//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Ted Kremenek 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.
//
//===----------------------------------------------------------------------===//
//
#include "llvm/Support/Allocator.h"
#include "llvm/ADT/FoldingSet.h"
+#include "llvm/System/DataTypes.h"
#include <cassert>
+#include <functional>
namespace llvm {
-
-//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
// Immutable AVL-Tree Definition.
//===----------------------------------------------------------------------===//
template <typename ImutInfo> class ImutAVLFactory;
+template <typename ImutInfo> class ImutAVLTreeInOrderIterator;
+template <typename ImutInfo> class ImutAVLTreeGenericIterator;
template <typename ImutInfo >
class ImutAVLTree : public FoldingSetNode {
- struct ComputeIsEqual;
public:
typedef typename ImutInfo::key_type_ref key_type_ref;
typedef typename ImutInfo::value_type value_type;
typedef typename ImutInfo::value_type_ref value_type_ref;
+
typedef ImutAVLFactory<ImutInfo> Factory;
friend class ImutAVLFactory<ImutInfo>;
-
- //===----------------------------------------------------===//
+
+ friend class ImutAVLTreeGenericIterator<ImutInfo>;
+ friend class FoldingSet<ImutAVLTree>;
+
+ typedef ImutAVLTreeInOrderIterator<ImutInfo> iterator;
+
+ //===----------------------------------------------------===//
// Public Interface.
- //===----------------------------------------------------===//
-
- ImutAVLTree* getLeft() const { return reinterpret_cast<ImutAVLTree*>(Left); }
-
- ImutAVLTree* getRight() const { return Right; }
-
- unsigned getHeight() const { return Height; }
-
+ //===----------------------------------------------------===//
+
+ /// getLeft - Returns a pointer to the left subtree. This value
+ /// is NULL if there is no left subtree.
+ ImutAVLTree *getLeft() const {
+ return reinterpret_cast<ImutAVLTree*>(Left & ~LeftFlags);
+ }
+
+ /// getRight - Returns a pointer to the right subtree. This value is
+ /// NULL if there is no right subtree.
+ 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; }
+
+ /// getValue - Returns the data value associated with the tree node.
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(Value(T));
-
+ key_type_ref CurrentKey = ImutInfo::KeyOfValue(T->getValue());
+
if (ImutInfo::isEqual(K,CurrentKey))
return T;
else if (ImutInfo::isLess(K,CurrentKey))
else
T = T->getRight();
}
-
+
return NULL;
}
+ /// getMaxElement - Find the subtree associated with the highest ranged
+ /// key value.
+ ImutAVLTree* getMaxElement() {
+ ImutAVLTree *T = this;
+ ImutAVLTree *Right = T->getRight();
+ while (Right) { T = Right; Right = T->getRight(); }
+ return T;
+ }
+
+ /// size - Returns the number of nodes in the tree, which includes
+ /// 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();
-
+
return n;
}
-
-
-
+
+ /// begin - Returns an iterator that iterates over the nodes of the tree
+ /// in an inorder traversal. The returned iterator thus refers to the
+ /// the tree node with the minimum data element.
+ iterator begin() const { return iterator(this); }
+
+ /// end - Returns an iterator for the tree that denotes the end of an
+ /// inorder traversal.
+ iterator end() const { return iterator(); }
+
+ bool ElementEqual(value_type_ref V) const {
+ // Compare the keys.
+ if (!ImutInfo::isEqual(ImutInfo::KeyOfValue(getValue()),
+ ImutInfo::KeyOfValue(V)))
+ return false;
+
+ // Also compare the data values.
+ if (!ImutInfo::isDataEqual(ImutInfo::DataOfValue(getValue()),
+ ImutInfo::DataOfValue(V)))
+ return false;
+
+ return true;
+ }
+
+ bool ElementEqual(const ImutAVLTree* RHS) const {
+ return ElementEqual(RHS->getValue());
+ }
+
+ /// isEqual - Compares two trees for structural equality and returns true
+ /// if they are equal. This worst case performance of this operation is
+ // linear in the sizes of the trees.
bool isEqual(const ImutAVLTree& RHS) const {
- // FIXME: Todo.
