static bool printAsmMRegister(X86AsmPrinter &P, const MachineOperand &MO,
                              char Mode, raw_ostream &O) {
  unsigned Reg = MO.getReg();
  switch (Mode) {
  default: return true;  // Unknown mode.
  case 'b': // Print QImode register
    Reg = getX86SubSuperRegister(Reg, 8);
    break;
  case 'h': // Print QImode high register
    Reg = getX86SubSuperRegister(Reg, 8, true);
    break;
  case 'w': // Print HImode register
    Reg = getX86SubSuperRegister(Reg, 16);
    break;
  case 'k': // Print SImode register
    Reg = getX86SubSuperRegister(Reg, 32);
    break;
  case 'q':
    // Print 64-bit register names if 64-bit integer registers are available.
    // Otherwise, print 32-bit register names.
    Reg = getX86SubSuperRegister(Reg, P.getSubtarget().is64Bit() ? 64 : 32);
    break;
  }

  O << '%' << X86ATTInstPrinter::getRegisterName(Reg);
  return false;
}

/// \brief Simplify things like MOV32rm to MOV32o32a.
static void SimplifyShortMoveForm(X86AsmPrinter &Printer, MCInst &Inst,
                                  unsigned Opcode) {
  // Don't make these simplifications in 64-bit mode; other assemblers don't
  // perform them because they make the code larger.
  if (Printer.getSubtarget().is64Bit())
    return;

  bool IsStore = Inst.getOperand(0).isReg() && Inst.getOperand(1).isReg();
  unsigned AddrBase = IsStore;
  unsigned RegOp = IsStore ? 0 : 5;
  unsigned AddrOp = AddrBase + 3;
  assert(Inst.getNumOperands() == 6 && Inst.getOperand(RegOp).isReg() &&
         Inst.getOperand(AddrBase + X86::AddrBaseReg).isReg() &&
         Inst.getOperand(AddrBase + X86::AddrScaleAmt).isImm() &&
         Inst.getOperand(AddrBase + X86::AddrIndexReg).isReg() &&
         Inst.getOperand(AddrBase + X86::AddrSegmentReg).isReg() &&
         (Inst.getOperand(AddrOp).isExpr() ||
          Inst.getOperand(AddrOp).isImm()) &&
         "Unexpected instruction!");

  // Check whether the destination register can be fixed.
  unsigned Reg = Inst.getOperand(RegOp).getReg();
  if (Reg != X86::AL && Reg != X86::AX && Reg != X86::EAX && Reg != X86::RAX)
    return;

  // Check whether this is an absolute address.
  // FIXME: We know TLVP symbol refs aren't, but there should be a better way
  // to do this here.
  bool Absolute = true;
  if (Inst.getOperand(AddrOp).isExpr()) {
    const MCExpr *MCE = Inst.getOperand(AddrOp).getExpr();
    if (const MCSymbolRefExpr *SRE = dyn_cast<MCSymbolRefExpr>(MCE))
      if (SRE->getKind() == MCSymbolRefExpr::VK_TLVP)
        Absolute = false;
  }

  if (Absolute &&
      (Inst.getOperand(AddrBase + X86::AddrBaseReg).getReg() != 0 ||
       Inst.getOperand(AddrBase + X86::AddrScaleAmt).getImm() != 1 ||
       Inst.getOperand(AddrBase + X86::AddrIndexReg).getReg() != 0))
    return;

  // If so, rewrite the instruction.
  MCOperand Saved = Inst.getOperand(AddrOp);
  MCOperand Seg = Inst.getOperand(AddrBase + X86::AddrSegmentReg);
  Inst = MCInst();
  Inst.setOpcode(Opcode);
  Inst.addOperand(Saved);
  Inst.addOperand(Seg);
}

/// printSymbolOperand - Print a raw symbol reference operand.  This handles
/// jump tables, constant pools, global address and external symbols, all of
/// which print to a label with various suffixes for relocation types etc.
static void printSymbolOperand(X86AsmPrinter &P, const MachineOperand &MO,
                               raw_ostream &O) {
  switch (MO.getType()) {
  default: llvm_unreachable("unknown symbol type!");
  case MachineOperand::MO_ConstantPoolIndex:
    P.GetCPISymbol(MO.getIndex())->print(O, P.MAI);
    P.printOffset(MO.getOffset(), O);
    break;
  case MachineOperand::MO_GlobalAddress: {
    const GlobalValue *GV = MO.getGlobal();

