Bug 118401 - fourthTier: FTL should better report its compile-times and it should be able to run in a mode where it doesn't spend time generating OSR exits
Summary: fourthTier: FTL should better report its compile-times and it should be able ...
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: 528+ (Nightly build)
Hardware: All All
: P2 Normal
Assignee: Filip Pizlo
URL:
Keywords:
Depends on:
Blocks: 118400
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Reported: 2013-07-04 12:12 PDT by Filip Pizlo
Modified: 2013-07-08 09:55 PDT (History)
7 users (show)

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Attachments
the patch (7.52 KB, patch)
2013-07-04 12:13 PDT, Filip Pizlo 		sam: review+
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Description Filip Pizlo 2013-07-04 12:12:30 PDT 
My current suspicion is that most of the time is spent in OSR exit computation.  We know we can do better there, so it would be useful to be able to confirm this hypothesis on a variety of benchmarks.
Comment 1 Filip Pizlo 2013-07-04 12:13:46 PDT 
Created attachment 206109 [details]
the patch
Comment 2 Filip Pizlo 2013-07-05 18:10:56 PDT 
Landed in http://trac.webkit.org/changeset/152432
Comment 3 Geoffrey Garen 2013-07-08 09:24:16 PDT 
> My current suspicion is that most of the time is spent in OSR exit computation.

Did this turn out to be true?
Comment 4 Filip Pizlo 2013-07-08 09:55:38 PDT 
(In reply to comment #3)
> > My current suspicion is that most of the time is spent in OSR exit computation.
> 
> Did this turn out to be true?

Currently LLVM compile times reduce by 30% if it doesn't have to deal with OSR exit marshaling.  So, no, it's not "most" of the time, right now.

But if you consider that we're also spending some significant fraction of time setting up pass managers, contexts, modules, execution engines, etc., I suspect that it'll be more than 30% if those other issues are fixed.