Refactored DSGraph.h:

* DSGraph.h   contains DSGraph
* DSNode.h    contains DSNode (soon UDSNode and MDSNode)
* DSSupport.h contains DSCallsite, DSTypeRec, and DSNodeHandler

llvm-svn: 4466

3 files changed, 536 insertions, 485 deletions

diff --git a/llvm/include/llvm/Analysis/DSGraph.h b/llvm/include/llvm/Analysis/DSGraph.h
index 931836a301c..04f80e16243 100644
--- a/llvm/include/llvm/Analysis/DSGraph.h
+++ b/llvm/include/llvm/Analysis/DSGraph.h
@@ -1,13 +1,13 @@
 //===- DSGraph.h - Represent a collection of data structures ----*- C++ -*-===//
 //
-// This header defines the primative classes that make up a data structure
-// graph.
+// This header defines the data structure graph.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_ANALYSIS_DSGRAPH_H
 #define LLVM_ANALYSIS_DSGRAPH_H
 
+#include "llvm/Analysis/DSNode.h"
 #include <vector>
 #include <map>
 #include <functional>
@@ -23,489 +23,6 @@ class DSNode;                  // Each node in the graph
 class DSGraph;                 // A graph for a function
 class DSNodeIterator;          // Data structure graph traversal iterator
 
-
-//===----------------------------------------------------------------------===//
-/// DSNodeHandle - Implement a "handle" to a data structure node that takes care
-/// of all of the add/un'refing of the node to prevent the backpointers in the
-/// graph from getting out of date.  This class represents a "pointer" in the
-/// graph, whose destination is an indexed offset into a node.
-///
-class DSNodeHandle {
-  DSNode *N;
-  unsigned Offset;
-public:
-  // Allow construction, destruction, and assignment...
-  DSNodeHandle(DSNode *n = 0, unsigned offs = 0) : N(0), Offset(offs) {
-    setNode(n);
-  }
-  DSNodeHandle(const DSNodeHandle &H) : N(0), Offset(H.Offset) { setNode(H.N); }
-  ~DSNodeHandle() { setNode((DSNode*)0); }
-  DSNodeHandle &operator=(const DSNodeHandle &H) {
-    setNode(H.N); Offset = H.Offset;
-    return *this;
-  }
-
-  bool operator<(const DSNodeHandle &H) const {  // Allow sorting
-    return N < H.N || (N == H.N && Offset < H.Offset);
-  }
-  bool operator>(const DSNodeHandle &H) const { return H < *this; }
-  bool operator==(const DSNodeHandle &H) const { // Allow comparison
-    return N == H.N && Offset == H.Offset;
-  }
-  bool operator!=(const DSNodeHandle &H) const { return !operator==(H); }
-
-  // Allow explicit conversion to DSNode...
-  DSNode *getNode() const { return N; }
-  unsigned getOffset() const { return Offset; }
-
-  inline void setNode(DSNode *N);  // Defined inline later...
-  void setOffset(unsigned O) { Offset = O; }
-
-  void addEdgeTo(unsigned LinkNo, const DSNodeHandle &N);
-  void addEdgeTo(const DSNodeHandle &N) { addEdgeTo(0, N); }
-
-  /// mergeWith - Merge the logical node pointed to by 'this' with the node
-  /// pointed to by 'N'.
-  ///
-  void mergeWith(const DSNodeHandle &N);
-
-  // hasLink - Return true if there is a link at the specified offset...
-  inline bool hasLink(unsigned Num) const;
-
-  /// getLink - Treat this current node pointer as a pointer to a structure of
-  /// some sort.  This method will return the pointer a mem[this+Num]
-  ///
-  inline const DSNodeHandle *getLink(unsigned Num) const;
-  inline DSNodeHandle *getLink(unsigned Num);
-
-  inline void setLink(unsigned Num, const DSNodeHandle &NH);
-};
-
-
-//===----------------------------------------------------------------------===//
-/// DSTypeRec - This structure is used to represent a single type that is held
-/// in a DSNode.
-///
-struct DSTypeRec {
-  const Type *Ty;                 // The type itself...
-  unsigned Offset;                // The offset in the node
-  bool isArray;                   // Have we accessed an array of elements?
-  
-  DSTypeRec() : Ty(0), Offset(0), isArray(false) {}
-  DSTypeRec(const Type *T, unsigned O) : Ty(T), Offset(O), isArray(false) {}
-  
-  bool operator<(const DSTypeRec &TR) const {
-    // Sort first by offset!
-    return Offset < TR.Offset || (Offset == TR.Offset && Ty < TR.Ty);
-  }
-  bool operator==(const DSTypeRec &TR) const {
-    return Ty == TR.Ty && Offset == TR.Offset;
-  }
-  bool operator!=(const DSTypeRec &TR) const { return !operator==(TR); }
-};
-
-
-
-//===----------------------------------------------------------------------===//
-/// DSNode - Data structure node class
-///
-/// This class represents an untyped memory object of Size bytes.  It keeps
-/// track of any pointers that have been stored into the object as well as the
-/// different types represented in this object.
-///
-class DSNode {
-  /// Links - Contains one entry for every _distinct_ pointer field in the
-  /// memory block.  These are demand allocated and indexed by the MergeMap
-  /// vector.
-  ///
-  std::vector<DSNodeHandle> Links;
-
-  /// MergeMap - Maps from every byte in the object to a signed byte number.
