LLVM  9.0.0svn
SmallVector.h
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1 //===- llvm/ADT/SmallVector.h - 'Normally small' vectors --------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the SmallVector class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_ADT_SMALLVECTOR_H
14 #define LLVM_ADT_SMALLVECTOR_H
15 
17 #include "llvm/Support/AlignOf.h"
18 #include "llvm/Support/Compiler.h"
20 #include "llvm/Support/MemAlloc.h"
23 #include <algorithm>
24 #include <cassert>
25 #include <cstddef>
26 #include <cstdlib>
27 #include <cstring>
28 #include <initializer_list>
29 #include <iterator>
30 #include <memory>
31 #include <new>
32 #include <type_traits>
33 #include <utility>
34 
35 namespace llvm {
36 
37 /// This is all the non-templated stuff common to all SmallVectors.
39 protected:
40  void *BeginX;
41  unsigned Size = 0, Capacity;
42 
43  SmallVectorBase() = delete;
44  SmallVectorBase(void *FirstEl, size_t TotalCapacity)
45  : BeginX(FirstEl), Capacity(TotalCapacity) {}
46 
47  /// This is an implementation of the grow() method which only works
48  /// on POD-like data types and is out of line to reduce code duplication.
49  void grow_pod(void *FirstEl, size_t MinCapacity, size_t TSize);
50 
51 public:
52  size_t size() const { return Size; }
53  size_t capacity() const { return Capacity; }
54 
55  LLVM_NODISCARD bool empty() const { return !Size; }
56 
57  /// Set the array size to \p N, which the current array must have enough
58  /// capacity for.
59  ///
60  /// This does not construct or destroy any elements in the vector.
61  ///
62  /// Clients can use this in conjunction with capacity() to write past the end
63  /// of the buffer when they know that more elements are available, and only
64  /// update the size later. This avoids the cost of value initializing elements
65  /// which will only be overwritten.
66  void set_size(size_t N) {
67  assert(N <= capacity());
68  Size = N;
69  }
70 };
71 
72 /// Figure out the offset of the first element.
73 template <class T, typename = void> struct SmallVectorAlignmentAndSize {
76 };
77 
78 /// This is the part of SmallVectorTemplateBase which does not depend on whether
79 /// the type T is a POD. The extra dummy template argument is used by ArrayRef
80 /// to avoid unnecessarily requiring T to be complete.
81 template <typename T, typename = void>
83  /// Find the address of the first element. For this pointer math to be valid
84  /// with small-size of 0 for T with lots of alignment, it's important that
85  /// SmallVectorStorage is properly-aligned even for small-size of 0.
86  void *getFirstEl() const {
87  return const_cast<void *>(reinterpret_cast<const void *>(
88  reinterpret_cast<const char *>(this) +
90  }
91  // Space after 'FirstEl' is clobbered, do not add any instance vars after it.
92 
93 protected:
95  : SmallVectorBase(getFirstEl(), Size) {}
96 
97  void grow_pod(size_t MinCapacity, size_t TSize) {
98  SmallVectorBase::grow_pod(getFirstEl(), MinCapacity, TSize);
99  }
100 
101  /// Return true if this is a smallvector which has not had dynamic
102  /// memory allocated for it.
103  bool isSmall() const { return BeginX == getFirstEl(); }
104 
105  /// Put this vector in a state of being small.
106  void resetToSmall() {
107  BeginX = getFirstEl();
108  Size = Capacity = 0; // FIXME: Setting Capacity to 0 is suspect.
109  }
110 
111 public:
112  using size_type = size_t;
114  using value_type = T;
115  using iterator = T *;
116  using const_iterator = const T *;
117 
118  using const_reverse_iterator = std::reverse_iterator<const_iterator>;
119  using reverse_iterator = std::reverse_iterator<iterator>;
120 
121  using reference = T &;
122  using const_reference = const T &;
123  using pointer = T *;
124  using const_pointer = const T *;
125 
126  // forward iterator creation methods.
127  iterator begin() { return (iterator)this->BeginX; }
128  const_iterator begin() const { return (const_iterator)this->BeginX; }
129  iterator end() { return begin() + size(); }
130  const_iterator end() const { return begin() + size(); }
131 
132  // reverse iterator creation methods.
137 
138  size_type size_in_bytes() const { return size() * sizeof(T); }
139  size_type max_size() const { return size_type(-1) / sizeof(T); }
140 
141  size_t capacity_in_bytes() const { return capacity() * sizeof(T); }
142 
143  /// Return a pointer to the vector's buffer, even if empty().
144  pointer data() { return pointer(begin()); }
145  /// Return a pointer to the vector's buffer, even if empty().
146  const_pointer data() const { return const_pointer(begin()); }
147 
149  assert(idx < size());
150  return begin()[idx];
151  }
153  assert(idx < size());
154  return begin()[idx];
155  }
156 
158  assert(!empty());
159  return begin()[0];
160  }
162  assert(!empty());
163  return begin()[0];
164  }
165 
167  assert(!empty());
168  return end()[-1];
169  }
171  assert(!empty());
172  return end()[-1];
173  }
174 };
175 
176 /// SmallVectorTemplateBase<TriviallyCopyable = false> - This is where we put method
177 /// implementations that are designed to work with non-POD-like T's.
