Add 'Permute' device op & example (#408)

* Add example folder for 'DeviceElementwise'

* Re-structure example files

* Move common parts into common.hpp

* Use more strict input

* Add more helper methods in 'DeviceElementwise'

* Use more specific method to write example

* Allow specify problem through command line argument

* Allow specify problem 'axes' through command line argument

* Add check to template type argument

* Add transpose_shape() to generalize shape permute

* Generalize transpose utility functions

* Use better name for tensor indices

* Add checks in helper functions

* Remove debug messages

* Refine error message for check_err()

* Generalize variable naming in example code

* Add device op 'DevicePermute'

This device op is clone of 'DeviceElementwise'

* Use 'DevicePermute' device op in example

* Remove 'elementwise' from identifiers

* Remove 'elementwise' from file paths

* Remove base class of 'DevicePermute'

* Let 'DevicePermute' inherit from 'BaseOperator'

* Add simple type traits to validate device op type

* Add static_assert() to check type constraints

* Create 'DevicePermuteBase' to generate methods

* Use indirect base type to generate methods

* Remove 'is_device_op<>' type traits

* Only accept single-input-single-output for 'DervicePermute'

* Simplify 'DevicePermute' interface

* Re-format 'DeviceElementwise'

* Use CRTP to generate overridden virtual method

* Remove unnecessary include directives

* Distinguish input & output shape in 'DevicePermute'

* Passing 'axes' to 'DevicePermute'

* Use more reasonable return value for Invoker::Run()

* Add 'GridwisePermute' kernel

This kernel is a clone of 'GridwiseElementwise_1D'

* Remove no-longer used type argument

* Check if input/output shape meet the requirement

* Remove no-longer used method

* Remove never-entered-if-clause

* Change problem description for 'DevicePermute'

* Transform descriptor into 3 dimensions

* Add debug code the verify result

* Add comment to indicate template argument location

* Add N/H/WPerBlock template parameter to 'DevicePermute'

* Rename 'GridwisePermute' to 'GridwiseCopy'

* Check tensor descriptor dimensions in 'GridwiseElementwise_1D'

* Add missing include directive

* Add 'BlockSize' parameter to 'DevicePermute'

* Remove no-longer used method

* Add 'BlockToTileMap' for 'GridwiseCopy'

* Use the normal Block2TileMap convention

* Rename 'BlockToTileMap' as 'Block2TileMap'

* Fix most of compilation errors

* Let 'Block2TileMap' map block to 2d coordinate

* Allow data transfer in 'GridwiseCopy'

* Fix wrong output descriptor for 2nd blockwise copy

* Rename 'GridwiseCopy' as 'GridwisePermute'

* Remove '1d' in identifiers

* Remove commented-out codes

* Remove 'MPerThread' template parameter

* Seperate template parameters

* Unify variable namming convention

* Use more verbose way to create expressions

* Add template parameter 'InBlockLdsExtraW'

* Release the constraint on In/OutGridDesc

* Use date type directly as template argument

* Re-arrange template arguments for blockwise copy

* Remove no-longer used template parameters

* Embed layout in the variable names

* Add GridwisePermute::CheckValidity()

* Extract local types as template parameters

* Rename local type alias

* Add more template parameters (vector width related)

* Calculate new SrcVectorDim/DstVectorDim after merge descriptor dimensions

* Fill tensor values start from 1

* Re-formate example code

* Avoid too-large block id

* Add comment

* Make sure 'SrcVectorDim' is not same as 'DstVectorDim'

* Add check for the 'VectorDim' & 'ScalarPerVector' template params

* Let 'DstVectorDim' equals 'SrcVectorDim' after transpose out grid desc

* Remove no-longer used template parameter 'NPerBlock'

* Fix wrong descriptor creation logics

* Specify problem in each examples

* Use better example name

* Add new example 'example_permute_NxHxW_fp32'

* Add example for demonstrating bundle multiple elems in tensor

* Add support to permute multiple elements together

* Change the default problem size

* Add span<> class template

* Use span<> to generalize check_err() interface

* Fix ambiguous ctor call

* Avoid create necessary objects

* Use helper functions to simplify example code

* Add example for 4xfp16 permute

* Disable failed-to-compile example

* Add check for the NUM_ELEMS_IN_BUNDLE

* Remove redundant parameter in helper lambda function

* Add check for the input tensor type's byte-size

* Check scalar-per-vector with padded length

* Use more verbose name to avoid name collision

* Use fixed 'VectorDim' & 'ScalarPerVector' for LDS

* Embed shape info in name of descriptor constructor

* Rename example folder '36_permute' into '37_permute'

* Avoid using too-large LDS in kernel code

* Remove redundant example

* Usw switch() to group similar codes

* Add const to the span<> type arguement

* Simply initialize tensor with floating point values

* Use fp16 as data type in all examples

* Enlarge tensor size in example

* Enalrge N-dim in example

* Add check for the bundled type in example

* Use more stricter error threshold

* Remove global load/store loop in kernel code

* Measure execution time by default

* Use faster device op config for example 'NxHxW_fp16'

* Use faster device op config for example '1xHxW_fp16'

* Use faster device op config for example 'HxWx4_fp16'

* Remove cmd arg parsing logics

* Rename functions

* Extract bundle permutation logic out

* Simplify permute bundle example

* Add Tensor<>::GetElementSpaceSizeInBytes()

* Add Tensor<>::data()

* Use new methods to simplify code

* Use type alias to replace duplicated code

* Use existing method to shorten code

* Allow FillUniformDistribution accept range arugment

* Intialize random values in range

* Add Tensor<>::size()

* Use more meaningful names in permute bundle example

* Use more meaningful names in permute element examples

* Use rangified copy() to copy elements

* Use function return value directly to eliminate variables

* Add to_array() conversion tool to eliminate more variables

* Add Tensor<>::AsSpan<>() to create view of tensor values

* Use AsSpan() to shorten check_err() calls

* Remove no-longer-used 'using' directives

* Move 'using' directive to proper code position

* Remove redudant variables

* Remove useless static_assert()

* Add check for range types

* Declare variable right before first use

* Move long return type as tailing return type

* Add BaseInvokerCRTP<> class template to generate method

* Create new base type for 'DervicePermute' implementations

* Move 'NumDim' template param to the first

* Rename 'DevicePermute' to 'DevicePermuteImpl'

* Add 'noexcept' specifier to CRTP generated method

* Move 'Block2TileMap' definition into 'GridwisePermute'

* Use type alias to reduce code

* Unify naming style in 'DevicePermute'

* Add comments in 'GridwisePermute'

* Rename permute example folder

* Use std::cerr to report error

* Use larger shape in examples

* Rename '38_permute' to '39_permute'

* Make sure we use unsigned type for shape & indices

* Remove opt-ed out assertion

* Remove template BaseInvokerCRTP<>

example/39_permute/CMakeLists.txt

+add_custom_target(example_permute)
+
+add_example_executable(example_permute_1xHxW_fp16 permute_1xHxW_fp16.cpp)
+add_example_executable(example_permute_NxHxW_fp16 permute_NxHxW_fp16.cpp)
+add_example_executable(example_permute_HxWx4_fp16 permute_HxWx4_fp16.cpp)
+
+add_dependencies(example_permute example_permute_1xHxW_fp16)
+add_dependencies(example_permute example_permute_NxHxW_fp16)
+add_dependencies(example_permute example_permute_HxWx4_fp16)

