[Bug tree-optimization/58955] [4.9 Regression] wrong code at -O3 on x86_64-linux-gnu

["su at cs dot ucdavis.edu" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58955

--- Comment #2 from Zhendong Su <su at cs dot ucdavis.edu> ---
Here is another testcase that seems related (also goes away with
-fno-tree-loop-distribute-patterns.  


--------------------------------

int printf (const char *, ...);

int a, b[10];

int
main ()
{
  for (; a < 2; a++)
    {
      b[a] = 1;
      b[a + 1] = 0;
    }
  printf ("%d\n", b[1]);
  return 0;
}