1//===- llvm/ADT/DenseMap.h - Dense probed hash table ------------*- 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 DenseMap class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_ADT_DENSEMAP_H
15#define LLVM_ADT_DENSEMAP_H
16
17#include "llvm/ADT/DenseMapInfo.h"
18#include "llvm/ADT/EpochTracker.h"
19#include "llvm/Support/AlignOf.h"
20#include "llvm/Support/Compiler.h"
21#include "llvm/Support/MathExtras.h"
22#include "llvm/Support/ReverseIteration.h"
23#include "llvm/Support/type_traits.h"
24#include <algorithm>
25#include <cassert>
26#include <cstddef>
27#include <cstring>
28#include <initializer_list>
29#include <iterator>
30#include <new>
31#include <type_traits>
32#include <utility>
33
34namespace llvm {
35
36namespace detail {
37
38// We extend a pair to allow users to override the bucket type with their own
39// implementation without requiring two members.
40template <typename KeyT, typename ValueT>
41struct DenseMapPair : public std::pair<KeyT, ValueT> {
42
43 // FIXME: Switch to inheriting constructors when we drop support for older
44 // clang versions.
45 // NOTE: This default constructor is declared with '{}' rather than
46 // '= default' to work around a separate bug in clang-3.8. This can
47 // also go when we switch to inheriting constructors.
48 DenseMapPair() {}
49
50 DenseMapPair(const KeyT &Key, const ValueT &Value)
51 : std::pair<KeyT, ValueT>(Key, Value) {}
52
53 DenseMapPair(KeyT &&Key, ValueT &&Value)
54 : std::pair<KeyT, ValueT>(std::move(Key), std::move(Value)) {}
55
56 template <typename AltKeyT, typename AltValueT>
57 DenseMapPair(AltKeyT &&AltKey, AltValueT &&AltValue,
58 typename std::enable_if<
59 std::is_convertible<AltKeyT, KeyT>::value &&
60 std::is_convertible<AltValueT, ValueT>::value>::type * = 0)
61 : std::pair<KeyT, ValueT>(std::forward<AltKeyT>(AltKey),
62 std::forward<AltValueT>(AltValue)) {}
63
64 template <typename AltPairT>
65 DenseMapPair(AltPairT &&AltPair,
66 typename std::enable_if<std::is_convertible<
67 AltPairT, std::pair<KeyT, ValueT>>::value>::type * = 0)
68 : std::pair<KeyT, ValueT>(std::forward<AltPairT>(AltPair)) {}
69
70 KeyT &getFirst() { return std::pair<KeyT, ValueT>::first; }
71 const KeyT &getFirst() const { return std::pair<KeyT, ValueT>::first; }
72 ValueT &getSecond() { return std::pair<KeyT, ValueT>::second; }
73 const ValueT &getSecond() const { return std::pair<KeyT, ValueT>::second; }
74};
75
76} // end namespace detail
77
78template <typename KeyT, typename ValueT,
79 typename KeyInfoT = DenseMapInfo<KeyT>,
80 typename Bucket = llvm::detail::DenseMapPair<KeyT, ValueT>,
81 bool IsConst = false>
82class DenseMapIterator;
83
84template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT,
85 typename BucketT>
86class DenseMapBase : public DebugEpochBase {
87 template <typename T>
88 using const_arg_type_t = typename const_pointer_or_const_ref<T>::type;
89
90public:
91 using size_type = unsigned;
92 using key_type = KeyT;
93 using mapped_type = ValueT;
94 using value_type = BucketT;
95
96 using iterator = DenseMapIterator<KeyT, ValueT, KeyInfoT, BucketT>;
97 using const_iterator =
98 DenseMapIterator<KeyT, ValueT, KeyInfoT, BucketT, true>;
99
100 inline iterator begin() {
101 // When the map is empty, avoid the overhead of advancing/retreating past
102 // empty buckets.
103 if (empty())
104 return end();
105 if (shouldReverseIterate<KeyT>())
106 return makeIterator(getBucketsEnd() - 1, getBuckets(), *this);
107 return makeIterator(getBuckets(), getBucketsEnd(), *this);
108 }
109 inline iterator end() {
110 return makeIterator(getBucketsEnd(), getBucketsEnd(), *this, true);
111 }
112 inline const_iterator begin() const {
113 if (empty())
114 return end();
115 if (shouldReverseIterate<KeyT>())
116 return makeConstIterator(getBucketsEnd() - 1, getBuckets(), *this);
117 return makeConstIterator(getBuckets(), getBucketsEnd(), *this);
118 }
119 inline const_iterator end() const {
120 return makeConstIterator(getBucketsEnd(), getBucketsEnd(), *this, true);
121 }
122
123 LLVM_NODISCARD bool empty() const {
124 return getNumEntries() == 0;
125 }
126 unsigned size() const { return getNumEntries(); }
127
128 /// Grow the densemap so that it can contain at least \p NumEntries items
129 /// before resizing again.
130 void reserve(size_type NumEntries) {
131 auto NumBuckets = getMinBucketToReserveForEntries(NumEntries);
132 incrementEpoch();
133 if (NumBuckets > getNumBuckets())
134 grow(NumBuckets);
135 }
136
137 void clear() {
138 incrementEpoch();
139 if (getNumEntries() == 0 && getNumTombstones() == 0) return;
140
141 // If the capacity of the array is huge, and the # elements used is small,
142 // shrink the array.
143 if (getNumEntries() * 4 < getNumBuckets() && getNumBuckets() > 64) {
144 shrink_and_clear();
145 return;
146 }
147
148 const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey();
149 if (isPodLike<KeyT>::value && isPodLike<ValueT>::value) {
150 // Use a simpler loop when these are trivial types.
151 for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P)
152 P->getFirst() = EmptyKey;
153 } else {
154 unsigned NumEntries = getNumEntries();
155 for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) {
156 if (!KeyInfoT::isEqual(P->getFirst(), EmptyKey)) {
157 if (!KeyInfoT::isEqual(P->getFirst(), TombstoneKey)) {
158 P->getSecond().~ValueT();
159 --NumEntries;
160 }
161 P->getFirst() = EmptyKey;
162 }
163 }
164 assert(NumEntries == 0 && "Node count imbalance!");
165 }
166 setNumEntries(0);
167 setNumTombstones(0);
168 }
169
170 /// Return 1 if the specified key is in the map, 0 otherwise.
