O3: Track if the RAS has been pushed or not to pop the RAS if neccessary.

Add new flag (named pushedRAS) in the PredictorHistory structure.
This flag tracks whether the RAS has been pushed or not during a prediction.
Then, in the squash function it is used to pop the RAS if necessary.

1 files changed, 4 insertions, 1 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;