| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___ALGORITHM_SORT_H |
| #define _LIBCPP___ALGORITHM_SORT_H |
| |
| #include <__config> |
| #include <__algorithm/comp.h> |
| #include <__algorithm/comp_ref_type.h> |
| #include <__algorithm/min_element.h> |
| #include <__algorithm/partial_sort.h> |
| #include <__algorithm/unwrap_iter.h> |
| #include <__utility/swap.h> |
| #include <memory> |
| #include <type_traits> // swap |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| #pragma GCC system_header |
| #endif |
| |
| _LIBCPP_PUSH_MACROS |
| #include <__undef_macros> |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| // stable, 2-3 compares, 0-2 swaps |
| |
| template <class _Compare, class _ForwardIterator> |
| _LIBCPP_CONSTEXPR_AFTER_CXX11 unsigned |
| __sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z, _Compare __c) |
| { |
| unsigned __r = 0; |
| if (!__c(*__y, *__x)) // if x <= y |
| { |
| if (!__c(*__z, *__y)) // if y <= z |
| return __r; // x <= y && y <= z |
| // x <= y && y > z |
| swap(*__y, *__z); // x <= z && y < z |
| __r = 1; |
| if (__c(*__y, *__x)) // if x > y |
| { |
| swap(*__x, *__y); // x < y && y <= z |
| __r = 2; |
| } |
| return __r; // x <= y && y < z |
| } |
| if (__c(*__z, *__y)) // x > y, if y > z |
| { |
| swap(*__x, *__z); // x < y && y < z |
| __r = 1; |
| return __r; |
| } |
| swap(*__x, *__y); // x > y && y <= z |
| __r = 1; // x < y && x <= z |
| if (__c(*__z, *__y)) // if y > z |
| { |
| swap(*__y, *__z); // x <= y && y < z |
| __r = 2; |
| } |
| return __r; |
| } // x <= y && y <= z |
| |
| // stable, 3-6 compares, 0-5 swaps |
| |
| template <class _Compare, class _ForwardIterator> |
| unsigned |
| __sort4(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3, |
| _ForwardIterator __x4, _Compare __c) |
| { |
| unsigned __r = _VSTD::__sort3<_Compare>(__x1, __x2, __x3, __c); |
| if (__c(*__x4, *__x3)) |
| { |
| swap(*__x3, *__x4); |
| ++__r; |
| if (__c(*__x3, *__x2)) |
| { |
| swap(*__x2, *__x3); |
| ++__r; |
| if (__c(*__x2, *__x1)) |
| { |
| swap(*__x1, *__x2); |
| ++__r; |
| } |
| } |
| } |
| return __r; |
| } |
| |
| // stable, 4-10 compares, 0-9 swaps |
| |
| template <class _Compare, class _ForwardIterator> |
| _LIBCPP_HIDDEN |
| unsigned |
| __sort5(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3, |
| _ForwardIterator __x4, _ForwardIterator __x5, _Compare __c) |
| { |
| unsigned __r = _VSTD::__sort4<_Compare>(__x1, __x2, __x3, __x4, __c); |
| if (__c(*__x5, *__x4)) |
| { |
| swap(*__x4, *__x5); |
| ++__r; |
| if (__c(*__x4, *__x3)) |
| { |
| swap(*__x3, *__x4); |
| ++__r; |
| if (__c(*__x3, *__x2)) |
| { |
| swap(*__x2, *__x3); |
| ++__r; |
| if (__c(*__x2, *__x1)) |
| { |
| swap(*__x1, *__x2); |
| ++__r; |
| } |
| } |
| } |
| } |
| return __r; |
| } |
| |
| // Assumes size > 0 |
| template <class _Compare, class _BidirectionalIterator> |
| _LIBCPP_CONSTEXPR_AFTER_CXX11 void |
| __selection_sort(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp) |
| { |
| _BidirectionalIterator __lm1 = __last; |
| for (--__lm1; __first != __lm1; ++__first) |
| { |
| _BidirectionalIterator __i = _VSTD::min_element<_BidirectionalIterator, |
| typename add_lvalue_reference<_Compare>::type> |
| (__first, __last, __comp); |
| if (__i != __first) |
| swap(*__first, *__i); |
| } |
| } |
| |
| template <class _Compare, class _BidirectionalIterator> |
| void |
| __insertion_sort(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp) |
| { |
| typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type; |
| if (__first != __last) |
| { |
| _BidirectionalIterator __i = __first; |
| for (++__i; __i != __last; ++__i) |
| { |
| _BidirectionalIterator __j = __i; |
| value_type __t(_VSTD::move(*__j)); |
| for (_BidirectionalIterator __k = __i; __k != __first && __comp(__t, *--__k); --__j) |
