Remove DSA.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32550 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 2435 deletions

diff --git a/lib/Analysis/DataStructure/DataStructure.cpp b/lib/Analysis/DataStructure/DataStructure.cpp
deleted file mode 100644
index 666b615825..0000000000
--- a/lib/Analysis/DataStructure/DataStructure.cpp
+++ /dev/null
@@ -1,2435 +0,0 @@
-//===- DataStructure.cpp - Implement the core data structure analysis -----===//
-//
-//                     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 implements the core data structure functionality.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/DataStructure/DSGraphTraits.h"
-#include "llvm/Constants.h"
-#include "llvm/Function.h"
-#include "llvm/GlobalVariable.h"
-#include "llvm/Instructions.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Target/TargetData.h"
-#include "llvm/Assembly/Writer.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SCCIterator.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Support/Timer.h"
-#include <algorithm>
-using namespace llvm;
-
-#define COLLAPSE_ARRAYS_AGGRESSIVELY 0
-
-namespace {
-  Statistic NumFolds          ("dsa", "Number of nodes completely folded");
-  Statistic NumCallNodesMerged("dsa", "Number of call nodes merged");
-  Statistic NumNodeAllocated  ("dsa", "Number of nodes allocated");
-  Statistic NumDNE            ("dsa", "Number of nodes removed by reachability");
-  Statistic NumTrivialDNE     ("dsa", "Number of nodes trivially removed");
-  Statistic NumTrivialGlobalDNE("dsa", "Number of globals trivially removed");
-  static cl::opt<unsigned>
-  DSAFieldLimit("dsa-field-limit", cl::Hidden,
-                cl::desc("Number of fields to track before collapsing a node"),
-                cl::init(256));
-}
-
-#if 0
-#define TIME_REGION(VARNAME, DESC) \
-   NamedRegionTimer VARNAME(DESC)
-#else
-#define TIME_REGION(VARNAME, DESC)
-#endif
-
-using namespace DS;
-
-/// isForwarding - Return true if this NodeHandle is forwarding to another
-/// one.
-bool DSNodeHandle::isForwarding() const {
-  return N && N->isForwarding();
-}
-
-DSNode *DSNodeHandle::HandleForwarding() const {
-  assert(N->isForwarding() && "Can only be invoked if forwarding!");
-  DEBUG(
-        { //assert not looping
-          DSNode* NH = N;
-          std::set<DSNode*> seen;
-          while(NH && NH->isForwarding()) {
-            assert(seen.find(NH) == seen.end() && "Loop detected");
-            seen.insert(NH);
-            NH = NH->ForwardNH.N;
-          }
-        }
-        );
-  // Handle node forwarding here!
-  DSNode *Next = N->ForwardNH.getNode();  // Cause recursive shrinkage
-  Offset += N->ForwardNH.getOffset();
-
-  if (--N->NumReferrers == 0) {
-    // Removing the last referrer to the node, sever the forwarding link
-    N->stopForwarding();
-  }
-
-  N = Next;
-  N->NumReferrers++;
-  if (N->Size <= Offset) {
-    assert(N->Size <= 1 && "Forwarded to shrunk but not collapsed node?");
-    Offset = 0;
-  }
-  return N;
-}
-
-//===----------------------------------------------------------------------===//
-// DSScalarMap Implementation
-//===----------------------------------------------------------------------===//
-
-DSNodeHandle &DSScalarMap::AddGlobal(GlobalValue *GV) {
-  assert(ValueMap.count(GV) == 0 && "GV already exists!");
-
-  // If the node doesn't exist, check to see if it's a global that is
-  // equated to another global in the program.
-  EquivalenceClasses<GlobalValue*>::iterator ECI = GlobalECs.findValue(GV);
-  if (ECI != GlobalECs.end()) {
-    GlobalValue *Leader = *GlobalECs.findLeader(ECI);
-    if (Leader != GV) {
-      GV = Leader;
-      iterator I = ValueMap.find(GV);
-      if (I != ValueMap.end())
-        return I->second;
-    }
-  }
-
-  // Okay, this is either not an equivalenced global or it is the leader, it
-  // will be inserted into the scalar map now.
-  GlobalSet.insert(GV);
-
-  return ValueMap.insert(std::make_pair(GV, DSNodeHandle())).first->second;
-}
-
-
-//===----------------------------------------------------------------------===//
-// DSNode Implementation
-//===----------------------------------------------------------------------===//
-
-DSNode::DSNode(const Type *T, DSGraph *G)
-  : NumReferrers(0), Size(0), ParentGraph(G), Ty(Type::VoidTy), NodeType(0) {
-  // Add the type entry if it is specified...
-  if (T) mergeTypeInfo(T, 0);
-  if (G) G->addNode(this);
-  ++NumNodeAllocated;
-}
-
-// DSNode copy constructor... do not copy over the referrers list!
