[Bug tree-optimization/18694] [4.0 regression] loop miscompilation at -O1 (-ftree-ch)

["kazu at cs dot umass dot edu" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From kazu at cs dot umass dot edu  2004-12-09 05:24 -------
Updated the testcase like so:

/* PR tree-optimization/18694

   The dominator optimization didn't take the PHI evaluation order
   into account when threading an edge.  */

extern void abort (void) __attribute__((noreturn));
extern void exit (int) __attribute__((noreturn));

void __attribute__((noinline))
foo (int i)
{
  int next_n = 1;
  int j = 0;

  for (; i != 0; i--)
    {
      int n;

      for (n = next_n; j < n; j++)
	next_n++;

      if (j != n)
	abort ();
    }
}

int
main (void)
{
  foo (2);
  exit (0);
}


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18694