diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h
index c3ad83c..a205792 100644
--- a/include/llvm/CodeGen/MachineInstr.h
+++ b/include/llvm/CodeGen/MachineInstr.h
@@ -38,26 +38,6 @@
 //   Representation of each machine instruction operand.
 //
 struct MachineOperand {
-private:
-  // Bit fields of the flags variable used for different operand properties
-  enum {
-    DEFFLAG     = 0x01,       // this is a def of the operand
-    USEFLAG     = 0x02        // this is a use of the operand
-  };
-
-public:
-  // UseType - This enum describes how the machine operand is used by
-  // the instruction. Note that the MachineInstr/Operator class
-  // currently uses bool arguments to represent this information
-  // instead of an enum.  Eventually this should change over to use
-  // this _easier to read_ representation instead.
-  //
-  enum UseType {
-    Use = USEFLAG,        /// only read
-    Def = DEFFLAG,        /// only written
-    UseAndDef = Use | Def /// read AND written
-  };
-
   enum MachineOperandType {
     MO_Register,                // Register operand.
     MO_Immediate,               // Immediate Operand
@@ -78,8 +58,8 @@
     int64_t immedVal;         // For MO_Immediate and MO_*Index.
   } contents;
 
-  char flags;                   // see bit field definitions above
-  MachineOperandType opType:8;  // Pack into 8 bits efficiently after flags.
+  MachineOperandType opType:8; // Discriminate the union.
+  bool IsDef : 1;              // True if this is a def, false if this is a use.
   
   /// offset - Offset to address of global or external, only valid for
   /// MO_GlobalAddress, MO_ExternalSym and MO_ConstantPoolIndex
@@ -95,7 +75,7 @@
 
   const MachineOperand &operator=(const MachineOperand &MO) {
     contents = MO.contents;
-    flags    = MO.flags;
+    IsDef    = MO.IsDef;
     opType   = MO.opType;
     offset   = MO.offset;
     return *this;
@@ -105,10 +85,6 @@
   ///
   MachineOperandType getType() const { return opType; }
 
-  /// getUseType - Returns the MachineOperandUseType of this operand.
-  ///
-  UseType getUseType() const { return UseType(flags & (USEFLAG|DEFFLAG)); }
-
   /// Accessors that tell you what kind of MachineOperand you're looking at.
   ///
   bool isReg() const { return opType == MO_Register; }
@@ -167,13 +143,10 @@
     return contents.SymbolName;
   }
 
-  /// MachineOperand methods for testing that work on any kind of
-  /// MachineOperand...
-  ///
-  bool isUse() const { return flags & USEFLAG; }
-  bool isDef() const { return flags & DEFFLAG; }
-  MachineOperand &setUse() { flags |= USEFLAG; return *this; }
-  MachineOperand &setDef() { flags |= DEFFLAG; return *this; }
+  bool isUse() const { return !IsDef; }
+  bool isDef() const { return IsDef; }
+  void setIsUse() { IsDef = false; }
+  void setIsDef() { IsDef = true; }
 
   /// getReg - Returns the register number.
   ///
@@ -216,9 +189,10 @@
   /// ChangeToRegister - Replace this operand with a new register operand of
   /// the specified value.  If an operand is known to be an register already,
   /// the setReg method should be used.
-  void ChangeToRegister(unsigned Reg) {
+  void ChangeToRegister(unsigned Reg, bool isDef) {
     opType = MO_Register;
     contents.RegNo = Reg;
+    IsDef = isDef;
   }
 
   friend std::ostream& operator<<(std::ostream& os, const MachineOperand& mop);
@@ -307,11 +281,10 @@
 
