LLVM  3.7.0
SmallVector.h
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1 //===- llvm/ADT/SmallVector.h - 'Normally small' vectors --------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the SmallVector class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_ADT_SMALLVECTOR_H
15 #define LLVM_ADT_SMALLVECTOR_H
16 
18 #include "llvm/Support/AlignOf.h"
19 #include "llvm/Support/Compiler.h"
22 #include <algorithm>
23 #include <cassert>
24 #include <cstddef>
25 #include <cstdlib>
26 #include <cstring>
27 #include <initializer_list>
28 #include <iterator>
29 #include <memory>
30 
31 namespace llvm {
32 
33 /// This is all the non-templated stuff common to all SmallVectors.
35 protected:
36  void *BeginX, *EndX, *CapacityX;
37 
38 protected:
39  SmallVectorBase(void *FirstEl, size_t Size)
40  : BeginX(FirstEl), EndX(FirstEl), CapacityX((char*)FirstEl+Size) {}
41 
42  /// This is an implementation of the grow() method which only works
43  /// on POD-like data types and is out of line to reduce code duplication.
44  void grow_pod(void *FirstEl, size_t MinSizeInBytes, size_t TSize);
45 
46 public:
47  /// This returns size()*sizeof(T).
48  size_t size_in_bytes() const {
49  return size_t((char*)EndX - (char*)BeginX);
50  }
51 
52  /// capacity_in_bytes - This returns capacity()*sizeof(T).
53  size_t capacity_in_bytes() const {
54  return size_t((char*)CapacityX - (char*)BeginX);
55  }
56 
57  bool LLVM_ATTRIBUTE_UNUSED_RESULT empty() const { return BeginX == EndX; }
58 };
59 
60 template <typename T, unsigned N> struct SmallVectorStorage;
61 
62 /// This is the part of SmallVectorTemplateBase which does not depend on whether
63 /// the type T is a POD. The extra dummy template argument is used by ArrayRef
64 /// to avoid unnecessarily requiring T to be complete.
65 template <typename T, typename = void>
67 private:
68  template <typename, unsigned> friend struct SmallVectorStorage;
69 
70  // Allocate raw space for N elements of type T. If T has a ctor or dtor, we
71  // don't want it to be automatically run, so we need to represent the space as
72  // something else. Use an array of char of sufficient alignment.
74  U FirstEl;
75  // Space after 'FirstEl' is clobbered, do not add any instance vars after it.
76 
77 protected:
78  SmallVectorTemplateCommon(size_t Size) : SmallVectorBase(&FirstEl, Size) {}
79 
80  void grow_pod(size_t MinSizeInBytes, size_t TSize) {
81  SmallVectorBase::grow_pod(&FirstEl, MinSizeInBytes, TSize);
82  }
83 
84  /// Return true if this is a smallvector which has not had dynamic
85  /// memory allocated for it.
86  bool isSmall() const {
87  return BeginX == static_cast<const void*>(&FirstEl);
88  }
89 
90  /// Put this vector in a state of being small.
91  void resetToSmall() {
92  BeginX = EndX = CapacityX = &FirstEl;
93  }
94 
95  void setEnd(T *P) { this->EndX = P; }
96 public:
97  typedef size_t size_type;
98  typedef ptrdiff_t difference_type;
99  typedef T value_type;
100  typedef T *iterator;
101  typedef const T *const_iterator;
102 
103  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
104  typedef std::reverse_iterator<iterator> reverse_iterator;
105 
106  typedef T &reference;
107  typedef const T &const_reference;
108  typedef T *pointer;
109  typedef const T *const_pointer;
110 
111  // forward iterator creation methods.
112  iterator begin() { return (iterator)this->BeginX; }
113  const_iterator begin() const { return (const_iterator)this->BeginX; }
114  iterator end() { return (iterator)this->EndX; }
115  const_iterator end() const { return (const_iterator)this->EndX; }
116 protected:
119 public:
120 
121  // reverse iterator creation methods.
126 
127  size_type size() const { return end()-begin(); }
128  size_type max_size() const { return size_type(-1) / sizeof(T); }
129 
130  /// Return the total number of elements in the currently allocated buffer.
131  size_t capacity() const { return capacity_ptr() - begin(); }
132 
133  /// Return a pointer to the vector's buffer, even if empty().
134  pointer data() { return pointer(begin()); }
135  /// Return a pointer to the vector's buffer, even if empty().
136  const_pointer data() const { return const_pointer(begin()); }
137 
139  assert(idx < size());
140  return begin()[idx];
141  }
143  assert(idx < size());
144  return begin()[idx];
145  }
146 
148  assert(!empty());
149  return begin()[0];
150  }
152  assert(!empty());
153  return begin()[0];
154  }
155 
157  assert(!empty());
158  return end()[-1];
159  }
161  assert(!empty());
162  return end()[-1];
163  }
164 };
165 
166 /// SmallVectorTemplateBase<isPodLike = false> - This is where we put method
167 /// implementations that are designed to work with non-POD-like T's.
168 template <typename T, bool isPodLike>
170 protected:
172 
173  static void destroy_range(T *S, T *E) {
174  while (S != E) {
175  --E;
176  E->~T();
177  }
178  }
179 
180  /// Use move-assignment to move the range [I, E) onto the
181  /// objects starting with "Dest". This is just <memory>'s
182  /// std::move, but not all stdlibs actually provide that.
