1669481 - Stop updating DOMExpandoGeneration IC stub fields

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, task, P3)

Description

[Jan de Mooij [:jandem]]

We have an optimization to update existing Baseline/Ion IC stubs if only the DOMExpandoGenerationField field changed. Unfortunately this complicates Warp transpiler support for these DOM proxies (see bug 1668831) and we don't do this for any other IC stubs.

evilpie added some logging and we almost never update stubs on popular websites and speedometer. There's also some risk of updating the same stub repeatedly in pathological cases and that could be worse than not updating at all.

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Bug 1669481 part 1 - Stop updating IC stubs for DOMExpandoGeneration changes. r?evilpie!

Updating stubs complicates Warp transpiler support for DOM proxies and doesn't
actually show up much on websites.

Comment 2

[Jan de Mooij [:jandem]]

Attachment: Bug 1669481 part 2 - Change DOMExpandoGeneration stub field to RawInt64. r?evilpie!

The Ion CacheIR implementation can now bake in the generation again instead of
loading it from the stub.

Depends on D92608

Comment 3

[Tom S. (please needinfo tschuster)]

When looking at the old patch in bug 1329195 I also noticed this change: https://hg.mozilla.org/mozilla-central/rev/80e4fe7ff7cb#l5.37 Not sure if that should be reverted as well.

Comment 4

[Jan de Mooij [:jandem]]

Attachment: Bug 1669481 part 3 - Remove IonCacheIRCompiler::stub_. r?evilpie!

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d9ca15f17655
part 1 - Stop updating IC stubs for DOMExpandoGeneration changes. r=evilpie
https://hg.mozilla.org/integration/autoland/rev/ca23b81385d4
part 2 - Change DOMExpandoGeneration stub field to RawInt64. r=evilpie
https://hg.mozilla.org/integration/autoland/rev/48b632dabf39
part 3 - Remove IonCacheIRCompiler::stub_. r=evilpie

Comment 6

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/d9ca15f17655
https://hg.mozilla.org/mozilla-central/rev/ca23b81385d4
https://hg.mozilla.org/mozilla-central/rev/48b632dabf39