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/*! \file

  \brief Epilogue for threadblock scoped GEMMs using Tensor Ops.

  The epilogue rearranges the result of a matrix product through shared memory to match canonical
  tensor layouts in global memory. Epilogues support conversion and reduction operations.

*/

#pragma once

#include "cutlass/cutlass.h"
#include "cutlass/numeric_types.h"
#include "cutlass/array.h"

#include "cutlass/gemm/gemm.h"

#include "cutlass/epilogue/threadblock/default_epilogue_tensor_op.h"
#include "cutlass/epilogue/threadblock/default_epilogue_volta_tensor_op.h"
#include "cutlass/epilogue/threadblock/epilogue.h"
#include "cutlass/epilogue/threadblock/epilogue_with_reduction.h"

#include "cutlass/layout/permute.h"

////////////////////////////////////////////////////////////////////////////////

namespace cutlass {
namespace epilogue {
namespace threadblock {

////////////////////////////////////////////////////////////////////////////////

/// Defines sensible defaults for epilogues for TensorOps.
template <
  typename Shape,
  typename WarpMmaTensorOp,
  int PartitionsK,
  typename ElementOutput,
  typename OutputOp,
  typename ReductionOp,
  int ElementsPerAccess,
  bool ScatterD = false,
  typename PermuteDLayout = layout::NoPermute
>
struct DefaultEpilogueWithReductionTensorOp {

  /// Use defaults related to the existing epilogue
  using Base = DefaultEpilogueTensorOp<
    Shape,
    WarpMmaTensorOp,
    PartitionsK,
    OutputOp,
    ElementsPerAccess
  >;

  /// Additional tensor tile iterator
  using TensorTileIterator = cutlass::epilogue::threadblock::PredicatedTileIterator<
    typename Base::OutputTileThreadMap,
    typename OutputOp::ElementTensor
  >;

  using OutputTileIterator = cutlass::epilogue::threadblock::PredicatedTileIterator<
    typename Base::OutputTileThreadMap,
    ElementOutput,
    ScatterD,
    PermuteDLayout
  >;

  /// Define the epilogue
  using Epilogue = EpilogueWithReduction<
    Shape,
    WarpMmaTensorOp,
    PartitionsK,
    OutputTileIterator,
    TensorTileIterator,
    typename WarpMmaTensorOp::ElementC,
    typename Base::AccumulatorFragmentIterator,
    typename Base::WarpTileIterator,
    typename Base::SharedLoadIterator,
    typename Base::OutputOp,
    ReductionOp,
    typename Base::Padding
  >;
};

////////////////////////////////////////////////////////////////////////////////

/// Defines sensible defaults for epilogues for TensorOps.
template <
  typename Shape,
  typename WarpMmaTensorOp,
  int PartitionsK,
  typename ElementOutput,
  typename OutputOp,
  typename ReductionOp,
  int ElementsPerAccess,
  bool ScatterD = false,
  typename PermuteDLayout = layout::NoPermute
>
struct DefaultEpilogueWithReductionVoltaTensorOp {

  /// Use defaults related to the existing epilogue
  using Base = DefaultEpilogueVoltaTensorOp<
    Shape,
    WarpMmaTensorOp,
    PartitionsK,
    OutputOp,
    ElementsPerAccess
  >;

  /// Additional tensor tile iterator
  using TensorTileIterator = cutlass::epilogue::threadblock::PredicatedTileIterator<
    typename Base::OutputTileThreadMap,
    typename OutputOp::ElementTensor
  >;

  using OutputTileIterator = cutlass::epilogue::threadblock::PredicatedTileIterator<
    typename Base::OutputTileThreadMap,
    ElementOutput,
    ScatterD,
    PermuteDLayout
  >;

  /// Define the epilogue
  using Epilogue = EpilogueWithReduction<
    Shape,
    WarpMmaTensorOp,
    PartitionsK,
    OutputTileIterator,
    TensorTileIterator,
    typename WarpMmaTensorOp::ElementC,
    typename Base::AccumulatorFragmentIterator,
    typename Base::WarpTileIterator,
    typename Base::SharedLoadIterator,
    typename Base::OutputOp,
    ReductionOp,
    typename Base::Padding
  >;
};

////////////////////////////////////////////////////////////////////////////////

} // namespace threadblock
} // namespace epilogue
} // namespace cutlass

////////////////////////////////////////////////////////////////////////////////