rob.hh

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/*
 * Copyright (c) 2012 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
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 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
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 * this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#ifndef __CPU_O3_ROB_HH__
#define __CPU_O3_ROB_HH__
 
#include <string>
#include <utility>
#include <vector>
 
#include "base/statistics.hh"
#include "base/types.hh"
#include "cpu/inst_seq.hh"
#include "cpu/o3/dyn_inst_ptr.hh"
#include "cpu/o3/limits.hh"
#include "cpu/reg_class.hh"
#include "enums/SMTQueuePolicy.hh"
 
namespace gem5
{
 
struct BaseO3CPUParams;
 
namespace o3
{
 
class CPU;
 
struct DerivO3CPUParams;
 
class ROB
{
  public:
    typedef std::pair<RegIndex, RegIndex> UnmapInfo;
    typedef typename std::list<DynInstPtr>::iterator InstIt;
 
    enum Status
    {
        Running,
        Idle,
        ROBSquashing
    };
 
  private:
    Status robStatus[MaxThreads];
 
    SMTQueuePolicy robPolicy;
 
  public:
    ROB(CPU *_cpu, const BaseO3CPUParams &params);
 
    std::string name() const;
 
    void setActiveThreads(std::list<ThreadID> *at_ptr);
 
    void drainSanityCheck() const;
 
    void takeOverFrom();
 
    void insertInst(const DynInstPtr &inst);
 
//    DynInstPtr readHeadInst();
 
    const DynInstPtr &readHeadInst(ThreadID tid);
 
    DynInstPtr findInst(ThreadID tid, InstSeqNum squash_inst);
 
//    DynInstPtr readTailInst();
 
    DynInstPtr readTailInst(ThreadID tid);
 
//    void retireHead();
 
    void retireHead(ThreadID tid);
 
//    bool isHeadReady();
 
    bool isHeadReady(ThreadID tid);
 
    bool canCommit();
 
    void resetEntries();
 
    int entryAmount(ThreadID num_threads);
 
    unsigned numFreeEntries();
 
    unsigned numFreeEntries(ThreadID tid);
 
    unsigned getMaxEntries(ThreadID tid)
    { return maxEntries[tid]; }
 
    unsigned getThreadEntries(ThreadID tid)
    { return threadEntries[tid]; }
 
    bool isFull()
    { return numInstsInROB == numEntries; }
 
    bool isFull(ThreadID tid)
    { return threadEntries[tid] == numEntries; }
 
    bool isEmpty() const
    { return numInstsInROB == 0; }
 
    bool isEmpty(ThreadID tid) const
    { return threadEntries[tid] == 0; }
 
    void doSquash(ThreadID tid);
 
    void squash(InstSeqNum squash_num, ThreadID tid);
 
    void updateHead();
 
    void updateTail();
 
//    uint64_t readHeadPC();
 
//    uint64_t readHeadPC(ThreadID tid);
 
//    uint64_t readHeadNextPC();
 
//    uint64_t readHeadNextPC(ThreadID tid);
 
//    InstSeqNum readHeadSeqNum();
 
//    InstSeqNum readHeadSeqNum(ThreadID tid);
 
//    uint64_t readTailPC();
 
//    uint64_t readTailPC(ThreadID tid);
 
//    InstSeqNum readTailSeqNum();
 
//    InstSeqNum readTailSeqNum(ThreadID tid);
 
    bool isDoneSquashing(ThreadID tid) const
    { return doneSquashing[tid]; }
 
    bool isDoneSquashing();
 
    int countInsts();
 
    size_t countInsts(ThreadID tid);
 
  private:
    void resetState();
 
    CPU *cpu;
 
    std::list<ThreadID> *activeThreads;
 
    unsigned numEntries;
 
    unsigned threadEntries[MaxThreads];
 
    unsigned maxEntries[MaxThreads];
 
    std::list<DynInstPtr> instList[MaxThreads];
 
    unsigned squashWidth;
 
  public:
    InstIt tail;
 
    InstIt head;
 
  private:
    InstIt squashIt[MaxThreads];
 
  public:
    int numInstsInROB;
 
    DynInstPtr dummyInst;
 
  private:
    InstSeqNum squashedSeqNum[MaxThreads];
 
    bool doneSquashing[MaxThreads];
 
    ThreadID numThreads;
 
 
    struct ROBStats : public statistics::Group
    {
        ROBStats(statistics::Group *parent);
 
        // The number of rob_reads
        statistics::Scalar reads;
        // The number of rob_writes
        statistics::Scalar writes;
    } stats;
};
 
} // namespace o3
} // namespace gem5
 
#endif //__CPU_O3_ROB_HH__