178 template <typename T, bool = is_trivially_copyable<T>::value>
180 protected:
182 
183  static void destroy_range(T *S, T *E) {
184  while (S != E) {
185  --E;
186  E->~T();
187  }
188  }
189 
190  /// Move the range [I, E) into the uninitialized memory starting with "Dest",
191  /// constructing elements as needed.
192  template<typename It1, typename It2>
193  static void uninitialized_move(It1 I, It1 E, It2 Dest) {
194  std::uninitialized_copy(std::make_move_iterator(I),
195  std::make_move_iterator(E), Dest);
196  }
197 
198  /// Copy the range [I, E) onto the uninitialized memory starting with "Dest",
199  /// constructing elements as needed.
200  template<typename It1, typename It2>
201  static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
202  std::uninitialized_copy(I, E, Dest);
203  }
204 
205  /// Grow the allocated memory (without initializing new elements), doubling
206  /// the size of the allocated memory. Guarantees space for at least one more
207  /// element, or MinSize more elements if specified.
208  void grow(size_t MinSize = 0);
209 
210 public:
211  void push_back(const T &Elt) {
212  if (LLVM_UNLIKELY(this->size() >= this->capacity()))
213  this->grow();
214  ::new ((void*) this->end()) T(Elt);
215  this->set_size(this->size() + 1);
216  }
217 
218  void push_back(T &&Elt) {
219  if (LLVM_UNLIKELY(this->size() >= this->capacity()))
220  this->grow();
221  ::new ((void*) this->end()) T(::std::move(Elt));
222  this->set_size(this->size() + 1);
223  }
224 
225  void pop_back() {
226  this->set_size(this->size() - 1);
227  this->end()->~T();
228  }
229 };
230 
231 // Define this out-of-line to dissuade the C++ compiler from inlining it.
232 template <typename T, bool TriviallyCopyable>
234  if (MinSize > UINT32_MAX)
235  report_bad_alloc_error("SmallVector capacity overflow during allocation");
236 
237  // Always grow, even from zero.
238  size_t NewCapacity = size_t(NextPowerOf2(this->capacity() + 2));
239  NewCapacity = std::min(std::max(NewCapacity, MinSize), size_t(UINT32_MAX));
240  T *NewElts = static_cast<T*>(llvm::safe_malloc(NewCapacity*sizeof(T)));
241 
242  // Move the elements over.
243  this->uninitialized_move(this->begin(), this->end(), NewElts);
244 
245  // Destroy the original elements.
246  destroy_range(this->begin(), this->end());
247 
248  // If this wasn't grown from the inline copy, deallocate the old space.
249  if (!this->isSmall())
250  free(this->begin());
251 
252  this->BeginX = NewElts;
253  this->Capacity = NewCapacity;
254 }
255 
256 /// SmallVectorTemplateBase<TriviallyCopyable = true> - This is where we put
257 /// method implementations that are designed to work with POD-like T's.
258 template <typename T>
260 protected:
262 
263  // No need to do a destroy loop for POD's.
264  static void destroy_range(T *, T *) {}
265 
266  /// Move the range [I, E) onto the uninitialized memory
267  /// starting with "Dest", constructing elements into it as needed.
268  template<typename It1, typename It2>
269  static void uninitialized_move(It1 I, It1 E, It2 Dest) {
270  // Just do a copy.
271  uninitialized_copy(I, E, Dest);
272  }
273 
274  /// Copy the range [I, E) onto the uninitialized memory
275  /// starting with "Dest", constructing elements into it as needed.
276  template<typename It1, typename It2>
277  static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
278  // Arbitrary iterator types; just use the basic implementation.
279  std::uninitialized_copy(I, E, Dest);
280  }
281 
282  /// Copy the range [I, E) onto the uninitialized memory
283  /// starting with "Dest", constructing elements into it as needed.
284  template <typename T1, typename T2>
285  static void uninitialized_copy(
286  T1 *I, T1 *E, T2 *Dest,
287  typename std::enable_if<std::is_same<typename std::remove_const<T1>::type,
288  T2>::value>::type * = nullptr) {
289  // Use memcpy for PODs iterated by pointers (which includes SmallVector
290  // iterators): std::uninitialized_copy optimizes to memmove, but we can
291  // use memcpy here. Note that I and E are iterators and thus might be
292  // invalid for memcpy if they are equal.
293  if (I != E)
294  memcpy(reinterpret_cast<void *>(Dest), I, (E - I) * sizeof(T));
295  }
296 
297  /// Double the size of the allocated memory, guaranteeing space for at
298  /// least one more element or MinSize if specified.
