[Bug tree-optimization/52028] New: [4.7 Regression] wrong code with -O2 -ftree-loop-distribution

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52028

             Bug #: 52028
           Summary: [4.7 Regression] wrong code with -O2
                    -ftree-loop-distribution
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: zso...@seznam.cz
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 26489
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26489
reduced testcase

Compiler output:
$ gcc -O2 -ftree-loop-distribution testcase4.c
$ valgrind -q ./a.out 
==32144== Conditional jump or move depends on uninitialised value(s)
==32144==    at 0x4C2D333: bcmp (in
/usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==32144==    by 0x4005F4: main (in /home/smatz/gcc-bug/1063/a.out)
==32144== 
==32144== Conditional jump or move depends on uninitialised value(s)
==32144==    at 0x4005F7: main (in /home/smatz/gcc-bug/1063/a.out)
==32144== 
Aborted

Tested revisions:
r183666 - fail
r180540 - fail
r178498 - fail
4.6 r180325 - OK