//===- llvm/Analysis/Dominators.h - Dominator Info Calculation --*- C++ -*-===//
-//
+//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+//
//===----------------------------------------------------------------------===//
//
// This file defines the following classes:
-// 1. ImmediateDominators: Calculates and holds a mapping between BasicBlocks
-// and their immediate dominator.
-// 2. DominatorSet: Calculates the [reverse] dominator set for a function
-// 3. DominatorTree: Represent the ImmediateDominator as an explicit tree
-// structure.
-// 4. DominanceFrontier: Calculate and hold the dominance frontier for a
+// 1. DominatorTree: Represent dominators as an explicit tree structure.
+// 2. DominanceFrontier: Calculate and hold the dominance frontier for a
// function.
//
// These data structures are listed in increasing order of complexity. It
-// takes longer to calculate the dominator frontier, for example, than the
-// ImmediateDominator mapping.
-//
+// takes longer to calculate the dominator frontier, for example, than the
+// DominatorTree mapping.
+//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_DOMINATORS_H
#define LLVM_ANALYSIS_DOMINATORS_H
#include "llvm/Pass.h"
+#include "llvm/Instruction.h"
+#include "llvm/Instructions.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Assembly/Writer.h"
+#include "llvm/Support/Compiler.h"
+#include <algorithm>
#include <set>
namespace llvm {
-class Instruction;
-
template <typename GraphType> struct GraphTraits;
//===----------------------------------------------------------------------===//
/// DominatorBase - Base class that other, more interesting dominator analyses
/// inherit from.
///
+template <class NodeT>
class DominatorBase : public FunctionPass {
protected:
- std::vector<BasicBlock*> Roots;
+ std::vector<NodeT*> Roots;
const bool IsPostDominators;
-
- inline DominatorBase(bool isPostDom) : Roots(), IsPostDominators(isPostDom) {}
+ inline DominatorBase(intptr_t ID, bool isPostDom) :
+ FunctionPass(ID), Roots(), IsPostDominators(isPostDom) {}
public:
+
/// getRoots - Return the root blocks of the current CFG. This may include
/// multiple blocks if we are computing post dominators. For forward
/// dominators, this will always be a single block (the entry node).
///
- inline const std::vector<BasicBlock*> &getRoots() const { return Roots; }
+ inline const std::vector<NodeT*> &getRoots() const { return Roots; }
/// isPostDominator - Returns true if analysis based of postdoms
///
//===----------------------------------------------------------------------===//
-/// ImmediateDominators - Calculate the immediate dominator for each node in a
-/// function.
-///
-class ImmediateDominatorsBase : public DominatorBase {
-protected:
- std::map<BasicBlock*, BasicBlock*> IDoms;
+// DomTreeNode - Dominator Tree Node
+template<class NodeT> class DominatorTreeBase;
+class PostDominatorTree;
+class MachineBasicBlock;
+
+template <class NodeT>
+class DomTreeNodeBase {
+ NodeT *TheBB;
+ DomTreeNodeBase<NodeT> *IDom;
+ std::vector<DomTreeNodeBase<NodeT> *> Children;
+ int DFSNumIn, DFSNumOut;
+
+ template<class N> friend class DominatorTreeBase;
+ friend class PostDominatorTree;
public:
- ImmediateDominatorsBase(bool isPostDom) : DominatorBase(isPostDom) {}
-
- virtual void releaseMemory() { IDoms.clear(); }
-
- // Accessor interface:
- typedef std::map<BasicBlock*, BasicBlock*> IDomMapType;
- typedef IDomMapType::const_iterator const_iterator;
- inline const_iterator begin() const { return IDoms.begin(); }
- inline const_iterator end() const { return IDoms.end(); }
- inline const_iterator find(BasicBlock* B) const { return IDoms.find(B);}
-
- /// operator[] - Return the idom for the specified basic block. The start
- /// node returns null, because it does not have an immediate dominator.
- ///
- inline BasicBlock *operator[](BasicBlock *BB) const {
- return get(BB);
+ typedef typename std::vector<DomTreeNodeBase<NodeT> *>::iterator iterator;
+ typedef typename std::vector<DomTreeNodeBase<NodeT> *>::const_iterator
+ const_iterator;
+
+ iterator begin() { return Children.begin(); }
+ iterator end() { return Children.end(); }
+ const_iterator begin() const { return Children.begin(); }
+ const_iterator end() const { return Children.end(); }
+
+ NodeT *getBlock() const { return TheBB; }
+ DomTreeNodeBase<NodeT> *getIDom() const { return IDom; }
+ const std::vector<DomTreeNodeBase<NodeT>*> &getChildren() const {
+ return Children;
}
-
- /// get() - Synonym for operator[].
