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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/97623] [9/10/11 Regression] Extremely slow O2 compile (>>O(n^2))
Date: Fri, 30 Oct 2020 13:28:12 +0000	[thread overview]
Message-ID: <bug-97623-4-9FANeJcLMO@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-97623-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97623

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
So this is the change improving the hoist insert situation but it is not a
solution for the back-to-back of PRE vs. hoist insertion.  Will have to think
about this some more and then eventually simply add some iteration limit - we
can stop after any arbitrary number of iterations after all, the cost is just
less optimization.

As a workaround for older code bases I suggest to use -fno-code-hoisting for
now.

If you are set up to try current trunk GCC then I'd be curious to know the
effect of the patch on the "real" case.

  parent reply	other threads:[~2020-10-30 13:28 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-29  2:02 [Bug c++/97623] New: " wsnyder at wsnyder dot org
2020-10-29  2:03 ` [Bug c++/97623] " wsnyder at wsnyder dot org
2020-10-29  7:17 ` [Bug tree-optimization/97623] [9/10/11 Regression] " rguenth at gcc dot gnu.org
2020-10-29  7:18 ` rguenth at gcc dot gnu.org
2020-10-30 12:35 ` rguenth at gcc dot gnu.org
2020-10-30 12:35 ` rguenth at gcc dot gnu.org
2020-10-30 13:25 ` cvs-commit at gcc dot gnu.org
2020-10-30 13:28 ` rguenth at gcc dot gnu.org [this message]
2020-10-30 13:55 ` wsnyder at wsnyder dot org
2020-11-03 14:16 ` rguenth at gcc dot gnu.org
2020-11-03 15:23 ` cvs-commit at gcc dot gnu.org
2020-11-06  1:50 ` wsnyder at wsnyder dot org
2020-11-06  9:52 ` rguenther at suse dot de
2020-11-06 12:37 ` wsnyder at wsnyder dot org
2020-11-06 13:00 ` rguenth at gcc dot gnu.org
2020-11-06 13:19 ` marxin at gcc dot gnu.org
2020-11-06 13:28 ` rguenth at gcc dot gnu.org
2020-11-06 13:45 ` rguenth at gcc dot gnu.org
2020-11-11 11:51 ` cvs-commit at gcc dot gnu.org
2020-11-11 16:11 ` tschwinge at gcc dot gnu.org
2020-11-11 17:17 ` cvs-commit at gcc dot gnu.org
2020-12-07 13:03 ` [Bug tree-optimization/97623] [9/10 " rguenth at gcc dot gnu.org
2021-01-11 13:37 ` cvs-commit at gcc dot gnu.org
2021-01-11 13:37 ` cvs-commit at gcc dot gnu.org
2021-01-11 13:39 ` [Bug tree-optimization/97623] [9 " rguenth at gcc dot gnu.org
2021-06-01  8:18 ` rguenth at gcc dot gnu.org
2022-05-27  8:56 ` rguenth at gcc dot gnu.org

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