-//===- llvm/ADT/DenseMap.h - A dense map implmentation ----------*- C++ -*-===//
-//
+//===- llvm/ADT/DenseMap.h - Dense probed hash table ------------*- C++ -*-===//
+//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
//===----------------------------------------------------------------------===//
//
-// This file implements a dense map. A dense map template takes two
-// types. The first is the mapped type and the second is a functor
-// that maps its argument to a size_t. On instantiation a "null" value
-// can be provided to be used as a "does not exist" indicator in the
-// map. A member function grow() is provided that given the value of
-// the maximally indexed key (the argument of the functor) makes sure
-// the map has enough space for it.
+// This file defines the DenseMap class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_DENSEMAP_H
#define LLVM_ADT_DENSEMAP_H
-#include <functional>
-#include <vector>
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/AlignOf.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/PointerLikeTypeTraits.h"
+#include "llvm/Support/type_traits.h"
+#include "llvm/ADT/DenseMapInfo.h"
+#include <algorithm>
+#include <iterator>
+#include <new>
+#include <utility>
+#include <cassert>
+#include <climits>
+#include <cstddef>
+#include <cstring>
namespace llvm {
- struct IdentityFunctor : std::unary_function<unsigned, unsigned> {
- unsigned operator()(unsigned Index) const {
- return Index;
+template<typename KeyT, typename ValueT,
+ typename KeyInfoT = DenseMapInfo<KeyT>,
+ bool IsConst = false>
+class DenseMapIterator;
+
+template<typename DerivedT,
+ typename KeyT, typename ValueT, typename KeyInfoT>
+class DenseMapBase {
+protected:
+ typedef std::pair<KeyT, ValueT> BucketT;
+
+public:
+ typedef KeyT key_type;
+ typedef ValueT mapped_type;
+ typedef BucketT value_type;
+
+ typedef DenseMapIterator<KeyT, ValueT, KeyInfoT> iterator;
+ typedef DenseMapIterator<KeyT, ValueT,
+ KeyInfoT, true> const_iterator;
+ inline iterator begin() {
+ // When the map is empty, avoid the overhead of AdvancePastEmptyBuckets().
+ return empty() ? end() : iterator(getBuckets(), getBucketsEnd());
+ }
+ inline iterator end() {
+ return iterator(getBucketsEnd(), getBucketsEnd(), true);
+ }
+ inline const_iterator begin() const {
+ return empty() ? end() : const_iterator(getBuckets(), getBucketsEnd());
+ }
+ inline const_iterator end() const {
+ return const_iterator(getBucketsEnd(), getBucketsEnd(), true);
+ }
+
+ bool empty() const { return getNumEntries() == 0; }
+ unsigned size() const { return getNumEntries(); }
+
+ /// Grow the densemap so that it has at least Size buckets. Does not shrink
+ void resize(size_t Size) {
+ if (Size > getNumBuckets())
+ grow(Size);
+ }
+
+ void clear() {
+ if (getNumEntries() == 0 && getNumTombstones() == 0) return;
+
+ // If the capacity of the array is huge, and the # elements used is small,
+ // shrink the array.
+ if (getNumEntries() * 4 < getNumBuckets() && getNumBuckets() > 64) {
+ shrink_and_clear();
+ return;
}
- };
- template <typename T, typename ToIndexT = IdentityFunctor>
- class DenseMap {
- typedef typename ToIndexT::argument_type IndexT;
- typedef std::vector<T> StorageT;
- StorageT storage_;
- T nullVal_;
- ToIndexT toIndex_;
+ const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey();
+ for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) {
+ if (!KeyInfoT::isEqual(P->first, EmptyKey)) {
+ if (!KeyInfoT::isEqual(P->first, TombstoneKey)) {
+ P->second.~ValueT();
+ decrementNumEntries();
+ }
+ P->first = EmptyKey;
+ }
+ }
+ assert(getNumEntries() == 0 && "Node count imbalance!");
+ setNumTombstones(0);
+ }
+
+ /// count - Return true if the specified key is in the map.
