Using array index hash code for string-to-number conversion.

src/v8natives.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 93 matching lines @@
             (-1e9 < string && string < -0.01))) {
       // Truncate number.
       return string | 0;
     }
     radix = 0;
   } else {
     radix = TO_INT32(radix);
     if (!(radix == 0 || (2 <= radix && radix <= 36)))
       return $NaN;
   }
-  return %StringParseInt(ToString(string), radix);
+  string = TO_STRING_INLINE(string);
+  if (%_HasCachedArrayIndex(string) &&
+      (radix == 0 || radix == 10)) {
+    return %_GetCachedArrayIndex(string);
+  }
+  return %StringParseInt(string, radix);
 }
 
 
 // ECMA-262 - 15.1.2.3
 function GlobalParseFloat(string) {
-  return %StringParseFloat(ToString(string));
+  string = TO_STRING_INLINE(string);
+  if (%_HasCachedArrayIndex(string)) return %_GetCachedArrayIndex(string);
+  return %StringParseFloat(string);
 }
 
 
 function GlobalEval(x) {
   if (!IS_STRING(x)) return x;
 
   var global_receiver = %GlobalReceiver(global);
   var this_is_global_receiver = (this === global_receiver);
   var global_is_detached = (global === global_receiver);
 
@@ skipping 1049 matching lines @@
 // ----------------------------------------------------------------------------
 
 function SetupFunction() {
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
     "bind", FunctionBind,
     "toString", FunctionToString
   ));
 }
 
 SetupFunction();