-  /// This map is neccesary due to the merging that is possible as part of the
-  /// unification algorithm.  To merge two distinct bytes of the object together
-  /// into a single logical byte, the indexes for the two bytes are set to the
-  /// same value.  This fully general merging is capable of representing all
-  /// manners of array merging if neccesary.
-  ///
-  /// This map is also used to map outgoing pointers to various byte offsets in
-  /// this data structure node.  If this value is >= 0, then it indicates that
-  /// the numbered entry in the Links vector contains the outgoing edge for this
-  /// byte offset.  In this way, the Links vector can be demand allocated and
-  /// byte elements of the node may be merged without needing a Link allocated
-  /// for it.
-  ///
-  /// Initially, each each element of the MergeMap is assigned a unique negative
-  /// number, which are then merged as the unification occurs.
-  ///
-  std::vector<signed char> MergeMap;
-
-  /// Referrers - Keep track of all of the node handles that point to this
-  /// DSNode.  These pointers may need to be updated to point to a different
-  /// node if this node gets merged with it.
-  ///
-  std::vector<DSNodeHandle*> Referrers;
-
-  /// TypeEntries - As part of the merging process of this algorithm, nodes of
-  /// different types can be represented by this single DSNode.  This vector is
-  /// kept sorted.
-  ///
-  std::vector<DSTypeRec> TypeEntries;
-
-  /// Globals - The list of global values that are merged into this node.
-  ///
-  std::vector<GlobalValue*> Globals;
-
-  void operator=(const DSNode &); // DO NOT IMPLEMENT
-public:
-  enum NodeTy {
-    ShadowNode = 0,        // Nothing is known about this node...
-    ScalarNode = 1 << 0,   // Scalar of the current function contains this value
-    AllocaNode = 1 << 1,   // This node was allocated with alloca
-    NewNode    = 1 << 2,   // This node was allocated with malloc
-    GlobalNode = 1 << 3,   // This node was allocated by a global var decl
-    Incomplete = 1 << 4,   // This node may not be complete
-    Modified   = 1 << 5,   // This node is modified in this context
-    Read       = 1 << 6,   // This node is read in this context
-  };
-  
-  /// NodeType - A union of the above bits.  "Shadow" nodes do not add any flags
-  /// to the nodes in the data structure graph, so it is possible to have nodes
-  /// with a value of 0 for their NodeType.  Scalar and Alloca markers go away
-  /// when function graphs are inlined.
-  ///
-  unsigned char NodeType;
-
-  DSNode(enum NodeTy NT, const Type *T);
-  DSNode(const DSNode &);
-
-  ~DSNode() {
-#ifndef NDEBUG
-    dropAllReferences();  // Only needed to satisfy assertion checks...
-    assert(Referrers.empty() && "Referrers to dead node exist!");
-#endif
-  }
-
-  // Iterator for graph interface...
-  typedef DSNodeIterator iterator;
-  typedef DSNodeIterator const_iterator;
-  inline iterator begin() const;   // Defined in DSGraphTraits.h
-  inline iterator end() const;
-
-  //===--------------------------------------------------
-  // Accessors
-
-  /// getSize - Return the maximum number of bytes occupied by this object...
-  ///
-  unsigned getSize() const { return MergeMap.size(); }
-
-  // getTypeEntries - Return the possible types and their offsets in this object
-  const std::vector<DSTypeRec> &getTypeEntries() const { return TypeEntries; }
-
-  /// getReferrers - Return a list of the pointers to this node...
-  ///
-  const std::vector<DSNodeHandle*> &getReferrers() const { return Referrers; }
-
-  /// isModified - Return true if this node may be modified in this context
-  ///
-  bool isModified() const { return (NodeType & Modified) != 0; }
-
-  /// isRead - Return true if this node may be read in this context
-  ///
-  bool isRead() const { return (NodeType & Read) != 0; }
-
-
-  /// hasLink - Return true if this memory object has a link at the specified
-  /// location.
-  ///
-  bool hasLink(unsigned i) const {
-    assert(i < getSize() && "Field Link index is out of range!");
-    return MergeMap[i] >= 0;
-  }
-
-  DSNodeHandle *getLink(unsigned i) {
-    if (hasLink(i))
-      return &Links[MergeMap[i]];
-    return 0;
-  }
-  const DSNodeHandle *getLink(unsigned i) const {
-    if (hasLink(i))
-      return &Links[MergeMap[i]];
-    return 0;
-  }
-
-  /// getMergeMapLabel - Return the merge map entry specified, to allow printing
-  /// out of DSNodes nicely for DOT graphs.
-  ///
-  int getMergeMapLabel(unsigned i) const {
-    assert(i < MergeMap.size() && "MergeMap index out of range!");
-    return MergeMap[i];
-  }
-
-  /// getTypeRec - This method returns the specified type record if it exists.
-  /// If it does not yet exist, the method checks to see whether or not the
-  /// request would result in an untrackable state.  If adding it would cause
-  /// untrackable state, we foldNodeCompletely the node and return the void
-  /// record, otherwise we add an new TypeEntry and return it.
-  ///
-  DSTypeRec &getTypeRec(const Type *Ty, unsigned Offset);
-
-  /// foldNodeCompletely - If we determine that this node has some funny
-  /// behavior happening to it that we cannot represent, we fold it down to a
-  /// single, completely pessimistic, node.  This node is represented as a
-  /// single byte with a single TypeEntry of "void".
-  ///
-  void foldNodeCompletely();
-
-  /// isNodeCompletelyFolded - Return true if this node has been completely
-  /// folded down to something that can never be expanded, effectively losing
-  /// all of the field sensitivity that may be present in the node.