-DSNode::DSNode(const DSNode &N, DSGraph *G, bool NullLinks)
-  : NumReferrers(0), Size(N.Size), ParentGraph(G),
-    Ty(N.Ty), Globals(N.Globals), NodeType(N.NodeType) {
-  if (!NullLinks) {
-    Links = N.Links;
-  } else
-    Links.resize(N.Links.size()); // Create the appropriate number of null links
-  G->addNode(this);
-  ++NumNodeAllocated;
-}
-
-/// getTargetData - Get the target data object used to construct this node.
-///
-const TargetData &DSNode::getTargetData() const {
-  return ParentGraph->getTargetData();
-}
-
-void DSNode::assertOK() const {
-  assert((Ty != Type::VoidTy ||
-          Ty == Type::VoidTy && (Size == 0 ||
-                                 (NodeType & DSNode::Array))) &&
-         "Node not OK!");
-
-  assert(ParentGraph && "Node has no parent?");
-  const DSScalarMap &SM = ParentGraph->getScalarMap();
-  for (unsigned i = 0, e = Globals.size(); i != e; ++i) {
-    assert(SM.global_count(Globals[i]));
-    assert(SM.find(Globals[i])->second.getNode() == this);
-  }
-}
-
-/// forwardNode - Mark this node as being obsolete, and all references to it
-/// should be forwarded to the specified node and offset.
-///
-void DSNode::forwardNode(DSNode *To, unsigned Offset) {
-  assert(this != To && "Cannot forward a node to itself!");
-  assert(ForwardNH.isNull() && "Already forwarding from this node!");
-  if (To->Size <= 1) Offset = 0;
-  assert((Offset < To->Size || (Offset == To->Size && Offset == 0)) &&
-         "Forwarded offset is wrong!");
-  ForwardNH.setTo(To, Offset);
-  NodeType = DEAD;
-  Size = 0;
-  Ty = Type::VoidTy;
-
-  // Remove this node from the parent graph's Nodes list.
-  ParentGraph->unlinkNode(this);
-  ParentGraph = 0;
-}
-
-// 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 DSNode::addGlobal(GlobalValue *GV) {
-  // First, check to make sure this is the leader if the global is in an
-  // equivalence class.
-  GV = getParentGraph()->getScalarMap().getLeaderForGlobal(GV);
-
-  // Keep the list sorted.
-  std::vector<GlobalValue*>::iterator I =
-    std::lower_bound(Globals.begin(), Globals.end(), GV);
-
-  if (I == Globals.end() || *I != GV) {
-    Globals.insert(I, GV);
-    NodeType |= GlobalNode;
-  }
-}
-
-// removeGlobal - Remove the specified global that is explicitly in the globals
-// list.
-void DSNode::removeGlobal(GlobalValue *GV) {
-  std::vector<GlobalValue*>::iterator I =
-    std::lower_bound(Globals.begin(), Globals.end(), GV);
-  assert(I != Globals.end() && *I == GV && "Global not in node!");
-  Globals.erase(I);
-}
-
-/// 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 DSNode::foldNodeCompletely() {
-  if (isNodeCompletelyFolded()) return;  // If this node is already folded...
-
-  ++NumFolds;
-
-  // If this node has a size that is <= 1, we don't need to create a forwarding
-  // node.
-  if (getSize() <= 1) {
-    NodeType |= DSNode::Array;
-    Ty = Type::VoidTy;
-    Size = 1;
-    assert(Links.size() <= 1 && "Size is 1, but has more links?");
-    Links.resize(1);
-  } else {
-    // Create the node we are going to forward to.  This is required because
-    // some referrers may have an offset that is > 0.  By forcing them to
-    // forward, the forwarder has the opportunity to correct the offset.
-    DSNode *DestNode = new DSNode(0, ParentGraph);
-    DestNode->NodeType = NodeType|DSNode::Array;
-    DestNode->Ty = Type::VoidTy;
-    DestNode->Size = 1;
-    DestNode->Globals.swap(Globals);
-
-    // Start forwarding to the destination node...
-    forwardNode(DestNode, 0);
-
-    if (!Links.empty()) {
-      DestNode->Links.reserve(1);
-
-      DSNodeHandle NH(DestNode);
-      DestNode->Links.push_back(Links[0]);
-
-      // If we have links, merge all of our outgoing links together...
-      for (unsigned i = Links.size()-1; i != 0; --i)
-        NH.getNode()->Links[0].mergeWith(Links[i]);
-      Links.clear();
-    } else {
-      DestNode->Links.resize(1);
-    }
-  }
-}
-
-/// 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 DSNode::isNodeCompletelyFolded() const {
-  return getSize() == 1 && Ty == Type::VoidTy && isArray();
-}
-
-/// addFullGlobalsList - Compute the full set of global values that are
-/// represented by this node.  Unlike getGlobalsList(), this requires fair
-/// amount of work to compute, so don't treat this method call as free.
