Mark HChange that convert to int32 with truncation with the appropiate flag....

src/hydrogen-instructions.h

 // Copyright 2011 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 922 matching lines @@
   }
 
   DECLARE_CONCRETE_INSTRUCTION(Throw, "throw")
 };
 
 
 class HChange: public HUnaryOperation {
  public:
   HChange(HValue* value,
           Representation from,
-          Representation to)
+          Representation to,
+          bool is_truncating)
       : HUnaryOperation(value), from_(from), to_(to) {
     ASSERT(!from.IsNone() && !to.IsNone());
     ASSERT(!from.Equals(to));
     set_representation(to);
     SetFlag(kUseGVN);
-
+    if (is_truncating) SetFlag(kTruncatingToInt32);
     if (from.IsInteger32() && to.IsTagged() && value->range() != NULL &&
         value->range()->IsInSmiRange()) {
       set_type(HType::Smi());
     }
   }
 
   virtual HValue* EnsureAndPropagateNotMinusZero(BitVector* visited);
 
   Representation from() const { return from_; }
   Representation to() const { return to_; }
   virtual Representation RequiredInputRepresentation(int index) const {
     return from_;
   }
 
-  bool CanTruncateToInt32() const {
-    for (int i = 0; i < uses()->length(); ++i) {
-      if (!uses()->at(i)->CheckFlag(HValue::kTruncatingToInt32)) return false;
-    }
-    return true;
-  }
+  bool CanTruncateToInt32() const { return CheckFlag(kTruncatingToInt32); }
 
   virtual void PrintDataTo(StringStream* stream);
 
   DECLARE_CONCRETE_INSTRUCTION(Change,
                                CanTruncateToInt32() ? "truncate" : "change")
 
  protected:
   virtual bool DataEquals(HValue* other) {
     if (!other->IsChange()) return false;
     HChange* change = HChange::cast(other);
     return value() == change->value()
-        && to().Equals(change->to())
-        && CanTruncateToInt32() == change->CanTruncateToInt32();
+        && to().Equals(change->to());
   }
 
  private:
   Representation from_;
   Representation to_;
 };
 
 
 class HSimulate: public HInstruction {
  public:
@@ skipping 2491 matching lines @@
   HValue* object() { return left(); }
   HValue* key() { return right(); }
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_