1 //===- Dominators.cpp - Dominator Calculation -----------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements simple dominator construction algorithms for finding
11 // forward dominators. Postdominators are available in libanalysis, but are not
12 // included in libvmcore, because it's not needed. Forward dominators are
13 // needed to support the Verifier pass.
15 //===----------------------------------------------------------------------===//
17 #include "llvm/Analysis/Dominators.h"
18 #include "llvm/Support/CFG.h"
19 #include "llvm/Assembly/Writer.h"
20 #include "llvm/ADT/DepthFirstIterator.h"
21 #include "llvm/ADT/SetOperations.h"
26 //===----------------------------------------------------------------------===//
27 // ImmediateDominators Implementation
28 //===----------------------------------------------------------------------===//
30 // Immediate Dominators construction - This pass constructs immediate dominator
31 // information for a flow-graph based on the algorithm described in this
34 // A Fast Algorithm for Finding Dominators in a Flowgraph
35 // T. Lengauer & R. Tarjan, ACM TOPLAS July 1979, pgs 121-141.
37 // This implements both the O(n*ack(n)) and the O(n*log(n)) versions of EVAL and
38 // LINK, but it turns out that the theoretically slower O(n*log(n))
39 // implementation is actually faster than the "efficient" algorithm (even for
40 // large CFGs) because the constant overheads are substantially smaller. The
41 // lower-complexity version can be enabled with the following #define:
43 #define BALANCE_IDOM_TREE 0
45 //===----------------------------------------------------------------------===//
47 static RegisterAnalysis<ImmediateDominators>
48 C("idom", "Immediate Dominators Construction", true);
50 unsigned ImmediateDominators::DFSPass(BasicBlock *V, InfoRec &VInfo,
55 Vertex.push_back(V); // Vertex[n] = V;
56 //Info[V].Ancestor = 0; // Ancestor[n] = 0
57 //Child[V] = 0; // Child[v] = 0
58 VInfo.Size = 1; // Size[v] = 1
60 for (succ_iterator SI = succ_begin(V), E = succ_end(V); SI != E; ++SI) {
61 InfoRec &SuccVInfo = Info[*SI];
62 if (SuccVInfo.Semi == 0) {
64 N = DFSPass(*SI, SuccVInfo, N);
70 void ImmediateDominators::Compress(BasicBlock *V, InfoRec &VInfo) {
71 BasicBlock *VAncestor = VInfo.Ancestor;
72 InfoRec &VAInfo = Info[VAncestor];
73 if (VAInfo.Ancestor == 0)
76 Compress(VAncestor, VAInfo);
78 BasicBlock *VAncestorLabel = VAInfo.Label;
79 BasicBlock *VLabel = VInfo.Label;
80 if (Info[VAncestorLabel].Semi < Info[VLabel].Semi)
81 VInfo.Label = VAncestorLabel;
83 VInfo.Ancestor = VAInfo.Ancestor;
86 BasicBlock *ImmediateDominators::Eval(BasicBlock *V) {
87 InfoRec &VInfo = Info[V];
88 #if !BALANCE_IDOM_TREE
89 // Higher-complexity but faster implementation
90 if (VInfo.Ancestor == 0)
95 // Lower-complexity but slower implementation
96 if (VInfo.Ancestor == 0)
99 BasicBlock *VLabel = VInfo.Label;
101 BasicBlock *VAncestorLabel = Info[VInfo.Ancestor].Label;
102 if (Info[VAncestorLabel].Semi >= Info[VLabel].Semi)
105 return VAncestorLabel;
109 void ImmediateDominators::Link(BasicBlock *V, BasicBlock *W, InfoRec &WInfo){
110 #if !BALANCE_IDOM_TREE
111 // Higher-complexity but faster implementation
114 // Lower-complexity but slower implementation
115 BasicBlock *WLabel = WInfo.Label;
116 unsigned WLabelSemi = Info[WLabel].Semi;
118 InfoRec *SInfo = &Info[S];
120 BasicBlock *SChild = SInfo->Child;
121 InfoRec *SChildInfo = &Info[SChild];
123 while (WLabelSemi < Info[SChildInfo->Label].Semi) {
124 BasicBlock *SChildChild = SChildInfo->Child;
125 if (SInfo->Size+Info[SChildChild].Size >= 2*SChildInfo->Size) {
126 SChildInfo->Ancestor = S;
127 SInfo->Child = SChild = SChildChild;
128 SChildInfo = &Info[SChild];
130 SChildInfo->Size = SInfo->Size;
131 S = SInfo->Ancestor = SChild;
133 SChild = SChildChild;
134 SChildInfo = &Info[SChild];
138 InfoRec &VInfo = Info[V];
139 SInfo->Label = WLabel;
141 assert(V != W && "The optimization here will not work in this case!");
142 unsigned WSize = WInfo.Size;
143 unsigned VSize = (VInfo.Size += WSize);
146 std::swap(S, VInfo.Child);