-void DSNode::addFullGlobalsList(std::vector<GlobalValue*> &List) const {
-  if (globals_begin() == globals_end()) return;
-
-  EquivalenceClasses<GlobalValue*> &EC = getParentGraph()->getGlobalECs();
-
-  for (globals_iterator I = globals_begin(), E = globals_end(); I != E; ++I) {
-    EquivalenceClasses<GlobalValue*>::iterator ECI = EC.findValue(*I);
-    if (ECI == EC.end())
-      List.push_back(*I);
-    else
-      List.insert(List.end(), EC.member_begin(ECI), EC.member_end());
-  }
-}
-
-/// addFullFunctionList - Identical to addFullGlobalsList, but only return the
-/// functions in the full list.
-void DSNode::addFullFunctionList(std::vector<Function*> &List) const {
-  if (globals_begin() == globals_end()) return;
-
-  EquivalenceClasses<GlobalValue*> &EC = getParentGraph()->getGlobalECs();
-
-  for (globals_iterator I = globals_begin(), E = globals_end(); I != E; ++I) {
-    EquivalenceClasses<GlobalValue*>::iterator ECI = EC.findValue(*I);
-    if (ECI == EC.end()) {
-      if (Function *F = dyn_cast<Function>(*I))
-        List.push_back(F);
-    } else {
-      for (EquivalenceClasses<GlobalValue*>::member_iterator MI =
-             EC.member_begin(ECI), E = EC.member_end(); MI != E; ++MI)
-        if (Function *F = dyn_cast<Function>(*MI))
-          List.push_back(F);
-    }
-  }
-}
-
-namespace {
-  /// TypeElementWalker Class - Used for implementation of physical subtyping...
-  ///
-  class TypeElementWalker {
-    struct StackState {
-      const Type *Ty;
-      unsigned Offset;
-      unsigned Idx;
-      StackState(const Type *T, unsigned Off = 0)
-        : Ty(T), Offset(Off), Idx(0) {}
-    };
-
-    std::vector<StackState> Stack;
-    const TargetData &TD;
-  public:
-    TypeElementWalker(const Type *T, const TargetData &td) : TD(td) {
-      Stack.push_back(T);
-      StepToLeaf();
-    }
-
-    bool isDone() const { return Stack.empty(); }
-    const Type *getCurrentType()   const { return Stack.back().Ty;     }
-    unsigned    getCurrentOffset() const { return Stack.back().Offset; }
-
-    void StepToNextType() {
-      PopStackAndAdvance();
-      StepToLeaf();
-    }
-
-  private:
-    /// PopStackAndAdvance - Pop the current element off of the stack and
-    /// advance the underlying element to the next contained member.
-    void PopStackAndAdvance() {
-      assert(!Stack.empty() && "Cannot pop an empty stack!");
-      Stack.pop_back();
-      while (!Stack.empty()) {
-        StackState &SS = Stack.back();
-        if (const StructType *ST = dyn_cast<StructType>(SS.Ty)) {
-          ++SS.Idx;
-          if (SS.Idx != ST->getNumElements()) {
-            const StructLayout *SL = TD.getStructLayout(ST);
-            SS.Offset +=
-               unsigned(SL->MemberOffsets[SS.Idx]-SL->MemberOffsets[SS.Idx-1]);
-            return;
-          }
-          Stack.pop_back();  // At the end of the structure
-        } else {
-          const ArrayType *AT = cast<ArrayType>(SS.Ty);
-          ++SS.Idx;
-          if (SS.Idx != AT->getNumElements()) {
-            SS.Offset += unsigned(TD.getTypeSize(AT->getElementType()));
-            return;
-          }
-          Stack.pop_back();  // At the end of the array
-        }
-      }
-    }
-
-    /// StepToLeaf - Used by physical subtyping to move to the first leaf node
-    /// on the type stack.
-    void StepToLeaf() {
-      if (Stack.empty()) return;
-      while (!Stack.empty() && !Stack.back().Ty->isFirstClassType()) {
-        StackState &SS = Stack.back();
-        if (const StructType *ST = dyn_cast<StructType>(SS.Ty)) {
-          if (ST->getNumElements() == 0) {
-            assert(SS.Idx == 0);
-            PopStackAndAdvance();
-          } else {
-            // Step into the structure...
