case 3:
        /* CN = [ 1  1  1 ]
                [ 1  w  w*]
                [ 1  w* w ]
        */
        re = Wpr(1);
        im = Wpi(1);
        Xr(0) = Yr(0) + Yr(1) + Yr(2);
        Xi(0) = Yi(0) + Yi(1) + Yi(2);

        Xr(1) = Xr(2) = Yr(0) + (Yr(1) + Yr(2))*re;
        Xi(1) = Xi(2) = Yi(0) + (Yi(1) + Yi(2))*re;
        ra = (Yi(2) - Yi(1))*im;
        ia = (Yr(1) - Yr(2))*im;
        Xr(1) += ra;
        Xi(1) += ia;
        Xr(2) -= ra;
        Xi(2) -= ia;
        break;