Minimal failing example of ClangJIT and Kokkos/mdspan

jit_fail.cpp

#include <experimental/mdspan>
#include <iostream>
#include <cstdlib>
#include <array>

namespace stdex = std::experimental;

template<const int x, const int y>
[[clang::jit]] void
kernel(stdex::mdspan<double, x, y>& f)
{
    for (int k = 0; k < y; ++k)
        for (int j = 0; j < x; ++j)
            f(j, k) = (j + 1) * (k + 1);
}

template<int x, int y>
[[clang::jit]]
void kernel_driver()
{
    // Construct
    constexpr int size = x * y;
    double* d = new double[size];
    for (int i=0;i<y;i++)
        for(int j=0;j<x;j++)
            d[i*x+j] = i * j;

    stdex::mdspan<double,x,y> f = stdex::mdspan<double, x, y>(d);

    // Execute
    kernel<x, y>(f);
    
    // Verify
    for (int k = 0; k < y; ++k)
    {
        for (int j = 0; j < x; ++j)
        {
            std::cout << f(j, k) << " ";
        }
        std::cout << std::endl;
    }
}

int main(int argc, char* argv[])
{
    int x = std::atoi(argv[1]);
    int y = std::atoi(argv[2]);
    kernel_driver<x, y>();
}

/*
 * compile with clang++ -fjit test.cpp -o jit
 * run with ./jit 2 2
 *
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
In file included from /home/aaals/test_jit/test.cpp:1:
In file included from /home/aaals/software/mdspan/include/experimental/mdspan:49:
In file included from /home/aaals/software/mdspan/include/experimental/__p0009_bits/basic_mdspan.hpp:48:
In file included from /home/aaals/software/mdspan/include/experimental/__p0009_bits/layout_right.hpp:47:
In file included from /home/aaals/software/mdspan/include/experimental/__p0009_bits/fixed_layout_impl.hpp:46:
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:108:23: error:
      no matching member function for call to '_select'
    return Idx == N ? _select<Size, DynamicOffset>(integral_constant<bool, Size ...
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:134:37: note:
      in instantiation of function template specialization
      'std::experimental::detail::mixed_static_and_dynamic_size_storage<std::integer_sequence<long,
      2, 2>, std::integer_sequence<long, 0, 0>, std::integer_sequence<unsigned long, 0,
      1> >::select_n<2, 0, 0, 0, 0>' requested here
    return _MDSPAN_FOLD_PLUS_RIGHT((select_n<Sizes, DynamicOffsets, Idxs, N, 0>(...
                                    ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/extents.hpp:240:30: note:
      in instantiation of function template specialization
      'std::experimental::detail::mixed_static_and_dynamic_size_storage<std::integer_sequence<long,
      2, 2>, std::integer_sequence<long, 0, 0>, std::integer_sequence<unsigned long, 0,
      1> >::get<0>' requested here
    return _storage.template get<N>();
                             ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/fixed_layout_impl.hpp:111:93: note:
      in instantiation of function template specialization
      'std::experimental::extents<2, 2>::__extent<0>' requested here
  ...N) ? base_t::__extents.template __extent<Idxs>() : 1), //* * ... * // 1);
                                     ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/fixed_layout_impl.hpp:150:67: note:
      in instantiation of function template specialization
      'std::experimental::detail::stride_storage_impl<std::experimental::extents<2, 2>,
      std::integer_sequence<unsigned long, 0, 1>,
      std::experimental::detail::layout_right_idx_conditional>::get_stride<0>' requested
      here
    return _MDSPAN_FOLD_PLUS_RIGHT((idxs * this->base_t::template get_stride<Idx...
                                                                  ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/basic_mdspan.hpp:253:30: note:
      in instantiation of function template specialization
      'std::experimental::detail::fixed_layout_common_impl<std::experimental::extents<2,
      2>, std::integer_sequence<unsigned long, 0, 1>,
      std::experimental::detail::layout_right_idx_conditional>::operator()<long, long>'
      requested here
    return acc_.access(ptr_, map_(index_type(indices)...));
                             ^
/home/aaals/test_jit/test.cpp:38:26: note: in instantiation of function template
      specialization 'std::experimental::basic_mdspan<double,
