From: Evan Cheng <evan.cheng@apple.com>
Date: Wed, 5 Dec 2007 03:14:33 +0000 (+0000)
Subject: Add a argument to storeRegToStackSlot and storeRegToAddr to specify whether
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d64b5c82b97ad1b74eb9fd2f23257a7899b0c307;p=oota-llvm.git

Add a argument to storeRegToStackSlot and storeRegToAddr to specify whether
the stored register is killed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44600 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/CodeGen/LiveIntervalAnalysis.h b/include/llvm/CodeGen/LiveIntervalAnalysis.h
index 1be8ea5ea04..a40d0abcb1c 100644
--- a/include/llvm/CodeGen/LiveIntervalAnalysis.h
+++ b/include/llvm/CodeGen/LiveIntervalAnalysis.h
@@ -278,6 +278,9 @@ namespace llvm {
                               SmallVector<unsigned, 2> &Ops,
                               bool isSS, int Slot, unsigned Reg);
 
+    bool canFoldMemoryOperand(MachineInstr *MI,
+                              SmallVector<unsigned, 2> &Ops) const;
+
     /// anyKillInMBBAfterIdx - Returns true if there is a kill of the specified
     /// VNInfo that's after the specified index but is within the basic block.
     bool anyKillInMBBAfterIdx(const LiveInterval &li, const VNInfo *VNI,
@@ -304,7 +307,7 @@ namespace llvm {
 
     /// rewriteInstructionForSpills, rewriteInstructionsForSpills - Helper functions
     /// for addIntervalsForSpills to rewrite uses / defs for the given live range.
-    void rewriteInstructionForSpills(const LiveInterval &li, bool TrySplit,
+    bool rewriteInstructionForSpills(const LiveInterval &li, bool TrySplit,
         unsigned id, unsigned index, unsigned end, MachineInstr *MI,
         MachineInstr *OrigDefMI, MachineInstr *DefMI, unsigned Slot, int LdSlot,
         bool isLoad, bool isLoadSS, bool DefIsReMat, bool CanDelete,
diff --git a/include/llvm/Target/MRegisterInfo.h b/include/llvm/Target/MRegisterInfo.h
index c4d16227574..08f76c4d353 100644
--- a/include/llvm/Target/MRegisterInfo.h
+++ b/include/llvm/Target/MRegisterInfo.h
@@ -493,10 +493,10 @@ public:
 
   virtual void storeRegToStackSlot(MachineBasicBlock &MBB,
                                    MachineBasicBlock::iterator MI,
-                                   unsigned SrcReg, int FrameIndex,
+                                   unsigned SrcReg, bool isKill, int FrameIndex,
                                    const TargetRegisterClass *RC) const = 0;
 
-  virtual void storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+  virtual void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill,
                               SmallVectorImpl<MachineOperand> &Addr,
                               const TargetRegisterClass *RC,
                               SmallVectorImpl<MachineInstr*> &NewMIs) const = 0;
@@ -553,12 +553,12 @@ public:
     return 0;
   }
 
-  /// getOpcodeAfterMemoryFold - Returns the opcode of the would be new
-  /// instruction after load / store is folded into an instruction of the
-  /// specified opcode. It returns zero if the specified unfolding is not
-  /// possible.
-  virtual unsigned getOpcodeAfterMemoryFold(unsigned Opc, unsigned OpNum) const{
-    return 0;
+  /// canFoldMemoryOperand - Returns true if the specified load / store is
+  /// folding is possible.
+  virtual
+  bool canFoldMemoryOperand(MachineInstr *MI,
+                            SmallVectorImpl<unsigned> &Ops) const{
+    return false;
   }
 
   /// unfoldMemoryOperand - Separate a single instruction which folded a load or
diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp
index 882c6a74404..9f765d43d40 100644
--- a/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/lib/CodeGen/PrologEpilogInserter.cpp
@@ -253,7 +253,7 @@ void PEI::saveCalleeSavedRegisters(MachineFunction &Fn) {
       MBB->addLiveIn(CSI[i].getReg());
 
       // Insert the spill to the stack frame.
-      RegInfo->storeRegToStackSlot(*MBB, I, CSI[i].getReg(),
+      RegInfo->storeRegToStackSlot(*MBB, I, CSI[i].getReg(), true,
                                    CSI[i].getFrameIdx(), CSI[i].getRegClass());
     }
   }
diff --git a/lib/CodeGen/RegAllocBigBlock.cpp b/lib/CodeGen/RegAllocBigBlock.cpp
index 227a238a86d..83c9ceb37b0 100644
--- a/lib/CodeGen/RegAllocBigBlock.cpp
+++ b/lib/CodeGen/RegAllocBigBlock.cpp
@@ -329,7 +329,7 @@ void RABigBlock::spillVirtReg(MachineBasicBlock &MBB,
     const TargetRegisterClass *RC = MF->getSSARegMap()->getRegClass(VirtReg);
     int FrameIndex = getStackSpaceFor(VirtReg, RC);
     DOUT << " to stack slot #" << FrameIndex;
-    RegInfo->storeRegToStackSlot(MBB, I, PhysReg, FrameIndex, RC);
+    RegInfo->storeRegToStackSlot(MBB, I, PhysReg, true, FrameIndex, RC);
     ++NumStores;   // Update statistics
   }
 
diff --git a/lib/CodeGen/RegAllocLocal.cpp b/lib/CodeGen/RegAllocLocal.cpp
index a666184b96e..4b4150a492a 100644
--- a/lib/CodeGen/RegAllocLocal.cpp
+++ b/lib/CodeGen/RegAllocLocal.cpp
@@ -286,7 +286,7 @@ void RALocal::spillVirtReg(MachineBasicBlock &MBB,
     const TargetRegisterClass *RC = MF->getSSARegMap()->getRegClass(VirtReg);
     int FrameIndex = getStackSpaceFor(VirtReg, RC);
     DOUT << " to stack slot #" << FrameIndex;
-    RegInfo->storeRegToStackSlot(MBB, I, PhysReg, FrameIndex, RC);
+    RegInfo->storeRegToStackSlot(MBB, I, PhysReg, true, FrameIndex, RC);
     ++NumStores;   // Update statistics
   }
 
diff --git a/lib/CodeGen/RegAllocSimple.cpp b/lib/CodeGen/RegAllocSimple.cpp
index f49dd4c5cfb..574559a7ac3 100644
--- a/lib/CodeGen/RegAllocSimple.cpp
+++ b/lib/CodeGen/RegAllocSimple.cpp
@@ -156,7 +156,7 @@ void RegAllocSimple::spillVirtReg(MachineBasicBlock &MBB,
 
