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/*! \file
  \brief 

*/

#pragma once

#include "cutlass/epilogue/threadblock/predicated_tile_iterator.h"
#include "cutlass/gemm/gemm.h"

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

namespace cutlass {
namespace epilogue {
namespace threadblock {

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

/// Defines the optimal thread map for SIMT accumulator layouts
template <
  typename ThreadblockShape_,
  typename WarpShape_,
  typename MmaSimtPolicy_,
  int PartitionsK,
  typename Element_,
  int ElementsPerAccess
>
struct DefaultThreadMapSimt {

  using ThreadblockShape = ThreadblockShape_;
  using WarpShape = WarpShape_;
  using MmaSimtPolicy = MmaSimtPolicy_;
  static int const kPartitionsK = PartitionsK;
  using Element = Element_;
  static int const kElementsPerAccess = ElementsPerAccess;

  //
  // Definitions
  //

  struct Detail {

    static int const kWarpSize = 32;

    static_assert(
      !(ThreadblockShape::kM % WarpShape::kM) &&
      !(ThreadblockShape::kN % WarpShape::kN), "Divisibility");

    /// Number of warps
    using WarpCount = gemm::GemmShape<
      ThreadblockShape::kM / WarpShape::kM,
      ThreadblockShape::kN / WarpShape::kN,
      kPartitionsK
    >;

    /// Computes number of thread-level matrix multiplies are needed to span a warp
    static int const kGroupCount =
      WarpShape::kM / (MmaSimtPolicy::WarpShape::kRow * MmaSimtPolicy::LaneMmaShape::kM);

    /// Number of participating threads
    static int const kThreads = WarpCount::kCount * kWarpSize;

    /// Number of iterations
    static int const kIterations = MmaSimtPolicy::LaneMmaShape::kM * kGroupCount;
  };

  //
  // ThreadMap
  //
  
  /// ThreadMap to be used by epilogue::PredicatedTileIterator satisfying concept OutputTileThreadMap
  using Type = OutputTileOptimalThreadMap<
    OutputTileShape<                          // Shape
      ThreadblockShape::kN, 
      1, 
      MmaSimtPolicy::WarpShape::kRow, 
      Detail::WarpCount::kM, 
      1>,
    OutputTileShape<                          // Count
      1, 
      MmaSimtPolicy::LaneMmaShape::kM, 
      Detail::kGroupCount, 
      1, 
      Detail::kIterations>,
    Detail::kThreads,
    kElementsPerAccess,
    sizeof_bits<Element>::value
  >;
};

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

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

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