example/39_permute/common.hpp

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#pragma once
+
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <cstdlib>
+#include <cstring>
+#include <iostream>
+#include <iterator>
+#include <numeric>
+#include <type_traits>
+#include <utility>
+
+#include "ck/ck.hpp"
+#include "ck/tensor_operation/gpu/device/impl/device_permute_impl.hpp"
+#include "ck/tensor_operation/gpu/element/binary_element_wise_operation.hpp"
+#include "ck/utility/type.hpp"
+
+#include "ck/library/utility/check_err.hpp"
+#include "ck/library/utility/device_memory.hpp"
+#include "ck/library/utility/fill.hpp"
+#include "ck/library/utility/host_tensor.hpp"
+#include "ck/library/utility/host_tensor_generator.hpp"
+
+using F16 = ck::half_t;
+using F32 = float;
+using F64 = double;
+
+struct Problem final
+{
+    static constexpr std::size_t NumDim = 3;
+
+    using Shape = std::array<std::size_t, NumDim>;
+    using Axes  = Shape;
+
+    Problem() = delete;
+
+    explicit Problem(const Shape& default_shape, const Axes& default_axes)
+        : shape(default_shape), axes(default_axes)
+    {
+    }
+
+    Shape shape;
+    Axes axes;
+};
+
+template <ck::index_t... Is>
+using S = ck::Sequence<Is...>;
+
+using PassThrough = ck::tensor_operation::element_wise::PassThrough;
+
+namespace detail {
+
+template <typename Array, std::size_t Difference>
+struct enlarge_array_size;
+
+template <typename T, std::size_t Size, std::size_t Difference>
+struct enlarge_array_size<std::array<T, Size>, Difference>
+{
+    using type = std::array<T, Size + Difference>;
+};
+
+template <typename Array, std::size_t Difference>
+using enlarge_array_size_t = typename enlarge_array_size<Array, Difference>::type;
+
+template <typename Array>
+struct get_array_size;
+
+template <typename T, std::size_t Size>
+struct get_array_size<std::array<T, Size>> : std::integral_constant<std::size_t, Size>
+{
+};
+
+template <typename Array>
+inline constexpr std::size_t get_array_size_v = get_array_size<Array>::value;
+
+template <typename T, typename = void>
+struct is_iterator : std::false_type
+{
+};
+
+template <typename T>
+struct is_iterator<T,
+                   std::void_t<decltype(*std::declval<T>()),
+                               decltype(++std::declval<std::add_lvalue_reference_t<T>>()),
+                               decltype(std::declval<std::add_lvalue_reference_t<T>>()++)>>
+    : std::true_type
+{
+};
+
+template <typename T>
+inline constexpr bool is_iterator_v = is_iterator<T>::value;
+
+struct Placeholder final
+{
+    template <typename T>
+    constexpr inline operator T() const noexcept;
+};
+
+template <typename Iterator, typename = void>
+struct is_output_iterator : std::false_type
+{
+};
+
+template <typename Iterator>
+struct is_output_iterator<
+    Iterator,
+    std::void_t<decltype(*std::declval<Iterator>() = std::declval<Placeholder>())>>
+    : std::bool_constant<is_iterator_v<Iterator>>
+{
+};
+
+template <typename T>
+inline constexpr bool is_output_iterator_v = is_output_iterator<T>::value;
+
+template <typename Iterator, typename = void>
+struct is_bidirectional_iterator : std::false_type
+{
+};
+
+template <typename Iterator>
+struct is_bidirectional_iterator<
+    Iterator,
+    std::void_t<decltype(--std::declval<std::add_lvalue_reference_t<Iterator>>()),
+                decltype(std::declval<std::add_lvalue_reference_t<Iterator>>()--)>>
+    : std::bool_constant<is_iterator_v<Iterator>>
+{
+};
+
+template <typename Iterator>
+inline constexpr bool is_bidirectional_iterator_v = is_bidirectional_iterator<Iterator>::value;
+
+template <typename Iterator, typename = void>
+struct is_random_access_iterator : std::false_type
+{
+};
+
+template <typename Iterator>
+struct is_random_access_iterator<Iterator,
+                                 std::void_t<decltype(std::declval<Iterator>() + 1),
+                                             decltype(std::declval<Iterator>() - 1),
+                                             decltype(std::declval<Iterator>()[1])>>
+    : std::bool_constant<is_iterator_v<Iterator>>
+{
+};
+
+template <typename Iterator>
+inline constexpr bool is_random_access_iterator_v = is_random_access_iterator<Iterator>::value;
+
+template <typename T, typename = void>
+struct is_range : std::false_type
+{
+};
+
+template <typename T>
+struct is_range<T,
+                std::void_t<decltype(begin(std::declval<T>())),
+                            decltype(end(std::declval<T>())),
+                            decltype(begin(std::declval<T>()) != end(std::declval<T>()))>>
+    : std::bool_constant<is_iterator_v<ck::remove_cvref_t<decltype(begin(std::declval<T>()))>>>
+{
+};
+
+template <typename T>
+inline constexpr bool is_range_v = is_range<T>::value;
+
+template <typename Range, typename = void>
+struct is_sized_range : std::false_type
+{
+};
+
+template <typename Range>
+struct is_sized_range<Range, std::void_t<decltype(size(std::declval<Range>()))>>
+    : std::bool_constant<is_range_v<Range>>
+{
+};
+
+template <typename Range>
+inline constexpr bool is_sized_range_v = is_sized_range<Range>::value;
+
+template <typename Range, typename = void>
+struct is_bidirectional_range : std::false_type
+{
+};
+
+template <typename Range>
+struct is_bidirectional_range<Range, std::void_t<>>
+    : std::bool_constant<
+          is_range_v<Range> &&
+          is_bidirectional_iterator_v<ck::remove_cvref_t<decltype(begin(std::declval<Range>()))>>>
+{
+};
+
+template <typename Range>
+inline constexpr bool is_bidirectional_range_v = is_bidirectional_range<Range>::value;
+
+template <typename Range, typename = void>
+struct is_random_access_range : std::false_type
+{
+};
+
+template <typename Range>
+struct is_random_access_range<Range, std::void_t<>>
+    : std::bool_constant<
+          is_range_v<Range> &&
+          is_random_access_iterator_v<ck::remove_cvref_t<decltype(begin(std::declval<Range>()))>>>
+{
+};
+
+template <typename Range>
+inline constexpr bool is_random_access_range_v = is_random_access_range<Range>::value;
+
+template <typename Range>
+class to_array_proxy
+{
+    static_assert(is_range_v<Range>);
+
+    public:
+    explicit to_array_proxy(const Range& source) noexcept : source_(source) {}
+
+    template <typename T, std::size_t Size>
+    operator std::array<T, Size>() const
+    {
+        std::array<T, Size> destination;
+
+        std::copy_n(std::begin(source_),
+                    std::min<std::size_t>(Size, std::size(source_)),
+                    std::begin(destination));
+
+        return destination;
+    }
+
+    private:
+    const Range& source_;
+};
+
+} // namespace detail
+
+template <typename Range>
+inline auto to_array(Range& range) noexcept
+    -> std::enable_if_t<detail::is_range_v<Range>,
+                        detail::to_array_proxy<ck::remove_cvref_t<Range>>>
+{
+    return detail::to_array_proxy<ck::remove_cvref_t<Range>>{range};
+}
+
+namespace ranges {
+template <typename InputRange, typename OutputIterator>
+inline auto copy(InputRange&& range, OutputIterator iter)
+    -> decltype(std::copy(std::begin(std::forward<InputRange>(range)),
+                          std::end(std::forward<InputRange>(range)),
+                          iter))
+{
+    return std::copy(std::begin(std::forward<InputRange>(range)),
+                     std::end(std::forward<InputRange>(range)),
+                     iter);
+}
+} // namespace ranges
+
+template <typename Axes>
+inline auto is_valid_axes(const Axes& axes)
+    -> std::enable_if_t<detail::is_random_access_range_v<Axes>, bool>
+{
+    using std::empty;
+    if(empty(axes))
+    {
+        return false;
+    }
+
+    using std::begin, std::end;
+    std::vector<std::size_t> sorted_axes(begin(axes), end(axes));
+
+    std::sort(begin(sorted_axes), end(sorted_axes));
+    const auto last = std::unique(begin(sorted_axes), end(sorted_axes));
+
+    return (last == end(sorted_axes)) && (*begin(sorted_axes) == 0) &&
+           (*std::prev(last) == size(axes) - 1);
+}
+
+template <typename Shape>
+inline auto is_valid_shape(const Shape& shape) -> std::enable_if_t<detail::is_range_v<Shape>, bool>
+{
+    static_assert(std::is_unsigned_v<ck::remove_cvref_t<decltype(*std::begin(shape))>>);
+
+    using std::begin, std::end;
+    using std::empty;
+    return !empty(shape) && std::all_of(begin(shape), end(shape), [](auto dim) { return 0 < dim; });
+}
+
+template <typename Shape, typename Indices>
+inline auto is_valid_indices(const Shape& shape, const Indices& indices)
+    -> std::enable_if_t<detail::is_sized_range_v<Shape> && detail::is_sized_range_v<Indices>, bool>
+{
+    static_assert(std::is_unsigned_v<ck::remove_cvref_t<decltype(*std::begin(indices))>>);
+
+    if(!is_valid_shape(shape))
+    {
+        return false;
+    }
+
+    using std::empty;
+    if(empty(indices))
+    {
+        return false;
+    }
+
+    using std::size;
+    if(size(shape) != size(indices))
+    {
+        return false;
+    }
+
+    using std::begin, std::end;
+
+    auto dim = begin(shape);
+    auto idx = begin(indices);
+    for(; dim != end(shape) && idx != end(indices); ++dim, ++idx)
+    {
+        if(*dim <= *idx)
+        {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+template <std::size_t Size>
+std::array<std::size_t, Size> transpose(const std::array<std::size_t, Size>& shape,
+                                        const std::array<std::size_t, Size>& axes)
+{
+    assert(is_valid_shape(shape) && is_valid_axes(axes));
+
+    std::array<std::size_t, Size> transposed;
+    auto iter = std::begin(transposed);
+    for(const auto axis : axes)
+    {
+        *iter++ = shape[axis];
+    }
+
+    return transposed;
+}
+
+auto extend_shape(const Problem::Shape& shape, std::size_t new_dim)
+{
+    detail::enlarge_array_size_t<Problem::Shape, 1> extended_shape;
+
+    using std::begin, std::end;
+
+    std::copy(begin(shape), end(shape), begin(extended_shape));
+    extended_shape.back() = new_dim;
+
+    return extended_shape;
+}
+
+auto extend_axes(const Problem::Axes& axes)
+{
+    detail::enlarge_array_size_t<Problem::Axes, 1> extended_axes;
+
+    using std::begin, std::end;
+
+    std::copy(begin(axes), end(axes), begin(extended_axes));
+    extended_axes.back() = detail::get_array_size_v<Problem::Axes>;
+
+    return extended_axes;
+}
+
+template <typename Shape, typename Indices>
+auto advance_indices(const Shape& shape, Indices& indices) -> std::enable_if_t<
+    detail::is_bidirectional_range_v<Shape> && detail::is_sized_range_v<Shape> &&
+        detail::is_bidirectional_range_v<Indices> && detail::is_sized_range_v<Indices>,
+    bool>
+{
+    using std::size;
+    if(!(is_valid_shape(shape) && is_valid_indices(shape, indices) && size(shape) == size(indices)))
+    {
+        return false;
+    }
+
+    bool carry = true;
+
+    using std::rbegin, std::rend;
+    auto dim = rbegin(shape);
+    auto idx = rbegin(indices);
+    for(; carry && dim != rend(shape) && idx != rend(indices); ++dim, ++idx)
+    {
+        *idx  = (*idx + carry);
+        carry = ((*idx == *dim) ? (*idx = 0, true) : false);
+    }
+
+    return !carry;
+}
+
+template <typename Src, typename Axes, typename Functor, typename Dest>
+auto host_permute(const Tensor<Src>& src, const Axes& axes, Functor functor, Tensor<Dest>& dest)
+    -> std::enable_if_t<detail::is_random_access_range_v<Axes> && detail::is_sized_range_v<Axes> &&
+                            std::is_invocable_v<Functor,
+                                                std::add_lvalue_reference_t<Dest>,
+                                                std::add_lvalue_reference_t<Src>>,
+                        bool>
+{
+    const auto& shape            = src.mDesc.GetLengths();
+    const auto& transposed_shape = dest.mDesc.GetLengths();
+    if(!(is_valid_shape(shape) && is_valid_shape(transposed_shape)))
+    {
+        return false;
+    }
+
+    using std::size;
+    if(!is_valid_axes(axes))
+    {
+        return false;
+    }
+
+    static_assert(detail::is_sized_range_v<ck::remove_cvref_t<decltype(shape)>> &&
+                  detail::is_sized_range_v<ck::remove_cvref_t<decltype(transposed_shape)>>);
+
+    if(size(shape) != size(transposed_shape))
+    {
+        return false;
+    }
+
+    static_assert(detail::is_random_access_range_v<ck::remove_cvref_t<decltype(shape)>> &&
+                  detail::is_random_access_range_v<ck::remove_cvref_t<decltype(transposed_shape)>>);
+    {
+        for(std::size_t idx = 0; idx < size(shape); ++idx)
+        {
+            if(transposed_shape[idx] != shape[axes[idx]])
+            {
+                return false;
+            }
+        }
+    }
+
+    std::vector<std::size_t> indices(size(shape), 0);
+    if(!is_valid_indices(shape, indices))
+    {
+        return false;
+    }
+
+    switch(size(shape))
+    {
+    case 3: {
+        do
+        {
+            Dest output = 0;
+            functor(output, src(indices[0], indices[1], indices[2]));
+            dest(indices[axes[0]], indices[axes[1]], indices[axes[2]]) = output;
+        } while(advance_indices(shape, indices));
+    }
+    break;
+    case 4: {
+        do
+        {
+            Dest output = 0;
+            functor(output, src(indices[0], indices[1], indices[2], indices[3]));
+            dest(indices[axes[0]], indices[axes[1]], indices[axes[2]], indices[axes[3]]) = output;
+        } while(advance_indices(shape, indices));
+    }
+    break;
+    default: return false;
+    }
+
+    return true;
+}

