diff options
| -rw-r--r-- | src/cpu/o3/bpred_unit.hh | 5 | ||||
| -rw-r--r-- | src/cpu/o3/bpred_unit_impl.hh | 7 |
2 files changed, 8 insertions, 4 deletions
diff --git a/src/cpu/o3/bpred_unit.hh b/src/cpu/o3/bpred_unit.hh index 8bfab11a9..c1afb4720 100644 --- a/src/cpu/o3/bpred_unit.hh +++ b/src/cpu/o3/bpred_unit.hh @@ -207,7 +207,7 @@ class BPredUnit bool pred_taken, void *bp_history, ThreadID _tid) : seqNum(seq_num), pc(instPC), bpHistory(bp_history), RASTarget(0), - RASIndex(0), tid(_tid), predTaken(pred_taken), usedRAS(0), + RASIndex(0), tid(_tid), predTaken(pred_taken), usedRAS(0), pushedRAS(0), wasCall(0), wasReturn(0), validBTB(0) {} @@ -242,6 +242,9 @@ class BPredUnit /** Whether or not the RAS was used. */ bool usedRAS; + /* Wether or not the RAS was pushed */ + bool pushedRAS; + /** Whether or not the instruction was a call. */ bool wasCall; diff --git a/src/cpu/o3/bpred_unit_impl.hh b/src/cpu/o3/bpred_unit_impl.hh index 1e75de90c..6f0e5e3e0 100644 --- a/src/cpu/o3/bpred_unit_impl.hh +++ b/src/cpu/o3/bpred_unit_impl.hh @@ -219,7 +219,7 @@ BPredUnit<Impl>::predict(DynInstPtr &inst, TheISA::PCState &pc, ThreadID tid) if (inst->isCall()) { RAS[tid].push(pc); - + predict_record.pushedRAS = true; // Record that it was a call so that the top RAS entry can // be popped off if the speculation is incorrect. predict_record.wasCall = true; @@ -253,6 +253,7 @@ BPredUnit<Impl>::predict(DynInstPtr &inst, TheISA::PCState &pc, ThreadID tid) tid, inst->seqNum, inst->pcState()); } else if (inst->isCall() && !inst->isUncondCtrl()) { RAS[tid].pop(); + predict_record.pushedRAS = false; } TheISA::advancePC(target, inst->staticInst); } @@ -308,7 +309,7 @@ BPredUnit<Impl>::squash(const InstSeqNum &squashed_sn, ThreadID tid) RAS[tid].restore(pred_hist.front().RASIndex, pred_hist.front().RASTarget); - } else if(pred_hist.front().wasCall && pred_hist.front().validBTB) { + } else if(pred_hist.front().wasCall && pred_hist.front().pushedRAS) { // Was a call but predicated false. Pop RAS here DPRINTF(Fetch, "BranchPred: [tid: %i] Squashing" " Call [sn:%i] PC: %s Popping RAS\n", tid, @@ -408,7 +409,7 @@ BPredUnit<Impl>::squash(const InstSeqNum &squashed_sn, hist_it->RASIndex, hist_it->RASTarget); RAS[tid].restore(hist_it->RASIndex, hist_it->RASTarget); - } else if (hist_it->wasCall && hist_it->validBTB) { + } else if (hist_it->wasCall && hist_it->pushedRAS) { //Was a Call but predicated false. Pop RAS here DPRINTF(Fetch, "BranchPred: [tid: %i] Incorrectly predicted" " Call [sn:%i] PC: %s Popping RAS\n", tid, |