299  void grow(size_t MinSize = 0) { this->grow_pod(MinSize, sizeof(T)); }
300 
301 public:
302  void push_back(const T &Elt) {
303  if (LLVM_UNLIKELY(this->size() >= this->capacity()))
304  this->grow();
305  memcpy(reinterpret_cast<void *>(this->end()), &Elt, sizeof(T));
306  this->set_size(this->size() + 1);
307  }
308 
309  void pop_back() { this->set_size(this->size() - 1); }
310 };
311 
312 /// This class consists of common code factored out of the SmallVector class to
313 /// reduce code duplication based on the SmallVector 'N' template parameter.
314 template <typename T>
315 class SmallVectorImpl : public SmallVectorTemplateBase<T> {
317 
318 public:
319  using iterator = typename SuperClass::iterator;
323 
324 protected:
325  // Default ctor - Initialize to empty.
326  explicit SmallVectorImpl(unsigned N)
327  : SmallVectorTemplateBase<T>(N) {}
328 
329 public:
330  SmallVectorImpl(const SmallVectorImpl &) = delete;
331 
333  // Subclass has already destructed this vector's elements.
334  // If this wasn't grown from the inline copy, deallocate the old space.
335  if (!this->isSmall())
336  free(this->begin());
337  }
338 
339  void clear() {
340  this->destroy_range(this->begin(), this->end());
341  this->Size = 0;
342  }
343 
345  if (N < this->size()) {
346  this->destroy_range(this->begin()+N, this->end());
347  this->set_size(N);
348  } else if (N > this->size()) {
349  if (this->capacity() < N)
350  this->grow(N);
351  for (auto I = this->end(), E = this->begin() + N; I != E; ++I)
352  new (&*I) T();
353  this->set_size(N);
354  }
355  }
356 
357  void resize(size_type N, const T &NV) {
358  if (N < this->size()) {
359  this->destroy_range(this->begin()+N, this->end());
360  this->set_size(N);
361  } else if (N > this->size()) {
362  if (this->capacity() < N)
363  this->grow(N);
364  std::uninitialized_fill(this->end(), this->begin()+N, NV);
365  this->set_size(N);
366  }
367  }
368 
370  if (this->capacity() < N)
371  this->grow(N);
372  }
373 
375  T Result = ::std::move(this->back());
376  this->pop_back();
377  return Result;
378  }
379 
380  void swap(SmallVectorImpl &RHS);
381 
382  /// Add the specified range to the end of the SmallVector.
383  template <typename in_iter,
384  typename = typename std::enable_if<std::is_convertible<
385  typename std::iterator_traits<in_iter>::iterator_category,
386  std::input_iterator_tag>::value>::type>
387  void append(in_iter in_start, in_iter in_end) {
388  size_type NumInputs = std::distance(in_start, in_end);
389  if (NumInputs > this->capacity() - this->size())
390  this->grow(this->size()+NumInputs);
391 
392  this->uninitialized_copy(in_start, in_end, this->end());
393  this->set_size(this->size() + NumInputs);
394  }
395 
396  /// Append \p NumInputs copies of \p Elt to the end.
397  void append(size_type NumInputs, const T &Elt) {
398  if (NumInputs > this->capacity() - this->size())
399  this->grow(this->size()+NumInputs);
400 
401  std::uninitialized_fill_n(this->end(), NumInputs, Elt);
402  this->set_size(this->size() + NumInputs);
403  }
404 
405  void append(std::initializer_list<T> IL) {
406  append(IL.begin(), IL.end());
407  }
408 
409  // FIXME: Consider assigning over existing elements, rather than clearing &
410  // re-initializing them - for all assign(...) variants.
411 
412  void assign(size_type NumElts, const T &Elt) {
413  clear();
414  if (this->capacity() < NumElts)
415  this->grow(NumElts);
416  this->set_size(NumElts);
417  std::uninitialized_fill(this->begin(), this->end(), Elt);
418  }
419 
420  template <typename in_iter,
421  typename = typename std::enable_if<std::is_convertible<
422  typename std::iterator_traits<in_iter>::iterator_category,
423  std::input_iterator_tag>::value>::type>
424  void assign(in_iter in_start, in_iter in_end) {
425  clear();
426  append(in_start, in_end);
427  }
428 
429  void assign(std::initializer_list<T> IL) {
430  clear();
431  append(IL);
432  }
433 
435  // Just cast away constness because this is a non-const member function.
436  iterator I = const_cast<iterator>(CI);
437 
438  assert(I >= this->begin() && "Iterator to erase is out of bounds.");
439  assert(I < this->end() && "Erasing at past-the-end iterator.");
440 
441  iterator N = I;
442  // Shift all elts down one.
443  std::move(I+1, this->end(), I);
444  // Drop the last elt.
445  this->pop_back();
446  return(N);
447  }
448 
450  // Just cast away constness because this is a non-const member function.
451  iterator S = const_cast<iterator>(CS);
452  iterator E = const_cast<iterator>(CE);
453 
454  assert(S >= this->begin() && "Range to erase is out of bounds.");
455  assert(S <= E && "Trying to erase invalid range.");
456  assert(E <= this->end() && "Trying to erase past the end.");
457 
458  iterator N = S;
459  // Shift all elts down.
