rename.hh

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/*
 * Copyright (c) 2012, 2017 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
 * Copyright (c) 2013 Advanced Micro Devices, Inc.
 * All rights reserved.
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 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
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#ifndef __CPU_O3_RENAME_HH__
#define __CPU_O3_RENAME_HH__
 
#include <list>
#include <utility>
 
#include "base/statistics.hh"
#include "config/the_isa.hh"
#include "cpu/timebuf.hh"
#include "sim/probe/probe.hh"
 
struct DerivO3CPUParams;
 
template<class Impl>
class DefaultRename
{
  public:
    // Typedefs from the Impl.
    typedef typename Impl::CPUPol CPUPol;
    typedef typename Impl::DynInstPtr DynInstPtr;
    typedef typename Impl::O3CPU O3CPU;
 
    // Typedefs from the CPUPol
    typedef typename CPUPol::DecodeStruct DecodeStruct;
    typedef typename CPUPol::RenameStruct RenameStruct;
    typedef typename CPUPol::TimeStruct TimeStruct;
    typedef typename CPUPol::FreeList FreeList;
    typedef typename CPUPol::RenameMap RenameMap;
    // These are used only for initialization.
    typedef typename CPUPol::IEW IEW;
    typedef typename CPUPol::Commit Commit;
 
    // A deque is used to queue the instructions. Barrier insts must
    // be added to the front of the queue, which is the only reason for
    // using a deque instead of a queue. (Most other stages use a
    // queue)
    typedef std::deque<DynInstPtr> InstQueue;
 
  public:
    enum RenameStatus {
        Active,
        Inactive
    };
 
    enum ThreadStatus {
        Running,
        Idle,
        StartSquash,
        Squashing,
        Blocked,
        Unblocking,
        SerializeStall
    };
 
  private:
    RenameStatus _status;
 
    ThreadStatus renameStatus[Impl::MaxThreads];
 
    typedef typename std::pair<InstSeqNum, PhysRegIdPtr> SeqNumRegPair;
    ProbePointArg<DynInstPtr> *ppRename;
    ProbePointArg<SeqNumRegPair> *ppSquashInRename;
 
  public:
    DefaultRename(O3CPU *_cpu, DerivO3CPUParams *params);
 
    std::string name() const;
 
    void regProbePoints();
 
    void setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr);
 
    void setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr);
 
    void setDecodeQueue(TimeBuffer<DecodeStruct> *dq_ptr);
 
    void setIEWStage(IEW *iew_stage)
    { iew_ptr = iew_stage; }
 
    void setCommitStage(Commit *commit_stage)
    { commit_ptr = commit_stage; }
 
  private:
    IEW *iew_ptr;
 
    Commit *commit_ptr;
 
  public:
    void startupStage();
 
    void clearStates(ThreadID tid);
 
    void setActiveThreads(std::list<ThreadID> *at_ptr);
 
    void setRenameMap(RenameMap rm_ptr[Impl::MaxThreads]);
 
    void setFreeList(FreeList *fl_ptr);
 
    void setScoreboard(Scoreboard *_scoreboard);
 
    void drainSanityCheck() const;
 
    bool isDrained() const;
 
    void takeOverFrom();
 
    void squash(const InstSeqNum &squash_seq_num, ThreadID tid);
 
    void tick();
 
    void dumpHistory();
 
  private:
    void resetStage();
 
    void rename(bool &status_change, ThreadID tid);
 
    void renameInsts(ThreadID tid);
 
    void skidInsert(ThreadID tid);
 
    void sortInsts();
 
    bool skidsEmpty();
 
    void updateStatus();
 
    bool block(ThreadID tid);
 
    bool unblock(ThreadID tid);
 
    void doSquash(const InstSeqNum &squash_seq_num, ThreadID tid);
 
    void removeFromHistory(InstSeqNum inst_seq_num, ThreadID tid);
 
    inline void renameSrcRegs(const DynInstPtr &inst, ThreadID tid);
 
    inline void renameDestRegs(const DynInstPtr &inst, ThreadID tid);
 
    inline int calcFreeROBEntries(ThreadID tid);
 
    inline int calcFreeIQEntries(ThreadID tid);
 
    inline int calcFreeLQEntries(ThreadID tid);
 
    inline int calcFreeSQEntries(ThreadID tid);
 
    unsigned validInsts();
 
    void readStallSignals(ThreadID tid);
 
    bool checkStall(ThreadID tid);
 
    void readFreeEntries(ThreadID tid);
 
    bool checkSignalsAndUpdate(ThreadID tid);
 
    void serializeAfter(InstQueue &inst_list, ThreadID tid);
 
    struct RenameHistory {
        RenameHistory(InstSeqNum _instSeqNum, const RegId& _archReg,
                      PhysRegIdPtr _newPhysReg,
                      PhysRegIdPtr _prevPhysReg)
            : instSeqNum(_instSeqNum), archReg(_archReg),
              newPhysReg(_newPhysReg), prevPhysReg(_prevPhysReg)
        {
        }
 