-  ///
-  bool isNodeCompletelyFolded() const;
-
-  /// setLink - Set the link at the specified offset to the specified
-  /// NodeHandle, replacing what was there.  It is uncommon to use this method,
-  /// instead one of the higher level methods should be used, below.
-  ///
-  void setLink(unsigned i, const DSNodeHandle &NH);
-
-  /// addEdgeTo - Add an edge from the current node to the specified node.  This
-  /// can cause merging of nodes in the graph.
-  ///
-  void addEdgeTo(unsigned Offset, const DSNodeHandle &NH);
-
-  /// mergeWith - Merge this node and the specified node, moving all links to
-  /// and from the argument node into the current node, deleting the node
-  /// argument.  Offset indicates what offset the specified node is to be merged
-  /// into the current node.
-  ///
-  /// The specified node may be a null pointer (in which case, nothing happens).
-  ///
-  void mergeWith(const DSNodeHandle &NH, unsigned Offset);
-
-  /// mergeIndexes - If we discover that two indexes are equivalent and must be
-  /// merged, this function is used to do the dirty work.
-  ///
-  void mergeIndexes(unsigned idx1, unsigned idx2) {
-    assert(idx1 < getSize() && idx2 < getSize() && "Indexes out of range!");
-    signed char MV1 = MergeMap[idx1];
-    signed char MV2 = MergeMap[idx2];
-    if (MV1 != MV2)
-      mergeMappedValues(MV1, MV2);
-  }
-
-
-  /// addGlobal - Add an entry for a global value to the Globals list.  This
-  /// also marks the node with the 'G' flag if it does not already have it.
-  ///
-  void addGlobal(GlobalValue *GV);
-  const std::vector<GlobalValue*> &getGlobals() const { return Globals; }
-  std::vector<GlobalValue*> &getGlobals() { return Globals; }
-
-  void print(std::ostream &O, const DSGraph *G) const;
-  void dump() const;
-
-  void dropAllReferences() {
-    Links.clear();
-  }
-
-  /// remapLinks - Change all of the Links in the current node according to the
-  /// specified mapping.
-  void remapLinks(std::map<const DSNode*, DSNode*> &OldNodeMap);
-
-private:
-  friend class DSNodeHandle;
-  // addReferrer - Keep the referrer set up to date...
-  void addReferrer(DSNodeHandle *H) { Referrers.push_back(H); }
-  void removeReferrer(DSNodeHandle *H);
-
-  /// rewriteMergeMap - Loop over the mergemap, replacing any references to the
-  /// index From to be references to the index To.
-  ///
-  void rewriteMergeMap(signed char From, signed char To) {
-    assert(From != To && "Cannot change something into itself!");
-    for (unsigned i = 0, e = MergeMap.size(); i != e; ++i)
-      if (MergeMap[i] == From)
-        MergeMap[i] = To;
-  }
-
-  /// mergeMappedValues - This is the higher level form of rewriteMergeMap.  It
-  /// is fully capable of merging links together if neccesary as well as simply
-  /// rewriting the map entries.
-  ///
-  void mergeMappedValues(signed char V1, signed char V2);
-
-  /// growNode - Attempt to grow the node to the specified size.  This may do
-  /// one of three things:
-  ///   1. Grow the node, return false
-  ///   2. Refuse to grow the node, but maintain a trackable situation, return
-  ///      false.
-  ///   3. Be unable to track if node was that size, so collapse the node and
-  ///      return true.
-  ///
-  bool growNode(unsigned RequestedSize);
-};
-
-
-//===----------------------------------------------------------------------===//
-// Define inline DSNodeHandle functions that depend on the definition of DSNode
-//
-
-inline void DSNodeHandle::setNode(DSNode *n) {
-  if (N) N->removeReferrer(this);
-  N = n;
-  if (N) N->addReferrer(this);
-}
-
-inline bool DSNodeHandle::hasLink(unsigned Num) const {
-  assert(N && "DSNodeHandle does not point to a node yet!");
-  return N->hasLink(Num+Offset);
-}
-
-
-/// getLink - Treat this current node pointer as a pointer to a structure of
-/// some sort.  This method will return the pointer a mem[this+Num]
-///
-inline const DSNodeHandle *DSNodeHandle::getLink(unsigned Num) const {
-  assert(N && "DSNodeHandle does not point to a node yet!");
-  return N->getLink(Num+Offset);
-}
-inline DSNodeHandle *DSNodeHandle::getLink(unsigned Num) {
-  assert(N && "DSNodeHandle does not point to a node yet!");
-  return N->getLink(Num+Offset);
-}
-
-inline void DSNodeHandle::setLink(unsigned Num, const DSNodeHandle &NH) {
-  assert(N && "DSNodeHandle does not point to a node yet!");
-  N->setLink(Num+Offset, NH);
-}
-
-///  addEdgeTo - Add an edge from the current node to the specified node.  This
-/// can cause merging of nodes in the graph.
-///
-inline void DSNodeHandle::addEdgeTo(unsigned LinkNo, const DSNodeHandle &Node) {
-  assert(N && "DSNodeHandle does not point to a node yet!");
-  N->addEdgeTo(LinkNo+Offset, Node);
-}
-
-/// mergeWith - Merge the logical node pointed to by 'this' with the node
-/// pointed to by 'N'.
-///
-inline void DSNodeHandle::mergeWith(const DSNodeHandle &Node) {
-  assert(N && "DSNodeHandle does not point to a node yet!");
-  N->mergeWith(Node, Offset);
-}
-
-
-//===----------------------------------------------------------------------===//
-/// DSCallSite - Representation of a call site via its call instruction,
-/// the DSNode handle for the callee function (or function pointer), and
-/// the DSNode handles for the function arguments.
