bc/lib/number.c

751    Let u = u0 + u1*(b^n)
753    Then uv = (B^2n+B^n)*u1*v1 + B^n*(u1-u0)*(v0-v1) + (B^n+1)*u0*v0
755    B is the base of storage, number of digits in u1,u0 close to equal.
761   bc_num u0, u1, v0, v1;
781     u0 = new_sub_num (ulen,0, u->n_value);
784     u0 = new_sub_num (n, 0, u->n_value+ulen-n);
794   _bc_rm_leading_zeros (u0);
795   u0len = u0->n_len;
806   bc_sub (u1, u0, &d1, 0);
823   if (bc_is_zero(u0) || bc_is_zero(v0))
826     _bc_rec_mul (u0, u0->n_len, v0, v0->n_len, &m3, 0);
842   bc_free_num (&u0);