https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100758
Martin Liška <marxin at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |Mayshao-oc at zhaoxin dot com
--- Comment #12 from Martin Liška <marxin at gcc dot gnu.org> ---
(In reply to ValdikSS from comment #11)
> Well, the function is called __builtin_cpu_supports, for which one might
> expect that it just checks CPUID and returns reliable results, while in
> reality it operates using the build-in CPU support list. The function does
> not return an error if it's unable to detect the feature, resulting in
> incorrect results, which makes the function unreliable. The fact that it may
> not always detect features which are present in the CPU is not documented,
> which brings the confusion among developers such as this bug.
Sure, it's not perfect, I can confirm that. I'm going to introduce a
documentation entry for this limitation.
>
> VIA processors have progressed into Zhaoxin CPU family which is fairly
> recent (2014-2019, with plans to release new processors soon).
Yep, and we support these (vendor == signature_SHANGHAI_ebx) correctly since
r13-713-ga239aff82c3771.
Maybe the author of the commit will be interested in old VIA CPUs?
