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

src/type-info.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 36 matching lines @@
 
 class TypeInfo {
  public:
   TypeInfo() : type_(kUnknownType) { }
 
   static inline TypeInfo Unknown();
   // We know it's a primitive type.
   static inline TypeInfo Primitive();
   // We know it's a number of some sort.
   static inline TypeInfo Number();
-  // We know it's signed or unsigned 32 bit integer.
+  // We know it's signed 32 bit integer.
   static inline TypeInfo Integer32();
   // We know it's a Smi.
   static inline TypeInfo Smi();
   // We know it's a heap number.
   static inline TypeInfo Double();
   // We know it's a string.
   static inline TypeInfo String();
   // We haven't started collecting info yet.
   static inline TypeInfo Uninitialized();
 
@@ skipping 38 matching lines @@
            t == kStringType);
     return TypeInfo(t);
   }
 
   // Return the weakest (least precise) common type.
   static TypeInfo Combine(TypeInfo a, TypeInfo b) {
     return TypeInfo(static_cast<Type>(a.type_ & b.type_));
   }
 
 
-  // Integer32 is an integer that can be represented as either a signed
-  // 32-bit integer or as an unsigned 32-bit integer. It has to be
-  // in the range [-2^31, 2^32 - 1]. We also have to check for negative 0
-  // as it is not an Integer32.
+  // Integer32 is an integer that can be represented as a signed
+  // 32-bit integer. It has to be in the range [-2^31, 2^31 - 1].
+  // We also have to check for negative 0 as it is not an Integer32.
   static inline bool IsInt32Double(double value) {
     const DoubleRepresentation minus_zero(-0.0);
     DoubleRepresentation rep(value);
     if (rep.bits == minus_zero.bits) return false;
-    if (value >= kMinInt && value <= kMaxUInt32) {
-      if (value <= kMaxInt && value == static_cast<int32_t>(value)) {
-        return true;
-      }
-      if (value == static_cast<uint32_t>(value)) return true;
+    if (value >= kMinInt && value <= kMaxInt) {
+      if (value == static_cast<int32_t>(value)) return true;
     }
     return false;
   }
 
   static TypeInfo TypeFromValue(Handle<Object> value);
 
   inline bool IsUnknown() {
     return type_ == kUnknownType;
   }
 
@@ skipping 96 matching lines @@
 }
 
 
 TypeInfo TypeInfo::Uninitialized() {
   return TypeInfo(kUninitializedType);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_TYPE_INFO_H_