   /// addRegOperand - Add a register operand.
   ///
-  void addRegOperand(unsigned Reg,
-                     MachineOperand::UseType UTy = MachineOperand::Use) {
+  void addRegOperand(unsigned Reg, bool IsDef) {
     MachineOperand &Op = AddNewOperand();
     Op.opType = MachineOperand::MO_Register;
-    Op.flags = UTy;
+    Op.IsDef = IsDef;
     Op.contents.RegNo = Reg;
     Op.offset = 0;
   }
@@ -322,7 +295,6 @@
   void addImmOperand(int64_t Val) {
     MachineOperand &Op = AddNewOperand();
     Op.opType = MachineOperand::MO_Immediate;
-    Op.flags = 0;
     Op.contents.immedVal = Val;
     Op.offset = 0;
   }
@@ -330,7 +302,6 @@
   void addMachineBasicBlockOperand(MachineBasicBlock *MBB) {
     MachineOperand &Op = AddNewOperand();
     Op.opType = MachineOperand::MO_MachineBasicBlock;
-    Op.flags = 0;
     Op.contents.MBB = MBB;
     Op.offset = 0;
   }
@@ -340,7 +311,6 @@
   void addFrameIndexOperand(unsigned Idx) {
     MachineOperand &Op = AddNewOperand();
     Op.opType = MachineOperand::MO_FrameIndex;
-    Op.flags = 0;
     Op.contents.immedVal = Idx;
     Op.offset = 0;
   }
@@ -351,7 +321,6 @@
   void addConstantPoolIndexOperand(unsigned Idx, int Offset) {
     MachineOperand &Op = AddNewOperand();
     Op.opType = MachineOperand::MO_ConstantPoolIndex;
-    Op.flags = 0;
     Op.contents.immedVal = Idx;
     Op.offset = Offset;
   }
@@ -362,7 +331,6 @@
   void addJumpTableIndexOperand(unsigned Idx) {
     MachineOperand &Op = AddNewOperand();
     Op.opType = MachineOperand::MO_JumpTableIndex;
-    Op.flags = 0;
     Op.contents.immedVal = Idx;
     Op.offset = 0;
   }
@@ -370,7 +338,6 @@
   void addGlobalAddressOperand(GlobalValue *GV, int Offset) {
     MachineOperand &Op = AddNewOperand();
     Op.opType = MachineOperand::MO_GlobalAddress;
-    Op.flags = 0;
     Op.contents.GV = GV;
     Op.offset = Offset;
   }
@@ -380,7 +347,6 @@
   void addExternalSymbolOperand(const char *SymName) {
     MachineOperand &Op = AddNewOperand();
     Op.opType = MachineOperand::MO_ExternalSymbol;
-    Op.flags = 0;
     Op.contents.SymbolName = SymName;
     Op.offset = 0;
   }
diff --git a/include/llvm/CodeGen/MachineInstrBuilder.h b/include/llvm/CodeGen/MachineInstrBuilder.h
index 0d4d07d..3a1335a 100644
--- a/include/llvm/CodeGen/MachineInstrBuilder.h
+++ b/include/llvm/CodeGen/MachineInstrBuilder.h
@@ -33,10 +33,8 @@
 
   /// addReg - Add a new virtual register operand...
   ///
-  const MachineInstrBuilder &addReg(
-    int RegNo,
-    MachineOperand::UseType Ty = MachineOperand::Use) const {
-    MI->addRegOperand(RegNo, Ty);
+  const MachineInstrBuilder &addReg(int RegNo, bool isDef = false) const {
+    MI->addRegOperand(RegNo, isDef);
     return *this;
   }
 
@@ -92,12 +90,10 @@
 /// destination virtual register.  NumOperands is the number of additional add*
 /// calls that are expected, not including the destination register.
 ///
-inline MachineInstrBuilder BuildMI(
-  int Opcode, unsigned NumOperands,
-  unsigned DestReg,
-  MachineOperand::UseType useType = MachineOperand::Def) {
+inline MachineInstrBuilder 
+BuildMI(int Opcode, unsigned NumOperands, unsigned DestReg) {
   return MachineInstrBuilder(new MachineInstr(Opcode, NumOperands+1))
-               .addReg(DestReg, useType);
+               .addReg(DestReg, true);
 }
 
 /// BuildMI - This version of the builder inserts the newly-built
@@ -112,7 +108,7 @@
                                    unsigned DestReg) {
   MachineInstr *MI = new MachineInstr(Opcode, NumOperands+1);
   BB.insert(I, MI);
-  return MachineInstrBuilder(MI).addReg(DestReg, MachineOperand::Def);
+  return MachineInstrBuilder(MI).addReg(DestReg, true);
 }
 
