// ----------------------------------------------------------------------------
// -                        Open3D: www.open3d.org                            -
// ----------------------------------------------------------------------------
// The MIT License (MIT)
//
// Copyright (c) 2018-2021 www.open3d.org
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
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// ----------------------------------------------------------------------------

#include "open3d/core/Dispatch.h"
#include "open3d/core/ParallelFor.h"
#include "open3d/core/Tensor.h"
#include "open3d/core/kernel/Arange.h"

namespace open3d {
namespace core {
namespace kernel {

void ArangeCPU(const Tensor& start,
               const Tensor& stop,
               const Tensor& step,
               Tensor& dst) {
    Dtype dtype = start.GetDtype();
    DISPATCH_DTYPE_TO_TEMPLATE(dtype, [&]() {
        scalar_t sstart = start.Item<scalar_t>();
        scalar_t sstep = step.Item<scalar_t>();
        scalar_t* dst_ptr = dst.GetDataPtr<scalar_t>();
        int64_t n = dst.GetLength();
        ParallelFor(start.GetDevice(), n, [&](int64_t workload_idx) {
            dst_ptr[workload_idx] =
                    sstart + static_cast<scalar_t>(sstep * workload_idx);
        });
    });
}

}  // namespace kernel
}  // namespace core
}  // namespace open3d
