//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Chris Lattner 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.
//
//===----------------------------------------------------------------------===//
//
#ifndef LLVM_ADT_DENSEMAP_H
#define LLVM_ADT_DENSEMAP_H
-#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/PointerLikeTypeTraits.h"
+#include "llvm/Support/MathExtras.h"
#include <cassert>
+#include <utility>
+#include <new>
namespace llvm {
-
+
template<typename T>
-struct DenseMapKeyInfo {
+struct DenseMapInfo {
//static inline T getEmptyKey();
//static inline T getTombstoneKey();
//static unsigned getHashValue(const T &Val);
+ //static bool isEqual(const T &LHS, const T &RHS);
//static bool isPod()
};
+// Provide DenseMapInfo for all pointers.
template<typename T>
-struct DenseMapKeyInfo<T*> {
- static inline T* getEmptyKey() { return (T*)-1; }
- static inline T* getTombstoneKey() { return (T*)-2; }
+struct DenseMapInfo<T*> {
+ static inline T* getEmptyKey() {
+ intptr_t Val = -1;
+ Val <<= PointerLikeTypeTraits<T*>::NumLowBitsAvailable;
+ return reinterpret_cast<T*>(Val);
+ }
+ static inline T* getTombstoneKey() {
+ intptr_t Val = -2;
+ Val <<= PointerLikeTypeTraits<T*>::NumLowBitsAvailable;
+ return reinterpret_cast<T*>(Val);
+ }
static unsigned getHashValue(const T *PtrVal) {
- return (unsigned)((uintptr_t)PtrVal >> 4) ^
- (unsigned)((uintptr_t)PtrVal >> 9);
+ return (unsigned((uintptr_t)PtrVal) >> 4) ^
+ (unsigned((uintptr_t)PtrVal) >> 9);
}
+ static bool isEqual(const T *LHS, const T *RHS) { return LHS == RHS; }
static bool isPod() { return true; }
};
+// Provide DenseMapInfo for chars.
+template<> struct DenseMapInfo<char> {
+ static inline char getEmptyKey() { return ~0; }
+ static inline char getTombstoneKey() { return ~0 - 1; }
+ static unsigned getHashValue(const char& Val) { return Val * 37; }
+ static bool isPod() { return true; }
+ static bool isEqual(const char &LHS, const char &RHS) {
+ return LHS == RHS;
+ }
+};
+
+// Provide DenseMapInfo for unsigned ints.
+template<> struct DenseMapInfo<unsigned> {
+ static inline unsigned getEmptyKey() { return ~0; }
+ static inline unsigned getTombstoneKey() { return ~0 - 1; }
+ static unsigned getHashValue(const unsigned& Val) { return Val * 37; }
+ static bool isPod() { return true; }
+ static bool isEqual(const unsigned& LHS, const unsigned& RHS) {
+ return LHS == RHS;
+ }
+};
-template<typename KeyT, typename ValueT>
+// Provide DenseMapInfo for unsigned longs.
+template<> struct DenseMapInfo<unsigned long> {
+ static inline unsigned long getEmptyKey() { return ~0L; }
+ static inline unsigned long getTombstoneKey() { return ~0L - 1L; }
+ static unsigned getHashValue(const unsigned long& Val) {
+ return (unsigned)(Val * 37L);
+ }
+ static bool isPod() { return true; }
+ static bool isEqual(const unsigned long& LHS, const unsigned long& RHS) {
+ return LHS == RHS;
+ }
+};
+
+// Provide DenseMapInfo for all pairs whose members have info.
+template<typename T, typename U>
+struct DenseMapInfo<std::pair<T, U> > {
+ typedef std::pair<T, U> Pair;
+ typedef DenseMapInfo<T> FirstInfo;
+ typedef DenseMapInfo<U> SecondInfo;
+
+ static inline Pair getEmptyKey() {
+ return std::make_pair(FirstInfo::getEmptyKey(),
+ SecondInfo::getEmptyKey());
+ }
+ static inline Pair getTombstoneKey() {
+ return std::make_pair(FirstInfo::getTombstoneKey(),
+ SecondInfo::getEmptyKey());
+ }
+ static unsigned getHashValue(const Pair& PairVal) {
+ uint64_t key = (uint64_t)FirstInfo::getHashValue(PairVal.first) << 32
+ | (uint64_t)SecondInfo::getHashValue(PairVal.second);
+ key += ~(key << 32);
+ key ^= (key >> 22);
+ key += ~(key << 13);
+ key ^= (key >> 8);
+ key += (key << 3);
+ key ^= (key >> 15);
+ key += ~(key << 27);
+ key ^= (key >> 31);
+ return (unsigned)key;
+ }
+ static bool isEqual(const Pair& LHS, const Pair& RHS) { return LHS == RHS; }
+ static bool isPod() { return FirstInfo::isPod() && SecondInfo::isPod(); }
+};
+
+template<typename KeyT, typename ValueT,
+ typename KeyInfoT = DenseMapInfo<KeyT>,
+ typename ValueInfoT = DenseMapInfo<ValueT> >
+class DenseMapIterator;
+template<typename KeyT, typename ValueT,
+ typename KeyInfoT = DenseMapInfo<KeyT>,
+ typename ValueInfoT = DenseMapInfo<ValueT> >
+class DenseMapConstIterator;
+
+template<typename KeyT, typename ValueT,
+ typename KeyInfoT = DenseMapInfo<KeyT>,
+ typename ValueInfoT = DenseMapInfo<ValueT> >
class DenseMap {
- struct BucketT { KeyT Key; ValueT Value; };
+ typedef std::pair<KeyT, ValueT> BucketT;
unsigned NumBuckets;
BucketT *Buckets;
-
+
unsigned NumEntries;
- DenseMap(const DenseMap &); // not implemented.
