Bug 31151

Summary:

Fix branchDouble behaviour on ARM THUMB2 JIT.

Product:

WebKit

Reporter:

Gavin Barraclough <barraclough>

Component:

JavaScriptCore

Assignee:

Gavin Barraclough <barraclough>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

loki, zherczeg

Priority:

Version:

528+ (Nightly build)

Hardware:

OS:

OS X 10.5

Attachments:

Description	Flags
The patch	oliver: review+

Gavin Barraclough

Reported 2009-11-04 20:51:18 PST

The ARMv7 JIT is currently using ARMv7Assembler::ConditionEQ to branch for DoubleEqualOrUnordered, however this is incorrect – ConditionEQ won't branch on unordered operands. Similarly, DoubleLessThanOrUnordered & DoubleLessThanOrEqualOrUnordered use ARMv7Assembler::ConditionLO & ARMv7Assembler::ConditionLS, whereas they should be using ARMv7Assembler::ConditionLT & ARMv7Assembler::ConditionLE. As a consequence, the JIT may currently incorrectly branch on double comparisons to NaN, for example, "if (Number.NaN < 0) print("Oh noes it isn't!");" Fix these, and fill out the missing DoubleConditions.

Attachments
The patch (3.77 KB, patch) 2009-11-04 20:54 PST, Gavin Barraclough	oliver: review+	Details Formatted Diff Diff
View All Add attachment proposed patch, testcase, etc.

Gavin Barraclough

Comment 1 2009-11-04 20:54:13 PST

Created attachment 42541 [details] The patch

Gavin Barraclough

Comment 2 2009-11-04 21:02:22 PST

Sending JavaScriptCore/ChangeLog Sending JavaScriptCore/assembler/MacroAssemblerARMv7.h Transmitting file data .. Committed revision 50541.

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