Bug 80371

Summary:

Checks for dead variables are not sufficient when fixing the expected values in DFG OSR entry

Product:

WebKit

Reporter:

Yuqiang Xian <yuqiang.xian>

Component:

JavaScriptCore

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

barraclough, fpizlo

Priority:

Version:

528+ (Nightly build)

Hardware:

Unspecified

OS:

Unspecified

Attachments:

Description	Flags
proposed patch	fpizlo: review+

Yuqiang Xian

Reported 2012-03-05 20:04:16 PST

A dead variable should be identified when there's no corresponding node in the block referencing it. But we currently failed to catch the case where there are some nodes referencing a variable but those nodes are actually not referenced by others so will be ignored in code generation. In such case we should also consider that variable to be a dead variable in the block and fix the expected values. This would fix the performance regression mentioned in bug 80365.

Attachments
proposed patch (2.45 KB, patch) 2012-03-05 20:25 PST, Yuqiang Xian	fpizlo: review+	Details Formatted Diff Diff
View All Add attachment proposed patch, testcase, etc.

Yuqiang Xian

Comment 1 2012-03-05 20:25:01 PST

Created attachment 130277 [details] proposed patch

Yuqiang Xian

Comment 2 2012-03-05 22:13:04 PST

Landed as http://trac.webkit.org/changeset/109859

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