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SmallVector.h
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 
17 #include "llvm/iterator_range.h"
18 #include "llvm/AlignOf.h"
19 #include "llvm/Compiler.h"
20 #include "llvm/MathExtras.h"
21 #include "llvm/type_traits.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 
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 
44  void grow_pod(void *FirstEl, size_t MinSizeInBytes, size_t TSize);
45 
46 public:
48  size_t size_in_bytes() const {
49  return size_t((char*)EndX - (char*)BeginX);
50  }
51 
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 
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 
86  bool isSmall() const {
87  return BeginX == static_cast<const void*>(&FirstEl);
88  }
89 
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:
117  iterator capacity_ptr() { return (iterator)this->CapacityX; }
118  const_iterator capacity_ptr() const { return (const_iterator)this->CapacityX;}
119 public:
120 
121  // reverse iterator creation methods.
122  reverse_iterator rbegin() { return reverse_iterator(end()); }
123  const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
124  reverse_iterator rend() { return reverse_iterator(begin()); }
125  const_reverse_iterator rend() const { return const_reverse_iterator(begin());}
126 
127  size_type size() const { return end()-begin(); }
128  size_type max_size() const { return size_type(-1) / sizeof(T); }
129 
131  size_t capacity() const { return capacity_ptr() - begin(); }
132 
134  pointer data() { return pointer(begin()); }
136  const_pointer data() const { return const_pointer(begin()); }
137 
138  reference operator[](size_type idx) {
139  assert(idx < size());
140  return begin()[idx];
141  }
142  const_reference operator[](size_type idx) const {
143  assert(idx < size());
144  return begin()[idx];
145  }
146 
147  reference front() {
148  assert(!empty());
149  return begin()[0];
150  }
151  const_reference front() const {
152  assert(!empty());
153  return begin()[0];
154  }
155 
156  reference back() {
157  assert(!empty());
158  return end()[-1];
159  }
160  const_reference back() const {
161  assert(!empty());
162  return end()[-1];
163  }
164 };
165 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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.
319  memcpy(Dest, I, (E-I)*sizeof(T));
320  }
321 
324  void grow(size_t MinSize = 0) {
325  this->grow_pod(MinSize*sizeof(T), sizeof(T));
326  }
327 public:
328  void push_back(const T &Elt) {
329  if (LLVM_UNLIKELY(this->EndX >= this->CapacityX))
330  this->grow();
331  memcpy(this->end(), &Elt, sizeof(T));
332  this->setEnd(this->end()+1);
333  }
334 
335  void pop_back() {
336  this->setEnd(this->end()-1);
337  }
338 };
339 
340 
343 template <typename T>
344 class SmallVectorImpl : public SmallVectorTemplateBase<T, isPodLike<T>::value> {
345  typedef SmallVectorTemplateBase<T, isPodLike<T>::value > SuperClass;
346 
347  SmallVectorImpl(const SmallVectorImpl&) = delete;
348 public:
349  typedef typename SuperClass::iterator iterator;
350  typedef typename SuperClass::size_type size_type;
351 
352 protected:
353  // Default ctor - Initialize to empty.
354  explicit SmallVectorImpl(unsigned N)
355  : SmallVectorTemplateBase<T, isPodLike<T>::value>(N*sizeof(T)) {
356  }
357 
358 public:
359  ~SmallVectorImpl() {
360  // Destroy the constructed elements in the vector.
361  this->destroy_range(this->begin(), this->end());
362 
363  // If this wasn't grown from the inline copy, deallocate the old space.