+ unsigned NumTombstones;
public:
- explicit DenseMap(unsigned NumInitBuckets = 8) {
+ typedef KeyT key_type;
+ typedef ValueT mapped_type;
+ typedef BucketT value_type;
+
+ DenseMap(const DenseMap& other) {
+ NumBuckets = 0;
+ CopyFrom(other);
+ }
+
+ explicit DenseMap(unsigned NumInitBuckets = 64) {
init(NumInitBuckets);
}
+
~DenseMap() {
const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey();
for (BucketT *P = Buckets, *E = Buckets+NumBuckets; P != E; ++P) {
- if (P->Key != EmptyKey && P->Key != TombstoneKey)
- P->Value.~ValueT();
- P->Key.~KeyT();
+ if (!KeyInfoT::isEqual(P->first, EmptyKey) &&
+ !KeyInfoT::isEqual(P->first, TombstoneKey))
+ P->second.~ValueT();
+ P->first.~KeyT();
}
- delete[] (char*)Buckets;
+ operator delete(Buckets);
}
-
+
+ typedef DenseMapIterator<KeyT, ValueT, KeyInfoT> iterator;
+ typedef DenseMapConstIterator<KeyT, ValueT, KeyInfoT> const_iterator;
+ inline iterator begin() {
+ return iterator(Buckets, Buckets+NumBuckets);
+ }
+ inline iterator end() {
+ return iterator(Buckets+NumBuckets, Buckets+NumBuckets);
+ }
+ inline const_iterator begin() const {
+ return const_iterator(Buckets, Buckets+NumBuckets);
+ }
+ inline const_iterator end() const {
+ return const_iterator(Buckets+NumBuckets, Buckets+NumBuckets);
+ }
+
+ bool empty() const { return NumEntries == 0; }
unsigned size() const { return NumEntries; }
-
+
+ /// Grow the densemap so that it has at least Size buckets. Does not shrink
+ void resize(size_t Size) { grow(Size); }
+
void clear() {
+ // If the capacity of the array is huge, and the # elements used is small,
+ // shrink the array.
+ if (NumEntries * 4 < NumBuckets && NumBuckets > 64) {
+ shrink_and_clear();
+ return;
+ }
+
const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey();
for (BucketT *P = Buckets, *E = Buckets+NumBuckets; P != E; ++P) {
- if (P->Key != EmptyKey && P->Key != TombstoneKey) {
- P->Key = EmptyKey;
- P->Value.~ValueT();
- --NumEntries;
+ if (!KeyInfoT::isEqual(P->first, EmptyKey)) {
+ if (!KeyInfoT::isEqual(P->first, TombstoneKey)) {
+ P->second.~ValueT();
+ --NumEntries;
+ }
+ P->first = EmptyKey;
}
}
assert(NumEntries == 0 && "Node count imbalance!");
+ NumTombstones = 0;
}
-
+
/// count - Return true if the specified key is in the map.
bool count(const KeyT &Val) const {
BucketT *TheBucket;
return LookupBucketFor(Val, TheBucket);
}
-
- ValueT &operator[](const KeyT &Val) {
+
+ iterator find(const KeyT &Val) {
+ BucketT *TheBucket;
+ if (LookupBucketFor(Val, TheBucket))
+ return iterator(TheBucket, Buckets+NumBuckets);
+ return end();
+ }
+ const_iterator find(const KeyT &Val) const {
BucketT *TheBucket;
if (LookupBucketFor(Val, TheBucket))
- return TheBucket->Value;
+ return const_iterator(TheBucket, Buckets+NumBuckets);
+ 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 {
+ BucketT *TheBucket;
+ if (LookupBucketFor(Val, TheBucket))
+ return TheBucket->second;
+ return ValueT();
+ }
+
+ std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) {
+ BucketT *TheBucket;
+ if (LookupBucketFor(KV.first, TheBucket))
+ return std::make_pair(iterator(TheBucket, Buckets+NumBuckets),
+ false); // Already in map.
