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From: "jakub 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: Thu, 23 Dec 2021 09:15:40 +0000	[thread overview]
Message-ID: <bug-103797-4-itVxY7fbwu@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 #15 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Uroš Bizjak from comment #12)
> (In reply to Jakub Jelinek from comment #10)
> > At least on your short testcase clang doesn't use divps either.
> > We do support mulv2sf3, addv2sf3 etc. but not divv2sf3 I bet because with
> > TARGET_MMX_WITH_SSE it would divide by zero in the 3rd and 4th elts,
> > but perhaps we could insert 1.0f, 1.0f into those elements of the divisor
> > before using divps?
> 
> It could be done, but I was under impression that the sequence to load 1.0f
> into topmost elements nullifies the benefit of operation to divide two

Sure, so perhaps we should somewhat increase the vectorization cost of V2SFmode
division so that we would use it only if it is part of longer sequences?

  parent reply	other threads:[~2021-12-23  9:15 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
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 [this message]
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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