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/*! \file
    \brief Tile traits used to construct global tile iterator for HGEMM. This is intended to
      partition the thread block-level tile into 2D subtiles loaded by the threads and facilitate
      memory accesses larger than 16 bits.
*/
#pragma once

#include <cutlass/coord.h>
#include <cutlass/gemm/gemm_global_tile.h>
#include <cutlass/matrix_traits.h>
#include <cutlass/reshape_tile.h>

namespace cutlass {
namespace gemm {

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

template <GemmOperand::Kind kOperand_,
          MatrixLayout::Kind kLayout_,
          typename Scalar_,
          typename Tile_,
          typename Threads_,
          int kAccessSize_>
struct HgemmCrosswiseGlobalTileTraits : public GemmGlobalTileTraits<
                                            // Which GEMM operand?
                                            kOperand_,
                                            // The layout.
                                            kLayout_,
                                            // The scalar.
                                            Scalar_,
                                            // The tile.
                                            Tile_,
                                            // The threads.
                                            Threads_,
                                            // The number of scalars per LDG/STG.
                                            kAccessSize_> {
  /// The base class.
  typedef GemmGlobalTileTraits<kOperand_, kLayout_, Scalar_, Tile_, Threads_, kAccessSize_> Base;
  /// The threads.
  typedef typename Base::Threads Threads;
  /// The threads strides.
  typedef Shape<1, 2, Base::Tile::kC> ThreadsDelta;
  /// The strides in each dimension between different loads/stores.
  typedef Shape<Base::Threads::kH * 2, 1, Base::Threads::kW, Base::kAccessSize> Delta;
  /// The number of iterations needed to load/store the tile.
  typedef Shape<Base::Tile::kH / Base::Threads::kH / 2,
                2,
                Base::Tile::kW / Base::Threads::kW,
                Base::Tile::kC / Base::kAccessSize>
      Iterations;
  /// Computes the thread offset in (H, W) based on thread ID
  struct ThreadOffset {
    CUTLASS_HOST_DEVICE
    Coord<4> operator()() const {
      int thread_offset_h = threadIdx.x / Threads::kW * ThreadsDelta::kH;
      int thread_offset_w = threadIdx.x % Threads::kW * ThreadsDelta::kW;

      return make_Coord(0, thread_offset_h, thread_offset_w, 0);
    }
  };
};

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

}  // namespace gemm
}  // namespace cutlass