| *__j = _VSTD::move(*__k); |
| *__j = _VSTD::move(__t); |
| } |
| } |
| } |
| |
| template <class _Compare, class _RandomAccessIterator> |
| void |
| __insertion_sort_3(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) |
| { |
| typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type; |
| _RandomAccessIterator __j = __first+2; |
| _VSTD::__sort3<_Compare>(__first, __first+1, __j, __comp); |
| for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i) |
| { |
| if (__comp(*__i, *__j)) |
| { |
| value_type __t(_VSTD::move(*__i)); |
| _RandomAccessIterator __k = __j; |
| __j = __i; |
| do |
| { |
| *__j = _VSTD::move(*__k); |
| __j = __k; |
| } while (__j != __first && __comp(__t, *--__k)); |
| *__j = _VSTD::move(__t); |
| } |
| __j = __i; |
| } |
| } |
| |
| template <class _Compare, class _RandomAccessIterator> |
| bool |
| __insertion_sort_incomplete(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) |
| { |
| switch (__last - __first) |
| { |
| case 0: |
| case 1: |
| return true; |
| case 2: |
| if (__comp(*--__last, *__first)) |
| swap(*__first, *__last); |
| return true; |
| case 3: |
| _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp); |
| return true; |
| case 4: |
| _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp); |
| return true; |
| case 5: |
| _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp); |
| return true; |
| } |
| typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type; |
| _RandomAccessIterator __j = __first+2; |
| _VSTD::__sort3<_Compare>(__first, __first+1, __j, __comp); |
| const unsigned __limit = 8; |
| unsigned __count = 0; |
| for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i) |
| { |
| if (__comp(*__i, *__j)) |
| { |
| value_type __t(_VSTD::move(*__i)); |
| _RandomAccessIterator __k = __j; |
| __j = __i; |
| do |
| { |
| *__j = _VSTD::move(*__k); |
| __j = __k; |
| } while (__j != __first && __comp(__t, *--__k)); |
| *__j = _VSTD::move(__t); |
| if (++__count == __limit) |
| return ++__i == __last; |
| } |
| __j = __i; |
| } |
| return true; |
| } |
| |
| template <class _Compare, class _BidirectionalIterator> |
| void |
| __insertion_sort_move(_BidirectionalIterator __first1, _BidirectionalIterator __last1, |
| typename iterator_traits<_BidirectionalIterator>::value_type* __first2, _Compare __comp) |
| { |
| typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type; |
| if (__first1 != __last1) |
| { |
| __destruct_n __d(0); |
| unique_ptr<value_type, __destruct_n&> __h(__first2, __d); |
| value_type* __last2 = __first2; |
| ::new ((void*)__last2) value_type(_VSTD::move(*__first1)); |
| __d.template __incr<value_type>(); |
| for (++__last2; ++__first1 != __last1; ++__last2) |
| { |
| value_type* __j2 = __last2; |
| value_type* __i2 = __j2; |
| if (__comp(*__first1, *--__i2)) |
| { |
| ::new ((void*)__j2) value_type(_VSTD::move(*__i2)); |
| __d.template __incr<value_type>(); |
| for (--__j2; __i2 != __first2 && __comp(*__first1, *--__i2); --__j2) |
| *__j2 = _VSTD::move(*__i2); |
| *__j2 = _VSTD::move(*__first1); |
| } |
| else |
| { |
| ::new ((void*)__j2) value_type(_VSTD::move(*__first1)); |
| __d.template __incr<value_type>(); |
| } |
| } |
| __h.release(); |
| } |
| } |
| |
| template <class _Compare, class _RandomAccessIterator> |
| void |
| __sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) |
| { |
| typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type; |
| typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type; |
| const difference_type __limit = is_trivially_copy_constructible<value_type>::value && |
| is_trivially_copy_assignable<value_type>::value ? 30 : 6; |
| while (true) |
| { |
| __restart: |
| difference_type __len = __last - __first; |
| switch (__len) |
| { |
| case 0: |
| case 1: |
| return; |
| case 2: |
