1 //===- llvm/ADT/DenseMap.h - Dense probed hash table ------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the DenseMap class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_ADT_DENSEMAP_H
15 #define LLVM_ADT_DENSEMAP_H
17 #include "llvm/ADT/DenseMapInfo.h"
18 #include "llvm/Support/AlignOf.h"
19 #include "llvm/Support/Compiler.h"
20 #include "llvm/Support/MathExtras.h"
21 #include "llvm/Support/PointerLikeTypeTraits.h"
22 #include "llvm/Support/type_traits.h"
34 template<typename KeyT, typename ValueT,
35 typename KeyInfoT = DenseMapInfo<KeyT>,
37 class DenseMapIterator;
39 template<typename DerivedT,
40 typename KeyT, typename ValueT, typename KeyInfoT>
43 typedef std::pair<KeyT, ValueT> BucketT;
46 typedef KeyT key_type;
47 typedef ValueT mapped_type;
48 typedef BucketT value_type;
50 typedef DenseMapIterator<KeyT, ValueT, KeyInfoT> iterator;
51 typedef DenseMapIterator<KeyT, ValueT,
52 KeyInfoT, true> const_iterator;
53 inline iterator begin() {
54 // When the map is empty, avoid the overhead of AdvancePastEmptyBuckets().
55 return empty() ? end() : iterator(getBuckets(), getBucketsEnd());
57 inline iterator end() {
58 return iterator(getBucketsEnd(), getBucketsEnd(), true);
60 inline const_iterator begin() const {
61 return empty() ? end() : const_iterator(getBuckets(), getBucketsEnd());
63 inline const_iterator end() const {
64 return const_iterator(getBucketsEnd(), getBucketsEnd(), true);
67 bool LLVM_ATTRIBUTE_UNUSED_RESULT empty() const {
68 return getNumEntries() == 0;
70 unsigned size() const { return getNumEntries(); }
72 /// Grow the densemap so that it has at least Size buckets. Does not shrink
73 void resize(size_t Size) {
74 if (Size > getNumBuckets())
79 if (getNumEntries() == 0 && getNumTombstones() == 0) return;
81 // If the capacity of the array is huge, and the # elements used is small,
83 if (getNumEntries() * 4 < getNumBuckets() && getNumBuckets() > 64) {
88 const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey();
89 for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) {
90 if (!KeyInfoT::isEqual(P->first, EmptyKey)) {
91 if (!KeyInfoT::isEqual(P->first, TombstoneKey)) {
93 decrementNumEntries();
98 assert(getNumEntries() == 0 && "Node count imbalance!");
102 /// count - Return true if the specified key is in the map.
103 bool count(const KeyT &Val) const {
104 const BucketT *TheBucket;
105 return LookupBucketFor(Val, TheBucket);
108 iterator find(const KeyT &Val) {
110 if (LookupBucketFor(Val, TheBucket))
111 return iterator(TheBucket, getBucketsEnd(), true);
114 const_iterator find(const KeyT &Val) const {
115 const BucketT *TheBucket;
116 if (LookupBucketFor(Val, TheBucket))
117 return const_iterator(TheBucket, getBucketsEnd(), true);
121 /// Alternate version of find() which allows a different, and possibly
122 /// less expensive, key type.
123 /// The DenseMapInfo is responsible for supplying methods
124 /// getHashValue(LookupKeyT) and isEqual(LookupKeyT, KeyT) for each key
126 template<class LookupKeyT>
127 iterator find_as(const LookupKeyT &Val) {
129 if (LookupBucketFor(Val, TheBucket))
130 return iterator(TheBucket, getBucketsEnd(), true);
133 template<class LookupKeyT>
134 const_iterator find_as(const LookupKeyT &Val) const {
135 const BucketT *TheBucket;
136 if (LookupBucketFor(Val, TheBucket))
137 return const_iterator(TheBucket, getBucketsEnd(), true);
141 /// lookup - Return the entry for the specified key, or a default
142 /// constructed value if no such entry exists.
143 ValueT lookup(const KeyT &Val) const {
144 const BucketT *TheBucket;
145 if (LookupBucketFor(Val, TheBucket))
146 return TheBucket->second;
150 // Inserts key,value pair into the map if the key isn't already in the map.