460  iterator I = std::move(E, this->end(), S);
461  // Drop the last elts.
462  this->destroy_range(I, this->end());
463  this->set_size(I - this->begin());
464  return(N);
465  }
466 
468  if (I == this->end()) { // Important special case for empty vector.
469  this->push_back(::std::move(Elt));
470  return this->end()-1;
471  }
472 
473  assert(I >= this->begin() && "Insertion iterator is out of bounds.");
474  assert(I <= this->end() && "Inserting past the end of the vector.");
475 
476  if (this->size() >= this->capacity()) {
477  size_t EltNo = I-this->begin();
478  this->grow();
479  I = this->begin()+EltNo;
480  }
481 
482  ::new ((void*) this->end()) T(::std::move(this->back()));
483  // Push everything else over.
484  std::move_backward(I, this->end()-1, this->end());
485  this->set_size(this->size() + 1);
486 
487  // If we just moved the element we're inserting, be sure to update
488  // the reference.
489  T *EltPtr = &Elt;
490  if (I <= EltPtr && EltPtr < this->end())
491  ++EltPtr;
492 
493  *I = ::std::move(*EltPtr);
494  return I;
495  }
496 
497  iterator insert(iterator I, const T &Elt) {
498  if (I == this->end()) { // Important special case for empty vector.
499  this->push_back(Elt);
500  return this->end()-1;
501  }
502 
503  assert(I >= this->begin() && "Insertion iterator is out of bounds.");
504  assert(I <= this->end() && "Inserting past the end of the vector.");
505 
506  if (this->size() >= this->capacity()) {
507  size_t EltNo = I-this->begin();
508  this->grow();
509  I = this->begin()+EltNo;
510  }
511  ::new ((void*) this->end()) T(std::move(this->back()));
512  // Push everything else over.
513  std::move_backward(I, this->end()-1, this->end());
514  this->set_size(this->size() + 1);
515 
516  // If we just moved the element we're inserting, be sure to update
517  // the reference.
518  const T *EltPtr = &Elt;
519  if (I <= EltPtr && EltPtr < this->end())
520  ++EltPtr;
521 
522  *I = *EltPtr;
523  return I;
524  }
525 
526  iterator insert(iterator I, size_type NumToInsert, const T &Elt) {
527  // Convert iterator to elt# to avoid invalidating iterator when we reserve()
528  size_t InsertElt = I - this->begin();
529 
530  if (I == this->end()) { // Important special case for empty vector.
531  append(NumToInsert, Elt);
532  return this->begin()+InsertElt;
533  }
534 
535  assert(I >= this->begin() && "Insertion iterator is out of bounds.");
536  assert(I <= this->end() && "Inserting past the end of the vector.");
537 
538  // Ensure there is enough space.
539  reserve(this->size() + NumToInsert);
540 
541  // Uninvalidate the iterator.
542  I = this->begin()+InsertElt;
543 
544  // If there are more elements between the insertion point and the end of the
545  // range than there are being inserted, we can use a simple approach to
546  // insertion. Since we already reserved space, we know that this won't
547  // reallocate the vector.
548  if (size_t(this->end()-I) >= NumToInsert) {
549  T *OldEnd = this->end();
550  append(std::move_iterator<iterator>(this->end() - NumToInsert),
551  std::move_iterator<iterator>(this->end()));
552 
553  // Copy the existing elements that get replaced.
554  std::move_backward(I, OldEnd-NumToInsert, OldEnd);
555 
556  std::fill_n(I, NumToInsert, Elt);
557  return I;
558  }
559 
560  // Otherwise, we're inserting more elements than exist already, and we're
561  // not inserting at the end.
562 
563  // Move over the elements that we're about to overwrite.
564  T *OldEnd = this->end();
565  this->set_size(this->size() + NumToInsert);
566  size_t NumOverwritten = OldEnd-I;
567  this->uninitialized_move(I, OldEnd, this->end()-NumOverwritten);
568 
569  // Replace the overwritten part.
570  std::fill_n(I, NumOverwritten, Elt);
571 
572  // Insert the non-overwritten middle part.
573  std::uninitialized_fill_n(OldEnd, NumToInsert-NumOverwritten, Elt);
574  return I;
575  }
576 
577  template <typename ItTy,
578  typename = typename std::enable_if<std::is_convertible<
579  typename std::iterator_traits<ItTy>::iterator_category,
580  std::input_iterator_tag>::value>::type>
582  // Convert iterator to elt# to avoid invalidating iterator when we reserve()
583  size_t InsertElt = I - this->begin();
584 
585  if (I == this->end()) { // Important special case for empty vector.
586  append(From, To);
587  return this->begin()+InsertElt;
588  }
589 
590  assert(I >= this->begin() && "Insertion iterator is out of bounds.");
591  assert(I <= this->end() && "Inserting past the end of the vector.");
592 
593  size_t NumToInsert = std::distance(From, To);
594 
595  // Ensure there is enough space.