- return true;
+ if (&RHS == this)
+ return true;
+
+ iterator LItr = begin(), LEnd = end();
+ iterator RItr = RHS.begin(), REnd = RHS.end();
+
+ while (LItr != LEnd && RItr != REnd) {
+ if (*LItr == *RItr) {
+ LItr.SkipSubTree();
+ RItr.SkipSubTree();
+ continue;
+ }
+
+ if (!LItr->ElementEqual(*RItr))
+ return false;
+
+ ++LItr;
+ ++RItr;
+ }
+
+ return LItr == LEnd && RItr == REnd;
}
-
+
+ /// isNotEqual - Compares two trees for structural inequality. Performance
+ /// is the same is isEqual.
bool isNotEqual(const ImutAVLTree& RHS) const { return !isEqual(RHS); }
-
- bool contains(const key_type_ref K) { return (bool) find(K); }
-
+
+ /// contains - Returns true if this tree contains a subtree (node) that
+ /// has an data element that matches the specified key. Complexity
+ /// is logarithmic in the size of the tree.
+ bool contains(key_type_ref K) { return (bool) find(K); }
+
+ /// foreach - A member template the accepts invokes operator() on a functor
+ /// object (specifed by Callback) for every node/subtree in the tree.
+ /// Nodes are visited using an inorder traversal.
template <typename Callback>
void foreach(Callback& C) {
if (ImutAVLTree* L = getLeft()) L->foreach(C);
-
- C(Value);
-
+
+ C(Value);
+
if (ImutAVLTree* R = getRight()) R->foreach(C);
}
-
+
+ /// verify - 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
+ /// 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;
-
- assert (getHeight() == ( HL > HR ? HL : HR ) + 1
+
+ assert (getHeight() == ( HL > HR ? HL : HR ) + 1
&& "Height calculation wrong.");
-
+
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 (!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.
//===----------------------------------------------------===//
-
+
private:
uintptr_t Left;
ImutAVLTree* Right;
unsigned Height;
value_type Value;
-
- //===----------------------------------------------------===//
- // Profiling or FoldingSet.
+ uint32_t Digest;
+
//===----------------------------------------------------===//
-
- static inline
- void Profile(FoldingSetNodeID& ID, ImutAVLTree* L, ImutAVLTree* R,
- unsigned H, value_type_ref V) {
- ID.AddPointer(L);
- ID.AddPointer(R);
- ID.AddInteger(H);
- ImutInfo::Profile(ID,V);
- }
-
-public:
-
- void Profile(FoldingSetNodeID& ID) {
- Profile(ID,getSafeLeft(),getRight(),getHeight(),getValue());
- }
-
- //===----------------------------------------------------===//
// Internal methods (node manipulation; used by Factory).
//===----------------------------------------------------===//
-
+
private:
-
+
+ enum { Mutable = 0x1, NoCachedDigest = 0x2, LeftFlags = 0x3 };
+
+ /// ImutAVLTree - Internal constructor that is only called by
+ /// ImutAVLFactory.
ImutAVLTree(ImutAVLTree* l, ImutAVLTree* r, value_type_ref v, unsigned height)
- : Left(reinterpret_cast<uintptr_t>(l) | 0x1),
- Right(r), Height(height), Value(v) {}
-
- bool isMutable() const { return Left & 0x1; }
-
- ImutAVLTree* getSafeLeft() const {
- return reinterpret_cast<ImutAVLTree*>(Left & ~0x1);
- }
-
- // Mutating operations. A tree root can be manipulated as long as
- // its reference has not "escaped" from internal methods of a
- // factory object (see below). When a tree pointer is externally
- // viewable by client code, the internal "mutable bit" is cleared
- // to mark the tree immutable. Note that a tree that still has
- // its mutable bit set may have children (subtrees) that are themselves
+ : Left(reinterpret_cast<uintptr_t>(l) | (Mutable | NoCachedDigest)),
+ Right(r), Height(height), Value(v), Digest(0) {}
+
+
+ /// isMutable - Returns true if the left and right subtree references
+ /// (as well as height) can be changed. If this method returns false,
+ /// the tree is truly immutable. Trees returned from an ImutAVLFactory
+ /// 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 Left & Mutable; }
+
+ /// 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 !(Left & NoCachedDigest); }
+
+ //===----------------------------------------------------===//
+ // Mutating operations. A tree root can be manipulated as
+ // long as its reference has not "escaped" from internal
+ // methods of a factory object (see below). When a tree
+ // pointer is externally viewable by client code, the
+ // internal "mutable bit" is cleared to mark the tree
+ // immutable. Note that a tree that still has its mutable
+ // bit set may have children (subtrees) that are themselves
// immutable.
