diff --git a/lib/CodeGen/RegAllocLinearScan.cpp b/lib/CodeGen/RegAllocLinearScan.cpp
index 8c20a63..e8296a7 100644
--- a/lib/CodeGen/RegAllocLinearScan.cpp
+++ b/lib/CodeGen/RegAllocLinearScan.cpp
@@ -105,7 +105,7 @@
                                 greater_ptr<LiveInterval> > IntervalHeap;
     IntervalHeap unhandled_;
     std::auto_ptr<PhysRegTracker> prt_;
-    std::auto_ptr<VirtRegMap> vrm_;
+    VirtRegMap* vrm_;
     std::auto_ptr<Spiller> spiller_;
 
   public:
@@ -126,6 +126,8 @@
       AU.addPreserved<LiveStacks>();
       AU.addRequired<MachineLoopInfo>();
       AU.addPreserved<MachineLoopInfo>();
+      AU.addRequired<VirtRegMap>();
+      AU.addPreserved<VirtRegMap>();
       AU.addPreservedID(MachineDominatorsID);
       MachineFunctionPass::getAnalysisUsage(AU);
     }
@@ -305,7 +307,7 @@
     ComputeRelatedRegClasses();
   
   if (!prt_.get()) prt_.reset(new PhysRegTracker(*tri_));
-  vrm_.reset(new VirtRegMap(*mf_));
+  vrm_ = &getAnalysis<VirtRegMap>();
   if (!spiller_.get()) spiller_.reset(createSpiller());
 
   initIntervalSets();
@@ -314,7 +316,6 @@
 
   // Rewrite spill code and update the PhysRegsUsed set.
   spiller_->runOnMachineFunction(*mf_, *vrm_);
-  vrm_.reset();  // Free the VirtRegMap
 
   assert(unhandled_.empty() && "Unhandled live intervals remain!");
   fixed_.clear();
diff --git a/lib/CodeGen/RegAllocPBQP.cpp b/lib/CodeGen/RegAllocPBQP.cpp
index 767e985..7f699f8 100644
--- a/lib/CodeGen/RegAllocPBQP.cpp
+++ b/lib/CodeGen/RegAllocPBQP.cpp
@@ -799,8 +799,7 @@
   lss = &getAnalysis<LiveStacks>();
   loopInfo = &getAnalysis<MachineLoopInfo>();
 
-  std::auto_ptr<VirtRegMap> vrmAutoPtr(new VirtRegMap(*mf));
-  vrm = vrmAutoPtr.get();
+  vrm = &getAnalysis<VirtRegMap>();
 
   DOUT << "PBQP Register Allocating for " << mf->getFunction()->getName() << "\n";
 
diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index 0bfbded..2c7037c 100644
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -43,20 +43,42 @@
 //  VirtRegMap implementation
 //===----------------------------------------------------------------------===//
 
-VirtRegMap::VirtRegMap(MachineFunction &mf)
-  : TII(*mf.getTarget().getInstrInfo()), MF(mf), 
-    Virt2PhysMap(NO_PHYS_REG), Virt2StackSlotMap(NO_STACK_SLOT),
-    Virt2ReMatIdMap(NO_STACK_SLOT), Virt2SplitMap(0),
-    Virt2SplitKillMap(0), ReMatMap(NULL), ReMatId(MAX_STACK_SLOT+1),
-    LowSpillSlot(NO_STACK_SLOT), HighSpillSlot(NO_STACK_SLOT) {
+char VirtRegMap::ID = 0;
+
+static RegisterPass<VirtRegMap>
+X("virtregmap", "Virtual Register Map");
+
+bool VirtRegMap::runOnMachineFunction(MachineFunction &mf) {
+  TII = mf.getTarget().getInstrInfo();
+  MF = &mf;
+  
+  ReMatId = MAX_STACK_SLOT+1;
+  LowSpillSlot = HighSpillSlot = NO_STACK_SLOT;
+  
+  Virt2PhysMap.clear();
+  Virt2StackSlotMap.clear();
+  Virt2ReMatIdMap.clear();
+  Virt2SplitMap.clear();
+  Virt2SplitKillMap.clear();
+  ReMatMap.clear();
+  ImplicitDefed.clear();
+  SpillSlotToUsesMap.clear();
+  MI2VirtMap.clear();
+  SpillPt2VirtMap.clear();
+  RestorePt2VirtMap.clear();
+  EmergencySpillMap.clear();
+  EmergencySpillSlots.clear();
+  
   SpillSlotToUsesMap.resize(8);
-  ImplicitDefed.resize(MF.getRegInfo().getLastVirtReg()+1-
+  ImplicitDefed.resize(MF->getRegInfo().getLastVirtReg()+1-
                        TargetRegisterInfo::FirstVirtualRegister);
   grow();
+  
+  return false;
 }
 
