libstdc++
base.h
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2 
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24 
25 /** @file parallel/base.h
26  * @brief Sequential helper functions.
27  * This file is a GNU parallel extension to the Standard C++ Library.
28  */
29 
30 // Written by Johannes Singler.
31 
32 #ifndef _GLIBCXX_PARALLEL_BASE_H
33 #define _GLIBCXX_PARALLEL_BASE_H 1
34 
35 #include <bits/c++config.h>
36 #include <bits/stl_function.h>
37 #include <omp.h>
38 #include <parallel/features.h>
40 #include <parallel/parallel.h>
41 
42 // Parallel mode namespaces.
43 
44 /**
45  * @namespace std::__parallel
46  * @brief GNU parallel code, replaces standard behavior with parallel behavior.
47  */
48 namespace std _GLIBCXX_VISIBILITY(default)
49 {
50  namespace __parallel { }
51 }
52 
53 /**
54  * @namespace __gnu_parallel
55  * @brief GNU parallel code for public use.
56  */
57 namespace __gnu_parallel
58 {
59  // Import all the parallel versions of components in namespace std.
60  using namespace std::__parallel;
61 }
62 
63 /**
64  * @namespace __gnu_sequential
65  * @brief GNU sequential classes for public use.
66  */
67 namespace __gnu_sequential
68 {
69  // Import whatever is the serial version.
70 #ifdef _GLIBCXX_PARALLEL
71  using namespace std::_GLIBCXX_STD_A;
72 #else
73  using namespace std;
74 #endif
75 }
76 
77 
78 namespace __gnu_parallel
79 {
80  // NB: Including this file cannot produce (unresolved) symbols from
81  // the OpenMP runtime unless the parallel mode is actually invoked
82  // and active, which imples that the OpenMP runtime is actually
83  // going to be linked in.
84  inline _ThreadIndex
85  __get_max_threads()
86  {
87  _ThreadIndex __i = omp_get_max_threads();
88  return __i > 1 ? __i : 1;
89  }
90 
91 
92  inline bool
93  __is_parallel(const _Parallelism __p) { return __p != sequential; }
94 
95 
96  /** @brief Calculates the rounded-down logarithm of @c __n for base 2.
97  * @param __n Argument.
98  * @return Returns 0 for any argument <1.
99  */
100  template<typename _Size>
101  inline _Size
102  __rd_log2(_Size __n)
103  {
104  _Size __k;
105  for (__k = 0; __n > 1; __n >>= 1)
106  ++__k;
107  return __k;
108  }
109 
110  /** @brief Encode two integers into one gnu_parallel::_CASable.
111  * @param __a First integer, to be encoded in the most-significant @c
112  * _CASable_bits/2 bits.
113  * @param __b Second integer, to be encoded in the least-significant
114  * @c _CASable_bits/2 bits.
115  * @return value encoding @c __a and @c __b.
116  * @see __decode2
117  */
118  inline _CASable
119  __encode2(int __a, int __b) //must all be non-negative, actually
120  {
121  return (((_CASable)__a) << (_CASable_bits / 2)) | (((_CASable)__b) << 0);
122  }
123 
124  /** @brief Decode two integers from one gnu_parallel::_CASable.
125  * @param __x __gnu_parallel::_CASable to decode integers from.
126  * @param __a First integer, to be decoded from the most-significant
127  * @c _CASable_bits/2 bits of @c __x.
128  * @param __b Second integer, to be encoded in the least-significant
129  * @c _CASable_bits/2 bits of @c __x.
