bool XCoreInstrInfo::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
				MachineBasicBlock::iterator MI,
			const std::vector<CalleeSavedInfo> &CSI) const
{
  if (CSI.empty()) {
    return true;
  }
  MachineFunction *MF = MBB.getParent();
  const MachineFrameInfo *MFI = MF->getFrameInfo();
  MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
  XCoreFunctionInfo *XFI = MF->getInfo<XCoreFunctionInfo>();
  
  bool emitFrameMoves = XCoreRegisterInfo::needsFrameMoves(*MF);

  DebugLoc DL = DebugLoc::getUnknownLoc();
  if (MI != MBB.end()) DL = MI->getDebugLoc();
  
  for (std::vector<CalleeSavedInfo>::const_iterator it = CSI.begin();
                                                    it != CSI.end(); ++it) {
    // Add the callee-saved register as live-in. It's killed at the spill.
    MBB.addLiveIn(it->getReg());

    storeRegToStackSlot(MBB, MI, it->getReg(), true,
                        it->getFrameIdx(), it->getRegClass());
    if (emitFrameMoves) {
      unsigned SaveLabelId = MMI->NextLabelID();
      BuildMI(MBB, MI, DL, get(XCore::DBG_LABEL)).addImm(SaveLabelId);
      XFI->getSpillLabels().push_back(
          std::pair<unsigned, CalleeSavedInfo>(SaveLabelId, *it));
    }
  }
  return true;
}

void XCoreFrameLowering::
processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
                                     RegScavenger *RS) const {
  XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();

  bool LRUsed = MF.getRegInfo().isPhysRegUsed(XCore::LR);

  if (!LRUsed && !MF.getFunction()->isVarArg() &&
      MF.getFrameInfo()->estimateStackSize(MF))
    // If we need to extend the stack it is more efficient to use entsp / retsp.
    // We force the LR to be saved so these instructions are used.
    LRUsed = true;

  if (MF.getMMI().callsUnwindInit() || MF.getMMI().callsEHReturn()) {
    // The unwinder expects to find spill slots for the exception info regs R0
    // & R1. These are used during llvm.eh.return() to 'restore' the exception
    // info. N.B. we do not spill or restore R0, R1 during normal operation.
    XFI->createEHSpillSlot(MF);
    // As we will  have a stack, we force the LR to be saved.
    LRUsed = true;
  }

  if (LRUsed) {
    // We will handle the LR in the prologue/epilogue
    // and allocate space on the stack ourselves.
    MF.getRegInfo().setPhysRegUnused(XCore::LR);
    XFI->createLRSpillSlot(MF);
  }

  if (hasFP(MF))
    // A callee save register is used to hold the FP.
    // This needs saving / restoring in the epilogue / prologue.
    XFI->createFPSpillSlot(MF);
}

void XCoreFrameLowering::
processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
                                     RegScavenger *RS) const {
  MachineFrameInfo *MFI = MF.getFrameInfo();
  bool LRUsed = MF.getRegInfo().isPhysRegUsed(XCore::LR);
  const TargetRegisterClass *RC = &XCore::GRRegsRegClass;
  XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
  if (LRUsed) {
    MF.getRegInfo().setPhysRegUnused(XCore::LR);

    bool isVarArg = MF.getFunction()->isVarArg();
    int FrameIdx;
    if (! isVarArg) {
      // A fixed offset of 0 allows us to save/restore LR using entsp/retsp.
      FrameIdx = MFI->CreateFixedObject(RC->getSize(), 0, true);
    } else {
      FrameIdx = MFI->CreateStackObject(RC->getSize(), RC->getAlignment(),
                                        false);
    }
    XFI->setUsesLR(FrameIdx);
    XFI->setLRSpillSlot(FrameIdx);
  }

  // A callee save register is used to hold the FP.
  // This needs saving / restoring in the epilogue / prologue.
  if (hasFP(MF))
    XFI->setFPSpillSlot(MFI->CreateStackObject(RC->getSize(),
                                               RC->getAlignment(),
                                               false));
}

bool XCoreFrameLowering::
spillCalleeSavedRegisters(MachineBasicBlock &MBB,
                          MachineBasicBlock::iterator MI,
                          const std::vector<CalleeSavedInfo> &CSI,
                          const TargetRegisterInfo *TRI) const {
  if (CSI.empty())
    return true;

  MachineFunction *MF = MBB.getParent();
  const TargetInstrInfo &TII = *MF->getSubtarget().getInstrInfo();
  XCoreFunctionInfo *XFI = MF->getInfo<XCoreFunctionInfo>();
  bool emitFrameMoves = XCoreRegisterInfo::needsFrameMoves(*MF);

  DebugLoc DL;
  if (MI != MBB.end() && !MI->isDebugValue())
    DL = MI->getDebugLoc();

  for (std::vector<CalleeSavedInfo>::const_iterator it = CSI.begin();
                                                    it != CSI.end(); ++it) {
    unsigned Reg = it->getReg();
    assert(Reg != XCore::LR && !(Reg == XCore::R10 && hasFP(*MF)) &&
           "LR & FP are always handled in emitPrologue");

