[Bug c/17806] New: compiler error: in verify_loop_structure, at cfgloop.c:1491 , works -O2, breaks with -O3

["olh at suse dot de" <gcc-bugzilla at gcc dot gnu dot org>]

from package 'superlu':

works with -O2

/home/olaf/toolchain/obj/gcc-head-2004-10-03/inst/libexec/gcc/powerpc-unknown-linux-gnu/4.0.0/cc1 /tmp/mmd.i -fpreprocessed -o /dev/null  -quiet -O3
mmd.c: In function 'mmdupd_':
mmd.c:573: error: Basic block 127 should be marked irreducible.
mmd.c:573: error: Edge from 127 to 98 should be marked irreducible.
mmd.c:573: error: Basic block 131 should be marked irreducible.
mmd.c:573: error: Edge from 131 to 107 should be marked irreducible.
mmd.c:573: internal compiler error: in verify_loop_structure, at cfgloop.c:1491
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

-- 
           Summary: compiler error: in verify_loop_structure, at
                    cfgloop.c:1491 , works -O2, breaks with -O3
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: olh at suse dot de
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: powerpc-linux
  GCC host triplet: powerpc-linux
GCC target triplet: powerpc-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17806