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___CXX03___PSTL_CPU_ALGOS_ANY_OF_H 10 #define _LIBCPP___CXX03___PSTL_CPU_ALGOS_ANY_OF_H 11 12 #include <__cxx03/__algorithm/any_of.h> 13 #include <__cxx03/__assert> 14 #include <__cxx03/__atomic/atomic.h> 15 #include <__cxx03/__atomic/memory_order.h> 16 #include <__cxx03/__config> 17 #include <__cxx03/__iterator/concepts.h> 18 #include <__cxx03/__pstl/backend_fwd.h> 19 #include <__cxx03/__pstl/cpu_algos/cpu_traits.h> 20 #include <__cxx03/__type_traits/is_execution_policy.h> 21 #include <__cxx03/__utility/move.h> 22 #include <__cxx03/__utility/pair.h> 23 #include <__cxx03/cstdint> 24 #include <__cxx03/optional> 25 26 _LIBCPP_PUSH_MACROS 27 #include <__cxx03/__undef_macros> 28 29 _LIBCPP_BEGIN_NAMESPACE_STD 30 namespace __pstl { 31 32 template <class _Backend, class _Index, class _Brick> 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> 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> 75 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___CXX03___PSTL_CPU_ALGOS_ANY_OF_H 100