130  * @see __encode2
131  */
132  inline void
133  __decode2(_CASable __x, int& __a, int& __b)
134  {
135  __a = (int)((__x >> (_CASable_bits / 2)) & _CASable_mask);
136  __b = (int)((__x >> 0 ) & _CASable_mask);
137  }
138 
139  //needed for parallel "numeric", even if "algorithm" not included
140 
141  /** @brief Equivalent to std::min. */
142  template<typename _Tp>
143  inline const _Tp&
144  min(const _Tp& __a, const _Tp& __b)
145  { return (__a < __b) ? __a : __b; }
146 
147  /** @brief Equivalent to std::max. */
148  template<typename _Tp>
149  inline const _Tp&
150  max(const _Tp& __a, const _Tp& __b)
151  { return (__a > __b) ? __a : __b; }
152 
153  /** @brief Constructs predicate for equality from strict weak
154  * ordering predicate
155  */
156  template<typename _T1, typename _T2, typename _Compare>
157  class _EqualFromLess : public std::binary_function<_T1, _T2, bool>
158  {
159  private:
160  _Compare& _M_comp;
161 
162  public:
163  _EqualFromLess(_Compare& __comp) : _M_comp(__comp) { }
164 
165  bool operator()(const _T1& __a, const _T2& __b)
166  { return !_M_comp(__a, __b) && !_M_comp(__b, __a); }
167  };
168 
169 
170  /** @brief Similar to std::unary_negate,
171  * but giving the argument types explicitly. */
172  template<typename _Predicate, typename argument_type>
174  : public std::unary_function<argument_type, bool>
175  {
176  protected:
177  _Predicate _M_pred;
178 
179  public:
180  explicit
181  __unary_negate(const _Predicate& __x) : _M_pred(__x) { }
182 
183  bool
184  operator()(const argument_type& __x)
185  { return !_M_pred(__x); }
186  };
187 
188  /** @brief Similar to std::binder1st,
189  * but giving the argument types explicitly. */
190  template<typename _Operation, typename _FirstArgumentType,
191  typename _SecondArgumentType, typename _ResultType>
193  : public std::unary_function<_SecondArgumentType, _ResultType>
194  {
195  protected:
196  _Operation _M_op;
197  _FirstArgumentType _M_value;
198 
199  public:
200  __binder1st(const _Operation& __x, const _FirstArgumentType& __y)
201  : _M_op(__x), _M_value(__y) { }
202 
203  _ResultType
204  operator()(const _SecondArgumentType& __x)
205  { return _M_op(_M_value, __x); }
206 
207  // _GLIBCXX_RESOLVE_LIB_DEFECTS
208  // 109. Missing binders for non-const sequence elements
209  _ResultType
210  operator()(_SecondArgumentType& __x) const
211  { return _M_op(_M_value, __x); }
212  };
213 
214  /**
215  * @brief Similar to std::binder2nd, but giving the argument types
216  * explicitly.
217  */
218  template<typename _Operation, typename _FirstArgumentType,
219  typename _SecondArgumentType, typename _ResultType>
221  : public std::unary_function<_FirstArgumentType, _ResultType>
222  {
223  protected:
224  _Operation _M_op;
225  _SecondArgumentType _M_value;
226 
227  public:
228  __binder2nd(const _Operation& __x, const _SecondArgumentType& __y)
229  : _M_op(__x), _M_value(__y) { }
230 
231  _ResultType
232  operator()(const _FirstArgumentType& __x) const
233  { return _M_op(__x, _M_value); }
234 
235  // _GLIBCXX_RESOLVE_LIB_DEFECTS
236  // 109. Missing binders for non-const sequence elements
237  _ResultType
238  operator()(_FirstArgumentType& __x)
239  { return _M_op(__x, _M_value); }
240  };
241 
242  /** @brief Similar to std::equal_to, but allows two different types. */
243  template<typename _T1, typename _T2>
244  struct _EqualTo : std::binary_function<_T1, _T2, bool>
245  {
246  bool operator()(const _T1& __t1, const _T2& __t2) const
247  { return __t1 == __t2; }
248  };
249 
250  /** @brief Similar to std::less, but allows two different types. */
251  template<typename _T1, typename _T2>
252  struct _Less : std::binary_function<_T1, _T2, bool>
253  {
254  bool
255  operator()(const _T1& __t1, const _T2& __t2) const
256  { return __t1 < __t2; }
257 
258  bool
259  operator()(const _T2& __t2, const _T1& __t1) const
260  { return __t2 < __t1; }
261  };
262 
263  // Partial specialization for one type. Same as std::less.
264  template<typename _Tp>
265  struct _Less<_Tp, _Tp>
266  : public std::less<_Tp> { };
267 
268  /** @brief Similar to std::plus, but allows two different types. */
269  template<typename _Tp1, typename _Tp2, typename _Result
270  = __typeof__(*static_cast<_Tp1*>(0)
271  + *static_cast<_Tp2*>(0))>
272  struct _Plus : public std::binary_function<_Tp1, _Tp2, _Result>
273  {
274  _Result
275  operator()(const _Tp1& __x, const _Tp2& __y) const
276  { return __x + __y; }
277  };
278 
279  // Partial specialization for one type. Same as std::plus.
