[Bug tree-optimization/40579] [4.3/4.4/4.5 Regression] gcc -O2 optimization causes infinite loop and wrong output

[rguenth at gcc dot gnu dot org]

------- Comment #3 from rguenth at gcc dot gnu dot org  2009-06-29 09:29 -------
Which is because we run into

static int
compare_values_warnv (tree val1, tree val2, bool *strict_overflow_p)
{
...
      /* We cannot compare overflowed values, except for overflow
         infinities.  */
      if (TREE_OVERFLOW (val1) || TREE_OVERFLOW (val2))
        {

and IVOPTs made the upper bound in the test TREE_OVERFLOW.

  if (x_5 != -2147483648(OVF))
    goto <bb 4>;


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40579