#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/IR/DominatorInternals.h"
-#include "llvm/IR/Dominators.h"
+#include "llvm/Support/GenericDomTreeConstruction.h"
+#include "llvm/Support/GenericDomTree.h"
namespace llvm {
+++ /dev/null
-//===- DominatorInternals.h - Dominator Calculation --------------*- C++ -*-==//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_IR_DOMINATOR_INTERNALS_H
-#define LLVM_IR_DOMINATOR_INTERNALS_H
-
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/IR/Dominators.h"
-
-//===----------------------------------------------------------------------===//
-//
-// DominatorTree 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 the O(n*log(n)) versions of EVAL and LINK, because it turns
-// out that the theoretically slower O(n*log(n)) implementation is actually
-// faster than the almost-linear O(n*alpha(n)) version, even for large CFGs.
-//
-//===----------------------------------------------------------------------===//
-
-namespace llvm {
-
-template<class GraphT>
-unsigned DFSPass(DominatorTreeBase<typename GraphT::NodeType>& DT,
- typename GraphT::NodeType* V, unsigned N) {
- // This is more understandable as a recursive algorithm, but we can't use the
- // recursive algorithm due to stack depth issues. Keep it here for
- // documentation purposes.
-#if 0
- InfoRec &VInfo = DT.Info[DT.Roots[i]];
- VInfo.DFSNum = VInfo.Semi = ++N;
- VInfo.Label = V;
-
- Vertex.push_back(V); // Vertex[n] = V;
-
- for (succ_iterator SI = succ_begin(V), E = succ_end(V); SI != E; ++SI) {
- InfoRec &SuccVInfo = DT.Info[*SI];
- if (SuccVInfo.Semi == 0) {
- SuccVInfo.Parent = V;
- N = DTDFSPass(DT, *SI, N);
- }
- }
-#else
- bool IsChildOfArtificialExit = (N != 0);
-
- SmallVector<std::pair<typename GraphT::NodeType*,
- typename GraphT::ChildIteratorType>, 32> Worklist;
- Worklist.push_back(std::make_pair(V, GraphT::child_begin(V)));
- while (!Worklist.empty()) {
- typename GraphT::NodeType* BB = Worklist.back().first;
- typename GraphT::ChildIteratorType NextSucc = Worklist.back().second;
-
- typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &BBInfo =
- DT.Info[BB];
-
- // First time we visited this BB?
- if (NextSucc == GraphT::child_begin(BB)) {
- BBInfo.DFSNum = BBInfo.Semi = ++N;
- BBInfo.Label = BB;
-
- DT.Vertex.push_back(BB); // Vertex[n] = V;
-
- if (IsChildOfArtificialExit)
- BBInfo.Parent = 1;
-
- IsChildOfArtificialExit = false;
- }
-
- // store the DFS number of the current BB - the reference to BBInfo might
- // get invalidated when processing the successors.
- unsigned BBDFSNum = BBInfo.DFSNum;
-
- // If we are done with this block, remove it from the worklist.
- if (NextSucc == GraphT::child_end(BB)) {
- Worklist.pop_back();
- continue;
- }
-
- // Increment the successor number for the next time we get to it.
- ++Worklist.back().second;
-
- // Visit the successor next, if it isn't already visited.
- typename GraphT::NodeType* Succ = *NextSucc;
-
- typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &SuccVInfo =
- DT.Info[Succ];
- if (SuccVInfo.Semi == 0) {
- SuccVInfo.Parent = BBDFSNum;
- Worklist.push_back(std::make_pair(Succ, GraphT::child_begin(Succ)));
- }
- }
-#endif
- return N;
-}
-
-template<class GraphT>
-typename GraphT::NodeType*
-Eval(DominatorTreeBase<typename GraphT::NodeType>& DT,
- typename GraphT::NodeType *VIn, unsigned LastLinked) {
- typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &VInInfo =
- DT.Info[VIn];
- if (VInInfo.DFSNum < LastLinked)
- return VIn;
-
- SmallVector<typename GraphT::NodeType*, 32> Work;
- SmallPtrSet<typename GraphT::NodeType*, 32> Visited;
-
- if (VInInfo.Parent >= LastLinked)
- Work.push_back(VIn);
-
- while (!Work.empty()) {
- typename GraphT::NodeType* V = Work.back();
- typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &VInfo =
- DT.Info[V];
- typename GraphT::NodeType* VAncestor = DT.Vertex[VInfo.Parent];
-
- // Process Ancestor first
- if (Visited.insert(VAncestor) && VInfo.Parent >= LastLinked) {
- Work.push_back(VAncestor);
- continue;
- }
- Work.pop_back();
-
- // Update VInfo based on Ancestor info
- if (VInfo.Parent < LastLinked)
- continue;
-
- typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &VAInfo =
- DT.Info[VAncestor];
- typename GraphT::NodeType* VAncestorLabel = VAInfo.Label;
- typename GraphT::NodeType* VLabel = VInfo.Label;
- if (DT.Info[VAncestorLabel].Semi < DT.Info[VLabel].Semi)
- VInfo.Label = VAncestorLabel;
- VInfo.Parent = VAInfo.Parent;
- }
-
- return VInInfo.Label;
-}
-
-template<class FuncT, class NodeT>
-void Calculate(DominatorTreeBase<typename GraphTraits<NodeT>::NodeType>& DT,
- FuncT& F) {
- typedef GraphTraits<NodeT> GraphT;
-
- unsigned N = 0;
- bool MultipleRoots = (DT.Roots.size() > 1);
- if (MultipleRoots) {
- typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &BBInfo =
- DT.Info[NULL];
- BBInfo.DFSNum = BBInfo.Semi = ++N;
- BBInfo.Label = NULL;
-
- DT.Vertex.push_back(NULL); // Vertex[n] = V;
- }
-
- // Step #1: Number blocks in depth-first order and initialize variables used
- // in later stages of the algorithm.
- for (unsigned i = 0, e = static_cast<unsigned>(DT.Roots.size());
- i != e; ++i)
- N = DFSPass<GraphT>(DT, DT.Roots[i], N);
-
- // it might be that some blocks did not get a DFS number (e.g., blocks of
- // infinite loops). In these cases an artificial exit node is required.
- MultipleRoots |= (DT.isPostDominator() && N != GraphTraits<FuncT*>::size(&F));
-
- // When naively implemented, the Lengauer-Tarjan algorithm requires a separate
- // bucket for each vertex. However, this is unnecessary, because each vertex
- // is only placed into a single bucket (that of its semidominator), and each
- // vertex's bucket is processed before it is added to any bucket itself.
- //
- // Instead of using a bucket per vertex, we use a single array Buckets that
- // has two purposes. Before the vertex V with preorder number i is processed,
- // Buckets[i] stores the index of the first element in V's bucket. After V's
- // bucket is processed, Buckets[i] stores the index of the next element in the
- // bucket containing V, if any.
- SmallVector<unsigned, 32> Buckets;
- Buckets.resize(N + 1);
- for (unsigned i = 1; i <= N; ++i)
- Buckets[i] = i;
-
- for (unsigned i = N; i >= 2; --i) {
- typename GraphT::NodeType* W = DT.Vertex[i];
- typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &WInfo =
- DT.Info[W];
-
- // Step #2: Implicitly define the immediate dominator of vertices
- for (unsigned j = i; Buckets[j] != i; j = Buckets[j]) {
- typename GraphT::NodeType* V = DT.Vertex[Buckets[j]];
- typename GraphT::NodeType* U = Eval<GraphT>(DT, V, i + 1);
- DT.IDoms[V] = DT.Info[U].Semi < i ? U : W;
- }
-
- // Step #3: Calculate the semidominators of all vertices
-
- // initialize the semi dominator to point to the parent node
- WInfo.Semi = WInfo.Parent;
- typedef GraphTraits<Inverse<NodeT> > InvTraits;
- for (typename InvTraits::ChildIteratorType CI =
- InvTraits::child_begin(W),
- E = InvTraits::child_end(W); CI != E; ++CI) {
- typename InvTraits::NodeType *N = *CI;
- if (DT.Info.count(N)) { // Only if this predecessor is reachable!
- unsigned SemiU = DT.Info[Eval<GraphT>(DT, N, i + 1)].Semi;
- if (SemiU < WInfo.Semi)
- WInfo.Semi = SemiU;
- }
- }
-
- // If V is a non-root vertex and sdom(V) = parent(V), then idom(V) is
- // necessarily parent(V). In this case, set idom(V) here and avoid placing
- // V into a bucket.
- if (WInfo.Semi == WInfo.Parent) {
- DT.IDoms[W] = DT.Vertex[WInfo.Parent];
- } else {
- Buckets[i] = Buckets[WInfo.Semi];
- Buckets[WInfo.Semi] = i;
- }
- }
-
- if (N >= 1) {
- typename GraphT::NodeType* Root = DT.Vertex[1];
- for (unsigned j = 1; Buckets[j] != 1; j = Buckets[j]) {
- typename GraphT::NodeType* V = DT.Vertex[Buckets[j]];
- DT.IDoms[V] = Root;
- }
- }
-
- // Step #4: Explicitly define the immediate dominator of each vertex
- for (unsigned i = 2; i <= N; ++i) {
- typename GraphT::NodeType* W = DT.Vertex[i];
- typename GraphT::NodeType*& WIDom = DT.IDoms[W];
- if (WIDom != DT.Vertex[DT.Info[W].Semi])
- WIDom = DT.IDoms[WIDom];
- }
-
- if (DT.Roots.empty()) return;
-
- // Add a node for the root. This node might be the actual root, if there is
- // one exit block, or it may be the virtual exit (denoted by (BasicBlock *)0)
- // which postdominates all real exits if there are multiple exit blocks, or
- // an infinite loop.
