SDValue
BlackfinTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
                                  CallingConv::ID CallConv, bool isVarArg,
                                  bool &isTailCall,
                                  const SmallVectorImpl<ISD::OutputArg> &Outs,
                                  const SmallVectorImpl<SDValue> &OutVals,
                                  const SmallVectorImpl<ISD::InputArg> &Ins,
                                  DebugLoc dl, SelectionDAG &DAG,
                                  SmallVectorImpl<SDValue> &InVals) const {
  // Blackfin target does not yet support tail call optimization.
  isTailCall = false;

  // Analyze operands of the call, assigning locations to each operand.
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
		 DAG.getTarget(), ArgLocs, *DAG.getContext());
  CCInfo.AllocateStack(12, 4);  // ABI requires 12 bytes stack space
  CCInfo.AnalyzeCallOperands(Outs, CC_Blackfin);

  // Get the size of the outgoing arguments stack space requirement.
  unsigned ArgsSize = CCInfo.getNextStackOffset();

  Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(ArgsSize, true));
  SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
  SmallVector<SDValue, 8> MemOpChains;

  // Walk the register/memloc assignments, inserting copies/loads.
  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
    CCValAssign &VA = ArgLocs[i];
    SDValue Arg = OutVals[i];

    // Promote the value if needed.
    switch (VA.getLocInfo()) {
    default: llvm_unreachable("Unknown loc info!");
    case CCValAssign::Full: break;
    case CCValAssign::SExt:
      Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
      break;
    case CCValAssign::ZExt:
      Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
      break;
    case CCValAssign::AExt:
      Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg);
      break;
    }

    // Arguments that can be passed on register must be kept at
    // RegsToPass vector
    if (VA.isRegLoc()) {
      RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
    } else {
      assert(VA.isMemLoc() && "CCValAssign must be RegLoc or MemLoc");
      int Offset = VA.getLocMemOffset();
      assert(Offset%4 == 0 && "Unaligned LocMemOffset");
      assert(VA.getLocVT()==MVT::i32 && "Illegal CCValAssign type");
      SDValue SPN = DAG.getCopyFromReg(Chain, dl, BF::SP, MVT::i32);
      SDValue OffsetN = DAG.getIntPtrConstant(Offset);
      OffsetN = DAG.getNode(ISD::ADD, dl, MVT::i32, SPN, OffsetN);
      MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, OffsetN,
                                         MachinePointerInfo(),false, false, 0));
    }
  }

  // Transform all store nodes into one single node because
  // all store nodes are independent of each other.
  if (!MemOpChains.empty())
    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
                        &MemOpChains[0], MemOpChains.size());

  // Build a sequence of copy-to-reg nodes chained together with token
  // chain and flag operands which copy the outgoing args into registers.
  // The InFlag in necessary since all emitted instructions must be
  // stuck together.
  SDValue InFlag;
  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
    Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
                             RegsToPass[i].second, InFlag);
    InFlag = Chain.getValue(1);
  }

  // If the callee is a GlobalAddress node (quite common, every direct call is)
  // turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
  // Likewise ExternalSymbol -> TargetExternalSymbol.
  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
    Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, MVT::i32);
  else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee))
    Callee = DAG.getTargetExternalSymbol(E->getSymbol(), MVT::i32);

  std::vector<EVT> NodeTys;
  NodeTys.push_back(MVT::Other);   // Returns a chain
  NodeTys.push_back(MVT::Glue);    // Returns a flag for retval copy to use.
  SDValue Ops[] = { Chain, Callee, InFlag };
  Chain = DAG.getNode(BFISD::CALL, dl, NodeTys, Ops,
                      InFlag.getNode() ? 3 : 2);
  InFlag = Chain.getValue(1);

  Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(ArgsSize, true),
                             DAG.getIntPtrConstant(0, true), InFlag);
  InFlag = Chain.getValue(1);

  // Assign locations to each value returned by this call.
  SmallVector<CCValAssign, 16> RVLocs;
  CCState RVInfo(CallConv, isVarArg, DAG.getMachineFunction(),
		 DAG.getTarget(), RVLocs, *DAG.getContext());

  RVInfo.AnalyzeCallResult(Ins, RetCC_Blackfin);

  // Copy all of the result registers out of their specified physreg.
  for (unsigned i = 0; i != RVLocs.size(); ++i) {
    CCValAssign &RV = RVLocs[i];
    unsigned Reg = RV.getLocReg();

    Chain = DAG.getCopyFromReg(Chain, dl, Reg,
                               RVLocs[i].getLocVT(), InFlag);
    SDValue Val = Chain.getValue(0);
    InFlag = Chain.getValue(2);
    Chain = Chain.getValue(1);

    // Callee is responsible for extending any i16 return values.
    switch (RV.getLocInfo()) {
    case CCValAssign::SExt:
      Val = DAG.getNode(ISD::AssertSext, dl, RV.getLocVT(), Val,
                        DAG.getValueType(RV.getValVT()));
      break;
    case CCValAssign::ZExt:
      Val = DAG.getNode(ISD::AssertZext, dl, RV.getLocVT(), Val,
                        DAG.getValueType(RV.getValVT()));
      break;
    default:
      break;
    }

    // Truncate to valtype
    if (RV.getLocInfo() != CCValAssign::Full)
      Val = DAG.getNode(ISD::TRUNCATE, dl, RV.getValVT(), Val);
    InVals.push_back(Val);
  }

  return Chain;
}
Exemple #2
0
/// LowerCCCCallTo - functions arguments are copied from virtual regs to
/// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
/// TODO: sret.
SDValue
MSP430TargetLowering::LowerCCCCallTo(SDValue Chain, SDValue Callee,
                                     CallingConv::ID CallConv, bool isVarArg,
                                     bool isTailCall,
                                     const SmallVectorImpl<ISD::OutputArg>
                                       &Outs,
                                     const SmallVectorImpl<SDValue> &OutVals,
                                     const SmallVectorImpl<ISD::InputArg> &Ins,
                                     DebugLoc dl, SelectionDAG &DAG,
                                     SmallVectorImpl<SDValue> &InVals) const {
  // Analyze operands of the call, assigning locations to each operand.
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
                 ArgLocs, *DAG.getContext());

  CCInfo.AnalyzeCallOperands(Outs, CC_MSP430);

  // Get a count of how many bytes are to be pushed on the stack.
  unsigned NumBytes = CCInfo.getNextStackOffset();

  Chain = DAG.getCALLSEQ_START(Chain ,DAG.getConstant(NumBytes,
                                                      getPointerTy(), true));

  SmallVector<std::pair<unsigned, SDValue>, 4> RegsToPass;
  SmallVector<SDValue, 12> MemOpChains;
  SDValue StackPtr;

  // Walk the register/memloc assignments, inserting copies/loads.
  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
    CCValAssign &VA = ArgLocs[i];

    SDValue Arg = OutVals[i];