-///
-/// One unusual aspect of this callsite record is the ResolvingCaller member.
-/// If this is non-null, then it indicates the function that allowed a call-site
-/// to finally be resolved.  Because of indirect calls, this function may not
-/// actually be the function that contains the Call instruction itself.  This is
-/// used by the BU and TD passes to communicate.
-/// 
-class DSCallSite {
-  CallInst    *Inst;                    // Actual call site
-  DSNodeHandle RetVal;                  // Returned value
-  DSNodeHandle Callee;                  // The function node called
-  std::vector<DSNodeHandle> CallArgs;   // The pointer arguments
-  Function    *ResolvingCaller;         // See comments above
-
-  static void InitNH(DSNodeHandle &NH, const DSNodeHandle &Src,
-                     const std::map<const DSNode*, DSNode*> &NodeMap) {
-    if (DSNode *N = Src.getNode()) {
-      std::map<const DSNode*, DSNode*>::const_iterator I = NodeMap.find(N);
-      assert(I != NodeMap.end() && "Not not in mapping!");
-
-      NH.setOffset(Src.getOffset());
-      NH.setNode(I->second);
-    }
-  }
-
-  static void InitNH(DSNodeHandle &NH, const DSNodeHandle &Src,
-                     const std::map<const DSNode*, DSNodeHandle> &NodeMap) {
-    if (DSNode *N = Src.getNode()) {
-      std::map<const DSNode*, DSNodeHandle>::const_iterator I = NodeMap.find(N);
-      assert(I != NodeMap.end() && "Not not in mapping!");
-
-      NH.setOffset(Src.getOffset()+I->second.getOffset());
-      NH.setNode(I->second.getNode());
-    }
-  }
-
-  DSCallSite();                         // DO NOT IMPLEMENT
-public:
-  /// Constructor.  Note - This ctor destroys the argument vector passed in.  On
-  /// exit, the argument vector is empty.
-  ///
-  DSCallSite(CallInst &inst, const DSNodeHandle &rv, const DSNodeHandle &callee,
-             std::vector<DSNodeHandle> &Args)
-    : Inst(&inst), RetVal(rv), Callee(callee), ResolvingCaller(0) {
-    Args.swap(CallArgs);
-  }
-
-  DSCallSite(const DSCallSite &DSCS)   // Simple copy ctor
-    : Inst(DSCS.Inst), RetVal(DSCS.RetVal),
-      Callee(DSCS.Callee), CallArgs(DSCS.CallArgs),
-      ResolvingCaller(DSCS.ResolvingCaller) {}
-
-  /// Mapping copy constructor - This constructor takes a preexisting call site
-  /// to copy plus a map that specifies how the links should be transformed.
-  /// This is useful when moving a call site from one graph to another.
-  ///
-  template<typename MapTy>
-  DSCallSite(const DSCallSite &FromCall, const MapTy &NodeMap) {
-    Inst = FromCall.Inst;
-    InitNH(RetVal, FromCall.RetVal, NodeMap);
-    InitNH(Callee, FromCall.Callee, NodeMap);
-
-    CallArgs.resize(FromCall.CallArgs.size());
-    for (unsigned i = 0, e = FromCall.CallArgs.size(); i != e; ++i)
-      InitNH(CallArgs[i], FromCall.CallArgs[i], NodeMap);
-    ResolvingCaller = FromCall.ResolvingCaller;
-  }
-
-  // Accessor functions...
-  Function           &getCaller()     const;
-  CallInst           &getCallInst()   const { return *Inst; }
-        DSNodeHandle &getRetVal()           { return RetVal; }
-        DSNodeHandle &getCallee()           { return Callee; }
-  const DSNodeHandle &getRetVal()     const { return RetVal; }
-  const DSNodeHandle &getCallee()     const { return Callee; }
-  void setCallee(const DSNodeHandle &H) { Callee = H; }
-
-  unsigned            getNumPtrArgs() const { return CallArgs.size(); }
-
-  Function           *getResolvingCaller() const { return ResolvingCaller; }
-  void setResolvingCaller(Function *F) { ResolvingCaller = F; }
-
-  DSNodeHandle &getPtrArg(unsigned i) {
-    assert(i < CallArgs.size() && "Argument to getPtrArgNode is out of range!");
-    return CallArgs[i];
-  }
-  const DSNodeHandle &getPtrArg(unsigned i) const {
-    assert(i < CallArgs.size() && "Argument to getPtrArgNode is out of range!");
-    return CallArgs[i];
-  }
-
-  bool operator<(const DSCallSite &CS) const {
-    if (RetVal < CS.RetVal) return true;
-    if (RetVal > CS.RetVal) return false;
-    if (Callee < CS.Callee) return true;
-    if (Callee > CS.Callee) return false;
-    return CallArgs < CS.CallArgs;
-  }
-
-  bool operator==(const DSCallSite &CS) const {
-    return RetVal == CS.RetVal && Callee == CS.Callee &&
-           CallArgs == CS.CallArgs;
-  }
-};
-
-
 //===----------------------------------------------------------------------===//
 /// DSGraph - The graph that represents a function.
