gem5/cpu/o3/fetch.hh
Nathan Binkert 13c005a8af shuffle files around for new directory structure
--HG--
rename : cpu/base_cpu.cc => cpu/base.cc
rename : cpu/base_cpu.hh => cpu/base.hh
rename : cpu/beta_cpu/2bit_local_pred.cc => cpu/o3/2bit_local_pred.cc
rename : cpu/beta_cpu/2bit_local_pred.hh => cpu/o3/2bit_local_pred.hh
rename : cpu/beta_cpu/alpha_full_cpu.cc => cpu/o3/alpha_cpu.cc
rename : cpu/beta_cpu/alpha_full_cpu.hh => cpu/o3/alpha_cpu.hh
rename : cpu/beta_cpu/alpha_full_cpu_builder.cc => cpu/o3/alpha_cpu_builder.cc
rename : cpu/beta_cpu/alpha_full_cpu_impl.hh => cpu/o3/alpha_cpu_impl.hh
rename : cpu/beta_cpu/alpha_dyn_inst.cc => cpu/o3/alpha_dyn_inst.cc
rename : cpu/beta_cpu/alpha_dyn_inst.hh => cpu/o3/alpha_dyn_inst.hh
rename : cpu/beta_cpu/alpha_dyn_inst_impl.hh => cpu/o3/alpha_dyn_inst_impl.hh
rename : cpu/beta_cpu/alpha_impl.hh => cpu/o3/alpha_impl.hh
rename : cpu/beta_cpu/alpha_params.hh => cpu/o3/alpha_params.hh
rename : cpu/beta_cpu/bpred_unit.cc => cpu/o3/bpred_unit.cc
rename : cpu/beta_cpu/bpred_unit.hh => cpu/o3/bpred_unit.hh
rename : cpu/beta_cpu/bpred_unit_impl.hh => cpu/o3/bpred_unit_impl.hh
rename : cpu/beta_cpu/btb.cc => cpu/o3/btb.cc
rename : cpu/beta_cpu/btb.hh => cpu/o3/btb.hh
rename : cpu/beta_cpu/comm.hh => cpu/o3/comm.hh
rename : cpu/beta_cpu/commit.cc => cpu/o3/commit.cc
rename : cpu/beta_cpu/commit.hh => cpu/o3/commit.hh
rename : cpu/beta_cpu/commit_impl.hh => cpu/o3/commit_impl.hh
rename : cpu/beta_cpu/full_cpu.cc => cpu/o3/cpu.cc
rename : cpu/beta_cpu/full_cpu.hh => cpu/o3/cpu.hh
rename : cpu/beta_cpu/cpu_policy.hh => cpu/o3/cpu_policy.hh
rename : cpu/beta_cpu/decode.cc => cpu/o3/decode.cc
rename : cpu/beta_cpu/decode.hh => cpu/o3/decode.hh
rename : cpu/beta_cpu/decode_impl.hh => cpu/o3/decode_impl.hh
rename : cpu/beta_cpu/fetch.cc => cpu/o3/fetch.cc
rename : cpu/beta_cpu/fetch.hh => cpu/o3/fetch.hh
rename : cpu/beta_cpu/fetch_impl.hh => cpu/o3/fetch_impl.hh
rename : cpu/beta_cpu/free_list.cc => cpu/o3/free_list.cc
rename : cpu/beta_cpu/free_list.hh => cpu/o3/free_list.hh
rename : cpu/beta_cpu/iew.cc => cpu/o3/iew.cc
rename : cpu/beta_cpu/iew.hh => cpu/o3/iew.hh
rename : cpu/beta_cpu/iew_impl.hh => cpu/o3/iew_impl.hh
rename : cpu/beta_cpu/inst_queue.cc => cpu/o3/inst_queue.cc
rename : cpu/beta_cpu/inst_queue.hh => cpu/o3/inst_queue.hh
rename : cpu/beta_cpu/inst_queue_impl.hh => cpu/o3/inst_queue_impl.hh
rename : cpu/beta_cpu/mem_dep_unit.cc => cpu/o3/mem_dep_unit.cc
rename : cpu/beta_cpu/mem_dep_unit.hh => cpu/o3/mem_dep_unit.hh
rename : cpu/beta_cpu/mem_dep_unit_impl.hh => cpu/o3/mem_dep_unit_impl.hh
rename : cpu/beta_cpu/ras.cc => cpu/o3/ras.cc
rename : cpu/beta_cpu/ras.hh => cpu/o3/ras.hh
