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[Bug tree-optimization/55022] [4.8/4.9 Regression] air.f90 is miscompliled with -m64 -O2 -fgraphite-identity after revision 190619
- From: "mircea.namolaru at inria dot fr" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Thu, 10 Apr 2014 16:01:49 +0000
- Subject: [Bug tree-optimization/55022] [4.8/4.9 Regression] air.f90 is miscompliled with -m64 -O2 -fgraphite-identity after revision 190619
- Auto-submitted: auto-generated
- References: <bug-55022-4 at http dot gcc dot gnu dot org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55022
Mircea Namolaru <mircea.namolaru at inria dot fr> changed:
What |Removed |Added
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CC| |mircea.namolaru at inria dot fr
--- Comment #17 from Mircea Namolaru <mircea.namolaru at inria dot fr> ---
Vladimir Kargov, Tobias Grosser and me found that the problem is caused by
incorrect folding of the floord operator. As a result Cloog translates the
expression
-4294967296*floord(_19-i_17,4294967296)
to the tree-SSA expression
4294967296*floord(_19-i_17,-4294967296)
This is wrong, in the first case floord is 0 and in the second is -1.