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| author | Matt Horsnell <Matt.Horsnell@arm.com> | 2011-01-18 16:30:05 -0600 |
|---|---|---|
| committer | Matt Horsnell <Matt.Horsnell@arm.com> | 2011-01-18 16:30:05 -0600 |
| commit | 62f2097917c977335d025e230146c6eb56a9bb5d (patch) | |
| tree | 68bc1883947fb893961ea2474903ed1de1a40007 /src/cpu/o3/fetch_impl.hh | |
| parent | 5ebf3b280867925917654f5362d3ece21dc2355e (diff) | |
| download | gem5-62f2097917c977335d025e230146c6eb56a9bb5d.tar.xz | |
O3: Fix mispredicts from non control instructions.
The squash inside the fetch unit should not attempt to remove them from the
branch predictor as non-control instructions are not pushed into the predictor.
Diffstat (limited to 'src/cpu/o3/fetch_impl.hh')
| -rw-r--r-- | src/cpu/o3/fetch_impl.hh | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/src/cpu/o3/fetch_impl.hh b/src/cpu/o3/fetch_impl.hh index 880158dfc..736a66c64 100644 --- a/src/cpu/o3/fetch_impl.hh +++ b/src/cpu/o3/fetch_impl.hh @@ -902,8 +902,14 @@ DefaultFetch<Impl>::checkSignalsAndUpdate(ThreadID tid) fromCommit->commitInfo[tid].doneSeqNum, tid); - // Also check if there's a mispredict that happened. - if (fromCommit->commitInfo[tid].branchMispredict) { + // If it was a branch mispredict on a control instruction, update the + // branch predictor with that instruction, otherwise just kill the + // invalid state we generated in after sequence number + assert(!fromCommit->commitInfo[tid].branchMispredict || + fromCommit->commitInfo[tid].mispredictInst); + + if (fromCommit->commitInfo[tid].branchMispredict && + fromCommit->commitInfo[tid].mispredictInst->isControl()) { branchPred.squash(fromCommit->commitInfo[tid].doneSeqNum, fromCommit->commitInfo[tid].pc, fromCommit->commitInfo[tid].branchTaken, |