280  template<typename _Tp>
281  struct _Plus<_Tp, _Tp, _Tp>
282  : public std::plus<_Tp> { };
283 
284  /** @brief Similar to std::multiplies, but allows two different types. */
285  template<typename _Tp1, typename _Tp2, typename _Result
286  = __typeof__(*static_cast<_Tp1*>(0)
287  * *static_cast<_Tp2*>(0))>
288  struct _Multiplies : public std::binary_function<_Tp1, _Tp2, _Result>
289  {
290  _Result
291  operator()(const _Tp1& __x, const _Tp2& __y) const
292  { return __x * __y; }
293  };
294 
295  // Partial specialization for one type. Same as std::multiplies.
296  template<typename _Tp>
297  struct _Multiplies<_Tp, _Tp, _Tp>
298  : public std::multiplies<_Tp> { };
299 
300  /** @brief _Iterator associated with __gnu_parallel::_PseudoSequence.
301  * If features the usual random-access iterator functionality.
302  * @param _Tp Sequence _M_value type.
303  * @param _DifferenceTp Sequence difference type.
304  */
305  template<typename _Tp, typename _DifferenceTp>
307  {
308  public:
309  typedef _DifferenceTp _DifferenceType;
310 
311  _PseudoSequenceIterator(const _Tp& __val, _DifferenceType __pos)
312  : _M_val(__val), _M_pos(__pos) { }
313 
314  // Pre-increment operator.
316  operator++()
317  {
318  ++_M_pos;
319  return *this;
320  }
321 
322  // Post-increment operator.
324  operator++(int)
325  { return _PseudoSequenceIterator(_M_pos++); }
326 
327  const _Tp&
328  operator*() const
329  { return _M_val; }
330 
331  const _Tp&
332  operator[](_DifferenceType) const
333  { return _M_val; }
334 
335  bool
336  operator==(const _PseudoSequenceIterator& __i2)
337  { return _M_pos == __i2._M_pos; }
338 
339  bool
340  operator!=(const _PseudoSequenceIterator& __i2)
341  { return _M_pos != __i2._M_pos; }
342 
343  _DifferenceType
345  { return _M_pos - __i2._M_pos; }
346 
347  private:
348  const _Tp& _M_val;
349  _DifferenceType _M_pos;
350  };
351 
352  /** @brief Sequence that conceptually consists of multiple copies of
353  the same element.
354  * The copies are not stored explicitly, of course.
355  * @param _Tp Sequence _M_value type.
356  * @param _DifferenceTp Sequence difference type.
357  */
358  template<typename _Tp, typename _DifferenceTp>
360  {
361  public:
362  typedef _DifferenceTp _DifferenceType;
363 
364  // Better cast down to uint64_t, than up to _DifferenceTp.
366 
367  /** @brief Constructor.
368  * @param __val Element of the sequence.
369  * @param __count Number of (virtual) copies.
370  */
371  _PseudoSequence(const _Tp& __val, _DifferenceType __count)
372  : _M_val(__val), _M_count(__count) { }
373 
374  /** @brief Begin iterator. */
375  iterator
376  begin() const
377  { return iterator(_M_val, 0); }
378 
379  /** @brief End iterator. */
380  iterator
381  end() const
382  { return iterator(_M_val, _M_count); }
383 
384  private:
385  const _Tp& _M_val;
386  _DifferenceType _M_count;
387  };
388 
389  /** @brief Compute the median of three referenced elements,
390  according to @c __comp.
391  * @param __a First iterator.
392  * @param __b Second iterator.
393  * @param __c Third iterator.
394  * @param __comp Comparator.
395  */
396  template<typename _RAIter, typename _Compare>
397  _RAIter
398  __median_of_three_iterators(_RAIter __a, _RAIter __b,
399  _RAIter __c, _Compare __comp)
400  {
401  if (__comp(*__a, *__b))
402  if (__comp(*__b, *__c))
403  return __b;
404  else
405  if (__comp(*__a, *__c))
406  return __c;
407  else
408  return __a;
409  else
410  {
411  // Just swap __a and __b.
