It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
new file mode 100644
index 0000000..9803ab8
--- /dev/null
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -0,0 +1,3694 @@
+//===-- SelectionDAG.cpp - Implement the SelectionDAG data structures -----===//
+//
+//                     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 implements the SelectionDAG class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/Constants.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Assembly/Writer.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Target/MRegisterInfo.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetLowering.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringExtras.h"
+#include <algorithm>
+#include <cmath>
+using namespace llvm;
+
+/// makeVTList - Return an instance of the SDVTList struct initialized with the
+/// specified members.
+static SDVTList makeVTList(const MVT::ValueType *VTs, unsigned NumVTs) {
+  SDVTList Res = {VTs, NumVTs};
+  return Res;
+}
+
+//===----------------------------------------------------------------------===//
+//                              ConstantFPSDNode Class
+//===----------------------------------------------------------------------===//
+
+/// isExactlyValue - We don't rely on operator== working on double values, as
+/// it returns true for things that are clearly not equal, like -0.0 and 0.0.
+/// As such, this method can be used to do an exact bit-for-bit comparison of
+/// two floating point values.
+bool ConstantFPSDNode::isExactlyValue(double V) const {
+  return DoubleToBits(V) == DoubleToBits(Value);
+}
+
+//===----------------------------------------------------------------------===//
+//                              ISD Namespace
+//===----------------------------------------------------------------------===//
+
+/// isBuildVectorAllOnes - Return true if the specified node is a
+/// BUILD_VECTOR where all of the elements are ~0 or undef.
+bool ISD::isBuildVectorAllOnes(const SDNode *N) {
+  // Look through a bit convert.
+  if (N->getOpcode() == ISD::BIT_CONVERT)
+    N = N->getOperand(0).Val;
+  
+  if (N->getOpcode() != ISD::BUILD_VECTOR) return false;
+  
+  unsigned i = 0, e = N->getNumOperands();
+  
+  // Skip over all of the undef values.
+  while (i != e && N->getOperand(i).getOpcode() == ISD::UNDEF)
+    ++i;
+  
+  // Do not accept an all-undef vector.
+  if (i == e) return false;
+  
+  // Do not accept build_vectors that aren't all constants or which have non-~0
+  // elements.
+  SDOperand NotZero = N->getOperand(i);
+  if (isa<ConstantSDNode>(NotZero)) {
+    if (!cast<ConstantSDNode>(NotZero)->isAllOnesValue())
+      return false;
+  } else if (isa<ConstantFPSDNode>(NotZero)) {
+    MVT::ValueType VT = NotZero.getValueType();
+    if (VT== MVT::f64) {
+      if (DoubleToBits(cast<ConstantFPSDNode>(NotZero)->getValue()) !=
+          (uint64_t)-1)
+        return false;
+    } else {
+      if (FloatToBits(cast<ConstantFPSDNode>(NotZero)->getValue()) !=
+          (uint32_t)-1)
+        return false;
+    }
+  } else
+    return false;
+  
+  // Okay, we have at least one ~0 value, check to see if the rest match or are
+  // undefs.
+  for (++i; i != e; ++i)
+    if (N->getOperand(i) != NotZero &&
+        N->getOperand(i).getOpcode() != ISD::UNDEF)
+      return false;
+  return true;
+}
+
+
+/// isBuildVectorAllZeros - Return true if the specified node is a
+/// BUILD_VECTOR where all of the elements are 0 or undef.
+bool ISD::isBuildVectorAllZeros(const SDNode *N) {
+  // Look through a bit convert.
+  if (N->getOpcode() == ISD::BIT_CONVERT)
+    N = N->getOperand(0).Val;
+  
+  if (N->getOpcode() != ISD::BUILD_VECTOR) return false;
+  
+  unsigned i = 0, e = N->getNumOperands();
+  
+  // Skip over all of the undef values.
+  while (i != e && N->getOperand(i).getOpcode() == ISD::UNDEF)
+    ++i;
+  
+  // Do not accept an all-undef vector.
+  if (i == e) return false;
+  
+  // Do not accept build_vectors that aren't all constants or which have non-~0
+  // elements.
+  SDOperand Zero = N->getOperand(i);
+  if (isa<ConstantSDNode>(Zero)) {
+    if (!cast<ConstantSDNode>(Zero)->isNullValue())
+      return false;
+  } else if (isa<ConstantFPSDNode>(Zero)) {
+    if (!cast<ConstantFPSDNode>(Zero)->isExactlyValue(0.0))
+      return false;
+  } else
+    return false;
+  
+  // Okay, we have at least one ~0 value, check to see if the rest match or are
+  // undefs.
+  for (++i; i != e; ++i)
+    if (N->getOperand(i) != Zero &&
+        N->getOperand(i).getOpcode() != ISD::UNDEF)
+      return false;
+  return true;
+}
+
+/// getSetCCSwappedOperands - Return the operation corresponding to (Y op X)
+/// when given the operation for (X op Y).
+ISD::CondCode ISD::getSetCCSwappedOperands(ISD::CondCode Operation) {
+  // To perform this operation, we just need to swap the L and G bits of the
+  // operation.
+  unsigned OldL = (Operation >> 2) & 1;
+  unsigned OldG = (Operation >> 1) & 1;
+  return ISD::CondCode((Operation & ~6) |  // Keep the N, U, E bits
+                       (OldL << 1) |       // New G bit
+                       (OldG << 2));        // New L bit.
+}
+
+/// getSetCCInverse - Return the operation corresponding to !(X op Y), where
+/// 'op' is a valid SetCC operation.
+ISD::CondCode ISD::getSetCCInverse(ISD::CondCode Op, bool isInteger) {
+  unsigned Operation = Op;
+  if (isInteger)
+    Operation ^= 7;   // Flip L, G, E bits, but not U.
+  else
+    Operation ^= 15;  // Flip all of the condition bits.
+  if (Operation > ISD::SETTRUE2)
+    Operation &= ~8;     // Don't let N and U bits get set.
+  return ISD::CondCode(Operation);
+}
+
+
+/// isSignedOp - For an integer comparison, return 1 if the comparison is a
+/// signed operation and 2 if the result is an unsigned comparison.  Return zero
+/// if the operation does not depend on the sign of the input (setne and seteq).
+static int isSignedOp(ISD::CondCode Opcode) {
+  switch (Opcode) {
+  default: assert(0 && "Illegal integer setcc operation!");
+  case ISD::SETEQ:
+  case ISD::SETNE: return 0;
+  case ISD::SETLT:
+  case ISD::SETLE:
+  case ISD::SETGT:
+  case ISD::SETGE: return 1;
+  case ISD::SETULT:
+  case ISD::SETULE:
+  case ISD::SETUGT:
+  case ISD::SETUGE: return 2;
+  }
+}
+
+/// getSetCCOrOperation - Return the result of a logical OR between different
+/// comparisons of identical values: ((X op1 Y) | (X op2 Y)).  This function
+/// returns SETCC_INVALID if it is not possible to represent the resultant
+/// comparison.
+ISD::CondCode ISD::getSetCCOrOperation(ISD::CondCode Op1, ISD::CondCode Op2,
+                                       bool isInteger) {
+  if (isInteger && (isSignedOp(Op1) | isSignedOp(Op2)) == 3)
+    // Cannot fold a signed integer setcc with an unsigned integer setcc.
+    return ISD::SETCC_INVALID;
+
+  unsigned Op = Op1 | Op2;  // Combine all of the condition bits.
+
+  // If the N and U bits get set then the resultant comparison DOES suddenly
+  // care about orderedness, and is true when ordered.
+  if (Op > ISD::SETTRUE2)
+    Op &= ~16;     // Clear the U bit if the N bit is set.
+  
+  // Canonicalize illegal integer setcc's.
+  if (isInteger && Op == ISD::SETUNE)  // e.g. SETUGT | SETULT
+    Op = ISD::SETNE;
+  
+  return ISD::CondCode(Op);
+}
+
+/// getSetCCAndOperation - Return the result of a logical AND between different
+/// comparisons of identical values: ((X op1 Y) & (X op2 Y)).  This
+/// function returns zero if it is not possible to represent the resultant
+/// comparison.
+ISD::CondCode ISD::getSetCCAndOperation(ISD::CondCode Op1, ISD::CondCode Op2,
+                                        bool isInteger) {
+  if (isInteger && (isSignedOp(Op1) | isSignedOp(Op2)) == 3)
+    // Cannot fold a signed setcc with an unsigned setcc.
+    return ISD::SETCC_INVALID;
+
+  // Combine all of the condition bits.
+  ISD::CondCode Result = ISD::CondCode(Op1 & Op2);
+  
+  // Canonicalize illegal integer setcc's.
+  if (isInteger) {
+    switch (Result) {
+    default: break;
+    case ISD::SETUO : Result = ISD::SETFALSE; break;  // SETUGT & SETULT
+    case ISD::SETUEQ: Result = ISD::SETEQ   ; break;  // SETUGE & SETULE
+    case ISD::SETOLT: Result = ISD::SETULT  ; break;  // SETULT & SETNE
+    case ISD::SETOGT: Result = ISD::SETUGT  ; break;  // SETUGT & SETNE
+    }
+  }
+  
+  return Result;
+}
+
+const TargetMachine &SelectionDAG::getTarget() const {
+  return TLI.getTargetMachine();
+}
+
+//===----------------------------------------------------------------------===//
+//                           SDNode Profile Support
+//===----------------------------------------------------------------------===//
+
+/// AddNodeIDOpcode - Add the node opcode to the NodeID data.
+///
+static void AddNodeIDOpcode(FoldingSetNodeID &ID, unsigned OpC)  {
+  ID.AddInteger(OpC);
+}
+
+/// AddNodeIDValueTypes - Value type lists are intern'd so we can represent them
+/// solely with their pointer.
+void AddNodeIDValueTypes(FoldingSetNodeID &ID, SDVTList VTList) {
+  ID.AddPointer(VTList.VTs);  
+}
+
+/// AddNodeIDOperands - Various routines for adding operands to the NodeID data.
+///
+static void AddNodeIDOperands(FoldingSetNodeID &ID,
+                              const SDOperand *Ops, unsigned NumOps) {
+  for (; NumOps; --NumOps, ++Ops) {
+    ID.AddPointer(Ops->Val);
+    ID.AddInteger(Ops->ResNo);
+  }
+}
+
+static void AddNodeIDNode(FoldingSetNodeID &ID,
+                          unsigned short OpC, SDVTList VTList, 
+                          const SDOperand *OpList, unsigned N) {
+  AddNodeIDOpcode(ID, OpC);
+  AddNodeIDValueTypes(ID, VTList);
+  AddNodeIDOperands(ID, OpList, N);
+}
+
+/// AddNodeIDNode - Generic routine for adding a nodes info to the NodeID
+/// data.
+static void AddNodeIDNode(FoldingSetNodeID &ID, SDNode *N) {
+  AddNodeIDOpcode(ID, N->getOpcode());
+  // Add the return value info.
+  AddNodeIDValueTypes(ID, N->getVTList());
+  // Add the operand info.
+  AddNodeIDOperands(ID, N->op_begin(), N->getNumOperands());
+
+  // Handle SDNode leafs with special info.
+  switch (N->getOpcode()) {
+  default: break;  // Normal nodes don't need extra info.
+  case ISD::TargetConstant:
+  case ISD::Constant:
+    ID.AddInteger(cast<ConstantSDNode>(N)->getValue());
+    break;
+  case ISD::TargetConstantFP:
+  case ISD::ConstantFP:
+    ID.AddDouble(cast<ConstantFPSDNode>(N)->getValue());
+    break;
+  case ISD::TargetGlobalAddress:
+  case ISD::GlobalAddress:
+  case ISD::TargetGlobalTLSAddress:
+  case ISD::GlobalTLSAddress: {
+    GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(N);
+    ID.AddPointer(GA->getGlobal());
+    ID.AddInteger(GA->getOffset());
+    break;
+  }
+  case ISD::BasicBlock:
+    ID.AddPointer(cast<BasicBlockSDNode>(N)->getBasicBlock());
+    break;
+  case ISD::Register:
+    ID.AddInteger(cast<RegisterSDNode>(N)->getReg());
+    break;
+  case ISD::SRCVALUE: {
+    SrcValueSDNode *SV = cast<SrcValueSDNode>(N);
+    ID.AddPointer(SV->getValue());
+    ID.AddInteger(SV->getOffset());
+    break;
+  }
+  case ISD::FrameIndex:
+  case ISD::TargetFrameIndex:
+    ID.AddInteger(cast<FrameIndexSDNode>(N)->getIndex());
+    break;
+  case ISD::JumpTable:
+  case ISD::TargetJumpTable:
+    ID.AddInteger(cast<JumpTableSDNode>(N)->getIndex());
+    break;
+  case ISD::ConstantPool:
+  case ISD::TargetConstantPool: {
+    ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(N);
+    ID.AddInteger(CP->getAlignment());
+    ID.AddInteger(CP->getOffset());
+    if (CP->isMachineConstantPoolEntry())
+      CP->getMachineCPVal()->AddSelectionDAGCSEId(ID);
+    else
+      ID.AddPointer(CP->getConstVal());
+    break;
+  }
+  case ISD::LOAD: {
+    LoadSDNode *LD = cast<LoadSDNode>(N);
+    ID.AddInteger(LD->getAddressingMode());
+    ID.AddInteger(LD->getExtensionType());
+    ID.AddInteger(LD->getLoadedVT());
+    ID.AddPointer(LD->getSrcValue());
+    ID.AddInteger(LD->getSrcValueOffset());
+    ID.AddInteger(LD->getAlignment());
+    ID.AddInteger(LD->isVolatile());
+    break;
+  }
+  case ISD::STORE: {
+    StoreSDNode *ST = cast<StoreSDNode>(N);
+    ID.AddInteger(ST->getAddressingMode());
+    ID.AddInteger(ST->isTruncatingStore());
+    ID.AddInteger(ST->getStoredVT());
+    ID.AddPointer(ST->getSrcValue());
+    ID.AddInteger(ST->getSrcValueOffset());
+    ID.AddInteger(ST->getAlignment());
+    ID.AddInteger(ST->isVolatile());
+    break;
+  }
+  }
+}
+
+//===----------------------------------------------------------------------===//
+//                              SelectionDAG Class
+//===----------------------------------------------------------------------===//
+
+/// RemoveDeadNodes - This method deletes all unreachable nodes in the
+/// SelectionDAG.
+void SelectionDAG::RemoveDeadNodes() {
+  // Create a dummy node (which is not added to allnodes), that adds a reference
+  // to the root node, preventing it from being deleted.
+  HandleSDNode Dummy(getRoot());
+
+  SmallVector<SDNode*, 128> DeadNodes;
+  
+  // Add all obviously-dead nodes to the DeadNodes worklist.
+  for (allnodes_iterator I = allnodes_begin(), E = allnodes_end(); I != E; ++I)
+    if (I->use_empty())
+      DeadNodes.push_back(I);
+
+  // Process the worklist, deleting the nodes and adding their uses to the
+  // worklist.
+  while (!DeadNodes.empty()) {
+    SDNode *N = DeadNodes.back();
+    DeadNodes.pop_back();
+    
+    // Take the node out of the appropriate CSE map.
+    RemoveNodeFromCSEMaps(N);
+
+    // Next, brutally remove the operand list.  This is safe to do, as there are
+    // no cycles in the graph.
+    for (SDNode::op_iterator I = N->op_begin(), E = N->op_end(); I != E; ++I) {
+      SDNode *Operand = I->Val;
+      Operand->removeUser(N);
+      
+      // Now that we removed this operand, see if there are no uses of it left.
+      if (Operand->use_empty())
+        DeadNodes.push_back(Operand);
+    }
+    if (N->OperandsNeedDelete)
+      delete[] N->OperandList;
+    N->OperandList = 0;
+    N->NumOperands = 0;
+    
+    // Finally, remove N itself.
+    AllNodes.erase(N);
+  }
+  
+  // If the root changed (e.g. it was a dead load, update the root).
+  setRoot(Dummy.getValue());
+}
+
+void SelectionDAG::RemoveDeadNode(SDNode *N, std::vector<SDNode*> &Deleted) {
+  SmallVector<SDNode*, 16> DeadNodes;
+  DeadNodes.push_back(N);
+
+  // Process the worklist, deleting the nodes and adding their uses to the
+  // worklist.
+  while (!DeadNodes.empty()) {
+    SDNode *N = DeadNodes.back();
+    DeadNodes.pop_back();
+    
+    // Take the node out of the appropriate CSE map.
+    RemoveNodeFromCSEMaps(N);
+
+    // Next, brutally remove the operand list.  This is safe to do, as there are
+    // no cycles in the graph.
+    for (SDNode::op_iterator I = N->op_begin(), E = N->op_end(); I != E; ++I) {
+      SDNode *Operand = I->Val;
+      Operand->removeUser(N);
+      
+      // Now that we removed this operand, see if there are no uses of it left.
+      if (Operand->use_empty())
+        DeadNodes.push_back(Operand);
+    }
+    if (N->OperandsNeedDelete)
+      delete[] N->OperandList;
+    N->OperandList = 0;
+    N->NumOperands = 0;
+    
+    // Finally, remove N itself.
+    Deleted.push_back(N);
+    AllNodes.erase(N);
+  }
+}
+
+void SelectionDAG::DeleteNode(SDNode *N) {
+  assert(N->use_empty() && "Cannot delete a node that is not dead!");
+
+  // First take this out of the appropriate CSE map.
+  RemoveNodeFromCSEMaps(N);
+
+  // Finally, remove uses due to operands of this node, remove from the 
+  // AllNodes list, and delete the node.
+  DeleteNodeNotInCSEMaps(N);
+}
+
+void SelectionDAG::DeleteNodeNotInCSEMaps(SDNode *N) {
+
+  // Remove it from the AllNodes list.
+  AllNodes.remove(N);
+    
+  // Drop all of the operands and decrement used nodes use counts.
+  for (SDNode::op_iterator I = N->op_begin(), E = N->op_end(); I != E; ++I)
+    I->Val->removeUser(N);
+  if (N->OperandsNeedDelete)
+    delete[] N->OperandList;
+  N->OperandList = 0;
+  N->NumOperands = 0;
+  
+  delete N;
+}
+
+/// RemoveNodeFromCSEMaps - Take the specified node out of the CSE map that
+/// correspond to it.  This is useful when we're about to delete or repurpose
+/// the node.  We don't want future request for structurally identical nodes
+/// to return N anymore.
+void SelectionDAG::RemoveNodeFromCSEMaps(SDNode *N) {
+  bool Erased = false;
+  switch (N->getOpcode()) {
+  case ISD::HANDLENODE: return;  // noop.
+  case ISD::STRING:
+    Erased = StringNodes.erase(cast<StringSDNode>(N)->getValue());
+    break;
+  case ISD::CONDCODE:
+    assert(CondCodeNodes[cast<CondCodeSDNode>(N)->get()] &&
+           "Cond code doesn't exist!");
+    Erased = CondCodeNodes[cast<CondCodeSDNode>(N)->get()] != 0;
+    CondCodeNodes[cast<CondCodeSDNode>(N)->get()] = 0;
+    break;
+  case ISD::ExternalSymbol:
+    Erased = ExternalSymbols.erase(cast<ExternalSymbolSDNode>(N)->getSymbol());
+    break;
+  case ISD::TargetExternalSymbol:
+    Erased =
+      TargetExternalSymbols.erase(cast<ExternalSymbolSDNode>(N)->getSymbol());
+    break;
+  case ISD::VALUETYPE:
+    Erased = ValueTypeNodes[cast<VTSDNode>(N)->getVT()] != 0;
+    ValueTypeNodes[cast<VTSDNode>(N)->getVT()] = 0;
+    break;
+  default:
+    // Remove it from the CSE Map.
