[Bug c++/12340] New: [3.2 regression] loop unroller + gcse produces wrong code

[rguenth at tat dot physik dot uni-tuebingen dot de]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12340

           Summary: [3.2 regression] loop unroller + gcse produces wrong
                    code
           Product: gcc
           Version: 3.3.2
            Status: UNCONFIRMED
          Severity: critical
          Priority: P1
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at tat dot physik dot uni-tuebingen dot de
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu

If compiling with -O2 -fno-exceptions -funroll-loops the testcase segfaults in a
destructor, with -fno-gcse added or -funroll-loops removed, the testcase is
fine. This problem does not appear on gcc 3.2.3 or gcc 3.4 with either
-funroll-loops or -fold-unroll-loops.

Testcase is available from

http://www.tat.physik.uni-tuebingen.de/~rguenth/gcc/brick_test1.bug.ii.gz

gcc-3.3 version tested is

g++-3.3 (GCC) 3.3.2 20030919 (prerelease)

Richard.