Bug 133967

Summary: [ftlopt] Fold constant Phis
Product: WebKit Reporter: Filip Pizlo <fpizlo>
Component: JavaScriptCoreAssignee: Filip Pizlo <fpizlo>
Status: RESOLVED FIXED    
Severity: Normal CC: barraclough, ggaren, mark.lam, mhahnenberg, msaboff, oliver, sam
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: All   
OS: All   
Attachments:
Description Flags
the patch
ggaren: review+
better patch mhahnenberg: review+

Description Filip Pizlo 2014-06-16 20:55:33 PDT
Patch forthcoming.
Comment 1 Filip Pizlo 2014-06-16 21:01:34 PDT
Created attachment 233213 [details]
the patch
Comment 2 Geoffrey Garen 2014-06-17 11:13:03 PDT
Comment on attachment 233213 [details]
the patch

View in context: https://bugs.webkit.org/attachment.cgi?id=233213&action=review

r=me

> Source/JavaScriptCore/dfg/DFGInPlaceAbstractState.h:136
> +    // This method is evil - it causes a huge maintenance headache and there is a gross amount of
> +    // code devoted to it. It would be much nicer to just always run the constant folder on each
> +    // block. But, the last time we did it, it was a 1% SunSpider regression:
> +    // https://bugs.webkit.org/show_bug.cgi?id=133947
> +    // So, we should probably keep this method.

I might be willing to eat 1% for this -- particularly if the overall effect on JetStream is less than 1%.
Comment 3 Filip Pizlo 2014-06-17 11:42:19 PDT
Created attachment 233245 [details]
better patch
Comment 4 Mark Hahnenberg 2014-06-17 11:44:28 PDT
Comment on attachment 233245 [details]
better patch

r=me
Comment 5 Filip Pizlo 2014-06-17 12:02:40 PDT
Landed in http://trac.webkit.org/changeset/170064