    // Add the callee-saved register as live-in. It's killed at the spill.
    MBB.addLiveIn(Reg);
    const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
    TII.storeRegToStackSlot(MBB, MI, Reg, true, it->getFrameIdx(), RC, TRI);
    if (emitFrameMoves) {
      auto Store = MI;
      --Store;
      XFI->getSpillLabels().push_back(std::make_pair(Store, *it));
    }
  }
  return true;
}

bool XCoreFrameLowering::
spillCalleeSavedRegisters(MachineBasicBlock &MBB,
                          MachineBasicBlock::iterator MI,
                          const std::vector<CalleeSavedInfo> &CSI,
                          const TargetRegisterInfo *TRI) const {
  if (CSI.empty())
    return true;

  MachineFunction *MF = MBB.getParent();
  const TargetInstrInfo &TII = *MF->getTarget().getInstrInfo();

  XCoreFunctionInfo *XFI = MF->getInfo<XCoreFunctionInfo>();
  bool emitFrameMoves = XCoreRegisterInfo::needsFrameMoves(*MF);

  DebugLoc DL;
  if (MI != MBB.end())
    DL = MI->getDebugLoc();

  for (std::vector<CalleeSavedInfo>::const_iterator it = CSI.begin();
                                                    it != CSI.end(); ++it) {
    // Add the callee-saved register as live-in. It's killed at the spill.
    MBB.addLiveIn(it->getReg());

    unsigned Reg = it->getReg();
    const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
    TII.storeRegToStackSlot(MBB, MI, Reg, true,
                            it->getFrameIdx(), RC, TRI);
    if (emitFrameMoves) {
      MCSymbol *SaveLabel = MF->getContext().CreateTempSymbol();
      BuildMI(MBB, MI, DL, TII.get(XCore::PROLOG_LABEL)).addSym(SaveLabel);
      XFI->getSpillLabels().push_back(std::make_pair(SaveLabel, *it));
    }
  }
  return true;
}

void XCoreFrameInfo::emitEpilogue(MachineFunction &MF,
                                     MachineBasicBlock &MBB) const {
  MachineFrameInfo *MFI            = MF.getFrameInfo();
  MachineBasicBlock::iterator MBBI = prior(MBB.end());
  const XCoreInstrInfo &TII =
    *static_cast<const XCoreInstrInfo*>(MF.getTarget().getInstrInfo());
  DebugLoc dl = MBBI->getDebugLoc();

  bool FP = hasFP(MF);
  if (FP) {
    // Restore the stack pointer.
    unsigned FramePtr = XCore::R10;
    BuildMI(MBB, MBBI, dl, TII.get(XCore::SETSP_1r))
      .addReg(FramePtr);
  }

  // Work out frame sizes.
  int FrameSize = MFI->getStackSize();

  assert(FrameSize%4 == 0 && "Misaligned frame size");

  FrameSize/=4;

  bool isU6 = isImmU6(FrameSize);

  if (!isU6 && !isImmU16(FrameSize)) {
    // FIXME could emit multiple instructions.
    report_fatal_error("emitEpilogue Frame size too big: " + Twine(FrameSize));
  }

  if (FrameSize) {
    XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();

    if (FP) {
      // Restore R10
      int FPSpillOffset = MFI->getObjectOffset(XFI->getFPSpillSlot());
      FPSpillOffset += FrameSize*4;
      loadFromStack(MBB, MBBI, XCore::R10, FPSpillOffset, dl, TII);
    }
    bool restoreLR = XFI->getUsesLR();
    if (restoreLR && MFI->getObjectOffset(XFI->getLRSpillSlot()) != 0) {
      int LRSpillOffset = MFI->getObjectOffset(XFI->getLRSpillSlot());
      LRSpillOffset += FrameSize*4;
      loadFromStack(MBB, MBBI, XCore::LR, LRSpillOffset, dl, TII);
      restoreLR = false;
    }
    if (restoreLR) {
      // Fold prologue into return instruction
      assert(MBBI->getOpcode() == XCore::RETSP_u6
        || MBBI->getOpcode() == XCore::RETSP_lu6);
      int Opcode = (isU6) ? XCore::RETSP_u6 : XCore::RETSP_lu6;
      BuildMI(MBB, MBBI, dl, TII.get(Opcode)).addImm(FrameSize);
      MBB.erase(MBBI);
    } else {
      int Opcode = (isU6) ? XCore::LDAWSP_ru6_RRegs : XCore::LDAWSP_lru6_RRegs;
      BuildMI(MBB, MBBI, dl, TII.get(Opcode), XCore::SP).addImm(FrameSize);
    }
  }
}

void XCoreFrameLowering::
processFunctionBeforeFrameFinalized(MachineFunction &MF,
                                    RegScavenger *RS) const {
  assert(RS && "requiresRegisterScavenging failed");
  MachineFrameInfo *MFI = MF.getFrameInfo();
  const TargetRegisterClass *RC = &XCore::GRRegsRegClass;
  XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
  // Reserve slots close to SP or frame pointer for Scavenging spills.
  // When using SP for small frames, we don't need any scratch registers.
  // When using SP for large frames, we may need 2 scratch registers.
  // When using FP, for large or small frames, we may need 1 scratch register.
  if (XFI->isLargeFrame(MF) || hasFP(MF))
    RS->addScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
                                                       RC->getAlignment(),
                                                       false));
  if (XFI->isLargeFrame(MF) && !hasFP(MF))
    RS->addScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
                                                       RC->getAlignment(),
                                                       false));
}

void XCoreFrameLowering::emitEpilogue(MachineFunction &MF,
                                     MachineBasicBlock &MBB) const {
  MachineFrameInfo *MFI = MF.getFrameInfo();
  MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
  const XCoreInstrInfo &TII = *MF.getSubtarget<XCoreSubtarget>().getInstrInfo();
  XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
  DebugLoc dl = MBBI->getDebugLoc();
  unsigned RetOpcode = MBBI->getOpcode();