example/39_permute/permute_1xHxW_fp16.cpp

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#include "common.hpp"
+
+using InDataType  = F16;
+using OutDataType = F16;
+
+// clang-format off
+using DevicePermuteInstance = ck::tensor_operation::device::DevicePermuteImpl
+// ######| NumDim|     InData|     OutData| Elementwise| Block|  NPer|  HPer|  WPer|   InBlock|      InBlockTransfer|           InBlockTransfer|       Src|       Dst|             Src|             Dst|
+// ######|       |       Type|        Type|   Operation|  Size| Block| Block| Block| LdsExtraW| ThreadClusterLengths| ThreadClusterArrangeOrder| VectorDim| VectorDim| ScalarPerVector| ScalarPerVector|
+// ######|       |           |            |            |      |      |      |      |          |                     |                          |          |          |                |                |
+// ######|       |           |            |            |      |      |      |      |          |                     |                          |          |          |                |                |
+         <      3, InDataType, OutDataType, PassThrough,   256,     1,    32,    32,         3,         S<1, 32,  8>,                S<0, 1, 2>,         2,         1,               2,               1>;
+// clang-format on
+
+#include "run_permute_element_example.inc"
+
+int main() { return !run_permute_element_example({1, 32000, 80}, {0, 2, 1}); }

example/39_permute/permute_HxWx4_fp16.cpp

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#include "common.hpp"
+
+using DataType   = F16;
+using BundleType = F64;
+
+static_assert(sizeof(BundleType) % sizeof(DataType) == 0);
+
+// clang-format off
+using DevicePermuteInstance = ck::tensor_operation::device::DevicePermuteImpl
+// ######| NumDim|     InData|     OutData| Elementwise| Block|  NPer|  HPer|  WPer|   InBlock|      InBlockTransfer|           InBlockTransfer|       Src|       Dst|             Src|             Dst|
+// ######|       |       Type|        Type|   Operation|  Size| Block| Block| Block| LdsExtraW| ThreadClusterLengths| ThreadClusterArrangeOrder| VectorDim| VectorDim| ScalarPerVector| ScalarPerVector|
+// ######|       |           |            |            |      |      |      |      |          |                     |                          |          |          |                |                |
+// ######|       |           |            |            |      |      |      |      |          |                     |                          |          |          |                |                |
+         <       3, BundleType, BundleType, PassThrough,   256,     1,    32,    32,         5,         S<1, 32,  8>,                S<0, 1, 2>,         2,         1,               4,               1>;
+// clang-format on
+
+#include "run_permute_bundle_example.inc"
+
+int main() { return !run_permute_bundle_example({1, 80, 32000}, {0, 2, 1}); }

example/39_permute/permute_NxHxW_fp16.cpp

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#include "common.hpp"
+
+using InDataType  = F16;
+using OutDataType = F16;
+
+// clang-format off
+using DevicePermuteInstance = ck::tensor_operation::device::DevicePermuteImpl
+// ######| NumDim|     InData|     OutData| Elementwise| Block|  NPer|  HPer|  WPer|   InBlock|      InBlockTransfer|           InBlockTransfer|       Src|       Dst|             Src|             Dst|
+// ######|       |       Type|        Type|   Operation|  Size| Block| Block| Block| LdsExtraW| ThreadClusterLengths| ThreadClusterArrangeOrder| VectorDim| VectorDim| ScalarPerVector| ScalarPerVector|
+// ######|       |           |            |            |      |      |      |      |          |                     |                          |          |          |                |                |
+// ######|       |           |            |            |      |      |      |      |          |                     |                          |          |          |                |                |
+         <      3, InDataType, OutDataType, PassThrough,   128,     4,    16,     8,         6,          S<2, 16, 4>,                S<0, 1, 2>,         2,         1,               2,               1>;
+// clang-format on
+
+#include "run_permute_element_example.inc"
+
+int main() { return !run_permute_element_example({121, 768, 80}, {0, 2, 1}); }

example/39_permute/run_permute_bundle_example.inc

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#pragma once
+
+bool run_permute_bundle(const Problem& problem)
+{
+    const auto& input_bundle_shape = problem.shape;
+    const auto& input_bundle_axes  = problem.axes;
+
+    const auto output_bundle_shape = transpose(input_bundle_shape, input_bundle_axes);
+
+    Tensor<BundleType> input_bundle_tensor(input_bundle_shape);
+    Tensor<BundleType> output_bundle_tensor(output_bundle_shape);
+
+    // initialize tensor by assigning DataType values
+    ck::utils::FillUniformDistribution<DataType>{-1.f, 1.f}(input_bundle_tensor.AsSpan<DataType>());
+
+    DeviceMem input_device_buf(input_bundle_tensor.GetElementSpaceSizeInBytes());
+    DeviceMem output_device_buf(output_bundle_tensor.GetElementSpaceSizeInBytes());
+
+    using std::data;
+    input_device_buf.ToDevice(data(input_bundle_tensor));
+
+    static_assert(std::is_default_constructible_v<DevicePermuteInstance>);
+
+    auto permute  = DevicePermuteInstance{};
+    auto argument = permute.MakeArgument(to_array(input_bundle_shape),
+                                         to_array(input_bundle_tensor.GetStrides()),
+                                         to_array(output_bundle_shape),
+                                         to_array(output_bundle_tensor.GetStrides()),
+                                         input_device_buf.GetDeviceBuffer(),
+                                         output_device_buf.GetDeviceBuffer(),
+                                         PassThrough{});
+
+    if(!permute.IsSupportedArgument(argument))
+    {
+        std::cerr << "The runtime parameters seems not supported by the device instance, exiting!"
+                  << std::endl;
+        return false;
+    };
+
+    auto invoker   = permute.MakeInvoker();
+    float ave_time = invoker.Run(argument, StreamConfig{nullptr, true});
+
+    std::cout << "Perf: " << ave_time << " ms" << std::endl;
+
+    output_device_buf.FromDevice(data(output_bundle_tensor));
+
+    constexpr std::size_t NumElemsInBundle = sizeof(BundleType) / sizeof(DataType);
+
+    // extend tensor shape from [N, H, W] to [N, H, W, NumElemsInBundle]
+    //               axes  from [0, 2, 1] to [0, 2, 1, 3]
+    const auto input_shape = extend_shape(input_bundle_shape, NumElemsInBundle);
+    const auto input_axes  = extend_axes(input_bundle_axes);
+
+    using std::begin;
+
+    Tensor<DataType> input_tensor(input_shape);
+    ranges::copy(input_bundle_tensor.AsSpan<const DataType>(), begin(input_tensor));
+
+    Tensor<DataType> output_tensor(transpose(input_shape, input_axes));
+    if(!host_permute(input_tensor, input_axes, PassThrough{}, output_tensor))
+    {
+        return false;
+    }
+
+    return ck::utils::check_err(output_bundle_tensor.AsSpan<const DataType>(),
+                                output_tensor.AsSpan<const DataType>(),
+                                "Error: incorrect results in output tensor",
+                                1e-6,
+                                1e-6);
+}
+
+bool run_permute_bundle_example(const Problem::Shape& shape, const Problem::Axes& axes)
+{
+    return run_permute_bundle(Problem{shape, axes});
+}