 /// BuildMI - This version of the builder inserts the newly-built
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
index d33e1ec..71f2bce 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
@@ -255,11 +255,11 @@
   // the machine instruction.
   unsigned ResultReg =
     RegMap->createVirtualRegister(getInstrOperandRegClass(MRI, TII, &II, 0));
-  MI->addRegOperand(ResultReg, MachineOperand::Def);
+  MI->addRegOperand(ResultReg, true);
   for (unsigned i = 1; i != NumResults; ++i) {
     const TargetRegisterClass *RC = getInstrOperandRegClass(MRI, TII, &II, i);
     assert(RC && "Isn't a register operand!");
-    MI->addRegOperand(RegMap->createVirtualRegister(RC), MachineOperand::Def);
+    MI->addRegOperand(RegMap->createVirtualRegister(RC), true);
   }
   return ResultReg;
 }
@@ -291,7 +291,7 @@
     
     // Get/emit the operand.
     unsigned VReg = getVR(Op, VRBaseMap);
-    MI->addRegOperand(VReg, MachineOperand::Use);
+    MI->addRegOperand(VReg, false);
     
     // Verify that it is right.
     assert(MRegisterInfo::isVirtualRegister(VReg) && "Not a vreg?");
@@ -307,7 +307,7 @@
     MI->addImmOperand(C->getValue());
   } else if (RegisterSDNode*R =
              dyn_cast<RegisterSDNode>(Op)) {
-    MI->addRegOperand(R->getReg(), MachineOperand::Use);
+    MI->addRegOperand(R->getReg(), false);
   } else if (GlobalAddressSDNode *TGA =
              dyn_cast<GlobalAddressSDNode>(Op)) {
     MI->addGlobalAddressOperand(TGA->getGlobal(), TGA->getOffset());
@@ -349,7 +349,7 @@
            Op.getValueType() != MVT::Flag &&
            "Chain and flag operands should occur at end of operand list!");
     unsigned VReg = getVR(Op, VRBaseMap);
-    MI->addRegOperand(VReg, MachineOperand::Use);
+    MI->addRegOperand(VReg, false);
     
     // Verify that it is right.
     assert(MRegisterInfo::isVirtualRegister(VReg) && "Not a vreg?");
@@ -402,7 +402,7 @@
           unsigned Reg = cast<RegisterSDNode>(Use->getOperand(1))->getReg();
           if (MRegisterInfo::isVirtualRegister(Reg)) {
             VRBase = Reg;
-            MI->addRegOperand(Reg, MachineOperand::Def);
+            MI->addRegOperand(Reg, true);
             break;
           }
         }
@@ -529,13 +529,13 @@
         case 1:  // Use of register.
           for (; NumVals; --NumVals, ++i) {
             unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
-            MI->addRegOperand(Reg, MachineOperand::Use);
+            MI->addRegOperand(Reg, false);
           }
           break;
         case 2:   // Def of register.
           for (; NumVals; --NumVals, ++i) {
             unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
-            MI->addRegOperand(Reg, MachineOperand::Def);
+            MI->addRegOperand(Reg, true);
           }
           break;
         case 3: { // Immediate.
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 317c1e9..b1f70cd 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -3547,7 +3547,7 @@
       MachineInstr *PHI = PHINodesToUpdate[i].first;
       assert(PHI->getOpcode() == TargetInstrInfo::PHI &&
              "This is not a machine PHI node that we are updating!");
-      PHI->addRegOperand(PHINodesToUpdate[i].second);
+      PHI->addRegOperand(PHINodesToUpdate[i].second, false);
       PHI->addMachineBasicBlockOperand(BB);
     }
     return;
@@ -3576,11 +3576,11 @@
       assert(PHI->getOpcode() == TargetInstrInfo::PHI &&
              "This is not a machine PHI node that we are updating!");
       if (PHIBB == JT.Default) {
-        PHI->addRegOperand(PHINodesToUpdate[pi].second);
+        PHI->addRegOperand(PHINodesToUpdate[pi].second, false);
         PHI->addMachineBasicBlockOperand(RangeBB);
       }
       if (BB->succ_end() != std::find(BB->succ_begin(),BB->succ_end(), PHIBB)) {
-        PHI->addRegOperand(PHINodesToUpdate[pi].second);
+        PHI->addRegOperand(PHINodesToUpdate[pi].second, false);
         PHI->addMachineBasicBlockOperand(BB);
       }
     }
@@ -3610,7 +3610,7 @@
       assert(PHI->getOpcode() == TargetInstrInfo::PHI &&
              "This is not a machine PHI node that we are updating!");
       if (PHIBB == SwitchCases[i].LHSBB || PHIBB == SwitchCases[i].RHSBB) {
-        PHI->addRegOperand(PHINodesToUpdate[pi].second);
+        PHI->addRegOperand(PHINodesToUpdate[pi].second, false);
         PHI->addMachineBasicBlockOperand(BB);
       }
     }
diff --git a/lib/Target/ARM/ARMRegisterInfo.cpp b/lib/Target/ARM/ARMRegisterInfo.cpp
index c5eef11..9e67081 100644
--- a/lib/Target/ARM/ARMRegisterInfo.cpp
+++ b/lib/Target/ARM/ARMRegisterInfo.cpp
@@ -107,7 +107,7 @@
   assert (Offset >= 0);
   if (Offset < 4096) {
     // Replace the FrameIndex with r13
-    MI.getOperand(FrameIdx).ChangeToRegister(ARM::R13);
+    MI.getOperand(FrameIdx).ChangeToRegister(ARM::R13, false);
     // Replace the ldr offset with Offset
     MI.getOperand(OffIdx).ChangeToImmediate(Offset);
   } else {
@@ -117,7 +117,7 @@
     BuildMI(*MBB2, II, ARM::addri, 2, ARM::R12).addReg(ARM::R13).addImm(Offset);
 
