash;
bool predIncorrect;
bool branchMispredict;
bool branchTaken;
};
decodeComm decodeInfo[Impl::MaxThreads];
struct renameComm {
};
renameComm renameInfo[Impl::MaxThreads];
struct iewComm {
// Also eventually include skid buffer space.
bool usedIQ;
unsigned freeIQEntries;
bool usedLSQ;
unsigned freeLSQEntries;
unsigned iqCount;
unsigned ldstqCount;
unsigned dispatched;
unsigned dispatchedToLSQ;
};
iewComm iewInfo[Impl::MaxThreads];
struct commitComm {
/////////////// For Decode, IEW, Rename, Fetch ///////////
bool squash;
bool robSquashing;
////////// For Fetch & IEW /////////////
// 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;
Update to make multiple instruction issue and different latencies work. Also change to ref counted DynInst. SConscript: Add branch predictor, BTB, load store queue, and storesets. arch/isa_parser.py: Specify the template parameter for AlphaDynInst base/traceflags.py: Add load store queue, store set, and mem dependence unit to the list of trace flags. cpu/base_dyn_inst.cc: Change formating, add in debug statement. cpu/base_dyn_inst.hh: Change DynInst to be RefCounted, add flag to clear whether or not this instruction can commit. This is likely to be removed in the future. cpu/beta_cpu/alpha_dyn_inst.cc: AlphaDynInst has been changed to be templated, so now this CC file is just used to force instantiations of AlphaDynInst. cpu/beta_cpu/alpha_dyn_inst.hh: Changed AlphaDynInst to be templated on Impl. Removed some unnecessary functions. cpu/beta_cpu/alpha_full_cpu.cc: AlphaFullCPU has been changed to be templated, so this CC file is now just used to force instantation of AlphaFullCPU. cpu/beta_cpu/alpha_full_cpu.hh: Change AlphaFullCPU to be templated on Impl. cpu/beta_cpu/alpha_impl.hh: Update it to reflect AlphaDynInst and AlphaFullCPU being templated on Impl. Also removed time buffers from here, as they are really a part of the CPU and are thus in the CPU policy now. cpu/beta_cpu/alpha_params.hh: Make AlphaSimpleParams inherit from the BaseFullCPU so that it doesn't need to specifically declare any parameters that are already in the BaseFullCPU. cpu/beta_cpu/comm.hh: Changed the structure of the time buffer communication structs. Now they include the size of the packet of instructions it is sending. Added some parameters to the backwards communication struct, mainly for squashing. cpu/beta_cpu/commit.hh: Update typenames to reflect change in location of time buffer structs. Update DynInst to DynInstPtr (it is refcounted now). cpu/beta_cpu/commit_impl.hh: Formatting changes mainly. Also sends back proper information on branch mispredicts so that the bpred unit can update itself. Updated behavior for non-speculative instructions (stores, any other non-spec instructions): once they reach the head of the ROB, the ROB signals back to the IQ that it can go ahead and issue the non-speculative instruction. The instruction itself is updated so that commit won't try to commit it again until it is done executing. cpu/beta_cpu/cpu_policy.hh: Added branch prediction unit, mem dependence prediction unit, load store queue. Moved time buffer structs from AlphaSimpleImpl to here. cpu/beta_cpu/decode.hh: Changed typedefs to reflect change in location of time buffer structs and also the change from DynInst to ref counted DynInstPtr. cpu/beta_cpu/decode_impl.hh: Continues to buffer instructions even while unblocking now. Changed how it loops through groups of instructions so it can properly block during the middle of a group of instructions. cpu/beta_cpu/fetch.hh: Changed typedefs to reflect change in location of time buffer structs and the change to ref counted DynInsts. Also added in branch brediction unit. cpu/beta_cpu/fetch_impl.hh: Add in branch prediction. Changed how fetch checks inputs and its current state to make for easier logic. cpu/beta_cpu/free_list.cc: Changed int regs and float regs to logically use one flat namespace. Future change will be moving them to a single scoreboard to conserve space. cpu/beta_cpu/free_list.hh: Mostly debugging statements. Might be removed for performance