1415124 - Nursery allocate cloned lexical environments

Status: RESOLVED FIXED

(Core :: JavaScript Engine, enhancement)

Description

[Jan de Mooij [:jandem]]

Attachment: Patch

In LexicalEnvironmentObject::clone and LexicalEnvironmentObject::recreate we currently pass TenuredHeap but we can just use DefaultHeap AFAIK. We already nursery allocate other environment objects (CallObjects for instance) so I don't expect problems with this.

Improves the micro-benchmark below from 1550 ms to 700 ms.

function f() {
    var arr = [];
    for (var i = 0; i < 10000000; i++)
        arr.push({});
    var t = new Date;
    for (let i = 0; i < 10000000; i++) {
        g = () => i;
    }
    print(new Date - t);
}
f();

Comment 1

[Jon Coppeard (:jonco)]

Comment on attachment 8925877 [details] [diff] [review]
Patch

Review of attachment 8925877 [details] [diff] [review]:
-----------------------------------------------------------------

Yes this looks fine.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/e4397a936799
Nursery allocate cloned LexicalEnvironmentObjects. r=jonco

Comment 3

[Guilherme Lima]

Either this or the patch from bug 1415161 regressed some benchmarks from Ares 6 on AWFY.

Comment 4

[Eliza Balazs [:ebalazs_]]

https://hg.mozilla.org/mozilla-central/rev/e4397a936799