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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/55157] Missed VRP with != 0 and multiply
Date: Mon, 07 Nov 2022 19:59:45 +0000 [thread overview]
Message-ID: <bug-55157-4-hh1aQpzfOI@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-55157-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55157
--- Comment #13 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Aldy Hernandez <aldyh@gcc.gnu.org>:
https://gcc.gnu.org/g:a239a63f868e29e9276088e7c0fb00804c2903ba
commit r13-3761-ga239a63f868e29e9276088e7c0fb00804c2903ba
Author: Aldy Hernandez <aldyh@redhat.com>
Date: Fri Nov 4 22:24:42 2022 +0100
Improve multiplication by powers of 2 in range-ops.
For unsigned numbers, multiplication by X, where X is a power of 2 is
[0,0][X,+INF].
This patch causes a regression to g++.dg/pr71488.C where
-Wstringop-overflow gets the same IL as before, but better ranges
cause it to issue a bogus warning. I will create a PR with some
notes.
No discernible changes in performance.
Tested on x86-64 Linux.
PR tree-optimization/55157
gcc/ChangeLog:
* range-op.cc (operator_mult::wi_fold): Optimize multiplications
by powers of 2.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/pr55157.c: New test.
next prev parent reply other threads:[~2022-11-07 19:59 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-31 21:51 [Bug tree-optimization/55157] New: Missing VRP pinskia at gcc dot gnu.org
2021-12-25 23:35 ` [Bug tree-optimization/55157] Missed VRP with != 0 and multiply pinskia at gcc dot gnu.org
2022-11-04 11:22 ` aldyh at gcc dot gnu.org
2022-11-04 11:39 ` aldyh at gcc dot gnu.org
2022-11-04 13:40 ` amacleod at redhat dot com
2022-11-04 15:44 ` aldyh at gcc dot gnu.org
2022-11-04 15:46 ` aldyh at gcc dot gnu.org
2022-11-04 19:45 ` aldyh at gcc dot gnu.org
2022-11-04 19:48 ` aldyh at gcc dot gnu.org
2022-11-04 20:03 ` aldyh at gcc dot gnu.org
2022-11-05 9:04 ` aldyh at gcc dot gnu.org
2022-11-07 19:59 ` cvs-commit at gcc dot gnu.org [this message]
2022-11-07 20:02 ` aldyh at gcc dot gnu.org
2022-11-08 18:26 ` pinskia at gcc dot gnu.org
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