Bug 100825 - DFG optimized string access code should be enabled
Summary: DFG optimized string access code should be enabled
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: 528+ (Nightly build)
Hardware: All All
: P2 Normal
Assignee: Filip Pizlo
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-10-31 01:06 PDT by Filip Pizlo
Modified: 2012-11-01 00:42 PDT (History)
1 user (show)

See Also:


Attachments
the patch (8.50 KB, patch)
2012-10-31 01:13 PDT, Filip Pizlo
oliver: review+
Details | Formatted Diff | Diff

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Description Filip Pizlo 2012-10-31 01:06:30 PDT
The DFG string access code kicks in only when the 'this' operand has a string prediction during parsing.

That will never happen.  No operand has any predictions during parsing.  Parsing doesn't have predictions.  Predictions don't exist until after prediction propagation runs.  Prediction propagation runs only after parsing completely finishes.

So, we should remove prediction checks from the code in the parser that recognizes string intrinsics.
Comment 1 Filip Pizlo 2012-10-31 01:13:29 PDT
Created attachment 171593 [details]
the patch
Comment 2 Filip Pizlo 2012-11-01 00:42:45 PDT
Landed in http://trac.webkit.org/changeset/133135