example/39_permute/run_permute_element_example.inc

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#pragma once
+
+bool run_permute_element(const Problem& problem)
+{
+    const auto& input_shape = problem.shape;
+    const auto& input_axes  = problem.axes;
+
+    const auto output_shape = transpose(input_shape, input_axes);
+
+    Tensor<InDataType> input_tensor(input_shape);
+    Tensor<OutDataType> output_tensor(output_shape);
+
+    ck::utils::FillUniformDistribution<InDataType>{-1.f, 1.f}(input_tensor);
+
+    DeviceMem input_device_buf(input_tensor.GetElementSpaceSizeInBytes());
+    DeviceMem output_device_buf(output_tensor.GetElementSpaceSizeInBytes());
+
+    using std::data;
+    input_device_buf.ToDevice(data(input_tensor));
+
+    static_assert(std::is_default_constructible_v<DevicePermuteInstance>);
+
+    auto permute  = DevicePermuteInstance{};
+    auto argument = permute.MakeArgument(to_array(input_shape),
+                                         to_array(input_tensor.GetStrides()),
+                                         to_array(output_shape),
+                                         to_array(output_tensor.GetStrides()),
+                                         input_device_buf.GetDeviceBuffer(),
+                                         output_device_buf.GetDeviceBuffer(),
+                                         PassThrough{});
+
+    if(!permute.IsSupportedArgument(argument))
+    {
+        std::cerr << "The runtime parameters seems not supported by the device instance, exiting!"
+                  << std::endl;
+        return false;
+    };
+
+    auto invoker   = permute.MakeInvoker();
+    float ave_time = invoker.Run(argument, StreamConfig{nullptr, true});
+
+    std::cout << "Perf: " << ave_time << " ms" << std::endl;
+
+    output_device_buf.FromDevice(data(output_tensor));
+
+    Tensor<OutDataType> output_tensor_host(output_shape);
+    if(!host_permute(input_tensor, input_axes, PassThrough{}, output_tensor_host))
+    {
+        return false;
+    }
+
+    return ck::utils::check_err(output_tensor.AsSpan<const OutDataType>(),
+                                output_tensor_host.AsSpan<const OutDataType>(),
+                                "Error: incorrect results in output tensor",
+                                1e-6,
+                                1e-6);
+}
+
+bool run_permute_element_example(const Problem::Shape& shape, const Problem::Axes& axes)
+{
+    return run_permute_element(Problem{shape, axes});
+}

include/ck/tensor_operation/gpu/device/device_base.hpp

@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include <cmath>
 #include <string>
 
 #include "ck/stream_config.hpp"

include/ck/tensor_operation/gpu/device/device_elementwise.hpp

@@ -222,14 +222,9 @@ struct DeviceElementwise
         }
     };
 
-    bool IsSupportedArgument(const BaseArgument* p_arg) override
+    static bool IsSupportedArgument(const Argument& arg)
     {
-        const Argument* pArg = dynamic_cast<const Argument*>(p_arg);
-
-        if(pArg == nullptr)
-            return false;
-
-        if(pArg->lengths_.back() % MPerThread != 0)
+        if(arg.lengths_.back() % MPerThread != 0)
             return false;
 
         auto IsScalarPerVectorValid = [&](const std::array<index_t, NumDim>& lengths,
@@ -247,19 +242,40 @@ struct DeviceElementwise
         bool valid = true;
         static_for<0, NumInput, 1>{}([&](auto I) {
             if(!IsScalarPerVectorValid(
-                   pArg->lengths_, pArg->inStridesArray_[I.value], InScalarPerVectorSeq::At(I)))
+                   arg.lengths_, arg.inStridesArray_[I.value], InScalarPerVectorSeq::At(I)))
                 valid = false;
         });
 
         static_for<0, NumOutput, 1>{}([&](auto I) {
             if(!IsScalarPerVectorValid(
-                   pArg->lengths_, pArg->outStridesArray_[I.value], OutScalarPerVectorSeq::At(I)))
+                   arg.lengths_, arg.outStridesArray_[I.value], OutScalarPerVectorSeq::At(I)))
                 valid = false;
         });
 
         return valid;
     };
 
+    bool IsSupportedArgument(const BaseArgument* p_arg) override
+    {
+        return IsSupportedArgument(*dynamic_cast<const Argument*>(p_arg));
+    }
+
+    static auto
+    MakeArgument(const std::array<index_t, NumDim> lengths,
+                 const std::array<std::array<index_t, NumDim>, NumInput> inStridesArray,
+                 const std::array<std::array<index_t, NumDim>, NumOutput> outStridesArray,
+                 const std::array<const void*, NumInput> in_dev_buffers,
+                 const std::array<void*, NumOutput> out_dev_buffers,
+                 ElementwiseOperation elementwise_op)
+    {
+        return Argument{lengths,
+                        inStridesArray,
+                        outStridesArray,
+                        in_dev_buffers,
+                        out_dev_buffers,
+                        elementwise_op};
+    }
+
     std::unique_ptr<BaseArgument>
     MakeArgumentPointer(const std::array<index_t, NumDim> lengths,
                         const std::array<std::array<index_t, NumDim>, NumInput> inStridesArray,

include/ck/tensor_operation/gpu/device/device_permute.hpp

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#pragma once
+
+#include <array>
+#include <cmath>
+#include <memory>
+#include <type_traits>
+
+#include "ck/tensor_operation/gpu/device/device_base.hpp"
+
+namespace ck {
+namespace tensor_operation {
+namespace device {
+
+template <index_t NumDim, typename InDataType, typename OutDataType, typename ElementwiseOperation>
+struct DevicePermute : BaseOperator
+{
+    using Lengths = std::array<index_t, NumDim>;
+    using Strides = Lengths;
+
+    virtual std::unique_ptr<BaseArgument>
+    MakeArgumentPointer(const Lengths& in_lengths,
+                        const Strides& in_strides,
+                        const Lengths& out_lengths,
+                        const Strides& out_strides,
+                        const void* in_dev_buffer,
+                        void* out_dev_buffer,
+                        ElementwiseOperation elementwise_op) = 0;
+
+    virtual std::unique_ptr<BaseInvoker> MakeInvokerPointer() = 0;
+};
+
+} // namespace device
+} // namespace tensor_operation
+} // namespace ck