151 // If the key is already in the map, it returns false and doesn't update the
153 std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) {
155 if (LookupBucketFor(KV.first, TheBucket))
156 return std::make_pair(iterator(TheBucket, getBucketsEnd(), true),
157 false); // Already in map.
159 // Otherwise, insert the new element.
160 TheBucket = InsertIntoBucket(KV.first, KV.second, TheBucket);
161 return std::make_pair(iterator(TheBucket, getBucketsEnd(), true), true);
164 #if LLVM_HAS_RVALUE_REFERENCES
165 // Inserts key,value pair into the map if the key isn't already in the map.
166 // If the key is already in the map, it returns false and doesn't update the
168 std::pair<iterator, bool> insert(std::pair<KeyT, ValueT> &&KV) {
170 if (LookupBucketFor(KV.first, TheBucket))
171 return std::make_pair(iterator(TheBucket, getBucketsEnd(), true),
172 false); // Already in map.
174 // Otherwise, insert the new element.
175 TheBucket = InsertIntoBucket(std::move(KV.first),
176 std::move(KV.second),
178 return std::make_pair(iterator(TheBucket, getBucketsEnd(), true), true);
182 /// insert - Range insertion of pairs.
183 template<typename InputIt>
184 void insert(InputIt I, InputIt E) {
190 bool erase(const KeyT &Val) {
192 if (!LookupBucketFor(Val, TheBucket))
193 return false; // not in map.
195 TheBucket->second.~ValueT();
196 TheBucket->first = getTombstoneKey();
197 decrementNumEntries();
198 incrementNumTombstones();
201 void erase(iterator I) {
202 BucketT *TheBucket = &*I;
203 TheBucket->second.~ValueT();
204 TheBucket->first = getTombstoneKey();
205 decrementNumEntries();
206 incrementNumTombstones();
209 value_type& FindAndConstruct(const KeyT &Key) {
211 if (LookupBucketFor(Key, TheBucket))
214 return *InsertIntoBucket(Key, ValueT(), TheBucket);
217 ValueT &operator[](const KeyT &Key) {
218 return FindAndConstruct(Key).second;
221 #if LLVM_HAS_RVALUE_REFERENCES
222 value_type& FindAndConstruct(KeyT &&Key) {
224 if (LookupBucketFor(Key, TheBucket))
227 return *InsertIntoBucket(std::move(Key), ValueT(), TheBucket);
230 ValueT &operator[](KeyT &&Key) {
231 return FindAndConstruct(std::move(Key)).second;
235 /// isPointerIntoBucketsArray - Return true if the specified pointer points
236 /// somewhere into the DenseMap's array of buckets (i.e. either to a key or
237 /// value in the DenseMap).
238 bool isPointerIntoBucketsArray(const void *Ptr) const {
239 return Ptr >= getBuckets() && Ptr < getBucketsEnd();
242 /// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets
243 /// array. In conjunction with the previous method, this can be used to
244 /// determine whether an insertion caused the DenseMap to reallocate.
245 const void *getPointerIntoBucketsArray() const { return getBuckets(); }
251 if (getNumBuckets() == 0) // Nothing to do.
254 const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey();
255 for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) {
256 if (!KeyInfoT::isEqual(P->first, EmptyKey) &&
257 !KeyInfoT::isEqual(P->first, TombstoneKey))
263 memset((void*)getBuckets(), 0x5a, sizeof(BucketT)*getNumBuckets());
271 assert((getNumBuckets() & (getNumBuckets()-1)) == 0 &&
272 "# initial buckets must be a power of two!");
273 const KeyT EmptyKey = getEmptyKey();
274 for (BucketT *B = getBuckets(), *E = getBucketsEnd(); B != E; ++B)
275 new (&B->first) KeyT(EmptyKey);
278 void moveFromOldBuckets(BucketT *OldBucketsBegin, BucketT *OldBucketsEnd) {
281 // Insert all the old elements.
282 const KeyT EmptyKey = getEmptyKey();
283 const KeyT TombstoneKey = getTombstoneKey();
284 for (BucketT *B = OldBucketsBegin, *E = OldBucketsEnd; B != E; ++B) {
285 if (!KeyInfoT::isEqual(B->first, EmptyKey) &&
286 !KeyInfoT::isEqual(B->first, TombstoneKey)) {
287 // Insert the key/value into the new table.
