1 //=- llvm/CodeGen/MachineDominators.h - Machine Dom Calculation --*- C++ -*-==//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines classes mirroring those in llvm/Analysis/Dominators.h,
11 // but for target-specific code rather than target-independent IR.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CODEGEN_MACHINEDOMINATORS_H
16 #define LLVM_CODEGEN_MACHINEDOMINATORS_H
18 #include "llvm/CodeGen/MachineBasicBlock.h"
19 #include "llvm/CodeGen/MachineFunction.h"
20 #include "llvm/CodeGen/MachineFunctionPass.h"
21 #include "llvm/Analysis/Dominators.h"
22 #include "llvm/Analysis/DominatorInternals.h"
27 inline void DominatorTreeBase<MachineBasicBlock>::addRoot(MachineBasicBlock* MBB) {
28 this->Roots.push_back(MBB);
31 EXTERN_TEMPLATE_INSTANTIATION(class DomTreeNodeBase<MachineBasicBlock>);
32 EXTERN_TEMPLATE_INSTANTIATION(class DominatorTreeBase<MachineBasicBlock>);
34 typedef DomTreeNodeBase<MachineBasicBlock> MachineDomTreeNode;
36 //===-------------------------------------
37 /// DominatorTree Class - Concrete subclass of DominatorTreeBase that is used to
38 /// compute a normal dominator tree.
40 class MachineDominatorTree : public MachineFunctionPass {
42 static char ID; // Pass ID, replacement for typeid
43 DominatorTreeBase<MachineBasicBlock>* DT;
45 MachineDominatorTree();
47 ~MachineDominatorTree();
49 DominatorTreeBase<MachineBasicBlock>& getBase() { return *DT; }
51 virtual void getAnalysisUsage(AnalysisUsage &AU) const;
53 /// getRoots - Return the root blocks of the current CFG. This may include
54 /// multiple blocks if we are computing post dominators. For forward
55 /// dominators, this will always be a single block (the entry node).
57 inline const std::vector<MachineBasicBlock*> &getRoots() const {
58 return DT->getRoots();
61 inline MachineBasicBlock *getRoot() const {
65 inline MachineDomTreeNode *getRootNode() const {
66 return DT->getRootNode();
69 virtual bool runOnMachineFunction(MachineFunction &F);
71 inline bool dominates(MachineDomTreeNode* A, MachineDomTreeNode* B) const {
72 return DT->dominates(A, B);
75 inline bool dominates(MachineBasicBlock* A, MachineBasicBlock* B) const {
76 return DT->dominates(A, B);
79 // dominates - Return true if A dominates B. This performs the
80 // special checks necessary if A and B are in the same basic block.
81 bool dominates(MachineInstr *A, MachineInstr *B) const {
82 MachineBasicBlock *BBA = A->getParent(), *BBB = B->getParent();
83 if (BBA != BBB) return DT->dominates(BBA, BBB);
85 // Loop through the basic block until we find A or B.
86 MachineBasicBlock::iterator I = BBA->begin();
87 for (; &*I != A && &*I != B; ++I) /*empty*/;
89 //if(!DT.IsPostDominators) {
90 // A dominates B if it is found first in the basic block.
93 // // A post-dominates B if B is found first in the basic block.
98 inline bool properlyDominates(const MachineDomTreeNode* A,
99 MachineDomTreeNode* B) const {
100 return DT->properlyDominates(A, B);
103 inline bool properlyDominates(MachineBasicBlock* A,
104 MachineBasicBlock* B) const {
105 return DT->properlyDominates(A, B);
108 /// findNearestCommonDominator - Find nearest common dominator basic block
109 /// for basic block A and B. If there is no such block then return NULL.
110 inline MachineBasicBlock *findNearestCommonDominator(MachineBasicBlock *A,
111 MachineBasicBlock *B) {
112 return DT->findNearestCommonDominator(A, B);
115 inline MachineDomTreeNode *operator[](MachineBasicBlock *BB) const {
116 return DT->getNode(BB);
119 /// getNode - return the (Post)DominatorTree node for the specified basic
120 /// block. This is the same as using operator[] on this class.
122 inline MachineDomTreeNode *getNode(MachineBasicBlock *BB) const {
123 return DT->getNode(BB);
126 /// addNewBlock - Add a new node to the dominator tree information. This
127 /// creates a new node as a child of DomBB dominator node,linking it into
128 /// the children list of the immediate dominator.
129 inline MachineDomTreeNode *addNewBlock(MachineBasicBlock *BB,
130 MachineBasicBlock *DomBB) {
131 return DT->addNewBlock(BB, DomBB);
134 /// changeImmediateDominator - This method is used to update the dominator
135 /// tree information when a node's immediate dominator changes.
137 inline void changeImmediateDominator(MachineBasicBlock *N,
138 MachineBasicBlock* NewIDom) {
139 DT->changeImmediateDominator(N, NewIDom);
142 inline void changeImmediateDominator(MachineDomTreeNode *N,
143 MachineDomTreeNode* NewIDom) {
144 DT->changeImmediateDominator(N, NewIDom);
147 /// eraseNode - Removes a node from the dominator tree. Block must not
148 /// domiante any other blocks. Removes node from its immediate dominator's
149 /// children list. Deletes dominator node associated with basic block BB.
150 inline void eraseNode(MachineBasicBlock *BB) {
154 /// splitBlock - BB is split and now it has one successor. Update dominator
155 /// tree to reflect this change.
156 inline void splitBlock(MachineBasicBlock* NewBB) {
157 DT->splitBlock(NewBB);
161 virtual void releaseMemory();
163 virtual void print(raw_ostream &OS, const Module*) const;
166 //===-------------------------------------
167 /// DominatorTree GraphTraits specialization so the DominatorTree can be
168 /// iterable by generic graph iterators.
171 template<class T> struct GraphTraits;
173 template <> struct GraphTraits<MachineDomTreeNode *> {
174 typedef MachineDomTreeNode NodeType;
175 typedef NodeType::iterator ChildIteratorType;
177 static NodeType *getEntryNode(NodeType *N) {
180 static inline ChildIteratorType child_begin(NodeType* N) {
183 static inline ChildIteratorType child_end(NodeType* N) {
188 template <> struct GraphTraits<MachineDominatorTree*>
189 : public GraphTraits<MachineDomTreeNode *> {
190 static NodeType *getEntryNode(MachineDominatorTree *DT) {
191 return DT->getRootNode();