596  reserve(this->size() + NumToInsert);
597 
598  // Uninvalidate the iterator.
599  I = this->begin()+InsertElt;
600 
601  // If there are more elements between the insertion point and the end of the
602  // range than there are being inserted, we can use a simple approach to
603  // insertion. Since we already reserved space, we know that this won't
604  // reallocate the vector.
605  if (size_t(this->end()-I) >= NumToInsert) {
606  T *OldEnd = this->end();
607  append(std::move_iterator<iterator>(this->end() - NumToInsert),
608  std::move_iterator<iterator>(this->end()));
609 
610  // Copy the existing elements that get replaced.
611  std::move_backward(I, OldEnd-NumToInsert, OldEnd);
612 
613  std::copy(From, To, I);
614  return I;
615  }
616 
617  // Otherwise, we're inserting more elements than exist already, and we're
618  // not inserting at the end.
619 
620  // Move over the elements that we're about to overwrite.
621  T *OldEnd = this->end();
622  this->set_size(this->size() + NumToInsert);
623  size_t NumOverwritten = OldEnd-I;
624  this->uninitialized_move(I, OldEnd, this->end()-NumOverwritten);
625 
626  // Replace the overwritten part.
627  for (T *J = I; NumOverwritten > 0; --NumOverwritten) {
628  *J = *From;
629  ++J; ++From;
630  }
631 
632  // Insert the non-overwritten middle part.
633  this->uninitialized_copy(From, To, OldEnd);
634  return I;
635  }
636 
637  void insert(iterator I, std::initializer_list<T> IL) {
638  insert(I, IL.begin(), IL.end());
639  }
640 
641  template <typename... ArgTypes> reference emplace_back(ArgTypes &&... Args) {
642  if (LLVM_UNLIKELY(this->size() >= this->capacity()))
643  this->grow();
644  ::new ((void *)this->end()) T(std::forward<ArgTypes>(Args)...);
645  this->set_size(this->size() + 1);
646  return this->back();
647  }
648 
649  SmallVectorImpl &operator=(const SmallVectorImpl &RHS);
650 
651  SmallVectorImpl &operator=(SmallVectorImpl &&RHS);
652 
653  bool operator==(const SmallVectorImpl &RHS) const {
654  if (this->size() != RHS.size()) return false;
655  return std::equal(this->begin(), this->end(), RHS.begin());
656  }
657  bool operator!=(const SmallVectorImpl &RHS) const {
658  return !(*this == RHS);
659  }
660 
661  bool operator<(const SmallVectorImpl &RHS) const {
662  return std::lexicographical_compare(this->begin(), this->end(),
663  RHS.begin(), RHS.end());
664  }
665 };
666 
667 template <typename T>
669  if (this == &RHS) return;
670 
671  // We can only avoid copying elements if neither vector is small.
672  if (!this->isSmall() && !RHS.isSmall()) {
673  std::swap(this->BeginX, RHS.BeginX);
674  std::swap(this->Size, RHS.Size);
675  std::swap(this->Capacity, RHS.Capacity);
676  return;
677  }
678  if (RHS.size() > this->capacity())
679  this->grow(RHS.size());
680  if (this->size() > RHS.capacity())
681  RHS.grow(this->size());
682 
683  // Swap the shared elements.
684  size_t NumShared = this->size();
685  if (NumShared > RHS.size()) NumShared = RHS.size();
686  for (size_type i = 0; i != NumShared; ++i)
687  std::swap((*this)[i], RHS[i]);
688 
689  // Copy over the extra elts.
690  if (this->size() > RHS.size()) {
691  size_t EltDiff = this->size() - RHS.size();
692  this->uninitialized_copy(this->begin()+NumShared, this->end(), RHS.end());
693  RHS.set_size(RHS.size() + EltDiff);
694  this->destroy_range(this->begin()+NumShared, this->end());
695  this->set_size(NumShared);
696  } else if (RHS.size() > this->size()) {
697  size_t EltDiff = RHS.size() - this->size();
698  this->uninitialized_copy(RHS.begin()+NumShared, RHS.end(), this->end());
699  this->set_size(this->size() + EltDiff);
700  this->destroy_range(RHS.begin()+NumShared, RHS.end());
701  RHS.set_size(NumShared);
702  }
703 }
704 
705 template <typename T>
708  // Avoid self-assignment.
709  if (this == &RHS) return *this;
710 
711  // If we already have sufficient space, assign the common elements, then
712  // destroy any excess.
713  size_t RHSSize = RHS.size();
714  size_t CurSize = this->size();
715  if (CurSize >= RHSSize) {
716  // Assign common elements.
717  iterator NewEnd;
718  if (RHSSize)
719  NewEnd = std::copy(RHS.begin(), RHS.begin()+RHSSize, this->begin());
720  else
721  NewEnd = this->begin();
722 
723  // Destroy excess elements.