412  if (__comp(*__a, *__c))
413  return __a;
414  else
415  if (__comp(*__b, *__c))
416  return __c;
417  else
418  return __b;
419  }
420  }
421 
422 #if _GLIBCXX_PARALLEL_ASSERTIONS && defined(__glibcxx_assert_impl)
423 # define _GLIBCXX_PARALLEL_ASSERT(_Condition) \
424  do { __glibcxx_assert_impl(_Condition); } while (false)
425 #else
426 # define _GLIBCXX_PARALLEL_ASSERT(_Condition) do { } while (false)
427 #endif
428 
429 } //namespace __gnu_parallel
430 
431 #endif /* _GLIBCXX_PARALLEL_BASE_H */
Includes the original header files concerned with iterators except for stream iterators....
Defines on whether to include algorithm variants.
End-user include file. Provides advanced settings and tuning options. This file is a GNU parallel ext...
constexpr complex< _Tp > operator*(const complex< _Tp > &__x, const complex< _Tp > &__y)
Return new complex value x times y.
Definition: complex:392
constexpr complex< _Tp > operator-(const complex< _Tp > &__x, const complex< _Tp > &__y)
Return new complex value x minus y.
Definition: complex:362
ISO C++ entities toplevel namespace is std.
GNU parallel code, replaces standard behavior with parallel behavior.
Definition: algo.h:64
GNU parallel code for public use.
uint16_t _ThreadIndex
Unsigned integer to index a thread number. The maximum thread number (for each processor) must fit in...
Definition: types.h:123
const _Tp & min(const _Tp &__a, const _Tp &__b)
Equivalent to std::min.
Definition: base.h:144
_RAIter __median_of_three_iterators(_RAIter __a, _RAIter __b, _RAIter __c, _Compare __comp)
Compute the median of three referenced elements, according to __comp.
Definition: base.h:398
_Parallelism
Run-time equivalents for the compile-time tags.
Definition: types.h:45
@ sequential
Not parallel.
Definition: types.h:47
_CASable __encode2(int __a, int __b)
Encode two integers into one gnu_parallel::_CASable.
Definition: base.h:119
const _Tp & max(const _Tp &__a, const _Tp &__b)
Equivalent to std::max.
Definition: base.h:150
int64_t _CASable
Longest compare-and-swappable integer type on this platform.
Definition: types.h:127
static const _CASable _CASable_mask
_CASable with the right half of bits set to 1.
Definition: types.h:133
static const int _CASable_bits
Number of bits of _CASable.
Definition: types.h:130
_Size __rd_log2(_Size __n)
Calculates the rounded-down logarithm of __n for base 2.
Definition: base.h:102
void __decode2(_CASable __x, int &__a, int &__b)
Decode two integers from one gnu_parallel::_CASable.
Definition: base.h:133
GNU sequential classes for public use.
argument_type argument_type
argument_type is the type of the argument
Definition: stl_function.h:108
One of the math functors.
Definition: stl_function.h:168
One of the math functors.
Definition: stl_function.h:188
One of the comparison functors.
Definition: stl_function.h:382
Common iterator class.
Constructs predicate for equality from strict weak ordering predicate.
Definition: base.h:158
Similar to std::unary_negate, but giving the argument types explicitly.
Definition: base.h:175
Similar to std::binder1st, but giving the argument types explicitly.
Definition: base.h:194
Similar to std::binder2nd, but giving the argument types explicitly.
Definition: base.h:222
Similar to std::equal_to, but allows two different types.
Definition: base.h:245
Similar to std::less, but allows two different types.
Definition: base.h:253
Similar to std::plus, but allows two different types.
Definition: base.h:273
Similar to std::multiplies, but allows two different types.
Definition: base.h:289
_Iterator associated with __gnu_parallel::_PseudoSequence. If features the usual random-access iterat...
Definition: base.h:307
Sequence that conceptually consists of multiple copies of the same element. The copies are not stored...
Definition: base.h:360
iterator begin() const
Begin iterator.
Definition: base.h:376
iterator end() const
End iterator.
Definition: base.h:381
_PseudoSequence(const _Tp &__val, _DifferenceType __count)
Constructor.
Definition: base.h:371