| if (__comp(*--__last, *__first)) |
| swap(*__first, *__last); |
| return; |
| case 3: |
| _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp); |
| return; |
| case 4: |
| _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp); |
| return; |
| case 5: |
| _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp); |
| return; |
| } |
| if (__len <= __limit) |
| { |
| _VSTD::__insertion_sort_3<_Compare>(__first, __last, __comp); |
| return; |
| } |
| // __len > 5 |
| _RandomAccessIterator __m = __first; |
| _RandomAccessIterator __lm1 = __last; |
| --__lm1; |
| unsigned __n_swaps; |
| { |
| difference_type __delta; |
| if (__len >= 1000) |
| { |
| __delta = __len/2; |
| __m += __delta; |
| __delta /= 2; |
| __n_swaps = _VSTD::__sort5<_Compare>(__first, __first + __delta, __m, __m+__delta, __lm1, __comp); |
| } |
| else |
| { |
| __delta = __len/2; |
| __m += __delta; |
| __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, __lm1, __comp); |
| } |
| } |
| // *__m is median |
| // partition [__first, __m) < *__m and *__m <= [__m, __last) |
| // (this inhibits tossing elements equivalent to __m around unnecessarily) |
| _RandomAccessIterator __i = __first; |
| _RandomAccessIterator __j = __lm1; |
| // j points beyond range to be tested, *__m is known to be <= *__lm1 |
| // The search going up is known to be guarded but the search coming down isn't. |
| // Prime the downward search with a guard. |
| if (!__comp(*__i, *__m)) // if *__first == *__m |
| { |
| // *__first == *__m, *__first doesn't go in first part |
| // manually guard downward moving __j against __i |
| while (true) |
| { |
| if (__i == --__j) |
| { |
| // *__first == *__m, *__m <= all other elements |
| // Parition instead into [__first, __i) == *__first and *__first < [__i, __last) |
| ++__i; // __first + 1 |
| __j = __last; |
| if (!__comp(*__first, *--__j)) // we need a guard if *__first == *(__last-1) |
| { |
| while (true) |
| { |
| if (__i == __j) |
| return; // [__first, __last) all equivalent elements |
| if (__comp(*__first, *__i)) |
| { |
| swap(*__i, *__j); |
| ++__n_swaps; |
| ++__i; |
| break; |
| } |
| ++__i; |
| } |
| } |
| // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1 |
| if (__i == __j) |
| return; |
| while (true) |
| { |
| while (!__comp(*__first, *__i)) |
| ++__i; |
| while (__comp(*__first, *--__j)) |
| ; |
| if (__i >= __j) |
| break; |
| swap(*__i, *__j); |
| ++__n_swaps; |
| ++__i; |
| } |
| // [__first, __i) == *__first and *__first < [__i, __last) |
| // The first part is sorted, sort the second part |
| // _VSTD::__sort<_Compare>(__i, __last, __comp); |
| __first = __i; |
| goto __restart; |
| } |
| if (__comp(*__j, *__m)) |
| { |
| swap(*__i, *__j); |
| ++__n_swaps; |
| break; // found guard for downward moving __j, now use unguarded partition |
| } |
| } |
| } |
| // It is known that *__i < *__m |
| ++__i; |
| // j points beyond range to be tested, *__m is known to be <= *__lm1 |
| // if not yet partitioned... |
| if (__i < __j) |
| { |
| // known that *(__i - 1) < *__m |
| // known that __i <= __m |
| while (true) |
| { |
| // __m still guards upward moving __i |
| while (__comp(*__i, *__m)) |
| ++__i; |
| // It is now known that a guard exists for downward moving __j |
| while (!__comp(*--__j, *__m)) |
| ; |
| if (__i > __j) |
| break; |
| swap(*__i, *__j); |
| ++__n_swaps; |
| // It is known that __m != __j |
| // If __m just moved, follow it |
| if (__m == __i) |
| __m = __j; |
| ++__i; |
| } |
| } |
| // [__first, __i) < *__m and *__m <= [__i, __last) |
| if (__i != __m && __comp(*__m, *__i)) |
| { |
| swap(*__i, *__m); |
| ++__n_swaps; |
| } |
| // [__first, __i) < *__i and *__i <= [__i+1, __last) |
| // If we were given a perfect partition, see if insertion sort is quick... |
| if (__n_swaps == 0) |
| { |
