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From: "unlvsur at live dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/107563] __builtin_shufflevector fails to pshufd instructions under default x86_64 compilation toggle which is the sse2 one
Date: Tue, 08 Nov 2022 00:11:49 +0000 [thread overview]
Message-ID: <bug-107563-4-l8K7jyjN5W@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-107563-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107563
--- Comment #4 from cqwrteur <unlvsur at live dot com> ---
(In reply to cqwrteur from comment #2)
> (In reply to cqwrteur from comment #0)
> > #if defined(__SSE2__)
> >
> > using temp_vec_type [[__gnu__::__vector_size__ (16)]] = char;
> > void foo(temp_vec_type& v) noexcept
> > {
> > v=__builtin_shufflevector(v,v,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0);
> > }
> >
> > #endif
> >
> > g++ -S pq.cc -Ofast
> > proves sse2 is enabled by default, but it does not call
> > https://www.felixcloutier.com/x86/pshufb
> > neither
> > https://www.felixcloutier.com/x86/pshufd
> >
> > while g++ -S pq.cc -Ofast -msse4.2 will generate them correctly. Which is
> > buggy
>
> pshufb is sse3 sorry. but pshufd is sse2. It can be used for generating the
> right instruction.
https://godbolt.org/z/6baWWoE4e
BTW. -msse3 does not use pshufb either. i do not know why
next prev parent reply other threads:[~2022-11-08 0:11 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-07 22:56 [Bug rtl-optimization/107563] New: __builtin_shufflevector fails to use pshufb and " unlvsur at live dot com
2022-11-07 23:00 ` [Bug target/107563] " unlvsur at live dot com
2022-11-07 23:05 ` [Bug target/107563] __builtin_shufflevector fails to " unlvsur at live dot com
2022-11-08 0:11 ` unlvsur at live dot com
2022-11-08 0:11 ` unlvsur at live dot com [this message]
2022-11-08 3:23 ` crazylht at gmail dot com
2022-11-08 3:33 ` crazylht at gmail dot com
2022-11-08 6:11 ` unlvsur at live dot com
2022-11-08 6:11 ` unlvsur at live dot com
2022-11-08 6:14 ` unlvsur at live dot com
2022-11-08 8:28 ` crazylht at gmail dot com
2024-05-15 4:47 ` cvs-commit at gcc dot gnu.org
2024-05-18 15:17 ` admin at levyhsu dot com
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