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// -*- C++ -*-
//===-- parallel_backend_utils.h ------------------------------------------===//
//
// 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 _PSTL_PARALLEL_BACKEND_UTILS_H
#define _PSTL_PARALLEL_BACKEND_UTILS_H
#include <iterator>
#include <utility>
#include "utils.h"
namespace __pstl
{
namespace __utils
{
//! Destroy sequence [xs,xe)
struct __serial_destroy
{
template <typename _RandomAccessIterator>
void
operator()(_RandomAccessIterator __zs, _RandomAccessIterator __ze)
{
typedef typename std::iterator_traits<_RandomAccessIterator>::value_type _ValueType;
while (__zs != __ze)
{
--__ze;
(*__ze).~_ValueType();
}
}
};
//! Merge sequences [__xs,__xe) and [__ys,__ye) to output sequence [__zs,(__xe-__xs)+(__ye-__ys)), using std::move
struct __serial_move_merge
{
const std::size_t _M_nmerge;
explicit __serial_move_merge(std::size_t __nmerge) : _M_nmerge(__nmerge) {}
template <class _RandomAccessIterator1, class _RandomAccessIterator2, class _RandomAccessIterator3, class _Compare,
class _MoveValueX, class _MoveValueY, class _MoveSequenceX, class _MoveSequenceY>
void
operator()(_RandomAccessIterator1 __xs, _RandomAccessIterator1 __xe, _RandomAccessIterator2 __ys,
_RandomAccessIterator2 __ye, _RandomAccessIterator3 __zs, _Compare __comp, _MoveValueX __move_value_x,
_MoveValueY __move_value_y, _MoveSequenceX __move_sequence_x, _MoveSequenceY __move_sequence_y)
{
constexpr bool __same_move_val = std::is_same<_MoveValueX, _MoveValueY>::value;
constexpr bool __same_move_seq = std::is_same<_MoveSequenceX, _MoveSequenceY>::value;
auto __n = _M_nmerge;
_PSTL_ASSERT(__n > 0);
auto __nx = __xe - __xs;
//auto __ny = __ye - __ys;
_RandomAccessIterator3 __zs_beg = __zs;
if (__xs != __xe)
{
if (__ys != __ye)
{
for (;;)
{
if (__comp(*__ys, *__xs))
{
const auto __i = __zs - __zs_beg;
if (__i < __nx)
__move_value_x(__ys, __zs);
else
__move_value_y(__ys, __zs);
++__zs, --__n;
if (++__ys == __ye)
{
break;
}
else if (__n == 0)
{
const auto __j = __zs - __zs_beg;
if (__same_move_seq || __j < __nx)
__zs = __move_sequence_x(__ys, __ye, __zs);
else
__zs = __move_sequence_y(__ys, __ye, __zs);
break;
}
}
else
{
const auto __i = __zs - __zs_beg;
if (__same_move_val || __i < __nx)
__move_value_x(__xs, __zs);
else
__move_value_y(__xs, __zs);
++__zs, --__n;
if (++__xs == __xe)
{
const auto __j = __zs - __zs_beg;
if (__same_move_seq || __j < __nx)
__move_sequence_x(__ys, __ye, __zs);
else
__move_sequence_y(__ys, __ye, __zs);
return;
}
else if (__n == 0)
{
const auto __j = __zs - __zs_beg;
if (__same_move_seq || __j < __nx)
{
__zs = __move_sequence_x(__xs, __xe, __zs);
__move_sequence_x(__ys, __ye, __zs);
}
else
{
__zs = __move_sequence_y(__xs, __xe, __zs);
__move_sequence_y(__ys, __ye, __zs);
}
return;
}
}
}
}
__ys = __xs;
__ye = __xe;
}
const auto __i = __zs - __zs_beg;
if (__same_move_seq || __i < __nx)
__move_sequence_x(__ys, __ye, __zs);
else
__move_sequence_y(__ys, __ye, __zs);
}
};
template <typename _ForwardIterator1, typename _ForwardIterator2, typename _OutputIterator, typename _Compare,
typename _CopyConstructRange>
_OutputIterator
__set_union_construct(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
_ForwardIterator2 __last2, _OutputIterator __result, _Compare __comp,
_CopyConstructRange __cc_range)
{
using _Tp = typename std::iterator_traits<_OutputIterator>::value_type;
for (; __first1 != __last1; ++__result)
{
if (__first2 == __last2)
return __cc_range(__first1, __last1, __result);
if (__comp(*__first2, *__first1))
{
::new (std::addressof(*__result)) _Tp(*__first2);
++__first2;
}
else
{
::new (std::addressof(*__result)) _Tp(*__first1);
if (!__comp(*__first1, *__first2))
++__first2;
++__first1;
}
}
return __cc_range(__first2, __last2, __result);
}
template <typename _ForwardIterator1, typename _ForwardIterator2, typename _OutputIterator, typename _Compare>
_OutputIterator
__set_intersection_construct(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
_ForwardIterator2 __last2, _OutputIterator __result, _Compare __comp)
{
using _Tp = typename std::iterator_traits<_OutputIterator>::value_type;
for (; __first1 != __last1 && __first2 != __last2;)
{
if (__comp(*__first1, *__first2))
++__first1;
else
{
if (!__comp(*__first2, *__first1))
{
::new (std::addressof(*__result)) _Tp(*__first1);
++__result;
++__first1;
}
++__first2;
}
}
return __result;
}
template <typename _ForwardIterator1, typename _ForwardIterator2, typename _OutputIterator, typename _Compare,
typename _CopyConstructRange>
_OutputIterator
__set_difference_construct(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
_ForwardIterator2 __last2, _OutputIterator __result, _Compare __comp,
_CopyConstructRange __cc_range)
{
using _Tp = typename std::iterator_traits<_OutputIterator>::value_type;
for (; __first1 != __last1;)
{
if (__first2 == __last2)
return __cc_range(__first1, __last1, __result);
if (__comp(*__first1, *__first2))
{
::new (std::addressof(*__result)) _Tp(*__first1);
++__result;
++__first1;
}
else
{
if (!__comp(*__first2, *__first1))
++__first1;
++__first2;
}
}
return __result;
}
template <typename _ForwardIterator1, typename _ForwardIterator2, typename _OutputIterator, typename _Compare,
typename _CopyConstructRange>
_OutputIterator
__set_symmetric_difference_construct(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2,
_ForwardIterator2 __last2, _OutputIterator __result, _Compare __comp,
_CopyConstructRange __cc_range)
{
using _Tp = typename std::iterator_traits<_OutputIterator>::value_type;
for (; __first1 != __last1;)
{
if (__first2 == __last2)
return __cc_range(__first1, __last1, __result);
if (__comp(*__first1, *__first2))
{
::new (std::addressof(*__result)) _Tp(*__first1);
++__result;
++__first1;
}
else
{
if (__comp(*__first2, *__first1))
{
::new (std::addressof(*__result)) _Tp(*__first2);
++__result;
}
else
++__first1;
++__first2;
}
}
return __cc_range(__first2, __last2, __result);
}
} // namespace __utils
} // namespace __pstl
#endif /* _PSTL_PARALLEL_BACKEND_UTILS_H */