+    Erased = CSEMap.RemoveNode(N);
+    break;
+  }
+#ifndef NDEBUG
+  // Verify that the node was actually in one of the CSE maps, unless it has a 
+  // flag result (which cannot be CSE'd) or is one of the special cases that are
+  // not subject to CSE.
+  if (!Erased && N->getValueType(N->getNumValues()-1) != MVT::Flag &&
+      !N->isTargetOpcode()) {
+    N->dump(this);
+    cerr << "\n";
+    assert(0 && "Node is not in map!");
+  }
+#endif
+}
+
+/// AddNonLeafNodeToCSEMaps - Add the specified node back to the CSE maps.  It
+/// has been taken out and modified in some way.  If the specified node already
+/// exists in the CSE maps, do not modify the maps, but return the existing node
+/// instead.  If it doesn't exist, add it and return null.
+///
+SDNode *SelectionDAG::AddNonLeafNodeToCSEMaps(SDNode *N) {
+  assert(N->getNumOperands() && "This is a leaf node!");
+  if (N->getOpcode() == ISD::HANDLENODE || N->getValueType(0) == MVT::Flag)
+    return 0;    // Never add these nodes.
+  
+  // Check that remaining values produced are not flags.
+  for (unsigned i = 1, e = N->getNumValues(); i != e; ++i)
+    if (N->getValueType(i) == MVT::Flag)
+      return 0;   // Never CSE anything that produces a flag.
+  
+  SDNode *New = CSEMap.GetOrInsertNode(N);
+  if (New != N) return New;  // Node already existed.
+  return 0;
+}
+
+/// FindModifiedNodeSlot - Find a slot for the specified node if its operands
+/// were replaced with those specified.  If this node is never memoized, 
+/// return null, otherwise return a pointer to the slot it would take.  If a
+/// node already exists with these operands, the slot will be non-null.
+SDNode *SelectionDAG::FindModifiedNodeSlot(SDNode *N, SDOperand Op,
+                                           void *&InsertPos) {
+  if (N->getOpcode() == ISD::HANDLENODE || N->getValueType(0) == MVT::Flag)
+    return 0;    // Never add these nodes.
+  
+  // Check that remaining values produced are not flags.
+  for (unsigned i = 1, e = N->getNumValues(); i != e; ++i)
+    if (N->getValueType(i) == MVT::Flag)
+      return 0;   // Never CSE anything that produces a flag.
+  
+  SDOperand Ops[] = { Op };
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, N->getOpcode(), N->getVTList(), Ops, 1);
+  return CSEMap.FindNodeOrInsertPos(ID, InsertPos);
+}
+
+/// FindModifiedNodeSlot - Find a slot for the specified node if its operands
+/// were replaced with those specified.  If this node is never memoized, 
+/// return null, otherwise return a pointer to the slot it would take.  If a
+/// node already exists with these operands, the slot will be non-null.
+SDNode *SelectionDAG::FindModifiedNodeSlot(SDNode *N, 
+                                           SDOperand Op1, SDOperand Op2,
+                                           void *&InsertPos) {
+  if (N->getOpcode() == ISD::HANDLENODE || N->getValueType(0) == MVT::Flag)
+    return 0;    // Never add these nodes.
+  
+  // Check that remaining values produced are not flags.
+  for (unsigned i = 1, e = N->getNumValues(); i != e; ++i)
+    if (N->getValueType(i) == MVT::Flag)
+      return 0;   // Never CSE anything that produces a flag.
+                                              
+  SDOperand Ops[] = { Op1, Op2 };
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, N->getOpcode(), N->getVTList(), Ops, 2);
+  return CSEMap.FindNodeOrInsertPos(ID, InsertPos);
+}
+
+
+/// FindModifiedNodeSlot - Find a slot for the specified node if its operands
+/// were replaced with those specified.  If this node is never memoized, 
+/// return null, otherwise return a pointer to the slot it would take.  If a
+/// node already exists with these operands, the slot will be non-null.
+SDNode *SelectionDAG::FindModifiedNodeSlot(SDNode *N, 
+                                           const SDOperand *Ops,unsigned NumOps,
+                                           void *&InsertPos) {
+  if (N->getOpcode() == ISD::HANDLENODE || N->getValueType(0) == MVT::Flag)
+    return 0;    // Never add these nodes.
+  
+  // Check that remaining values produced are not flags.
+  for (unsigned i = 1, e = N->getNumValues(); i != e; ++i)
+    if (N->getValueType(i) == MVT::Flag)
+      return 0;   // Never CSE anything that produces a flag.
+  
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, N->getOpcode(), N->getVTList(), Ops, NumOps);
+  
+  if (const LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
+    ID.AddInteger(LD->getAddressingMode());
+    ID.AddInteger(LD->getExtensionType());
+    ID.AddInteger(LD->getLoadedVT());
+    ID.AddPointer(LD->getSrcValue());
+    ID.AddInteger(LD->getSrcValueOffset());
+    ID.AddInteger(LD->getAlignment());
+    ID.AddInteger(LD->isVolatile());
+  } else if (const StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
+    ID.AddInteger(ST->getAddressingMode());
+    ID.AddInteger(ST->isTruncatingStore());
+    ID.AddInteger(ST->getStoredVT());
+    ID.AddPointer(ST->getSrcValue());
+    ID.AddInteger(ST->getSrcValueOffset());
+    ID.AddInteger(ST->getAlignment());
+    ID.AddInteger(ST->isVolatile());
+  }
+  
+  return CSEMap.FindNodeOrInsertPos(ID, InsertPos);
+}
+
+
+SelectionDAG::~SelectionDAG() {
+  while (!AllNodes.empty()) {
+    SDNode *N = AllNodes.begin();
+    N->SetNextInBucket(0);
+    if (N->OperandsNeedDelete)
+      delete [] N->OperandList;
+    N->OperandList = 0;
+    N->NumOperands = 0;
+    AllNodes.pop_front();
+  }
+}
+
+SDOperand SelectionDAG::getZeroExtendInReg(SDOperand Op, MVT::ValueType VT) {
+  if (Op.getValueType() == VT) return Op;
+  int64_t Imm = ~0ULL >> (64-MVT::getSizeInBits(VT));
+  return getNode(ISD::AND, Op.getValueType(), Op,
+                 getConstant(Imm, Op.getValueType()));
+}
+
+SDOperand SelectionDAG::getString(const std::string &Val) {
+  StringSDNode *&N = StringNodes[Val];
+  if (!N) {
+    N = new StringSDNode(Val);
+    AllNodes.push_back(N);
+  }
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getConstant(uint64_t Val, MVT::ValueType VT, bool isT) {
+  assert(MVT::isInteger(VT) && "Cannot create FP integer constant!");
+  assert(!MVT::isVector(VT) && "Cannot create Vector ConstantSDNodes!");
+  
+  // Mask out any bits that are not valid for this constant.
+  Val &= MVT::getIntVTBitMask(VT);
+
+  unsigned Opc = isT ? ISD::TargetConstant : ISD::Constant;
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, Opc, getVTList(VT), 0, 0);
+  ID.AddInteger(Val);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new ConstantSDNode(isT, Val, VT);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+
+SDOperand SelectionDAG::getConstantFP(double Val, MVT::ValueType VT,
+                                      bool isTarget) {
+  assert(MVT::isFloatingPoint(VT) && "Cannot create integer FP constant!");
+  MVT::ValueType EltVT =
+    MVT::isVector(VT) ? MVT::getVectorElementType(VT) : VT;
+  if (EltVT == MVT::f32)
+    Val = (float)Val;  // Mask out extra precision.
+
+  // Do the map lookup using the actual bit pattern for the floating point
+  // value, so that we don't have problems with 0.0 comparing equal to -0.0, and
+  // we don't have issues with SNANs.
+  unsigned Opc = isTarget ? ISD::TargetConstantFP : ISD::ConstantFP;
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, Opc, getVTList(EltVT), 0, 0);
+  ID.AddDouble(Val);
+  void *IP = 0;
+  SDNode *N = NULL;
+  if ((N = CSEMap.FindNodeOrInsertPos(ID, IP)))
+    if (!MVT::isVector(VT))
+      return SDOperand(N, 0);
+  if (!N) {
+    N = new ConstantFPSDNode(isTarget, Val, EltVT);
+    CSEMap.InsertNode(N, IP);
+    AllNodes.push_back(N);
+  }
+
+  SDOperand Result(N, 0);
+  if (MVT::isVector(VT)) {
+    SmallVector<SDOperand, 8> Ops;
+    Ops.assign(MVT::getVectorNumElements(VT), Result);
+    Result = getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size());
+  }
+  return Result;
+}
+
+SDOperand SelectionDAG::getGlobalAddress(const GlobalValue *GV,
+                                         MVT::ValueType VT, int Offset,
+                                         bool isTargetGA) {
+  const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
+  unsigned Opc;
+  if (GVar && GVar->isThreadLocal())
+    Opc = isTargetGA ? ISD::TargetGlobalTLSAddress : ISD::GlobalTLSAddress;
+  else
+    Opc = isTargetGA ? ISD::TargetGlobalAddress : ISD::GlobalAddress;
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, Opc, getVTList(VT), 0, 0);
+  ID.AddPointer(GV);
+  ID.AddInteger(Offset);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+   return SDOperand(E, 0);
+  SDNode *N = new GlobalAddressSDNode(isTargetGA, GV, VT, Offset);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getFrameIndex(int FI, MVT::ValueType VT,
+                                      bool isTarget) {
+  unsigned Opc = isTarget ? ISD::TargetFrameIndex : ISD::FrameIndex;
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, Opc, getVTList(VT), 0, 0);
+  ID.AddInteger(FI);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new FrameIndexSDNode(FI, VT, isTarget);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getJumpTable(int JTI, MVT::ValueType VT, bool isTarget){
+  unsigned Opc = isTarget ? ISD::TargetJumpTable : ISD::JumpTable;
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, Opc, getVTList(VT), 0, 0);
+  ID.AddInteger(JTI);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new JumpTableSDNode(JTI, VT, isTarget);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getConstantPool(Constant *C, MVT::ValueType VT,
+                                        unsigned Alignment, int Offset,
+                                        bool isTarget) {
+  unsigned Opc = isTarget ? ISD::TargetConstantPool : ISD::ConstantPool;
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, Opc, getVTList(VT), 0, 0);
+  ID.AddInteger(Alignment);
+  ID.AddInteger(Offset);
+  ID.AddPointer(C);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new ConstantPoolSDNode(isTarget, C, VT, Offset, Alignment);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+
+SDOperand SelectionDAG::getConstantPool(MachineConstantPoolValue *C,
+                                        MVT::ValueType VT,
+                                        unsigned Alignment, int Offset,
+                                        bool isTarget) {
+  unsigned Opc = isTarget ? ISD::TargetConstantPool : ISD::ConstantPool;
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, Opc, getVTList(VT), 0, 0);
+  ID.AddInteger(Alignment);
+  ID.AddInteger(Offset);
+  C->AddSelectionDAGCSEId(ID);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new ConstantPoolSDNode(isTarget, C, VT, Offset, Alignment);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+
+SDOperand SelectionDAG::getBasicBlock(MachineBasicBlock *MBB) {
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::BasicBlock, getVTList(MVT::Other), 0, 0);
+  ID.AddPointer(MBB);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new BasicBlockSDNode(MBB);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getValueType(MVT::ValueType VT) {
+  if ((unsigned)VT >= ValueTypeNodes.size())
+    ValueTypeNodes.resize(VT+1);
+  if (ValueTypeNodes[VT] == 0) {
+    ValueTypeNodes[VT] = new VTSDNode(VT);
+    AllNodes.push_back(ValueTypeNodes[VT]);
+  }
+
+  return SDOperand(ValueTypeNodes[VT], 0);
+}
+
+SDOperand SelectionDAG::getExternalSymbol(const char *Sym, MVT::ValueType VT) {
+  SDNode *&N = ExternalSymbols[Sym];
+  if (N) return SDOperand(N, 0);
+  N = new ExternalSymbolSDNode(false, Sym, VT);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getTargetExternalSymbol(const char *Sym,
+                                                MVT::ValueType VT) {
+  SDNode *&N = TargetExternalSymbols[Sym];
+  if (N) return SDOperand(N, 0);
+  N = new ExternalSymbolSDNode(true, Sym, VT);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getCondCode(ISD::CondCode Cond) {
+  if ((unsigned)Cond >= CondCodeNodes.size())
+    CondCodeNodes.resize(Cond+1);
+  
+  if (CondCodeNodes[Cond] == 0) {
+    CondCodeNodes[Cond] = new CondCodeSDNode(Cond);
+    AllNodes.push_back(CondCodeNodes[Cond]);
+  }
+  return SDOperand(CondCodeNodes[Cond], 0);
+}
+
+SDOperand SelectionDAG::getRegister(unsigned RegNo, MVT::ValueType VT) {
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::Register, getVTList(VT), 0, 0);
+  ID.AddInteger(RegNo);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new RegisterSDNode(RegNo, VT);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getSrcValue(const Value *V, int Offset) {
+  assert((!V || isa<PointerType>(V->getType())) &&
+         "SrcValue is not a pointer?");
+
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::SRCVALUE, getVTList(MVT::Other), 0, 0);
+  ID.AddPointer(V);
+  ID.AddInteger(Offset);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new SrcValueSDNode(V, Offset);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::FoldSetCC(MVT::ValueType VT, SDOperand N1,
+                                  SDOperand N2, ISD::CondCode Cond) {
+  // These setcc operations always fold.
+  switch (Cond) {
+  default: break;
+  case ISD::SETFALSE:
+  case ISD::SETFALSE2: return getConstant(0, VT);
+  case ISD::SETTRUE:
+  case ISD::SETTRUE2:  return getConstant(1, VT);
+    
+  case ISD::SETOEQ:
+  case ISD::SETOGT:
+  case ISD::SETOGE:
+  case ISD::SETOLT:
+  case ISD::SETOLE:
+  case ISD::SETONE:
+  case ISD::SETO:
+  case ISD::SETUO:
+  case ISD::SETUEQ:
+  case ISD::SETUNE:
+    assert(!MVT::isInteger(N1.getValueType()) && "Illegal setcc for integer!");
+    break;
+  }
+  
+  if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val)) {
+    uint64_t C2 = N2C->getValue();
+    if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val)) {
+      uint64_t C1 = N1C->getValue();
+      
+      // Sign extend the operands if required
+      if (ISD::isSignedIntSetCC(Cond)) {
+        C1 = N1C->getSignExtended();
+        C2 = N2C->getSignExtended();
+      }
+      
+      switch (Cond) {
+      default: assert(0 && "Unknown integer setcc!");
+      case ISD::SETEQ:  return getConstant(C1 == C2, VT);
+      case ISD::SETNE:  return getConstant(C1 != C2, VT);
+      case ISD::SETULT: return getConstant(C1 <  C2, VT);
+      case ISD::SETUGT: return getConstant(C1 >  C2, VT);
+      case ISD::SETULE: return getConstant(C1 <= C2, VT);
+      case ISD::SETUGE: return getConstant(C1 >= C2, VT);
+      case ISD::SETLT:  return getConstant((int64_t)C1 <  (int64_t)C2, VT);
+      case ISD::SETGT:  return getConstant((int64_t)C1 >  (int64_t)C2, VT);
+      case ISD::SETLE:  return getConstant((int64_t)C1 <= (int64_t)C2, VT);
+      case ISD::SETGE:  return getConstant((int64_t)C1 >= (int64_t)C2, VT);
+      }
+    }
+  }
+  if (ConstantFPSDNode *N1C = dyn_cast<ConstantFPSDNode>(N1.Val))
+    if (ConstantFPSDNode *N2C = dyn_cast<ConstantFPSDNode>(N2.Val)) {
+      double C1 = N1C->getValue(), C2 = N2C->getValue();
+      
+      switch (Cond) {
+      default: break; // FIXME: Implement the rest of these!
+      case ISD::SETEQ:  return getConstant(C1 == C2, VT);
+      case ISD::SETNE:  return getConstant(C1 != C2, VT);
+      case ISD::SETLT:  return getConstant(C1 < C2, VT);
+      case ISD::SETGT:  return getConstant(C1 > C2, VT);
+      case ISD::SETLE:  return getConstant(C1 <= C2, VT);
+      case ISD::SETGE:  return getConstant(C1 >= C2, VT);
+      }
+    } else {
+      // Ensure that the constant occurs on the RHS.
+      return getSetCC(VT, N2, N1, ISD::getSetCCSwappedOperands(Cond));
+    }
+      
+  // Could not fold it.
+  return SDOperand();
+}
+
+/// MaskedValueIsZero - Return true if 'V & Mask' is known to be zero.  We use
+/// this predicate to simplify operations downstream.  Mask is known to be zero
+/// for bits that V cannot have.
+bool SelectionDAG::MaskedValueIsZero(SDOperand Op, uint64_t Mask, 
+                                     unsigned Depth) const {
+  // The masks are not wide enough to represent this type!  Should use APInt.
+  if (Op.getValueType() == MVT::i128)
+    return false;
+  
+  uint64_t KnownZero, KnownOne;
+  ComputeMaskedBits(Op, Mask, KnownZero, KnownOne, Depth);
+  assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
+  return (KnownZero & Mask) == Mask;
+}
+
+/// ComputeMaskedBits - Determine which of the bits specified in Mask are
+/// known to be either zero or one and return them in the KnownZero/KnownOne
+/// bitsets.  This code only analyzes bits in Mask, in order to short-circuit
+/// processing.
+void SelectionDAG::ComputeMaskedBits(SDOperand Op, uint64_t Mask, 
+                                     uint64_t &KnownZero, uint64_t &KnownOne,
+                                     unsigned Depth) const {
+  KnownZero = KnownOne = 0;   // Don't know anything.
+  if (Depth == 6 || Mask == 0)
+    return;  // Limit search depth.
+  
+  // The masks are not wide enough to represent this type!  Should use APInt.
+  if (Op.getValueType() == MVT::i128)
+    return;
+  
+  uint64_t KnownZero2, KnownOne2;
+
+  switch (Op.getOpcode()) {
+  case ISD::Constant:
+    // We know all of the bits for a constant!
+    KnownOne = cast<ConstantSDNode>(Op)->getValue() & Mask;
+    KnownZero = ~KnownOne & Mask;
+    return;
+  case ISD::AND:
+    // If either the LHS or the RHS are Zero, the result is zero.
+    ComputeMaskedBits(Op.getOperand(1), Mask, KnownZero, KnownOne, Depth+1);
+    Mask &= ~KnownZero;
+    ComputeMaskedBits(Op.getOperand(0), Mask, KnownZero2, KnownOne2, Depth+1);
+    assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
+    assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); 
+
+    // Output known-1 bits are only known if set in both the LHS & RHS.
+    KnownOne &= KnownOne2;
+    // Output known-0 are known to be clear if zero in either the LHS | RHS.