171 size_type count(const_arg_type_t<KeyT> Val) const {
172 const BucketT *TheBucket;
173 return LookupBucketFor(Val, TheBucket) ? 1 : 0;
174 }
175
176 iterator find(const_arg_type_t<KeyT> Val) {
177 BucketT *TheBucket;
178 if (LookupBucketFor(Val, TheBucket))
179 return makeIterator(TheBucket, getBucketsEnd(), *this, true);
180 return end();
181 }
182 const_iterator find(const_arg_type_t<KeyT> Val) const {
183 const BucketT *TheBucket;
184 if (LookupBucketFor(Val, TheBucket))
185 return makeConstIterator(TheBucket, getBucketsEnd(), *this, true);
186 return end();
187 }
188
189 /// Alternate version of find() which allows a different, and possibly
190 /// less expensive, key type.
191 /// The DenseMapInfo is responsible for supplying methods
192 /// getHashValue(LookupKeyT) and isEqual(LookupKeyT, KeyT) for each key
193 /// type used.
194 template<class LookupKeyT>
195 iterator find_as(const LookupKeyT &Val) {
196 BucketT *TheBucket;
197 if (LookupBucketFor(Val, TheBucket))
198 return makeIterator(TheBucket, getBucketsEnd(), *this, true);
199 return end();
200 }
201 template<class LookupKeyT>
202 const_iterator find_as(const LookupKeyT &Val) const {
203 const BucketT *TheBucket;
204 if (LookupBucketFor(Val, TheBucket))
205 return makeConstIterator(TheBucket, getBucketsEnd(), *this, true);
206 return end();
207 }
208
209 /// lookup - Return the entry for the specified key, or a default
210 /// constructed value if no such entry exists.
211 ValueT lookup(const_arg_type_t<KeyT> Val) const {
212 const BucketT *TheBucket;
213 if (LookupBucketFor(Val, TheBucket))
214 return TheBucket->getSecond();
215 return ValueT();
216 }
217
218 // Inserts key,value pair into the map if the key isn't already in the map.
219 // If the key is already in the map, it returns false and doesn't update the
220 // value.
221 std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) {
222 return try_emplace(KV.first, KV.second);
223 }
224
225 // Inserts key,value pair into the map if the key isn't already in the map.
226 // If the key is already in the map, it returns false and doesn't update the
227 // value.
228 std::pair<iterator, bool> insert(std::pair<KeyT, ValueT> &&KV) {
229 return try_emplace(std::move(KV.first), std::move(KV.second));
230 }
231
232 // Inserts key,value pair into the map if the key isn't already in the map.
233 // The value is constructed in-place if the key is not in the map, otherwise
234 // it is not moved.
235 template <typename... Ts>
236 std::pair<iterator, bool> try_emplace(KeyT &&Key, Ts &&... Args) {
237 BucketT *TheBucket;
238 if (LookupBucketFor(Key, TheBucket))
239 return std::make_pair(
240 makeIterator(TheBucket, getBucketsEnd(), *this, true),
241 false); // Already in map.
242
243 // Otherwise, insert the new element.
244 TheBucket =
245 InsertIntoBucket(TheBucket, std::move(Key), std::forward<Ts>(Args)...);
246 return std::make_pair(
247 makeIterator(TheBucket, getBucketsEnd(), *this, true),
248 true);
249 }
250
251 // Inserts key,value pair into the map if the key isn't already in the map.
252 // The value is constructed in-place if the key is not in the map, otherwise
253 // it is not moved.
254 template <typename... Ts>
255 std::pair<iterator, bool> try_emplace(const KeyT &Key, Ts &&... Args) {
256 BucketT *TheBucket;
257 if (LookupBucketFor(Key, TheBucket))
258 return std::make_pair(
259 makeIterator(TheBucket, getBucketsEnd(), *this, true),
260 false); // Already in map.
261
262 // Otherwise, insert the new element.
263 TheBucket = InsertIntoBucket(TheBucket, Key, std::forward<Ts>(Args)...);
264 return std::make_pair(
265 makeIterator(TheBucket, getBucketsEnd(), *this, true),
266 true);
267 }
268
269 /// Alternate version of insert() which allows a different, and possibly
270 /// less expensive, key type.
271 /// The DenseMapInfo is responsible for supplying methods
272 /// getHashValue(LookupKeyT) and isEqual(LookupKeyT, KeyT) for each key
273 /// type used.
274 template <typename LookupKeyT>
275 std::pair<iterator, bool> insert_as(std::pair<KeyT, ValueT> &&KV,
276 const LookupKeyT &Val) {
277 BucketT *TheBucket;
278 if (LookupBucketFor(Val, TheBucket))
279 return std::make_pair(
280 makeIterator(TheBucket, getBucketsEnd(), *this, true),
281 false); // Already in map.
282
283 // Otherwise, insert the new element.
284 TheBucket = InsertIntoBucketWithLookup(TheBucket, std::move(KV.first),
285 std::move(KV.second), Val);
286 return std::make_pair(
287 makeIterator(TheBucket, getBucketsEnd(), *this, true),
288 true);
289 }
290
291 /// insert - Range insertion of pairs.
292 template<typename InputIt>
293 void insert(InputIt I, InputIt E) {
294 for (; I != E; ++I)
295 insert(*I);
296 }
297
298 bool erase(const KeyT &Val) {
299 BucketT *TheBucket;
300 if (!LookupBucketFor(Val, TheBucket))
301 return false; // not in map.
302
303 TheBucket->getSecond().~ValueT();
304 TheBucket->getFirst() = getTombstoneKey();
305 decrementNumEntries();
306 incrementNumTombstones();
307 return true;
308 }
309 void erase(iterator I) {
310 BucketT *TheBucket = &*I;
311 TheBucket->getSecond().~ValueT();
312 TheBucket->getFirst() = getTombstoneKey();
313 decrementNumEntries();
314 incrementNumTombstones();
315 }
316
317 value_type& FindAndConstruct(const KeyT &Key) {
318 BucketT *TheBucket;
319 if (LookupBucketFor(Key, TheBucket))
320 return *TheBucket;
321
322 return *InsertIntoBucket(TheBucket, Key);
323 }
324
325 ValueT &operator[](const KeyT &Key) {
326 return FindAndConstruct(Key).second;
327 }
328
329 value_type& FindAndConstruct(KeyT &&Key) {
330 BucketT *TheBucket;
331 if (LookupBucketFor(Key, TheBucket))
332 return *TheBucket;
333
334 return *InsertIntoBucket(TheBucket, std::move(Key));
335 }
336
337 ValueT &operator[](KeyT &&Key) {
338 return FindAndConstruct(std::move(Key)).second;
339 }
340
341 /// isPointerIntoBucketsArray - Return true if the specified pointer points
342 /// somewhere into the DenseMap's array of buckets (i.e. either to a key or
343 /// value in the DenseMap).
