[Bug middle-end/69537] [6 Regression] Incorrect -Wmaybe-uninitialized warning with enum variable

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69537

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Ok, so this is the check copied from fold-const.c:

  (if (TREE_CODE (TREE_TYPE (@0)) == INTEGER_TYPE

and thus we reject the ENUM_TYPE here:

  if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
      && CONVERT_EXPR_P (arg0))
    {
      /* If we are widening one operand of an integer comparison,
         see if the other operand is similarly being widened.  Perhaps we
         can do the comparison in the narrower type.  */
      tem = fold_widened_comparison (loc, code, type, arg0, arg1);
      if (tem)
        return tem;

      /* Or if we are changing signedness.  */
      tem = fold_sign_changed_comparison (loc, code, type, arg0, arg1);
      if (tem)
        return tem;
    }

not sure how this was optimized before.  Note that we happily accepted
non-INTEGER_TYPE operand of the conversion.

When moving the code I didn't want to change the predicate to INTEGRAL_TYPE_P
but I guess this is what I am going to test now (without trying to track
down how exactly we got to bypass that back in time...).