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[Bug tree-optimization/61607] DOM missed jump threading and destroyed loops
- From: "law at redhat dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Fri, 27 Jun 2014 06:21:13 +0000
- Subject: [Bug tree-optimization/61607] DOM missed jump threading and destroyed loops
- Auto-submitted: auto-generated
- References: <bug-61607-4 at http dot gcc dot gnu dot org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61607
Jeffrey A. Law <law at redhat dot com> changed:
What |Removed |Added
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CC| |law at redhat dot com
--- Comment #7 from Jeffrey A. Law <law at redhat dot com> ---
In my testing, the missed thread is due to not following the chain of
SSA_NAME_VALUEs. We ought to easily discover that the two conditionals outside
the loop are in fact equivalent and fully threadable.
With a quick hack to follow the chain of values we're able to trivially
discover both of the interesting jump threading opportunities:
k.c.079t.dom1: Registering jump thread: (6, 7) incoming edge; (7, 8) normal;
k.c.079t.dom1: Registering jump thread: (5, 7) incoming edge; (7, 9) normal;