183  template<typename It1, typename It2>
184  static It2 move(It1 I, It1 E, It2 Dest) {
185  for (; I != E; ++I, ++Dest)
186  *Dest = ::std::move(*I);
187  return Dest;
188  }
189 
190  /// Use move-assignment to move the range
191  /// [I, E) onto the objects ending at "Dest", moving objects
192  /// in reverse order. This is just <algorithm>'s
193  /// std::move_backward, but not all stdlibs actually provide that.
194  template<typename It1, typename It2>
195  static It2 move_backward(It1 I, It1 E, It2 Dest) {
196  while (I != E)
197  *--Dest = ::std::move(*--E);
198  return Dest;
199  }
200 
201  /// Move the range [I, E) into the uninitialized memory starting with "Dest",
202  /// constructing elements as needed.
203  template<typename It1, typename It2>
204  static void uninitialized_move(It1 I, It1 E, It2 Dest) {
205  for (; I != E; ++I, ++Dest)
206  ::new ((void*) &*Dest) T(::std::move(*I));
207  }
208 
209  /// Copy the range [I, E) onto the uninitialized memory starting with "Dest",
210  /// constructing elements as needed.
211  template<typename It1, typename It2>
212  static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
213  std::uninitialized_copy(I, E, Dest);
214  }
215 
216  /// Grow the allocated memory (without initializing new elements), doubling
217  /// the size of the allocated memory. Guarantees space for at least one more
218  /// element, or MinSize more elements if specified.
219  void grow(size_t MinSize = 0);
220 
221 public:
222  void push_back(const T &Elt) {
223  if (LLVM_UNLIKELY(this->EndX >= this->CapacityX))
224  this->grow();
225  ::new ((void*) this->end()) T(Elt);
226  this->setEnd(this->end()+1);
227  }
228 
229  void push_back(T &&Elt) {
230  if (LLVM_UNLIKELY(this->EndX >= this->CapacityX))
231  this->grow();
232  ::new ((void*) this->end()) T(::std::move(Elt));
233  this->setEnd(this->end()+1);
234  }
235 
236  void pop_back() {
237  this->setEnd(this->end()-1);
238  this->end()->~T();
239  }
240 };
241 
242 // Define this out-of-line to dissuade the C++ compiler from inlining it.
243 template <typename T, bool isPodLike>
245  size_t CurCapacity = this->capacity();
246  size_t CurSize = this->size();
247  // Always grow, even from zero.
248  size_t NewCapacity = size_t(NextPowerOf2(CurCapacity+2));
249  if (NewCapacity < MinSize)
250  NewCapacity = MinSize;
251  T *NewElts = static_cast<T*>(malloc(NewCapacity*sizeof(T)));
252 
253  // Move the elements over.
254  this->uninitialized_move(this->begin(), this->end(), NewElts);
255 
256  // Destroy the original elements.
257  destroy_range(this->begin(), this->end());
258 
259  // If this wasn't grown from the inline copy, deallocate the old space.
260  if (!this->isSmall())
261  free(this->begin());
262 
263  this->setEnd(NewElts+CurSize);
264  this->BeginX = NewElts;
265  this->CapacityX = this->begin()+NewCapacity;
266 }
267 
268 
269 /// SmallVectorTemplateBase<isPodLike = true> - This is where we put method
270 /// implementations that are designed to work with POD-like T's.
271 template <typename T>
273 protected:
275 
276  // No need to do a destroy loop for POD's.
277  static void destroy_range(T *, T *) {}
278 
279  /// Use move-assignment to move the range [I, E) onto the
280  /// objects starting with "Dest". For PODs, this is just memcpy.
281  template<typename It1, typename It2>
282  static It2 move(It1 I, It1 E, It2 Dest) {
283  return ::std::copy(I, E, Dest);
284  }
285 
286  /// Use move-assignment to move the range [I, E) onto the objects ending at
287  /// "Dest", moving objects in reverse order.
288  template<typename It1, typename It2>
289  static It2 move_backward(It1 I, It1 E, It2 Dest) {
290  return ::std::copy_backward(I, E, Dest);
291  }
292 
293  /// Move the range [I, E) onto the uninitialized memory
294  /// starting with "Dest", constructing elements into it as needed.
295  template<typename It1, typename It2>
296  static void uninitialized_move(It1 I, It1 E, It2 Dest) {
297  // Just do a copy.
298  uninitialized_copy(I, E, Dest);
299  }
300 
301  /// Copy the range [I, E) onto the uninitialized memory
302  /// starting with "Dest", constructing elements into it as needed.
303  template<typename It1, typename It2>
304  static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
305  // Arbitrary iterator types; just use the basic implementation.
306  std::uninitialized_copy(I, E, Dest);
307  }
308 
309  /// Copy the range [I, E) onto the uninitialized memory
310  /// starting with "Dest", constructing elements into it as needed.
311  template <typename T1, typename T2>
312  static void uninitialized_copy(
313  T1 *I, T1 *E, T2 *Dest,
314  typename std::enable_if<std::is_same<typename std::remove_const<T1>::type,
315  T2>::value>::type * = nullptr) {
316  // Use memcpy for PODs iterated by pointers (which includes SmallVector
317  // iterators): std::uninitialized_copy optimizes to memmove, but we can
318  // use memcpy here. Note that I and E are iterators and thus might be
319  // invalid for memcpy if they are equal.