include/ck/tensor_operation/gpu/device/impl/device_permute_impl.hpp

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#pragma once
+
+#include <array>
+#include <memory>
+#include <utility>
+
+#include "ck/utility/math.hpp"
+#include "ck/utility/sequence.hpp"
+#include "ck/tensor_operation/gpu/device/device_base.hpp"
+#include "ck/tensor_operation/gpu/device/device_permute.hpp"
+#include "ck/tensor_operation/gpu/device/matrix_padder.hpp"
+#include "ck/tensor_operation/gpu/grid/gridwise_permute.hpp"
+#include "ck/tensor_description/tensor_descriptor_helper.hpp"
+
+#include "ck/host_utility/kernel_launch.hpp"
+
+namespace ck {
+namespace tensor_operation {
+namespace device {
+
+// Swap last 2 dimensions
+// input shape: [d[0], d[1], d[2], ..., d[NumDim-3], d[NumDim-2], d[NumDim-1]]
+//                                                                ^^^^^^^^^^^
+// output shape: [d[0], d[1], d[2], ..., d[NumDim-3], d[NumDim-1], d[NumDim-2]]
+//                                                    ^^^^^^^^^^^
+template <index_t NumDim,
+          typename InDataType,
+          typename OutDataType,
+          typename ElementwiseOperation,
+          index_t BlockSize,
+          index_t NPerBlock,
+          index_t HPerBlock,
+          index_t WPerBlock,
+          index_t InBlockLdsExtraW,
+          typename InBlockTransferThreadClusterLengths,
+          typename InBlockTransferThreadClusterArrangeOrder,
+          index_t SrcVectorDim,
+          index_t DstVectorDim,
+          index_t SrcScalarPerVector,
+          index_t DstScalarPerVector>
+struct DevicePermuteImpl : DevicePermute<NumDim, InDataType, OutDataType, ElementwiseOperation>
+{
+    using BaseType = DevicePermute<NumDim, InDataType, OutDataType, ElementwiseOperation>;
+    using typename BaseType::Lengths;
+    using typename BaseType::Strides;
+
+    static_assert(3 <= NumDim, "Only accept at least 3D dimension tensor");
+    static_assert((NumDim - 2) <= SrcVectorDim && SrcVectorDim < NumDim);
+    static_assert((NumDim - 2) <= DstVectorDim && DstVectorDim < NumDim);
+    static_assert(SrcVectorDim != DstVectorDim);
+
+    template <index_t N = NumDim>
+    static auto ConvertArrayToTuple(const std::array<index_t, NumDim>& array)
+    {
+        static_assert(1 <= N && N <= NumDim);
+
+        return generate_tuple([&](auto I) { return array[I]; }, Number<N>{});
+    }
+
+    static auto MakeDescriptor_N_H_W(const Lengths& lengths, const Strides& stride)
+    {
+        // create nd descriptor, shape: [d[0], d[1], d[2], ..., d[NumDim-3], d[NumDim-2],
+        // d[NumDim-1]]
+        const auto desc =
+            make_naive_tensor_descriptor(ConvertArrayToTuple(lengths), ConvertArrayToTuple(stride));
+
+        // merge nd to 3d descriptor, shape: [(d[0] * d[1] * d[2] * ... * d[NumDim-3]), d[NumDim-2],
+        // d[NumDim-1]]
+        //                                   => [N, H, W]
+        const index_t H       = *std::next(rbegin(lengths));
+        const index_t W       = *rbegin(lengths);
+        const auto desc_n_h_w = transform_tensor_descriptor(
+            desc,
+            make_tuple(make_merge_transform(ConvertArrayToTuple<NumDim - 2>(lengths)),
+                       make_pass_through_transform(H),
+                       make_pass_through_transform(W)),
+            make_tuple(generate_sequence_v2([&](auto I) { return I; }, Number<NumDim - 2>{}),
+                       Sequence<NumDim - 2>{},
+                       Sequence<NumDim - 1>{}),
+            make_tuple(Sequence<0>{}, Sequence<1>{}, Sequence<2>{}));
+
+        return PadTensorDescriptor(
+            desc_n_h_w, make_tuple(NPerBlock, HPerBlock, WPerBlock), Sequence<true, true, true>{});
+    }
+
+    using InGridDesc  = decltype(MakeDescriptor_N_H_W({1, 1}, {1, 1}));
+    using OutGridDesc = InGridDesc;
+
+    using GridwisePermute = GridwisePermute<
+        InGridDesc,
+        OutGridDesc,
+        InDataType,
+        OutDataType,
+        ElementwiseOperation,
+        BlockSize,
+        NPerBlock,
+        HPerBlock,
+        WPerBlock,
+        InBlockLdsExtraW,
+        InBlockTransferThreadClusterLengths,
+        InBlockTransferThreadClusterArrangeOrder,
+        SrcVectorDim - (NumDim - 3), // calculate new SrcVectorDim for the merged descriptor
+        DstVectorDim - (NumDim - 3), // calculate new DstVectorDim for the merged descriptor
+        SrcScalarPerVector,
+        DstScalarPerVector>;
+
+    using Block2TileMap = typename GridwisePermute::DefaultBlock2TileMap;
+
+    struct Argument : public BaseArgument
+    {
+        Argument(const Lengths& in_lengths,
+                 const Strides& in_strides,
+                 const Lengths& out_lengths,
+                 const Strides& out_strides,
+                 const void* in_dev_buffer,
+                 void* out_dev_buffer,
+                 ElementwiseOperation elementwise_op)
+            : in_dev_buffer_(static_cast<const InDataType*>(in_dev_buffer)),
+              out_dev_buffer_(static_cast<OutDataType*>(out_dev_buffer)),
+              in_grid_desc_(MakeDescriptor_N_H_W(in_lengths, in_strides)),
+              out_grid_desc_(MakeDescriptor_N_H_W(out_lengths, out_strides)),
+              in_lengths_(in_lengths),
+              in_strides_(in_strides),
+              out_lengths_(out_lengths),
+              out_strides_(out_strides),
+              elementwise_op_(elementwise_op),
+              block_2_tile_map_(GridwisePermute::MakeDefaultBlock2TileMap(in_grid_desc_))
+        {
+        }
+
+        const InDataType* in_dev_buffer_;
+        OutDataType* out_dev_buffer_;
+        InGridDesc in_grid_desc_;
+        OutGridDesc out_grid_desc_;
+
+        Lengths in_lengths_;
+        Strides in_strides_;
+        Lengths out_lengths_;
+        Strides out_strides_;
+
+        ElementwiseOperation elementwise_op_;
+
+        Block2TileMap block_2_tile_map_;
+    };
+
+    struct Invoker : BaseInvoker
+    {
+        static float Run(const Argument& arg, const StreamConfig& stream_config = StreamConfig{})
+        {
+            const index_t grid_size = arg.block_2_tile_map_.CalculateGridSize(arg.in_grid_desc_);
+
+            const auto kernel = kernel_nd_permute<GridwisePermute,
+                                                  InGridDesc,
+                                                  OutGridDesc,
+                                                  InDataType,
+                                                  OutDataType,
+                                                  ElementwiseOperation,
+                                                  Block2TileMap>;
+
+            float elapsed_time = launch_and_time_kernel(stream_config,
+                                                        kernel,
+                                                        dim3(grid_size),
+                                                        dim3(BlockSize),
+                                                        0,
+                                                        arg.in_grid_desc_,
+                                                        arg.out_grid_desc_,
+                                                        arg.in_dev_buffer_,
+                                                        arg.out_dev_buffer_,
+                                                        arg.elementwise_op_,
+                                                        arg.block_2_tile_map_);
+            return elapsed_time;
+        }
+
+        float Run(const BaseArgument* arg,
+                  const StreamConfig& stream_config = StreamConfig{}) override final
+        {
+            const auto* const argument = dynamic_cast<const Argument*>(arg);
+            if(!argument)
+            {
+                return NAN;
+            }
+
+            return Run(*argument, stream_config);
+        }
+    };
+
+    static bool IsSupportedArgument(const Argument& arg)
+    {
+        constexpr auto GetPaddedLength = [](index_t length, index_t tile_length) {
+            return math::integer_divide_ceil(length, tile_length) * tile_length;
+        };
+
+        constexpr auto IsScalarPerVectorValid =
+            [](index_t length, index_t stride, index_t scalar_per_vector) {
+                if(stride == 1 && length % scalar_per_vector == 0)
+                {
+                    return true;
+                }
+                else if(stride != 1 && scalar_per_vector == 1)
+                {
+                    return true;
+                }
+
+                return false;
+            };
+
+        return IsScalarPerVectorValid(arg.in_lengths_[SrcVectorDim],
+                                      arg.in_strides_[SrcVectorDim],
+                                      SrcScalarPerVector) &&
+               IsScalarPerVectorValid(
+                   GetPaddedLength(arg.in_lengths_[SrcVectorDim],
+                                   (SrcVectorDim == NumDim - 2 ? HPerBlock : WPerBlock)),
+                   arg.in_strides_[SrcVectorDim],
+                   SrcScalarPerVector) &&
+               IsScalarPerVectorValid(arg.out_lengths_[DstVectorDim],
+                                      arg.out_strides_[DstVectorDim],
+                                      DstScalarPerVector) &&
+               IsScalarPerVectorValid(
+                   GetPaddedLength(arg.out_lengths_[DstVectorDim],
+                                   (DstVectorDim == NumDim - 2 ? HPerBlock : WPerBlock)),
+                   arg.in_strides_[DstVectorDim],
+                   DstScalarPerVector) &&
+               GridwisePermute::CheckValidity(arg.in_grid_desc_, arg.out_grid_desc_);
+    };
+
+    // override methods inherited from 'BaseOperator'
+    bool IsSupportedArgument(const BaseArgument* arg) override final
+    {
+        const auto* const argument = dynamic_cast<const Argument*>(arg);
+        if(!argument)
+        {
+            return false;
+        }
+
+        return IsSupportedArgument(*argument);
+    }
+
+    // override methods inherited from 'DevicePermute'
+    std::unique_ptr<BaseArgument>
+    MakeArgumentPointer(const Lengths& in_lengths,
+                        const Strides& in_strides,
+                        const Lengths& out_lengths,
+                        const Strides& out_strides,
+                        const void* in_dev_buffer,
+                        void* out_dev_buffer,
+                        ElementwiseOperation elementwise_op) override final
+    {
+        return std::make_unique<Argument>(in_lengths,
+                                          in_strides,
+                                          out_lengths,
+                                          out_strides,
+                                          in_dev_buffer,
+                                          out_dev_buffer,
+                                          elementwise_op);
+    }
+
+    std::unique_ptr<BaseInvoker> MakeInvokerPointer() override final
+    {
+        return std::make_unique<Invoker>();
+    };
+
+    // other constructor methods
+    template <typename... Args>
+    static std::enable_if_t<std::is_constructible_v<Argument, Args...>, Argument>
+    MakeArgument(Args&&... args) noexcept(std::is_nothrow_constructible_v<Argument, Args...>)
+    {
+        return Argument{std::forward<Args>(args)...};
+    }
+
+    static std::enable_if_t<std::is_default_constructible_v<Invoker>, Invoker>
+    MakeInvoker() noexcept(std::is_nothrow_default_constructible_v<Invoker>)
+    {
+        return Invoker{};
+    }
+};
+
+} // namespace device
+} // namespace tensor_operation
+} // namespace ck

include/ck/tensor_operation/gpu/grid/gridwise_elementwise_1d.hpp

@@ -83,6 +83,8 @@ struct GridwiseElementwise_1D
 
         auto in_global_buf_tuple = generate_tuple(
             [&](auto I) {
+                static_assert(in_grid_1d_desc_tuple[I].GetNumOfDimension() == 1);
+
                 return make_dynamic_buffer<AddressSpaceEnum::Global>(
                     p_in_global_tuple[I], in_grid_1d_desc_tuple[I].GetElementSpaceSize());
             },
@@ -90,6 +92,8 @@ struct GridwiseElementwise_1D
 
