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Diffstat (limited to 'contrib/llvm-project/clang/lib/Headers/cuda_wrappers/algorithm')
| -rw-r--r-- | contrib/llvm-project/clang/lib/Headers/cuda_wrappers/algorithm | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/contrib/llvm-project/clang/lib/Headers/cuda_wrappers/algorithm b/contrib/llvm-project/clang/lib/Headers/cuda_wrappers/algorithm new file mode 100644 index 000000000000..3f59f28ae35b --- /dev/null +++ b/contrib/llvm-project/clang/lib/Headers/cuda_wrappers/algorithm @@ -0,0 +1,116 @@ +/*===---- algorithm - CUDA wrapper for <algorithm> -------------------------=== + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + * + *===-----------------------------------------------------------------------=== + */ + +#ifndef __CLANG_CUDA_WRAPPERS_ALGORITHM +#define __CLANG_CUDA_WRAPPERS_ALGORITHM + +// This header defines __device__ overloads of std::min/max. +// +// Ideally we'd declare these functions only if we're <= C++11. In C++14, +// these functions are constexpr, and so are implicitly __host__ __device__. +// +// However, the compiler being in C++14 mode does not imply that the standard +// library supports C++14. There is no macro we can test to check that the +// stdlib has constexpr std::min/max. Thus we have to unconditionally define +// our device overloads. +// +// A host+device function cannot be overloaded, and a constexpr function +// implicitly become host device if there's no explicitly host or device +// overload preceding it. So the simple thing to do would be to declare our +// device min/max overloads, and then #include_next <algorithm>. This way our +// device overloads would come first, and so if we have a C++14 stdlib, its +// min/max won't become host+device and conflict with our device overloads. +// +// But that also doesn't work. libstdc++ is evil and declares std::min/max in +// an internal header that is included *before* <algorithm>. Thus by the time +// we're inside of this file, std::min/max may already have been declared, and +// thus we can't prevent them from becoming host+device if they're constexpr. +// +// Therefore we perpetrate the following hack: We mark our __device__ overloads +// with __attribute__((enable_if(true, ""))). This causes the signature of the +// function to change without changing anything else about it. (Except that +// overload resolution will prefer it over the __host__ __device__ version +// rather than considering them equally good). + +#include_next <algorithm> + +// We need to define these overloads in exactly the namespace our standard +// library uses (including the right inline namespace), otherwise they won't be +// picked up by other functions in the standard library (e.g. functions in +// <complex>). Thus the ugliness below. +#ifdef _LIBCPP_BEGIN_NAMESPACE_STD +_LIBCPP_BEGIN_NAMESPACE_STD +#else +namespace std { +#ifdef _GLIBCXX_BEGIN_NAMESPACE_VERSION +_GLIBCXX_BEGIN_NAMESPACE_VERSION +#endif +#endif + +#pragma push_macro("_CPP14_CONSTEXPR") +#if __cplusplus >= 201402L +#define _CPP14_CONSTEXPR constexpr +#else +#define _CPP14_CONSTEXPR +#endif + +template <class __T, class __Cmp> +__attribute__((enable_if(true, ""))) +inline _CPP14_CONSTEXPR __host__ __device__ const __T & +max(const __T &__a, const __T &__b, __Cmp __cmp) { + return __cmp(__a, __b) ? __b : __a; +} + +template <class __T> +__attribute__((enable_if(true, ""))) +inline _CPP14_CONSTEXPR __host__ __device__ const __T & +max(const __T &__a, const __T &__b) { + return __a < __b ? __b : __a; +} + +template <class __T, class __Cmp> +__attribute__((enable_if(true, ""))) +inline _CPP14_CONSTEXPR __host__ __device__ const __T & +min(const __T &__a, const __T &__b, __Cmp __cmp) { + return __cmp(__b, __a) ? __b : __a; +} + +template <class __T> +__attribute__((enable_if(true, ""))) +inline _CPP14_CONSTEXPR __host__ __device__ const __T & +min(const __T &__a, const __T &__b) { + return __b < __a ? __b : __a; +} + +#pragma pop_macro("_CPP14_CONSTEXPR") + +#ifdef _LIBCPP_END_NAMESPACE_STD +_LIBCPP_END_NAMESPACE_STD +#else +#ifdef _GLIBCXX_BEGIN_NAMESPACE_VERSION +_GLIBCXX_END_NAMESPACE_VERSION +#endif +} // namespace std +#endif + +#endif // __CLANG_CUDA_WRAPPERS_ALGORITHM |