    // Promote the value if needed.
    switch (VA.getLocInfo()) {
      default: llvm_unreachable("Unknown loc info!");
      case CCValAssign::Full: break;
      case CCValAssign::SExt:
        Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
        break;
      case CCValAssign::ZExt:
        Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
        break;
      case CCValAssign::AExt:
        Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg);
        break;
    }

    // Arguments that can be passed on register must be kept at RegsToPass
    // vector
    if (VA.isRegLoc()) {
      RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
    } else {
      assert(VA.isMemLoc());

      if (StackPtr.getNode() == 0)
        StackPtr = DAG.getCopyFromReg(Chain, dl, MSP430::SPW, getPointerTy());

      SDValue PtrOff = DAG.getNode(ISD::ADD, dl, getPointerTy(),
                                   StackPtr,
                                   DAG.getIntPtrConstant(VA.getLocMemOffset()));


      MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
                                         MachinePointerInfo(),false, false, 0));
    }
  }

  // Transform all store nodes into one single node because all store nodes are
  // independent of each other.
  if (!MemOpChains.empty())
    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
                        &MemOpChains[0], MemOpChains.size());

  // Build a sequence of copy-to-reg nodes chained together with token chain and
  // flag operands which copy the outgoing args into registers.  The InFlag in
  // necessary since all emitted instructions must be stuck together.
  SDValue InFlag;
  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
    Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
                             RegsToPass[i].second, InFlag);
    InFlag = Chain.getValue(1);
  }

  // If the callee is a GlobalAddress node (quite common, every direct call is)
  // turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
  // Likewise ExternalSymbol -> TargetExternalSymbol.
  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
    Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, MVT::i16);
  else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee))
    Callee = DAG.getTargetExternalSymbol(E->getSymbol(), MVT::i16);

  // Returns a chain & a flag for retval copy to use.
  SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
  SmallVector<SDValue, 8> Ops;
  Ops.push_back(Chain);
  Ops.push_back(Callee);

  // Add argument registers to the end of the list so that they are
  // known live into the call.
  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
    Ops.push_back(DAG.getRegister(RegsToPass[i].first,
                                  RegsToPass[i].second.getValueType()));

  if (InFlag.getNode())
    Ops.push_back(InFlag);

  Chain = DAG.getNode(MSP430ISD::CALL, dl, NodeTys, &Ops[0], Ops.size());
  InFlag = Chain.getValue(1);

  // Create the CALLSEQ_END node.
  Chain = DAG.getCALLSEQ_END(Chain,
                             DAG.getConstant(NumBytes, getPointerTy(), true),
                             DAG.getConstant(0, getPointerTy(), true),
                             InFlag);
  InFlag = Chain.getValue(1);

  // Handle result values, copying them out of physregs into vregs that we
  // return.
  return LowerCallResult(Chain, InFlag, CallConv, isVarArg, Ins, dl,
                         DAG, InVals);
}
// TODO refactor?
SDValue AVM2TargetLowering::
LowerCall(SDValue Chain, SDValue Callee,
          CallingConv::ID CallConv, bool isVarArg, bool& isTailCall,
          const SmallVectorImpl<ISD::OutputArg> &Outs,
          const SmallVectorImpl<SDValue> &OutVals,
          const SmallVectorImpl<ISD::InputArg> &Ins,
          DebugLoc DL, SelectionDAG &DAG,
          SmallVectorImpl<SDValue> &InVals) const
{
    // AVM2 target does not yet support tail call optimization.
    isTailCall = false;

    // Count the size of the outgoing arguments.
    unsigned ArgsSize = 0;

    for (unsigned i = 0, e = Outs.size(); i != e; ++i) {
        switch (OutVals[i].getValueType().getSimpleVT().SimpleTy) {
        default:
            assert(0 && "Unknown value type!");
        case MVT::i1:
        case MVT::i8:
        case MVT::i16:
        case MVT::i32:
        case MVT::f32:
            ArgsSize += 4;
            break;
        case MVT::i64:
        case MVT::f64:
            ArgsSize += 8;
            break;
        }
    }

    unsigned Align = getTargetMachine().getFrameLowering()->getStackAlignment();
    unsigned AlignAdjust = (Align - (ArgsSize % Align)) % Align;
    ArgsSize += AlignAdjust;
    unsigned ArgOffset = 0;

    Chain = DAG.getCALLSEQ_START(Chain,DAG.getIntPtrConstant(ArgsSize, true));
    // Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(ArgsSize, true));

    // Analyze operands of the call, assigning locations to each operand.
    SmallVector<CCValAssign, 16> ArgLocs;
    CCState CCInfo(CallConv, isVarArg, DAG.getTarget(), ArgLocs, *DAG.getContext());
    CCInfo.AnalyzeCallOperands(Outs, CC_AVM2_32);

    SDValue StackPtr;
    SmallVector<SDValue, 8> MemOpChains;
    for (unsigned i = 0, e = Outs.size(); i != e; ++i) {
        SDValue Val = OutVals[i];
        EVT ObjectVT = Val.getValueType();
        SDValue ValToStore(0, 0);
        unsigned ObjSize;
        switch (ObjectVT.getSimpleVT().SimpleTy) {
        default:
            assert(0 && "Unhandled argument type!");
        case MVT::i1:
        case MVT::i8:
        case MVT::i16: {
            CCValAssign &VA = ArgLocs[i];
            // Promote the integer to 32-bits.  If the input type is signed, use a
            // sign extend, otherwise use a zero extend.
            ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
            if (VA.getLocInfo() == CCValAssign::SExt) {
                ExtendKind = ISD::SIGN_EXTEND;
            } else if (VA.getLocInfo() == CCValAssign::ZExt) {
                ExtendKind = ISD::ZERO_EXTEND;
            } else if (VA.getLocInfo() == CCValAssign::AExt) {
                ExtendKind = ISD::ANY_EXTEND;
            }
            Val = DAG.getNode(ExtendKind, DL, MVT::i32, Val);
            // FALL THROUGH
        }
        case MVT::i32: // TODO unify
            ObjSize = 4;
            ValToStore = Val;
            break;
        case MVT::f32:
            ObjSize = 4;
            ValToStore = Val;
            break;
        case MVT::f64:
            ObjSize = 8;
            ValToStore = Val;
            break;
        case MVT::i64:
            ObjSize = 8;
            ValToStore = Val; // Whole thing is passed in memory.
            break;
        }


        if (ValToStore.getNode()) {
            SDValue StackPtr = DAG.getRegister(AVM2::ESP, MVT::i32);
            SDValue PtrOff = DAG.getConstant(ArgOffset, MVT::i32);
            PtrOff = DAG.getNode(ISD::ADD, DL, MVT::i32, StackPtr, PtrOff);
            if(ObjectVT == MVT::i64) { // 2 stores for 64 bit
                SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, ValToStore, DAG.getConstant(0, MVT::i32));
                SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, ValToStore, DAG.getConstant(1, MVT::i32));
                SDValue PtrOff4 = DAG.getNode(ISD::ADD, DL, MVT::i32, PtrOff, DAG.getConstant(4, MVT::i32));

