Bug 68723 - Resolve opcodes should have value profiling.
Summary: Resolve opcodes should have value profiling.
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: 68677
  Show dependency treegraph
 
Reported: 2011-09-23 13:29 PDT by Filip Pizlo
Modified: 2011-09-23 16:27 PDT (History)
3 users (show)

See Also:


Attachments
the patch (13.71 KB, patch)
2011-09-23 15:27 PDT, Filip Pizlo
oliver: review+
Details | Formatted Diff | Diff

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Description Filip Pizlo 2011-09-23 13:29:18 PDT
We want all operations that load values from the heap to have value profiling.  The Resolve opcodes are the last ones that don't.
Comment 1 Filip Pizlo 2011-09-23 15:27:13 PDT
Created attachment 108546 [details]
the patch

This is pretty much performance neutral.  There is a spurious, but totally reproducible, 0.3% slow-down in V8 on my MacBook Pro.  There are similarly sized, though not as reproducible, speed-ups in SunSpider and Kraken.  I checked and none of the benchmarks that have performance variations make any use of any of the affected opcodes.  So these are just insignificant variations due to code layout.
Comment 2 Filip Pizlo 2011-09-23 16:27:36 PDT
Landed in r95887.