724  this->destroy_range(NewEnd, this->end());
725 
726  // Trim.
727  this->set_size(RHSSize);
728  return *this;
729  }
730 
731  // If we have to grow to have enough elements, destroy the current elements.
732  // This allows us to avoid copying them during the grow.
733  // FIXME: don't do this if they're efficiently moveable.
734  if (this->capacity() < RHSSize) {
735  // Destroy current elements.
736  this->destroy_range(this->begin(), this->end());
737  this->set_size(0);
738  CurSize = 0;
739  this->grow(RHSSize);
740  } else if (CurSize) {
741  // Otherwise, use assignment for the already-constructed elements.
742  std::copy(RHS.begin(), RHS.begin()+CurSize, this->begin());
743  }
744 
745  // Copy construct the new elements in place.
746  this->uninitialized_copy(RHS.begin()+CurSize, RHS.end(),
747  this->begin()+CurSize);
748 
749  // Set end.
750  this->set_size(RHSSize);
751  return *this;
752 }
753 
754 template <typename T>
756  // Avoid self-assignment.
757  if (this == &RHS) return *this;
758 
759  // If the RHS isn't small, clear this vector and then steal its buffer.
760  if (!RHS.isSmall()) {
761  this->destroy_range(this->begin(), this->end());
762  if (!this->isSmall()) free(this->begin());
763  this->BeginX = RHS.BeginX;
764  this->Size = RHS.Size;
765  this->Capacity = RHS.Capacity;
766  RHS.resetToSmall();
767  return *this;
768  }
769 
770  // If we already have sufficient space, assign the common elements, then
771  // destroy any excess.
772  size_t RHSSize = RHS.size();
773  size_t CurSize = this->size();
774  if (CurSize >= RHSSize) {
775  // Assign common elements.
776  iterator NewEnd = this->begin();
777  if (RHSSize)
778  NewEnd = std::move(RHS.begin(), RHS.end(), NewEnd);
779 
780  // Destroy excess elements and trim the bounds.
781  this->destroy_range(NewEnd, this->end());
782  this->set_size(RHSSize);
783 
784  // Clear the RHS.
785  RHS.clear();
786 
787  return *this;
788  }
789 
790  // If we have to grow to have enough elements, destroy the current elements.
791  // This allows us to avoid copying them during the grow.
792  // FIXME: this may not actually make any sense if we can efficiently move
793  // elements.
794  if (this->capacity() < RHSSize) {
795  // Destroy current elements.
796  this->destroy_range(this->begin(), this->end());
797  this->set_size(0);
798  CurSize = 0;
799  this->grow(RHSSize);
800  } else if (CurSize) {
801  // Otherwise, use assignment for the already-constructed elements.
802  std::move(RHS.begin(), RHS.begin()+CurSize, this->begin());
803  }
804 
805  // Move-construct the new elements in place.
806  this->uninitialized_move(RHS.begin()+CurSize, RHS.end(),
807  this->begin()+CurSize);
808 
809  // Set end.
810  this->set_size(RHSSize);
811 
812  RHS.clear();
813  return *this;
814 }
815 
816 /// Storage for the SmallVector elements. This is specialized for the N=0 case
817 /// to avoid allocating unnecessary storage.
818 template <typename T, unsigned N>
821 };
822 
823 /// We need the storage to be properly aligned even for small-size of 0 so that
824 /// the pointer math in \a SmallVectorTemplateCommon::getFirstEl() is
825 /// well-defined.
826 template <typename T> struct alignas(alignof(T)) SmallVectorStorage<T, 0> {};
827 
828 /// This is a 'vector' (really, a variable-sized array), optimized
829 /// for the case when the array is small. It contains some number of elements
830 /// in-place, which allows it to avoid heap allocation when the actual number of
831 /// elements is below that threshold. This allows normal "small" cases to be
832 /// fast without losing generality for large inputs.
833 ///
834 /// Note that this does not attempt to be exception safe.
835 ///
836 template <typename T, unsigned N>
838 public:
840 
842  // Destroy the constructed elements in the vector.
843  this->destroy_range(this->begin(), this->end());
844  }
845 
846  explicit SmallVector(size_t Size, const T &Value = T())
847  : SmallVectorImpl<T>(N) {
848  this->assign(Size, Value);
849  }
850 
851  template <typename ItTy,
852  typename = typename std::enable_if<std::is_convertible<
853  typename std::iterator_traits<ItTy>::iterator_category,
854  std::input_iterator_tag>::value>::type>
856  this->append(S, E);
857  }
858 
859  template <typename RangeTy>
861  : SmallVectorImpl<T>(N) {
862  this->append(R.begin(), R.end());
863  }
864 
865  SmallVector(std::initializer_list<T> IL) : SmallVectorImpl<T>(N) {
866  this->assign(IL);
867  }
868 
870  if (!RHS.empty())
872  }
873 
874  const SmallVector &operator=(const SmallVector &RHS) {
876  return *this;
877  }
878 
880  if (!RHS.empty())
881  SmallVectorImpl<T>::operator=(::std::move(RHS));
882  }
883 
885  if (!RHS.empty())
886  SmallVectorImpl<T>::operator=(::std::move(RHS));
887  }
888 
890  SmallVectorImpl<T>::operator=(::std::move(RHS));
891  return *this;
892  }
893 
895  SmallVectorImpl<T>::operator=(::std::move(RHS));
896  return *this;
897  }
898 
899  const SmallVector &operator=(std::initializer_list<T> IL) {
900  this->assign(IL);
901  return *this;
902  }
903 };
904 
905 template <typename T, unsigned N>
906 inline size_t capacity_in_bytes(const SmallVector<T, N> &X) {
907  return X.capacity_in_bytes();
908 }
909 
910 } // end namespace llvm
911 
912 namespace std {
913 
914  /// Implement std::swap in terms of SmallVector swap.
