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//                        Kokkos v. 3.0
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#ifndef KOKKOS_EXPERIMENTAL_VIEWTILE_HPP
#define KOKKOS_EXPERIMENTAL_VIEWTILE_HPP

//----------------------------------------------------------------------------
//----------------------------------------------------------------------------

namespace Kokkos {
namespace Impl {

// ===========================================================================
#ifdef KOKKOS_ENABLE_DEPRECATED_CODE

// View mapping for rank two tiled array

template <class L>
struct is_layout_tile : public std::false_type {};

template <unsigned N0, unsigned N1>
struct is_layout_tile<Kokkos::LayoutTileLeft<N0, N1, true> >
    : public std::true_type {};

template <class Dimension, class Layout>
struct ViewOffset<
    Dimension, Layout,
    typename std::enable_if<((Dimension::rank == 2) &&
                             is_layout_tile<Layout>::value)>::type> {
 public:
  enum { SHIFT_0 = Kokkos::Impl::integral_power_of_two(Layout::N0) };
  enum { SHIFT_1 = Kokkos::Impl::integral_power_of_two(Layout::N1) };
  enum { SHIFT_T = SHIFT_0 + SHIFT_1 };
  enum { MASK_0 = Layout::N0 - 1 };
  enum { MASK_1 = Layout::N1 - 1 };

  // Is an irregular layout that does not have uniform striding for each index.
  using is_mapping_plugin = std::true_type;
  using is_regular        = std::false_type;

  typedef size_t size_type;
  typedef Dimension dimension_type;
  typedef Layout array_layout;

  dimension_type m_dim;
  size_type m_tile_N0;

  //----------------------------------------

  // Only instantiated for rank 2
  template <typename I0, typename I1>
  KOKKOS_INLINE_FUNCTION constexpr size_type operator()(I0 const& i0,
                                                        I1 const& i1, int = 0,
                                                        int = 0, int = 0,
                                                        int = 0, int = 0,
                                                        int = 0) const {
    return /* ( ( Tile offset                               ) * Tile size ) */
        (((i0 >> SHIFT_0) + m_tile_N0 * (i1 >> SHIFT_1)) << SHIFT_T) +
        /* ( Offset within tile                       ) */
        ((i0 & MASK_0) + ((i1 & MASK_1) << SHIFT_0));
  }

  //----------------------------------------

  KOKKOS_INLINE_FUNCTION constexpr array_layout layout() const {
    return array_layout(m_dim.N0, m_dim.N1);
  }

  KOKKOS_INLINE_FUNCTION constexpr size_type dimension_0() const {
    return m_dim.N0;
  }
  KOKKOS_INLINE_FUNCTION constexpr size_type dimension_1() const {
    return m_dim.N1;
  }
  KOKKOS_INLINE_FUNCTION constexpr size_type dimension_2() const { return 1; }
  KOKKOS_INLINE_FUNCTION constexpr size_type dimension_3() const { return 1; }
  KOKKOS_INLINE_FUNCTION constexpr size_type dimension_4() const { return 1; }
  KOKKOS_INLINE_FUNCTION constexpr size_type dimension_5() const { return 1; }
  KOKKOS_INLINE_FUNCTION constexpr size_type dimension_6() const { return 1; }
  KOKKOS_INLINE_FUNCTION constexpr size_type dimension_7() const { return 1; }

  KOKKOS_INLINE_FUNCTION constexpr size_type size() const {
    return m_dim.N0 * m_dim.N1;
  }

  // Strides are meaningless due to irregularity
  KOKKOS_INLINE_FUNCTION constexpr size_type stride_0() const { return 0; }
  KOKKOS_INLINE_FUNCTION constexpr size_type stride_1() const { return 0; }
  KOKKOS_INLINE_FUNCTION constexpr size_type stride_2() const { return 0; }
  KOKKOS_INLINE_FUNCTION constexpr size_type stride_3() const { return 0; }
  KOKKOS_INLINE_FUNCTION constexpr size_type stride_4() const { return 0; }
  KOKKOS_INLINE_FUNCTION constexpr size_type stride_5() const { return 0; }
  KOKKOS_INLINE_FUNCTION constexpr size_type stride_6() const { return 0; }
  KOKKOS_INLINE_FUNCTION constexpr size_type stride_7() const { return 0; }

