for (i=2; i<N; i*=2) {
for (i=1; i<N; i*=2) {
    public void init(final int N) {        int i;        this.add(new SplitJoin1(N));        for (i=2; i<N; i*=2) {            this.add(new Butterfly1(i, N));            this.add(new Butterfly2(i, N));        }    }