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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/105338] [12 Regression] Regression: jump or cmove generated for pattern (x ? CST : 0)
Date: Fri, 22 Apr 2022 11:20:08 +0000 [thread overview]
Message-ID: <bug-105338-4-rdqbkLMPuB@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-105338-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105338
--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #5)
> (In reply to Jakub Jelinek from comment #3)
> > Before fwprop1, the code looks roughly the same except for the swapped
> > branches,
> > so in C
> > if (tmp83 != 0)
> > tmp82 = 5;
> > else
> > tmp82 = tmp83;
> > vs.
> > if (tmp83 == 0)
> > tmp82 = tmp83;
> > else
> > tmp82 = 5;
>
> Specifically for this we could also look to canonicalize this in
> uncprop which introduces the copies, making sure to rewrite this into
> an equality compare?
When un-propagating into a PHI in uncprop_into_successor_phis mark the
BB of the PHI node.
In uncprop_dom_walker::before_dom_children, when it is marked, match
a diamond/half-diamond with the immediate dominator and do the rewrite
of the conditional and swapping of edge flags.
next prev parent reply other threads:[~2022-04-22 11:20 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-21 17:47 [Bug rtl-optimization/105338] New: " denis.campredon at gmail dot com
2022-04-22 6:13 ` [Bug rtl-optimization/105338] [12 Regression] " rguenth at gcc dot gnu.org
2022-04-22 9:17 ` jakub at gcc dot gnu.org
2022-04-22 9:48 ` pinskia at gcc dot gnu.org
2022-04-22 11:00 ` jakub at gcc dot gnu.org
2022-04-22 11:11 ` rguenth at gcc dot gnu.org
2022-04-22 11:14 ` rguenth at gcc dot gnu.org
2022-04-22 11:20 ` rguenth at gcc dot gnu.org [this message]
2022-04-22 12:28 ` jakub at gcc dot gnu.org
2022-04-22 13:59 ` jakub at gcc dot gnu.org
2022-04-22 14:11 ` jakub at gcc dot gnu.org
2022-04-22 14:24 ` [Bug target/105338] " jakub at gcc dot gnu.org
2022-04-23 8:26 ` cvs-commit at gcc dot gnu.org
2022-04-25 14:48 ` jakub at gcc dot gnu.org
2022-04-26 5:05 ` denis.campredon at gmail dot com
2022-04-26 8:21 ` jakub at gcc dot gnu.org
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