344 bool isPointerIntoBucketsArray(const void *Ptr) const {
345 return Ptr >= getBuckets() && Ptr < getBucketsEnd();
346 }
347
348 /// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets
349 /// array. In conjunction with the previous method, this can be used to
350 /// determine whether an insertion caused the DenseMap to reallocate.
351 const void *getPointerIntoBucketsArray() const { return getBuckets(); }
352
353protected:
354 DenseMapBase() = default;
355
356 void destroyAll() {
357 if (getNumBuckets() == 0) // Nothing to do.
358 return;
359
360 const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey();
361 for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) {
362 if (!KeyInfoT::isEqual(P->getFirst(), EmptyKey) &&
363 !KeyInfoT::isEqual(P->getFirst(), TombstoneKey))
364 P->getSecond().~ValueT();
365 P->getFirst().~KeyT();
366 }
367 }
368
369 void initEmpty() {
370 setNumEntries(0);
371 setNumTombstones(0);
372
373 assert((getNumBuckets() & (getNumBuckets()-1)) == 0 &&
374 "# initial buckets must be a power of two!");
375 const KeyT EmptyKey = getEmptyKey();
376 for (BucketT *B = getBuckets(), *E = getBucketsEnd(); B != E; ++B)
377 ::new (&B->getFirst()) KeyT(EmptyKey);
378 }
379
380 /// Returns the number of buckets to allocate to ensure that the DenseMap can
381 /// accommodate \p NumEntries without need to grow().
382 unsigned getMinBucketToReserveForEntries(unsigned NumEntries) {
383 // Ensure that "NumEntries * 4 < NumBuckets * 3"
384 if (NumEntries == 0)
385 return 0;
386 // +1 is required because of the strict equality.
387 // For example if NumEntries is 48, we need to return 401.
388 return NextPowerOf2(NumEntries * 4 / 3 + 1);
389 }
390
391 void moveFromOldBuckets(BucketT *OldBucketsBegin, BucketT *OldBucketsEnd) {
392 initEmpty();
393
394 // Insert all the old elements.
395 const KeyT EmptyKey = getEmptyKey();
396 const KeyT TombstoneKey = getTombstoneKey();
397 for (BucketT *B = OldBucketsBegin, *E = OldBucketsEnd; B != E; ++B) {
398 if (!KeyInfoT::isEqual(B->getFirst(), EmptyKey) &&
399 !KeyInfoT::isEqual(B->getFirst(), TombstoneKey)) {
400 // Insert the key/value into the new table.
401 BucketT *DestBucket;
402 bool FoundVal = LookupBucketFor(B->getFirst(), DestBucket);
403 (void)FoundVal; // silence warning.
404 assert(!FoundVal && "Key already in new map?");
405 DestBucket->getFirst() = std::move(B->getFirst());
406 ::new (&DestBucket->getSecond()) ValueT(std::move(B->getSecond()));
407 incrementNumEntries();
408
409 // Free the value.
410 B->getSecond().~ValueT();
411 }
412 B->getFirst().~KeyT();
413 }
414 }
415
416 template <typename OtherBaseT>
417 void copyFrom(
418 const DenseMapBase<OtherBaseT, KeyT, ValueT, KeyInfoT, BucketT> &other) {
419 assert(&other != this);
420 assert(getNumBuckets() == other.getNumBuckets());
421
422 setNumEntries(other.getNumEntries());
423 setNumTombstones(other.getNumTombstones());
424
425 if (isPodLike<KeyT>::value && isPodLike<ValueT>::value)
426 memcpy(reinterpret_cast<void *>(getBuckets()), other.getBuckets(),
427 getNumBuckets() * sizeof(BucketT));
428 else
429 for (size_t i = 0; i < getNumBuckets(); ++i) {
430 ::new (&getBuckets()[i].getFirst())
431 KeyT(other.getBuckets()[i].getFirst());
432 if (!KeyInfoT::isEqual(getBuckets()[i].getFirst(), getEmptyKey()) &&
433 !KeyInfoT::isEqual(getBuckets()[i].getFirst(), getTombstoneKey()))
434 ::new (&getBuckets()[i].getSecond())
435 ValueT(other.getBuckets()[i].getSecond());
436 }
437 }
438
439 static unsigned getHashValue(const KeyT &Val) {
440 return KeyInfoT::getHashValue(Val);
441 }
442
443 template<typename LookupKeyT>
444 static unsigned getHashValue(const LookupKeyT &Val) {
445 return KeyInfoT::getHashValue(Val);
446 }
447
448 static const KeyT getEmptyKey() {
449 static_assert(std::is_base_of<DenseMapBase, DerivedT>::value,
450 "Must pass the derived type to this template!");
451 return KeyInfoT::getEmptyKey();
452 }
453
454 static const KeyT getTombstoneKey() {
455 return KeyInfoT::getTombstoneKey();
456 }
457
458private:
459 iterator makeIterator(BucketT *P, BucketT *E,
460 DebugEpochBase &Epoch,
461 bool NoAdvance=false) {
462 if (shouldReverseIterate<KeyT>()) {
463 BucketT *B = P == getBucketsEnd() ? getBuckets() : P + 1;
464 return iterator(B, E, Epoch, NoAdvance);
465 }
466 return iterator(P, E, Epoch, NoAdvance);
467 }
468
469 const_iterator makeConstIterator(const BucketT *P, const BucketT *E,
470 const DebugEpochBase &Epoch,
471 const bool NoAdvance=false) const {
472 if (shouldReverseIterate<KeyT>()) {
473 const BucketT *B = P == getBucketsEnd() ? getBuckets() : P + 1;
474 return const_iterator(B, E, Epoch, NoAdvance);
475 }
476 return const_iterator(P, E, Epoch, NoAdvance);
477 }
478
479 unsigned getNumEntries() const {
480 return static_cast<const DerivedT *>(this)->getNumEntries();
481 }
482
483 void setNumEntries(unsigned Num) {
484 static_cast<DerivedT *>(this)->setNumEntries(Num);
485 }
486
487 void incrementNumEntries() {
488 setNumEntries(getNumEntries() + 1);
489 }
490
491 void decrementNumEntries() {