rename : cpu/beta_cpu/regfile.hh => cpu/o3/regfile.hh
rename : cpu/beta_cpu/rename.cc => cpu/o3/rename.cc
rename : cpu/beta_cpu/rename.hh => cpu/o3/rename.hh
rename : cpu/beta_cpu/rename_impl.hh => cpu/o3/rename_impl.hh
rename : cpu/beta_cpu/rename_map.cc => cpu/o3/rename_map.cc
rename : cpu/beta_cpu/rename_map.hh => cpu/o3/rename_map.hh
rename : cpu/beta_cpu/rob.cc => cpu/o3/rob.cc
rename : cpu/beta_cpu/rob.hh => cpu/o3/rob.hh
rename : cpu/beta_cpu/rob_impl.hh => cpu/o3/rob_impl.hh
rename : cpu/beta_cpu/sat_counter.cc => cpu/o3/sat_counter.cc
rename : cpu/beta_cpu/sat_counter.hh => cpu/o3/sat_counter.hh
rename : cpu/beta_cpu/store_set.cc => cpu/o3/store_set.cc
rename : cpu/beta_cpu/store_set.hh => cpu/o3/store_set.hh
rename : cpu/beta_cpu/tournament_pred.cc => cpu/o3/tournament_pred.cc
rename : cpu/beta_cpu/tournament_pred.hh => cpu/o3/tournament_pred.hh
rename : cpu/ooo_cpu/ooo_cpu.cc => cpu/ozone/cpu.cc
rename : cpu/ooo_cpu/ooo_cpu.hh => cpu/ozone/cpu.hh
rename : cpu/ooo_cpu/ooo_impl.hh => cpu/ozone/cpu_impl.hh
rename : cpu/ooo_cpu/ea_list.cc => cpu/ozone/ea_list.cc
rename : cpu/ooo_cpu/ea_list.hh => cpu/ozone/ea_list.hh
rename : cpu/simple_cpu/simple_cpu.cc => cpu/simple/cpu.cc
rename : cpu/simple_cpu/simple_cpu.hh => cpu/simple/cpu.hh
rename : cpu/full_cpu/smt.hh => cpu/smt.hh
rename : cpu/full_cpu/op_class.hh => encumbered/cpu/full/op_class.hh
extra : convert_revision : c4a891d8d6d3e0e9e5ea56be47d851da44d8c032
2005-06-04 20:50:10 -04:00

224 lines
6.7 KiB
C++

/*
* Copyright (c) 2004-2005 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
// Todo: SMT fetch,
// Add a way to get a stage's current status.
#ifndef __CPU_BETA_CPU_SIMPLE_FETCH_HH__
#define __CPU_BETA_CPU_SIMPLE_FETCH_HH__
#include "base/statistics.hh"
#include "base/timebuf.hh"
#include "cpu/pc_event.hh"
#include "mem/mem_interface.hh"
#include "sim/eventq.hh"
/**
* SimpleFetch class to fetch a single instruction each cycle. SimpleFetch
* will stall if there's an Icache miss, but otherwise assumes a one cycle
* Icache hit.
*/
template <class Impl>
class SimpleFetch
{
public:
/** Typedefs from Impl. */
typedef typename Impl::ISA ISA;
typedef typename Impl::CPUPol CPUPol;
typedef typename Impl::DynInst DynInst;
typedef typename Impl::DynInstPtr DynInstPtr;
typedef typename Impl::FullCPU FullCPU;
typedef typename Impl::Params Params;
typedef typename CPUPol::BPredUnit BPredUnit;
typedef typename CPUPol::FetchStruct FetchStruct;
typedef typename CPUPol::TimeStruct TimeStruct;
/** Typedefs from ISA. */
typedef typename ISA::MachInst MachInst;
public:
enum Status {
Running,
Idle,
Squashing,
Blocked,
IcacheMissStall,
IcacheMissComplete
};
// May eventually need statuses on a per thread basis.