+    KnownZero |= KnownZero2;
+    return;
+  case ISD::OR:
+    ComputeMaskedBits(Op.getOperand(1), Mask, KnownZero, KnownOne, Depth+1);
+    Mask &= ~KnownOne;
+    ComputeMaskedBits(Op.getOperand(0), Mask, KnownZero2, KnownOne2, Depth+1);
+    assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
+    assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); 
+    
+    // Output known-0 bits are only known if clear in both the LHS & RHS.
+    KnownZero &= KnownZero2;
+    // Output known-1 are known to be set if set in either the LHS | RHS.
+    KnownOne |= KnownOne2;
+    return;
+  case ISD::XOR: {
+    ComputeMaskedBits(Op.getOperand(1), Mask, KnownZero, KnownOne, Depth+1);
+    ComputeMaskedBits(Op.getOperand(0), Mask, KnownZero2, KnownOne2, Depth+1);
+    assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
+    assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); 
+    
+    // Output known-0 bits are known if clear or set in both the LHS & RHS.
+    uint64_t KnownZeroOut = (KnownZero & KnownZero2) | (KnownOne & KnownOne2);
+    // Output known-1 are known to be set if set in only one of the LHS, RHS.
+    KnownOne = (KnownZero & KnownOne2) | (KnownOne & KnownZero2);
+    KnownZero = KnownZeroOut;
+    return;
+  }
+  case ISD::SELECT:
+    ComputeMaskedBits(Op.getOperand(2), Mask, KnownZero, KnownOne, Depth+1);
+    ComputeMaskedBits(Op.getOperand(1), Mask, KnownZero2, KnownOne2, Depth+1);
+    assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
+    assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); 
+    
+    // Only known if known in both the LHS and RHS.
+    KnownOne &= KnownOne2;
+    KnownZero &= KnownZero2;
+    return;
+  case ISD::SELECT_CC:
+    ComputeMaskedBits(Op.getOperand(3), Mask, KnownZero, KnownOne, Depth+1);
+    ComputeMaskedBits(Op.getOperand(2), Mask, KnownZero2, KnownOne2, Depth+1);
+    assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
+    assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); 
+    
+    // Only known if known in both the LHS and RHS.
+    KnownOne &= KnownOne2;
+    KnownZero &= KnownZero2;
+    return;
+  case ISD::SETCC:
+    // If we know the result of a setcc has the top bits zero, use this info.
+    if (TLI.getSetCCResultContents() == TargetLowering::ZeroOrOneSetCCResult)
+      KnownZero |= (MVT::getIntVTBitMask(Op.getValueType()) ^ 1ULL);
+    return;
+  case ISD::SHL:
+    // (shl X, C1) & C2 == 0   iff   (X & C2 >>u C1) == 0
+    if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
+      ComputeMaskedBits(Op.getOperand(0), Mask >> SA->getValue(),
+                        KnownZero, KnownOne, Depth+1);
+      assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
+      KnownZero <<= SA->getValue();
+      KnownOne  <<= SA->getValue();
+      KnownZero |= (1ULL << SA->getValue())-1;  // low bits known zero.
+    }
+    return;
+  case ISD::SRL:
+    // (ushr X, C1) & C2 == 0   iff  (-1 >> C1) & C2 == 0
+    if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
+      MVT::ValueType VT = Op.getValueType();
+      unsigned ShAmt = SA->getValue();
+
+      uint64_t TypeMask = MVT::getIntVTBitMask(VT);
+      ComputeMaskedBits(Op.getOperand(0), (Mask << ShAmt) & TypeMask,
+                        KnownZero, KnownOne, Depth+1);
+      assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
+      KnownZero &= TypeMask;
+      KnownOne  &= TypeMask;
+      KnownZero >>= ShAmt;
+      KnownOne  >>= ShAmt;
+
+      uint64_t HighBits = (1ULL << ShAmt)-1;
+      HighBits <<= MVT::getSizeInBits(VT)-ShAmt;
+      KnownZero |= HighBits;  // High bits known zero.
+    }
+    return;
+  case ISD::SRA:
+    if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
+      MVT::ValueType VT = Op.getValueType();
+      unsigned ShAmt = SA->getValue();
+
+      // Compute the new bits that are at the top now.
+      uint64_t TypeMask = MVT::getIntVTBitMask(VT);
+
+      uint64_t InDemandedMask = (Mask << ShAmt) & TypeMask;
+      // If any of the demanded bits are produced by the sign extension, we also
+      // demand the input sign bit.
+      uint64_t HighBits = (1ULL << ShAmt)-1;
+      HighBits <<= MVT::getSizeInBits(VT) - ShAmt;
+      if (HighBits & Mask)
+        InDemandedMask |= MVT::getIntVTSignBit(VT);
+      
+      ComputeMaskedBits(Op.getOperand(0), InDemandedMask, KnownZero, KnownOne,
+                        Depth+1);
+      assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
+      KnownZero &= TypeMask;
+      KnownOne  &= TypeMask;
+      KnownZero >>= ShAmt;
+      KnownOne  >>= ShAmt;
+      
+      // Handle the sign bits.
+      uint64_t SignBit = MVT::getIntVTSignBit(VT);
+      SignBit >>= ShAmt;  // Adjust to where it is now in the mask.
+      
+      if (KnownZero & SignBit) {       
+        KnownZero |= HighBits;  // New bits are known zero.
+      } else if (KnownOne & SignBit) {
+        KnownOne  |= HighBits;  // New bits are known one.
+      }
+    }
+    return;
+  case ISD::SIGN_EXTEND_INREG: {
+    MVT::ValueType EVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
+    
+    // Sign extension.  Compute the demanded bits in the result that are not 
+    // present in the input.
+    uint64_t NewBits = ~MVT::getIntVTBitMask(EVT) & Mask;
+
+    uint64_t InSignBit = MVT::getIntVTSignBit(EVT);
+    int64_t InputDemandedBits = Mask & MVT::getIntVTBitMask(EVT);
+    
+    // If the sign extended bits are demanded, we know that the sign
+    // bit is demanded.
+    if (NewBits)
+      InputDemandedBits |= InSignBit;
+    
+    ComputeMaskedBits(Op.getOperand(0), InputDemandedBits,
+                      KnownZero, KnownOne, Depth+1);
+    assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
+    
+    // If the sign bit of the input is known set or clear, then we know the
+    // top bits of the result.
+    if (KnownZero & InSignBit) {          // Input sign bit known clear
+      KnownZero |= NewBits;
+      KnownOne  &= ~NewBits;
+    } else if (KnownOne & InSignBit) {    // Input sign bit known set
+      KnownOne  |= NewBits;
+      KnownZero &= ~NewBits;
+    } else {                              // Input sign bit unknown
+      KnownZero &= ~NewBits;
+      KnownOne  &= ~NewBits;
+    }
+    return;
+  }
+  case ISD::CTTZ:
+  case ISD::CTLZ:
+  case ISD::CTPOP: {
+    MVT::ValueType VT = Op.getValueType();
+    unsigned LowBits = Log2_32(MVT::getSizeInBits(VT))+1;
+    KnownZero = ~((1ULL << LowBits)-1) & MVT::getIntVTBitMask(VT);
+    KnownOne  = 0;
+    return;
+  }
+  case ISD::LOAD: {
+    if (ISD::isZEXTLoad(Op.Val)) {
+      LoadSDNode *LD = cast<LoadSDNode>(Op);
+      MVT::ValueType VT = LD->getLoadedVT();
+      KnownZero |= ~MVT::getIntVTBitMask(VT) & Mask;
+    }
+    return;
+  }
+  case ISD::ZERO_EXTEND: {
+    uint64_t InMask  = MVT::getIntVTBitMask(Op.getOperand(0).getValueType());
+    uint64_t NewBits = (~InMask) & Mask;
+    ComputeMaskedBits(Op.getOperand(0), Mask & InMask, KnownZero, 
+                      KnownOne, Depth+1);
+    KnownZero |= NewBits & Mask;
+    KnownOne  &= ~NewBits;
+    return;
+  }
+  case ISD::SIGN_EXTEND: {
+    MVT::ValueType InVT = Op.getOperand(0).getValueType();
+    unsigned InBits    = MVT::getSizeInBits(InVT);
+    uint64_t InMask    = MVT::getIntVTBitMask(InVT);
+    uint64_t InSignBit = 1ULL << (InBits-1);
+    uint64_t NewBits   = (~InMask) & Mask;
+    uint64_t InDemandedBits = Mask & InMask;
+
+    // If any of the sign extended bits are demanded, we know that the sign
+    // bit is demanded.
+    if (NewBits & Mask)
+      InDemandedBits |= InSignBit;
+    
+    ComputeMaskedBits(Op.getOperand(0), InDemandedBits, KnownZero, 
+                      KnownOne, Depth+1);
+    // If the sign bit is known zero or one, the  top bits match.
+    if (KnownZero & InSignBit) {
+      KnownZero |= NewBits;
+      KnownOne  &= ~NewBits;
+    } else if (KnownOne & InSignBit) {
+      KnownOne  |= NewBits;
+      KnownZero &= ~NewBits;
+    } else {   // Otherwise, top bits aren't known.
+      KnownOne  &= ~NewBits;
+      KnownZero &= ~NewBits;
+    }
+    return;
+  }
+  case ISD::ANY_EXTEND: {
+    MVT::ValueType VT = Op.getOperand(0).getValueType();
+    ComputeMaskedBits(Op.getOperand(0), Mask & MVT::getIntVTBitMask(VT),
+                      KnownZero, KnownOne, Depth+1);
+    return;
+  }
+  case ISD::TRUNCATE: {
+    ComputeMaskedBits(Op.getOperand(0), Mask, KnownZero, KnownOne, Depth+1);
+    assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
+    uint64_t OutMask = MVT::getIntVTBitMask(Op.getValueType());
+    KnownZero &= OutMask;
+    KnownOne &= OutMask;
+    break;
+  }
+  case ISD::AssertZext: {
+    MVT::ValueType VT = cast<VTSDNode>(Op.getOperand(1))->getVT();
+    uint64_t InMask = MVT::getIntVTBitMask(VT);
+    ComputeMaskedBits(Op.getOperand(0), Mask & InMask, KnownZero, 
+                      KnownOne, Depth+1);
+    KnownZero |= (~InMask) & Mask;
+    return;
+  }
+  case ISD::ADD: {
+    // If either the LHS or the RHS are Zero, the result is zero.
+    ComputeMaskedBits(Op.getOperand(1), Mask, KnownZero, KnownOne, Depth+1);
+    ComputeMaskedBits(Op.getOperand(0), Mask, KnownZero2, KnownOne2, Depth+1);
+    assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
+    assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?"); 
+    
+    // Output known-0 bits are known if clear or set in both the low clear bits
+    // common to both LHS & RHS.  For example, 8+(X<<3) is known to have the
+    // low 3 bits clear.
+    uint64_t KnownZeroOut = std::min(CountTrailingZeros_64(~KnownZero), 
+                                     CountTrailingZeros_64(~KnownZero2));
+    
+    KnownZero = (1ULL << KnownZeroOut) - 1;
+    KnownOne = 0;
+    return;
+  }
+  case ISD::SUB: {
+    ConstantSDNode *CLHS = dyn_cast<ConstantSDNode>(Op.getOperand(0));
+    if (!CLHS) return;
+
+    // We know that the top bits of C-X are clear if X contains less bits
+    // than C (i.e. no wrap-around can happen).  For example, 20-X is
+    // positive if we can prove that X is >= 0 and < 16.
+    MVT::ValueType VT = CLHS->getValueType(0);
+    if ((CLHS->getValue() & MVT::getIntVTSignBit(VT)) == 0) {  // sign bit clear
+      unsigned NLZ = CountLeadingZeros_64(CLHS->getValue()+1);
+      uint64_t MaskV = (1ULL << (63-NLZ))-1; // NLZ can't be 64 with no sign bit
+      MaskV = ~MaskV & MVT::getIntVTBitMask(VT);
+      ComputeMaskedBits(Op.getOperand(1), MaskV, KnownZero, KnownOne, Depth+1);
+
+      // If all of the MaskV bits are known to be zero, then we know the output
+      // top bits are zero, because we now know that the output is from [0-C].
+      if ((KnownZero & MaskV) == MaskV) {
+        unsigned NLZ2 = CountLeadingZeros_64(CLHS->getValue());
+        KnownZero = ~((1ULL << (64-NLZ2))-1) & Mask;  // Top bits known zero.
+        KnownOne = 0;   // No one bits known.
+      } else {
+        KnownZero = KnownOne = 0;  // Otherwise, nothing known.
+      }
+    }
+    return;
+  }
+  default:
+    // Allow the target to implement this method for its nodes.
+    if (Op.getOpcode() >= ISD::BUILTIN_OP_END) {
+  case ISD::INTRINSIC_WO_CHAIN:
+  case ISD::INTRINSIC_W_CHAIN:
+  case ISD::INTRINSIC_VOID:
+      TLI.computeMaskedBitsForTargetNode(Op, Mask, KnownZero, KnownOne, *this);
+    }
+    return;
+  }
+}
+
+/// ComputeNumSignBits - Return the number of times the sign bit of the
+/// register is replicated into the other bits.  We know that at least 1 bit
+/// is always equal to the sign bit (itself), but other cases can give us
+/// information.  For example, immediately after an "SRA X, 2", we know that
+/// the top 3 bits are all equal to each other, so we return 3.
+unsigned SelectionDAG::ComputeNumSignBits(SDOperand Op, unsigned Depth) const{
+  MVT::ValueType VT = Op.getValueType();
+  assert(MVT::isInteger(VT) && "Invalid VT!");
+  unsigned VTBits = MVT::getSizeInBits(VT);
+  unsigned Tmp, Tmp2;
+  
+  if (Depth == 6)
+    return 1;  // Limit search depth.
+
+  switch (Op.getOpcode()) {
+  default: break;
+  case ISD::AssertSext:
+    Tmp = MVT::getSizeInBits(cast<VTSDNode>(Op.getOperand(1))->getVT());
+    return VTBits-Tmp+1;
+  case ISD::AssertZext:
+    Tmp = MVT::getSizeInBits(cast<VTSDNode>(Op.getOperand(1))->getVT());
+    return VTBits-Tmp;
+    
+  case ISD::Constant: {
+    uint64_t Val = cast<ConstantSDNode>(Op)->getValue();
+    // If negative, invert the bits, then look at it.
+    if (Val & MVT::getIntVTSignBit(VT))
+      Val = ~Val;
+    
+    // Shift the bits so they are the leading bits in the int64_t.
+    Val <<= 64-VTBits;
+    
+    // Return # leading zeros.  We use 'min' here in case Val was zero before
+    // shifting.  We don't want to return '64' as for an i32 "0".
+    return std::min(VTBits, CountLeadingZeros_64(Val));
+  }
+    
+  case ISD::SIGN_EXTEND:
+    Tmp = VTBits-MVT::getSizeInBits(Op.getOperand(0).getValueType());
+    return ComputeNumSignBits(Op.getOperand(0), Depth+1) + Tmp;
+    
+  case ISD::SIGN_EXTEND_INREG:
+    // Max of the input and what this extends.
+    Tmp = MVT::getSizeInBits(cast<VTSDNode>(Op.getOperand(1))->getVT());
+    Tmp = VTBits-Tmp+1;
+    
+    Tmp2 = ComputeNumSignBits(Op.getOperand(0), Depth+1);
+    return std::max(Tmp, Tmp2);
+
+  case ISD::SRA:
+    Tmp = ComputeNumSignBits(Op.getOperand(0), Depth+1);
+    // SRA X, C   -> adds C sign bits.
+    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
+      Tmp += C->getValue();
+      if (Tmp > VTBits) Tmp = VTBits;
+    }
+    return Tmp;
+  case ISD::SHL:
+    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
+      // shl destroys sign bits.
+      Tmp = ComputeNumSignBits(Op.getOperand(0), Depth+1);
+      if (C->getValue() >= VTBits ||      // Bad shift.
+          C->getValue() >= Tmp) break;    // Shifted all sign bits out.
+      return Tmp - C->getValue();
+    }
+    break;
+  case ISD::AND:
+  case ISD::OR:
+  case ISD::XOR:    // NOT is handled here.
+    // Logical binary ops preserve the number of sign bits.
+    Tmp = ComputeNumSignBits(Op.getOperand(0), Depth+1);
+    if (Tmp == 1) return 1;  // Early out.
+    Tmp2 = ComputeNumSignBits(Op.getOperand(1), Depth+1);
+    return std::min(Tmp, Tmp2);
+
+  case ISD::SELECT:
+    Tmp = ComputeNumSignBits(Op.getOperand(0), Depth+1);
+    if (Tmp == 1) return 1;  // Early out.
+    Tmp2 = ComputeNumSignBits(Op.getOperand(1), Depth+1);
+    return std::min(Tmp, Tmp2);
+    
+  case ISD::SETCC:
+    // If setcc returns 0/-1, all bits are sign bits.
+    if (TLI.getSetCCResultContents() ==
+        TargetLowering::ZeroOrNegativeOneSetCCResult)
+      return VTBits;
+    break;
+  case ISD::ROTL:
+  case ISD::ROTR:
+    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
+      unsigned RotAmt = C->getValue() & (VTBits-1);
+      
+      // Handle rotate right by N like a rotate left by 32-N.
+      if (Op.getOpcode() == ISD::ROTR)
+        RotAmt = (VTBits-RotAmt) & (VTBits-1);
+
+      // If we aren't rotating out all of the known-in sign bits, return the
+      // number that are left.  This handles rotl(sext(x), 1) for example.
+      Tmp = ComputeNumSignBits(Op.getOperand(0), Depth+1);
+      if (Tmp > RotAmt+1) return Tmp-RotAmt;
+    }
+    break;
+  case ISD::ADD:
+    // Add can have at most one carry bit.  Thus we know that the output
+    // is, at worst, one more bit than the inputs.
+    Tmp = ComputeNumSignBits(Op.getOperand(0), Depth+1);
+    if (Tmp == 1) return 1;  // Early out.
+      
+    // Special case decrementing a value (ADD X, -1):
+    if (ConstantSDNode *CRHS = dyn_cast<ConstantSDNode>(Op.getOperand(0)))
+      if (CRHS->isAllOnesValue()) {
+        uint64_t KnownZero, KnownOne;
+        uint64_t Mask = MVT::getIntVTBitMask(VT);
+        ComputeMaskedBits(Op.getOperand(0), Mask, KnownZero, KnownOne, Depth+1);
+        
+        // If the input is known to be 0 or 1, the output is 0/-1, which is all
+        // sign bits set.
+        if ((KnownZero|1) == Mask)
+          return VTBits;
+        
+        // If we are subtracting one from a positive number, there is no carry
+        // out of the result.
+        if (KnownZero & MVT::getIntVTSignBit(VT))
+          return Tmp;
+      }
+      
+    Tmp2 = ComputeNumSignBits(Op.getOperand(1), Depth+1);
+    if (Tmp2 == 1) return 1;
+      return std::min(Tmp, Tmp2)-1;
+    break;
+    
+  case ISD::SUB:
+    Tmp2 = ComputeNumSignBits(Op.getOperand(1), Depth+1);
+    if (Tmp2 == 1) return 1;
+      
+    // Handle NEG.
