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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/109154] [13 regression] jump threading de-optimizes nested floating point comparisons
Date: Wed, 29 Mar 2023 06:38:18 +0000 [thread overview]
Message-ID: <bug-109154-4-EBho2Nania@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-109154-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109154
--- Comment #39 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Andrew Macleod from comment #37)
> Created attachment 54780 [details]
> in progress patch
>
> Well call me a liar.
>
> It took me a while to understand why, but if we leave it to single
> dependencies only, the impact is relatively linear. I wrote a bunch of
> code, then deleted most of it as I found the engine was bypassing my code
> and doing it on its own.
>
> The attached patch is the core. It actually works to a depth of 5
> recomputations. my sample of:
> int a = left * 2;
> int b = a - 4;
> int c = b % 7;
> func (a,b ,c);
> int d = c * 4;
> if (left == 20)
> {
> func (b,c,d);
>
> produces
> <bb 5> :
> func (36, 1, 4);
>
> IT also changes your program somewhat.
>
> Try applying it and see if it does what you want. It bootstraps, regression
> are running.. but based on the minimal code impact, I wouldn't expect
> incorrect failures.
>
> Performance impact on building GCC is barely half a percent in VRP, and
> 0.05% overall compile time. pretty minimal.
>
> Im still working with it to tweak it, I just wanted you to be able to see if
> it helps. I presume we dont want to add a new --param this late in the
> game. But it seems we can set a reasonable number and not run into much
> trouble.
There is no problem with adding --params, and those are always better than
magic numbers.
Btw, I originally wondered why we don't re-compute zone1_12 because it's
in the imports of the successor (OK, the empty successors single successor
block) and expected those to trigger re-computes.
next prev parent reply other threads:[~2023-03-29 6:38 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-16 11:57 [Bug tree-optimization/109154] New: [13 regression] aarch64 -mcpu=neoverse-v1 microbude performance regression pgodbole at nvidia dot com
2023-03-16 13:11 ` [Bug tree-optimization/109154] " tnfchris at gcc dot gnu.org
2023-03-16 14:58 ` [Bug target/109154] " rguenth at gcc dot gnu.org
2023-03-16 17:03 ` tnfchris at gcc dot gnu.org
2023-03-16 17:03 ` [Bug target/109154] [13 regression] jump threading with de-optimizes nested floating point comparisons tnfchris at gcc dot gnu.org
2023-03-22 10:20 ` [Bug tree-optimization/109154] [13 regression] jump threading " aldyh at gcc dot gnu.org
2023-03-22 10:29 ` avieira at gcc dot gnu.org
2023-03-22 12:22 ` rguenth at gcc dot gnu.org
2023-03-22 12:42 ` rguenth at gcc dot gnu.org
2023-03-22 13:11 ` aldyh at gcc dot gnu.org
2023-03-22 14:00 ` amacleod at redhat dot com
2023-03-22 14:39 ` aldyh at gcc dot gnu.org
2023-03-27 8:09 ` rguenth at gcc dot gnu.org
2023-03-27 9:30 ` jakub at gcc dot gnu.org
2023-03-27 9:42 ` aldyh at gcc dot gnu.org
2023-03-27 9:44 ` jakub at gcc dot gnu.org
2023-03-27 10:18 ` rguenther at suse dot de
2023-03-27 10:40 ` jakub at gcc dot gnu.org