320  if (I != E)
321  memcpy(Dest, I, (E - I) * sizeof(T));
322  }
323 
324  /// Double the size of the allocated memory, guaranteeing space for at
325  /// least one more element or MinSize if specified.
326  void grow(size_t MinSize = 0) {
327  this->grow_pod(MinSize*sizeof(T), sizeof(T));
328  }
329 public:
330  void push_back(const T &Elt) {
331  if (LLVM_UNLIKELY(this->EndX >= this->CapacityX))
332  this->grow();
333  memcpy(this->end(), &Elt, sizeof(T));
334  this->setEnd(this->end()+1);
335  }
336 
337  void pop_back() {
338  this->setEnd(this->end()-1);
339  }
340 };
341 
342 
343 /// This class consists of common code factored out of the SmallVector class to
344 /// reduce code duplication based on the SmallVector 'N' template parameter.
345 template <typename T>
346 class SmallVectorImpl : public SmallVectorTemplateBase<T, isPodLike<T>::value> {
347  typedef SmallVectorTemplateBase<T, isPodLike<T>::value > SuperClass;
348 
349  SmallVectorImpl(const SmallVectorImpl&) = delete;
350 public:
351  typedef typename SuperClass::iterator iterator;
353 
354 protected:
355  // Default ctor - Initialize to empty.
356  explicit SmallVectorImpl(unsigned N)
357  : SmallVectorTemplateBase<T, isPodLike<T>::value>(N*sizeof(T)) {
358  }
359 
360 public:
362  // Destroy the constructed elements in the vector.
363  this->destroy_range(this->begin(), this->end());
364 
365  // If this wasn't grown from the inline copy, deallocate the old space.
366  if (!this->isSmall())
367  free(this->begin());
368  }
369 
370 
371  void clear() {
372  this->destroy_range(this->begin(), this->end());
373  this->EndX = this->BeginX;
374  }
375 
377  if (N < this->size()) {
378  this->destroy_range(this->begin()+N, this->end());
379  this->setEnd(this->begin()+N);
380  } else if (N > this->size()) {
381  if (this->capacity() < N)
382  this->grow(N);
383  for (auto I = this->end(), E = this->begin() + N; I != E; ++I)
384  new (&*I) T();
385  this->setEnd(this->begin()+N);
386  }
387  }
388 
389  void resize(size_type N, const T &NV) {
390  if (N < this->size()) {
391  this->destroy_range(this->begin()+N, this->end());
392  this->setEnd(this->begin()+N);
393  } else if (N > this->size()) {
394  if (this->capacity() < N)
395  this->grow(N);
396  std::uninitialized_fill(this->end(), this->begin()+N, NV);
397  this->setEnd(this->begin()+N);
398  }
399  }
400 
402  if (this->capacity() < N)
403  this->grow(N);
404  }
405 
407  T Result = ::std::move(this->back());
408  this->pop_back();
409  return Result;
410  }
411 
412  void swap(SmallVectorImpl &RHS);
413 
414  /// Add the specified range to the end of the SmallVector.
415  template<typename in_iter>
416  void append(in_iter in_start, in_iter in_end) {
417  size_type NumInputs = std::distance(in_start, in_end);
418  // Grow allocated space if needed.
419  if (NumInputs > size_type(this->capacity_ptr()-this->end()))
420  this->grow(this->size()+NumInputs);
421 
422  // Copy the new elements over.
423  this->uninitialized_copy(in_start, in_end, this->end());
424  this->setEnd(this->end() + NumInputs);
425  }
426 
427  /// Add the specified range to the end of the SmallVector.
428  void append(size_type NumInputs, const T &Elt) {
429  // Grow allocated space if needed.
430  if (NumInputs > size_type(this->capacity_ptr()-this->end()))
431  this->grow(this->size()+NumInputs);
432 
433  // Copy the new elements over.
434  std::uninitialized_fill_n(this->end(), NumInputs, Elt);
435  this->setEnd(this->end() + NumInputs);
436  }
437 
438  void append(std::initializer_list<T> IL) {
439  append(IL.begin(), IL.end());
440  }
441 
442  void assign(size_type NumElts, const T &Elt) {
443  clear();
444  if (this->capacity() < NumElts)
445  this->grow(NumElts);
446  this->setEnd(this->begin()+NumElts);
447  std::uninitialized_fill(this->begin(), this->end(), Elt);
448  }
449 
450  void assign(std::initializer_list<T> IL) {
451  clear();
452  append(IL);
453  }
454 
456  assert(I >= this->begin() && "Iterator to erase is out of bounds.");
457  assert(I < this->end() && "Erasing at past-the-end iterator.");
458 
459  iterator N = I;
460  // Shift all elts down one.
461  this->move(I+1, this->end(), I);
462  // Drop the last elt.
463  this->pop_back();
464  return(N);
465  }
466 
468  assert(S >= this->begin() && "Range to erase is out of bounds.");
469  assert(S <= E && "Trying to erase invalid range.");
470  assert(E <= this->end() && "Trying to erase past the end.");
471 
472  iterator N = S;
473  // Shift all elts down.