- typename GraphT::NodeType* Root = !MultipleRoots ? DT.Roots[0] : 0;
-
- DT.DomTreeNodes[Root] = DT.RootNode =
- new DomTreeNodeBase<typename GraphT::NodeType>(Root, 0);
-
- // Loop over all of the reachable blocks in the function...
- for (unsigned i = 2; i <= N; ++i) {
- typename GraphT::NodeType* W = DT.Vertex[i];
-
- DomTreeNodeBase<typename GraphT::NodeType> *BBNode = DT.DomTreeNodes[W];
- if (BBNode) continue; // Haven't calculated this node yet?
-
- typename GraphT::NodeType* ImmDom = DT.getIDom(W);
-
- assert(ImmDom || DT.DomTreeNodes[NULL]);
-
- // Get or calculate the node for the immediate dominator
- DomTreeNodeBase<typename GraphT::NodeType> *IDomNode =
- DT.getNodeForBlock(ImmDom);
-
- // Add a new tree node for this BasicBlock, and link it as a child of
- // IDomNode
- DomTreeNodeBase<typename GraphT::NodeType> *C =
- new DomTreeNodeBase<typename GraphT::NodeType>(W, IDomNode);
- DT.DomTreeNodes[W] = IDomNode->addChild(C);
- }
-
- // Free temporary memory used to construct idom's
- DT.IDoms.clear();
- DT.Info.clear();
- std::vector<typename GraphT::NodeType*>().swap(DT.Vertex);
-
- DT.updateDFSNumbers();
-}
-
-}
-
-#endif
#include "llvm/ADT/GraphTraits.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Function.h"
#include "llvm/Pass.h"
#include "llvm/Support/CFG.h"
+#include "llvm/Support/GenericDomTree.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
namespace llvm {
-//===----------------------------------------------------------------------===//
-/// DominatorBase - Base class that other, more interesting dominator analyses
-/// inherit from.
-///
-template <class NodeT>
-class DominatorBase {
-protected:
- std::vector<NodeT*> Roots;
- const bool IsPostDominators;
- inline explicit DominatorBase(bool isPostDom) :
- Roots(), IsPostDominators(isPostDom) {}
-public:
-
- /// getRoots - Return the root blocks of the current CFG. This may include
- /// multiple blocks if we are computing post dominators. For forward
- /// dominators, this will always be a single block (the entry node).
- ///
- inline const std::vector<NodeT*> &getRoots() const { return Roots; }
-
- /// isPostDominator - Returns true if analysis based of postdoms
- ///
- bool isPostDominator() const { return IsPostDominators; }
-};
-
-
-//===----------------------------------------------------------------------===//
-// DomTreeNode - Dominator Tree Node
-template<class NodeT> class DominatorTreeBase;
-struct PostDominatorTree;
-class MachineBasicBlock;
-
-template <class NodeT>
-class DomTreeNodeBase {
- NodeT *TheBB;
- DomTreeNodeBase<NodeT> *IDom;
- std::vector<DomTreeNodeBase<NodeT> *> Children;
- int DFSNumIn, DFSNumOut;
-
- template<class N> friend class DominatorTreeBase;
- friend struct PostDominatorTree;
-public:
- typedef typename std::vector<DomTreeNodeBase<NodeT> *>::iterator iterator;
- typedef typename std::vector<DomTreeNodeBase<NodeT> *>::const_iterator
- const_iterator;
-
- iterator begin() { return Children.begin(); }
- iterator end() { return Children.end(); }
- const_iterator begin() const { return Children.begin(); }
- const_iterator end() const { return Children.end(); }
-
- NodeT *getBlock() const { return TheBB; }
- DomTreeNodeBase<NodeT> *getIDom() const { return IDom; }
- const std::vector<DomTreeNodeBase<NodeT>*> &getChildren() const {
- return Children;
- }
-
- DomTreeNodeBase(NodeT *BB, DomTreeNodeBase<NodeT> *iDom)
- : TheBB(BB), IDom(iDom), DFSNumIn(-1), DFSNumOut(-1) { }
-
- DomTreeNodeBase<NodeT> *addChild(DomTreeNodeBase<NodeT> *C) {
- Children.push_back(C);
- return C;
- }
-
- size_t getNumChildren() const {
- return Children.size();
- }
-
- void clearAllChildren() {
- Children.clear();
- }
-
- bool compare(const DomTreeNodeBase<NodeT> *Other) const {
- if (getNumChildren() != Other->getNumChildren())
- return true;
-
- SmallPtrSet<const NodeT *, 4> OtherChildren;
- for (const_iterator I = Other->begin(), E = Other->end(); I != E; ++I) {
- const NodeT *Nd = (*I)->getBlock();
- OtherChildren.insert(Nd);
- }
-
- for (const_iterator I = begin(), E = end(); I != E; ++I) {
- const NodeT *N = (*I)->getBlock();
- if (OtherChildren.count(N) == 0)
- return true;
- }
- return false;
- }
-
- void setIDom(DomTreeNodeBase<NodeT> *NewIDom) {
- assert(IDom && "No immediate dominator?");
- if (IDom != NewIDom) {
- typename std::vector<DomTreeNodeBase<NodeT>*>::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);
- }
- }
-
- /// getDFSNumIn/getDFSNumOut - These are an internal implementation detail, do
- /// not call them.
- unsigned getDFSNumIn() const { return DFSNumIn; }
- unsigned getDFSNumOut() const { return DFSNumOut; }
-private:
- // Return true if this node is dominated by other. Use this only if DFS info
- // is valid.
- bool DominatedBy(const DomTreeNodeBase<NodeT> *other) const {
- return this->DFSNumIn >= other->DFSNumIn &&
- this->DFSNumOut <= other->DFSNumOut;
- }
-};
-
EXTERN_TEMPLATE_INSTANTIATION(class DomTreeNodeBase<BasicBlock>);
-EXTERN_TEMPLATE_INSTANTIATION(class DomTreeNodeBase<MachineBasicBlock>);
-
-template<class NodeT>
-inline raw_ostream &operator<<(raw_ostream &o,
- const DomTreeNodeBase<NodeT> *Node) {
- if (Node->getBlock())
- Node->getBlock()->printAsOperand(o, false);
- else
- o << " <<exit node>>";
-
- o << " {" << Node->getDFSNumIn() << "," << Node->getDFSNumOut() << "}";
-
- return o << "\n";
-}
-
-template<class NodeT>
-inline void PrintDomTree(const DomTreeNodeBase<NodeT> *N, raw_ostream &o,
- unsigned Lev) {
- o.indent(2*Lev) << "[" << Lev << "] " << N;
- for (typename DomTreeNodeBase<NodeT>::const_iterator I = N->begin(),
- E = N->end(); I != E; ++I)
- PrintDomTree<NodeT>(*I, o, Lev+1);
-}
+EXTERN_TEMPLATE_INSTANTIATION(class DominatorTreeBase<BasicBlock>);
typedef DomTreeNodeBase<BasicBlock> DomTreeNode;
-//===----------------------------------------------------------------------===//
-/// DominatorTree - Calculate the immediate dominator tree for a function.
-///
-
-template<class FuncT, class N>
-void Calculate(DominatorTreeBase<typename GraphTraits<N>::NodeType>& DT,
- FuncT& F);
-
-template<class NodeT>
-class DominatorTreeBase : public DominatorBase<NodeT> {
- bool dominatedBySlowTreeWalk(const DomTreeNodeBase<NodeT> *A,
- const DomTreeNodeBase<NodeT> *B) const {
- assert(A != B);
- assert(isReachableFromEntry(B));
- assert(isReachableFromEntry(A));
-
- const DomTreeNodeBase<NodeT> *IDom;
- while ((IDom = B->getIDom()) != 0 && IDom != A && IDom != B)
- B = IDom; // Walk up the tree
- return IDom != 0;
- }
-
-protected:
- typedef DenseMap<NodeT*, DomTreeNodeBase<NodeT>*> DomTreeNodeMapType;
- DomTreeNodeMapType DomTreeNodes;
- DomTreeNodeBase<NodeT> *RootNode;
-
- bool DFSInfoValid;
- unsigned int SlowQueries;
- // Information record used during immediate dominators computation.
- struct InfoRec {
- unsigned DFSNum;
- unsigned Parent;
- unsigned Semi;
- NodeT *Label;
-
- InfoRec() : DFSNum(0), Parent(0), Semi(0), Label(0) {}
- };
-
- DenseMap<NodeT*, NodeT*> IDoms;
-
- // Vertex - Map the DFS number to the BasicBlock*
- std::vector<NodeT*> Vertex;
-
- // Info - Collection of information used during the computation of idoms.
- DenseMap<NodeT*, InfoRec> Info;
-
- void reset() {
- for (typename DomTreeNodeMapType::iterator I = this->DomTreeNodes.begin(),
- E = DomTreeNodes.end(); I != E; ++I)
- delete I->second;
- DomTreeNodes.clear();
- IDoms.clear();
- this->Roots.clear();
- Vertex.clear();
- RootNode = 0;
- }
-
- // NewBB is split and now it has one successor. Update dominator tree to
- // reflect this change.