     // Replace the FrameIndex with r12
-    MI.getOperand(FrameIdx).ChangeToRegister(ARM::R12);
+    MI.getOperand(FrameIdx).ChangeToRegister(ARM::R12, false);
   }
 }
 
diff --git a/lib/Target/Alpha/AlphaRegisterInfo.cpp b/lib/Target/Alpha/AlphaRegisterInfo.cpp
index 772840a..1b6fa44 100644
--- a/lib/Target/Alpha/AlphaRegisterInfo.cpp
+++ b/lib/Target/Alpha/AlphaRegisterInfo.cpp
@@ -67,14 +67,18 @@
                                        MachineBasicBlock::iterator MI,
                                        unsigned SrcReg, int FrameIdx,
                                        const TargetRegisterClass *RC) const {
-  //std::cerr << "Trying to store " << getPrettyName(SrcReg) << " to " << FrameIdx << "\n";
+  //std::cerr << "Trying to store " << getPrettyName(SrcReg) << " to "
+  //<< FrameIdx << "\n";
   //BuildMI(MBB, MI, Alpha::WTF, 0).addReg(SrcReg);
   if (RC == Alpha::F4RCRegisterClass)
-    BuildMI(MBB, MI, Alpha::STS, 3).addReg(SrcReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
+    BuildMI(MBB, MI, Alpha::STS, 3)
+      .addReg(SrcReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
   else if (RC == Alpha::F8RCRegisterClass)
-    BuildMI(MBB, MI, Alpha::STT, 3).addReg(SrcReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
+    BuildMI(MBB, MI, Alpha::STT, 3)
+      .addReg(SrcReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
   else if (RC == Alpha::GPRCRegisterClass)
-    BuildMI(MBB, MI, Alpha::STQ, 3).addReg(SrcReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
+    BuildMI(MBB, MI, Alpha::STQ, 3)
+      .addReg(SrcReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
   else
     abort();
 }
@@ -84,13 +88,17 @@
                                         MachineBasicBlock::iterator MI,
                                         unsigned DestReg, int FrameIdx,
                                         const TargetRegisterClass *RC) const {
-  //std::cerr << "Trying to load " << getPrettyName(DestReg) << " to " << FrameIdx << "\n";
+  //std::cerr << "Trying to load " << getPrettyName(DestReg) << " to "
+  //<< FrameIdx << "\n";
   if (RC == Alpha::F4RCRegisterClass)
-    BuildMI(MBB, MI, Alpha::LDS, 2, DestReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
+    BuildMI(MBB, MI, Alpha::LDS, 2, DestReg)
+      .addFrameIndex(FrameIdx).addReg(Alpha::F31);
   else if (RC == Alpha::F8RCRegisterClass)
-    BuildMI(MBB, MI, Alpha::LDT, 2, DestReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
+    BuildMI(MBB, MI, Alpha::LDT, 2, DestReg)
+      .addFrameIndex(FrameIdx).addReg(Alpha::F31);
   else if (RC == Alpha::GPRCRegisterClass)
-    BuildMI(MBB, MI, Alpha::LDQ, 2, DestReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
+    BuildMI(MBB, MI, Alpha::LDQ, 2, DestReg)
+      .addFrameIndex(FrameIdx).addReg(Alpha::F31);
   else
     abort();
 }
@@ -243,7 +251,7 @@
   int FrameIndex = MI.getOperand(i).getFrameIndex();
 
