diff options
Diffstat (limited to 'include/llvm/ADT/ImmutableSet.h')
| -rw-r--r-- | include/llvm/ADT/ImmutableSet.h | 553 |
1 files changed, 290 insertions, 263 deletions
diff --git a/include/llvm/ADT/ImmutableSet.h b/include/llvm/ADT/ImmutableSet.h index 70c3caf..3ca910c 100644 --- a/include/llvm/ADT/ImmutableSet.h +++ b/include/llvm/ADT/ImmutableSet.h @@ -15,10 +15,13 @@ #define LLVM_ADT_IMSET_H #include "llvm/Support/Allocator.h" +#include "llvm/ADT/DenseMap.h" #include "llvm/ADT/FoldingSet.h" -#include "llvm/System/DataTypes.h" +#include "llvm/Support/DataTypes.h" #include <cassert> #include <functional> +#include <vector> +#include <stdio.h> namespace llvm { @@ -32,7 +35,7 @@ template <typename ImutInfo> class ImutAVLTreeInOrderIterator; template <typename ImutInfo> class ImutAVLTreeGenericIterator; template <typename ImutInfo > -class ImutAVLTree : public FoldingSetNode { +class ImutAVLTree { public: typedef typename ImutInfo::key_type_ref key_type_ref; typedef typename ImutInfo::value_type value_type; @@ -43,7 +46,6 @@ public: friend class ImutIntervalAVLFactory<ImutInfo>; friend class ImutAVLTreeGenericIterator<ImutInfo>; - friend class FoldingSet<ImutAVLTree>; typedef ImutAVLTreeInOrderIterator<ImutInfo> iterator; @@ -51,29 +53,27 @@ public: // Public Interface. //===----------------------------------------------------===// - /// getLeft - Returns a pointer to the left subtree. This value + /// Return a pointer to the left subtree. This value /// is NULL if there is no left subtree. - ImutAVLTree *getLeft() const { return Left; } + ImutAVLTree *getLeft() const { return left; } - /// getRight - Returns a pointer to the right subtree. This value is + /// Return a pointer to the right subtree. This value is /// NULL if there is no right subtree. - ImutAVLTree *getRight() const { return Right; } + ImutAVLTree *getRight() const { return right; } /// getHeight - Returns the height of the tree. A tree with no subtrees /// has a height of 1. - unsigned getHeight() const { return Height; } + unsigned getHeight() const { return height; } /// getValue - Returns the data value associated with the tree node. - const value_type& getValue() const { return Value; } + const value_type& getValue() const { return value; } /// find - Finds the subtree associated with the specified key value. /// This method returns NULL if no matching subtree is found. ImutAVLTree* find(key_type_ref K) { ImutAVLTree *T = this; - while (T) { key_type_ref CurrentKey = ImutInfo::KeyOfValue(T->getValue()); - if (ImutInfo::isEqual(K,CurrentKey)) return T; else if (ImutInfo::isLess(K,CurrentKey)) @@ -81,7 +81,6 @@ public: else T = T->getRight(); } - return NULL; } @@ -90,7 +89,7 @@ public: ImutAVLTree* getMaxElement() { ImutAVLTree *T = this; ImutAVLTree *Right = T->getRight(); - while (Right) { T = Right; Right = T->getRight(); } + while (Right) { T = right; right = T->getRight(); } return T; } @@ -98,10 +97,10 @@ public: /// both leaves and non-leaf nodes. unsigned size() const { unsigned n = 1; - - if (const ImutAVLTree* L = getLeft()) n += L->size(); - if (const ImutAVLTree* R = getRight()) n += R->size(); - + if (const ImutAVLTree* L = getLeft()) + n += L->size(); + if (const ImutAVLTree* R = getRight()) + n += R->size(); return n; } @@ -114,7 +113,7 @@ public: /// inorder traversal. iterator end() const { return iterator(); } - bool ElementEqual(value_type_ref V) const { + bool isElementEqual(value_type_ref V) const { // Compare the keys. if (!ImutInfo::isEqual(ImutInfo::KeyOfValue(getValue()), ImutInfo::KeyOfValue(V))) @@ -128,8 +127,8 @@ public: return true; } - bool ElementEqual(const ImutAVLTree* RHS) const { - return ElementEqual(RHS->getValue()); + bool isElementEqual(const ImutAVLTree* RHS) const { + return