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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 tree-optimization/108757] We do not simplify (a - (N*M)) / N + M -> a / N Date: Mon, 04 Sep 2023 02:46:46 +0000 [thread overview] Message-ID: <bug-108757-4-Cx0OXY7QDR@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-108757-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108757 --- Comment #25 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jiu Fu Guo <guojiufu@gcc.gnu.org>: https://gcc.gnu.org/g:1aceceb1e2d6e86ce183c8cc448750fa03b6f79e commit r14-3644-g1aceceb1e2d6e86ce183c8cc448750fa03b6f79e Author: Jiufu Guo <guojiufu@linux.ibm.com> Date: Mon Sep 4 10:31:04 2023 +0800 Optimize '(X - N * M) / N' to 'X / N - M' if valid Integer expression "(X - N * M) / N" can be optimized to "X / N - M" with the below conditions: 1. There is no wrap/overflow/underflow. wrap/overflow/underflow breaks the arithmetic operation. 2. "X - N * M" and "X" are not of opposite sign. Here, the operation "/" would be "trunc_div", the fractional part is discarded. If "X - N * M" and "X" are in different signs, then trunc_div discards the fractional parts (of /N) in different directions. PR tree-optimization/108757 gcc/ChangeLog: * match.pd ((X - N * M) / N): New pattern. ((X + N * M) / N): New pattern. ((X + C) div_rshift N): New pattern. gcc/testsuite/ChangeLog: * gcc.dg/pr108757-1.c: New test. * gcc.dg/pr108757-2.c: New test. * gcc.dg/pr108757.h: New test.
next prev parent reply other threads:[~2023-09-04 2:46 UTC|newest] Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-02-10 22:26 [Bug tree-optimization/108757] New: " bergner at gcc dot gnu.org 2023-02-10 22:28 ` [Bug tree-optimization/108757] " bergner at gcc dot gnu.org 2023-02-10 22:33 ` pinskia at gcc dot gnu.org 2023-02-10 22:40 ` pinskia at gcc dot gnu.org 2023-02-11 13:14 ` anlauf at gcc dot gnu.org 2023-02-11 16:38 ` segher at gcc dot gnu.org 2023-02-11 17:32 ` bergner at gcc dot gnu.org 2023-02-11 17:55 ` segher at gcc dot gnu.org 2023-02-11 18:05 ` bergner at gcc dot gnu.org 2023-02-11 18:15 ` segher at gcc dot gnu.org 2023-02-11 19:45 ` chip.kerchner at ibm dot com 2023-02-11 21:55 ` chip.kerchner at ibm dot com 2023-02-11 22:03 ` chip.kerchner at ibm dot com 2023-02-13 20:13 ` chip.kerchner at ibm dot com 2023-02-13 20:20 ` pinskia at gcc dot gnu.org 2023-02-13 20:27 ` [Bug rtl-optimization/108757] " pinskia at gcc dot gnu.org 2023-02-13 20:36 ` chip.kerchner at ibm dot com 2023-02-13 20:37 ` chip.kerchner at ibm dot com 2023-02-13 20:58 ` [Bug tree-optimization/108757] " pinskia at gcc dot gnu.org 2023-02-13 20:59 ` pinskia at gcc dot gnu.org 2023-02-13 21:01 ` pinskia at gcc dot gnu.org 2023-05-11 13:15 ` guojiufu at gcc dot gnu.org 2023-05-11 17:32 ` pinskia at gcc dot gnu.org 2023-05-12 1:52 ` guojiufu at gcc dot gnu.org 2023-05-12 6:25 ` guojiufu at gcc dot gnu.org 2023-05-12 9:35 ` guojiufu at gcc dot gnu.org 2023-09-04 2:46 ` cvs-commit at gcc dot gnu.org [this message] 2023-09-04 3:26 ` guojiufu at gcc dot gnu.org
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