Bug 141169

Summary: REGRESSION(r179477): arguments simplification no longer works
Product: WebKit Reporter: Filip Pizlo <fpizlo>
Component: JavaScriptCoreAssignee: Filip Pizlo <fpizlo>
Status: RESOLVED FIXED    
Severity: Normal    
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: All   
OS: All   
Attachments:
Description Flags
the patch mark.lam: review+

Description Filip Pizlo 2015-02-02 13:56:24 PST 
That change broke arguments simplification because PhantomLocal on the arguments register tells arguments simplification that it can't simplify anything.  PhantomLocal also confuses the Flush strength reduction and we were also missing some other cases there.  This resolves all of those issues.
Comment 1 Filip Pizlo 2015-02-02 14:01:47 PST 
Created attachment 245898 [details]
the patch
Comment 2 Mark Lam 2015-02-02 14:14:37 PST 
Comment on attachment 245898 [details]
the patch

You added a CPS rethreading phase.  Have you run perf numbers to make sure that there's no regression?

r=me if no perf regression.
Comment 3 Filip Pizlo 2015-02-02 15:34:35 PST 
(In reply to comment #2)
> Comment on attachment 245898 [details]
> the patch
> 
> You added a CPS rethreading phase.  Have you run perf numbers to make sure
> that there's no regression?
> 
> r=me if no perf regression.

Performance is good.  This is a progression on earley and no significant changes elsewhere.
Comment 4 Filip Pizlo 2015-02-02 15:36:56 PST 
Landed in http://trac.webkit.org/changeset/179504