isElementEqual(RHS->getValue()); } /// isEqual - Compares two trees for structural equality and returns true @@ -144,12 +143,12 @@ public: while (LItr != LEnd && RItr != REnd) { if (*LItr == *RItr) { - LItr.SkipSubTree(); - RItr.SkipSubTree(); + LItr.skipSubTree(); + RItr.skipSubTree(); continue; } - if (!LItr->ElementEqual(*RItr)) + if (!LItr->isElementEqual(*RItr)) return false; ++LItr; @@ -173,22 +172,24 @@ public: /// Nodes are visited using an inorder traversal. template <typename Callback> void foreach(Callback& C) { - if (ImutAVLTree* L = getLeft()) L->foreach(C); + if (ImutAVLTree* L = getLeft()) + L->foreach(C); - C(Value); + C(value); - if (ImutAVLTree* R = getRight()) R->foreach(C); + if (ImutAVLTree* R = getRight()) + R->foreach(C); } - /// verify - A utility method that checks that the balancing and + /// validateTree - A utility method that checks that the balancing and /// ordering invariants of the tree are satisifed. It is a recursive /// method that returns the height of the tree, which is then consumed - /// by the enclosing verify call. External callers should ignore the + /// by the enclosing validateTree call. External callers should ignore the /// return value. An invalid tree will cause an assertion to fire in /// a debug build. - unsigned verify() const { - unsigned HL = getLeft() ? getLeft()->verify() : 0; - unsigned HR = getRight() ? getRight()->verify() : 0; + unsigned validateTree() const { + unsigned HL = getLeft() ? getLeft()->validateTree() : 0; + unsigned HR = getRight() ? getRight()->validateTree() : 0; (void) HL; (void) HR; @@ -198,37 +199,39 @@ public: assert((HL > HR ? HL-HR : HR-HL) <= 2 && "Balancing invariant violated"); - assert(!getLeft() - || ImutInfo::isLess(ImutInfo::KeyOfValue(getLeft()->getValue()), - ImutInfo::KeyOfValue(getValue())) - && "Value in left child is not less that current value"); + assert((!getLeft() || + ImutInfo::isLess(ImutInfo::KeyOfValue(getLeft()->getValue()), + ImutInfo::KeyOfValue(getValue()))) && + "Value in left child is not less that current value"); - assert(!getRight() - || ImutInfo::isLess(ImutInfo::KeyOfValue(getValue()), - ImutInfo::KeyOfValue(getRight()->getValue())) - && "Current value is not less that value of right child"); + assert(!(getRight() || + ImutInfo::isLess(ImutInfo::KeyOfValue(getValue()), + ImutInfo::KeyOfValue(getRight()->getValue()))) && + "Current value is not less that value of right child"); return getHeight(); } - /// Profile - Profiling for ImutAVLTree. - void Profile(llvm::FoldingSetNodeID& ID) { - ID.AddInteger(ComputeDigest()); - } - //===----------------------------------------------------===// - // Internal Values. + // Internal values. //===----------------------------------------------------===// private: - ImutAVLTree* Left; - ImutAVLTree* Right; - unsigned Height : 28; - unsigned Mutable : 1; - unsigned CachedDigest : 1; - value_type Value; - uint32_t Digest; + Factory *factory; + ImutAVLTree *left; + ImutAVLTree *right; + ImutAVLTree *prev; + ImutAVLTree *next; + + unsigned height : 28; + unsigned IsMutable : 1; + unsigned IsDigestCached : 1; + unsigned IsCanonicalized : 1; + + value_type value; + uint32_t digest; + uint32_t refCount; //===----------------------------------------------------===// // Internal methods (node manipulation; used by Factory). @@ -237,10 +240,15 @@ private: private: /// ImutAVLTree - Internal constructor that is only called by /// ImutAVLFactory. - ImutAVLTree(ImutAVLTree* l, ImutAVLTree* r, value_type_ref v, + ImutAVLTree(Factory *f, ImutAVLTree* l, ImutAVLTree* r, value_type_ref v, unsigned height) - : Left(l), Right(r), Height(height), Mutable(true), CachedDigest(false), - Value(v), Digest(0) {} + : factory(f), left(l), right(r), prev(0), next(0), height(height), + IsMutable(true), IsDigestCached(false), IsCanonicalized(0), + value(v), digest(0), refCount(0) + { + if (left) left->retain(); + if (right) right->retain(); + } /// isMutable - Returns true if the left and right subtree references /// (as well as height) can be changed. If this method returns false, @@ -248,11 +256,11 @@ private: /// object should always have this method return true. Further, if this /// method returns false for an instance of ImutAVLTree, all subtrees /// will also have this method return false. The converse is not true. - bool isMutable() const { return Mutable; } + bool isMutable() const { return IsMutable; } /// hasCachedDigest - Returns true if the digest for this tree is cached. /// This can only be true if the tree is immutable. - bool hasCachedDigest() const { return CachedDigest; } + bool hasCachedDigest() const { return IsDigestCached; } //===----------------------------------------------------===// // Mutating operations. A tree root can be manipulated as @@ -265,51 +273,32 @@ private: // immutable. //===----------------------------------------------------===// - /// MarkImmutable - Clears the mutable flag for a tree. After this happens, + /// markImmutable - Clears the mutable flag for a tree. After this happens, /// it is an error to call setLeft(), setRight(), and setHeight(). - void MarkImmutable() { + void markImmutable() { assert(isMutable() && "Mutable flag already removed."); - Mutable = false; + IsMutable = false; } - /// MarkedCachedDigest - Clears the NoCachedDigest flag for a tree. - void MarkedCachedDigest() { + /// markedCachedDigest - Clears the NoCachedDigest flag for a tree. + void markedCachedDigest() { assert(!hasCachedDigest() && "NoCachedDigest flag already removed."); - CachedDigest = true; - } - - /// setLeft - Changes the reference of the left subtree. Used internally - /// by ImutAVLFactory. - void setLeft(ImutAVLTree* NewLeft) { - assert(isMutable() && - "Only a mutable tree can have its left subtree changed."); - Left = NewLeft; - CachedDigest = false; - } - - /// setRight - Changes the reference of the right subtree. Used internally - /// by ImutAVLFactory. - void setRight(ImutAVLTree* NewRight) { - assert(isMutable() && - "Only a mutable tree can have its right subtree changed."); - - Right = NewRight; - CachedDigest = false; + IsDigestCached = true; } /// setHeight - Changes the height of the tree. Used internally by /// ImutAVLFactory. void setHeight(unsigned h) { assert(isMutable() && "Only a mutable tree can have its height changed."); - Height = h; + height = h; } static inline - uint32_t ComputeDigest(ImutAVLTree* L, ImutAVLTree* R, value_type_ref V) { + uint32_t computeDigest(ImutAVLTree* L, ImutAVLTree* R, value_type_ref V) { uint32_t digest = 0; if (L) - digest += L->ComputeDigest(); + digest += L->computeDigest(); // Compute digest of stored data. FoldingSetNodeID ID; @@ -317,22 +306,54 @@ private: digest += ID.ComputeHash(); if (R) - digest += R->ComputeDigest(); + digest += R->computeDigest(); return digest; } - inline uint32_t ComputeDigest() { + inline uint32_t computeDigest() { // Check the lowest bit to determine if digest has actually been // pre-computed. if (hasCachedDigest()) - return Digest; + return digest; - uint32_t X = ComputeDigest(getLeft(), getRight(), getValue()); - Digest = X; - MarkedCachedDigest(); + uint32_t X = computeDigest(getLeft(), getRight(), getValue()); + digest = X; + markedCachedDigest(); return X; } + + //===----------------------------------------------------===// + // Reference count operations. + //===----------------------------------------------------===// + +public: + void retain() { ++refCount; } + void release() { + assert(refCount > 0); + if (--refCount == 0) + destroy(); + } + void