364  if (!this->isSmall())
365  free(this->begin());
366  }
367 
368 
369  void clear() {
370  this->destroy_range(this->begin(), this->end());
371  this->EndX = this->BeginX;
372  }
373 
374  void resize(size_type N) {
375  if (N < this->size()) {
376  this->destroy_range(this->begin()+N, this->end());
377  this->setEnd(this->begin()+N);
378  } else if (N > this->size()) {
379  if (this->capacity() < N)
380  this->grow(N);
381  for (auto I = this->end(), E = this->begin() + N; I != E; ++I)
382  new (&*I) T();
383  this->setEnd(this->begin()+N);
384  }
385  }
386 
387  void resize(size_type N, const T &NV) {
388  if (N < this->size()) {
389  this->destroy_range(this->begin()+N, this->end());
390  this->setEnd(this->begin()+N);
391  } else if (N > this->size()) {
392  if (this->capacity() < N)
393  this->grow(N);
394  std::uninitialized_fill(this->end(), this->begin()+N, NV);
395  this->setEnd(this->begin()+N);
396  }
397  }
398 
399  void reserve(size_type N) {
400  if (this->capacity() < N)
401  this->grow(N);
402  }
403 
404  T LLVM_ATTRIBUTE_UNUSED_RESULT pop_back_val() {
405  T Result = ::std::move(this->back());
406  this->pop_back();
407  return Result;
408  }
409 
410  void swap(SmallVectorImpl &RHS);
411 
413  template<typename in_iter>
414  void append(in_iter in_start, in_iter in_end) {
415  size_type NumInputs = std::distance(in_start, in_end);
416  // Grow allocated space if needed.
417  if (NumInputs > size_type(this->capacity_ptr()-this->end()))
418  this->grow(this->size()+NumInputs);
419 
420  // Copy the new elements over.
421  this->uninitialized_copy(in_start, in_end, this->end());
422  this->setEnd(this->end() + NumInputs);
423  }
424 
426  void append(size_type NumInputs, const T &Elt) {
427  // Grow allocated space if needed.
428  if (NumInputs > size_type(this->capacity_ptr()-this->end()))
429  this->grow(this->size()+NumInputs);
430 
431  // Copy the new elements over.
432  std::uninitialized_fill_n(this->end(), NumInputs, Elt);
433  this->setEnd(this->end() + NumInputs);
434  }
435 
436  void append(std::initializer_list<T> IL) {
437  append(IL.begin(), IL.end());
438  }
439 
440  void assign(size_type NumElts, const T &Elt) {
441  clear();
442  if (this->capacity() < NumElts)
443  this->grow(NumElts);
444  this->setEnd(this->begin()+NumElts);
445  std::uninitialized_fill(this->begin(), this->end(), Elt);
446  }
447 
448  void assign(std::initializer_list<T> IL) {
449  clear();
450  append(IL);
451  }
452 
453  iterator erase(iterator I) {
454  assert(I >= this->begin() && "Iterator to erase is out of bounds.");
455  assert(I < this->end() && "Erasing at past-the-end iterator.");
456 
457  iterator N = I;
458  // Shift all elts down one.
459  this->move(I+1, this->end(), I);
460  // Drop the last elt.
461  this->pop_back();
462  return(N);
463  }
464 
465  iterator erase(iterator S, iterator E) {
466  assert(S >= this->begin() && "Range to erase is out of bounds.");
467  assert(S <= E && "Trying to erase invalid range.");
468  assert(E <= this->end() && "Trying to erase past the end.");
469 
470  iterator N = S;
471  // Shift all elts down.
472  iterator I = this->move(E, this->end(), S);
473  // Drop the last elts.
474  this->destroy_range(I, this->end());
475  this->setEnd(I);
476  return(N);
477  }
478 
479  iterator insert(iterator I, T &&Elt) {
480  if (I == this->end()) { // Important special case for empty vector.
481  this->push_back(::std::move(Elt));
482  return this->end()-1;
483  }
484 
485  assert(I >= this->begin() && "Insertion iterator is out of bounds.");
486  assert(I <= this->end() && "Inserting past the end of the vector.");
487 
488  if (this->EndX >= this->CapacityX) {
489  size_t EltNo = I-this->begin();
490  this->grow();
491  I = this->begin()+EltNo;
492  }
493 
494  ::new ((void*) this->end()) T(::std::move(this->back()));
495  // Push everything else over.
496  this->move_backward(I, this->end()-1, this->end());
497  this->setEnd(this->end()+1);
498 
499  // If we just moved the element we're inserting, be sure to update
500  // the reference.
