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diff --git a/include/llvm/Analysis/Dominators.h b/include/llvm/Analysis/Dominators.h
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+//===- llvm/Analysis/Dominators.h - Dominator Info Calculation --*- C++ -*-===//
+//
+//                     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 defines the following classes:
+//  1. DominatorTree: Represent dominators as an explicit tree structure.
+//  2. DominanceFrontier: Calculate and hold the dominance frontier for a
+//     function.
+//
+//  These data structures are listed in increasing order of complexity.  It
+//  takes longer to calculate the dominator frontier, for example, than the
+//  DominatorTree mapping.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_DOMINATORS_H
+#define LLVM_ANALYSIS_DOMINATORS_H
+
+#include "llvm/Pass.h"
+#include <set>
+
+namespace llvm {
+
+class Instruction;
+
+template <typename GraphType> struct GraphTraits;
+
+//===----------------------------------------------------------------------===//
+/// DominatorBase - Base class that other, more interesting dominator analyses
+/// inherit from.
+///
+class DominatorBase : public FunctionPass {
+protected:
+  std::vector<BasicBlock*> Roots;
+  const bool IsPostDominators;
+  inline DominatorBase(intptr_t ID, bool isPostDom) : 
+    FunctionPass(ID), 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<BasicBlock*> &getRoots() const { return Roots; }
+
+  /// isPostDominator - Returns true if analysis based of postdoms
+  ///
+  bool isPostDominator() const { return IsPostDominators; }
+};
+
+
+//===----------------------------------------------------------------------===//
+// DomTreeNode - Dominator Tree Node
+class DominatorTreeBase;
+class PostDominatorTree;
+class DomTreeNode {
+  BasicBlock *TheBB;
+  DomTreeNode *IDom;
+  std::vector<DomTreeNode*> Children;
+  int DFSNumIn, DFSNumOut;
+
+  friend class DominatorTreeBase;
+  friend class PostDominatorTree;
+public:
+  typedef std::vector<DomTreeNode*>::iterator iterator;
+  typedef std::vector<DomTreeNode*>::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(); }
+  
+  inline BasicBlock *getBlock() const { return TheBB; }
+  inline DomTreeNode *getIDom() const { return IDom; }
+  inline const std::vector<DomTreeNode*> &getChildren() const { return Children; }
+  
+  inline DomTreeNode(BasicBlock *BB, DomTreeNode *iDom)
+    : TheBB(BB), IDom(iDom), DFSNumIn(-1), DFSNumOut(-1) { }
+  inline DomTreeNode *addChild(DomTreeNode *C) { Children.push_back(C); return C; }
+  void setIDom(DomTreeNode *NewIDom);
+
+private:
+  // Return true if this node is dominated by other. Use this only if DFS info is valid.
+  bool DominatedBy(const DomTreeNode *other) const {
+    return this->DFSNumIn >= other->DFSNumIn &&
+      this->DFSNumOut <= other->DFSNumOut;
+  }
+
+  /// assignDFSNumber - Assign In and Out numbers while walking dominator tree
+  /// in dfs order.
+  void assignDFSNumber(int num);
+};
+
+//===----------------------------------------------------------------------===//
+/// DominatorTree - Calculate the immediate dominator tree for a function.
+///
+class DominatorTreeBase : public DominatorBase {
+
+protected:
+  void reset();
+  typedef std::map<BasicBlock*, DomTreeNode*> DomTreeNodeMapType;
+  DomTreeNodeMapType DomTreeNodes;
+  DomTreeNode *RootNode;
+
+  bool DFSInfoValid;
+  unsigned int SlowQueries;
+  // Information record used during immediate dominators computation.
+  struct InfoRec {
+    unsigned Semi;
+    unsigned Size;
+    BasicBlock *Label, *Parent, *Child, *Ancestor;
+
+    std::vector<BasicBlock*> Bucket;
+
+    InfoRec() : Semi(0), Size(0), Label(0), Parent(0), Child(0), Ancestor(0){}
+  };
+
+  std::map<BasicBlock*, BasicBlock*> IDoms;
+
+  // Vertex - Map the DFS number to the BasicBlock*
+  std::vector<BasicBlock*> Vertex;
+
+  // Info - Collection of information used during the computation of idoms.
+  std::map<BasicBlock*, InfoRec> Info;
+
+  void updateDFSNumbers();
+
+  public:
+  DominatorTreeBase(intptr_t ID, bool isPostDom) 
+    : DominatorBase(ID, isPostDom), DFSInfoValid(false), SlowQueries(0) {}
+  ~DominatorTreeBase() { reset(); }
+
+  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 DomTreeNode *getNode(BasicBlock *BB) const {
+    DomTreeNodeMapType::const_iterator i = DomTreeNodes.find(BB);
+    return (i != DomTreeNodes.end()) ? i->second : 0;
+  }
+
+  inline DomTreeNode *operator[](BasicBlock *BB) const {
+    return getNode(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.
