wreciprocal
ATTRIBUTE_WARN_UNUSED_RET int wreciprocal(word_t dh, word_t dl, word_t *reciprocal);
ret = wreciprocal(tmp_nn.val[1], tmp_nn.val[0], p_reciprocal);
ret = wreciprocal(b_normalized.val[ptr->wlen - 1],
ATTRIBUTE_WARN_UNUSED_RET int wreciprocal(word_t dh, word_t dl, word_t *reciprocal);