474  iterator I = this->move(E, this->end(), S);
475  // Drop the last elts.
476  this->destroy_range(I, this->end());
477  this->setEnd(I);
478  return(N);
479  }
480 
482  if (I == this->end()) { // Important special case for empty vector.
483  this->push_back(::std::move(Elt));
484  return this->end()-1;
485  }
486 
487  assert(I >= this->begin() && "Insertion iterator is out of bounds.");
488  assert(I <= this->end() && "Inserting past the end of the vector.");
489 
490  if (this->EndX >= this->CapacityX) {
491  size_t EltNo = I-this->begin();
492  this->grow();
493  I = this->begin()+EltNo;
494  }
495 
496  ::new ((void*) this->end()) T(::std::move(this->back()));
497  // Push everything else over.
498  this->move_backward(I, this->end()-1, this->end());
499  this->setEnd(this->end()+1);
500 
501  // If we just moved the element we're inserting, be sure to update
502  // the reference.
503  T *EltPtr = &Elt;
504  if (I <= EltPtr && EltPtr < this->EndX)
505  ++EltPtr;
506 
507  *I = ::std::move(*EltPtr);
508  return I;
509  }
510 
511  iterator insert(iterator I, const T &Elt) {
512  if (I == this->end()) { // Important special case for empty vector.
513  this->push_back(Elt);
514  return this->end()-1;
515  }
516 
517  assert(I >= this->begin() && "Insertion iterator is out of bounds.");
518  assert(I <= this->end() && "Inserting past the end of the vector.");
519 
520  if (this->EndX >= this->CapacityX) {
521  size_t EltNo = I-this->begin();
522  this->grow();
523  I = this->begin()+EltNo;
524  }
525  ::new ((void*) this->end()) T(std::move(this->back()));
526  // Push everything else over.
527  this->move_backward(I, this->end()-1, this->end());
528  this->setEnd(this->end()+1);
529 
530  // If we just moved the element we're inserting, be sure to update
531  // the reference.
532  const T *EltPtr = &Elt;
533  if (I <= EltPtr && EltPtr < this->EndX)
534  ++EltPtr;
535 
536  *I = *EltPtr;
537  return I;
538  }
539 
540  iterator insert(iterator I, size_type NumToInsert, const T &Elt) {
541  // Convert iterator to elt# to avoid invalidating iterator when we reserve()
542  size_t InsertElt = I - this->begin();
543 
544  if (I == this->end()) { // Important special case for empty vector.
545  append(NumToInsert, Elt);
546  return this->begin()+InsertElt;
547  }
548 
549  assert(I >= this->begin() && "Insertion iterator is out of bounds.");
550  assert(I <= this->end() && "Inserting past the end of the vector.");
551 
552  // Ensure there is enough space.
553  reserve(this->size() + NumToInsert);
554 
555  // Uninvalidate the iterator.
556  I = this->begin()+InsertElt;
557 
558  // If there are more elements between the insertion point and the end of the
559  // range than there are being inserted, we can use a simple approach to
560  // insertion. Since we already reserved space, we know that this won't
561  // reallocate the vector.
562  if (size_t(this->end()-I) >= NumToInsert) {
563  T *OldEnd = this->end();
564  append(std::move_iterator<iterator>(this->end() - NumToInsert),
565  std::move_iterator<iterator>(this->end()));
566 
567  // Copy the existing elements that get replaced.
568  this->move_backward(I, OldEnd-NumToInsert, OldEnd);
569 
570  std::fill_n(I, NumToInsert, Elt);
571  return I;
572  }
573 
574  // Otherwise, we're inserting more elements than exist already, and we're
575  // not inserting at the end.
576 
577  // Move over the elements that we're about to overwrite.
578  T *OldEnd = this->end();
579  this->setEnd(this->end() + NumToInsert);
580  size_t NumOverwritten = OldEnd-I;
581  this->uninitialized_move(I, OldEnd, this->end()-NumOverwritten);
582 
583  // Replace the overwritten part.
584  std::fill_n(I, NumOverwritten, Elt);
585 
586  // Insert the non-overwritten middle part.
587  std::uninitialized_fill_n(OldEnd, NumToInsert-NumOverwritten, Elt);
588  return I;
589  }
590 
591  template<typename ItTy>
592  iterator insert(iterator I, ItTy From, ItTy To) {
593  // Convert iterator to elt# to avoid invalidating iterator when we reserve()
594  size_t InsertElt = I - this->begin();
595 
596  if (I == this->end()) { // Important special case for empty vector.
597  append(From, To);
598  return this->begin()+InsertElt;
599  }
600 
601  assert(I >= this->begin() && "Insertion iterator is out of bounds.");
602  assert(I <= this->end() && "Inserting past the end of the vector.");
603 
604  size_t NumToInsert = std::distance(From, To);
605 
606  // Ensure there is enough space.
607  reserve(this->size() + NumToInsert);
608 
609  // Uninvalidate the iterator.
610  I = this->begin()+InsertElt;
611 
612  // If there are more elements between the insertion point and the end of the
613  // range than there are being inserted, we can use a simple approach to
614  // insertion. Since we already reserved space, we know that this won't
615  // reallocate the vector.