492 setNumEntries(getNumEntries() - 1);
493 }
494
495 unsigned getNumTombstones() const {
496 return static_cast<const DerivedT *>(this)->getNumTombstones();
497 }
498
499 void setNumTombstones(unsigned Num) {
500 static_cast<DerivedT *>(this)->setNumTombstones(Num);
501 }
502
503 void incrementNumTombstones() {
504 setNumTombstones(getNumTombstones() + 1);
505 }
506
507 void decrementNumTombstones() {
508 setNumTombstones(getNumTombstones() - 1);
509 }
510
511 const BucketT *getBuckets() const {
512 return static_cast<const DerivedT *>(this)->getBuckets();
513 }
514
515 BucketT *getBuckets() {
516 return static_cast<DerivedT *>(this)->getBuckets();
517 }
518
519 unsigned getNumBuckets() const {
520 return static_cast<const DerivedT *>(this)->getNumBuckets();
521 }
522
523 BucketT *getBucketsEnd() {
524 return getBuckets() + getNumBuckets();
525 }
526
527 const BucketT *getBucketsEnd() const {
528 return getBuckets() + getNumBuckets();
529 }
530
531 void grow(unsigned AtLeast) {
532 static_cast<DerivedT *>(this)->grow(AtLeast);
533 }
534
535 void shrink_and_clear() {
536 static_cast<DerivedT *>(this)->shrink_and_clear();
537 }
538
539 template <typename KeyArg, typename... ValueArgs>
540 BucketT *InsertIntoBucket(BucketT *TheBucket, KeyArg &&Key,
541 ValueArgs &&... Values) {
542 TheBucket = InsertIntoBucketImpl(Key, Key, TheBucket);
543
544 TheBucket->getFirst() = std::forward<KeyArg>(Key);
545 ::new (&TheBucket->getSecond()) ValueT(std::forward<ValueArgs>(Values)...);
546 return TheBucket;
547 }
548
549 template <typename LookupKeyT>
550 BucketT *InsertIntoBucketWithLookup(BucketT *TheBucket, KeyT &&Key,
551 ValueT &&Value, LookupKeyT &Lookup) {
552 TheBucket = InsertIntoBucketImpl(Key, Lookup, TheBucket);
553
554 TheBucket->getFirst() = std::move(Key);
555 ::new (&TheBucket->getSecond()) ValueT(std::move(Value));
556 return TheBucket;
557 }
558
559 template <typename LookupKeyT>
560 BucketT *InsertIntoBucketImpl(const KeyT &Key, const LookupKeyT &Lookup,
561 BucketT *TheBucket) {
562 incrementEpoch();
563
564 // If the load of the hash table is more than 3/4, or if fewer than 1/8 of
565 // the buckets are empty (meaning that many are filled with tombstones),
566 // grow the table.
567 //
568 // The later case is tricky. For example, if we had one empty bucket with
569 // tons of tombstones, failing lookups (e.g. for insertion) would have to
570 // probe almost the entire table until it found the empty bucket. If the
571 // table completely filled with tombstones, no lookup would ever succeed,
572 // causing infinite loops in lookup.
573 unsigned NewNumEntries = getNumEntries() + 1;
574 unsigned NumBuckets = getNumBuckets();
575 if (LLVM_UNLIKELY(NewNumEntries * 4 >= NumBuckets * 3)) {
576 this->grow(NumBuckets * 2);
577 LookupBucketFor(Lookup, TheBucket);
578 NumBuckets = getNumBuckets();
579 } else if (LLVM_UNLIKELY(NumBuckets-(NewNumEntries+getNumTombstones()) <=
580 NumBuckets/8)) {
581 this->grow(NumBuckets);
582 LookupBucketFor(Lookup, TheBucket);
583 }
584 assert(TheBucket);
585
586 // Only update the state after we've grown our bucket space appropriately
587 // so that when growing buckets we have self-consistent entry count.
588 incrementNumEntries();
589
590 // If we are writing over a tombstone, remember this.
591 const KeyT EmptyKey = getEmptyKey();
592 if (!KeyInfoT::isEqual(TheBucket->getFirst(), EmptyKey))
593 decrementNumTombstones();
594
595 return TheBucket;
596 }
597
598 /// LookupBucketFor - Lookup the appropriate bucket for Val, returning it in
599 /// FoundBucket. If the bucket contains the key and a value, this returns
600 /// true, otherwise it returns a bucket with an empty marker or tombstone and
601 /// returns false.
602 template<typename LookupKeyT>
603 bool LookupBucketFor(const LookupKeyT &Val,
604 const BucketT *&FoundBucket) const {
605 const BucketT *BucketsPtr = getBuckets();
606 const unsigned NumBuckets = getNumBuckets();
607
608 if (NumBuckets == 0) {
609 FoundBucket = nullptr;
610 return false;
611 }
612
613 // FoundTombstone - Keep track of whether we find a tombstone while probing.
614 const BucketT *FoundTombstone = nullptr;
615 const KeyT EmptyKey = getEmptyKey();
616 const KeyT TombstoneKey = getTombstoneKey();
617 assert(!KeyInfoT::isEqual(Val, EmptyKey) &&
618 !KeyInfoT::isEqual(Val, TombstoneKey) &&
619 "Empty/Tombstone value shouldn't be inserted into map!");
620
621 unsigned BucketNo = getHashValue(Val) & (NumBuckets-1);
622 unsigned ProbeAmt = 1;
623 while (true) {
624 const BucketT *ThisBucket = BucketsPtr + BucketNo;
625 // Found Val's bucket? If so, return it.
626 if (LLVM_LIKELY(KeyInfoT::isEqual(Val, ThisBucket->getFirst()))) {
627 FoundBucket = ThisBucket;
628 return true;
629 }
630
631 // If we found an empty bucket, the key doesn't exist in the set.
632 // Insert it and return the default value.
633 if (LLVM_LIKELY(KeyInfoT::isEqual(ThisBucket->getFirst(), EmptyKey))) {
634 // If we've already seen a tombstone while probing, fill it in instead
635 // of the empty bucket we eventually probed to.
