| //===-- llvm/ADT/FoldingSet.h - Uniquing Hash Set ---------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines a hash set that can be used to remove duplication of nodes |
| // in a graph. This code was originally created by Chris Lattner for use with |
| // SelectionDAGCSEMap, but was isolated to provide use across the llvm code set. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_ADT_FOLDINGSET_H |
| #define LLVM_ADT_FOLDINGSET_H |
| |
| #include "llvm/Support/DataTypes.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include <string> |
| |
| namespace llvm { |
| class APFloat; |
| class APInt; |
| |
| /// This folding set used for two purposes: |
| /// 1. Given information about a node we want to create, look up the unique |
| /// instance of the node in the set. If the node already exists, return |
| /// it, otherwise return the bucket it should be inserted into. |
| /// 2. Given a node that has already been created, remove it from the set. |
| /// |
| /// This class is implemented as a single-link chained hash table, where the |
| /// "buckets" are actually the nodes themselves (the next pointer is in the |
| /// node). The last node points back to the bucket to simplify node removal. |
| /// |
| /// Any node that is to be included in the folding set must be a subclass of |
| /// FoldingSetNode. The node class must also define a Profile method used to |
| /// establish the unique bits of data for the node. The Profile method is |
| /// passed a FoldingSetNodeID object which is used to gather the bits. Just |
| /// call one of the Add* functions defined in the FoldingSetImpl::NodeID class. |
| /// NOTE: That the folding set does not own the nodes and it is the |
| /// responsibility of the user to dispose of the nodes. |
| /// |
| /// Eg. |
| /// class MyNode : public FoldingSetNode { |
| /// private: |
| /// std::string Name; |
| /// unsigned Value; |
| /// public: |
| /// MyNode(const char *N, unsigned V) : Name(N), Value(V) {} |
| /// ... |
| /// void Profile(FoldingSetNodeID &ID) { |
| /// ID.AddString(Name); |
| /// ID.AddInteger(Value); |
| /// } |
| /// ... |
| /// }; |
| /// |
| /// To define the folding set itself use the FoldingSet template; |
| /// |
| /// Eg. |
| /// FoldingSet<MyNode> MyFoldingSet; |
| /// |
| /// Four public methods are available to manipulate the folding set; |
| /// |
| /// 1) If you have an existing node that you want add to the set but unsure |
| /// that the node might already exist then call; |
| /// |
| /// MyNode *M = MyFoldingSet.GetOrInsertNode(N); |
| /// |
| /// If The result is equal to the input then the node has been inserted. |
| /// Otherwise, the result is the node existing in the folding set, and the |
| /// input can be discarded (use the result instead.) |
| /// |
| /// 2) If you are ready to construct a node but want to check if it already |
| /// exists, then call FindNodeOrInsertPos with a FoldingSetNodeID of the bits to |
| /// check; |
| /// |
| /// FoldingSetNodeID ID; |
| /// ID.AddString(Name); |
| /// ID.AddInteger(Value); |
| /// void *InsertPoint; |
| /// |
| /// MyNode *M = MyFoldingSet.FindNodeOrInsertPos(ID, InsertPoint); |
| /// |
| /// If found then M with be non-NULL, else InsertPoint will point to where it |
| /// should be inserted using InsertNode. |
| /// |
| /// 3) If you get a NULL result from FindNodeOrInsertPos then you can as a new |
| /// node with FindNodeOrInsertPos; |
| /// |
| /// InsertNode(N, InsertPoint); |
| /// |
| /// 4) Finally, if you want to remove a node from the folding set call; |
| /// |
| /// bool WasRemoved = RemoveNode(N); |
| /// |
| /// The result indicates whether the node existed in the folding set. |
| |
| class FoldingSetNodeID; |
| |
| //===----------------------------------------------------------------------===// |
| /// FoldingSetImpl - Implements the folding set functionality. The main |
| /// structure is an array of buckets. Each bucket is indexed by the hash of |
| /// the nodes it contains. The bucket itself points to the nodes contained |
| /// in the bucket via a singly linked list. The last node in the list points |