616  if (size_t(this->end()-I) >= NumToInsert) {
617  T *OldEnd = this->end();
618  append(std::move_iterator<iterator>(this->end() - NumToInsert),
619  std::move_iterator<iterator>(this->end()));
620 
621  // Copy the existing elements that get replaced.
622  this->move_backward(I, OldEnd-NumToInsert, OldEnd);
623 
624  std::copy(From, To, I);
625  return I;
626  }
627 
628  // Otherwise, we're inserting more elements than exist already, and we're
629  // not inserting at the end.
630 
631  // Move over the elements that we're about to overwrite.
632  T *OldEnd = this->end();
633  this->setEnd(this->end() + NumToInsert);
634  size_t NumOverwritten = OldEnd-I;
635  this->uninitialized_move(I, OldEnd, this->end()-NumOverwritten);
636 
637  // Replace the overwritten part.
638  for (T *J = I; NumOverwritten > 0; --NumOverwritten) {
639  *J = *From;
640  ++J; ++From;
641  }
642 
643  // Insert the non-overwritten middle part.
644  this->uninitialized_copy(From, To, OldEnd);
645  return I;
646  }
647 
648  void insert(iterator I, std::initializer_list<T> IL) {
649  insert(I, IL.begin(), IL.end());
650  }
651 
652  template <typename... ArgTypes> void emplace_back(ArgTypes &&... Args) {
653  if (LLVM_UNLIKELY(this->EndX >= this->CapacityX))
654  this->grow();
655  ::new ((void *)this->end()) T(std::forward<ArgTypes>(Args)...);
656  this->setEnd(this->end() + 1);
657  }
658 
660 
662 
663  bool operator==(const SmallVectorImpl &RHS) const {
664  if (this->size() != RHS.size()) return false;
665  return std::equal(this->begin(), this->end(), RHS.begin());
666  }
667  bool operator!=(const SmallVectorImpl &RHS) const {
668  return !(*this == RHS);
669  }
670 
671  bool operator<(const SmallVectorImpl &RHS) const {
672  return std::lexicographical_compare(this->begin(), this->end(),
673  RHS.begin(), RHS.end());
674  }
675 
676  /// Set the array size to \p N, which the current array must have enough
677  /// capacity for.
678  ///
679  /// This does not construct or destroy any elements in the vector.
680  ///
681  /// Clients can use this in conjunction with capacity() to write past the end
682  /// of the buffer when they know that more elements are available, and only
683  /// update the size later. This avoids the cost of value initializing elements
684  /// which will only be overwritten.
686  assert(N <= this->capacity());
687  this->setEnd(this->begin() + N);
688  }
689 };
690 
691 
692 template <typename T>
694  if (this == &RHS) return;
695 
696  // We can only avoid copying elements if neither vector is small.
697  if (!this->isSmall() && !RHS.isSmall()) {
698  std::swap(this->BeginX, RHS.BeginX);
699  std::swap(this->EndX, RHS.EndX);
700  std::swap(this->CapacityX, RHS.CapacityX);
701  return;
702  }
703  if (RHS.size() > this->capacity())
704  this->grow(RHS.size());
705  if (this->size() > RHS.capacity())
706  RHS.grow(this->size());
707 
708  // Swap the shared elements.
709  size_t NumShared = this->size();
710  if (NumShared > RHS.size()) NumShared = RHS.size();
711  for (size_type i = 0; i != NumShared; ++i)
712  std::swap((*this)[i], RHS[i]);
713 
714  // Copy over the extra elts.
715  if (this->size() > RHS.size()) {
716  size_t EltDiff = this->size() - RHS.size();
717  this->uninitialized_copy(this->begin()+NumShared, this->end(), RHS.end());
718  RHS.setEnd(RHS.end()+EltDiff);
719  this->destroy_range(this->begin()+NumShared, this->end());
720  this->setEnd(this->begin()+NumShared);
721  } else if (RHS.size() > this->size()) {
722  size_t EltDiff = RHS.size() - this->size();
723  this->uninitialized_copy(RHS.begin()+NumShared, RHS.end(), this->end());
724  this->setEnd(this->end() + EltDiff);
725  this->destroy_range(RHS.begin()+NumShared, RHS.end());
726  RHS.setEnd(RHS.begin()+NumShared);
727  }
728 }
729 
730 template <typename T>
733  // Avoid self-assignment.
734  if (this == &RHS) return *this;
735 
736  // If we already have sufficient space, assign the common elements, then
737  // destroy any excess.
738  size_t RHSSize = RHS.size();
739  size_t CurSize = this->size();
740  if (CurSize >= RHSSize) {
741  // Assign common elements.
742  iterator NewEnd;
743  if (RHSSize)
744  NewEnd = std::copy(RHS.begin(), RHS.begin()+RHSSize, this->begin());
745  else
746  NewEnd = this->begin();
747 
748  // Destroy excess elements.
749  this->destroy_range(NewEnd, this->end());
750 
751  // Trim.
752  this->setEnd(NewEnd);
753  return *this;
754  }
755 
756  // If we have to grow to have enough elements, destroy the current elements.
757  // This allows us to avoid copying them during the grow.
758  // FIXME: don't do this if they're efficiently moveable.