  // Work out frame sizes.
  // We will adjust the SP in stages towards the final FrameSize.
  int RemainingAdj = MFI->getStackSize();
  assert(RemainingAdj%4 == 0 && "Misaligned frame size");
  RemainingAdj /= 4;

  if (RetOpcode == XCore::EH_RETURN) {
    // 'Restore' the exception info the unwinder has placed into the stack
    // slots.
    SmallVector<StackSlotInfo,2> SpillList;
    GetEHSpillList(SpillList, MFI, XFI, MF.getSubtarget().getTargetLowering());
    RestoreSpillList(MBB, MBBI, dl, TII, RemainingAdj, SpillList);

    // Return to the landing pad.
    unsigned EhStackReg = MBBI->getOperand(0).getReg();
    unsigned EhHandlerReg = MBBI->getOperand(1).getReg();
    BuildMI(MBB, MBBI, dl, TII.get(XCore::SETSP_1r)).addReg(EhStackReg);
    BuildMI(MBB, MBBI, dl, TII.get(XCore::BAU_1r)).addReg(EhHandlerReg);
    MBB.erase(MBBI);  // Erase the previous return instruction.
    return;
  }

  bool restoreLR = XFI->hasLRSpillSlot();
  bool UseRETSP = restoreLR && RemainingAdj
                  && (MFI->getObjectOffset(XFI->getLRSpillSlot()) == 0);
  if (UseRETSP)
    restoreLR = false;
  bool FP = hasFP(MF);

  if (FP) // Restore the stack pointer.
    BuildMI(MBB, MBBI, dl, TII.get(XCore::SETSP_1r)).addReg(FramePtr);

  // If necessary, restore LR and FP from the stack, as we EXTSP.
  SmallVector<StackSlotInfo,2> SpillList;
  GetSpillList(SpillList, MFI, XFI, restoreLR, FP);
  RestoreSpillList(MBB, MBBI, dl, TII, RemainingAdj, SpillList);

  if (RemainingAdj) {
    // Complete all but one of the remaining Stack adjustments.
    IfNeededLDAWSP(MBB, MBBI, dl, TII, 0, RemainingAdj);
    if (UseRETSP) {
      // Fold prologue into return instruction
      assert(RetOpcode == XCore::RETSP_u6
             || RetOpcode == XCore::RETSP_lu6);
      int Opcode = isImmU6(RemainingAdj) ? XCore::RETSP_u6 : XCore::RETSP_lu6;
      MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII.get(Opcode))
                                  .addImm(RemainingAdj);
      for (unsigned i = 3, e = MBBI->getNumOperands(); i < e; ++i)
        MIB->addOperand(MBBI->getOperand(i)); // copy any variadic operands
      MBB.erase(MBBI);  // Erase the previous return instruction.
    } else {
      int Opcode = isImmU6(RemainingAdj) ? XCore::LDAWSP_ru6 :
                                           XCore::LDAWSP_lru6;
      BuildMI(MBB, MBBI, dl, TII.get(Opcode), XCore::SP).addImm(RemainingAdj);
      // Don't erase the return instruction.
    }
  } // else Don't erase the return instruction.
}

void XCoreFrameLowering::emitPrologue(MachineFunction &MF,
                                      MachineBasicBlock &MBB) const {
  assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
  MachineBasicBlock::iterator MBBI = MBB.begin();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  MachineModuleInfo *MMI = &MF.getMMI();
  const MCRegisterInfo *MRI = MMI->getContext().getRegisterInfo();
  const XCoreInstrInfo &TII = *MF.getSubtarget<XCoreSubtarget>().getInstrInfo();
  XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
  // Debug location must be unknown since the first debug location is used
  // to determine the end of the prologue.
  DebugLoc dl;

  if (MFI->getMaxAlignment() > getStackAlignment())
    report_fatal_error("emitPrologue unsupported alignment: "
                       + Twine(MFI->getMaxAlignment()));

  const AttributeSet &PAL = MF.getFunction()->getAttributes();
  if (PAL.hasAttrSomewhere(Attribute::Nest))
    BuildMI(MBB, MBBI, dl, TII.get(XCore::LDWSP_ru6), XCore::R11).addImm(0);
    // FIX: Needs addMemOperand() but can't use getFixedStack() or getStack().