158 bool ImmediateDominators::runOnFunction(Function &F) {
159 IDoms.clear(); // Reset from the last time we were run...
160 BasicBlock *Root = &F.getEntryBlock();
162 Roots.push_back(Root);
166 // Step #1: Number blocks in depth-first order and initialize variables used
167 // in later stages of the algorithm.
169 for (unsigned i = 0, e = Roots.size(); i != e; ++i)
170 N = DFSPass(Roots[i], Info[Roots[i]], 0);
172 for (unsigned i = N; i >= 2; --i) {
173 BasicBlock *W = Vertex[i];
174 InfoRec &WInfo = Info[W];
176 // Step #2: Calculate the semidominators of all vertices
177 for (pred_iterator PI = pred_begin(W), E = pred_end(W); PI != E; ++PI)
178 if (Info.count(*PI)) { // Only if this predecessor is reachable!
179 unsigned SemiU = Info[Eval(*PI)].Semi;
180 if (SemiU < WInfo.Semi)
184 Info[Vertex[WInfo.Semi]].Bucket.push_back(W);
186 BasicBlock *WParent = WInfo.Parent;
187 Link(WParent, W, WInfo);
189 // Step #3: Implicitly define the immediate dominator of vertices
190 std::vector<BasicBlock*> &WParentBucket = Info[WParent].Bucket;
191 while (!WParentBucket.empty()) {
192 BasicBlock *V = WParentBucket.back();
193 WParentBucket.pop_back();
194 BasicBlock *U = Eval(V);
195 IDoms[V] = Info[U].Semi < Info[V].Semi ? U : WParent;
199 // Step #4: Explicitly define the immediate dominator of each vertex
200 for (unsigned i = 2; i <= N; ++i) {
201 BasicBlock *W = Vertex[i];
202 BasicBlock *&WIDom = IDoms[W];
203 if (WIDom != Vertex[Info[W].Semi])
204 WIDom = IDoms[WIDom];
207 // Free temporary memory used to construct idom's
209 std::vector<BasicBlock*>().swap(Vertex);
214 void ImmediateDominatorsBase::print(std::ostream &o, const Module* ) const {
215 Function *F = getRoots()[0]->getParent();
216 for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
217 o << " Immediate Dominator For Basic Block:";
218 WriteAsOperand(o, I, false);
220 if (BasicBlock *ID = get(I))
221 WriteAsOperand(o, ID, false);
223 o << " <<exit node>>";
231 //===----------------------------------------------------------------------===//
232 // DominatorSet Implementation
233 //===----------------------------------------------------------------------===//
235 static RegisterAnalysis<DominatorSet>
236 B("domset", "Dominator Set Construction", true);
238 // dominates - Return true if A dominates B. This performs the special checks
239 // necessary if A and B are in the same basic block.
241 bool DominatorSetBase::dominates(Instruction *A, Instruction *B) const {
242 BasicBlock *BBA = A->getParent(), *BBB = B->getParent();
243 if (BBA != BBB) return dominates(BBA, BBB);
245 // Loop through the basic block until we find A or B.
246 BasicBlock::iterator I = BBA->begin();
247 for (; &*I != A && &*I != B; ++I) /*empty*/;
249 if(!IsPostDominators) {
250 // A dominates B if it is found first in the basic block.
253 // A post-dominates B if B is found first in the basic block.
259 // runOnFunction - This method calculates the forward dominator sets for the
260 // specified function.
