Rework mdspan concept emulation (#2213)

It is proving difficult to handle for msvc and also the one we are using in libcu++ it much cleaner Gets #2160 compiling on MSVC
NVIDIA · Aug 9, 2024 · 8e20c9a · 8e20c9a
1 parent f95f211
commit 8e20c9a
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Showing 10 changed files with 216 additions and 437 deletions.
diff --git a/libcudacxx/include/cuda/std/__mdspan/default_accessor.h b/libcudacxx/include/cuda/std/__mdspan/default_accessor.h
@@ -72,10 +72,9 @@ struct default_accessor
 
   __MDSPAN_INLINE_FUNCTION_DEFAULTED constexpr default_accessor() noexcept = default;
 
-  __MDSPAN_TEMPLATE_REQUIRES(class _OtherElementType,
-                             /* requires */ (_CCCL_TRAIT(is_convertible, _OtherElementType (*)[], element_type (*)[])))
-  __MDSPAN_INLINE_FUNCTION
-  constexpr default_accessor(default_accessor<_OtherElementType>) noexcept {}
+  _LIBCUDACXX_TEMPLATE(class _OtherElementType)
+  _LIBCUDACXX_REQUIRES(_CCCL_TRAIT(is_convertible, _OtherElementType (*)[], element_type (*)[]))
+  __MDSPAN_INLINE_FUNCTION constexpr default_accessor(default_accessor<_OtherElementType>) noexcept {}
 
   __MDSPAN_INLINE_FUNCTION
   constexpr data_handle_type offset(data_handle_type __p, size_t __i) const noexcept

diff --git a/libcudacxx/include/cuda/std/__mdspan/extents.h b/libcudacxx/include/cuda/std/__mdspan/extents.h
@@ -248,16 +248,13 @@ class extents
   __MDSPAN_INLINE_FUNCTION_DEFAULTED constexpr extents() noexcept = default;
 
   // Converting constructor
-  __MDSPAN_TEMPLATE_REQUIRES(
-    class _OtherIndexType,
-    size_t... _OtherExtents,
-    /* requires */
-    (
-      /* multi-stage check to protect from invalid pack expansion when sizes don't match? */
-      decltype(__detail::__check_compatible_extents(
-        integral_constant<bool, sizeof...(_Extents) == sizeof...(_OtherExtents)>{},
-        _CUDA_VSTD::integer_sequence<size_t, _Extents...>{},
-        _CUDA_VSTD::integer_sequence<size_t, _OtherExtents...>{}))::value))
+  _LIBCUDACXX_TEMPLATE(class _OtherIndexType, size_t... _OtherExtents)
+  _LIBCUDACXX_REQUIRES(
+    /* multi-stage check to protect from invalid pack expansion when sizes don't match? */
+    (decltype(__detail::__check_compatible_extents(
+      integral_constant<bool, sizeof...(_Extents) == sizeof...(_OtherExtents)>{},
+      _CUDA_VSTD::integer_sequence<size_t, _Extents...>{},
+      _CUDA_VSTD::integer_sequence<size_t, _OtherExtents...>{}))::value))
   __MDSPAN_INLINE_FUNCTION
   __MDSPAN_CONDITIONAL_EXPLICIT(
     (((_Extents != dynamic_extent) && (_OtherExtents == dynamic_extent)) || ...)
@@ -287,23 +284,23 @@ class extents
   }
 