destroy() { + if (left) + left->release(); + if (right) + right->release(); + if (IsCanonicalized) { + if (next) + next->prev = prev; + + if (prev) + prev->next = next; + else + factory->Cache[computeDigest()] = next; + } + + // We need to clear the mutability bit in case we are + // destroying the node as part of a sweep in ImutAVLFactory::recoverNodes(). + IsMutable = false; + factory->freeNodes.push_back(this); + } }; //===----------------------------------------------------------------------===// @@ -341,14 +362,17 @@ private: template <typename ImutInfo > class ImutAVLFactory { + friend class ImutAVLTree<ImutInfo>; typedef ImutAVLTree<ImutInfo> TreeTy; typedef typename TreeTy::value_type_ref value_type_ref; typedef typename TreeTy::key_type_ref key_type_ref; - typedef FoldingSet<TreeTy> CacheTy; + typedef DenseMap<unsigned, TreeTy*> CacheTy; CacheTy Cache; uintptr_t Allocator; + std::vector<TreeTy*> createdNodes; + std::vector<TreeTy*> freeNodes; bool ownsAllocator() const { return Allocator & 0x1 ? false : true; @@ -373,55 +397,56 @@ public: if (ownsAllocator()) delete &getAllocator(); } - TreeTy* Add(TreeTy* T, value_type_ref V) { - T = Add_internal(V,T); - MarkImmutable(T); + TreeTy* add(TreeTy* T, value_type_ref V) { + T = add_internal(V,T); + markImmutable(T); + recoverNodes(); return T; } - TreeTy* Remove(TreeTy* T, key_type_ref V) { - T = Remove_internal(V,T); - MarkImmutable(T); + TreeTy* remove(TreeTy* T, key_type_ref V) { + T = remove_internal(V,T); + markImmutable(T); + recoverNodes(); return T; } - TreeTy* GetEmptyTree() const { return NULL; } + TreeTy* getEmptyTree() const { return NULL; } +protected: + //===--------------------------------------------------===// // A bunch of quick helper functions used for reasoning // about the properties of trees and their children. // These have succinct names so that the balancing code // is as terse (and readable) as possible. //===--------------------------------------------------===// -protected: - bool isEmpty(TreeTy* T) const { return !T; } - unsigned Height(TreeTy* T) const { return T ? T->getHeight() : 0; } - TreeTy* Left(TreeTy* T) const { return T->getLeft(); } - TreeTy* Right(TreeTy* T) const { return T->getRight(); } - value_type_ref Value(TreeTy* T) const { return T->Value; } + bool isEmpty(TreeTy* T) const { return !T; } + unsigned getHeight(TreeTy* T) const { return T ? T->getHeight() : 0; } + TreeTy* getLeft(TreeTy* T) const { return T->getLeft(); } + TreeTy* getRight(TreeTy* T) const { return T->getRight(); } + value_type_ref getValue(TreeTy* T) const { return T->value; } - unsigned IncrementHeight(TreeTy* L, TreeTy* R) const { - unsigned hl = Height(L); - unsigned hr = Height(R); + unsigned incrementHeight(TreeTy* L, TreeTy* R) const { + unsigned hl = getHeight(L); + unsigned hr = getHeight(R); return (hl > hr ? hl : hr) + 1; } - static bool CompareTreeWithSection(TreeTy* T, + static bool compareTreeWithSection(TreeTy* T, typename TreeTy::iterator& TI, typename TreeTy::iterator& TE) { - typename TreeTy::iterator I = T->begin(), E = T->end(); - - for ( ; I!=E ; ++I, ++TI) - if (TI == TE || !I->ElementEqual(*TI)) + for ( ; I!=E ; ++I, ++TI) { + if (TI == TE || !I->isElementEqual(*TI)) return false; - + } return true; } //===--------------------------------------------------===// - // "CreateNode" is used to generate new tree roots that link + // "createNode" is used to generate new tree roots that link // to other trees. The functon may also simply move links // in an existing root if that root is still marked mutable. // This is necessary because otherwise our balancing code @@ -430,181 +455,188 @@ protected: // returned to the caller. //===--------------------------------------------------===// - TreeTy* CreateNode(TreeTy* L, value_type_ref