+    if (ConstantSDNode *CLHS = dyn_cast<ConstantSDNode>(Op.getOperand(0)))
+      if (CLHS->getValue() == 0) {
+        uint64_t KnownZero, KnownOne;
+        uint64_t Mask = MVT::getIntVTBitMask(VT);
+        ComputeMaskedBits(Op.getOperand(1), Mask, KnownZero, KnownOne, Depth+1);
+        // If the input is known to be 0 or 1, the output is 0/-1, which is all
+        // sign bits set.
+        if ((KnownZero|1) == Mask)
+          return VTBits;
+        
+        // If the input is known to be positive (the sign bit is known clear),
+        // the output of the NEG has the same number of sign bits as the input.
+        if (KnownZero & MVT::getIntVTSignBit(VT))
+          return Tmp2;
+        
+        // Otherwise, we treat this like a SUB.
+      }
+    
+    // Sub can have at most one carry bit.  Thus we know that the output
+    // is, at worst, one more bit than the inputs.
+    Tmp = ComputeNumSignBits(Op.getOperand(0), Depth+1);
+    if (Tmp == 1) return 1;  // Early out.
+      return std::min(Tmp, Tmp2)-1;
+    break;
+  case ISD::TRUNCATE:
+    // FIXME: it's tricky to do anything useful for this, but it is an important
+    // case for targets like X86.
+    break;
+  }
+  
+  // Handle LOADX separately here. EXTLOAD case will fallthrough.
+  if (Op.getOpcode() == ISD::LOAD) {
+    LoadSDNode *LD = cast<LoadSDNode>(Op);
+    unsigned ExtType = LD->getExtensionType();
+    switch (ExtType) {
+    default: break;
+    case ISD::SEXTLOAD:    // '17' bits known
+      Tmp = MVT::getSizeInBits(LD->getLoadedVT());
+      return VTBits-Tmp+1;
+    case ISD::ZEXTLOAD:    // '16' bits known
+      Tmp = MVT::getSizeInBits(LD->getLoadedVT());
+      return VTBits-Tmp;
+    }
+  }
+
+  // Allow the target to implement this method for its nodes.
+  if (Op.getOpcode() >= ISD::BUILTIN_OP_END ||
+      Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN || 
+      Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
+      Op.getOpcode() == ISD::INTRINSIC_VOID) {
+    unsigned NumBits = TLI.ComputeNumSignBitsForTargetNode(Op, Depth);
+    if (NumBits > 1) return NumBits;
+  }
+  
+  // Finally, if we can prove that the top bits of the result are 0's or 1's,
+  // use this information.
+  uint64_t KnownZero, KnownOne;
+  uint64_t Mask = MVT::getIntVTBitMask(VT);
+  ComputeMaskedBits(Op, Mask, KnownZero, KnownOne, Depth);
+  
+  uint64_t SignBit = MVT::getIntVTSignBit(VT);
+  if (KnownZero & SignBit) {        // SignBit is 0
+    Mask = KnownZero;
+  } else if (KnownOne & SignBit) {  // SignBit is 1;
+    Mask = KnownOne;
+  } else {
+    // Nothing known.
+    return 1;
+  }
+  
+  // Okay, we know that the sign bit in Mask is set.  Use CLZ to determine
+  // the number of identical bits in the top of the input value.
+  Mask ^= ~0ULL;
+  Mask <<= 64-VTBits;
+  // Return # leading zeros.  We use 'min' here in case Val was zero before
+  // shifting.  We don't want to return '64' as for an i32 "0".
+  return std::min(VTBits, CountLeadingZeros_64(Mask));
+}
+
+
+/// getNode - Gets or creates the specified node.
+///
+SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT) {
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, Opcode, getVTList(VT), 0, 0);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new SDNode(Opcode, SDNode::getSDVTList(VT));
+  CSEMap.InsertNode(N, IP);
+  
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
+                                SDOperand Operand) {
+  unsigned Tmp1;
+  // Constant fold unary operations with an integer constant operand.
+  if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Operand.Val)) {
+    uint64_t Val = C->getValue();
+    switch (Opcode) {
+    default: break;
+    case ISD::SIGN_EXTEND: return getConstant(C->getSignExtended(), VT);
+    case ISD::ANY_EXTEND:
+    case ISD::ZERO_EXTEND: return getConstant(Val, VT);
+    case ISD::TRUNCATE:    return getConstant(Val, VT);
+    case ISD::SINT_TO_FP:  return getConstantFP(C->getSignExtended(), VT);
+    case ISD::UINT_TO_FP:  return getConstantFP(C->getValue(), VT);
+    case ISD::BIT_CONVERT:
+      if (VT == MVT::f32 && C->getValueType(0) == MVT::i32)
+        return getConstantFP(BitsToFloat(Val), VT);
+      else if (VT == MVT::f64 && C->getValueType(0) == MVT::i64)
+        return getConstantFP(BitsToDouble(Val), VT);
+      break;
+    case ISD::BSWAP:
+      switch(VT) {
+      default: assert(0 && "Invalid bswap!"); break;
+      case MVT::i16: return getConstant(ByteSwap_16((unsigned short)Val), VT);
+      case MVT::i32: return getConstant(ByteSwap_32((unsigned)Val), VT);
+      case MVT::i64: return getConstant(ByteSwap_64(Val), VT);
+      }
+      break;
+    case ISD::CTPOP:
+      switch(VT) {
+      default: assert(0 && "Invalid ctpop!"); break;
+      case MVT::i1: return getConstant(Val != 0, VT);
+      case MVT::i8: 
+        Tmp1 = (unsigned)Val & 0xFF;
+        return getConstant(CountPopulation_32(Tmp1), VT);
+      case MVT::i16:
+        Tmp1 = (unsigned)Val & 0xFFFF;
+        return getConstant(CountPopulation_32(Tmp1), VT);
+      case MVT::i32:
+        return getConstant(CountPopulation_32((unsigned)Val), VT);
+      case MVT::i64:
+        return getConstant(CountPopulation_64(Val), VT);
+      }
+    case ISD::CTLZ:
+      switch(VT) {
+      default: assert(0 && "Invalid ctlz!"); break;
+      case MVT::i1: return getConstant(Val == 0, VT);
+      case MVT::i8: 
+        Tmp1 = (unsigned)Val & 0xFF;
+        return getConstant(CountLeadingZeros_32(Tmp1)-24, VT);
+      case MVT::i16:
+        Tmp1 = (unsigned)Val & 0xFFFF;
+        return getConstant(CountLeadingZeros_32(Tmp1)-16, VT);
+      case MVT::i32:
+        return getConstant(CountLeadingZeros_32((unsigned)Val), VT);
+      case MVT::i64:
+        return getConstant(CountLeadingZeros_64(Val), VT);
+      }
+    case ISD::CTTZ:
+      switch(VT) {
+      default: assert(0 && "Invalid cttz!"); break;
+      case MVT::i1: return getConstant(Val == 0, VT);
+      case MVT::i8: 
+        Tmp1 = (unsigned)Val | 0x100;
+        return getConstant(CountTrailingZeros_32(Tmp1), VT);
+      case MVT::i16:
+        Tmp1 = (unsigned)Val | 0x10000;
+        return getConstant(CountTrailingZeros_32(Tmp1), VT);
+      case MVT::i32:
+        return getConstant(CountTrailingZeros_32((unsigned)Val), VT);
+      case MVT::i64:
+        return getConstant(CountTrailingZeros_64(Val), VT);
+      }
+    }
+  }
+
+  // Constant fold unary operations with an floating point constant operand.
+  if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Operand.Val))
+    switch (Opcode) {
+    case ISD::FNEG:
+      return getConstantFP(-C->getValue(), VT);
+    case ISD::FABS:
+      return getConstantFP(fabs(C->getValue()), VT);
+    case ISD::FP_ROUND:
+    case ISD::FP_EXTEND:
+      return getConstantFP(C->getValue(), VT);
+    case ISD::FP_TO_SINT:
+      return getConstant((int64_t)C->getValue(), VT);
+    case ISD::FP_TO_UINT:
+      return getConstant((uint64_t)C->getValue(), VT);
+    case ISD::BIT_CONVERT:
+      if (VT == MVT::i32 && C->getValueType(0) == MVT::f32)
+        return getConstant(FloatToBits(C->getValue()), VT);
+      else if (VT == MVT::i64 && C->getValueType(0) == MVT::f64)
+        return getConstant(DoubleToBits(C->getValue()), VT);
+      break;
+    }
+
+  unsigned OpOpcode = Operand.Val->getOpcode();
+  switch (Opcode) {
+  case ISD::TokenFactor:
+    return Operand;         // Factor of one node?  No factor.
+  case ISD::FP_ROUND:
+  case ISD::FP_EXTEND:
+    assert(MVT::isFloatingPoint(VT) &&
+           MVT::isFloatingPoint(Operand.getValueType()) && "Invalid FP cast!");
+    break;
+  case ISD::SIGN_EXTEND:
+    assert(MVT::isInteger(VT) && MVT::isInteger(Operand.getValueType()) &&
+           "Invalid SIGN_EXTEND!");
+    if (Operand.getValueType() == VT) return Operand;   // noop extension
+    assert(Operand.getValueType() < VT && "Invalid sext node, dst < src!");
+    if (OpOpcode == ISD::SIGN_EXTEND || OpOpcode == ISD::ZERO_EXTEND)
+      return getNode(OpOpcode, VT, Operand.Val->getOperand(0));
+    break;
+  case ISD::ZERO_EXTEND:
+    assert(MVT::isInteger(VT) && MVT::isInteger(Operand.getValueType()) &&
+           "Invalid ZERO_EXTEND!");
+    if (Operand.getValueType() == VT) return Operand;   // noop extension
+    assert(Operand.getValueType() < VT && "Invalid zext node, dst < src!");
+    if (OpOpcode == ISD::ZERO_EXTEND)   // (zext (zext x)) -> (zext x)
+      return getNode(ISD::ZERO_EXTEND, VT, Operand.Val->getOperand(0));
+    break;
+  case ISD::ANY_EXTEND:
+    assert(MVT::isInteger(VT) && MVT::isInteger(Operand.getValueType()) &&
+           "Invalid ANY_EXTEND!");
+    if (Operand.getValueType() == VT) return Operand;   // noop extension
+    assert(Operand.getValueType() < VT && "Invalid anyext node, dst < src!");
+    if (OpOpcode == ISD::ZERO_EXTEND || OpOpcode == ISD::SIGN_EXTEND)
+      // (ext (zext x)) -> (zext x)  and  (ext (sext x)) -> (sext x)
+      return getNode(OpOpcode, VT, Operand.Val->getOperand(0));
+    break;
+  case ISD::TRUNCATE:
+    assert(MVT::isInteger(VT) && MVT::isInteger(Operand.getValueType()) &&
+           "Invalid TRUNCATE!");
+    if (Operand.getValueType() == VT) return Operand;   // noop truncate
+    assert(Operand.getValueType() > VT && "Invalid truncate node, src < dst!");
+    if (OpOpcode == ISD::TRUNCATE)
+      return getNode(ISD::TRUNCATE, VT, Operand.Val->getOperand(0));
+    else if (OpOpcode == ISD::ZERO_EXTEND || OpOpcode == ISD::SIGN_EXTEND ||
+             OpOpcode == ISD::ANY_EXTEND) {
+      // If the source is smaller than the dest, we still need an extend.
+      if (Operand.Val->getOperand(0).getValueType() < VT)
+        return getNode(OpOpcode, VT, Operand.Val->getOperand(0));
+      else if (Operand.Val->getOperand(0).getValueType() > VT)
+        return getNode(ISD::TRUNCATE, VT, Operand.Val->getOperand(0));
+      else
+        return Operand.Val->getOperand(0);
+    }
+    break;
+  case ISD::BIT_CONVERT:
+    // Basic sanity checking.
+    assert(MVT::getSizeInBits(VT) == MVT::getSizeInBits(Operand.getValueType())
+           && "Cannot BIT_CONVERT between types of different sizes!");
+    if (VT == Operand.getValueType()) return Operand;  // noop conversion.
+    if (OpOpcode == ISD::BIT_CONVERT)  // bitconv(bitconv(x)) -> bitconv(x)
+      return getNode(ISD::BIT_CONVERT, VT, Operand.getOperand(0));
+    if (OpOpcode == ISD::UNDEF)
+      return getNode(ISD::UNDEF, VT);
+    break;
+  case ISD::SCALAR_TO_VECTOR:
+    assert(MVT::isVector(VT) && !MVT::isVector(Operand.getValueType()) &&
+           MVT::getVectorElementType(VT) == Operand.getValueType() &&
+           "Illegal SCALAR_TO_VECTOR node!");
+    break;
+  case ISD::FNEG:
+    if (OpOpcode == ISD::FSUB)   // -(X-Y) -> (Y-X)
+      return getNode(ISD::FSUB, VT, Operand.Val->getOperand(1),
+                     Operand.Val->getOperand(0));
+    if (OpOpcode == ISD::FNEG)  // --X -> X
+      return Operand.Val->getOperand(0);
+    break;
+  case ISD::FABS:
+    if (OpOpcode == ISD::FNEG)  // abs(-X) -> abs(X)
+      return getNode(ISD::FABS, VT, Operand.Val->getOperand(0));
+    break;
+  }
+
+  SDNode *N;
+  SDVTList VTs = getVTList(VT);
+  if (VT != MVT::Flag) { // Don't CSE flag producing nodes
+    FoldingSetNodeID ID;
+    SDOperand Ops[1] = { Operand };
+    AddNodeIDNode(ID, Opcode, VTs, Ops, 1);
+    void *IP = 0;
+    if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+      return SDOperand(E, 0);
+    N = new UnarySDNode(Opcode, VTs, Operand);
+    CSEMap.InsertNode(N, IP);
+  } else {
+    N = new UnarySDNode(Opcode, VTs, Operand);
+  }
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+
+
+SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
+                                SDOperand N1, SDOperand N2) {
+#ifndef NDEBUG
+  switch (Opcode) {
+  case ISD::TokenFactor:
+    assert(VT == MVT::Other && N1.getValueType() == MVT::Other &&
+           N2.getValueType() == MVT::Other && "Invalid token factor!");
+    break;
+  case ISD::AND:
+  case ISD::OR:
+  case ISD::XOR:
+  case ISD::UDIV:
+  case ISD::UREM:
+  case ISD::MULHU:
+  case ISD::MULHS:
+    assert(MVT::isInteger(VT) && "This operator does not apply to FP types!");
+    // fall through
+  case ISD::ADD:
+  case ISD::SUB:
+  case ISD::MUL:
+  case ISD::SDIV:
+  case ISD::SREM:
+    assert(MVT::isInteger(N1.getValueType()) && "Should use F* for FP ops");
+    // fall through.
+  case ISD::FADD:
+  case ISD::FSUB:
+  case ISD::FMUL:
+  case ISD::FDIV:
+  case ISD::FREM:
+    assert(N1.getValueType() == N2.getValueType() &&
+           N1.getValueType() == VT && "Binary operator types must match!");
+    break;
+  case ISD::FCOPYSIGN:   // N1 and result must match.  N1/N2 need not match.
+    assert(N1.getValueType() == VT &&
+           MVT::isFloatingPoint(N1.getValueType()) && 
+           MVT::isFloatingPoint(N2.getValueType()) &&
+           "Invalid FCOPYSIGN!");
+    break;
+  case ISD::SHL:
+  case ISD::SRA:
+  case ISD::SRL:
+  case ISD::ROTL:
+  case ISD::ROTR:
+    assert(VT == N1.getValueType() &&
+           "Shift operators return type must be the same as their first arg");
+    assert(MVT::isInteger(VT) && MVT::isInteger(N2.getValueType()) &&
+           VT != MVT::i1 && "Shifts only work on integers");
+    break;
+  case ISD::FP_ROUND_INREG: {
+    MVT::ValueType EVT = cast<VTSDNode>(N2)->getVT();
+    assert(VT == N1.getValueType() && "Not an inreg round!");
+    assert(MVT::isFloatingPoint(VT) && MVT::isFloatingPoint(EVT) &&
+           "Cannot FP_ROUND_INREG integer types");
+    assert(EVT <= VT && "Not rounding down!");
+    break;
+  }
+  case ISD::AssertSext:
+  case ISD::AssertZext:
+  case ISD::SIGN_EXTEND_INREG: {
+    MVT::ValueType EVT = cast<VTSDNode>(N2)->getVT();
+    assert(VT == N1.getValueType() && "Not an inreg extend!");
+    assert(MVT::isInteger(VT) && MVT::isInteger(EVT) &&
+           "Cannot *_EXTEND_INREG FP types");
+    assert(EVT <= VT && "Not extending!");
+  }
+
+  default: break;
+  }
+#endif
+
+  ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
+  ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val);
+  if (N1C) {
+    if (Opcode == ISD::SIGN_EXTEND_INREG) {
+      int64_t Val = N1C->getValue();
+      unsigned FromBits = MVT::getSizeInBits(cast<VTSDNode>(N2)->getVT());
+      Val <<= 64-FromBits;
+      Val >>= 64-FromBits;
+      return getConstant(Val, VT);
+    }
+    
+    if (N2C) {
+      uint64_t C1 = N1C->getValue(), C2 = N2C->getValue();
+      switch (Opcode) {
+      case ISD::ADD: return getConstant(C1 + C2, VT);
+      case ISD::SUB: return getConstant(C1 - C2, VT);
+      case ISD::MUL: return getConstant(C1 * C2, VT);
+      case ISD::UDIV:
+        if (C2) return getConstant(C1 / C2, VT);
+        break;
+      case ISD::UREM :
+        if (C2) return getConstant(C1 % C2, VT);
+        break;
+      case ISD::SDIV :
+        if (C2) return getConstant(N1C->getSignExtended() /
+                                   N2C->getSignExtended(), VT);
+        break;
+      case ISD::SREM :
+        if (C2) return getConstant(N1C->getSignExtended() %
+                                   N2C->getSignExtended(), VT);
+        break;
+      case ISD::AND  : return getConstant(C1 & C2, VT);
+      case ISD::OR   : return getConstant(C1 | C2, VT);
+      case ISD::XOR  : return getConstant(C1 ^ C2, VT);
+      case ISD::SHL  : return getConstant(C1 << C2, VT);
+      case ISD::SRL  : return getConstant(C1 >> C2, VT);
+      case ISD::SRA  : return getConstant(N1C->getSignExtended() >>(int)C2, VT);
+      case ISD::ROTL : 
+        return getConstant((C1 << C2) | (C1 >> (MVT::getSizeInBits(VT) - C2)),
+                           VT);
+      case ISD::ROTR : 
+        return getConstant((C1 >> C2) | (C1 << (MVT::getSizeInBits(VT) - C2)), 
+                           VT);
+      default: break;
+      }
+    } else {      // Cannonicalize constant to RHS if commutative
+      if (isCommutativeBinOp(Opcode)) {
+        std::swap(N1C, N2C);
+        std::swap(N1, N2);
+      }
+    }
+  }
+
+  ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1.Val);
+  ConstantFPSDNode *N2CFP = dyn_cast<ConstantFPSDNode>(N2.Val);
+  if (N1CFP) {
+    if (N2CFP) {
+      double C1 = N1CFP->getValue(), C2 = N2CFP->getValue();
+      switch (Opcode) {
+      case ISD::FADD: return getConstantFP(C1 + C2, VT);
+      case ISD::FSUB: return getConstantFP(C1 - C2, VT);
+      case ISD::FMUL: return getConstantFP(C1 * C2, VT);
+      case ISD::FDIV:
+        if (C2) return getConstantFP(C1 / C2, VT);
+        break;
+      case ISD::FREM :
+        if (C2) return getConstantFP(fmod(C1, C2), VT);
+        break;
+      case ISD::FCOPYSIGN: {
+        union {
+          double   F;
+          uint64_t I;
+        } u1;
+        u1.F = C1;
+        if (int64_t(DoubleToBits(C2)) < 0)  // Sign bit of RHS set?