+  ///
+  DomTreeNode *getRootNode() { return RootNode; }
+  const DomTreeNode *getRootNode() const { return RootNode; }
+
+  /// properlyDominates - Returns true iff this dominates N and this != N.
+  /// Note that this is not a constant time operation!
+  ///
+  bool properlyDominates(const DomTreeNode *A, DomTreeNode *B) const {
+    if (A == 0 || B == 0) return false;
+    return dominatedBySlowTreeWalk(A, B);
+  }
+
+  inline bool properlyDominates(BasicBlock *A, BasicBlock *B) {
+    return properlyDominates(getNode(A), getNode(B));
+  }
+
+  bool dominatedBySlowTreeWalk(const DomTreeNode *A, 
+                               const DomTreeNode *B) const {
+    const DomTreeNode *IDom;
+    if (A == 0 || B == 0) return false;
+    while ((IDom = B->getIDom()) != 0 && IDom != A && IDom != B)
+      B = IDom;   // Walk up the tree
+    return IDom != 0;
+  }
+
+
+  /// isReachableFromEntry - Return true if A is dominated by the entry
+  /// block of the function containing it.
+  const bool isReachableFromEntry(BasicBlock* A);
+  
+  /// dominates - Returns true iff A dominates B.  Note that this is not a
+  /// constant time operation!
+  ///
+  inline bool dominates(const DomTreeNode *A, DomTreeNode *B) {
+    if (B == A) 
+      return true;  // A node trivially dominates itself.
+
+    if (A == 0 || B == 0)
+      return false;
+
+    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);
+  }
+
+  inline bool dominates(BasicBlock *A, BasicBlock *B) {
+    if (A == B) 
+      return true;
+    
+    return dominates(getNode(A), getNode(B));
+  }
+
+  /// findNearestCommonDominator - Find nearest common dominator basic block
+  /// for basic block A and B. If there is no such block then return NULL.
+  BasicBlock *findNearestCommonDominator(BasicBlock *A, BasicBlock *B);
+
+  // dominates - Return true if A dominates B. This performs the
+  // special checks necessary if A and B are in the same basic block.
+  bool dominates(Instruction *A, Instruction *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.
+  DomTreeNode *addNewBlock(BasicBlock *BB, BasicBlock *DomBB) {
+    assert(getNode(BB) == 0 && "Block already in dominator tree!");
+    DomTreeNode *IDomNode = getNode(DomBB);
+    assert(IDomNode && "Not immediate dominator specified for block!");
+    DFSInfoValid = false;
+    return DomTreeNodes[BB] = 
+      IDomNode->addChild(new DomTreeNode(BB, IDomNode));
+  }
+
+  /// changeImmediateDominator - This method is used to update the dominator
+  /// tree information when a node's immediate dominator changes.
+  ///
+  void changeImmediateDominator(DomTreeNode *N, DomTreeNode *NewIDom) {
+    assert(N && NewIDom && "Cannot change null node pointers!");
+    DFSInfoValid = false;
+    N->setIDom(NewIDom);
+  }
+
+  void changeImmediateDominator(BasicBlock *BB, BasicBlock *NewBB) {
+    changeImmediateDominator(getNode(BB), getNode(NewBB));
+  }
+
+  /// removeNode - Removes a node from the dominator tree.  Block must not
+  /// dominate any other blocks.  Invalidates any node pointing to removed
+  /// block.
+  void removeNode(BasicBlock *BB) {
+    assert(getNode(BB) && "Removing node that isn't in dominator tree.");
+    DomTreeNodes.erase(BB);
+  }
+
+  /// print - Convert to human readable form
+  ///
+  virtual void print(std::ostream &OS, const Module* = 0) const;
+  void print(std::ostream *OS, const Module* M = 0) const {
+    if (OS) print(*OS, M);
+  }
+  virtual void dump();
+};
+
+//===-------------------------------------
+/// DominatorTree Class - Concrete subclass of DominatorTreeBase that is used to
+/// compute a normal dominator tree.
+///
+class DominatorTree : public DominatorTreeBase {
+public:
+  static char ID; // Pass ID, replacement for typeid
+  DominatorTree() : DominatorTreeBase((intptr_t)&ID, false) {}
+  
+  BasicBlock *getRoot() const {
+    assert(Roots.size() == 1 && "Should always have entry node!");
+    return Roots[0];
+  }
+  
+  virtual bool runOnFunction(Function &F);
+  
+  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+    AU.setPreservesAll();
+  }
+
+  /// splitBlock
+  /// BB is split and now it has one successor. Update dominator tree to
+  /// reflect this change.
