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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/114700] Front-end optimization generates wrong code with -ftrapv.
Date: Fri, 12 Apr 2024 05:56:44 +0000	[thread overview]
Message-ID: <bug-114700-4-c5yH6C9Vh8@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-114700-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114700

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
That that GCC doesn't promise that -ftrapv preserves all overflows and traps,
it merely guarantees that all overflows that actually happen trap.  So GCC is
fine to contract some expressions where the overall number of overflows can
only
decrease.

That's not a bug with -ftrapv.

It is considered a bug with -fsanitize=undefined though.

  parent reply	other threads:[~2024-04-12  5:56 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-12  2:22 [Bug c/114700] New: " lin1.hu at intel dot com
2024-04-12  2:34 ` [Bug middle-end/114700] " pinskia at gcc dot gnu.org
2024-04-12  2:47 ` lin1.hu at intel dot com
2024-04-12  2:47 ` lin1.hu at intel dot com
2024-04-12  3:21 ` pinskia at gcc dot gnu.org
2024-04-12  3:26 ` pinskia at gcc dot gnu.org
2024-04-12  3:35 ` pinskia at gcc dot gnu.org
2024-04-12  3:53 ` lin1.hu at intel dot com
2024-04-12  3:56 ` lin1.hu at intel dot com
2024-04-12  5:56 ` rguenth at gcc dot gnu.org [this message]
2024-04-12  6:33 ` [Bug middle-end/114700] Front-end optimization generates wrong code with -fsanitize=undefined xry111 at gcc dot gnu.org
2024-04-12  6:44 ` lin1.hu at intel dot com
2024-04-12  7:12 ` lin1.hu at intel dot com
2024-04-12  7:14 ` xry111 at gcc dot gnu.org
2024-04-12  8:51 ` lin1.hu at intel dot com
2024-04-12 10:15 ` [Bug middle-end/114700] middle-end " jakub at gcc dot gnu.org
2024-04-12 10:25 ` jakub at gcc dot gnu.org
2024-04-15  3:43 ` [Bug middle-end/114700] middle-end optimization generates causes -fsanitize=undefined not to happen in some cases lin1.hu at intel dot com
2024-04-15  6:49 ` jakub at gcc dot gnu.org
2024-04-15  7:44 ` lin1.hu at intel dot com
2024-04-17  1:50 ` lin1.hu at intel dot com

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