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___ALGORITHM_PSTL_BACKENDS_CPU_BACKEND_ANY_OF_H 10 #define _LIBCPP___ALGORITHM_PSTL_BACKENDS_CPU_BACKEND_ANY_OF_H 11 12 #include <__algorithm/any_of.h> 13 #include <__algorithm/find_if.h> 14 #include <__algorithm/pstl_backends/cpu_backends/backend.h> 15 #include <__atomic/atomic.h> 16 #include <__atomic/memory_order.h> 17 #include <__config> 18 #include <__functional/operations.h> 19 #include <__iterator/concepts.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 #if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17 27 28 _LIBCPP_PUSH_MACROS 29 # include <__undef_macros> 30 31 _LIBCPP_BEGIN_NAMESPACE_STD 32 33 template <class _Index, class _Brick> 34 _LIBCPP_HIDE_FROM_ABI optional<bool> __parallel_or(_Index __first, _Index __last, _Brick __f) { 35 std::atomic<bool> __found(false); 36 auto __ret = __par_backend::__parallel_for(__first, __last, [__f, &__found](_Index __i, _Index __j) { 37 if (!__found.load(std::memory_order_relaxed) && __f(__i, __j)) { 38 __found.store(true, std::memory_order_relaxed); 39 __par_backend::__cancel_execution(); 40 } 41 }); 42 if (!__ret) 43 return nullopt; 44 return static_cast<bool>(__found); 45 } 46 47 // TODO: check whether __simd_first() can be used here 48 template <class _Index, class _DifferenceType, class _Pred> 49 _LIBCPP_HIDE_FROM_ABI bool __simd_or(_Index __first, _DifferenceType __n, _Pred __pred) noexcept { 50 _DifferenceType __block_size = 4 < __n ? 4 : __n; 51 const _Index __last = __first + __n; 52 while (__last != __first) { 53 int32_t __flag = 1; 54 _PSTL_PRAGMA_SIMD_REDUCTION(& : __flag) 55 for (_DifferenceType __i = 0; __i < __block_size; ++__i) 56 if (__pred(*(__first + __i))) 57 __flag = 0; 58 if (!__flag) 59 return true; 60 61 __first += __block_size; 62 if (__last - __first >= __block_size << 1) { 63 // Double the block _Size. Any unnecessary iterations can be amortized against work done so far. 64 __block_size <<= 1; 65 } else { 66 __block_size = __last - __first; 67 } 68 } 69 return false; 70 } 71 72 template <class _ExecutionPolicy, class _ForwardIterator, class _Predicate> 73 _LIBCPP_HIDE_FROM_ABI optional<bool> 74 __pstl_any_of(__cpu_backend_tag, _ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) { 75 if constexpr (__is_parallel_execution_policy_v<_ExecutionPolicy> && 76 __has_random_access_iterator_category_or_concept<_ForwardIterator>::value) { 77 return std::__parallel_or( 78 __first, __last, [&__pred](_ForwardIterator __brick_first, _ForwardIterator __brick_last) { 79 auto __res = std::__pstl_any_of<__remove_parallel_policy_t<_ExecutionPolicy>>( 80 __cpu_backend_tag{}, __brick_first, __brick_last, __pred); 81 _LIBCPP_ASSERT_INTERNAL(__res, "unseq/seq should never try to allocate!"); 82 return *std::move(__res); 83 }); 84 } else if constexpr (__is_unsequenced_execution_policy_v<_ExecutionPolicy> && 85 __has_random_access_iterator_category_or_concept<_ForwardIterator>::value) { 86 return std::__simd_or(__first, __last - __first, __pred); 87 } else { 88 return std::any_of(__first, __last, __pred); 89 } 90 } 91 92 _LIBCPP_END_NAMESPACE_STD 93 94 _LIBCPP_POP_MACROS 95 96 #endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17 97 98 #endif // _LIBCPP___ALGORITHM_PSTL_BACKENDS_CPU_BACKEND_ANY_OF_H 99