636 FoundBucket = FoundTombstone ? FoundTombstone : ThisBucket;
637 return false;
638 }
639
640 // If this is a tombstone, remember it. If Val ends up not in the map, we
641 // prefer to return it than something that would require more probing.
642 if (KeyInfoT::isEqual(ThisBucket->getFirst(), TombstoneKey) &&
643 !FoundTombstone)
644 FoundTombstone = ThisBucket; // Remember the first tombstone found.
645
646 // Otherwise, it's a hash collision or a tombstone, continue quadratic
647 // probing.
648 BucketNo += ProbeAmt++;
649 BucketNo &= (NumBuckets-1);
650 }
651 }
652
653 template <typename LookupKeyT>
654 bool LookupBucketFor(const LookupKeyT &Val, BucketT *&FoundBucket) {
655 const BucketT *ConstFoundBucket;
656 bool Result = const_cast<const DenseMapBase *>(this)
657 ->LookupBucketFor(Val, ConstFoundBucket);
658 FoundBucket = const_cast<BucketT *>(ConstFoundBucket);
659 return Result;
660 }
661
662public:
663 /// Return the approximate size (in bytes) of the actual map.
664 /// This is just the raw memory used by DenseMap.
665 /// If entries are pointers to objects, the size of the referenced objects
666 /// are not included.
667 size_t getMemorySize() const {
668 return getNumBuckets() * sizeof(BucketT);
669 }
670};
671
672/// Equality comparison for DenseMap.
673///
674/// Iterates over elements of LHS confirming that each (key, value) pair in LHS
675/// is also in RHS, and that no additional pairs are in RHS.
676/// Equivalent to N calls to RHS.find and N value comparisons. Amortized
677/// complexity is linear, worst case is O(N^2) (if every hash collides).
678template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT,
679 typename BucketT>
680bool operator==(
681 const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &LHS,
682 const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &RHS) {
683 if (LHS.size() != RHS.size())
684 return false;
685
686 for (auto &KV : LHS) {
687 auto I = RHS.find(KV.first);
688 if (I == RHS.end() || I->second != KV.second)
689 return false;
690 }
691
692 return true;
693}
694
695/// Inequality comparison for DenseMap.
696///
697/// Equivalent to !(LHS == RHS). See operator== for performance notes.
698template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT,
699 typename BucketT>
700bool operator!=(
701 const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &LHS,
702 const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &RHS) {
703 return !(LHS == RHS);
704}
705
706template <typename KeyT, typename ValueT,
707 typename KeyInfoT = DenseMapInfo<KeyT>,
708 typename BucketT = llvm::detail::DenseMapPair<KeyT, ValueT>>
709class DenseMap : public DenseMapBase<DenseMap<KeyT, ValueT, KeyInfoT, BucketT>,
710 KeyT, ValueT, KeyInfoT, BucketT> {
711 friend class DenseMapBase<DenseMap, KeyT, ValueT, KeyInfoT, BucketT>;
712
713 // Lift some types from the dependent base class into this class for
714 // simplicity of referring to them.
715 using BaseT = DenseMapBase<DenseMap, KeyT, ValueT, KeyInfoT, BucketT>;
716
717 BucketT *Buckets;
718 unsigned NumEntries;
719 unsigned NumTombstones;
720 unsigned NumBuckets;
721
722public:
723 /// Create a DenseMap wth an optional \p InitialReserve that guarantee that
724 /// this number of elements can be inserted in the map without grow()
725 explicit DenseMap(unsigned InitialReserve = 0) { init(InitialReserve); }
726
727 DenseMap(const DenseMap &other) : BaseT() {
728 init(0);
729 copyFrom(other);
730 }
731
732 DenseMap(DenseMap &&other) : BaseT() {
733 init(0);
734 swap(other);
735 }
736
737 template<typename InputIt>
738 DenseMap(const InputIt &I, const InputIt &E) {
739 init(std::distance(I, E));
740 this->insert(I, E);
741 }
742
743 DenseMap(std::initializer_list<typename BaseT::value_type> Vals) {
744 init(Vals.size());
745 this->insert(Vals.begin(), Vals.end());
746 }
747
748 ~DenseMap() {
749 this->destroyAll();
750 operator delete(Buckets);
751 }
752
753 void swap(DenseMap& RHS) {
754 this->incrementEpoch();
755 RHS.incrementEpoch();
756 std::swap(Buckets, RHS.Buckets);
757 std::swap(NumEntries, RHS.NumEntries);
758 std::swap(NumTombstones, RHS.NumTombstones);
759 std::swap(NumBuckets, RHS.NumBuckets);
760 }
761
762 DenseMap& operator=(const DenseMap& other) {
763 if (&other != this)
764 copyFrom(other);
765 return *this;
766 }
767
768 DenseMap& operator=(DenseMap &&other) {
769 this->destroyAll();
770 operator delete(Buckets);
771 init(0);
772 swap(other);
773 return *this;
774 }
775
776 void copyFrom(const DenseMap& other) {
777 this->destroyAll();
778 operator delete(Buckets);
779 if (allocateBuckets(other.NumBuckets)) {
780 this->BaseT::copyFrom(other);
781 } else {
782 NumEntries = 0;
783 NumTombstones = 0;
784 }
785 }
786
787 void init(unsigned InitNumEntries) {
788 auto InitBuckets = BaseT::getMinBucketToReserveForEntries(InitNumEntries);
789 if (allocateBuckets(InitBuckets)) {
790 this->BaseT::initEmpty();
791 } else {
792 NumEntries = 0;
793 NumTombstones = 0;
794 }
795 }
796
797 void grow(unsigned AtLeast) {
798 unsigned OldNumBuckets = NumBuckets;
799 BucketT *OldBuckets = Buckets;
800
801 allocateBuckets(std::max<unsigned>(64, static_cast<unsigned>(NextPowerOf2(AtLeast-1))));
802 assert(Buckets);
803 if (!OldBuckets) {
804 this->BaseT::initEmpty();
805 return;
806 }
807
808 this->moveFromOldBuckets(OldBuckets, OldBuckets+OldNumBuckets);
809
810 // Free the old table.
811 operator delete(OldBuckets);
812 }
813
814 void shrink_and_clear() {
815 unsigned OldNumEntries = NumEntries;
816 this->destroyAll();
817
818 // Reduce the number of buckets.