759  if (this->capacity() < RHSSize) {
760  // Destroy current elements.
761  this->destroy_range(this->begin(), this->end());
762  this->setEnd(this->begin());
763  CurSize = 0;
764  this->grow(RHSSize);
765  } else if (CurSize) {
766  // Otherwise, use assignment for the already-constructed elements.
767  std::copy(RHS.begin(), RHS.begin()+CurSize, this->begin());
768  }
769 
770  // Copy construct the new elements in place.
771  this->uninitialized_copy(RHS.begin()+CurSize, RHS.end(),
772  this->begin()+CurSize);
773 
774  // Set end.
775  this->setEnd(this->begin()+RHSSize);
776  return *this;
777 }
778 
779 template <typename T>
781  // Avoid self-assignment.
782  if (this == &RHS) return *this;
783 
784  // If the RHS isn't small, clear this vector and then steal its buffer.
785  if (!RHS.isSmall()) {
786  this->destroy_range(this->begin(), this->end());
787  if (!this->isSmall()) free(this->begin());
788  this->BeginX = RHS.BeginX;
789  this->EndX = RHS.EndX;
790  this->CapacityX = RHS.CapacityX;
791  RHS.resetToSmall();
792  return *this;
793  }
794 
795  // If we already have sufficient space, assign the common elements, then
796  // destroy any excess.
797  size_t RHSSize = RHS.size();
798  size_t CurSize = this->size();
799  if (CurSize >= RHSSize) {
800  // Assign common elements.
801  iterator NewEnd = this->begin();
802  if (RHSSize)
803  NewEnd = this->move(RHS.begin(), RHS.end(), NewEnd);
804 
805  // Destroy excess elements and trim the bounds.
806  this->destroy_range(NewEnd, this->end());
807  this->setEnd(NewEnd);
808 
809  // Clear the RHS.
810  RHS.clear();
811 
812  return *this;
813  }
814 
815  // If we have to grow to have enough elements, destroy the current elements.
816  // This allows us to avoid copying them during the grow.
817  // FIXME: this may not actually make any sense if we can efficiently move
818  // elements.
819  if (this->capacity() < RHSSize) {
820  // Destroy current elements.
821  this->destroy_range(this->begin(), this->end());
822  this->setEnd(this->begin());
823  CurSize = 0;
824  this->grow(RHSSize);
825  } else if (CurSize) {
826  // Otherwise, use assignment for the already-constructed elements.
827  this->move(RHS.begin(), RHS.begin()+CurSize, this->begin());
828  }
829 
830  // Move-construct the new elements in place.
831  this->uninitialized_move(RHS.begin()+CurSize, RHS.end(),
832  this->begin()+CurSize);
833 
834  // Set end.
835  this->setEnd(this->begin()+RHSSize);
836 
837  RHS.clear();
838  return *this;
839 }
840 
841 /// Storage for the SmallVector elements which aren't contained in
842 /// SmallVectorTemplateCommon. There are 'N-1' elements here. The remaining '1'
843 /// element is in the base class. This is specialized for the N=1 and N=0 cases
844 /// to avoid allocating unnecessary storage.
845 template <typename T, unsigned N>
846 struct SmallVectorStorage {
848 };
849 template <typename T> struct SmallVectorStorage<T, 1> {};
850 template <typename T> struct SmallVectorStorage<T, 0> {};
851 
852 /// This is a 'vector' (really, a variable-sized array), optimized
853 /// for the case when the array is small. It contains some number of elements
854 /// in-place, which allows it to avoid heap allocation when the actual number of
855 /// elements is below that threshold. This allows normal "small" cases to be
856 /// fast without losing generality for large inputs.
857 ///
858 /// Note that this does not attempt to be exception safe.
859 ///
860 template <typename T, unsigned N>
861 class SmallVector : public SmallVectorImpl<T> {
862  /// Inline space for elements which aren't stored in the base class.
863  SmallVectorStorage<T, N> Storage;
864 public:
866  }
867 
868  explicit SmallVector(size_t Size, const T &Value = T())
869  : SmallVectorImpl<T>(N) {
870  this->assign(Size, Value);
871  }
872 
873  template<typename ItTy>
874  SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(N) {
875  this->append(S, E);
876  }
877 
878  template <typename RangeTy>
880  : SmallVectorImpl<T>(N) {
881  this->append(R.begin(), R.end());
882  }
883 
884  SmallVector(std::initializer_list<T> IL) : SmallVectorImpl<T>(N) {
885  this->assign(IL);
886  }
887 
889  if (!RHS.empty())
891  }
892 
893  const SmallVector &operator=(const SmallVector &RHS) {
895  return *this;
896  }
897 
899  if (!RHS.empty())
900  SmallVectorImpl<T>::operator=(::std::move(RHS));
901  }
902 
904  SmallVectorImpl<T>::operator=(::std::move(RHS));
905  return *this;
906  }
907 
909  if (!RHS.empty())
910  SmallVectorImpl<T>::operator=(::std::move(RHS));
911  }
912 
914  SmallVectorImpl<T>::operator=(::std::move(RHS));
915  return *this;
916  }
917 
918  const SmallVector &operator=(std::initializer_list<T> IL) {
919  this->assign(IL);
920  return *this;
921  }
922 };
923 
924 template<typename T, unsigned N>
925 static inline size_t capacity_in_bytes(const SmallVector<T, N> &X) {
926  return X.capacity_in_bytes();
927 }
928 
929 } // End llvm namespace
930 
931 namespace std {
932  /// Implement std::swap in terms of SmallVector swap.
