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/MachineFunctionPass.h"
19 #include "llvm/CodeGen/MachineBasicBlock.h"
20 #include "llvm/CodeGen/MachineFunction.h"
21 #include "llvm/CodeGen/MachineInstr.h"
22 #include "llvm/Analysis/Dominators.h"
23 #include "llvm/Analysis/DominatorInternals.h"
27 inline void WriteAsOperand(std::ostream &, const MachineBasicBlock*, bool t) { }
30 inline void DominatorTreeBase<MachineBasicBlock>::addRoot(MachineBasicBlock* MBB) {
31 this->Roots.push_back(MBB);
34 EXTERN_TEMPLATE_INSTANTIATION(class DomTreeNodeBase<MachineBasicBlock>);
35 EXTERN_TEMPLATE_INSTANTIATION(class DominatorTreeBase<MachineBasicBlock>);
37 typedef DomTreeNodeBase<MachineBasicBlock> MachineDomTreeNode;
39 //===-------------------------------------
40 /// DominatorTree Class - Concrete subclass of DominatorTreeBase that is used to
41 /// compute a normal dominator tree.
43 class MachineDominatorTree : public MachineFunctionPass {
45 static char ID; // Pass ID, replacement for typeid
46 DominatorTreeBase<MachineBasicBlock>* DT;
48 MachineDominatorTree() : MachineFunctionPass(intptr_t(&ID)) {
49 DT = new DominatorTreeBase<MachineBasicBlock>(false);
52 ~MachineDominatorTree() {
57 DominatorTreeBase<MachineBasicBlock>& getBase() { return *DT; }
59 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
61 MachineFunctionPass::getAnalysisUsage(AU);
64 /// getRoots - Return the root blocks of the current CFG. This may include
65 /// multiple blocks if we are computing post dominators. For forward
66 /// dominators, this will always be a single block (the entry node).
68 inline const std::vector<MachineBasicBlock*> &getRoots() const {
69 return DT->getRoots();
72 inline MachineBasicBlock *getRoot() const {
76 inline MachineDomTreeNode *getRootNode() const {
77 return DT->getRootNode();
80 virtual bool runOnMachineFunction(MachineFunction &F) {
86 inline bool dominates(MachineDomTreeNode* A, MachineDomTreeNode* B) const {
87 return DT->dominates(A, B);
90 inline bool dominates(MachineBasicBlock* A, MachineBasicBlock* B) const {
91 return DT->dominates(A, B);
94 // dominates - Return true if A dominates B. This performs the
95 // special checks necessary if A and B are in the same basic block.
96 bool dominates(MachineInstr *A, MachineInstr *B) const {
97 MachineBasicBlock *BBA = A->getParent(), *BBB = B->getParent();
98 if (BBA != BBB) return DT->dominates(BBA, BBB);
100 // Loop through the basic block until we find A or B.
101 MachineBasicBlock::iterator I = BBA->begin();
102 for (; &*I != A && &*I != B; ++I) /*empty*/;
104 //if(!DT.IsPostDominators) {
105 // A dominates B if it is found first in the basic block.
108 // // A post-dominates B if B is found first in the basic block.
113 inline bool properlyDominates(const MachineDomTreeNode* A,
114 MachineDomTreeNode* B) const {
115 return DT->properlyDominates(A, B);
118 inline bool properlyDominates(MachineBasicBlock* A,
119 MachineBasicBlock* B) const {
120 return DT->properlyDominates(A, B);
123 /// findNearestCommonDominator - Find nearest common dominator basic block
124 /// for basic block A and B. If there is no such block then return NULL.
125 inline MachineBasicBlock *findNearestCommonDominator(MachineBasicBlock *A,
126 MachineBasicBlock *B) {
127 return DT->findNearestCommonDominator(A, B);
130 inline MachineDomTreeNode *operator[](MachineBasicBlock *BB) const {
131 return DT->getNode(BB);
134 /// getNode - return the (Post)DominatorTree node for the specified basic
135 /// block. This is the same as using operator[] on this class.
137 inline MachineDomTreeNode *getNode(MachineBasicBlock *BB) const {
138 return DT->getNode(BB);
141 /// addNewBlock - Add a new node to the dominator tree information. This
142 /// creates a new node as a child of DomBB dominator node,linking it into
143 /// the children list of the immediate dominator.
144 inline MachineDomTreeNode *addNewBlock(MachineBasicBlock *BB,
145 MachineBasicBlock *DomBB) {
146 return DT->addNewBlock(BB, DomBB);
149 /// changeImmediateDominator - This method is used to update the dominator
150 /// tree information when a node's immediate dominator changes.
152 inline void changeImmediateDominator(MachineBasicBlock *N,
153 MachineBasicBlock* NewIDom) {
154 DT->changeImmediateDominator(N, NewIDom);
157 inline void changeImmediateDominator(MachineDomTreeNode *N,
158 MachineDomTreeNode* NewIDom) {
159 DT->changeImmediateDominator(N, NewIDom);
162 /// eraseNode - Removes a node from the dominator tree. Block must not
163 /// domiante any other blocks. Removes node from its immediate dominator's
164 /// children list. Deletes dominator node associated with basic block BB.
165 inline void eraseNode(MachineBasicBlock *BB) {
169 /// splitBlock - BB is split and now it has one successor. Update dominator
170 /// tree to reflect this change.
171 inline void splitBlock(MachineBasicBlock* NewBB) {
172 DT->splitBlock(NewBB);
176 virtual void releaseMemory() {
180 virtual void print(std::ostream &OS, const Module* M= 0) const {
185 //===-------------------------------------
186 /// DominatorTree GraphTraits specialization so the DominatorTree can be
187 /// iterable by generic graph iterators.
190 template<class T> struct GraphTraits;
192 template <> struct GraphTraits<MachineDomTreeNode *> {
193 typedef MachineDomTreeNode NodeType;
194 typedef NodeType::iterator ChildIteratorType;
196 static NodeType *getEntryNode(NodeType *N) {
199 static inline ChildIteratorType child_begin(NodeType* N) {
202 static inline ChildIteratorType child_end(NodeType* N) {
207 template <> struct GraphTraits<MachineDominatorTree*>
208 : public GraphTraits<MachineDomTreeNode *> {
209 static NodeType *getEntryNode(MachineDominatorTree *DT) {
210 return DT->getRootNode();