-
- void RemoveMutableFlag() {
- assert (Left & 0x1 && "Mutable flag already removed.");
- Left &= ~0x1;
+ //===----------------------------------------------------===//
+
+ /// MarkImmutable - Clears the mutable flag for a tree. After this happens,
+ /// it is an error to call setLeft(), setRight(), and setHeight().
+ void MarkImmutable() {
+ assert(isMutable() && "Mutable flag already removed.");
+ Left &= ~Mutable;
}
+ /// MarkedCachedDigest - Clears the NoCachedDigest flag for a tree.
+ void MarkedCachedDigest() {
+ assert(!hasCachedDigest() && "NoCachedDigest flag already removed.");
+ Left &= ~NoCachedDigest;
+ }
+
+ /// setLeft - Changes the reference of the left subtree. Used internally
+ /// by ImutAVLFactory.
void setLeft(ImutAVLTree* NewLeft) {
- assert (isMutable());
- Left = reinterpret_cast<uintptr_t>(NewLeft) | 0x1;
+ assert(isMutable() &&
+ "Only a mutable tree can have its left subtree changed.");
+ Left = reinterpret_cast<uintptr_t>(NewLeft) | LeftFlags;
}
-
+
+ /// setRight - Changes the reference of the right subtree. Used internally
+ /// by ImutAVLFactory.
void setRight(ImutAVLTree* NewRight) {
- assert (isMutable());
+ assert(isMutable() &&
+ "Only a mutable tree can have its right subtree changed.");
+
Right = NewRight;
+ // Set the NoCachedDigest flag.
+ Left = Left | NoCachedDigest;
+
}
-
+
+ /// setHeight - Changes the height of the tree. Used internally by
+ /// ImutAVLFactory.
void setHeight(unsigned h) {
- assert (isMutable());
+ assert(isMutable() && "Only a mutable tree can have its height changed.");
Height = h;
}
+
+ static inline
+ uint32_t ComputeDigest(ImutAVLTree* L, ImutAVLTree* R, value_type_ref V) {
+ uint32_t digest = 0;
+
+ if (L)
+ digest += L->ComputeDigest();
+
+ // Compute digest of stored data.
+ FoldingSetNodeID ID;
+ ImutInfo::Profile(ID,V);
+ digest += ID.ComputeHash();
+
+ if (R)
+ digest += R->ComputeDigest();
+
+ return digest;
+ }
+
+ inline uint32_t ComputeDigest() {
+ // Check the lowest bit to determine if digest has actually been
+ // pre-computed.
+ if (hasCachedDigest())
+ return Digest;
+
+ uint32_t X = ComputeDigest(getLeft(), getRight(), getValue());
+ Digest = X;
+ MarkedCachedDigest();
+ return X;
+ }
};
-//===----------------------------------------------------------------------===//
+//===----------------------------------------------------------------------===//
// Immutable AVL-Tree Factory class.
//===----------------------------------------------------------------------===//
-template <typename ImutInfo >
+template <typename ImutInfo >
class ImutAVLFactory {
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;
-
- CacheTy Cache;
- BumpPtrAllocator Allocator;
-
- //===--------------------------------------------------===//
+
+ CacheTy Cache;
+ uintptr_t Allocator;
+
+ bool ownsAllocator() const {
+ return Allocator & 0x1 ? false : true;
+ }
+
+ BumpPtrAllocator& getAllocator() const {
+ return *reinterpret_cast<BumpPtrAllocator*>(Allocator & ~0x1);
+ }
+
+ //===--------------------------------------------------===//
// Public interface.
//===--------------------------------------------------===//
-
+
public:
- ImutAVLFactory() {}
-
+ ImutAVLFactory()
+ : Allocator(reinterpret_cast<uintptr_t>(new BumpPtrAllocator())) {}
+
+ ImutAVLFactory(BumpPtrAllocator& Alloc)
+ : Allocator(reinterpret_cast<uintptr_t>(&Alloc) | 0x1) {}
+
+ ~ImutAVLFactory() {
+ if (ownsAllocator()) delete &getAllocator();
+ }
+
TreeTy* Add(TreeTy* T, value_type_ref V) {
T = Add_internal(V,T);
MarkImmutable(T);
return T;
}
-
+
TreeTy* Remove(TreeTy* T, key_type_ref V) {
T = Remove_internal(V,T);
MarkImmutable(T);
return T;
}
-
+
TreeTy* GetEmptyTree() const { return NULL; }
-
- //===--------------------------------------------------===//
+
+ //===--------------------------------------------------===//
// 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.
