[Webkit-unassigned] [Bug 258708] New: [LibWebRTC] Enable AVX2 extensions only if host supports AVX2

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=258708

            Bug ID: 258708
           Summary: [LibWebRTC] Enable AVX2 extensions only if host
                    supports AVX2
           Product: WebKit
           Version: WebKit Nightly Build
          Hardware: Unspecified
                OS: Unspecified
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: New Bugs
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: dpino at igalia.com

265400 at main updated the CMake list of LibWebRTC sources after update to M115 (265320 at main).

In the sources update, a new block was added to include specialized files that make use of AVX2 extensions if the host is X64. This condition is too broad, since not all X64 computers have support for AVX2 extensions (rare nowadays, but it may happen).

Another issue we found out was that since the AVX2 files are built with `-march=native` the host may emit AVX512 instructions if the host supports that extension. This may cause compatibility issues if a binary is built in a host with AVX512 support and it is executed in a host without AVX512 suport (the result will be a crash due to 'invalid instruction').

The build flag `m=no-avx512f` prevents emitting AVX512 instructions.

https://stackoverflow.com/questions/60815316/disabling-all-avx512-extensions

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20230630/23580bc8/attachment-0001.htm>