Bug 37571 – Do YARR JIT fallback earlier than the JIT code generation

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Peter Varga]

Now the detection of the YARR JIT fallback to pcre happens during the JIT code generation phase.
It can be done earlier in the YARR compiler phase. Thus the unnecessary code generation can be avoided in the fallback cases.

This modification improve performance to YARR JIT when it does fallback.
The WindScorpion's email.js regexp performance test run 1.26x as fast (3463.2ms +/- 0.4% -> 2754.4ms +/-0.4%).

You download our benchmark suit from this link: http://www.sed.hu/webkit/?page=downloads&dl=windscorpion.zip

[Peter Varga]

Created attachment 53329 [details]
proposed patch v1

Move the YARR JIT fallback detection from RegexJIT.cpp to RegexCompiler.cpp.

[Geoffrey Garen]

Can you provide SunSpider results too please?

[Geoffrey Garen]

Comment on attachment 53329 [details]
proposed patch v1

r-, waiting on SunSpider results.

[Andras Becsi]

(In reply to comment #2)
> Can you provide SunSpider results too please?
I do not think SunSpider has tests where this fallback occures, so the gain won't show there, but let's test.

[Csaba Osztrogonác]

Comment on attachment 53329 [details]
proposed patch v1

SunSpider result: 642.5ms +/- 0.6% -> 639.6ms +/- 0.3%
V8 result: 3432.1ms +/- 0.4% -> 3442.6ms +/- 0.2%

There are no gains on SunSpider and on V8 as we expected, 
so I marked the patch with r? flag to wait for review.

[Geoffrey Garen]

Comment on attachment 53329 [details]
proposed patch v1

r=me

[Zoltan Herczeg]

nice work!

[WebKit Commit Bot]

Comment on attachment 53329 [details]
proposed patch v1

Clearing flags on attachment: 53329

Committed r57608: <http://trac.webkit.org/changeset/57608>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.