X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FVMCore%2FDominators.cpp;h=f3dad824461dd9e7ded770765fd37899a386cb80;hb=b08ba8824e0e8bf1d4a68594c5efb65bf640ecc1;hp=9bd51bf4d91d59c89a79c982b5bc6d8164c066f7;hpb=9dea3a340a8e3db7eab92ea78c20e317ac4c2545;p=oota-llvm.git diff --git a/lib/VMCore/Dominators.cpp b/lib/VMCore/Dominators.cpp index 9bd51bf4d91..f3dad824461 100644 --- a/lib/VMCore/Dominators.cpp +++ b/lib/VMCore/Dominators.cpp @@ -2,8 +2,8 @@ // // The LLVM Compiler Infrastructure // -// This file was developed by the LLVM research group and is distributed under -// the University of Illinois Open Source License. See LICENSE.TXT for details. +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // @@ -16,449 +16,251 @@ #include "llvm/Analysis/Dominators.h" #include "llvm/Support/CFG.h" -#include "llvm/Assembly/Writer.h" +#include "llvm/Support/Compiler.h" +#include "llvm/Support/Debug.h" #include "llvm/ADT/DepthFirstIterator.h" #include "llvm/ADT/SetOperations.h" #include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/Analysis/DominatorInternals.h" #include "llvm/Instructions.h" +#include "llvm/Support/raw_ostream.h" +#include "llvm/Support/CommandLine.h" #include using namespace llvm; +// Always verify dominfo if expensive checking is enabled. +#ifdef XDEBUG +static bool VerifyDomInfo = true; +#else +static bool VerifyDomInfo = false; +#endif +static cl::opt +VerifyDomInfoX("verify-dom-info", cl::location(VerifyDomInfo), + cl::desc("Verify dominator info (time consuming)")); + //===----------------------------------------------------------------------===// -// ImmediateDominators Implementation +// DominatorTree Implementation //===----------------------------------------------------------------------===// // -// Immediate Dominators construction - This pass constructs immediate dominator -// information for a flow-graph based on the algorithm described in this -// document: -// -// A Fast Algorithm for Finding Dominators in a Flowgraph -// T. Lengauer & R. Tarjan, ACM TOPLAS July 1979, pgs 121-141. -// -// This implements both the O(n*ack(n)) and the O(n*log(n)) versions of EVAL and -// LINK, but it turns out that the theoretically slower O(n*log(n)) -// implementation is actually faster than the "efficient" algorithm (even for -// large CFGs) because the constant overheads are substantially smaller. The -// lower-complexity version can be enabled with the following #define: -// -#define BALANCE_IDOM_TREE 0 +// Provide public access to DominatorTree information. Implementation details +// can be found in DominatorCalculation.h. // //===----------------------------------------------------------------------===// -static RegisterPass -C("idom", "Immediate Dominators Construction", true); +TEMPLATE_INSTANTIATION(class llvm::DomTreeNodeBase); +TEMPLATE_INSTANTIATION(class llvm::DominatorTreeBase); -namespace { - class DFCalculateWorkObject { - public: - DFCalculateWorkObject(BasicBlock *B, BasicBlock *P, - const DominatorTree::Node *N, - const DominatorTree::Node *PN) - : currentBB(B), parentBB(P), Node(N), parentNode(PN) {} - BasicBlock *currentBB; - BasicBlock *parentBB; - const DominatorTree::Node *Node; - const DominatorTree::Node *parentNode; - }; -} -unsigned ImmediateDominators::DFSPass(BasicBlock *V, InfoRec &VInfo, - unsigned N) { - VInfo.Semi = ++N; - VInfo.Label = V; - - Vertex.push_back(V); // Vertex[n] = V; - //Info[V].Ancestor = 0; // Ancestor[n] = 0 - //Child[V] = 0; // Child[v] = 0 - VInfo.Size = 1; // Size[v] = 1 +char DominatorTree::ID = 0; +INITIALIZE_PASS(DominatorTree, "domtree", + "Dominator Tree Construction", true, true); - for (succ_iterator SI = succ_begin(V), E = succ_end(V); SI != E; ++SI) { - InfoRec &SuccVInfo = Info[*SI]; - if (SuccVInfo.Semi == 0) { - SuccVInfo.Parent = V; - N = DFSPass(*SI, SuccVInfo, N); - } - } - return N; +bool DominatorTree::runOnFunction(Function &F) { + DT->recalculate(F); + return false; } -void ImmediateDominators::Compress(BasicBlock *V, InfoRec &VInfo) { - BasicBlock *VAncestor = VInfo.Ancestor; - InfoRec &VAInfo = Info[VAncestor]; - if (VAInfo.Ancestor == 0) - return; - - Compress(VAncestor, VAInfo); +void DominatorTree::verifyAnalysis() const { + if (!VerifyDomInfo) return; - BasicBlock *VAncestorLabel = VAInfo.Label; - BasicBlock *VLabel = VInfo.Label; - if (Info[VAncestorLabel].Semi < Info[VLabel].Semi) - VInfo.Label = VAncestorLabel; + Function &F = *getRoot()->getParent(); - VInfo.Ancestor = VAInfo.Ancestor; + DominatorTree OtherDT; + OtherDT.getBase().recalculate(F); + assert(!compare(OtherDT) && "Invalid DominatorTree