870814 - IonMonkey: Enable native dense int32 when ic isn't monitored

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Hannes Verschore [:h4writer]]

Attachment: Patch

In bug 870627 we have slow performance, because of an ic not getting added in a cache that isn't monitored.

Comment 1

[Hannes Verschore [:h4writer]]

Comment on attachment 747989 [details] [diff] [review]
Patch

I think attachDenseElement doesn't depend on the value of cache.monitoredResult. So that this is correct...

Comment 2

[Hannes Verschore [:h4writer]]

Brings the performance down from 50s to 15s of linpack. It's a start. (v8 performance is 0.8s)
(Looking at the performance of v8, I assume we don't want a cache here, but somehow we should be able to predict this is actually monomorphic during compilation.)

Comment 3

[Jan de Mooij [:jandem]]

Comment on attachment 747989 [details] [diff] [review]
Patch

Review of attachment 747989 [details] [diff] [review]:
-----------------------------------------------------------------

Looks good.

(In reply to Hannes Verschore [:h4writer] from comment #2)
> (Looking at the performance of v8, I assume we don't want a cache here, but
> somehow we should be able to predict this is actually monomorphic during
> compilation.)

We should be able to use Baseline IC's here: if the IC only saw dense accesses, Ion should inline the dense path directly.

Comment 4

[Hannes Verschore [:h4writer]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/bf0bcf4ecf28

I'll look if I can add this optimization to look at Baseline IC's for dense accesses. Good way to look at Baseline code again ;).

Comment 5

[Boris Zbarsky [:bzbarsky]]

This was a nice 3-4% win on Dromaeo-CSS, for what it's worth.  Thank you!

Comment 6

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/bf0bcf4ecf28

Comment 7

[Hannes Verschore [:h4writer]]

(In reply to Boris Zbarsky (:bz) from comment #5)
> This was a nice 3-4% win on Dromaeo-CSS, for what it's worth.  Thank you!

Cool. I hope the next patches for the GWT benchmarks also improve Dramaeo-css :D