 ///
diff --git a/llvm/include/llvm/Analysis/DSNode.h b/llvm/include/llvm/Analysis/DSNode.h
new file mode 100644
index 00000000000..a1542cbdf0a
--- /dev/null
+++ b/llvm/include/llvm/Analysis/DSNode.h
@@ -0,0 +1,315 @@
+//===- DSSupport.h - Support for datastructure graphs -----------*- C++ -*-===//
+//
+// Support for graph nodes, call sites, and types.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_DSNODE_H
+#define LLVM_ANALYSIS_DSNODE_H
+
+#include "llvm/Analysis/DSSupport.h"
+#include <vector>
+#include <map>
+#include <functional>
+#include <string>
+
+class Function;
+class CallInst;
+class Value;
+class GlobalValue;
+class Type;
+
+class DSNode;                  // Each node in the graph
+class DSGraph;                 // A graph for a function
+class DSNodeIterator;          // Data structure graph traversal iterator
+
+//===----------------------------------------------------------------------===//
+/// DSNode - Data structure node class
+///
+/// This class represents an untyped memory object of Size bytes.  It keeps
+/// track of any pointers that have been stored into the object as well as the
+/// different types represented in this object.
+///
+class DSNode {
+  /// Links - Contains one entry for every _distinct_ pointer field in the
+  /// memory block.  These are demand allocated and indexed by the MergeMap
+  /// vector.
+  ///
+  std::vector<DSNodeHandle> Links;
+
+  /// MergeMap - Maps from every byte in the object to a signed byte number.
+  /// This map is neccesary due to the merging that is possible as part of the
+  /// unification algorithm.  To merge two distinct bytes of the object together
+  /// into a single logical byte, the indexes for the two bytes are set to the
+  /// same value.  This fully general merging is capable of representing all
+  /// manners of array merging if neccesary.
+  ///
+  /// This map is also used to map outgoing pointers to various byte offsets in
+  /// this data structure node.  If this value is >= 0, then it indicates that
+  /// the numbered entry in the Links vector contains the outgoing edge for this
+  /// byte offset.  In this way, the Links vector can be demand allocated and
+  /// byte elements of the node may be merged without needing a Link allocated
+  /// for it.
+  ///
+  /// Initially, each each element of the MergeMap is assigned a unique negative
+  /// number, which are then merged as the unification occurs.
+  ///
+  std::vector<signed char> MergeMap;
+
+  /// Referrers - Keep track of all of the node handles that point to this
+  /// DSNode.  These pointers may need to be updated to point to a different
+  /// node if this node gets merged with it.
+  ///
+  std::vector<DSNodeHandle*> Referrers;
+
+  /// TypeEntries - As part of the merging process of this algorithm, nodes of
+  /// different types can be represented by this single DSNode.  This vector is
+  /// kept sorted.
+  ///
+  std::vector<DSTypeRec> TypeEntries;
+
+  /// Globals - The list of global values that are merged into this node.
+  ///
+  std::vector<GlobalValue*> Globals;
+
+  void operator=(const DSNode &); // DO NOT IMPLEMENT
+public:
+  enum NodeTy {
+    ShadowNode = 0,        // Nothing is known about this node...
+    ScalarNode = 1 << 0,   // Scalar of the current function contains this value
+    AllocaNode = 1 << 1,   // This node was allocated with alloca
+    NewNode    = 1 << 2,   // This node was allocated with malloc
+    GlobalNode = 1 << 3,   // This node was allocated by a global var decl
+    Incomplete = 1 << 4,   // This node may not be complete
+    Modified   = 1 << 5,   // This node is modified in this context
+    Read       = 1 << 6,   // This node is read in this context
+  };
+  
+  /// NodeType - A union of the above bits.  "Shadow" nodes do not add any flags
+  /// to the nodes in the data structure graph, so it is possible to have nodes
+  /// with a value of 0 for their NodeType.  Scalar and Alloca markers go away
+  /// when function graphs are inlined.
+  ///
+  unsigned char NodeType;
+
+  DSNode(enum NodeTy NT, const Type *T);
+  DSNode(const DSNode &);
+
+  ~DSNode() {
+#ifndef NDEBUG
+    dropAllReferences();  // Only needed to satisfy assertion checks...
+    assert(Referrers.empty() && "Referrers to dead node exist!");
+#endif
+  }
+
+  // Iterator for graph interface...
+  typedef DSNodeIterator iterator;
+  typedef DSNodeIterator const_iterator;
+  inline iterator begin() const;   // Defined in DSGraphTraits.h
+  inline iterator end() const;
+
+  //===--------------------------------------------------
+  // Accessors
+
+  /// getSize - Return the maximum number of bytes occupied by this object...
+  ///
+  unsigned getSize() const { return MergeMap.size(); }
+
+  // getTypeEntries - Return the possible types and their offsets in this object
+  const std::vector<DSTypeRec> &getTypeEntries() const { return TypeEntries; }
+
+  /// getReferrers - Return a list of the pointers to this node...
+  ///
+  const std::vector<DSNodeHandle*> &getReferrers() const { return Referrers; }
+
+  /// isModified - Return true if this node may be modified in this context
+  ///
+  bool isModified() const { return (NodeType & Modified) != 0; }
+
+  /// isRead - Return true if this node may be read in this context
+  ///
+  bool isRead() const { return (NodeType & Read) != 0; }
+
+
+  /// hasLink - Return true if this memory object has a link at the specified
+  /// location.
+  ///
+  bool hasLink(unsigned i) const {
+    assert(i < getSize() && "Field Link index is out of range!");
+    return MergeMap[i] >= 0;
+  }
+
+  DSNodeHandle *getLink(unsigned i) {
+    if (hasLink(i))
+      return &Links[MergeMap[i]];
+    return 0;
+  }
+  const DSNodeHandle *getLink(unsigned i) const {
+    if (hasLink(i))
+      return &Links[MergeMap[i]];
+    return 0;
+  }
+
+  /// getMergeMapLabel - Return the merge map entry specified, to allow printing
+  /// out of DSNodes nicely for DOT graphs.