in future. cpu/beta_cpu/full_cpu.cc: Added in some debugging statements. Updated BaseFullCPU to take a params object. cpu/beta_cpu/full_cpu.hh: Added params class within BaseCPU that other param classes will be able to inherit from. Updated typedefs to reflect change in location of time buffer structs and ref counted DynInst. cpu/beta_cpu/iew.hh: Updated typedefs to reflect change in location of time buffer structs and use of ref counted DynInsts. cpu/beta_cpu/iew_impl.hh: Added in load store queue, updated iew to be able to execute non- speculative instructions, instead of having them execute in commit. cpu/beta_cpu/inst_queue.hh: Updated change to ref counted DynInsts. Changed inst queue to hold non-speculative instructions as well, which are issued only when commit signals backwards that a nonspeculative instruction is at the head of the ROB. cpu/beta_cpu/inst_queue_impl.hh: Updated to allow for non-speculative instructions to be in the inst queue. Also added some debug functions. cpu/beta_cpu/regfile.hh: Added debugging statements, changed formatting. cpu/beta_cpu/rename.hh: Updated typedefs, added some functions to clean up code. cpu/beta_cpu/rename_impl.hh: Moved some code into functions to make it easier to read. cpu/beta_cpu/rename_map.cc: Changed int and float reg behavior to use a single flat namespace. In the future, the rename maps can be combined to a single rename map to save space. cpu/beta_cpu/rename_map.hh: Added destructor. cpu/beta_cpu/rob.hh: Updated it with change from DynInst to ref counted DynInst. cpu/beta_cpu/rob_impl.hh: Formatting, updated to use ref counted DynInst. cpu/static_inst.hh: Updated forward declaration for AlphaDynInst now that it is templated. --HG-- extra : convert_revision : 1045f240ee9b6a4bd368e1806aca029ebbdc6dd3
2004-09-23 20:06:03 +02:00
////////////// For Rename /////////////////
// Rename should re-read number of free rob entries
bool usedROB;
// Notify Rename that the ROB is empty
bool emptyROB;
// Tell Rename how many free entries it has in the ROB
unsigned freeROBEntries;
///////////// For Fetch //////////////////
// Provide fetch the instruction that mispredicted, if this
// pointer is not-null a misprediction occured
DynInstPtr mispredictInst;
// Was the branch taken or not
bool branchTaken;
// The pc of the next instruction to execute. This is the next
// instruction for a branch mispredict, but the same instruction for
// order violation and the like
TheISA::PCState pc;
// Instruction that caused the a non-mispredict squash
DynInstPtr squashInst;
// If an interrupt is pending and fetch should stall
bool interruptPending;
// If the interrupt ended up being cleared before being handled
bool clearInterrupt;
//////////// For IEW //////////////////
Update to make multiple instruction issue and different latencies work. Also change to ref counted DynInst. SConscript: Add branch predictor, BTB, load store queue, and storesets. arch/isa_parser.py: Specify the template parameter for AlphaDynInst base/traceflags.py: Add load store queue, store set, and mem dependence unit to the list of trace flags. cpu/base_dyn_inst.cc: Change formating, add in debug statement. cpu/base_dyn_inst.hh: Change DynInst to be RefCounted, add flag to clear whether or not this instruction can commit. This is likely to be removed in the future. cpu/beta_cpu/alpha_dyn_inst.cc: AlphaDynInst has been changed to be templated, so now this CC file is just used to force instantiations of AlphaDynInst. cpu/beta_cpu/alpha_dyn_inst.hh: Changed AlphaDynInst to be templated on Impl. Removed some unnecessary functions. cpu/beta_cpu/alpha_full_cpu.cc: AlphaFullCPU has been changed to be templated, so this CC file is now just used to force instantation of AlphaFullCPU. cpu/beta_cpu/alpha_full_cpu.hh: Change AlphaFullCPU to be templated on Impl. cpu/beta_cpu/alpha_impl.hh: Update it to reflect AlphaDynInst and AlphaFullCPU being templated on Impl. Also removed time buffers from here, as they are really a part of the CPU and are thus in the CPU policy now. cpu/beta_cpu/alpha_params.hh: Make AlphaSimpleParams