_nn_cmp_shift
MUST_HAVE(!_nn_cmp_shift(a, b, (u8)(a->wlen - b->wlen), &cmp) && (cmp < 0), ret, err);
ret = _nn_cmp_shift(r, b, shift, &cmp); EG(ret, err);
ret = _nn_cmp_shift(r, b, shift, &cmp); EG(ret, err);
ret = _nn_cmp_shift(&a_shift, b_norm, (u8)(new_wlen - b_wlen), &cmp); EG(ret, err);
MUST_HAVE(((!_nn_cmp_shift(&a_shift, b_norm, (u8)(new_wlen - b_wlen), &cmp)) && (cmp < 0)), ret, err);