   // Add move instruction(s)
   ++NumStores;
-  RegInfo->storeRegToStackSlot(MBB, I, PhysReg, FrameIdx, RC);
+  RegInfo->storeRegToStackSlot(MBB, I, PhysReg, true, FrameIdx, RC);
 }
 
 
diff --git a/lib/CodeGen/RegisterScavenging.cpp b/lib/CodeGen/RegisterScavenging.cpp
index 15592128480..9cb7453d3d3 100644
--- a/lib/CodeGen/RegisterScavenging.cpp
+++ b/lib/CodeGen/RegisterScavenging.cpp
@@ -282,7 +282,7 @@ unsigned RegScavenger::scavengeRegister(const TargetRegisterClass *RC,
     RegInfo->eliminateFrameIndex(II, SPAdj, this);
   }
 
-  RegInfo->storeRegToStackSlot(*MBB, I, SReg, ScavengingFrameIndex, RC);
+  RegInfo->storeRegToStackSlot(*MBB, I, SReg, true, ScavengingFrameIndex, RC);
   MachineBasicBlock::iterator II = prior(I);
   RegInfo->eliminateFrameIndex(II, SPAdj, this);
   ScavengedReg = SReg;
diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index 58fc40b2174..6c04439bcb9 100644
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -208,7 +208,8 @@ bool SimpleSpiller::runOnMachineFunction(MachineFunction &MF, VirtRegMap &VRM) {
               }
 
               if (MO.isDef()) {
-                MRI.storeRegToStackSlot(MBB, next(MII), PhysReg, StackSlot, RC);
+                MRI.storeRegToStackSlot(MBB, next(MII), PhysReg, true,
+                                        StackSlot, RC);
                 ++NumStores;
               }
             }
@@ -861,7 +862,7 @@ void LocalSpiller::SpillRegToStackSlot(MachineBasicBlock &MBB,
                                   BitVector &RegKills,
                                   std::vector<MachineOperand*> &KillOps,
                                   VirtRegMap &VRM) {
-  MRI->storeRegToStackSlot(MBB, next(MII), PhysReg, StackSlot, RC);
+  MRI->storeRegToStackSlot(MBB, next(MII), PhysReg, true, StackSlot, RC);
   DOUT << "Store:\t" << *next(MII);
 
   // If there is a dead store to this stack slot, nuke it now.
@@ -984,9 +985,10 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) {
         const TargetRegisterClass *RC = RegMap->getRegClass(VirtReg);
         unsigned Phys = VRM.getPhys(VirtReg);
         int StackSlot = VRM.getStackSlot(VirtReg);
-        MRI->storeRegToStackSlot(MBB, next(MII), Phys, StackSlot, RC);
-        DOUT << "Store:\t" << *next(MII);
-        VRM.virtFolded(VirtReg, next(MII), VirtRegMap::isMod);
+        MRI->storeRegToStackSlot(MBB, next(MII), Phys, false, StackSlot, RC);
+        MachineInstr *StoreMI = next(MII);
+        DOUT << "Store:\t" << StoreMI;
+        VRM.virtFolded(VirtReg, StoreMI, VirtRegMap::isMod);
       }
       NextMII = next(MII);
     }
@@ -1011,12 +1013,6 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) {
       assert(MRegisterInfo::isVirtualRegister(VirtReg) &&
              "Not a virtual or a physical register?");
 
-      // Assumes this is the last use of a split interval. IsKill will be unset
-      // if reg is use later unless it's a two-address operand.
-      if (MO.isUse() && VRM.getPreSplitReg(VirtReg) &&
-          TID->getOperandConstraint(i, TOI::TIED_TO) == -1)
-        MI.getOperand(i).setIsKill();
-
       unsigned SubIdx = MO.getSubReg();
       if (VRM.isAssignedReg(VirtReg)) {
         // This virtual register was assigned a physreg!
diff --git a/lib/Target/ARM/ARMRegisterInfo.cpp b/lib/Target/ARM/ARMRegisterInfo.cpp
index f1665dc0b49..70360705a69 100644
--- a/lib/Target/ARM/ARMRegisterInfo.cpp
+++ b/lib/Target/ARM/ARMRegisterInfo.cpp
@@ -158,31 +158,32 @@ static const MachineInstrBuilder &ARMInstrAddOperand(MachineInstrBuilder &MIB,
 