501  T *EltPtr = &Elt;
502  if (I <= EltPtr && EltPtr < this->EndX)
503  ++EltPtr;
504 
505  *I = ::std::move(*EltPtr);
506  return I;
507  }
508 
509  iterator insert(iterator I, const T &Elt) {
510  if (I == this->end()) { // Important special case for empty vector.
511  this->push_back(Elt);
512  return this->end()-1;
513  }
514 
515  assert(I >= this->begin() && "Insertion iterator is out of bounds.");
516  assert(I <= this->end() && "Inserting past the end of the vector.");
517 
518  if (this->EndX >= this->CapacityX) {
519  size_t EltNo = I-this->begin();
520  this->grow();
521  I = this->begin()+EltNo;
522  }
523  ::new ((void*) this->end()) T(std::move(this->back()));
524  // Push everything else over.
525  this->move_backward(I, this->end()-1, this->end());
526  this->setEnd(this->end()+1);
527 
528  // If we just moved the element we're inserting, be sure to update
529  // the reference.
530  const T *EltPtr = &Elt;
531  if (I <= EltPtr && EltPtr < this->EndX)
532  ++EltPtr;
533 
534  *I = *EltPtr;
535  return I;
536  }
537 
538  iterator insert(iterator I, size_type NumToInsert, const T &Elt) {
539  // Convert iterator to elt# to avoid invalidating iterator when we reserve()
540  size_t InsertElt = I - this->begin();
541 
542  if (I == this->end()) { // Important special case for empty vector.
543  append(NumToInsert, Elt);
544  return this->begin()+InsertElt;
545  }
546 
547  assert(I >= this->begin() && "Insertion iterator is out of bounds.");
548  assert(I <= this->end() && "Inserting past the end of the vector.");
549 
550  // Ensure there is enough space.
551  reserve(this->size() + NumToInsert);
552 
553  // Uninvalidate the iterator.
554  I = this->begin()+InsertElt;
555 
556  // If there are more elements between the insertion point and the end of the
557  // range than there are being inserted, we can use a simple approach to
558  // insertion. Since we already reserved space, we know that this won't
559  // reallocate the vector.
560  if (size_t(this->end()-I) >= NumToInsert) {
561  T *OldEnd = this->end();
562  append(std::move_iterator<iterator>(this->end() - NumToInsert),
563  std::move_iterator<iterator>(this->end()));
564 
565  // Copy the existing elements that get replaced.
566  this->move_backward(I, OldEnd-NumToInsert, OldEnd);
567 
568  std::fill_n(I, NumToInsert, Elt);
569  return I;
570  }
571 
572  // Otherwise, we're inserting more elements than exist already, and we're
573  // not inserting at the end.
574 
575  // Move over the elements that we're about to overwrite.
576  T *OldEnd = this->end();
577  this->setEnd(this->end() + NumToInsert);
578  size_t NumOverwritten = OldEnd-I;
579  this->uninitialized_move(I, OldEnd, this->end()-NumOverwritten);
580 
581  // Replace the overwritten part.
582  std::fill_n(I, NumOverwritten, Elt);
583 
584  // Insert the non-overwritten middle part.
585  std::uninitialized_fill_n(OldEnd, NumToInsert-NumOverwritten, Elt);
586  return I;
587  }
588 
589  template<typename ItTy>
590  iterator insert(iterator I, ItTy From, ItTy To) {
591  // Convert iterator to elt# to avoid invalidating iterator when we reserve()
592  size_t InsertElt = I - this->begin();
593 
594  if (I == this->end()) { // Important special case for empty vector.
595  append(From, To);
596  return this->begin()+InsertElt;
597  }
598 
599  assert(I >= this->begin() && "Insertion iterator is out of bounds.");
600  assert(I <= this->end() && "Inserting past the end of the vector.");
601 
602  size_t NumToInsert = std::distance(From, To);
603 
604  // Ensure there is enough space.