-            assert(SS.Idx < ST->getNumElements());
-            const StructLayout *SL = TD.getStructLayout(ST);
-            Stack.push_back(StackState(ST->getElementType(SS.Idx),
-                            SS.Offset+unsigned(SL->MemberOffsets[SS.Idx])));
-          }
-        } else {
-          const ArrayType *AT = cast<ArrayType>(SS.Ty);
-          if (AT->getNumElements() == 0) {
-            assert(SS.Idx == 0);
-            PopStackAndAdvance();
-          } else {
-            // Step into the array...
-            assert(SS.Idx < AT->getNumElements());
-            Stack.push_back(StackState(AT->getElementType(),
-                                       SS.Offset+SS.Idx*
-                             unsigned(TD.getTypeSize(AT->getElementType()))));
-          }
-        }
-      }
-    }
-  };
-} // end anonymous namespace
-
-/// ElementTypesAreCompatible - Check to see if the specified types are
-/// "physically" compatible.  If so, return true, else return false.  We only
-/// have to check the fields in T1: T2 may be larger than T1.  If AllowLargerT1
-/// is true, then we also allow a larger T1.
-///
-static bool ElementTypesAreCompatible(const Type *T1, const Type *T2,
-                                      bool AllowLargerT1, const TargetData &TD){
-  TypeElementWalker T1W(T1, TD), T2W(T2, TD);
-
-  while (!T1W.isDone() && !T2W.isDone()) {
-    if (T1W.getCurrentOffset() != T2W.getCurrentOffset())
-      return false;
-
-    const Type *T1 = T1W.getCurrentType();
-    const Type *T2 = T2W.getCurrentType();
-    if (T1 != T2 && !T1->canLosslesslyBitCastTo(T2))
-      return false;
-
-    T1W.StepToNextType();
-    T2W.StepToNextType();
-  }
-
-  return AllowLargerT1 || T1W.isDone();
-}
-
-
-/// mergeTypeInfo - This method merges the specified type into the current node
-/// at the specified offset.  This may update the current node's type record if
-/// this gives more information to the node, it may do nothing to the node if
-/// this information is already known, or it may merge the node completely (and
-/// return true) if the information is incompatible with what is already known.
-///
-/// This method returns true if the node is completely folded, otherwise false.
-///
-bool DSNode::mergeTypeInfo(const Type *NewTy, unsigned Offset,
-                           bool FoldIfIncompatible) {
-  DOUT << "merging " << *NewTy << " at " << Offset << " with " << *Ty << "\n";
-  const TargetData &TD = getTargetData();
-  // Check to make sure the Size member is up-to-date.  Size can be one of the
-  // following:
-  //  Size = 0, Ty = Void: Nothing is known about this node.
-  //  Size = 0, Ty = FnTy: FunctionPtr doesn't have a size, so we use zero
-  //  Size = 1, Ty = Void, Array = 1: The node is collapsed
-  //  Otherwise, sizeof(Ty) = Size
-  //
-  assert(((Size == 0 && Ty == Type::VoidTy && !isArray()) ||
-          (Size == 0 && !Ty->isSized() && !isArray()) ||
-          (Size == 1 && Ty == Type::VoidTy && isArray()) ||
-          (Size == 0 && !Ty->isSized() && !isArray()) ||
-          (TD.getTypeSize(Ty) == Size)) &&
-         "Size member of DSNode doesn't match the type structure!");
-  assert(NewTy != Type::VoidTy && "Cannot merge void type into DSNode!");
-
-  if (Offset == 0 && NewTy == Ty)
-    return false;  // This should be a common case, handle it efficiently
-
-  // Return true immediately if the node is completely folded.
-  if (isNodeCompletelyFolded()) return true;
-
-  // If this is an array type, eliminate the outside arrays because they won't
-  // be used anyway.  This greatly reduces the size of large static arrays used
-  // as global variables, for example.
-  //
-  bool WillBeArray = false;
-  while (const ArrayType *AT = dyn_cast<ArrayType>(NewTy)) {
-    // FIXME: we might want to keep small arrays, but must be careful about
-    // things like: [2 x [10000 x int*]]
-    NewTy = AT->getElementType();
-    WillBeArray = true;
-  }
-
-  // Figure out how big the new type we're merging in is...
-  unsigned NewTySize = NewTy->isSized() ? (unsigned)TD.getTypeSize(NewTy) : 0;
-
-  // Otherwise check to see if we can fold this type into the current node.  If
-  // we can't, we fold the node completely, if we can, we potentially update our
-  // internal state.
-  //
-  if (Ty == Type::VoidTy) {
-    // If this is the first type that this node has seen, just accept it without
-    // question....
-    assert(Offset == 0 && !isArray() &&
-           "Cannot have an offset into a void node!");
-
-    // If this node would have to have an unreasonable number of fields, just
-    // collapse it.  This can occur for fortran common blocks, which have stupid
-    // things like { [100000000 x double], [1000000 x double] }.