- ///
- inline BasicBlock *get(BasicBlock *BB) const {
- std::map<BasicBlock*, BasicBlock*>::const_iterator I = IDoms.find(BB);
- return I != IDoms.end() ? I->second : 0;
+
+ DomTreeNodeBase(NodeT *BB, DomTreeNodeBase<NodeT> *iDom)
+ : TheBB(BB), IDom(iDom), DFSNumIn(-1), DFSNumOut(-1) { }
+
+ DomTreeNodeBase<NodeT> *addChild(DomTreeNodeBase<NodeT> *C) {
+ Children.push_back(C);
+ return C;
}
-
- //===--------------------------------------------------------------------===//
- // API to update Immediate(Post)Dominators information based on modifications
- // to the CFG...
-
- /// addNewBlock - Add a new block to the CFG, with the specified immediate
- /// dominator.
- ///
- void addNewBlock(BasicBlock *BB, BasicBlock *IDom) {
- assert(get(BB) == 0 && "BasicBlock already in idom info!");
- IDoms[BB] = IDom;
+
+ void setIDom(DomTreeNodeBase<NodeT> *NewIDom) {
+ assert(IDom && "No immediate dominator?");
+ if (IDom != NewIDom) {
+ std::vector<DomTreeNodeBase<BasicBlock>*>::iterator I =
+ std::find(IDom->Children.begin(), IDom->Children.end(), this);
+ assert(I != IDom->Children.end() &&
+ "Not in immediate dominator children set!");
+ // I am no longer your child...
+ IDom->Children.erase(I);
+
+ // Switch to new dominator
+ IDom = NewIDom;
+ IDom->Children.push_back(this);
+ }
}
-
- /// setImmediateDominator - Update the immediate dominator information to
- /// change the current immediate dominator for the specified block to another
- /// block. This method requires that BB already have an IDom, otherwise just
- /// use addNewBlock.
- ///
- void setImmediateDominator(BasicBlock *BB, BasicBlock *NewIDom) {
- assert(IDoms.find(BB) != IDoms.end() && "BB doesn't have idom yet!");
- IDoms[BB] = NewIDom;
+
+ /// getDFSNumIn/getDFSNumOut - These are an internal implementation detail, do
+ /// not call them.
+ unsigned getDFSNumIn() const { return DFSNumIn; }
+ unsigned getDFSNumOut() const { return DFSNumOut; }
+private:
+ // Return true if this node is dominated by other. Use this only if DFS info
+ // is valid.
+ bool DominatedBy(const DomTreeNodeBase<NodeT> *other) const {
+ return this->DFSNumIn >= other->DFSNumIn &&
+ this->DFSNumOut <= other->DFSNumOut;
}
-
- /// print - Convert to human readable form
- ///
- virtual void print(std::ostream &OS) const;
};
-//===-------------------------------------
-/// ImmediateDominators Class - Concrete subclass of ImmediateDominatorsBase
-/// that is used to compute a normal immediate dominator set.
-///
-struct ImmediateDominators : public ImmediateDominatorsBase {
- ImmediateDominators() : ImmediateDominatorsBase(false) {}
-
- BasicBlock *getRoot() const {
- assert(Roots.size() == 1 && "Should always have entry node!");
- return Roots[0];
- }
+EXTERN_TEMPLATE_INSTANTIATION(class DomTreeNodeBase<BasicBlock>);
+
+template<class NodeT>
+static std::ostream &operator<<(std::ostream &o,
+ const DomTreeNodeBase<NodeT> *Node) {
+ if (Node->getBlock())
+ WriteAsOperand(o, Node->getBlock(), false);
+ else
+ o << " <<exit node>>";
+
+ o << " {" << Node->getDFSNumIn() << "," << Node->getDFSNumOut() << "}";
+
+ return o << "\n";
+}
+
+template<class NodeT>
+static void PrintDomTree(const DomTreeNodeBase<NodeT> *N, std::ostream &o,
+ unsigned Lev) {
+ o << std::string(2*Lev, ' ') << "[" << Lev << "] " << N;
+ for (typename DomTreeNodeBase<NodeT>::const_iterator I = N->begin(),
+ E = N->end(); I != E; ++I)
+ PrintDomTree<NodeT>(*I, o, Lev+1);
+}
+
+typedef DomTreeNodeBase<BasicBlock> DomTreeNode;
+typedef DomTreeNodeBase<MachineBasicBlock> MachineDomTreeNode;
- virtual bool runOnFunction(Function &F);
+//===----------------------------------------------------------------------===//
+/// DominatorTree - Calculate the immediate dominator tree for a function.