 void ARMRegisterInfo::
 storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
-                    unsigned SrcReg, int FI,
+                    unsigned SrcReg, bool isKill, int FI,
                     const TargetRegisterClass *RC) const {
   if (RC == ARM::GPRRegisterClass) {
     MachineFunction &MF = *MBB.getParent();
     ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
     if (AFI->isThumbFunction())
-      BuildMI(MBB, I, TII.get(ARM::tSpill)).addReg(SrcReg, false, false, true)
+      BuildMI(MBB, I, TII.get(ARM::tSpill)).addReg(SrcReg, false, false, isKill)
         .addFrameIndex(FI).addImm(0);
     else
       AddDefaultPred(BuildMI(MBB, I, TII.get(ARM::STR))
-                     .addReg(SrcReg, false, false, true)
+                     .addReg(SrcReg, false, false, isKill)
                      .addFrameIndex(FI).addReg(0).addImm(0));
   } else if (RC == ARM::DPRRegisterClass) {
     AddDefaultPred(BuildMI(MBB, I, TII.get(ARM::FSTD))
-                   .addReg(SrcReg, false, false, true)
+                   .addReg(SrcReg, false, false, isKill)
                    .addFrameIndex(FI).addImm(0));
   } else {
     assert(RC == ARM::SPRRegisterClass && "Unknown regclass!");
     AddDefaultPred(BuildMI(MBB, I, TII.get(ARM::FSTS))
-                   .addReg(SrcReg, false, false, true)
+                   .addReg(SrcReg, false, false, isKill)
                    .addFrameIndex(FI).addImm(0));
   }
 }
 
 void ARMRegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+                                     bool isKill,
                                      SmallVectorImpl<MachineOperand> &Addr,
                                      const TargetRegisterClass *RC,
                                  SmallVectorImpl<MachineInstr*> &NewMIs) const {
@@ -192,7 +193,7 @@ void ARMRegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
     if (AFI->isThumbFunction()) {
       Opc = Addr[0].isFrameIndex() ? ARM::tSpill : ARM::tSTR;
       MachineInstrBuilder MIB = 
-        BuildMI(TII.get(Opc)).addReg(SrcReg, false, false, true);
+        BuildMI(TII.get(Opc)).addReg(SrcReg, false, false, isKill);
       for (unsigned i = 0, e = Addr.size(); i != e; ++i)
         MIB = ARMInstrAddOperand(MIB, Addr[i]);
       NewMIs.push_back(MIB);
@@ -207,7 +208,7 @@ void ARMRegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
   }
 
   MachineInstrBuilder MIB = 
-    BuildMI(TII.get(Opc)).addReg(SrcReg, false, false, true);
+    BuildMI(TII.get(Opc)).addReg(SrcReg, false, false, isKill);
   for (unsigned i = 0, e = Addr.size(); i != e; ++i)
     MIB = ARMInstrAddOperand(MIB, Addr[i]);
   AddDefaultPred(MIB);
@@ -426,6 +427,39 @@ MachineInstr *ARMRegisterInfo::foldMemoryOperand(MachineInstr *MI,
   return NewMI;
 }
 
+bool ARMRegisterInfo::canFoldMemoryOperand(MachineInstr *MI,
+                                         SmallVectorImpl<unsigned> &Ops) const {
+  if (Ops.size() != 1) return NULL;
+
+  unsigned OpNum = Ops[0];
+  unsigned Opc = MI->getOpcode();
+  switch (Opc) {
+  default: break;
+  case ARM::MOVr:
+    // If it is updating CPSR, then it cannot be foled.
+    return MI->getOperand(4).getReg() != ARM::CPSR;
+  case ARM::tMOVr: {
+    if (OpNum == 0) { // move -> store
+      unsigned SrcReg = MI->getOperand(1).getReg();
+      if (isPhysicalRegister(SrcReg) && !isLowRegister(SrcReg))
+        // tSpill cannot take a high register operand.
+        return false;
+    } else {          // move -> load
+      unsigned DstReg = MI->getOperand(0).getReg();
+      if (isPhysicalRegister(DstReg) && !isLowRegister(DstReg))
+        // tRestore cannot target a high register operand.
+        return false;
+    }
+    return true;
+  }
+  case ARM::FCPYS:
+  case ARM::FCPYD:
+    return true;
+  }
+
+  return false;
+}
+
 const unsigned*
 ARMRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
   static const unsigned CalleeSavedRegs[] = {
diff --git a/lib/Target/ARM/ARMRegisterInfo.h b/lib/Target/ARM/ARMRegisterInfo.h
index ed53e4e2da5..85ef153f94a 100644
--- a/lib/Target/ARM/ARMRegisterInfo.h
+++ b/lib/Target/ARM/ARMRegisterInfo.h
@@ -48,10 +48,10 @@ public:
 
   void storeRegToStackSlot(MachineBasicBlock &MBB,
                            MachineBasicBlock::iterator MBBI,
-                           unsigned SrcReg, int FrameIndex,
+                           unsigned SrcReg, bool isKill, int FrameIndex,
                            const TargetRegisterClass *RC) const;
 
-  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill,
                       SmallVectorImpl<MachineOperand> &Addr,
                       const TargetRegisterClass *RC,
                       SmallVectorImpl<MachineInstr*> &NewMIs) const;
@@ -84,6 +84,9 @@ public:
     return 0;
   }
 
+  bool canFoldMemoryOperand(MachineInstr *MI,
+                            SmallVectorImpl<unsigned> &Ops) const;
+
   const unsigned *getCalleeSavedRegs(const MachineFunction *MF = 0) const;
 