+ bool count(const KeyT &Val) const {
+ const BucketT *TheBucket;
+ return LookupBucketFor(Val, TheBucket);
+ }
+
+ iterator find(const KeyT &Val) {
+ BucketT *TheBucket;
+ if (LookupBucketFor(Val, TheBucket))
+ return iterator(TheBucket, getBucketsEnd(), true);
+ return end();
+ }
+ const_iterator find(const KeyT &Val) const {
+ const BucketT *TheBucket;
+ if (LookupBucketFor(Val, TheBucket))
+ return const_iterator(TheBucket, getBucketsEnd(), true);
+ return end();
+ }
+
+ /// Alternate version of find() which allows a different, and possibly
+ /// less expensive, key type.
+ /// The DenseMapInfo is responsible for supplying methods
+ /// getHashValue(LookupKeyT) and isEqual(LookupKeyT, KeyT) for each key
+ /// type used.
+ template<class LookupKeyT>
+ iterator find_as(const LookupKeyT &Val) {
+ BucketT *TheBucket;
+ if (LookupBucketFor(Val, TheBucket))
+ return iterator(TheBucket, getBucketsEnd(), true);
+ return end();
+ }
+ template<class LookupKeyT>
+ const_iterator find_as(const LookupKeyT &Val) const {
+ const BucketT *TheBucket;
+ if (LookupBucketFor(Val, TheBucket))
+ return const_iterator(TheBucket, getBucketsEnd(), true);
+ return end();
+ }
+
+ /// lookup - Return the entry for the specified key, or a default
+ /// constructed value if no such entry exists.
+ ValueT lookup(const KeyT &Val) const {
+ const BucketT *TheBucket;
+ if (LookupBucketFor(Val, TheBucket))
+ return TheBucket->second;
+ return ValueT();
+ }
+
+ // Inserts key,value pair into the map if the key isn't already in the map.
+ // If the key is already in the map, it returns false and doesn't update the
+ // value.
+ std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) {
+ BucketT *TheBucket;
+ if (LookupBucketFor(KV.first, TheBucket))
+ return std::make_pair(iterator(TheBucket, getBucketsEnd(), true),
+ false); // Already in map.
+
+ // Otherwise, insert the new element.
+ TheBucket = InsertIntoBucket(KV.first, KV.second, TheBucket);
+ return std::make_pair(iterator(TheBucket, getBucketsEnd(), true), true);
+ }
+
+ /// insert - Range insertion of pairs.
+ template<typename InputIt>
+ void insert(InputIt I, InputIt E) {
+ for (; I != E; ++I)
+ insert(*I);
+ }
+
+
+ bool erase(const KeyT &Val) {
+ BucketT *TheBucket;
+ if (!LookupBucketFor(Val, TheBucket))
+ return false; // not in map.
- public:
- DenseMap() : nullVal_(T()) { }
+ TheBucket->second.~ValueT();
+ TheBucket->first = getTombstoneKey();
+ decrementNumEntries();
+ incrementNumTombstones();
+ return true;
+ }
+ void erase(iterator I) {
+ BucketT *TheBucket = &*I;
+ TheBucket->second.~ValueT();
+ TheBucket->first = getTombstoneKey();
+ decrementNumEntries();
+ incrementNumTombstones();
+ }
- explicit DenseMap(const T& val) : nullVal_(val) { }
+ value_type& FindAndConstruct(const KeyT &Key) {
+ BucketT *TheBucket;
+ if (LookupBucketFor(Key, TheBucket))
+ return *TheBucket;
- typename StorageT::reference operator[](IndexT n) {
- assert(toIndex_(n) < storage_.size() && "index out of bounds!");
- return storage_[toIndex_(n)];
+ return *InsertIntoBucket(Key, ValueT(), TheBucket);
+ }
+
+ ValueT &operator[](const KeyT &Key) {
+ return FindAndConstruct(Key).second;
+ }
+
+#if LLVM_USE_RVALUE_REFERENCES
+ value_type& FindAndConstruct(KeyT &&Key) {
+ BucketT *TheBucket;
+ if (LookupBucketFor(Key, TheBucket))
+ return *TheBucket;
+
+ return *InsertIntoBucket(Key, ValueT(), TheBucket);
+ }
+
+ ValueT &operator[](KeyT &&Key) {
+ return FindAndConstruct(Key).second;
+ }
+#endif
+
+ /// isPointerIntoBucketsArray - Return true if the specified pointer points
+ /// somewhere into the DenseMap's array of buckets (i.e. either to a key or
+ /// value in the DenseMap).
