1 files changed, 13 insertions, 4 deletions
diff --git a/lib/CodeGen/PHIElimination.h b/lib/CodeGen/PHIElimination.h
index b0b71ce..1bcc9dc 100644
--- a/lib/CodeGen/PHIElimination.h
+++ b/lib/CodeGen/PHIElimination.h
@@ -16,8 +16,6 @@
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/Target/TargetInstrInfo.h"
 
-#include <map>
-
 namespace llvm {
 
   /// Lower PHI instructions to copies.  
@@ -120,8 +118,8 @@ namespace llvm {
       return I;
     }
 
-    typedef std::pair<const MachineBasicBlock*, unsigned> BBVRegPair;
-    typedef std::map<BBVRegPair, unsigned> VRegPHIUse;
+    typedef std::pair<unsigned, unsigned> BBVRegPair;
+    typedef DenseMap<BBVRegPair, unsigned> VRegPHIUse;
 
     VRegPHIUse VRegPHIUseCount;
     PHIDefMap PHIDefs;
@@ -129,6 +127,17 @@ namespace llvm {
 
     // Defs of PHI sources which are implicit_def.
     SmallPtrSet<MachineInstr*, 4> ImpDefs;
+
+    // Lowered PHI nodes may be reused. We provide special DenseMap traits to
+    // match PHI nodes with identical arguments.
+    struct PHINodeTraits : public DenseMapInfo<MachineInstr*> {
+      static unsigned getHashValue(const MachineInstr *PtrVal);
+      static bool isEqual(const MachineInstr *LHS, const MachineInstr *RHS);
+    };
+
+    // Map reusable lowered PHI node -> incoming join register.
+    typedef DenseMap<MachineInstr*, unsigned, PHINodeTraits> LoweredPHIMap;
+    LoweredPHIMap LoweredPHIs;
   };
 
 }