819 unsigned NewNumBuckets = 0;
820 if (OldNumEntries)
821 NewNumBuckets = std::max(64, 1 << (Log2_32_Ceil(OldNumEntries) + 1));
822 if (NewNumBuckets == NumBuckets) {
823 this->BaseT::initEmpty();
824 return;
825 }
826
827 operator delete(Buckets);
828 init(NewNumBuckets);
829 }
830
831private:
832 unsigned getNumEntries() const {
833 return NumEntries;
834 }
835
836 void setNumEntries(unsigned Num) {
837 NumEntries = Num;
838 }
839
840 unsigned getNumTombstones() const {
841 return NumTombstones;
842 }
843
844 void setNumTombstones(unsigned Num) {
845 NumTombstones = Num;
846 }
847
848 BucketT *getBuckets() const {
849 return Buckets;
850 }
851
852 unsigned getNumBuckets() const {
853 return NumBuckets;
854 }
855
856 bool allocateBuckets(unsigned Num) {
857 NumBuckets = Num;
858 if (NumBuckets == 0) {
859 Buckets = nullptr;
860 return false;
861 }
862
863 Buckets = static_cast<BucketT*>(operator new(sizeof(BucketT) * NumBuckets));
864 return true;
865 }
866};
867
868template <typename KeyT, typename ValueT, unsigned InlineBuckets = 4,
869 typename KeyInfoT = DenseMapInfo<KeyT>,
870 typename BucketT = llvm::detail::DenseMapPair<KeyT, ValueT>>
871class SmallDenseMap
872 : public DenseMapBase<
873 SmallDenseMap<KeyT, ValueT, InlineBuckets, KeyInfoT, BucketT>, KeyT,
874 ValueT, KeyInfoT, BucketT> {
875 friend class DenseMapBase<SmallDenseMap, KeyT, ValueT, KeyInfoT, BucketT>;
876
877 // Lift some types from the dependent base class into this class for
878 // simplicity of referring to them.
879 using BaseT = DenseMapBase<SmallDenseMap, KeyT, ValueT, KeyInfoT, BucketT>;
880
881 static_assert(isPowerOf2_64(InlineBuckets),
882 "InlineBuckets must be a power of 2.");
883
884 unsigned Small : 1;
885 unsigned NumEntries : 31;
886 unsigned NumTombstones;
887
888 struct LargeRep {
889 BucketT *Buckets;
890 unsigned NumBuckets;
891 };
892
893 /// A "union" of an inline bucket array and the struct representing
894 /// a large bucket. This union will be discriminated by the 'Small' bit.
895 AlignedCharArrayUnion<BucketT[InlineBuckets], LargeRep> storage;
896
897public:
898 explicit SmallDenseMap(unsigned NumInitBuckets = 0) {
899 init(NumInitBuckets);
900 }
901
902 SmallDenseMap(const SmallDenseMap &other) : BaseT() {
903 init(0);
904 copyFrom(other);
905 }
906
907 SmallDenseMap(SmallDenseMap &&other) : BaseT() {
908 init(0);
909 swap(other);
910 }
911
912 template<typename InputIt>
913 SmallDenseMap(const InputIt &I, const InputIt &E) {
914 init(NextPowerOf2(std::distance(I, E)));
915 this->insert(I, E);
916 }
917
918 ~SmallDenseMap() {
919 this->destroyAll();
920 deallocateBuckets();
921 }
922
923 void swap(SmallDenseMap& RHS) {
924 unsigned TmpNumEntries = RHS.NumEntries;
925 RHS.NumEntries = NumEntries;
926 NumEntries = TmpNumEntries;
927 std::swap(NumTombstones, RHS.NumTombstones);
928
929 const KeyT EmptyKey = this->getEmptyKey();
930 const KeyT TombstoneKey = this->getTombstoneKey();
931 if (Small && RHS.Small) {
932 // If we're swapping inline bucket arrays, we have to cope with some of
933 // the tricky bits of DenseMap's storage system: the buckets are not
934 // fully initialized. Thus we swap every key, but we may have
935 // a one-directional move of the value.
936 for (unsigned i = 0, e = InlineBuckets; i != e; ++i) {
937 BucketT *LHSB = &getInlineBuckets()[i],
938 *RHSB = &RHS.getInlineBuckets()[i];
939 bool hasLHSValue = (!KeyInfoT::isEqual(LHSB->getFirst(), EmptyKey) &&
940 !KeyInfoT::isEqual(LHSB->getFirst(), TombstoneKey));
941 bool hasRHSValue = (!KeyInfoT::isEqual(RHSB->getFirst(), EmptyKey) &&
942 !KeyInfoT::isEqual(RHSB->getFirst(), TombstoneKey));
943 if (hasLHSValue && hasRHSValue) {
944 // Swap together if we can...
945 std::swap(*LHSB, *RHSB);
946 continue;
947 }
948 // Swap separately and handle any assymetry.
949 std::swap(LHSB->getFirst(), RHSB->getFirst());
950 if (hasLHSValue) {
951 ::new (&RHSB->getSecond()) ValueT(std::move(LHSB->getSecond()));
952 LHSB->getSecond().~ValueT();
953 } else if (hasRHSValue) {
954 ::new (&LHSB->getSecond()) ValueT(std::move(RHSB->getSecond()));
955 RHSB->getSecond().~ValueT();
956 }
957 }
958 return;
959 }
960 if (!Small && !RHS.Small) {
961 std::swap(getLargeRep()->Buckets, RHS.getLargeRep()->Buckets);
962 std::swap(getLargeRep()->NumBuckets, RHS.getLargeRep()->NumBuckets);
963 return;
964 }
965
966 SmallDenseMap &SmallSide = Small ? *this : RHS;
967 SmallDenseMap &LargeSide = Small ? RHS : *this;
968
969 // First stash the large side's rep and move the small side across.
970 LargeRep TmpRep = std::move(*LargeSide.getLargeRep());
971 LargeSide.getLargeRep()->~LargeRep();
972 LargeSide.Small = true;
973 // This is similar to the standard move-from-old-buckets, but the bucket
974 // count hasn't actually rotated in this case. So we have to carefully
975 // move construct the keys and values into their new locations, but there
976 // is no need to re-hash things.
