Bug 64654

Summary: DFG JIT compare/branch code emits is-integer tests even when a value is definitely not an integer
Product: WebKit Reporter: Filip Pizlo <fpizlo>
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Status: RESOLVED FIXED    
Severity: Normal CC: barraclough, fpizlo, webkit.review.bot
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: All   
OS: All   
Attachments:
Description Flags
the patch
none
the patch (fix Platform.h)
none
the patch (fix style) none

Filip Pizlo
Reported 2011-07-16 14:15:56 PDT
The DFG JIT's support for comparisons and branching may emit tests to see if the operands are integers. If they are, the comparison can be done more quickly by doing an Int32 compare. But in some cases, the compiler knows statically that one or both of the operands are definitely not integers. In that case, the JIT should always emit a slow call and omit the unnecessary is-int test.
Attachments
the patch (12.24 KB, patch)
2011-07-16 14:22 PDT, Filip Pizlo 		no flags
DetailsFormatted DiffDiff
the patch (fix Platform.h) (11.69 KB, patch)
2011-07-16 14:23 PDT, Filip Pizlo 		no flags
DetailsFormatted DiffDiff
the patch (fix style) (11.69 KB, patch)
2011-07-16 14:26 PDT, Filip Pizlo 		no flags
DetailsFormatted DiffDiff
Show Obsolete (2) View All Add attachment proposed patch, testcase, etc.
Filip Pizlo
Comment 1 2011-07-16 14:22:06 PDT
Created attachment 101098 [details] the patch
Filip Pizlo
Comment 2 2011-07-16 14:23:27 PDT
Created attachment 101099 [details] the patch (fix Platform.h) Previous patch accidentally had a change to Platform.h that it should not have had.
WebKit Review Bot
Comment 3 2011-07-16 14:24:00 PDT
Attachment 101098 [details] did not pass style-queue: Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/JavaScriptCore/ChangeLog', u'Source..." exit_code: 1 Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp:437: One line control clauses should not use braces. [whitespace/braces] [4] Total errors found: 1 in 5 files If any of these errors are false positives, please file a bug against check-webkit-style.
WebKit Review Bot
Comment 4 2011-07-16 14:24:55 PDT
Attachment 101099 [details] did not pass style-queue: Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/JavaScriptCore/ChangeLog', u'Source..." exit_code: 1 Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp:437: One line control clauses should not use braces. [whitespace/braces] [4] Total errors found: 1 in 4 files If any of these errors are false positives, please file a bug against check-webkit-style.
Filip Pizlo
Comment 5 2011-07-16 14:26:28 PDT
Created attachment 101100 [details] the patch (fix style)
WebKit Review Bot
Comment 6 2011-07-16 18:47:58 PDT
Comment on attachment 101100 [details] the patch (fix style) Clearing flags on attachment: 101100 Committed r91160: <http://trac.webkit.org/changeset/91160>
WebKit Review Bot
Comment 7 2011-07-16 18:48:03 PDT
All reviewed patches have been landed. Closing bug.
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