Special handle for mul/div minus one when kAllUsesTruncatingToInt32

src/hydrogen-instructions.h

 // Copyright 2012 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 4607 matching lines @@
   virtual bool IsCommutative() const V8_OVERRIDE {
     return !representation().IsTagged();
   }
 
   virtual void UpdateRepresentation(Representation new_rep,
                                     HInferRepresentationPhase* h_infer,
                                     const char* reason) V8_OVERRIDE {
     HArithmeticBinaryOperation::UpdateRepresentation(new_rep, h_infer, reason);
   }
 
+  bool MulMinusOne();
+
   DECLARE_CONCRETE_INSTRUCTION(Mul)
 
  protected:
   virtual bool DataEquals(HValue* other) V8_OVERRIDE { return true; }
 
   virtual Range* InferRange(Zone* zone) V8_OVERRIDE;
 
  private:
   HMul(HValue* context, HValue* left, HValue* right)
       : HArithmeticBinaryOperation(context, left, right) {
@@ skipping 2426 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_