2029024 - Add additional JIT hints for IC states

Status: RESOLVED FIXED

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

Description

[Denis Palmeiro [:denispal]]

We can get a small win (~0.5%) on Speedometer3 by caching hints for IC state modes and inlining candidate states. The former pre-initializes ICs to their previously observed Megamorphic/Generic modes, skipping the warmup cycle where ICs start at Specialized and must transition through failures. The latter pre-seeds call sites that previously reached TrialInliningState::Candidate, so trial inlining fires on the first call of a subsequent navigation rather than requiring another full warmup.

Comment 1

[Denis Palmeiro [:denispal]]

Attachment: Bug 2029024: Pre-initialize Baseline IC modes from JitHints cache. r=iain!

Comment 2

[Denis Palmeiro [:denispal]]

Attachment: Bug 2029024: Pre-seed TrialInliningState::Candidate and enteredCount from JitHints cache. r=iain!

Comment 3

[Denis Palmeiro [:denispal]]

Attachment: Bug 2029024: Add jit-test for IC mode hints. r=iain!

Comment 4

[Denis Palmeiro [:denispal]]

Attachment: Bug 2029024: Add jit-test for call candidate hints. r=iain!

Comment 5

[Denis Palmeiro [:denispal]]

Iain helped find some glaring issues with the inlining candidates approach so will remove those patches. But caching IC states does still seem to improve Speedometer3 by about 0.7% overall. https://perf.compare/compare-results?baseRev=b9b51bd68b3e53942d90b53e9807fa35fbe544e9&baseRepo=try&newRev=27dfec9936a19d9bd220ff91d6656dd7da2e2d0f&newRepo=try&framework=13

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/881751867c49
https://hg.mozilla.org/integration/autoland/rev/d11b727e1981
Pre-initialize Baseline IC modes from JitHints cache. r=iain
https://github.com/mozilla-firefox/firefox/commit/d48a340f90b3
https://hg.mozilla.org/integration/autoland/rev/e47d36d4c86c
Add jit-test for IC mode hints. r=iain

Comment 7

[pstanciu]

https://hg.mozilla.org/mozilla-central/rev/d11b727e1981
https://hg.mozilla.org/mozilla-central/rev/e47d36d4c86c

Comment 8

[Florin Bilt]

(In reply to pstanciu from comment #7)

https://hg.mozilla.org/mozilla-central/rev/d11b727e1981
https://hg.mozilla.org/mozilla-central/rev/e47d36d4c86c

Perfherder has detected a browsertime performance change from push e47d36d4c86c6ef81802f2965174e9398cb17664.

No action is required from the author; this comment is provided for informational purposes only.

Improvement	Test	Platform	Options	Absolute values [old vs new]	Performance Profiles
4%	speedometer3 Charts-chartjs/total (doc)	linux2404-64-nightlyasrelease	fission webrender	80.79 ms -> 77.28 ms	Before/After
3%	speedometer3 Charts-chartjs/total (doc)	linux2404-64-nightlyasrelease	fission webrender	79.47 ms -> 77.37 ms	Before/After

Need Help or Information?

If you have any questions, please reach out to [e-mail]. Alternatively, you can find help on Slack by joining #perf-help, and on Matrix you can find help by joining #perftest.

Details of the alert can be found in the alert summary, including links to graphs and comparisons for each of the affected tests.

Comment 9

[Acasandrei Beatrice (needinfo me)]

(In reply to Pulsebot from comment #6)

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/881751867c49
https://hg.mozilla.org/integration/autoland/rev/d11b727e1981
Pre-initialize Baseline IC modes from JitHints cache. r=iain
https://github.com/mozilla-firefox/firefox/commit/d48a340f90b3
https://hg.mozilla.org/integration/autoland/rev/e47d36d4c86c
Add jit-test for IC mode hints. r=iain

Perfherder has detected a talos performance change from push e47d36d4c86c6ef81802f2965174e9398cb17664.

No action is required from the author; this comment is provided for informational purposes only.

Improvement	Test	Platform	Options	Absolute values [old vs new]
6%	pdfpaint issue5909_original.pdf (doc)	macosx1470-64-shippable	e10s fission stylo webrender-sw	369.53 ms -> 346.49 ms

Need Help or Information?

If you have any questions, please reach out to [e-mail]. Alternatively, you can find help on Slack by joining #perf-help, and on Matrix you can find help by joining #perftest.

Details of the alert can be found in the alert summary, including links to graphs and comparisons for each of the affected tests.