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| author | Rico Amslinger <rico.amslinger@informatik.uni-augsburg.de> | 2017-08-24 15:07:44 +0200 |
|---|---|---|
| committer | Rico Amslinger <rico.amslinger@informatik.uni-augsburg.de> | 2017-09-06 07:39:11 +0000 |
| commit | 725b19a8154fa557ab3057f07d7cd3c6d798789d (patch) | |
| tree | 014dd92e03bbb9927302fc2e71931893df9bae69 | |
| parent | 29d7c72b89949199653ab05f5bbb298c733b08b7 (diff) | |
| download | gem5-725b19a8154fa557ab3057f07d7cd3c6d798789d.tar.xz | |
cpu: Fix bi-mode branch predictor thresholds
When different sizes were set for the choice and global saturation
counter (e.g. ex5_big), the threshold calculation used the wrong
size. Thus the branch predictor always predicted "not taken" for
choice > global.
Change-Id: I076549ff1482e2280cef24a0d16b7bb2122d4110
Reviewed-on: https://gem5-review.googlesource.com/4560
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
| -rw-r--r-- | src/cpu/pred/bi_mode.cc | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/cpu/pred/bi_mode.cc b/src/cpu/pred/bi_mode.cc index 69af4584a..e8fda7387 100644 --- a/src/cpu/pred/bi_mode.cc +++ b/src/cpu/pred/bi_mode.cc @@ -68,8 +68,8 @@ BiModeBP::BiModeBP(const BiModeBPParams *params) globalHistoryMask = globalPredictorSize - 1; choiceThreshold = (ULL(1) << (choiceCtrBits - 1)) - 1; - takenThreshold = (ULL(1) << (choiceCtrBits - 1)) - 1; - notTakenThreshold = (ULL(1) << (choiceCtrBits - 1)) - 1; + takenThreshold = (ULL(1) << (globalCtrBits - 1)) - 1; + notTakenThreshold = (ULL(1) << (globalCtrBits - 1)) - 1; } /* |