1fe6060f1SDimitry Andric // -*- C++ -*- 2fe6060f1SDimitry Andric //===----------------------------------------------------------------------===// 3fe6060f1SDimitry Andric // 4fe6060f1SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5fe6060f1SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 6fe6060f1SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7fe6060f1SDimitry Andric // 8fe6060f1SDimitry Andric //===----------------------------------------------------------------------===// 9fe6060f1SDimitry Andric 10fe6060f1SDimitry Andric #ifndef _LIBCPP___ALGORITHM_COUNT_H 11fe6060f1SDimitry Andric #define _LIBCPP___ALGORITHM_COUNT_H 12fe6060f1SDimitry Andric 135f757f3fSDimitry Andric #include <__algorithm/iterator_operations.h> 145f757f3fSDimitry Andric #include <__algorithm/min.h> 155f757f3fSDimitry Andric #include <__bit/invert_if.h> 165f757f3fSDimitry Andric #include <__bit/popcount.h> 17fe6060f1SDimitry Andric #include <__config> 185f757f3fSDimitry Andric #include <__functional/identity.h> 195f757f3fSDimitry Andric #include <__functional/invoke.h> 205f757f3fSDimitry Andric #include <__fwd/bit_reference.h> 21fe6060f1SDimitry Andric #include <__iterator/iterator_traits.h> 22fe6060f1SDimitry Andric 23fe6060f1SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 24fe6060f1SDimitry Andric # pragma GCC system_header 25fe6060f1SDimitry Andric #endif 26fe6060f1SDimitry Andric 275f757f3fSDimitry Andric _LIBCPP_PUSH_MACROS 285f757f3fSDimitry Andric #include <__undef_macros> 295f757f3fSDimitry Andric 30fe6060f1SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 31fe6060f1SDimitry Andric 325f757f3fSDimitry Andric // generic implementation 335f757f3fSDimitry Andric template <class _AlgPolicy, class _Iter, class _Sent, class _Tp, class _Proj> 345f757f3fSDimitry Andric _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 typename _IterOps<_AlgPolicy>::template __difference_type<_Iter> 355f757f3fSDimitry Andric __count(_Iter __first, _Sent __last, const _Tp& __value, _Proj& __proj) { 365f757f3fSDimitry Andric typename _IterOps<_AlgPolicy>::template __difference_type<_Iter> __r(0); 37fe6060f1SDimitry Andric for (; __first != __last; ++__first) 385f757f3fSDimitry Andric if (std::__invoke(__proj, *__first) == __value) 39fe6060f1SDimitry Andric ++__r; 40fe6060f1SDimitry Andric return __r; 41fe6060f1SDimitry Andric } 42fe6060f1SDimitry Andric 435f757f3fSDimitry Andric // __bit_iterator implementation 445f757f3fSDimitry Andric template <bool _ToCount, class _Cp, bool _IsConst> 455f757f3fSDimitry Andric _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 typename __bit_iterator<_Cp, _IsConst>::difference_type 465f757f3fSDimitry Andric __count_bool(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n) { 475f757f3fSDimitry Andric using _It = __bit_iterator<_Cp, _IsConst>; 485f757f3fSDimitry Andric using __storage_type = typename _It::__storage_type; 495f757f3fSDimitry Andric using difference_type = typename _It::difference_type; 505f757f3fSDimitry Andric 515f757f3fSDimitry Andric const int __bits_per_word = _It::__bits_per_word; 525f757f3fSDimitry Andric difference_type __r = 0; 535f757f3fSDimitry Andric // do first partial word 545f757f3fSDimitry Andric if (__first.__ctz_ != 0) { 555f757f3fSDimitry Andric __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_); 565f757f3fSDimitry Andric __storage_type __dn = std::min(__clz_f, __n); 575f757f3fSDimitry Andric __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn)); 585f757f3fSDimitry Andric __r = std::__libcpp_popcount(std::__invert_if<!_ToCount>(*__first.__seg_) & __m); 595f757f3fSDimitry Andric __n -= __dn; 605f757f3fSDimitry Andric ++__first.__seg_; 615f757f3fSDimitry Andric } 625f757f3fSDimitry Andric // do middle whole words 635f757f3fSDimitry Andric for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word) 645f757f3fSDimitry Andric __r += std::__libcpp_popcount(std::__invert_if<!_ToCount>(*__first.__seg_)); 655f757f3fSDimitry Andric // do last partial word 665f757f3fSDimitry Andric if (__n > 0) { 675f757f3fSDimitry Andric __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n); 685f757f3fSDimitry Andric __r += std::__libcpp_popcount(std::__invert_if<!_ToCount>(*__first.__seg_) & __m); 695f757f3fSDimitry Andric } 705f757f3fSDimitry Andric return __r; 715f757f3fSDimitry Andric } 725f757f3fSDimitry Andric 735f757f3fSDimitry Andric template <class, class _Cp, bool _IsConst, class _Tp, class _Proj, __enable_if_t<__is_identity<_Proj>::value, int> = 0> 745f757f3fSDimitry Andric _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __iter_diff_t<__bit_iterator<_Cp, _IsConst> > 755f757f3fSDimitry Andric __count(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, const _Tp& __value, _Proj&) { 765f757f3fSDimitry Andric if (__value) 775f757f3fSDimitry Andric return std::__count_bool<true>(__first, static_cast<typename _Cp::size_type>(__last - __first)); 785f757f3fSDimitry Andric return std::__count_bool<false>(__first, static_cast<typename _Cp::size_type>(__last - __first)); 795f757f3fSDimitry Andric } 805f757f3fSDimitry Andric 815f757f3fSDimitry Andric template <class _InputIterator, class _Tp> 82*0fca6ea1SDimitry Andric _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __iter_diff_t<_InputIterator> 835f757f3fSDimitry Andric count(_InputIterator __first, _InputIterator __last, const _Tp& __value) { 845f757f3fSDimitry Andric __identity __proj; 855f757f3fSDimitry Andric return std::__count<_ClassicAlgPolicy>(__first, __last, __value, __proj); 865f757f3fSDimitry Andric } 875f757f3fSDimitry Andric 88fe6060f1SDimitry Andric _LIBCPP_END_NAMESPACE_STD 89fe6060f1SDimitry Andric 905f757f3fSDimitry Andric _LIBCPP_POP_MACROS 915f757f3fSDimitry Andric 92fe6060f1SDimitry Andric #endif // _LIBCPP___ALGORITHM_COUNT_H 93