-    unsigned NumFields = (NewTySize+DS::PointerSize-1) >> DS::PointerShift;
-    if (NumFields > DSAFieldLimit) {
-      foldNodeCompletely();
-      return true;
-    }
-
-    Ty = NewTy;
-    NodeType &= ~Array;
-    if (WillBeArray) NodeType |= Array;
-    Size = NewTySize;
-
-    // Calculate the number of outgoing links from this node.
-    Links.resize(NumFields);
-    return false;
-  }
-
-  // Handle node expansion case here...
-  if (Offset+NewTySize > Size) {
-    // It is illegal to grow this node if we have treated it as an array of
-    // objects...
-    if (isArray()) {
-      if (FoldIfIncompatible) foldNodeCompletely();
-      return true;
-    }
-
-    // If this node would have to have an unreasonable number of fields, just
-    // collapse it.  This can occur for fortran common blocks, which have stupid
-    // things like { [100000000 x double], [1000000 x double] }.
-    unsigned NumFields = (NewTySize+Offset+DS::PointerSize-1) >> DS::PointerShift;
-    if (NumFields > DSAFieldLimit) {
-      foldNodeCompletely();
-      return true;
-    }
-
-    if (Offset) {
-      //handle some common cases:
-      // Ty:    struct { t1, t2, t3, t4, ..., tn}
-      // NewTy: struct { offset, stuff...}
-      // try merge with NewTy: struct {t1, t2, stuff...} if offset lands exactly
-      // on a field in Ty
-      if (isa<StructType>(NewTy) && isa<StructType>(Ty)) {
-        DOUT << "Ty: " << *Ty << "\nNewTy: " << *NewTy << "@" << Offset << "\n";
-        const StructType *STy = cast<StructType>(Ty);
-        const StructLayout &SL = *TD.getStructLayout(STy);
-        unsigned i = SL.getElementContainingOffset(Offset);
-        //Either we hit it exactly or give up
-        if (SL.MemberOffsets[i] != Offset) {
-          if (FoldIfIncompatible) foldNodeCompletely();
-          return true;
-        }
-        std::vector<const Type*> nt;
-        for (unsigned x = 0; x < i; ++x)
-          nt.push_back(STy->getElementType(x));
-        STy = cast<StructType>(NewTy);
-        nt.insert(nt.end(), STy->element_begin(), STy->element_end());
-        //and merge
-        STy = StructType::get(nt);
-        DOUT << "Trying with: " << *STy << "\n";
-        return mergeTypeInfo(STy, 0);
-      }
-
-      //Ty: struct { t1, t2, t3 ... tn}
-      //NewTy T offset x
-      //try merge with NewTy: struct : {t1, t2, T} if offset lands on a field
-      //in Ty
-      if (isa<StructType>(Ty)) {
-        DOUT << "Ty: " << *Ty << "\nNewTy: " << *NewTy << "@" << Offset << "\n";
-        const StructType *STy = cast<StructType>(Ty);
-        const StructLayout &SL = *TD.getStructLayout(STy);
-        unsigned i = SL.getElementContainingOffset(Offset);
-        //Either we hit it exactly or give up
-        if (SL.MemberOffsets[i] != Offset) {
-          if (FoldIfIncompatible) foldNodeCompletely();
-          return true;
-        }
-        std::vector<const Type*> nt;
-        for (unsigned x = 0; x < i; ++x)
-          nt.push_back(STy->getElementType(x));
-        nt.push_back(NewTy);
-        //and merge
-        STy = StructType::get(nt);
-        DOUT << "Trying with: " << *STy << "\n";
-        return mergeTypeInfo(STy, 0);
-      }
-
-      assert(0 &&
-             "UNIMP: Trying to merge a growth type into "
-             "offset != 0: Collapsing!");
-      abort();
-      if (FoldIfIncompatible) foldNodeCompletely();
-      return true;
-
-    }
-
-
-    // Okay, the situation is nice and simple, we are trying to merge a type in
-    // at offset 0 that is bigger than our current type.  Implement this by
-    // switching to the new type and then merge in the smaller one, which should
-    // hit the other code path here.  If the other code path decides it's not
-    // ok, it will collapse the node as appropriate.
-    //
-
-    const Type *OldTy = Ty;
-    Ty = NewTy;
-    NodeType &= ~Array;
-    if (WillBeArray) NodeType |= Array;
-    Size = NewTySize;
-
-    // Must grow links to be the appropriate size...
-    Links.resize(NumFields);
-
-    // Merge in the old type now... which is guaranteed to be smaller than the
-    // "current" type.
-    return mergeTypeInfo(OldTy, 0);
-  }
-
-  assert(Offset <= Size &&
-         "Cannot merge something into a part of our type that doesn't exist!");
-
-  // Find the section of Ty that NewTy overlaps with... first we find the
-  // type that starts at offset Offset.