+ bool isPointerIntoBucketsArray(const void *Ptr) const {
+ return Ptr >= getBuckets() && Ptr < getBucketsEnd();
+ }
+
+ /// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets
+ /// array. In conjunction with the previous method, this can be used to
+ /// determine whether an insertion caused the DenseMap to reallocate.
+ const void *getPointerIntoBucketsArray() const { return getBuckets(); }
+
+protected:
+ DenseMapBase() {}
+
+ void destroyAll() {
+ if (getNumBuckets() == 0) // Nothing to do.
+ return;
+
+ const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey();
+ for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) {
+ if (!KeyInfoT::isEqual(P->first, EmptyKey) &&
+ !KeyInfoT::isEqual(P->first, TombstoneKey))
+ P->second.~ValueT();
+ P->first.~KeyT();
}
- typename StorageT::const_reference operator[](IndexT n) const {
- assert(toIndex_(n) < storage_.size() && "index out of bounds!");
- return storage_[toIndex_(n)];
+#ifndef NDEBUG
+ memset((void*)getBuckets(), 0x5a, sizeof(BucketT)*getNumBuckets());
+#endif
+ }
+
+ void initEmpty() {
+ setNumEntries(0);
+ setNumTombstones(0);
+
+ assert((getNumBuckets() & (getNumBuckets()-1)) == 0 &&
+ "# initial buckets must be a power of two!");
+ const KeyT EmptyKey = getEmptyKey();
+ for (BucketT *B = getBuckets(), *E = getBucketsEnd(); B != E; ++B)
+ new (&B->first) KeyT(EmptyKey);
+ }
+
+ void moveFromOldBuckets(BucketT *OldBucketsBegin, BucketT *OldBucketsEnd) {
+ initEmpty();
+
+ // Insert all the old elements.
+ const KeyT EmptyKey = getEmptyKey();
+ const KeyT TombstoneKey = getTombstoneKey();
+ for (BucketT *B = OldBucketsBegin, *E = OldBucketsEnd; 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);
+ (void)FoundVal; // silence warning.
+ assert(!FoundVal && "Key already in new map?");
+ DestBucket->first = llvm_move(B->first);
+ new (&DestBucket->second) ValueT(llvm_move(B->second));
+ incrementNumEntries();
+
+ // Free the value.
