X64: Ignore extra bits in Smi::value()

src/objects-inl.h

 // Copyright 2006-2008 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 681 matching lines @@
 #define WRITE_BYTE_FIELD(p, offset, value) \
   (*reinterpret_cast<byte*>(FIELD_ADDR(p, offset)) = value)
 
 
 Object** HeapObject::RawField(HeapObject* obj, int byte_offset) {
   return &READ_FIELD(obj, byte_offset);
 }
 
 
 int Smi::value() {
-  return static_cast<int>(reinterpret_cast<intptr_t>(this) >> kSmiTagSize);
+  return static_cast<int>(reinterpret_cast<intptr_t>(this)) >> kSmiTagSize;
 }
 
 
 Smi* Smi::FromInt(int value) {
   ASSERT(Smi::IsValid(value));
   intptr_t tagged_value =
       (static_cast<intptr_t>(value) << kSmiTagSize) | kSmiTag;
   return reinterpret_cast<Smi*>(tagged_value);
 }
 
@@ skipping 1983 matching lines @@
 #undef WRITE_INT_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_