Bug 162343

Summary: Add a Fence opcode to B3
Product: WebKit Reporter: Filip Pizlo <fpizlo>
Component: JavaScriptCoreAssignee: Filip Pizlo <fpizlo>
Status: RESOLVED FIXED    
Severity: Normal CC: commit-queue, jfbastien
Priority: P2    
Version: WebKit Nightly Build   
Hardware: All   
OS: All   
Bug Depends on:    
Bug Blocks: 162350, 162316, 162342, 162349    
Attachments:
Description Flags
the patch ggaren: review+

Filip Pizlo
Reported 2016-09-21 09:40:44 PDT
Patch forthcoming.
Attachments
the patch (29.84 KB, patch)
2016-09-21 11:30 PDT, Filip Pizlo 		ggaren: review+
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Filip Pizlo
Comment 1 2016-09-21 11:30:55 PDT
Created attachment 289469 [details] the patch
WebKit Commit Bot
Comment 2 2016-09-21 11:32:42 PDT
Attachment 289469 [details] did not pass style-queue: ERROR: Source/JavaScriptCore/b3/B3FenceValue.h:80: The parameter name "origin" adds no information, so it should be removed. [readability/parameter_name] [5] ERROR: Source/JavaScriptCore/b3/B3FenceValue.h:82: The parameter name "origin" adds no information, so it should be removed. [readability/parameter_name] [5] Total errors found: 2 in 19 files If any of these errors are false positives, please file a bug against check-webkit-style.
JF Bastien
Comment 3 2016-09-21 11:45:21 PDT
FYI an idempotent locked access to top-of-stack can kinda serve as a less-expensive fence on x86. Something like lock or4i [RSP-8] 0
Geoffrey Garen
Comment 4 2016-09-21 11:47:55 PDT
Comment on attachment 289469 [details] the patch r=me I still hate threads.
Filip Pizlo
Comment 5 2016-09-21 12:09:34 PDT
(In reply to comment #3) > FYI an idempotent locked access to top-of-stack can kinda serve as a > less-expensive fence on x86. Something like lock or4i [RSP-8] 0 Huh. Does this correctly guard the store-load case? Should we change WTF's storeLoadFence to do this as well?
Filip Pizlo
Comment 6 2016-09-21 12:12:01 PDT
Landed in https://trac.webkit.org/changeset/206226
Note You need to log in before you can comment on or make changes to this bug.