//===--------------------------------------------------===//
private:
-
- bool isEmpty(TreeTy* T) const {
- return !T;
- }
-
- unsigned Height(TreeTy* T) const {
- return T ? T->getHeight() : 0;
- }
-
- TreeTy* Left(TreeTy* T) const {
- assert (T);
- return T->getSafeLeft();
- }
-
- TreeTy* Right(TreeTy* T) const {
- assert (T);
- return T->getRight();
- }
-
- value_type_ref Value(TreeTy* T) const {
- assert (T);
- return T->Value;
- }
-
+
+ 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; }
+
unsigned IncrementHeight(TreeTy* L, TreeTy* R) const {
unsigned hl = Height(L);
unsigned hr = Height(R);
return ( hl > hr ? hl : hr ) + 1;
}
-
- //===--------------------------------------------------===//
- // "Create" is used to generate new tree roots that link
+
+ 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))
+ return false;
+
+ return true;
+ }
+
+ //===--------------------------------------------------===//
+ // "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
// then discarded later before the finished tree is
// returned to the caller.
//===--------------------------------------------------===//
-
- TreeTy* Create(TreeTy* L, value_type_ref V, TreeTy* R) {
- FoldingSetNodeID ID;
- unsigned height = IncrementHeight(L,R);
-
- TreeTy::Profile(ID,L,R,height,V);
- void* InsertPos;
-
- if (TreeTy* T = Cache.FindNodeOrInsertPos(ID,InsertPos))
- return T;
-
- assert (InsertPos != NULL);
-
- // FIXME: more intelligent calculation of alignment.
- TreeTy* T = (TreeTy*) Allocator.Allocate(sizeof(*T),16);
- new (T) TreeTy(L,R,V,height);
-
- Cache.InsertNode(T,InsertPos);
- return T;
+
+ 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));
+ return T;
}
-
- TreeTy* Create(TreeTy* L, TreeTy* OldTree, TreeTy* R) {
+
+ TreeTy* CreateNode(TreeTy* L, TreeTy* OldTree, TreeTy* R) {
assert (!isEmpty(OldTree));
-
+
if (OldTree->isMutable()) {
OldTree->setLeft(L);
OldTree->setRight(R);
OldTree->setHeight(IncrementHeight(L,R));
return OldTree;
}
- else return Create(L, Value(OldTree), R);
+ else
+ return CreateNode(L, Value(OldTree), R);
}
-
+
/// Balance - 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);
-
+
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);
-
+
if (Height(LL) >= Height(LR))
- return Create(LL, L, Create(LR,V,R));
-
+ 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);
-
- return Create(Create(LL,L,LRL), LR, Create(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);
-
+
if (Height(RR) >= Height(RL))
- return Create(Create(L,V,RL), R, RR);
-
+ 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);
-
- return Create(Create(L,V,RLL), RL, Create(RLR,R,RR));
+
+ return CreateNode(CreateNode(L,V,RLL), RL, CreateNode(RLR,R,RR));
}
else
- return Create(L,V,R);
+ return CreateNode(L,V,R);
}
-
+
/// 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) {
if (isEmpty(T))
- return Create(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));
-
+
if (ImutInfo::isEqual(K,KCurrent))
- return Create(Left(T), V, Right(T));
+ return CreateNode(Left(T), V, Right(T));
else if (ImutInfo::isLess(K,KCurrent))
return Balance(Add_internal(V,Left(T)), Value(T), Right(T));
else
return Balance(Left(T), Value(T), Add_internal(V,Right(T)));
}
-
- /// Remove_interal - 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) {
if (isEmpty(T))
return T;
-
+
assert (!T->isMutable());
-
+
key_type_ref KCurrent = ImutInfo::KeyOfValue(Value(T));
-
+
if (ImutInfo::isEqual(K,KCurrent))
return CombineLeftRightTrees(Left(T),Right(T));
else if (ImutInfo::isLess(K,KCurrent))
else
return Balance(Left(T), Value(T), Remove_internal(K,Right(T)));
}
-
+
TreeTy* CombineLeftRightTrees(TreeTy* L, TreeTy* R) {
- if (isEmpty(L)) return R;
+ if (isEmpty(L)) return R;
if (isEmpty(R)) return L;
-
- TreeTy* OldNode;
+
+ TreeTy* OldNode;
TreeTy* NewRight = RemoveMinBinding(R,OldNode);
return Balance(L,Value(OldNode),NewRight);
}
-
+
TreeTy* RemoveMinBinding(TreeTy* T, TreeTy*& NodeRemoved) {
assert (!isEmpty(T));
-
+
if (isEmpty(Left(T))) {
NodeRemoved = T;
return Right(T);
}
-
+
return Balance(RemoveMinBinding(Left(T),NodeRemoved),Value(T),Right(T));
- }
-
+ }
+
/// MarkImmutable - Clears the mutable bits of a root and all of its
/// descendants.
