From: Jakub Jelinek <jakub@redhat.com>
To: Tobias Burnus <tobias@codesourcery.com>
Cc: gcc-patches <gcc-patches@gcc.gnu.org>
Subject: Re: [patch] invoke.texi: Update -fopenmp and -fopenmp-simd for omp::decl and loop semantic
Date: Tue, 26 Sep 2023 09:54:08 +0200 [thread overview]
Message-ID: <ZRKOII/aOKZEGQKu@tucnak> (raw)
In-Reply-To: <c456c0a8-def8-4737-b884-a758b1156136@codesourcery.com>
On Mon, Sep 25, 2023 at 08:24:14PM +0200, Tobias Burnus wrote:
> I stumbled over this during the ARM64 talk at the cauldron as they
> consider using -fopenmp-simd by default.
>
> → https://gcc.gnu.org/wiki/cauldron2023 (I put my talk/BoF slides up;
> others aren't, yet)
>
> I did stumble over 'omp loop' with SIMD. It turns out that -fopenmp-simd
> just turns 'loop' into 'simd', ignoring whatever value the user has
> specified for the bind value.
I think that is desirable, because with -fopenmp-simd binding to teams,
parallel and thread are the same thing, there is exactly one team and
one thread in parallel. Sure, one can have multiple threads with
-fopenmp-simd, but those are POSIX threads, while the binding of loop is
to the OpenMP constructs.
Even loop binds(team) is a way to express the iterations are vectorizable...
Jakub
prev parent reply other threads:[~2023-09-26 7:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-25 18:24 Tobias Burnus
2023-09-26 7:34 ` Richard Biener
2023-09-26 7:49 ` Jakub Jelinek
2023-09-26 7:50 ` Richard Biener
2023-09-26 7:54 ` Jakub Jelinek [this message]
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