X86InstrInfo.cpp

  // Emit the load instruction.
  SDNode *Load = 0;
  if (FoldedLoad) {
    MVT::ValueType VT = *RC->vt_begin();
    Load = DAG.getTargetNode(getLoadRegOpcode(RC, RI.getStackAlignment()), VT,
                             MVT::Other, &AddrOps[0], AddrOps.size());
    NewNodes.push_back(Load);
  }

  // Emit the data processing instruction.
  std::vector<MVT::ValueType> VTs;
  const TargetRegisterClass *DstRC = 0;
  if (TID.getNumDefs() > 0) {
    const TargetOperandInfo &DstTOI = TID.OpInfo[0];
    DstRC = DstTOI.isLookupPtrRegClass()
      ? getPointerRegClass() : RI.getRegClass(DstTOI.RegClass);
    VTs.push_back(*DstRC->vt_begin());
  }
  for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) {
    MVT::ValueType VT = N->getValueType(i);
    if (VT != MVT::Other && i >= (unsigned)TID.getNumDefs())
      VTs.push_back(VT);
  }
  if (Load)
    BeforeOps.push_back(SDOperand(Load, 0));
  std::copy(AfterOps.begin(), AfterOps.end(), std::back_inserter(BeforeOps));
  SDNode *NewNode= DAG.getTargetNode(Opc, VTs, &BeforeOps[0], BeforeOps.size());
  NewNodes.push_back(NewNode);

  // Emit the store instruction.
  if (FoldedStore) {
    AddrOps.pop_back();
    AddrOps.push_back(SDOperand(NewNode, 0));
    AddrOps.push_back(Chain);
    SDNode *Store = DAG.getTargetNode(getStoreRegOpcode(DstRC, RI.getStackAlignment()),
                                      MVT::Other, &AddrOps[0], AddrOps.size());
    NewNodes.push_back(Store);
  }

  return true;
}

unsigned X86InstrInfo::getOpcodeAfterMemoryUnfold(unsigned Opc,
                                      bool UnfoldLoad, bool UnfoldStore) const {
  DenseMap<unsigned*, std::pair<unsigned,unsigned> >::iterator I =
    MemOp2RegOpTable.find((unsigned*)Opc);
  if (I == MemOp2RegOpTable.end())
    return 0;
  bool FoldedLoad = I->second.second & (1 << 4);
  bool FoldedStore = I->second.second & (1 << 5);
  if (UnfoldLoad && !FoldedLoad)
    return 0;
  if (UnfoldStore && !FoldedStore)
    return 0;
  return I->second.first;
}

bool X86InstrInfo::BlockHasNoFallThrough(MachineBasicBlock &MBB) const {
  if (MBB.empty()) return false;
  
  switch (MBB.back().getOpcode()) {
  case X86::TCRETURNri:
  case X86::TCRETURNdi:
  case X86::RET:     // Return.
  case X86::RETI:
  case X86::TAILJMPd:
  case X86::TAILJMPr:
  case X86::TAILJMPm:
  case X86::JMP:     // Uncond branch.
  case X86::JMP32r:  // Indirect branch.
  case X86::JMP64r:  // Indirect branch (64-bit).
  case X86::JMP32m:  // Indirect branch through mem.
  case X86::JMP64m:  // Indirect branch through mem (64-bit).
    return true;
  default: return false;
  }
}

bool X86InstrInfo::
ReverseBranchCondition(std::vector<MachineOperand> &Cond) const {
  assert(Cond.size() == 1 && "Invalid X86 branch condition!");
  Cond[0].setImm(GetOppositeBranchCondition((X86::CondCode)Cond[0].getImm()));
  return false;
}

const TargetRegisterClass *X86InstrInfo::getPointerRegClass() const {
  const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
  if (Subtarget->is64Bit())
    return &X86::GR64RegClass;
  else
    return &X86::GR32RegClass;
}