libstdc++-v3/include/parallel/algobase.h

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the terms
   7 // of the GNU General Public License as published by the Free Software
   8 // Foundation; either version 3, or (at your option) any later
   9 // version.
  10
  11 // This library is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /** @file parallel/algobase.h
  26  *  @brief Parallel STL function calls corresponding to the
  27  *  stl_algobase.h header.  The functions defined here mainly do case
  28  *  switches and call the actual parallelized versions in other files.
  29  *  Inlining policy: Functions that basically only contain one
  30  *  function call, are declared inline.
  31  *  This file is a GNU parallel extension to the Standard C++ Library.
  32  */
  33
  34 // Written by Johannes Singler and Felix Putze.
  35
  36 #ifndef _GLIBCXX_PARALLEL_ALGOBASE_H
  37 #define _GLIBCXX_PARALLEL_ALGOBASE_H 1
  38
  39 #include <bits/stl_algobase.h>
  40 #include <parallel/base.h>
  41 #include <parallel/tags.h>
  42 #include <parallel/settings.h>
  43 #include <parallel/find.h>
  44 #include <parallel/find_selectors.h>
  45
  46 namespace std
  47 {
  48 namespace __parallel
  49 {
  50   // NB: equal and lexicographical_compare require mismatch.
  51
  52   // Sequential fallback
  53   template<typename _IIter1, typename _IIter2>
  54     inline pair<_IIter1, _IIter2>
  55     mismatch(_IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2,
  56              __gnu_parallel::sequential_tag)
  57     { return _GLIBCXX_STD_P::mismatch(__begin1, __end1, __begin2); }
  58
  59   // Sequential fallback
  60   template<typename _IIter1, typename _IIter2, typename _Predicate>
  61     inline pair<_IIter1, _IIter2>
  62     mismatch(_IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2,
  63              _Predicate __pred, __gnu_parallel::sequential_tag)
  64     { return _GLIBCXX_STD_P::mismatch(__begin1, __end1, __begin2, __pred); }
  65
  66   // Sequential fallback for input iterator case
  67   template<typename _IIter1, typename _IIter2,
  68            typename _Predicate, typename _IteratorTag1, typename _IteratorTag2>
  69     inline pair<_IIter1, _IIter2>
  70     __mismatch_switch(_IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2,
  71                       _Predicate __pred, _IteratorTag1, _IteratorTag2)
  72     { return _GLIBCXX_STD_P::mismatch(__begin1, __end1, __begin2, __pred); }
  73
  74   // Parallel mismatch for random access iterators
  75   template<typename _RAIter1, typename _RAIter2, typename _Predicate>
  76     pair<_RAIter1, _RAIter2>
  77     __mismatch_switch(_RAIter1 __begin1, _RAIter1 __end1,
  78                       _RAIter2 __begin2, _Predicate __pred,
  79                       random_access_iterator_tag, random_access_iterator_tag)
  80     {
  81       if (_GLIBCXX_PARALLEL_CONDITION(true))
  82         {
  83           _RAIter1 __res =
  84             __gnu_parallel::__find_template(__begin1, __end1, __begin2, __pred,
  85                                             __gnu_parallel::
  86                                             __mismatch_selector()).first;
  87           return make_pair(__res , __begin2 + (__res - __begin1));
  88         }
  89       else
  90         return _GLIBCXX_STD_P::mismatch(__begin1, __end1, __begin2, __pred);
  91     }
  92
  93   // Public interface
  94   template<typename _IIter1, typename _IIter2>
  95     inline pair<_IIter1, _IIter2>
  96     mismatch(_IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2)
  97     {
  98       typedef std::iterator_traits<_IIter1> _Iterator1Traits;
  99       typedef std::iterator_traits<_IIter2> _Iterator2Traits;
 100       typedef typename _Iterator1Traits::value_type _ValueType1;
 101       typedef typename _Iterator2Traits::value_type _ValueType2;
 102       typedef typename _Iterator1Traits::iterator_category _IteratorCategory1;
 103       typedef typename _Iterator2Traits::iterator_category _IteratorCategory2;
 104
 105       typedef __gnu_parallel::_EqualTo<_ValueType1, _ValueType2> _EqualTo;
 106
 107       return __mismatch_switch(__begin1, __end1, __begin2, _EqualTo(),
 108                                _IteratorCategory1(), _IteratorCategory2());
 109     }
 110
 111   // Public interface
 112   template<typename _IIter1, typename _IIter2, typename _Predicate>
 113     inline pair<_IIter1, _IIter2>
 114     mismatch(_IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2,