+///
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.setPreservesAll();
- }
+template<class NodeT>
+class DominatorTreeBase : public DominatorBase<NodeT> {
+protected:
+ typedef DenseMap<NodeT*, DomTreeNodeBase<NodeT>*> DomTreeNodeMapType;
+ DomTreeNodeMapType DomTreeNodes;
+ DomTreeNodeBase<NodeT> *RootNode;
-private:
+ bool DFSInfoValid;
+ unsigned int SlowQueries;
+ // Information record used during immediate dominators computation.
struct InfoRec {
unsigned Semi;
unsigned Size;
- BasicBlock *Label, *Parent, *Child, *Ancestor;
-
- std::vector<BasicBlock*> Bucket;
-
- InfoRec() : Semi(0), Size(0), Label(0), Parent(0), Child(0), Ancestor(0){}
- };
+ NodeT *Label, *Parent, *Child, *Ancestor;
- // Vertex - Map the DFS number to the BasicBlock*
- std::vector<BasicBlock*> Vertex;
+ std::vector<NodeT*> Bucket;
- // Info - Collection of information used during the computation of idoms.
- std::map<BasicBlock*, InfoRec> Info;
+ InfoRec() : Semi(0), Size(0), Label(0), Parent(0), Child(0), Ancestor(0) {}
+ };
- unsigned DFSPass(BasicBlock *V, InfoRec &VInfo, unsigned N);
- void Compress(BasicBlock *V, InfoRec &VInfo);
- BasicBlock *Eval(BasicBlock *v);
- void Link(BasicBlock *V, BasicBlock *W, InfoRec &WInfo);
-};
+ DenseMap<NodeT*, NodeT*> IDoms;
+ // Vertex - Map the DFS number to the BasicBlock*
+ std::vector<NodeT*> Vertex;
+ // Info - Collection of information used during the computation of idoms.
+ DenseMap<NodeT*, InfoRec> Info;
+
+ void reset() {
+ for (typename DomTreeNodeMapType::iterator I = this->DomTreeNodes.begin(),
+ E = DomTreeNodes.end(); I != E; ++I)
+ delete I->second;
+ DomTreeNodes.clear();
+ IDoms.clear();
+ this->Roots.clear();
+ Vertex.clear();
+ RootNode = 0;
+ }
-//===----------------------------------------------------------------------===//
-/// DominatorSet - Maintain a set<BasicBlock*> for every basic block in a
-/// function, that represents the blocks that dominate the block. If the block
-/// is unreachable in this function, the set will be empty. This cannot happen
-/// for reachable code, because every block dominates at least itself.
-///
-struct DominatorSetBase : public DominatorBase {
- typedef std::set<BasicBlock*> DomSetType; // Dom set for a bb
- // Map of dom sets
- typedef std::map<BasicBlock*, DomSetType> DomSetMapType;
-protected:
- DomSetMapType Doms;
public:
- DominatorSetBase(bool isPostDom) : DominatorBase(isPostDom) {}
-
- virtual void releaseMemory() { Doms.clear(); }
-
- // Accessor interface:
- typedef DomSetMapType::const_iterator const_iterator;
- typedef DomSetMapType::iterator iterator;
- inline const_iterator begin() const { return Doms.begin(); }
- inline iterator begin() { return Doms.begin(); }
- inline const_iterator end() const { return Doms.end(); }
- inline iterator end() { return Doms.end(); }
- inline const_iterator find(BasicBlock* B) const { return Doms.find(B); }
- inline iterator find(BasicBlock* B) { return Doms.find(B); }
+ DominatorTreeBase(intptr_t ID, bool isPostDom)
+ : DominatorBase<NodeT>(ID, isPostDom), DFSInfoValid(false), SlowQueries(0) {}
+ ~DominatorTreeBase() { reset(); }
+ virtual void releaseMemory() { reset(); }
- /// getDominators - Return the set of basic blocks that dominate the specified
- /// block.
+ /// getNode - return the (Post)DominatorTree node for the specified basic
+ /// block. This is the same as using operator[] on this class.
///
- inline const DomSetType &getDominators(BasicBlock *BB) const {
- const_iterator I = find(BB);
- assert(I != end() && "BB not in function!");
- return I->second;
+ inline DomTreeNodeBase<NodeT> *getNode(NodeT *BB) const {
+ typename DomTreeNodeMapType::const_iterator I = DomTreeNodes.find(BB);
+ return I != DomTreeNodes.end() ? I->second : 0;
}
- /// isReachable - Return true if the specified basicblock is reachable. If
- /// the block is reachable, we have dominator set information for it.
- ///
- bool isReachable(BasicBlock *BB) const {
- return !getDominators(BB).empty();
+ inline DomTreeNodeBase<NodeT> *operator[](NodeT *BB) const {
+ return getNode(BB);
}
- /// dominates - Return true if A dominates B.
