+private:
+ unsigned getNumEntries() const {
+ return NumEntries;
+ }
+ void setNumEntries(unsigned Num) {
+ NumEntries = Num;
+ }
+
+ unsigned getNumTombstones() const {
+ return NumTombstones;
+ }
+ void setNumTombstones(unsigned Num) {
+ NumTombstones = Num;
+ }
+
+ BucketT *getBuckets() const {
+ return Buckets;
+ }
+
+ unsigned getNumBuckets() const {
+ return NumBuckets;
+ }
+
+ bool allocateBuckets(unsigned Num) {
+ NumBuckets = Num;
+ if (NumBuckets == 0) {
+ Buckets = nullptr;
+ return false;
+ }
+
+ Buckets = static_cast<BucketT*>(operator new(sizeof(BucketT) * NumBuckets));
+ return true;
+ }
+};
+
+template <typename KeyT, typename ValueT, unsigned InlineBuckets = 4,
+ typename KeyInfoT = DenseMapInfo<KeyT>,
+ typename BucketT = detail::DenseMapPair<KeyT, ValueT>>
+class SmallDenseMap
+ : public DenseMapBase<
+ SmallDenseMap<KeyT, ValueT, InlineBuckets, KeyInfoT, BucketT>, KeyT,
+ ValueT, KeyInfoT, BucketT> {
+ // Lift some types from the dependent base class into this class for
+ // simplicity of referring to them.
+ typedef DenseMapBase<SmallDenseMap, KeyT, ValueT, KeyInfoT, BucketT> BaseT;
+ friend class DenseMapBase<SmallDenseMap, KeyT, ValueT, KeyInfoT, BucketT>;
+
+ unsigned Small : 1;
+ unsigned NumEntries : 31;
+ unsigned NumTombstones;
+
+ struct LargeRep {
+ BucketT *Buckets;
+ unsigned NumBuckets;
+ };
+
+ /// A "union" of an inline bucket array and the struct representing
+ /// a large bucket. This union will be discriminated by the 'Small' bit.
+ AlignedCharArrayUnion<BucketT[InlineBuckets], LargeRep> storage;
+
+public:
+ explicit SmallDenseMap(unsigned NumInitBuckets = 0) {
+ init(NumInitBuckets);
+ }
+
+ SmallDenseMap(const SmallDenseMap &other) : BaseT() {
+ init(0);
+ copyFrom(other);
+ }
+
+ SmallDenseMap(SmallDenseMap &&other) : BaseT() {
+ init(0);
+ swap(other);
+ }
+
+ template<typename InputIt>
+ SmallDenseMap(const InputIt &I, const InputIt &E) {
+ init(NextPowerOf2(std::distance(I, E)));
+ this->insert(I, E);
+ }
+
+ ~SmallDenseMap() {
+ this->destroyAll();
+ deallocateBuckets();
+ }
+
+ void swap(SmallDenseMap& RHS) {
+ unsigned TmpNumEntries = RHS.NumEntries;
+ RHS.NumEntries = NumEntries;
+ NumEntries = TmpNumEntries;
+ std::swap(NumTombstones, RHS.NumTombstones);
+
+ const KeyT EmptyKey = this->getEmptyKey();
+ const KeyT TombstoneKey = this->getTombstoneKey();
+ if (Small && RHS.Small) {
+ // If we're swapping inline bucket arrays, we have to cope with some of
+ // the tricky bits of DenseMap's storage system: the buckets are not
+ // fully initialized. Thus we swap every key, but we may have
+ // a one-directional move of the value.
+ for (unsigned i = 0, e = InlineBuckets; i != e; ++i) {
+ BucketT *LHSB = &getInlineBuckets()[i],
+ *RHSB = &RHS.getInlineBuckets()[i];
+ bool hasLHSValue = (!KeyInfoT::isEqual(LHSB->getFirst(), EmptyKey) &&
+ !KeyInfoT::isEqual(LHSB->getFirst(), TombstoneKey));
+ bool hasRHSValue = (!KeyInfoT::isEqual(RHSB->getFirst(), EmptyKey) &&
+ !KeyInfoT::isEqual(RHSB->getFirst(), TombstoneKey));
+ if (hasLHSValue && hasRHSValue) {
+ // Swap together if we can...
+ std::swap(*LHSB, *RHSB);
+ continue;
+ }
+ // Swap separately and handle any assymetry.
