1 files changed, 50 insertions, 13 deletions

diff --git a/src/cpu/o3/bpred_unit_impl.hh b/src/cpu/o3/bpred_unit_impl.hh
index e0292e232..8502f342c 100644
--- a/src/cpu/o3/bpred_unit_impl.hh
+++ b/src/cpu/o3/bpred_unit_impl.hh
@@ -1,4 +1,16 @@
 /*
+ * Copyright (c) 2011 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
  * Copyright (c) 2004-2005 The Regents of The University of Michigan
  * All rights reserved.
  *
@@ -166,12 +178,11 @@ BPredUnit<Impl>::predict(DynInstPtr &inst, TheISA::PCState &pc, ThreadID tid)
         BPUncond(bp_history);
     } else {
         ++condPredicted;
-
         pred_taken = BPLookup(pc.instAddr(), bp_history);
 
-        DPRINTF(Fetch, "BranchPred: [tid:%i]: Branch predictor predicted %i "
-                "for PC %s\n",
-                tid, pred_taken, inst->pcState());
+        DPRINTF(Fetch, "BranchPred:[tid:%i]: [sn:%i] Branch predictor"
+                " predicted %i for PC %s\n",
+                tid, inst->seqNum,  pred_taken, inst->pcState());
     }
 
     DPRINTF(Fetch, "BranchPred: [tid:%i]: [sn:%i] Creating prediction history "
@@ -231,6 +242,15 @@ BPredUnit<Impl>::predict(DynInstPtr &inst, TheISA::PCState &pc, ThreadID tid)
                 DPRINTF(Fetch, "BranchPred: [tid:%i]: BTB doesn't have a "
                         "valid entry.\n",tid);
                 pred_taken = false;
+                // The Direction of the branch predictor is altered because the
+                // BTB did not have an entry
+                // The predictor needs to be updated accordingly
+                if (!inst->isCall() && !inst->isReturn()) {
+                      BPBTBUpdate(pc.instAddr(), bp_history);
+                      DPRINTF(Fetch, "BranchPred: [tid:%i]:[sn:%i] BPBTBUpdate"
+                              " called for %s\n",
+                              tid, inst->seqNum, inst->pcState());
+                }
                 TheISA::advancePC(target, inst->staticInst);
             }
 
@@ -261,7 +281,7 @@ BPredUnit<Impl>::update(const InstSeqNum &done_sn, ThreadID tid)
         // Update the branch predictor with the correct results.
         BPUpdate(predHist[tid].back().pc,
                  predHist[tid].back().predTaken,
-                 predHist[tid].back().bpHistory);
+                 predHist[tid].back().bpHistory, false);
 
         predHist[tid].pop_back();
     }
@@ -356,12 +376,15 @@ BPredUnit<Impl>::squash(const InstSeqNum &squashed_sn,
         }
 
         BPUpdate((*hist_it).pc, actually_taken,
-                 pred_hist.front().bpHistory);
-
-        BTB.update((*hist_it).pc, corrTarget, tid);
-
-        DPRINTF(Fetch, "BranchPred: [tid:%i]: Removing history for [sn:%i] "
-                "PC %s.\n", tid, (*hist_it).seqNum, (*hist_it).pc);
+                 pred_hist.front().bpHistory, true);
+        if (actually_taken){
+            DPRINTF(Fetch,"BranchPred: [tid: %i] BTB Update called for [sn:%i]"
+                           " PC: %s\n", tid,(*hist_it).seqNum, (*hist_it).pc);
+            BTB.update((*hist_it).pc, corrTarget, tid);
+        }
+        DPRINTF(Fetch, "BranchPred: [tid:%i]: Removing history for [sn:%i]"
+                       " PC %s  Actually Taken: %i\n", tid, (*hist_it).seqNum,
+                       (*hist_it).pc, actually_taken);
 
         pred_hist.erase(hist_it);
 
@@ -407,12 +430,26 @@ BPredUnit<Impl>::BPLookup(Addr instPC, void * &bp_history)
 
 template <class Impl>
 void
-BPredUnit<Impl>::BPUpdate(Addr instPC, bool taken, void *bp_history)
+BPredUnit<Impl>::BPBTBUpdate(Addr instPC, void * &bp_history)
+{
+    if (predictor == Local) {
+        return localBP->BTBUpdate(instPC, bp_history);
+    } else if (predictor == Tournament) {
+        return tournamentBP->BTBUpdate(instPC, bp_history);
+    } else {
+        panic("Predictor type is unexpected value!");
+    }
+}
+
+template <class Impl>
+void
+BPredUnit<Impl>::BPUpdate(Addr instPC, bool taken, void *bp_history,
+                 bool squashed)
 {
     if (predictor == Local) {
         localBP->update(instPC, taken, bp_history);
     } else if (predictor == Tournament) {
-        tournamentBP->update(instPC, taken, bp_history);
+        tournamentBP->update(instPC, taken, bp_history, squashed);
     } else {
         panic("Predictor type is unexpected value!");
     }