-  //
-  unsigned O = 0;
-  const Type *SubType = Ty;
-  while (O < Offset) {
-    assert(Offset-O < TD.getTypeSize(SubType) && "Offset out of range!");
-
-    switch (SubType->getTypeID()) {
-    case Type::StructTyID: {
-      const StructType *STy = cast<StructType>(SubType);
-      const StructLayout &SL = *TD.getStructLayout(STy);
-      unsigned i = SL.getElementContainingOffset(Offset-O);
-
-      // The offset we are looking for must be in the i'th element...
-      SubType = STy->getElementType(i);
-      O += (unsigned)SL.MemberOffsets[i];
-      break;
-    }
-    case Type::ArrayTyID: {
-      SubType = cast<ArrayType>(SubType)->getElementType();
-      unsigned ElSize = (unsigned)TD.getTypeSize(SubType);
-      unsigned Remainder = (Offset-O) % ElSize;
-      O = Offset-Remainder;
-      break;
-    }
-    default:
-      if (FoldIfIncompatible) foldNodeCompletely();
-      return true;
-    }
-  }
-
-  assert(O == Offset && "Could not achieve the correct offset!");
-
-  // If we found our type exactly, early exit
-  if (SubType == NewTy) return false;
-
-  // Differing function types don't require us to merge.  They are not values
-  // anyway.
-  if (isa<FunctionType>(SubType) &&
-      isa<FunctionType>(NewTy)) return false;
-
-  unsigned SubTypeSize = SubType->isSized() ?
-       (unsigned)TD.getTypeSize(SubType) : 0;
-
-  // Ok, we are getting desperate now.  Check for physical subtyping, where we
-  // just require each element in the node to be compatible.
-  if (NewTySize <= SubTypeSize && NewTySize && NewTySize < 256 &&
-      SubTypeSize && SubTypeSize < 256 &&
-      ElementTypesAreCompatible(NewTy, SubType, !isArray(), TD))
-    return false;
-
-  // Okay, so we found the leader type at the offset requested.  Search the list
-  // of types that starts at this offset.  If SubType is currently an array or
-  // structure, the type desired may actually be the first element of the
-  // composite type...
-  //
-  unsigned PadSize = SubTypeSize; // Size, including pad memory which is ignored
-  while (SubType != NewTy) {
-    const Type *NextSubType = 0;
-    unsigned NextSubTypeSize = 0;
-    unsigned NextPadSize = 0;
-    switch (SubType->getTypeID()) {
-    case Type::StructTyID: {
-      const StructType *STy = cast<StructType>(SubType);
-      const StructLayout &SL = *TD.getStructLayout(STy);
-      if (SL.MemberOffsets.size() > 1)
-        NextPadSize = (unsigned)SL.MemberOffsets[1];
-      else
-        NextPadSize = SubTypeSize;
-      NextSubType = STy->getElementType(0);
-      NextSubTypeSize = (unsigned)TD.getTypeSize(NextSubType);
-      break;
-    }
-    case Type::ArrayTyID:
-      NextSubType = cast<ArrayType>(SubType)->getElementType();
-      NextSubTypeSize = (unsigned)TD.getTypeSize(NextSubType);
-      NextPadSize = NextSubTypeSize;
-      break;
-    default: ;
-      // fall out
-    }
-
-    if (NextSubType == 0)
-      break;   // In the default case, break out of the loop
-
-    if (NextPadSize < NewTySize)
-      break;   // Don't allow shrinking to a smaller type than NewTySize
-    SubType = NextSubType;
-    SubTypeSize = NextSubTypeSize;
-    PadSize = NextPadSize;
-  }
-
-  // If we found the type exactly, return it...
-  if (SubType == NewTy)
-    return false;
-
-  // Check to see if we have a compatible, but different type...
-  if (NewTySize == SubTypeSize) {
-    // Check to see if this type is obviously convertible... int -> uint f.e.
-    if (NewTy->canLosslesslyBitCastTo(SubType))
-      return false;
-
-    // Check to see if we have a pointer & integer mismatch going on here,
-    // loading a pointer as a long, for example.
-    //
-    if (SubType->isInteger() && isa<PointerType>(NewTy) ||
-        NewTy->isInteger() && isa<PointerType>(SubType))
-      return false;
-  } else if (NewTySize > SubTypeSize && NewTySize <= PadSize) {
-    // We are accessing the field, plus some structure padding.  Ignore the
-    // structure padding.