void MarkImmutable(TreeTy* T) {
if (!T || !T->isMutable())
return;
-
- T->RemoveMutableFlag();
+
+ T->MarkImmutable();
MarkImmutable(Left(T));
MarkImmutable(Right(T));
}
+
+public:
+ 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('L')+'V'+Contents('R').
+ typename TreeTy::iterator TI = T->begin(), TE = T->end();
+
+ // First compare Contents('L') with the (initial) contents of T.
+ if (!CompareTreeWithSection(TNew->getLeft(), TI, TE))
+ continue;
+
+ // Now compare the new data element.
+ if (TI == TE || !TI->ElementEqual(TNew->getValue()))
+ continue;
+
+ ++TI;
+
+ // Now compare the remainder of 'T' with 'R'.
+ if (!CompareTreeWithSection(TNew->getRight(), TI, TE))
+ continue;
+
+ if (TI != TE)
+ continue; // Contents('R') did not match suffix of 'T'.
+
+ // Trees did match! Return 'T'.
+ return T;
+ }
+
+ // 'TNew' is the only tree of its kind. Return it.
+ Cache.InsertNode(TNew, (void*) &*Cache.bucket_end(hash));
+ return TNew;
+ }
};
-//===----------------------------------------------------------------------===//
+//===----------------------------------------------------------------------===//
+// Immutable AVL-Tree Iterators.
+//===----------------------------------------------------------------------===//
+
+template <typename ImutInfo>
+class ImutAVLTreeGenericIterator {
+ SmallVector<uintptr_t,20> stack;
+public:
+ enum VisitFlag { VisitedNone=0x0, VisitedLeft=0x1, VisitedRight=0x3,
+ Flags=0x3 };
+
+ typedef ImutAVLTree<ImutInfo> TreeTy;
+ typedef ImutAVLTreeGenericIterator<ImutInfo> _Self;
+
+ inline ImutAVLTreeGenericIterator() {}
+ inline ImutAVLTreeGenericIterator(const TreeTy* Root) {
+ if (Root) stack.push_back(reinterpret_cast<uintptr_t>(Root));
+ }
+
+ TreeTy* operator*() const {
+ assert (!stack.empty());
+ return reinterpret_cast<TreeTy*>(stack.back() & ~Flags);
+ }
+
+ uintptr_t getVisitState() {
+ assert (!stack.empty());
+ return stack.back() & Flags;
+ }
+
+
+ bool AtEnd() const { return stack.empty(); }
+
+ bool AtBeginning() const {
+ return stack.size() == 1 && getVisitState() == VisitedNone;
+ }
+
+ void SkipToParent() {
+ assert (!stack.empty());
+ stack.pop_back();
+
+ if (stack.empty())
+ return;
+
+ switch (getVisitState()) {
+ case VisitedNone:
+ stack.back() |= VisitedLeft;
+ break;
+ case VisitedLeft:
+ stack.back() |= VisitedRight;
+ break;
+ default:
+ assert (false && "Unreachable.");
+ }
+ }
+
+ 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;
+ }
+
+ inline bool operator!=(const _Self& x) const { return !operator==(x); }
+
+ _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();
+ 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;
+ }
+};
+
+template <typename ImutInfo>
+class ImutAVLTreeInOrderIterator {
+ typedef ImutAVLTreeGenericIterator<ImutInfo> InternalIteratorTy;
+ InternalIteratorTy InternalItr;
+
+public:
+ typedef ImutAVLTree<ImutInfo> TreeTy;
+ typedef ImutAVLTreeInOrderIterator<ImutInfo> _Self;
+
+ ImutAVLTreeInOrderIterator(const TreeTy* Root) : InternalItr(Root) {
+ if (Root) operator++(); // Advance to first element.
