2 files changed, 20 insertions, 25 deletions

diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h
index a8a8f6f..66be26c 100644
--- a/include/llvm/CodeGen/MachineInstr.h
+++ b/include/llvm/CodeGen/MachineInstr.h
@@ -179,17 +179,16 @@ public:
     return MemRefsEnd - MemRefs == 1;
   }
 
+  enum MICheckType {
+    CheckDefs,      // Check all operands for equality
+    IgnoreDefs,     // Ignore all definitions
+    IgnoreVRegDefs  // Ignore virtual register definitions
+  };
+
   /// isIdenticalTo - Return true if this instruction is identical to (same
   /// opcode and same operands as) the specified instruction.
-  bool isIdenticalTo(const MachineInstr *Other) const {
-    if (Other->getOpcode() != getOpcode() ||
-        Other->getNumOperands() != getNumOperands())
-      return false;
-    for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
-      if (!getOperand(i).isIdenticalTo(Other->getOperand(i)))
-        return false;
-    return true;
-  }
+  bool isIdenticalTo(const MachineInstr *Other,
+                     MICheckType Check = CheckDefs) const;
 
   /// removeFromParent - This method unlinks 'this' from the containing basic
   /// block, and returns it, but does not delete it.
diff --git a/include/llvm/Target/TargetInstrInfo.h b/include/llvm/Target/TargetInstrInfo.h
index d95e4e8..4b26beb 100644
--- a/include/llvm/Target/TargetInstrInfo.h
+++ b/include/llvm/Target/TargetInstrInfo.h
@@ -19,14 +19,14 @@
 
 namespace llvm {
 
-class MCAsmInfo;
-class TargetRegisterClass;
-class TargetRegisterInfo;
-class LiveVariables;
 class CalleeSavedInfo;
+class LiveVariables;
+class MCAsmInfo;
+class MachineMemOperand;
 class SDNode;
 class SelectionDAG;
-class MachineMemOperand;
+class TargetRegisterClass;
+class TargetRegisterInfo;
 
 template<class T> class SmallVectorImpl;
 
@@ -243,13 +243,11 @@ public:
   virtual bool findCommutedOpIndices(MachineInstr *MI, unsigned &SrcOpIdx1,
                                      unsigned &SrcOpIdx2) const = 0;
 
-  /// isIdentical - Return true if two instructions are identical. This differs
-  /// from MachineInstr::isIdenticalTo() in that it does not require the
-  /// virtual destination registers to be the same. This is used by MachineLICM
-  /// and other MI passes to perform CSE.
-  virtual bool isIdentical(const MachineInstr *MI,
-                           const MachineInstr *Other,
-                           const MachineRegisterInfo *MRI) const = 0;
+  /// produceSameValue - Return true if two machine instructions would produce
+  /// identical values. By default, this is only true when the two instructions
+  /// are deemed identical except for defs.
+  virtual bool produceSameValue(const MachineInstr *MI0,
+                                const MachineInstr *MI1) const = 0;
 
   /// AnalyzeBranch - Analyze the branching code at the end of MBB, returning
   /// true if it cannot be understood (e.g. it's a switch dispatch or isn't
@@ -560,10 +558,8 @@ public:
                              const TargetRegisterInfo *TRI) const;
   virtual MachineInstr *duplicate(MachineInstr *Orig,
                                   MachineFunction &MF) const;
-  virtual bool isIdentical(const MachineInstr *MI,
-                           const MachineInstr *Other,
-                           const MachineRegisterInfo *MRI) const;
-
+  virtual bool produceSameValue(const MachineInstr *MI0,
+                                const MachineInstr *MI1) const;
   virtual unsigned GetFunctionSizeInBytes(const MachineFunction &MF) const;
 };