  // Work out frame sizes.
  // We will adjust the SP in stages towards the final FrameSize.
  assert(MFI->getStackSize()%4 == 0 && "Misaligned frame size");
  const int FrameSize = MFI->getStackSize() / 4;
  int Adjusted = 0;

  bool saveLR = XFI->hasLRSpillSlot();
  bool UseENTSP = saveLR && FrameSize
                  && (MFI->getObjectOffset(XFI->getLRSpillSlot()) == 0);
  if (UseENTSP)
    saveLR = false;
  bool FP = hasFP(MF);
  bool emitFrameMoves = XCoreRegisterInfo::needsFrameMoves(MF);

  if (UseENTSP) {
    // Allocate space on the stack at the same time as saving LR.
    Adjusted = (FrameSize > MaxImmU16) ? MaxImmU16 : FrameSize;
    int Opcode = isImmU6(Adjusted) ? XCore::ENTSP_u6 : XCore::ENTSP_lu6;
    MBB.addLiveIn(XCore::LR);
    MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII.get(Opcode));
    MIB.addImm(Adjusted);
    MIB->addRegisterKilled(XCore::LR, MF.getSubtarget().getRegisterInfo(),
                           true);
    if (emitFrameMoves) {
      EmitDefCfaOffset(MBB, MBBI, dl, TII, MMI, Adjusted*4);
      unsigned DRegNum = MRI->getDwarfRegNum(XCore::LR, true);
      EmitCfiOffset(MBB, MBBI, dl, TII, MMI, DRegNum, 0);
    }
  }

  // If necessary, save LR and FP to the stack, as we EXTSP.
  SmallVector<StackSlotInfo,2> SpillList;
  GetSpillList(SpillList, MFI, XFI, saveLR, FP);
  // We want the nearest (negative) offsets first, so reverse list.
  std::reverse(SpillList.begin(), SpillList.end());
  for (unsigned i = 0, e = SpillList.size(); i != e; ++i) {
    assert(SpillList[i].Offset % 4 == 0 && "Misaligned stack offset");
    assert(SpillList[i].Offset <= 0 && "Unexpected positive stack offset");
    int OffsetFromTop = - SpillList[i].Offset/4;
    IfNeededExtSP(MBB, MBBI, dl, TII, MMI, OffsetFromTop, Adjusted, FrameSize,
                  emitFrameMoves);
    int Offset = Adjusted - OffsetFromTop;
    int Opcode = isImmU6(Offset) ? XCore::STWSP_ru6 : XCore::STWSP_lru6;
    MBB.addLiveIn(SpillList[i].Reg);
    BuildMI(MBB, MBBI, dl, TII.get(Opcode))
      .addReg(SpillList[i].Reg, RegState::Kill)
      .addImm(Offset)
      .addMemOperand(getFrameIndexMMO(MBB, SpillList[i].FI,
                                      MachineMemOperand::MOStore));
    if (emitFrameMoves) {
      unsigned DRegNum = MRI->getDwarfRegNum(SpillList[i].Reg, true);
      EmitCfiOffset(MBB, MBBI, dl, TII, MMI, DRegNum, SpillList[i].Offset);
    }
  }

  // Complete any remaining Stack adjustment.
  IfNeededExtSP(MBB, MBBI, dl, TII, MMI, FrameSize, Adjusted, FrameSize,
                emitFrameMoves);
  assert(Adjusted==FrameSize && "IfNeededExtSP has not completed adjustment");

  if (FP) {
    // Set the FP from the SP.
    BuildMI(MBB, MBBI, dl, TII.get(XCore::LDAWSP_ru6), FramePtr).addImm(0);
    if (emitFrameMoves)
      EmitDefCfaRegister(MBB, MBBI, dl, TII, MMI,
                         MRI->getDwarfRegNum(FramePtr, true));
  }

  if (emitFrameMoves) {
    // Frame moves for callee saved.
    for (const auto &SpillLabel : XFI->getSpillLabels()) {
      MachineBasicBlock::iterator Pos = SpillLabel.first;
      ++Pos;
      const CalleeSavedInfo &CSI = SpillLabel.second;
      int Offset = MFI->getObjectOffset(CSI.getFrameIdx());
      unsigned DRegNum = MRI->getDwarfRegNum(CSI.getReg(), true);
      EmitCfiOffset(MBB, Pos, dl, TII, MMI, DRegNum, Offset);
    }
//.........这里部分代码省略.........

void XCoreFrameLowering::emitEpilogue(MachineFunction &MF,
                                     MachineBasicBlock &MBB) const {
  MachineFrameInfo *MFI            = MF.getFrameInfo();
  MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
  const XCoreInstrInfo &TII =
    *static_cast<const XCoreInstrInfo*>(MF.getTarget().getInstrInfo());
  XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
  DebugLoc dl = MBBI->getDebugLoc();

  // Work out frame sizes.
  // We will adjust the SP in stages towards the final FrameSize.
  int RemainingAdj = MFI->getStackSize();
  assert(RemainingAdj%4 == 0 && "Misaligned frame size");
  RemainingAdj /= 4;

  bool restoreLR = XFI->getUsesLR();
  bool UseRETSP = restoreLR && RemainingAdj
                  && (MFI->getObjectOffset(XFI->getLRSpillSlot()) == 0);
  if (UseRETSP)
    restoreLR = false;
  bool FP = hasFP(MF);

  if (FP) // Restore the stack pointer.
    BuildMI(MBB, MBBI, dl, TII.get(XCore::SETSP_1r)).addReg(FramePtr);