262 bool DominatorSet::runOnFunction(Function &F) {
263 BasicBlock *Root = &F.getEntryBlock();
265 Roots.push_back(Root);
266 assert(pred_begin(Root) == pred_end(Root) &&
267 "Root node has predecessors in function!");
269 ImmediateDominators &ID = getAnalysis<ImmediateDominators>();
271 if (Roots.empty()) return false;
273 // Root nodes only dominate themselves.
274 for (unsigned i = 0, e = Roots.size(); i != e; ++i)
275 Doms[Roots[i]].insert(Roots[i]);
277 // Loop over all of the blocks in the function, calculating dominator sets for
279 for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
280 if (BasicBlock *IDom = ID[I]) { // Get idom if block is reachable
281 DomSetType &DS = Doms[I];
282 assert(DS.empty() && "Domset already filled in for this block?");
283 DS.insert(I); // Blocks always dominate themselves
285 // Insert all dominators into the set...
287 // If we have already computed the dominator sets for our immediate
288 // dominator, just use it instead of walking all the way up to the root.
289 DomSetType &IDS = Doms[IDom];
291 DS.insert(IDS.begin(), IDS.end());
299 // Ensure that every basic block has at least an empty set of nodes. This
300 // is important for the case when there is unreachable blocks.
308 static std::ostream &operator<<(std::ostream &o,
309 const std::set<BasicBlock*> &BBs) {
310 for (std::set<BasicBlock*>::const_iterator I = BBs.begin(), E = BBs.end();
313 WriteAsOperand(o, *I, false);
315 o << " <<exit node>>";
320 void DominatorSetBase::print(std::ostream &o, const Module* ) const {
321 for (const_iterator I = begin(), E = end(); I != E; ++I) {
322 o << " DomSet For BB: ";
324 WriteAsOperand(o, I->first, false);
326 o << " <<exit node>>";
327 o << " is:\t" << I->second << "\n";
331 //===----------------------------------------------------------------------===//
332 // DominatorTree Implementation
333 //===----------------------------------------------------------------------===//
335 static RegisterAnalysis<DominatorTree>
336 E("domtree", "Dominator Tree Construction", true);
338 // DominatorTreeBase::reset - Free all of the tree node memory.
340 void DominatorTreeBase::reset() {
341 for (NodeMapType::iterator I = Nodes.begin(), E = Nodes.end(); I != E; ++I)
347 void DominatorTreeBase::Node::setIDom(Node *NewIDom) {
348 assert(IDom && "No immediate dominator?");
349 if (IDom != NewIDom) {
350 std::vector<Node*>::iterator I =
351 std::find(IDom->Children.begin(), IDom->Children.end(), this);
352 assert(I != IDom->Children.end() &&
353 "Not in immediate dominator children set!");
354 // I am no longer your child...
355 IDom->Children.erase(I);
357 // Switch to new dominator
359 IDom->Children.push_back(this);
363 DominatorTreeBase::Node *DominatorTree::getNodeForBlock(BasicBlock *BB) {
364 Node *&BBNode = Nodes[BB];
365 if (BBNode) return BBNode;
367 // Haven't calculated this node yet? Get or calculate the node for the
368 // immediate dominator.
369 BasicBlock *IDom = getAnalysis<ImmediateDominators>()[BB];
370 Node *IDomNode = getNodeForBlock(IDom);
372 // Add a new tree node for this BasicBlock, and link it as a child of
374 return BBNode = IDomNode->addChild(new Node(BB, IDomNode));
377 void DominatorTree::calculate(const ImmediateDominators &ID) {
378 assert(Roots.size() == 1 && "DominatorTree should have 1 root block!");
379 BasicBlock *Root = Roots[0];
380 Nodes[Root] = RootNode = new Node(Root, 0); // Add a node for the root...
382 Function *F = Root->getParent();
383 // Loop over all of the reachable blocks in the function...
384 for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I)
385 if (BasicBlock *ImmDom = ID.get(I)) { // Reachable block.
386 Node *&BBNode = Nodes[I];
387 if (!BBNode) { // Haven't calculated this node yet?
