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_ANY_OF_H 10 #define _LIBCPP___PSTL_CPU_ALGOS_ANY_OF_H 11 12 #include <__algorithm/any_of.h> 13 #include <__assert> 14 #include <__atomic/atomic.h> 15 #include <__atomic/memory_order.h> 16 #include <__config> 17 #include <__iterator/concepts.h> 18 #include <__pstl/backend_fwd.h> 19 #include <__pstl/cpu_algos/cpu_traits.h> 20 #include <__type_traits/is_execution_policy.h> 21 #include <__utility/move.h> 22 #include <__utility/pair.h> 23 #include <cstdint> 24 #include <optional> 25 26 _LIBCPP_PUSH_MACROS 27 #include <__undef_macros> 28 29 #if _LIBCPP_STD_VER >= 17 30 31 _LIBCPP_BEGIN_NAMESPACE_STD 32 namespace __pstl { 33 34 template <class _Backend, class _Index, class _Brick> 35 _LIBCPP_HIDE_FROM_ABI optional<bool> __parallel_or(_Index __first, _Index __last, _Brick __f) { 36 std::atomic<bool> __found(false); 37 auto __ret = __cpu_traits<_Backend>::__for_each(__first, __last, [__f, &__found](_Index __i, _Index __j) { 38 if (!__found.load(std::memory_order_relaxed) && __f(__i, __j)) { 39 __found.store(true, std::memory_order_relaxed); 40 __cpu_traits<_Backend>::__cancel_execution(); 41 } 42 }); 43 if (!__ret) 44 return nullopt; 45 return static_cast<bool>(__found); 46 } 47 48 // TODO: check whether __simd_first() can be used here 49 template <class _Index, class _DifferenceType, class _Pred> 50 _LIBCPP_HIDE_FROM_ABI bool __simd_or(_Index __first, _DifferenceType __n, _Pred __pred) noexcept { 51 _DifferenceType __block_size = 4 < __n ? 4 : __n; 52 const _Index __last = __first + __n; 53 while (__last != __first) { 54 int32_t __flag = 1; 55 _PSTL_PRAGMA_SIMD_REDUCTION(& : __flag) 56 for (_DifferenceType __i = 0; __i < __block_size; ++__i) 57 if (__pred(*(__first + __i))) 58 __flag = 0; 59 if (!__flag) 60 return true; 61 62 __first += __block_size; 63 if (__last - __first >= __block_size << 1) { 64 // Double the block _Size. Any unnecessary iterations can be amortized against work done so far. 65 __block_size <<= 1; 66 } else { 67 __block_size = __last - __first; 68 } 69 } 70 return false; 71 } 72 73 template <class _Backend, class _RawExecutionPolicy> 74 struct __cpu_parallel_any_of { 75 template <class _Policy, class _ForwardIterator, class _Predicate> 76 _LIBCPP_HIDE_FROM_ABI optional<bool> 77 operator()(_Policy&& __policy, _ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) const noexcept { 78 if constexpr (__is_parallel_execution_policy_v<_RawExecutionPolicy> && 79 __has_random_access_iterator_category_or_concept<_ForwardIterator>::value) { 80 return __pstl::__parallel_or<_Backend>( 81 __first, __last, [&__policy, &__pred](_ForwardIterator __brick_first, _ForwardIterator __brick_last) { 82 using _AnyOfUnseq = __pstl::__any_of<_Backend, __remove_parallel_policy_t<_RawExecutionPolicy>>; 83 auto __res = _AnyOfUnseq()(std::__remove_parallel_policy(__policy), __brick_first, __brick_last, __pred); 84 _LIBCPP_ASSERT_INTERNAL(__res, "unseq/seq should never try to allocate!"); 85 return *std::move(__res); 86 }); 87 } else if constexpr (__is_unsequenced_execution_policy_v<_RawExecutionPolicy> && 88 __has_random_access_iterator_category_or_concept<_ForwardIterator>::value) { 89 return __pstl::__simd_or(__first, __last - __first, __pred); 90 } else { 91 return std::any_of(__first, __last, __pred); 92 } 93 } 94 }; 95 96 } // namespace __pstl 97 _LIBCPP_END_NAMESPACE_STD 98 99 #endif // _LIBCPP_STD_VER >= 17 100 101 _LIBCPP_POP_MACROS 102 103 #endif // _LIBCPP___PSTL_CPU_ALGOS_ANY_OF_H 104