Bug 141499 – [Win] [64-bit] Remove MSVC 2013 FMA3 Bug Workaround

• Component: WebKit Misc.
• Status: RESOLVED FIXED

[Brent Fulgham]

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.

[Radar WebKit Bug Importer]

<rdar://problem/19808410>

[Brent Fulgham]

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>.

(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 :)

Created attachment 274683 [details]
Patch

[Brent Fulgham]

Comment on attachment 274683 [details]
Patch

r=me. Please make sure Windows EWS is happy before landing! :-)

(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!

Committed r198559: <http://trac.webkit.org/changeset/198559>