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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/97832] AoSoA complex caxpy-like loops: AVX2+FMA -Ofast 7 times slower than -O3
Date: Mon, 16 Nov 2020 11:11:56 +0000	[thread overview]
Message-ID: <bug-97832-4-DC6omNwOz8@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-97832-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97832

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
It's again reassociation making a mess out of the natural SLP opportunity (and
thus SLP discovery fails miserably).

One idea worth playing with would be to change reassociation to rank references
from the same load group (as later vectorization would discover) the same.

That said, further analysis and maybe a smaller testcase to look at is useful
here.  There is, after all, the opportunity to turn "bad" association at the
source level to good for vectorization when -ffast-math is enabled as well.

  parent reply	other threads:[~2020-11-16 11:11 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-14 20:44 [Bug target/97832] New: " already5chosen at yahoo dot com
2020-11-16  7:21 ` [Bug target/97832] " rguenth at gcc dot gnu.org
2020-11-16 11:11 ` rguenth at gcc dot gnu.org [this message]
2020-11-16 20:11 ` already5chosen at yahoo dot com
2020-11-17  9:21 ` [Bug tree-optimization/97832] " rguenth at gcc dot gnu.org
2020-11-17 10:18 ` rguenth at gcc dot gnu.org
2020-11-18  8:53 ` rguenth at gcc dot gnu.org
2020-11-18  9:15 ` rguenth at gcc dot gnu.org
2020-11-18 13:23 ` rguenth at gcc dot gnu.org
2020-11-18 13:39 ` rguenth at gcc dot gnu.org
2020-11-19 19:55 ` already5chosen at yahoo dot com
2020-11-20  7:10 ` rguenth at gcc dot gnu.org
2021-06-09 12:41 ` cvs-commit at gcc dot gnu.org
2021-06-09 12:54 ` rguenth at gcc dot gnu.org
2022-01-21  0:16 ` pinskia at gcc dot gnu.org
2022-11-24 23:22 ` already5chosen at yahoo dot com
2022-11-25  8:16 ` rguenth at gcc dot gnu.org
2022-11-25 13:19 ` already5chosen at yahoo dot com
2022-11-25 20:46 ` rguenth at gcc dot gnu.org
2022-11-25 21:27 ` amonakov at gcc dot gnu.org
2022-11-26 18:27 ` already5chosen at yahoo dot com
2022-11-26 18:36 ` already5chosen at yahoo dot com
2022-11-26 19:36 ` amonakov at gcc dot gnu.org
2022-11-26 22:00 ` already5chosen at yahoo dot com
2022-11-28  6:29 ` crazylht at gmail dot com
2022-11-28  6:42 ` crazylht at gmail dot com
2022-11-28  7:21 ` rguenther at suse dot de
2022-11-28  7:24 ` crazylht at gmail dot com

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