Bug 128832 - Baseline JIT should have a fast path to bypass the write barrier on op_enter
Summary: Baseline JIT should have a fast path to bypass the write barrier on op_enter
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: 528+ (Nightly build)
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Mark Hahnenberg
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-02-14 11:46 PST by Mark Hahnenberg
Modified: 2014-02-14 13:25 PST (History)
1 user (show)

See Also:

Attachments
Patch (4.68 KB, patch)
2014-02-14 12:06 PST, Mark Hahnenberg 		fpizlo: review+
Details | Formatted Diff | Diff
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Description Mark Hahnenberg 2014-02-14 11:46:07 PST 
<rdar://problem/16072244>
Comment 1 Mark Hahnenberg 2014-02-14 12:06:25 PST 
Created attachment 224241 [details]
Patch
Comment 2 Mark Hahnenberg 2014-02-14 13:12:49 PST 
Committed r164128: <http://trac.webkit.org/changeset/164128>
Comment 3 Geoffrey Garen 2014-02-14 13:14:50 PST 
Comment on attachment 224241 [details]
Patch

Shouldn't we check the remembered set bit instead?

Many functions will be old, and checking the mark bit won't save anything for old objects.
Comment 4 Mark Hahnenberg 2014-02-14 13:25:22 PST 
(In reply to comment #3)
> (From update of attachment 224241 [details])
> Shouldn't we check the remembered set bit instead?
> 
> Many functions will be old, and checking the mark bit won't save anything for old objects.

The thinking was that if you're in the baseline JIT you might still be young, but I think checking the remembered set bit as well is an improvement.