+ B->second.~ValueT();
+ }
+ B->first.~KeyT();
}
- void clear() {
- storage_.clear();
+#ifndef NDEBUG
+ if (OldBucketsBegin != OldBucketsEnd)
+ memset((void*)OldBucketsBegin, 0x5a,
+ sizeof(BucketT) * (OldBucketsEnd - OldBucketsBegin));
+#endif
+ }
+
+ template <typename OtherBaseT>
+ void copyFrom(const DenseMapBase<OtherBaseT, KeyT, ValueT, KeyInfoT>& other) {
+ assert(getNumBuckets() == other.getNumBuckets());
+
+ setNumEntries(other.getNumEntries());
+ setNumTombstones(other.getNumTombstones());
+
+ if (isPodLike<KeyT>::value && isPodLike<ValueT>::value)
+ memcpy(getBuckets(), other.getBuckets(),
+ getNumBuckets() * sizeof(BucketT));
+ else
+ for (size_t i = 0; i < getNumBuckets(); ++i) {
+ new (&getBuckets()[i].first) KeyT(other.getBuckets()[i].first);
+ if (!KeyInfoT::isEqual(getBuckets()[i].first, getEmptyKey()) &&
+ !KeyInfoT::isEqual(getBuckets()[i].first, getTombstoneKey()))
+ new (&getBuckets()[i].second) ValueT(other.getBuckets()[i].second);
+ }
+ }
+
+ void swap(DenseMapBase& RHS) {
+ std::swap(getNumEntries(), RHS.getNumEntries());
+ std::swap(getNumTombstones(), RHS.getNumTombstones());
+ }
+
+ static unsigned getHashValue(const KeyT &Val) {
+ return KeyInfoT::getHashValue(Val);
+ }
+ template<typename LookupKeyT>
+ static unsigned getHashValue(const LookupKeyT &Val) {
+ return KeyInfoT::getHashValue(Val);
+ }
+ static const KeyT getEmptyKey() {
+ return KeyInfoT::getEmptyKey();
+ }
+ static const KeyT getTombstoneKey() {
+ return KeyInfoT::getTombstoneKey();
+ }
+
+private:
+ unsigned getNumEntries() const {
+ return static_cast<const DerivedT *>(this)->getNumEntries();
+ }
+ void setNumEntries(unsigned Num) {
+ static_cast<DerivedT *>(this)->setNumEntries(Num);
+ }
+ void incrementNumEntries() {
+ setNumEntries(getNumEntries() + 1);
+ }
+ void decrementNumEntries() {
+ setNumEntries(getNumEntries() - 1);
+ }
+ unsigned getNumTombstones() const {
+ return static_cast<const DerivedT *>(this)->getNumTombstones();
+ }
+ void setNumTombstones(unsigned Num) {
+ static_cast<DerivedT *>(this)->setNumTombstones(Num);
+ }
+ void incrementNumTombstones() {
+ setNumTombstones(getNumTombstones() + 1);
+ }
+ void decrementNumTombstones() {
+ setNumTombstones(getNumTombstones() - 1);
+ }
+ const BucketT *getBuckets() const {
+ return static_cast<const DerivedT *>(this)->getBuckets();
+ }
+ BucketT *getBuckets() {
+ return static_cast<DerivedT *>(this)->getBuckets();
+ }
+ unsigned getNumBuckets() const {
+ return static_cast<const DerivedT *>(this)->getNumBuckets();
+ }
+ BucketT *getBucketsEnd() {
+ return getBuckets() + getNumBuckets();
+ }
+ const BucketT *getBucketsEnd() const {
+ return getBuckets() + getNumBuckets();
+ }
+
+ void grow(unsigned AtLeast) {
+ static_cast<DerivedT *>(this)->grow(AtLeast);
+ }
+
+ void shrink_and_clear() {
+ static_cast<DerivedT *>(this)->shrink_and_clear();
+ }
+
+
+ BucketT *InsertIntoBucket(const KeyT &Key, const ValueT &Value,
+ BucketT *TheBucket) {
+ TheBucket = InsertIntoBucketImpl(Key, TheBucket);
+
+ TheBucket->first = Key;
+ new (&TheBucket->second) ValueT(Value);
+ return TheBucket;
+ }
+
+#if LLVM_USE_RVALUE_REFERENCES
+ BucketT *InsertIntoBucket(const KeyT &Key, ValueT &&Value,
+ BucketT *TheBucket) {
+ TheBucket = InsertIntoBucketImpl(Key, TheBucket);
+
+ TheBucket->first = Key;
+ new (&TheBucket->second) ValueT(std::move(Value));
+ return TheBucket;
+ }
+
+ BucketT *InsertIntoBucket(KeyT &&Key, ValueT &&Value, BucketT *TheBucket) {
+ TheBucket = InsertIntoBucketImpl(Key, TheBucket);
+
+ TheBucket->first = std::move(Key);
+ new (&TheBucket->second) ValueT(std::move(Value));
+ return TheBucket;
+ }
+#endif
+
+ BucketT *InsertIntoBucketImpl(const KeyT &Key, 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.
