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From: "rsandifo at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/58079] internal compiler error: in do_SUBST, at combine.c:711
Date: Tue, 06 Aug 2013 21:14:00 -0000	[thread overview]
Message-ID: <bug-58079-4-yxLlJqtXy1@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-58079-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58079

rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rsandifo at gcc dot gnu.org
           Assignee|unassigned at gcc dot gnu.org      |rsandifo at gcc dot gnu.org

--- Comment #4 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> ---
(In reply to Mikael Pettersson from comment #3)
> Started with Uros' PR54457 patch in r191928.  I'm not sure if that patch was
> wrong or if it exposed a problem in the mips backend.

Looks like a latent combine bug that's being exposed by the better
subreg optimisation.  simplify_comparison is legitimately widening
a QImode comparison to SImode (since the target doesn't support
QImode comparisons), but combine_simplify_rtx is then trying to substitute
these widened values in-place, which trips the sanity check in do_SUBST.

I'm about to post a patch for comments.


  parent reply	other threads:[~2013-08-06 21:14 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-04 13:24 [Bug c/58079] New: " JuergenUrban at gmx dot de
2013-08-04 21:20 ` [Bug rtl-optimization/58079] " jbglaw@lug-owl.de
2013-08-05  8:42 ` mikpe at it dot uu.se
2013-08-05 12:05 ` mikpe at it dot uu.se
2013-08-06 21:14 ` rsandifo at gcc dot gnu.org [this message]
2013-08-08 18:45 ` rsandifo at gcc dot gnu.org
2013-08-08 18:49 ` rsandifo at gcc dot gnu.org
2013-09-14 20:12 ` danglin at gcc dot gnu.org
2013-09-28 16:18 ` steve at sk2 dot org
2013-10-28 16:04 ` ubizjak at gmail dot com
2013-10-29 15:44 ` [Bug rtl-optimization/58079] [4.8 Regression] " uros at gcc dot gnu.org
2013-10-29 16:06 ` ubizjak at gmail dot com

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