                MemOpChains.push_back(DAG.getStore(Chain, DL, Lo, PtrOff, MachinePointerInfo(), false, false, 0));
                MemOpChains.push_back(DAG.getStore(Chain, DL, Hi, PtrOff4, MachinePointerInfo(), false, false, 0));
            } else
                MemOpChains.push_back(DAG.getStore(Chain, DL, ValToStore,
                                                   PtrOff, MachinePointerInfo(),
                                                   false, false, 0));
        }

        ArgOffset += ObjSize;
    }

    // Emit all stores, make sure the occur before any copies into physregs.
    if (!MemOpChains.empty()) {
        Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, &MemOpChains[0], MemOpChains.size());
    }

    std::vector<EVT> NodeTys;
    NodeTys.push_back(MVT::Other); // Returns a chain
    NodeTys.push_back(MVT::Glue);  // Returns a flag for retval copy to use.
    SDValue Ops[] = { Chain, Callee };
    Chain = DAG.getNode(AVM2ISD::CALL, DL, NodeTys, Ops, 2);
    SDValue InFlag = Chain.getValue(1);
    // Chain = DAG.getNode(ISD::CALLSEQ_END, DL, MVT::Other, Chain, DAG.getConstant(ArgsSize, getPointerTy()));
    Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(ArgsSize, true), DAG.getIntPtrConstant(0, true), InFlag);

    // If the function returns void, just return the chain.
    if (Ins.empty()) {
        return Chain;
    }

    InFlag = Chain.getValue(1);

    /*
    	// Assign locations to each value returned by this call.
    	SmallVector<CCValAssign, 16> RVLocs;
    	CCState RVInfo(CallConv, isVarArg, DAG.getTarget(),
    				   RVLocs, *DAG.getContext());

    	RVInfo.AnalyzeCallResult(Ins, RetCC_AVM2_32);
    	const MVT::SimpleValueType RetTyVT = RVLocs.size() == 0 ? MVT::isVoid : RVLocs[0].getValVT().SimpleTy;

    	// Copy all of the result registers out of their specified physreg.
    	for (unsigned i = 0; i != RVLocs.size(); ++i) {
    		unsigned Reg = RVLocs[i].getLocReg();
    		Chain = DAG.getCopyFromReg(Chain, DL, Reg,
    								   RVLocs[i].getValVT(), InFlag).getValue(1);
    		InFlag = Chain.getValue(2);
    		InVals.push_back(Chain.getValue(0));
    	}
    */

    SmallVector<CCValAssign, 16> RVLocs;
    CCState RVInfo(CallConv, isVarArg, DAG.getTarget(),
                   RVLocs, *DAG.getContext());
    if(!RVInfo.CheckReturn(Ins, RetCC_AVM2_32)) {
      report_fatal_error("Flascc does not yet support LLVM SIMD intrinsics.\n");
    }

    for (unsigned i = 0, e = Ins.size(); i != e; ++i) {

        const MVT::SimpleValueType RetTyVT = Ins[i].VT.SimpleTy;

        SDValue RetVal;
        if (RetTyVT != MVT::isVoid) {
            // SDVTList Tys = DAG.getVTList(AVM2::EAX, MVT::i32, MVT::Glue);

            switch (RetTyVT) {
            default:
                assert(0 && "Unknown value type to return!");
            case MVT::i1:
            case MVT::i8:
            case MVT::i16: {
                assert( i <= 1 && "More than 2 return values for i1/i8/i16." );
                if( i == 0 ) {
                    RetVal = DAG.getCopyFromReg(Chain, DL, AVM2::EAX, MVT::i32, InFlag);
                } else {
                    RetVal = DAG.getCopyFromReg(Chain, DL, AVM2::EDX, MVT::i32, InFlag);
                }

                Chain = RetVal.getValue(1);
                InFlag = Chain.getValue(2);

                // Add a note to keep track of whether it is sign or zero extended.
                CCValAssign &VA = RVLocs[i];
                ISD::NodeType AssertKind = ISD::AssertZext;
                if (VA.getLocInfo() == CCValAssign::SExt) {
                    AssertKind = ISD::AssertSext;
                }
                RetVal = DAG.getNode(AssertKind, DL, MVT::i32, RetVal,
                                     DAG.getValueType(RetTyVT));
                RetVal = DAG.getNode(ISD::TRUNCATE, DL, RetTyVT, RetVal);
                break;
            }
            case MVT::i32:
                assert( i <= 1 && "More than 2 return values for i32." );
                if( i == 0 ) {
                    RetVal = DAG.getCopyFromReg(Chain, DL, AVM2::EAX, MVT::i32, InFlag);
                } else {
                    RetVal = DAG.getCopyFromReg(Chain, DL, AVM2::EDX, MVT::i32, InFlag);
                }

                Chain = RetVal.getValue(1);
                InFlag = Chain.getValue(2);
                // Chain = DAG.getCopyFromReg(Chain, DL, AVM2::EAX, MVT::i32, InFlag);
                break;
            case MVT::f32:
                assert( i == 0 && "More than 1 return value for f32." );
                RetVal = DAG.getCopyFromReg(Chain, DL, AVM2::SST0, MVT::f32, InFlag);
                Chain = RetVal.getValue(1);
                InFlag = Chain.getValue(2);
                break;
            case MVT::f64:
                assert( i == 0 && "More than 1 return value for f64." );
                RetVal = DAG.getCopyFromReg(Chain, DL, AVM2::ST0, MVT::f64, InFlag);
                Chain = RetVal.getValue(1);
                InFlag = Chain.getValue(2);
                break;
            case MVT::i64: {
                assert( i == 0 && "More than 1 return value for i64." );
                SDValue Lo = DAG.getCopyFromReg(Chain, DL, AVM2::EAX, MVT::i32, InFlag);
                SDValue Hi = DAG.getCopyFromReg(Lo.getValue(1), DL, AVM2::EDX, MVT::i32,
                                                Lo.getValue(2));
                RetVal = DAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, Lo, Hi);
                Chain = Hi.getValue(1);
                InFlag = Chain.getValue(2);
            }
            break;
            }
        }

        InVals.push_back(Chain.getValue(0));
    }


#ifdef _DEBUG
    int InVals_size = InVals.size();
    int Ins_size = Ins.size();
    const char* err;

    // pre-check conditions that will assert in TargetLowering::LowerCallTo()
    if( InVals_size != Ins_size ) {
        // "LowerCall didn't emit the correct number of values!"
        Ins_size = InVals_size;
    }

    for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
        if( !InVals[i].getNode()  ) {
            err = "LowerCall emitted a null value!";
        }

        EVT vt = Ins[i].VT;
        if( vt != InVals[i].getValueType() ) {
            err = "LowerCall emitted a value with the wrong type!";
            EVT vt1 = Ins[i].VT;
            EVT vt2 = InVals[i].getValueType();
            vt1 = vt2;
        }
    }