+ unsigned NewNumEntries = getNumEntries() + 1;
+ unsigned NumBuckets = getNumBuckets();
+ if (NewNumEntries*4 >= NumBuckets*3) {
+ this->grow(NumBuckets * 2);
+ LookupBucketFor(Key, TheBucket);
+ NumBuckets = getNumBuckets();
}
+ if (NumBuckets-(NewNumEntries+getNumTombstones()) <= NumBuckets/8) {
+ this->grow(NumBuckets);
+ LookupBucketFor(Key, TheBucket);
+ }
+
+ // Only update the state after we've grown our bucket space appropriately
+ // so that when growing buckets we have self-consistent entry count.
+ incrementNumEntries();
+
+ // If we are writing over a tombstone, remember this.
+ if (!KeyInfoT::isEqual(TheBucket->first, getEmptyKey()))
+ decrementNumTombstones();
+
+ return TheBucket;
+ }
- void grow(IndexT n) {
- unsigned NewSize = toIndex_(n) + 1;
- if (NewSize > storage_.size())
- storage_.resize(NewSize, nullVal_);
+ /// 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.
+ template<typename LookupKeyT>
+ bool LookupBucketFor(const LookupKeyT &Val,
+ const BucketT *&FoundBucket) const {
+ const BucketT *BucketsPtr = getBuckets();
+ const unsigned NumBuckets = getNumBuckets();
+
+ if (NumBuckets == 0) {
+ FoundBucket = 0;
+ return false;
}
- typename StorageT::size_type size() const {
- return storage_.size();
+ // FoundTombstone - Keep track of whether we find a tombstone while probing.
+ const 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!");
+
+ unsigned BucketNo = getHashValue(Val) & (NumBuckets-1);
+ unsigned ProbeAmt = 1;
+ while (1) {
+ const BucketT *ThisBucket = BucketsPtr + BucketNo;
+ // Found Val's bucket? If so, return it.
+ if (KeyInfoT::isEqual(Val, ThisBucket->first)) {
+ 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++;
+ BucketNo &= (NumBuckets-1);
}
+ }
+
+ template <typename LookupKeyT>
+ bool LookupBucketFor(const LookupKeyT &Val, BucketT *&FoundBucket) {
+ const BucketT *ConstFoundBucket;
+ bool Result = const_cast<const DenseMapBase *>(this)
+ ->LookupBucketFor(Val, ConstFoundBucket);
+ FoundBucket = const_cast<BucketT *>(ConstFoundBucket);
+ return Result;
+ }
+
+public:
+ /// Return the approximate size (in bytes) of the actual map.
+ /// This is just the raw memory used by DenseMap.
+ /// If entries are pointers to objects, the size of the referenced objects
+ /// are not included.
+ size_t getMemorySize() const {
+ return getNumBuckets() * sizeof(BucketT);
+ }
+};
+
+template<typename KeyT, typename ValueT,
+ typename KeyInfoT = DenseMapInfo<KeyT> >
+class DenseMap
+ : public DenseMapBase<DenseMap<KeyT, ValueT, KeyInfoT>,
+ KeyT, ValueT, KeyInfoT> {
+ // Lift some types from the dependent base class into this class for
+ // simplicity of referring to them.