      std::experimental::extents<2, 2>, std::experimental::layout_right,
      std::experimental::accessor_basic<double> >::operator()<int, int, 0>' requested
      here
            std::cout << f(j, k) << " ";
                         ^
/home/aaals/test_jit/test.cpp:48:5: note: in instantiation of function template
      specialization 'kernel_driver<2, 2>' requested here
    kernel_driver<x, y>();
    ^
/home/aaals/test_jit/test.cpp:48:5: note: in instantiation of function template
      specialization 'kernel_driver<2, 2>' requested here
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:85:23: note:
      candidate function template not viable: no known conversion from
      'integral_constant<[...], 2L == dynamic_extent aka false>' to
      'integral_constant<[...], true>' for 1st argument
  constexpr ptrdiff_t _select(true_type) const noexcept { return dynamic_sizes.t...
                      ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:88:23: note:
      candidate function template not viable: no known conversion from
      'integral_constant<...>' to 'integral_constant<...>' for 1st argument
  constexpr ptrdiff_t _select(false_type) const noexcept { return Size; }
                      ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:108:23: error:
      no matching member function for call to '_select'
    return Idx == N ? _select<Size, DynamicOffset>(integral_constant<bool, Size ...
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:134:37: note:
      in instantiation of function template specialization
      'std::experimental::detail::mixed_static_and_dynamic_size_storage<std::integer_sequence<long,
      2, 2>, std::integer_sequence<long, 0, 0>, std::integer_sequence<unsigned long, 0,
      1> >::select_n<2, 0, 1, 0, 0>' requested here
    return _MDSPAN_FOLD_PLUS_RIGHT((select_n<Sizes, DynamicOffsets, Idxs, N, 0>(...
                                    ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/extents.hpp:240:30: note:
      in instantiation of function template specialization
      'std::experimental::detail::mixed_static_and_dynamic_size_storage<std::integer_sequence<long,
      2, 2>, std::integer_sequence<long, 0, 0>, std::integer_sequence<unsigned long, 0,
      1> >::get<0>' requested here
    return _storage.template get<N>();
                             ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/fixed_layout_impl.hpp:111:93: note:
      in instantiation of function template specialization
      'std::experimental::extents<2, 2>::__extent<0>' requested here
  ...N) ? base_t::__extents.template __extent<Idxs>() : 1), /* * ... * * / 1);
                                     ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/fixed_layout_impl.hpp:150:67: note:
      in instantiation of function template specialization
      'std::experimental::detail::stride_storage_impl<std::experimental::extents<2, 2>,
      std::integer_sequence<unsigned long, 0, 1>,
      std::experimental::detail::layout_right_idx_conditional>::get_stride<0>' requested
      here
    return _MDSPAN_FOLD_PLUS_RIGHT((idxs * this->base_t::template get_stride<Idx...
                                                                  ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/basic_mdspan.hpp:253:30: note:
      in instantiation of function template specialization
      'std::experimental::detail::fixed_layout_common_impl<std::experimental::extents<2,
      2>, std::integer_sequence<unsigned long, 0, 1>,
      std::experimental::detail::layout_right_idx_conditional>::operator()<long, long>'
      requested here
    return acc_.access(ptr_, map_(index_type(indices)...));
                             ^
/home/aaals/test_jit/test.cpp:38:26: note: in instantiation of function template
      specialization 'std::experimental::basic_mdspan<double,
      std::experimental::extents<2, 2>, std::experimental::layout_right,
      std::experimental::accessor_basic<double> >::operator()<int, int, 0>' requested
      here
            std::cout << f(j, k) << " ";
                         ^
/home/aaals/test_jit/test.cpp:48:5: note: in instantiation of function template
      specialization 'kernel_driver<2, 2>' requested here
    kernel_driver<x, y>();
    ^