    MCSymbol *GVSym;
    if (MO.getTargetFlags() == X86II::MO_DARWIN_STUB)
      GVSym = P.getSymbolWithGlobalValueBase(GV, "$stub");
    else if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
             MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE ||
             MO.getTargetFlags() == X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE)
      GVSym = P.getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
    else
      GVSym = P.getSymbol(GV);

    // Handle dllimport linkage.
    if (MO.getTargetFlags() == X86II::MO_DLLIMPORT)
      GVSym =
          P.OutContext.getOrCreateSymbol(Twine("__imp_") + GVSym->getName());

    if (MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
        MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE) {
      MCSymbol *Sym = P.getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
      MachineModuleInfoImpl::StubValueTy &StubSym =
          P.MMI->getObjFileInfo<MachineModuleInfoMachO>().getGVStubEntry(Sym);
      if (!StubSym.getPointer())
        StubSym = MachineModuleInfoImpl::
          StubValueTy(P.getSymbol(GV), !GV->hasInternalLinkage());
    } else if (MO.getTargetFlags() == X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE){
      MCSymbol *Sym = P.getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
      MachineModuleInfoImpl::StubValueTy &StubSym =
          P.MMI->getObjFileInfo<MachineModuleInfoMachO>().getHiddenGVStubEntry(
              Sym);
      if (!StubSym.getPointer())
        StubSym = MachineModuleInfoImpl::
          StubValueTy(P.getSymbol(GV), !GV->hasInternalLinkage());
    } else if (MO.getTargetFlags() == X86II::MO_DARWIN_STUB) {
      MCSymbol *Sym = P.getSymbolWithGlobalValueBase(GV, "$stub");
      MachineModuleInfoImpl::StubValueTy &StubSym =
          P.MMI->getObjFileInfo<MachineModuleInfoMachO>().getFnStubEntry(Sym);
      if (!StubSym.getPointer())
        StubSym = MachineModuleInfoImpl::
          StubValueTy(P.getSymbol(GV), !GV->hasInternalLinkage());
    }

    // If the name begins with a dollar-sign, enclose it in parens.  We do this
    // to avoid having it look like an integer immediate to the assembler.
    if (GVSym->getName()[0] != '$')
      GVSym->print(O, P.MAI);
    else {
      O << '(';
      GVSym->print(O, P.MAI);
      O << ')';
    }
    P.printOffset(MO.getOffset(), O);
    break;
  }
  }

  switch (MO.getTargetFlags()) {
  default:
    llvm_unreachable("Unknown target flag on GV operand");
  case X86II::MO_NO_FLAG:    // No flag.
    break;
  case X86II::MO_DARWIN_NONLAZY:
  case X86II::MO_DLLIMPORT:
  case X86II::MO_DARWIN_STUB:
    // These affect the name of the symbol, not any suffix.
    break;
  case X86II::MO_GOT_ABSOLUTE_ADDRESS:
    O << " + [.-";
    P.MF->getPICBaseSymbol()->print(O, P.MAI);
    O << ']';
    break;
  case X86II::MO_PIC_BASE_OFFSET:
  case X86II::MO_DARWIN_NONLAZY_PIC_BASE:
  case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE:
    O << '-';
    P.MF->getPICBaseSymbol()->print(O, P.MAI);
    break;
  case X86II::MO_TLSGD:     O << "@TLSGD";     break;
  case X86II::MO_TLSLD:     O << "@TLSLD";     break;
  case X86II::MO_TLSLDM:    O << "@TLSLDM";    break;
  case X86II::MO_GOTTPOFF:  O << "@GOTTPOFF";  break;
  case X86II::MO_INDNTPOFF: O << "@INDNTPOFF"; break;
  case X86II::MO_TPOFF:     O << "@TPOFF";     break;
  case X86II::MO_DTPOFF:    O << "@DTPOFF";    break;
  case X86II::MO_NTPOFF:    O << "@NTPOFF";    break;
  case X86II::MO_GOTNTPOFF: O << "@GOTNTPOFF"; break;
  case X86II::MO_GOTPCREL:  O << "@GOTPCREL";  break;
  case X86II::MO_GOT:       O << "@GOT";       break;
//.........这里部分代码省略.........