         auto out_global_buf_tuple = generate_tuple(
             [&](auto I) {
+                static_assert(out_grid_1d_desc_tuple[I].GetNumOfDimension() == 1);
+
                 return make_dynamic_buffer<AddressSpaceEnum::Global>(
                     p_out_global_tuple[I], out_grid_1d_desc_tuple[I].GetElementSpaceSize());
             },

include/ck/tensor_operation/gpu/grid/gridwise_permute.hpp

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#pragma once
+
+#include <functional>
+#include <numeric>
+#include <iterator>
+
+#include "ck/tensor_description/cluster_descriptor.hpp"
+#include "ck/utility/data_type.hpp"
+#include "ck/tensor_operation/gpu/block/thread_group_tensor_slice_transfer_v4r1.hpp"
+#include "ck/tensor_operation/gpu/thread/threadwise_tensor_slice_transfer.hpp"
+#include "ck/tensor_operation/gpu/element/element_wise_operation.hpp"
+
+namespace ck {
+
+template <typename GridwisePermute,
+          typename InGridDesc,
+          typename OutGridDesc,
+          typename InDataType,
+          typename OutDataType,
+          typename ElementwiseOperation,
+          typename Block2TileMap>
+__global__ void kernel_nd_permute(const InGridDesc in_grid_desc,
+                                  const OutGridDesc out_grid_desc,
+                                  const InDataType* p_in_global,
+                                  OutDataType* p_out_global,
+                                  const ElementwiseOperation elementwise_op,
+                                  const Block2TileMap block_2_tile_map)
+{
+    __shared__ char p_shared[GridwisePermute::GetSharedMemoryNumberOfByte()];
+
+    GridwisePermute::Run(in_grid_desc,
+                         out_grid_desc,
+                         p_in_global,
+                         p_out_global,
+                         p_shared,
+                         elementwise_op,
+                         block_2_tile_map);
+}
+
+template <typename InGridDesc,
+          typename OutGridDesc,
+          typename InDataType,
+          typename OutDataType,
+          typename ElementwiseOperation,
+          index_t BlockSize,
+          index_t NPerBlock,
+          index_t HPerBlock,
+          index_t WPerBlock,
+          index_t InBlockLdsExtraW,
+          typename InBlockTransferThreadClusterLengths,
+          typename InBlockTransferThreadClusterArrangeOrder,
+          index_t SrcVectorDim,
+          index_t DstVectorDim,
+          index_t SrcScalarPerVector,
+          index_t DstScalarPerVector>
+struct GridwisePermute
+{
+    static_assert(InGridDesc::GetNumOfDimension() == OutGridDesc::GetNumOfDimension());
+    static_assert(3 <= InGridDesc::GetNumOfDimension());
+    static_assert((InGridDesc::GetNumOfDimension() - 2) <= SrcVectorDim &&
+                  SrcVectorDim < InGridDesc::GetNumOfDimension());
+    static_assert((OutGridDesc::GetNumOfDimension() - 2) <= DstVectorDim &&
+                  DstVectorDim < OutGridDesc::GetNumOfDimension());
+    static_assert(SrcVectorDim != DstVectorDim);
+
+    static constexpr auto I0 = Number<0>{};
+    static constexpr auto I1 = Number<1>{};
+    static constexpr auto I2 = Number<2>{};
+
+    using ThisThreadBlock = ThisThreadBlock<BlockSize>;
+
+    struct Block2TileMap
+    {
+        static constexpr index_t NumDim = InGridDesc::GetNumOfDimension();
+        static_assert(3 <= NumDim);
+
+        static constexpr auto I0 = Number<0>{};
+
+        Block2TileMap()                     = delete;
+        Block2TileMap(const Block2TileMap&) = default;
+        Block2TileMap(Block2TileMap&&)      = delete;
+
+        ~Block2TileMap() = default;
+
+        Block2TileMap& operator=(const Block2TileMap&) = delete;
+        Block2TileMap& operator=(Block2TileMap&&) = delete;
+
+        explicit Block2TileMap(const InGridDesc& desc) : desc_(desc) {}
+
+        __host__ constexpr index_t CalculateGridSize(const InGridDesc& desc) const
+        {
+            const auto N0 =
+                math::integer_divide_ceil(desc.GetLength(Number<NumDim - 3>{}), NPerBlock);
+            const auto H0 =
+                math::integer_divide_ceil(desc.GetLength(Number<NumDim - 2>{}), HPerBlock);
+            const auto W0 =
+                math::integer_divide_ceil(desc.GetLength(Number<NumDim - 1>{}), WPerBlock);
+
+            const index_t grid_size = N0 * H0 * W0;
+
+            return grid_size;
+        }
+
+        template <typename TopIdx>
+        __host__ __device__ constexpr auto CalculateBottomIndex(const TopIdx& idx_top) const
+        {
+            static_assert(TopIdx::Size() == 1);
+
+            auto block_1d_id = idx_top[I0];
+
+            const auto N0 =
+                math::integer_divide_ceil(desc_.GetLength(Number<NumDim - 3>{}), NPerBlock);
+            const auto H0 =
+                math::integer_divide_ceil(desc_.GetLength(Number<NumDim - 2>{}), HPerBlock);
+            const auto W0 =
+                math::integer_divide_ceil(desc_.GetLength(Number<NumDim - 1>{}), WPerBlock);
+
+            block_1d_id = block_1d_id % (N0 * H0 * W0);
+
+            index_t idx_N0 = block_1d_id / (H0 * W0);
+            index_t idx_H0 = (block_1d_id % (H0 * W0)) / W0;
+            index_t idx_W0 = block_1d_id % W0;
+
+            return make_tuple(idx_N0, idx_H0, idx_W0);
+        }
+
+        private:
+        const InGridDesc desc_;
+    };
+
+    using DefaultBlock2TileMap = Block2TileMap;
+
+    // use an [NPerBlock, HPerBlock, WPerBlock] tensor as element-copy relay
+    __host__ __device__ static constexpr auto GetInBlockDesc_NPerBlock_HPerBlock_WPerBlock()
+    {
+        return make_naive_tensor_descriptor(
+            make_tuple(Number<NPerBlock>{}, Number<HPerBlock>{}, Number<WPerBlock>{}),
+            make_tuple(Number<HPerBlock*(WPerBlock + InBlockLdsExtraW)>{},
+                       Number<WPerBlock + InBlockLdsExtraW>{},
+                       I1));
+    }
+
+    // for N-dimension descriptor, reserve its last 2 dimensions, then merge its leading dimensions
+    // into single one. finally, form a 3D descriptor: [d(0), d(1), ..., d(N - 2), d(N - 1)] ->
+    // [(d(0) x d(1) x ...), d(N - 2), d(N - 1)]
+    template <typename GridDesc>
+    __host__ __device__ static constexpr auto GetMergedDesc(const GridDesc& desc)
+    {
+        constexpr index_t NumDim = GridDesc::GetNumOfDimension();
+        static_assert(3 <= NumDim);
+
+        const auto merged_desc = transform_tensor_descriptor(
+            desc,
+            make_tuple(make_merge_transform(generate_tuple(
+                           [&](auto I) { return desc.GetLength(I); }, Number<NumDim - 2>{})),
+                       make_pass_through_transform(desc.GetLength(Number<NumDim - 2>{})),
+                       make_pass_through_transform(desc.GetLength(Number<NumDim - 1>{}))),
+            make_tuple(generate_sequence_v2([&](auto I) { return I; }, Number<NumDim - 2>{}),
+                       Sequence<NumDim - 2>{},
+                       Sequence<NumDim - 1>{}),
+            make_tuple(Sequence<0>{}, Sequence<1>{}, Sequence<2>{}));
+        return merged_desc;
+    }
+
+    __host__ __device__ static constexpr index_t GetSharedMemoryNumberOfByte()
+    {
+        constexpr auto in_block_desc_nperblock_hperblock_wperblock =
+            GetInBlockDesc_NPerBlock_HPerBlock_WPerBlock();
+
+        return in_block_desc_nperblock_hperblock_wperblock.GetElementSpaceSize() *
+               sizeof(InDataType);
+    }
+
+    __host__ __device__ static constexpr auto MakeDefaultBlock2TileMap(const InGridDesc& desc)
+    {
+        return DefaultBlock2TileMap{desc};
+    }
+
+    __host__ __device__ static constexpr bool CheckValidity(const InGridDesc& in_grid_desc,
+                                                            const OutGridDesc& out_grid_desc)
+    {
+        constexpr index_t NumDim = InGridDesc::GetNumOfDimension();
+
+        // check if we only swap last 2 dimensions
+        bool valid = true;
+        static_for<0, NumDim - 2, 1>{}([&](auto I) {
+            if(valid && in_grid_desc.GetLength(I) != out_grid_desc.GetLength(I))
+            {
+                valid = false;
+            }
+        });
+
+        return valid &&
+               (in_grid_desc.GetLength(Number<NumDim - 1>{}) ==
+                out_grid_desc.GetLength(Number<NumDim - 2>{})) &&
+               (in_grid_desc.GetLength(Number<NumDim - 2>{}) ==
+                out_grid_desc.GetLength(Number<NumDim - 1>{}));
+    }
+
+    template <typename Block2TileMap>
+    __device__ static void Run(const InGridDesc in_grid_desc,
+                               const OutGridDesc out_grid_desc,
+                               const InDataType* p_in_global,
+                               OutDataType* p_out_global,
+                               void* __restrict__ p_shared,
+                               const ElementwiseOperation elementwise_op,
+                               const Block2TileMap& block_2_tile_map)
+    {
+        auto in_global_buf = make_dynamic_buffer<AddressSpaceEnum::Global>(
+            p_in_global, in_grid_desc.GetElementSpaceSize());
+
+        auto out_global_buf = make_dynamic_buffer<AddressSpaceEnum::Global>(
+            p_out_global, out_grid_desc.GetElementSpaceSize());
+
+        // each workgroup handles an [NPerBlock, HPerBlock, WPerBLock] slice-transpose problem
+        const auto block_work_idx =
+            block_2_tile_map.CalculateBottomIndex(make_multi_index(get_block_1d_id()));
+
+        const index_t n_block_data_idx_on_grid =
+            __builtin_amdgcn_readfirstlane(block_work_idx[I0] * NPerBlock);
+
+        const index_t h_block_data_idx_on_grid =
+            __builtin_amdgcn_readfirstlane(block_work_idx[I1] * HPerBlock);
+
+        const index_t w_block_data_idx_on_grid =
+            __builtin_amdgcn_readfirstlane(block_work_idx[I2] * WPerBlock);
+
+        // create [NPerBlock, HPerBlock, WPerBLock] shaped LDS buffer
+        constexpr auto in_block_desc_nperblock_hperblock_wperblock =
+            GetInBlockDesc_NPerBlock_HPerBlock_WPerBlock();
+
+        auto in_block_buf = make_dynamic_buffer<AddressSpaceEnum::Lds>(
+            static_cast<InDataType*>(p_shared),
+            in_block_desc_nperblock_hperblock_wperblock.GetElementSpaceSize());
+
+        using BlockSliceLengths          = Sequence<NPerBlock, HPerBlock, WPerBlock>;
+        using InBlockTransferAccessOrder = Sequence<0, 1, 2>;
+
+        constexpr index_t SrcVectorDimAfterMerge =
+            SrcVectorDim - (InGridDesc::GetNumOfDimension() - 3);
+        constexpr index_t DstVectorDimAfterMerge = SrcVectorDimAfterMerge;
+
+        using ck::tensor_operation::element_wise::PassThrough;
+
+        // merge input descriptor into [(in_grid_desc.GetLength(0) x in_grid_desc.GetLength(1) x
+        // ...), in_grid_desc.GetLength(NumDim - 2), in_grid_desc.GetLength(NumDim - 1)]
+        const auto in_grid_desc_n_h_w = GetMergedDesc(in_grid_desc);
+
+        // a workgroup copies an [NPerBlock, HPerBlock, WPerBlock] slice from global memory to LDS
+        auto in_global_load = ThreadGroupTensorSliceTransfer_v4r1<
+            ThisThreadBlock,
+            ElementwiseOperation,
+            PassThrough,
+            InMemoryDataOperationEnum::Set,
+            BlockSliceLengths,
+            InBlockTransferThreadClusterLengths,
+            InBlockTransferThreadClusterArrangeOrder,
+            InDataType,
+            InDataType,
+            decltype(in_grid_desc_n_h_w),
+            decltype(in_block_desc_nperblock_hperblock_wperblock),
+            InBlockTransferAccessOrder,
+            InBlockTransferAccessOrder,
+            SrcVectorDimAfterMerge,
+            2,
+            SrcScalarPerVector,
+            1,
+            1,
+            1,
+            true,
+            true>(in_grid_desc_n_h_w,
+                  make_multi_index(
+                      n_block_data_idx_on_grid, h_block_data_idx_on_grid, w_block_data_idx_on_grid),
+                  PassThrough{},
+                  in_block_desc_nperblock_hperblock_wperblock,
+                  make_multi_index(0, 0, 0),
+                  PassThrough{});
+
+        // merge output descriptor into [(out_grid_desc.GetLength(0) x out_grid_desc.GetLength(1) x
+        // ...), out_grid_desc.GetLength(NumDim - 2), out_grid_desc.GetLength(NumDim - 1)]
+        const auto out_grid_desc_n_w_h = GetMergedDesc(out_grid_desc);
+
+        // create transposed view of output tensor
+        const auto out_grid_desc_n_h_w = transform_tensor_descriptor(
+            out_grid_desc_n_w_h,
+            make_tuple(make_pass_through_transform(out_grid_desc_n_w_h.GetLength(I0)),
+                       make_pass_through_transform(out_grid_desc_n_w_h.GetLength(I1)),
+                       make_pass_through_transform(out_grid_desc_n_w_h.GetLength(I2))),
+            make_tuple(Sequence<0>{}, Sequence<1>{}, Sequence<2>{}),
+            make_tuple(Sequence<0>{}, Sequence<2>{}, Sequence<1>{}));
+
+        // a workgroup copies an [NPerBlock, HPerBlock, WPerBlock] slice from LDS to global memory
+        auto out_global_store = ThreadGroupTensorSliceTransfer_v4r1<
+            ThisThreadBlock,
+            ElementwiseOperation,
+            PassThrough,
+            InMemoryDataOperationEnum::Set,
+            BlockSliceLengths,
+            InBlockTransferThreadClusterLengths,
+            InBlockTransferThreadClusterArrangeOrder,
+            InDataType,
+            OutDataType,
+            decltype(in_block_desc_nperblock_hperblock_wperblock),
+            decltype(out_grid_desc_n_h_w),
+            InBlockTransferAccessOrder,
+            InBlockTransferAccessOrder,
+            2,
+            DstVectorDimAfterMerge,
+            1,
+            DstScalarPerVector,
+            1,
+            1,
+            true,
+            true>(in_block_desc_nperblock_hperblock_wperblock,
+                  make_multi_index(0, 0, 0),
+                  PassThrough{},
+                  out_grid_desc_n_h_w,
+                  make_multi_index(
+                      n_block_data_idx_on_grid, h_block_data_idx_on_grid, w_block_data_idx_on_grid),
+                  elementwise_op);
+
+        in_global_load.Run(in_grid_desc_n_h_w,
+                           in_global_buf,
+                           in_block_desc_nperblock_hperblock_wperblock,
+                           in_block_buf,
+                           I0);
+
+        out_global_store.Run(in_block_desc_nperblock_hperblock_wperblock,
+                             in_block_buf,
+                             out_grid_desc_n_h_w,
+                             out_global_buf,
+                             I0);
+    }
+};
+
+} // namespace ck