+  ///
+  int getMergeMapLabel(unsigned i) const {
+    assert(i < MergeMap.size() && "MergeMap index out of range!");
+    return MergeMap[i];
+  }
+
+  /// getTypeRec - This method returns the specified type record if it exists.
+  /// If it does not yet exist, the method checks to see whether or not the
+  /// request would result in an untrackable state.  If adding it would cause
+  /// untrackable state, we foldNodeCompletely the node and return the void
+  /// record, otherwise we add an new TypeEntry and return it.
+  ///
+  DSTypeRec &getTypeRec(const Type *Ty, unsigned Offset);
+
+  /// foldNodeCompletely - If we determine that this node has some funny
+  /// behavior happening to it that we cannot represent, we fold it down to a
+  /// single, completely pessimistic, node.  This node is represented as a
+  /// single byte with a single TypeEntry of "void".
+  ///
+  void foldNodeCompletely();
+
+  /// isNodeCompletelyFolded - Return true if this node has been completely
+  /// folded down to something that can never be expanded, effectively losing
+  /// all of the field sensitivity that may be present in the node.
+  ///
+  bool isNodeCompletelyFolded() const;
+
+  /// setLink - Set the link at the specified offset to the specified
+  /// NodeHandle, replacing what was there.  It is uncommon to use this method,
+  /// instead one of the higher level methods should be used, below.
+  ///
+  void setLink(unsigned i, const DSNodeHandle &NH);
+
+  /// addEdgeTo - Add an edge from the current node to the specified node.  This
+  /// can cause merging of nodes in the graph.
+  ///
+  void addEdgeTo(unsigned Offset, const DSNodeHandle &NH);
+
+  /// mergeWith - Merge this node and the specified node, moving all links to
+  /// and from the argument node into the current node, deleting the node
+  /// argument.  Offset indicates what offset the specified node is to be merged
+  /// into the current node.
+  ///
+  /// The specified node may be a null pointer (in which case, nothing happens).
+  ///
+  void mergeWith(const DSNodeHandle &NH, unsigned Offset);
+
+  /// mergeIndexes - If we discover that two indexes are equivalent and must be
+  /// merged, this function is used to do the dirty work.
+  ///
+  void mergeIndexes(unsigned idx1, unsigned idx2) {
+    assert(idx1 < getSize() && idx2 < getSize() && "Indexes out of range!");
+    signed char MV1 = MergeMap[idx1];
+    signed char MV2 = MergeMap[idx2];
+    if (MV1 != MV2)
+      mergeMappedValues(MV1, MV2);
+  }
+
+
+  /// addGlobal - Add an entry for a global value to the Globals list.  This
+  /// also marks the node with the 'G' flag if it does not already have it.
+  ///
+  void addGlobal(GlobalValue *GV);
+  const std::vector<GlobalValue*> &getGlobals() const { return Globals; }
+  std::vector<GlobalValue*> &getGlobals() { return Globals; }
+
+  void print(std::ostream &O, const DSGraph *G) const;
+  void dump() const;
+
+  void dropAllReferences() {
+    Links.clear();
+  }
+
+  /// remapLinks - Change all of the Links in the current node according to the
+  /// specified mapping.
+  void remapLinks(std::map<const DSNode*, DSNode*> &OldNodeMap);
+
+private:
+  friend class DSNodeHandle;
+  // addReferrer - Keep the referrer set up to date...
+  void addReferrer(DSNodeHandle *H) { Referrers.push_back(H); }
+  void removeReferrer(DSNodeHandle *H);
+
+  /// rewriteMergeMap - Loop over the mergemap, replacing any references to the
+  /// index From to be references to the index To.
+  ///
+  void rewriteMergeMap(signed char From, signed char To) {
+    assert(From != To && "Cannot change something into itself!");
+    for (unsigned i = 0, e = MergeMap.size(); i != e; ++i)
+      if (MergeMap[i] == From)
+        MergeMap[i] = To;
+  }
+
+  /// mergeMappedValues - This is the higher level form of rewriteMergeMap.  It
+  /// is fully capable of merging links together if neccesary as well as simply
+  /// rewriting the map entries.
+  ///
+  void mergeMappedValues(signed char V1, signed char V2);
+
+  /// growNode - Attempt to grow the node to the specified size.  This may do
+  /// one of three things:
+  ///   1. Grow the node, return false
+  ///   2. Refuse to grow the node, but maintain a trackable situation, return
+  ///      false.
+  ///   3. Be unable to track if node was that size, so collapse the node and
+  ///      return true.
