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From: "mpolacek at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/55270] [4.8 Regression] ICE in get_loop_body, at cfgloop.c:823
Date: Mon, 28 Jan 2013 13:34:00 -0000	[thread overview]
Message-ID: <bug-55270-4-5jHZL8ADDX@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-55270-4@http.gcc.gnu.org/bugzilla/>


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55270

--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> 2013-01-28 13:33:47 UTC ---
The problem here is in dfs_enumerate_from, which wrongly detects the number of
BBs in a loop.  get_loop_body_with_size calls dfs_enumerate_from with reverse =
1, thus we go against direction of edges.  I.e., we start at the header, then
go through its predecessors and if the predecessor hasn't been visited yet and
is dominated by the header, we count it.  But, we don't count BB which only has
an exit edge--thus its successor is outside of the loop.  Moving in !reverse
direction doesn't seem to help.  I'm not exactly sure what to do here, I'm
afraid of touching dfs_enumerate_from algorithm ;).


  parent reply	other threads:[~2013-01-28 13:34 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-11 10:25 [Bug rtl-optimization/55270] New: " antoine.balestrat at gmail dot com
2012-11-13 10:20 ` [Bug rtl-optimization/55270] " mpolacek at gcc dot gnu.org
2013-01-26 14:11 ` antoine.balestrat at gmail dot com
2013-01-26 14:28 ` mpolacek at gcc dot gnu.org
2013-01-28 13:34 ` mpolacek at gcc dot gnu.org [this message]
2013-01-28 13:35 ` [Bug rtl-optimization/55270] [4.8 Regression] " mpolacek at gcc dot gnu.org
2013-01-28 13:39 ` rguenther at suse dot de
2013-01-28 13:43 ` mpolacek at gcc dot gnu.org
2013-01-28 13:48 ` rguenth at gcc dot gnu.org
2013-01-28 14:03 ` rguenth at gcc dot gnu.org
2013-01-28 16:43 ` mpolacek at gcc dot gnu.org
2013-01-29  9:01 ` rguenther at suse dot de
2013-01-29  9:39 ` mpolacek at gcc dot gnu.org
2013-01-29 10:40 ` rguenth at gcc dot gnu.org
2013-01-29 11:39 ` rguenth at gcc dot gnu.org

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