diff options
| -rw-r--r-- | src/cpu/pred/tournament.cc | 55 |
1 files changed, 38 insertions, 17 deletions
diff --git a/src/cpu/pred/tournament.cc b/src/cpu/pred/tournament.cc index 96ee87615..ad696f00a 100644 --- a/src/cpu/pred/tournament.cc +++ b/src/cpu/pred/tournament.cc @@ -36,8 +36,8 @@ TournamentBP::TournamentBP(unsigned _localPredictorSize, unsigned _localHistoryTableSize, unsigned _localHistoryBits, unsigned _globalPredictorSize, - unsigned _globalCtrBits, unsigned _globalHistoryBits, + unsigned _globalCtrBits, unsigned _choicePredictorSize, unsigned _choiceCtrBits, unsigned _instShiftAmt) @@ -247,12 +247,47 @@ TournamentBP::update(Addr &branch_addr, bool taken, void *bp_history) // decerement the counter. Otherwise increment the // counter. if (history->localPredTaken == taken) { - choiceCtrs[globalHistory].decrement(); + choiceCtrs[history->globalHistory].decrement(); } else if (history->globalPredTaken == taken){ - choiceCtrs[globalHistory].increment(); + choiceCtrs[history->globalHistory].increment(); } + } + // Update the counters and local history with the proper + // resolution of the branch. Global history is updated + // speculatively and restored upon squash() calls, so it does not + // need to be updated. + if (taken) { + localCtrs[local_predictor_idx].increment(); + globalCtrs[history->globalHistory].increment(); + + updateLocalHistTaken(local_history_idx); + } else { + localCtrs[local_predictor_idx].decrement(); + globalCtrs[history->globalHistory].decrement(); + + updateLocalHistNotTaken(local_history_idx); + } + + bool mispredict = false; + + //global predictor used and mispredicted + if (history->globalUsed && history->globalPredTaken != taken) + mispredict = true; + //local predictor used and mispredicted + else if (!history->globalUsed && history->localPredTaken != taken) + mispredict = true; + + if (mispredict) { + if (taken) { + globalHistory = globalHistory | 1; + } else { + unsigned mask = globalHistoryMask - 1; + globalHistory = globalHistory & mask; + } + + } // We're done with this history, now delete it. delete history; } @@ -261,21 +296,7 @@ TournamentBP::update(Addr &branch_addr, bool taken, void *bp_history) local_history_idx < localHistoryTableSize && local_predictor_idx < localPredictorSize); - // Update the counters and local history with the proper - // resolution of the branch. Global history is updated - // speculatively and restored upon squash() calls, so it does not - // need to be updated. - if (taken) { - localCtrs[local_predictor_idx].increment(); - globalCtrs[globalHistory].increment(); - updateLocalHistTaken(local_history_idx); - } else { - localCtrs[local_predictor_idx].decrement(); - globalCtrs[globalHistory].decrement(); - - updateLocalHistNotTaken(local_history_idx); - } } void |