1 files changed, 37 insertions, 12 deletions

diff --git a/src/cpu/o3/2bit_local_pred.hh b/src/cpu/o3/2bit_local_pred.hh
index 97433e542..0a2a71d3e 100644
--- a/src/cpu/o3/2bit_local_pred.hh
+++ b/src/cpu/o3/2bit_local_pred.hh
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004-2005 The Regents of The University of Michigan
+ * Copyright (c) 2004-2006 The Regents of The University of Michigan
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -24,43 +24,65 @@
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Kevin Lim
  */
 
-#ifndef __CPU_O3_CPU_2BIT_LOCAL_PRED_HH__
-#define __CPU_O3_CPU_2BIT_LOCAL_PRED_HH__
+#ifndef __CPU_O3_2BIT_LOCAL_PRED_HH__
+#define __CPU_O3_2BIT_LOCAL_PRED_HH__
 
 // For Addr type.
 #include "arch/isa_traits.hh"
 #include "cpu/o3/sat_counter.hh"
 
-class DefaultBP
+#include <vector>
+
+/**
+ * Implements a local predictor that uses the PC to index into a table of
+ * counters.  Note that any time a pointer to the bp_history is given, it
+ * should be NULL using this predictor because it does not have any branch
+ * predictor state that needs to be recorded or updated; the update can be
+ * determined solely by the branch being taken or not taken.
+ */
+class LocalBP
 {
   public:
     /**
      * Default branch predictor constructor.
+     * @param localPredictorSize Size of the local predictor.
+     * @param localCtrBits Number of bits per counter.
+     * @param instShiftAmt Offset amount for instructions to ignore alignment.
      */
-    DefaultBP(unsigned localPredictorSize, unsigned localCtrBits,
-              unsigned instShiftAmt);
+    LocalBP(unsigned localPredictorSize, unsigned localCtrBits,
+            unsigned instShiftAmt);
 
     /**
      * Looks up the given address in the branch predictor and returns
      * a true/false value as to whether it is taken.
      * @param branch_addr The address of the branch to look up.
+     * @param bp_history Pointer to any bp history state.
      * @return Whether or not the branch is taken.
      */
-    bool lookup(Addr &branch_addr);
+    bool lookup(Addr &branch_addr, void * &bp_history);
 
     /**
      * Updates the branch predictor with the actual result of a branch.
      * @param branch_addr The address of the branch to update.
      * @param taken Whether or not the branch was taken.
      */
-    void update(Addr &branch_addr, bool taken);
+    void update(Addr &branch_addr, bool taken, void *bp_history);
 
-  private:
+    void squash(void *bp_history)
+    { assert(bp_history == NULL); }
 
-    /** Returns the taken/not taken prediction given the value of the
+    void reset();
+
+  private:
+    /**
+     *  Returns the taken/not taken prediction given the value of the
      *  counter.
+     *  @param count The value of the counter.
+     *  @return The prediction based on the counter value.
      */
     inline bool getPrediction(uint8_t &count);
 
@@ -68,11 +90,14 @@ class DefaultBP
     inline unsigned getLocalIndex(Addr &PC);
 
     /** Array of counters that make up the local predictor. */
-    SatCounter *localCtrs;
+    std::vector<SatCounter> localCtrs;
 
     /** Size of the local predictor. */
     unsigned localPredictorSize;
 
+    /** Number of sets. */
+    unsigned localPredictorSets;
+
     /** Number of bits of the local predictor's counters. */
     unsigned localCtrBits;
 
@@ -83,4 +108,4 @@ class DefaultBP
     unsigned indexMask;
 };
 
-#endif // __CPU_O3_CPU_2BIT_LOCAL_PRED_HH__
+#endif // __CPU_O3_2BIT_LOCAL_PRED_HH__