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From: "spam.brian.taylor at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/57328] Missed optimization: Unable to vectorize Fortran min and max intrinsics
Date: Tue, 21 May 2013 18:17:00 -0000 [thread overview]
Message-ID: <bug-57328-4-e7EijLTRdk@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-57328-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57328
--- Comment #7 from Brian Taylor <spam.brian.taylor at gmail dot com> ---
(In reply to Jakub Jelinek from comment #5)
> But vectorization reorders the loop iterations, thus say if some value is
> sNaN, you'd get exceptions in different order. So, I'm afraid without
> -ffast-math you can vectorize this only if the user says that the order of
> iterations doesn't matter (say using OpenMP 4.0 #pragma omp simd or Cilk+
> #pragma simd).
I'm not sure this is actually a problem (or perhaps there is a another bug),
because as I noted in the PR replacing min or max with a "functionally
equivalent" sequence of if statements allows vectorization.
next prev parent reply other threads:[~2013-05-21 18:17 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-19 2:39 [Bug fortran/57328] New: " spam.brian.taylor at gmail dot com
2013-05-21 1:03 ` [Bug fortran/57328] " bdavis at gcc dot gnu.org
2013-05-21 7:08 ` burnus at gcc dot gnu.org
2013-05-21 9:16 ` rguenth at gcc dot gnu.org
2013-05-21 9:56 ` glisse at gcc dot gnu.org
2013-05-21 10:16 ` jakub at gcc dot gnu.org
2013-05-21 11:21 ` glisse at gcc dot gnu.org
2013-05-21 18:17 ` spam.brian.taylor at gmail dot com [this message]
2013-05-21 20:25 ` bdavis at gcc dot gnu.org
2013-05-21 21:25 ` [Bug tree-optimization/57328] " glisse at gcc dot gnu.org
2013-05-22 14:22 ` glisse at gcc dot gnu.org
2013-06-13 20:29 ` glisse at gcc dot gnu.org
2014-05-19 8:09 ` rguenth at gcc dot gnu.org
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