-    return false;
-  }
-
-  Module *M = 0;
-  if (getParentGraph()->retnodes_begin() != getParentGraph()->retnodes_end())
-    M = getParentGraph()->retnodes_begin()->first->getParent();
-
-  DOUT << "MergeTypeInfo Folding OrigTy: ";
-  DEBUG(WriteTypeSymbolic(*cerr.stream(), Ty, M) << "\n due to:";
-        WriteTypeSymbolic(*cerr.stream(), NewTy, M) << " @ " << Offset << "!\n"
-                                                    << "SubType: ";
-        WriteTypeSymbolic(*cerr.stream(), SubType, M) << "\n\n");
-
-  if (FoldIfIncompatible) foldNodeCompletely();
-  return true;
-}
-
-
-
-/// addEdgeTo - Add an edge from the current node to the specified node.  This
-/// can cause merging of nodes in the graph.
-///
-void DSNode::addEdgeTo(unsigned Offset, const DSNodeHandle &NH) {
-  if (NH.isNull()) return;       // Nothing to do
-
-  if (isNodeCompletelyFolded())
-    Offset = 0;
-
-  DSNodeHandle &ExistingEdge = getLink(Offset);
-  if (!ExistingEdge.isNull()) {
-    // Merge the two nodes...
-    ExistingEdge.mergeWith(NH);
-  } else {                             // No merging to perform...
-    setLink(Offset, NH);               // Just force a link in there...
-  }
-}
-
-
-/// MergeSortedVectors - Efficiently merge a vector into another vector where
-/// duplicates are not allowed and both are sorted.  This assumes that 'T's are
-/// efficiently copyable and have sane comparison semantics.
-///
-static void MergeSortedVectors(std::vector<GlobalValue*> &Dest,
-                               const std::vector<GlobalValue*> &Src) {
-  // By far, the most common cases will be the simple ones.  In these cases,
-  // avoid having to allocate a temporary vector...
-  //
-  if (Src.empty()) {             // Nothing to merge in...
-    return;
-  } else if (Dest.empty()) {     // Just copy the result in...
-    Dest = Src;
-  } else if (Src.size() == 1) {  // Insert a single element...
-    const GlobalValue *V = Src[0];
-    std::vector<GlobalValue*>::iterator I =
-      std::lower_bound(Dest.begin(), Dest.end(), V);
-    if (I == Dest.end() || *I != Src[0])  // If not already contained...
-      Dest.insert(I, Src[0]);
-  } else if (Dest.size() == 1) {
-    GlobalValue *Tmp = Dest[0];           // Save value in temporary...
-    Dest = Src;                           // Copy over list...
-    std::vector<GlobalValue*>::iterator I =
-      std::lower_bound(Dest.begin(), Dest.end(), Tmp);
-    if (I == Dest.end() || *I != Tmp)     // If not already contained...
-      Dest.insert(I, Tmp);
-
-  } else {
-    // Make a copy to the side of Dest...
-    std::vector<GlobalValue*> Old(Dest);
-
-    // Make space for all of the type entries now...
-    Dest.resize(Dest.size()+Src.size());
-
-    // Merge the two sorted ranges together... into Dest.
-    std::merge(Old.begin(), Old.end(), Src.begin(), Src.end(), Dest.begin());
-
-    // Now erase any duplicate entries that may have accumulated into the
-    // vectors (because they were in both of the input sets)
-    Dest.erase(std::unique(Dest.begin(), Dest.end()), Dest.end());
-  }
-}
-
-void DSNode::mergeGlobals(const std::vector<GlobalValue*> &RHS) {
-  MergeSortedVectors(Globals, RHS);
-}
-
-// MergeNodes - Helper function for DSNode::mergeWith().
-// This function does the hard work of merging two nodes, CurNodeH
-// and NH after filtering out trivial cases and making sure that
-// CurNodeH.offset >= NH.offset.
-//
-// ***WARNING***
-// Since merging may cause either node to go away, we must always
-// use the node-handles to refer to the nodes.  These node handles are
-// automatically updated during merging, so will always provide access
-// to the correct node after a merge.
-//
-void DSNode::MergeNodes(DSNodeHandle& CurNodeH, DSNodeHandle& NH) {
-  assert(CurNodeH.getOffset() >= NH.getOffset() &&
-         "This should have been enforced in the caller.");
-  assert(CurNodeH.getNode()->getParentGraph()==NH.getNode()->getParentGraph() &&
-         "Cannot merge two nodes that are not in the same graph!");
-
-  // Now we know that Offset >= NH.Offset, so convert it so our "Offset" (with
-  // respect to NH.Offset) is now zero.  NOffset is the distance from the base
-  // of our object that N starts from.
-  //
-  unsigned NOffset = CurNodeH.getOffset()-NH.getOffset();
-  unsigned NSize = NH.getNode()->getSize();
-
-  // If the two nodes are of different size, and the smaller node has the array
-  // bit set, collapse!
