Using unsigned shifts and masks when dealing with 64-bit addresses.

test/cctest/test-api.cc

 // Copyright 2007-2009 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 856 matching lines @@
   expected_ptr = reinterpret_cast<void*>(1);
   TestExternalPointerWrapping();
 
   expected_ptr = reinterpret_cast<void*>(0xdeadbeef);
   TestExternalPointerWrapping();
 
   expected_ptr = reinterpret_cast<void*>(0xdeadbeef + 1);
   TestExternalPointerWrapping();
 
 #if defined(V8_HOST_ARCH_X64)
+  // Check a value with a leading 1 bit in x64 Smi encoding.
+  expected_ptr = reinterpret_cast<void*>(0x400000000);
+  TestExternalPointerWrapping();
+
   expected_ptr = reinterpret_cast<void*>(0xdeadbeefdeadbeef);
   TestExternalPointerWrapping();
 
   expected_ptr = reinterpret_cast<void*>(0xdeadbeefdeadbeef + 1);
   TestExternalPointerWrapping();
 #endif
 }
 
 
 THREADED_TEST(FindInstanceInPrototypeChain) {
@@ skipping 11279 matching lines @@
   v8::Context::Scope context_scope(context.local());
 
   v8::Handle<v8::ObjectTemplate> tmpl = v8::ObjectTemplate::New();
   tmpl->SetNamedPropertyHandler(Getter, NULL, NULL, NULL, Enumerator);
   context->Global()->Set(v8_str("o"), tmpl->NewInstance());
   v8::Handle<v8::Array> result = v8::Handle<v8::Array>::Cast(CompileRun(
         "var result = []; for (var k in o) result.push(k); result"));
   CHECK_EQ(1, result->Length());
   CHECK_EQ(v8_str("universalAnswer"), result->Get(0));
 }