float2 multiplyComplex(float2 c1, float2 c2) {
    return (float2) (c1.x*c2.x-c1.y*c2.y, c1.x*c2.y+c1.y*c2.x);
}

/**
 * Perform a 1D FFT on each row along one axis.
 */

__kernel void execFFT(__global float2* matrix, float sign, __local float2* w, __local float2* data0, __local float2* data1) {
    const int i = get_local_id(0);
    w[i] = (float2) (cos(-sign*i*2*M_PI/SIZE), sin(-sign*i*2*M_PI/SIZE));
    data0[i] = matrix[i];
    barrier(CLK_LOCAL_MEM_FENCE);
    COMPUTE_FFT
}