 #  ifdef __NVCC__
-  __MDSPAN_TEMPLATE_REQUIRES(
-    class... _Integral,
-    /* requires */ (
-      // TODO: check whether the other version works with newest NVCC, doesn't with 11.4
-      // NVCC seems to pick up rank_dynamic from the wrong extents type???
-      __MDSPAN_FOLD_AND(_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _Integral, index_type) /* && ... */)
-      && __MDSPAN_FOLD_AND(_CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _Integral) /* && ... */) &&
-      // NVCC chokes on the fold thingy here so wrote the workaround
-      ((sizeof...(_Integral) == __detail::__count_dynamic_extents<_Extents...>::val)
-       || (sizeof...(_Integral) == sizeof...(_Extents)))))
+  _LIBCUDACXX_TEMPLATE(class... _Integral)
+  _LIBCUDACXX_REQUIRES(
+    // TODO: check whether the other version works with newest NVCC, doesn't with 11.4
+    // NVCC seems to pick up rank_dynamic from the wrong extents type???
+    __MDSPAN_FOLD_AND(_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _Integral, index_type) /* && ... */)
+      _LIBCUDACXX_AND __MDSPAN_FOLD_AND(
+        _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _Integral) /* && ... */) _LIBCUDACXX_AND
+    // NVCC chokes on the fold thingy here so wrote the workaround
+    ((sizeof...(_Integral) == __detail::__count_dynamic_extents<_Extents...>::val)
+     || (sizeof...(_Integral) == sizeof...(_Extents))))
 #  else
-  __MDSPAN_TEMPLATE_REQUIRES(
-    class... _Integral,
-    /* requires */ (
-      __MDSPAN_FOLD_AND(_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _Integral, index_type) /* && ... */)
-      && __MDSPAN_FOLD_AND(_CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _Integral) /* && ... */)
-      && ((sizeof...(_Integral) == rank_dynamic()) || (sizeof...(_Integral) == rank()))))
+  _LIBCUDACXX_TEMPLATE(class... _Integral)
+  _LIBCUDACXX_REQUIRES(
+    __MDSPAN_FOLD_AND(_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _Integral, index_type) /* && ... */)
+      _LIBCUDACXX_AND __MDSPAN_FOLD_AND(
+        _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _Integral) /* && ... */)
+        _LIBCUDACXX_AND((sizeof...(_Integral) == rank_dynamic()) || (sizeof...(_Integral) == rank())))
 #  endif
   __MDSPAN_INLINE_FUNCTION
   explicit constexpr extents(_Integral... __exts) noexcept
@@ -337,21 +334,16 @@ class extents
 #  ifdef __NVCC__
   // NVCC seems to pick up rank_dynamic from the wrong extents type???
   // NVCC chokes on the fold thingy here so wrote the workaround
-  __MDSPAN_TEMPLATE_REQUIRES(
-    class _IndexType,
-    size_t _Np,
-    /* requires */
-    (_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _IndexType, index_type)
-     && _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _IndexType)
-     && ((_Np == __detail::__count_dynamic_extents<_Extents...>::val) || (_Np == sizeof...(_Extents)))))
+  _LIBCUDACXX_TEMPLATE(class _IndexType, size_t _Np)
+  _LIBCUDACXX_REQUIRES(
+    _CCCL_TRAIT(_CUDA_VSTD::is_convertible, _IndexType, index_type)
+      _LIBCUDACXX_AND _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _IndexType)
+        _LIBCUDACXX_AND((_Np == __detail::__count_dynamic_extents<_Extents...>::val) || (_Np == sizeof...(_Extents))))
 #  else
-  __MDSPAN_TEMPLATE_REQUIRES(
-    class _IndexType,
-    size_t _Np,
-    /* requires */
-    (_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _IndexType, index_type)
-     && _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _IndexType)
-     && (_Np == rank() || _Np == rank_dynamic())))
+  _LIBCUDACXX_TEMPLATE(class _IndexType, size_t _Np)
+  _LIBCUDACXX_REQUIRES(_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _IndexType, index_type)
+                         _LIBCUDACXX_AND _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _IndexType)
+                           _LIBCUDACXX_AND(_Np == rank() || _Np == rank_dynamic()))
 #  endif
   __MDSPAN_CONDITIONAL_EXPLICIT(_Np != rank_dynamic())
   __MDSPAN_INLINE_FUNCTION
@@ -386,21 +378,16 @@ class extents
 #  ifdef __NVCC__
   // NVCC seems to pick up rank_dynamic from the wrong extents type???
   // NVCC chokes on the fold thingy here so wrote the workaround
-  __MDSPAN_TEMPLATE_REQUIRES(
-    class _IndexType,
-    size_t _Np,
-    /* requires */
-    (_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _IndexType, index_type)
-     && _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _IndexType)
-     && ((_Np == __detail::__count_dynamic_extents<_Extents...>::val) || (_Np == sizeof...(_Extents)))))
+  _LIBCUDACXX_TEMPLATE(class _IndexType, size_t _Np)
+  _LIBCUDACXX_REQUIRES(
+    _CCCL_TRAIT(_CUDA_VSTD::is_convertible, _IndexType, index_type)
+      _LIBCUDACXX_AND _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _IndexType)
+        _LIBCUDACXX_AND((_Np == __detail::__count_dynamic_extents<_Extents...>::val) || (_Np == sizeof...(_Extents))))
 #  else
-  __MDSPAN_TEMPLATE_REQUIRES(
-    class _IndexType,
-    size_t _Np,
-    /* requires */
-    (_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _IndexType, index_type)
-     && _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _IndexType)
-     && (_Np == rank() || _Np == rank_dynamic())))
+  _LIBCUDACXX_TEMPLATE(class _IndexType, size_t _Np)
+  _LIBCUDACXX_REQUIRES(_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _IndexType, index_type)
+                         _LIBCUDACXX_AND _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _IndexType)
+                           _LIBCUDACXX_AND(_Np == rank() || _Np == rank_dynamic()))
 #  endif
   __MDSPAN_CONDITIONAL_EXPLICIT(_Np != rank_dynamic())
   __MDSPAN_INLINE_FUNCTION