   const TargetRegisterClass* const*
diff --git a/lib/Target/Alpha/AlphaRegisterInfo.cpp b/lib/Target/Alpha/AlphaRegisterInfo.cpp
index b8e2c268271..8185a796f76 100644
--- a/lib/Target/Alpha/AlphaRegisterInfo.cpp
+++ b/lib/Target/Alpha/AlphaRegisterInfo.cpp
@@ -61,28 +61,29 @@ AlphaRegisterInfo::AlphaRegisterInfo(const TargetInstrInfo &tii)
 void
 AlphaRegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
                                        MachineBasicBlock::iterator MI,
-                                       unsigned SrcReg, int FrameIdx,
-                                       const TargetRegisterClass *RC) const {
+                                     unsigned SrcReg, bool isKill, int FrameIdx,
+                                     const TargetRegisterClass *RC) const {
   //cerr << "Trying to store " << getPrettyName(SrcReg) << " to "
   //     << FrameIdx << "\n";
   //BuildMI(MBB, MI, Alpha::WTF, 0).addReg(SrcReg);
   if (RC == Alpha::F4RCRegisterClass)
     BuildMI(MBB, MI, TII.get(Alpha::STS))
-      .addReg(SrcReg, false, false, true)
+      .addReg(SrcReg, false, false, isKill)
       .addFrameIndex(FrameIdx).addReg(Alpha::F31);
   else if (RC == Alpha::F8RCRegisterClass)
     BuildMI(MBB, MI, TII.get(Alpha::STT))
-      .addReg(SrcReg, false, false, true)
+      .addReg(SrcReg, false, false, isKill)
       .addFrameIndex(FrameIdx).addReg(Alpha::F31);
   else if (RC == Alpha::GPRCRegisterClass)
     BuildMI(MBB, MI, TII.get(Alpha::STQ))
-      .addReg(SrcReg, false, false, true)
+      .addReg(SrcReg, false, false, isKill)
       .addFrameIndex(FrameIdx).addReg(Alpha::F31);
   else
     abort();
 }
 
 void AlphaRegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+                                       bool isKill,
                                        SmallVectorImpl<MachineOperand> &Addr,
                                        const TargetRegisterClass *RC,
                                  SmallVectorImpl<MachineInstr*> &NewMIs) const {
@@ -96,7 +97,7 @@ void AlphaRegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
   else
     abort();
   MachineInstrBuilder MIB = 
-    BuildMI(TII.get(Opc)).addReg(SrcReg, false, false, true);
+    BuildMI(TII.get(Opc)).addReg(SrcReg, false, false, isKill);
   for (unsigned i = 0, e = Addr.size(); i != e; ++i) {
     MachineOperand &MO = Addr[i];
     if (MO.isRegister())
diff --git a/lib/Target/Alpha/AlphaRegisterInfo.h b/lib/Target/Alpha/AlphaRegisterInfo.h
index 04565f7bb22..7a846dcc4d7 100644
--- a/lib/Target/Alpha/AlphaRegisterInfo.h
+++ b/lib/Target/Alpha/AlphaRegisterInfo.h
@@ -30,10 +30,10 @@ struct AlphaRegisterInfo : public AlphaGenRegisterInfo {
   /// Code Generation virtual methods...
   void storeRegToStackSlot(MachineBasicBlock &MBB,
                            MachineBasicBlock::iterator MBBI,
-                           unsigned SrcReg, int FrameIndex,
+                           unsigned SrcReg, bool isKill, int FrameIndex,
                            const TargetRegisterClass *RC) const;
 
-  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill,
                       SmallVectorImpl<MachineOperand> &Addr,
                       const TargetRegisterClass *RC,
                       SmallVectorImpl<MachineInstr*> &NewMIs) const;
diff --git a/lib/Target/CellSPU/SPURegisterInfo.cpp b/lib/Target/CellSPU/SPURegisterInfo.cpp
index a9c7333dc75..683d97652cf 100644
--- a/lib/Target/CellSPU/SPURegisterInfo.cpp
+++ b/lib/Target/CellSPU/SPURegisterInfo.cpp
@@ -194,7 +194,7 @@ SPURegisterInfo::SPURegisterInfo(const SPUSubtarget &subtarget,
 void
 SPURegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
                                      MachineBasicBlock::iterator MI,
-                                     unsigned SrcReg, int FrameIdx,
+                                     unsigned SrcReg, bool isKill, int FrameIdx,
                                      const TargetRegisterClass *RC) const
 {
   MachineOpCode opc;
@@ -227,10 +227,12 @@ SPURegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
     abort();
   }
 
-  addFrameReference(BuildMI(MBB, MI, TII.get(opc)).addReg(SrcReg), FrameIdx);
+  addFrameReference(BuildMI(MBB, MI, TII.get(opc))
+                    .addReg(SrcReg, false, false, isKill), FrameIdx);
 }
 
 void SPURegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+                                     bool isKill,
                                      SmallVectorImpl<MachineOperand> &Addr,
                                      const TargetRegisterClass *RC,
                                      SmallVectorImpl<MachineInstr*> &NewMIs) const {
@@ -258,7 +260,7 @@ void SPURegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
       abort();
     }
     MachineInstrBuilder MIB = BuildMI(TII.get(Opc))
-      .addReg(SrcReg, false, false, true);
+      .addReg(SrcReg, false, false, isKill);
     for (unsigned i = 0, e = Addr.size(); i != e; ++i) {
       MachineOperand &MO = Addr[i];
       if (MO.isRegister())
diff --git a/lib/Target/CellSPU/SPURegisterInfo.h b/lib/Target/CellSPU/SPURegisterInfo.h
index 07e16d809a0..1eca442cae8 100644
--- a/lib/Target/CellSPU/SPURegisterInfo.h
+++ b/lib/Target/CellSPU/SPURegisterInfo.h
@@ -44,11 +44,11 @@ namespace llvm {
     //! Store a register to a stack slot, based on its register class.
     void storeRegToStackSlot(MachineBasicBlock &MBB,
                              MachineBasicBlock::iterator MBBI,
-                             unsigned SrcReg, int FrameIndex,
+                             unsigned SrcReg, bool isKill, int FrameIndex,
                              const TargetRegisterClass *RC) const;
 
