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/*! \file
    \brief Abstractions for loading and storing matrices using the CUDA WMMA API.
*/
#pragma once

#if defined(__CUDACC__) && (!defined(__CUDA_ARCH__) || __CUDA_ARCH__ >= 700)

// Dependent header files should use the following macro to guard all code using
// nvcuda::wmma:: to enable compilation for CUDA Compute Capabilities < sm_70.
// Earlier shader models not support Tensor Cores.
#define CUTLASS_USE_WMMA_API

#include "stdio.h"

#include <crt/mma.h>
#include <cutlass/fragment.h>
#include <cutlass/load_store.h>
#include <cutlass/matrix_traits.h>
#include <cutlass/shape.h>
#include <cutlass/vector.h>

namespace cutlass {

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

/// Statically maps cutlass::MatrixLayout => nvcuda::wmma layout tags
template <MatrixLayout::Kind kLayout_>
struct WmmaLayout {
  typedef nvcuda::wmma::col_major Layout;
};

/// Statically maps cutlass::MatrixLayout => nvcuda::wmma layout tags
template <>
struct WmmaLayout<MatrixLayout::kRowMajor> {
  typedef nvcuda::wmma::row_major Layout;
};

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

/// Adapter to nvcuda::wmma fragment load and store operations
template <GemmOperand::Kind kOperand_,
          MatrixLayout::Kind kLayout_,
          typename Scalar_,
          typename WmmaShape_>
struct WmmaMatrix {};

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

/// Adapter to nvcuda::wmma fragment accessors for A operand
template <MatrixLayout::Kind kLayout_, typename Scalar_, typename WmmaShape_>
struct WmmaMatrix<GemmOperand::kA, kLayout_, Scalar_, WmmaShape_>
    : public nvcuda::wmma::fragment<
          /// The nvcuda::wmma operand name.
          nvcuda::wmma::matrix_a,
          /// The dimensions.
          WmmaShape_::kW,
          WmmaShape_::kH,
          WmmaShape_::kD,
          /// The scalar.
          Scalar_,
          /// The layout.
          typename WmmaLayout<kLayout_>::Layout> {
  /// This type.
  typedef WmmaMatrix<GemmOperand::kA, kLayout_, Scalar_, WmmaShape_> This_;

  /// Fill-in the element.
  CUTLASS_DEVICE This_& operator=(Scalar_ const& x) {
    nvcuda::wmma::fill_fragment(*this, x);
    return *this;
  }

  /// Load from memory.
  CUTLASS_DEVICE void load(Scalar_ const* pointer, int const stride) {
    nvcuda::wmma::load_matrix_sync(*this, pointer, stride);
  }

  /// Store to memory.
  CUTLASS_DEVICE void store(Scalar_* pointer, int const stride) const {
    nvcuda::wmma::store_matrix_sync(pointer, *this, stride);
  }
};

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

/// Adapter to nvcuda::wmma fragment accessors for B operand
template <MatrixLayout::Kind kLayout_, typename Scalar_, typename WmmaShape_>
struct WmmaMatrix<GemmOperand::kB, kLayout_, Scalar_, WmmaShape_>
    : public nvcuda::wmma::fragment<
          /// The nvcuda::wmma operand name.
          nvcuda::wmma::matrix_b,
          /// The dimensions.
          WmmaShape_::kW,
          WmmaShape_::kH,
          WmmaShape_::kD,
          /// The scalar.
          Scalar_,
          /// The layout.
          typename WmmaLayout<kLayout_>::Layout> {
  /// This type.
  typedef WmmaMatrix<GemmOperand::kB, kLayout_, Scalar_, WmmaShape_> This_;

  /// Fill-in the element.
  CUTLASS_DEVICE This_& operator=(Scalar_ const& x) {
    nvcuda::wmma::fill_fragment(*this, x);
    return *this;
  }

  /// Load from memory.
  CUTLASS_DEVICE void load(Scalar_ const* pointer, int const stride) {
    nvcuda::wmma::load_matrix_sync(*this, pointer, stride);
  }

  /// Store to memory.
  CUTLASS_DEVICE void store(Scalar_* pointer, int const stride) const {
    nvcuda::wmma::store_matrix_sync(pointer, *this, stride);
  }
};

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

/// Adapter to nvcuda::wmma fragment accessors for C operand
template <MatrixLayout::Kind kLayout_, typename Scalar_, typename WmmaShape_>
struct WmmaMatrix<GemmOperand::kC, kLayout_, Scalar_, WmmaShape_>
    : public nvcuda::wmma::fragment<
          /// The nvcuda::wmma operand name.
          nvcuda::wmma::accumulator,
          /// The dimensions.
          WmmaShape_::kW,
          WmmaShape_::kH,
          WmmaShape_::kD,
          /// The scalar.
          Scalar_> {
  /// This type.
  typedef WmmaMatrix<GemmOperand::kC, kLayout_, Scalar_, WmmaShape_> This_;
  /// The layout.
  static MatrixLayout::Kind const kLayout = kLayout_;

  /// Fill-in the element.
  CUTLASS_DEVICE This_& operator=(Scalar_ const& x) {
    nvcuda::wmma::fill_fragment(*this, x);
    return *this;
  }

  /// Load from memory.
  CUTLASS_DEVICE void load(Scalar_ const* pointer, int const stride) {
    bool const kIsRowMajor = kLayout == MatrixLayout::kRowMajor;
    nvcuda::wmma::load_matrix_sync(
        *this,
        pointer,
        stride,
        kIsRowMajor ? nvcuda::wmma::mem_row_major : nvcuda::wmma::mem_col_major);
  }

  /// Store to memory.
  CUTLASS_DEVICE void store(Scalar_* pointer, int const stride) const {
    bool const kIsRowMajor = kLayout == MatrixLayout::kRowMajor;
    nvcuda::wmma::store_matrix_sync(
        pointer,
        *this,
        stride,
        kIsRowMajor ? nvcuda::wmma::mem_row_major : nvcuda::wmma::mem_col_major);
  }
};

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

}  // namespace cutlass

#endif  // defined CUTLASS_USE_WMMA_API