Status _status;
bool stalled;
public:
class CacheCompletionEvent : public Event
{
private:
SimpleFetch *fetch;
public:
CacheCompletionEvent(SimpleFetch *_fetch);
virtual void process();
virtual const char *description();
};
public:
/** SimpleFetch constructor. */
SimpleFetch(Params &params);
void regStats();
void setCPU(FullCPU *cpu_ptr);
void setTimeBuffer(TimeBuffer<TimeStruct> *time_buffer);
void setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr);
void processCacheCompletion();
private:
/**
* Looks up in the branch predictor to see if the next PC should be
* either next PC+=MachInst or a branch target.
* @params next_PC Next PC variable passed in by reference. It is
* expected to be set to the current PC; it will be updated with what
* the next PC will be.
* @return Whether or not a branch was predicted as taken.
*/
bool lookupAndUpdateNextPC(DynInstPtr &inst, Addr &next_PC);
/**
* Fetches the cache line that contains fetch_PC. Returns any
* fault that happened. Puts the data into the class variable
* cacheData.
* @params fetch_PC The PC address that is being fetched from.
* @return Any fault that occured.
*/
Fault fetchCacheLine(Addr fetch_PC);
inline void doSquash(const Addr &new_PC);
void squashFromDecode(const Addr &new_PC, const InstSeqNum &seq_num);
public:
// Figure out PC vs next PC and how it should be updated
void squash(const Addr &new_PC);
void tick();
void fetch();
// Align an address (typically a PC) to the start of an I-cache block.
// We fold in the PISA 64- to 32-bit conversion here as well.
Addr icacheBlockAlignPC(Addr addr)
{
addr = ISA::realPCToFetchPC(addr);
return (addr & ~(cacheBlkMask));
}
private:
/** Pointer to the FullCPU. */
FullCPU *cpu;
/** Time buffer interface. */
TimeBuffer<TimeStruct> *timeBuffer;
/** Wire to get decode's information from backwards time buffer. */
typename TimeBuffer<TimeStruct>::wire fromDecode;
/** Wire to get rename's information from backwards time buffer. */
typename TimeBuffer<TimeStruct>::wire fromRename;
/** Wire to get iew's information from backwards time buffer. */
typename TimeBuffer<TimeStruct>::wire fromIEW;
/** Wire to get commit's information from backwards time buffer. */
typename TimeBuffer<TimeStruct>::wire fromCommit;
/** Internal fetch instruction queue. */
TimeBuffer<FetchStruct> *fetchQueue;
//Might be annoying how this name is different than the queue.
/** Wire used to write any information heading to decode. */
typename TimeBuffer<FetchStruct>::wire toDecode;
/** Icache interface. */
MemInterface *icacheInterface;
/** BPredUnit. */
BPredUnit branchPred;
/** Memory request used to access cache. */
MemReqPtr memReq;
/** Decode to fetch delay, in ticks. */
unsigned decodeToFetchDelay;
/** Rename to fetch delay, in ticks. */
unsigned renameToFetchDelay;
/** IEW to fetch delay, in ticks. */
unsigned iewToFetchDelay;
/** Commit to fetch delay, in ticks. */
unsigned commitToFetchDelay;
/** The width of fetch in instructions. */
unsigned fetchWidth;
/** Cache block size. */
int cacheBlkSize;
/** Mask to get a cache block's address. */
Addr cacheBlkMask;
/** The cache line being fetched. */
uint8_t *cacheData;
/** Size of instructions. */
int instSize;
/** Icache stall statistics. */
Counter lastIcacheStall;
Stats::Scalar<> icacheStallCycles;
Stats::Scalar<> fetchedInsts;
Stats::Scalar<> predictedBranches;
Stats::Scalar<> fetchCycles;
Stats::Scalar<> fetchSquashCycles;
Stats::Scalar<> fetchBlockedCycles;
Stats::Scalar<> fetchedCacheLines;
Stats::Distribution<> fetch_nisn_dist;
};
#endif //__CPU_BETA_CPU_SIMPLE_FETCH_HH__