977 for (unsigned i = 0, e = InlineBuckets; i != e; ++i) {
978 BucketT *NewB = &LargeSide.getInlineBuckets()[i],
979 *OldB = &SmallSide.getInlineBuckets()[i];
980 ::new (&NewB->getFirst()) KeyT(std::move(OldB->getFirst()));
981 OldB->getFirst().~KeyT();
982 if (!KeyInfoT::isEqual(NewB->getFirst(), EmptyKey) &&
983 !KeyInfoT::isEqual(NewB->getFirst(), TombstoneKey)) {
984 ::new (&NewB->getSecond()) ValueT(std::move(OldB->getSecond()));
985 OldB->getSecond().~ValueT();
986 }
987 }
988
989 // The hard part of moving the small buckets across is done, just move
990 // the TmpRep into its new home.
991 SmallSide.Small = false;
992 new (SmallSide.getLargeRep()) LargeRep(std::move(TmpRep));
993 }
994
995 SmallDenseMap& operator=(const SmallDenseMap& other) {
996 if (&other != this)
997 copyFrom(other);
998 return *this;
999 }
1000
1001 SmallDenseMap& operator=(SmallDenseMap &&other) {
1002 this->destroyAll();
1003 deallocateBuckets();
1004 init(0);
1005 swap(other);
1006 return *this;
1007 }
1008
1009 void copyFrom(const SmallDenseMap& other) {
1010 this->destroyAll();
1011 deallocateBuckets();
1012 Small = true;
1013 if (other.getNumBuckets() > InlineBuckets) {
1014 Small = false;
1015 new (getLargeRep()) LargeRep(allocateBuckets(other.getNumBuckets()));
1016 }
1017 this->BaseT::copyFrom(other);
1018 }
1019
1020 void init(unsigned InitBuckets) {
1021 Small = true;
1022 if (InitBuckets > InlineBuckets) {
1023 Small = false;
1024 new (getLargeRep()) LargeRep(allocateBuckets(InitBuckets));
1025 }
1026 this->BaseT::initEmpty();
1027 }
1028
1029 void grow(unsigned AtLeast) {
1030 if (AtLeast >= InlineBuckets)
1031 AtLeast = std::max<unsigned>(64, NextPowerOf2(AtLeast-1));
1032
1033 if (Small) {
1034 if (AtLeast < InlineBuckets)
1035 return; // Nothing to do.
1036
1037 // First move the inline buckets into a temporary storage.
1038 AlignedCharArrayUnion<BucketT[InlineBuckets]> TmpStorage;
1039 BucketT *TmpBegin = reinterpret_cast<BucketT *>(TmpStorage.buffer);
1040 BucketT *TmpEnd = TmpBegin;
1041
1042 // Loop over the buckets, moving non-empty, non-tombstones into the
1043 // temporary storage. Have the loop move the TmpEnd forward as it goes.
1044 const KeyT EmptyKey = this->getEmptyKey();
1045 const KeyT TombstoneKey = this->getTombstoneKey();
1046 for (BucketT *P = getBuckets(), *E = P + InlineBuckets; P != E; ++P) {
1047 if (!KeyInfoT::isEqual(P->getFirst(), EmptyKey) &&
1048 !KeyInfoT::isEqual(P->getFirst(), TombstoneKey)) {
1049 assert(size_t(TmpEnd - TmpBegin) < InlineBuckets &&
1050 "Too many inline buckets!");
1051 ::new (&TmpEnd->getFirst()) KeyT(std::move(P->getFirst()));
1052 ::new (&TmpEnd->getSecond()) ValueT(std::move(P->getSecond()));
1053 ++TmpEnd;
1054 P->getSecond().~ValueT();
1055 }
1056 P->getFirst().~KeyT();
1057 }
1058
1059 // Now make this map use the large rep, and move all the entries back
1060 // into it.
1061 Small = false;
1062 new (getLargeRep()) LargeRep(allocateBuckets(AtLeast));
1063 this->moveFromOldBuckets(TmpBegin, TmpEnd);
1064 return;
1065 }
1066
1067 LargeRep OldRep = std::move(*getLargeRep());
1068 getLargeRep()->~LargeRep();
1069 if (AtLeast <= InlineBuckets) {
1070 Small = true;
1071 } else {
1072 new (getLargeRep()) LargeRep(allocateBuckets(AtLeast));
1073 }
1074
1075 this->moveFromOldBuckets(OldRep.Buckets, OldRep.Buckets+OldRep.NumBuckets);
1076
1077 // Free the old table.
1078 operator delete(OldRep.Buckets);
1079 }
1080
1081 void shrink_and_clear() {
1082 unsigned OldSize = this->size();
1083 this->destroyAll();
1084
1085 // Reduce the number of buckets.
1086 unsigned NewNumBuckets = 0;
1087 if (OldSize) {
1088 NewNumBuckets = 1 << (Log2_32_Ceil(OldSize) + 1);
1089 if (NewNumBuckets > InlineBuckets && NewNumBuckets < 64u)
1090 NewNumBuckets = 64;
1091 }
1092 if ((Small && NewNumBuckets <= InlineBuckets) ||
1093 (!Small && NewNumBuckets == getLargeRep()->NumBuckets)) {
1094 this->BaseT::initEmpty();
1095 return;
1096 }
1097
1098 deallocateBuckets();
1099 init(NewNumBuckets);
1100 }
1101
1102private:
1103 unsigned getNumEntries() const {
1104 return NumEntries;
1105 }
1106
1107 void setNumEntries(unsigned Num) {
1108 // NumEntries is hardcoded to be 31 bits wide.
1109 assert(Num < (1U << 31) && "Cannot support more than 1<<31 entries");
1110 NumEntries = Num;
1111 }
1112
1113 unsigned getNumTombstones() const {
1114 return NumTombstones;
1115 }
1116
1117 void setNumTombstones(unsigned Num) {
1118 NumTombstones = Num;
1119 }
1120
1121 const BucketT *getInlineBuckets() const {
1122 assert(Small);
1123 // Note that this cast does not violate aliasing rules as we assert that
1124 // the memory's dynamic type is the small, inline bucket buffer, and the
1125 // 'storage.buffer' static type is 'char *'.
1126 return reinterpret_cast<const BucketT *>(storage.buffer);
1127 }
1128
1129 BucketT *getInlineBuckets() {
1130 return const_cast<BucketT *>(
1131 const_cast<const SmallDenseMap *>(this)->getInlineBuckets());
1132 }
1133
1134 const LargeRep *getLargeRep() const {
1135 assert(!Small);
1136 // Note, same rule about aliasing as with getInlineBuckets.
