1809359 - Inline SetElementMegamorphic in Ion

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, enhancement, P1)

Description

[Alex Thayer [:alexical] (she/her)]

So, given that we have a cache for megamorphic gets, and SetElementMegamorphic calls are hot in speedometer, it seems like we could speed things up by populating a cache on SetElementMegamorphic VM calls, and utilizing that cache from Ion code. The cache would map shape and id to a (maybe) new shape and slot.

Comment 1

[Alex Thayer [:alexical] (she/her)]

Attachment: Bug 1809359 - Inline SetElementMegamorphic r?jandem

Comment 2

[Alex Thayer [:alexical] (she/her)]

The attached patch gets us a 4% win on React-TodoMVC, a 5% win on React-Redux-TodoMVC, a 4% win on React-Elm-TodoMVC, and possibly a 1% win on matrix-react-bench. (perfherder - sorry for the grandprixbench noise, also I think the medium confidence regressions from that are spurious.)

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8129ee5398d5
Inline SetElementMegamorphic r=jandem

Comment 4

[Marian-Vasile Laza]

https://hg.mozilla.org/mozilla-central/rev/8129ee5398d5

Comment 5

[Mayank Bansal]

Also seems to improve all AWFY-Elm-TodoMVC/* benchmarks