388 // Get or calculate the node for the immediate dominator
389 Node *IDomNode = getNodeForBlock(ImmDom);
391 // Add a new tree node for this BasicBlock, and link it as a child of
393 BBNode = IDomNode->addChild(new Node(I, IDomNode));
398 static std::ostream &operator<<(std::ostream &o,
399 const DominatorTreeBase::Node *Node) {
400 if (Node->getBlock())
401 WriteAsOperand(o, Node->getBlock(), false);
403 o << " <<exit node>>";
407 static void PrintDomTree(const DominatorTreeBase::Node *N, std::ostream &o,
409 o << std::string(2*Lev, ' ') << "[" << Lev << "] " << N;
410 for (DominatorTreeBase::Node::const_iterator I = N->begin(), E = N->end();
412 PrintDomTree(*I, o, Lev+1);
415 void DominatorTreeBase::print(std::ostream &o, const Module* ) const {
416 o << "=============================--------------------------------\n"
417 << "Inorder Dominator Tree:\n";
418 PrintDomTree(getRootNode(), o, 1);
422 //===----------------------------------------------------------------------===//
423 // DominanceFrontier Implementation
424 //===----------------------------------------------------------------------===//
426 static RegisterAnalysis<DominanceFrontier>
427 G("domfrontier", "Dominance Frontier Construction", true);
429 const DominanceFrontier::DomSetType &
430 DominanceFrontier::calculate(const DominatorTree &DT,
431 const DominatorTree::Node *Node) {
432 // Loop over CFG successors to calculate DFlocal[Node]
433 BasicBlock *BB = Node->getBlock();
434 DomSetType &S = Frontiers[BB]; // The new set to fill in...
436 for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB);
438 // Does Node immediately dominate this successor?
439 if (DT[*SI]->getIDom() != Node)
443 // At this point, S is DFlocal. Now we union in DFup's of our children...
444 // Loop through and visit the nodes that Node immediately dominates (Node's
445 // children in the IDomTree)
447 for (DominatorTree::Node::const_iterator NI = Node->begin(), NE = Node->end();
449 DominatorTree::Node *IDominee = *NI;
450 const DomSetType &ChildDF = calculate(DT, IDominee);
452 DomSetType::const_iterator CDFI = ChildDF.begin(), CDFE = ChildDF.end();
453 for (; CDFI != CDFE; ++CDFI) {
454 if (!Node->properlyDominates(DT[*CDFI]))
462 void DominanceFrontierBase::print(std::ostream &o, const Module* ) const {
463 for (const_iterator I = begin(), E = end(); I != E; ++I) {
464 o << " DomFrontier for BB";
466 WriteAsOperand(o, I->first, false);
468 o << " <<exit node>>";
469 o << " is:\t" << I->second << "\n";
473 //===----------------------------------------------------------------------===//
474 // ETOccurrence Implementation
475 //===----------------------------------------------------------------------===//
477 void ETOccurrence::Splay() {
478 ETOccurrence *father;
479 ETOccurrence *grandfather;
487 fatherdepth = Parent->Depth;
488 grandfather = father->Parent;
490 // If we have no grandparent, a single zig or zag will do.
492 setDepthAdd(fatherdepth);
493 MinOccurrence = father->MinOccurrence;
496 // See what we have to rotate
497 if (father->Left == this) {
499 father->setLeft(Right);
502 father->Left->setDepthAdd(occdepth);
505 father->setRight(Left);
508 father->Right->setDepthAdd(occdepth);
510 father->setDepth(-occdepth);
513 father->recomputeMin();
517 // If we have a grandfather, we need to do some
518 // combination of zig and zag.