   // Add the base register of R30 (SP) or R15 (FP).
-  MI.getOperand(i + 1).ChangeToRegister(FP ? Alpha::R15 : Alpha::R30);
+  MI.getOperand(i + 1).ChangeToRegister(FP ? Alpha::R15 : Alpha::R30, false);
 
   // Now add the frame object offset to the offset from the virtual frame index.
   int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex);
@@ -256,11 +264,12 @@
         " for stack size: " << MF.getFrameInfo()->getStackSize() << "\n");
 
   if (Offset > IMM_HIGH || Offset < IMM_LOW) {
-    DEBUG(std::cerr << "Unconditionally using R28 for evil purposes Offset: " << Offset << "\n");
-    //so in this case, we need to use a temporary register, and move the original
-    //inst off the SP/FP
+    DEBUG(std::cerr << "Unconditionally using R28 for evil purposes Offset: "
+          << Offset << "\n");
+    //so in this case, we need to use a temporary register, and move the
+    //original inst off the SP/FP
     //fix up the old:
-    MI.getOperand(i + 1).ChangeToRegister(Alpha::R28);
+    MI.getOperand(i + 1).ChangeToRegister(Alpha::R28, false);
     MI.getOperand(i).ChangeToImmediate(getLower16(Offset));
     //insert the new
     MachineInstr* nMI=BuildMI(Alpha::LDAH, 2, Alpha::R28)
@@ -335,9 +344,11 @@
   //now if we need to, save the old FP and set the new
   if (FP)
   {
-    BuildMI(MBB, MBBI, Alpha::STQ, 3).addReg(Alpha::R15).addImm(0).addReg(Alpha::R30);
+    BuildMI(MBB, MBBI, Alpha::STQ, 3)
+      .addReg(Alpha::R15).addImm(0).addReg(Alpha::R30);
     //this must be the last instr in the prolog
-    BuildMI(MBB, MBBI, Alpha::BIS, 2, Alpha::R15).addReg(Alpha::R30).addReg(Alpha::R30);
+    BuildMI(MBB, MBBI, Alpha::BIS, 2, Alpha::R15)
+      .addReg(Alpha::R30).addReg(Alpha::R30);
   }
 
 }
@@ -346,7 +357,8 @@
                                      MachineBasicBlock &MBB) const {
   const MachineFrameInfo *MFI = MF.getFrameInfo();
   MachineBasicBlock::iterator MBBI = prior(MBB.end());
-  assert(MBBI->getOpcode() == Alpha::RETDAG || MBBI->getOpcode() == Alpha::RETDAGp
+  assert(MBBI->getOpcode() == Alpha::RETDAG ||
+         MBBI->getOpcode() == Alpha::RETDAGp
          && "Can only insert epilog into returning blocks");
 
   bool FP = hasFP(MF);
diff --git a/lib/Target/IA64/IA64RegisterInfo.cpp b/lib/Target/IA64/IA64RegisterInfo.cpp
index 7fcd502..ff92750 100644
--- a/lib/Target/IA64/IA64RegisterInfo.cpp
+++ b/lib/Target/IA64/IA64RegisterInfo.cpp
@@ -85,7 +85,8 @@
 