        InstSeqNum instSeqNum;
        RegId archReg;
        PhysRegIdPtr newPhysReg;
        PhysRegIdPtr prevPhysReg;
    };
 
    std::list<RenameHistory> historyBuffer[Impl::MaxThreads];
 
    O3CPU *cpu;
 
    TimeBuffer<TimeStruct> *timeBuffer;
 
    typename TimeBuffer<TimeStruct>::wire fromIEW;
 
    typename TimeBuffer<TimeStruct>::wire fromCommit;
 
    typename TimeBuffer<TimeStruct>::wire toDecode;
 
    TimeBuffer<RenameStruct> *renameQueue;
 
    typename TimeBuffer<RenameStruct>::wire toIEW;
 
    TimeBuffer<DecodeStruct> *decodeQueue;
 
    typename TimeBuffer<DecodeStruct>::wire fromDecode;
 
    InstQueue insts[Impl::MaxThreads];
 
    InstQueue skidBuffer[Impl::MaxThreads];
 
    RenameMap *renameMap[Impl::MaxThreads];
 
    FreeList *freeList;
 
    std::list<ThreadID> *activeThreads;
 
    Scoreboard *scoreboard;
 
    int instsInProgress[Impl::MaxThreads];
 
    int loadsInProgress[Impl::MaxThreads];
 
    int storesInProgress[Impl::MaxThreads];
 
    bool wroteToTimeBuffer;
 
    struct FreeEntries {
        unsigned iqEntries;
        unsigned robEntries;
        unsigned lqEntries;
        unsigned sqEntries;
    };
 
    FreeEntries freeEntries[Impl::MaxThreads];
 
    bool emptyROB[Impl::MaxThreads];
 
    struct Stalls {
        bool iew;
        bool commit;
    };
 
    Stalls stalls[Impl::MaxThreads];
 
    DynInstPtr serializeInst[Impl::MaxThreads];
 
    bool serializeOnNextInst[Impl::MaxThreads];
 
    int iewToRenameDelay;
 
    int decodeToRenameDelay;
 
    unsigned commitToRenameDelay;
 
    unsigned renameWidth;
 
    unsigned commitWidth;
 
    unsigned toIEWIndex;
 
    bool blockThisCycle;
 
    bool resumeSerialize;
 
    bool resumeUnblocking;
 
    ThreadID numThreads;
 
    unsigned skidBufferMax;
 
    enum FullSource {
        ROB,
        IQ,
        LQ,
        SQ,
        NONE
    };
 
    inline void incrFullStat(const FullSource &source);
 
    struct RenameStats : public Stats::Group {
        RenameStats(Stats::Group *parent);
 
        Stats::Scalar squashCycles;
        Stats::Scalar idleCycles;
        Stats::Scalar blockCycles;
        Stats::Scalar serializeStallCycles;
        Stats::Scalar runCycles;
        Stats::Scalar unblockCycles;
        Stats::Scalar renamedInsts;
        Stats::Scalar squashedInsts;
        Stats::Scalar ROBFullEvents;
        Stats::Scalar IQFullEvents;
        Stats::Scalar LQFullEvents;
        Stats::Scalar SQFullEvents;
        Stats::Scalar fullRegistersEvents;
        Stats::Scalar renamedOperands;
        Stats::Scalar lookups;
        Stats::Scalar intLookups;
        Stats::Scalar fpLookups;
        Stats::Scalar vecLookups;
        Stats::Scalar vecPredLookups;
        Stats::Scalar committedMaps;
        Stats::Scalar undoneMaps;
        Stats::Scalar serializing;
        Stats::Scalar tempSerializing;
        Stats::Scalar skidInsts;
    } stats;
};
 
#endif // __CPU_O3_RENAME_HH__