#endif

    return Chain;
}
Exemple #4
0
/// LowerCall - functions arguments are copied from virtual regs to
/// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
/// TODO: isVarArg, isTailCall.
SDValue MBlazeTargetLowering::
LowerCall(SDValue Chain, SDValue Callee, CallingConv::ID CallConv,
          bool isVarArg, bool &isTailCall,
          const SmallVectorImpl<ISD::OutputArg> &Outs,
          const SmallVectorImpl<SDValue> &OutVals,
          const SmallVectorImpl<ISD::InputArg> &Ins,
          DebugLoc dl, SelectionDAG &DAG,
          SmallVectorImpl<SDValue> &InVals) const {
    // MBlaze does not yet support tail call optimization
    isTailCall = false;

    // The MBlaze requires stack slots for arguments passed to var arg
    // functions even if they are passed in registers.
    bool needsRegArgSlots = isVarArg;

    MachineFunction &MF = DAG.getMachineFunction();
    MachineFrameInfo *MFI = MF.getFrameInfo();
    const TargetFrameInfo &TFI = *MF.getTarget().getFrameInfo();

    // Analyze operands of the call, assigning locations to each operand.
    SmallVector<CCValAssign, 16> ArgLocs;
    CCState CCInfo(CallConv, isVarArg, getTargetMachine(), ArgLocs,
                   *DAG.getContext());
    CCInfo.AnalyzeCallOperands(Outs, CC_MBlaze);

    // Get a count of how many bytes are to be pushed on the stack.
    unsigned NumBytes = CCInfo.getNextStackOffset();

    // Variable argument function calls require a minimum of 24-bytes of stack
    if (isVarArg && NumBytes < 24) NumBytes = 24;

    Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(NumBytes, true));

    SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
    SmallVector<SDValue, 8> MemOpChains;

    // Walk the register/memloc assignments, inserting copies/loads.
    for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
        CCValAssign &VA = ArgLocs[i];
        MVT RegVT = VA.getLocVT();
        SDValue Arg = OutVals[i];

        // Promote the value if needed.
        switch (VA.getLocInfo()) {
        default:
            llvm_unreachable("Unknown loc info!");
        case CCValAssign::Full:
            break;
        case CCValAssign::SExt:
            Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, RegVT, Arg);
            break;
        case CCValAssign::ZExt:
            Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, RegVT, Arg);
            break;
        case CCValAssign::AExt:
            Arg = DAG.getNode(ISD::ANY_EXTEND, dl, RegVT, Arg);
            break;
        }

        // Arguments that can be passed on register must be kept at
        // RegsToPass vector
        if (VA.isRegLoc()) {
            RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
        } else {
            // Register can't get to this point...
            assert(VA.isMemLoc());

            // Since we are alread passing values on the stack we don't
            // need to worry about creating additional slots for the
            // values passed via registers.
            needsRegArgSlots = false;

            // Create the frame index object for this incoming parameter
            unsigned ArgSize = VA.getValVT().getSizeInBits()/8;
            unsigned StackLoc = VA.getLocMemOffset() + 4;
            int FI = MFI->CreateFixedObject(ArgSize, StackLoc, true);

            SDValue PtrOff = DAG.getFrameIndex(FI,getPointerTy());

            // emit ISD::STORE whichs stores the
            // parameter value to a stack Location
            MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
                                               MachinePointerInfo(),
                                               false, false, 0));
        }
    }

    // If we need to reserve stack space for the arguments passed via registers
    // then create a fixed stack object at the beginning of the stack.
    if (needsRegArgSlots && TFI.hasReservedCallFrame(MF))
        MFI->CreateFixedObject(28,0,true);

    // Transform all store nodes into one single node because all store
    // nodes are independent of each other.
    if (!MemOpChains.empty())
        Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
                            &MemOpChains[0], MemOpChains.size());

    // Build a sequence of copy-to-reg nodes chained together with token
    // chain and flag operands which copy the outgoing args into registers.
    // The InFlag in necessary since all emited instructions must be
    // stuck together.
    SDValue InFlag;
    for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
        Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
                                 RegsToPass[i].second, InFlag);
        InFlag = Chain.getValue(1);
    }

    // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
    // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
    // node so that legalize doesn't hack it.
    if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
        Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl,
                                            getPointerTy(), 0, 0);
    else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee))
        Callee = DAG.getTargetExternalSymbol(S->getSymbol(),
                                             getPointerTy(), 0);

    // MBlazeJmpLink = #chain, #target_address, #opt_in_flags...
    //             = Chain, Callee, Reg#1, Reg#2, ...
    //
    // Returns a chain & a flag for retval copy to use.
    SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Flag);
    SmallVector<SDValue, 8> Ops;
    Ops.push_back(Chain);
    Ops.push_back(Callee);

    // Add argument registers to the end of the list so that they are
    // known live into the call.
    for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
        Ops.push_back(DAG.getRegister(RegsToPass[i].first,
                                      RegsToPass[i].second.getValueType()));
    }

    if (InFlag.getNode())
        Ops.push_back(InFlag);

    Chain  = DAG.getNode(MBlazeISD::JmpLink, dl, NodeTys, &Ops[0], Ops.size());
    InFlag = Chain.getValue(1);

    // Create the CALLSEQ_END node.
    Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
                               DAG.getIntPtrConstant(0, true), InFlag);
    if (!Ins.empty())
        InFlag = Chain.getValue(1);

    // Handle result values, copying them out of physregs into vregs that we
    // return.
    return LowerCallResult(Chain, InFlag, CallConv, isVarArg,
                           Ins, dl, DAG, InVals);
}
Exemple #5
0
SDValue
Cpu0TargetLowering::LowerCall(SDValue InChain, SDValue Callee,
                              CallingConv::ID CallConv, bool isVarArg,
                              bool doesNotRet, bool &isTailCall,
                              const SmallVectorImpl<ISD::OutputArg> &Outs,
                              const SmallVectorImpl<SDValue> &OutVals,
                              const SmallVectorImpl<ISD::InputArg> &Ins,
                              DebugLoc dl, SelectionDAG &DAG,
                              SmallVectorImpl<SDValue> &InVals) const {
#if 1
  // Cpu0 target does not yet support tail call optimization.
  isTailCall = false;

  MachineFunction &MF = DAG.getMachineFunction();
  MachineFrameInfo *MFI = MF.getFrameInfo();
  const TargetFrameLowering *TFL = MF.getTarget().getFrameLowering();
  bool IsPIC = getTargetMachine().getRelocationModel() == Reloc::PIC_;
  Cpu0FunctionInfo *Cpu0FI = MF.getInfo<Cpu0FunctionInfo>();

  // Analyze operands of the call, assigning locations to each operand.
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
                 getTargetMachine(), ArgLocs, *DAG.getContext());