+ /// getRootNode - This returns the entry node for the CFG of the function. If
+ /// this tree represents the post-dominance relations for a function, however,
+ /// this root may be a node with the block == NULL. This is the case when
+ /// there are multiple exit nodes from a particular function. Consumers of
+ /// post-dominance information must be capable of dealing with this
+ /// possibility.
///
- inline bool dominates(BasicBlock *A, BasicBlock *B) const {
- return getDominators(B).count(A) != 0;
- }
+ DomTreeNodeBase<NodeT> *getRootNode() { return RootNode; }
+ const DomTreeNodeBase<NodeT> *getRootNode() const { return RootNode; }
- /// properlyDominates - Return true if A dominates B and A != B.
+ /// properlyDominates - Returns true iff this dominates N and this != N.
+ /// Note that this is not a constant time operation!
///
- bool properlyDominates(BasicBlock *A, BasicBlock *B) const {
- return dominates(A, B) && A != B;
+ bool properlyDominates(const DomTreeNodeBase<NodeT> *A,
+ DomTreeNodeBase<NodeT> *B) const {
+ if (A == 0 || B == 0) return false;
+ return dominatedBySlowTreeWalk(A, B);
}
- /// print - Convert to human readable form
- ///
- virtual void print(std::ostream &OS) const;
-
- /// dominates - Return true if A dominates B. This performs the special
- /// checks necessary if A and B are in the same basic block.
- ///
- bool dominates(Instruction *A, Instruction *B) const;
-
- //===--------------------------------------------------------------------===//
- // API to update (Post)DominatorSet information based on modifications to
- // the CFG...
-
- /// addBasicBlock - Call to update the dominator set with information about a
- /// new block that was inserted into the function.
- ///
- void addBasicBlock(BasicBlock *BB, const DomSetType &Dominators) {
- assert(find(BB) == end() && "Block already in DominatorSet!");
- Doms.insert(std::make_pair(BB, Dominators));
+ inline bool properlyDominates(NodeT *A, NodeT *B) {
+ return properlyDominates(getNode(A), getNode(B));
}
- /// addDominator - If a new block is inserted into the CFG, then method may be
- /// called to notify the blocks it dominates that it is in their set.
- ///
- void addDominator(BasicBlock *BB, BasicBlock *NewDominator) {
- iterator I = find(BB);
- assert(I != end() && "BB is not in DominatorSet!");
- I->second.insert(NewDominator);
+ bool dominatedBySlowTreeWalk(const DomTreeNodeBase<NodeT> *A,
+ const DomTreeNodeBase<NodeT> *B) const {
+ const DomTreeNodeBase<NodeT> *IDom;
+ if (A == 0 || B == 0) return false;
+ while ((IDom = B->getIDom()) != 0 && IDom != A && IDom != B)
+ B = IDom; // Walk up the tree
+ return IDom != 0;
}
-};
-//===-------------------------------------
-/// DominatorSet Class - Concrete subclass of DominatorSetBase that is used to
-/// compute a normal dominator set.
-///
-struct DominatorSet : public DominatorSetBase {
- DominatorSet() : DominatorSetBase(false) {}
-
- virtual bool runOnFunction(Function &F);
-
- BasicBlock *getRoot() const {
- assert(Roots.size() == 1 && "Should always have entry node!");
- return Roots[0];
+ /// isReachableFromEntry - Return true if A is dominated by the entry
+ /// block of the function containing it.
+ const bool isReachableFromEntry(NodeT* A) {
+ assert (!this->isPostDominator()
+ && "This is not implemented for post dominators");
+ return dominates(&A->getParent()->getEntryBlock(), A);
}
-
- /// getAnalysisUsage - This simply provides a dominator set
+
+ /// dominates - Returns true iff A dominates B. Note that this is not a
+ /// constant time operation!
///
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<ImmediateDominators>();
- AU.setPreservesAll();
- }
-};
+ inline bool dominates(const DomTreeNodeBase<NodeT> *A,
+ DomTreeNodeBase<NodeT> *B) {
+ if (B == A)
+ return true; // A node trivially dominates itself.
+
+ if (A == 0 || B == 0)
+ return false;
+
+ if (DFSInfoValid)
+ return B->DominatedBy(A);
+
+ // If we end up with too many slow queries, just update the
+ // DFS numbers on the theory that we are going to keep querying.
+ SlowQueries++;
+ if (SlowQueries > 32) {
+ updateDFSNumbers();
+ return B->DominatedBy(A);
+ }
+ return dominatedBySlowTreeWalk(A, B);
+ }
-//===----------------------------------------------------------------------===//
-/// DominatorTree - Calculate the immediate dominator tree for a function.