diff --git a/libcudacxx/include/cuda/std/__mdspan/layout_left.h b/libcudacxx/include/cuda/std/__mdspan/layout_left.h
@@ -121,8 +121,8 @@ class layout_left::mapping
       : __extents(__exts)
   {}
 
-  __MDSPAN_TEMPLATE_REQUIRES(class _OtherExtents,
-                             /* requires */ (_CCCL_TRAIT(_CUDA_VSTD::is_constructible, extents_type, _OtherExtents)))
+  _LIBCUDACXX_TEMPLATE(class _OtherExtents)
+  _LIBCUDACXX_REQUIRES(_CCCL_TRAIT(_CUDA_VSTD::is_constructible, extents_type, _OtherExtents))
   __MDSPAN_CONDITIONAL_EXPLICIT((!_CUDA_VSTD::is_convertible<_OtherExtents, extents_type>::value)) // needs two () due
                                                                                                    // to comma
   __MDSPAN_INLINE_FUNCTION constexpr mapping(
@@ -135,9 +135,9 @@ class layout_left::mapping
      */
   }
 
-  __MDSPAN_TEMPLATE_REQUIRES(class _OtherExtents,
-                             /* requires */ (_CCCL_TRAIT(_CUDA_VSTD::is_constructible, extents_type, _OtherExtents)
-                                             && (extents_type::rank() <= 1)))
+  _LIBCUDACXX_TEMPLATE(class _OtherExtents)
+  _LIBCUDACXX_REQUIRES(_CCCL_TRAIT(_CUDA_VSTD::is_constructible, extents_type, _OtherExtents)
+                         _LIBCUDACXX_AND(extents_type::rank() <= 1))
   __MDSPAN_CONDITIONAL_EXPLICIT((!_CUDA_VSTD::is_convertible<_OtherExtents, extents_type>::value)) // needs two () due
                                                                                                    // to comma
   __MDSPAN_INLINE_FUNCTION constexpr mapping(
@@ -150,8 +150,8 @@ class layout_left::mapping
      */
   }
 
-  __MDSPAN_TEMPLATE_REQUIRES(class _OtherExtents,
-                             /* requires */ (_CCCL_TRAIT(_CUDA_VSTD::is_constructible, extents_type, _OtherExtents)))
+  _LIBCUDACXX_TEMPLATE(class _OtherExtents)
+  _LIBCUDACXX_REQUIRES(_CCCL_TRAIT(_CUDA_VSTD::is_constructible, extents_type, _OtherExtents))
   __MDSPAN_CONDITIONAL_EXPLICIT((extents_type::rank() > 0))
   __MDSPAN_INLINE_FUNCTION constexpr mapping(
     layout_stride::mapping<_OtherExtents> const& __other) // NOLINT(google-explicit-constructor)
@@ -190,11 +190,10 @@ class layout_left::mapping
 
   //--------------------------------------------------------------------------------
 
-  __MDSPAN_TEMPLATE_REQUIRES(
-    class... _Indices,
-    /* requires */ ((sizeof...(_Indices) == extents_type::rank())
-                    && __MDSPAN_FOLD_AND((_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _Indices, index_type)
-                                          && _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _Indices)))))
+  _LIBCUDACXX_TEMPLATE(class... _Indices)
+  _LIBCUDACXX_REQUIRES((sizeof...(_Indices) == extents_type::rank()) _LIBCUDACXX_AND __MDSPAN_FOLD_AND(
+    (_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _Indices, index_type)
+     && _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _Indices))))
   _CCCL_HOST_DEVICE constexpr index_type operator()(_Indices... __idxs) const noexcept
   {
     // Immediately cast incoming indices to `index_type`
@@ -227,8 +226,8 @@ class layout_left::mapping
     return true;
   }
 
