bn_mul_comba8
void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b);
bn_mul_comba8(r, a, b);
bn_mul_comba8(&(t[n2]), t, &(t[n]));
bn_mul_comba8(r, a, b);
bn_mul_comba8(&(r[n2]), &(a[n]), &(b[n]));
bn_mul_comba8(&(t[n2]), t, &(t[n]));
bn_mul_comba8(r, a, b);
bn_mul_comba8(rr->d, a->d, b->d);