+
+ NumEntries = other.NumEntries;
+ NumTombstones = other.NumTombstones;
+
+ if (NumBuckets)
+ operator delete(Buckets);
+ Buckets = static_cast<BucketT*>(operator new(sizeof(BucketT) *
+ other.NumBuckets));
+
+ if (KeyInfoT::isPod() && ValueInfoT::isPod())
+ memcpy(Buckets, other.Buckets, other.NumBuckets * sizeof(BucketT));
+ else
+ for (size_t i = 0; i < other.NumBuckets; ++i) {
+ new (&Buckets[i].first) KeyT(other.Buckets[i].first);
+ if (!KeyInfoT::isEqual(Buckets[i].first, getEmptyKey()) &&
+ !KeyInfoT::isEqual(Buckets[i].first, getTombstoneKey()))
+ new (&Buckets[i].second) ValueT(other.Buckets[i].second);
+ }
+ NumBuckets = other.NumBuckets;
+ }
+
+ BucketT *InsertIntoBucket(const KeyT &Key, const ValueT &Value,
+ BucketT *TheBucket) {
+ // If the load of the hash table is more than 3/4, or if fewer than 1/8 of
+ // the buckets are empty (meaning that many are filled with tombstones),
+ // grow the table.
+ //
+ // The later case is tricky. For example, if we had one empty bucket with
+ // tons of tombstones, failing lookups (e.g. for insertion) would have to
+ // probe almost the entire table until it found the empty bucket. If the
+ // table completely filled with tombstones, no lookup would ever succeed,
+ // causing infinite loops in lookup.
+ if (NumEntries*4 >= NumBuckets*3 ||
+ NumBuckets-(NumEntries+NumTombstones) < NumBuckets/8) {
+ this->grow(NumBuckets * 2);
+ LookupBucketFor(Key, TheBucket);
+ }
+ ++NumEntries;
+
+ // If we are writing over a tombstone, remember this.
+ if (!KeyInfoT::isEqual(TheBucket->first, getEmptyKey()))
+ --NumTombstones;
+
+ TheBucket->first = Key;
+ new (&TheBucket->second) ValueT(Value);
+ return TheBucket;
+ }
+
+ static unsigned getHashValue(const KeyT &Val) {
+ return KeyInfoT::getHashValue(Val);
+ }
+ static const KeyT getEmptyKey() {
+ return KeyInfoT::getEmptyKey();
+ }
+ static const KeyT getTombstoneKey() {
+ return KeyInfoT::getTombstoneKey();
+ }
+
+ /// LookupBucketFor - Lookup the appropriate bucket for Val, returning it in
+ /// FoundBucket. If the bucket contains the key and a value, this returns
+ /// true, otherwise it returns a bucket with an empty marker or tombstone and
+ /// returns false.
+ bool LookupBucketFor(const KeyT &Val, BucketT *&FoundBucket) const {
+ unsigned BucketNo = getHashValue(Val);
+ unsigned ProbeAmt = 1;
+ BucketT *BucketsPtr = Buckets;
+
+ // FoundTombstone - Keep track of whether we find a tombstone while probing.
+ BucketT *FoundTombstone = 0;
+ const KeyT EmptyKey = getEmptyKey();
+ const KeyT TombstoneKey = getTombstoneKey();
+ assert(!KeyInfoT::isEqual(Val, EmptyKey) &&
+ !KeyInfoT::isEqual(Val, TombstoneKey) &&
+ "Empty/Tombstone value shouldn't be inserted into map!");
+
+ while (1) {
+ BucketT *ThisBucket = BucketsPtr + (BucketNo & (NumBuckets-1));
+ // Found Val's bucket? If so, return it.
+ if (KeyInfoT::isEqual(ThisBucket->first, Val)) {
+ FoundBucket = ThisBucket;
+ return true;
+ }
+
+ // If we found an empty bucket, the key doesn't exist in the set.
+ // Insert it and return the default value.
+ if (KeyInfoT::isEqual(ThisBucket->first, EmptyKey)) {
+ // If we've already seen a tombstone while probing, fill it in instead
+ // of the empty bucket we eventually probed to.
+ if (FoundTombstone) ThisBucket = FoundTombstone;
+ FoundBucket = FoundTombstone ? FoundTombstone : ThisBucket;
+ return false;
+ }
+
+ // If this is a tombstone, remember it. If Val ends up not in the map, we
+ // prefer to return it than something that would require more probing.
+ if (KeyInfoT::isEqual(ThisBucket->first, TombstoneKey) && !FoundTombstone)
+ FoundTombstone = ThisBucket; // Remember the first tombstone found.
+
+ // Otherwise, it's a hash collision or a tombstone, continue quadratic
+ // probing.
+ BucketNo += ProbeAmt++;
+ }
+ }
+
+ void init(unsigned InitBuckets) {
+ NumEntries = 0;
+ NumTombstones = 0;
+ NumBuckets = InitBuckets;
+ assert(InitBuckets && (InitBuckets & (InitBuckets-1)) == 0 &&
+ "# initial buckets must be a power of two!");
+ Buckets = static_cast<BucketT*>(operator new(sizeof(BucketT)*InitBuckets));
+ // Initialize all the keys to EmptyKey.
+ const KeyT EmptyKey = getEmptyKey();
+ for (unsigned i = 0; i != InitBuckets; ++i)
+ new (&Buckets[i].first) KeyT(EmptyKey);
+ }
+
+ void grow(unsigned AtLeast) {
+ unsigned OldNumBuckets = NumBuckets;
+ BucketT *OldBuckets = Buckets;
+
+ // Double the number of buckets.