/home/aaals/test_jit/test.cpp:48:5: note: in instantiation of function template
      specialization 'kernel_driver<2, 2>' requested here
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:85:23: note:
      candidate function template not viable: no known conversion from
      'integral_constant<[...], 2L == dynamic_extent aka false>' to
      'integral_constant<[...], true>' for 1st argument
  constexpr ptrdiff_t _select(true_type) const noexcept { return dynamic_sizes.t...
                      ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:88:23: note:
      candidate function template not viable: no known conversion from
      'integral_constant<...>' to 'integral_constant<...>' for 1st argument
  constexpr ptrdiff_t _select(false_type) const noexcept { return Size; }
                      ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:108:23: error:
      no matching member function for call to '_select'
    return Idx == N ? _select<Size, DynamicOffset>(integral_constant<bool, Size ...
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:134:37: note:
      in instantiation of function template specialization
      'std::experimental::detail::mixed_static_and_dynamic_size_storage<std::integer_sequence<long,
      2, 2>, std::integer_sequence<long, 0, 0>, std::integer_sequence<unsigned long, 0,
      1> >::select_n<2, 0, 0, 1, 0>' requested here
    return _MDSPAN_FOLD_PLUS_RIGHT((select_n<Sizes, DynamicOffsets, Idxs, N, 0>(...
                                    ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/extents.hpp:240:30: note:
      in instantiation of function template specialization
      'std::experimental::detail::mixed_static_and_dynamic_size_storage<std::integer_sequence<long,
      2, 2>, std::integer_sequence<long, 0, 0>, std::integer_sequence<unsigned long, 0,
      1> >::get<1>' requested here
    return _storage.template get<N>();
                             ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/fixed_layout_impl.hpp:111:93: note:
      in instantiation of function template specialization
      'std::experimental::extents<2, 2>::__extent<1>' requested here
  ...N) ? base_t::__extents.template __extent<Idxs>() : 1), /* * ... * * / 1);
                                     ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/fixed_layout_impl.hpp:150:67: note:
      in instantiation of function template specialization
      'std::experimental::detail::stride_storage_impl<std::experimental::extents<2, 2>,
      std::integer_sequence<unsigned long, 0, 1>,
      std::experimental::detail::layout_right_idx_conditional>::get_stride<0>' requested
      here
    return _MDSPAN_FOLD_PLUS_RIGHT((idxs * this->base_t::template get_stride<Idx...
                                                                  ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/basic_mdspan.hpp:253:30: note:
      in instantiation of function template specialization
      'std::experimental::detail::fixed_layout_common_impl<std::experimental::extents<2,
      2>, std::integer_sequence<unsigned long, 0, 1>,
      std::experimental::detail::layout_right_idx_conditional>::operator()<long, long>'
      requested here
    return acc_.access(ptr_, map_(index_type(indices)...));
                             ^
/home/aaals/test_jit/test.cpp:38:26: note: in instantiation of function template
      specialization 'std::experimental::basic_mdspan<double,
      std::experimental::extents<2, 2>, std::experimental::layout_right,
      std::experimental::accessor_basic<double> >::operator()<int, int, 0>' requested
      here
            std::cout << f(j, k) << " ";
                         ^
/home/aaals/test_jit/test.cpp:48:5: note: in instantiation of function template
      specialization 'kernel_driver<2, 2>' requested here
    kernel_driver<x, y>();
    ^
/home/aaals/test_jit/test.cpp:48:5: note: in instantiation of function template
      specialization 'kernel_driver<2, 2>' requested here
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:85:23: note:
      candidate function template not viable: no known conversion from
      'integral_constant<[...], 2L == dynamic_extent aka false>' to
      'integral_constant<[...], true>' for 1st argument
  constexpr ptrdiff_t _select(true_type) const noexcept { return dynamic_sizes.t...
