fft_tw_2xN_alt(_y, n, m, _table_w) { var y = _y; var table_w = begin(_table_w); for (k in range(n/2*1i64)) { for (j in range(m*1i64)) { //breakpoint(); var t = y[k+j*n]; var s = y[k+n/2+j*n]; var w_k = _table_w[k]; var sw = w_k * s; y.st[k+j*n] <= t+sw; y.st[k+n/2+j*n] <= t-sw; } } }