+  ///
+  bool growNode(unsigned RequestedSize);
+};
+
+
+//===----------------------------------------------------------------------===//
+// Define inline DSNodeHandle functions that depend on the definition of DSNode
+//
+
+inline void DSNodeHandle::setNode(DSNode *n) {
+  if (N) N->removeReferrer(this);
+  N = n;
+  if (N) N->addReferrer(this);
+}
+
+inline bool DSNodeHandle::hasLink(unsigned Num) const {
+  assert(N && "DSNodeHandle does not point to a node yet!");
+  return N->hasLink(Num+Offset);
+}
+
+
+/// getLink - Treat this current node pointer as a pointer to a structure of
+/// some sort.  This method will return the pointer a mem[this+Num]
+///
+inline const DSNodeHandle *DSNodeHandle::getLink(unsigned Num) const {
+  assert(N && "DSNodeHandle does not point to a node yet!");
+  return N->getLink(Num+Offset);
+}
+inline DSNodeHandle *DSNodeHandle::getLink(unsigned Num) {
+  assert(N && "DSNodeHandle does not point to a node yet!");
+  return N->getLink(Num+Offset);
+}
+
+inline void DSNodeHandle::setLink(unsigned Num, const DSNodeHandle &NH) {
+  assert(N && "DSNodeHandle does not point to a node yet!");
+  N->setLink(Num+Offset, NH);
+}
+
+///  addEdgeTo - Add an edge from the current node to the specified node.  This
+/// can cause merging of nodes in the graph.
+///
+inline void DSNodeHandle::addEdgeTo(unsigned LinkNo, const DSNodeHandle &Node) {
+  assert(N && "DSNodeHandle does not point to a node yet!");
+  N->addEdgeTo(LinkNo+Offset, Node);
+}
+
+/// mergeWith - Merge the logical node pointed to by 'this' with the node
+/// pointed to by 'N'.
+///
+inline void DSNodeHandle::mergeWith(const DSNodeHandle &Node) {
+  assert(N && "DSNodeHandle does not point to a node yet!");
+  N->mergeWith(Node, Offset);
+}
+
+#endif
diff --git a/llvm/include/llvm/Analysis/DSSupport.h b/llvm/include/llvm/Analysis/DSSupport.h
new file mode 100644
index 00000000000..b3c3ed02965
--- /dev/null
+++ b/llvm/include/llvm/Analysis/DSSupport.h
@@ -0,0 +1,219 @@
+//===- DSSupport.h - Support for datastructure graphs -----------*- C++ -*-===//
+//
+// Support for graph nodes, call sites, and types.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_DSSUPPORT_H
+#define LLVM_ANALYSIS_DSSUPPORT_H
+
+#include <vector>
+#include <map>
+#include <functional>
+#include <string>
+
+class Function;
+class CallInst;
+class Value;
+class GlobalValue;
+class Type;
+
+class DSNode;                  // Each node in the graph
+class DSGraph;                 // A graph for a function
+class DSNodeIterator;          // Data structure graph traversal iterator
+
+//===----------------------------------------------------------------------===//
+/// DSNodeHandle - Implement a "handle" to a data structure node that takes care
+/// of all of the add/un'refing of the node to prevent the backpointers in the
+/// graph from getting out of date.  This class represents a "pointer" in the
+/// graph, whose destination is an indexed offset into a node.
+///
+class DSNodeHandle {
+  DSNode *N;
+  unsigned Offset;
+public:
+  // Allow construction, destruction, and assignment...
+  DSNodeHandle(DSNode *n = 0, unsigned offs = 0) : N(0), Offset(offs) {
+    setNode(n);
+  }
+  DSNodeHandle(const DSNodeHandle &H) : N(0), Offset(H.Offset) { setNode(H.N); }
+  ~DSNodeHandle() { setNode((DSNode*)0); }
+  DSNodeHandle &operator=(const DSNodeHandle &H) {
+    setNode(H.N); Offset = H.Offset;
+    return *this;
+  }
+
+  bool operator<(const DSNodeHandle &H) const {  // Allow sorting
+    return N < H.N || (N == H.N && Offset < H.Offset);
+  }
+  bool operator>(const DSNodeHandle &H) const { return H < *this; }
+  bool operator==(const DSNodeHandle &H) const { // Allow comparison
+    return N == H.N && Offset == H.Offset;
+  }
+  bool operator!=(const DSNodeHandle &H) const { return !operator==(H); }
+
+  // Allow explicit conversion to DSNode...
+  DSNode *getNode() const { return N; }
+  unsigned getOffset() const { return Offset; }
+
+  inline void setNode(DSNode *N);  // Defined inline later...
+  void setOffset(unsigned O) { Offset = O; }
+
+  void addEdgeTo(unsigned LinkNo, const DSNodeHandle &N);
+  void addEdgeTo(const DSNodeHandle &N) { addEdgeTo(0, N); }
+
+  /// mergeWith - Merge the logical node pointed to by 'this' with the node
+  /// pointed to by 'N'.
+  ///
+  void mergeWith(const DSNodeHandle &N);
+
+  // hasLink - Return true if there is a link at the specified offset...
+  inline bool hasLink(unsigned Num) const;
+
+  /// getLink - Treat this current node pointer as a pointer to a structure of
+  /// some sort.  This method will return the pointer a mem[this+Num]
+  ///
+  inline const DSNodeHandle *getLink(unsigned Num) const;
+  inline DSNodeHandle *getLink(unsigned Num);
+
+  inline void setLink(unsigned Num, const DSNodeHandle &NH);
+};
+
+
+//===----------------------------------------------------------------------===//
+/// DSTypeRec - This structure is used to represent a single type that is held
+/// in a DSNode.
+///
+struct DSTypeRec {
+  const Type *Ty;                 // The type itself...
+  unsigned Offset;                // The offset in the node
+  bool isArray;                   // Have we accessed an array of elements?
+  
+  DSTypeRec() : Ty(0), Offset(0), isArray(false) {}
+  DSTypeRec(const Type *T, unsigned O) : Ty(T), Offset(O), isArray(false) {}
+  
+  bool operator<(const DSTypeRec &TR) const {
+    // Sort first by offset!
