diff options
Diffstat (limited to 'include/llvm/Analysis/Dominators.h')
| -rw-r--r-- | include/llvm/Analysis/Dominators.h | 265 |
1 files changed, 36 insertions, 229 deletions
diff --git a/include/llvm/Analysis/Dominators.h b/include/llvm/Analysis/Dominators.h index 73c6e62..230e83d 100644 --- a/include/llvm/Analysis/Dominators.h +++ b/include/llvm/Analysis/Dominators.h @@ -7,14 +7,8 @@ // //===----------------------------------------------------------------------===// // -// This file defines the following classes: -// 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 -// DominatorTree mapping. +// This file defines the DominatorTree class, which provides fast and efficient +// dominance queries. // //===----------------------------------------------------------------------===// @@ -23,19 +17,15 @@ #include "llvm/Pass.h" #include "llvm/Function.h" -#include "llvm/Instructions.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/DepthFirstIterator.h" #include "llvm/ADT/GraphTraits.h" #include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/SmallVector.h" -#include "llvm/Assembly/Writer.h" #include "llvm/Support/CFG.h" #include "llvm/Support/Compiler.h" #include "llvm/Support/raw_ostream.h" #include <algorithm> -#include <map> -#include <set> namespace llvm { @@ -205,15 +195,11 @@ protected: // Information record used during immediate dominators computation. struct InfoRec { unsigned DFSNum; + unsigned Parent; unsigned Semi; - unsigned Size; - NodeT *Label, *Child; - unsigned Parent, Ancestor; - - std::vector<NodeT*> Bucket; + NodeT *Label; - InfoRec() : DFSNum(0), Semi(0), Size(0), Label(0), Child(0), Parent(0), - Ancestor(0) {} + InfoRec() : DFSNum(0), Parent(0), Semi(0), Label(0) {} }; DenseMap<NodeT*, NodeT*> IDoms; @@ -303,9 +289,6 @@ public: : DominatorBase<NodeT>(isPostDom), DFSInfoValid(false), SlowQueries(0) {} virtual ~DominatorTreeBase() { reset(); } - // FIXME: Should remove this - virtual bool runOnFunction(Function &F) { return false; } - /// compare - Return false if the other dominator tree base matches this /// dominator tree base. Otherwise return true. bool compare(DominatorTreeBase &Other) const { @@ -361,8 +344,15 @@ public: return dominatedBySlowTreeWalk(A, B); } - inline bool properlyDominates(NodeT *A, NodeT *B) { - return properlyDominates(getNode(A), getNode(B)); + inline bool properlyDominates(const NodeT *A, const NodeT *B) { + if (A == B) + return false; + + // Cast away the const qualifiers here. This is ok since + // this function doesn't actually return the values returned + // from getNode. + return properlyDominates(getNode(const_cast<NodeT *>(A)), + getNode(const_cast<NodeT *>(B))); } bool dominatedBySlowTreeWalk(const DomTreeNodeBase<NodeT> *A, @@ -377,7 +367,7 @@ public: /// isReachableFromEntry - Return true if A is dominated by the entry /// block of the function containing it. - bool isReachableFromEntry(NodeT* A) { + bool isReachableFromEntry(const NodeT* A) { assert(!this->isPostDominator() && "This is not implemented for post dominators"); return dominates(&A->getParent()->front(), A); @@ -478,6 +468,13 @@ public: return NULL; } + const NodeT *findNearestCommonDominator(const NodeT *A, const NodeT *B) { + // Cast away the const qualifiers here. This is ok since + // const is re-introduced on the return type. + return findNearestCommonDominator(const_cast<NodeT *>(A), + const_cast<NodeT *>(B)); + } + //===--------------------------------------------------------------------===// // API to update (Post)DominatorTree information based on modifications to // the CFG... @@ -509,7 +506,7 @@ public: } /// eraseNode - Removes a node from the dominator tree. Block must not - /// domiante any other blocks. Removes node from its immediate dominator's + /// dominate 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); @@ -556,7 +553,7 @@ public: o << "Inorder PostDominator Tree: "; else o << "Inorder Dominator Tree: "; - if (this->DFSInfoValid) + if (!this->DFSInfoValid) o << "DFSNumbers invalid: " << SlowQueries << " slow queries."; o << "\n"; @@ -567,18 +564,10 @@ public: 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, - unsigned DFSNumV, typename GraphT::NodeType* W, - typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &WInfo); + typename GraphT::NodeType* V, + unsigned LastLinked); template<class GraphT> friend unsigned DFSPass(DominatorTreeBase<typename GraphT::NodeType>& DT, @@ -703,6 +692,7 @@ public: DominatorTreeBase<BasicBlock>* DT; DominatorTree() : FunctionPass(ID) { + initializeDominatorTreePass(*PassRegistry::getPassRegistry()); DT = new DominatorTreeBase<BasicBlock>(false); } @@ -751,7 +741,7 @@ public: AU.setPreservesAll(); } - inline bool dominates(DomTreeNode* A, DomTreeNode* B) const { + inline bool dominates(const DomTreeNode* A, const DomTreeNode* B) const { return DT->dominates(A, B); } @@ -767,7 +757,7 @@ public: return DT->properlyDominates(A, B); } - bool properlyDominates(BasicBlock *A, BasicBlock *B) const { + bool properlyDominates(const BasicBlock *A, const BasicBlock *B) const { return DT->properlyDominates(A, B); } @@ -777,6 +767,11 @@ public: return DT->findNearestCommonDominator(A, B); } + inline const BasicBlock *findNearestCommonDominator(const BasicBlock *A, + const BasicBlock *B) { + return DT->findNearestCommonDominator(A, B); + } + inline