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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
32namespace __pstl {
33
34template <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
49template <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
73template <class _Backend, class _RawExecutionPolicy>
74struct __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

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source code of libcxx/include/__pstl/cpu_algos/any_of.h