289 bool FoundVal = LookupBucketFor(B->first, DestBucket);
290 (void)FoundVal; // silence warning.
291 assert(!FoundVal && "Key already in new map?");
292 DestBucket->first = llvm_move(B->first);
293 new (&DestBucket->second) ValueT(llvm_move(B->second));
294 incrementNumEntries();
303 if (OldBucketsBegin != OldBucketsEnd)
304 memset((void*)OldBucketsBegin, 0x5a,
305 sizeof(BucketT) * (OldBucketsEnd - OldBucketsBegin));
309 template <typename OtherBaseT>
310 void copyFrom(const DenseMapBase<OtherBaseT, KeyT, ValueT, KeyInfoT>& other) {
311 assert(getNumBuckets() == other.getNumBuckets());
313 setNumEntries(other.getNumEntries());
314 setNumTombstones(other.getNumTombstones());
316 if (isPodLike<KeyT>::value && isPodLike<ValueT>::value)
317 memcpy(getBuckets(), other.getBuckets(),
318 getNumBuckets() * sizeof(BucketT));
320 for (size_t i = 0; i < getNumBuckets(); ++i) {
321 new (&getBuckets()[i].first) KeyT(other.getBuckets()[i].first);
322 if (!KeyInfoT::isEqual(getBuckets()[i].first, getEmptyKey()) &&
323 !KeyInfoT::isEqual(getBuckets()[i].first, getTombstoneKey()))
324 new (&getBuckets()[i].second) ValueT(other.getBuckets()[i].second);
328 void swap(DenseMapBase& RHS) {
329 std::swap(getNumEntries(), RHS.getNumEntries());
330 std::swap(getNumTombstones(), RHS.getNumTombstones());
333 static unsigned getHashValue(const KeyT &Val) {
334 return KeyInfoT::getHashValue(Val);
336 template<typename LookupKeyT>
337 static unsigned getHashValue(const LookupKeyT &Val) {
338 return KeyInfoT::getHashValue(Val);
340 static const KeyT getEmptyKey() {
341 return KeyInfoT::getEmptyKey();
343 static const KeyT getTombstoneKey() {
344 return KeyInfoT::getTombstoneKey();
348 unsigned getNumEntries() const {
349 return static_cast<const DerivedT *>(this)->getNumEntries();
351 void setNumEntries(unsigned Num) {
352 static_cast<DerivedT *>(this)->setNumEntries(Num);
354 void incrementNumEntries() {
355 setNumEntries(getNumEntries() + 1);
357 void decrementNumEntries() {
358 setNumEntries(getNumEntries() - 1);
360 unsigned getNumTombstones() const {
361 return static_cast<const DerivedT *>(this)->getNumTombstones();
363 void setNumTombstones(unsigned Num) {
364 static_cast<DerivedT *>(this)->setNumTombstones(Num);
366 void incrementNumTombstones() {
367 setNumTombstones(getNumTombstones() + 1);
369 void decrementNumTombstones() {
370 setNumTombstones(getNumTombstones() - 1);
372 const BucketT *getBuckets() const {
373 return static_cast<const DerivedT *>(this)->getBuckets();
375 BucketT *getBuckets() {
376 return static_cast<DerivedT *>(this)->getBuckets();
378 unsigned getNumBuckets() const {
379 return static_cast<const DerivedT *>(this)->getNumBuckets();
381 BucketT *getBucketsEnd() {
382 return getBuckets() + getNumBuckets();
384 const BucketT *getBucketsEnd() const {
385 return getBuckets() + getNumBuckets();
388 void grow(unsigned AtLeast) {
389 static_cast<DerivedT *>(this)->grow(AtLeast);
392 void shrink_and_clear() {
393 static_cast<DerivedT *>(this)->shrink_and_clear();
397 BucketT *InsertIntoBucket(const KeyT &Key, const ValueT &Value,
398 BucketT *TheBucket) {
399 TheBucket = InsertIntoBucketImpl(Key, TheBucket);
401 TheBucket->first = Key;
402 new (&TheBucket->second) ValueT(Value);
406 #if LLVM_HAS_RVALUE_REFERENCES
407 BucketT *InsertIntoBucket(const KeyT &Key, ValueT &&Value,
