1 //=- llvm/CodeGen/MachineDominators.h - Machine Dom Calculation --*- C++ -*-==//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Owen Anderson and is distributed under
6 // the University of Illinois Open Source 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 void WriteAsOperand(std::ostream &, const MachineBasicBlock*, bool t) { }
29 //===-------------------------------------
30 /// DominatorTree Class - Concrete subclass of DominatorTreeBase that is used to
31 /// compute a normal dominator tree.
33 class MachineDominatorTree : public MachineFunctionPass {
35 static char ID; // Pass ID, replacement for typeid
36 DominatorTreeBase<MachineBasicBlock>* DT;
38 MachineDominatorTree() : MachineFunctionPass(intptr_t(&ID)) {
39 DT = new DominatorTreeBase<MachineBasicBlock>(false);
42 ~MachineDominatorTree() {
47 /// getRoots - Return the root blocks of the current CFG. This may include
48 /// multiple blocks if we are computing post dominators. For forward
49 /// dominators, this will always be a single block (the entry node).
51 inline const std::vector<MachineBasicBlock*> &getRoots() const {
52 return DT->getRoots();
55 inline MachineBasicBlock *getRoot() const {
59 inline MachineDomTreeNode *getRootNode() const {
60 return DT->getRootNode();
63 virtual bool runOnFunction(Function &F);
65 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
69 inline bool dominates(MachineDomTreeNode* A, MachineDomTreeNode* B) const {
70 return DT->dominates(A, B);
73 inline bool dominates(MachineBasicBlock* A, MachineBasicBlock* B) const {
74 return DT->dominates(A, B);
77 // dominates - Return true if A dominates B. This performs the
78 // special checks necessary if A and B are in the same basic block.
79 bool dominates(MachineInstr *A, MachineInstr *B) const {
80 MachineBasicBlock *BBA = A->getParent(), *BBB = B->getParent();
81 if (BBA != BBB) return DT->dominates(BBA, BBB);
83 // Loop through the basic block until we find A or B.
84 MachineBasicBlock::iterator I = BBA->begin();
85 for (; &*I != A && &*I != B; ++I) /*empty*/;
87 //if(!DT.IsPostDominators) {
88 // A dominates B if it is found first in the basic block.
91 // // A post-dominates B if B is found first in the basic block.
96 inline bool properlyDominates(const MachineDomTreeNode* A,
97 MachineDomTreeNode* B) const {
98 return DT->properlyDominates(A, B);
101 inline bool properlyDominates(MachineBasicBlock* A,
102 MachineBasicBlock* B) const {
103 return DT->properlyDominates(A, B);
106 /// findNearestCommonDominator - Find nearest common dominator basic block
107 /// for basic block A and B. If there is no such block then return NULL.
108 inline MachineBasicBlock *findNearestCommonDominator(MachineBasicBlock *A,
109 MachineBasicBlock *B) {
110 return DT->findNearestCommonDominator(A, B);
113 inline MachineDomTreeNode *operator[](MachineBasicBlock *BB) const {
114 return DT->getNode(BB);
117 /// getNode - return the (Post)DominatorTree node for the specified basic
118 /// block. This is the same as using operator[] on this class.
120 inline MachineDomTreeNode *getNode(MachineBasicBlock *BB) const {
121 return DT->getNode(BB);
124 /// addNewBlock - Add a new node to the dominator tree information. This
125 /// creates a new node as a child of DomBB dominator node,linking it into
126 /// the children list of the immediate dominator.
127 inline MachineDomTreeNode *addNewBlock(MachineBasicBlock *BB,
128 MachineBasicBlock *DomBB) {
129 return DT->addNewBlock(BB, DomBB);
132 /// changeImmediateDominator - This method is used to update the dominator
133 /// tree information when a node's immediate dominator changes.
135 inline void changeImmediateDominator(MachineBasicBlock *N,
136 MachineBasicBlock* NewIDom) {
137 DT->changeImmediateDominator(N, NewIDom);
140 inline void changeImmediateDominator(MachineDomTreeNode *N,
141 MachineDomTreeNode* NewIDom) {
142 DT->changeImmediateDominator(N, NewIDom);
145 /// eraseNode - Removes a node from the dominator tree. Block must not
146 /// domiante any other blocks. Removes node from its immediate dominator's
147 /// children list. Deletes dominator node associated with basic block BB.
148 inline void eraseNode(MachineBasicBlock *BB) {
152 /// splitBlock - BB is split and now it has one successor. Update dominator
153 /// tree to reflect this change.
154 inline void splitBlock(MachineBasicBlock* NewBB) {
155 DT->splitBlock(NewBB);
159 virtual void releaseMemory() {
163 virtual void print(std::ostream &OS, const Module* M= 0) const {