- template<class N, class GraphT>
- void Split(DominatorTreeBase<typename GraphT::NodeType>& DT,
- typename GraphT::NodeType* NewBB) {
- assert(std::distance(GraphT::child_begin(NewBB),
- GraphT::child_end(NewBB)) == 1 &&
- "NewBB should have a single successor!");
- typename GraphT::NodeType* NewBBSucc = *GraphT::child_begin(NewBB);
-
- std::vector<typename GraphT::NodeType*> PredBlocks;
- typedef GraphTraits<Inverse<N> > InvTraits;
- for (typename InvTraits::ChildIteratorType PI =
- InvTraits::child_begin(NewBB),
- PE = InvTraits::child_end(NewBB); PI != PE; ++PI)
- PredBlocks.push_back(*PI);
-
- assert(!PredBlocks.empty() && "No predblocks?");
-
- bool NewBBDominatesNewBBSucc = true;
- for (typename InvTraits::ChildIteratorType PI =
- InvTraits::child_begin(NewBBSucc),
- E = InvTraits::child_end(NewBBSucc); PI != E; ++PI) {
- typename InvTraits::NodeType *ND = *PI;
- if (ND != NewBB && !DT.dominates(NewBBSucc, ND) &&
- DT.isReachableFromEntry(ND)) {
- NewBBDominatesNewBBSucc = false;
- break;
- }
- }
-
- // Find NewBB's immediate dominator and create new dominator tree node for
- // NewBB.
- NodeT *NewBBIDom = 0;
- unsigned i = 0;
- for (i = 0; i < PredBlocks.size(); ++i)
- if (DT.isReachableFromEntry(PredBlocks[i])) {
- NewBBIDom = PredBlocks[i];
- break;
- }
-
- // It's possible that none of the predecessors of NewBB are reachable;
- // in that case, NewBB itself is unreachable, so nothing needs to be
- // changed.
- if (!NewBBIDom)
- return;
-
- for (i = i + 1; i < PredBlocks.size(); ++i) {
- if (DT.isReachableFromEntry(PredBlocks[i]))
- NewBBIDom = DT.findNearestCommonDominator(NewBBIDom, PredBlocks[i]);
- }
-
- // Create the new dominator tree node... and set the idom of NewBB.
- DomTreeNodeBase<NodeT> *NewBBNode = DT.addNewBlock(NewBB, NewBBIDom);
-
- // If NewBB strictly dominates other blocks, then it is now the immediate
- // dominator of NewBBSucc. Update the dominator tree as appropriate.
- if (NewBBDominatesNewBBSucc) {
- DomTreeNodeBase<NodeT> *NewBBSuccNode = DT.getNode(NewBBSucc);
- DT.changeImmediateDominator(NewBBSuccNode, NewBBNode);
- }
- }
-
-public:
- explicit DominatorTreeBase(bool isPostDom)
- : DominatorBase<NodeT>(isPostDom), DFSInfoValid(false), SlowQueries(0) {}
- virtual ~DominatorTreeBase() { reset(); }
-
- /// compare - Return false if the other dominator tree base matches this
- /// dominator tree base. Otherwise return true.
- bool compare(DominatorTreeBase &Other) const {
-
- const DomTreeNodeMapType &OtherDomTreeNodes = Other.DomTreeNodes;
- if (DomTreeNodes.size() != OtherDomTreeNodes.size())
- return true;
-
- for (typename DomTreeNodeMapType::const_iterator
- I = this->DomTreeNodes.begin(),
- E = this->DomTreeNodes.end(); I != E; ++I) {
- NodeT *BB = I->first;
- typename DomTreeNodeMapType::const_iterator OI = OtherDomTreeNodes.find(BB);
- if (OI == OtherDomTreeNodes.end())
- return true;
-
- DomTreeNodeBase<NodeT>* MyNd = I->second;
- DomTreeNodeBase<NodeT>* OtherNd = OI->second;
-
- if (MyNd->compare(OtherNd))
- return true;
- }
-
- return false;
- }
-
- virtual void releaseMemory() { reset(); }
-
- /// getNode - return the (Post)DominatorTree node for the specified basic
- /// block. This is the same as using operator[] on this class.
- ///
- inline DomTreeNodeBase<NodeT> *getNode(NodeT *BB) const {
- return DomTreeNodes.lookup(BB);
- }
-
- /// getRootNode - This returns the entry node for the CFG of the function. If
- /// this tree represents the post-dominance relations for a function, however,
- /// this root may be a node with the block == NULL. This is the case when
- /// there are multiple exit nodes from a particular function. Consumers of
- /// post-dominance information must be capable of dealing with this
- /// possibility.
- ///
- DomTreeNodeBase<NodeT> *getRootNode() { return RootNode; }
- const DomTreeNodeBase<NodeT> *getRootNode() const { return RootNode; }
-
- /// Get all nodes dominated by R, including R itself.
- void getDescendants(NodeT *R, SmallVectorImpl<NodeT *> &Result) const {
- Result.clear();
- const DomTreeNodeBase<NodeT> *RN = getNode(R);
- if (RN == NULL)
- return; // If R is unreachable, it will not be present in the DOM tree.
- SmallVector<const DomTreeNodeBase<NodeT> *, 8> WL;
- WL.push_back(RN);
-
- while (!WL.empty()) {
- const DomTreeNodeBase<NodeT> *N = WL.pop_back_val();
- Result.push_back(N->getBlock());
- WL.append(N->begin(), N->end());
- }
- }
-
- /// properlyDominates - Returns true iff A dominates B and A != B.
- /// Note that this is not a constant time operation!
- ///
- bool properlyDominates(const DomTreeNodeBase<NodeT> *A,
- const DomTreeNodeBase<NodeT> *B) {
- if (A == 0 || B == 0)
- return false;
- if (A == B)
- return false;
- return dominates(A, B);
- }
-
- bool properlyDominates(const NodeT *A, const NodeT *B);
-
- /// isReachableFromEntry - Return true if A is dominated by the entry
- /// block of the function containing it.
- bool isReachableFromEntry(const NodeT* A) const {
- assert(!this->isPostDominator() &&
- "This is not implemented for post dominators");
- return isReachableFromEntry(getNode(const_cast<NodeT *>(A)));
- }
-
- inline bool isReachableFromEntry(const DomTreeNodeBase<NodeT> *A) const {
- return A;
- }
-
- /// dominates - Returns true iff A dominates B. Note that this is not a
- /// constant time operation!
- ///
- inline bool dominates(const DomTreeNodeBase<NodeT> *A,
- const DomTreeNodeBase<NodeT> *B) {
- // A node trivially dominates itself.
- if (B == A)
- return true;
-
- // An unreachable node is dominated by anything.
- if (!isReachableFromEntry(B))
- return true;
-
- // And dominates nothing.
- if (!isReachableFromEntry(A))
- return false;
-
- // Compare the result of the tree walk and the dfs numbers, if expensive
- // checks are enabled.
-#ifdef XDEBUG
- assert((!DFSInfoValid ||
- (dominatedBySlowTreeWalk(A, B) == B->DominatedBy(A))) &&
- "Tree walk disagrees with dfs numbers!");
-#endif
-
- if (DFSInfoValid)
- return B->DominatedBy(A);
-
- // If we end up with too many slow queries, just update the
- // DFS numbers on the theory that we are going to keep querying.
- SlowQueries++;
- if (SlowQueries > 32) {
- updateDFSNumbers();
- return B->DominatedBy(A);
- }
-
- return dominatedBySlowTreeWalk(A, B);
- }
-
- bool dominates(const NodeT *A, const NodeT *B);
-
- NodeT *getRoot() const {
- assert(this->Roots.size() == 1 && "Should always have entry node!");
- return this->Roots[0];
- }
-
- /// findNearestCommonDominator - Find nearest common dominator basic block
- /// for basic block A and B. If there is no such block then return NULL.
- NodeT *findNearestCommonDominator(NodeT *A, NodeT *B) {
- assert(A->getParent() == B->getParent() &&
- "Two blocks are not in same function");
-
- // If either A or B is a entry block then it is nearest common dominator
- // (for forward-dominators).
- if (!this->isPostDominator()) {
- NodeT &Entry = A->getParent()->front();
- if (A == &Entry || B == &Entry)
- return &Entry;
- }
-
- // If B dominates A then B is nearest common dominator.
- if (dominates(B, A))
- return B;
-
- // If A dominates B then A is nearest common dominator.
- if (dominates(A, B))
- return A;
-
- DomTreeNodeBase<NodeT> *NodeA = getNode(A);
- DomTreeNodeBase<NodeT> *NodeB = getNode(B);
-
- // Collect NodeA dominators set.
- SmallPtrSet<DomTreeNodeBase<NodeT>*, 16> NodeADoms;
- NodeADoms.insert(NodeA);
- DomTreeNodeBase<NodeT> *IDomA = NodeA->getIDom();
- while (IDomA) {
- NodeADoms.insert(IDomA);
- IDomA = IDomA->getIDom();
- }
-
- // Walk NodeB immediate dominators chain and find common dominator node.
- DomTreeNodeBase<NodeT> *IDomB = NodeB->getIDom();
- while (IDomB) {
- if (NodeADoms.count(IDomB) != 0)
- return IDomB->getBlock();
-
- IDomB = IDomB->getIDom();
- }
-
- return NULL;
- }
-
- const NodeT *findNearestCommonDominator(const NodeT *A, const NodeT *B) {
- // Cast away the const qualifiers here. This is ok since
- // const is re-introduced on the return type.
- return findNearestCommonDominator(const_cast<NodeT *>(A),
- const_cast<NodeT *>(B));
- }
-
- //===--------------------------------------------------------------------===//
- // API to update (Post)DominatorTree information based on modifications to
- // the CFG...
-
- /// addNewBlock - Add a new node to the dominator tree information. This
- /// creates a new node as a child of DomBB dominator node,linking it into
- /// the children list of the immediate dominator.
- DomTreeNodeBase<NodeT> *addNewBlock(NodeT *BB, NodeT *DomBB) {
- assert(getNode(BB) == 0 && "Block already in dominator tree!");
- DomTreeNodeBase<NodeT> *IDomNode = getNode(DomBB);
- assert(IDomNode && "Not immediate dominator specified for block!");
- DFSInfoValid = false;
- return DomTreeNodes[BB] =
- IDomNode->addChild(new DomTreeNodeBase<NodeT>(BB, IDomNode));
- }
-
- /// changeImmediateDominator - This method is used to update the dominator
- /// tree information when a node's immediate dominator changes.
