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authorDimitry Andric <dim@FreeBSD.org>2021-07-29 20:15:26 +0000
committerDimitry Andric <dim@FreeBSD.org>2021-07-29 20:15:26 +0000
commit344a3780b2e33f6ca763666c380202b18aab72a3 (patch)
treef0b203ee6eb71d7fdd792373e3c81eb18d6934dd /libcxx/include/__algorithm/sort.h
parentb60736ec1405bb0a8dd40989f67ef4c93da068ab (diff)
Diffstat (limited to 'libcxx/include/__algorithm/sort.h')
-rw-r--r--libcxx/include/__algorithm/sort.h530
1 files changed, 530 insertions, 0 deletions
diff --git a/libcxx/include/__algorithm/sort.h b/libcxx/include/__algorithm/sort.h
new file mode 100644
index 000000000000..39ec21302d20
--- /dev/null
+++ b/libcxx/include/__algorithm/sort.h
@@ -0,0 +1,530 @@
+//===----------------------------------------------------------------------===//
+//
+// 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