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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/108365] [9/10/11/12/13 Regression] Wrong code with -O0 Date: Tue, 10 Jan 2023 23:36:27 +0000 [thread overview] Message-ID: <bug-108365-4-r0CfrjIIcg@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-108365-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108365 --- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- With r9-1730 or later, I think the problem is that something decides to narrow the division from long long to int. In long long it is well defined if b is non-zero as -2147483648LL / -1LL is 2147483648LL. But when we instead narrow it to -2147483648 / -1 is UB which triggers division by zero exception. We don't seem to narrow: int foo (int x, int y) { return (long long) x / (long long) y; } so probably we do it only if the dividend is constant or something similar; if yes, then the fix would be stop narrowing if the dividend is the minimum of the narrower type.
next prev parent reply other threads:[~2023-01-10 23:36 UTC|newest] Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-01-10 22:47 [Bug tree-optimization/108365] New: " vsevolod.livinskiy at gmail dot com 2023-01-10 22:55 ` [Bug tree-optimization/108365] " pinskia at gcc dot gnu.org 2023-01-10 22:55 ` pinskia at gcc dot gnu.org 2023-01-10 23:07 ` [Bug middle-end/108365] " jakub at gcc dot gnu.org 2023-01-10 23:15 ` pinskia at gcc dot gnu.org 2023-01-10 23:36 ` jakub at gcc dot gnu.org [this message] 2023-01-10 23:59 ` jakub at gcc dot gnu.org 2023-01-11 11:47 ` [Bug c++/108365] " jakub at gcc dot gnu.org 2023-01-11 12:10 ` rguenth at gcc dot gnu.org 2023-01-14 9:18 ` cvs-commit at gcc dot gnu.org 2023-01-14 9:23 ` [Bug c++/108365] [9/10/11/12 " jakub at gcc dot gnu.org 2023-02-10 17:47 ` cvs-commit at gcc dot gnu.org 2023-02-10 18:00 ` [Bug c++/108365] [10/11 " jakub at gcc dot gnu.org 2023-05-02 20:14 ` cvs-commit at gcc dot gnu.org 2023-05-03 9:37 ` [Bug c++/108365] [10 " jakub at gcc dot gnu.org 2023-05-03 15:21 ` cvs-commit at gcc dot gnu.org 2023-05-04 7:23 ` jakub at gcc dot gnu.org
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