Refactor type checks in v8natives.js and runtime.js....

src/x64/full-codegen-x64.cc

 // 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 1973 matching lines @@
   __ cmpq(rbx, Immediate(FIRST_JS_OBJECT_TYPE));
   __ j(below, if_false);
   __ cmpq(rbx, Immediate(LAST_JS_OBJECT_TYPE));
   __ j(below_equal, if_true);
   __ jmp(if_false);
 
   Apply(context_, if_true, if_false);
 }
 
 
+void FullCodeGenerator::EmitIsSpecObject(ZoneList<Expression*>* args) {
+  ASSERT(args->length() == 1);
+
+  VisitForValue(args->at(0), kAccumulator);
+
+  Label materialize_true, materialize_false;
+  Label* if_true = NULL;
+  Label* if_false = NULL;
+  PrepareTest(&materialize_true, &materialize_false, &if_true, &if_false);
+
+  __ JumpIfSmi(rax, if_false);
+  __ CmpObjectType(rax, FIRST_JS_OBJECT_TYPE, rbx);
+  __ j(above_equal, if_true);
+  __ jmp(if_false);
+
+  Apply(context_, if_true, if_false);
+}
+
+
 void FullCodeGenerator::EmitIsUndetectableObject(ZoneList<Expression*>* args) {
   ASSERT(args->length() == 1);
 
   VisitForValue(args->at(0), kAccumulator);
 
   Label materialize_true, materialize_false;
   Label* if_true = NULL;
   Label* if_false = NULL;
   PrepareTest(&materialize_true, &materialize_false, &if_true, &if_false);
 
@@ skipping 1238 matching lines @@
   __ ret(0);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64