Bug 197478

Summary: Consider using isLive() check for cells in value profiles
Product: WebKit Reporter: Saam Barati <saam>
Component: JavaScriptCoreAssignee: Saam Barati <saam>
Status: NEW ---    
Severity: Normal CC: benjamin, fpizlo, ggaren, gskachkov, guijemont, keith_miller, mark.lam, msaboff, rmorisset, ticaiolima, tzagallo, ysuzuki
Priority: P2    
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
See Also: https://bugs.webkit.org/show_bug.cgi?id=197052

Description Saam Barati 2019-05-01 14:53:34 PDT 
This would allow us to:
- Not update profiles on GC ticks
- Not writeBarrier CodeBlocks when they execute

Worst case, we see something that lies as to what the value really is. But we shouldn't see garbage.
Comment 1 Saam Barati 2019-05-01 14:57:04 PDT 
(In reply to Saam Barati from comment #0)
> This would allow us to:
> - Not update profiles on GC ticks
> - Not writeBarrier CodeBlocks when they execute
> 
> Worst case, we see something that lies as to what the value really is. But
> we shouldn't see garbage.

We also wouldn't have to emit a writeBarrier for OSR exit.