info!"); } -BasicBlock *ImmediateDominators::Eval(BasicBlock *V) { - InfoRec &VInfo = Info[V]; -#if !BALANCE_IDOM_TREE - // Higher-complexity but faster implementation - if (VInfo.Ancestor == 0) - return V; - Compress(V, VInfo); - return VInfo.Label; -#else - // Lower-complexity but slower implementation - if (VInfo.Ancestor == 0) - return VInfo.Label; - Compress(V, VInfo); - BasicBlock *VLabel = VInfo.Label; - - BasicBlock *VAncestorLabel = Info[VInfo.Ancestor].Label; - if (Info[VAncestorLabel].Semi >= Info[VLabel].Semi) - return VLabel; - else - return VAncestorLabel; -#endif -} - -void ImmediateDominators::Link(BasicBlock *V, BasicBlock *W, InfoRec &WInfo){ -#if !BALANCE_IDOM_TREE - // Higher-complexity but faster implementation - WInfo.Ancestor = V; -#else - // Lower-complexity but slower implementation - BasicBlock *WLabel = WInfo.Label; - unsigned WLabelSemi = Info[WLabel].Semi; - BasicBlock *S = W; - InfoRec *SInfo = &Info[S]; - - BasicBlock *SChild = SInfo->Child; - InfoRec *SChildInfo = &Info[SChild]; - - while (WLabelSemi < Info[SChildInfo->Label].Semi) { - BasicBlock *SChildChild = SChildInfo->Child; - if (SInfo->Size+Info[SChildChild].Size >= 2*SChildInfo->Size) { - SChildInfo->Ancestor = S; - SInfo->Child = SChild = SChildChild; - SChildInfo = &Info[SChild]; - } else { - SChildInfo->Size = SInfo->Size; - S = SInfo->Ancestor = SChild; - SInfo = SChildInfo; - SChild = SChildChild; - SChildInfo = &Info[SChild]; - } - } - - InfoRec &VInfo = Info[V]; - SInfo->Label = WLabel; - - assert(V != W && "The optimization here will not work in this case!"); - unsigned WSize = WInfo.Size; - unsigned VSize = (VInfo.Size += WSize); - - if (VSize < 2*WSize) - std::swap(S, VInfo.Child); - - while (S) { - SInfo = &Info[S]; - SInfo->Ancestor = V; - S = SInfo->Child; - } -#endif +void DominatorTree::print(raw_ostream &OS, const Module *) const { + DT->print(OS); } - - -bool ImmediateDominators::runOnFunction(Function &F) { - IDoms.clear(); // Reset from the last time we were run... - BasicBlock *Root = &F.getEntryBlock(); - Roots.clear(); - Roots.push_back(Root); - - Vertex.push_back(0); - - // Step #1: Number blocks in depth-first order and initialize variables used - // in later stages of the algorithm. - unsigned N = 0; - for (unsigned i = 0, e = Roots.size(); i != e; ++i) - N = DFSPass(Roots[i], Info[Roots[i]], 0); - - for (unsigned i = N; i >= 2; --i) { - BasicBlock *W = Vertex[i]; - InfoRec &WInfo = Info[W]; - - // Step #2: Calculate the semidominators of all vertices - for (pred_iterator PI = pred_begin(W), E = pred_end(W); PI != E; ++PI) - if (Info.count(*PI)) { // Only if this predecessor is reachable! - unsigned SemiU = Info[Eval(*PI)].Semi; - if (SemiU < WInfo.Semi) - WInfo.Semi = SemiU; - } - - Info[Vertex[WInfo.Semi]].Bucket.push_back(W); - - BasicBlock *WParent = WInfo.Parent; - Link(WParent, W, WInfo); - - // Step #3: Implicitly define the immediate dominator of vertices - std::vector &WParentBucket = Info[WParent].Bucket; - while (!WParentBucket.empty()) { - BasicBlock *V = WParentBucket.back(); - WParentBucket.pop_back(); - BasicBlock *U = Eval(V); - IDoms[V] = Info[U].Semi < Info[V].Semi ? U : WParent; - } - } - - // Step #4: Explicitly define the immediate dominator of each vertex - for (unsigned i = 2; i <= N; ++i) { - BasicBlock *W = Vertex[i]; - BasicBlock *&WIDom = IDoms[W]; - if (WIDom != Vertex[Info[W].Semi]) - WIDom = IDoms[WIDom]; - } - - // Free temporary memory used to construct idom's - Info.clear(); - std::vector().swap(Vertex); - - return false; -} - -/// dominates - Return true if A dominates B. -/// -bool ImmediateDominatorsBase::dominates(BasicBlock *A, BasicBlock *B) const { - assert(A && B && "Null pointers?"); +// dominates - Return true if A dominates a use in B. This performs the +// special checks necessary if A and B are in the same basic block. +bool DominatorTree::dominates(const Instruction *A, const Instruction *B) const{ + const BasicBlock *BBA = A->getParent(), *BBB = B->getParent(); + + // If A is an invoke instruction, its value is only available in this normal + // successor block. + if (const InvokeInst *II = dyn_cast(A)) + BBA = II->getNormalDest(); - // Walk up the dominator tree from B to determine if A dom B. - while (A != B && B) - B = get(B); - return A == B; -} - -void ImmediateDominatorsBase::print(std::ostream &o, const Module* ) const { - Function *F = getRoots()[0]->getParent(); - for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) { - o << " Immediate Dominator For Basic Block:"; - WriteAsOperand(o, I, false); - o << " is:"; - if (BasicBlock *ID = get(I)) - WriteAsOperand(o, ID, false); - else - o << " <>"; - o << "\n"; - } - o << "\n"; -} - - - -//===----------------------------------------------------------------------===// -// DominatorSet Implementation -//===----------------------------------------------------------------------===// - -static RegisterPass -B("domset", "Dominator Set Construction", true); - -// dominates - Return true if A dominates B. This performs the special checks -// necessary if A and B are in the same basic block. -// -bool DominatorSetBase::dominates(Instruction *A, Instruction *B) const { - BasicBlock *BBA = A->getParent(), *BBB = B->getParent(); if (BBA != BBB) return dominates(BBA, BBB); - + // It is not possible to determine dominance between two PHI nodes // based on their ordering. if (isa(A) && isa(B)) return false; - + // Loop through the basic block until we find A or B. - BasicBlock::iterator I = BBA->begin(); - for (; &*I != A && &*I != B; ++I) /*empty*/; - - if(!IsPostDominators) { - // A dominates B if it is found first in the basic block. - return &*I == A; - } else { - // A post-dominates B if B is found first in the basic block. - return &*I == B; - } + BasicBlock::const_iterator I = BBA->begin(); + for (; &*I != A && &*I != B; ++I) + /*empty*/; + + return &*I == A; } -// runOnFunction - This method calculates the forward dominator sets for the -// specified function. -// -bool DominatorSet::runOnFunction(Function &F) { - BasicBlock *Root = &F.getEntryBlock(); - Roots.clear(); - Roots.push_back(Root); - assert(pred_begin(Root) == pred_end(Root) && - "Root node has predecessors in function!"); - - ImmediateDominators &ID = getAnalysis(); - Doms.clear(); - if (Roots.empty()) return false; - // Root nodes only dominate themselves. - for (unsigned i = 0, e = Roots.size(); i != e; ++i) - Doms[Roots[i]].insert(Roots[i]); +//===----------------------------------------------------------------------===// +// DominanceFrontier Implementation +//===----------------------------------------------------------------------===// - // Loop over all of the blocks in the function, calculating dominator sets for - // each function. - for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) - if (BasicBlock *IDom = ID[I]) { // Get idom if block is reachable - DomSetType &DS = Doms[I]; - assert(DS.empty() && "Domset already filled in for this block?"); - DS.insert(I); // Blocks always dominate themselves +char DominanceFrontier::ID = 0; +INITIALIZE_PASS(DominanceFrontier, "domfrontier", + "Dominance Frontier Construction", true, true); + +void DominanceFrontier::verifyAnalysis() const { + if (!VerifyDomInfo) return; + + DominatorTree &DT = getAnalysis(); + + DominanceFrontier OtherDF; + const std::vector &DTRoots = DT.getRoots(); + OtherDF.calculate(DT, DT.getNode(DTRoots[0])); + assert(!compare(OtherDF) && "Invalid DominanceFrontier info!"); +} + +// NewBB is split and now it has one successor. Update dominance frontier to +// reflect this change. +void DominanceFrontier::splitBlock(BasicBlock *NewBB) { + assert(NewBB->getTerminator()->getNumSuccessors() == 1 && + "NewBB should have a single successor!"); + BasicBlock *NewBBSucc = NewBB->getTerminator()->getSuccessor(0); + + // NewBBSucc inherits original NewBB frontier. + DominanceFrontier::iterator NewBBI = find(NewBB); + if (NewBBI != end()) + addBasicBlock(NewBBSucc, NewBBI->second); + + // If NewBB dominates NewBBSucc, then DF(NewBB) is now going to be the + // DF(NewBBSucc) without the stuff that the new block does not dominate + // a predecessor of. + DominatorTree &DT = getAnalysis(); + DomTreeNode *NewBBNode = DT.getNode(NewBB); + DomTreeNode *NewBBSuccNode = DT.getNode(NewBBSucc); + if (DT.dominates(NewBBNode, NewBBSuccNode)) { + DominanceFrontier::iterator DFI = find(NewBBSucc); + if (DFI != end()) { + DominanceFrontier::DomSetType Set = DFI->second; + // Filter out stuff in Set that we do not dominate a predecessor of. + for (DominanceFrontier::DomSetType::iterator SetI = Set.begin(), + E = Set.end(); SetI != E;) { + bool DominatesPred = false; + for (pred_iterator PI = pred_begin(*SetI), E = pred_end(*SetI); + PI != E; ++PI) + if (DT.dominates(NewBBNode, DT.getNode(*PI))) { + DominatesPred = true; + break; + } + if (!DominatesPred) + Set.erase(SetI++); + else + ++SetI; + } - // Insert all dominators into the set... - while (IDom) { - // If we have already computed the dominator sets for our immediate - // dominator, just use it instead of walking all the way up to the root. - DomSetType &IDS = Doms[IDom]; - if (!IDS.empty()) { - DS.insert(IDS.begin(), IDS.end()); - break; - } else { - DS.insert(IDom); - IDom = ID[IDom]; + if (NewBBI != end()) { + for (DominanceFrontier::DomSetType::iterator SetI = Set.begin(), + E = Set.end(); SetI != E; ++SetI) { + BasicBlock *SB = *SetI; + addToFrontier(NewBBI, SB); } - } - } else { - // Ensure that every basic block has at least an empty set of nodes. This - // is important for the case when there is unreachable blocks. - Doms[I]; + } else + addBasicBlock(NewBB, Set); } - - return false; -} - -namespace llvm { -static std::ostream &operator<<(std::ostream &o, - const std::set &BBs) { - for (std::set::const_iterator I = BBs.begin(), E = BBs.end(); - I != E; ++I) - if (*I) - WriteAsOperand(o, *I, false); - else - o << " <>"; - return o; -} -} - -void DominatorSetBase::print(std::ostream &o, const Module* ) const { - for (const_iterator I = begin(), E = end(); I != E; ++I) { - o << " DomSet For BB: "; - if (I->first) - WriteAsOperand(o, I->first, false); - else - o << " <>"; - o << " is:\t" << I->second << "\n"; + + } else { + // DF(NewBB) is {NewBBSucc} because NewBB does not strictly dominate + // NewBBSucc, but it does dominate itself (and there is an edge (NewBB -> + // NewBBSucc)). NewBBSucc is the single successor of NewBB. + DominanceFrontier::DomSetType NewDFSet; + NewDFSet.insert(NewBBSucc); + addBasicBlock(NewBB, NewDFSet); } -} - -//===----------------------------------------------------------------------===// -// DominatorTree Implementation -//===----------------------------------------------------------------------===// - -static RegisterPass -E("domtree", "Dominator Tree Construction", true); - -// DominatorTreeBase::reset - Free all of the tree node memory. -// -void DominatorTreeBase::reset() { - for (NodeMapType::iterator I = Nodes.begin(), E = Nodes.end(); I != E; ++I) - delete I->second; - Nodes.clear(); - RootNode = 0; -} -void DominatorTreeBase::Node::setIDom(Node *NewIDom) { - assert(IDom && "No immediate dominator?"); - if (IDom != NewIDom) { - std::vector::iterator I = - std::find(IDom->Children.begin(), IDom->Children.end(), this); - assert(I != IDom->Children.end() && - "Not in immediate dominator children set!"); - // I am no longer your child... - IDom->Children.erase(I); - - // Switch to new dominator - IDom = NewIDom; - IDom->Children.push_back(this); + // Now update dominance frontiers which either used to contain NewBBSucc + // or which now need to include NewBB. + + // Collect the set of blocks which dominate a predecessor of NewBB or + // NewSuccBB and which don't dominate both. This is an initial + // approximation of the blocks whose dominance frontiers will need updates. + SmallVector AllPredDoms; + + // Compute the block which dominates both NewBBSucc and NewBB. This is + // the immediate dominator of NewBBSucc unless NewBB dominates NewBBSucc. + // The code below which climbs dominator trees will stop at this point, + // because from this point up, dominance frontiers are unaffected. + DomTreeNode *DominatesBoth = 0; + if (NewBBSuccNode) { + DominatesBoth = NewBBSuccNode->getIDom(); + if (DominatesBoth == NewBBNode) + DominatesBoth = NewBBNode->getIDom(); } -} - -DominatorTreeBase::Node *DominatorTree::getNodeForBlock(BasicBlock *BB) { - Node *&BBNode = Nodes[BB]; - if (BBNode) return BBNode; - - // Haven't calculated this node yet? Get or calculate the node for the - // immediate dominator. - BasicBlock *IDom = getAnalysis()[BB]; - Node *IDomNode = getNodeForBlock(IDom); - // Add a new tree node for this BasicBlock, and link it as a child of - // IDomNode - return BBNode = IDomNode->addChild(new Node(BB, IDomNode)); -} - -void DominatorTree::calculate(const ImmediateDominators &ID) { - assert(Roots.size() == 1 && "DominatorTree should have 1 root block!"); - BasicBlock *Root = Roots[0]; - Nodes[Root] = RootNode = new Node(Root, 0); // Add a node for the root... - - Function *F = Root->getParent(); - // Loop over all of the reachable blocks in the function... - for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) - if (BasicBlock *ImmDom = ID.get(I)) { // Reachable block. - Node *&BBNode = Nodes[I]; - if (!BBNode) { // Haven't calculated this node yet? - // Get or calculate the node for the immediate dominator - Node *IDomNode = getNodeForBlock(ImmDom); - - // Add a new tree node for this BasicBlock, and link it as a child of - // IDomNode - BBNode = IDomNode->addChild(new Node(I, IDomNode)); - } + // Collect the set of all blocks which dominate a predecessor of NewBB. + SmallPtrSet NewBBPredDoms; + for (pred_iterator PI = pred_begin(NewBB), E = pred_end(NewBB); PI != E; ++PI) + for (DomTreeNode *DTN = DT.getNode(*PI); DTN; DTN = DTN->getIDom()) { + if (DTN == DominatesBoth) + break; + if (!NewBBPredDoms.insert(DTN)) + break; + AllPredDoms.push_back(DTN); } -} -static std::ostream &operator<<(std::ostream &o, - const DominatorTreeBase::Node *Node) { - if (Node->getBlock()) - WriteAsOperand(o, Node->getBlock(), false); - else - o << " <>"; - return o << "\n"; -} + // Collect the set of all blocks which dominate a predecessor of NewSuccBB. + SmallPtrSet NewBBSuccPredDoms; + for (pred_iterator PI = pred_begin(NewBBSucc), + E = pred_end(NewBBSucc); PI != E; ++PI) + for (DomTreeNode *DTN = DT.getNode(*PI); DTN; DTN = DTN->getIDom()) { + if (DTN == DominatesBoth) + break; + if (!NewBBSuccPredDoms.insert(DTN)) + break; + if (!NewBBPredDoms.count(DTN)) + AllPredDoms.push_back(DTN); + } -static void PrintDomTree(const DominatorTreeBase::Node *N, std::ostream &o, - unsigned Lev) { - o << std::string(2*Lev, ' ') << "[" << Lev << "] " << N; - for (DominatorTreeBase::Node::const_iterator I = N->begin(), E = N->end(); - I != E; ++I) - PrintDomTree(*I, o, Lev+1); + // Visit all relevant dominance frontiers and make any needed updates. + for (SmallVectorImpl::const_iterator I = AllPredDoms.begin(), + E = AllPredDoms.end(); I != E; ++I) { + DomTreeNode *DTN = *I; + iterator DFI = find((*I)->getBlock()); + + // Only consider nodes that have NewBBSucc in their dominator frontier. + if (DFI == end() || !DFI->second.count(NewBBSucc)) continue; + + // If the block dominates a predecessor of NewBB but does not properly + // dominate NewBB itself, add NewBB to its dominance frontier. + if (NewBBPredDoms.count(DTN) && + !DT.properlyDominates(DTN, NewBBNode)) + addToFrontier(DFI, NewBB); + + // If the block does not dominate a predecessor of NewBBSucc or + // properly dominates NewBBSucc itself, remove NewBBSucc from its + // dominance frontier. + if (!NewBBSuccPredDoms.count(DTN) || + DT.properlyDominates(DTN, NewBBSuccNode)) + removeFromFrontier(DFI, NewBBSucc); + } } -void DominatorTreeBase::print(std::ostream &o, const Module* ) const { - o << "=============================--------------------------------\n" - << "Inorder Dominator Tree:\n"; - PrintDomTree(getRootNode(), o, 1); +namespace { + class DFCalculateWorkObject { + public: + DFCalculateWorkObject(BasicBlock *B, BasicBlock *P, + const DomTreeNode *N, + const DomTreeNode *PN) + : currentBB(B), parentBB(P), Node(N), parentNode(PN) {} + BasicBlock *currentBB; + BasicBlock *parentBB; + const DomTreeNode *Node; + const DomTreeNode *parentNode; + }; } - -//===----------------------------------------------------------------------===// -// DominanceFrontier Implementation -//===----------------------------------------------------------------------===// - -static RegisterPass -G("domfrontier", "Dominance Frontier Construction", true); - const DominanceFrontier::DomSetType & DominanceFrontier::calculate(const DominatorTree &DT, - const DominatorTree::Node *Node) { + const DomTreeNode *Node) { BasicBlock *BB = Node->getBlock(); DomSetType *Result = NULL; @@ -472,8 +274,8 @@ DominanceFrontier::calculate(const DominatorTree &DT, BasicBlock *currentBB = currentW->currentBB; BasicBlock *parentBB = currentW->parentBB; - const DominatorTree::Node *currentNode = currentW->Node; - const DominatorTree::Node *parentNode = currentW->parentNode; + const DomTreeNode *currentNode = currentW->Node; + const DomTreeNode *parentNode = currentW->parentNode; assert (currentBB && "Invalid work object. Missing current Basic Block"); assert (currentNode && "Invalid work object. Missing current Node"); DomSetType &S = Frontiers[currentBB]; @@ -495,12 +297,13 @@ DominanceFrontier::calculate(const DominatorTree &DT, // Loop through and visit the nodes that Node immediately dominates (Node's // children in the IDomTree) bool visitChild = false; - for (DominatorTree::Node::const_iterator NI = currentNode->begin(), + for (DomTreeNode::const_iterator NI = currentNode->begin(), NE = currentNode->end(); NI != NE; ++NI) { - DominatorTree::Node *IDominee = *NI; + DomTreeNode *IDominee = *NI; BasicBlock *childBB = IDominee->getBlock(); if (visited.count(childBB) == 0) { - workList.push_back(DFCalculateWorkObject(childBB, currentBB, IDominee, currentNode)); + workList.push_back(DFCalculateWorkObject(childBB, currentBB, + IDominee, currentNode)); visitChild = true; } } @@ -517,7 +320,7 @@ DominanceFrontier::calculate(const DominatorTree &DT, DomSetType::const_iterator CDFI = S.begin(), CDFE = S.end(); DomSetType &parentSet = Frontiers[parentBB]; for (; CDFI != CDFE; ++CDFI) { - if (!parentNode->properlyDominates(DT[*CDFI])) + if (!DT.properlyDominates(parentNode, DT[*CDFI])) parentSet.insert(*CDFI); } workList.pop_back(); @@ -528,548 +331,30 @@ DominanceFrontier::calculate(const DominatorTree &DT, return *Result; } -void DominanceFrontierBase::print(std::ostream &o, const Module* ) const { +void DominanceFrontierBase::print(raw_ostream &OS, const Module* ) const { for (const_iterator I = begin(), E = end(); I != E; ++I) { - o << " DomFrontier for BB"; + OS << " DomFrontier for BB "; if (I->first) - WriteAsOperand(o, I->first, false); + WriteAsOperand(OS, I->first, false); else - o << " <>"; - o << " is:\t" << I->second << "\n"; - } -} - -//===----------------------------------------------------------------------===// -// ETOccurrence Implementation -//===----------------------------------------------------------------------===// - -void ETOccurrence::Splay() { - ETOccurrence *father; - ETOccurrence *grandfather; - int occdepth; - int fatherdepth; - - while (Parent) { - occdepth = Depth; - - father = Parent; - fatherdepth = Parent->Depth; - grandfather = father->Parent; - - // If we have no grandparent, a single zig or zag will do. - if (!grandfather) { - setDepthAdd(fatherdepth); - MinOccurrence = father->MinOccurrence; - Min = father->Min; - - // See what we have to rotate - if (father->Left == this) { - // Zig - father->setLeft(Right); - setRight(father); - if (father->Left) - father->Left->setDepthAdd(occdepth); - } else { - // Zag - father->setRight(Left); - setLeft(father); - if (father->Right) - father->Right->setDepthAdd(occdepth); - } - father->setDepth(-occdepth); - Parent = NULL; - - father->recomputeMin(); - return; - } + OS << " <>"; + OS << " is:\t"; - // If we have a grandfather, we need to do some - // combination of zig and zag. - int grandfatherdepth = grandfather->Depth; + const std::set &BBs = I->second; - setDepthAdd(fatherdepth + grandfatherdepth); - MinOccurrence = grandfather->MinOccurrence; - Min = grandfather->Min; - - ETOccurrence *greatgrandfather = grandfather->Parent; - - if (grandfather->Left == father) { - if (father->Left == this) { - // Zig zig - grandfather->setLeft(father->Right); - father->setLeft(Right); - setRight(father); - father->setRight(grandfather); - - father->setDepth(-occdepth); - - if (father->Left) - father->Left->setDepthAdd(occdepth); - - grandfather->setDepth(-fatherdepth); - if (grandfather->Left) - grandfather->Left->setDepthAdd(fatherdepth); - } else { - // Zag zig - grandfather->setLeft(Right); - father->setRight(Left); - setLeft(father); - setRight(grandfather); - - father->setDepth(-occdepth); - if (father->Right) - father->Right->setDepthAdd(occdepth); - grandfather->setDepth(-occdepth - fatherdepth); - if (grandfather->Left) - grandfather->Left->setDepthAdd(occdepth + fatherdepth); - } - } else { - if (father->Left == this) { - // Zig zag - grandfather->setRight(Left); - father->setLeft(Right); - setLeft(grandfather); - setRight(father); - - father->setDepth(-occdepth); - if (father->Left) - father->Left->setDepthAdd(occdepth); - grandfather->setDepth(-occdepth - fatherdepth); - if (grandfather->Right) - grandfather->Right->setDepthAdd(occdepth + fatherdepth); - } else { // Zag Zag - grandfather->setRight(father->Left); - father->setRight(Left); - setLeft(father); - father->setLeft(grandfather); - - father->setDepth(-occdepth); - if (father->Right) - father->Right->setDepthAdd(occdepth); - grandfather->setDepth(-fatherdepth); - if (grandfather->Right) - grandfather->Right->setDepthAdd(fatherdepth); - } - } - - // Might need one more rotate depending on greatgrandfather. - setParent(greatgrandfather); - if (greatgrandfather) { - if (greatgrandfather->Left == grandfather) - greatgrandfather->Left = this; + for (std::set::const_iterator I = BBs.begin(), E = BBs.end(); + I != E; ++I) { + OS << ' '; + if (*I) + WriteAsOperand(OS, *I, false); else - greatgrandfather->Right = this; - + OS << "<>"; } - grandfather->recomputeMin(); - father->recomputeMin(); + OS << "\n"; } } -//===----------------------------------------------------------------------===// -// ETNode implementation -//===----------------------------------------------------------------------===// - -void ETNode::Split() { - ETOccurrence *right, *left; - ETOccurrence *rightmost = RightmostOcc; - ETOccurrence *parent; - - // Update the occurrence tree first. - RightmostOcc->Splay(); - - // Find the leftmost occurrence in the rightmost subtree, then splay - // around it. - for (right = rightmost->Right; right->Left; right = right->Left); - - right->Splay(); - - // Start splitting - right->Left->Parent = NULL; - parent = ParentOcc; - parent->Splay(); - ParentOcc = NULL; - - left = parent->Left; - parent->Right->Parent = NULL; - - right->setLeft(left); - - right->recomputeMin(); - - rightmost->Splay(); - rightmost->Depth = 0; - rightmost->Min = 0; - - delete parent; - - // Now update *our* tree - - if (Father->Son == this) - Father->Son = Right; - - if (Father->Son == this) - Father->Son = NULL; - else { - Left->Right = Right; - Right->Left = Left; - } - Left = Right = NULL; - Father = NULL; -} - -void ETNode::setFather(ETNode *NewFather) { - ETOccurrence *rightmost; - ETOccurrence *leftpart; - ETOccurrence *NewFatherOcc; - ETOccurrence *temp; - - // First update the path in the splay tree - NewFatherOcc = new ETOccurrence(NewFather); - - rightmost = NewFather->RightmostOcc; - rightmost->Splay(); - - leftpart = rightmost->Left; - - temp = RightmostOcc; - temp->Splay(); - - NewFatherOcc->setLeft(leftpart); - NewFatherOcc->setRight(temp); - - temp->Depth++; - temp->Min++; - NewFatherOcc->recomputeMin(); - - rightmost->setLeft(NewFatherOcc); - - if (NewFatherOcc->Min + rightmost->Depth < rightmost->Min) { - rightmost->Min = NewFatherOcc->Min + rightmost->Depth; - rightmost->MinOccurrence = NewFatherOcc->MinOccurrence; - } - - delete ParentOcc; - ParentOcc = NewFatherOcc; - - // Update *our* tree - ETNode *left; - ETNode *right; - - Father = NewFather; - right = Father->Son; - - if (right) - left = right->Left; - else - left = right = this; - - left->Right = this; - right->Left = this; - Left = left; - Right = right; - - Father->Son = this; -} - -bool ETNode::Below(ETNode *other) { - ETOccurrence *up = other->RightmostOcc; - ETOccurrence *down = RightmostOcc; - - if (this == other) - return true; - - up->Splay(); - - ETOccurrence *left, *right; - left = up->Left; - right = up->Right; - - if (!left) - return false; - - left->Parent = NULL; - - if (right) - right->Parent = NULL; - - down->Splay(); - - if (left == down || left->Parent != NULL) { - if (right) - right->Parent = up; - up->setLeft(down); - } else { - left->Parent = up; - - // If the two occurrences are in different trees, put things - // back the way they were. - if (right && right->Parent != NULL) - up->setRight(down); - else - up->setRight(right); - return false; - } - - if (down->Depth <= 0) - return false; - - return !down->Right || down->Right->Min + down->Depth >= 0; -} - -ETNode *ETNode::NCA(ETNode *other) { - ETOccurrence *occ1 = RightmostOcc; - ETOccurrence *occ2 = other->RightmostOcc; - - ETOccurrence *left, *right, *ret; - ETOccurrence *occmin; - int mindepth; - - if (this == other) - return this; - - occ1->Splay(); - left = occ1->Left; - right = occ1->Right; - - if (left) - left->Parent = NULL; - - if (right) - right->Parent = NULL; - occ2->Splay(); - - if (left == occ2 || (left && left->Parent != NULL)) { - ret = occ2->Right; - - occ1->setLeft(occ2); - if (right) - right->Parent = occ1; - } else { - ret = occ2->Left; - - occ1->setRight(occ2); - if (left) - left->Parent = occ1; - } - - if (occ2->Depth > 0) { - occmin = occ1; - mindepth = occ1->Depth; - } else { - occmin = occ2; - mindepth = occ2->Depth + occ1->Depth; - } - - if (ret && ret->Min + occ1->Depth + occ2->Depth < mindepth) - return ret->MinOccurrence->OccFor; - else - return occmin->OccFor; -} - -void ETNode::assignDFSNumber(int num) { - std::vector workStack; - std::set visitedNodes; - - workStack.push_back(this); - visitedNodes.insert(this); - this->DFSNumIn = num++; - - while (!workStack.empty()) { - ETNode *Node = workStack.back(); - - // If this is leaf node then set DFSNumOut and pop the stack - if (!Node->Son) { - Node->DFSNumOut = num++; - workStack.pop_back(); - continue; - } - - ETNode *son = Node->Son; - - // Visit Node->Son first - if (visitedNodes.count(son) == 0) { - son->DFSNumIn = num++; - workStack.push_back(son); - visitedNodes.insert(son); - continue; - } - - bool visitChild = false; - // Visit remaining children - for (ETNode *s = son->Right; s != son && !visitChild; s = s->Right) { - if (visitedNodes.count(s) == 0) { - visitChild = true; - s->DFSNumIn = num++; - workStack.push_back(s); - visitedNodes.insert(s); - } - } - - if (!visitChild) { - // If we reach here means all children are visited - Node->DFSNumOut = num++; - workStack.pop_back(); - } - } -} - -//===----------------------------------------------------------------------===// -// ETForest implementation -//===----------------------------------------------------------------------===// - -static RegisterPass -D("etforest", "ET Forest Construction", true); - -void ETForestBase::reset() { - for (ETMapType::iterator I = Nodes.begin(), E = Nodes.end(); I != E; ++I) - delete I->second; - Nodes.clear(); -} - -void ETForestBase::updateDFSNumbers() -{ - int dfsnum = 0; - // Iterate over all nodes in depth first order. - for (unsigned i = 0, e = Roots.size(); i != e; ++i) - for (df_iterator I = df_begin(Roots[i]), - E = df_end(Roots[i]); I != E; ++I) { - BasicBlock *BB = *I; - if (!getNode(BB)->hasFather()) - getNode(BB)->assignDFSNumber(dfsnum); - } - SlowQueries = 0; - DFSInfoValid = true; -} - -// dominates - Return true if A dominates B. THis performs the -// special checks necessary if A and B are in the same basic block. -bool ETForestBase::dominates(Instruction *A, Instruction *B) { - BasicBlock *BBA = A->getParent(), *BBB = B->getParent(); - if (BBA != BBB) return dominates(BBA, BBB); - - // Loop through the basic block until we find A or B. - BasicBlock::iterator I = BBA->begin(); - for (; &*I != A && &*I != B; ++I) /*empty*/; - - // It is not possible to determine dominance between two PHI nodes - // based on their ordering. - if (isa(A) && isa(B)) - return false; - - if(!IsPostDominators) { - // A dominates B if it is found first in the basic block. - return &*I == A; - } else { - // A post-dominates B if B is found first in the basic block. - return &*I == B; - } -} - -ETNode *ETForest::getNodeForBlock(BasicBlock *BB) { - ETNode *&BBNode = Nodes[BB]; - if (BBNode) return BBNode; - - // Haven't calculated this node yet? Get or calculate the node for the - // immediate dominator. - BasicBlock *IDom = getAnalysis()[BB]; - - // If we are unreachable, we may not have an immediate dominator. - if (!IDom) - return BBNode = new ETNode(BB); - else { - ETNode *IDomNode = getNodeForBlock(IDom); - - // Add a new tree node for this BasicBlock, and link it as a child of - // IDomNode - BBNode = new ETNode(BB); - BBNode->setFather(IDomNode); - return BBNode; - } -} - -void ETForest::calculate(const ImmediateDominators &ID) { - assert(Roots.size() == 1 && "ETForest should have 1 root block!"); - BasicBlock *Root = Roots[0]; - Nodes[Root] = new ETNode(Root); // Add a node for the root - - Function *F = Root->getParent(); - // Loop over all of the reachable blocks in the function... - for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) - if (BasicBlock *ImmDom = ID.get(I)) { // Reachable block. - ETNode *&BBNode = Nodes[I]; - if (!BBNode) { // Haven't calculated this node yet? - // Get or calculate the node for the immediate dominator - ETNode *IDomNode = getNodeForBlock(ImmDom); - - // Add a new ETNode for this BasicBlock, and set it's parent - // to it's immediate dominator. - BBNode = new ETNode(I); - BBNode->setFather(IDomNode); - } - } - - // Make sure we've got nodes around for every block - for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) { - ETNode *&BBNode = Nodes[I]; - if (!BBNode) - BBNode = new ETNode(I); - } - - updateDFSNumbers (); -} - -//===----------------------------------------------------------------------===// -// ETForestBase Implementation -//===----------------------------------------------------------------------===// - -void ETForestBase::addNewBlock(BasicBlock *BB, BasicBlock *IDom) { - ETNode *&BBNode = Nodes[BB]; - assert(!BBNode && "BasicBlock already in ET-Forest"); - - BBNode = new ETNode(BB); - BBNode->setFather(getNode(IDom)); - DFSInfoValid = false; -} - -void ETForestBase::setImmediateDominator(BasicBlock *BB, BasicBlock *newIDom) { - assert(getNode(BB) && "BasicBlock not in ET-Forest"); - assert(getNode(newIDom) && "IDom not in ET-Forest"); - - ETNode *Node = getNode(BB); - if (Node->hasFather()) { - if (Node->getFather()->getData() == newIDom) - return; - Node->Split(); - } - Node->setFather(getNode(newIDom)); - DFSInfoValid= false; -} - -void ETForestBase::print(std::ostream &o, const Module *) const { - o << "=============================--------------------------------\n"; - o << "ET Forest:\n"; - o << "DFS Info "; - if (DFSInfoValid) - o << "is"; - else - o << "is not"; - o << " up to date\n"; - - Function *F = getRoots()[0]->getParent(); - for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) { - o << " DFS Numbers For Basic Block:"; - WriteAsOperand(o, I, false); - o << " are:"; - if (ETNode *EN = getNode(I)) { - o << "In: " << EN->getDFSNumIn(); - o << " Out: " << EN->getDFSNumOut() << "\n"; - } else { - o << "No associated ETNode"; - } - o << "\n"; - } - o << "\n"; +void DominanceFrontierBase::dump() const { + print(dbgs()); } -DEFINING_FILE_FOR(DominatorSet)