605  reserve(this->size() + NumToInsert);
606 
607  // Uninvalidate the iterator.
608  I = this->begin()+InsertElt;
609 
610  // If there are more elements between the insertion point and the end of the
611  // range than there are being inserted, we can use a simple approach to
612  // insertion. Since we already reserved space, we know that this won't
613  // reallocate the vector.
614  if (size_t(this->end()-I) >= NumToInsert) {
615  T *OldEnd = this->end();
616  append(std::move_iterator<iterator>(this->end() - NumToInsert),
617  std::move_iterator<iterator>(this->end()));
618 
619  // Copy the existing elements that get replaced.
620  this->move_backward(I, OldEnd-NumToInsert, OldEnd);
621 
622  std::copy(From, To, I);
623  return I;
624  }
625 
626  // Otherwise, we're inserting more elements than exist already, and we're
627  // not inserting at the end.
628 
629  // Move over the elements that we're about to overwrite.
630  T *OldEnd = this->end();
631  this->setEnd(this->end() + NumToInsert);
632  size_t NumOverwritten = OldEnd-I;
633  this->uninitialized_move(I, OldEnd, this->end()-NumOverwritten);
634 
635  // Replace the overwritten part.
636  for (T *J = I; NumOverwritten > 0; --NumOverwritten) {
637  *J = *From;
638  ++J; ++From;
639  }
640 
641  // Insert the non-overwritten middle part.
642  this->uninitialized_copy(From, To, OldEnd);
643  return I;
644  }
645 
646  void insert(iterator I, std::initializer_list<T> IL) {
647  insert(I, IL.begin(), IL.end());
648  }
649 
650  template <typename... ArgTypes> void emplace_back(ArgTypes &&... Args) {
651  if (LLVM_UNLIKELY(this->EndX >= this->CapacityX))
652  this->grow();
653  ::new ((void *)this->end()) T(std::forward<ArgTypes>(Args)...);
654  this->setEnd(this->end() + 1);
655  }
656 
657  SmallVectorImpl &operator=(const SmallVectorImpl &RHS);
658 
659  SmallVectorImpl &operator=(SmallVectorImpl &&RHS);
660 
661  bool operator==(const SmallVectorImpl &RHS) const {
662  if (this->size() != RHS.size()) return false;
663  return std::equal(this->begin(), this->end(), RHS.begin());
664  }
665  bool operator!=(const SmallVectorImpl &RHS) const {
666  return !(*this == RHS);
667  }
668 
669  bool operator<(const SmallVectorImpl &RHS) const {
670  return std::lexicographical_compare(this->begin(), this->end(),
671  RHS.begin(), RHS.end());
672  }
673 
683  void set_size(size_type N) {
684  assert(N <= this->capacity());
685  this->setEnd(this->begin() + N);
686  }
687 };
688 
689 
690 template <typename T>
691 void SmallVectorImpl<T>::swap(SmallVectorImpl<T> &RHS) {
692  if (this == &RHS) return;
693 
694  // We can only avoid copying elements if neither vector is small.
695  if (!this->isSmall() && !RHS.isSmall()) {
696  std::swap(this->BeginX, RHS.BeginX);
697  std::swap(this->EndX, RHS.EndX);
698  std::swap(this->CapacityX, RHS.CapacityX);
699  return;
700  }
701  if (RHS.size() > this->capacity())
702  this->grow(RHS.size());
703  if (this->size() > RHS.capacity())
704  RHS.grow(this->size());
705 
706  // Swap the shared elements.
707  size_t NumShared = this->size();
708  if (NumShared > RHS.size()) NumShared = RHS.size();
709  for (size_type i = 0; i != NumShared; ++i)
710  std::swap((*this)[i], RHS[i]);
711 
712  // Copy over the extra elts.
