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

src/runtime.js

 // Copyright 2006-2008 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 62 matching lines @@
         return %_ObjectEquals(x, y) ? 0 : 1;
       }
       if (y == null) return 1;  // not equal
       return %NumberEquals(%ToNumber(x), %ToNumber(y));
     } else if (x == null) {
       // NOTE: This checks for both null and undefined.
       return (y == null) ? 0 : 1;
     } else {
       // x is not a number, boolean, null or undefined.
       if (y == null) return 1;  // not equal
-      if (IS_SPEC_OBJECT_OR_NULL(y)) {
+      if (IS_SPEC_OBJECT(y)) {
         return %_ObjectEquals(x, y) ? 0 : 1;
       }
 
       x = %ToPrimitive(x, NO_HINT);
     }
   }
 }
 
 // ECMA-262, section 11.9.4, page 56.
 function STRICT_EQUALS(x) {
@@ skipping 244 matching lines @@
 */
 
 // ECMA-262, section 11.4.1, page 46.
 function DELETE(key) {
   return %DeleteProperty(%ToObject(this), %ToString(key));
 }
 
 
 // ECMA-262, section 11.8.7, page 54.
 function IN(x) {
-  if (x == null || !IS_SPEC_OBJECT_OR_NULL(x)) {
+  if (!IS_SPEC_OBJECT(x)) {
     throw %MakeTypeError('invalid_in_operator_use', [this, x]);
   }
   return %_IsNonNegativeSmi(this) ? %HasElement(x, this) : %HasProperty(x, %ToString(this));
 }
 
 
 // ECMA-262, section 11.8.6, page 54. To make the implementation more
 // efficient, the return value should be zero if the 'this' is an
 // instance of F, and non-zero if not. This makes it possible to avoid
 // an expensive ToBoolean conversion in the generated code.
 function INSTANCE_OF(F) {
   var V = this;
   if (!IS_FUNCTION(F)) {
     throw %MakeTypeError('instanceof_function_expected', [V]);
   }
 
   // If V is not an object, return false.
-  if (IS_NULL(V) || !IS_SPEC_OBJECT_OR_NULL(V)) {
+  if (!IS_SPEC_OBJECT(V)) {
     return 1;
   }
 
   // Get the prototype of F; if it is not an object, throw an error.
   var O = F.prototype;
-  if (IS_NULL(O) || !IS_SPEC_OBJECT_OR_NULL(O)) {
+  if (!IS_SPEC_OBJECT(O)) {
     throw %MakeTypeError('instanceof_nonobject_proto', [O]);
   }
 
   // Return whether or not O is in the prototype chain of V.
   return %IsInPrototypeChain(O, V) ? 0 : 1;
 }
 
 
 // Get an array of property keys for the given object. Used in
 // for-in statements.
@@ skipping 93 matching lines @@
    - - -   C o n v e r s i o n s   - - -
    -------------------------------------
 */
 
 // ECMA-262, section 9.1, page 30. Use null/undefined for no hint,
 // (1) for number hint, and (2) for string hint.
 function ToPrimitive(x, hint) {
   // Fast case check.
   if (IS_STRING(x)) return x;
   // Normal behavior.
-  if (!IS_SPEC_OBJECT_OR_NULL(x)) return x;
-  if (x == null) return x;  // check for null, undefined
+  if (!IS_SPEC_OBJECT(x)) return x;
   if (hint == NO_HINT) hint = (IS_DATE(x)) ? STRING_HINT : NUMBER_HINT;
   return (hint == NUMBER_HINT) ? %DefaultNumber(x) : %DefaultString(x);
 }
 
 
 // ECMA-262, section 9.2, page 30
 function ToBoolean(x) {
   if (IS_BOOLEAN(x)) return x;
   if (IS_STRING(x)) return x.length != 0;
   if (x == null) return false;
@@ skipping 78 matching lines @@
 
 
 /* ---------------------------------
    - - -   U t i l i t i e s   - - -
    ---------------------------------
 */
 
 // Returns if the given x is a primitive value - not an object or a
 // function.
 function IsPrimitive(x) {
-  if (!IS_SPEC_OBJECT_OR_NULL(x)) {
-    return true;
-  } else {
-    // Even though the type of null is "object", null is still
-    // considered a primitive value.
-    return IS_NULL(x);
-  }
+  // Even though the type of null is "object", null is still
+  // considered a primitive value. IS_SPEC_OBJECT handles this correctly
+  // (i.e., it will return false if x is null).
+  return !IS_SPEC_OBJECT(x);
 }
 
 
 // ECMA-262, section 8.6.2.6, page 28.
 function DefaultNumber(x) {
   if (IS_FUNCTION(x.valueOf)) {
     var v = x.valueOf();
     if (%IsPrimitive(v)) return v;
   }
 
@@ skipping 21 matching lines @@
   throw %MakeTypeError('cannot_convert_to_primitive', []);
 }
 
 
 // NOTE: Setting the prototype for Array must take place as early as
 // possible due to code generation for array literals.  When
 // generating code for a array literal a boilerplate array is created
 // that is cloned when running the code.  It is essiential that the
 // boilerplate gets the right prototype.
 %FunctionSetPrototype($Array, new $Array(0));