+    return Offset < TR.Offset || (Offset == TR.Offset && Ty < TR.Ty);
+  }
+  bool operator==(const DSTypeRec &TR) const {
+    return Ty == TR.Ty && Offset == TR.Offset;
+  }
+  bool operator!=(const DSTypeRec &TR) const { return !operator==(TR); }
+};
+
+
+
+
+
+//===----------------------------------------------------------------------===//
+/// DSCallSite - Representation of a call site via its call instruction,
+/// the DSNode handle for the callee function (or function pointer), and
+/// the DSNode handles for the function arguments.
+///
+/// One unusual aspect of this callsite record is the ResolvingCaller member.
+/// If this is non-null, then it indicates the function that allowed a call-site
+/// to finally be resolved.  Because of indirect calls, this function may not
+/// actually be the function that contains the Call instruction itself.  This is
+/// used by the BU and TD passes to communicate.
+/// 
+class DSCallSite {
+  CallInst    *Inst;                    // Actual call site
+  DSNodeHandle RetVal;                  // Returned value
+  DSNodeHandle Callee;                  // The function node called
+  std::vector<DSNodeHandle> CallArgs;   // The pointer arguments
+  Function    *ResolvingCaller;         // See comments above
+
+  static void InitNH(DSNodeHandle &NH, const DSNodeHandle &Src,
+                     const std::map<const DSNode*, DSNode*> &NodeMap) {
+    if (DSNode *N = Src.getNode()) {
+      std::map<const DSNode*, DSNode*>::const_iterator I = NodeMap.find(N);
+      assert(I != NodeMap.end() && "Not not in mapping!");
+
+      NH.setOffset(Src.getOffset());
+      NH.setNode(I->second);
+    }
+  }
+
+  static void InitNH(DSNodeHandle &NH, const DSNodeHandle &Src,
+                     const std::map<const DSNode*, DSNodeHandle> &NodeMap) {
+    if (DSNode *N = Src.getNode()) {
+      std::map<const DSNode*, DSNodeHandle>::const_iterator I = NodeMap.find(N);
+      assert(I != NodeMap.end() && "Not not in mapping!");
+
+      NH.setOffset(Src.getOffset()+I->second.getOffset());
+      NH.setNode(I->second.getNode());
+    }
+  }
+
+  DSCallSite();                         // DO NOT IMPLEMENT
+public:
+  /// Constructor.  Note - This ctor destroys the argument vector passed in.  On
+  /// exit, the argument vector is empty.
+  ///
+  DSCallSite(CallInst &inst, const DSNodeHandle &rv, const DSNodeHandle &callee,
+             std::vector<DSNodeHandle> &Args)
+    : Inst(&inst), RetVal(rv), Callee(callee), ResolvingCaller(0) {
+    Args.swap(CallArgs);
+  }
+
+  DSCallSite(const DSCallSite &DSCS)   // Simple copy ctor
+    : Inst(DSCS.Inst), RetVal(DSCS.RetVal),
+      Callee(DSCS.Callee), CallArgs(DSCS.CallArgs),
+      ResolvingCaller(DSCS.ResolvingCaller) {}
+
+  /// Mapping copy constructor - This constructor takes a preexisting call site
+  /// to copy plus a map that specifies how the links should be transformed.
+  /// This is useful when moving a call site from one graph to another.
+  ///
+  template<typename MapTy>
+  DSCallSite(const DSCallSite &FromCall, const MapTy &NodeMap) {
+    Inst = FromCall.Inst;
+    InitNH(RetVal, FromCall.RetVal, NodeMap);
+    InitNH(Callee, FromCall.Callee, NodeMap);
+
+    CallArgs.resize(FromCall.CallArgs.size());
+    for (unsigned i = 0, e = FromCall.CallArgs.size(); i != e; ++i)
+      InitNH(CallArgs[i], FromCall.CallArgs[i], NodeMap);
+    ResolvingCaller = FromCall.ResolvingCaller;
+  }
+
+  // Accessor functions...
+  Function           &getCaller()     const;
+  CallInst           &getCallInst()   const { return *Inst; }
+        DSNodeHandle &getRetVal()           { return RetVal; }
+        DSNodeHandle &getCallee()           { return Callee; }
+  const DSNodeHandle &getRetVal()     const { return RetVal; }
+  const DSNodeHandle &getCallee()     const { return Callee; }
+  void setCallee(const DSNodeHandle &H) { Callee = H; }
+
+  unsigned            getNumPtrArgs() const { return CallArgs.size(); }
+
+  Function           *getResolvingCaller() const { return ResolvingCaller; }
+  void setResolvingCaller(Function *F) { ResolvingCaller = F; }
+
+  DSNodeHandle &getPtrArg(unsigned i) {
+    assert(i < CallArgs.size() && "Argument to getPtrArgNode is out of range!");
+    return CallArgs[i];
+  }
+  const DSNodeHandle &getPtrArg(unsigned i) const {
+    assert(i < CallArgs.size() && "Argument to getPtrArgNode is out of range!");
+    return CallArgs[i];
+  }
+
+  bool operator<(const DSCallSite &CS) const {
+    if (RetVal < CS.RetVal) return true;
+    if (RetVal > CS.RetVal) return false;
+    if (Callee < CS.Callee) return true;
+    if (Callee > CS.Callee) return false;
+    return CallArgs < CS.CallArgs;
+  }
+
+  bool operator==(const DSCallSite &CS) const {
+    return RetVal == CS.RetVal && Callee == CS.Callee &&
+           CallArgs == CS.CallArgs;
+  }
+};
+
+
+#endif