+ typedef DenseMapBase<DenseMap, KeyT, ValueT, KeyInfoT> BaseT;
+ typedef typename BaseT::BucketT BucketT;
+ friend class DenseMapBase<DenseMap, KeyT, ValueT, KeyInfoT>;
+
+ BucketT *Buckets;
+ unsigned NumEntries;
+ unsigned NumTombstones;
+ unsigned NumBuckets;
+
+public:
+ explicit DenseMap(unsigned NumInitBuckets = 0) {
+ init(NumInitBuckets);
+ }
+
+ DenseMap(const DenseMap &other) {
+ init(0);
+ copyFrom(other);
+ }
+
+#if LLVM_USE_RVALUE_REFERENCES
+ DenseMap(DenseMap &&other) {
+ init(0);
+ swap(other);
+ }
+#endif
+
+ template<typename InputIt>
+ DenseMap(const InputIt &I, const InputIt &E) {
+ init(NextPowerOf2(std::distance(I, E)));
+ this->insert(I, E);
+ }
+
+ ~DenseMap() {
+ this->destroyAll();
+ operator delete(Buckets);
+ }
+
+ void swap(DenseMap& RHS) {
+ std::swap(Buckets, RHS.Buckets);
+ std::swap(NumEntries, RHS.NumEntries);
+ std::swap(NumTombstones, RHS.NumTombstones);
+ std::swap(NumBuckets, RHS.NumBuckets);
+ }
+
+ DenseMap& operator=(const DenseMap& other) {
+ copyFrom(other);
+ return *this;
+ }
+
+#if LLVM_USE_RVALUE_REFERENCES
+ DenseMap& operator=(DenseMap &&other) {
+ this->destroyAll();
+ operator delete(Buckets);
+ init(0);
+ swap(other);
+ return *this;
+ }
+#endif
+
+ void copyFrom(const DenseMap& other) {
+ this->destroyAll();
+ operator delete(Buckets);
+ if (allocateBuckets(other.NumBuckets)) {
+ this->BaseT::copyFrom(other);
+ } else {
+ NumEntries = 0;
+ NumTombstones = 0;
+ }
+ }
+
+ void init(unsigned InitBuckets) {
+ if (allocateBuckets(InitBuckets)) {
+ this->BaseT::initEmpty();
+ } else {
+ NumEntries = 0;
+ NumTombstones = 0;
+ }
+ }
+
+ void grow(unsigned AtLeast) {
+ unsigned OldNumBuckets = NumBuckets;
+ BucketT *OldBuckets = Buckets;
+
+ allocateBuckets(std::max<unsigned>(64, NextPowerOf2(AtLeast)));
+ assert(Buckets);
+ if (!OldBuckets) {
+ this->BaseT::initEmpty();
+ return;
+ }
+
+ this->moveFromOldBuckets(OldBuckets, OldBuckets+OldNumBuckets);
+
+ // Free the old table.
+ operator delete(OldBuckets);
+ }
+
+ void shrink_and_clear() {
+ unsigned OldNumEntries = NumEntries;
+ this->destroyAll();
+
+ // Reduce the number of buckets.
+ unsigned NewNumBuckets = 0;
+ if (OldNumEntries)
+ NewNumBuckets = std::max(64, 1 << (Log2_32_Ceil(OldNumEntries) + 1));
+ if (NewNumBuckets == NumBuckets) {
+ this->BaseT::initEmpty();
+ return;
+ }
+
+ operator delete(Buckets);
+ init(NewNumBuckets);
+ }
+
+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 = 0;
+ 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> >
+class SmallDenseMap
+ : public DenseMapBase<SmallDenseMap<KeyT, ValueT, InlineBuckets, KeyInfoT>,
+ KeyT, ValueT, KeyInfoT> {
+ // Lift some types from the dependent base class into this class for
+ // simplicity of referring to them.
+ typedef DenseMapBase<SmallDenseMap, KeyT, ValueT, KeyInfoT> BaseT;
+ typedef typename BaseT::BucketT BucketT;
+ friend class DenseMapBase<SmallDenseMap, KeyT, ValueT, KeyInfoT>;
+
+ unsigned Small : 1;
+ unsigned NumEntries : 31;
+ unsigned NumTombstones;
+
+ struct LargeRep {
+ BucketT *Buckets;
+ unsigned NumBuckets;
};
-} // End llvm namespace
+ /// 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) {
+ init(0);
+ copyFrom(other);
+ }
+
+#if LLVM_USE_RVALUE_REFERENCES
+ SmallDenseMap(SmallDenseMap &&other) {
+ init(0);
+ swap(other);
+ }
+#endif
+
+ 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->first, EmptyKey) &&
+ !KeyInfoT::isEqual(LHSB->first, TombstoneKey));
+ bool hasRHSValue = (!KeyInfoT::isEqual(RHSB->first, EmptyKey) &&
+ !KeyInfoT::isEqual(RHSB->first, TombstoneKey));
+ if (hasLHSValue && hasRHSValue) {
+ // Swap together if we can...