- ///
- void changeImmediateDominator(DomTreeNodeBase<NodeT> *N,
- DomTreeNodeBase<NodeT> *NewIDom) {
- assert(N && NewIDom && "Cannot change null node pointers!");
- DFSInfoValid = false;
- N->setIDom(NewIDom);
- }
-
- void changeImmediateDominator(NodeT *BB, NodeT *NewBB) {
- changeImmediateDominator(getNode(BB), getNode(NewBB));
- }
-
- /// eraseNode - Removes a node from the dominator tree. Block must not
- /// dominate any other blocks. Removes node from its immediate dominator's
- /// children list. Deletes dominator node associated with basic block BB.
- void eraseNode(NodeT *BB) {
- DomTreeNodeBase<NodeT> *Node = getNode(BB);
- assert(Node && "Removing node that isn't in dominator tree.");
- assert(Node->getChildren().empty() && "Node is not a leaf node.");
-
- // Remove node from immediate dominator's children list.
- DomTreeNodeBase<NodeT> *IDom = Node->getIDom();
- if (IDom) {
- typename std::vector<DomTreeNodeBase<NodeT>*>::iterator I =
- std::find(IDom->Children.begin(), IDom->Children.end(), Node);
- assert(I != IDom->Children.end() &&
- "Not in immediate dominator children set!");
- // I am no longer your child...
- IDom->Children.erase(I);
- }
-
- DomTreeNodes.erase(BB);
- delete Node;
- }
-
- /// removeNode - Removes a node from the dominator tree. Block must not
- /// dominate any other blocks. Invalidates any node pointing to removed
- /// block.
- void removeNode(NodeT *BB) {
- assert(getNode(BB) && "Removing node that isn't in dominator tree.");
- DomTreeNodes.erase(BB);
- }
-
- /// splitBlock - BB is split and now it has one successor. Update dominator
- /// tree to reflect this change.
- void splitBlock(NodeT* NewBB) {
- if (this->IsPostDominators)
- this->Split<Inverse<NodeT*>, GraphTraits<Inverse<NodeT*> > >(*this, NewBB);
- else
- this->Split<NodeT*, GraphTraits<NodeT*> >(*this, NewBB);
- }
-
- /// print - Convert to human readable form
- ///
- void print(raw_ostream &o) const {
- o << "=============================--------------------------------\n";
- if (this->isPostDominator())
- o << "Inorder PostDominator Tree: ";
- else
- o << "Inorder Dominator Tree: ";
- if (!this->DFSInfoValid)
- o << "DFSNumbers invalid: " << SlowQueries << " slow queries.";
- o << "\n";
-
- // The postdom tree can have a null root if there are no returns.
- if (getRootNode())
- PrintDomTree<NodeT>(getRootNode(), o, 1);
- }
-
-protected:
- template<class GraphT>
- friend typename GraphT::NodeType* Eval(
- DominatorTreeBase<typename GraphT::NodeType>& DT,
- typename GraphT::NodeType* V,
- unsigned LastLinked);
-
- template<class GraphT>
- friend unsigned DFSPass(DominatorTreeBase<typename GraphT::NodeType>& DT,
- typename GraphT::NodeType* V,
- unsigned N);
-
- template<class FuncT, class N>
- friend void Calculate(DominatorTreeBase<typename GraphTraits<N>::NodeType>& DT,
- FuncT& F);
-
- /// updateDFSNumbers - Assign In and Out numbers to the nodes while walking
- /// dominator tree in dfs order.
- void updateDFSNumbers() {
- unsigned DFSNum = 0;
-
- SmallVector<std::pair<DomTreeNodeBase<NodeT>*,
- typename DomTreeNodeBase<NodeT>::iterator>, 32> WorkStack;
-
- DomTreeNodeBase<NodeT> *ThisRoot = getRootNode();
-
- if (!ThisRoot)
- return;
-
- // Even in the case of multiple exits that form the post dominator root
- // nodes, do not iterate over all exits, but start from the virtual root
- // node. Otherwise bbs, that are not post dominated by any exit but by the
- // virtual root node, will never be assigned a DFS number.
- WorkStack.push_back(std::make_pair(ThisRoot, ThisRoot->begin()));
- ThisRoot->DFSNumIn = DFSNum++;
-
- while (!WorkStack.empty()) {
- DomTreeNodeBase<NodeT> *Node = WorkStack.back().first;
- typename DomTreeNodeBase<NodeT>::iterator ChildIt =
- WorkStack.back().second;
-
- // If we visited all of the children of this node, "recurse" back up the
- // stack setting the DFOutNum.
- if (ChildIt == Node->end()) {
- Node->DFSNumOut = DFSNum++;
- WorkStack.pop_back();
- } else {
- // Otherwise, recursively visit this child.
- DomTreeNodeBase<NodeT> *Child = *ChildIt;
- ++WorkStack.back().second;
-
- WorkStack.push_back(std::make_pair(Child, Child->begin()));
- Child->DFSNumIn = DFSNum++;
- }
- }
-
- SlowQueries = 0;
- DFSInfoValid = true;
- }
-
- DomTreeNodeBase<NodeT> *getNodeForBlock(NodeT *BB) {
- if (DomTreeNodeBase<NodeT> *Node = getNode(BB))
- return Node;
-
- // Haven't calculated this node yet? Get or calculate the node for the
- // immediate dominator.
- NodeT *IDom = getIDom(BB);
-
- assert(IDom || this->DomTreeNodes[NULL]);
- DomTreeNodeBase<NodeT> *IDomNode = getNodeForBlock(IDom);
-
- // Add a new tree node for this BasicBlock, and link it as a child of
- // IDomNode
- DomTreeNodeBase<NodeT> *C = new DomTreeNodeBase<NodeT>(BB, IDomNode);
- return this->DomTreeNodes[BB] = IDomNode->addChild(C);
- }
-
- inline NodeT *getIDom(NodeT *BB) const {
- return IDoms.lookup(BB);
- }
-
- inline void addRoot(NodeT* BB) {
- this->Roots.push_back(BB);
- }
-
-public:
- /// recalculate - compute a dominator tree for the given function
- template<class FT>
- void recalculate(FT& F) {
- typedef GraphTraits<FT*> TraitsTy;
- reset();
- this->Vertex.push_back(0);
-
- if (!this->IsPostDominators) {
- // Initialize root
- NodeT *entry = TraitsTy::getEntryNode(&F);
- this->Roots.push_back(entry);
- this->IDoms[entry] = 0;
- this->DomTreeNodes[entry] = 0;
-
- Calculate<FT, NodeT*>(*this, F);
- } else {
- // Initialize the roots list
- for (typename TraitsTy::nodes_iterator I = TraitsTy::nodes_begin(&F),
- E = TraitsTy::nodes_end(&F); I != E; ++I) {
- if (TraitsTy::child_begin(I) == TraitsTy::child_end(I))
- addRoot(I);
-
- // Prepopulate maps so that we don't get iterator invalidation issues later.
- this->IDoms[I] = 0;
- this->DomTreeNodes[I] = 0;
- }
-
- Calculate<FT, Inverse<NodeT*> >(*this, F);
- }
- }
-};
-
-// These two functions are declared out of line as a workaround for building
-// with old (< r147295) versions of clang because of pr11642.
-template<class NodeT>
-bool DominatorTreeBase<NodeT>::dominates(const NodeT *A, const NodeT *B) {
- if (A == B)
- return true;
-
- // Cast away the const qualifiers here. This is ok since
- // this function doesn't actually return the values returned
- // from getNode.
- return dominates(getNode(const_cast<NodeT *>(A)),
- getNode(const_cast<NodeT *>(B)));
-}
-template<class NodeT>
-bool
-DominatorTreeBase<NodeT>::properlyDominates(const NodeT *A, const NodeT *B) {
- if (A == B)
- return false;
-
- // Cast away the const qualifiers here. This is ok since
- // this function doesn't actually return the values returned
- // from getNode.
- return dominates(getNode(const_cast<NodeT *>(A)),
- getNode(const_cast<NodeT *>(B)));
-}
-
-EXTERN_TEMPLATE_INSTANTIATION(class DominatorTreeBase<BasicBlock>);
-
class BasicBlockEdge {
const BasicBlock *Start;
const BasicBlock *End;
FunctionPass *
createVerifierPass(VerifierFailureAction action = AbortProcessAction);
+/// \brief Check a function for errors, useful for use when debugging a
+/// pass.
+bool verifyFunction(const Function &F,
+ VerifierFailureAction action = AbortProcessAction);
+
/// \brief Check a module for errors.
///
/// If there are no errors, the function returns false. If an error is found,
VerifierFailureAction action = AbortProcessAction,
std::string *ErrorInfo = 0);
-/// \brief Check a function for errors, useful for use when debugging a
-/// pass.
-bool verifyFunction(const Function &F,
- VerifierFailureAction action = AbortProcessAction);
-
} // End llvm namespace
#endif
--- /dev/null
+//===- GenericDomTree.h - Generic dominator trees for graphs ----*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+/// This file defines a set of templates that efficiently compute a dominator
+/// tree over a generic graph. This is used typically in LLVM for fast
+/// dominance queries on the CFG, but is fully generic w.r.t. the underlying
+/// graph types.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_GENERIC_DOM_TREE_H
+#define LLVM_SUPPORT_GENERIC_DOM_TREE_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/GraphTraits.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/CFG.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+
+namespace llvm {
+
+//===----------------------------------------------------------------------===//
+/// DominatorBase - Base class that other, more interesting dominator analyses
+/// inherit from.