+ }
+
+ ImutAVLTreeInOrderIterator() : InternalItr() {}
+
+ inline bool operator==(const _Self& x) const {
+ return InternalItr == x.InternalItr;
+ }
+
+ inline bool operator!=(const _Self& x) const { return !operator==(x); }
+
+ inline TreeTy* operator*() const { return *InternalItr; }
+ inline TreeTy* operator->() const { return *InternalItr; }
+
+ inline _Self& operator++() {
+ do ++InternalItr;
+ while (!InternalItr.AtEnd() &&
+ InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft);
+
+ return *this;
+ }
+
+ inline _Self& operator--() {
+ do --InternalItr;
+ while (!InternalItr.AtBeginning() &&
+ InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft);
+
+ return *this;
+ }
+
+ inline void SkipSubTree() {
+ InternalItr.SkipToParent();
+
+ while (!InternalItr.AtEnd() &&
+ InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft)
+ ++InternalItr;
+ }
+};
+
+//===----------------------------------------------------------------------===//
// Trait classes for Profile information.
//===----------------------------------------------------------------------===//
struct ImutProfileInfo {
typedef const T value_type;
typedef const T& value_type_ref;
-
+
static inline void Profile(FoldingSetNodeID& ID, value_type_ref X) {
- X.Profile(ID);
- }
+ FoldingSetTrait<T>::Profile(X,ID);
+ }
};
/// Profile traits for integers.
template <typename T>
-struct ImutProfileInteger {
+struct ImutProfileInteger {
typedef const T value_type;
typedef const T& value_type_ref;
-
+
static inline void Profile(FoldingSetNodeID& ID, value_type_ref X) {
ID.AddInteger(X);
- }
+ }
};
#define PROFILE_INTEGER_INFO(X)\
struct ImutProfileInfo<T*> {
typedef const T* value_type;
typedef value_type value_type_ref;
-
+
static inline void Profile(FoldingSetNodeID &ID, value_type_ref X) {
ID.AddPointer(X);
}
};
-//===----------------------------------------------------------------------===//
+//===----------------------------------------------------------------------===//
// Trait classes that contain element comparison operators and type
// definitions used by ImutAVLTree, ImmutableSet, and ImmutableMap. These
// inherit from the profile traits (ImutProfileInfo) to include operations
typedef typename ImutProfileInfo<T>::value_type_ref value_type_ref;
typedef value_type key_type;
typedef value_type_ref key_type_ref;
-
+ typedef bool data_type;
+ typedef bool data_type_ref;
+
static inline key_type_ref KeyOfValue(value_type_ref D) { return D; }
-
- static inline bool isEqual(key_type_ref LHS, key_type_ref RHS) {
+ static inline data_type_ref DataOfValue(value_type_ref) { return true; }
+
+ static inline bool isEqual(key_type_ref LHS, key_type_ref RHS) {
return std::equal_to<key_type>()(LHS,RHS);
}
-
+
static inline bool isLess(key_type_ref LHS, key_type_ref RHS) {
return std::less<key_type>()(LHS,RHS);
}
+
+ static inline bool isDataEqual(data_type_ref,data_type_ref) { return true; }
};
/// ImutContainerInfo - Specialization for pointer values to treat pointers
typedef typename ImutProfileInfo<T*>::value_type_ref value_type_ref;
typedef value_type key_type;
typedef value_type_ref key_type_ref;
-
+ typedef bool data_type;
+ typedef bool data_type_ref;
+
static inline key_type_ref KeyOfValue(value_type_ref D) { return D; }
-
+ static inline data_type_ref DataOfValue(value_type_ref) { return true; }
+
static inline bool isEqual(key_type_ref LHS, key_type_ref RHS) {
return LHS == RHS;
}
-
+
static inline bool isLess(key_type_ref LHS, key_type_ref RHS) {
return LHS < RHS;
}
+
+ static inline bool isDataEqual(data_type_ref,data_type_ref) { return true; }
};
-//===----------------------------------------------------------------------===//
+//===----------------------------------------------------------------------===//
// Immutable Set
//===----------------------------------------------------------------------===//
public:
typedef typename ValInfo::value_type value_type;