inherit from the BaseFullCPU so that it doesn't need to specifically declare any parameters that are already in the BaseFullCPU. cpu/beta_cpu/comm.hh: Changed the structure of the time buffer communication structs. Now they include the size of the packet of instructions it is sending. Added some parameters to the backwards communication struct, mainly for squashing. cpu/beta_cpu/commit.hh: Update typenames to reflect change in location of time buffer structs. Update DynInst to DynInstPtr (it is refcounted now). cpu/beta_cpu/commit_impl.hh: Formatting changes mainly. Also sends back proper information on branch mispredicts so that the bpred unit can update itself. Updated behavior for non-speculative instructions (stores, any other non-spec instructions): once they reach the head of the ROB, the ROB signals back to the IQ that it can go ahead and issue the non-speculative instruction. The instruction itself is updated so that commit won't try to commit it again until it is done executing. cpu/beta_cpu/cpu_policy.hh: Added branch prediction unit, mem dependence prediction unit, load store queue. Moved time buffer structs from AlphaSimpleImpl to here. cpu/beta_cpu/decode.hh: Changed typedefs to reflect change in location of time buffer structs and also the change from DynInst to ref counted DynInstPtr. cpu/beta_cpu/decode_impl.hh: Continues to buffer instructions even while unblocking now. Changed how it loops through groups of instructions so it can properly block during the middle of a group of instructions. cpu/beta_cpu/fetch.hh: Changed typedefs to reflect change in location of time buffer structs and the change to ref counted DynInsts. Also added in branch brediction unit. cpu/beta_cpu/fetch_impl.hh: Add in branch prediction. Changed how fetch checks inputs and its current state to make for easier logic. cpu/beta_cpu/free_list.cc: Changed int regs and float regs to logically use one flat namespace. Future change will be moving them to a single scoreboard to conserve space. cpu/beta_cpu/free_list.hh: Mostly debugging statements. Might be removed for performance in future. cpu/beta_cpu/full_cpu.cc: Added in some debugging statements. Updated BaseFullCPU to take a params object. cpu/beta_cpu/full_cpu.hh: Added params class within BaseCPU that other param classes will be able to inherit from. Updated typedefs to reflect change in location of time buffer structs and ref counted DynInst. cpu/beta_cpu/iew.hh: Updated typedefs to reflect change in location of time buffer structs and use of ref counted DynInsts. cpu/beta_cpu/iew_impl.hh: Added in load store queue, updated iew to be able to execute non- speculative instructions, instead of having them execute in commit. cpu/beta_cpu/inst_queue.hh: Updated change to ref counted DynInsts. Changed inst queue to hold non-speculative instructions as well, which are issued only when commit signals backwards that a nonspeculative instruction is at the head of the ROB. cpu/beta_cpu/inst_queue_impl.hh: Updated to allow for non-speculative instructions to be in the inst queue. Also added some debug functions. cpu/beta_cpu/regfile.hh: Added debugging statements, changed formatting. cpu/beta_cpu/rename.hh: Updated typedefs, added some functions to clean up code. cpu/beta_cpu/rename_impl.hh: Moved some code into functions to make it easier to read. cpu/beta_cpu/rename_map.cc: Changed int and float reg behavior to use a single flat namespace. In the future, the rename maps can be combined to a single rename map to save space. cpu/beta_cpu/rename_map.hh: Added destructor. cpu/beta_cpu/rob.hh: Updated it with change from DynInst to ref counted DynInst. cpu/beta_cpu/rob_impl.hh: Formatting, updated to use ref counted DynInst. cpu/static_inst.hh: Updated forward declaration for AlphaDynInst now that it is templated. --HG-- extra : convert_revision : 1045f240ee9b6a4bd368e1806aca029ebbdc6dd3
2004-09-23 20:06:03 +02:00
// 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.
bool uncached;
DynInstPtr uncachedLoad;
};
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_COMM_HH__