1531073 - Inline ArrayIteratorPrototypeOptimizable with a constant when possible

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, enhancement)

Description

[André Bargull [:anba]]

bug 1358501 makes this easy to do.

Comment 1

[André Bargull [:anba]]

Attachment: bug1531073.patch

Improves this µ-benchmark from 135ms to 110ms for me. (new Int32Array(xs[i & 1]) is now even slower in comparison at ~190ms for that µ-benchmark. Whoops...)

function f() {
    var xs = [[1,2,3,4,5,6,7,8], [1,2,3,4,5,6,7,8]];
    var r = 0;
    var t = dateNow();
    for (var i = 0; i < 1000000; ++i) {
        r += Int32Array.from(xs[i & 1]).length;
    }
    return [dateNow() - t, r];
}

Comment 2

[Jan de Mooij [:jandem]]

Comment on attachment 9047113 [details] [diff] [review]
bug1531073.patch

Review of attachment 9047113 [details] [diff] [review]:
-----------------------------------------------------------------

Nice idea.

Comment 3

[André Bargull [:anba]]

Try: https://treeherder.mozilla.org/#/jobs?repo=try&revision=4560138211a857448a63866564ce712defe988c5

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/14d519134002
Inline ArrayIteratorPrototypeOptimizable with a constant when possible. r=jandem

Comment 5

[Cristina Coroiu [:ccoroiu]]

https://hg.mozilla.org/mozilla-central/rev/14d519134002