src/cpu/simple/probes/simpoint.hh

/*
 * Copyright (c) 2012-2014 ARM Limited
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 *
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 * property including but not limited to intellectual property relating
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 * terms below provided that you ensure that this notice is replicated
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 *
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 * met: redistributions of source code must retain the above copyright
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 * this software without specific prior written permission.
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#ifndef __CPU_SIMPLE_PROBES_SIMPOINT_HH__
#define __CPU_SIMPLE_PROBES_SIMPOINT_HH__

#include <unordered_map>

#include "base/output.hh"
#include "cpu/simple_thread.hh"
#include "params/SimPoint.hh"
#include "sim/probe/probe.hh"

namespace gem5
{

/**
 * Probe for SimPoints BBV generation
 */

/**
 *  Start and end address of basic block for SimPoint profiling.
 *  This structure is used to look up the hash table of BBVs.
 *  - first: PC of first inst in basic block
 *  - second: PC of last inst in basic block
 */
typedef std::pair<Addr, Addr> BasicBlockRange;

} // namespace gem5

/** Overload hash function for BasicBlockRange type */
namespace std
{
template <>
struct hash<gem5::BasicBlockRange>
{
  public:
    size_t operator()(const gem5::BasicBlockRange &bb) const
    {
        return hash<gem5::Addr>()(bb.first + bb.second);
    }
};
} // namespace std

namespace gem5
{

class SimPoint : public ProbeListenerObject
{
  public:
    SimPoint(const SimPointParams &params);
    virtual ~SimPoint();

    virtual void init();

    virtual void regProbeListeners();

    /**
     * Profile basic blocks for SimPoints.
     * Called at every macro inst to increment basic block inst counts and
     * to profile block if end of block.
     */
    void profile(const std::pair<SimpleThread*, StaticInstPtr>&);

  private:
    /** SimPoint profiling interval size in instructions */
    const uint64_t intervalSize;

    /** Inst count in current basic block */
    uint64_t intervalCount;
    /** Excess inst count from previous interval*/
    uint64_t intervalDrift;
    /** Pointer to SimPoint BBV output stream */
    OutputStream *simpointStream;

    /** Basic Block information */
    struct BBInfo
    {
        /** Unique ID */
        uint64_t id;
        /** Num of static insts in BB */
        uint64_t insts;
        /** Accumulated dynamic inst count executed by BB */
        uint64_t count;
    };

    /** Hash table containing all previously seen basic blocks */
    std::unordered_map<BasicBlockRange, BBInfo> bbMap;
    /** Currently executing basic block */
    BasicBlockRange currentBBV;
    /** inst count in current basic block */
    uint64_t currentBBVInstCount;
};

} // namespace gem5

#endif // __CPU_SIMPLE_PROBES_SIMPOINT_HH__