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 _LIBCPP_BEGIN_NAMESPACE_STD
30 namespace __pstl {
31
32 template <class _Backend, class _Index, class _Brick>
__parallel_or(_Index __first,_Index __last,_Brick __f)33 _LIBCPP_HIDE_FROM_ABI optional<bool> __parallel_or(_Index __first, _Index __last, _Brick __f) {
34 std::atomic<bool> __found(false);
35 auto __ret = __cpu_traits<_Backend>::__for_each(__first, __last, [__f, &__found](_Index __i, _Index __j) {
36 if (!__found.load(std::memory_order_relaxed) && __f(__i, __j)) {
37 __found.store(true, std::memory_order_relaxed);
38 __cpu_traits<_Backend>::__cancel_execution();
39 }
40 });
41 if (!__ret)
42 return nullopt;
43 return static_cast<bool>(__found);
44 }
45
46 // TODO: check whether __simd_first() can be used here
47 template <class _Index, class _DifferenceType, class _Pred>
__simd_or(_Index __first,_DifferenceType __n,_Pred __pred)48 _LIBCPP_HIDE_FROM_ABI bool __simd_or(_Index __first, _DifferenceType __n, _Pred __pred) noexcept {
49 _DifferenceType __block_size = 4 < __n ? 4 : __n;
50 const _Index __last = __first + __n;
51 while (__last != __first) {
52 int32_t __flag = 1;
53 _PSTL_PRAGMA_SIMD_REDUCTION(& : __flag)
54 for (_DifferenceType __i = 0; __i < __block_size; ++__i)
55 if (__pred(*(__first + __i)))
56 __flag = 0;
57 if (!__flag)
58 return true;
59
60 __first += __block_size;
61 if (__last - __first >= __block_size << 1) {
62 // Double the block _Size. Any unnecessary iterations can be amortized against work done so far.
63 __block_size <<= 1;
64 } else {
65 __block_size = __last - __first;
66 }
67 }
68 return false;
69 }
70
71 template <class _Backend, class _RawExecutionPolicy>
72 struct __cpu_parallel_any_of {
73 template <class _Policy, class _ForwardIterator, class _Predicate>
74 _LIBCPP_HIDE_FROM_ABI optional<bool>
operator__cpu_parallel_any_of75 operator()(_Policy&& __policy, _ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) const noexcept {
76 if constexpr (__is_parallel_execution_policy_v<_RawExecutionPolicy> &&
77 __has_random_access_iterator_category_or_concept<_ForwardIterator>::value) {
78 return __pstl::__parallel_or<_Backend>(
79 __first, __last, [&__policy, &__pred](_ForwardIterator __brick_first, _ForwardIterator __brick_last) {
80 using _AnyOfUnseq = __pstl::__any_of<_Backend, __remove_parallel_policy_t<_RawExecutionPolicy>>;
81 auto __res = _AnyOfUnseq()(std::__remove_parallel_policy(__policy), __brick_first, __brick_last, __pred);
82 _LIBCPP_ASSERT_INTERNAL(__res, "unseq/seq should never try to allocate!");
83 return *std::move(__res);
84 });
85 } else if constexpr (__is_unsequenced_execution_policy_v<_RawExecutionPolicy> &&
86 __has_random_access_iterator_category_or_concept<_ForwardIterator>::value) {
87 return __pstl::__simd_or(__first, __last - __first, __pred);
88 } else {
89 return std::any_of(__first, __last, __pred);
90 }
91 }
92 };
93
94 } // namespace __pstl
95 _LIBCPP_END_NAMESPACE_STD
96
97 _LIBCPP_POP_MACROS
98
99 #endif // _LIBCPP___PSTL_CPU_ALGOS_ANY_OF_H
100