519 int grandfatherdepth = grandfather->Depth;
521 setDepthAdd(fatherdepth + grandfatherdepth);
522 MinOccurrence = grandfather->MinOccurrence;
523 Min = grandfather->Min;
525 ETOccurrence *greatgrandfather = grandfather->Parent;
527 if (grandfather->Left == father) {
528 if (father->Left == this) {
530 grandfather->setLeft(father->Right);
531 father->setLeft(Right);
533 father->setRight(grandfather);
535 father->setDepth(-occdepth);
538 father->Left->setDepthAdd(occdepth);
540 grandfather->setDepth(-fatherdepth);
541 if (grandfather->Left)
542 grandfather->Left->setDepthAdd(fatherdepth);
545 grandfather->setLeft(Right);
546 father->setRight(Left);
548 setRight(grandfather);
550 father->setDepth(-occdepth);
552 father->Right->setDepthAdd(occdepth);
553 grandfather->setDepth(-occdepth - fatherdepth);
554 if (grandfather->Left)
555 grandfather->Left->setDepthAdd(occdepth + fatherdepth);
558 if (father->Left == this) {
560 grandfather->setRight(Left);
561 father->setLeft(Right);
562 setLeft(grandfather);
565 father->setDepth(-occdepth);
567 father->Left->setDepthAdd(occdepth);
568 grandfather->setDepth(-occdepth - fatherdepth);
569 if (grandfather->Right)
570 grandfather->Right->setDepthAdd(occdepth + fatherdepth);
572 grandfather->setRight(father->Left);
573 father->setRight(Left);
575 father->setLeft(grandfather);
577 father->setDepth(-occdepth);
579 father->Right->setDepthAdd(occdepth);
580 grandfather->setDepth(-fatherdepth);
581 if (grandfather->Right)
582 grandfather->Right->setDepthAdd(fatherdepth);
586 // Might need one more rotate depending on greatgrandfather.
587 setParent(greatgrandfather);
588 if (greatgrandfather) {
589 if (greatgrandfather->Left == grandfather)
590 greatgrandfather->Left = this;
592 greatgrandfather->Right = this;
595 grandfather->recomputeMin();
596 father->recomputeMin();
600 //===----------------------------------------------------------------------===//
601 // ETNode implementation
602 //===----------------------------------------------------------------------===//
604 void ETNode::Split() {
605 ETOccurrence *right, *left;
606 ETOccurrence *rightmost = RightmostOcc;
607 ETOccurrence *parent;
609 // Update the occurrence tree first.
610 RightmostOcc->Splay();
612 // Find the leftmost occurrence in the rightmost subtree, then splay
614 for (right = rightmost->Right; right->Left; right = right->Left);
619 right->Left->Parent = NULL;
625 parent->Right->Parent = NULL;
627 right->setLeft(left);
629 right->recomputeMin();
632 rightmost->Depth = 0;
637 // Now update *our* tree
639 if (Father->Son == this)
642 if (Father->Son == this)
652 void ETNode::setFather(ETNode *NewFather) {
653 ETOccurrence *rightmost;
654 ETOccurrence *leftpart;
655 ETOccurrence *NewFatherOcc;
658 // First update the path in the splay tree
659 NewFatherOcc = new ETOccurrence(NewFather);
661 rightmost = NewFather->RightmostOcc;
664 leftpart = rightmost->Left;
669 NewFatherOcc->setLeft(leftpart);
670 NewFatherOcc->setRight(temp);
674 NewFatherOcc->recomputeMin();
676 rightmost->setLeft(NewFatherOcc);
678 if (NewFatherOcc->Min + rightmost->Depth < rightmost->Min) {
679 rightmost->Min = NewFatherOcc->Min + rightmost->Depth;
680 rightmost->MinOccurrence = NewFatherOcc->MinOccurrence;
684 ParentOcc = NewFatherOcc;
706 bool ETNode::Below(ETNode *other) {
707 ETOccurrence *up = other->RightmostOcc;
708 ETOccurrence *down = RightmostOcc;
715 ETOccurrence *left, *right;
725 right->Parent = NULL;
729 if (left == down || left->Parent != NULL) {
736 // If the two occurrences are in different trees, put things
737 // back the way they were.
738 if (right && right->Parent != NULL)
745 if (down->Depth <= 0)
748 return !down->Right || down->Right->Min + down->Depth >= 0;
751 ETNode *ETNode::NCA(ETNode *other) {
752 ETOccurrence *occ1 = RightmostOcc;
753 ETOccurrence *occ2 = other->RightmostOcc;
755 ETOccurrence *left, *right, *ret;
756 ETOccurrence *occmin;
770 right->Parent = NULL;
773 if (left == occ2 || (left && left->Parent != NULL)) {
778 right->Parent = occ1;
782 occ1->setRight(occ2);
787 if (occ2->Depth > 0) {
789 mindepth = occ1->Depth;
792 mindepth = occ2->Depth + occ1->Depth;
795 if (ret && ret->Min + occ1->Depth + occ2->Depth < mindepth)
796 return ret->MinOccurrence->OccFor;
798 return occmin->OccFor;
801 //===----------------------------------------------------------------------===//
802 // ETForest implementation
803 //===----------------------------------------------------------------------===//
805 static RegisterAnalysis<ETForest>
806 D("etforest", "ET Forest Construction", true);
808 void ETForestBase::reset() {
809 for (ETMapType::iterator I = Nodes.begin(), E = Nodes.end(); I != E; ++I)
814 void ETForestBase::updateDFSNumbers()
817 // Iterate over all nodes in depth first order.