+///
+template <class NodeT>
+class DominatorBase {
+protected:
+ std::vector<NodeT*> Roots;
+ const bool IsPostDominators;
+ inline explicit DominatorBase(bool isPostDom) :
+ Roots(), IsPostDominators(isPostDom) {}
+public:
+
+ /// getRoots - Return the root blocks of the current CFG. This may include
+ /// multiple blocks if we are computing post dominators. For forward
+ /// dominators, this will always be a single block (the entry node).
+ ///
+ inline const std::vector<NodeT*> &getRoots() const { return Roots; }
+
+ /// isPostDominator - Returns true if analysis based of postdoms
+ ///
+ bool isPostDominator() const { return IsPostDominators; }
+};
+
+
+//===----------------------------------------------------------------------===//
+// DomTreeNodeBase - Dominator Tree Node
+template<class NodeT> class DominatorTreeBase;
+struct PostDominatorTree;
+
+template <class NodeT>
+class DomTreeNodeBase {
+ NodeT *TheBB;
+ DomTreeNodeBase<NodeT> *IDom;
+ std::vector<DomTreeNodeBase<NodeT> *> Children;
+ int DFSNumIn, DFSNumOut;
+
+ template<class N> friend class DominatorTreeBase;
+ friend struct PostDominatorTree;
+public:
+ typedef typename std::vector<DomTreeNodeBase<NodeT> *>::iterator iterator;
+ typedef typename std::vector<DomTreeNodeBase<NodeT> *>::const_iterator
+ const_iterator;
+
+ iterator begin() { return Children.begin(); }
+ iterator end() { return Children.end(); }
+ const_iterator begin() const { return Children.begin(); }
+ const_iterator end() const { return Children.end(); }
+
+ NodeT *getBlock() const { return TheBB; }
+ DomTreeNodeBase<NodeT> *getIDom() const { return IDom; }
+ const std::vector<DomTreeNodeBase<NodeT>*> &getChildren() const {
+ return Children;
+ }
+
+ DomTreeNodeBase(NodeT *BB, DomTreeNodeBase<NodeT> *iDom)
+ : TheBB(BB), IDom(iDom), DFSNumIn(-1), DFSNumOut(-1) { }
+
+ DomTreeNodeBase<NodeT> *addChild(DomTreeNodeBase<NodeT> *C) {
+ Children.push_back(C);
+ return C;
+ }
+
+ size_t getNumChildren() const {
+ return Children.size();
+ }
+
+ void clearAllChildren() {
+ Children.clear();
+ }
+
+ bool compare(const DomTreeNodeBase<NodeT> *Other) const {
+ if (getNumChildren() != Other->getNumChildren())
+ return true;
+
+ SmallPtrSet<const NodeT *, 4> OtherChildren;
+ for (const_iterator I = Other->begin(), E = Other->end(); I != E; ++I) {
+ const NodeT *Nd = (*I)->getBlock();
+ OtherChildren.insert(Nd);
+ }
+
+ for (const_iterator I = begin(), E = end(); I != E; ++I) {
+ const NodeT *N = (*I)->getBlock();
+ if (OtherChildren.count(N) == 0)
+ return true;
+ }
+ return false;
+ }
+
+ void setIDom(DomTreeNodeBase<NodeT> *NewIDom) {
+ assert(IDom && "No immediate dominator?");
+ if (IDom != NewIDom) {
+ typename std::vector<DomTreeNodeBase<NodeT>*>::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);
+ }
+ }
+
+ /// getDFSNumIn/getDFSNumOut - These are an internal implementation detail, do
+ /// not call them.
+ unsigned getDFSNumIn() const { return DFSNumIn; }
+ unsigned getDFSNumOut() const { return DFSNumOut; }
+private:
+ // Return true if this node is dominated by other. Use this only if DFS info
+ // is valid.
+ bool DominatedBy(const DomTreeNodeBase<NodeT> *other) const {
+ return this->DFSNumIn >= other->DFSNumIn &&
+ this->DFSNumOut <= other->DFSNumOut;
+ }
+};
+
+template<class NodeT>
+inline raw_ostream &operator<<(raw_ostream &o,
+ const DomTreeNodeBase<NodeT> *Node) {
+ if (Node->getBlock())
+ Node->getBlock()->printAsOperand(o, false);
+ else
+ o << " <<exit node>>";
+
+ o << " {" << Node->getDFSNumIn() << "," << Node->getDFSNumOut() << "}";
+
+ return o << "\n";
+}
+
+template<class NodeT>
+inline void PrintDomTree(const DomTreeNodeBase<NodeT> *N, raw_ostream &o,
+ unsigned Lev) {
+ o.indent(2*Lev) << "[" << Lev << "] " << N;
+ for (typename DomTreeNodeBase<NodeT>::const_iterator I = N->begin(),
+ E = N->end(); I != E; ++I)
+ PrintDomTree<NodeT>(*I, o, Lev+1);
+}
+
+//===----------------------------------------------------------------------===//
+/// DominatorTree - Calculate the immediate dominator tree for a function.
+///
+
+template<class FuncT, class N>
+void Calculate(DominatorTreeBase<typename GraphTraits<N>::NodeType>& DT,
+ FuncT& F);
+
+template<class NodeT>
+class DominatorTreeBase : public DominatorBase<NodeT> {
+ bool dominatedBySlowTreeWalk(const DomTreeNodeBase<NodeT> *A,
+ const DomTreeNodeBase<NodeT> *B) const {
+ assert(A != B);
+ assert(isReachableFromEntry(B));
+ assert(isReachableFromEntry(A));
+
+ const DomTreeNodeBase<NodeT> *IDom;
+ while ((IDom = B->getIDom()) != 0 && IDom != A && IDom != B)
+ B = IDom; // Walk up the tree
+ return IDom != 0;
+ }
+
+protected:
+ typedef DenseMap<NodeT*, DomTreeNodeBase<NodeT>*> DomTreeNodeMapType;
+ DomTreeNodeMapType DomTreeNodes;
+ DomTreeNodeBase<NodeT> *RootNode;
+
+ bool DFSInfoValid;
+ unsigned int SlowQueries;
+ // Information record used during immediate dominators computation.
+ struct InfoRec {
+ unsigned DFSNum;
+ unsigned Parent;
+ unsigned Semi;
+ NodeT *Label;
+
+ InfoRec() : DFSNum(0), Parent(0), Semi(0), Label(0) {}
+ };
+
+ DenseMap<NodeT*, NodeT*> IDoms;
+
+ // Vertex - Map the DFS number to the NodeT*
+ std::vector<NodeT*> Vertex;
+
+ // Info - Collection of information used during the computation of idoms.
+ DenseMap<NodeT*, InfoRec> Info;
+
+ void reset() {
+ for (typename DomTreeNodeMapType::iterator I = this->DomTreeNodes.begin(),
+ E = DomTreeNodes.end(); I != E; ++I)
+ delete I->second;
+ DomTreeNodes.clear();
+ IDoms.clear();
+ this->Roots.clear();
+ Vertex.clear();
+ RootNode = 0;
+ }
+
+ // NewBB is split and now it has one successor. Update dominator tree to
+ // reflect this change.
+ template<class N, class GraphT>
+ void Split(DominatorTreeBase<typename GraphT::NodeType>& DT,
+ typename GraphT::NodeType* NewBB) {
+ assert(std::distance(GraphT::child_begin(NewBB),
+ GraphT::child_end(NewBB)) == 1 &&
+ "NewBB should have a single successor!");
+ typename GraphT::NodeType* NewBBSucc = *GraphT::child_begin(NewBB);
+
+ std::vector<typename GraphT::NodeType*> PredBlocks;
+ typedef GraphTraits<Inverse<N> > InvTraits;
+ for (typename InvTraits::ChildIteratorType PI =
+ InvTraits::child_begin(NewBB),
+ PE = InvTraits::child_end(NewBB); PI != PE; ++PI)
+ PredBlocks.push_back(*PI);
+
+ assert(!PredBlocks.empty() && "No predblocks?");
+
+ bool NewBBDominatesNewBBSucc = true;
+ for (typename InvTraits::ChildIteratorType PI =
+ InvTraits::child_begin(NewBBSucc),
+ E = InvTraits::child_end(NewBBSucc); PI != E; ++PI) {
+ typename InvTraits::NodeType *ND = *PI;
+ if (ND != NewBB && !DT.dominates(NewBBSucc, ND) &&
+ DT.isReachableFromEntry(ND)) {
+ NewBBDominatesNewBBSucc = false;
+ break;
+ }
+ }
+
+ // Find NewBB's immediate dominator and create new dominator tree node for
+ // NewBB.
+ NodeT *NewBBIDom = 0;
+ unsigned i = 0;
+ for (i = 0; i < PredBlocks.size(); ++i)
+ if (DT.isReachableFromEntry(PredBlocks[i])) {
+ NewBBIDom = PredBlocks[i];
+ break;
+ }
+
+ // It's possible that none of the predecessors of NewBB are reachable;
+ // in that case, NewBB itself is unreachable, so nothing needs to be
+ // changed.
+ if (!NewBBIDom)
+ return;
+
+ for (i = i + 1; i < PredBlocks.size(); ++i) {
+ if (DT.isReachableFromEntry(PredBlocks[i]))
+ NewBBIDom = DT.findNearestCommonDominator(NewBBIDom, PredBlocks[i]);
+ }
+
+ // Create the new dominator tree node... and set the idom of NewBB.
+ DomTreeNodeBase<NodeT> *NewBBNode = DT.addNewBlock(NewBB, NewBBIDom);
+
+ // If NewBB strictly dominates other blocks, then it is now the immediate
+ // dominator of NewBBSucc. Update the dominator tree as appropriate.
