Bug 197478 - Consider using isLive() check for cells in value profiles
Summary: Consider using isLive() check for cells in value profiles
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Saam Barati
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-05-01 14:53 PDT by Saam Barati
Modified: 2019-05-01 14:57 PDT (History)
12 users (show)

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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.