  // If necessary, restore LR and FP from the stack, as we EXTSP.
  SmallVector<std::pair<unsigned,int>,2> SpillList;
  GetSpillList(SpillList, MFI, XFI, restoreLR, FP);
  unsigned i = SpillList.size();
  while (i--) {
    unsigned SpilledReg = SpillList[i].first;
    int SpillOffset = SpillList[i].second;
    assert(SpillOffset % 4 == 0 && "Misaligned stack offset");
    assert(SpillOffset <= 0 && "Unexpected positive stack offset");
    int OffsetFromTop = - SpillOffset/4;
    IfNeededLDAWSP(MBB, MBBI, dl, TII, OffsetFromTop, RemainingAdj);
    int Offset = RemainingAdj - OffsetFromTop;
    int Opcode = isImmU6(Offset) ? XCore::LDWSP_ru6 : XCore::LDWSP_lru6;
    BuildMI(MBB, MBBI, dl, TII.get(Opcode), SpilledReg).addImm(Offset);
  }

  if (RemainingAdj) {
    // Complete all but one of the remaining Stack adjustments.
    IfNeededLDAWSP(MBB, MBBI, dl, TII, 0, RemainingAdj);
    if (UseRETSP) {
      // Fold prologue into return instruction
      assert(MBBI->getOpcode() == XCore::RETSP_u6
             || MBBI->getOpcode() == XCore::RETSP_lu6);
      int Opcode = isImmU6(RemainingAdj) ? XCore::RETSP_u6 : XCore::RETSP_lu6;
      MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII.get(Opcode))
                                  .addImm(RemainingAdj);
      for (unsigned i = 3, e = MBBI->getNumOperands(); i < e; ++i)
        MIB->addOperand(MBBI->getOperand(i)); // copy any variadic operands
      MBB.erase(MBBI);  // Erase the previous return instruction.
    } else {
      int Opcode = isImmU6(RemainingAdj) ? XCore::LDAWSP_ru6 :
                                           XCore::LDAWSP_lru6;
      BuildMI(MBB, MBBI, dl, TII.get(Opcode), XCore::SP).addImm(RemainingAdj);
      // Don't erase the return instruction.
    }
  } // else Don't erase the return instruction.
}

void XCoreFrameLowering::emitPrologue(MachineFunction &MF) const {
  MachineBasicBlock &MBB = MF.front();   // Prolog goes in entry BB
  MachineBasicBlock::iterator MBBI = MBB.begin();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  MachineModuleInfo *MMI = &MF.getMMI();
  const MCRegisterInfo *MRI = MMI->getContext().getRegisterInfo();
  const XCoreInstrInfo &TII =
    *static_cast<const XCoreInstrInfo*>(MF.getTarget().getInstrInfo());
  XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();

  if (MFI->getMaxAlignment() > getStackAlignment())
    report_fatal_error("emitPrologue unsupported alignment: "
                       + Twine(MFI->getMaxAlignment()));

  const AttributeSet &PAL = MF.getFunction()->getAttributes();
  if (PAL.hasAttrSomewhere(Attribute::Nest))
    BuildMI(MBB, MBBI, dl, TII.get(XCore::LDWSP_ru6), XCore::R11).addImm(0);

  // Work out frame sizes.
  // We will adjust the SP in stages towards the final FrameSize.
  assert(MFI->getStackSize()%4 == 0 && "Misaligned frame size");
  const int FrameSize = MFI->getStackSize() / 4;
  int Adjusted = 0;

  bool saveLR = XFI->getUsesLR();
  bool UseENTSP = saveLR && FrameSize
                  && (MFI->getObjectOffset(XFI->getLRSpillSlot()) == 0);
  if (UseENTSP)
    saveLR = false;
  bool FP = hasFP(MF);
  bool emitFrameMoves = XCoreRegisterInfo::needsFrameMoves(MF);

  if (UseENTSP) {
    // Allocate space on the stack at the same time as saving LR.
    Adjusted = (FrameSize > MaxImmU16) ? MaxImmU16 : FrameSize;
    int Opcode = isImmU6(Adjusted) ? XCore::ENTSP_u6 : XCore::ENTSP_lu6;
    BuildMI(MBB, MBBI, dl, TII.get(Opcode)).addImm(Adjusted);
    MBB.addLiveIn(XCore::LR);
    if (emitFrameMoves) {
      EmitDefCfaOffset(MBB, MBBI, dl, TII, MMI, Adjusted*4);
      unsigned DRegNum = MRI->getDwarfRegNum(XCore::LR, true);
      EmitCfiOffset(MBB, MBBI, dl, TII, MMI, DRegNum, 0, NULL);
    }
  }