+ std::swap(*LHSB, *RHSB);
+ continue;
+ }
+ // Swap separately and handle any assymetry.
+ std::swap(LHSB->first, RHSB->first);
+ if (hasLHSValue) {
+ new (&RHSB->second) ValueT(llvm_move(LHSB->second));
+ LHSB->second.~ValueT();
+ } else if (hasRHSValue) {
+ new (&LHSB->second) ValueT(llvm_move(RHSB->second));
+ RHSB->second.~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 = llvm_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->first) KeyT(llvm_move(OldB->first));
+ OldB->first.~KeyT();
+ if (!KeyInfoT::isEqual(NewB->first, EmptyKey) &&
+ !KeyInfoT::isEqual(NewB->first, TombstoneKey)) {
+ new (&NewB->second) ValueT(llvm_move(OldB->second));
+ OldB->second.~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(llvm_move(TmpRep));
+ }
+
+ SmallDenseMap& operator=(const SmallDenseMap& other) {
+ copyFrom(other);
+ return *this;
+ }
+
+#if LLVM_USE_RVALUE_REFERENCES
+ SmallDenseMap& operator=(SmallDenseMap &&other) {
+ this->destroyAll();
+ deallocateBuckets();
+ init(0);
+ swap(other);
+ return *this;
+ }
+#endif
+
+ void copyFrom(const SmallDenseMap& other) {
+ this->destroyAll();
+ deallocateBuckets();
+ Small = true;
+ if (other.getNumBuckets() > InlineBuckets) {
+ Small = false;
+ 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));
+
+ 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->first, EmptyKey) &&
+ !KeyInfoT::isEqual(P->first, TombstoneKey)) {
+ assert(size_t(TmpEnd - TmpBegin) < InlineBuckets &&
+ "Too many inline buckets!");
+ new (&TmpEnd->first) KeyT(llvm_move(P->first));
+ new (&TmpEnd->second) ValueT(llvm_move(P->second));
+ ++TmpEnd;
+ P->second.~ValueT();
+ }
+ P->first.~KeyT();
+ }
+
+ // Now make this map use the large rep, and move all the entries back
+ // into it.
+ Small = false;
+ new (getLargeRep()) LargeRep(allocateBuckets(AtLeast));
+ this->moveFromOldBuckets(TmpBegin, TmpEnd);
+ return;
+ }
+
+ LargeRep OldRep = llvm_move(*getLargeRep());
+ getLargeRep()->~LargeRep();
+ if (AtLeast <= InlineBuckets) {
+ Small = true;
+ } else {
+ new (getLargeRep()) LargeRep(allocateBuckets(AtLeast));
+ }
+
+ this->moveFromOldBuckets(OldRep.Buckets, OldRep.Buckets+OldRep.NumBuckets);
+
+ // Free the old table.
+ operator delete(OldRep.Buckets);
+ }
+
+ void shrink_and_clear() {
+ unsigned OldSize = this->size();
+ this->destroyAll();
+
+ // Reduce the number of buckets.
+ unsigned NewNumBuckets = 0;
+ if (OldSize) {
+ NewNumBuckets = 1 << (Log2_32_Ceil(OldSize) + 1);
+ if (NewNumBuckets > InlineBuckets && NewNumBuckets < 64u)
+ NewNumBuckets = 64;
+ }
+ if ((Small && NewNumBuckets <= InlineBuckets) ||
+ (!Small && NewNumBuckets == getLargeRep()->NumBuckets)) {
+ this->BaseT::initEmpty();
+ return;
+ }
+
+ deallocateBuckets();
+ init(NewNumBuckets);
+ }
+
+private:
+ unsigned getNumEntries() const {
+ return NumEntries;
+ }
+ void setNumEntries(unsigned Num) {
+ assert(Num < INT_MAX && "Cannot support more than INT_MAX entries");
+ NumEntries = Num;
+ }
+
+ unsigned getNumTombstones() const {
+ return NumTombstones;
+ }
+ void setNumTombstones(unsigned Num) {
+ NumTombstones = Num;
+ }
+
+ const BucketT *getInlineBuckets() const {
+ assert(Small);
+ // Note that this cast does not violate aliasing rules as we assert that
+ // the memory's dynamic type is the small, inline bucket buffer, and the
+ // 'storage.buffer' static type is 'char *'.