-  __MDSPAN_TEMPLATE_REQUIRES(class _Ext = _Extents,
-                             /* requires */ (_Ext::rank() > 0))
+  _LIBCUDACXX_TEMPLATE(class _Ext = _Extents)
+  _LIBCUDACXX_REQUIRES((_Ext::rank() > 0))
   __MDSPAN_INLINE_FUNCTION
   constexpr index_type stride(rank_type __i) const noexcept
   {

diff --git a/libcudacxx/include/cuda/std/__mdspan/layout_right.h b/libcudacxx/include/cuda/std/__mdspan/layout_right.h
@@ -126,8 +126,8 @@ class layout_right::mapping
       : __extents(__exts)
   {}
 
-  __MDSPAN_TEMPLATE_REQUIRES(class _OtherExtents,
-                             /* requires */ (_CCCL_TRAIT(_CUDA_VSTD::is_constructible, extents_type, _OtherExtents)))
+  _LIBCUDACXX_TEMPLATE(class _OtherExtents)
+  _LIBCUDACXX_REQUIRES(_CCCL_TRAIT(_CUDA_VSTD::is_constructible, extents_type, _OtherExtents))
   __MDSPAN_CONDITIONAL_EXPLICIT((!_CUDA_VSTD::is_convertible<_OtherExtents, extents_type>::value)) // needs two () due
                                                                                                    // to comma
   __MDSPAN_INLINE_FUNCTION constexpr mapping(
@@ -140,9 +140,9 @@ class layout_right::mapping
      */
   }
 
-  __MDSPAN_TEMPLATE_REQUIRES(class _OtherExtents,
-                             /* requires */ (_CCCL_TRAIT(_CUDA_VSTD::is_constructible, extents_type, _OtherExtents)
-                                             && (extents_type::rank() <= 1)))
+  _LIBCUDACXX_TEMPLATE(class _OtherExtents)
+  _LIBCUDACXX_REQUIRES(_CCCL_TRAIT(_CUDA_VSTD::is_constructible, extents_type, _OtherExtents)
+                         _LIBCUDACXX_AND(extents_type::rank() <= 1))
   __MDSPAN_CONDITIONAL_EXPLICIT((!_CUDA_VSTD::is_convertible<_OtherExtents, extents_type>::value)) // needs two () due
                                                                                                    // to comma
   __MDSPAN_INLINE_FUNCTION constexpr mapping(
@@ -155,8 +155,8 @@ class layout_right::mapping
      */
   }
 
-  __MDSPAN_TEMPLATE_REQUIRES(class _OtherExtents,
-                             /* requires */ (_CCCL_TRAIT(_CUDA_VSTD::is_constructible, extents_type, _OtherExtents)))
+  _LIBCUDACXX_TEMPLATE(class _OtherExtents)
+  _LIBCUDACXX_REQUIRES(_CCCL_TRAIT(_CUDA_VSTD::is_constructible, extents_type, _OtherExtents))
   __MDSPAN_CONDITIONAL_EXPLICIT((extents_type::rank() > 0))
   __MDSPAN_INLINE_FUNCTION constexpr mapping(
     layout_stride::mapping<_OtherExtents> const& __other) // NOLINT(google-explicit-constructor)
@@ -195,11 +195,10 @@ class layout_right::mapping
 
   //--------------------------------------------------------------------------------
 
-  __MDSPAN_TEMPLATE_REQUIRES(
-    class... _Indices,
-    /* requires */ ((sizeof...(_Indices) == extents_type::rank())
-                    && __MDSPAN_FOLD_AND((_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _Indices, index_type)
-                                          && _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _Indices)))))
+  _LIBCUDACXX_TEMPLATE(class... _Indices)
+  _LIBCUDACXX_REQUIRES((sizeof...(_Indices) == extents_type::rank()) _LIBCUDACXX_AND __MDSPAN_FOLD_AND(
+    (_CCCL_TRAIT(_CUDA_VSTD::is_convertible, _Indices, index_type)
+     && _CCCL_TRAIT(_CUDA_VSTD::is_nothrow_constructible, index_type, _Indices))))
   _CCCL_HOST_DEVICE constexpr index_type operator()(_Indices... __idxs) const noexcept
   {
     return __compute_offset(__rank_count<0, extents_type::rank()>(), static_cast<index_type>(__idxs)...);
@@ -230,8 +229,8 @@ class layout_right::mapping
     return true;
   }
 
-  __MDSPAN_TEMPLATE_REQUIRES(class _Ext = _Extents,
-                             /* requires */ (_Ext::rank() > 0))
+  _LIBCUDACXX_TEMPLATE(class _Ext = _Extents)
+  _LIBCUDACXX_REQUIRES((_Ext::rank() > 0))
   __MDSPAN_INLINE_FUNCTION
   constexpr index_type stride(rank_type __i) const noexcept
   {