2bit_local.hh

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#ifndef __CPU_PRED_2BIT_LOCAL_PRED_HH__
#define __CPU_PRED_2BIT_LOCAL_PRED_HH__
 
#include <vector>
 
#include "base/sat_counter.hh"
#include "base/types.hh"
#include "cpu/pred/bpred_unit.hh"
#include "params/LocalBP.hh"
 
namespace gem5
{
 
namespace branch_prediction
{

class LocalBP : public BPredUnit
{
  public:
    LocalBP(const LocalBPParams &params);
 
    // Overriding interface functions
    bool lookup(ThreadID tid, Addr pc, void * &bp_history) override;
 
    void updateHistories(ThreadID tid, Addr pc, bool uncond, bool taken,
                         Addr target, const StaticInstPtr &inst,
                         void * &bp_history) override;
 
    void update(ThreadID tid, Addr pc, bool taken,
                void * &bp_history, bool squashed,
                const StaticInstPtr & inst, Addr target) override;
 
    void squash(ThreadID tid, void * &bp_history) override
    { assert(bp_history == NULL); }
 
  private:
    inline bool getPrediction(uint8_t &count);

    inline unsigned getLocalIndex(Addr &PC);

    const unsigned localPredictorSize;

    const unsigned localCtrBits;

    const unsigned localPredictorSets;

    std::vector<SatCounter8> localCtrs;

    const unsigned indexMask;
};
 
} // namespace branch_prediction
} // namespace gem5
 
#endif // __CPU_PRED_2BIT_LOCAL_PRED_HH__