Bug 141499

Summary: [Win] [64-bit] Remove MSVC 2013 FMA3 Bug Workaround
Product: WebKit Reporter: Brent Fulgham <bfulgham>
Component: WebKit Misc.Assignee: peavo
Status: RESOLVED FIXED    
Severity: Normal CC: bfulgham, peavo, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on: 141498    
Bug Blocks:    
Attachments:
Description Flags
Patch bfulgham: review+

Description Brent Fulgham 2015-02-11 21:32:24 PST 
At Microsoft's suggestion, we have disabled FMA3 support for 64-bit builds due to a bug in the MSVC 2013 runtime libraries. When we switch to Visual Studio 2015 (or newer), where this bug is fixed, we should remove this workaround so that we can enjoy the improved vector instruction support.

See <https://connect.microsoft.com/VisualStudio/feedback/details/811093/visual-studio-2013-rtm-c-x64-code-generation-bug-for-avx2-instructions> for some comments from Microsoft on this topic.
Comment 1 Radar WebKit Bug Importer 2015-02-11 21:33:23 PST 
<rdar://problem/19808410>
Comment 2 Brent Fulgham 2016-03-22 10:40:44 PDT 
Per: If you have a spare minute, would you mind removing this old work-around, now that we are standardized on VS2015?

Basically this task is to roll out <http://trac.webkit.org/changeset/179993>.
Comment 3 peavo 2016-03-22 12:05:42 PDT 
(In reply to comment #2)
> Per: If you have a spare minute, would you mind removing this old
> work-around, now that we are standardized on VS2015?
> 
> Basically this task is to roll out <http://trac.webkit.org/changeset/179993>.

No problem, I'll create a patch :)
Comment 4 peavo 2016-03-22 14:07:28 PDT 
Created attachment 274683 [details]
Patch
Comment 5 Brent Fulgham 2016-03-22 14:49:31 PDT 
Comment on attachment 274683 [details]
Patch

r=me. Please make sure Windows EWS is happy before landing! :-)
Comment 6 peavo 2016-03-22 14:53:25 PDT 
(In reply to comment #5)
> Comment on attachment 274683 [details]
> Patch
> 
> r=me. Please make sure Windows EWS is happy before landing! :-)

Thanks for reviewing!
Comment 7 peavo 2016-03-22 15:21:36 PDT 
Committed r198559: <http://trac.webkit.org/changeset/198559>