+ if (NewBBDominatesNewBBSucc) {
+ DomTreeNodeBase<NodeT> *NewBBSuccNode = DT.getNode(NewBBSucc);
+ DT.changeImmediateDominator(NewBBSuccNode, NewBBNode);
+ }
+ }
+
+public:
+ explicit DominatorTreeBase(bool isPostDom)
+ : DominatorBase<NodeT>(isPostDom), DFSInfoValid(false), SlowQueries(0) {}
+ virtual ~DominatorTreeBase() { reset(); }
+
+ /// compare - Return false if the other dominator tree base matches this
+ /// dominator tree base. Otherwise return true.
+ bool compare(DominatorTreeBase &Other) const {
+
+ const DomTreeNodeMapType &OtherDomTreeNodes = Other.DomTreeNodes;
+ if (DomTreeNodes.size() != OtherDomTreeNodes.size())
+ return true;
+
+ for (typename DomTreeNodeMapType::const_iterator
+ I = this->DomTreeNodes.begin(),
+ E = this->DomTreeNodes.end(); I != E; ++I) {
+ NodeT *BB = I->first;
+ typename DomTreeNodeMapType::const_iterator OI = OtherDomTreeNodes.find(BB);
+ if (OI == OtherDomTreeNodes.end())
+ return true;
+
+ DomTreeNodeBase<NodeT>* MyNd = I->second;
+ DomTreeNodeBase<NodeT>* OtherNd = OI->second;
+
+ if (MyNd->compare(OtherNd))
+ return true;
+ }
+
+ return false;
+ }
+
+ virtual void releaseMemory() { reset(); }
+
+ /// getNode - return the (Post)DominatorTree node for the specified basic
+ /// block. This is the same as using operator[] on this class.
+ ///
+ inline DomTreeNodeBase<NodeT> *getNode(NodeT *BB) const {
+ return DomTreeNodes.lookup(BB);
+ }
+
+ /// getRootNode - This returns the entry node for the CFG of the function. If
+ /// this tree represents the post-dominance relations for a function, however,
+ /// this root may be a node with the block == NULL. This is the case when
+ /// there are multiple exit nodes from a particular function. Consumers of
+ /// post-dominance information must be capable of dealing with this
+ /// possibility.
+ ///
+ DomTreeNodeBase<NodeT> *getRootNode() { return RootNode; }
+ const DomTreeNodeBase<NodeT> *getRootNode() const { return RootNode; }
+
+ /// Get all nodes dominated by R, including R itself.
+ void getDescendants(NodeT *R, SmallVectorImpl<NodeT *> &Result) const {
+ Result.clear();
+ const DomTreeNodeBase<NodeT> *RN = getNode(R);
+ if (RN == NULL)
+ return; // If R is unreachable, it will not be present in the DOM tree.
+ SmallVector<const DomTreeNodeBase<NodeT> *, 8> WL;
+ WL.push_back(RN);
+
+ while (!WL.empty()) {
+ const DomTreeNodeBase<NodeT> *N = WL.pop_back_val();
+ Result.push_back(N->getBlock());
+ WL.append(N->begin(), N->end());
+ }
+ }
+
+ /// properlyDominates - Returns true iff A dominates B and A != B.
+ /// Note that this is not a constant time operation!
+ ///
+ bool properlyDominates(const DomTreeNodeBase<NodeT> *A,
+ const DomTreeNodeBase<NodeT> *B) {
+ if (A == 0 || B == 0)
+ return false;
+ if (A == B)
+ return false;
+ return dominates(A, B);
+ }
+
+ bool properlyDominates(const NodeT *A, const NodeT *B);
+
+ /// isReachableFromEntry - Return true if A is dominated by the entry
+ /// block of the function containing it.
+ bool isReachableFromEntry(const NodeT* A) const {
+ assert(!this->isPostDominator() &&
+ "This is not implemented for post dominators");
+ return isReachableFromEntry(getNode(const_cast<NodeT *>(A)));
+ }
+
+ inline bool isReachableFromEntry(const DomTreeNodeBase<NodeT> *A) const {
+ return A;
+ }
+
+ /// dominates - Returns true iff A dominates B. Note that this is not a
+ /// constant time operation!
+ ///
+ inline bool dominates(const DomTreeNodeBase<NodeT> *A,
+ const DomTreeNodeBase<NodeT> *B) {
+ // A node trivially dominates itself.
+ if (B == A)
+ return true;
+
+ // An unreachable node is dominated by anything.
+ if (!isReachableFromEntry(B))
+ return true;
+
+ // And dominates nothing.
+ if (!isReachableFromEntry(A))
+ return false;
+
+ // Compare the result of the tree walk and the dfs numbers, if expensive
+ // checks are enabled.
+#ifdef XDEBUG
+ assert((!DFSInfoValid ||
+ (dominatedBySlowTreeWalk(A, B) == B->DominatedBy(A))) &&
+ "Tree walk disagrees with dfs numbers!");
+#endif
+
+ if (DFSInfoValid)
+ return B->DominatedBy(A);
+
+ // If we end up with too many slow queries, just update the
+ // DFS numbers on the theory that we are going to keep querying.
+ SlowQueries++;
+ if (SlowQueries > 32) {
+ updateDFSNumbers();
+ return B->DominatedBy(A);
+ }
+
+ return dominatedBySlowTreeWalk(A, B);
+ }
+
+ bool dominates(const NodeT *A, const NodeT *B);
+
+ NodeT *getRoot() const {
+ assert(this->Roots.size() == 1 && "Should always have entry node!");
+ return this->Roots[0];
+ }
+
+ /// findNearestCommonDominator - Find nearest common dominator basic block
+ /// for basic block A and B. If there is no such block then return NULL.
+ NodeT *findNearestCommonDominator(NodeT *A, NodeT *B) {
+ assert(A->getParent() == B->getParent() &&
+ "Two blocks are not in same function");
+
+ // If either A or B is a entry block then it is nearest common dominator
+ // (for forward-dominators).
+ if (!this->isPostDominator()) {
+ NodeT &Entry = A->getParent()->front();
+ if (A == &Entry || B == &Entry)
+ return &Entry;
+ }
+
+ // If B dominates A then B is nearest common dominator.
+ if (dominates(B, A))
+ return B;
+
+ // If A dominates B then A is nearest common dominator.
+ if (dominates(A, B))
+ return A;
+
+ DomTreeNodeBase<NodeT> *NodeA = getNode(A);
+ DomTreeNodeBase<NodeT> *NodeB = getNode(B);
+
+ // Collect NodeA dominators set.
+ SmallPtrSet<DomTreeNodeBase<NodeT>*, 16> NodeADoms;
+ NodeADoms.insert(NodeA);
+ DomTreeNodeBase<NodeT> *IDomA = NodeA->getIDom();
+ while (IDomA) {
+ NodeADoms.insert(IDomA);
+ IDomA = IDomA->getIDom();
+ }
+
+ // Walk NodeB immediate dominators chain and find common dominator node.
+ DomTreeNodeBase<NodeT> *IDomB = NodeB->getIDom();
+ while (IDomB) {
+ if (NodeADoms.count(IDomB) != 0)
+ return IDomB->getBlock();
+
+ IDomB = IDomB->getIDom();
+ }
+
+ return NULL;
+ }
+
+ const NodeT *findNearestCommonDominator(const NodeT *A, const NodeT *B) {
+ // Cast away the const qualifiers here. This is ok since
+ // const is re-introduced on the return type.
+ return findNearestCommonDominator(const_cast<NodeT *>(A),
+ const_cast<NodeT *>(B));
+ }
+
+ //===--------------------------------------------------------------------===//
+ // API to update (Post)DominatorTree information based on modifications to
+ // the CFG...
+
+ /// addNewBlock - Add a new node to the dominator tree information. This
+ /// creates a new node as a child of DomBB dominator node,linking it into
+ /// the children list of the immediate dominator.
+ DomTreeNodeBase<NodeT> *addNewBlock(NodeT *BB, NodeT *DomBB) {
+ assert(getNode(BB) == 0 && "Block already in dominator tree!");
+ DomTreeNodeBase<NodeT> *IDomNode = getNode(DomBB);
+ assert(IDomNode && "Not immediate dominator specified for block!");
+ DFSInfoValid = false;
+ return DomTreeNodes[BB] =
+ IDomNode->addChild(new DomTreeNodeBase<NodeT>(BB, IDomNode));
+ }
+
+ /// changeImmediateDominator - This method is used to update the dominator
+ /// tree information when a node's immediate dominator changes.
+ ///
+ void changeImmediateDominator(DomTreeNodeBase<NodeT> *N,
+ DomTreeNodeBase<NodeT> *NewIDom) {
+ assert(N && NewIDom && "Cannot change null node pointers!");
+ DFSInfoValid = false;
+ N->setIDom(NewIDom);
+ }
+
+ void changeImmediateDominator(NodeT *BB, NodeT *NewBB) {
+ changeImmediateDominator(getNode(BB), getNode(NewBB));
+ }
+
+ /// eraseNode - Removes a node from the dominator tree. Block must not
+ /// dominate any other blocks. Removes node from its immediate dominator's
+ /// children list. Deletes dominator node associated with basic block BB.
+ void eraseNode(NodeT *BB) {
+ DomTreeNodeBase<NodeT> *Node = getNode(BB);
+ assert(Node && "Removing node that isn't in dominator tree.");
+ assert(Node->getChildren().empty() && "Node is not a leaf node.");
+
+ // Remove node from immediate dominator's children list.
+ DomTreeNodeBase<NodeT> *IDom = Node->getIDom();
+ if (IDom) {
+ typename std::vector<DomTreeNodeBase<NodeT>*>::iterator I =
+ std::find(IDom->Children.begin(), IDom->Children.end(), Node);
+ assert(I != IDom->Children.end() &&
+ "Not in immediate dominator children set!");
+ // I am no longer your child...