+ std::swap(LHSB->getFirst(), RHSB->getFirst());
+ if (hasLHSValue) {
+ new (&RHSB->getSecond()) ValueT(std::move(LHSB->getSecond()));
+ LHSB->getSecond().~ValueT();
+ } else if (hasRHSValue) {
+ new (&LHSB->getSecond()) ValueT(std::move(RHSB->getSecond()));
+ RHSB->getSecond().~ValueT();
+ }
+ }
+ return;
+ }
+ if (!Small && !RHS.Small) {
+ std::swap(getLargeRep()->Buckets, RHS.getLargeRep()->Buckets);
+ std::swap(getLargeRep()->NumBuckets, RHS.getLargeRep()->NumBuckets);
+ return;
+ }
+
+ SmallDenseMap &SmallSide = Small ? *this : RHS;
+ SmallDenseMap &LargeSide = Small ? RHS : *this;
+
+ // First stash the large side's rep and move the small side across.
+ LargeRep TmpRep = std::move(*LargeSide.getLargeRep());
+ LargeSide.getLargeRep()->~LargeRep();
+ LargeSide.Small = true;
+ // This is similar to the standard move-from-old-buckets, but the bucket
+ // count hasn't actually rotated in this case. So we have to carefully
+ // move construct the keys and values into their new locations, but there
+ // is no need to re-hash things.
+ for (unsigned i = 0, e = InlineBuckets; i != e; ++i) {
+ BucketT *NewB = &LargeSide.getInlineBuckets()[i],
+ *OldB = &SmallSide.getInlineBuckets()[i];
+ new (&NewB->getFirst()) KeyT(std::move(OldB->getFirst()));
+ OldB->getFirst().~KeyT();
+ if (!KeyInfoT::isEqual(NewB->getFirst(), EmptyKey) &&
+ !KeyInfoT::isEqual(NewB->getFirst(), TombstoneKey)) {
+ new (&NewB->getSecond()) ValueT(std::move(OldB->getSecond()));
+ OldB->getSecond().~ValueT();
+ }
+ }
+
+ // The hard part of moving the small buckets across is done, just move
+ // the TmpRep into its new home.
+ SmallSide.Small = false;
+ new (SmallSide.getLargeRep()) LargeRep(std::move(TmpRep));
+ }
+
+ SmallDenseMap& operator=(const SmallDenseMap& other) {
+ if (&other != this)
+ copyFrom(other);
+ return *this;
+ }
+
+ SmallDenseMap& operator=(SmallDenseMap &&other) {
+ this->destroyAll();
+ deallocateBuckets();
+ init(0);
+ swap(other);
+ return *this;
+ }
+
+ void copyFrom(const SmallDenseMap& other) {
+ this->destroyAll();
+ deallocateBuckets();
+ Small = true;
+ if (other.getNumBuckets() > InlineBuckets) {
+ Small = false;
+ new (getLargeRep()) LargeRep(allocateBuckets(other.getNumBuckets()));
+ }
+ this->BaseT::copyFrom(other);
+ }
+
+ void init(unsigned InitBuckets) {
+ Small = true;
+ if (InitBuckets > InlineBuckets) {
+ Small = false;
+ new (getLargeRep()) LargeRep(allocateBuckets(InitBuckets));
+ }
+ this->BaseT::initEmpty();
+ }
+
+ void grow(unsigned AtLeast) {
+ if (AtLeast >= InlineBuckets)
+ AtLeast = std::max<unsigned>(64, NextPowerOf2(AtLeast-1));
+
+ if (Small) {
+ if (AtLeast < InlineBuckets)
+ return; // Nothing to do.
+
+ // First move the inline buckets into a temporary storage.
+ AlignedCharArrayUnion<BucketT[InlineBuckets]> TmpStorage;
+ BucketT *TmpBegin = reinterpret_cast<BucketT *>(TmpStorage.buffer);
+ BucketT *TmpEnd = TmpBegin;
+
+ // Loop over the buckets, moving non-empty, non-tombstones into the
+ // temporary storage. Have the loop move the TmpEnd forward as it goes.
+ const KeyT EmptyKey = this->getEmptyKey();
+ const KeyT TombstoneKey = this->getTombstoneKey();
+ for (BucketT *P = getBuckets(), *E = P + InlineBuckets; P != E; ++P) {
+ if (!KeyInfoT::isEqual(P->getFirst(), EmptyKey) &&
+ !KeyInfoT::isEqual(P->getFirst(), TombstoneKey)) {
+ assert(size_t(TmpEnd - TmpBegin) < InlineBuckets &&
+ "Too many inline buckets!");
+ new (&TmpEnd->getFirst()) KeyT(std::move(P->getFirst()));
+ new (&TmpEnd->getSecond()) ValueT(std::move(P->getSecond()));
+ ++TmpEnd;
+ P->getSecond().~ValueT();
+ }
+ P->getFirst().~KeyT();