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From: "rearnsha at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/54300] [4.7, 4.8, 4.9 Regression] regcprop incorrectly looks through parallel register swap operation
Date: Tue, 08 Oct 2013 09:47:00 -0000 [thread overview]
Message-ID: <bug-54300-4-uSCcwR4lz4@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-54300-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54300
--- Comment #11 from Richard Earnshaw <rearnsha at gcc dot gnu.org> ---
(In reply to Eric Botcazou from comment #10)
> > and regcprop substitues d19 for d18 in insn 27, missing the fact that insn
> > 73 is swapping the two values (thus clobbering the old d19 value).
>
> It's probably fooled by single_set returning the first set of the insn
> because of the REG_UNUSED note. I wonder whether it's a generic pitfall of
> single_set.
Hmm, interesting. Perhaps single_set should not do this if the dead set
clobbers an input.
next prev parent reply other threads:[~2013-10-08 9:47 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-17 15:28 [Bug target/54300] New: [4.7/4.8 Regression] Erroneous optimization causes wrong Neon data management eric.batut at allegorithmic dot com
2012-08-18 8:12 ` [Bug target/54300] " rguenth at gcc dot gnu.org
2012-08-20 16:11 ` eric.batut at allegorithmic dot com
2012-09-07 10:33 ` rguenth at gcc dot gnu.org
2012-09-20 10:26 ` jakub at gcc dot gnu.org
2012-10-25 12:56 ` eric.batut at allegorithmic dot com
2012-10-25 23:03 ` steven at gcc dot gnu.org
2012-12-03 15:42 ` rguenth at gcc dot gnu.org
2013-01-10 22:19 ` [Bug target/54300] [4.7 " pinskia at gcc dot gnu.org
2013-01-11 10:42 ` eric.batut at allegorithmic dot com
2013-04-11 8:00 ` rguenth at gcc dot gnu.org
2013-08-20 16:32 ` eric.batut at allegorithmic dot com
2013-10-04 17:29 ` [Bug rtl-optimization/54300] " rearnsha at gcc dot gnu.org
2013-10-08 9:36 ` [Bug rtl-optimization/54300] [4.7, 4.8, 4.9 Regression] regcprop incorrectly looks through parallel register swap operation ebotcazou at gcc dot gnu.org
2013-10-08 9:47 ` rearnsha at gcc dot gnu.org [this message]
2013-10-08 10:54 ` ebotcazou at gcc dot gnu.org
2013-11-20 13:55 ` rearnsha at gcc dot gnu.org
2013-12-05 9:56 ` [Bug rtl-optimization/54300] [4.7, 4.8 " steven at gcc dot gnu.org
2013-12-09 14:54 ` rearnsha at gcc dot gnu.org
2014-01-09 15:19 ` rearnsha at gcc dot gnu.org
2014-01-10 16:55 ` rearnsha at gcc dot gnu.org
2014-01-10 16:56 ` rearnsha at gcc dot gnu.org
2014-08-29 1:27 ` gregory.0xf0 at gmail dot com
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