713  if (this->size() > RHS.size()) {
714  size_t EltDiff = this->size() - RHS.size();
715  this->uninitialized_copy(this->begin()+NumShared, this->end(), RHS.end());
716  RHS.setEnd(RHS.end()+EltDiff);
717  this->destroy_range(this->begin()+NumShared, this->end());
718  this->setEnd(this->begin()+NumShared);
719  } else if (RHS.size() > this->size()) {
720  size_t EltDiff = RHS.size() - this->size();
721  this->uninitialized_copy(RHS.begin()+NumShared, RHS.end(), this->end());
722  this->setEnd(this->end() + EltDiff);
723  this->destroy_range(RHS.begin()+NumShared, RHS.end());
724  RHS.setEnd(RHS.begin()+NumShared);
725  }
726 }
727 
728 template <typename T>
729 SmallVectorImpl<T> &SmallVectorImpl<T>::
730  operator=(const SmallVectorImpl<T> &RHS) {
731  // Avoid self-assignment.
732  if (this == &RHS) return *this;
733 
734  // If we already have sufficient space, assign the common elements, then
735  // destroy any excess.
736  size_t RHSSize = RHS.size();
737  size_t CurSize = this->size();
738  if (CurSize >= RHSSize) {
739  // Assign common elements.
740  iterator NewEnd;
741  if (RHSSize)
742  NewEnd = std::copy(RHS.begin(), RHS.begin()+RHSSize, this->begin());
743  else
744  NewEnd = this->begin();
745 
746  // Destroy excess elements.
747  this->destroy_range(NewEnd, this->end());
748 
749  // Trim.
750  this->setEnd(NewEnd);
751  return *this;
752  }
753 
754  // If we have to grow to have enough elements, destroy the current elements.
755  // This allows us to avoid copying them during the grow.
756  // FIXME: don't do this if they're efficiently moveable.
757  if (this->capacity() < RHSSize) {
758  // Destroy current elements.
759  this->destroy_range(this->begin(), this->end());
760  this->setEnd(this->begin());
761  CurSize = 0;
762  this->grow(RHSSize);
763  } else if (CurSize) {
764  // Otherwise, use assignment for the already-constructed elements.
765  std::copy(RHS.begin(), RHS.begin()+CurSize, this->begin());
766  }
767 
768  // Copy construct the new elements in place.
769  this->uninitialized_copy(RHS.begin()+CurSize, RHS.end(),
770  this->begin()+CurSize);
771 
772  // Set end.
773  this->setEnd(this->begin()+RHSSize);
774  return *this;
775 }
776 
777 template <typename T>
778 SmallVectorImpl<T> &SmallVectorImpl<T>::operator=(SmallVectorImpl<T> &&RHS) {
779  // Avoid self-assignment.
780  if (this == &RHS) return *this;
781 
782  // If the RHS isn't small, clear this vector and then steal its buffer.
783  if (!RHS.isSmall()) {
784  this->destroy_range(this->begin(), this->end());
785  if (!this->isSmall()) free(this->begin());
786  this->BeginX = RHS.BeginX;
787  this->EndX = RHS.EndX;
788  this->CapacityX = RHS.CapacityX;
789  RHS.resetToSmall();
790  return *this;
791  }
792 
793  // If we already have sufficient space, assign the common elements, then
794  // destroy any excess.
795  size_t RHSSize = RHS.size();
796  size_t CurSize = this->size();
797  if (CurSize >= RHSSize) {
798  // Assign common elements.
799  iterator NewEnd = this->begin();
800  if (RHSSize)
801  NewEnd = this->move(RHS.begin(), RHS.end(), NewEnd);
802 
803  // Destroy excess elements and trim the bounds.
804  this->destroy_range(NewEnd, this->end());
805  this->setEnd(NewEnd);
806 
807  // Clear the RHS.
808  RHS.clear();
809 
810  return *this;
811  }
812 
813  // If we have to grow to have enough elements, destroy the current elements.
814  // This allows us to avoid copying them during the grow.
815  // FIXME: this may not actually make any sense if we can efficiently move
816  // elements.
817  if (this->capacity() < RHSSize) {
818  // Destroy current elements.
819  this->destroy_range(this->begin(), this->end());
820  this->setEnd(this->begin());
821  CurSize = 0;
822  this->grow(RHSSize);
823  } else if (CurSize) {
824  // Otherwise, use assignment for the already-constructed elements.