1137 return reinterpret_cast<const LargeRep *>(storage.buffer);
1138 }
1139
1140 LargeRep *getLargeRep() {
1141 return const_cast<LargeRep *>(
1142 const_cast<const SmallDenseMap *>(this)->getLargeRep());
1143 }
1144
1145 const BucketT *getBuckets() const {
1146 return Small ? getInlineBuckets() : getLargeRep()->Buckets;
1147 }
1148
1149 BucketT *getBuckets() {
1150 return const_cast<BucketT *>(
1151 const_cast<const SmallDenseMap *>(this)->getBuckets());
1152 }
1153
1154 unsigned getNumBuckets() const {
1155 return Small ? InlineBuckets : getLargeRep()->NumBuckets;
1156 }
1157
1158 void deallocateBuckets() {
1159 if (Small)
1160 return;
1161
1162 operator delete(getLargeRep()->Buckets);
1163 getLargeRep()->~LargeRep();
1164 }
1165
1166 LargeRep allocateBuckets(unsigned Num) {
1167 assert(Num > InlineBuckets && "Must allocate more buckets than are inline");
1168 LargeRep Rep = {
1169 static_cast<BucketT*>(operator new(sizeof(BucketT) * Num)), Num
1170 };
1171 return Rep;
1172 }
1173};
1174
1175template <typename KeyT, typename ValueT, typename KeyInfoT, typename Bucket,
1176 bool IsConst>
1177class DenseMapIterator : DebugEpochBase::HandleBase {
1178 friend class DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, true>;
1179 friend class DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, false>;
1180
1181 using ConstIterator = DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, true>;
1182
1183public:
1184 using difference_type = ptrdiff_t;
1185 using value_type =
1186 typename std::conditional<IsConst, const Bucket, Bucket>::type;
1187 using pointer = value_type *;
1188 using reference = value_type &;
1189 using iterator_category = std::forward_iterator_tag;
1190
1191private:
1192 pointer Ptr = nullptr;
1193 pointer End = nullptr;
1194
1195public:
1196 DenseMapIterator() = default;
1197
1198 DenseMapIterator(pointer Pos, pointer E, const DebugEpochBase &Epoch,
1199 bool NoAdvance = false)
1200 : DebugEpochBase::HandleBase(&Epoch), Ptr(Pos), End(E) {
1201 assert(isHandleInSync() && "invalid construction!");
1202
1203 if (NoAdvance) return;
1204 if (shouldReverseIterate<KeyT>()) {
1205 RetreatPastEmptyBuckets();
1206 return;
1207 }
1208 AdvancePastEmptyBuckets();
1209 }
1210
1211 // Converting ctor from non-const iterators to const iterators. SFINAE'd out
1212 // for const iterator destinations so it doesn't end up as a user defined copy
1213 // constructor.
1214 template <bool IsConstSrc,
1215 typename = typename std::enable_if<!IsConstSrc && IsConst>::type>
1216 DenseMapIterator(
1217 const DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, IsConstSrc> &I)
1218 : DebugEpochBase::HandleBase(I), Ptr(I.Ptr), End(I.End) {}
1219
1220 reference operator*() const {
1221 assert(isHandleInSync() && "invalid iterator access!");
1222 if (shouldReverseIterate<KeyT>())
1223 return Ptr[-1];
1224 return *Ptr;
1225 }
1226 pointer operator->() const {
1227 assert(isHandleInSync() && "invalid iterator access!");
1228 if (shouldReverseIterate<KeyT>())
1229 return &(Ptr[-1]);
1230 return Ptr;
1231 }
1232
1233 bool operator==(const ConstIterator &RHS) const {
1234 assert((!Ptr || isHandleInSync()) && "handle not in sync!");
1235 assert((!RHS.Ptr || RHS.isHandleInSync()) && "handle not in sync!");
1236 assert(getEpochAddress() == RHS.getEpochAddress() &&
1237 "comparing incomparable iterators!");
1238 return Ptr == RHS.Ptr;
1239 }
1240 bool operator!=(const ConstIterator &RHS) const {
1241 assert((!Ptr || isHandleInSync()) && "handle not in sync!");
1242 assert((!RHS.Ptr || RHS.isHandleInSync()) && "handle not in sync!");
1243 assert(getEpochAddress() == RHS.getEpochAddress() &&
1244 "comparing incomparable iterators!");
1245 return Ptr != RHS.Ptr;
1246 }
1247
1248 inline DenseMapIterator& operator++() { // Preincrement
1249 assert(isHandleInSync() && "invalid iterator access!");
1250 if (shouldReverseIterate<KeyT>()) {
1251 --Ptr;
1252 RetreatPastEmptyBuckets();
1253 return *this;
1254 }
1255 ++Ptr;
1256 AdvancePastEmptyBuckets();
1257 return *this;
1258 }
1259 DenseMapIterator operator++(int) { // Postincrement
1260 assert(isHandleInSync() && "invalid iterator access!");
1261 DenseMapIterator tmp = *this; ++*this; return tmp;
1262 }
1263
1264private:
1265 void AdvancePastEmptyBuckets() {
1266 assert(Ptr <= End);
1267 const KeyT Empty = KeyInfoT::getEmptyKey();
1268 const KeyT Tombstone = KeyInfoT::getTombstoneKey();
1269
1270 while (Ptr != End && (KeyInfoT::isEqual(Ptr->getFirst(), Empty) ||
1271 KeyInfoT::isEqual(Ptr->getFirst(), Tombstone)))
1272 ++Ptr;
1273 }
1274
1275 void RetreatPastEmptyBuckets() {
1276 assert(Ptr >= End);
1277 const KeyT Empty = KeyInfoT::getEmptyKey();
1278 const KeyT Tombstone = KeyInfoT::getTombstoneKey();
1279
1280 while (Ptr != End && (KeyInfoT::isEqual(Ptr[-1].getFirst(), Empty) ||
1281 KeyInfoT::isEqual(Ptr[-1].getFirst(), Tombstone)))
1282 --Ptr;
1283 }
1284};
1285
1286template <typename KeyT, typename ValueT, typename KeyInfoT>
1287inline size_t capacity_in_bytes(const DenseMap<KeyT, ValueT, KeyInfoT> &X) {
1288 return X.getMemorySize();
1289}
1290
1291} // end namespace llvm
1292
1293#endif // LLVM_ADT_DENSEMAP_H
1294