2023-03-27 10:44 ` jakub at gcc dot gnu.org
2023-03-27 10:54 ` rguenth at gcc dot gnu.org
2023-03-27 10:56 ` jakub at gcc dot gnu.org
2023-03-27 10:59 ` jakub at gcc dot gnu.org
2023-03-27 17:07 ` jakub at gcc dot gnu.org
2023-03-28 8:33 ` rguenth at gcc dot gnu.org
2023-03-28 9:01 ` cvs-commit at gcc dot gnu.org
2023-03-28 10:07 ` tnfchris at gcc dot gnu.org
2023-03-28 10:08 ` tnfchris at gcc dot gnu.org
2023-03-28 12:18 ` jakub at gcc dot gnu.org
2023-03-28 12:25 ` rguenth at gcc dot gnu.org
2023-03-28 12:42 ` rguenth at gcc dot gnu.org
2023-03-28 13:19 ` rguenth at gcc dot gnu.org
2023-03-28 13:44 ` jakub at gcc dot gnu.org
2023-03-28 13:52 ` jakub at gcc dot gnu.org
2023-03-28 15:31 ` amacleod at redhat dot com
2023-03-28 15:40 ` jakub at gcc dot gnu.org
2023-03-28 15:53 ` amacleod at redhat dot com
2023-03-28 15:58 ` jakub at gcc dot gnu.org
2023-03-28 16:42 ` amacleod at redhat dot com
2023-03-28 21:12 ` amacleod at redhat dot com
2023-03-29 6:33 ` cvs-commit at gcc dot gnu.org
2023-03-29 6:38 ` rguenth at gcc dot gnu.org [this message]
2023-03-29 22:41 ` amacleod at redhat dot com
2023-03-30 18:17 ` cvs-commit at gcc dot gnu.org
2023-04-05 9:28 ` tnfchris at gcc dot gnu.org
2023-04-05 9:34 ` ktkachov at gcc dot gnu.org
2023-04-11 9:36 ` rguenth at gcc dot gnu.org
2023-04-13 16:54 ` jakub at gcc dot gnu.org
2023-04-13 17:25 ` rguenther at suse dot de
2023-04-13 17:29 ` jakub at gcc dot gnu.org
2023-04-14 18:10 ` jakub at gcc dot gnu.org
2023-04-14 18:14 ` jakub at gcc dot gnu.org
2023-04-14 18:22 ` jakub at gcc dot gnu.org
2023-04-14 19:09 ` jakub at gcc dot gnu.org
2023-04-15 10:10 ` cvs-commit at gcc dot gnu.org
2023-04-17 11:07 ` jakub at gcc dot gnu.org
2023-04-25 18:32 ` [Bug tree-optimization/109154] [13/14 " tnfchris at gcc dot gnu.org
2023-04-25 18:34 ` jakub at gcc dot gnu.org
2023-04-26 6:58 ` rguenth at gcc dot gnu.org
2023-04-26 9:43 ` tnfchris at gcc dot gnu.org
2023-04-26 10:07 ` jakub at gcc dot gnu.org
2023-07-07 18:10 ` tnfchris at gcc dot gnu.org
2023-07-10 7:15 ` rguenth at gcc dot gnu.org
2023-07-10 10:33 ` tnfchris at gcc dot gnu.org
2023-07-10 10:46 ` rguenth at gcc dot gnu.org
2023-07-10 11:02 ` tnfchris at gcc dot gnu.org
2023-07-10 11:27 ` rguenth at gcc dot gnu.org
2023-07-10 11:49 ` tnfchris at gcc dot gnu.org
2023-07-14 10:22 ` cvs-commit at gcc dot gnu.org
2023-07-14 10:22 ` cvs-commit at gcc dot gnu.org
2023-07-27 9:25 ` rguenth at gcc dot gnu.org
2023-10-02 10:53 ` cvs-commit at gcc dot gnu.org
2023-10-18 8:54 ` cvs-commit at gcc dot gnu.org
2023-10-18 8:54 ` cvs-commit at gcc dot gnu.org
2023-10-18 8:54 ` cvs-commit at gcc dot gnu.org
2023-10-18 8:55 ` cvs-commit at gcc dot gnu.org
2023-11-09 14:20 ` cvs-commit at gcc dot gnu.org
2023-11-09 14:20 ` cvs-commit at gcc dot gnu.org
2023-11-09 14:20 ` cvs-commit at gcc dot gnu.org
2023-11-09 14:20 ` cvs-commit at gcc dot gnu.org
2023-11-09 14:20 ` cvs-commit at gcc dot gnu.org
2023-11-09 14:20 ` cvs-commit at gcc dot gnu.org
2023-11-09 14:20 ` cvs-commit at gcc dot gnu.org
2023-11-09 14:20 ` cvs-commit at gcc dot gnu.org
2023-11-09 14:25 ` [Bug tree-optimization/109154] [13 " tnfchris at gcc dot gnu.org
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