Status: New
Owner: ----
New issue 2100 by wonchun: TypedArray length property access slow
http://code.google.com/p/v8/issues/detail?id=2100
Unlike plain arrays, typed array's length property seems very slow to
access. In the attached repro, I have a loop that looks like this:
function normal(a) {
var sum = 0;
for (var i = 0; i < a.length; i++) {
sum += a[i];
}
return sum;
}
With specialized versions for
[normal, typed] x
[array.length in loop, array.length hoisted to local]
On Firefox 11 you get the expected fastness:
normal: 41ms
normal_hoisted: 41ms
typed: 39ms
typed_hoisted: 39ms
On Chrome 19, typed is over 10x slower than typed_hoisted:
normal: 38ms
normal_hoisted: 37ms
typed: 406ms <== !!!
typed_hoisted: 30ms
Attachments:
array_length.html 1.3 KB
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