  // If necessary, save LR and FP to the stack, as we EXTSP.
  SmallVector<std::pair<unsigned,int>,2> SpillList;
  GetSpillList(SpillList, MFI, XFI, saveLR, FP);
  for (unsigned i = 0, e = SpillList.size(); i != e; ++i) {
    unsigned SpillReg = SpillList[i].first;
    int SpillOffset = SpillList[i].second;
    assert(SpillOffset % 4 == 0 && "Misaligned stack offset");
    assert(SpillOffset <= 0 && "Unexpected positive stack offset");
    int OffsetFromTop = - SpillOffset/4;
    IfNeededExtSP(MBB, MBBI, dl, TII, MMI, OffsetFromTop, Adjusted, FrameSize,
                  emitFrameMoves);
    int Offset = Adjusted - OffsetFromTop;
    int Opcode = isImmU6(Offset) ? XCore::STWSP_ru6 : XCore::STWSP_lru6;
    BuildMI(MBB, MBBI, dl, TII.get(Opcode)).addReg(SpillReg).addImm(Offset);
    MBB.addLiveIn(SpillReg);
    if (emitFrameMoves) {
      unsigned DRegNum = MRI->getDwarfRegNum(SpillReg, true);
      EmitCfiOffset(MBB, MBBI, dl, TII, MMI, DRegNum, SpillOffset, NULL);
    }
  }

  // Complete any remaining Stack adjustment.
  IfNeededExtSP(MBB, MBBI, dl, TII, MMI, FrameSize, Adjusted, FrameSize,
                emitFrameMoves);
  assert(Adjusted==FrameSize && "IfNeededExtSP has not completed adjustment");

  if (FP) {
    // Set the FP from the SP.
    BuildMI(MBB, MBBI, dl, TII.get(XCore::LDAWSP_ru6), FramePtr).addImm(0);
    if (emitFrameMoves)
      EmitDefCfaRegister(MBB, MBBI, dl, TII, MMI,
                         MRI->getDwarfRegNum(FramePtr, true));
  }

  if (emitFrameMoves) {
    // Frame moves for callee saved.
    std::vector<std::pair<MCSymbol*, CalleeSavedInfo> >&SpillLabels =
        XFI->getSpillLabels();
    for (unsigned I = 0, E = SpillLabels.size(); I != E; ++I) {
      MCSymbol *SpillLabel = SpillLabels[I].first;
      CalleeSavedInfo &CSI = SpillLabels[I].second;
      int Offset = MFI->getObjectOffset(CSI.getFrameIdx());
      unsigned DRegNum = MRI->getDwarfRegNum(CSI.getReg(), true);
      EmitCfiOffset(MBB, MBBI, dl, TII, MMI, DRegNum, Offset, SpillLabel);
    }
  }
}

void XCoreRegisterInfo::emitPrologue(MachineFunction &MF) const {
  MachineBasicBlock &MBB = MF.front();   // Prolog goes in entry BB
  MachineBasicBlock::iterator MBBI = MBB.begin();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
  XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();

  bool FP = hasFP(MF);

  // Work out frame sizes.
  int FrameSize = MFI->getStackSize();

  assert(FrameSize%4 == 0 && "Misaligned frame size");
  
  FrameSize/=4;
  
  bool isU6 = isImmU6(FrameSize);

  if (!isU6 && !isImmU16(FrameSize)) {
    // FIXME could emit multiple instructions.
    cerr << "emitPrologue Frame size too big: " << FrameSize << "\n";
    abort();
  }
  bool emitFrameMoves = needsFrameMoves(MF);

  // Do we need to allocate space on the stack?
  if (FrameSize) {
    bool saveLR = XFI->getUsesLR();
    bool LRSavedOnEntry = false;
    int Opcode;
    if (saveLR && (MFI->getObjectOffset(XFI->getLRSpillSlot()) == 0)) {
      Opcode = (isU6) ? XCore::ENTSP_u6 : XCore::ENTSP_lu6;
      MBB.addLiveIn(XCore::LR);
      saveLR = false;
      LRSavedOnEntry = true;
    } else {
      Opcode = (isU6) ? XCore::EXTSP_u6 : XCore::EXTSP_lu6;
    }
    BuildMI(MBB, MBBI, TII.get(Opcode)).addImm(FrameSize);
    
    if (emitFrameMoves) {
      std::vector<MachineMove> &Moves = MMI->getFrameMoves();
      
      // Show update of SP.
      unsigned FrameLabelId = MMI->NextLabelID();
      BuildMI(MBB, MBBI, TII.get(XCore::DBG_LABEL)).addImm(FrameLabelId);
      
      MachineLocation SPDst(MachineLocation::VirtualFP);
      MachineLocation SPSrc(MachineLocation::VirtualFP, -FrameSize * 4);
      Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
      
      if (LRSavedOnEntry) {
        MachineLocation CSDst(MachineLocation::VirtualFP, 0);
        MachineLocation CSSrc(XCore::LR);
        Moves.push_back(MachineMove(FrameLabelId, CSDst, CSSrc));
      }
    }
    if (saveLR) {
      int LRSpillOffset = MFI->getObjectOffset(XFI->getLRSpillSlot());
      storeToStack(MBB, MBBI, XCore::LR, LRSpillOffset + FrameSize*4);
      MBB.addLiveIn(XCore::LR);
      
      if (emitFrameMoves) {
        unsigned SaveLRLabelId = MMI->NextLabelID();
        BuildMI(MBB, MBBI, TII.get(XCore::DBG_LABEL)).addImm(SaveLRLabelId);
        MachineLocation CSDst(MachineLocation::VirtualFP, LRSpillOffset);
        MachineLocation CSSrc(XCore::LR);
        MMI->getFrameMoves().push_back(MachineMove(SaveLRLabelId,
                                                   CSDst, CSSrc));
      }
    }
  }
  