408 BucketT *TheBucket) {
409 TheBucket = InsertIntoBucketImpl(Key, TheBucket);
411 TheBucket->first = Key;
412 new (&TheBucket->second) ValueT(std::move(Value));
416 BucketT *InsertIntoBucket(KeyT &&Key, ValueT &&Value, BucketT *TheBucket) {
417 TheBucket = InsertIntoBucketImpl(Key, TheBucket);
419 TheBucket->first = std::move(Key);
420 new (&TheBucket->second) ValueT(std::move(Value));
425 BucketT *InsertIntoBucketImpl(const KeyT &Key, BucketT *TheBucket) {
426 // If the load of the hash table is more than 3/4, or if fewer than 1/8 of
427 // the buckets are empty (meaning that many are filled with tombstones),
430 // The later case is tricky. For example, if we had one empty bucket with
431 // tons of tombstones, failing lookups (e.g. for insertion) would have to
432 // probe almost the entire table until it found the empty bucket. If the
433 // table completely filled with tombstones, no lookup would ever succeed,
434 // causing infinite loops in lookup.
435 unsigned NewNumEntries = getNumEntries() + 1;
436 unsigned NumBuckets = getNumBuckets();
437 if (NewNumEntries*4 >= NumBuckets*3) {
438 this->grow(NumBuckets * 2);
439 LookupBucketFor(Key, TheBucket);
440 NumBuckets = getNumBuckets();
442 if (NumBuckets-(NewNumEntries+getNumTombstones()) <= NumBuckets/8) {
443 this->grow(NumBuckets * 2);
444 LookupBucketFor(Key, TheBucket);
448 // Only update the state after we've grown our bucket space appropriately
449 // so that when growing buckets we have self-consistent entry count.
450 incrementNumEntries();
452 // If we are writing over a tombstone, remember this.
453 const KeyT EmptyKey = getEmptyKey();
454 if (!KeyInfoT::isEqual(TheBucket->first, EmptyKey))
455 decrementNumTombstones();
460 /// LookupBucketFor - Lookup the appropriate bucket for Val, returning it in
461 /// FoundBucket. If the bucket contains the key and a value, this returns
462 /// true, otherwise it returns a bucket with an empty marker or tombstone and
464 template<typename LookupKeyT>
465 bool LookupBucketFor(const LookupKeyT &Val,
466 const BucketT *&FoundBucket) const {
467 const BucketT *BucketsPtr = getBuckets();
468 const unsigned NumBuckets = getNumBuckets();
470 if (NumBuckets == 0) {
475 // FoundTombstone - Keep track of whether we find a tombstone while probing.
476 const BucketT *FoundTombstone = 0;
477 const KeyT EmptyKey = getEmptyKey();
478 const KeyT TombstoneKey = getTombstoneKey();
479 assert(!KeyInfoT::isEqual(Val, EmptyKey) &&
480 !KeyInfoT::isEqual(Val, TombstoneKey) &&
481 "Empty/Tombstone value shouldn't be inserted into map!");
483 unsigned BucketNo = getHashValue(Val) & (NumBuckets-1);
484 unsigned ProbeAmt = 1;
486 const BucketT *ThisBucket = BucketsPtr + BucketNo;
487 // Found Val's bucket? If so, return it.
488 if (KeyInfoT::isEqual(Val, ThisBucket->first)) {
489 FoundBucket = ThisBucket;
493 // If we found an empty bucket, the key doesn't exist in the set.
494 // Insert it and return the default value.
495 if (KeyInfoT::isEqual(ThisBucket->first, EmptyKey)) {
496 // If we've already seen a tombstone while probing, fill it in instead
497 // of the empty bucket we eventually probed to.
498 FoundBucket = FoundTombstone ? FoundTombstone : ThisBucket;
502 // If this is a tombstone, remember it. If Val ends up not in the map, we
503 // prefer to return it than something that would require more probing.
