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From: "hubicka at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/103797] Clang vectorized LightPixel while GCC does not
Date: Wed, 22 Dec 2021 20:29:15 +0000	[thread overview]
Message-ID: <bug-103797-4-0NFgvY28Qt@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-103797-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103797

--- Comment #11 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
Aha, I did not noticed that we need special patterns (I extecpted this is
problem to solve in machine independent code).  So I guess we have
 1) SLP should vectorize the 3 accesses with -ffast-math to only one vector
operation (as opposed to one vector+one scalar it does now)
 2) we could adddivv2sf3 pattern which initializes the elt 4 of the operand2 to
1.0f to avoid funny results
 3) we need to figure out why SLP vectorization is not even considered in the
original testcase (which I do not seem to be able to dig out with reasonable
effort in a way that it preserves original properties - to be vectorized by
clang and not vectorized by gcc)

  parent reply	other threads:[~2021-12-22 20:29 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-21 23:29 [Bug tree-optimization/103797] New: " hubicka at gcc dot gnu.org
2021-12-22  1:16 ` [Bug tree-optimization/103797] " pinskia at gcc dot gnu.org
2021-12-22  8:46 ` marxin at gcc dot gnu.org
2021-12-22  9:14 ` hubicka at kam dot mff.cuni.cz
2021-12-22  9:21 ` marxin at gcc dot gnu.org
2021-12-22 11:08 ` hubicka at kam dot mff.cuni.cz
2021-12-22 11:08 ` hubicka at kam dot mff.cuni.cz
2021-12-22 11:30 ` marxin at gcc dot gnu.org
2021-12-22 13:44 ` hubicka at gcc dot gnu.org
2021-12-22 14:30 ` pinskia at gcc dot gnu.org
2021-12-22 14:59 ` hubicka at kam dot mff.cuni.cz
2021-12-22 19:34 ` jakub at gcc dot gnu.org
2021-12-22 20:29 ` hubicka at gcc dot gnu.org [this message]
2021-12-23  8:12 ` ubizjak at gmail dot com
2021-12-23  8:52 ` ubizjak at gmail dot com
2021-12-23  8:58 ` ubizjak at gmail dot com
2021-12-23  9:15 ` jakub at gcc dot gnu.org
2021-12-23  9:47 ` hubicka at kam dot mff.cuni.cz
2021-12-23 11:16 ` ubizjak at gmail dot com
2021-12-24 16:10 ` cvs-commit at gcc dot gnu.org
2022-01-03 13:37 ` hubicka at gcc dot gnu.org
2022-01-04 13:16 ` rguenth at gcc dot gnu.org
2022-01-07  6:39 ` pinskia at gcc dot gnu.org

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