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-rw-r--r--src/cpu/o3/bpred_unit.hh5
-rw-r--r--src/cpu/o3/bpred_unit_impl.hh7
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,