+
+ // Otherwise, insert the new element.
+ TheBucket = InsertIntoBucket(KV.first, KV.second, TheBucket);
+ return std::make_pair(iterator(TheBucket, Buckets+NumBuckets),
+ 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.
+
+ TheBucket->second.~ValueT();
+ TheBucket->first = getTombstoneKey();
+ --NumEntries;
+ ++NumTombstones;
+ return true;
+ }
+ bool erase(iterator I) {
+ BucketT *TheBucket = &*I;
+ TheBucket->second.~ValueT();
+ TheBucket->first = getTombstoneKey();
+ --NumEntries;
+ ++NumTombstones;
+ return true;
+ }
+
+ value_type& FindAndConstruct(const KeyT &Key) {
+ BucketT *TheBucket;
+ if (LookupBucketFor(Key, TheBucket))
+ return *TheBucket;
+
+ return *InsertIntoBucket(Key, ValueT(), TheBucket);
+ }
+
+ ValueT &operator[](const KeyT &Key) {
+ return FindAndConstruct(Key).second;
+ }
+
+ DenseMap& operator=(const DenseMap& other) {
+ CopyFrom(other);
+ return *this;
+ }
- // If the load of the hash table is more than 3/4, grow it.
- if (NumEntries*4 >= NumBuckets*3) {
- this->grow();
- LookupBucketFor(Val, TheBucket);
+ /// 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 >= Buckets && Ptr < Buckets+NumBuckets;
+ }
+
+ /// 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 Buckets; }
+
+private:
+ void CopyFrom(const DenseMap& other) {
+ if (NumBuckets != 0 && (!KeyInfoT::isPod() || !ValueInfoT::isPod())) {
+ const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey();
+ for (BucketT *P = Buckets, *E = Buckets+NumBuckets; P != E; ++P) {
+ if (!KeyInfoT::isEqual(P->first, EmptyKey) &&
+ !KeyInfoT::isEqual(P->first, TombstoneKey))
+ P->second.~ValueT();
+ P->first.~KeyT();
+ }
}
+
+ 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.
++NumEntries;
- TheBucket->Key = Val;
- new (&TheBucket->Value) ValueT();
- return TheBucket->Value;
+ if (NumEntries*4 >= NumBuckets*3 ||
+ NumBuckets-(NumEntries+NumTombstones) < NumBuckets/8) {
+ this->grow(NumBuckets * 2);
+ LookupBucketFor(Key, TheBucket);
+ }
+
+ // 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;
}
-
-private:
- unsigned getHashValue(const KeyT &Val) const {
- return DenseMapKeyInfo<KeyT>::getHashValue(Val);
+
+ static unsigned getHashValue(const KeyT &Val) {
+ return KeyInfoT::getHashValue(Val);
}
- const KeyT getEmptyKey() const { return DenseMapKeyInfo<KeyT>::getEmptyKey();}
- const KeyT getTombstoneKey() const {
- return DenseMapKeyInfo<KeyT>::getTombstoneKey();
+ 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
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(Val != EmptyKey && Val != TombstoneKey &&
+ 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 (ThisBucket->Key == Val) {
+ 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 (ThisBucket->Key == EmptyKey) {
+ 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 (ThisBucket->Key == TombstoneKey && !FoundTombstone)
+ 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 &&
+ assert(InitBuckets && (InitBuckets & (InitBuckets-1)) == 0 &&
"# initial buckets must be a power of two!");
- Buckets = (BucketT*)new char[sizeof(BucketT)*InitBuckets];
+ 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].Key) KeyT(EmptyKey);
+ new (&Buckets[i].first) KeyT(EmptyKey);
}
-
- void grow() {
+
+ void grow(unsigned AtLeast) {
unsigned OldNumBuckets = NumBuckets;
BucketT *OldBuckets = Buckets;
-
+
// Double the number of buckets.
- NumBuckets <<= 1;
- Buckets = (BucketT*)new char[sizeof(BucketT)*NumBuckets];
+ 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].Key) KeyT(EmptyKey);
+ 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 (B->Key != EmptyKey && B->Key != TombstoneKey) {
+ 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->Key, DestBucket);
+ bool FoundVal = LookupBucketFor(B->first, DestBucket);
+ FoundVal = FoundVal; // silence warning.
assert(!FoundVal && "Key already in new map?");
- DestBucket->Key = B->Key;
- new (&DestBucket->Value) ValueT(B->Value);
-
+ DestBucket->first = B->first;
+ new (&DestBucket->second) ValueT(B->second);
+
// Free the value.
- B->Value.~ValueT();
+ B->second.~ValueT();
}
- B->Key.~KeyT();
+ B->first.~KeyT();
}
-
+
// Free the old table.
- delete[] (char*)OldBuckets;
+ 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;
}
};
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