V, TreeTy* R) { + TreeTy* createNode(TreeTy* L, value_type_ref V, TreeTy* R) { BumpPtrAllocator& A = getAllocator(); - TreeTy* T = (TreeTy*) A.Allocate<TreeTy>(); - new (T) TreeTy(L, R, V, IncrementHeight(L,R)); + TreeTy* T; + if (!freeNodes.empty()) { + T = freeNodes.back(); + freeNodes.pop_back(); + assert(T != L); + assert(T != R); + } + else { + T = (TreeTy*) A.Allocate<TreeTy>(); + } + new (T) TreeTy(this, L, R, V, incrementHeight(L,R)); + createdNodes.push_back(T); return T; } - TreeTy* CreateNode(TreeTy* L, TreeTy* OldTree, TreeTy* R) { - assert(!isEmpty(OldTree)); + TreeTy* createNode(TreeTy* newLeft, TreeTy* oldTree, TreeTy* newRight) { + return createNode(newLeft, getValue(oldTree), newRight); + } - if (OldTree->isMutable()) { - OldTree->setLeft(L); - OldTree->setRight(R); - OldTree->setHeight(IncrementHeight(L, R)); - return OldTree; + void recoverNodes() { + for (unsigned i = 0, n = createdNodes.size(); i < n; ++i) { + TreeTy *N = createdNodes[i]; + if (N->isMutable() && N->refCount == 0) + N->destroy(); } - else - return CreateNode(L, Value(OldTree), R); + createdNodes.clear(); } - /// Balance - Used by Add_internal and Remove_internal to + /// balanceTree - Used by add_internal and remove_internal to /// balance a newly created tree. - TreeTy* Balance(TreeTy* L, value_type_ref V, TreeTy* R) { - - unsigned hl = Height(L); - unsigned hr = Height(R); + TreeTy* balanceTree(TreeTy* L, value_type_ref V, TreeTy* R) { + unsigned hl = getHeight(L); + unsigned hr = getHeight(R); if (hl > hr + 2) { assert(!isEmpty(L) && "Left tree cannot be empty to have a height >= 2"); - TreeTy* LL = Left(L); - TreeTy* LR = Right(L); + TreeTy *LL = getLeft(L); + TreeTy *LR = getRight(L); - if (Height(LL) >= Height(LR)) - return CreateNode(LL, L, CreateNode(LR,V,R)); + if (getHeight(LL) >= getHeight(LR)) + return createNode(LL, L, createNode(LR,V,R)); assert(!isEmpty(LR) && "LR cannot be empty because it has a height >= 1"); - TreeTy* LRL = Left(LR); - TreeTy* LRR = Right(LR); + TreeTy *LRL = getLeft(LR); + TreeTy *LRR = getRight(LR); - return CreateNode(CreateNode(LL,L,LRL), LR, CreateNode(LRR,V,R)); + return createNode(createNode(LL,L,LRL), LR, createNode(LRR,V,R)); } else if (hr > hl + 2) { assert(!isEmpty(R) && "Right tree cannot be empty to have a height >= 2"); - TreeTy* RL = Left(R); - TreeTy* RR = Right(R); + TreeTy *RL = getLeft(R); + TreeTy *RR = getRight(R); - if (Height(RR) >= Height(RL)) - return CreateNode(CreateNode(L,V,RL), R, RR); + if (getHeight(RR) >= getHeight(RL)) + return createNode(createNode(L,V,RL), R, RR); assert(!isEmpty(RL) && "RL cannot be empty because it has a height >= 1"); - TreeTy* RLL = Left(RL); - TreeTy* RLR = Right(RL); + TreeTy *RLL = getLeft(RL); + TreeTy *RLR = getRight(RL); - return CreateNode(CreateNode(L,V,RLL), RL, CreateNode(RLR,R,RR)); + return createNode(createNode(L,V,RLL), RL, createNode(RLR,R,RR)); } else - return CreateNode(L,V,R); + return createNode(L,V,R); } - /// Add_internal - Creates a new tree that includes the specified + /// add_internal - Creates a new tree that includes the specified /// data and the data from the original tree. If the original tree /// already contained the data item, the original tree is returned. - TreeTy* Add_internal(value_type_ref V, TreeTy* T) { + TreeTy* add_internal(value_type_ref V, TreeTy* T) { if (isEmpty(T)) - return CreateNode(T, V, T); - + return createNode(T, V, T); assert(!T->isMutable()); key_type_ref K = ImutInfo::KeyOfValue(V); - key_type_ref KCurrent = ImutInfo::KeyOfValue(Value(T)); + key_type_ref KCurrent = ImutInfo::KeyOfValue(getValue(T)); if (ImutInfo::isEqual(K,KCurrent)) - return CreateNode(Left(T), V, Right(T)); + return createNode(getLeft(T), V, getRight(T)); else if (ImutInfo::isLess(K,KCurrent)) - return Balance(Add_internal(V,Left(T)), Value(T), Right(T)); + return balanceTree(add_internal(V, getLeft(T)), getValue(T), getRight(T)); else - return Balance(Left(T), Value(T), Add_internal(V,Right(T))); + return balanceTree(getLeft(T), getValue(T), add_internal(V, getRight(T))); } - /// Remove_internal - Creates a new tree that includes all the data + /// remove_internal - Creates a new tree that includes all the data /// from the original tree except the specified data. If the /// specified data did not exist in the original tree, the original /// tree is returned. - TreeTy* Remove_internal(key_type_ref K, TreeTy* T) { + TreeTy* remove_internal(key_type_ref K, TreeTy* T) { if (isEmpty(T)) return T; assert(!T->isMutable()); - key_type_ref KCurrent = ImutInfo::KeyOfValue(Value(T)); + key_type_ref KCurrent = ImutInfo::KeyOfValue(getValue(T)); - if (ImutInfo::isEqual(K,KCurrent)) - return CombineLeftRightTrees(Left(T),Right(T)); - else if (ImutInfo::isLess(K,KCurrent)) - return Balance(Remove_internal(K,Left(T)), Value(T), Right(T)); - else - return Balance(Left(T), Value(T), Remove_internal(K,Right(T))); + if (ImutInfo::isEqual(K,KCurrent)) { + return combineTrees(getLeft(T), getRight(T)); + } else if (ImutInfo::isLess(K,KCurrent)) { + return balanceTree(remove_internal(K, getLeft(T)), + getValue(T), getRight(T)); + } else { + return balanceTree(getLeft(T), getValue(T), + remove_internal(K, getRight(T))); + } } - TreeTy* CombineLeftRightTrees(TreeTy* L, TreeTy* R) { - if (isEmpty(L)) return R; - if (isEmpty(R)) return L; - + TreeTy* combineTrees(TreeTy* L, TreeTy* R) { + if (isEmpty(L)) + return R; + if (isEmpty(R)) + return L; TreeTy* OldNode; - TreeTy* NewRight = RemoveMinBinding(R,OldNode); - return Balance(L,Value(OldNode),NewRight); + TreeTy* newRight = removeMinBinding(R,OldNode); + return balanceTree(L, getValue(OldNode), newRight); } - TreeTy* RemoveMinBinding(TreeTy* T, TreeTy*& NodeRemoved) { + TreeTy* removeMinBinding(TreeTy* T, TreeTy*& Noderemoved) { assert(!isEmpty(T)); - - if (isEmpty(Left(T))) { - NodeRemoved = T; - return Right(T); + if (isEmpty(getLeft(T))) { + Noderemoved = T; + return getRight(T); } - - return Balance(RemoveMinBinding(Left(T),NodeRemoved),Value(T),Right(T)); + return balanceTree(removeMinBinding(getLeft(T), Noderemoved), + getValue(T), getRight(T)); } - /// MarkImmutable - Clears the mutable bits of a root and all of its + /// markImmutable - Clears the mutable bits of a root and all of its /// descendants. - void MarkImmutable(TreeTy* T) { + void markImmutable(TreeTy* T) { if (!T || !T->isMutable()) return; - - T->MarkImmutable(); - MarkImmutable(Left(T)); - MarkImmutable(Right(T)); + T->markImmutable(); + markImmutable(getLeft(T)); + markImmutable(getRight(T)); } public: - TreeTy *GetCanonicalTree(TreeTy *TNew) { + TreeTy *getCanonicalTree(TreeTy *TNew) { if (!TNew) - return NULL; - - // Search the FoldingSet bucket for a Tree with the same digest. - FoldingSetNodeID ID; - unsigned digest = TNew->ComputeDigest(); - ID.AddInteger(digest); - unsigned hash = ID.ComputeHash(); - - typename CacheTy::bucket_iterator I = Cache.bucket_begin(hash); - typename CacheTy::bucket_iterator E = Cache.bucket_end(hash); - - for (; I != E; ++I) { - TreeTy *T = &*I; - - if (T->ComputeDigest() != digest) - continue; - - // We found a collision. Perform a comparison of Contents('T') - // with Contents('TNew') - typename TreeTy::iterator TI = T->begin(), TE = T->end(); - - if (!CompareTreeWithSection(TNew, TI, TE)) - continue; - - if (TI != TE) - continue; // T has more contents than TNew. - - // Trees did match! Return 'T'. - return T; + return 0; + + if (TNew->IsCanonicalized) + return TNew; + + // Search the hashtable for another tree with