915  template<typename T>
916  inline void
918  LHS.swap(RHS);
919  }
920 
921  /// Implement std::swap in terms of SmallVector swap.
922  template<typename T, unsigned N>
923  inline void
925  LHS.swap(RHS);
926  }
927 
928 } // end namespace std
929 
930 #endif // LLVM_ADT_SMALLVECTOR_H
void grow_pod(void *FirstEl, size_t MinCapacity, 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:42
static void destroy_range(T *S, T *E)
Definition: SmallVector.h:183
std::reverse_iterator< const_iterator > const_reverse_iterator
Definition: SmallVector.h:118
const_iterator end(StringRef path)
Get end iterator over path.
Definition: Path.cpp:233
reference emplace_back(ArgTypes &&... Args)
Definition: SmallVector.h:641
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:277
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
GCNRegPressure max(const GCNRegPressure &P1, const GCNRegPressure &P2)
const_iterator begin(StringRef path, Style style=Style::native)
Get begin iterator over path.
Definition: Path.cpp:224
DiagnosticInfoOptimizationBase::Argument NV
bool operator!=(const SmallVectorImpl &RHS) const
Definition: SmallVector.h:657
AlignedCharArrayUnion< SmallVectorBase > Base
Definition: SmallVector.h:74
This class represents lattice values for constants.
Definition: AllocatorList.h:23
const_iterator begin() const
Definition: SmallVector.h:128
#define LLVM_UNLIKELY(EXPR)
Definition: Compiler.h:191
const_pointer data() const
Return a pointer to the vector&#39;s buffer, even if empty().
Definition: SmallVector.h:146
void push_back(const T &Elt)
Definition: SmallVector.h:211
This provides a very simple, boring adaptor for a begin and end iterator into a range type...
bool isSmall() const
Return true if this is a smallvector which has not had dynamic memory allocated for it...
Definition: SmallVector.h:103
void assign(in_iter in_start, in_iter in_end)
Definition: SmallVector.h:424
SmallVector(ItTy S, ItTy E)
Definition: SmallVector.h:855
const SmallVector & operator=(SmallVector &&RHS)
Definition: SmallVector.h:889
iterator insert(iterator I, const T &Elt)
Definition: SmallVector.h:497
iterator insert(iterator I, size_type NumToInsert, const T &Elt)
Definition: SmallVector.h:526
void append(size_type NumInputs, const T &Elt)
Append NumInputs copies of Elt to the end.
Definition: SmallVector.h:397
block Block Frequency true
void reserve(size_type N)
Definition: SmallVector.h:369
void grow_pod(size_t MinCapacity, size_t TSize)
Definition: SmallVector.h:97
const_reverse_iterator rend() const
Definition: SmallVector.h:136
void append(SmallVectorImpl< char > &path, const Twine &a, const Twine &b="", const Twine &c="", const Twine &d="")
Append to path.
Definition: Path.cpp:455
Definition: BitVector.h:937
size_t capacity_in_bytes(const BitVector &X)
Definition: BitVector.h:931
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APFloat.h:41
void resize(size_type N, const T &NV)
Definition: SmallVector.h:357
This file defines counterparts of C library allocation functions defined in the namespace &#39;std&#39;...
void assign(size_type NumElts, const T &Elt)
Definition: SmallVector.h:412
SmallVector(SmallVectorImpl< T > &&RHS)
Definition: SmallVector.h:884
const SmallVector & operator=(const SmallVector &RHS)
Definition: SmallVector.h:874
SmallVector(SmallVector &&RHS)
Definition: SmallVector.h:879
AlignedCharArrayUnion< T > FirstEl
Definition: SmallVector.h:75
const_reference front() const
Definition: SmallVector.h:161
SmallVectorTemplateBase<TriviallyCopyable = false> - This is where we put method implementations that...
Definition: SmallVector.h:179
void grow(size_t MinSize=0)
Grow the allocated memory (without initializing new elements), doubling the size of the allocated mem...
Definition: SmallVector.h:233
void swap(SmallVectorImpl &RHS)
Definition: SmallVector.h:668
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
void set_size(size_t N)
Set the array size to N, which the current array must have enough capacity for.