+          u1.I |= 1ULL << 63;      // Set the sign bit of the LHS.
+        else 
+          u1.I &= (1ULL << 63)-1;  // Clear the sign bit of the LHS.
+        return getConstantFP(u1.F, VT);
+      }
+      default: break;
+      }
+    } else {      // Cannonicalize constant to RHS if commutative
+      if (isCommutativeBinOp(Opcode)) {
+        std::swap(N1CFP, N2CFP);
+        std::swap(N1, N2);
+      }
+    }
+  }
+  
+  // Canonicalize an UNDEF to the RHS, even over a constant.
+  if (N1.getOpcode() == ISD::UNDEF) {
+    if (isCommutativeBinOp(Opcode)) {
+      std::swap(N1, N2);
+    } else {
+      switch (Opcode) {
+      case ISD::FP_ROUND_INREG:
+      case ISD::SIGN_EXTEND_INREG:
+      case ISD::SUB:
+      case ISD::FSUB:
+      case ISD::FDIV:
+      case ISD::FREM:
+      case ISD::SRA:
+        return N1;     // fold op(undef, arg2) -> undef
+      case ISD::UDIV:
+      case ISD::SDIV:
+      case ISD::UREM:
+      case ISD::SREM:
+      case ISD::SRL:
+      case ISD::SHL:
+        if (!MVT::isVector(VT)) 
+          return getConstant(0, VT);    // fold op(undef, arg2) -> 0
+        // For vectors, we can't easily build an all zero vector, just return
+        // the LHS.
+        return N2;
+      }
+    }
+  }
+  
+  // Fold a bunch of operators when the RHS is undef. 
+  if (N2.getOpcode() == ISD::UNDEF) {
+    switch (Opcode) {
+    case ISD::ADD:
+    case ISD::ADDC:
+    case ISD::ADDE:
+    case ISD::SUB:
+    case ISD::FADD:
+    case ISD::FSUB:
+    case ISD::FMUL:
+    case ISD::FDIV:
+    case ISD::FREM:
+    case ISD::UDIV:
+    case ISD::SDIV:
+    case ISD::UREM:
+    case ISD::SREM:
+    case ISD::XOR:
+      return N2;       // fold op(arg1, undef) -> undef
+    case ISD::MUL: 
+    case ISD::AND:
+    case ISD::SRL:
+    case ISD::SHL:
+      if (!MVT::isVector(VT)) 
+        return getConstant(0, VT);  // fold op(arg1, undef) -> 0
+      // For vectors, we can't easily build an all zero vector, just return
+      // the LHS.
+      return N1;
+    case ISD::OR:
+      if (!MVT::isVector(VT)) 
+        return getConstant(MVT::getIntVTBitMask(VT), VT);
+      // For vectors, we can't easily build an all one vector, just return
+      // the LHS.
+      return N1;
+    case ISD::SRA:
+      return N1;
+    }
+  }
+
+  // Fold operations.
+  switch (Opcode) {
+  case ISD::TokenFactor:
+    // Fold trivial token factors.
+    if (N1.getOpcode() == ISD::EntryToken) return N2;
+    if (N2.getOpcode() == ISD::EntryToken) return N1;
+    break;
+      
+  case ISD::AND:
+    // (X & 0) -> 0.  This commonly occurs when legalizing i64 values, so it's
+    // worth handling here.
+    if (N2C && N2C->getValue() == 0)
+      return N2;
+    break;
+  case ISD::OR:
+  case ISD::XOR:
+    // (X ^| 0) -> X.  This commonly occurs when legalizing i64 values, so it's
+    // worth handling here.
+    if (N2C && N2C->getValue() == 0)
+      return N1;
+    break;
+  case ISD::FP_ROUND_INREG:
+    if (cast<VTSDNode>(N2)->getVT() == VT) return N1;  // Not actually rounding.
+    break;
+  case ISD::SIGN_EXTEND_INREG: {
+    MVT::ValueType EVT = cast<VTSDNode>(N2)->getVT();
+    if (EVT == VT) return N1;  // Not actually extending
+    break;
+  }
+  case ISD::EXTRACT_VECTOR_ELT:
+    assert(N2C && "Bad EXTRACT_VECTOR_ELT!");
+
+    // EXTRACT_VECTOR_ELT of CONCAT_VECTORS is often formed while lowering is
+    // expanding copies of large vectors from registers.
+    if (N1.getOpcode() == ISD::CONCAT_VECTORS &&
+        N1.getNumOperands() > 0) {
+      unsigned Factor =
+        MVT::getVectorNumElements(N1.getOperand(0).getValueType());
+      return getNode(ISD::EXTRACT_VECTOR_ELT, VT,
+                     N1.getOperand(N2C->getValue() / Factor),
+                     getConstant(N2C->getValue() % Factor, N2.getValueType()));
+    }
+
+    // EXTRACT_VECTOR_ELT of BUILD_VECTOR is often formed while lowering is
+    // expanding large vector constants.
+    if (N1.getOpcode() == ISD::BUILD_VECTOR)
+      return N1.getOperand(N2C->getValue());
+
+    // EXTRACT_VECTOR_ELT of INSERT_VECTOR_ELT is often formed when vector
+    // operations are lowered to scalars.
+    if (N1.getOpcode() == ISD::INSERT_VECTOR_ELT)
+      if (ConstantSDNode *IEC = dyn_cast<ConstantSDNode>(N1.getOperand(2))) {
+        if (IEC == N2C)
+          return N1.getOperand(1);
+        else
+          return getNode(ISD::EXTRACT_VECTOR_ELT, VT, N1.getOperand(0), N2);
+      }
+    break;
+  case ISD::EXTRACT_ELEMENT:
+    assert(N2C && (unsigned)N2C->getValue() < 2 && "Bad EXTRACT_ELEMENT!");
+    
+    // EXTRACT_ELEMENT of BUILD_PAIR is often formed while legalize is expanding
+    // 64-bit integers into 32-bit parts.  Instead of building the extract of
+    // the BUILD_PAIR, only to have legalize rip it apart, just do it now. 
+    if (N1.getOpcode() == ISD::BUILD_PAIR)
+      return N1.getOperand(N2C->getValue());
+    
+    // EXTRACT_ELEMENT of a constant int is also very common.
+    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(N1)) {
+      unsigned Shift = MVT::getSizeInBits(VT) * N2C->getValue();
+      return getConstant(C->getValue() >> Shift, VT);
+    }
+    break;
+
+  // FIXME: figure out how to safely handle things like
+  // int foo(int x) { return 1 << (x & 255); }
+  // int bar() { return foo(256); }
+#if 0
+  case ISD::SHL:
+  case ISD::SRL:
+  case ISD::SRA:
+    if (N2.getOpcode() == ISD::SIGN_EXTEND_INREG &&
+        cast<VTSDNode>(N2.getOperand(1))->getVT() != MVT::i1)
+      return getNode(Opcode, VT, N1, N2.getOperand(0));
+    else if (N2.getOpcode() == ISD::AND)
+      if (ConstantSDNode *AndRHS = dyn_cast<ConstantSDNode>(N2.getOperand(1))) {
+        // If the and is only masking out bits that cannot effect the shift,
+        // eliminate the and.
+        unsigned NumBits = MVT::getSizeInBits(VT);
+        if ((AndRHS->getValue() & (NumBits-1)) == NumBits-1)
+          return getNode(Opcode, VT, N1, N2.getOperand(0));
+      }
+    break;
+#endif
+  }
+
+  // Memoize this node if possible.
+  SDNode *N;
+  SDVTList VTs = getVTList(VT);
+  if (VT != MVT::Flag) {
+    SDOperand Ops[] = { N1, N2 };
+    FoldingSetNodeID ID;
+    AddNodeIDNode(ID, Opcode, VTs, Ops, 2);
+    void *IP = 0;
+    if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+      return SDOperand(E, 0);
+    N = new BinarySDNode(Opcode, VTs, N1, N2);
+    CSEMap.InsertNode(N, IP);
+  } else {
+    N = new BinarySDNode(Opcode, VTs, N1, N2);
+  }
+
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
+                                SDOperand N1, SDOperand N2, SDOperand N3) {
+  // Perform various simplifications.
+  ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
+  ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val);
+  switch (Opcode) {
+  case ISD::SETCC: {
+    // Use FoldSetCC to simplify SETCC's.
+    SDOperand Simp = FoldSetCC(VT, N1, N2, cast<CondCodeSDNode>(N3)->get());
+    if (Simp.Val) return Simp;
+    break;
+  }
+  case ISD::SELECT:
+    if (N1C)
+      if (N1C->getValue())
+        return N2;             // select true, X, Y -> X
+      else
+        return N3;             // select false, X, Y -> Y
+
+    if (N2 == N3) return N2;   // select C, X, X -> X
+    break;
+  case ISD::BRCOND:
+    if (N2C)
+      if (N2C->getValue()) // Unconditional branch
+        return getNode(ISD::BR, MVT::Other, N1, N3);
+      else
+        return N1;         // Never-taken branch
+    break;
+  case ISD::VECTOR_SHUFFLE:
+    assert(VT == N1.getValueType() && VT == N2.getValueType() &&
+           MVT::isVector(VT) && MVT::isVector(N3.getValueType()) &&
+           N3.getOpcode() == ISD::BUILD_VECTOR &&
+           MVT::getVectorNumElements(VT) == N3.getNumOperands() &&
+           "Illegal VECTOR_SHUFFLE node!");
+    break;
+  case ISD::BIT_CONVERT:
+    // Fold bit_convert nodes from a type to themselves.
+    if (N1.getValueType() == VT)
+      return N1;
+    break;
+  }
+
+  // Memoize node if it doesn't produce a flag.
+  SDNode *N;
+  SDVTList VTs = getVTList(VT);
+  if (VT != MVT::Flag) {
+    SDOperand Ops[] = { N1, N2, N3 };
+    FoldingSetNodeID ID;
+    AddNodeIDNode(ID, Opcode, VTs, Ops, 3);
+    void *IP = 0;
+    if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+      return SDOperand(E, 0);
+    N = new TernarySDNode(Opcode, VTs, N1, N2, N3);
+    CSEMap.InsertNode(N, IP);
+  } else {
+    N = new TernarySDNode(Opcode, VTs, N1, N2, N3);
+  }
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
+                                SDOperand N1, SDOperand N2, SDOperand N3,
+                                SDOperand N4) {
+  SDOperand Ops[] = { N1, N2, N3, N4 };
+  return getNode(Opcode, VT, Ops, 4);
+}
+
+SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
+                                SDOperand N1, SDOperand N2, SDOperand N3,
+                                SDOperand N4, SDOperand N5) {
+  SDOperand Ops[] = { N1, N2, N3, N4, N5 };
+  return getNode(Opcode, VT, Ops, 5);
+}
+
+SDOperand SelectionDAG::getLoad(MVT::ValueType VT,
+                                SDOperand Chain, SDOperand Ptr,
+                                const Value *SV, int SVOffset,
+                                bool isVolatile, unsigned Alignment) {
+  if (Alignment == 0) { // Ensure that codegen never sees alignment 0
+    const Type *Ty = 0;
+    if (VT != MVT::iPTR) {
+      Ty = MVT::getTypeForValueType(VT);
+    } else if (SV) {
+      const PointerType *PT = dyn_cast<PointerType>(SV->getType());
+      assert(PT && "Value for load must be a pointer");
+      Ty = PT->getElementType();
+    }  
+    assert(Ty && "Could not get type information for load");
+    Alignment = TLI.getTargetData()->getABITypeAlignment(Ty);
+  }
+  SDVTList VTs = getVTList(VT, MVT::Other);
+  SDOperand Undef = getNode(ISD::UNDEF, Ptr.getValueType());
+  SDOperand Ops[] = { Chain, Ptr, Undef };
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::LOAD, VTs, Ops, 3);
+  ID.AddInteger(ISD::UNINDEXED);
+  ID.AddInteger(ISD::NON_EXTLOAD);
+  ID.AddInteger(VT);
+  ID.AddPointer(SV);
+  ID.AddInteger(SVOffset);
+  ID.AddInteger(Alignment);
+  ID.AddInteger(isVolatile);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new LoadSDNode(Ops, VTs, ISD::UNINDEXED,
+                             ISD::NON_EXTLOAD, VT, SV, SVOffset, Alignment,
+                             isVolatile);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getExtLoad(ISD::LoadExtType ExtType, MVT::ValueType VT,
+                                   SDOperand Chain, SDOperand Ptr,
+                                   const Value *SV,
+                                   int SVOffset, MVT::ValueType EVT,
+                                   bool isVolatile, unsigned Alignment) {
+  // If they are asking for an extending load from/to the same thing, return a
+  // normal load.
+  if (VT == EVT)
+    ExtType = ISD::NON_EXTLOAD;
+
+  if (MVT::isVector(VT))
+    assert(EVT == MVT::getVectorElementType(VT) && "Invalid vector extload!");
+  else
+    assert(EVT < VT && "Should only be an extending load, not truncating!");
+  assert((ExtType == ISD::EXTLOAD || MVT::isInteger(VT)) &&
+         "Cannot sign/zero extend a FP/Vector load!");
+  assert(MVT::isInteger(VT) == MVT::isInteger(EVT) &&
+         "Cannot convert from FP to Int or Int -> FP!");
+
+  if (Alignment == 0) { // Ensure that codegen never sees alignment 0
+    const Type *Ty = 0;
+    if (VT != MVT::iPTR) {
+      Ty = MVT::getTypeForValueType(VT);
+    } else if (SV) {
+      const PointerType *PT = dyn_cast<PointerType>(SV->getType());
+      assert(PT && "Value for load must be a pointer");
+      Ty = PT->getElementType();
+    }  
+    assert(Ty && "Could not get type information for load");
+    Alignment = TLI.getTargetData()->getABITypeAlignment(Ty);
+  }
+  SDVTList VTs = getVTList(VT, MVT::Other);
+  SDOperand Undef = getNode(ISD::UNDEF, Ptr.getValueType());
+  SDOperand Ops[] = { Chain, Ptr, Undef };
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::LOAD, VTs, Ops, 3);
+  ID.AddInteger(ISD::UNINDEXED);
+  ID.AddInteger(ExtType);
+  ID.AddInteger(EVT);
+  ID.AddPointer(SV);
+  ID.AddInteger(SVOffset);
+  ID.AddInteger(Alignment);
+  ID.AddInteger(isVolatile);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new LoadSDNode(Ops, VTs, ISD::UNINDEXED, ExtType, EVT,
+                             SV, SVOffset, Alignment, isVolatile);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand
+SelectionDAG::getIndexedLoad(SDOperand OrigLoad, SDOperand Base,
+                             SDOperand Offset, ISD::MemIndexedMode AM) {
+  LoadSDNode *LD = cast<LoadSDNode>(OrigLoad);
+  assert(LD->getOffset().getOpcode() == ISD::UNDEF &&
+         "Load is already a indexed load!");
+  MVT::ValueType VT = OrigLoad.getValueType();
+  SDVTList VTs = getVTList(VT, Base.getValueType(), MVT::Other);
+  SDOperand Ops[] = { LD->getChain(), Base, Offset };
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::LOAD, VTs, Ops, 3);
+  ID.AddInteger(AM);
+  ID.AddInteger(LD->getExtensionType());
+  ID.AddInteger(LD->getLoadedVT());
+  ID.AddPointer(LD->getSrcValue());
+  ID.AddInteger(LD->getSrcValueOffset());
+  ID.AddInteger(LD->getAlignment());
+  ID.AddInteger(LD->isVolatile());
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new LoadSDNode(Ops, VTs, AM,
+                             LD->getExtensionType(), LD->getLoadedVT(),
+                             LD->getSrcValue(), LD->getSrcValueOffset(),
+                             LD->getAlignment(), LD->isVolatile());
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getStore(SDOperand Chain, SDOperand Val,
+                                 SDOperand Ptr, const Value *SV, int SVOffset,
+                                 bool isVolatile, unsigned Alignment) {
+  MVT::ValueType VT = Val.getValueType();
+
+  if (Alignment == 0) { // Ensure that codegen never sees alignment 0
+    const Type *Ty = 0;
+    if (VT != MVT::iPTR) {
+      Ty = MVT::getTypeForValueType(VT);
+    } else if (SV) {
+      const PointerType *PT = dyn_cast<PointerType>(SV->getType());
+      assert(PT && "Value for store must be a pointer");
+      Ty = PT->getElementType();
+    }
+    assert(Ty && "Could not get type information for store");
+    Alignment = TLI.getTargetData()->getABITypeAlignment(Ty);
+  }
+  SDVTList VTs = getVTList(MVT::Other);
+  SDOperand Undef = getNode(ISD::UNDEF, Ptr.getValueType());
+  SDOperand Ops[] = { Chain, Val, Ptr, Undef };
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::STORE, VTs, Ops, 4);
+  ID.AddInteger(ISD::UNINDEXED);
+  ID.AddInteger(false);
+  ID.AddInteger(VT);
+  ID.AddPointer(SV);
+  ID.AddInteger(SVOffset);
+  ID.AddInteger(Alignment);
+  ID.AddInteger(isVolatile);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new StoreSDNode(Ops, VTs, ISD::UNINDEXED, false,
+                              VT, SV, SVOffset, Alignment, isVolatile);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getTruncStore(SDOperand Chain, SDOperand Val,
+                                      SDOperand Ptr, const Value *SV,
+                                      int SVOffset, MVT::ValueType SVT,
+                                      bool isVolatile, unsigned Alignment) {
+  MVT::ValueType VT = Val.getValueType();
+  bool isTrunc = VT != SVT;
+
+  assert(VT > SVT && "Not a truncation?");
+  assert(MVT::isInteger(VT) == MVT::isInteger(SVT) &&
+         "Can't do FP-INT conversion!");
+
+  if (Alignment == 0) { // Ensure that codegen never sees alignment 0
+    const Type *Ty = 0;
+    if (VT != MVT::iPTR) {
+      Ty = MVT::getTypeForValueType(VT);
+    } else if (SV) {
+      const PointerType *PT = dyn_cast<PointerType>(SV->getType());
+      assert(PT && "Value for store must be a pointer");
+      Ty = PT->getElementType();
+    }
+    assert(Ty && "Could not get type information for store");
+    Alignment = TLI.getTargetData()->getABITypeAlignment(Ty);
+  }
+  SDVTList VTs = getVTList(MVT::Other);
+  SDOperand Undef = getNode(ISD::UNDEF, Ptr.getValueType());
+  SDOperand Ops[] = { Chain, Val, Ptr, Undef };
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::STORE, VTs, Ops, 4);
+  ID.AddInteger(ISD::UNINDEXED);
+  ID.AddInteger(isTrunc);
+  ID.AddInteger(SVT);
+  ID.AddPointer(SV);
+  ID.AddInteger(SVOffset);
+  ID.AddInteger(Alignment);
+  ID.AddInteger(isVolatile);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new StoreSDNode(Ops, VTs, ISD::UNINDEXED, isTrunc,
+                              SVT, SV, SVOffset, Alignment, isVolatile);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand
+SelectionDAG::getIndexedStore(SDOperand OrigStore, SDOperand Base,
+                              SDOperand Offset, ISD::MemIndexedMode AM) {
+  StoreSDNode *ST = cast<StoreSDNode>(OrigStore);
+  assert(ST->getOffset().getOpcode() == ISD::UNDEF &&
+         "Store is already a indexed store!");
+  SDVTList VTs = getVTList(Base.getValueType(), MVT::Other);
+  SDOperand Ops[] = { ST->getChain(), ST->getValue(), Base, Offset };
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::STORE, VTs, Ops, 4);
+  ID.AddInteger(AM);
+  ID.AddInteger(ST->isTruncatingStore());
+  ID.AddInteger(ST->getStoredVT());
+  ID.AddPointer(ST->getSrcValue());
+  ID.AddInteger(ST->getSrcValueOffset());
+  ID.AddInteger(ST->getAlignment());
+  ID.AddInteger(ST->isVolatile());
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDOperand(E, 0);
+  SDNode *N = new StoreSDNode(Ops, VTs, AM,
+                              ST->isTruncatingStore(), ST->getStoredVT(),
+                              ST->getSrcValue(), ST->getSrcValueOffset(),
+                              ST->getAlignment(), ST->isVolatile());
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getVAArg(MVT::ValueType VT,
+                                 SDOperand Chain, SDOperand Ptr,
+                                 SDOperand SV) {
+  SDOperand Ops[] = { Chain, Ptr, SV };
+  return getNode(ISD::VAARG, getVTList(VT, MVT::Other), Ops, 3);
+}
+
+SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
+                                const SDOperand *Ops, unsigned NumOps) {
+  switch (NumOps) {
+  case 0: return getNode(Opcode, VT);
+  case 1: return getNode(Opcode, VT, Ops[0]);
+  case 2: return getNode(Opcode, VT, Ops[0], Ops[1]);
+  case 3: return getNode(Opcode, VT, Ops[0], Ops[1], Ops[2]);
+  default: break;
+  }
+  
+  switch (Opcode) {
+  default: break;
+  case ISD::SELECT_CC: {
+    assert(NumOps == 5 && "SELECT_CC takes 5 operands!");
+    assert(Ops[0].getValueType() == Ops[1].getValueType() &&
+           "LHS and RHS of condition must have same type!");
+    assert(Ops[2].getValueType() == Ops[3].getValueType() &&
+           "True and False arms of SelectCC must have same type!");
+    assert(Ops[2].getValueType() == VT &&
+           "select_cc node must be of same type as true and false value!");
+    break;
+  }
+  case ISD::BR_CC: {
+    assert(NumOps == 5 && "BR_CC takes 5 operands!");
+    assert(Ops[2].getValueType() == Ops[3].getValueType() &&
+           "LHS/RHS of comparison should match types!");
+    break;
+  }
+  }
+
+  // Memoize nodes.
