cpu: Implement per-thread GHRs

Branch predictors that use GHRs should index them on a
per-thread basis.  This makes that so.

This is a re-spin of fb51231 after the revert (bd1c6789).

1 files changed, 10 insertions, 9 deletions

diff --git a/src/cpu/pred/bi_mode.hh b/src/cpu/pred/bi_mode.hh
index 120a6ffd9..96b3b2ef7 100644
--- a/src/cpu/pred/bi_mode.hh
+++ b/src/cpu/pred/bi_mode.hh
@@ -57,16 +57,17 @@ class BiModeBP : public BPredUnit
 {
   public:
     BiModeBP(const BiModeBPParams *params);
-    void uncondBranch(Addr pc, void * &bp_history);
-    void squash(void *bp_history);
-    bool lookup(Addr branch_addr, void * &bp_history);
-    void btbUpdate(Addr branch_addr, void * &bp_history);
-    void update(Addr branch_addr, bool taken, void *bp_history, bool squashed);
-    void retireSquashed(void *bp_history);
-    unsigned getGHR(void *bp_history) const;
+    void uncondBranch(ThreadID tid, Addr pc, void * &bp_history);
+    void squash(ThreadID tid, void *bp_history);
+    bool lookup(ThreadID tid, Addr branch_addr, void * &bp_history);
+    void btbUpdate(ThreadID tid, Addr branch_addr, void * &bp_history);
+    void update(ThreadID tid, Addr branch_addr, bool taken, void *bp_history,
+                bool squashed);
+    void retireSquashed(ThreadID tid, void *bp_history);
+    unsigned getGHR(ThreadID tid, void *bp_history) const;
 
   private:
-    void updateGlobalHistReg(bool taken);
+    void updateGlobalHistReg(ThreadID tid, bool taken);
 
     struct BPHistory {
         unsigned globalHistoryReg;
@@ -95,7 +96,7 @@ class BiModeBP : public BPredUnit
     // not-taken direction predictors
     std::vector<SatCounter> notTakenCounters;
 
-    unsigned globalHistoryReg;
+    std::vector<unsigned> globalHistoryReg;
     unsigned globalHistoryBits;
     unsigned historyRegisterMask;