 115              _Predicate __pred)
 116     {
 117       typedef std::iterator_traits<_IIter1> _Iterator1Traits;
 118       typedef std::iterator_traits<_IIter2> _Iterator2Traits;
 119       typedef typename _Iterator1Traits::iterator_category _IteratorCategory1;
 120       typedef typename _Iterator2Traits::iterator_category _IteratorCategory2;
 121
 122       return __mismatch_switch(__begin1, __end1, __begin2, __pred,
 123                                _IteratorCategory1(), _IteratorCategory2());
 124     }
 125
 126   // Sequential fallback
 127   template<typename _IIter1, typename _IIter2>
 128     inline bool
 129     equal(_IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2,
 130           __gnu_parallel::sequential_tag)
 131     { return _GLIBCXX_STD_P::equal(__begin1, __end1, __begin2); }
 132
 133   // Sequential fallback
 134   template<typename _IIter1, typename _IIter2, typename _Predicate>
 135     inline bool
 136     equal(_IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2,
 137           _Predicate __pred, __gnu_parallel::sequential_tag)
 138     { return _GLIBCXX_STD_P::equal(__begin1, __end1, __begin2, __pred); }
 139
 140   // Public interface
 141   template<typename _IIter1, typename _IIter2>
 142     inline bool
 143     equal(_IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2)
 144     { return mismatch(__begin1, __end1, __begin2).first == __end1; }
 145
 146   // Public interface
 147   template<typename _IIter1, typename _IIter2, typename _Predicate>
 148     inline bool
 149     equal(_IIter1 __begin1, _IIter1 __end1, _IIter2 __begin2,
 150           _Predicate __pred)
 151     { return mismatch(__begin1, __end1, __begin2, __pred).first == __end1; }
 152
 153   // Sequential fallback
 154   template<typename _IIter1, typename _IIter2>
 155     inline bool
 156     lexicographical_compare(_IIter1 __begin1, _IIter1 __end1,
 157                             _IIter2 __begin2, _IIter2 __end2,
 158                             __gnu_parallel::sequential_tag)
 159     { return _GLIBCXX_STD_P::lexicographical_compare(__begin1, __end1,
 160                                                      __begin2, __end2); }
 161
 162   // Sequential fallback
 163   template<typename _IIter1, typename _IIter2, typename _Predicate>
 164     inline bool
 165     lexicographical_compare(_IIter1 __begin1, _IIter1 __end1,
 166                             _IIter2 __begin2, _IIter2 __end2,
 167                             _Predicate __pred, __gnu_parallel::sequential_tag)
 168     { return _GLIBCXX_STD_P::lexicographical_compare(
 169                __begin1, __end1, __begin2, __end2, __pred); }
 170
 171   // Sequential fallback for input iterator case
 172   template<typename _IIter1, typename _IIter2,
 173            typename _Predicate, typename _IteratorTag1, typename _IteratorTag2>
 174     inline bool
 175     __lexicographical_compare_switch(_IIter1 __begin1, _IIter1 __end1,
 176                                      _IIter2 __begin2, _IIter2 __end2,
 177                                      _Predicate __pred,
 178                                      _IteratorTag1, _IteratorTag2)
 179     { return _GLIBCXX_STD_P::lexicographical_compare(
 180                __begin1, __end1, __begin2, __end2, __pred); }
 181
 182   // Parallel lexicographical_compare for random access iterators
 183   // Limitation: Both valuetypes must be the same
 184   template<typename _RAIter1, typename _RAIter2, typename _Predicate>
 185     bool
 186     __lexicographical_compare_switch(_RAIter1 __begin1, _RAIter1 __end1,
 187                                      _RAIter2 __begin2, _RAIter2 __end2,
 188                                      _Predicate __pred,
 189                                      random_access_iterator_tag,
 190                                      random_access_iterator_tag)
 191     {
 192       if (_GLIBCXX_PARALLEL_CONDITION(true))
 193         {
 194           typedef iterator_traits<_RAIter1> _TraitsType1;
 195           typedef typename _TraitsType1::value_type _ValueType1;
 196
 197           typedef iterator_traits<_RAIter2> _TraitsType2;
 198           typedef typename _TraitsType2::value_type _ValueType2;
 199
 200           typedef __gnu_parallel::
 201                   _EqualFromLess<_ValueType1, _ValueType2, _Predicate>
 202                   _EqualFromLessCompare;
 203
 204           // Longer sequence in first place.