+ IDom->Children.erase(I);
+ }
+
+ DomTreeNodes.erase(BB);
+ delete Node;
+ }
+
+ /// removeNode - Removes a node from the dominator tree. Block must not
+ /// dominate any other blocks. Invalidates any node pointing to removed
+ /// block.
+ void removeNode(NodeT *BB) {
+ assert(getNode(BB) && "Removing node that isn't in dominator tree.");
+ DomTreeNodes.erase(BB);
+ }
+
+ /// splitBlock - BB is split and now it has one successor. Update dominator
+ /// tree to reflect this change.
+ void splitBlock(NodeT* NewBB) {
+ if (this->IsPostDominators)
+ this->Split<Inverse<NodeT*>, GraphTraits<Inverse<NodeT*> > >(*this, NewBB);
+ else
+ this->Split<NodeT*, GraphTraits<NodeT*> >(*this, NewBB);
+ }
+
+ /// print - Convert to human readable form
+ ///
+ void print(raw_ostream &o) const {
+ o << "=============================--------------------------------\n";
+ if (this->isPostDominator())
+ o << "Inorder PostDominator Tree: ";
+ else
+ o << "Inorder Dominator Tree: ";
+ if (!this->DFSInfoValid)
+ o << "DFSNumbers invalid: " << SlowQueries << " slow queries.";
+ o << "\n";
+
+ // The postdom tree can have a null root if there are no returns.
+ if (getRootNode())
+ PrintDomTree<NodeT>(getRootNode(), o, 1);
+ }
+
+protected:
+ template<class GraphT>
+ friend typename GraphT::NodeType* Eval(
+ DominatorTreeBase<typename GraphT::NodeType>& DT,
+ typename GraphT::NodeType* V,
+ unsigned LastLinked);
+
+ template<class GraphT>
+ friend unsigned DFSPass(DominatorTreeBase<typename GraphT::NodeType>& DT,
+ typename GraphT::NodeType* V,
+ unsigned N);
+
+ template<class FuncT, class N>
+ friend void Calculate(DominatorTreeBase<typename GraphTraits<N>::NodeType>& DT,
+ FuncT& F);
+
+ /// updateDFSNumbers - Assign In and Out numbers to the nodes while walking
+ /// dominator tree in dfs order.
+ void updateDFSNumbers() {
+ unsigned DFSNum = 0;
+
+ SmallVector<std::pair<DomTreeNodeBase<NodeT>*,
+ typename DomTreeNodeBase<NodeT>::iterator>, 32> WorkStack;
+
+ DomTreeNodeBase<NodeT> *ThisRoot = getRootNode();
+
+ if (!ThisRoot)
+ return;
+
+ // Even in the case of multiple exits that form the post dominator root
+ // nodes, do not iterate over all exits, but start from the virtual root
+ // node. Otherwise bbs, that are not post dominated by any exit but by the
+ // virtual root node, will never be assigned a DFS number.
+ WorkStack.push_back(std::make_pair(ThisRoot, ThisRoot->begin()));
+ ThisRoot->DFSNumIn = DFSNum++;
+
+ while (!WorkStack.empty()) {
+ DomTreeNodeBase<NodeT> *Node = WorkStack.back().first;
+ typename DomTreeNodeBase<NodeT>::iterator ChildIt =
+ WorkStack.back().second;
+
+ // If we visited all of the children of this node, "recurse" back up the
+ // stack setting the DFOutNum.
+ if (ChildIt == Node->end()) {
+ Node->DFSNumOut = DFSNum++;
+ WorkStack.pop_back();
+ } else {
+ // Otherwise, recursively visit this child.
+ DomTreeNodeBase<NodeT> *Child = *ChildIt;
+ ++WorkStack.back().second;
+
+ WorkStack.push_back(std::make_pair(Child, Child->begin()));
+ Child->DFSNumIn = DFSNum++;
+ }
+ }
+
+ SlowQueries = 0;
+ DFSInfoValid = true;
+ }
+
+ DomTreeNodeBase<NodeT> *getNodeForBlock(NodeT *BB) {
+ if (DomTreeNodeBase<NodeT> *Node = getNode(BB))
+ return Node;
+
+ // Haven't calculated this node yet? Get or calculate the node for the
+ // immediate dominator.
+ NodeT *IDom = getIDom(BB);
+
+ assert(IDom || this->DomTreeNodes[NULL]);
+ DomTreeNodeBase<NodeT> *IDomNode = getNodeForBlock(IDom);
+
+ // Add a new tree node for this NodeT, and link it as a child of
+ // IDomNode
+ DomTreeNodeBase<NodeT> *C = new DomTreeNodeBase<NodeT>(BB, IDomNode);
+ return this->DomTreeNodes[BB] = IDomNode->addChild(C);
+ }
+
+ inline NodeT *getIDom(NodeT *BB) const {
+ return IDoms.lookup(BB);
+ }
+
+ inline void addRoot(NodeT* BB) {
+ this->Roots.push_back(BB);
+ }
+
+public:
+ /// recalculate - compute a dominator tree for the given function
+ template<class FT>
+ void recalculate(FT& F) {
+ typedef GraphTraits<FT*> TraitsTy;
+ reset();
+ this->Vertex.push_back(0);
+
+ if (!this->IsPostDominators) {
+ // Initialize root
+ NodeT *entry = TraitsTy::getEntryNode(&F);
+ this->Roots.push_back(entry);
+ this->IDoms[entry] = 0;
+ this->DomTreeNodes[entry] = 0;
+
+ Calculate<FT, NodeT*>(*this, F);
+ } else {
+ // Initialize the roots list
+ for (typename TraitsTy::nodes_iterator I = TraitsTy::nodes_begin(&F),
+ E = TraitsTy::nodes_end(&F); I != E; ++I) {
+ if (TraitsTy::child_begin(I) == TraitsTy::child_end(I))
+ addRoot(I);
+
+ // Prepopulate maps so that we don't get iterator invalidation issues later.
+ this->IDoms[I] = 0;
+ this->DomTreeNodes[I] = 0;
+ }
+
+ Calculate<FT, Inverse<NodeT*> >(*this, F);
+ }
+ }
+};
+
+// These two functions are declared out of line as a workaround for building
+// with old (< r147295) versions of clang because of pr11642.
+template<class NodeT>
+bool DominatorTreeBase<NodeT>::dominates(const NodeT *A, const NodeT *B) {
+ if (A == B)
+ return true;
+
+ // Cast away the const qualifiers here. This is ok since
+ // this function doesn't actually return the values returned
+ // from getNode.
+ return dominates(getNode(const_cast<NodeT *>(A)),
+ getNode(const_cast<NodeT *>(B)));
+}
+template<class NodeT>
+bool
+DominatorTreeBase<NodeT>::properlyDominates(const NodeT *A, const NodeT *B) {
+ if (A == B)
+ return false;
+
+ // Cast away the const qualifiers here. This is ok since
+ // this function doesn't actually return the values returned
+ // from getNode.
+ return dominates(getNode(const_cast<NodeT *>(A)),
+ getNode(const_cast<NodeT *>(B)));
+}
+
+}
+
+#endif
--- /dev/null
+//===- GenericDomTreeConstruction.h - Dominator Calculation ------*- C++ -*-==//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+/// Generic dominator tree construction - This file provides rouitens to
+/// 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 the O(n*log(n)) versions of EVAL and LINK, because it turns
+/// out that the theoretically slower O(n*log(n)) implementation is actually
+/// faster than the almost-linear O(n*alpha(n)) version, even for large CFGs.
+///
+//===----------------------------------------------------------------------===//
+
+
+#ifndef LLVM_SUPPORT_GENERIC_DOM_TREE_CONSTRUCTION_H
+#define LLVM_SUPPORT_GENERIC_DOM_TREE_CONSTRUCTION_H
+
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/Support/GenericDomTree.h"
+
+namespace llvm {
+
+template<class GraphT>
+unsigned DFSPass(DominatorTreeBase<typename GraphT::NodeType>& DT,
+ typename GraphT::NodeType* V, unsigned N) {
+ // This is more understandable as a recursive algorithm, but we can't use the
+ // recursive algorithm due to stack depth issues. Keep it here for
+ // documentation purposes.
+#if 0
+ InfoRec &VInfo = DT.Info[DT.Roots[i]];
+ VInfo.DFSNum = VInfo.Semi = ++N;
+ VInfo.Label = V;
+
+ Vertex.push_back(V); // Vertex[n] = V;
+
+ for (succ_iterator SI = succ_begin(V), E = succ_end(V); SI != E; ++SI) {
+ InfoRec &SuccVInfo = DT.Info[*SI];
+ if (SuccVInfo.Semi == 0) {
+ SuccVInfo.Parent = V;
+ N = DTDFSPass(DT, *SI, N);
+ }
+ }
+#else
+ bool IsChildOfArtificialExit = (N != 0);
+
+ SmallVector<std::pair<typename GraphT::NodeType*,
+ typename GraphT::ChildIteratorType>, 32> Worklist;
+ Worklist.push_back(std::make_pair(V, GraphT::child_begin(V)));
+ while (!Worklist.empty()) {
+ typename GraphT::NodeType* BB = Worklist.back().first;
+ typename GraphT::ChildIteratorType NextSucc = Worklist.back().second;
+
+ typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &BBInfo =
+ DT.Info[BB];
+
+ // First time we visited this BB?
+ if (NextSucc == GraphT::child_begin(BB)) {
+ BBInfo.DFSNum = BBInfo.Semi = ++N;
+ BBInfo.Label = BB;
+
+ DT.Vertex.push_back(BB); // Vertex[n] = V;
+
+ if (IsChildOfArtificialExit)
+ BBInfo.Parent = 1;
+
+ IsChildOfArtificialExit = false;
+ }
+
+ // store the DFS number of the current BB - the reference to BBInfo might
+ // get invalidated when processing the successors.
