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/*! \file
\brief Defies functors for mapping blockIdx to partitions of the batched
reduction computation.
*/
#pragma once
#include "cutlass/coord.h"

namespace cutlass {
namespace reduction {
struct DefaultBlockSwizzle {
    /// Ctor
    CUTLASS_HOST_DEVICE DefaultBlockSwizzle() {}

    /// Swizzle the block index.
    CUTLASS_DEVICE dim3 swizzle() { return blockIdx; }

    ///
    CUTLASS_HOST_DEVICE dim3 get_grid_layout(Coord<3> const& problem_size,
                                             Coord<3> const& OutputTile) {
        assert(OutputTile[0] == 1 && OutputTile[1] == 1);
        assert((problem_size[0] * problem_size[1] * problem_size[2]) %
                       OutputTile[2] ==
               0);
        dim3 grid;
        grid.x = problem_size[0] * problem_size[1] * problem_size[2] /
                 OutputTile[2];
        return grid;
    }

    ///
    CUTLASS_DEVICE Coord<3> get_threadblock_offset(Coord<3> const& SubTile) {
        assert(SubTile[0] == 1 && SubTile[1] == 1);
        dim3 block = swizzle();
        Coord<3> threadblock_offset = make_Coord(0, 0, block.x * SubTile[2]);
        return threadblock_offset;
    }
};
}  // namespace reduction
}  // namespace cutlass
