Use typefeedback for bitwise operations....

src/hydrogen-instructions.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2025 matching lines @@
   HValue* length() const { return right(); }
 
   DECLARE_CONCRETE_INSTRUCTION(BoundsCheck, "bounds_check")
 };
 
 
 class HBitwiseBinaryOperation: public HBinaryOperation {
  public:
   HBitwiseBinaryOperation(HValue* left, HValue* right)
       : HBinaryOperation(left, right) {
-    // Default to truncating, Integer32, UseGVN.
-    set_representation(Representation::Integer32());
-    SetFlag(kTruncatingToInt32);
-    SetFlag(kUseGVN);
+    set_representation(Representation::Tagged());
+    SetFlag(kFlexibleRepresentation);
+    SetFlagMask(AllSideEffects());
   }
 
   virtual Representation RequiredInputRepresentation(int index) const {
-    return Representation::Integer32();
+    return representation();
   }
 
+  virtual void RepresentationChanged(Representation to) {
+    if (!to.IsTagged()) {
+      ASSERT(to.IsInteger32());
+      ClearFlagMask(AllSideEffects());
+      SetFlag(kTruncatingToInt32);
+      SetFlag(kUseGVN);
+    }
+  }
+
+  HType CalculateInferredType() const;
+
   DECLARE_INSTRUCTION(BitwiseBinaryOperation)
 };
 
 
 class HArithmeticBinaryOperation: public HBinaryOperation {
  public:
   HArithmeticBinaryOperation(HValue* left, HValue* right)
       : HBinaryOperation(left, right) {
     set_representation(Representation::Tagged());
     SetFlag(kFlexibleRepresentation);
@@ skipping 1075 matching lines @@
   HValue* object() const { return left(); }
   HValue* key() const { return right(); }
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_