include/ck/tensor_operation/gpu/thread/threadwise_tensor_slice_transfer_v3r1.hpp

@@ -6,6 +6,7 @@
 #include "ck/utility/common_header.hpp"
 #include "ck/tensor_description/tensor_descriptor.hpp"
 #include "ck/tensor_description/tensor_descriptor_helper.hpp"
+#include "ck/tensor_operation/gpu/thread/threadwise_tensor_slice_transfer.hpp"
 #include "ck/tensor/static_tensor.hpp"
 
 namespace ck {

include/ck/utility/span.hpp

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#pragma once
+
+#include <cstddef>
+#include <array>
+#include <type_traits>
+
+namespace ck {
+
+template <typename T>
+class span
+{
+    public:
+    using element_type    = T;
+    using value_type      = std::remove_cv_t<element_type>;
+    using size_type       = std::size_t;
+    using difference_type = std::ptrdiff_t;
+    using pointer         = element_type*;
+    using const_pointer   = const element_type*;
+    using reference       = element_type&;
+    using const_reference = const element_type&;
+    using iterator        = pointer;
+    using const_iterator  = pointer;
+
+    constexpr span() : span(nullptr, size_type{0}) {}
+
+    constexpr span(pointer first, size_type count) : ptr_(first), size_(count) {}
+
+    constexpr span(pointer first, pointer last) : span(first, last - first) {}
+
+    template <std::size_t N>
+    constexpr span(element_type (&arr)[N]) noexcept : span(arr, N)
+    {
+    }
+
+    template <std::size_t N>
+    constexpr span(std::array<value_type, N>& arr) noexcept : span(arr.data(), N)
+    {
+    }
+
+    template <typename Container>
+    constexpr span(const Container& container) : span(container.data(), container.size())
+    {
+    }
+
+    constexpr iterator begin() const noexcept { return ptr_; }
+    constexpr const_iterator cbegin() const noexcept { return begin(); }
+
+    constexpr iterator end() const noexcept { return begin() + size(); }
+    constexpr const_iterator cend() const noexcept { return end(); }
+
+    constexpr reference front() const { return *begin(); }
+    constexpr reference back() const { return *(--end()); }
+
+    constexpr reference operator[](size_type idx) const { return *(begin() + idx); }
+    constexpr pointer data() const noexcept { return ptr_; }
+
+    constexpr size_type size() const noexcept { return size_; }
+
+    private:
+    pointer ptr_;
+    size_type size_;
+};
+
+} // namespace ck

library/include/ck/library/utility/check_err.hpp

@@ -15,6 +15,7 @@
 
 #include "ck/ck.hpp"
 #include "ck/utility/data_type.hpp"
+#include "ck/utility/span.hpp"
 #include "ck/utility/type.hpp"
 #include "ck/host_utility/io.hpp"
 
