rename.hh

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 * to a hardware implementation of the functionality of the software
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 * Copyright (c) 2004-2006 The Regents of The University of Michigan
 * Copyright (c) 2013 Advanced Micro Devices, Inc.
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#ifndef __CPU_O3_RENAME_HH__
#define __CPU_O3_RENAME_HH__
 
#include <list>
#include <utility>
 
#include "base/statistics.hh"
#include "cpu/o3/comm.hh"
#include "cpu/o3/commit.hh"
#include "cpu/o3/dyn_inst_ptr.hh"
#include "cpu/o3/free_list.hh"
#include "cpu/o3/iew.hh"
#include "cpu/o3/limits.hh"
#include "cpu/timebuf.hh"
#include "sim/probe/probe.hh"
 
namespace gem5
{
 
struct BaseO3CPUParams;
 
namespace o3
{

class Rename
{
  public:
    // 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,
        ThreadStatusMax
    };
 
  private:
    RenameStatus _status;

    ThreadStatus renameStatus[MaxThreads];

    typedef std::pair<InstSeqNum, PhysRegIdPtr> SeqNumRegPair;
    ProbePointArg<DynInstPtr> *ppRename;
    ProbePointArg<SeqNumRegPair> *ppSquashInRename;
 
  public:
    Rename(CPU *_cpu, const BaseO3CPUParams &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(UnifiedRenameMap::PerThreadUnifiedRenameMap& rm_ptr);

    void setFreeList(UnifiedFreeList *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);

    void renameSrcRegs(const DynInstPtr &inst, ThreadID tid);

    void renameDestRegs(const DynInstPtr &inst, ThreadID tid);

    int calcFreeROBEntries(ThreadID tid);

    int calcFreeIQEntries(ThreadID tid);

    int calcFreeLQEntries(ThreadID tid);

    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[MaxThreads];

    CPU *cpu;

    TimeBuffer<TimeStruct> *timeBuffer;

    TimeBuffer<TimeStruct>::wire fromIEW;

    TimeBuffer<TimeStruct>::wire fromCommit;

    TimeBuffer<TimeStruct>::wire toDecode;

    TimeBuffer<RenameStruct> *renameQueue;

    TimeBuffer<RenameStruct>::wire toIEW;

    TimeBuffer<DecodeStruct> *decodeQueue;

    TimeBuffer<DecodeStruct>::wire fromDecode;

    InstQueue insts[MaxThreads];

    InstQueue skidBuffer[MaxThreads];

    UnifiedRenameMap *renameMap[MaxThreads];

    UnifiedFreeList *freeList;

    std::vector<PhysRegIdPtr> freeingInProgress[MaxThreads];

    std::list<ThreadID> *activeThreads;

    Scoreboard *scoreboard;

    int instsInProgress[MaxThreads];

    int loadsInProgress[MaxThreads];

    int storesInProgress[MaxThreads];

    bool wroteToTimeBuffer;

    struct FreeEntries
    {
        unsigned iqEntries;
        unsigned robEntries;
        unsigned lqEntries;
        unsigned sqEntries;
    };

    FreeEntries freeEntries[MaxThreads];

    bool emptyROB[MaxThreads];

    struct Stalls
    {
        bool iew;
        bool commit;
    };

    Stalls stalls[MaxThreads];

    DynInstPtr serializeInst[MaxThreads];

    bool serializeOnNextInst[MaxThreads];

    int iewToRenameDelay;

    int decodeToRenameDelay;

    unsigned commitToRenameDelay;

    unsigned renameWidth;

    unsigned toIEWIndex;

    bool blockThisCycle;

    bool resumeSerialize;

    bool resumeUnblocking;

    ThreadID numThreads;

    unsigned skidBufferMax;

    enum FullSource
    {
        ROB,
        IQ,
        LQ,
        SQ,
        NONE
    };

    void incrFullStat(const FullSource &source);
 
    struct RenameStats : public statistics::Group
    {
        static std::string statusStrings[ThreadStatusMax];
        static std::string statusDefinitions[ThreadStatusMax];
 
        RenameStats(statistics::Group *parent);

        statistics::Vector status;
        statistics::Scalar renamedInsts;
        statistics::Scalar squashedInsts;
        statistics::Scalar ROBFullEvents;
        statistics::Scalar IQFullEvents;
        statistics::Scalar LQFullEvents;
        statistics::Scalar SQFullEvents;
        statistics::Scalar fullRegistersEvents;
        statistics::Scalar renamedOperands;
        statistics::Scalar lookups;
        statistics::Scalar intLookups;
        statistics::Scalar fpLookups;
        statistics::Scalar vecLookups;
        statistics::Scalar vecPredLookups;
        statistics::Scalar matLookups;
        statistics::Scalar committedMaps;
        statistics::Scalar undoneMaps;
        statistics::Scalar serializing;
        statistics::Scalar tempSerializing;
        statistics::Scalar skidInsts;
        statistics::Scalar intReturned;
        statistics::Scalar fpReturned;
    } stats;
};
 
} // namespace o3
} // namespace gem5
 
#endif // __CPU_O3_RENAME_HH__