504 if (KeyInfoT::isEqual(ThisBucket->first, TombstoneKey) && !FoundTombstone)
505 FoundTombstone = ThisBucket; // Remember the first tombstone found.
507 // Otherwise, it's a hash collision or a tombstone, continue quadratic
509 BucketNo += ProbeAmt++;
510 BucketNo &= (NumBuckets-1);
514 template <typename LookupKeyT>
515 bool LookupBucketFor(const LookupKeyT &Val, BucketT *&FoundBucket) {
516 const BucketT *ConstFoundBucket;
517 bool Result = const_cast<const DenseMapBase *>(this)
518 ->LookupBucketFor(Val, ConstFoundBucket);
519 FoundBucket = const_cast<BucketT *>(ConstFoundBucket);
524 /// Return the approximate size (in bytes) of the actual map.
525 /// This is just the raw memory used by DenseMap.
526 /// If entries are pointers to objects, the size of the referenced objects
527 /// are not included.
528 size_t getMemorySize() const {
529 return getNumBuckets() * sizeof(BucketT);
533 template<typename KeyT, typename ValueT,
534 typename KeyInfoT = DenseMapInfo<KeyT> >
536 : public DenseMapBase<DenseMap<KeyT, ValueT, KeyInfoT>,
537 KeyT, ValueT, KeyInfoT> {
538 // Lift some types from the dependent base class into this class for
539 // simplicity of referring to them.
540 typedef DenseMapBase<DenseMap, KeyT, ValueT, KeyInfoT> BaseT;
541 typedef typename BaseT::BucketT BucketT;
542 friend class DenseMapBase<DenseMap, KeyT, ValueT, KeyInfoT>;
546 unsigned NumTombstones;
550 explicit DenseMap(unsigned NumInitBuckets = 0) {
551 init(NumInitBuckets);
554 DenseMap(const DenseMap &other) : BaseT() {
559 #if LLVM_HAS_RVALUE_REFERENCES
560 DenseMap(DenseMap &&other) : BaseT() {
566 template<typename InputIt>
567 DenseMap(const InputIt &I, const InputIt &E) {
568 init(NextPowerOf2(std::distance(I, E)));
574 operator delete(Buckets);
577 void swap(DenseMap& RHS) {
578 std::swap(Buckets, RHS.Buckets);
579 std::swap(NumEntries, RHS.NumEntries);
580 std::swap(NumTombstones, RHS.NumTombstones);
581 std::swap(NumBuckets, RHS.NumBuckets);
584 DenseMap& operator=(const DenseMap& other) {
589 #if LLVM_HAS_RVALUE_REFERENCES
590 DenseMap& operator=(DenseMap &&other) {
592 operator delete(Buckets);
599 void copyFrom(const DenseMap& other) {
601 operator delete(Buckets);
602 if (allocateBuckets(other.NumBuckets)) {
603 this->BaseT::copyFrom(other);
610 void init(unsigned InitBuckets) {
611 if (allocateBuckets(InitBuckets)) {
612 this->BaseT::initEmpty();
619 void grow(unsigned AtLeast) {
620 unsigned OldNumBuckets = NumBuckets;
621 BucketT *OldBuckets = Buckets;
623 allocateBuckets(std::max<unsigned>(64, static_cast<unsigned>(NextPowerOf2(AtLeast-1))));
626 this->BaseT::initEmpty();
630 this->moveFromOldBuckets(OldBuckets, OldBuckets+OldNumBuckets);
632 // Free the old table.
633 operator delete(OldBuckets);
636 void shrink_and_clear() {
637 unsigned OldNumEntries = NumEntries;
640 // Reduce the number of buckets.
641 unsigned NewNumBuckets = 0;
643 NewNumBuckets = std::max(64, 1 << (Log2_32_Ceil(OldNumEntries) + 1));
644 if (NewNumBuckets == NumBuckets) {
645 this->BaseT::initEmpty();
649 operator delete(Buckets);
654 unsigned getNumEntries() const {
657 void setNumEntries(unsigned Num) {
661 unsigned getNumTombstones() const {
662 return NumTombstones;
664 void setNumTombstones(unsigned Num) {
668 BucketT *getBuckets() const {
672 unsigned getNumBuckets() const {
676 bool allocateBuckets(unsigned Num) {
678 if (NumBuckets == 0) {
683 Buckets = static_cast<BucketT*>(operator new(sizeof(BucketT) * NumBuckets));
688 template<typename KeyT, typename ValueT,
689 unsigned InlineBuckets = 4,
690 typename KeyInfoT = DenseMapInfo<KeyT> >
692 : public DenseMapBase<SmallDenseMap<KeyT, ValueT, InlineBuckets, KeyInfoT>,
693 KeyT, ValueT, KeyInfoT> {
694 // Lift some types from the dependent base class into this class for
695 // simplicity of referring to them.