  if (FP) {
    // Save R10 to the stack.
    int FPSpillOffset = MFI->getObjectOffset(XFI->getFPSpillSlot());
    storeToStack(MBB, MBBI, XCore::R10, FPSpillOffset + FrameSize*4);
    // R10 is live-in. It is killed at the spill.
    MBB.addLiveIn(XCore::R10);
    if (emitFrameMoves) {
      unsigned SaveR10LabelId = MMI->NextLabelID();
      BuildMI(MBB, MBBI, TII.get(XCore::DBG_LABEL)).addImm(SaveR10LabelId);
      MachineLocation CSDst(MachineLocation::VirtualFP, FPSpillOffset);
      MachineLocation CSSrc(XCore::R10);
      MMI->getFrameMoves().push_back(MachineMove(SaveR10LabelId,
                                                 CSDst, CSSrc));
    }
    // Set the FP from the SP.
    unsigned FramePtr = XCore::R10;
    BuildMI(MBB, MBBI, TII.get(XCore::LDAWSP_ru6), FramePtr)
      .addImm(0);
    if (emitFrameMoves) {
      // Show FP is now valid.
      unsigned FrameLabelId = MMI->NextLabelID();
      BuildMI(MBB, MBBI, TII.get(XCore::DBG_LABEL)).addImm(FrameLabelId);
      MachineLocation SPDst(FramePtr);
      MachineLocation SPSrc(MachineLocation::VirtualFP);
      MMI->getFrameMoves().push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
    }
  }
//.........这里部分代码省略.........

void XCoreFrameLowering::emitPrologue(MachineFunction &MF) const {
  MachineBasicBlock &MBB = MF.front();   // Prolog goes in entry BB
  MachineBasicBlock::iterator MBBI = MBB.begin();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  MachineModuleInfo *MMI = &MF.getMMI();
  const XCoreInstrInfo &TII =
    *static_cast<const XCoreInstrInfo*>(MF.getTarget().getInstrInfo());
  XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();

  bool FP = hasFP(MF);
  const AttributeSet &PAL = MF.getFunction()->getAttributes();

  if (PAL.hasAttrSomewhere(Attribute::Nest))
    loadFromStack(MBB, MBBI, XCore::R11, 0, dl, TII);

  // Work out frame sizes.
  int FrameSize = MFI->getStackSize();
  assert(FrameSize%4 == 0 && "Misaligned frame size");
  FrameSize/=4;

  bool isU6 = isImmU6(FrameSize);

  if (!isU6 && !isImmU16(FrameSize)) {
    // FIXME could emit multiple instructions.
    report_fatal_error("emitPrologue Frame size too big: " + Twine(FrameSize));
  }
  bool emitFrameMoves = XCoreRegisterInfo::needsFrameMoves(MF);

  bool saveLR = XFI->getUsesLR();
  // Do we need to allocate space on the stack?
  if (FrameSize) {
    int Opcode;
    if (saveLR && (MFI->getObjectOffset(XFI->getLRSpillSlot()) == 0)) {
      Opcode = (isU6) ? XCore::ENTSP_u6 : XCore::ENTSP_lu6;
      MBB.addLiveIn(XCore::LR);
      saveLR = false;
    } else {
      Opcode = (isU6) ? XCore::EXTSP_u6 : XCore::EXTSP_lu6;
    }
    BuildMI(MBB, MBBI, dl, TII.get(Opcode)).addImm(FrameSize);

    if (emitFrameMoves) {

      // Show update of SP.
      MCSymbol *FrameLabel = MMI->getContext().CreateTempSymbol();
      BuildMI(MBB, MBBI, dl, TII.get(XCore::PROLOG_LABEL)).addSym(FrameLabel);
    }
  }
  if (saveLR) {
    int LRSpillOffset = MFI->getObjectOffset(XFI->getLRSpillSlot());
    storeToStack(MBB, MBBI, XCore::LR, LRSpillOffset + FrameSize*4, dl, TII);
    MBB.addLiveIn(XCore::LR);

    if (emitFrameMoves) {
      MCSymbol *SaveLRLabel = MMI->getContext().CreateTempSymbol();
      BuildMI(MBB, MBBI, dl, TII.get(XCore::PROLOG_LABEL)).addSym(SaveLRLabel);
    }
  }

  if (FP) {
    // Save R10 to the stack.
    int FPSpillOffset = MFI->getObjectOffset(XFI->getFPSpillSlot());
    storeToStack(MBB, MBBI, XCore::R10, FPSpillOffset + FrameSize*4, dl, TII);
    // R10 is live-in. It is killed at the spill.
    MBB.addLiveIn(XCore::R10);
    if (emitFrameMoves) {
      MCSymbol *SaveR10Label = MMI->getContext().CreateTempSymbol();
      BuildMI(MBB, MBBI, dl, TII.get(XCore::PROLOG_LABEL)).addSym(SaveR10Label);
    }
    // Set the FP from the SP.
    unsigned FramePtr = XCore::R10;
    BuildMI(MBB, MBBI, dl, TII.get(XCore::LDAWSP_ru6), FramePtr)
      .addImm(0);
    if (emitFrameMoves) {
      // Show FP is now valid.
      MCSymbol *FrameLabel = MMI->getContext().CreateTempSymbol();
      BuildMI(MBB, MBBI, dl, TII.get(XCore::PROLOG_LABEL)).addSym(FrameLabel);
    }
  }
}