818 for (unsigned i = 0, e = Roots.size(); i != e; ++i)
819 for (df_iterator<BasicBlock*> I = df_begin(Roots[i]),
820 E = df_end(Roots[i]); I != E; ++I) {
822 if (!getNode(BB)->hasFather())
823 getNode(BB)->assignDFSNumber(dfsnum);
829 ETNode *ETForest::getNodeForBlock(BasicBlock *BB) {
830 ETNode *&BBNode = Nodes[BB];
831 if (BBNode) return BBNode;
833 // Haven't calculated this node yet? Get or calculate the node for the
834 // immediate dominator.
835 BasicBlock *IDom = getAnalysis<ImmediateDominators>()[BB];
837 // If we are unreachable, we may not have an immediate dominator.
839 return BBNode = new ETNode(BB);
841 ETNode *IDomNode = getNodeForBlock(IDom);
843 // Add a new tree node for this BasicBlock, and link it as a child of
845 BBNode = new ETNode(BB);
846 BBNode->setFather(IDomNode);
851 void ETForest::calculate(const ImmediateDominators &ID) {
852 assert(Roots.size() == 1 && "ETForest should have 1 root block!");
853 BasicBlock *Root = Roots[0];
854 Nodes[Root] = new ETNode(Root); // Add a node for the root
856 Function *F = Root->getParent();
857 // Loop over all of the reachable blocks in the function...
858 for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I)
859 if (BasicBlock *ImmDom = ID.get(I)) { // Reachable block.
860 ETNode *&BBNode = Nodes[I];
861 if (!BBNode) { // Haven't calculated this node yet?
862 // Get or calculate the node for the immediate dominator
863 ETNode *IDomNode = getNodeForBlock(ImmDom);
865 // Add a new ETNode for this BasicBlock, and set it's parent
866 // to it's immediate dominator.
867 BBNode = new ETNode(I);
868 BBNode->setFather(IDomNode);
872 // Make sure we've got nodes around for every block
873 for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
874 ETNode *&BBNode = Nodes[I];
876 BBNode = new ETNode(I);
882 //===----------------------------------------------------------------------===//
883 // ETForestBase Implementation
884 //===----------------------------------------------------------------------===//
886 void ETForestBase::addNewBlock(BasicBlock *BB, BasicBlock *IDom) {
887 ETNode *&BBNode = Nodes[BB];
888 assert(!BBNode && "BasicBlock already in ET-Forest");
890 BBNode = new ETNode(BB);
891 BBNode->setFather(getNode(IDom));
892 DFSInfoValid = false;
895 void ETForestBase::setImmediateDominator(BasicBlock *BB, BasicBlock *newIDom) {
896 assert(getNode(BB) && "BasicBlock not in ET-Forest");
897 assert(getNode(newIDom) && "IDom not in ET-Forest");
899 ETNode *Node = getNode(BB);
900 if (Node->hasFather()) {
901 if (Node->getFather()->getData<BasicBlock>() == newIDom)
905 Node->setFather(getNode(newIDom));
909 void ETForestBase::print(std::ostream &o, const Module *) const {
910 o << "=============================--------------------------------\n";
917 o << " up to date\n";
919 Function *F = getRoots()[0]->getParent();
920 for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
921 o << " DFS Numbers For Basic Block:";
922 WriteAsOperand(o, I, false);
924 if (ETNode *EN = getNode(I)) {
925 o << "In: " << EN->getDFSNumIn();
926 o << " Out: " << EN->getDFSNumOut() << "\n";
928 o << "No associated ETNode";
935 DEFINING_FILE_FOR(DominatorSet)