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/*
* 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: Update with statuses.
//Need to handle delaying writes to the writeback bus if it's full at the
//given time.
#ifndef __CPU_BETA_CPU_SIMPLE_IEW_HH__
#define __CPU_BETA_CPU_SIMPLE_IEW_HH__
#include <queue>
#include "base/statistics.hh"
#include "base/timebuf.hh"
#include "cpu/o3/comm.hh"
template<class Impl>
class SimpleIEW
{
private:
//Typedefs from Impl
typedef typename Impl::ISA ISA;
typedef typename Impl::CPUPol CPUPol;
typedef typename Impl::DynInstPtr DynInstPtr;
typedef typename Impl::FullCPU FullCPU;
typedef typename Impl::Params Params;
typedef typename CPUPol::IQ IQ;
typedef typename CPUPol::RenameMap RenameMap;
typedef typename CPUPol::LDSTQ LDSTQ;
typedef typename CPUPol::TimeStruct TimeStruct;
typedef typename CPUPol::IEWStruct IEWStruct;
typedef typename CPUPol::RenameStruct RenameStruct;
typedef typename CPUPol::IssueStruct IssueStruct;
friend class Impl::FullCPU;
public:
enum Status {
Running,
Blocked,
Idle,
Squashing,
Unblocking
};
private:
Status _status;
Status _issueStatus;
Status _exeStatus;
Status _wbStatus;
public:
class WritebackEvent : public Event {
private:
DynInstPtr inst;
SimpleIEW<Impl> *iewStage;
public:
WritebackEvent(DynInstPtr &_inst, SimpleIEW<Impl> *_iew);
virtual void process();
virtual const char *description();
};
public:
SimpleIEW(Params ¶ms);
void regStats();
void setCPU(FullCPU *cpu_ptr);
void setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr);
void setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr);
void setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr);
void setRenameMap(RenameMap *rm_ptr);
void squash();
void squashDueToBranch(DynInstPtr &inst);
void squashDueToMem(DynInstPtr &inst);
void block();
inline void unblock();
void wakeDependents(DynInstPtr &inst);
void instToCommit(DynInstPtr &inst);
private:
void dispatchInsts();
void executeInsts();
public:
void tick();
void iew();
//Interfaces to objects inside and outside of IEW.
/** Time buffer interface. */
TimeBuffer<TimeStruct> *timeBuffer;
/** Wire to get commit's output from backwards time buffer. */
typename TimeBuffer<TimeStruct>::wire fromCommit;
/** Wire to write information heading to previous stages. */
typename TimeBuffer<TimeStruct>::wire toRename;
/** Rename instruction queue interface. */
TimeBuffer<RenameStruct> *renameQueue;
/** Wire to get rename's output from rename queue. */
typename TimeBuffer<RenameStruct>::wire fromRename;
/** Issue stage queue. */
TimeBuffer<IssueStruct> issueToExecQueue;
/** Wire to read information from the issue stage time queue. */
typename TimeBuffer<IssueStruct>::wire fromIssue;
/**
* IEW stage time buffer. Holds ROB indices of instructions that
* can be marked as completed.
*/
TimeBuffer<IEWStruct> *iewQueue;
/** Wire to write infromation heading to commit. */
typename TimeBuffer<IEWStruct>::wire toCommit;
//Will need internal queue to hold onto instructions coming from
//the rename stage in case of a stall.
/** Skid buffer between rename and IEW. */
std::queue<RenameStruct> skidBuffer;
protected:
/** Instruction queue. */
IQ instQueue;
LDSTQ ldstQueue;
#ifndef FULL_SYSTEM
public:
void lsqWriteback();
#endif
private:
/** Pointer to rename map. Might not want this stage to directly
* access this though...
*/
RenameMap *renameMap;
/** CPU interface. */
FullCPU *cpu;
private:
/** Commit to IEW delay, in ticks. */
unsigned commitToIEWDelay;
/** Rename to IEW delay, in ticks. */
unsigned renameToIEWDelay;
/**
* Issue to execute delay, in ticks. What this actually represents is
* the amount of time it takes for an instruction to wake up, be
* scheduled, and sent to a FU for execution.
*/
unsigned issueToExecuteDelay;
/** Width of issue's read path, in instructions. The read path is both
* the skid buffer and the rename instruction queue.
* Note to self: is this really different than issueWidth?
*/
unsigned issueReadWidth;
/** Width of issue, in instructions. */
unsigned issueWidth;
/** Width of execute, in instructions. Might make more sense to break
* down into FP vs int.
*/
unsigned executeWidth;
/** Number of cycles stage has been squashing. Used so that the stage
* knows when it can start unblocking, which is when the previous stage
* has received the stall signal and clears up its outputs.
*/
unsigned cyclesSquashing;
Stats::Scalar<> iewIdleCycles;
Stats::Scalar<> iewSquashCycles;
Stats::Scalar<> iewBlockCycles;
Stats::Scalar<> iewUnblockCycles;
// Stats::Scalar<> iewWBInsts;
Stats::Scalar<> iewDispatchedInsts;
Stats::Scalar<> iewDispSquashedInsts;
Stats::Scalar<> iewDispLoadInsts;
Stats::Scalar<> iewDispStoreInsts;
Stats::Scalar<> iewDispNonSpecInsts;
Stats::Scalar<> iewIQFullEvents;
Stats::Scalar<> iewExecutedInsts;
Stats::Scalar<> iewExecLoadInsts;
Stats::Scalar<> iewExecStoreInsts;
Stats::Scalar<> iewExecSquashedInsts;
Stats::Scalar<> memOrderViolationEvents;
Stats::Scalar<> predictedTakenIncorrect;
};
#endif // __CPU_BETA_CPU_IEW_HH__
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