the same digest, and + // if find a collision compare those trees by their contents. + unsigned digest = TNew->computeDigest(); + TreeTy *&entry = Cache[digest]; + do { + if (!entry) + break; + for (TreeTy *T = entry ; T != 0; T = T->next) { + // Compare the Contents('T') with Contents('TNew') + typename TreeTy::iterator TI = T->begin(), TE = T->end(); + if (!compareTreeWithSection(TNew, TI, TE)) + continue; + if (TI != TE) + continue; // T has more contents than TNew. + // Trees did match! Return 'T'. + if (TNew->refCount == 0) + TNew->destroy(); + return T; + } + entry->prev = TNew; + TNew->next = entry; } + while (false); - // 'TNew' is the only tree of its kind. Return it. - Cache.InsertNode(TNew, (void*) &*Cache.bucket_end(hash)); + entry = TNew; + TNew->IsCanonicalized = true; return TNew; } }; - //===----------------------------------------------------------------------===// // Immutable AVL-Tree Iterators. //===----------------------------------------------------------------------===// @@ -635,19 +667,17 @@ public: } - bool AtEnd() const { return stack.empty(); } + bool atEnd() const { return stack.empty(); } - bool AtBeginning() const { + bool atBeginning() const { return stack.size() == 1 && getVisitState() == VisitedNone; } - void SkipToParent() { + void skipToParent() { assert(!stack.empty()); stack.pop_back(); - if (stack.empty()) return; - switch (getVisitState()) { case VisitedNone: stack.back() |= VisitedLeft; @@ -663,11 +693,9 @@ public: inline bool operator==(const _Self& x) const { if (stack.size() != x.stack.size()) return false; - for (unsigned i = 0 ; i < stack.size(); i++) if (stack[i] != x.stack[i]) return false; - return true; } @@ -675,70 +703,52 @@ public: _Self& operator++() { assert(!stack.empty()); - TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags); assert(Current); - switch (getVisitState()) { case VisitedNone: if (TreeTy* L = Current->getLeft()) stack.push_back(reinterpret_cast<uintptr_t>(L)); else stack.back() |= VisitedLeft; - break; - case VisitedLeft: if (TreeTy* R = Current->getRight()) stack.push_back(reinterpret_cast<uintptr_t>(R)); else stack.back() |= VisitedRight; - break; - case VisitedRight: - SkipToParent(); + skipToParent(); break; - default: assert(false && "Unreachable."); } - return *this; } _Self& operator--() { assert(!stack.empty()); - TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags); assert(Current); - switch (getVisitState()) { case VisitedNone: stack.pop_back(); break; - case VisitedLeft: stack.back() &= ~Flags; // Set state to "VisitedNone." - if (TreeTy* L = Current->getLeft()) stack.push_back(reinterpret_cast<uintptr_t>(L) | VisitedRight); - break; - case VisitedRight: stack.back() &= ~Flags; stack.back() |= VisitedLeft; - if (TreeTy* R = Current->getRight()) stack.push_back(reinterpret_cast<uintptr_t>(R) | VisitedRight); - break; - default: assert(false && "Unreachable."); } - return *this; } }; @@ -769,7 +779,7 @@ public: inline _Self& operator++() { do ++InternalItr; - while (!InternalItr.AtEnd() && + while (!InternalItr.atEnd() && InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft); return *this; @@ -777,16 +787,16 @@ public: inline _Self& operator--() { do --InternalItr; - while (!InternalItr.AtBeginning() && + while (!InternalItr.atBeginning() && InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft); return *this; } - inline void SkipSubTree() { - InternalItr.SkipToParent(); + inline void skipSubTree() { + InternalItr.skipToParent(); - while (!InternalItr.AtEnd() && + while (!InternalItr.atEnd() && InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft) ++InternalItr; } @@ -927,7 +937,23 @@ public: /// should use a Factory object to create sets instead of directly /// invoking the constructor, but