+  void splitBlock(BasicBlock *BB);
+private:
+  void calculate(Function& F);
+  DomTreeNode *getNodeForBlock(BasicBlock *BB);
+  unsigned DFSPass(BasicBlock *V, InfoRec &VInfo, unsigned N);
+  void Compress(BasicBlock *V);
+  BasicBlock *Eval(BasicBlock *v);
+  void Link(BasicBlock *V, BasicBlock *W, InfoRec &WInfo);
+  inline BasicBlock *getIDom(BasicBlock *BB) const {
+      std::map<BasicBlock*, BasicBlock*>::const_iterator I = IDoms.find(BB);
+      return I != IDoms.end() ? I->second : 0;
+    }
+};
+
+//===-------------------------------------
+/// DominatorTree GraphTraits specialization so the DominatorTree can be
+/// iterable by generic graph iterators.
+///
+template <> struct GraphTraits<DomTreeNode*> {
+  typedef DomTreeNode NodeType;
+  typedef NodeType::iterator  ChildIteratorType;
+  
+  static NodeType *getEntryNode(NodeType *N) {
+    return N;
+  }
+  static inline ChildIteratorType child_begin(NodeType* N) {
+    return N->begin();
+  }
+  static inline ChildIteratorType child_end(NodeType* N) {
+    return N->end();
+  }
+};
+
+template <> struct GraphTraits<DominatorTree*>
+  : public GraphTraits<DomTreeNode*> {
+  static NodeType *getEntryNode(DominatorTree *DT) {
+    return DT->getRootNode();
+  }
+};
+
+
+//===----------------------------------------------------------------------===//
+/// DominanceFrontierBase - Common base class for computing forward and inverse
+/// dominance frontiers for a function.
+///
+class DominanceFrontierBase : public DominatorBase {
+public:
+  typedef std::set<BasicBlock*>             DomSetType;    // Dom set for a bb
+  typedef std::map<BasicBlock*, DomSetType> DomSetMapType; // Dom set map
+protected:
+  DomSetMapType Frontiers;
+public:
+  DominanceFrontierBase(intptr_t ID, bool isPostDom) 
+    : DominatorBase(ID, isPostDom) {}
+
+  virtual void releaseMemory() { Frontiers.clear(); }
+
+  // Accessor interface:
+  typedef DomSetMapType::iterator iterator;
+  typedef DomSetMapType::const_iterator const_iterator;
+  iterator       begin()       { return Frontiers.begin(); }
+  const_iterator begin() const { return Frontiers.begin(); }
+  iterator       end()         { return Frontiers.end(); }
+  const_iterator end()   const { return Frontiers.end(); }
+  iterator       find(BasicBlock *B)       { return Frontiers.find(B); }
+  const_iterator find(BasicBlock *B) const { return Frontiers.find(B); }
+
+  void addBasicBlock(BasicBlock *BB, const DomSetType &frontier) {
+    assert(find(BB) == end() && "Block already in DominanceFrontier!");
+    Frontiers.insert(std::make_pair(BB, frontier));
+  }
+
+  void addToFrontier(iterator I, BasicBlock *Node) {
+    assert(I != end() && "BB is not in DominanceFrontier!");
+    I->second.insert(Node);
+  }
+
+  void removeFromFrontier(iterator I, BasicBlock *Node) {
+    assert(I != end() && "BB is not in DominanceFrontier!");
+    assert(I->second.count(Node) && "Node is not in DominanceFrontier of BB");
+    I->second.erase(Node);
+  }
+
+  /// print - Convert to human readable form
+  ///
+  virtual void print(std::ostream &OS, const Module* = 0) const;
+  void print(std::ostream *OS, const Module* M = 0) const {
+    if (OS) print(*OS, M);
+  }
+  virtual void dump();
+};
+
+
+//===-------------------------------------
+/// DominanceFrontier Class - Concrete subclass of DominanceFrontierBase that is
+/// used to compute a forward dominator frontiers.
+///
+class DominanceFrontier : public DominanceFrontierBase {
+public:
+  static char ID; // Pass ID, replacement for typeid
+  DominanceFrontier() : 
+    DominanceFrontierBase((intptr_t)& ID, false) {}
+
+  BasicBlock *getRoot() const {
+    assert(Roots.size() == 1 && "Should always have entry node!");
+    return Roots[0];
+  }
+
+  virtual bool runOnFunction(Function &) {
+    Frontiers.clear();
+    DominatorTree &DT = getAnalysis<DominatorTree>();
+    Roots = DT.getRoots();
+    assert(Roots.size() == 1 && "Only one entry block for forward domfronts!");
+    calculate(DT, DT[Roots[0]]);
+    return false;
+  }
+
+  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+    AU.setPreservesAll();
+    AU.addRequired<DominatorTree>();
+  }
+
+  /// splitBlock
+  /// BB is split and now it has one successor. Update dominace frontier to
+  /// reflect this change.
+  void splitBlock(BasicBlock *BB);
+
+private:
+  const DomSetType &calculate(const DominatorTree &DT,
+                              const DomTreeNode *Node);
+};
+
+
+} // End llvm namespace
+
+#endif