825  this->move(RHS.begin(), RHS.begin()+CurSize, this->begin());
826  }
827 
828  // Move-construct the new elements in place.
829  this->uninitialized_move(RHS.begin()+CurSize, RHS.end(),
830  this->begin()+CurSize);
831 
832  // Set end.
833  this->setEnd(this->begin()+RHSSize);
834 
835  RHS.clear();
836  return *this;
837 }
838 
843 template <typename T, unsigned N>
844 struct SmallVectorStorage {
845  typename SmallVectorTemplateCommon<T>::U InlineElts[N - 1];
846 };
847 template <typename T> struct SmallVectorStorage<T, 1> {};
848 template <typename T> struct SmallVectorStorage<T, 0> {};
849 
858 template <typename T, unsigned N>
859 class SmallVector : public SmallVectorImpl<T> {
861  SmallVectorStorage<T, N> Storage;
862 public:
864  }
865 
866  explicit SmallVector(size_t Size, const T &Value = T())
867  : SmallVectorImpl<T>(N) {
868  this->assign(Size, Value);
869  }
870 
871  template<typename ItTy>
872  SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(N) {
873  this->append(S, E);
874  }
875 
876  template <typename RangeTy>
878  : SmallVectorImpl<T>(N) {
879  this->append(R.begin(), R.end());
880  }
881 
882  SmallVector(std::initializer_list<T> IL) : SmallVectorImpl<T>(N) {
883  this->assign(IL);
884  }
885 
886  SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(N) {
887  if (!RHS.empty())
889  }
890 
891  const SmallVector &operator=(const SmallVector &RHS) {
893  return *this;
894  }
895 
897  if (!RHS.empty())
898  SmallVectorImpl<T>::operator=(::std::move(RHS));
899  }
900 
901  const SmallVector &operator=(SmallVector &&RHS) {
902  SmallVectorImpl<T>::operator=(::std::move(RHS));
903  return *this;
904  }
905 
907  if (!RHS.empty())
908  SmallVectorImpl<T>::operator=(::std::move(RHS));
909  }
910 
911  const SmallVector &operator=(SmallVectorImpl<T> &&RHS) {
912  SmallVectorImpl<T>::operator=(::std::move(RHS));
913  return *this;
914  }
915 
916  const SmallVector &operator=(std::initializer_list<T> IL) {
917  this->assign(IL);
918  return *this;
919  }
920 };
921 
922 template<typename T, unsigned N>
923 static inline size_t capacity_in_bytes(const SmallVector<T, N> &X) {
924  return X.capacity_in_bytes();
925 }
926 
927 } // namespace llvm
928 
929 namespace std {
931  template<typename T>
932  inline void
934  LHS.swap(RHS);
935  }
936 
938  template<typename T, unsigned N>
939  inline void
941  LHS.swap(RHS);
942  }
943 } // namespace std
944 
945 #endif
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
size_t capacity() const
Return the total number of elements in the currently allocated buffer.
Definition: SmallVector.h:131
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...
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
void append(size_type NumInputs, const T &Elt)
Add the specified range to the end of the SmallVector.
Definition: SmallVector.h:426
size_t capacity_in_bytes() const
capacity_in_bytes - This returns capacity()*sizeof(T).
Definition: SmallVector.h:53
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
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
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: StringRef.h:23
SmallVectorTemplateBase<isPodLike = false> - This is where we put method implementations that are desig...
Definition: SmallVector.h:169
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
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
void append(in_iter in_start, in_iter in_end)
Add the specified range to the end of the SmallVector.
Definition: SmallVector.h:414
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:859
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:324
A range adaptor for a pair of iterators.
Definition: iterator_range.h:31
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:683
pointer data()
Return a pointer to the vector's buffer, even if empty().
Definition: SmallVector.h:134
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
size_t size_in_bytes() const
This returns size()*sizeof(T).
Definition: SmallVector.h:48
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(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
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