933  template<typename T>
934  inline void
936  LHS.swap(RHS);
937  }
938 
939  /// Implement std::swap in terms of SmallVector swap.
940  template<typename T, unsigned N>
941  inline void
943  LHS.swap(RHS);
944  }
945 }
946 
947 #endif
SuperClass::iterator iterator
Definition: SmallVector.h:351
std::reverse_iterator< iterator > reverse_iterator
Definition: SmallVector.h:104
void push_back(const T &Elt)
Definition: SmallVector.h:222
const_iterator end(StringRef path)
Get end iterator over path.
Definition: Path.cpp:240
static void uninitialized_copy(It1 I, It1 E, It2 Dest)
Copy the range [I, E) onto the uninitialized memory starting with "Dest", constructing elements into ...
Definition: SmallVector.h:304
#define LLVM_ATTRIBUTE_UNUSED_RESULT
Definition: Compiler.h:128
size_t capacity() const
Return the total number of elements in the currently allocated buffer.
Definition: SmallVector.h:131
#define LLVM_UNLIKELY(EXPR)
Definition: Compiler.h:174
static It2 move_backward(It1 I, It1 E, It2 Dest)
Use move-assignment to move the range [I, E) onto the objects ending at "Dest", moving objects in rev...
Definition: SmallVector.h:289
static It2 move(It1 I, It1 E, It2 Dest)
Use move-assignment to move the range [I, E) onto the objects starting with "Dest".
Definition: SmallVector.h:184
This provides a very simple, boring adaptor for a begin and end iterator into a range type...
const SmallVector & operator=(SmallVector &&RHS)
Definition: SmallVector.h:903
iterator insert(iterator I, const T &Elt)
Definition: SmallVector.h:511
iterator insert(iterator I, size_type NumToInsert, const T &Elt)
Definition: SmallVector.h:540
static void uninitialized_move(It1 I, It1 E, It2 Dest)
Move the range [I, E) into the uninitialized memory starting with "Dest", constructing elements as ne...
Definition: SmallVector.h:204
const_iterator begin(StringRef path)
Get begin iterator over path.
Definition: Path.cpp:232
void append(size_type NumInputs, const T &Elt)
Add the specified range to the end of the SmallVector.
Definition: SmallVector.h:428
size_t capacity_in_bytes() const
capacity_in_bytes - This returns capacity()*sizeof(T).
Definition: SmallVector.h:53
void reserve(size_type N)
Definition: SmallVector.h:401
static It2 move_backward(It1 I, It1 E, It2 Dest)
Use move-assignment to move the range [I, E) onto the objects ending at "Dest", moving objects in rev...
Definition: SmallVector.h:195
const_iterator end() const
Definition: SmallVector.h:115
SmallVectorTemplateBase(size_t Size)
Definition: SmallVector.h:171
static void uninitialized_copy(It1 I, It1 E, It2 Dest)
Copy the range [I, E) onto the uninitialized memory starting with "Dest", constructing elements as ne...
Definition: SmallVector.h:212
T LLVM_ATTRIBUTE_UNUSED_RESULT pop_back_val()
Definition: SmallVector.h:406
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APInt.h:33
void resize(size_type N, const T &NV)
Definition: SmallVector.h:389
void assign(size_type NumElts, const T &Elt)
Definition: SmallVector.h:442
const_reverse_iterator rend() const
Definition: SmallVector.h:125
bool LLVM_ATTRIBUTE_UNUSED_RESULT empty() const
Definition: SmallVector.h:57
#define T
SmallVector(SmallVectorImpl< T > &&RHS)
Definition: SmallVector.h:908
const SmallVector & operator=(const SmallVector &RHS)
Definition: SmallVector.h:893
SmallVector(SmallVector &&RHS)
Definition: SmallVector.h:898
#define P(N)
SmallVectorTemplateBase<isPodLike = false> - This is where we put method implementations that are desig...
Definition: SmallVector.h:169
#define true
Definition: ConvertUTF.c:66
static It2 move(It1 I, It1 E, It2 Dest)
Use move-assignment to move the range [I, E) onto the objects starting with "Dest".
Definition: SmallVector.h:282
const_reference front() const
Definition: SmallVector.h:151
bool operator==(const SmallVectorImpl &RHS) const
Definition: SmallVector.h:663
void swap(SmallVectorImpl &RHS)
Definition: SmallVector.h:693
const_iterator begin() const
Definition: SmallVector.h:113
const_reference back() const
Definition: SmallVector.h:160
void grow(size_t MinSize=0)
Grow the allocated memory (without initializing new elements), doubling the size of the allocated mem...
Definition: SmallVector.h:244
reference operator[](size_type idx)
Definition: SmallVector.h:138
bool operator!=(const SmallVectorImpl &RHS) const
Definition: SmallVector.h:667
SmallVectorImpl(unsigned N)
Definition: SmallVector.h:356
bool operator<(const SmallVectorImpl &RHS) const
Definition: SmallVector.h:671
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang","erlang-compatible garbage collector")
SmallVectorBase(void *FirstEl, size_t Size)
Definition: SmallVector.h:39
void assign(std::initializer_list< T > IL)
Definition: SmallVector.h:450
iterator erase(iterator S, iterator E)
Definition: SmallVector.h:467
void append(in_iter in_start, in_iter in_end)
Add the specified range to the end of the SmallVector.