  KOKKOS_INLINE_FUNCTION constexpr size_type span() const {
    // ( TileDim0 * ( TileDim1 ) ) * TileSize
    return (m_tile_N0 * ((m_dim.N1 + MASK_1) >> SHIFT_1)) << SHIFT_T;
  }

  KOKKOS_INLINE_FUNCTION constexpr bool span_is_contiguous() const {
    // Only if dimensions align with tile size
    return (m_dim.N0 & MASK_0) == 0 && (m_dim.N1 & MASK_1) == 0;
  }

  //----------------------------------------

  KOKKOS_DEFAULTED_FUNCTION ~ViewOffset()                 = default;
  KOKKOS_DEFAULTED_FUNCTION ViewOffset()                  = default;
  KOKKOS_DEFAULTED_FUNCTION ViewOffset(const ViewOffset&) = default;
  KOKKOS_DEFAULTED_FUNCTION ViewOffset& operator=(const ViewOffset&) = default;

  template <unsigned TrivialScalarSize>
  KOKKOS_INLINE_FUNCTION constexpr ViewOffset(
      std::integral_constant<unsigned, TrivialScalarSize> const&,
      array_layout const arg_layout)
      : m_dim(arg_layout.dimension[0], arg_layout.dimension[1], 0, 0, 0, 0, 0,
              0),
        m_tile_N0((arg_layout.dimension[0] + MASK_0) >>
                  SHIFT_0 /* number of tiles in first dimension */) {}
};

template <typename T, unsigned N0, unsigned N1, class... P, typename iType0,
          typename iType1>
struct ViewMapping<
    void, Kokkos::ViewTraits<T**, Kokkos::LayoutTileLeft<N0, N1, true>, P...>,
    Kokkos::LayoutTileLeft<N0, N1, true>, iType0, iType1> {
  typedef Kokkos::LayoutTileLeft<N0, N1, true> src_layout;
  typedef Kokkos::ViewTraits<T**, src_layout, P...> src_traits;
  typedef Kokkos::ViewTraits<T[N0][N1], LayoutLeft, P...> traits;
  typedef Kokkos::View<T[N0][N1], LayoutLeft, P...> type;

  KOKKOS_INLINE_FUNCTION static void assign(
      ViewMapping<traits, void>& dst, const ViewMapping<src_traits, void>& src,
      const src_layout&, const size_t i_tile0, const size_t i_tile1) {
    typedef ViewMapping<traits, void> dst_map_type;
    typedef ViewMapping<src_traits, void> src_map_type;
    typedef typename dst_map_type::handle_type dst_handle_type;
    typedef typename dst_map_type::offset_type dst_offset_type;
    typedef typename src_map_type::offset_type src_offset_type;

    dst = dst_map_type(
        dst_handle_type(src.m_impl_handle +
                        ((i_tile0 + src.m_impl_offset.m_tile_N0 * i_tile1)
                         << src_offset_type::SHIFT_T)),
        dst_offset_type());
  }
};

#endif  // KOKKOS_ENABLE_DEPRECATED_CODE
// ===============================================================================

} /* namespace Impl */
} /* namespace Kokkos */

namespace Kokkos {

// ==============================================================================
#ifdef KOKKOS_ENABLE_DEPRECATED_CODE

template <typename T, unsigned N0, unsigned N1, class... P>
KOKKOS_INLINE_FUNCTION Kokkos::View<T[N0][N1], LayoutLeft, P...> tile_subview(
    const Kokkos::View<T**, Kokkos::LayoutTileLeft<N0, N1, true>, P...>& src,
    const size_t i_tile0, const size_t i_tile1) {
  // Force the specialized ViewMapping for extracting a tile
  // by using the first subview argument as the layout.
  typedef Kokkos::LayoutTileLeft<N0, N1, true> SrcLayout;

  return Kokkos::View<T[N0][N1], LayoutLeft, P...>(src, SrcLayout(), i_tile0,
                                                   i_tile1);
}

#endif  // KOKKOS_ENABLE_DEPRECATED_CODE
// ===============================================================================

} /* namespace Kokkos */

//----------------------------------------------------------------------------
//----------------------------------------------------------------------------

#endif /* #ifndef KOKKOS_EXPERIENTAL_VIEWTILE_HPP */
