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-rw-r--r--src/cpu/pred/tournament.cc55
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