                      ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:88:23: note:
      candidate function template not viable: no known conversion from
      'integral_constant<...>' to 'integral_constant<...>' for 1st argument
  constexpr ptrdiff_t _select(false_type) const noexcept { return Size; }
                      ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:108:23: error:
      no matching member function for call to '_select'
    return Idx == N ? _select<Size, DynamicOffset>(integral_constant<bool, Size ...
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:134:37: note:
      in instantiation of function template specialization
      'std::experimental::detail::mixed_static_and_dynamic_size_storage<std::integer_sequence<long,
      2, 2>, std::integer_sequence<long, 0, 0>, std::integer_sequence<unsigned long, 0,
      1> >::select_n<2, 0, 1, 1, 0>' requested here
    return _MDSPAN_FOLD_PLUS_RIGHT((select_n<Sizes, DynamicOffsets, Idxs, N, 0>(...
                                    ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/extents.hpp:240:30: note:
      in instantiation of function template specialization
      'std::experimental::detail::mixed_static_and_dynamic_size_storage<std::integer_sequence<long,
      2, 2>, std::integer_sequence<long, 0, 0>, std::integer_sequence<unsigned long, 0,
      1> >::get<1>' requested here
    return _storage.template get<N>();
                             ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/fixed_layout_impl.hpp:111:93: note:
      in instantiation of function template specialization
      'std::experimental::extents<2, 2>::__extent<1>' requested here
  ...N) ? base_t::__extents.template __extent<Idxs>() : 1), /* * ... * * / 1);
                                     ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/fixed_layout_impl.hpp:150:67: note:
      in instantiation of function template specialization
      'std::experimental::detail::stride_storage_impl<std::experimental::extents<2, 2>,
      std::integer_sequence<unsigned long, 0, 1>,
      std::experimental::detail::layout_right_idx_conditional>::get_stride<0>' requested
      here
    return _MDSPAN_FOLD_PLUS_RIGHT((idxs * this->base_t::template get_stride<Idx...
                                                                  ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/basic_mdspan.hpp:253:30: note:
      in instantiation of function template specialization
      'std::experimental::detail::fixed_layout_common_impl<std::experimental::extents<2,
      2>, std::integer_sequence<unsigned long, 0, 1>,
      std::experimental::detail::layout_right_idx_conditional>::operator()<long, long>'
      requested here
    return acc_.access(ptr_, map_(index_type(indices)...));
                             ^
/home/aaals/test_jit/test.cpp:38:26: note: in instantiation of function template
      specialization 'std::experimental::basic_mdspan<double,
      std::experimental::extents<2, 2>, std::experimental::layout_right,
      std::experimental::accessor_basic<double> >::operator()<int, int, 0>' requested
      here
            std::cout << f(j, k) << " ";
                         ^
/home/aaals/test_jit/test.cpp:48:5: note: in instantiation of function template
      specialization 'kernel_driver<2, 2>' requested here
    kernel_driver<x, y>();
    ^
/home/aaals/test_jit/test.cpp:48:5: note: in instantiation of function template
      specialization 'kernel_driver<2, 2>' requested here
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:85:23: note:
      candidate function template not viable: no known conversion from
      'integral_constant<[...], 2L == dynamic_extent aka false>' to
      'integral_constant<[...], true>' for 1st argument
  constexpr ptrdiff_t _select(true_type) const noexcept { return dynamic_sizes.t...
                      ^
/home/aaals/software/mdspan/include/experimental/__p0009_bits/mixed_size_storage.hpp:88:23: note:
      candidate function template not viable: no known conversion from
      'integral_constant<...>' to 'integral_constant<...>' for 1st argument
  constexpr ptrdiff_t _select(false_type) const noexcept { return Size; }
                      ^
LLVM ERROR: Clang JIT failed!
*/