[Bug middle-end/107088] [13 Regression] cselib ICE building __trunctfxf2 on ia64

["stefansf at linux dot ibm.com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107088

--- Comment #1 from Stefan Schulze Frielinghaus <stefansf at linux dot ibm.com> ---
The patch introduces

scalar_int_mode int_mode;
if (REG_P (x) && is_int_mode (mode, &int_mode)
    && REG_VALUES (REGNO (x)) != NULL
    && (!cselib_current_insn || !DEBUG_INSN_P (cselib_current_insn)))
  {
    rtx copy = shallow_copy_rtx (x);
    scalar_int_mode narrow_mode_iter;
    FOR_EACH_MODE_UNTIL (narrow_mode_iter, int_mode)   // <--------
      {
        PUT_MODE_RAW (copy, narrow_mode_iter);
        cselib_val *v = cselib_lookup (copy, narrow_mode_iter, 0, VOIDmode);
        if (v)
          {
            rtx sub = lowpart_subreg (narrow_mode_iter, e->val_rtx, int_mode);
            if (sub)
              new_elt_loc_list (v, sub);
          }
      }
  }

The failing assert is at the for-loop which is supposed to iterate only over
integer modes up to int_mode. I'm not familiar with ia64; is there any machine
which I could use for debugging?

The failing assert is

gcc_checking_assert (m_mode != E_VOIDmode);

which is triggered by get_known_wider. Would be interesting to see the initial
value of int_mode and if/how FOR_EACH_MODE_UNTIL actually ends up with
E_VOIDmode.