DomTreeNode *operator[](BasicBlock *BB) const { return DT->getNode(BB); } @@ -807,7 +802,7 @@ public: } /// eraseNode - Removes a node from the dominator tree. Block must not - /// domiante any other blocks. Removes node from its immediate dominator's + /// dominate any other blocks. Removes node from its immediate dominator's /// children list. Deletes dominator node associated with basic block BB. inline void eraseNode(BasicBlock *BB) { DT->eraseNode(BB); @@ -819,7 +814,7 @@ public: DT->splitBlock(NewBB); } - bool isReachableFromEntry(BasicBlock* A) { + bool isReachableFromEntry(const BasicBlock* A) { return DT->isReachableFromEntry(A); } @@ -876,194 +871,6 @@ template <> struct GraphTraits<DominatorTree*> }; -//===----------------------------------------------------------------------===// -/// DominanceFrontierBase - Common base class for computing forward and inverse -/// dominance frontiers for a function. -/// -class DominanceFrontierBase : public FunctionPass { -public: - typedef std::set<BasicBlock*> DomSetType; // Dom set for a bb - typedef std::map<BasicBlock*, DomSetType> DomSetMapType; // Dom set map -protected: - DomSetMapType Frontiers; - std::vector<BasicBlock*> Roots; - const bool IsPostDominators; - -public: - DominanceFrontierBase(char &ID, bool isPostDom) - : FunctionPass(ID), IsPostDominators(isPostDom) {} - - /// 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; } - - /// isPostDominator - Returns true if analysis based of postdoms - /// - bool isPostDominator() const { return IsPostDominators; } - - virtual void releaseMemory() { Frontiers.clear(); } - - // Accessor interface: - typedef DomSetMapType::iterator iterator; - typedef DomSetMapType::const_iterator const_iterator; - iterator begin() { return Frontiers.begin(); } - const_iterator begin() const { return Frontiers.begin(); } - iterator end() { return Frontiers.end(); } - const_iterator end() const { return Frontiers.end(); } - iterator find(BasicBlock *B) { return Frontiers.find(B); } - const_iterator find(BasicBlock *B) const { return Frontiers.find(B); } - - iterator addBasicBlock(BasicBlock *BB, const DomSetType &frontier) { - assert(find(BB) == end() && "Block already in DominanceFrontier!"); - return Frontiers.insert(std::make_pair(BB, frontier)).first; - } - - /// 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); - } - - void removeFromFrontier(iterator I, BasicBlock *Node) { - assert(I != end() && "BB is not in DominanceFrontier!"); - assert(I->second.count(Node) && "Node is not in DominanceFrontier of BB"); - I->second.erase(Node); - } - - /// compareDomSet - Return false if two domsets match. Otherwise - /// return true; - bool compareDomSet(DomSetType &DS1, const DomSetType &DS2) const { - std::set<BasicBlock *> tmpSet; - for (DomSetType::const_iterator I = DS2.begin(), - E = DS2.end(); I != E; ++I) - tmpSet.insert(*I); - - for (DomSetType::const_iterator I = DS1.begin(), - E = DS1.end(); I != E; ) { - BasicBlock *Node = *I++; - - if (tmpSet.erase(Node) == 0) - // Node is in DS1 but not in DS2. - return true; - } - - if (!tmpSet.empty()) - // There are nodes that are in DS2 but not in DS1. - return true; - - // DS1 and DS2 matches. - return false; - } - - /// compare - Return true if the other dominance frontier base matches - /// this dominance frontier base. Otherwise return false. - bool compare(DominanceFrontierBase &Other) const { - DomSetMapType tmpFrontiers; - for (DomSetMapType::const_iterator I = Other.begin(), - E = Other.end(); I != E; ++I) - tmpFrontiers.insert(std::make_pair(I->first, I->second)); - - for (DomSetMapType::iterator I = tmpFrontiers.begin(), - E = tmpFrontiers.end(); I != E; ) { - BasicBlock *Node = I->first; - const_iterator DFI = find(Node); - if (DFI == end()) - return true; - - if (compareDomSet(I->second, DFI->second)) - return true; - - ++I; - tmpFrontiers.erase(Node); - } - - if (!tmpFrontiers.empty()) - return true; - - return false; - } - - /// print - Convert to human readable form - /// - virtual void print(raw_ostream &OS, const Module* = 0) const; - - /// dump - Dump the dominance frontier to dbgs(). - void dump() const; -}; - - -//===------------------------------------- -/// DominanceFrontier Class - Concrete subclass of DominanceFrontierBase that is -/// used to compute a forward dominator frontiers. -/// -class DominanceFrontier : public DominanceFrontierBase { -public: - static char ID; // Pass ID, replacement for typeid - DominanceFrontier() : - DominanceFrontierBase(ID, false) {} - - BasicBlock *getRoot() const { - assert(Roots.size() == 1 && "Should always have entry node!"); - return Roots[0]; - } - - virtual bool runOnFunction(Function &) { - Frontiers.clear(); - DominatorTree &DT = getAnalysis<DominatorTree>(); - Roots = DT.getRoots(); - assert(Roots.size() == 1 && "Only one entry block for forward domfronts!"); - calculate(DT, DT[Roots[0]]); - return false; - } - - virtual void verifyAnalysis() const; - - virtual void getAnalysisUsage(AnalysisUsage &AU) const { - 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); - // If BB was an entry block then its frontier is empty. - if (DFI == end()) - return; - 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); - } - - const DomSetType &calculate(const DominatorTree &DT, - const DomTreeNode *Node); -}; - - } // End llvm namespace #endif |