Definition: SmallVector.h:416
uint64_t NextPowerOf2(uint64_t A)
NextPowerOf2 - Returns the next power of two (in 64-bits) that is strictly greater than A...
Definition: MathExtras.h:582
iterator erase(iterator I)
Definition: SmallVector.h:455
const_reference operator[](size_type idx) const
Definition: SmallVector.h:142
const_iterator capacity_ptr() const
Definition: SmallVector.h:118
isPodLike - This is a type trait that is used to determine whether a given type can be copied around ...
Definition: ArrayRef.h:365
const SmallVector & operator=(SmallVectorImpl< T > &&RHS)
Definition: SmallVector.h:913
SmallVector(ItTy S, ItTy E)
Definition: SmallVector.h:874
static size_t capacity_in_bytes(const DenseMap< KeyT, ValueT, KeyInfoT > &X)
Definition: DenseMap.h:1068
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:861
bool isSmall() const
Return true if this is a smallvector which has not had dynamic memory allocated for it...
Definition: SmallVector.h:86
void grow(size_t MinSize=0)
Double the size of the allocated memory, guaranteeing space for at least one more element or MinSize ...
Definition: SmallVector.h:326
std::reverse_iterator< const_iterator > const_reverse_iterator
Definition: SmallVector.h:103
iterator insert(iterator I, ItTy From, ItTy To)
Definition: SmallVector.h:592
SmallVectorTemplateCommon< T >::U InlineElts[N-1]
Definition: SmallVector.h:847
IteratorT end() const
IteratorT begin() const
SmallVector(std::initializer_list< T > IL)
Definition: SmallVector.h:884
void swap(llvm::BitVector &LHS, llvm::BitVector &RHS)
Implement std::swap in terms of BitVector swap.
Definition: BitVector.h:576
A range adaptor for a pair of iterators.
void append(std::initializer_list< T > IL)
Definition: SmallVector.h:438
SmallVectorImpl & operator=(const SmallVectorImpl &RHS)
Definition: SmallVector.h:732
iterator insert(iterator I, T &&Elt)
Definition: SmallVector.h:481
SuperClass::size_type size_type
Definition: SmallVector.h:352
void insert(iterator I, std::initializer_list< T > IL)
Definition: SmallVector.h:648
static void destroy_range(T *S, T *E)
Definition: SmallVector.h:173
This is the part of SmallVectorTemplateBase which does not depend on whether the type T is a POD...
Definition: SmallVector.h:66
void set_size(size_type N)
Set the array size to N, which the current array must have enough capacity for.
Definition: SmallVector.h:685
void emplace_back(ArgTypes &&...Args)
Definition: SmallVector.h:652
pointer data()
Return a pointer to the vector's buffer, even if empty().
Definition: SmallVector.h:134
#define I(x, y, z)
Definition: MD5.cpp:54
#define N
static void uninitialized_copy(T1 *I, T1 *E, T2 *Dest, typename std::enable_if< std::is_same< typename std::remove_const< T1 >::type, T2 >::value >::type *=nullptr)
Copy the range [I, E) onto the uninitialized memory starting with "Dest", constructing elements into ...
Definition: SmallVector.h:312
This is all the non-templated stuff common to all SmallVectors.
Definition: SmallVector.h:34
void size_t size
size_t size_in_bytes() const
This returns size()*sizeof(T).
Definition: SmallVector.h:48
SmallVectorTemplateCommon(size_t Size)
Definition: SmallVector.h:78
SmallVector(const SmallVector &RHS)
Definition: SmallVector.h:888
LLVM Value Representation.
Definition: Value.h:69
static void uninitialized_move(It1 I, It1 E, It2 Dest)
Move the range [I, E) onto the uninitialized memory starting with "Dest", constructing elements into ...
Definition: SmallVector.h:296
void grow_pod(size_t MinSizeInBytes, size_t TSize)
Definition: SmallVector.h:80
void grow_pod(void *FirstEl, size_t MinSizeInBytes, size_t TSize)
This is an implementation of the grow() method which only works on POD-like data types and is out of ...
Definition: SmallVector.cpp:19
Storage for the SmallVector elements which aren't contained in SmallVectorTemplateCommon.
Definition: SmallVector.h:60
SmallVector(const llvm::iterator_range< RangeTy > R)
Definition: SmallVector.h:879
#define T1
size_type max_size() const
Definition: SmallVector.h:128
const SmallVector & operator=(std::initializer_list< T > IL)
Definition: SmallVector.h:918
void resetToSmall()
Put this vector in a state of being small.
Definition: SmallVector.h:91
const_pointer data() const
Return a pointer to the vector's buffer, even if empty().
Definition: SmallVector.h:136
SmallVector(size_t Size, const T &Value=T())
Definition: SmallVector.h:868
const_reverse_iterator rbegin() const
Definition: SmallVector.h:123
void resize(size_type N)
Definition: SmallVector.h:376