permute.cl

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#if defined(cl_khr_fp16)
#pragma OPENCL EXTENSION cl_khr_fp16 : enable
#endif

__kernel void permute(const int nthreads,
                      __global Dtype* bottom_data,
                      global int* permute_order,
                      global int* oldStride,
                      global int* newStride,
                      const int num_axes,
                      __global Dtype* top_data)
{
    for (int i = get_global_id(0); i < nthreads; i += get_global_size(0))
    {
        int oldPosition = 0;
        int newPosition = i;

        for (int j = 0; j < num_axes; ++j)
        {
            int order = permute_order[j];
            oldPosition += (newPosition / newStride[j]) * oldStride[order];
            newPosition %= newStride[j];
        }

        top_data[i] = bottom_data[oldPosition];
    }
}