cuda::std::simd core functionalities

libcudacxx/include/cuda/std/__fwd/simd.h

@@ -0,0 +1,62 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of libcu++ in the CUDA C++ Core Libraries,
+// under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+// SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _CUDA_STD___FWD_SIMD_H
+#define _CUDA_STD___FWD_SIMD_H
+
+#include <cuda/std/detail/__config>
+
+#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
+#  pragma GCC system_header
+#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
+#  pragma clang system_header
+#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
+#  pragma system_header
+#endif // no system header
+
+#include <cuda/std/__cstddef/types.h>
+#include <cuda/std/__simd/abi.h>
+#include <cuda/std/__simd/exposition.h>
+
+#include <cuda/std/__cccl/prologue.h>
+
+_CCCL_BEGIN_NAMESPACE_CUDA_STD_SIMD
+
+template <typename _Tp, typename _Abi = native<_Tp>, typename = void>
+class basic_vec;
+
+template <size_t _Bytes, typename _Abi = native<__integer_from<_Bytes>>, typename = void>
+class basic_mask;
+
+template <typename _Tp, __simd_size_type _Np = __simd_size_v<_Tp, native<_Tp>>>
+using vec = basic_vec<_Tp, __deduce_abi_t<_Tp, _Np>>;
+
+template <typename _Tp, __simd_size_type _Np = __simd_size_v<_Tp, native<_Tp>>>
+using mask = basic_mask<sizeof(_Tp), __deduce_abi_t<_Tp, _Np>>;
+
+// specializations
+
+template <typename _Tp, typename _Abi>
+struct __simd_storage;
+
+template <typename _Tp, typename _Abi>
+struct __simd_operations;
+
+template <size_t _Bytes, typename _Abi>
+struct __mask_storage;
+
+template <size_t _Bytes, typename _Abi>
+struct __mask_operations;
+
+_CCCL_END_NAMESPACE_CUDA_STD_SIMD
+
+#include <cuda/std/__cccl/epilogue.h>
+
+#endif // _CUDA_STD___FWD_SIMD_H

libcudacxx/include/cuda/std/__internal/namespaces.h

@@ -77,6 +77,10 @@
 #define _CCCL_BEGIN_NAMESPACE_CUDA_DRIVER              _CCCL_BEGIN_NAMESPACE(cuda::__driver)
 #define _CCCL_END_NAMESPACE_CUDA_DRIVER                _CCCL_END_NAMESPACE(cuda::__driver)
 
+// Namespaces related to <simd>
+#define _CCCL_BEGIN_NAMESPACE_CUDA_STD_SIMD _CCCL_BEGIN_NAMESPACE(cuda::std::simd)
+#define _CCCL_END_NAMESPACE_CUDA_STD_SIMD   _CCCL_END_NAMESPACE(cuda::std::simd)
+
 // Namespaces related to <ranges>
 #define _CCCL_BEGIN_NAMESPACE_CUDA_STD_RANGES _CCCL_BEGIN_NAMESPACE(cuda::std::ranges)
 #define _CCCL_END_NAMESPACE_CUDA_STD_RANGES   _CCCL_END_NAMESPACE(cuda::std::ranges)

libcudacxx/include/cuda/std/__simd/abi.h

@@ -0,0 +1,50 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of libcu++ in the CUDA C++ Core Libraries,
+// under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+// SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _CUDA_STD___SIMD_ABI_H
+#define _CUDA_STD___SIMD_ABI_H
+
+#include <cuda/std/detail/__config>
+
+#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
+#  pragma GCC system_header
+#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
+#  pragma clang system_header
+#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
+#  pragma system_header
+#endif // no system header
+
+#include <cuda/std/__cstddef/types.h>
+
+#include <cuda/std/__cccl/prologue.h>
+
+_CCCL_BEGIN_NAMESPACE_CUDA_STD_SIMD
+
+using __simd_size_type = ptrdiff_t;
+
+// [simd.expos.abi], simd ABI tags
+template <__simd_size_type _Np>
+struct __fixed_size; // internal ABI tag
+
+template <__simd_size_type _Np>
+using fixed_size = __fixed_size<_Np>; // implementation-defined ABI
+
+// TODO(fbusato): this could be optimized by using max access size / sizeof(T)
+template <typename>
+using native = fixed_size<1>; // implementation-defined ABI
+
+template <typename, __simd_size_type _Np>
+using __deduce_abi_t = fixed_size<_Np>; // exposition-only
+
+_CCCL_END_NAMESPACE_CUDA_STD_SIMD
+
+#include <cuda/std/__cccl/epilogue.h>
+
+#endif // _CUDA_STD___SIMD_ABI_H