806646 - IonMonkey: Fix v8-regexp performance

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[David Anderson [:dvander] - inactive, e-mail if emergency]

Our score on v8-regexp is about 1300, to Crankshaft and JSC's 3650. A 180% improvement would increase our overall v8 score by ~13-14%.

This depends on bug 740015 (updating Yarr again), but that alone doesn't change our score. Newer versions of Yarr have a special JIT mode that can match without capturing subexpressions, and we'll need to use that for applicable regex functions.

Comment 1

[Hugh Nougher [:Hughman]]

Seems like a not-so-nice 50% regression during mid-november (possibly due to octane upgrade) put us back close to where we started a year ago.

Comment 2

[Sean Stangl [:sstangl]]

Yes, octane-regexp changed to require creation of the results array. Our previous optimization, MatchOnly mode, therefore no longer applies.

Comment 3

[Hugh Nougher [:Hughman]]

AWFY says that Chrome x86 is 40% faster on Win8 than OSX while Firefox stays about the same. I wonder what trick they use to do that?

Comment 4

[Carlos Alén Silva]

Perhaps the keywords "meta" and/or "tracking" should be added to this bug.

Comment 5

[Mayank Bansal]

:iain, is there anything to do here or the dependent bugs?

Comment 6

[Iain Ireland [:iain]]

Running locally it seems like we're about 6-7% slower than V8. Given that we don't really care about Octane these days, I think that's close enough that we don't need a metabug.