Make the Integer32 type info only cover the signed 32 bit integers....

src/ia32/macro-assembler-ia32.cc

 // Copyright 2006-2009 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 1531 matching lines @@
     Label done;
     bool push_pop = (scratch.is(no_reg) && dst.is(source));
     ASSERT(!scratch.is(source));
     if (push_pop) {
       push(dst);
       scratch = dst;
     }
     if (scratch.is(no_reg)) scratch = dst;
     cvttsd2si(scratch, FieldOperand(source, HeapNumber::kValueOffset));
     cmp(scratch, 0x80000000u);
-    if (push_pop || dst.is(source)) {
+    if (push_pop) {
       j(not_equal, &done);
-      if (push_pop) {
-        pop(dst);
-        jmp(on_not_int32);
-      }
+      pop(dst);
+      jmp(on_not_int32);
     } else {
       j(equal, on_not_int32);
     }
 
     bind(&done);
     if (push_pop) {
       add(Operand(esp), Immediate(kPointerSize));  // Pop.
     }
     if (!scratch.is(dst)) {
       mov(dst, scratch);
@@ skipping 103 matching lines @@
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32