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/Analysis/DominatorInternals.h"
19 #include "llvm/Analysis/Dominators.h"
20 #include "llvm/CodeGen/MachineBasicBlock.h"
21 #include "llvm/CodeGen/MachineFunction.h"
22 #include "llvm/CodeGen/MachineFunctionPass.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(const MachineDomTreeNode* A,
72 const MachineDomTreeNode* B) const {
73 return DT->dominates(A, B);
76 inline bool dominates(const MachineBasicBlock* A,
77 const MachineBasicBlock* B) const {
78 return DT->dominates(A, B);
81 // dominates - Return true if A dominates B. This performs the
82 // special checks necessary if A and B are in the same basic block.
83 bool dominates(const MachineInstr *A, const MachineInstr *B) const {
84 const MachineBasicBlock *BBA = A->getParent(), *BBB = B->getParent();
85 if (BBA != BBB) return DT->dominates(BBA, BBB);
87 // Loop through the basic block until we find A or B.
88 MachineBasicBlock::const_iterator I = BBA->begin();
89 for (; &*I != A && &*I != B; ++I)
92 //if(!DT.IsPostDominators) {
93 // A dominates B if it is found first in the basic block.
96 // // A post-dominates B if B is found first in the basic block.
101 inline bool properlyDominates(const MachineDomTreeNode* A,
102 const MachineDomTreeNode* B) const {
103 return DT->properlyDominates(A, B);
106 inline bool properlyDominates(const MachineBasicBlock* A,
107 const MachineBasicBlock* B) const {
108 return DT->properlyDominates(A, B);
111 /// findNearestCommonDominator - Find nearest common dominator basic block
112 /// for basic block A and B. If there is no such block then return NULL.
113 inline MachineBasicBlock *findNearestCommonDominator(MachineBasicBlock *A,
114 MachineBasicBlock *B) {
115 return DT->findNearestCommonDominator(A, B);
118 inline MachineDomTreeNode *operator[](MachineBasicBlock *BB) const {
119 return DT->getNode(BB);
122 /// getNode - return the (Post)DominatorTree node for the specified basic
123 /// block. This is the same as using operator[] on this class.
125 inline MachineDomTreeNode *getNode(MachineBasicBlock *BB) const {
126 return DT->getNode(BB);
129 /// addNewBlock - Add a new node to the dominator tree information. This
130 /// creates a new node as a child of DomBB dominator node,linking it into
131 /// the children list of the immediate dominator.
132 inline MachineDomTreeNode *addNewBlock(MachineBasicBlock *BB,
133 MachineBasicBlock *DomBB) {
134 return DT->addNewBlock(BB, DomBB);
137 /// changeImmediateDominator - This method is used to update the dominator
138 /// tree information when a node's immediate dominator changes.
140 inline void changeImmediateDominator(MachineBasicBlock *N,
141 MachineBasicBlock* NewIDom) {
142 DT->changeImmediateDominator(N, NewIDom);
145 inline void changeImmediateDominator(MachineDomTreeNode *N,
146 MachineDomTreeNode* NewIDom) {
147 DT->changeImmediateDominator(N, NewIDom);
150 /// eraseNode - Removes a node from the dominator tree. Block must not
151 /// dominate any other blocks. Removes node from its immediate dominator's
152 /// children list. Deletes dominator node associated with basic block BB.
153 inline void eraseNode(MachineBasicBlock *BB) {
157 /// splitBlock - BB is split and now it has one successor. Update dominator
158 /// tree to reflect this change.
159 inline void splitBlock(MachineBasicBlock* NewBB) {
160 DT->splitBlock(NewBB);
163 /// isReachableFromEntry - Return true if A is dominated by the entry
164 /// block of the function containing it.
165 bool isReachableFromEntry(const MachineBasicBlock *A) {
166 return DT->isReachableFromEntry(A);
169 virtual void releaseMemory();
171 virtual void print(raw_ostream &OS, const Module*) const;
174 //===-------------------------------------
175 /// DominatorTree GraphTraits specialization so the DominatorTree can be
176 /// iterable by generic graph iterators.
179 template<class T> struct GraphTraits;
181 template <> struct GraphTraits<MachineDomTreeNode *> {
182 typedef MachineDomTreeNode NodeType;
183 typedef NodeType::iterator ChildIteratorType;
185 static NodeType *getEntryNode(NodeType *N) {
188 static inline ChildIteratorType child_begin(NodeType* N) {
191 static inline ChildIteratorType child_end(NodeType* N) {
196 template <> struct GraphTraits<MachineDominatorTree*>
197 : public GraphTraits<MachineDomTreeNode *> {
198 static NodeType *getEntryNode(MachineDominatorTree *DT) {
199 return DT->getRootNode();