696 typedef DenseMapBase<SmallDenseMap, KeyT, ValueT, KeyInfoT> BaseT;
697 typedef typename BaseT::BucketT BucketT;
698 friend class DenseMapBase<SmallDenseMap, KeyT, ValueT, KeyInfoT>;
701 unsigned NumEntries : 31;
702 unsigned NumTombstones;
709 /// A "union" of an inline bucket array and the struct representing
710 /// a large bucket. This union will be discriminated by the 'Small' bit.
711 AlignedCharArrayUnion<BucketT[InlineBuckets], LargeRep> storage;
714 explicit SmallDenseMap(unsigned NumInitBuckets = 0) {
715 init(NumInitBuckets);
718 SmallDenseMap(const SmallDenseMap &other) : BaseT() {
723 #if LLVM_HAS_RVALUE_REFERENCES
724 SmallDenseMap(SmallDenseMap &&other) : BaseT() {
730 template<typename InputIt>
731 SmallDenseMap(const InputIt &I, const InputIt &E) {
732 init(NextPowerOf2(std::distance(I, E)));
741 void swap(SmallDenseMap& RHS) {
742 unsigned TmpNumEntries = RHS.NumEntries;
743 RHS.NumEntries = NumEntries;
744 NumEntries = TmpNumEntries;
745 std::swap(NumTombstones, RHS.NumTombstones);
747 const KeyT EmptyKey = this->getEmptyKey();
748 const KeyT TombstoneKey = this->getTombstoneKey();
749 if (Small && RHS.Small) {
750 // If we're swapping inline bucket arrays, we have to cope with some of
751 // the tricky bits of DenseMap's storage system: the buckets are not
752 // fully initialized. Thus we swap every key, but we may have
753 // a one-directional move of the value.
754 for (unsigned i = 0, e = InlineBuckets; i != e; ++i) {
755 BucketT *LHSB = &getInlineBuckets()[i],
756 *RHSB = &RHS.getInlineBuckets()[i];
757 bool hasLHSValue = (!KeyInfoT::isEqual(LHSB->first, EmptyKey) &&
758 !KeyInfoT::isEqual(LHSB->first, TombstoneKey));
759 bool hasRHSValue = (!KeyInfoT::isEqual(RHSB->first, EmptyKey) &&
760 !KeyInfoT::isEqual(RHSB->first, TombstoneKey));
761 if (hasLHSValue && hasRHSValue) {
762 // Swap together if we can...
763 std::swap(*LHSB, *RHSB);
766 // Swap separately and handle any assymetry.
767 std::swap(LHSB->first, RHSB->first);
769 new (&RHSB->second) ValueT(llvm_move(LHSB->second));
770 LHSB->second.~ValueT();
771 } else if (hasRHSValue) {
772 new (&LHSB->second) ValueT(llvm_move(RHSB->second));
773 RHSB->second.~ValueT();
778 if (!Small && !RHS.Small) {
779 std::swap(getLargeRep()->Buckets, RHS.getLargeRep()->Buckets);
780 std::swap(getLargeRep()->NumBuckets, RHS.getLargeRep()->NumBuckets);
784 SmallDenseMap &SmallSide = Small ? *this : RHS;
785 SmallDenseMap &LargeSide = Small ? RHS : *this;
787 // First stash the large side's rep and move the small side across.
788 LargeRep TmpRep = llvm_move(*LargeSide.getLargeRep());
789 LargeSide.getLargeRep()->~LargeRep();
790 LargeSide.Small = true;
791 // This is similar to the standard move-from-old-buckets, but the bucket
792 // count hasn't actually rotated in this case. So we have to carefully
793 // move construct the keys and values into their new locations, but there
794 // is no need to re-hash things.
