Esempio n. 1
0
template <> bool AVRDAGToDAGISel::select<ISD::STORE>(SDNode *N) {
  // Use the STD{W}SPQRr pseudo instruction when passing arguments through
  // the stack on function calls for further expansion during the PEI phase.
  const StoreSDNode *ST = cast<StoreSDNode>(N);
  SDValue BasePtr = ST->getBasePtr();

  // Early exit when the base pointer is a frame index node or a constant.
  if (isa<FrameIndexSDNode>(BasePtr) || isa<ConstantSDNode>(BasePtr) ||
      BasePtr.isUndef()) {
    return false;
  }

  const RegisterSDNode *RN = dyn_cast<RegisterSDNode>(BasePtr.getOperand(0));
  // Only stores where SP is the base pointer are valid.
  if (!RN || (RN->getReg() != AVR::SP)) {
    return false;
  }

  int CST = (int)cast<ConstantSDNode>(BasePtr.getOperand(1))->getZExtValue();
  SDValue Chain = ST->getChain();
  EVT VT = ST->getValue().getValueType();
  SDLoc DL(N);
  SDValue Offset = CurDAG->getTargetConstant(CST, DL, MVT::i16);
  SDValue Ops[] = {BasePtr.getOperand(0), Offset, ST->getValue(), Chain};
  unsigned Opc = (VT == MVT::i16) ? AVR::STDWSPQRr : AVR::STDSPQRr;

  SDNode *ResNode = CurDAG->getMachineNode(Opc, DL, MVT::Other, Ops);

  // Transfer memory operands.
  MachineSDNode::mmo_iterator MemOp = MF->allocateMemRefsArray(1);
  MemOp[0] = ST->getMemOperand();
  cast<MachineSDNode>(ResNode)->setMemRefs(MemOp, MemOp + 1);

  ReplaceUses(SDValue(N, 0), SDValue(ResNode, 0));
  CurDAG->RemoveDeadNode(N);

  return true;
}