+ return reinterpret_cast<const BucketT *>(storage.buffer);
+ }
+ BucketT *getInlineBuckets() {
+ return const_cast<BucketT *>(
+ const_cast<const SmallDenseMap *>(this)->getInlineBuckets());
+ }
+ const LargeRep *getLargeRep() const {
+ assert(!Small);
+ // Note, same rule about aliasing as with getInlineBuckets.
+ return reinterpret_cast<const LargeRep *>(storage.buffer);
+ }
+ LargeRep *getLargeRep() {
+ return const_cast<LargeRep *>(
+ const_cast<const SmallDenseMap *>(this)->getLargeRep());
+ }
+
+ const BucketT *getBuckets() const {
+ return Small ? getInlineBuckets() : getLargeRep()->Buckets;
+ }
+ BucketT *getBuckets() {
+ return const_cast<BucketT *>(
+ const_cast<const SmallDenseMap *>(this)->getBuckets());
+ }
+ unsigned getNumBuckets() const {
+ return Small ? InlineBuckets : getLargeRep()->NumBuckets;
+ }
+
+ void deallocateBuckets() {
+ if (Small)
+ return;
+
+ operator delete(getLargeRep()->Buckets);
+ getLargeRep()->~LargeRep();
+ }
+
+ LargeRep allocateBuckets(unsigned Num) {
+ assert(Num > InlineBuckets && "Must allocate more buckets than are inline");
+ LargeRep Rep = {
+ static_cast<BucketT*>(operator new(sizeof(BucketT) * Num)), Num
+ };
+ return Rep;
+ }
+};
+
+template<typename KeyT, typename ValueT,
+ typename KeyInfoT, bool IsConst>
+class DenseMapIterator {
+ typedef std::pair<KeyT, ValueT> Bucket;
+ typedef DenseMapIterator<KeyT, ValueT,
+ KeyInfoT, true> ConstIterator;
+ friend class DenseMapIterator<KeyT, ValueT, KeyInfoT, true>;
+public:
+ typedef ptrdiff_t difference_type;
+ typedef typename conditional<IsConst, const Bucket, Bucket>::type value_type;
+ typedef value_type *pointer;
+ typedef value_type &reference;
+ typedef std::forward_iterator_tag iterator_category;
+private:
+ pointer Ptr, End;
+public:
+ DenseMapIterator() : Ptr(0), End(0) {}
+
+ DenseMapIterator(pointer Pos, pointer E, bool NoAdvance = false)
+ : Ptr(Pos), End(E) {
+ if (!NoAdvance) AdvancePastEmptyBuckets();
+ }
+
+ // If IsConst is true this is a converting constructor from iterator to
+ // const_iterator and the default copy constructor is used.
+ // Otherwise this is a copy constructor for iterator.
+ DenseMapIterator(const DenseMapIterator<KeyT, ValueT,
+ KeyInfoT, false>& I)
+ : Ptr(I.Ptr), End(I.End) {}
+
+ reference operator*() const {
+ return *Ptr;
+ }
+ pointer operator->() const {
+ return Ptr;
+ }
+
+ bool operator==(const ConstIterator &RHS) const {
+ return Ptr == RHS.operator->();
+ }
+ bool operator!=(const ConstIterator &RHS) const {
+ return Ptr != RHS.operator->();
+ }
+
+ 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>
+static inline size_t
+capacity_in_bytes(const DenseMap<KeyT, ValueT, KeyInfoT> &X) {
+ return X.getMemorySize();
+}
+
+} // end namespace llvm
#endif