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From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/95810] Spurious UBSan warning when computing the opposite of the absolute value of INT_MIN
Date: Wed, 24 Jun 2020 08:41:17 +0000 [thread overview]
Message-ID: <bug-95810-4-uFWXKmbztU@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-95810-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95810
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:
https://gcc.gnu.org/g:01e10b0ee77e82cb331414c569e02dc7a2c4999e
commit r11-1620-g01e10b0ee77e82cb331414c569e02dc7a2c4999e
Author: Jakub Jelinek <jakub@redhat.com>
Date: Wed Jun 24 10:40:02 2020 +0200
fold-const: Fix A <= 0 ? A : -A folding [PR95810]
We folded A <= 0 ? A : -A into -ABS (A), which is for signed integral types
incorrect - can invoke on INT_MIN UB twice, once on ABS and once on its
negation.
The following patch fixes it by instead folding it to (type)-ABSU (A).
2020-06-24 Jakub Jelinek <jakub@redhat.com>
PR middle-end/95810
* fold-const.c (fold_cond_expr_with_comparison): Optimize
A <= 0 ? A : -A into (type)-absu(A) rather than -abs(A).
* gcc.dg/ubsan/pr95810.c: New test.
next prev parent reply other threads:[~2020-06-24 8:41 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-22 7:52 [Bug tree-optimization/95810] New: " felix.von.s at posteo dot de
2020-06-22 8:51 ` [Bug middle-end/95810] " pinskia at gcc dot gnu.org
2020-06-22 9:36 ` jakub at gcc dot gnu.org
2020-06-22 9:53 ` jakub at gcc dot gnu.org
2020-06-24 8:41 ` cvs-commit at gcc dot gnu.org [this message]
2020-09-16 19:22 ` cvs-commit at gcc dot gnu.org
2021-04-28 17:56 ` [Bug middle-end/95810] [8 only] " pinskia at gcc dot gnu.org
2021-05-14 14:02 ` jakub at gcc dot gnu.org
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