bn_div_words
#if defined(BN_LLONG) && defined(BN_DIV2W) && !defined(bn_div_words)
q = bn_div_words(n0, n1, d0);
q = bn_div_words(n0, n1, d0);
BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d);
d = bn_div_words(ret, l, w);