Bug 86580 - DFG should have sparse conditional constant propagation
Summary: DFG should have sparse conditional constant propagation
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: 528+ (Nightly build)
Hardware: All All
: P2 Normal
Assignee: Nobody
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-05-16 00:03 PDT by Filip Pizlo
Modified: 2012-05-23 19:28 PDT (History)
4 users (show)

See Also:


Attachments
work in progress (6.26 KB, patch)
2012-05-16 00:05 PDT, Filip Pizlo
no flags Details | Formatted Diff | Diff
more (18.95 KB, patch)
2012-05-16 12:48 PDT, Filip Pizlo
no flags Details | Formatted Diff | Diff
the patch (20.31 KB, patch)
2012-05-16 14:28 PDT, Filip Pizlo
oliver: review+
Details | Formatted Diff | Diff

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Description Filip Pizlo 2012-05-16 00:03:25 PDT
Without it, we won't be able to make this loop evaporate, because the CFA will execute the "i++" basic block and pollute i.

for (var i = 0; i < 1; ++i) doThings(i);

Patch forthcoming, though I foresee this generating some bugs, so though the patch is simple it'll probably take a while to fully bake.
Comment 1 Filip Pizlo 2012-05-16 00:05:44 PDT
Created attachment 142166 [details]
work in progress
Comment 2 Filip Pizlo 2012-05-16 12:48:38 PDT
Created attachment 142326 [details]
more
Comment 3 Filip Pizlo 2012-05-16 14:28:58 PDT
Created attachment 142346 [details]
the patch

Yup it works.
Comment 4 Filip Pizlo 2012-05-16 17:41:45 PDT
Landed in http://trac.webkit.org/changeset/117370
Comment 5 Filip Pizlo 2012-05-23 19:28:23 PDT
Merged in http://trac.webkit.org/changeset/118309