1368461 - Allow nursery-allocating most RegExp objects

Status: RESOLVED FIXED

(Core :: JavaScript Engine, enhancement)

Description

[Jan de Mooij [:jandem]]

Attachment: Part 1 - Nursery-allocate in CloneRegExpObject

See bug 1368419.

Nursery-allocating in CloneRegExpObject wins a few hundred points on Octane-regexp and when I run just the six-speed regex-u tests:

before:

regex-u-es5: 197
regex-u-es6: 254

after:

regex-u-es5: 108
regex-u-es6: 158

Comment 1

[Jan de Mooij [:jandem]]

Actually, js::RegExpAlloc can also nursery allocate in a lot of cases, for instance when it's called by the RegExpCreate intrinsic. I'll post another patch for that.

Comment 2

[Jan de Mooij [:jandem]]

Attachment: Part 2 - Pass NewObjectKind to RegExpAlloc

Passes NewObjectKind to RegExpAlloc so the parser/XDR/etc can allocate tenured but most other callers can nursery allocate.

This improves the following micro-benchmark from 375 to 283 ms:
--
function f() {
    var re;
    var t = new Date;
    for (var i = 0; i < 1000000; i++)
	re = new RegExp("foo");
    print(new Date - t);
    return re;
}
f();
--

And this one from 285 to 183 ms (although we can do much better here I think).
--
function f() {
    var res;
    var t = new Date;
    for (var i = 0; i < 1000000; i++)
	res = "foo12345".match(i % 128);
    print(new Date - t);
    return res;
}
f();
--

Comment 3

[Jan de Mooij [:jandem]]

Good QF bug, makes things faster and helps avoid full GCs.

Comment 4

[Jon Coppeard (:jonco) (PTO until 27th Jan)]

Comment on attachment 8872315 [details] [diff] [review]
Part 1 - Nursery-allocate in CloneRegExpObject

Review of attachment 8872315 [details] [diff] [review]:
-----------------------------------------------------------------

Nice!

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/5be34c2d1de5
part 1 - Allow nursery allocation for RegExps allocated by CloneRegExpObject. r=jonco
https://hg.mozilla.org/integration/mozilla-inbound/rev/5f12fd37c3bd
part 2 - Pass NewObjectKind to RegExpAlloc so most callers can use nursery allocation. r=jonco

Comment 6

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/5be34c2d1de5
https://hg.mozilla.org/mozilla-central/rev/5f12fd37c3bd