795 for (unsigned i = 0, e = InlineBuckets; i != e; ++i) {
796 BucketT *NewB = &LargeSide.getInlineBuckets()[i],
797 *OldB = &SmallSide.getInlineBuckets()[i];
798 new (&NewB->first) KeyT(llvm_move(OldB->first));
800 if (!KeyInfoT::isEqual(NewB->first, EmptyKey) &&
801 !KeyInfoT::isEqual(NewB->first, TombstoneKey)) {
802 new (&NewB->second) ValueT(llvm_move(OldB->second));
803 OldB->second.~ValueT();
807 // The hard part of moving the small buckets across is done, just move
808 // the TmpRep into its new home.
809 SmallSide.Small = false;
810 new (SmallSide.getLargeRep()) LargeRep(llvm_move(TmpRep));
813 SmallDenseMap& operator=(const SmallDenseMap& other) {
818 #if LLVM_HAS_RVALUE_REFERENCES
819 SmallDenseMap& operator=(SmallDenseMap &&other) {
828 void copyFrom(const SmallDenseMap& other) {
832 if (other.getNumBuckets() > InlineBuckets) {
834 allocateBuckets(other.getNumBuckets());
836 this->BaseT::copyFrom(other);
839 void init(unsigned InitBuckets) {
841 if (InitBuckets > InlineBuckets) {
843 new (getLargeRep()) LargeRep(allocateBuckets(InitBuckets));
845 this->BaseT::initEmpty();
848 void grow(unsigned AtLeast) {
849 if (AtLeast >= InlineBuckets)
850 AtLeast = std::max<unsigned>(64, NextPowerOf2(AtLeast-1));
853 if (AtLeast < InlineBuckets)
854 return; // Nothing to do.
856 // First move the inline buckets into a temporary storage.
857 AlignedCharArrayUnion<BucketT[InlineBuckets]> TmpStorage;
858 BucketT *TmpBegin = reinterpret_cast<BucketT *>(TmpStorage.buffer);
859 BucketT *TmpEnd = TmpBegin;
861 // Loop over the buckets, moving non-empty, non-tombstones into the
862 // temporary storage. Have the loop move the TmpEnd forward as it goes.
863 const KeyT EmptyKey = this->getEmptyKey();
864 const KeyT TombstoneKey = this->getTombstoneKey();
865 for (BucketT *P = getBuckets(), *E = P + InlineBuckets; P != E; ++P) {
866 if (!KeyInfoT::isEqual(P->first, EmptyKey) &&
867 !KeyInfoT::isEqual(P->first, TombstoneKey)) {
868 assert(size_t(TmpEnd - TmpBegin) < InlineBuckets &&
869 "Too many inline buckets!");
870 new (&TmpEnd->first) KeyT(llvm_move(P->first));
871 new (&TmpEnd->second) ValueT(llvm_move(P->second));
878 // Now make this map use the large rep, and move all the entries back
881 new (getLargeRep()) LargeRep(allocateBuckets(AtLeast));
882 this->moveFromOldBuckets(TmpBegin, TmpEnd);
886 LargeRep OldRep = llvm_move(*getLargeRep());
887 getLargeRep()->~LargeRep();
888 if (AtLeast <= InlineBuckets) {
891 new (getLargeRep()) LargeRep(allocateBuckets(AtLeast));
894 this->moveFromOldBuckets(OldRep.Buckets, OldRep.Buckets+OldRep.NumBuckets);
896 // Free the old table.
897 operator delete(OldRep.Buckets);
900 void shrink_and_clear() {
901 unsigned OldSize = this->size();
904 // Reduce the number of buckets.
905 unsigned NewNumBuckets = 0;
907 NewNumBuckets = 1 << (Log2_32_Ceil(OldSize) + 1);
908 if (NewNumBuckets > InlineBuckets && NewNumBuckets < 64u)
911 if ((Small && NewNumBuckets <= InlineBuckets) ||
912 (!Small && NewNumBuckets == getLargeRep()->NumBuckets)) {
913 this->BaseT::initEmpty();
922 unsigned getNumEntries() const {
925 void setNumEntries(unsigned Num) {
926 assert(Num < INT_MAX && "Cannot support more than INT_MAX entries");
930 unsigned getNumTombstones() const {
931 return NumTombstones;
933 void setNumTombstones(unsigned Num) {
937 const BucketT *getInlineBuckets() const {
939 // Note that this cast does not violate aliasing rules as we assert that
940 // the memory's dynamic type is the small, inline bucket buffer, and the
941 // 'storage.buffer' static type is 'char *'.