there are cases where make this /// constructor public is useful. - explicit ImmutableSet(TreeTy* R) : Root(R) {} + explicit ImmutableSet(TreeTy* R) : Root(R) { + if (Root) { Root->retain(); } + } + ImmutableSet(const ImmutableSet &X) : Root(X.Root) { + if (Root) { Root->retain(); } + } + ImmutableSet &operator=(const ImmutableSet &X) { + if (Root != X.Root) { + if (X.Root) { X.Root->retain(); } + if (Root) { Root->release(); } + Root = X.Root; + } + return *this; + } + ~ImmutableSet() { + if (Root) { Root->release(); } + } class Factory { typename TreeTy::Factory F; @@ -940,33 +966,33 @@ public: Factory(BumpPtrAllocator& Alloc, bool canonicalize = true) : F(Alloc), Canonicalize(canonicalize) {} - /// GetEmptySet - Returns an immutable set that contains no elements. - ImmutableSet GetEmptySet() { - return ImmutableSet(F.GetEmptyTree()); + /// getEmptySet - Returns an immutable set that contains no elements. + ImmutableSet getEmptySet() { + return ImmutableSet(F.getEmptyTree()); } - /// Add - Creates a new immutable set that contains all of the values + /// add - Creates a new immutable set that contains all of the values /// of the original set with the addition of the specified value. If /// the original set already included the value, then the original set is /// returned and no memory is allocated. The time and space complexity /// of this operation is logarithmic in the size of the original set. /// The memory allocated to represent the set is released when the /// factory object that created the set is destroyed. - ImmutableSet Add(ImmutableSet Old, value_type_ref V) { - TreeTy *NewT = F.Add(Old.Root, V); - return ImmutableSet(Canonicalize ? F.GetCanonicalTree(NewT) : NewT); + ImmutableSet add(ImmutableSet Old, value_type_ref V) { + TreeTy *NewT = F.add(Old.Root, V); + return ImmutableSet(Canonicalize ? F.getCanonicalTree(NewT) : NewT); } - /// Remove - Creates a new immutable set that contains all of the values + /// remove - Creates a new immutable set that contains all of the values /// of the original set with the exception of the specified value. If /// the original set did not contain the value, the original set is /// returned and no memory is allocated. The time and space complexity /// of this operation is logarithmic in the size of the original set. /// The memory allocated to represent the set is released when the /// factory object that created the set is destroyed. - ImmutableSet Remove(ImmutableSet Old, value_type_ref V) { - TreeTy *NewT = F.Remove(Old.Root, V); - return ImmutableSet(Canonicalize ? F.GetCanonicalTree(NewT) : NewT); + ImmutableSet remove(ImmutableSet Old, value_type_ref V) { + TreeTy *NewT = F.remove(Old.Root, V); + return ImmutableSet(Canonicalize ? F.getCanonicalTree(NewT) : NewT); } BumpPtrAllocator& getAllocator() { return F.getAllocator(); } @@ -978,20 +1004,21 @@ public: friend class Factory; - /// contains - Returns true if the set contains the specified value. + /// Returns true if the set contains the specified value. bool contains(value_type_ref V) const { return Root ? Root->contains(V) : false; } - bool operator==(ImmutableSet RHS) const { + bool operator==(const ImmutableSet &RHS) const { return Root && RHS.Root ? Root->isEqual(*RHS.Root) : Root == RHS.Root; } - bool operator!=(ImmutableSet RHS) const { + bool operator!=(const ImmutableSet &RHS) const { return Root && RHS.Root ? Root->isNotEqual(*RHS.Root) : Root != RHS.Root; } TreeTy *getRoot() { + if (Root) { Root->retain(); } return Root; } @@ -1049,7 +1076,7 @@ public: // For testing. //===--------------------------------------------------===// - void verify() const { if (Root) Root->verify(); } + void validateTree() const { if (Root) Root->validateTree(); } }; } // end namespace llvm |