| /// back to the bucket to facilitate node removal. |
| /// |
| class FoldingSetImpl { |
| protected: |
| /// Buckets - Array of bucket chains. |
| /// |
| void **Buckets; |
| |
| /// NumBuckets - Length of the Buckets array. Always a power of 2. |
| /// |
| unsigned NumBuckets; |
| |
| /// NumNodes - Number of nodes in the folding set. Growth occurs when NumNodes |
| /// is greater than twice the number of buckets. |
| unsigned NumNodes; |
| |
| public: |
| explicit FoldingSetImpl(unsigned Log2InitSize = 6); |
| virtual ~FoldingSetImpl(); |
| |
| //===--------------------------------------------------------------------===// |
| /// Node - This class is used to maintain the singly linked bucket list in |
| /// a folding set. |
| /// |
| class Node { |
| private: |
| // NextInFoldingSetBucket - next link in the bucket list. |
| void *NextInFoldingSetBucket; |
| |
| public: |
| |
| Node() : NextInFoldingSetBucket(0) {} |
| |
| // Accessors |
| void *getNextInBucket() const { return NextInFoldingSetBucket; } |
| void SetNextInBucket(void *N) { NextInFoldingSetBucket = N; } |
| }; |
| |
| /// clear - Remove all nodes from the folding set. |
| void clear(); |
| |
| /// RemoveNode - Remove a node from the folding set, returning true if one |
| /// was removed or false if the node was not in the folding set. |
| bool RemoveNode(Node *N); |
| |
| /// GetOrInsertNode - If there is an existing simple Node exactly |
| /// equal to the specified node, return it. Otherwise, insert 'N' and return |
| /// it instead. |
| Node *GetOrInsertNode(Node *N); |
| |
| /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists, |
| /// return it. If not, return the insertion token that will make insertion |
| /// faster. |
| Node *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos); |
| |
| /// InsertNode - Insert the specified node into the folding set, knowing that |
| /// it is not already in the folding set. InsertPos must be obtained from |
| /// FindNodeOrInsertPos. |
| void InsertNode(Node *N, void *InsertPos); |
| |
| /// size - Returns the number of nodes in the folding set. |
| unsigned size() const { return NumNodes; } |
| |
| /// empty - Returns true if there are no nodes in the folding set. |
| bool empty() const { return NumNodes == 0; } |
| |
| private: |
| |
| /// GrowHashTable - Double the size of the hash table and rehash everything. |
| /// |
| void GrowHashTable(); |
| |
| protected: |
| |
| /// GetNodeProfile - Instantiations of the FoldingSet template implement |
| /// this function to gather data bits for the given node. |
| virtual void GetNodeProfile(FoldingSetNodeID &ID, Node *N) const = 0; |
| }; |
| |
| //===----------------------------------------------------------------------===// |
| /// FoldingSetTrait - This trait class is used to define behavior of how |
| /// to "profile" (in the FoldingSet parlance) an object of a given type. |
| /// The default behavior is to invoke a 'Profile' method on an object, but |
| /// through template specialization the behavior can be tailored for specific |
| /// types. Combined with the FoldingSetNodeWrapper classs, one can add objects |
| /// to FoldingSets that were not originally designed to have that behavior. |
| /// |
| template<typename T> struct FoldingSetTrait { |
| static inline void Profile(const T& X, FoldingSetNodeID& ID) { X.Profile(ID);} |
| static inline void Profile(T& X, FoldingSetNodeID& ID) { X.Profile(ID); } |
| }; |
| |
| //===--------------------------------------------------------------------===// |
| /// FoldingSetNodeID - This class is used to gather all the unique data bits of |
| /// a node. When all the bits are gathered this class is used to produce a |
| /// hash value for the node. |
| /// |
| class FoldingSetNodeID { |
| /// Bits - Vector of all the data bits that make the node unique. |
| /// Use a SmallVector to avoid a heap allocation in the common case. |
| SmallVector<unsigned, 32> Bits; |
| |
| public: |
| FoldingSetNodeID() {} |
| |
| /// getRawData - Return the ith entry in the Bits data. |
| /// |
| unsigned getRawData(unsigned i) const { |
| return Bits[i]; |