  CCInfo.AnalyzeCallOperands(Outs, CC_Cpu0);

  // Get a count of how many bytes are to be pushed on the stack.
  unsigned NextStackOffset = CCInfo.getNextStackOffset();

  // Chain is the output chain of the last Load/Store or CopyToReg node.
  // ByValChain is the output chain of the last Memcpy node created for copying
  // byval arguments to the stack.
  SDValue Chain, CallSeqStart, ByValChain;
  SDValue NextStackOffsetVal = DAG.getIntPtrConstant(NextStackOffset, true);
  Chain = CallSeqStart = DAG.getCALLSEQ_START(InChain, NextStackOffsetVal);
  ByValChain = InChain;
#if 0
  // If this is the first call, create a stack frame object that points to
  // a location to which .cprestore saves $gp.
  if (IsO32 && IsPIC && Cpu0FI->globalBaseRegFixed() && !Cpu0FI->getGPFI())
    Cpu0FI->setGPFI(MFI->CreateFixedObject(4, 0, true));
#endif
  // Get the frame index of the stack frame object that points to the location
  // of dynamically allocated area on the stack.
  int DynAllocFI = Cpu0FI->getDynAllocFI();
#if 0
  // Update size of the maximum argument space.
  // For O32, a minimum of four words (16 bytes) of argument space is
  // allocated.
  if (IsO32)
    NextStackOffset = std::max(NextStackOffset, (unsigned)16);
#endif
  unsigned MaxCallFrameSize = Cpu0FI->getMaxCallFrameSize();

  if (MaxCallFrameSize < NextStackOffset) {
    Cpu0FI->setMaxCallFrameSize(NextStackOffset);

    // Set the offsets relative to $sp of the $gp restore slot and dynamically
    // allocated stack space. These offsets must be aligned to a boundary
    // determined by the stack alignment of the ABI.
    unsigned StackAlignment = TFL->getStackAlignment();
    NextStackOffset = (NextStackOffset + StackAlignment - 1) /
                      StackAlignment * StackAlignment;

    if (Cpu0FI->needGPSaveRestore())
      MFI->setObjectOffset(Cpu0FI->getGPFI(), NextStackOffset);

    MFI->setObjectOffset(DynAllocFI, NextStackOffset);
  }

  // With EABI is it possible to have 16 args on registers.
  SmallVector<std::pair<unsigned, SDValue>, 16> RegsToPass;
  SmallVector<SDValue, 8> MemOpChains;

  int FirstFI = -MFI->getNumFixedObjects() - 1, LastFI = 0;

  // Walk the register/memloc assignments, inserting copies/loads.
  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
    SDValue Arg = OutVals[i];
    CCValAssign &VA = ArgLocs[i];
    MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT();
    ISD::ArgFlagsTy Flags = Outs[i].Flags;

    // ByVal Arg.
    if (Flags.isByVal()) {
      assert(Flags.getByValSize() &&
             "ByVal args of size 0 should have been ignored by front-end.");
#if 0
      if (IsO32)
        WriteByValArg(ByValChain, Chain, dl, RegsToPass, MemOpChains, LastFI,
                      MFI, DAG, Arg, VA, Flags, getPointerTy(),
                      Subtarget->isLittle());
#endif
#if 0
      else
        PassByValArg64(ByValChain, Chain, dl, RegsToPass, MemOpChains, LastFI,
                       MFI, DAG, Arg, VA, Flags, getPointerTy(),
                       Subtarget->isLittle());
#endif
      continue;
    }

    // Promote the value if needed.
    switch (VA.getLocInfo()) {
    default: llvm_unreachable("Unknown loc info!");
    case CCValAssign::Full:
#if 0
      if (VA.isRegLoc()) {
        if ((ValVT == MVT::f32 && LocVT == MVT::i32) ||
            (ValVT == MVT::f64 && LocVT == MVT::i64))
          Arg = DAG.getNode(ISD::BITCAST, dl, LocVT, Arg);
        else if (ValVT == MVT::f64 && LocVT == MVT::i32) {
          SDValue Lo = DAG.getNode(Cpu0ISD::ExtractElementF64, dl, MVT::i32,
                                   Arg, DAG.getConstant(0, MVT::i32));
          SDValue Hi = DAG.getNode(Cpu0ISD::ExtractElementF64, dl, MVT::i32,
                                   Arg, DAG.getConstant(1, MVT::i32));
          if (!Subtarget->isLittle())
            std::swap(Lo, Hi);
          unsigned LocRegLo = VA.getLocReg();
          unsigned LocRegHigh = getNextIntArgReg(LocRegLo);
          RegsToPass.push_back(std::make_pair(LocRegLo, Lo));
          RegsToPass.push_back(std::make_pair(LocRegHigh, Hi));
          continue;
        }
      }
#else
	  assert("CCValAssign::Full:");	// Gamma debug
#endif
      break;
    case CCValAssign::SExt:
      Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, LocVT, Arg);
      break;
    case CCValAssign::ZExt:
      Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, LocVT, Arg);
      break;
    case CCValAssign::AExt:
      Arg = DAG.getNode(ISD::ANY_EXTEND, dl, LocVT, Arg);
      break;
    }

    // Arguments that can be passed on register must be kept at
    // RegsToPass vector
    if (VA.isRegLoc()) {
      RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
      continue;
    }

    // Register can't get to this point...
    assert(VA.isMemLoc());

    // Create the frame index object for this incoming parameter
    LastFI = MFI->CreateFixedObject(ValVT.getSizeInBits()/8,
                                    VA.getLocMemOffset(), true);
    SDValue PtrOff = DAG.getFrameIndex(LastFI, getPointerTy());

    // emit ISD::STORE whichs stores the
    // parameter value to a stack Location
    MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
                                       MachinePointerInfo(), false, false, 0));
  }

  // Extend range of indices of frame objects for outgoing arguments that were
  // created during this function call. Skip this step if no such objects were
  // created.
  if (LastFI)
    Cpu0FI->extendOutArgFIRange(FirstFI, LastFI);

  // If a memcpy has been created to copy a byval arg to a stack, replace the
  // chain input of CallSeqStart with ByValChain.
  if (InChain != ByValChain)
    DAG.UpdateNodeOperands(CallSeqStart.getNode(), ByValChain,
                           NextStackOffsetVal);

  // Transform all store nodes into one single node because all store
  // nodes are independent of each other.
  if (!MemOpChains.empty())
    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
                        &MemOpChains[0], MemOpChains.size());

  // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
  // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
  // node so that legalize doesn't hack it.
  unsigned char OpFlag;
#if 0 // cpu0 int 32 only
  bool IsPICCall = (IsN64 || IsPIC); // true if calls are translated to jalr $25
#else
  bool IsPICCall = IsPIC; // true if calls are translated to jalr $25
#endif
  bool GlobalOrExternal = false;
  SDValue CalleeLo;