 205           if ((__end1 - __begin1) < (__end2 - __begin2))
 206             {
 207               typedef pair<_RAIter1, _RAIter2> _SpotType;
 208               _SpotType __mm = __mismatch_switch(__begin1, __end1, __begin2,
 209                                              _EqualFromLessCompare(__pred),
 210                                              random_access_iterator_tag(),
 211                                              random_access_iterator_tag());
 212
 213               return (__mm.first == __end1)
 214                         || bool(__pred(*__mm.first, *__mm.second));
 215             }
 216           else
 217             {
 218               typedef pair<_RAIter2, _RAIter1> _SpotType;
 219               _SpotType __mm = __mismatch_switch(__begin2, __end2, __begin1,
 220                                              _EqualFromLessCompare(__pred),
 221                                              random_access_iterator_tag(),
 222                                              random_access_iterator_tag());
 223
 224               return (__mm.first != __end2)
 225                         && bool(__pred(*__mm.second, *__mm.first));
 226             }
 227         }
 228       else
 229         return _GLIBCXX_STD_P::lexicographical_compare(
 230                  __begin1, __end1, __begin2, __end2, __pred);
 231     }
 232
 233   // Public interface
 234   template<typename _IIter1, typename _IIter2>
 235     inline bool
 236     lexicographical_compare(_IIter1 __begin1, _IIter1 __end1,
 237                             _IIter2 __begin2, _IIter2 __end2)
 238     {
 239       typedef iterator_traits<_IIter1> _TraitsType1;
 240       typedef typename _TraitsType1::value_type _ValueType1;
 241       typedef typename _TraitsType1::iterator_category _IteratorCategory1;
 242
 243       typedef iterator_traits<_IIter2> _TraitsType2;
 244       typedef typename _TraitsType2::value_type _ValueType2;
 245       typedef typename _TraitsType2::iterator_category _IteratorCategory2;
 246       typedef __gnu_parallel::_Less<_ValueType1, _ValueType2> _LessType;
 247
 248       return __lexicographical_compare_switch(
 249                __begin1, __end1, __begin2, __end2, _LessType(),
 250                _IteratorCategory1(), _IteratorCategory2());
 251     }
 252
 253   // Public interface
 254   template<typename _IIter1, typename _IIter2, typename _Predicate>
 255     inline bool
 256     lexicographical_compare(_IIter1 __begin1, _IIter1 __end1,
 257                             _IIter2 __begin2, _IIter2 __end2,
 258                             _Predicate __pred)
 259     {
 260       typedef iterator_traits<_IIter1> _TraitsType1;
 261       typedef typename _TraitsType1::iterator_category _IteratorCategory1;
 262
 263       typedef iterator_traits<_IIter2> _TraitsType2;
 264       typedef typename _TraitsType2::iterator_category _IteratorCategory2;
 265
 266       return __lexicographical_compare_switch(
 267                __begin1, __end1, __begin2, __end2, __pred,
 268                _IteratorCategory1(), _IteratorCategory2());
 269     }
 270 } // end namespace
 271 } // end namespace
 272
 273 #endif /* _GLIBCXX_PARALLEL_ALGOBASE_H */