_nn_exp_monty_ladder_ltr
return _nn_exp_monty_ladder_ltr(out, base, exp, mod, r, r_square, mpinv);
ret = _nn_exp_monty_ladder_ltr(&_out, base, exp, mod, NULL, NULL, WORD(0)); EG(ret, err);
ret = _nn_exp_monty_ladder_ltr(out, base, exp, mod, NULL, NULL, WORD(0));