[Bug target/86393] GCC-8 appears to not detect AVX512 on iMac Pro 2018

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86393

Eric Gallager <egallager at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |iains at gcc dot gnu.org
           See Also|                            |https://bugs.llvm.org/show_
                   |                            |bug.cgi?id=36202

--- Comment #8 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to MCCCS from comment #7)
> The problem was that the LLVM assembler required -mavx512f. I've researched
> it and found that this LLVM bug was fixed months and shipped with LLVM 7.
> Apple updates Xcode's LLVM with one year delay, and it should be fixed the
> next year with 10.15.
> 
> To sum up: this is llvm 6 bug
> 
> https://bugs.llvm.org/show_bug.cgi?id=36202
> https://llvm.org/viewvc/llvm-project?view=revision&revision=324106

It still might be worth handling this on the GCC end in the meantime though.