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* [Bug tree-optimization/94785] New: Failure to detect abs pattern using multiplication
@ 2020-04-27 7:57 gabravier at gmail dot com
2020-04-27 8:06 ` [Bug middle-end/94785] " rguenth at gcc dot gnu.org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: gabravier at gmail dot com @ 2020-04-27 7:57 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94785
Bug ID: 94785
Summary: Failure to detect abs pattern using multiplication
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: gabravier at gmail dot com
Target Milestone: ---
unsigned r(int v)
{
return (1 | -(v < 0)) * v;
}
`r` is equivalent to `abs(v)`. GCC does not make the transformation to an
`abs`.
Example of the optimization not being done : https://godbolt.org/z/Rw-hBt
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug middle-end/94785] Failure to detect abs pattern using multiplication 2020-04-27 7:57 [Bug tree-optimization/94785] New: Failure to detect abs pattern using multiplication gabravier at gmail dot com @ 2020-04-27 8:06 ` rguenth at gcc dot gnu.org 2020-12-30 11:08 ` jakub at gcc dot gnu.org ` (3 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: rguenth at gcc dot gnu.org @ 2020-04-27 8:06 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94785 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|tree-optimization |middle-end Status|UNCONFIRMED |NEW Ever confirmed|0 |1 Keywords| |easyhack Last reconfirmed| |2020-04-27 --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- Note you likely want 1U | -(... as otherwise you implicitely assert that v != INT_MIN due to -1 * INT_MIN invoking undefined overflow. We still can do the transform to abs, of course. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug middle-end/94785] Failure to detect abs pattern using multiplication 2020-04-27 7:57 [Bug tree-optimization/94785] New: Failure to detect abs pattern using multiplication gabravier at gmail dot com 2020-04-27 8:06 ` [Bug middle-end/94785] " rguenth at gcc dot gnu.org @ 2020-12-30 11:08 ` jakub at gcc dot gnu.org 2020-12-31 10:08 ` cvs-commit at gcc dot gnu.org ` (2 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: jakub at gcc dot gnu.org @ 2020-12-30 11:08 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94785 Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |jakub at gcc dot gnu.org --- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Created attachment 49859 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49859&action=edit gcc11-pr94785.patch Untested fix. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug middle-end/94785] Failure to detect abs pattern using multiplication 2020-04-27 7:57 [Bug tree-optimization/94785] New: Failure to detect abs pattern using multiplication gabravier at gmail dot com 2020-04-27 8:06 ` [Bug middle-end/94785] " rguenth at gcc dot gnu.org 2020-12-30 11:08 ` jakub at gcc dot gnu.org @ 2020-12-31 10:08 ` cvs-commit at gcc dot gnu.org 2020-12-31 10:13 ` jakub at gcc dot gnu.org 2021-11-16 3:32 ` cvs-commit at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: cvs-commit at gcc dot gnu.org @ 2020-12-31 10:08 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94785 --- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>: https://gcc.gnu.org/g:8f12ce2ea3be12de4f83d3c419bdb1dc5036b202 commit r11-6377-g8f12ce2ea3be12de4f83d3c419bdb1dc5036b202 Author: Jakub Jelinek <jakub@redhat.com> Date: Thu Dec 31 11:08:15 2020 +0100 match.pd: Add (-(X < 0) | 1) * X -> abs (X) etc. simplifications [PR94785] The following patch adds two simplifications to recognize idioms for ABS_EXPR resp. ABSU_EXPR. 2020-12-31 Jakub Jelinek <jakub@redhat.com> PR tree-optimization/94785 * match.pd ((-(X < 0) | 1) * X -> abs (X)): New simplification. ((-(X < 0) | 1U) * X -> absu (X)): Likewise. * gcc.dg/tree-ssa/pr94785.c: New test. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug middle-end/94785] Failure to detect abs pattern using multiplication 2020-04-27 7:57 [Bug tree-optimization/94785] New: Failure to detect abs pattern using multiplication gabravier at gmail dot com ` (2 preceding siblings ...) 2020-12-31 10:08 ` cvs-commit at gcc dot gnu.org @ 2020-12-31 10:13 ` jakub at gcc dot gnu.org 2021-11-16 3:32 ` cvs-commit at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: jakub at gcc dot gnu.org @ 2020-12-31 10:13 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94785 Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Resolution|--- |FIXED Status|ASSIGNED |RESOLVED --- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Fixed for GCC 11. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug middle-end/94785] Failure to detect abs pattern using multiplication 2020-04-27 7:57 [Bug tree-optimization/94785] New: Failure to detect abs pattern using multiplication gabravier at gmail dot com ` (3 preceding siblings ...) 2020-12-31 10:13 ` jakub at gcc dot gnu.org @ 2021-11-16 3:32 ` cvs-commit at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: cvs-commit at gcc dot gnu.org @ 2021-11-16 3:32 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94785 --- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Andrew Pinski <pinskia@gcc.gnu.org>: https://gcc.gnu.org/g:3200de91bc70bfd6d4b7b40e769bc82756b9b555 commit r12-5291-g3200de91bc70bfd6d4b7b40e769bc82756b9b555 Author: Andrew Pinski <apinski@marvell.com> Date: Mon Nov 15 22:55:09 2021 +0000 tree-optimization: [PR103245] Improve detection of abs pattern using multiplication So while working on PR 103228 (and a few others), I noticed the testcase for PR 94785 was failing. The problem is that the nop_convert moved from being inside the IOR to be outside of it. I also noticed the patch for PR 103228 was not needed to reproduce the issue either. This patch combines the two patterns together for the abs match when using multiplication and adds a few places where nop_convert are optional. OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions. PR tree-optimization/103245 gcc/ChangeLog: * match.pd: Combine the abs pattern matching using multiplication. Adding optional nop_convert too. gcc/testsuite/ChangeLog: * gcc.dg/tree-ssa/pr103245-1.c: New test. ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-11-16 3:32 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-04-27 7:57 [Bug tree-optimization/94785] New: Failure to detect abs pattern using multiplication gabravier at gmail dot com 2020-04-27 8:06 ` [Bug middle-end/94785] " rguenth at gcc dot gnu.org 2020-12-30 11:08 ` jakub at gcc dot gnu.org 2020-12-31 10:08 ` cvs-commit at gcc dot gnu.org 2020-12-31 10:13 ` jakub at gcc dot gnu.org 2021-11-16 3:32 ` cvs-commit at gcc dot gnu.org
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