1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___PSTL_CPU_ALGOS_CPU_TRAITS_H 10 #define _LIBCPP___PSTL_CPU_ALGOS_CPU_TRAITS_H 11 12 #include <__config> 13 #include <cstddef> 14 15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 16 # pragma GCC system_header 17 #endif 18 19 _LIBCPP_PUSH_MACROS 20 #include <__undef_macros> 21 22 _LIBCPP_BEGIN_NAMESPACE_STD 23 namespace __pstl { 24 25 // __cpu_traits 26 // 27 // This traits class encapsulates the basis operations for a CPU-based implementation of the PSTL. 28 // All the operations in the PSTL can be implemented from these basis operations, so a pure CPU backend 29 // only needs to customize these traits in order to get an implementation of the whole PSTL. 30 // 31 // Basis operations 32 // ================ 33 // 34 // template <class _RandomAccessIterator, class _Functor> 35 // optional<__empty> __for_each(_RandomAccessIterator __first, _RandomAccessIterator __last, _Functor __func); 36 // - __func must take a subrange of [__first, __last) that should be executed in serial 37 // 38 // template <class _Iterator, class _UnaryOp, class _Tp, class _BinaryOp, class _Reduction> 39 // optional<_Tp> __transform_reduce(_Iterator __first, _Iterator __last, _UnaryOp, _Tp __init, _BinaryOp, _Reduction); 40 // 41 // template <class _RandomAccessIterator1, 42 // class _RandomAccessIterator2, 43 // class _RandomAccessIterator3, 44 // class _Compare, 45 // class _LeafMerge> 46 // optional<_RandomAccessIterator3> __merge(_RandomAccessIterator1 __first1, 47 // _RandomAccessIterator1 __last1, 48 // _RandomAccessIterator2 __first2, 49 // _RandomAccessIterator2 __last2, 50 // _RandomAccessIterator3 __outit, 51 // _Compare __comp, 52 // _LeafMerge __leaf_merge); 53 // 54 // template <class _RandomAccessIterator, class _Comp, class _LeafSort> 55 // optional<__empty> __stable_sort(_RandomAccessIterator __first, 56 // _RandomAccessIterator __last, 57 // _Comp __comp, 58 // _LeafSort __leaf_sort); 59 // 60 // void __cancel_execution(); 61 // Cancel the execution of other jobs - they aren't needed anymore. This is not a binding request, 62 // some backends may not actually be able to cancel jobs. 63 // 64 // constexpr size_t __lane_size; 65 // Size of SIMD lanes. 66 // TODO: Merge this with __native_vector_size from __algorithm/simd_utils.h 67 // 68 // 69 // Exception handling 70 // ================== 71 // 72 // CPU backends are expected to report errors (i.e. failure to allocate) by returning a disengaged `optional` from their 73 // implementation. Exceptions shouldn't be used to report an internal failure-to-allocate, since all exceptions are 74 // turned into a program termination at the front-end level. When a backend returns a disengaged `optional` to the 75 // frontend, the frontend will turn that into a call to `std::__throw_bad_alloc();` to report the internal failure to 76 // the user. 77 78 template <class _Backend> 79 struct __cpu_traits; 80 81 } // namespace __pstl 82 _LIBCPP_END_NAMESPACE_STD 83 84 _LIBCPP_POP_MACROS 85 86 #endif // _LIBCPP___PSTL_CPU_ALGOS_CPU_TRAITS_H 87