+  SDNode *N;
+  SDVTList VTs = getVTList(VT);
+  if (VT != MVT::Flag) {
+    FoldingSetNodeID ID;
+    AddNodeIDNode(ID, Opcode, VTs, Ops, NumOps);
+    void *IP = 0;
+    if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+      return SDOperand(E, 0);
+    N = new SDNode(Opcode, VTs, Ops, NumOps);
+    CSEMap.InsertNode(N, IP);
+  } else {
+    N = new SDNode(Opcode, VTs, Ops, NumOps);
+  }
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDOperand SelectionDAG::getNode(unsigned Opcode,
+                                std::vector<MVT::ValueType> &ResultTys,
+                                const SDOperand *Ops, unsigned NumOps) {
+  return getNode(Opcode, getNodeValueTypes(ResultTys), ResultTys.size(),
+                 Ops, NumOps);
+}
+
+SDOperand SelectionDAG::getNode(unsigned Opcode,
+                                const MVT::ValueType *VTs, unsigned NumVTs,
+                                const SDOperand *Ops, unsigned NumOps) {
+  if (NumVTs == 1)
+    return getNode(Opcode, VTs[0], Ops, NumOps);
+  return getNode(Opcode, makeVTList(VTs, NumVTs), Ops, NumOps);
+}  
+  
+SDOperand SelectionDAG::getNode(unsigned Opcode, SDVTList VTList,
+                                const SDOperand *Ops, unsigned NumOps) {
+  if (VTList.NumVTs == 1)
+    return getNode(Opcode, VTList.VTs[0], Ops, NumOps);
+
+  switch (Opcode) {
+  // FIXME: figure out how to safely handle things like
+  // int foo(int x) { return 1 << (x & 255); }
+  // int bar() { return foo(256); }
+#if 0
+  case ISD::SRA_PARTS:
+  case ISD::SRL_PARTS:
+  case ISD::SHL_PARTS:
+    if (N3.getOpcode() == ISD::SIGN_EXTEND_INREG &&
+        cast<VTSDNode>(N3.getOperand(1))->getVT() != MVT::i1)
+      return getNode(Opcode, VT, N1, N2, N3.getOperand(0));
+    else if (N3.getOpcode() == ISD::AND)
+      if (ConstantSDNode *AndRHS = dyn_cast<ConstantSDNode>(N3.getOperand(1))) {
+        // If the and is only masking out bits that cannot effect the shift,
+        // eliminate the and.
+        unsigned NumBits = MVT::getSizeInBits(VT)*2;
+        if ((AndRHS->getValue() & (NumBits-1)) == NumBits-1)
+          return getNode(Opcode, VT, N1, N2, N3.getOperand(0));
+      }
+    break;
+#endif
+  }
+
+  // Memoize the node unless it returns a flag.
+  SDNode *N;
+  if (VTList.VTs[VTList.NumVTs-1] != MVT::Flag) {
+    FoldingSetNodeID ID;
+    AddNodeIDNode(ID, Opcode, VTList, Ops, NumOps);
+    void *IP = 0;
+    if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+      return SDOperand(E, 0);
+    if (NumOps == 1)
+      N = new UnarySDNode(Opcode, VTList, Ops[0]);
+    else if (NumOps == 2)
+      N = new BinarySDNode(Opcode, VTList, Ops[0], Ops[1]);
+    else if (NumOps == 3)
+      N = new TernarySDNode(Opcode, VTList, Ops[0], Ops[1], Ops[2]);
+    else
+      N = new SDNode(Opcode, VTList, Ops, NumOps);
+    CSEMap.InsertNode(N, IP);
+  } else {
+    if (NumOps == 1)
+      N = new UnarySDNode(Opcode, VTList, Ops[0]);
+    else if (NumOps == 2)
+      N = new BinarySDNode(Opcode, VTList, Ops[0], Ops[1]);
+    else if (NumOps == 3)
+      N = new TernarySDNode(Opcode, VTList, Ops[0], Ops[1], Ops[2]);
+    else
+      N = new SDNode(Opcode, VTList, Ops, NumOps);
+  }
+  AllNodes.push_back(N);
+  return SDOperand(N, 0);
+}
+
+SDVTList SelectionDAG::getVTList(MVT::ValueType VT) {
+  if (!MVT::isExtendedVT(VT))
+    return makeVTList(SDNode::getValueTypeList(VT), 1);
+
+  for (std::list<std::vector<MVT::ValueType> >::iterator I = VTList.begin(),
+       E = VTList.end(); I != E; ++I) {
+    if (I->size() == 1 && (*I)[0] == VT)
+      return makeVTList(&(*I)[0], 1);
+  }
+  std::vector<MVT::ValueType> V;
+  V.push_back(VT);
+  VTList.push_front(V);
+  return makeVTList(&(*VTList.begin())[0], 1);
+}
+
+SDVTList SelectionDAG::getVTList(MVT::ValueType VT1, MVT::ValueType VT2) {
+  for (std::list<std::vector<MVT::ValueType> >::iterator I = VTList.begin(),
+       E = VTList.end(); I != E; ++I) {
+    if (I->size() == 2 && (*I)[0] == VT1 && (*I)[1] == VT2)
+      return makeVTList(&(*I)[0], 2);
+  }
+  std::vector<MVT::ValueType> V;
+  V.push_back(VT1);
+  V.push_back(VT2);
+  VTList.push_front(V);
+  return makeVTList(&(*VTList.begin())[0], 2);
+}
+SDVTList SelectionDAG::getVTList(MVT::ValueType VT1, MVT::ValueType VT2,
+                                 MVT::ValueType VT3) {
+  for (std::list<std::vector<MVT::ValueType> >::iterator I = VTList.begin(),
+       E = VTList.end(); I != E; ++I) {
+    if (I->size() == 3 && (*I)[0] == VT1 && (*I)[1] == VT2 &&
+        (*I)[2] == VT3)
+      return makeVTList(&(*I)[0], 3);
+  }
+  std::vector<MVT::ValueType> V;
+  V.push_back(VT1);
+  V.push_back(VT2);
+  V.push_back(VT3);
+  VTList.push_front(V);
+  return makeVTList(&(*VTList.begin())[0], 3);
+}
+
+SDVTList SelectionDAG::getVTList(const MVT::ValueType *VTs, unsigned NumVTs) {
+  switch (NumVTs) {
+    case 0: assert(0 && "Cannot have nodes without results!");
+    case 1: return getVTList(VTs[0]);
+    case 2: return getVTList(VTs[0], VTs[1]);
+    case 3: return getVTList(VTs[0], VTs[1], VTs[2]);
+    default: break;
+  }
+
+  for (std::list<std::vector<MVT::ValueType> >::iterator I = VTList.begin(),
+       E = VTList.end(); I != E; ++I) {
+    if (I->size() != NumVTs || VTs[0] != (*I)[0] || VTs[1] != (*I)[1]) continue;
+   
+    bool NoMatch = false;
+    for (unsigned i = 2; i != NumVTs; ++i)
+      if (VTs[i] != (*I)[i]) {
+        NoMatch = true;
+        break;
+      }
+    if (!NoMatch)
+      return makeVTList(&*I->begin(), NumVTs);
+  }
+  
+  VTList.push_front(std::vector<MVT::ValueType>(VTs, VTs+NumVTs));
+  return makeVTList(&*VTList.begin()->begin(), NumVTs);
+}
+
+
+/// UpdateNodeOperands - *Mutate* the specified node in-place to have the
+/// specified operands.  If the resultant node already exists in the DAG,
+/// this does not modify the specified node, instead it returns the node that
+/// already exists.  If the resultant node does not exist in the DAG, the
+/// input node is returned.  As a degenerate case, if you specify the same
+/// input operands as the node already has, the input node is returned.
+SDOperand SelectionDAG::
+UpdateNodeOperands(SDOperand InN, SDOperand Op) {
+  SDNode *N = InN.Val;
+  assert(N->getNumOperands() == 1 && "Update with wrong number of operands");
+  
+  // Check to see if there is no change.
+  if (Op == N->getOperand(0)) return InN;
+  
+  // See if the modified node already exists.
+  void *InsertPos = 0;
+  if (SDNode *Existing = FindModifiedNodeSlot(N, Op, InsertPos))
+    return SDOperand(Existing, InN.ResNo);
+  
+  // Nope it doesn't.  Remove the node from it's current place in the maps.
+  if (InsertPos)
+    RemoveNodeFromCSEMaps(N);
+  
+  // Now we update the operands.
+  N->OperandList[0].Val->removeUser(N);
+  Op.Val->addUser(N);
+  N->OperandList[0] = Op;
+  
+  // If this gets put into a CSE map, add it.
+  if (InsertPos) CSEMap.InsertNode(N, InsertPos);
+  return InN;
+}
+
+SDOperand SelectionDAG::
+UpdateNodeOperands(SDOperand InN, SDOperand Op1, SDOperand Op2) {
+  SDNode *N = InN.Val;
+  assert(N->getNumOperands() == 2 && "Update with wrong number of operands");
+  
+  // Check to see if there is no change.
+  if (Op1 == N->getOperand(0) && Op2 == N->getOperand(1))
+    return InN;   // No operands changed, just return the input node.
+  
+  // See if the modified node already exists.
+  void *InsertPos = 0;
+  if (SDNode *Existing = FindModifiedNodeSlot(N, Op1, Op2, InsertPos))
+    return SDOperand(Existing, InN.ResNo);
+  
+  // Nope it doesn't.  Remove the node from it's current place in the maps.
+  if (InsertPos)
+    RemoveNodeFromCSEMaps(N);
+  
+  // Now we update the operands.
+  if (N->OperandList[0] != Op1) {
+    N->OperandList[0].Val->removeUser(N);
+    Op1.Val->addUser(N);
+    N->OperandList[0] = Op1;
+  }
+  if (N->OperandList[1] != Op2) {
+    N->OperandList[1].Val->removeUser(N);
+    Op2.Val->addUser(N);
+    N->OperandList[1] = Op2;
+  }
+  
+  // If this gets put into a CSE map, add it.
+  if (InsertPos) CSEMap.InsertNode(N, InsertPos);
+  return InN;
+}
+
+SDOperand SelectionDAG::
+UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2, SDOperand Op3) {
+  SDOperand Ops[] = { Op1, Op2, Op3 };
+  return UpdateNodeOperands(N, Ops, 3);
+}
+
+SDOperand SelectionDAG::
+UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2, 
+                   SDOperand Op3, SDOperand Op4) {
+  SDOperand Ops[] = { Op1, Op2, Op3, Op4 };
+  return UpdateNodeOperands(N, Ops, 4);
+}
+
+SDOperand SelectionDAG::
+UpdateNodeOperands(SDOperand N, SDOperand Op1, SDOperand Op2,
+                   SDOperand Op3, SDOperand Op4, SDOperand Op5) {
+  SDOperand Ops[] = { Op1, Op2, Op3, Op4, Op5 };
+  return UpdateNodeOperands(N, Ops, 5);
+}
+
+
+SDOperand SelectionDAG::
+UpdateNodeOperands(SDOperand InN, SDOperand *Ops, unsigned NumOps) {
+  SDNode *N = InN.Val;
+  assert(N->getNumOperands() == NumOps &&
+         "Update with wrong number of operands");
+  
+  // Check to see if there is no change.
+  bool AnyChange = false;
+  for (unsigned i = 0; i != NumOps; ++i) {
+    if (Ops[i] != N->getOperand(i)) {
+      AnyChange = true;
+      break;
+    }
+  }
+  
+  // No operands changed, just return the input node.
+  if (!AnyChange) return InN;
+  
+  // See if the modified node already exists.
+  void *InsertPos = 0;
+  if (SDNode *Existing = FindModifiedNodeSlot(N, Ops, NumOps, InsertPos))
+    return SDOperand(Existing, InN.ResNo);
+  
+  // Nope it doesn't.  Remove the node from it's current place in the maps.
+  if (InsertPos)
+    RemoveNodeFromCSEMaps(N);
+  
+  // Now we update the operands.
+  for (unsigned i = 0; i != NumOps; ++i) {
+    if (N->OperandList[i] != Ops[i]) {
+      N->OperandList[i].Val->removeUser(N);
+      Ops[i].Val->addUser(N);
+      N->OperandList[i] = Ops[i];
+    }
+  }
+
+  // If this gets put into a CSE map, add it.
+  if (InsertPos) CSEMap.InsertNode(N, InsertPos);
+  return InN;
+}
+
+
+/// MorphNodeTo - This frees the operands of the current node, resets the
+/// opcode, types, and operands to the specified value.  This should only be
+/// used by the SelectionDAG class.
+void SDNode::MorphNodeTo(unsigned Opc, SDVTList L,
+                         const SDOperand *Ops, unsigned NumOps) {
+  NodeType = Opc;
+  ValueList = L.VTs;
+  NumValues = L.NumVTs;
+  
+  // Clear the operands list, updating used nodes to remove this from their
+  // use list.
+  for (op_iterator I = op_begin(), E = op_end(); I != E; ++I)
+    I->Val->removeUser(this);
+  
+  // If NumOps is larger than the # of operands we currently have, reallocate
+  // the operand list.
+  if (NumOps > NumOperands) {
+    if (OperandsNeedDelete)
+      delete [] OperandList;
+    OperandList = new SDOperand[NumOps];
+    OperandsNeedDelete = true;
+  }
+  
+  // Assign the new operands.
+  NumOperands = NumOps;
+  
+  for (unsigned i = 0, e = NumOps; i != e; ++i) {
+    OperandList[i] = Ops[i];
+    SDNode *N = OperandList[i].Val;
+    N->Uses.push_back(this);
+  }
+}
+
+/// SelectNodeTo - These are used for target selectors to *mutate* the
+/// specified node to have the specified return type, Target opcode, and
+/// operands.  Note that target opcodes are stored as
+/// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field.
+///
+/// Note that SelectNodeTo returns the resultant node.  If there is already a
+/// node of the specified opcode and operands, it returns that node instead of
+/// the current one.
+SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned TargetOpc,
+                                   MVT::ValueType VT) {
+  SDVTList VTs = getVTList(VT);
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::BUILTIN_OP_END+TargetOpc, VTs, 0, 0);
+  void *IP = 0;
+  if (SDNode *ON = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return ON;
+   
+  RemoveNodeFromCSEMaps(N);
+  
+  N->MorphNodeTo(ISD::BUILTIN_OP_END+TargetOpc, VTs, 0, 0);
+
+  CSEMap.InsertNode(N, IP);
+  return N;
+}
+
+SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned TargetOpc,
+                                   MVT::ValueType VT, SDOperand Op1) {
+  // If an identical node already exists, use it.
+  SDVTList VTs = getVTList(VT);
+  SDOperand Ops[] = { Op1 };
+  
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::BUILTIN_OP_END+TargetOpc, VTs, Ops, 1);
+  void *IP = 0;
+  if (SDNode *ON = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return ON;
+                                       
+  RemoveNodeFromCSEMaps(N);
+  N->MorphNodeTo(ISD::BUILTIN_OP_END+TargetOpc, VTs, Ops, 1);
+  CSEMap.InsertNode(N, IP);
+  return N;
+}
+
+SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned TargetOpc,
+                                   MVT::ValueType VT, SDOperand Op1,
+                                   SDOperand Op2) {
+  // If an identical node already exists, use it.
+  SDVTList VTs = getVTList(VT);
+  SDOperand Ops[] = { Op1, Op2 };
+  
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::BUILTIN_OP_END+TargetOpc, VTs, Ops, 2);
+  void *IP = 0;
+  if (SDNode *ON = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return ON;
+                                       
+  RemoveNodeFromCSEMaps(N);
+  
+  N->MorphNodeTo(ISD::BUILTIN_OP_END+TargetOpc, VTs, Ops, 2);
+  
+  CSEMap.InsertNode(N, IP);   // Memoize the new node.
+  return N;
+}
+
+SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned TargetOpc,
+                                   MVT::ValueType VT, SDOperand Op1,
+                                   SDOperand Op2, SDOperand Op3) {
+  // If an identical node already exists, use it.
+  SDVTList VTs = getVTList(VT);
+  SDOperand Ops[] = { Op1, Op2, Op3 };
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::BUILTIN_OP_END+TargetOpc, VTs, Ops, 3);
+  void *IP = 0;
+  if (SDNode *ON = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return ON;
+                                       
+  RemoveNodeFromCSEMaps(N);
+  
+  N->MorphNodeTo(ISD::BUILTIN_OP_END+TargetOpc, VTs, Ops, 3);
+
+  CSEMap.InsertNode(N, IP);   // Memoize the new node.