   if(RC == IA64::PRRegisterClass ) // if a bool, we use pseudocode
     // (SrcReg) DestReg = cmp.eq.unc(r0, r0)
-    BuildMI(MBB, MI, IA64::PCMPEQUNC, 3, DestReg).addReg(IA64::r0).addReg(IA64::r0).addReg(SrcReg);
+    BuildMI(MBB, MI, IA64::PCMPEQUNC, 3, DestReg)
+      .addReg(IA64::r0).addReg(IA64::r0).addReg(SrcReg);
   else // otherwise, MOV works (for both gen. regs and FP regs)
     BuildMI(MBB, MI, IA64::MOV, 1, DestReg).addReg(SrcReg);
 }
@@ -152,7 +153,7 @@
   MBB.erase(I);
 }
 
-void IA64RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II) const{
+void IA64RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II)const{
   unsigned i = 0;
   MachineInstr &MI = *II;
   MachineBasicBlock &MBB = *MI.getParent();
@@ -170,7 +171,7 @@
   // choose a base register: ( hasFP? framepointer : stack pointer )
   unsigned BaseRegister = FP ? IA64::r5 : IA64::r12;
   // Add the base register
-  MI.getOperand(i).ChangeToRegister(BaseRegister);
+  MI.getOperand(i).ChangeToRegister(BaseRegister, false);
 
   // Now add the frame object offset to the offset from r1.
   int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex);
@@ -181,20 +182,16 @@
   Offset += MF.getFrameInfo()->getStackSize();
 
   // XXX: we use 'r22' as another hack+slash temporary register here :(
-  if ( Offset <= 8191 && Offset >= -8192) { // smallish offset
-    //fix up the old:
-    MI.getOperand(i).ChangeToRegister(IA64::r22);
-    MI.getOperand(i).setUse(); // mark r22 as being used
-                               // (the bundler wants to know this)
+  if (Offset <= 8191 && Offset >= -8192) { // smallish offset
+    // Fix up the old:
+    MI.getOperand(i).ChangeToRegister(IA64::r22, false);
     //insert the new
     MachineInstr* nMI=BuildMI(IA64::ADDIMM22, 2, IA64::r22)
       .addReg(BaseRegister).addImm(Offset);
     MBB.insert(II, nMI);
   } else { // it's big
     //fix up the old:
-    MI.getOperand(i).ChangeToRegister(IA64::r22);
-    MI.getOperand(i).setUse(); // mark r22 as being used
-                               // (the bundler wants to know this)
+    MI.getOperand(i).ChangeToRegister(IA64::r22, false);
     MachineInstr* nMI;
     nMI=BuildMI(IA64::MOVLIMM64, 1, IA64::r22).addImm(Offset);
     MBB.insert(II, nMI);
@@ -242,7 +239,8 @@
 
   unsigned numOutRegsUsed=MF.getInfo<IA64FunctionInfo>()->outRegsUsed;
 
-  // XXX FIXME : this code should be a bit more reliable (in case there _isn't_ a pseudo_alloc in the MBB)
+  // XXX FIXME : this code should be a bit more reliable (in case there _isn't_
+  // a pseudo_alloc in the MBB)
   unsigned dstRegOfPseudoAlloc;
   for(MBBI = MBB.begin(); /*MBBI->getOpcode() != IA64::PSEUDO_ALLOC*/; ++MBBI) {
     assert(MBBI != MBB.end());
@@ -284,7 +282,7 @@
 
   // adjust stack pointer: r12 -= numbytes
   if (NumBytes <= 8191) {
-    MI=BuildMI(IA64::ADDIMM22, 2, IA64::r12).addReg(IA64::r12).addImm(-NumBytes);
+    MI=BuildMI(IA64::ADDIMM22,2,IA64::r12).addReg(IA64::r12).addImm(-NumBytes);
     MBB.insert(MBBI, MI);
   } else { // we use r22 as a scratch register here
     MI=BuildMI(IA64::MOVLIMM64, 1, IA64::r22).addImm(-NumBytes);
@@ -332,7 +330,7 @@
   if (NumBytes != 0)
   {
     if (NumBytes <= 8191) {
-      MI=BuildMI(IA64::ADDIMM22, 2, IA64::r12).addReg(IA64::r12).addImm(NumBytes);
+      MI=BuildMI(IA64::ADDIMM22,2,IA64::r12).addReg(IA64::r12).addImm(NumBytes);
       MBB.insert(MBBI, MI);
     } else {
       MI=BuildMI(IA64::MOVLIMM64, 1, IA64::r22).addImm(NumBytes);
diff --git a/lib/Target/PowerPC/PPCRegisterInfo.cpp b/lib/Target/PowerPC/PPCRegisterInfo.cpp
index bf50e35..34c23bd 100644
--- a/lib/Target/PowerPC/PPCRegisterInfo.cpp
+++ b/lib/Target/PowerPC/PPCRegisterInfo.cpp
@@ -421,7 +421,7 @@
   int FrameIndex = MI.getOperand(i).getFrameIndex();
 