-///
-struct DominatorTreeBase : public DominatorBase {
- class Node;
-protected:
- std::map<BasicBlock*, Node*> Nodes;
- void reset();
- typedef std::map<BasicBlock*, Node*> NodeMapType;
+ inline bool dominates(NodeT *A, NodeT *B) {
+ if (A == B)
+ return true;
+
+ return dominates(getNode(A), getNode(B));
+ }
- Node *RootNode;
-public:
- class Node {
- friend class DominatorTree;
- friend class PostDominatorTree;
- friend class DominatorTreeBase;
- BasicBlock *TheBB;
- Node *IDom;
- std::vector<Node*> Children;
- public:
- typedef std::vector<Node*>::iterator iterator;
- typedef std::vector<Node*>::const_iterator const_iterator;
-
- iterator begin() { return Children.begin(); }
- iterator end() { return Children.end(); }
- const_iterator begin() const { return Children.begin(); }
- const_iterator end() const { return Children.end(); }
-
- inline BasicBlock *getBlock() const { return TheBB; }
- inline Node *getIDom() const { return IDom; }
- inline const std::vector<Node*> &getChildren() const { return Children; }
-
- /// dominates - Returns true iff this dominates N. Note that this is not a
- /// constant time operation!
- ///
- inline bool dominates(const Node *N) const {
- const Node *IDom;
- while ((IDom = N->getIDom()) != 0 && IDom != this)
- N = IDom; // Walk up the tree
- return IDom != 0;
+ /// findNearestCommonDominator - Find nearest common dominator basic block
+ /// for basic block A and B. If there is no such block then return NULL.
+ NodeT *findNearestCommonDominator(NodeT *A, NodeT *B) {
+
+ assert (!this->isPostDominator()
+ && "This is not implemented for post dominators");
+ assert (A->getParent() == B->getParent()
+ && "Two blocks are not in same function");
+
+ // If either A or B is a entry block then it is nearest common dominator.
+ NodeT &Entry = A->getParent()->getEntryBlock();
+ if (A == &Entry || B == &Entry)
+ return &Entry;
+
+ // If B dominates A then B is nearest common dominator.
+ if (dominates(B, A))
+ return B;
+
+ // If A dominates B then A is nearest common dominator.
+ if (dominates(A, B))
+ return A;
+
+ DomTreeNodeBase<NodeT> *NodeA = getNode(A);
+ DomTreeNodeBase<NodeT> *NodeB = getNode(B);
+
+ // Collect NodeA dominators set.
+ SmallPtrSet<DomTreeNodeBase<NodeT>*, 16> NodeADoms;
+ NodeADoms.insert(NodeA);
+ DomTreeNodeBase<NodeT> *IDomA = NodeA->getIDom();
+ while (IDomA) {
+ NodeADoms.insert(IDomA);
+ IDomA = IDomA->getIDom();
}
- private:
- inline Node(BasicBlock *BB, Node *iDom) : TheBB(BB), IDom(iDom) {}
- inline Node *addChild(Node *C) { Children.push_back(C); return C; }
+ // Walk NodeB immediate dominators chain and find common dominator node.
+ DomTreeNodeBase<NodeT> *IDomB = NodeB->getIDom();
+ while(IDomB) {
+ if (NodeADoms.count(IDomB) != 0)
+ return IDomB->getBlock();
- void setIDom(Node *NewIDom);
- };
-
-public:
- DominatorTreeBase(bool isPostDom) : DominatorBase(isPostDom) {}
- ~DominatorTreeBase() { reset(); }
-
- virtual void releaseMemory() { reset(); }
+ IDomB = IDomB->getIDom();
+ }
- /// getNode - return the (Post)DominatorTree node for the specified basic
- /// block. This is the same as using operator[] on this class.
- ///
- inline Node *getNode(BasicBlock *BB) const {
- NodeMapType::const_iterator i = Nodes.find(BB);
- return (i != Nodes.end()) ? i->second : 0;
+ return NULL;
}
- inline Node *operator[](BasicBlock *BB) const {
- return getNode(BB);
+ // dominates - Return true if A dominates B. This performs the
+ // special checks necessary if A and B are in the same basic block.
+ bool dominates(Instruction *A, Instruction *B) {
+ NodeT *BBA = A->getParent(), *BBB = B->getParent();
+ if (BBA != BBB) return this->dominates(BBA, BBB);
+
+ // It is not possible to determine dominance between two PHI nodes
+ // based on their ordering.
+ if (isa<PHINode>(A) && isa<PHINode>(B))
+ return false;
+
+ // Loop through the basic block until we find A or B.
+ typename NodeT::iterator I = BBA->begin();
+ for (; &*I != A && &*I != B; ++I) /*empty*/;
+
+ if(!this->IsPostDominators) {
+ // A dominates B if it is found first in the basic block.
+ return &*I == A;
+ } else {
+ // A post-dominates B if B is found first in the basic block.
+ return &*I == B;
+ }
}
- /// getRootNode - This returns the entry node for the CFG of the function. If
- /// this tree represents the post-dominance relations for a function, however,
- /// this root may be a node with the block == NULL. This is the case when
- /// there are multiple exit nodes from a particular function. Consumers of
- /// post-dominance information must be capable of dealing with this
- /// possibility.
- ///
- Node *getRootNode() { return RootNode; }
- const Node *getRootNode() const { return RootNode; }
-
//===--------------------------------------------------------------------===//
// API to update (Post)DominatorTree information based on modifications to
// the CFG...
- /// createNewNode - Add a new node to the dominator tree information. This
- /// creates a new node as a child of IDomNode, linking it into the children
- /// list of the immediate dominator.
- ///
- Node *createNewNode(BasicBlock *BB, Node *IDomNode) {
+ /// addNewBlock - Add a new node to the dominator tree information. This
+ /// creates a new node as a child of DomBB dominator node,linking it into
+ /// the children list of the immediate dominator.
+ DomTreeNodeBase<NodeT> *addNewBlock(NodeT *BB, NodeT *DomBB) {
assert(getNode(BB) == 0 && "Block already in dominator tree!");
+ DomTreeNodeBase<NodeT> *IDomNode = getNode(DomBB);
assert(IDomNode && "Not immediate dominator specified for block!");
- return Nodes[BB] = IDomNode->addChild(new Node(BB, IDomNode));
+ DFSInfoValid = false;
+ return DomTreeNodes[BB] =
+ IDomNode->addChild(new DomTreeNode(BB, IDomNode));
}
/// changeImmediateDominator - This method is used to update the dominator
/// tree information when a node's immediate dominator changes.
///
- void changeImmediateDominator(Node *Node, Node *NewIDom) {
- assert(Node && NewIDom && "Cannot change null node pointers!");
- Node->setIDom(NewIDom);
+ void changeImmediateDominator(DomTreeNodeBase<NodeT> *N,
+ DomTreeNodeBase<NodeT> *NewIDom) {
+ assert(N && NewIDom && "Cannot change null node pointers!");
+ DFSInfoValid = false;
+ N->setIDom(NewIDom);
+ }
+
+ void changeImmediateDominator(NodeT *BB, NodeT *NewBB) {
+ changeImmediateDominator(getNode(BB), getNode(NewBB));
+ }
+
+ /// eraseNode - Removes a node from the dominator tree. Block must not
+ /// domiante any other blocks. Removes node from its immediate dominator's
+ /// children list. Deletes dominator node associated with basic block BB.
+ void eraseNode(NodeT *BB) {
+ DomTreeNodeBase<NodeT> *Node = getNode(BB);
+ assert (Node && "Removing node that isn't in dominator tree.");
+ assert (Node->getChildren().empty() && "Node is not a leaf node.");
+
+ // Remove node from immediate dominator's children list.
+ DomTreeNodeBase<NodeT> *IDom = Node->getIDom();
+ if (IDom) {
+ typename std::vector<DomTreeNodeBase<NodeT>*>::iterator I =
+ std::find(IDom->Children.begin(), IDom->Children.end(), Node);
+ assert(I != IDom->Children.end() &&
+ "Not in immediate dominator children set!");
+ // I am no longer your child...
+ IDom->Children.erase(I);
+ }
+
+ DomTreeNodes.erase(BB);
+ delete Node;
+ }
+
+ /// removeNode - Removes a node from the dominator tree. Block must not
+ /// dominate any other blocks. Invalidates any node pointing to removed
+ /// block.
+ void removeNode(NodeT *BB) {
+ assert(getNode(BB) && "Removing node that isn't in dominator tree.");
+ DomTreeNodes.erase(BB);
}
/// print - Convert to human readable form
///
- virtual void print(std::ostream &OS) const;
+ virtual void print(std::ostream &o, const Module* ) const {
+ o << "=============================--------------------------------\n";
+ o << "Inorder Dominator Tree: ";
+ if (this->DFSInfoValid)
+ o << "DFSNumbers invalid: " << SlowQueries << " slow queries.";
+ o << "\n";
+
+ PrintDomTree<NodeT>(getRootNode(), o, 1);
+ }
+
+ void print(std::ostream *OS, const Module* M = 0) const {
+ if (OS) print(*OS, M);
+ }
+
+ virtual void dump() {
+ print(llvm::cerr);
+ }
+
+protected:
+ template<class GraphT> friend void Compress(DominatorTreeBase<typename GraphT::NodeType>& DT,
+ typename GraphT::NodeType* VIn);
+ template<class GraphT> friend typename GraphT::NodeType* Eval(
+ DominatorTreeBase<typename GraphT::NodeType>& DT,
+ typename GraphT::NodeType* V);
+ template<class GraphT> friend void Link(DominatorTreeBase<typename GraphT::NodeType>& DT,
+ typename GraphT::NodeType* V,
+ typename GraphT::NodeType* W,
+ typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &WInfo);
+
+ template<class GraphT> friend unsigned DFSPass(
+ DominatorTreeBase<typename GraphT::NodeType>& DT,
+ typename GraphT::NodeType* V,
+ unsigned N);
+
+ template<class N, class GraphT> friend void Calculate(DominatorTreeBase<typename GraphT::NodeType>& DT,
+ Function& F);
+
+ /// updateDFSNumbers - Assign In and Out numbers to the nodes while walking
+ /// dominator tree in dfs order.
+ void updateDFSNumbers() {
+ unsigned DFSNum = 0;
+
+ SmallVector<std::pair<DomTreeNodeBase<NodeT>*,
+ typename DomTreeNodeBase<NodeT>::iterator>, 32> WorkStack;
+
+ for (unsigned i = 0, e = this->Roots.size(); i != e; ++i) {
+ DomTreeNodeBase<NodeT> *ThisRoot = getNode(this->Roots[i]);
+ WorkStack.push_back(std::make_pair(ThisRoot, ThisRoot->begin()));
+ ThisRoot->DFSNumIn = DFSNum++;
+
+ while (!WorkStack.empty()) {
+ DomTreeNodeBase<NodeT> *Node = WorkStack.back().first;
+ typename DomTreeNodeBase<NodeT>::iterator ChildIt =
+ WorkStack.back().second;
+
+ // If we visited all of the children of this node, "recurse" back up the
+ // stack setting the DFOutNum.
+ if (ChildIt == Node->end()) {
+ Node->DFSNumOut = DFSNum++;
+ WorkStack.pop_back();
+ } else {
+ // Otherwise, recursively visit this child.
+ DomTreeNodeBase<NodeT> *Child = *ChildIt;
+ ++WorkStack.back().second;
+
+ WorkStack.push_back(std::make_pair(Child, Child->begin()));
+ Child->DFSNumIn = DFSNum++;
+ }
+ }
+ }
+
+ SlowQueries = 0;
+ DFSInfoValid = true;
+ }
+
+ DomTreeNodeBase<NodeT> *getNodeForBlock(NodeT *BB) {
+ if (DomTreeNodeBase<NodeT> *BBNode = this->DomTreeNodes[BB])
+ return BBNode;
+
+ // Haven't calculated this node yet? Get or calculate the node for the
+ // immediate dominator.
+ NodeT *IDom = getIDom(BB);
+ DomTreeNodeBase<NodeT> *IDomNode = getNodeForBlock(IDom);
+
+ // Add a new tree node for this BasicBlock, and link it as a child of
+ // IDomNode
+ DomTreeNodeBase<NodeT> *C = new DomTreeNodeBase<NodeT>(BB, IDomNode);
+ return this->DomTreeNodes[BB] = IDomNode->addChild(C);
+ }
+
+ inline NodeT *getIDom(NodeT *BB) const {
+ typename DenseMap<NodeT*, NodeT*>::const_iterator I = IDoms.find(BB);
+ return I != IDoms.end() ? I->second : 0;
+ }
};
+EXTERN_TEMPLATE_INSTANTIATION(class DominatorTreeBase<BasicBlock>);
//===-------------------------------------
/// DominatorTree Class - Concrete subclass of DominatorTreeBase that is used to
/// compute a normal dominator tree.
///
-struct DominatorTree : public DominatorTreeBase {
- DominatorTree() : DominatorTreeBase(false) {}
-
+class DominatorTree : public DominatorTreeBase<BasicBlock> {
+public:
+ static char ID; // Pass ID, replacement for typeid
+ DominatorTree() : DominatorTreeBase<BasicBlock>(intptr_t(&ID), false) {}
+
BasicBlock *getRoot() const {
assert(Roots.size() == 1 && "Should always have entry node!");
return Roots[0];
}
-
- virtual bool runOnFunction(Function &F) {
- reset(); // Reset from the last time we were run...
- ImmediateDominators &ID = getAnalysis<ImmediateDominators>();
- Roots = ID.getRoots();
- calculate(ID);
- return false;
- }
-
+
+ virtual bool runOnFunction(Function &F);
+
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
- AU.addRequired<ImmediateDominators>();
}
-private:
- void calculate(const ImmediateDominators &ID);
- Node *getNodeForBlock(BasicBlock *BB);
+
+ /// splitBlock
+ /// BB is split and now it has one successor. Update dominator tree to
+ /// reflect this change.
+ void splitBlock(BasicBlock *BB);
};
//===-------------------------------------
/// DominatorTree GraphTraits specialization so the DominatorTree can be
/// iterable by generic graph iterators.