typedef typename ValInfo::value_type_ref value_type_ref;
-
-private:
typedef ImutAVLTree<ValInfo> TreeTy;
- TreeTy* Root;
-
- ImmutableSet(TreeTy* R) : Root(R) {}
+
+private:
+ TreeTy *Root;
public:
-
+ /// Constructs a set from a pointer to a tree root. In general one
+ /// 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) {}
+
class Factory {
typename TreeTy::Factory F;
-
+ const bool Canonicalize;
+
public:
- Factory() {}
-
- ImmutableSet GetEmptySet() { return ImmutableSet(F.GetEmptyTree()); }
-
+ Factory(bool canonicalize = true)
+ : Canonicalize(canonicalize) {}
+
+ 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());
+ }
+
+ /// 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) {
- return ImmutableSet(F.Add(Old.Root,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
+ /// 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) {
- return ImmutableSet(F.Remove(Old.Root,V));
+ TreeTy *NewT = F.Remove(Old.Root, V);
+ return ImmutableSet(Canonicalize ? F.GetCanonicalTree(NewT) : NewT);
}
-
+
+ BumpPtrAllocator& getAllocator() { return F.getAllocator(); }
+
private:
- Factory(const Factory& RHS) {};
- void operator=(const Factory& RHS) {};
+ Factory(const Factory& RHS) {}
+ void operator=(const Factory& RHS) {}
};
-
+
friend class Factory;
-
- bool contains(const value_type_ref V) const {
+
+ /// contains - 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 {
return Root && RHS.Root ? Root->isEqual(*RHS.Root) : Root == RHS.Root;
}
-
+
bool operator!=(ImmutableSet RHS) const {
return Root && RHS.Root ? Root->isNotEqual(*RHS.Root) : Root != RHS.Root;
}
-
+
+ TreeTy *getRoot() {
+ return Root;
+ }
+
+ /// isEmpty - Return true if the set contains no elements.
bool isEmpty() const { return !Root; }
-
+
+ /// isSingleton - Return true if the set contains exactly one element.
+ /// This method runs in constant time.
+ bool isSingleton() const { return getHeight() == 1; }
+
template <typename Callback>
void foreach(Callback& C) { if (Root) Root->foreach(C); }
-
+
template <typename Callback>
void foreach() { if (Root) { Callback C; Root->foreach(C); } }
-
- //===--------------------------------------------------===//
+
+ //===--------------------------------------------------===//
+ // Iterators.
+ //===--------------------------------------------------===//
+
+ class iterator {
+ typename TreeTy::iterator itr;
+ iterator(TreeTy* t) : itr(t) {}
+ friend class ImmutableSet<ValT,ValInfo>;
+ public:
+ iterator() {}
+ inline value_type_ref operator*() const { return itr->getValue(); }
+ inline iterator& operator++() { ++itr; return *this; }
+ inline iterator operator++(int) { iterator tmp(*this); ++itr; return tmp; }
+ inline iterator& operator--() { --itr; return *this; }
+ inline iterator operator--(int) { iterator tmp(*this); --itr; return tmp; }
+ inline bool operator==(const iterator& RHS) const { return RHS.itr == itr; }
+ inline bool operator!=(const iterator& RHS) const { return RHS.itr != itr; }
+ inline value_type *operator->() const { return &(operator*()); }
+ };
+
+ iterator begin() const { return iterator(Root); }
+ iterator end() const { return iterator(); }
+
+ //===--------------------------------------------------===//
+ // Utility methods.
+ //===--------------------------------------------------===//
+
+ inline unsigned getHeight() const { return Root ? Root->getHeight() : 0; }
+
+ static inline void Profile(FoldingSetNodeID& ID, const ImmutableSet& S) {
+ ID.AddPointer(S.Root);
+ }
+
+ inline void Profile(FoldingSetNodeID& ID) const {
+ return Profile(ID,*this);
+ }
+
+ //===--------------------------------------------------===//
// For testing.
- //===--------------------------------------------------===//
-
+ //===--------------------------------------------------===//
+
void verify() const { if (Root) Root->verify(); }
- unsigned getHeight() const { return Root ? Root->getHeight() : 0; }
};
} // end namespace llvm