     //! Store a register to an address, based on its register class
-    void storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+    void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill,
 			SmallVectorImpl<MachineOperand> &Addr,
 			const TargetRegisterClass *RC,
 			SmallVectorImpl<MachineInstr*> &NewMIs) const;
diff --git a/lib/Target/IA64/IA64RegisterInfo.cpp b/lib/Target/IA64/IA64RegisterInfo.cpp
index af1af3110dd..2490f88420a 100644
--- a/lib/Target/IA64/IA64RegisterInfo.cpp
+++ b/lib/Target/IA64/IA64RegisterInfo.cpp
@@ -38,22 +38,23 @@ IA64RegisterInfo::IA64RegisterInfo(const TargetInstrInfo &tii)
 
 void IA64RegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
                                            MachineBasicBlock::iterator MI,
-                                           unsigned SrcReg, int FrameIdx,
+                                           unsigned SrcReg, bool isKill,
+                                           int FrameIdx,
                                            const TargetRegisterClass *RC) const{
 
   if (RC == IA64::FPRegisterClass) {
     BuildMI(MBB, MI, TII.get(IA64::STF_SPILL)).addFrameIndex(FrameIdx)
-      .addReg(SrcReg, false, false, true);
+      .addReg(SrcReg, false, false, isKill);
   } else if (RC == IA64::GRRegisterClass) {
     BuildMI(MBB, MI, TII.get(IA64::ST8)).addFrameIndex(FrameIdx)
-      .addReg(SrcReg, false, false, true);
+      .addReg(SrcReg, false, false, isKill);
   } else if (RC == IA64::PRRegisterClass) {
     /* we use IA64::r2 as a temporary register for doing this hackery. */
     // first we load 0:
     BuildMI(MBB, MI, TII.get(IA64::MOV), IA64::r2).addReg(IA64::r0);
     // then conditionally add 1:
     BuildMI(MBB, MI, TII.get(IA64::CADDIMM22), IA64::r2).addReg(IA64::r2)
-      .addImm(1).addReg(SrcReg, false, false, true);
+      .addImm(1).addReg(SrcReg, false, false, isKill);
     // and then store it to the stack
     BuildMI(MBB, MI, TII.get(IA64::ST8)).addFrameIndex(FrameIdx).addReg(IA64::r2);
   } else assert(0 &&
@@ -61,6 +62,7 @@ void IA64RegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
 }
 
 void IA64RegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+                                      bool isKill,
                                       SmallVectorImpl<MachineOperand> &Addr,
                                       const TargetRegisterClass *RC,
                                  SmallVectorImpl<MachineInstr*> &NewMIs) const {
@@ -86,7 +88,7 @@ void IA64RegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
     else
       MIB.addFrameIndex(MO.getFrameIndex());
   }
-  MIB.addReg(SrcReg, false, false, true);
+  MIB.addReg(SrcReg, false, false, isKill);
   NewMIs.push_back(MIB);
   return;
 
diff --git a/lib/Target/IA64/IA64RegisterInfo.h b/lib/Target/IA64/IA64RegisterInfo.h
index 3f86a4c1743..0ac5b7cae71 100644
--- a/lib/Target/IA64/IA64RegisterInfo.h
+++ b/lib/Target/IA64/IA64RegisterInfo.h
@@ -31,10 +31,10 @@ struct IA64RegisterInfo : public IA64GenRegisterInfo {
   /// Code Generation virtual methods...
   void storeRegToStackSlot(MachineBasicBlock &MBB,
                            MachineBasicBlock::iterator MI,
-                           unsigned SrcReg, int FrameIndex,
+                           unsigned SrcReg, bool isKill, int FrameIndex,
                            const TargetRegisterClass *RC) const;
 
-  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill,
                       SmallVectorImpl<MachineOperand> &Addr,
                       const TargetRegisterClass *RC,
                       SmallVectorImpl<MachineInstr*> &NewMIs) const;
diff --git a/lib/Target/Mips/MipsRegisterInfo.cpp b/lib/Target/Mips/MipsRegisterInfo.cpp
index 37c09331d5d..81591897d5d 100644
--- a/lib/Target/Mips/MipsRegisterInfo.cpp
+++ b/lib/Target/Mips/MipsRegisterInfo.cpp
@@ -85,24 +85,25 @@ getRegisterNumbering(unsigned RegEnum)
 
 void MipsRegisterInfo::
 storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
-          unsigned SrcReg, int FI, 
+          unsigned SrcReg, bool isKill, int FI, 
           const TargetRegisterClass *RC) const 
 {
   if (RC == Mips::CPURegsRegisterClass)
-    BuildMI(MBB, I, TII.get(Mips::SW)).addReg(SrcReg, false, false, true)
+    BuildMI(MBB, I, TII.get(Mips::SW)).addReg(SrcReg, false, false, isKill)
           .addImm(0).addFrameIndex(FI);
   else
     assert(0 && "Can't store this register to stack slot");
 }
 
 void MipsRegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+                                      bool isKill,
                                       SmallVectorImpl<MachineOperand> &Addr,
                                       const TargetRegisterClass *RC,
                                  SmallVectorImpl<MachineInstr*> &NewMIs) const {
   if (RC != Mips::CPURegsRegisterClass)
     assert(0 && "Can't store this register");
   MachineInstrBuilder MIB = BuildMI(TII.get(Mips::SW))
-    .addReg(SrcReg, false, false, true);
+    .addReg(SrcReg, false, false, isKill);
   for (unsigned i = 0, e = Addr.size(); i != e; ++i) {
     MachineOperand &MO = Addr[i];
     if (MO.isRegister())
diff --git a/lib/Target/Mips/MipsRegisterInfo.h b/lib/Target/Mips/MipsRegisterInfo.h
index 4ebb7369756..a3fad4a13b6 100644
--- a/lib/Target/Mips/MipsRegisterInfo.h
+++ b/lib/Target/Mips/MipsRegisterInfo.h
@@ -34,10 +34,10 @@ struct MipsRegisterInfo : public MipsGenRegisterInfo {
   /// Code Generation virtual methods...
   void storeRegToStackSlot(MachineBasicBlock &MBB,
                            MachineBasicBlock::iterator MBBI,
-                           unsigned SrcReg, int FrameIndex,
+                           unsigned SrcReg, bool isKill, int FrameIndex,
                            const TargetRegisterClass *RC) const;
 