+  return N;
+}
+
+SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned TargetOpc,
+                                   MVT::ValueType VT, const SDOperand *Ops,
+                                   unsigned NumOps) {
+  // If an identical node already exists, use it.
+  SDVTList VTs = getVTList(VT);
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::BUILTIN_OP_END+TargetOpc, VTs, Ops, NumOps);
+  void *IP = 0;
+  if (SDNode *ON = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return ON;
+                                       
+  RemoveNodeFromCSEMaps(N);
+  N->MorphNodeTo(ISD::BUILTIN_OP_END+TargetOpc, VTs, Ops, NumOps);
+  
+  CSEMap.InsertNode(N, IP);   // Memoize the new node.
+  return N;
+}
+
+SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned TargetOpc, 
+                                   MVT::ValueType VT1, MVT::ValueType VT2,
+                                   SDOperand Op1, SDOperand Op2) {
+  SDVTList VTs = getVTList(VT1, VT2);
+  FoldingSetNodeID ID;
+  SDOperand Ops[] = { Op1, Op2 };
+  AddNodeIDNode(ID, ISD::BUILTIN_OP_END+TargetOpc, VTs, Ops, 2);
+  void *IP = 0;
+  if (SDNode *ON = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return ON;
+
+  RemoveNodeFromCSEMaps(N);
+  N->MorphNodeTo(ISD::BUILTIN_OP_END+TargetOpc, VTs, Ops, 2);
+  CSEMap.InsertNode(N, IP);   // Memoize the new node.
+  return N;
+}
+
+SDNode *SelectionDAG::SelectNodeTo(SDNode *N, unsigned TargetOpc,
+                                   MVT::ValueType VT1, MVT::ValueType VT2,
+                                   SDOperand Op1, SDOperand Op2, 
+                                   SDOperand Op3) {
+  // If an identical node already exists, use it.
+  SDVTList VTs = getVTList(VT1, VT2);
+  SDOperand Ops[] = { Op1, Op2, Op3 };
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::BUILTIN_OP_END+TargetOpc, VTs, Ops, 3);
+  void *IP = 0;
+  if (SDNode *ON = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return ON;
+
+  RemoveNodeFromCSEMaps(N);
+
+  N->MorphNodeTo(ISD::BUILTIN_OP_END+TargetOpc, VTs, Ops, 3);
+  CSEMap.InsertNode(N, IP);   // Memoize the new node.
+  return N;
+}
+
+
+/// getTargetNode - These are used for target selectors to create a new node
+/// with specified return type(s), target opcode, and operands.
+///
+/// Note that getTargetNode returns the resultant node.  If there is already a
+/// node of the specified opcode and operands, it returns that node instead of
+/// the current one.
+SDNode *SelectionDAG::getTargetNode(unsigned Opcode, MVT::ValueType VT) {
+  return getNode(ISD::BUILTIN_OP_END+Opcode, VT).Val;
+}
+SDNode *SelectionDAG::getTargetNode(unsigned Opcode, MVT::ValueType VT,
+                                    SDOperand Op1) {
+  return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1).Val;
+}
+SDNode *SelectionDAG::getTargetNode(unsigned Opcode, MVT::ValueType VT,
+                                    SDOperand Op1, SDOperand Op2) {
+  return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2).Val;
+}
+SDNode *SelectionDAG::getTargetNode(unsigned Opcode, MVT::ValueType VT,
+                                    SDOperand Op1, SDOperand Op2,
+                                    SDOperand Op3) {
+  return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3).Val;
+}
+SDNode *SelectionDAG::getTargetNode(unsigned Opcode, MVT::ValueType VT,
+                                    const SDOperand *Ops, unsigned NumOps) {
+  return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Ops, NumOps).Val;
+}
+SDNode *SelectionDAG::getTargetNode(unsigned Opcode, MVT::ValueType VT1,
+                                    MVT::ValueType VT2, SDOperand Op1) {
+  const MVT::ValueType *VTs = getNodeValueTypes(VT1, VT2);
+  return getNode(ISD::BUILTIN_OP_END+Opcode, VTs, 2, &Op1, 1).Val;
+}
+SDNode *SelectionDAG::getTargetNode(unsigned Opcode, MVT::ValueType VT1,
+                                    MVT::ValueType VT2, SDOperand Op1,
+                                    SDOperand Op2) {
+  const MVT::ValueType *VTs = getNodeValueTypes(VT1, VT2);
+  SDOperand Ops[] = { Op1, Op2 };
+  return getNode(ISD::BUILTIN_OP_END+Opcode, VTs, 2, Ops, 2).Val;
+}
+SDNode *SelectionDAG::getTargetNode(unsigned Opcode, MVT::ValueType VT1,
+                                    MVT::ValueType VT2, SDOperand Op1,
+                                    SDOperand Op2, SDOperand Op3) {
+  const MVT::ValueType *VTs = getNodeValueTypes(VT1, VT2);
+  SDOperand Ops[] = { Op1, Op2, Op3 };
+  return getNode(ISD::BUILTIN_OP_END+Opcode, VTs, 2, Ops, 3).Val;
+}
+SDNode *SelectionDAG::getTargetNode(unsigned Opcode, MVT::ValueType VT1, 
+                                    MVT::ValueType VT2,
+                                    const SDOperand *Ops, unsigned NumOps) {
+  const MVT::ValueType *VTs = getNodeValueTypes(VT1, VT2);
+  return getNode(ISD::BUILTIN_OP_END+Opcode, VTs, 2, Ops, NumOps).Val;
+}
+SDNode *SelectionDAG::getTargetNode(unsigned Opcode, MVT::ValueType VT1,
+                                    MVT::ValueType VT2, MVT::ValueType VT3,
+                                    SDOperand Op1, SDOperand Op2) {
+  const MVT::ValueType *VTs = getNodeValueTypes(VT1, VT2, VT3);
+  SDOperand Ops[] = { Op1, Op2 };
+  return getNode(ISD::BUILTIN_OP_END+Opcode, VTs, 3, Ops, 2).Val;
+}
+SDNode *SelectionDAG::getTargetNode(unsigned Opcode, MVT::ValueType VT1,
+                                    MVT::ValueType VT2, MVT::ValueType VT3,
+                                    SDOperand Op1, SDOperand Op2,
+                                    SDOperand Op3) {
+  const MVT::ValueType *VTs = getNodeValueTypes(VT1, VT2, VT3);
+  SDOperand Ops[] = { Op1, Op2, Op3 };
+  return getNode(ISD::BUILTIN_OP_END+Opcode, VTs, 3, Ops, 3).Val;
+}
+SDNode *SelectionDAG::getTargetNode(unsigned Opcode, MVT::ValueType VT1, 
+                                    MVT::ValueType VT2, MVT::ValueType VT3,
+                                    const SDOperand *Ops, unsigned NumOps) {
+  const MVT::ValueType *VTs = getNodeValueTypes(VT1, VT2, VT3);
+  return getNode(ISD::BUILTIN_OP_END+Opcode, VTs, 3, Ops, NumOps).Val;
+}
+
+/// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
+/// This can cause recursive merging of nodes in the DAG.
+///
+/// This version assumes From/To have a single result value.
+///
+void SelectionDAG::ReplaceAllUsesWith(SDOperand FromN, SDOperand ToN,
+                                      std::vector<SDNode*> *Deleted) {
+  SDNode *From = FromN.Val, *To = ToN.Val;
+  assert(From->getNumValues() == 1 && To->getNumValues() == 1 &&
+         "Cannot replace with this method!");
+  assert(From != To && "Cannot replace uses of with self");
+  
+  while (!From->use_empty()) {
+    // Process users until they are all gone.
+    SDNode *U = *From->use_begin();
+    
+    // This node is about to morph, remove its old self from the CSE maps.
+    RemoveNodeFromCSEMaps(U);
+    
+    for (SDOperand *I = U->OperandList, *E = U->OperandList+U->NumOperands;
+         I != E; ++I)
+      if (I->Val == From) {
+        From->removeUser(U);
+        I->Val = To;
+        To->addUser(U);
+      }
+
+    // Now that we have modified U, add it back to the CSE maps.  If it already
+    // exists there, recursively merge the results together.
+    if (SDNode *Existing = AddNonLeafNodeToCSEMaps(U)) {
+      ReplaceAllUsesWith(U, Existing, Deleted);
+      // U is now dead.
+      if (Deleted) Deleted->push_back(U);
+      DeleteNodeNotInCSEMaps(U);
+    }
+  }
+}
+
+/// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
+/// This can cause recursive merging of nodes in the DAG.
+///
+/// This version assumes From/To have matching types and numbers of result
+/// values.
+///
+void SelectionDAG::ReplaceAllUsesWith(SDNode *From, SDNode *To,
+                                      std::vector<SDNode*> *Deleted) {
+  assert(From != To && "Cannot replace uses of with self");
+  assert(From->getNumValues() == To->getNumValues() &&
+         "Cannot use this version of ReplaceAllUsesWith!");
+  if (From->getNumValues() == 1) {  // If possible, use the faster version.
+    ReplaceAllUsesWith(SDOperand(From, 0), SDOperand(To, 0), Deleted);
+    return;
+  }
+  
+  while (!From->use_empty()) {
+    // Process users until they are all gone.
+    SDNode *U = *From->use_begin();
+    
+    // This node is about to morph, remove its old self from the CSE maps.
+    RemoveNodeFromCSEMaps(U);
+    
+    for (SDOperand *I = U->OperandList, *E = U->OperandList+U->NumOperands;
+         I != E; ++I)
+      if (I->Val == From) {
+        From->removeUser(U);
+        I->Val = To;
+        To->addUser(U);
+      }
+        
+    // Now that we have modified U, add it back to the CSE maps.  If it already
+    // exists there, recursively merge the results together.
+    if (SDNode *Existing = AddNonLeafNodeToCSEMaps(U)) {
+      ReplaceAllUsesWith(U, Existing, Deleted);
+      // U is now dead.
+      if (Deleted) Deleted->push_back(U);
+      DeleteNodeNotInCSEMaps(U);
+    }
+  }
+}
+
+/// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
+/// This can cause recursive merging of nodes in the DAG.
+///
+/// This version can replace From with any result values.  To must match the
+/// number and types of values returned by From.
+void SelectionDAG::ReplaceAllUsesWith(SDNode *From,
+                                      const SDOperand *To,
+                                      std::vector<SDNode*> *Deleted) {
+  if (From->getNumValues() == 1 && To[0].Val->getNumValues() == 1) {
+    // Degenerate case handled above.
+    ReplaceAllUsesWith(SDOperand(From, 0), To[0], Deleted);
+    return;
+  }
+
+  while (!From->use_empty()) {
+    // Process users until they are all gone.
+    SDNode *U = *From->use_begin();
+    
+    // This node is about to morph, remove its old self from the CSE maps.
+    RemoveNodeFromCSEMaps(U);
+    
+    for (SDOperand *I = U->OperandList, *E = U->OperandList+U->NumOperands;
+         I != E; ++I)
+      if (I->Val == From) {
+        const SDOperand &ToOp = To[I->ResNo];
+        From->removeUser(U);
+        *I = ToOp;
+        ToOp.Val->addUser(U);
+      }
+        
+    // Now that we have modified U, add it back to the CSE maps.  If it already
+    // exists there, recursively merge the results together.
+    if (SDNode *Existing = AddNonLeafNodeToCSEMaps(U)) {
+      ReplaceAllUsesWith(U, Existing, Deleted);
+      // U is now dead.
+      if (Deleted) Deleted->push_back(U);
+      DeleteNodeNotInCSEMaps(U);
+    }
+  }
+}
+
+/// ReplaceAllUsesOfValueWith - Replace any uses of From with To, leaving
+/// uses of other values produced by From.Val alone.  The Deleted vector is
+/// handled the same was as for ReplaceAllUsesWith.
+void SelectionDAG::ReplaceAllUsesOfValueWith(SDOperand From, SDOperand To,
+                                             std::vector<SDNode*> &Deleted) {
+  assert(From != To && "Cannot replace a value with itself");
+  // Handle the simple, trivial, case efficiently.
+  if (From.Val->getNumValues() == 1 && To.Val->getNumValues() == 1) {
+    ReplaceAllUsesWith(From, To, &Deleted);
+    return;
+  }
+  
+  // Get all of the users of From.Val.  We want these in a nice,
+  // deterministically ordered and uniqued set, so we use a SmallSetVector.
+  SmallSetVector<SDNode*, 16> Users(From.Val->use_begin(), From.Val->use_end());
+
+  while (!Users.empty()) {
+    // We know that this user uses some value of From.  If it is the right
+    // value, update it.
+    SDNode *User = Users.back();
+    Users.pop_back();
+    
+    for (SDOperand *Op = User->OperandList,
+         *E = User->OperandList+User->NumOperands; Op != E; ++Op) {
+      if (*Op == From) {
+        // Okay, we know this user needs to be updated.  Remove its old self
+        // from the CSE maps.
+        RemoveNodeFromCSEMaps(User);
+        
+        // Update all operands that match "From".
+        for (; Op != E; ++Op) {
+          if (*Op == From) {
+            From.Val->removeUser(User);
+            *Op = To;
+            To.Val->addUser(User);
+          }
+        }
+                   
+        // Now that we have modified User, add it back to the CSE maps.  If it
+        // already exists there, recursively merge the results together.
+        if (SDNode *Existing = AddNonLeafNodeToCSEMaps(User)) {
+          unsigned NumDeleted = Deleted.size();
+          ReplaceAllUsesWith(User, Existing, &Deleted);
+          
+          // User is now dead.
+          Deleted.push_back(User);
+          DeleteNodeNotInCSEMaps(User);
+          
+          // We have to be careful here, because ReplaceAllUsesWith could have
+          // deleted a user of From, which means there may be dangling pointers
+          // in the "Users" setvector.  Scan over the deleted node pointers and
+          // remove them from the setvector.
+          for (unsigned i = NumDeleted, e = Deleted.size(); i != e; ++i)
+            Users.remove(Deleted[i]);
+        }
+        break;   // Exit the operand scanning loop.
+      }
+    }
+  }
+}
+
+
+/// AssignNodeIds - Assign a unique node id for each node in the DAG based on
+/// their allnodes order. It returns the maximum id.
+unsigned SelectionDAG::AssignNodeIds() {
+  unsigned Id = 0;
+  for (allnodes_iterator I = allnodes_begin(), E = allnodes_end(); I != E; ++I){
+    SDNode *N = I;
+    N->setNodeId(Id++);
+  }
+  return Id;
+}
+
+/// AssignTopologicalOrder - Assign a unique node id for each node in the DAG
+/// based on their topological order. It returns the maximum id and a vector
+/// of the SDNodes* in assigned order by reference.
+unsigned SelectionDAG::AssignTopologicalOrder(std::vector<SDNode*> &TopOrder) {
+  unsigned DAGSize = AllNodes.size();
+  std::vector<unsigned> InDegree(DAGSize);
+  std::vector<SDNode*> Sources;
+
+  // Use a two pass approach to avoid using a std::map which is slow.
+  unsigned Id = 0;
+  for (allnodes_iterator I = allnodes_begin(),E = allnodes_end(); I != E; ++I){
+    SDNode *N = I;
+    N->setNodeId(Id++);
+    unsigned Degree = N->use_size();
+    InDegree[N->getNodeId()] = Degree;
+    if (Degree == 0)
+      Sources.push_back(N);
+  }
+
+  TopOrder.clear();
+  while (!Sources.empty()) {
+    SDNode *N = Sources.back();
+    Sources.pop_back();
+    TopOrder.push_back(N);
+    for (SDNode::op_iterator I = N->op_begin(), E = N->op_end(); I != E; ++I) {
+      SDNode *P = I->Val;
+      unsigned Degree = --InDegree[P->getNodeId()];
+      if (Degree == 0)
+        Sources.push_back(P);
+    }
+  }
+
+  // Second pass, assign the actual topological order as node ids.
+  Id = 0;
+  for (std::vector<SDNode*>::iterator TI = TopOrder.begin(),TE = TopOrder.end();
+       TI != TE; ++TI)
+    (*TI)->setNodeId(Id++);
+
+  return Id;
+}
+
+
+
+//===----------------------------------------------------------------------===//
+//                              SDNode Class
+//===----------------------------------------------------------------------===//
+
+// Out-of-line virtual method to give class a home.
+void SDNode::ANCHOR() {}
+void UnarySDNode::ANCHOR() {}
+void BinarySDNode::ANCHOR() {}
+void TernarySDNode::ANCHOR() {}
+void HandleSDNode::ANCHOR() {}
+void StringSDNode::ANCHOR() {}
+void ConstantSDNode::ANCHOR() {}
+void ConstantFPSDNode::ANCHOR() {}
+void GlobalAddressSDNode::ANCHOR() {}
+void FrameIndexSDNode::ANCHOR() {}
+void JumpTableSDNode::ANCHOR() {}
+void ConstantPoolSDNode::ANCHOR() {}
+void BasicBlockSDNode::ANCHOR() {}
+void SrcValueSDNode::ANCHOR() {}
+void RegisterSDNode::ANCHOR() {}
+void ExternalSymbolSDNode::ANCHOR() {}
+void CondCodeSDNode::ANCHOR() {}
+void VTSDNode::ANCHOR() {}
+void LoadSDNode::ANCHOR() {}
+void StoreSDNode::ANCHOR() {}
+
+HandleSDNode::~HandleSDNode() {
+  SDVTList VTs = { 0, 0 };
+  MorphNodeTo(ISD::HANDLENODE, VTs, 0, 0);  // Drops operand uses.
+}
+
+GlobalAddressSDNode::GlobalAddressSDNode(bool isTarget, const GlobalValue *GA,
+                                         MVT::ValueType VT, int o)
+  : SDNode(isa<GlobalVariable>(GA) &&
+           dyn_cast<GlobalVariable>(GA)->isThreadLocal() ?
+           // Thread Local
+           (isTarget ? ISD::TargetGlobalTLSAddress : ISD::GlobalTLSAddress) :
+           // Non Thread Local
+           (isTarget ? ISD::TargetGlobalAddress : ISD::GlobalAddress),
+           getSDVTList(VT)), Offset(o) {
+  TheGlobal = const_cast<GlobalValue*>(GA);
+}
+
+/// Profile - Gather unique data for the node.
+///
+void SDNode::Profile(FoldingSetNodeID &ID) {
+  AddNodeIDNode(ID, this);
+}
+
+/// getValueTypeList - Return a pointer to the specified value type.
+///
+MVT::ValueType *SDNode::getValueTypeList(MVT::ValueType VT) {
+  static MVT::ValueType VTs[MVT::LAST_VALUETYPE];
+  VTs[VT] = VT;
+  return &VTs[VT];
+}
+  
+/// hasNUsesOfValue - Return true if there are exactly NUSES uses of the
+/// indicated value.  This method ignores uses of other values defined by this
+/// operation.
+bool SDNode::hasNUsesOfValue(unsigned NUses, unsigned Value) const {
+  assert(Value < getNumValues() && "Bad value!");
+
+  // If there is only one value, this is easy.
+  if (getNumValues() == 1)
+    return use_size() == NUses;
+  if (Uses.size() < NUses) return false;
+
+  SDOperand TheValue(const_cast<SDNode *>(this), Value);
+
+  SmallPtrSet<SDNode*, 32> UsersHandled;
+
+  for (SDNode::use_iterator UI = Uses.begin(), E = Uses.end(); UI != E; ++UI) {
+    SDNode *User = *UI;
+    if (User->getNumOperands() == 1 ||
+        UsersHandled.insert(User))     // First time we've seen this?