  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
    if (IsPICCall && G->getGlobal()->hasInternalLinkage()) {
      OpFlag = Cpu0II::MO_GOT;
#if 0
      unsigned char LoFlag = IsO32 ? Cpu0II::MO_ABS_LO : Cpu0II::MO_GOT_OFST;
#else
      unsigned char LoFlag = Cpu0II::MO_ABS_LO;
#endif
      Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, getPointerTy(), 0,
                                          OpFlag);
      CalleeLo = DAG.getTargetGlobalAddress(G->getGlobal(), dl, getPointerTy(),
                                            0, LoFlag);
    } else {
      OpFlag = IsPICCall ? Cpu0II::MO_GOT_CALL : Cpu0II::MO_NO_FLAG;
      Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl,
                                          getPointerTy(), 0, OpFlag);
    }

    GlobalOrExternal = true;
  }
  else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
    if (!IsPIC) // static
      OpFlag = Cpu0II::MO_NO_FLAG;
    else // O32 & PIC
      OpFlag = Cpu0II::MO_GOT_CALL;
    Callee = DAG.getTargetExternalSymbol(S->getSymbol(), getPointerTy(),
                                         OpFlag);
    GlobalOrExternal = true;
  }

  SDValue InFlag;

  // Create nodes that load address of callee and copy it to T9
  if (IsPICCall) {
    if (GlobalOrExternal) {
      // Load callee address
      Callee = DAG.getNode(Cpu0ISD::Wrapper, dl, getPointerTy(),
                           GetGlobalReg(DAG, getPointerTy()), Callee);
      SDValue LoadValue = DAG.getLoad(getPointerTy(), dl, DAG.getEntryNode(),
                                      Callee, MachinePointerInfo::getGOT(),
                                      false, false, false, 0);

      // Use GOT+LO if callee has internal linkage.
      if (CalleeLo.getNode()) {
        SDValue Lo = DAG.getNode(Cpu0ISD::Lo, dl, getPointerTy(), CalleeLo);
        Callee = DAG.getNode(ISD::ADD, dl, getPointerTy(), LoadValue, Lo);
      } else
        Callee = LoadValue;
    }
  }

  // T9 should contain the address of the callee function if
  // -reloction-model=pic or it is an indirect call.
  if (IsPICCall || !GlobalOrExternal) {
    // copy to T9
    unsigned T9Reg = Cpu0::T9;
    Chain = DAG.getCopyToReg(Chain, dl, T9Reg, Callee, SDValue(0, 0));
    InFlag = Chain.getValue(1);
    Callee = DAG.getRegister(T9Reg, getPointerTy());
  }

  // Build a sequence of copy-to-reg nodes chained together with token
  // chain and flag operands which copy the outgoing args into registers.
  // The InFlag in necessary since all emitted instructions must be
  // stuck together.
  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
    Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
                             RegsToPass[i].second, InFlag);
    InFlag = Chain.getValue(1);
  }

  // Cpu0JmpLink = #chain, #target_address, #opt_in_flags...
  //             = Chain, Callee, Reg#1, Reg#2, ...
  //
  // Returns a chain & a flag for retval copy to use.
  SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
  SmallVector<SDValue, 8> Ops;
  Ops.push_back(Chain);
  Ops.push_back(Callee);

  // Add argument registers to the end of the list so that they are
  // known live into the call.
  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
    Ops.push_back(DAG.getRegister(RegsToPass[i].first,
                                  RegsToPass[i].second.getValueType()));

  // Add a register mask operand representing the call-preserved registers.
  const TargetRegisterInfo *TRI = getTargetMachine().getRegisterInfo();
  const uint32_t *Mask = TRI->getCallPreservedMask(CallConv);
  assert(Mask && "Missing call preserved mask for calling convention");
  Ops.push_back(DAG.getRegisterMask(Mask));

  if (InFlag.getNode())
    Ops.push_back(InFlag);

  Chain  = DAG.getNode(Cpu0ISD::JmpLink, dl, NodeTys, &Ops[0], Ops.size());
  InFlag = Chain.getValue(1);

  // Create the CALLSEQ_END node.
  Chain = DAG.getCALLSEQ_END(Chain,
                             DAG.getIntPtrConstant(NextStackOffset, true),
                             DAG.getIntPtrConstant(0, true), InFlag);
  InFlag = Chain.getValue(1);

  // Handle result values, copying them out of physregs into vregs that we
  // return.
  return LowerCallResult(Chain, InFlag, CallConv, isVarArg,
                         Ins, dl, DAG, InVals);
#else
  return InChain;
#endif
}
// LowerCCCCallTo - functions arguments are copied from virtual regs to
// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
SDValue LanaiTargetLowering::LowerCCCCallTo(
    SDValue Chain, SDValue Callee, CallingConv::ID CallConv, bool IsVarArg,
    bool IsTailCall, const SmallVectorImpl<ISD::OutputArg> &Outs,
    const SmallVectorImpl<SDValue> &OutVals,
    const SmallVectorImpl<ISD::InputArg> &Ins, SDLoc DL, SelectionDAG &DAG,
    SmallVectorImpl<SDValue> &InVals) const {
  // Analyze operands of the call, assigning locations to each operand.
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs,
                 *DAG.getContext());
  GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee);
  MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();

  NumFixedArgs = 0;
  if (IsVarArg && G) {
    const Function *CalleeFn = dyn_cast<Function>(G->getGlobal());
    if (CalleeFn)
      NumFixedArgs = CalleeFn->getFunctionType()->getNumParams();
  }
  if (NumFixedArgs)
    CCInfo.AnalyzeCallOperands(Outs, CC_Lanai32_VarArg);
  else {
    if (CallConv == CallingConv::Fast)
      CCInfo.AnalyzeCallOperands(Outs, CC_Lanai32_Fast);
    else
      CCInfo.AnalyzeCallOperands(Outs, CC_Lanai32);
  }

  // Get a count of how many bytes are to be pushed on the stack.
  unsigned NumBytes = CCInfo.getNextStackOffset();

  // Create local copies for byval args.
  SmallVector<SDValue, 8> ByValArgs;
  for (unsigned I = 0, E = Outs.size(); I != E; ++I) {
    ISD::ArgFlagsTy Flags = Outs[I].Flags;
    if (!Flags.isByVal())
      continue;

    SDValue Arg = OutVals[I];
    unsigned Size = Flags.getByValSize();
    unsigned Align = Flags.getByValAlign();

    int FI = MFI->CreateStackObject(Size, Align, false);
    SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
    SDValue SizeNode = DAG.getConstant(Size, DL, MVT::i32);

    Chain = DAG.getMemcpy(Chain, DL, FIPtr, Arg, SizeNode, Align,
                          /*IsVolatile=*/false,
                          /*AlwaysInline=*/false,
                          /*IsTailCall=*/false, MachinePointerInfo(),
                          MachinePointerInfo());
    ByValArgs.push_back(FIPtr);
  }