-  if (NSize != CurNodeH.getNode()->getSize()) {
-#if COLLAPSE_ARRAYS_AGGRESSIVELY
-    if (NSize < CurNodeH.getNode()->getSize()) {
-      if (NH.getNode()->isArray())
-        NH.getNode()->foldNodeCompletely();
-    } else if (CurNodeH.getNode()->isArray()) {
-      NH.getNode()->foldNodeCompletely();
-    }
-#endif
-  }
-
-  // Merge the type entries of the two nodes together...
-  if (NH.getNode()->Ty != Type::VoidTy)
-    CurNodeH.getNode()->mergeTypeInfo(NH.getNode()->Ty, NOffset);
-  assert(!CurNodeH.getNode()->isDeadNode());
-
-  // If we are merging a node with a completely folded node, then both nodes are
-  // now completely folded.
-  //
-  if (CurNodeH.getNode()->isNodeCompletelyFolded()) {
-    if (!NH.getNode()->isNodeCompletelyFolded()) {
-      NH.getNode()->foldNodeCompletely();
-      assert(NH.getNode() && NH.getOffset() == 0 &&
-             "folding did not make offset 0?");
-      NOffset = NH.getOffset();
-      NSize = NH.getNode()->getSize();
-      assert(NOffset == 0 && NSize == 1);
-    }
-  } else if (NH.getNode()->isNodeCompletelyFolded()) {
-    CurNodeH.getNode()->foldNodeCompletely();
-    assert(CurNodeH.getNode() && CurNodeH.getOffset() == 0 &&
-           "folding did not make offset 0?");
-    NSize = NH.getNode()->getSize();
-    NOffset = NH.getOffset();
-    assert(NOffset == 0 && NSize == 1);
-  }
-
-  DSNode *N = NH.getNode();
-  if (CurNodeH.getNode() == N || N == 0) return;
-  assert(!CurNodeH.getNode()->isDeadNode());
-
-  // Merge the NodeType information.
-  CurNodeH.getNode()->NodeType |= N->NodeType;
-
-  // Start forwarding to the new node!
-  N->forwardNode(CurNodeH.getNode(), NOffset);
-  assert(!CurNodeH.getNode()->isDeadNode());
-
-  // Make all of the outgoing links of N now be outgoing links of CurNodeH.
-  //
-  for (unsigned i = 0; i < N->getNumLinks(); ++i) {
-    DSNodeHandle &Link = N->getLink(i << DS::PointerShift);
-    if (Link.getNode()) {
-      // Compute the offset into the current node at which to
-      // merge this link.  In the common case, this is a linear
-      // relation to the offset in the original node (with
-      // wrapping), but if the current node gets collapsed due to
-      // recursive merging, we must make sure to merge in all remaining
-      // links at offset zero.
-      unsigned MergeOffset = 0;
-      DSNode *CN = CurNodeH.getNode();
-      if (CN->Size != 1)
-        MergeOffset = ((i << DS::PointerShift)+NOffset) % CN->getSize();
-      CN->addEdgeTo(MergeOffset, Link);
-    }
-  }
-
-  // Now that there are no outgoing edges, all of the Links are dead.
-  N->Links.clear();
-
-  // Merge the globals list...
-  if (!N->Globals.empty()) {
-    CurNodeH.getNode()->mergeGlobals(N->Globals);
-
-    // Delete the globals from the old node...
-    std::vector<GlobalValue*>().swap(N->Globals);
-  }
-}
-
-
-/// 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, we update it to
-/// point to this node).
-///
-void DSNode::mergeWith(const DSNodeHandle &NH, unsigned Offset) {
-  DSNode *N = NH.getNode();
-  if (N == this && NH.getOffset() == Offset)
-    return;  // Noop
-
-  // If the RHS is a null node, make it point to this node!
-  if (N == 0) {
-    NH.mergeWith(DSNodeHandle(this, Offset));
-    return;
-  }
-
-  assert(!N->isDeadNode() && !isDeadNode());
-  assert(!hasNoReferrers() && "Should not try to fold a useless node!");
-
-  if (N == this) {
-    // We cannot merge two pieces of the same node together, collapse the node
-    // completely.
-    DOUT << "Attempting to merge two chunks of the same node together!\n";
-    foldNodeCompletely();
-    return;
-  }
-
-  // If both nodes are not at offset 0, make sure that we are merging the node
-  // at an later offset into the node with the zero offset.
-  //
-  if (Offset < NH.getOffset()) {
-    N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
-    return;
-  } else if (Offset == NH.getOffset() && getSize() < N->getSize()) {
-    // If the offsets are the same, merge the smaller node into the bigger node
-    N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
-    return;
-  }
-
-  // Ok, now we can merge the two nodes.  Use a static helper that works with
-  // two node handles, since "this" may get merged away at intermedi