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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/108482] [13 Regression] ice in expand_LOOP_DIST_ALIAS with -O3 -ftrivial-auto-var-init=zero
Date: Sat, 21 Jan 2023 20:13:04 +0000	[thread overview]
Message-ID: <bug-108482-4-HJt0PGyYXL@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-108482-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108482

--- Comment #12 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is just a latent bug exposed by Richi's copyprop improvement.


Folding statement: ivtmp_37 = ivtmp_38 - 1;
gimple_simplified to ivtmp_37 = 1;
Folded into: ivtmp_37 = 1;

Folding statement: if (ivtmp_37 != 0)
Not folded

While trunk (GCC 13):
Folding statement: ivtmp_9 = ivtmp_39 - 1;
Queued stmt for removal.  Folds to: 1
Folding statement: if (ivtmp_9 != 0)
gimple_simplified to if (1 != 0)
Folded into: if (1 != 0)

Which is the correct thing to do and removes an branch earlier.
Which then removes a few extra loops.
Except now LOOP_DIST_ALIAS is not conditionalizing two loops any more.

  parent reply	other threads:[~2023-01-21 20:13 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-20 16:24 [Bug c/108482] New: ice in expand_LOOP_DIST_ALIAS, at internal-fn.cc:2737 dcb314 at hotmail dot com
2023-01-20 16:32 ` [Bug c/108482] " dcb314 at hotmail dot com
2023-01-20 21:13 ` [Bug tree-optimization/108482] [13 Regression] ice in expand_LOOP_DIST_ALIAS with -O3 -ftrivial-auto-var-init=zero pinskia at gcc dot gnu.org
2023-01-20 21:15 ` pinskia at gcc dot gnu.org
2023-01-20 21:19 ` pinskia at gcc dot gnu.org
2023-01-21 14:19 ` dcb314 at hotmail dot com
2023-01-21 14:20 ` dcb314 at hotmail dot com
2023-01-21 14:49 ` dcb314 at hotmail dot com
2023-01-21 15:18 ` dcb314 at hotmail dot com
2023-01-21 16:31 ` dcb314 at hotmail dot com
2023-01-21 16:52 ` dcb314 at hotmail dot com
2023-01-21 16:57 ` dcb314 at hotmail dot com
2023-01-21 20:13 ` pinskia at gcc dot gnu.org [this message]
2023-01-23  7:24 ` rguenth at gcc dot gnu.org
2023-01-23 10:51 ` cvs-commit at gcc dot gnu.org
2023-01-23 10:51 ` rguenth at gcc dot gnu.org

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