#ifndef __CPU_BETA_CPU_2BIT_LOCAL_PRED_HH__ #define __CPU_BETA_CPU_2BIT_LOCAL_PRED_HH__ // For Addr type. #include "arch/alpha/isa_traits.hh" #include "cpu/beta_cpu/sat_counter.hh" class DefaultBP { public: /** * Default branch predictor constructor. */ DefaultBP(unsigned localPredictorSize, unsigned localCtrBits, unsigned instShiftAmt); /** * Looks up the given address in the branch predictor and returns * a true/false value as to whether it is taken. * @param branch_addr The address of the branch to look up. * @return Whether or not the branch is taken. */ bool lookup(Addr &branch_addr); /** * Updates the branch predictor with the actual result of a branch. * @param branch_addr The address of the branch to update. * @param taken Whether or not the branch was taken. */ void update(Addr &branch_addr, bool taken); private: inline bool getPrediction(uint8_t &count); inline unsigned getLocalIndex(Addr &PC); /** Array of counters that make up the local predictor. */ SatCounter *localCtrs; /** Size of the local predictor. */ unsigned localPredictorSize; /** Number of bits of the local predictor's counters. */ unsigned localCtrBits; /** Number of bits to shift the PC when calculating index. */ unsigned instShiftAmt; /** Mask to get index bits. */ unsigned indexMask; }; #endif // __CPU_BETA_CPU_2BIT_LOCAL_PRED_HH__