-  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill,
                       SmallVectorImpl<MachineOperand> &Addr,
                       const TargetRegisterClass *RC,
                       SmallVectorImpl<MachineInstr*> &NewMIs) const;
diff --git a/lib/Target/PowerPC/PPCRegisterInfo.cpp b/lib/Target/PowerPC/PPCRegisterInfo.cpp
index 09b0e515790..dec49bd16a7 100644
--- a/lib/Target/PowerPC/PPCRegisterInfo.cpp
+++ b/lib/Target/PowerPC/PPCRegisterInfo.cpp
@@ -104,39 +104,39 @@ PPCRegisterInfo::PPCRegisterInfo(const PPCSubtarget &ST,
 }
 
 static void StoreRegToStackSlot(const TargetInstrInfo &TII,
-                                unsigned SrcReg, int FrameIdx,
+                                unsigned SrcReg, bool isKill, int FrameIdx,
                                 const TargetRegisterClass *RC,
                                 SmallVectorImpl<MachineInstr*> &NewMIs) {
   if (RC == PPC::GPRCRegisterClass) {
     if (SrcReg != PPC::LR) {
       NewMIs.push_back(addFrameReference(BuildMI(TII.get(PPC::STW))
-                                .addReg(SrcReg, false, false, true), FrameIdx));
+                                .addReg(SrcReg, false, false, isKill), FrameIdx));
     } else {
       // FIXME: this spills LR immediately to memory in one step.  To do this,
       // we use R11, which we know cannot be used in the prolog/epilog.  This is
       // a hack.
       NewMIs.push_back(BuildMI(TII.get(PPC::MFLR), PPC::R11));
       NewMIs.push_back(addFrameReference(BuildMI(TII.get(PPC::STW))
-                              .addReg(PPC::R11, false, false, true), FrameIdx));
+                              .addReg(PPC::R11, false, false, isKill), FrameIdx));
     }
   } else if (RC == PPC::G8RCRegisterClass) {
     if (SrcReg != PPC::LR8) {
       NewMIs.push_back(addFrameReference(BuildMI(TII.get(PPC::STD))
-                                .addReg(SrcReg, false, false, true), FrameIdx));
+                                .addReg(SrcReg, false, false, isKill), FrameIdx));
     } else {
       // FIXME: this spills LR immediately to memory in one step.  To do this,
       // we use R11, which we know cannot be used in the prolog/epilog.  This is
       // a hack.
       NewMIs.push_back(BuildMI(TII.get(PPC::MFLR8), PPC::X11));
       NewMIs.push_back(addFrameReference(BuildMI(TII.get(PPC::STD))
-                              .addReg(PPC::X11, false, false, true), FrameIdx));
+                              .addReg(PPC::X11, false, false, isKill), FrameIdx));
     }
   } else if (RC == PPC::F8RCRegisterClass) {
     NewMIs.push_back(addFrameReference(BuildMI(TII.get(PPC::STFD))
-                                .addReg(SrcReg, false, false, true), FrameIdx));
+                                .addReg(SrcReg, false, false, isKill), FrameIdx));
   } else if (RC == PPC::F4RCRegisterClass) {
     NewMIs.push_back(addFrameReference(BuildMI(TII.get(PPC::STFS))
-                                .addReg(SrcReg, false, false, true), FrameIdx));
+                                .addReg(SrcReg, false, false, isKill), FrameIdx));
   } else if (RC == PPC::CRRCRegisterClass) {
     // FIXME: We use R0 here, because it isn't available for RA.
     // We need to store the CR in the low 4-bits of the saved value.  First,
@@ -153,7 +153,7 @@ static void StoreRegToStackSlot(const TargetInstrInfo &TII,
     }
     
     NewMIs.push_back(addFrameReference(BuildMI(TII.get(PPC::STW))
-                               .addReg(PPC::R0, false, false, true), FrameIdx));
+                               .addReg(PPC::R0, false, false, isKill), FrameIdx));
   } else if (RC == PPC::VRRCRegisterClass) {
     // We don't have indexed addressing for vector loads.  Emit:
     // R0 = ADDI FI#
@@ -163,7 +163,7 @@ static void StoreRegToStackSlot(const TargetInstrInfo &TII,
     NewMIs.push_back(addFrameReference(BuildMI(TII.get(PPC::ADDI), PPC::R0),
                                        FrameIdx, 0, 0));
     NewMIs.push_back(BuildMI(TII.get(PPC::STVX))
-           .addReg(SrcReg, false, false, true).addReg(PPC::R0).addReg(PPC::R0));
+           .addReg(SrcReg, false, false, isKill).addReg(PPC::R0).addReg(PPC::R0));
   } else {
     assert(0 && "Unknown regclass!");
     abort();
@@ -173,20 +173,22 @@ static void StoreRegToStackSlot(const TargetInstrInfo &TII,
 void
 PPCRegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
                                      MachineBasicBlock::iterator MI,
-                                     unsigned SrcReg, int FrameIdx,
+                                     unsigned SrcReg, bool isKill, int FrameIdx,
                                      const TargetRegisterClass *RC) const {
   SmallVector<MachineInstr*, 4> NewMIs;
-  StoreRegToStackSlot(TII, SrcReg, FrameIdx, RC, NewMIs);
+  StoreRegToStackSlot(TII, SrcReg, isKill, FrameIdx, RC, NewMIs);
   for (unsigned i = 0, e = NewMIs.size(); i != e; ++i)
     MBB.insert(MI, NewMIs[i]);
 }
 
 void PPCRegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+                                     bool isKill,
                                      SmallVectorImpl<MachineOperand> &Addr,
                                      const TargetRegisterClass *RC,
                                  SmallVectorImpl<MachineInstr*> &NewMIs) const {
   if (Addr[0].isFrameIndex()) {
-    StoreRegToStackSlot(TII, SrcReg, Addr[0].getFrameIndex(), RC, NewMIs);
+    StoreRegToStackSlot(TII, SrcReg, isKill, Addr[0].getFrameIndex(), RC,
+                        NewMIs);
     return;
   }
 