| bool __fs = _VSTD::__insertion_sort_incomplete<_Compare>(__first, __i, __comp); |
| if (_VSTD::__insertion_sort_incomplete<_Compare>(__i+1, __last, __comp)) |
| { |
| if (__fs) |
| return; |
| __last = __i; |
| continue; |
| } |
| else |
| { |
| if (__fs) |
| { |
| __first = ++__i; |
| continue; |
| } |
| } |
| } |
| // sort smaller range with recursive call and larger with tail recursion elimination |
| if (__i - __first < __last - __i) |
| { |
| _VSTD::__sort<_Compare>(__first, __i, __comp); |
| // _VSTD::__sort<_Compare>(__i+1, __last, __comp); |
| __first = ++__i; |
| } |
| else |
| { |
| _VSTD::__sort<_Compare>(__i+1, __last, __comp); |
| // _VSTD::__sort<_Compare>(__first, __i, __comp); |
| __last = __i; |
| } |
| } |
| } |
| |
| template <class _Compare, class _Tp> |
| inline _LIBCPP_INLINE_VISIBILITY |
| void |
| __sort(_Tp** __first, _Tp** __last, __less<_Tp*>&) |
| { |
| __less<uintptr_t> __comp; |
| _VSTD::__sort<__less<uintptr_t>&, uintptr_t*>((uintptr_t*)__first, (uintptr_t*)__last, __comp); |
| } |
| |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<char>&, char*>(char*, char*, __less<char>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<short>&, short*>(short*, short*, __less<short>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<int>&, int*>(int*, int*, __less<int>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long>&, long*>(long*, long*, __less<long>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long long>&, long long*>(long long*, long long*, __less<long long>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<float>&, float*>(float*, float*, __less<float>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<double>&, double*>(double*, double*, __less<double>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long double>&, long double*>(long double*, long double*, __less<long double>&)) |
| |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<char>&, char*>(char*, char*, __less<char>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<short>&, short*>(short*, short*, __less<short>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<int>&, int*>(int*, int*, __less<int>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long>&, long*>(long*, long*, __less<long>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long long>&, long long*>(long long*, long long*, __less<long long>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<float>&, float*>(float*, float*, __less<float>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<double>&, double*>(double*, double*, __less<double>&)) |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long double>&, long double*>(long double*, long double*, __less<long double>&)) |
| |
| _LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS unsigned __sort5<__less<long double>&, long double*>(long double*, long double*, long double*, long double*, long double*, __less<long double>&)) |
| |
| template <class _RandomAccessIterator, class _Compare> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 |
| void |
| sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) |
| { |
| typedef typename __comp_ref_type<_Compare>::type _Comp_ref; |
| if (__libcpp_is_constant_evaluated()) { |
| _VSTD::__partial_sort<_Comp_ref>(__first, __last, __last, _Comp_ref(__comp)); |
| } else { |
| _VSTD::__sort<_Comp_ref>(_VSTD::__unwrap_iter(__first), _VSTD::__unwrap_iter(__last), _Comp_ref(__comp)); |
| } |
| } |
| |
| template <class _RandomAccessIterator> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 |
| void |
| sort(_RandomAccessIterator __first, _RandomAccessIterator __last) |
| { |
| _VSTD::sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>()); |
| } |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| _LIBCPP_POP_MACROS |
| |
| #endif // _LIBCPP___ALGORITHM_SORT_H |