942 return reinterpret_cast<const BucketT *>(storage.buffer);
944 BucketT *getInlineBuckets() {
945 return const_cast<BucketT *>(
946 const_cast<const SmallDenseMap *>(this)->getInlineBuckets());
948 const LargeRep *getLargeRep() const {
950 // Note, same rule about aliasing as with getInlineBuckets.
951 return reinterpret_cast<const LargeRep *>(storage.buffer);
953 LargeRep *getLargeRep() {
954 return const_cast<LargeRep *>(
955 const_cast<const SmallDenseMap *>(this)->getLargeRep());
958 const BucketT *getBuckets() const {
959 return Small ? getInlineBuckets() : getLargeRep()->Buckets;
961 BucketT *getBuckets() {
962 return const_cast<BucketT *>(
963 const_cast<const SmallDenseMap *>(this)->getBuckets());
965 unsigned getNumBuckets() const {
966 return Small ? InlineBuckets : getLargeRep()->NumBuckets;
969 void deallocateBuckets() {
973 operator delete(getLargeRep()->Buckets);
974 getLargeRep()->~LargeRep();
977 LargeRep allocateBuckets(unsigned Num) {
978 assert(Num > InlineBuckets && "Must allocate more buckets than are inline");
980 static_cast<BucketT*>(operator new(sizeof(BucketT) * Num)), Num
986 template<typename KeyT, typename ValueT,
987 typename KeyInfoT, bool IsConst>
988 class DenseMapIterator {
989 typedef std::pair<KeyT, ValueT> Bucket;
990 typedef DenseMapIterator<KeyT, ValueT,
991 KeyInfoT, true> ConstIterator;
992 friend class DenseMapIterator<KeyT, ValueT, KeyInfoT, true>;
994 typedef ptrdiff_t difference_type;
995 typedef typename conditional<IsConst, const Bucket, Bucket>::type value_type;
996 typedef value_type *pointer;
997 typedef value_type &reference;
998 typedef std::forward_iterator_tag iterator_category;
1002 DenseMapIterator() : Ptr(0), End(0) {}
1004 DenseMapIterator(pointer Pos, pointer E, bool NoAdvance = false)
1005 : Ptr(Pos), End(E) {
1006 if (!NoAdvance) AdvancePastEmptyBuckets();
1009 // If IsConst is true this is a converting constructor from iterator to
1010 // const_iterator and the default copy constructor is used.
1011 // Otherwise this is a copy constructor for iterator.
1012 DenseMapIterator(const DenseMapIterator<KeyT, ValueT,
1013 KeyInfoT, false>& I)
1014 : Ptr(I.Ptr), End(I.End) {}
1016 reference operator*() const {
1019 pointer operator->() const {
1023 bool operator==(const ConstIterator &RHS) const {
1024 return Ptr == RHS.operator->();
1026 bool operator!=(const ConstIterator &RHS) const {
1027 return Ptr != RHS.operator->();
1030 inline DenseMapIterator& operator++() { // Preincrement
1032 AdvancePastEmptyBuckets();
1035 DenseMapIterator operator++(int) { // Postincrement
1036 DenseMapIterator tmp = *this; ++*this; return tmp;
1040 void AdvancePastEmptyBuckets() {
1041 const KeyT Empty = KeyInfoT::getEmptyKey();
1042 const KeyT Tombstone = KeyInfoT::getTombstoneKey();
1044 while (Ptr != End &&
1045 (KeyInfoT::isEqual(Ptr->first, Empty) ||
1046 KeyInfoT::isEqual(Ptr->first, Tombstone)))
1051 template<typename KeyT, typename ValueT, typename KeyInfoT>
1052 static inline size_t
1053 capacity_in_bytes(const DenseMap<KeyT, ValueT, KeyInfoT> &X) {
1054 return X.getMemorySize();
1057 } // end namespace llvm