@@ -206,7 +208,7 @@ void PPCRegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
     abort();
   }
   MachineInstrBuilder MIB = BuildMI(TII.get(Opc))
-    .addReg(SrcReg, false, false, true);
+    .addReg(SrcReg, false, false, isKill);
   for (unsigned i = 0, e = Addr.size(); i != e; ++i) {
     MachineOperand &MO = Addr[i];
     if (MO.isRegister())
diff --git a/lib/Target/PowerPC/PPCRegisterInfo.h b/lib/Target/PowerPC/PPCRegisterInfo.h
index 8647a339195..687af569717 100644
--- a/lib/Target/PowerPC/PPCRegisterInfo.h
+++ b/lib/Target/PowerPC/PPCRegisterInfo.h
@@ -37,10 +37,10 @@ public:
   /// Code Generation virtual methods...
   void storeRegToStackSlot(MachineBasicBlock &MBB,
                            MachineBasicBlock::iterator MBBI,
-                           unsigned SrcReg, int FrameIndex,
+                           unsigned SrcReg, bool isKill, int FrameIndex,
                            const TargetRegisterClass *RC) const;
 
-  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill,
                       SmallVectorImpl<MachineOperand> &Addr,
                       const TargetRegisterClass *RC,
                       SmallVectorImpl<MachineInstr*> &NewMIs) const;
diff --git a/lib/Target/Sparc/SparcRegisterInfo.cpp b/lib/Target/Sparc/SparcRegisterInfo.cpp
index fcd0dfcca25..dc2f9e89ff2 100644
--- a/lib/Target/Sparc/SparcRegisterInfo.cpp
+++ b/lib/Target/Sparc/SparcRegisterInfo.cpp
@@ -32,23 +32,24 @@ SparcRegisterInfo::SparcRegisterInfo(SparcSubtarget &st,
 
 void SparcRegisterInfo::
 storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
-                    unsigned SrcReg, int FI,
+                    unsigned SrcReg, bool isKill, int FI,
                     const TargetRegisterClass *RC) const {
   // On the order of operands here: think "[FrameIdx + 0] = SrcReg".
   if (RC == SP::IntRegsRegisterClass)
     BuildMI(MBB, I, TII.get(SP::STri)).addFrameIndex(FI).addImm(0)
-      .addReg(SrcReg, false, false, true);
+      .addReg(SrcReg, false, false, isKill);
   else if (RC == SP::FPRegsRegisterClass)
     BuildMI(MBB, I, TII.get(SP::STFri)).addFrameIndex(FI).addImm(0)
-      .addReg(SrcReg, false, false, true);
+      .addReg(SrcReg, false, false, isKill);
   else if (RC == SP::DFPRegsRegisterClass)
     BuildMI(MBB, I, TII.get(SP::STDFri)).addFrameIndex(FI).addImm(0)
-      .addReg(SrcReg, false, false, true);
+      .addReg(SrcReg, false, false, isKill);
   else
     assert(0 && "Can't store this register to stack slot");
 }
 
 void SparcRegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+                                       bool isKill,
                                        SmallVectorImpl<MachineOperand> &Addr,
                                        const TargetRegisterClass *RC,
                                  SmallVectorImpl<MachineInstr*> &NewMIs) const {
@@ -71,7 +72,7 @@ void SparcRegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
     else
       MIB.addFrameIndex(MO.getFrameIndex());
   }
-  MIB.addReg(SrcReg, false, false, true);
+  MIB.addReg(SrcReg, false, false, isKill);
   NewMIs.push_back(MIB);
   return;
 }
diff --git a/lib/Target/Sparc/SparcRegisterInfo.h b/lib/Target/Sparc/SparcRegisterInfo.h
index 347b631ecf4..8049fadda1b 100644
--- a/lib/Target/Sparc/SparcRegisterInfo.h
+++ b/lib/Target/Sparc/SparcRegisterInfo.h
@@ -32,10 +32,10 @@ struct SparcRegisterInfo : public SparcGenRegisterInfo {
   /// Code Generation virtual methods...
   void storeRegToStackSlot(MachineBasicBlock &MBB,
                            MachineBasicBlock::iterator MBBI,
-                           unsigned SrcReg, int FrameIndex,
+                           unsigned SrcReg, bool isKill, int FrameIndex,
                            const TargetRegisterClass *RC) const;
 
-  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill,
                       SmallVectorImpl<MachineOperand> &Addr,
                       const TargetRegisterClass *RC,
                       SmallVectorImpl<MachineInstr*> &NewMIs) const;
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 122dd9ed758..a1c118291f8 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -834,14 +834,15 @@ static unsigned getStoreRegOpcode(const TargetRegisterClass *RC,
 
 void X86RegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
                                           MachineBasicBlock::iterator MI,
-                                          unsigned SrcReg, int FrameIdx,
+                                          unsigned SrcReg, bool isKill, int FrameIdx,
                                           const TargetRegisterClass *RC) const {
   unsigned Opc = getStoreRegOpcode(RC, StackAlign);
   addFrameReference(BuildMI(MBB, MI, TII.get(Opc)), FrameIdx)
-    .addReg(SrcReg, false, false, true);
+    .addReg(SrcReg, false, false, isKill);
 }
 
 void X86RegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+                                     bool isKill,
                                      SmallVectorImpl<MachineOperand> &Addr,
                                      const TargetRegisterClass *RC,
                                  SmallVectorImpl<MachineInstr*> &NewMIs) const {
@@ -849,7 +850,7 @@ void X86RegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
   MachineInstrBuilder MIB = BuildMI(TII.get(Opc));
   for (unsigned i = 0, e = Addr.size(); i != e; ++i)
     MIB = X86InstrAddOperand(MIB, Addr[i]);
-  MIB.addReg(SrcReg, false, false, true);
+  MIB.addReg(SrcReg, false, false, isKill);
   NewMIs.push_back(MIB);
 }
 
