Add a method to clear optional optimization information from a Value.

llvm-svn: 76215

llvm/include/llvm/Value.h

@@ -146,6 +146,12 @@ public:
   // Only use when in type resolution situations!
   void uncheckedReplaceAllUsesWith(Value *V);
 
+  /// clearOptionalData - Clear any optional optimization data from this Value.
+  /// Transformation passes must call this method whenever changing the IR
+  /// in a way that would affect the values produced by this Value, unless
+  /// it takes special care to ensure correctness in some other way.
+  void clearOptionalData() { SubclassOptionalData = 0; }
+
   //----------------------------------------------------------------------
   // Methods for handling the chain of uses of this Value.
   //