Correctify instanceof and make it optimizable.

src/runtime.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This files contains runtime support implemented in JavaScript.
 
 // CAUTION: Some of the functions specified in this file are called
 // directly from compiled code. These are the functions with names in
 // ALL CAPS. The compiled code passes the first argument in 'this'.
 
@@ skipping 417 matching lines @@
   if (%_IsNonNegativeSmi(this)) {
     if (IS_ARRAY(x) && %_HasFastPackedElements(x)) {
       return this < x.length;
     }
     return %HasElement(x, this);
   }
   return %HasProperty(x, %$toName(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_SPEC_FUNCTION(F)) {
-    throw %MakeTypeError(kInstanceofFunctionExpected, F);
-  }
-
-  // If V is not an object, return false.
-  if (!IS_SPEC_OBJECT(V)) {
-    return 1;
-  }
-
-  // Check if function is bound, if so, get [[BoundFunction]] from it
-  // and use that instead of F.
-  var bindings = %BoundFunctionGetBindings(F);
-  if (bindings) {
-    F = bindings[kBoundFunctionIndex];  // Always a non-bound function.
-  }
-  // Get the prototype of F; if it is not an object, throw an error.
-  var O = F.prototype;
-  if (!IS_SPEC_OBJECT(O)) {
-    throw %MakeTypeError(kInstanceofNonobjectProto, O);
-  }
-
-  // Return whether or not O is in the prototype chain of V.
-  return %IsInPrototypeChain(O, V) ? 0 : 1;
-}
-
-
 function CALL_NON_FUNCTION() {
   var delegate = %GetFunctionDelegate(this);
   if (!IS_FUNCTION(delegate)) {
     var callsite = %RenderCallSite();
     if (callsite == "") callsite = typeof this;
     throw %MakeTypeError(kCalledNonCallable, callsite);
   }
   return %Apply(delegate, this, arguments, 0, %_ArgumentsLength());
 }
 
@@ skipping 412 matching lines @@
   BIT_AND_STRONG,
   BIT_XOR,
   BIT_XOR_STRONG,
   SHL,
   SHL_STRONG,
   SAR,
   SAR_STRONG,
   SHR,
   SHR_STRONG,
   IN,
-  INSTANCE_OF,
   CALL_NON_FUNCTION,
   CALL_NON_FUNCTION_AS_CONSTRUCTOR,
   CALL_FUNCTION_PROXY,
   CALL_FUNCTION_PROXY_AS_CONSTRUCTOR,
   CONCAT_ITERABLE_TO_ARRAY,
   APPLY_PREPARE,
   REFLECT_APPLY_PREPARE,
   REFLECT_CONSTRUCT_PREPARE,
   STACK_OVERFLOW,
   TO_NUMBER,
   TO_STRING,
   TO_NAME,
 });
 
 utils.ExportToRuntime(function(to) {
   to["to_integer_fun"] = ToInteger;
   to["to_length_fun"] = ToLength;
   to["to_number_fun"] = ToNumber;
   to["to_string_fun"] = ToString;
 });
 
 utils.Export(function(to) {
   to.ToBoolean = ToBoolean;
   to.ToNumber = ToNumber;
   to.ToString = ToString;
 })
 
 })