@@ -32,7 +33,7 @@ check_err(const std::vector<T>& out,
 {
     if(out.size() != ref.size())
     {
-        std::cout << msg << " out.size() != ref.size(), :" << out.size() << " != " << ref.size()
+        std::cerr << msg << " out.size() != ref.size(), :" << out.size() << " != " << ref.size()
                   << std::endl;
         return false;
     }
@@ -50,7 +51,7 @@ check_err(const std::vector<T>& out,
             err_count++;
             if(err_count < 5)
             {
-                std::cout << msg << std::setw(12) << std::setprecision(7) << " out[" << i
+                std::cerr << msg << std::setw(12) << std::setprecision(7) << " out[" << i
                           << "] != ref[" << i << "]: " << out[i] << " != " << ref[i] << std::endl;
             }
             res = false;
@@ -58,7 +59,7 @@ check_err(const std::vector<T>& out,
     }
     if(!res)
     {
-        std::cout << std::setw(12) << std::setprecision(7) << "max err: " << max_err << std::endl;
+        std::cerr << std::setw(12) << std::setprecision(7) << "max err: " << max_err << std::endl;
     }
     return res;
 }
@@ -73,7 +74,7 @@ check_err(const std::vector<T>& out,
 {
     if(out.size() != ref.size())
     {
-        std::cout << msg << " out.size() != ref.size(), :" << out.size() << " != " << ref.size()
+        std::cerr << msg << " out.size() != ref.size(), :" << out.size() << " != " << ref.size()
                   << std::endl;
         return false;
     }
@@ -94,7 +95,7 @@ check_err(const std::vector<T>& out,
             err_count++;
             if(err_count < 5)
             {
-                std::cout << msg << std::setw(12) << std::setprecision(7) << " out[" << i
+                std::cerr << msg << std::setw(12) << std::setprecision(7) << " out[" << i
                           << "] != ref[" << i << "]: " << o << " != " << r << std::endl;
             }
             res = false;
@@ -102,22 +103,22 @@ check_err(const std::vector<T>& out,
     }
     if(!res)
     {
-        std::cout << std::setw(12) << std::setprecision(7) << "max err: " << max_err << std::endl;
+        std::cerr << std::setw(12) << std::setprecision(7) << "max err: " << max_err << std::endl;
     }
     return res;
 }
 
 template <typename T>
-typename std::enable_if<std::is_same<T, half_t>::value, bool>::type
-check_err(const std::vector<T>& out,
-          const std::vector<T>& ref,
+typename std::enable_if<std::is_same_v<T, half_t>, bool>::type
+check_err(span<const T> out,
+          span<const T> ref,
           const std::string& msg = "Error: Incorrect results!",
           double rtol            = 1e-3,
           double atol            = 1e-3)
 {
     if(out.size() != ref.size())
     {
-        std::cout << msg << " out.size() != ref.size(), :" << out.size() << " != " << ref.size()
+        std::cerr << msg << " out.size() != ref.size(), :" << out.size() << " != " << ref.size()
                   << std::endl;
         return false;
     }
@@ -137,7 +138,7 @@ check_err(const std::vector<T>& out,
             err_count++;
             if(err_count < 5)
             {
-                std::cout << msg << std::setw(12) << std::setprecision(7) << " out[" << i
+                std::cerr << msg << std::setw(12) << std::setprecision(7) << " out[" << i
                           << "] != ref[" << i << "]: " << o << " != " << r << std::endl;
             }
             res = false;
@@ -145,11 +146,22 @@ check_err(const std::vector<T>& out,
     }
     if(!res)
     {
-        std::cout << std::setw(12) << std::setprecision(7) << "max err: " << max_err << std::endl;
+        std::cerr << std::setw(12) << std::setprecision(7) << "max err: " << max_err << std::endl;
     }
     return res;
 }
 
+template <typename T>
+typename std::enable_if<std::is_same<T, half_t>::value, bool>::type
+check_err(const std::vector<T>& out,
+          const std::vector<T>& ref,
+          const std::string& msg = "Error: Incorrect results!",
+          double rtol            = 1e-3,
+          double atol            = 1e-3)
+{
+    return check_err(span<const T>{out}, span<const T>{ref}, msg, rtol, atol);
+}
+
 template <typename T>
 std::enable_if_t<(std::is_integral_v<T> && !std::is_same_v<T, bhalf_t>)
 #ifdef CK_EXPERIMENTAL_BIT_INT_EXTENSION_INT4
@@ -194,7 +206,7 @@ check_err(const std::vector<T>& out,
     }
     if(!res)
     {
-        std::cout << "max err: " << max_err << std::endl;
+        std::cerr << "max err: " << max_err << std::endl;
     }
     return res;
 }

library/include/ck/library/utility/fill.hpp

@@ -5,7 +5,10 @@
 
 #include <algorithm>
 #include <cmath>
+#include <iterator>
 #include <random>
+#include <type_traits>
+#include <utility>
 
 #include "ck/utility/data_type.hpp"
 
@@ -25,6 +28,15 @@ struct FillUniformDistribution
         std::uniform_real_distribution<float> dis(a_, b_);
         std::generate(first, last, [&dis, &gen]() { return ck::type_convert<T>(dis(gen)); });
     }
+
+    template <typename ForwardRange>
+    auto operator()(ForwardRange&& range) -> std::void_t<decltype(
+        std::declval<FillUniformDistribution>()(std::begin(std::forward<ForwardRange>(range)),
+                                                std::end(std::forward<ForwardRange>(range))))>
+    {
+        (*this)(std::begin(std::forward<ForwardRange>(range)),
+                std::end(std::forward<ForwardRange>(range)));
+    }
 };
 
 // Normally FillUniformDistributionIntegerValue should use std::uniform_int_distribution as below.

library/include/ck/library/utility/host_tensor.hpp

@@ -3,15 +3,16 @@
 
 #pragma once
 
-#include <thread>
-#include <vector>
-#include <numeric>
 #include <algorithm>
-#include <utility>
 #include <cassert>
 #include <iostream>
+#include <numeric>
+#include <thread>
+#include <utility>
+#include <vector>
 
 #include "ck/utility/data_type.hpp"
+#include "ck/utility/span.hpp"
 
 template <typename Range>
 std::ostream& LogRange(std::ostream& os, Range&& range, std::string delim)
@@ -235,6 +236,9 @@ auto make_ParallelTensorFunctor(F f, Xs... xs)
 template <typename T>
 struct Tensor
 {
+    using Descriptor = HostTensorDescriptor;
+    using Data       = std::vector<T>;
+
     template <typename X>
     Tensor(std::initializer_list<X> lens) : mDesc(lens), mData(mDesc.GetElementSpaceSize())
     {
@@ -251,7 +255,7 @@ struct Tensor
     {
     }
 
-    Tensor(const HostTensorDescriptor& desc) : mDesc(desc), mData(mDesc.GetElementSpaceSize()) {}
+    Tensor(const Descriptor& desc) : mDesc(desc), mData(mDesc.GetElementSpaceSize()) {}
 
     template <typename OutT>
     Tensor<OutT> CopyAsType() const
@@ -278,9 +282,9 @@ struct Tensor
     {
     }
 
-    const std::vector<std::size_t>& GetLengths() const { return mDesc.GetLengths(); }
+    decltype(auto) GetLengths() const { return mDesc.GetLengths(); }
 
-    const std::vector<std::size_t>& GetStrides() const { return mDesc.GetStrides(); }
+    decltype(auto) GetStrides() const { return mDesc.GetStrides(); }
 
     std::size_t GetNumOfDimension() const { return mDesc.GetNumOfDimension(); }
 
@@ -288,6 +292,8 @@ struct Tensor
 
     std::size_t GetElementSpaceSize() const { return mDesc.GetElementSpaceSize(); }
 
+    std::size_t GetElementSpaceSizeInBytes() const { return sizeof(T) * GetElementSpaceSize(); }
+
     void SetZero()
     {
         for(auto& v : mData)
@@ -425,14 +431,40 @@ struct Tensor
         return mData[mDesc.GetOffsetFromMultiIndex(idx)];
     }
 
-    typename std::vector<T>::iterator begin() { return mData.begin(); }
+    typename Data::iterator begin() { return mData.begin(); }
+
+    typename Data::iterator end() { return mData.end(); }
 
-    typename std::vector<T>::iterator end() { return mData.end(); }
+    typename Data::pointer data() { return mData.data(); }
 
-    typename std::vector<T>::const_iterator begin() const { return mData.begin(); }
+    typename Data::const_iterator begin() const { return mData.begin(); }
 
-    typename std::vector<T>::const_iterator end() const { return mData.end(); }
+    typename Data::const_iterator end() const { return mData.end(); }
+
+    typename Data::const_pointer data() const { return mData.data(); }
+
+    typename Data::size_type size() const { return mData.size(); }
+
+    template <typename U = T>
+    auto AsSpan() const
+    {
+        constexpr std::size_t FromSize = sizeof(T);
+        constexpr std::size_t ToSize   = sizeof(U);
+
+        using Element = std::add_const_t<std::remove_reference_t<U>>;
+        return ck::span<Element>{reinterpret_cast<Element*>(data()), size() * FromSize / ToSize};
+    }
+
+    template <typename U = T>
+    auto AsSpan()
+    {
+        constexpr std::size_t FromSize = sizeof(T);
+        constexpr std::size_t ToSize   = sizeof(U);
+
+        using Element = std::remove_reference_t<U>;
+        return ck::span<Element>{reinterpret_cast<Element*>(data()), size() * FromSize / ToSize};
+    }
 
-    HostTensorDescriptor mDesc;
-    std::vector<T> mData;
+    Descriptor mDesc;
+    Data mData;
 };