Revision: 4126
Author: [email protected]
Date: Mon Mar 15 03:14:59 2010
Log: Optimized Array.prototype.{lastIndexOf,indexOf} by special casing
comparison to undefined.
Review URL: http://codereview.chromium.org/851008
http://code.google.com/p/v8/source/detail?r=4126
Modified:
/branches/bleeding_edge/src/array.js
=======================================
--- /branches/bleeding_edge/src/array.js Fri Mar 12 10:27:31 2010
+++ /branches/bleeding_edge/src/array.js Mon Mar 15 03:14:59 2010
@@ -994,11 +994,16 @@
// If index is still negative, search the entire array.
if (index < 0) index = 0;
}
+ if (!IS_UNDEFINED(element)) {
+ for (var i = index; i < length; i++) {
+ if (this[i] === element) return i;
+ }
+ return -1;
+ }
// Lookup through the array.
for (var i = index; i < length; i++) {
- var current = this[i];
- if (!IS_UNDEFINED(current) || i in this) {
- if (current === element) return i;
+ if (IS_UNDEFINED(this[i]) && i in this) {
+ return i;
}
}
return -1;
@@ -1018,10 +1023,15 @@
else if (index >= length) index = length - 1;
}
// Lookup through the array.
+ if (!IS_UNDEFINED(element)) {
+ for (var i = index; i >= 0; i--) {
+ if (this[i] === element) return i;
+ }
+ return -1;
+ }
for (var i = index; i >= 0; i--) {
- var current = this[i];
- if (!IS_UNDEFINED(current) || i in this) {
- if (current === element) return i;
+ if (IS_UNDEFINED(this[i]) && i in this) {
+ return i;
}
}
return -1;
--
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