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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/113105] Missing optimzation: fold `div(v, a) * b + rem(v, a)` to `div(v, a) * (b - a) + v` Date: Thu, 21 Dec 2023 16:09:59 +0000 [thread overview] Message-ID: <bug-113105-4-9RNMaH1ij6@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-113105-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113105 --- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> --- When it is signed v / a * b + v % a, I think it can introduce UB which wasn't there originally. E.g. for v = 0, a = INT_MIN and b = 3. So, if it isn't done just for unsigned types, parts of it need to be done in unsigned.
next prev parent reply other threads:[~2023-12-21 16:09 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-12-21 8:50 [Bug tree-optimization/113105] New: " xxs_chy at outlook dot com 2023-12-21 16:06 ` [Bug tree-optimization/113105] " pinskia at gcc dot gnu.org 2023-12-21 16:09 ` jakub at gcc dot gnu.org [this message] 2023-12-21 17:16 ` xxs_chy at outlook dot com 2023-12-21 17:50 ` jakub at gcc dot gnu.org 2023-12-21 22:51 ` jakub at gcc dot gnu.org 2023-12-23 10:02 ` xxs_chy at outlook dot com 2024-05-30 4:46 ` pinskia at gcc dot gnu.org
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