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From: "marxin at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/100758] __builtin_cpu_supports does not (always) detect "sse2"
Date: Wed, 01 Feb 2023 14:32:32 +0000 [thread overview]
Message-ID: <bug-100758-4-rkSeBIyook@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-100758-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100758
Martin Liška <marxin at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
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?
next prev parent reply other threads:[~2023-02-01 14:32 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-25 18:37 [Bug c/100758] New: " gcc at eckner dot net
2021-05-26 7:57 ` [Bug target/100758] " marxin at gcc dot gnu.org
2021-05-26 9:12 ` gcc at eckner dot net
2021-05-26 9:23 ` marxin at gcc dot gnu.org
2021-05-26 9:46 ` gcc at eckner dot net
2021-05-26 9:54 ` rguenth at gcc dot gnu.org
2021-05-26 10:09 ` marxin at gcc dot gnu.org
2021-05-26 10:13 ` gcc at eckner dot net
2021-06-01 13:26 ` marxin at gcc dot gnu.org
2023-01-27 20:48 ` iam at valdikss dot org.ru
2023-02-01 14:03 ` marxin at gcc dot gnu.org
2023-02-01 14:23 ` iam at valdikss dot org.ru
2023-02-01 14:32 ` marxin at gcc dot gnu.org [this message]
2023-02-09 10:50 ` cvs-commit at gcc dot gnu.org
2023-02-09 11:40 ` jakub at gcc dot gnu.org
2023-02-09 11:47 ` marxin at gcc dot gnu.org
2023-02-09 12:22 ` jakub at gcc dot gnu.org
2023-02-09 16:22 ` gcc at eckner dot net
2023-02-09 16:37 ` jakub at gcc dot gnu.org
2023-02-09 16:45 ` cvs-commit at gcc dot gnu.org
2023-02-09 20:37 ` gcc at eckner dot net
2023-02-09 21:35 ` iam at valdikss dot org.ru
2023-02-10 8:27 ` marxin at gcc dot gnu.org
2023-02-10 9:45 ` jakub at gcc dot gnu.org
2023-02-20 9:50 ` Mayshao-oc at zhaoxin dot com
2023-03-19 5:29 ` cvs-commit at gcc dot gnu.org
2023-05-02 20:14 ` cvs-commit at gcc dot gnu.org
2023-05-03 15:21 ` cvs-commit at gcc dot gnu.org
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