Definition: SmallVector.h:66
std::reverse_iterator< iterator > reverse_iterator
Definition: SmallVector.h:119
reference operator[](size_type idx)
Definition: SmallVector.h:148
#define offsetof(TYPE, MEMBER)
SmallVectorImpl(unsigned N)
Definition: SmallVector.h:326
size_t capacity() const
Definition: SmallVector.h:53
const_reverse_iterator rbegin() const
Definition: SmallVector.h:134
void assign(std::initializer_list< T > IL)
Definition: SmallVector.h:429
uint64_t NextPowerOf2(uint64_t A)
Returns the next power of two (in 64-bits) that is strictly greater than A.
Definition: MathExtras.h:639
iterator erase(const_iterator CI)
Definition: SmallVector.h:434
size_t size() const
Definition: SmallVector.h:52
void swap(llvm::SmallVector< T, N > &LHS, llvm::SmallVector< T, N > &RHS)
Implement std::swap in terms of SmallVector swap.
Definition: SmallVector.h:924
SmallVector(const iterator_range< RangeTy > &R)
Definition: SmallVector.h:860
void report_bad_alloc_error(const char *Reason, bool GenCrashDiag=true)
Reports a bad alloc error, calling any user defined bad alloc error handler.
const_reference back() const
Definition: SmallVector.h:170
LLVM_ATTRIBUTE_RETURNS_NONNULL void * safe_malloc(size_t Sz)
Definition: MemAlloc.h:25
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:201
const SmallVector & operator=(SmallVectorImpl< T > &&RHS)
Definition: SmallVector.h:894
BlockVerifier::State From
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:837
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:299
LLVM_NODISCARD T pop_back_val()
Definition: SmallVector.h:374
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:193
SmallVector(std::initializer_list< T > IL)
Definition: SmallVector.h:865
void swap(llvm::BitVector &LHS, llvm::BitVector &RHS)
Implement std::swap in terms of BitVector swap.
Definition: BitVector.h:940
bool operator<(const SmallVectorImpl &RHS) const
Definition: SmallVector.h:661
A range adaptor for a pair of iterators.
void append(std::initializer_list< T > IL)
Definition: SmallVector.h:405
SmallVectorImpl & operator=(const SmallVectorImpl &RHS)
Definition: SmallVector.h:707
This union template exposes a suitably aligned and sized character array member which can hold elemen...
Definition: AlignOf.h:137
const_reference operator[](size_type idx) const
Definition: SmallVector.h:152
static void clear(coro::Shape &Shape)
Definition: Coroutines.cpp:211
iterator insert(iterator I, T &&Elt)
Definition: SmallVector.h:467
void insert(iterator I, std::initializer_list< T > IL)
Definition: SmallVector.h:637
void append(in_iter in_start, in_iter in_end)
Add the specified range to the end of the SmallVector.
Definition: SmallVector.h:387
iterator erase(const_iterator CS, const_iterator CE)
Definition: SmallVector.h:449
SmallVectorTemplateBase(size_t Size)
Definition: SmallVector.h:181
This is the part of SmallVectorTemplateBase which does not depend on whether the type T is a POD...
Definition: SmallVector.h:82
size_type size_in_bytes() const
Definition: SmallVector.h:138
pointer data()
Return a pointer to the vector&#39;s buffer, even if empty().
Definition: SmallVector.h:144
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:55
#define I(x, y, z)
Definition: MD5.cpp:58
#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:285
This is all the non-templated stuff common to all SmallVectors.
Definition: SmallVector.h:38
SmallVectorBase(void *FirstEl, size_t TotalCapacity)
Definition: SmallVector.h:44
SmallVectorTemplateCommon(size_t Size)
Definition: SmallVector.h:94
#define LLVM_NODISCARD
LLVM_NODISCARD - Warn if a type or return value is discarded.
Definition: Compiler.h:128
SmallVector(const SmallVector &RHS)
Definition: SmallVector.h:869
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
LLVM Value Representation.
Definition: Value.h:72
iterator insert(iterator I, ItTy From, ItTy To)
Definition: SmallVector.h:581
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:269
IteratorT begin() const
const_iterator end() const
Definition: SmallVector.h:130
Storage for the SmallVector elements.
Definition: SmallVector.h:819
bool operator==(const SmallVectorImpl &RHS) const
Definition: SmallVector.h:653
OutputIt copy(R &&Range, OutputIt Out)
Definition: STLExtras.h:1244
IteratorT end() const
constexpr char Args[]
Key for Kernel::Metadata::mArgs.
#define T1
const SmallVector & operator=(std::initializer_list< T > IL)
Definition: SmallVector.h:899
void resetToSmall()
Put this vector in a state of being small.
Definition: SmallVector.h:106
SmallVector(size_t Size, const T &Value=T())
Definition: SmallVector.h:846
void resize(size_type N)
Definition: SmallVector.h:344
Figure out the offset of the first element.
Definition: SmallVector.h:73