@@ -1195,11 +1196,27 @@ MachineInstr* X86RegisterInfo::foldMemoryOperand(MachineInstr *MI,
 }
 
 
-unsigned X86RegisterInfo::getOpcodeAfterMemoryFold(unsigned Opc,
-                                                   unsigned OpNum) const {
+bool X86RegisterInfo::canFoldMemoryOperand(MachineInstr *MI,
+                                         SmallVectorImpl<unsigned> &Ops) const {
   // Check switch flag 
   if (NoFusing) return 0;
-  const DenseMap<unsigned*, unsigned> *OpcodeTablePtr = NULL;
+
+  if (Ops.size() == 2 && Ops[0] == 0 && Ops[1] == 1) {
+    switch (MI->getOpcode()) {
+    default: return false;
+    case X86::TEST8rr: 
+    case X86::TEST16rr:
+    case X86::TEST32rr:
+    case X86::TEST64rr:
+      return true;
+    }
+  }
+
+  if (Ops.size() != 1)
+    return false;
+
+  unsigned OpNum = Ops[0];
+  unsigned Opc = MI->getOpcode();
   unsigned NumOps = TII.getNumOperands(Opc);
   bool isTwoAddr = NumOps > 1 &&
     TII.getOperandConstraint(Opc, 1, TOI::TIED_TO) != -1;
@@ -1207,18 +1224,16 @@ unsigned X86RegisterInfo::getOpcodeAfterMemoryFold(unsigned Opc,
   // Folding a memory location into the two-address part of a two-address
   // instruction is different than folding it other places.  It requires
   // replacing the *two* registers with the memory location.
+  const DenseMap<unsigned*, unsigned> *OpcodeTablePtr = NULL;
   if (isTwoAddr && NumOps >= 2 && OpNum < 2) { 
     OpcodeTablePtr = &RegOp2MemOpTable2Addr;
   } else if (OpNum == 0) { // If operand 0
     switch (Opc) {
     case X86::MOV16r0:
-      return X86::MOV16mi;
     case X86::MOV32r0:
-      return X86::MOV32mi;
     case X86::MOV64r0:
-      return X86::MOV64mi32;
     case X86::MOV8r0:
-      return X86::MOV8mi;
+      return true;
     default: break;
     }
     OpcodeTablePtr = &RegOp2MemOpTable0;
@@ -1233,9 +1248,9 @@ unsigned X86RegisterInfo::getOpcodeAfterMemoryFold(unsigned Opc,
     DenseMap<unsigned*, unsigned>::iterator I =
       OpcodeTablePtr->find((unsigned*)Opc);
     if (I != OpcodeTablePtr->end())
-      return I->second;
+      return true;
   }
-  return 0;
+  return false;
 }
 
 bool X86RegisterInfo::unfoldMemoryOperand(MachineFunction &MF, MachineInstr *MI,
@@ -1335,7 +1350,7 @@ bool X86RegisterInfo::unfoldMemoryOperand(MachineFunction &MF, MachineInstr *MI,
     const TargetOperandInfo &DstTOI = TID.OpInfo[0];
     const TargetRegisterClass *DstRC = (DstTOI.Flags & M_LOOK_UP_PTR_REG_CLASS)
       ? TII.getPointerRegClass() : getRegClass(DstTOI.RegClass);
-    storeRegToAddr(MF, Reg, AddrOps, DstRC, NewMIs);
+    storeRegToAddr(MF, Reg, true, AddrOps, DstRC, NewMIs);
   }
 
   return true;
diff --git a/lib/Target/X86/X86RegisterInfo.h b/lib/Target/X86/X86RegisterInfo.h
index c74d2e769df..eda48c20e24 100644
--- a/lib/Target/X86/X86RegisterInfo.h
+++ b/lib/Target/X86/X86RegisterInfo.h
@@ -101,10 +101,10 @@ public:
 
   void storeRegToStackSlot(MachineBasicBlock &MBB,
                            MachineBasicBlock::iterator MI,
-                           unsigned SrcReg, int FrameIndex,
+                           unsigned SrcReg, bool isKill, int FrameIndex,
                            const TargetRegisterClass *RC) const;
 
-  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
+  void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill,
                       SmallVectorImpl<MachineOperand> &Addr,
                       const TargetRegisterClass *RC,
                       SmallVectorImpl<MachineInstr*> &NewMIs) const;
@@ -148,11 +148,9 @@ public:
                                   SmallVectorImpl<unsigned> &Ops,
                                   MachineInstr* LoadMI) const;
 
-  /// getOpcodeAfterMemoryFold - Returns the opcode of the would be new
-  /// instruction after load / store is folded into an instruction of the
-  /// specified opcode. It returns zero if the specified unfolding is not
-  /// possible.
-  unsigned getOpcodeAfterMemoryFold(unsigned Opc, unsigned OpNum) const;
+  /// canFoldMemoryOperand - Returns true if the specified load / store is
+  /// folding is possible.
+  bool canFoldMemoryOperand(MachineInstr*, SmallVectorImpl<unsigned> &) const;
 
   /// unfoldMemoryOperand - Separate a single instruction which folded a load or
   /// a store or a load and a store into two or more instruction. If this is