///
-template <> struct GraphTraits<DominatorTree::Node*> {
- typedef DominatorTree::Node NodeType;
+template <> struct GraphTraits<DomTreeNode *> {
+ typedef DomTreeNode NodeType;
typedef NodeType::iterator ChildIteratorType;
-
+
static NodeType *getEntryNode(NodeType *N) {
return N;
}
};
template <> struct GraphTraits<DominatorTree*>
- : public GraphTraits<DominatorTree::Node*> {
+ : public GraphTraits<DomTreeNode *> {
static NodeType *getEntryNode(DominatorTree *DT) {
return DT->getRootNode();
}
};
+
//===----------------------------------------------------------------------===//
-/// DominanceFrontier - Calculate the dominance frontiers for a function.
+/// DominanceFrontierBase - Common base class for computing forward and inverse
+/// dominance frontiers for a function.
///
-struct DominanceFrontierBase : public DominatorBase {
+class DominanceFrontierBase : public DominatorBase<BasicBlock> {
+public:
typedef std::set<BasicBlock*> DomSetType; // Dom set for a bb
typedef std::map<BasicBlock*, DomSetType> DomSetMapType; // Dom set map
protected:
DomSetMapType Frontiers;
public:
- DominanceFrontierBase(bool isPostDom) : DominatorBase(isPostDom) {}
+ DominanceFrontierBase(intptr_t ID, bool isPostDom)
+ : DominatorBase<BasicBlock>(ID, isPostDom) {}
virtual void releaseMemory() { Frontiers.clear(); }
Frontiers.insert(std::make_pair(BB, frontier));
}
+ /// removeBlock - Remove basic block BB's frontier.
+ void removeBlock(BasicBlock *BB) {
+ assert(find(BB) != end() && "Block is not in DominanceFrontier!");
+ for (iterator I = begin(), E = end(); I != E; ++I)
+ I->second.erase(BB);
+ Frontiers.erase(BB);
+ }
+
void addToFrontier(iterator I, BasicBlock *Node) {
assert(I != end() && "BB is not in DominanceFrontier!");
I->second.insert(Node);
/// print - Convert to human readable form
///
- virtual void print(std::ostream &OS) const;
+ virtual void print(std::ostream &OS, const Module* = 0) const;
+ void print(std::ostream *OS, const Module* M = 0) const {
+ if (OS) print(*OS, M);
+ }
+ virtual void dump();
};
//===-------------------------------------
-/// DominatorTree Class - Concrete subclass of DominatorTreeBase that is used to
-/// compute a normal dominator tree.
+/// DominanceFrontier Class - Concrete subclass of DominanceFrontierBase that is
+/// used to compute a forward dominator frontiers.
///
-struct DominanceFrontier : public DominanceFrontierBase {
- DominanceFrontier() : DominanceFrontierBase(false) {}
+class DominanceFrontier : public DominanceFrontierBase {
+public:
+ static char ID; // Pass ID, replacement for typeid
+ DominanceFrontier() :
+ DominanceFrontierBase(intptr_t(&ID), false) {}
BasicBlock *getRoot() const {
assert(Roots.size() == 1 && "Should always have entry node!");
AU.setPreservesAll();
AU.addRequired<DominatorTree>();
}
+
+ /// splitBlock - BB is split and now it has one successor. Update dominance
+ /// frontier to reflect this change.
+ void splitBlock(BasicBlock *BB);
+
+ /// BasicBlock BB's new dominator is NewBB. Update BB's dominance frontier
+ /// to reflect this change.
+ void changeImmediateDominator(BasicBlock *BB, BasicBlock *NewBB,
+ DominatorTree *DT) {
+ // NewBB is now dominating BB. Which means BB's dominance
+ // frontier is now part of NewBB's dominance frontier. However, BB
+ // itself is not member of NewBB's dominance frontier.
+ DominanceFrontier::iterator NewDFI = find(NewBB);
+ DominanceFrontier::iterator DFI = find(BB);
+ DominanceFrontier::DomSetType BBSet = DFI->second;
+ for (DominanceFrontier::DomSetType::iterator BBSetI = BBSet.begin(),
+ BBSetE = BBSet.end(); BBSetI != BBSetE; ++BBSetI) {
+ BasicBlock *DFMember = *BBSetI;
+ // Insert only if NewBB dominates DFMember.
+ if (!DT->dominates(NewBB, DFMember))
+ NewDFI->second.insert(DFMember);
+ }
+ NewDFI->second.erase(BB);
+ }
+
private:
const DomSetType &calculate(const DominatorTree &DT,
- const DominatorTree::Node *Node);
+ const DomTreeNode *Node);
};
+
} // End llvm namespace
#endif
projects / oota-llvm.git / blobdiff