   // Replace the FrameIndex with base register with GPR1 (SP) or GPR31 (FP).
-  MI.getOperand(i).ChangeToRegister(hasFP(MF) ? PPC::R31 : PPC::R1);
+  MI.getOperand(i).ChangeToRegister(hasFP(MF) ? PPC::R31 : PPC::R1, false);
 
   // Take into account whether it's an add or mem instruction
   unsigned OffIdx = (i == 2) ? 1 : 2;
@@ -466,8 +466,8 @@
            "No indexed form of load or store available!");
     unsigned NewOpcode = ImmToIdxMap.find(MI.getOpcode())->second;
     MI.setOpcode(NewOpcode);
-    MI.getOperand(1).ChangeToRegister(MI.getOperand(i).getReg());
-    MI.getOperand(2).ChangeToRegister(PPC::R0);
+    MI.getOperand(1).ChangeToRegister(MI.getOperand(i).getReg(), false);
+    MI.getOperand(2).ChangeToRegister(PPC::R0, false);
   } else {
     if (isIXAddr) {
       assert((Offset & 3) == 0 && "Invalid frame offset!");
diff --git a/lib/Target/Sparc/SparcRegisterInfo.cpp b/lib/Target/Sparc/SparcRegisterInfo.cpp
index 7331ebd..81ebdba 100644
--- a/lib/Target/Sparc/SparcRegisterInfo.cpp
+++ b/lib/Target/Sparc/SparcRegisterInfo.cpp
@@ -147,7 +147,7 @@
   if (Offset >= -4096 && Offset <= 4095) {
     // If the offset is small enough to fit in the immediate field, directly
     // encode it.
-    MI.getOperand(i).ChangeToRegister(SP::I6);
+    MI.getOperand(i).ChangeToRegister(SP::I6, false);
     MI.getOperand(i+1).ChangeToImmediate(Offset);
   } else {
     // Otherwise, emit a G1 = SETHI %hi(offset).  FIXME: it would be better to 
@@ -158,7 +158,7 @@
     BuildMI(*MI.getParent(), II, SP::ADDrr, 2, 
             SP::G1).addReg(SP::G1).addReg(SP::I6);
     // Insert: G1+%lo(offset) into the user.
-    MI.getOperand(i).ChangeToRegister(SP::G1);
+    MI.getOperand(i).ChangeToRegister(SP::G1, false);
     MI.getOperand(i+1).ChangeToImmediate(Offset & ((1 << 10)-1));
   }
 }
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 89cc8f2..e4c05c6 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -168,7 +168,7 @@
       assert(MO.isReg() && "Expected to fold into reg operand!");
       MIB = addFrameReference(MIB, FrameIndex);
     } else if (MO.isReg())
-      MIB = MIB.addReg(MO.getReg(), MO.getUseType());
+      MIB = MIB.addReg(MO.getReg(), MO.isDef());
     else if (MO.isImm())
       MIB = MIB.addImm(MO.getImm());
     else if (MO.isGlobalAddress())
@@ -795,7 +795,7 @@
 
   // This must be part of a four operand memory reference.  Replace the
   // FrameIndex with base register with EBP.  Add add an offset to the offset.
-  MI.getOperand(i).ChangeToRegister(hasFP(MF) ? X86::EBP : X86::ESP);
+  MI.getOperand(i).ChangeToRegister(hasFP(MF) ? X86::EBP : X86::ESP, false);
 
   // Now add the frame object offset to the offset from EBP.
   int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +