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lammps/lib/kokkos/core/src/Kokkos_Layout.hpp
2023-03-03 09:22:33 -07:00

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//@HEADER
// ************************************************************************
//
// Kokkos v. 4.0
// Copyright (2022) National Technology & Engineering
// Solutions of Sandia, LLC (NTESS).
//
// Under the terms of Contract DE-NA0003525 with NTESS,
// the U.S. Government retains certain rights in this software.
//
// Part of Kokkos, under the Apache License v2.0 with LLVM Exceptions.
// See https://kokkos.org/LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//@HEADER
/// \file Kokkos_Layout.hpp
/// \brief Declaration of various \c MemoryLayout options.
#ifndef KOKKOS_IMPL_PUBLIC_INCLUDE
#include <Kokkos_Macros.hpp>
static_assert(false,
"Including non-public Kokkos header files is not allowed.");
#endif
#ifndef KOKKOS_LAYOUT_HPP
#define KOKKOS_LAYOUT_HPP
#include <cstddef>
#include <impl/Kokkos_Traits.hpp>
namespace Kokkos {
enum { ARRAY_LAYOUT_MAX_RANK = 8 };
//----------------------------------------------------------------------------
/// \struct LayoutLeft
/// \brief Memory layout tag indicating left-to-right (Fortran scheme)
/// striding of multi-indices.
///
/// This is an example of a \c MemoryLayout template parameter of
/// View. The memory layout describes how View maps from a
/// multi-index (i0, i1, ..., ik) to a memory location.
///
/// "Layout left" indicates a mapping where the leftmost index i0
/// refers to contiguous access, and strides increase for dimensions
/// going right from there (i1, i2, ...). This layout imitates how
/// Fortran stores multi-dimensional arrays. For the special case of
/// a two-dimensional array, "layout left" is also called "column
/// major."
struct LayoutLeft {
//! Tag this class as a kokkos array layout
using array_layout = LayoutLeft;
size_t dimension[ARRAY_LAYOUT_MAX_RANK];
enum : bool { is_extent_constructible = true };
LayoutLeft(LayoutLeft const&) = default;
LayoutLeft(LayoutLeft&&) = default;
LayoutLeft& operator=(LayoutLeft const&) = default;
LayoutLeft& operator=(LayoutLeft&&) = default;
KOKKOS_INLINE_FUNCTION
explicit constexpr LayoutLeft(size_t N0 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N1 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N2 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N3 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N4 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N5 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N6 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N7 = KOKKOS_IMPL_CTOR_DEFAULT_ARG)
: dimension{N0, N1, N2, N3, N4, N5, N6, N7} {}
friend bool operator==(const LayoutLeft& left, const LayoutLeft& right) {
for (unsigned int rank = 0; rank < ARRAY_LAYOUT_MAX_RANK; ++rank)
if (left.dimension[rank] != right.dimension[rank]) return false;
return true;
}
friend bool operator!=(const LayoutLeft& left, const LayoutLeft& right) {
return !(left == right);
}
};
//----------------------------------------------------------------------------
/// \struct LayoutRight
/// \brief Memory layout tag indicating right-to-left (C or
/// lexigraphical scheme) striding of multi-indices.
///
/// This is an example of a \c MemoryLayout template parameter of
/// View. The memory layout describes how View maps from a
/// multi-index (i0, i1, ..., ik) to a memory location.
///
/// "Right layout" indicates a mapping where the rightmost index ik
/// refers to contiguous access, and strides increase for dimensions
/// going left from there. This layout imitates how C stores
/// multi-dimensional arrays. For the special case of a
/// two-dimensional array, "layout right" is also called "row major."
struct LayoutRight {
//! Tag this class as a kokkos array layout
using array_layout = LayoutRight;
size_t dimension[ARRAY_LAYOUT_MAX_RANK];
enum : bool { is_extent_constructible = true };
LayoutRight(LayoutRight const&) = default;
LayoutRight(LayoutRight&&) = default;
LayoutRight& operator=(LayoutRight const&) = default;
LayoutRight& operator=(LayoutRight&&) = default;
KOKKOS_INLINE_FUNCTION
explicit constexpr LayoutRight(size_t N0 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N1 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N2 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N3 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N4 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N5 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N6 = KOKKOS_IMPL_CTOR_DEFAULT_ARG,
size_t N7 = KOKKOS_IMPL_CTOR_DEFAULT_ARG)
: dimension{N0, N1, N2, N3, N4, N5, N6, N7} {}
friend bool operator==(const LayoutRight& left, const LayoutRight& right) {
for (unsigned int rank = 0; rank < ARRAY_LAYOUT_MAX_RANK; ++rank)
if (left.dimension[rank] != right.dimension[rank]) return false;
return true;
}
friend bool operator!=(const LayoutRight& left, const LayoutRight& right) {
return !(left == right);
}
};
//----------------------------------------------------------------------------
/// \struct LayoutStride
/// \brief Memory layout tag indicated arbitrarily strided
/// multi-index mapping into contiguous memory.
struct LayoutStride {
//! Tag this class as a kokkos array layout
using array_layout = LayoutStride;
size_t dimension[ARRAY_LAYOUT_MAX_RANK];
size_t stride[ARRAY_LAYOUT_MAX_RANK];
enum : bool { is_extent_constructible = false };
LayoutStride(LayoutStride const&) = default;
LayoutStride(LayoutStride&&) = default;
LayoutStride& operator=(LayoutStride const&) = default;
LayoutStride& operator=(LayoutStride&&) = default;
/** \brief Compute strides from ordered dimensions.
*
* Values of order uniquely form the set [0..rank)
* and specify ordering of the dimensions.
* Order = {0,1,2,...} is LayoutLeft
* Order = {...,2,1,0} is LayoutRight
*/
template <typename iTypeOrder, typename iTypeDimen>
KOKKOS_INLINE_FUNCTION static LayoutStride order_dimensions(
int const rank, iTypeOrder const* const order,
iTypeDimen const* const dimen) {
LayoutStride tmp;
// Verify valid rank order:
int check_input = ARRAY_LAYOUT_MAX_RANK < rank ? 0 : int(1 << rank) - 1;
for (int r = 0; r < ARRAY_LAYOUT_MAX_RANK; ++r) {
tmp.dimension[r] = KOKKOS_IMPL_CTOR_DEFAULT_ARG;
tmp.stride[r] = 0;
}
for (int r = 0; r < rank; ++r) {
check_input &= ~int(1 << order[r]);
}
if (0 == check_input) {
size_t n = 1;
for (int r = 0; r < rank; ++r) {
tmp.stride[order[r]] = n;
n *= (dimen[order[r]]);
tmp.dimension[r] = dimen[r];
}
}
return tmp;
}
KOKKOS_INLINE_FUNCTION
explicit constexpr LayoutStride(
size_t N0 = KOKKOS_IMPL_CTOR_DEFAULT_ARG, size_t S0 = 0,
size_t N1 = KOKKOS_IMPL_CTOR_DEFAULT_ARG, size_t S1 = 0,
size_t N2 = KOKKOS_IMPL_CTOR_DEFAULT_ARG, size_t S2 = 0,
size_t N3 = KOKKOS_IMPL_CTOR_DEFAULT_ARG, size_t S3 = 0,
size_t N4 = KOKKOS_IMPL_CTOR_DEFAULT_ARG, size_t S4 = 0,
size_t N5 = KOKKOS_IMPL_CTOR_DEFAULT_ARG, size_t S5 = 0,
size_t N6 = KOKKOS_IMPL_CTOR_DEFAULT_ARG, size_t S6 = 0,
size_t N7 = KOKKOS_IMPL_CTOR_DEFAULT_ARG, size_t S7 = 0)
: dimension{N0, N1, N2, N3, N4, N5, N6, N7}, stride{S0, S1, S2, S3,
S4, S5, S6, S7} {}
friend bool operator==(const LayoutStride& left, const LayoutStride& right) {
for (unsigned int rank = 0; rank < ARRAY_LAYOUT_MAX_RANK; ++rank)
if (left.dimension[rank] != right.dimension[rank] ||
left.stride[rank] != right.stride[rank])
return false;
return true;
}
friend bool operator!=(const LayoutStride& left, const LayoutStride& right) {
return !(left == right);
}
};
// ===================================================================================
//////////////////////////////////////////////////////////////////////////////////////
enum class Iterate {
Default,
Left, // Left indices stride fastest
Right // Right indices stride fastest
};
// To check for LayoutTiled
// This is to hide extra compile-time 'identifier' info within the LayoutTiled
// class by not relying on template specialization to include the ArgN*'s
template <typename LayoutTiledCheck, class Enable = void>
struct is_layouttiled : std::false_type {};
template <typename LayoutTiledCheck>
struct is_layouttiled<LayoutTiledCheck,
std::enable_if_t<LayoutTiledCheck::is_array_layout_tiled>>
: std::true_type {};
namespace Experimental {
/// LayoutTiled
// Must have Rank >= 2
template <
Kokkos::Iterate OuterP, Kokkos::Iterate InnerP, unsigned ArgN0,
unsigned ArgN1, unsigned ArgN2 = 0, unsigned ArgN3 = 0, unsigned ArgN4 = 0,
unsigned ArgN5 = 0, unsigned ArgN6 = 0, unsigned ArgN7 = 0,
bool IsPowerOfTwo =
(Kokkos::Impl::is_integral_power_of_two(ArgN0) &&
Kokkos::Impl::is_integral_power_of_two(ArgN1) &&
(Kokkos::Impl::is_integral_power_of_two(ArgN2) || (ArgN2 == 0)) &&
(Kokkos::Impl::is_integral_power_of_two(ArgN3) || (ArgN3 == 0)) &&
(Kokkos::Impl::is_integral_power_of_two(ArgN4) || (ArgN4 == 0)) &&
(Kokkos::Impl::is_integral_power_of_two(ArgN5) || (ArgN5 == 0)) &&
(Kokkos::Impl::is_integral_power_of_two(ArgN6) || (ArgN6 == 0)) &&
(Kokkos::Impl::is_integral_power_of_two(ArgN7) || (ArgN7 == 0)))>
struct LayoutTiled {
static_assert(IsPowerOfTwo,
"LayoutTiled must be given power-of-two tile dimensions");
using array_layout = LayoutTiled<OuterP, InnerP, ArgN0, ArgN1, ArgN2, ArgN3,
ArgN4, ArgN5, ArgN6, ArgN7, IsPowerOfTwo>;
static constexpr Iterate outer_pattern = OuterP;
static constexpr Iterate inner_pattern = InnerP;
enum { N0 = ArgN0 };
enum { N1 = ArgN1 };
enum { N2 = ArgN2 };
enum { N3 = ArgN3 };
enum { N4 = ArgN4 };
enum { N5 = ArgN5 };
enum { N6 = ArgN6 };
enum { N7 = ArgN7 };
size_t dimension[ARRAY_LAYOUT_MAX_RANK];
enum : bool { is_extent_constructible = true };
LayoutTiled(LayoutTiled const&) = default;
LayoutTiled(LayoutTiled&&) = default;
LayoutTiled& operator=(LayoutTiled const&) = default;
LayoutTiled& operator=(LayoutTiled&&) = default;
KOKKOS_INLINE_FUNCTION
explicit constexpr LayoutTiled(size_t argN0 = 0, size_t argN1 = 0,
size_t argN2 = 0, size_t argN3 = 0,
size_t argN4 = 0, size_t argN5 = 0,
size_t argN6 = 0, size_t argN7 = 0)
: dimension{argN0, argN1, argN2, argN3, argN4, argN5, argN6, argN7} {}
friend bool operator==(const LayoutTiled& left, const LayoutTiled& right) {