| } |
| |
| /// Add* - Add various data types to Bit data. |
| /// |
| void AddPointer(const void *Ptr); |
| void AddInteger(signed I); |
| void AddInteger(unsigned I); |
| void AddInteger(long I); |
| void AddInteger(unsigned long I); |
| void AddInteger(long long I); |
| void AddInteger(unsigned long long I); |
| void AddString(const std::string &String); |
| void AddString(const char* String); |
| |
| template <typename T> |
| inline void Add(const T& x) { FoldingSetTrait<T>::Profile(x, *this); } |
| |
| /// clear - Clear the accumulated profile, allowing this FoldingSetNodeID |
| /// object to be used to compute a new profile. |
| inline void clear() { Bits.clear(); } |
| |
| /// ComputeHash - Compute a strong hash value for this FoldingSetNodeID, used |
| /// to lookup the node in the FoldingSetImpl. |
| unsigned ComputeHash() const; |
| |
| /// operator== - Used to compare two nodes to each other. |
| /// |
| bool operator==(const FoldingSetNodeID &RHS) const; |
| }; |
| |
| // Convenience type to hide the implementation of the folding set. |
| typedef FoldingSetImpl::Node FoldingSetNode; |
| template<class T> class FoldingSetIterator; |
| template<class T> class FoldingSetBucketIterator; |
| |
| //===----------------------------------------------------------------------===// |
| /// FoldingSet - This template class is used to instantiate a specialized |
| /// implementation of the folding set to the node class T. T must be a |
| /// subclass of FoldingSetNode and implement a Profile function. |
| /// |
| template<class T> class FoldingSet : public FoldingSetImpl { |
| private: |
| /// GetNodeProfile - Each instantiatation of the FoldingSet needs to provide a |
| /// way to convert nodes into a unique specifier. |
| virtual void GetNodeProfile(FoldingSetNodeID &ID, Node *N) const { |
| T *TN = static_cast<T *>(N); |
| FoldingSetTrait<T>::Profile(*TN,ID); |
| } |
| |
| public: |
| explicit FoldingSet(unsigned Log2InitSize = 6) |
| : FoldingSetImpl(Log2InitSize) |
| {} |
| |
| typedef FoldingSetIterator<T> iterator; |
| iterator begin() { return iterator(Buckets); } |
| iterator end() { return iterator(Buckets+NumBuckets); } |
| |
| typedef FoldingSetIterator<const T> const_iterator; |
| const_iterator begin() const { return const_iterator(Buckets); } |
| const_iterator end() const { return const_iterator(Buckets+NumBuckets); } |
| |
| typedef FoldingSetBucketIterator<T> bucket_iterator; |
| |
| bucket_iterator bucket_begin(unsigned hash) { |
| return bucket_iterator(Buckets + (hash & (NumBuckets-1))); |
| } |
| |
| bucket_iterator bucket_end(unsigned hash) { |
| return bucket_iterator(Buckets + (hash & (NumBuckets-1)), true); |
| } |
| |
| /// GetOrInsertNode - If there is an existing simple Node exactly |
| /// equal to the specified node, return it. Otherwise, insert 'N' and |
| /// return it instead. |
| T *GetOrInsertNode(Node *N) { |
| return static_cast<T *>(FoldingSetImpl::GetOrInsertNode(N)); |
| } |
| |
| /// FindNodeOrInsertPos - Look up the node specified by ID. If it exists, |
| /// return it. If not, return the insertion token that will make insertion |
| /// faster. |
| T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) { |
| return static_cast<T *>(FoldingSetImpl::FindNodeOrInsertPos(ID, InsertPos)); |
| } |
| }; |
| |
| //===----------------------------------------------------------------------===// |
| /// FoldingSetIteratorImpl - This is the common iterator support shared by all |
| /// folding sets, which knows how to walk the folding set hash table. |
| class FoldingSetIteratorImpl { |
| protected: |
| FoldingSetNode *NodePtr; |
| FoldingSetIteratorImpl(void **Bucket); |
| void advance(); |
| |
| public: |
| bool operator==(const FoldingSetIteratorImpl &RHS) const { |
| return NodePtr == RHS.NodePtr; |
| } |
| bool operator!=(const FoldingSetIteratorImpl &RHS) const { |
| return NodePtr != RHS.NodePtr; |
| } |
| }; |
| |
| |
| template<class T> |
| class FoldingSetIterator : public FoldingSetIteratorImpl { |
| public: |
| explicit FoldingSetIterator(void **Bucket) : FoldingSetIteratorImpl(Bucket) {} |
| |
| T &operator*() const { |
| return *static_cast<T*>(NodePtr); |
| } |
| |
| T *operator->() const { |
| return static_cast<T*>(NodePtr); |
| } |
| |
| inline FoldingSetIterator& operator++() { // Preincrement |
| advance(); |
| return *this; |
| } |
| FoldingSetIterator operator++(int) { // Postincrement |
| FoldingSetIterator tmp = *this; ++*this; return tmp; |
| } |
| }; |
| |
| //===----------------------------------------------------------------------===// |
| /// FoldingSetBucketIteratorImpl - This is the common bucket iterator support |
| /// shared by all folding sets, which knows how to walk a particular bucket |
| /// of a folding set hash table. |
| |
| class FoldingSetBucketIteratorImpl { |
| protected: |
| void *Ptr; |
| |
| explicit FoldingSetBucketIteratorImpl(void **Bucket); |
| |
| FoldingSetBucketIteratorImpl(void **Bucket, bool) |
| : Ptr(Bucket) {} |
| |
| void advance() { |
| void *Probe = static_cast<FoldingSetNode*>(Ptr)->getNextInBucket(); |
| uintptr_t x = reinterpret_cast<uintptr_t>(Probe) & ~0x1; |
| Ptr = reinterpret_cast<void*>(x); |
| } |
| |
| public: |
| bool operator==(const FoldingSetBucketIteratorImpl &RHS) const { |
| return Ptr == RHS.Ptr; |
| } |
| bool operator!=(const FoldingSetBucketIteratorImpl &RHS) const { |
| return Ptr != RHS.Ptr; |
| } |
| }; |
| |
| |
| template<class T> |
| class FoldingSetBucketIterator : public FoldingSetBucketIteratorImpl { |
| public: |
| explicit FoldingSetBucketIterator(void **Bucket) : |
| FoldingSetBucketIteratorImpl(Bucket) {} |
| |
| FoldingSetBucketIterator(void **Bucket, bool) : |
| FoldingSetBucketIteratorImpl(Bucket, true) {} |
| |
| T& operator*() const { return *static_cast<T*>(Ptr); } |
| T* operator->() const { return static_cast<T*>(Ptr); } |
| |
| inline FoldingSetBucketIterator& operator++() { // Preincrement |
| advance(); |
| return *this; |
| } |
| FoldingSetBucketIterator operator++(int) { // Postincrement |
| FoldingSetBucketIterator tmp = *this; ++*this; return tmp; |
| } |
| }; |
| |
| //===----------------------------------------------------------------------===// |
| /// FoldingSetNodeWrapper - This template class is used to "wrap" arbitrary |
| /// types in an enclosing object so that they can be inserted into FoldingSets. |
| template <typename T> |
| class FoldingSetNodeWrapper : public FoldingSetNode { |
| T data; |
| public: |
| explicit FoldingSetNodeWrapper(const T& x) : data(x) {} |
| virtual ~FoldingSetNodeWrapper() {} |
| |
| template<typename A1> |
| explicit FoldingSetNodeWrapper(const A1& a1) |
| : data(a1) {} |
| |
| template <typename A1, typename A2> |
| explicit FoldingSetNodeWrapper(const A1& a1, const A2& a2) |
| : data(a1,a2) {} |
| |
| template <typename A1, typename A2, typename A3> |
| explicit FoldingSetNodeWrapper(const A1& a1, const A2& a2, const A3& a3) |
| : data(a1,a2,a3) {} |
| |
| template <typename A1, typename A2, typename A3, typename A4> |
| explicit FoldingSetNodeWrapper(const A1& a1, const A2& a2, const A3& a3, |
| const A4& a4) |
| : data(a1,a2,a3,a4) {} |
| |
| template <typename A1, typename A2, typename A3, typename A4, typename A5> |
| explicit FoldingSetNodeWrapper(const A1& a1, const A2& a2, const A3& a3, |
| const A4& a4, const A5& a5) |
| : data(a1,a2,a3,a4,a5) {} |
| |
| |
| void Profile(FoldingSetNodeID& ID) { FoldingSetTrait<T>::Profile(data, ID); } |
| |
| T& getValue() { return data; } |
| const T& getValue() const { return data; } |
| |
| operator T&() { return data; } |
| operator const T&() const { return data; } |
| }; |
| |
| //===----------------------------------------------------------------------===// |
| // Partial specializations of FoldingSetTrait. |
| |
| template<typename T> struct FoldingSetTrait<T*> { |
| static inline void Profile(const T* X, FoldingSetNodeID& ID) { |
| ID.AddPointer(X); |
| } |
| static inline void Profile(T* X, FoldingSetNodeID& ID) { |
| ID.AddPointer(X); |
| } |
| }; |
| |
| template<typename T> struct FoldingSetTrait<const T*> { |
| static inline void Profile(const T* X, FoldingSetNodeID& ID) { |
| ID.AddPointer(X); |
| } |
| }; |
| |
| } // End of namespace llvm. |
| |
| #endif |