Rewrote equality check in CompareStub to do quick pointer comparison first.

test/cctest/test-api.cc

 // Copyright 2007-2008 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 2369 matching lines @@
   ExpectObject("undetectable&&true", obj);
   ExpectObject("undetectable&&false", obj);
   ExpectBoolean("undetectable||true", true);
   ExpectBoolean("undetectable||false", false);
 
   ExpectBoolean("undetectable==null", true);
   ExpectBoolean("undetectable==undefined", true);
   ExpectBoolean("undetectable==undetectable", true);
 
   ExpectBoolean("undetectable===null", false);
-  ExpectBoolean("undetectable===undefined", true);
+  ExpectBoolean("undetectable===undefined", false);
   ExpectBoolean("undetectable===undetectable", true);
 }
 
 
 THREADED_TEST(UndetectableString) {
   v8::HandleScope scope;
   LocalContext env;
 
   Local<String> obj = String::NewUndetectable("foo");
   env->Global()->Set(v8_str("undetectable"), obj);
@@ skipping 14 matching lines @@
   ExpectObject("undetectable&&true", obj);
   ExpectObject("undetectable&&false", obj);
   ExpectBoolean("undetectable||true", true);
   ExpectBoolean("undetectable||false", false);
 
   ExpectBoolean("undetectable==null", true);
   ExpectBoolean("undetectable==undefined", true);
   ExpectBoolean("undetectable==undetectable", true);
 
   ExpectBoolean("undetectable===null", false);
-  ExpectBoolean("undetectable===undefined", true);
+  ExpectBoolean("undetectable===undefined", false);
   ExpectBoolean("undetectable===undetectable", true);
 }
 
 
 template <typename T> static void USE(T) { }
 
 
 // This test is not intended to be run, just type checked.
 static void PersistentHandles() {
   USE(PersistentHandles);
@@ skipping 3693 matching lines @@
   // Check without 'eval' or 'with'.
   v8::Handle<v8::Value> res =
       CompileRun("function f() { x = 42; return x; }; f()");
   // Check with 'eval'.
   res = CompileRun("function f() { eval('1'); y = 42; return y; }; f()");
   CHECK_EQ(v8::Integer::New(42), res);
   // Check with 'with'.
   res = CompileRun("function f() { with (this) { y = 42 }; return y; }; f()");
   CHECK_EQ(v8::Integer::New(42), res);
 }