 void VirtRegMap::grow() {
-  unsigned LastVirtReg = MF.getRegInfo().getLastVirtReg();
+  unsigned LastVirtReg = MF->getRegInfo().getLastVirtReg();
   Virt2PhysMap.grow(LastVirtReg);
   Virt2StackSlotMap.grow(LastVirtReg);
   Virt2ReMatIdMap.grow(LastVirtReg);
@@ -70,8 +92,8 @@
   assert(TargetRegisterInfo::isVirtualRegister(virtReg));
   assert(Virt2StackSlotMap[virtReg] == NO_STACK_SLOT &&
          "attempt to assign stack slot to already spilled register");
-  const TargetRegisterClass* RC = MF.getRegInfo().getRegClass(virtReg);
-  int SS = MF.getFrameInfo()->CreateStackObject(RC->getSize(),
+  const TargetRegisterClass* RC = MF->getRegInfo().getRegClass(virtReg);
+  int SS = MF->getFrameInfo()->CreateStackObject(RC->getSize(),
                                                 RC->getAlignment());
   if (LowSpillSlot == NO_STACK_SLOT)
     LowSpillSlot = SS;
@@ -90,7 +112,7 @@
   assert(Virt2StackSlotMap[virtReg] == NO_STACK_SLOT &&
          "attempt to assign stack slot to already spilled register");
   assert((SS >= 0 ||
-          (SS >= MF.getFrameInfo()->getObjectIndexBegin())) &&
+          (SS >= MF->getFrameInfo()->getObjectIndexBegin())) &&
          "illegal fixed frame index");
   Virt2StackSlotMap[virtReg] = SS;
 }
@@ -115,7 +137,7 @@
     EmergencySpillSlots.find(RC);
   if (I != EmergencySpillSlots.end())
     return I->second;
-  int SS = MF.getFrameInfo()->CreateStackObject(RC->getSize(),
+  int SS = MF->getFrameInfo()->CreateStackObject(RC->getSize(),
                                                 RC->getAlignment());
   if (LowSpillSlot == NO_STACK_SLOT)
     LowSpillSlot = SS;
@@ -126,7 +148,7 @@
 }
 
 void VirtRegMap::addSpillSlotUse(int FI, MachineInstr *MI) {
-  if (!MF.getFrameInfo()->isFixedObjectIndex(FI)) {
+  if (!MF->getFrameInfo()->isFixedObjectIndex(FI)) {
     // If FI < LowSpillSlot, this stack reference was produced by
     // instruction selection and is not a spill
     if (FI >= LowSpillSlot) {
@@ -163,7 +185,7 @@
     if (!MO.isFI())
       continue;
     int FI = MO.getIndex();
-    if (MF.getFrameInfo()->isFixedObjectIndex(FI))
+    if (MF->getFrameInfo()->isFixedObjectIndex(FI))
       continue;
     // This stack reference was produced by instruction selection and
     // is not a spill
@@ -179,19 +201,19 @@
   EmergencySpillMap.erase(MI);
 }
 