+ unsigned BBDFSNum = BBInfo.DFSNum;
+
+ // If we are done with this block, remove it from the worklist.
+ if (NextSucc == GraphT::child_end(BB)) {
+ Worklist.pop_back();
+ continue;
+ }
+
+ // Increment the successor number for the next time we get to it.
+ ++Worklist.back().second;
+
+ // Visit the successor next, if it isn't already visited.
+ typename GraphT::NodeType* Succ = *NextSucc;
+
+ typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &SuccVInfo =
+ DT.Info[Succ];
+ if (SuccVInfo.Semi == 0) {
+ SuccVInfo.Parent = BBDFSNum;
+ Worklist.push_back(std::make_pair(Succ, GraphT::child_begin(Succ)));
+ }
+ }
+#endif
+ return N;
+}
+
+template<class GraphT>
+typename GraphT::NodeType*
+Eval(DominatorTreeBase<typename GraphT::NodeType>& DT,
+ typename GraphT::NodeType *VIn, unsigned LastLinked) {
+ typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &VInInfo =
+ DT.Info[VIn];
+ if (VInInfo.DFSNum < LastLinked)
+ return VIn;
+
+ SmallVector<typename GraphT::NodeType*, 32> Work;
+ SmallPtrSet<typename GraphT::NodeType*, 32> Visited;
+
+ if (VInInfo.Parent >= LastLinked)
+ Work.push_back(VIn);
+
+ while (!Work.empty()) {
+ typename GraphT::NodeType* V = Work.back();
+ typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &VInfo =
+ DT.Info[V];
+ typename GraphT::NodeType* VAncestor = DT.Vertex[VInfo.Parent];
+
+ // Process Ancestor first
+ if (Visited.insert(VAncestor) && VInfo.Parent >= LastLinked) {
+ Work.push_back(VAncestor);
+ continue;
+ }
+ Work.pop_back();
+
+ // Update VInfo based on Ancestor info
+ if (VInfo.Parent < LastLinked)
+ continue;
+
+ typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &VAInfo =
+ DT.Info[VAncestor];
+ typename GraphT::NodeType* VAncestorLabel = VAInfo.Label;
+ typename GraphT::NodeType* VLabel = VInfo.Label;
+ if (DT.Info[VAncestorLabel].Semi < DT.Info[VLabel].Semi)
+ VInfo.Label = VAncestorLabel;
+ VInfo.Parent = VAInfo.Parent;
+ }
+
+ return VInInfo.Label;
+}
+
+template<class FuncT, class NodeT>
+void Calculate(DominatorTreeBase<typename GraphTraits<NodeT>::NodeType>& DT,
+ FuncT& F) {
+ typedef GraphTraits<NodeT> GraphT;
+
+ unsigned N = 0;
+ bool MultipleRoots = (DT.Roots.size() > 1);
+ if (MultipleRoots) {
+ typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &BBInfo =
+ DT.Info[NULL];
+ BBInfo.DFSNum = BBInfo.Semi = ++N;
+ BBInfo.Label = NULL;
+
+ DT.Vertex.push_back(NULL); // Vertex[n] = V;
+ }
+
+ // Step #1: Number blocks in depth-first order and initialize variables used
+ // in later stages of the algorithm.
+ for (unsigned i = 0, e = static_cast<unsigned>(DT.Roots.size());
+ i != e; ++i)
+ N = DFSPass<GraphT>(DT, DT.Roots[i], N);
+
+ // it might be that some blocks did not get a DFS number (e.g., blocks of
+ // infinite loops). In these cases an artificial exit node is required.
+ MultipleRoots |= (DT.isPostDominator() && N != GraphTraits<FuncT*>::size(&F));
+
+ // When naively implemented, the Lengauer-Tarjan algorithm requires a separate
+ // bucket for each vertex. However, this is unnecessary, because each vertex
+ // is only placed into a single bucket (that of its semidominator), and each
+ // vertex's bucket is processed before it is added to any bucket itself.
+ //
+ // Instead of using a bucket per vertex, we use a single array Buckets that
+ // has two purposes. Before the vertex V with preorder number i is processed,
+ // Buckets[i] stores the index of the first element in V's bucket. After V's
+ // bucket is processed, Buckets[i] stores the index of the next element in the
+ // bucket containing V, if any.
+ SmallVector<unsigned, 32> Buckets;
+ Buckets.resize(N + 1);
+ for (unsigned i = 1; i <= N; ++i)
+ Buckets[i] = i;
+
+ for (unsigned i = N; i >= 2; --i) {
+ typename GraphT::NodeType* W = DT.Vertex[i];
+ typename DominatorTreeBase<typename GraphT::NodeType>::InfoRec &WInfo =
+ DT.Info[W];
+
+ // Step #2: Implicitly define the immediate dominator of vertices
+ for (unsigned j = i; Buckets[j] != i; j = Buckets[j]) {
+ typename GraphT::NodeType* V = DT.Vertex[Buckets[j]];
+ typename GraphT::NodeType* U = Eval<GraphT>(DT, V, i + 1);
+ DT.IDoms[V] = DT.Info[U].Semi < i ? U : W;
+ }
+
+ // Step #3: Calculate the semidominators of all vertices
+
+ // initialize the semi dominator to point to the parent node
+ WInfo.Semi = WInfo.Parent;
+ typedef GraphTraits<Inverse<NodeT> > InvTraits;
+ for (typename InvTraits::ChildIteratorType CI =
+ InvTraits::child_begin(W),
+ E = InvTraits::child_end(W); CI != E; ++CI) {
+ typename InvTraits::NodeType *N = *CI;
+ if (DT.Info.count(N)) { // Only if this predecessor is reachable!
+ unsigned SemiU = DT.Info[Eval<GraphT>(DT, N, i + 1)].Semi;
+ if (SemiU < WInfo.Semi)
+ WInfo.Semi = SemiU;
+ }
+ }
+
+ // If V is a non-root vertex and sdom(V) = parent(V), then idom(V) is
+ // necessarily parent(V). In this case, set idom(V) here and avoid placing
+ // V into a bucket.
+ if (WInfo.Semi == WInfo.Parent) {
+ DT.IDoms[W] = DT.Vertex[WInfo.Parent];
+ } else {
+ Buckets[i] = Buckets[WInfo.Semi];
+ Buckets[WInfo.Semi] = i;
+ }
+ }
+
+ if (N >= 1) {
+ typename GraphT::NodeType* Root = DT.Vertex[1];
+ for (unsigned j = 1; Buckets[j] != 1; j = Buckets[j]) {
+ typename GraphT::NodeType* V = DT.Vertex[Buckets[j]];
+ DT.IDoms[V] = Root;
+ }
+ }
+
+ // Step #4: Explicitly define the immediate dominator of each vertex
+ for (unsigned i = 2; i <= N; ++i) {
+ typename GraphT::NodeType* W = DT.Vertex[i];
+ typename GraphT::NodeType*& WIDom = DT.IDoms[W];
+ if (WIDom != DT.Vertex[DT.Info[W].Semi])
+ WIDom = DT.IDoms[WIDom];
+ }
+
+ if (DT.Roots.empty()) return;
+
+ // Add a node for the root. This node might be the actual root, if there is
+ // one exit block, or it may be the virtual exit (denoted by (BasicBlock *)0)
+ // which postdominates all real exits if there are multiple exit blocks, or
+ // an infinite loop.
+ typename GraphT::NodeType* Root = !MultipleRoots ? DT.Roots[0] : 0;
+
+ DT.DomTreeNodes[Root] = DT.RootNode =
+ new DomTreeNodeBase<typename GraphT::NodeType>(Root, 0);
+
+ // Loop over all of the reachable blocks in the function...
+ for (unsigned i = 2; i <= N; ++i) {
+ typename GraphT::NodeType* W = DT.Vertex[i];
+
+ DomTreeNodeBase<typename GraphT::NodeType> *BBNode = DT.DomTreeNodes[W];
+ if (BBNode) continue; // Haven't calculated this node yet?
+
+ typename GraphT::NodeType* ImmDom = DT.getIDom(W);
+
+ assert(ImmDom || DT.DomTreeNodes[NULL]);
+
+ // Get or calculate the node for the immediate dominator
+ DomTreeNodeBase<typename GraphT::NodeType> *IDomNode =
+ DT.getNodeForBlock(ImmDom);
+
+ // Add a new tree node for this BasicBlock, and link it as a child of
+ // IDomNode
+ DomTreeNodeBase<typename GraphT::NodeType> *C =
+ new DomTreeNodeBase<typename GraphT::NodeType>(W, IDomNode);
+ DT.DomTreeNodes[W] = IDomNode->addChild(C);
+ }
+
+ // Free temporary memory used to construct idom's
+ DT.IDoms.clear();
+ DT.Info.clear();
+ std::vector<typename GraphT::NodeType*>().swap(DT.Vertex);
+
+ DT.updateDFSNumbers();
+}
+
+}
+
+#endif
#include "llvm/Analysis/PostDominators.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/SetOperations.h"
-#include "llvm/IR/DominatorInternals.h"
+#include "llvm/Support/GenericDomTreeConstruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/Support/CFG.h"
#include "llvm/Support/Debug.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/Passes.h"
-#include "llvm/IR/DominatorInternals.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
-#include "llvm/IR/DominatorInternals.h"
#include "llvm/IR/Instructions.h"
#include "llvm/Support/CFG.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/GenericDomTreeConstruction.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
using namespace llvm;
//===----------------------------------------------------------------------===//
//
// Provide public access to DominatorTree information. Implementation details
-// can be found in DominatorInternals.h.
+// can be found in Dominators.h, GenericDomTree.h, and
+// GenericDomTreeConstruction.h.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachinePostDominators.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/IR/DominatorInternals.h"
#include "llvm/IR/Dominators.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/DominatorInternals.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
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