[Bug libstdc++/87071] libstdc++ crashes during GPU driver initialization with suspected attempt to execute unsupported instruction by Athlon64 X2 TK-57

[virtuousfox at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87071

--- Comment #9 from Sergey Kondakov <virtuousfox at gmail dot com> ---
(In reply to Alexander Monakov from comment #8)
> You should have mentioned you were using a custom-compiled Mesa, not the
> distribution package (both here and in the original report to Mesa project).
> 
> For some reason the disasm in the provided log is unusable (shows assembly
> of the outermost frame), but downloading your package shows that failing
> instruction is
> 
>    928ea:       c5 fa 6f 05 0e 09 c3 00         vmovdqu 0xc3090e(%rip),%xmm0
> # cc3200 <amdgpu_winsys_create@@Base+0x1539a0>
> 
> i.e. an AVX instruction, not supported on the CPU. Given that you were using
> Clang to compile the package, this is not a GCC issue.

You actually managed to get some info from separate package ? Amazing.

I should have but half of my system is customized in some way, by me or by
others via OBS's community repositories, at this point + it's rolling release
distro. And my attention was completely drawn from Mesa. But here's the
interesting part: a guy from openSUSE just figured out that offending code was
launched by in-Mesa "SWR", Intel's AVX-based software renderer, which, for some
reason, tried to do something even though it should not load unless explicitly
requested or if direct rendering has failed. And it doesn't, if Mesa is built
with gcc & linked with ld, even with it enabled !

One thing doesn't build with gcc, other fails with clang… there is no peace
with Mesa. Anyway, thanks for your advices, I was getting desperate with that
weird issue.