-void VirtRegMap::print(std::ostream &OS) const {
-  const TargetRegisterInfo* TRI = MF.getTarget().getRegisterInfo();
+void VirtRegMap::print(std::ostream &OS, const Module* M) const {
+  const TargetRegisterInfo* TRI = MF->getTarget().getRegisterInfo();
 
   OS << "********** REGISTER MAP **********\n";
   for (unsigned i = TargetRegisterInfo::FirstVirtualRegister,
-         e = MF.getRegInfo().getLastVirtReg(); i <= e; ++i) {
+         e = MF->getRegInfo().getLastVirtReg(); i <= e; ++i) {
     if (Virt2PhysMap[i] != (unsigned)VirtRegMap::NO_PHYS_REG)
       OS << "[reg" << i << " -> " << TRI->getName(Virt2PhysMap[i])
          << "]\n";
   }
 
   for (unsigned i = TargetRegisterInfo::FirstVirtualRegister,
-         e = MF.getRegInfo().getLastVirtReg(); i <= e; ++i)
+         e = MF->getRegInfo().getLastVirtReg(); i <= e; ++i)
     if (Virt2StackSlotMap[i] != VirtRegMap::NO_STACK_SLOT)
       OS << "[reg" << i << " -> fi#" << Virt2StackSlotMap[i] << "]\n";
   OS << '\n';
diff --git a/lib/CodeGen/VirtRegMap.h b/lib/CodeGen/VirtRegMap.h
index 7627d67..2e9c899 100644
--- a/lib/CodeGen/VirtRegMap.h
+++ b/lib/CodeGen/VirtRegMap.h
@@ -17,6 +17,7 @@
 #ifndef LLVM_CODEGEN_VIRTREGMAP_H
 #define LLVM_CODEGEN_VIRTREGMAP_H
 
+#include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/IndexedMap.h"
@@ -30,7 +31,7 @@
   class MachineFunction;
   class TargetInstrInfo;
 
-  class VirtRegMap {
+  class VirtRegMap : public MachineFunctionPass {
   public:
     enum {
       NO_PHYS_REG = 0,
@@ -43,9 +44,9 @@
                           std::pair<unsigned, ModRef> > MI2VirtMapTy;
 
   private:
-    const TargetInstrInfo &TII;
+    const TargetInstrInfo *TII;
 
-    MachineFunction &MF;
+    MachineFunction *MF;
     /// Virt2PhysMap - This is a virtual to physical register
     /// mapping. Each virtual register is required to have an entry in
     /// it; even spilled virtual registers (the register mapped to a
@@ -125,7 +126,19 @@
     void operator=(const VirtRegMap&); // DO NOT IMPLEMENT
 
   public:
-    explicit VirtRegMap(MachineFunction &mf);
+    static char ID;
+    VirtRegMap() : MachineFunctionPass(&ID), Virt2PhysMap(NO_PHYS_REG),
+                   Virt2StackSlotMap(NO_STACK_SLOT), 
+                   Virt2ReMatIdMap(NO_STACK_SLOT), Virt2SplitMap(0),
+                   Virt2SplitKillMap(0), ReMatMap(NULL),
+                   ReMatId(MAX_STACK_SLOT+1),
+                   LowSpillSlot(NO_STACK_SLOT), HighSpillSlot(NO_STACK_SLOT) { }
+    virtual bool runOnMachineFunction(MachineFunction &MF);
+
+    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+      AU.setPreservesAll();
+      MachineFunctionPass::getAnalysisUsage(AU);
+    }
 
     void grow();
 
@@ -417,7 +430,7 @@
     /// the folded instruction map and spill point map.
     void RemoveMachineInstrFromMaps(MachineInstr *MI);
 
-    void print(std::ostream &OS) const;
+    void print(std::ostream &OS, const Module* M = 0) const;
     void print(std::ostream *OS) const { if (OS) print(*OS); }
     void dump() const;
   };