  Chain = DAG.getCALLSEQ_START(
      Chain,
      DAG.getConstant(NumBytes, DL, getPointerTy(DAG.getDataLayout()), true),
      DL);

  SmallVector<std::pair<unsigned, SDValue>, 4> RegsToPass;
  SmallVector<SDValue, 12> MemOpChains;
  SDValue StackPtr;

  // Walk the register/memloc assignments, inserting copies/loads.
  for (unsigned I = 0, J = 0, E = ArgLocs.size(); I != E; ++I) {
    CCValAssign &VA = ArgLocs[I];
    SDValue Arg = OutVals[I];
    ISD::ArgFlagsTy Flags = Outs[I].Flags;

    // Promote the value if needed.
    switch (VA.getLocInfo()) {
    case CCValAssign::Full:
      break;
    case CCValAssign::SExt:
      Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, VA.getLocVT(), Arg);
      break;
    case CCValAssign::ZExt:
      Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Arg);
      break;
    case CCValAssign::AExt:
      Arg = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Arg);
      break;
    default:
      llvm_unreachable("Unknown loc info!");
    }

    // Use local copy if it is a byval arg.
    if (Flags.isByVal())
      Arg = ByValArgs[J++];

    // Arguments that can be passed on register must be kept at RegsToPass
    // vector
    if (VA.isRegLoc()) {
      RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
    } else {
      assert(VA.isMemLoc());

      if (StackPtr.getNode() == 0)
        StackPtr = DAG.getCopyFromReg(Chain, DL, Lanai::SP,
                                      getPointerTy(DAG.getDataLayout()));

      SDValue PtrOff =
          DAG.getNode(ISD::ADD, DL, getPointerTy(DAG.getDataLayout()), StackPtr,
                      DAG.getIntPtrConstant(VA.getLocMemOffset(), DL));

      MemOpChains.push_back(DAG.getStore(
          Chain, DL, Arg, PtrOff, MachinePointerInfo(), false, false, 0));
    }
  }

  // Transform all store nodes into one single node because all store nodes are
  // independent of each other.
  if (!MemOpChains.empty())
    Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other,
                        ArrayRef<SDValue>(&MemOpChains[0], MemOpChains.size()));

  SDValue InFlag;

  // Build a sequence of copy-to-reg nodes chained together with token chain and
  // flag operands which copy the outgoing args into registers.  The InFlag in
  // necessary since all emitted instructions must be stuck together.
  for (unsigned I = 0, E = RegsToPass.size(); I != E; ++I) {
    Chain = DAG.getCopyToReg(Chain, DL, RegsToPass[I].first,
                             RegsToPass[I].second, InFlag);
    InFlag = Chain.getValue(1);
  }

  // If the callee is a GlobalAddress node (quite common, every direct call is)
  // turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
  // Likewise ExternalSymbol -> TargetExternalSymbol.
  uint8_t OpFlag = LanaiII::MO_NO_FLAG;
  if (G) {
    Callee = DAG.getTargetGlobalAddress(
        G->getGlobal(), DL, getPointerTy(DAG.getDataLayout()), 0, OpFlag);
  } else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee)) {
    Callee = DAG.getTargetExternalSymbol(
        E->getSymbol(), getPointerTy(DAG.getDataLayout()), OpFlag);
  }

  // Returns a chain & a flag for retval copy to use.
  SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
  SmallVector<SDValue, 8> Ops;
  Ops.push_back(Chain);
  Ops.push_back(Callee);

  // Add a register mask operand representing the call-preserved registers.
  // TODO: Should return-twice functions be handled?
  const uint32_t *Mask =
      TRI->getCallPreservedMask(DAG.getMachineFunction(), CallConv);
  assert(Mask && "Missing call preserved mask for calling convention");
  Ops.push_back(DAG.getRegisterMask(Mask));

  // Add argument registers to the end of the list so that they are
  // known live into the call.
  for (unsigned I = 0, E = RegsToPass.size(); I != E; ++I)
    Ops.push_back(DAG.getRegister(RegsToPass[I].first,
                                  RegsToPass[I].second.getValueType()));

  if (InFlag.getNode())
    Ops.push_back(InFlag);

  Chain = DAG.getNode(LanaiISD::CALL, DL, NodeTys,
                      ArrayRef<SDValue>(&Ops[0], Ops.size()));
  InFlag = Chain.getValue(1);

  // Create the CALLSEQ_END node.
  Chain = DAG.getCALLSEQ_END(
      Chain,
      DAG.getConstant(NumBytes, DL, getPointerTy(DAG.getDataLayout()), true),
      DAG.getConstant(0, DL, getPointerTy(DAG.getDataLayout()), true), InFlag,
      DL);
  InFlag = Chain.getValue(1);

  // Handle result values, copying them out of physregs into vregs that we
  // return.
  return LowerCallResult(Chain, InFlag, CallConv, IsVarArg, Ins, DL, DAG,
                         InVals);
}
SDValue
SparcTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
                               CallingConv::ID CallConv, bool isVarArg,
                               bool &isTailCall,
                               const SmallVectorImpl<ISD::OutputArg> &Outs,
                               const SmallVectorImpl<ISD::InputArg> &Ins,
                               DebugLoc dl, SelectionDAG &DAG,
                               SmallVectorImpl<SDValue> &InVals) const {
  // Sparc target does not yet support tail call optimization.
  isTailCall = false;

#if 0
  // Analyze operands of the call, assigning locations to each operand.
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CallConv, isVarArg, DAG.getTarget(), ArgLocs);
  CCInfo.AnalyzeCallOperands(Outs, CC_Sparc32);

  // Get the size of the outgoing arguments stack space requirement.
  unsigned ArgsSize = CCInfo.getNextStackOffset();
  // FIXME: We can't use this until f64 is known to take two GPRs.
#else
  (void)CC_Sparc32;

  // Count the size of the outgoing arguments.
  unsigned ArgsSize = 0;
  for (unsigned i = 0, e = Outs.size(); i != e; ++i) {
    switch (Outs[i].Val.getValueType().getSimpleVT().SimpleTy) {
      default: llvm_unreachable("Unknown value type!");
      case MVT::i1:
      case MVT::i8:
      case MVT::i16:
      case MVT::i32:
      case MVT::f32:
        ArgsSize += 4;
        break;
      case MVT::i64:
      case MVT::f64:
        ArgsSize += 8;
        break;
    }
  }
  if (ArgsSize > 4*6)
    ArgsSize -= 4*6;    // Space for first 6 arguments is prereserved.
  else
    ArgsSize = 0;
#endif

  // Keep stack frames 8-byte aligned.
  ArgsSize = (ArgsSize+7) & ~7;

  Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(ArgsSize, true));

  SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
  SmallVector<SDValue, 8> MemOpChains;

#if 0
  // Walk the register/memloc assignments, inserting copies/loads.
  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
    CCValAssign &VA = ArgLocs[i];
    SDValue Arg = Outs[i].Val;

