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[Bug tree-optimization/55018] [4.6/4.7/4.8 Regression] CDDCE pass is too aggressive sometimes with infinite loops and with some functions
- From: "jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Mon, 22 Oct 2012 14:30:42 +0000
- Subject: [Bug tree-optimization/55018] [4.6/4.7/4.8 Regression] CDDCE pass is too aggressive sometimes with infinite loops and with some functions
- Auto-submitted: auto-generated
- References: <bug-55018-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55018
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |jakub at gcc dot gnu.org
--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-10-22 14:30:42 UTC ---
Yeah, I think this is a CDDCE bug, in particular incorrect assumption about
post-dominators in presence of infinite loops.
The problem is that with infinite loops, worst case all basic blocks on a path
from a conditional to an infinite loop that is control dependent on the
conditional can have fake edge to exit and therefore find_control_dependence
stops on those.