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//=- llvm/CodeGen/MachineDominators.h - Machine Dom Calculation --*- C++ -*-==//
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// The LLVM Compiler Infrastructure
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//===----------------------------------------------------------------------===//
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// This file defines classes mirroring those in llvm/Analysis/Dominators.h,
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// but for target-specific code rather than target-independent IR.
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CODEGEN_MACHINEDOMINATORS_H
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#define LLVM_CODEGEN_MACHINEDOMINATORS_H
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#include "llvm/CodeGen/MachineBasicBlock.h"
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#include "llvm/CodeGen/MachineFunction.h"
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#include "llvm/CodeGen/MachineFunctionPass.h"
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#include "llvm/Analysis/Dominators.h"
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#include "llvm/Analysis/DominatorInternals.h"
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inline void DominatorTreeBase<MachineBasicBlock>::addRoot(MachineBasicBlock* MBB) {
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this->Roots.push_back(MBB);
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EXTERN_TEMPLATE_INSTANTIATION(class DomTreeNodeBase<MachineBasicBlock>);
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EXTERN_TEMPLATE_INSTANTIATION(class DominatorTreeBase<MachineBasicBlock>);
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typedef DomTreeNodeBase<MachineBasicBlock> MachineDomTreeNode;
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//===-------------------------------------
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/// DominatorTree Class - Concrete subclass of DominatorTreeBase that is used to
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/// compute a normal dominator tree.
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class MachineDominatorTree : public MachineFunctionPass {
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static char ID; // Pass ID, replacement for typeid
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DominatorTreeBase<MachineBasicBlock>* DT;
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MachineDominatorTree();
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~MachineDominatorTree();
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DominatorTreeBase<MachineBasicBlock>& getBase() { return *DT; }
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virtual void getAnalysisUsage(AnalysisUsage &AU) const;
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/// getRoots - Return the root blocks of the current CFG. This may include
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/// multiple blocks if we are computing post dominators. For forward
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/// dominators, this will always be a single block (the entry node).
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inline const std::vector<MachineBasicBlock*> &getRoots() const {
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return DT->getRoots();
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inline MachineBasicBlock *getRoot() const {
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inline MachineDomTreeNode *getRootNode() const {
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return DT->getRootNode();
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virtual bool runOnMachineFunction(MachineFunction &F);
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inline bool dominates(MachineDomTreeNode* A, MachineDomTreeNode* B) const {
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return DT->dominates(A, B);
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inline bool dominates(MachineBasicBlock* A, MachineBasicBlock* B) const {
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return DT->dominates(A, B);
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// dominates - Return true if A dominates B. This performs the
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// special checks necessary if A and B are in the same basic block.
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bool dominates(MachineInstr *A, MachineInstr *B) const {
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MachineBasicBlock *BBA = A->getParent(), *BBB = B->getParent();
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if (BBA != BBB) return DT->dominates(BBA, BBB);
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// Loop through the basic block until we find A or B.
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MachineBasicBlock::iterator I = BBA->begin();
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for (; &*I != A && &*I != B; ++I) /*empty*/;
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//if(!DT.IsPostDominators) {
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// A dominates B if it is found first in the basic block.
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// // A post-dominates B if B is found first in the basic block.
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inline bool properlyDominates(const MachineDomTreeNode* A,
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MachineDomTreeNode* B) const {
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return DT->properlyDominates(A, B);
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inline bool properlyDominates(MachineBasicBlock* A,
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MachineBasicBlock* B) const {
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return DT->properlyDominates(A, B);
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/// findNearestCommonDominator - Find nearest common dominator basic block
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/// for basic block A and B. If there is no such block then return NULL.
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inline MachineBasicBlock *findNearestCommonDominator(MachineBasicBlock *A,
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MachineBasicBlock *B) {
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return DT->findNearestCommonDominator(A, B);
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inline MachineDomTreeNode *operator[](MachineBasicBlock *BB) const {
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return DT->getNode(BB);
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/// getNode - return the (Post)DominatorTree node for the specified basic
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/// block. This is the same as using operator[] on this class.
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inline MachineDomTreeNode *getNode(MachineBasicBlock *BB) const {
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return DT->getNode(BB);
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/// addNewBlock - Add a new node to the dominator tree information. This
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/// creates a new node as a child of DomBB dominator node,linking it into
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/// the children list of the immediate dominator.
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inline MachineDomTreeNode *addNewBlock(MachineBasicBlock *BB,
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MachineBasicBlock *DomBB) {
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return DT->addNewBlock(BB, DomBB);
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/// changeImmediateDominator - This method is used to update the dominator
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/// tree information when a node's immediate dominator changes.
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inline void changeImmediateDominator(MachineBasicBlock *N,
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MachineBasicBlock* NewIDom) {
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DT->changeImmediateDominator(N, NewIDom);
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inline void changeImmediateDominator(MachineDomTreeNode *N,
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MachineDomTreeNode* NewIDom) {
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DT->changeImmediateDominator(N, NewIDom);
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/// eraseNode - Removes a node from the dominator tree. Block must not
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/// domiante any other blocks. Removes node from its immediate dominator's
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/// children list. Deletes dominator node associated with basic block BB.
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inline void eraseNode(MachineBasicBlock *BB) {
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/// splitBlock - BB is split and now it has one successor. Update dominator
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/// tree to reflect this change.
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inline void splitBlock(MachineBasicBlock* NewBB) {
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DT->splitBlock(NewBB);
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virtual void releaseMemory();
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virtual void print(raw_ostream &OS, const Module*) const;
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//===-------------------------------------
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/// DominatorTree GraphTraits specialization so the DominatorTree can be
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/// iterable by generic graph iterators.
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template<class T> struct GraphTraits;
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template <> struct GraphTraits<MachineDomTreeNode *> {
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typedef MachineDomTreeNode NodeType;
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typedef NodeType::iterator ChildIteratorType;
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static NodeType *getEntryNode(NodeType *N) {
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static inline ChildIteratorType child_begin(NodeType* N) {
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static inline ChildIteratorType child_end(NodeType* N) {
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template <> struct GraphTraits<MachineDominatorTree*>
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: public GraphTraits<MachineDomTreeNode *> {
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static NodeType *getEntryNode(MachineDominatorTree *DT) {
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return DT->getRootNode();