+      for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i)
+        if (User->getOperand(i) == TheValue) {
+          if (NUses == 0)
+            return false;   // too many uses
+          --NUses;
+        }
+  }
+
+  // Found exactly the right number of uses?
+  return NUses == 0;
+}
+
+
+/// isOnlyUse - Return true if this node is the only use of N.
+///
+bool SDNode::isOnlyUse(SDNode *N) const {
+  bool Seen = false;
+  for (SDNode::use_iterator I = N->use_begin(), E = N->use_end(); I != E; ++I) {
+    SDNode *User = *I;
+    if (User == this)
+      Seen = true;
+    else
+      return false;
+  }
+
+  return Seen;
+}
+
+/// isOperand - Return true if this node is an operand of N.
+///
+bool SDOperand::isOperand(SDNode *N) const {
+  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
+    if (*this == N->getOperand(i))
+      return true;
+  return false;
+}
+
+bool SDNode::isOperand(SDNode *N) const {
+  for (unsigned i = 0, e = N->NumOperands; i != e; ++i)
+    if (this == N->OperandList[i].Val)
+      return true;
+  return false;
+}
+
+static void findPredecessor(SDNode *N, const SDNode *P, bool &found,
+                            SmallPtrSet<SDNode *, 32> &Visited) {
+  if (found || !Visited.insert(N))
+    return;
+
+  for (unsigned i = 0, e = N->getNumOperands(); !found && i != e; ++i) {
+    SDNode *Op = N->getOperand(i).Val;
+    if (Op == P) {
+      found = true;
+      return;
+    }
+    findPredecessor(Op, P, found, Visited);
+  }
+}
+
+/// isPredecessor - Return true if this node is a predecessor of N. This node
+/// is either an operand of N or it can be reached by recursively traversing
+/// up the operands.
+/// NOTE: this is an expensive method. Use it carefully.
+bool SDNode::isPredecessor(SDNode *N) const {
+  SmallPtrSet<SDNode *, 32> Visited;
+  bool found = false;
+  findPredecessor(N, this, found, Visited);
+  return found;
+}
+
+uint64_t SDNode::getConstantOperandVal(unsigned Num) const {
+  assert(Num < NumOperands && "Invalid child # of SDNode!");
+  return cast<ConstantSDNode>(OperandList[Num])->getValue();
+}
+
+std::string SDNode::getOperationName(const SelectionDAG *G) const {
+  switch (getOpcode()) {
+  default:
+    if (getOpcode() < ISD::BUILTIN_OP_END)
+      return "<<Unknown DAG Node>>";
+    else {
+      if (G) {
+        if (const TargetInstrInfo *TII = G->getTarget().getInstrInfo())
+          if (getOpcode()-ISD::BUILTIN_OP_END < TII->getNumOpcodes())
+            return TII->getName(getOpcode()-ISD::BUILTIN_OP_END);
+
+        TargetLowering &TLI = G->getTargetLoweringInfo();
+        const char *Name =
+          TLI.getTargetNodeName(getOpcode());
+        if (Name) return Name;
+      }
+
+      return "<<Unknown Target Node>>";
+    }
+   
+  case ISD::PCMARKER:      return "PCMarker";
+  case ISD::READCYCLECOUNTER: return "ReadCycleCounter";
+  case ISD::SRCVALUE:      return "SrcValue";
+  case ISD::EntryToken:    return "EntryToken";
+  case ISD::TokenFactor:   return "TokenFactor";
+  case ISD::AssertSext:    return "AssertSext";
+  case ISD::AssertZext:    return "AssertZext";
+
+  case ISD::STRING:        return "String";
+  case ISD::BasicBlock:    return "BasicBlock";
+  case ISD::VALUETYPE:     return "ValueType";
+  case ISD::Register:      return "Register";
+
+  case ISD::Constant:      return "Constant";
+  case ISD::ConstantFP:    return "ConstantFP";
+  case ISD::GlobalAddress: return "GlobalAddress";
+  case ISD::GlobalTLSAddress: return "GlobalTLSAddress";
+  case ISD::FrameIndex:    return "FrameIndex";
+  case ISD::JumpTable:     return "JumpTable";
+  case ISD::GLOBAL_OFFSET_TABLE: return "GLOBAL_OFFSET_TABLE";
+  case ISD::RETURNADDR: return "RETURNADDR";
+  case ISD::FRAMEADDR: return "FRAMEADDR";
+  case ISD::FRAME_TO_ARGS_OFFSET: return "FRAME_TO_ARGS_OFFSET";
+  case ISD::EXCEPTIONADDR: return "EXCEPTIONADDR";
+  case ISD::EHSELECTION: return "EHSELECTION";
+  case ISD::EH_RETURN: return "EH_RETURN";
+  case ISD::ConstantPool:  return "ConstantPool";
+  case ISD::ExternalSymbol: return "ExternalSymbol";
+  case ISD::INTRINSIC_WO_CHAIN: {
+    unsigned IID = cast<ConstantSDNode>(getOperand(0))->getValue();
+    return Intrinsic::getName((Intrinsic::ID)IID);
+  }
+  case ISD::INTRINSIC_VOID:
+  case ISD::INTRINSIC_W_CHAIN: {
+    unsigned IID = cast<ConstantSDNode>(getOperand(1))->getValue();
+    return Intrinsic::getName((Intrinsic::ID)IID);
+  }
+
+  case ISD::BUILD_VECTOR:   return "BUILD_VECTOR";
+  case ISD::TargetConstant: return "TargetConstant";
+  case ISD::TargetConstantFP:return "TargetConstantFP";
+  case ISD::TargetGlobalAddress: return "TargetGlobalAddress";
+  case ISD::TargetGlobalTLSAddress: return "TargetGlobalTLSAddress";
+  case ISD::TargetFrameIndex: return "TargetFrameIndex";
+  case ISD::TargetJumpTable:  return "TargetJumpTable";
+  case ISD::TargetConstantPool:  return "TargetConstantPool";
+  case ISD::TargetExternalSymbol: return "TargetExternalSymbol";
+
+  case ISD::CopyToReg:     return "CopyToReg";
+  case ISD::CopyFromReg:   return "CopyFromReg";
+  case ISD::UNDEF:         return "undef";
+  case ISD::MERGE_VALUES:  return "merge_values";
+  case ISD::INLINEASM:     return "inlineasm";
+  case ISD::LABEL:         return "label";
+  case ISD::HANDLENODE:    return "handlenode";
+  case ISD::FORMAL_ARGUMENTS: return "formal_arguments";
+  case ISD::CALL:          return "call";
+    
+  // Unary operators
+  case ISD::FABS:   return "fabs";
+  case ISD::FNEG:   return "fneg";
+  case ISD::FSQRT:  return "fsqrt";
+  case ISD::FSIN:   return "fsin";
+  case ISD::FCOS:   return "fcos";
+  case ISD::FPOWI:  return "fpowi";
+
+  // Binary operators
+  case ISD::ADD:    return "add";
+  case ISD::SUB:    return "sub";
+  case ISD::MUL:    return "mul";
+  case ISD::MULHU:  return "mulhu";
+  case ISD::MULHS:  return "mulhs";
+  case ISD::SDIV:   return "sdiv";
+  case ISD::UDIV:   return "udiv";
+  case ISD::SREM:   return "srem";
+  case ISD::UREM:   return "urem";
+  case ISD::AND:    return "and";
+  case ISD::OR:     return "or";
+  case ISD::XOR:    return "xor";
+  case ISD::SHL:    return "shl";
+  case ISD::SRA:    return "sra";
+  case ISD::SRL:    return "srl";
+  case ISD::ROTL:   return "rotl";
+  case ISD::ROTR:   return "rotr";
+  case ISD::FADD:   return "fadd";
+  case ISD::FSUB:   return "fsub";
+  case ISD::FMUL:   return "fmul";
+  case ISD::FDIV:   return "fdiv";
+  case ISD::FREM:   return "frem";
+  case ISD::FCOPYSIGN: return "fcopysign";
+
+  case ISD::SETCC:       return "setcc";
+  case ISD::SELECT:      return "select";
+  case ISD::SELECT_CC:   return "select_cc";
+  case ISD::INSERT_VECTOR_ELT:   return "insert_vector_elt";
+  case ISD::EXTRACT_VECTOR_ELT:  return "extract_vector_elt";
+  case ISD::CONCAT_VECTORS:      return "concat_vectors";
+  case ISD::EXTRACT_SUBVECTOR:   return "extract_subvector";
+  case ISD::SCALAR_TO_VECTOR:    return "scalar_to_vector";
+  case ISD::VECTOR_SHUFFLE:      return "vector_shuffle";
+  case ISD::CARRY_FALSE:         return "carry_false";
+  case ISD::ADDC:        return "addc";
+  case ISD::ADDE:        return "adde";
+  case ISD::SUBC:        return "subc";
+  case ISD::SUBE:        return "sube";
+  case ISD::SHL_PARTS:   return "shl_parts";
+  case ISD::SRA_PARTS:   return "sra_parts";
+  case ISD::SRL_PARTS:   return "srl_parts";
+
+  // Conversion operators.
+  case ISD::SIGN_EXTEND: return "sign_extend";
+  case ISD::ZERO_EXTEND: return "zero_extend";
+  case ISD::ANY_EXTEND:  return "any_extend";
+  case ISD::SIGN_EXTEND_INREG: return "sign_extend_inreg";
+  case ISD::TRUNCATE:    return "truncate";
+  case ISD::FP_ROUND:    return "fp_round";
+  case ISD::FP_ROUND_INREG: return "fp_round_inreg";
+  case ISD::FP_EXTEND:   return "fp_extend";
+
+  case ISD::SINT_TO_FP:  return "sint_to_fp";
+  case ISD::UINT_TO_FP:  return "uint_to_fp";
+  case ISD::FP_TO_SINT:  return "fp_to_sint";
+  case ISD::FP_TO_UINT:  return "fp_to_uint";
+  case ISD::BIT_CONVERT: return "bit_convert";
+
+    // Control flow instructions
+  case ISD::BR:      return "br";
+  case ISD::BRIND:   return "brind";
+  case ISD::BR_JT:   return "br_jt";
+  case ISD::BRCOND:  return "brcond";
+  case ISD::BR_CC:   return "br_cc";
+  case ISD::RET:     return "ret";
+  case ISD::CALLSEQ_START:  return "callseq_start";
+  case ISD::CALLSEQ_END:    return "callseq_end";
+
+    // Other operators
+  case ISD::LOAD:               return "load";
+  case ISD::STORE:              return "store";
+  case ISD::VAARG:              return "vaarg";
+  case ISD::VACOPY:             return "vacopy";
+  case ISD::VAEND:              return "vaend";
+  case ISD::VASTART:            return "vastart";
+  case ISD::DYNAMIC_STACKALLOC: return "dynamic_stackalloc";
+  case ISD::EXTRACT_ELEMENT:    return "extract_element";
+  case ISD::BUILD_PAIR:         return "build_pair";
+  case ISD::STACKSAVE:          return "stacksave";
+  case ISD::STACKRESTORE:       return "stackrestore";
+    
+  // Block memory operations.
+  case ISD::MEMSET:  return "memset";
+  case ISD::MEMCPY:  return "memcpy";
+  case ISD::MEMMOVE: return "memmove";
+
+  // Bit manipulation
+  case ISD::BSWAP:   return "bswap";
+  case ISD::CTPOP:   return "ctpop";
+  case ISD::CTTZ:    return "cttz";
+  case ISD::CTLZ:    return "ctlz";
+
+  // Debug info
+  case ISD::LOCATION: return "location";
+  case ISD::DEBUG_LOC: return "debug_loc";
+
+  case ISD::CONDCODE:
+    switch (cast<CondCodeSDNode>(this)->get()) {
+    default: assert(0 && "Unknown setcc condition!");
+    case ISD::SETOEQ:  return "setoeq";
+    case ISD::SETOGT:  return "setogt";
+    case ISD::SETOGE:  return "setoge";
+    case ISD::SETOLT:  return "setolt";
+    case ISD::SETOLE:  return "setole";
+    case ISD::SETONE:  return "setone";
+
+    case ISD::SETO:    return "seto";
+    case ISD::SETUO:   return "setuo";
+    case ISD::SETUEQ:  return "setue";
+    case ISD::SETUGT:  return "setugt";
+    case ISD::SETUGE:  return "setuge";
+    case ISD::SETULT:  return "setult";
+    case ISD::SETULE:  return "setule";
+    case ISD::SETUNE:  return "setune";
+
+    case ISD::SETEQ:   return "seteq";
+    case ISD::SETGT:   return "setgt";
+    case ISD::SETGE:   return "setge";
+    case ISD::SETLT:   return "setlt";
+    case ISD::SETLE:   return "setle";
+    case ISD::SETNE:   return "setne";
+    }
+  }
+}
+
+const char *SDNode::getIndexedModeName(ISD::MemIndexedMode AM) {
+  switch (AM) {
+  default:
+    return "";
+  case ISD::PRE_INC:
+    return "<pre-inc>";
+  case ISD::PRE_DEC:
+    return "<pre-dec>";
+  case ISD::POST_INC:
+    return "<post-inc>";
+  case ISD::POST_DEC:
+    return "<post-dec>";
+  }
+}
+
+void SDNode::dump() const { dump(0); }
+void SDNode::dump(const SelectionDAG *G) const {
+  cerr << (void*)this << ": ";
+
+  for (unsigned i = 0, e = getNumValues(); i != e; ++i) {
+    if (i) cerr << ",";
+    if (getValueType(i) == MVT::Other)
+      cerr << "ch";
+    else
+      cerr << MVT::getValueTypeString(getValueType(i));
+  }
+  cerr << " = " << getOperationName(G);
+
+  cerr << " ";
+  for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
+    if (i) cerr << ", ";
+    cerr << (void*)getOperand(i).Val;
+    if (unsigned RN = getOperand(i).ResNo)
+      cerr << ":" << RN;
+  }
+
+  if (const ConstantSDNode *CSDN = dyn_cast<ConstantSDNode>(this)) {
+    cerr << "<" << CSDN->getValue() << ">";
+  } else if (const ConstantFPSDNode *CSDN = dyn_cast<ConstantFPSDNode>(this)) {
+    cerr << "<" << CSDN->getValue() << ">";
+  } else if (const GlobalAddressSDNode *GADN =
+             dyn_cast<GlobalAddressSDNode>(this)) {
+    int offset = GADN->getOffset();
+    cerr << "<";
+    WriteAsOperand(*cerr.stream(), GADN->getGlobal()) << ">";
+    if (offset > 0)
+      cerr << " + " << offset;
+    else
+      cerr << " " << offset;
+  } else if (const FrameIndexSDNode *FIDN = dyn_cast<FrameIndexSDNode>(this)) {
+    cerr << "<" << FIDN->getIndex() << ">";
+  } else if (const JumpTableSDNode *JTDN = dyn_cast<JumpTableSDNode>(this)) {
+    cerr << "<" << JTDN->getIndex() << ">";
+  } else if (const ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(this)){
+    int offset = CP->getOffset();
+    if (CP->isMachineConstantPoolEntry())
+      cerr << "<" << *CP->getMachineCPVal() << ">";
+    else
+      cerr << "<" << *CP->getConstVal() << ">";
+    if (offset > 0)
+      cerr << " + " << offset;
+    else
+      cerr << " " << offset;
+  } else if (const BasicBlockSDNode *BBDN = dyn_cast<BasicBlockSDNode>(this)) {
+    cerr << "<";
+    const Value *LBB = (const Value*)BBDN->getBasicBlock()->getBasicBlock();
+    if (LBB)
+      cerr << LBB->getName() << " ";
+    cerr << (const void*)BBDN->getBasicBlock() << ">";
+  } else if (const RegisterSDNode *R = dyn_cast<RegisterSDNode>(this)) {
+    if (G && R->getReg() && MRegisterInfo::isPhysicalRegister(R->getReg())) {
+      cerr << " " <<G->getTarget().getRegisterInfo()->getName(R->getReg());
+    } else {
+      cerr << " #" << R->getReg();
+    }
+  } else if (const ExternalSymbolSDNode *ES =
+             dyn_cast<ExternalSymbolSDNode>(this)) {
+    cerr << "'" << ES->getSymbol() << "'";
+  } else if (const SrcValueSDNode *M = dyn_cast<SrcValueSDNode>(this)) {
+    if (M->getValue())
+      cerr << "<" << M->getValue() << ":" << M->getOffset() << ">";
+    else
+      cerr << "<null:" << M->getOffset() << ">";
+  } else if (const VTSDNode *N = dyn_cast<VTSDNode>(this)) {
+    cerr << ":" << MVT::getValueTypeString(N->getVT());
+  } else if (const LoadSDNode *LD = dyn_cast<LoadSDNode>(this)) {
+    bool doExt = true;
+    switch (LD->getExtensionType()) {
+    default: doExt = false; break;
+    case ISD::EXTLOAD:
+      cerr << " <anyext ";
+      break;
+    case ISD::SEXTLOAD:
+      cerr << " <sext ";
+      break;
+    case ISD::ZEXTLOAD:
+      cerr << " <zext ";
+      break;
+    }
+    if (doExt)
+      cerr << MVT::getValueTypeString(LD->getLoadedVT()) << ">";
+
+    const char *AM = getIndexedModeName(LD->getAddressingMode());
+    if (AM != "")
+      cerr << " " << AM;
+  } else if (const StoreSDNode *ST = dyn_cast<StoreSDNode>(this)) {
+    if (ST->isTruncatingStore())
+      cerr << " <trunc "
+           << MVT::getValueTypeString(ST->getStoredVT()) << ">";
+
+    const char *AM = getIndexedModeName(ST->getAddressingMode());
+    if (AM != "")
+      cerr << " " << AM;
+  }
+}
+
+static void DumpNodes(const SDNode *N, unsigned indent, const SelectionDAG *G) {
+  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
+    if (N->getOperand(i).Val->hasOneUse())
+      DumpNodes(N->getOperand(i).Val, indent+2, G);
+    else
+      cerr << "\n" << std::string(indent+2, ' ')
+           << (void*)N->getOperand(i).Val << ": <multiple use>";
+
+
+  cerr << "\n" << std::string(indent, ' ');
+  N->dump(G);
+}
+
+void SelectionDAG::dump() const {
+  cerr << "SelectionDAG has " << AllNodes.size() << " nodes:";
+  std::vector<const SDNode*> Nodes;
+  for (allnodes_const_iterator I = allnodes_begin(), E = allnodes_end();
+       I != E; ++I)
+    Nodes.push_back(I);
+  
+  std::sort(Nodes.begin(), Nodes.end());
+
+  for (unsigned i = 0, e = Nodes.size(); i != e; ++i) {
+    if (!Nodes[i]->hasOneUse() && Nodes[i] != getRoot().Val)
+      DumpNodes(Nodes[i], 2, this);
+  }
+
+  if (getRoot().Val) DumpNodes(getRoot().Val, 2, this);
+
+  cerr << "\n\n";
+}
+
+const Type *ConstantPoolSDNode::getType() const {
+  if (isMachineConstantPoolEntry())
+    return Val.MachineCPVal->getType();
+  return Val.ConstVal->getType();
+}