for (unsigned int rank = 0; rank < ARRAY_LAYOUT_MAX_RANK; ++rank)
if (left.dimension[rank] != right.dimension[rank]) return false;
return true;
}
friend bool operator!=(const LayoutTiled& left, const LayoutTiled& right) {
return !(left == right);
}
};
} // namespace Experimental
// For use with view_copy
template <typename... Layout>
struct layout_iterate_type_selector {
static const Kokkos::Iterate outer_iteration_pattern =
Kokkos::Iterate::Default;
static const Kokkos::Iterate inner_iteration_pattern =
Kokkos::Iterate::Default;
};
template <>
struct layout_iterate_type_selector<Kokkos::LayoutRight> {
static const Kokkos::Iterate outer_iteration_pattern = Kokkos::Iterate::Right;
static const Kokkos::Iterate inner_iteration_pattern = Kokkos::Iterate::Right;
};
template <>
struct layout_iterate_type_selector<Kokkos::LayoutLeft> {
static const Kokkos::Iterate outer_iteration_pattern = Kokkos::Iterate::Left;
static const Kokkos::Iterate inner_iteration_pattern = Kokkos::Iterate::Left;
};
template <>
struct layout_iterate_type_selector<Kokkos::LayoutStride> {
static const Kokkos::Iterate outer_iteration_pattern =
Kokkos::Iterate::Default;
static const Kokkos::Iterate inner_iteration_pattern =
Kokkos::Iterate::Default;
};
template <unsigned ArgN0, unsigned ArgN1, unsigned ArgN2, unsigned ArgN3,
unsigned ArgN4, unsigned ArgN5, unsigned ArgN6, unsigned ArgN7>
struct layout_iterate_type_selector<Kokkos::Experimental::LayoutTiled<
Kokkos::Iterate::Left, Kokkos::Iterate::Left, ArgN0, ArgN1, ArgN2, ArgN3,
ArgN4, ArgN5, ArgN6, ArgN7, true>> {
static const Kokkos::Iterate outer_iteration_pattern = Kokkos::Iterate::Left;
static const Kokkos::Iterate inner_iteration_pattern = Kokkos::Iterate::Left;
};
template <unsigned ArgN0, unsigned ArgN1, unsigned ArgN2, unsigned ArgN3,
unsigned ArgN4, unsigned ArgN5, unsigned ArgN6, unsigned ArgN7>
struct layout_iterate_type_selector<Kokkos::Experimental::LayoutTiled<
Kokkos::Iterate::Right, Kokkos::Iterate::Left, ArgN0, ArgN1, ArgN2, ArgN3,
ArgN4, ArgN5, ArgN6, ArgN7, true>> {
static const Kokkos::Iterate outer_iteration_pattern = Kokkos::Iterate::Right;
static const Kokkos::Iterate inner_iteration_pattern = Kokkos::Iterate::Left;
};
template <unsigned ArgN0, unsigned ArgN1, unsigned ArgN2, unsigned ArgN3,
unsigned ArgN4, unsigned ArgN5, unsigned ArgN6, unsigned ArgN7>
struct layout_iterate_type_selector<Kokkos::Experimental::LayoutTiled<
Kokkos::Iterate::Left, Kokkos::Iterate::Right, ArgN0, ArgN1, ArgN2, ArgN3,
ArgN4, ArgN5, ArgN6, ArgN7, true>> {
static const Kokkos::Iterate outer_iteration_pattern = Kokkos::Iterate::Left;
static const Kokkos::Iterate inner_iteration_pattern = Kokkos::Iterate::Right;
};
template <unsigned ArgN0, unsigned ArgN1, unsigned ArgN2, unsigned ArgN3,
unsigned ArgN4, unsigned ArgN5, unsigned ArgN6, unsigned ArgN7>
struct layout_iterate_type_selector<Kokkos::Experimental::LayoutTiled<
Kokkos::Iterate::Right, Kokkos::Iterate::Right, ArgN0, ArgN1, ArgN2, ArgN3,
ArgN4, ArgN5, ArgN6, ArgN7, true>> {
static const Kokkos::Iterate outer_iteration_pattern = Kokkos::Iterate::Right;
static const Kokkos::Iterate inner_iteration_pattern = Kokkos::Iterate::Right;
};
} // namespace Kokkos
#endif // #ifndef KOKKOS_LAYOUT_HPP