void XCoreFrameLowering::emitPrologue(MachineFunction &MF) const {
  MachineBasicBlock &MBB = MF.front();   // Prolog goes in entry BB
  MachineBasicBlock::iterator MBBI = MBB.begin();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  MachineModuleInfo *MMI = &MF.getMMI();
  const XCoreRegisterInfo *RegInfo =
    static_cast<const XCoreRegisterInfo*>(MF.getTarget().getRegisterInfo());
  const XCoreInstrInfo &TII =
    *static_cast<const XCoreInstrInfo*>(MF.getTarget().getInstrInfo());
  XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();

  bool FP = hasFP(MF);
  bool Nested = MF.getFunction()->getAttributes().hasAttrSomewhere(Attribute::Nest);

  if (Nested) {
    loadFromStack(MBB, MBBI, XCore::R11, 0, dl, TII);
  }

  // Work out frame sizes.
  int FrameSize = MFI->getStackSize();
  assert(FrameSize%4 == 0 && "Misaligned frame size");
  FrameSize/=4;

  bool isU6 = isImmU6(FrameSize);

  if (!isU6 && !isImmU16(FrameSize)) {
    // FIXME could emit multiple instructions.
    report_fatal_error("emitPrologue Frame size too big: " + Twine(FrameSize));
  }
  bool emitFrameMoves = RegInfo->needsFrameMoves(MF);

  // Do we need to allocate space on the stack?
  if (FrameSize) {
    bool saveLR = XFI->getUsesLR();
    bool LRSavedOnEntry = false;
    int Opcode;
    if (saveLR && (MFI->getObjectOffset(XFI->getLRSpillSlot()) == 0)) {
      Opcode = (isU6) ? XCore::ENTSP_u6 : XCore::ENTSP_lu6;
      MBB.addLiveIn(XCore::LR);
      saveLR = false;
      LRSavedOnEntry = true;
    } else {
      Opcode = (isU6) ? XCore::EXTSP_u6 : XCore::EXTSP_lu6;
    }
    BuildMI(MBB, MBBI, dl, TII.get(Opcode)).addImm(FrameSize);

    if (emitFrameMoves) {
      std::vector<MachineMove> &Moves = MMI->getFrameMoves();

      // Show update of SP.
      MCSymbol *FrameLabel = MMI->getContext().CreateTempSymbol();
      BuildMI(MBB, MBBI, dl, TII.get(XCore::PROLOG_LABEL)).addSym(FrameLabel);

      MachineLocation SPDst(MachineLocation::VirtualFP);
      MachineLocation SPSrc(MachineLocation::VirtualFP, -FrameSize * 4);
      Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));

      if (LRSavedOnEntry) {
        MachineLocation CSDst(MachineLocation::VirtualFP, 0);
        MachineLocation CSSrc(XCore::LR);
        Moves.push_back(MachineMove(FrameLabel, CSDst, CSSrc));
      }
    }
    if (saveLR) {
      int LRSpillOffset = MFI->getObjectOffset(XFI->getLRSpillSlot());
      storeToStack(MBB, MBBI, XCore::LR, LRSpillOffset + FrameSize*4, dl, TII);
      MBB.addLiveIn(XCore::LR);

      if (emitFrameMoves) {
        MCSymbol *SaveLRLabel = MMI->getContext().CreateTempSymbol();
        BuildMI(MBB, MBBI, dl, TII.get(XCore::PROLOG_LABEL)).addSym(SaveLRLabel);
        MachineLocation CSDst(MachineLocation::VirtualFP, LRSpillOffset);
        MachineLocation CSSrc(XCore::LR);
        MMI->getFrameMoves().push_back(MachineMove(SaveLRLabel, CSDst, CSSrc));
      }
    }
  }

  if (FP) {
    // Save R10 to the stack.
    int FPSpillOffset = MFI->getObjectOffset(XFI->getFPSpillSlot());
    storeToStack(MBB, MBBI, XCore::R10, FPSpillOffset + FrameSize*4, dl, TII);
    // R10 is live-in. It is killed at the spill.
    MBB.addLiveIn(XCore::R10);
    if (emitFrameMoves) {
      MCSymbol *SaveR10Label = MMI->getContext().CreateTempSymbol();
      BuildMI(MBB, MBBI, dl, TII.get(XCore::PROLOG_LABEL)).addSym(SaveR10Label);
      MachineLocation CSDst(MachineLocation::VirtualFP, FPSpillOffset);
      MachineLocation CSSrc(XCore::R10);
      MMI->getFrameMoves().push_back(MachineMove(SaveR10Label, CSDst, CSSrc));
    }
    // Set the FP from the SP.
    unsigned FramePtr = XCore::R10;
    BuildMI(MBB, MBBI, dl, TII.get(XCore::LDAWSP_ru6), FramePtr)
      .addImm(0);
    if (emitFrameMoves) {
      // Show FP is now valid.
      MCSymbol *FrameLabel = MMI->getContext().CreateTempSymbol();
      BuildMI(MBB, MBBI, dl, TII.get(XCore::PROLOG_LABEL)).addSym(FrameLabel);
//.........这里部分代码省略.........