[Bug middle-end/36227] New: [4.3/4.4 Regression] POINTER_PLUS folding introduces undefined overflow

["rguenth at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

unsigned long * sat_add(unsigned long *ptr, unsigned long i, unsigned long
*end)
{
  if ((unsigned long)ptr + i * sizeof(*ptr) > (unsigned long)ptr)
    return ptr + i;
  else
    return end;
}

is folded to

  if (ptr + (long unsigned int) (i * 8) > ptr)
    {
      return ptr + (long unsigned int) (i * 8);
    }
  else
    {
      return end;
    }


-- 
           Summary: [4.3/4.4 Regression] POINTER_PLUS folding introduces
                    undefined overflow
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36227