+ while (NumBuckets <= AtLeast)
+ NumBuckets <<= 1;
+ NumTombstones = 0;
+ Buckets = static_cast<BucketT*>(operator new(sizeof(BucketT)*NumBuckets));
+
+ // Initialize all the keys to EmptyKey.
+ const KeyT EmptyKey = getEmptyKey();
+ for (unsigned i = 0, e = NumBuckets; i != e; ++i)
+ new (&Buckets[i].first) KeyT(EmptyKey);
+
+ // Insert all the old elements.
+ const KeyT TombstoneKey = getTombstoneKey();
+ for (BucketT *B = OldBuckets, *E = OldBuckets+OldNumBuckets; B != E; ++B) {
+ if (!KeyInfoT::isEqual(B->first, EmptyKey) &&
+ !KeyInfoT::isEqual(B->first, TombstoneKey)) {
+ // Insert the key/value into the new table.
+ BucketT *DestBucket;
+ bool FoundVal = LookupBucketFor(B->first, DestBucket);
+ FoundVal = FoundVal; // silence warning.
+ assert(!FoundVal && "Key already in new map?");
+ DestBucket->first = B->first;
+ new (&DestBucket->second) ValueT(B->second);
+
+ // Free the value.
+ B->second.~ValueT();
+ }
+ B->first.~KeyT();
+ }
+
+ // Free the old table.
+ operator delete(OldBuckets);
+ }
+
+ void shrink_and_clear() {
+ unsigned OldNumBuckets = NumBuckets;
+ BucketT *OldBuckets = Buckets;
+
+ // Reduce the number of buckets.
+ NumBuckets = NumEntries > 32 ? 1 << (Log2_32_Ceil(NumEntries) + 1)
+ : 64;
+ NumTombstones = 0;
+ Buckets = static_cast<BucketT*>(operator new(sizeof(BucketT)*NumBuckets));
+
+ // Initialize all the keys to EmptyKey.
+ const KeyT EmptyKey = getEmptyKey();
+ for (unsigned i = 0, e = NumBuckets; i != e; ++i)
+ new (&Buckets[i].first) KeyT(EmptyKey);
+
+ // Free the old buckets.
+ const KeyT TombstoneKey = getTombstoneKey();
+ for (BucketT *B = OldBuckets, *E = OldBuckets+OldNumBuckets; B != E; ++B) {
+ if (!KeyInfoT::isEqual(B->first, EmptyKey) &&
+ !KeyInfoT::isEqual(B->first, TombstoneKey)) {
+ // Free the value.
+ B->second.~ValueT();
+ }
+ B->first.~KeyT();
+ }
+
+ // Free the old table.
+ operator delete(OldBuckets);
+
+ NumEntries = 0;
+ }
+};
+
+template<typename KeyT, typename ValueT, typename KeyInfoT, typename ValueInfoT>
+class DenseMapIterator {
+ typedef std::pair<KeyT, ValueT> BucketT;
+protected:
+ const BucketT *Ptr, *End;
+public:
+ DenseMapIterator(void) : Ptr(0), End(0) {}
+
+ DenseMapIterator(const BucketT *Pos, const BucketT *E) : Ptr(Pos), End(E) {
+ AdvancePastEmptyBuckets();
+ }
+
+ std::pair<KeyT, ValueT> &operator*() const {
+ return *const_cast<BucketT*>(Ptr);
+ }
+ std::pair<KeyT, ValueT> *operator->() const {
+ return const_cast<BucketT*>(Ptr);
+ }
+
+ bool operator==(const DenseMapIterator &RHS) const {
+ return Ptr == RHS.Ptr;
+ }
+ bool operator!=(const DenseMapIterator &RHS) const {
+ return Ptr != RHS.Ptr;
+ }
+
+ inline DenseMapIterator& operator++() { // Preincrement
+ ++Ptr;
+ AdvancePastEmptyBuckets();
+ return *this;
+ }
+ DenseMapIterator operator++(int) { // Postincrement
+ DenseMapIterator tmp = *this; ++*this; return tmp;
+ }
+
+private:
+ void AdvancePastEmptyBuckets() {
+ const KeyT Empty = KeyInfoT::getEmptyKey();
+ const KeyT Tombstone = KeyInfoT::getTombstoneKey();
+
+ while (Ptr != End &&
+ (KeyInfoT::isEqual(Ptr->first, Empty) ||
+ KeyInfoT::isEqual(Ptr->first, Tombstone)))
+ ++Ptr;
+ }
+};
+
+template<typename KeyT, typename ValueT, typename KeyInfoT, typename ValueInfoT>
+class DenseMapConstIterator : public DenseMapIterator<KeyT, ValueT, KeyInfoT> {
+public:
+ DenseMapConstIterator(void) : DenseMapIterator<KeyT, ValueT, KeyInfoT>() {}
+ DenseMapConstIterator(const std::pair<KeyT, ValueT> *Pos,
+ const std::pair<KeyT, ValueT> *E)
+ : DenseMapIterator<KeyT, ValueT, KeyInfoT>(Pos, E) {
+ }
+ const std::pair<KeyT, ValueT> &operator*() const {
+ return *this->Ptr;
+ }
+ const std::pair<KeyT, ValueT> *operator->() const {
+ return this->Ptr;
+ }