    // Promote the value if needed.
    switch (VA.getLocInfo()) {
    default: llvm_unreachable("Unknown loc info!");
    case CCValAssign::Full: break;
    case CCValAssign::SExt:
      Arg = DAG.getNode(ISD::SIGN_EXTEND, VA.getLocVT(), Arg);
      break;
    case CCValAssign::ZExt:
      Arg = DAG.getNode(ISD::ZERO_EXTEND, VA.getLocVT(), Arg);
      break;
    case CCValAssign::AExt:
      Arg = DAG.getNode(ISD::ANY_EXTEND, VA.getLocVT(), Arg);
      break;
    }

    // Arguments that can be passed on register must be kept at
    // RegsToPass vector
    if (VA.isRegLoc()) {
      RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
      continue;
    }

    assert(VA.isMemLoc());

    // Create a store off the stack pointer for this argument.
    SDValue StackPtr = DAG.getRegister(SP::O6, MVT::i32);
    // FIXME: VERIFY THAT 68 IS RIGHT.
    SDValue PtrOff = DAG.getIntPtrConstant(VA.getLocMemOffset()+68);
    PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff);
    MemOpChains.push_back(DAG.getStore(Chain, Arg, PtrOff, NULL, 0,
                                       false, false, 0));
  }

#else
  static const unsigned ArgRegs[] = {
    SP::I0, SP::I1, SP::I2, SP::I3, SP::I4, SP::I5
  };
  unsigned ArgOffset = 68;

  for (unsigned i = 0, e = Outs.size(); i != e; ++i) {
    SDValue Val = Outs[i].Val;
    EVT ObjectVT = Val.getValueType();
    SDValue ValToStore(0, 0);
    unsigned ObjSize;
    switch (ObjectVT.getSimpleVT().SimpleTy) {
    default: llvm_unreachable("Unhandled argument type!");
    case MVT::i32:
      ObjSize = 4;

      if (RegsToPass.size() >= 6) {
        ValToStore = Val;
      } else {
        RegsToPass.push_back(std::make_pair(ArgRegs[RegsToPass.size()], Val));
      }
      break;
    case MVT::f32:
      ObjSize = 4;
      if (RegsToPass.size() >= 6) {
        ValToStore = Val;
      } else {
        // Convert this to a FP value in an int reg.
        Val = DAG.getNode(ISD::BIT_CONVERT, dl, MVT::i32, Val);
        RegsToPass.push_back(std::make_pair(ArgRegs[RegsToPass.size()], Val));
      }
      break;
    case MVT::f64: {
      ObjSize = 8;
      if (RegsToPass.size() >= 6) {
        ValToStore = Val;    // Whole thing is passed in memory.
        break;
      }

      // Break into top and bottom parts by storing to the stack and loading
      // out the parts as integers.  Top part goes in a reg.
      SDValue StackPtr = DAG.CreateStackTemporary(MVT::f64, MVT::i32);
      SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, 
                                   Val, StackPtr, NULL, 0,
                                   false, false, 0);
      // Sparc is big-endian, so the high part comes first.
      SDValue Hi = DAG.getLoad(MVT::i32, dl, Store, StackPtr, NULL, 0,
                               false, false, 0);
      // Increment the pointer to the other half.
      StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
                             DAG.getIntPtrConstant(4));
      // Load the low part.
      SDValue Lo = DAG.getLoad(MVT::i32, dl, Store, StackPtr, NULL, 0,
                               false, false, 0);

      RegsToPass.push_back(std::make_pair(ArgRegs[RegsToPass.size()], Hi));

      if (RegsToPass.size() >= 6) {
        ValToStore = Lo;
        ArgOffset += 4;
        ObjSize = 4;
      } else {
        RegsToPass.push_back(std::make_pair(ArgRegs[RegsToPass.size()], Lo));
      }
      break;
    }
    case MVT::i64: {
      ObjSize = 8;
      if (RegsToPass.size() >= 6) {
        ValToStore = Val;    // Whole thing is passed in memory.
        break;
      }

      // Split the value into top and bottom part.  Top part goes in a reg.
      SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, Val,
                                 DAG.getConstant(1, MVT::i32));
      SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, Val,
                                 DAG.getConstant(0, MVT::i32));
      RegsToPass.push_back(std::make_pair(ArgRegs[RegsToPass.size()], Hi));

      if (RegsToPass.size() >= 6) {
        ValToStore = Lo;
        ArgOffset += 4;
        ObjSize = 4;
      } else {
        RegsToPass.push_back(std::make_pair(ArgRegs[RegsToPass.size()], Lo));
      }
      break;
    }
    }

    if (ValToStore.getNode()) {
      SDValue StackPtr = DAG.getRegister(SP::O6, MVT::i32);
      SDValue PtrOff = DAG.getConstant(ArgOffset, MVT::i32);
      PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
      MemOpChains.push_back(DAG.getStore(Chain, dl, ValToStore, 
                                         PtrOff, NULL, 0,
                                         false, false, 0));
    }
    ArgOffset += ObjSize;
  }
#endif

  // Emit all stores, make sure the occur before any copies into physregs.
  if (!MemOpChains.empty())
    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
                        &MemOpChains[0], MemOpChains.size());

  // Build a sequence of copy-to-reg nodes chained together with token
  // chain and flag operands which copy the outgoing args into registers.
  // The InFlag in necessary since all emited instructions must be
  // stuck together.
  SDValue InFlag;
  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
    unsigned Reg = RegsToPass[i].first;
    // Remap I0->I7 -> O0->O7.
    if (Reg >= SP::I0 && Reg <= SP::I7)
      Reg = Reg-SP::I0+SP::O0;

    Chain = DAG.getCopyToReg(Chain, dl, Reg, RegsToPass[i].second, InFlag);
    InFlag = Chain.getValue(1);
  }

  // If the callee is a GlobalAddress node (quite common, every direct call is)
  // turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
  // Likewise ExternalSymbol -> TargetExternalSymbol.
  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
    Callee = DAG.getTargetGlobalAddress(G->getGlobal(), MVT::i32);
  else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee))
    Callee = DAG.getTargetExternalSymbol(E->getSymbol(), MVT::i32);

  std::vector<EVT> NodeTys;
  NodeTys.push_back(MVT::Other);   // Returns a chain
  NodeTys.push_back(MVT::Flag);    // Returns a flag for retval copy to use.
  SDValue Ops[] = { Chain, Callee, InFlag };
  Chain = DAG.getNode(SPISD::CALL, dl, NodeTys, Ops, InFlag.getNode() ? 3 : 2);
  InFlag = Chain.getValue(1);

  Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(ArgsSize, true),
                             DAG.getIntPtrConstant(0, true), InFlag);
  InFlag = Chain.getValue(1);

  // Assign locations to each value returned by this call.
  SmallVector<CCValAssign, 16> RVLocs;
  CCState RVInfo(CallConv, isVarArg, DAG.getTarget(),
                 RVLocs, *DAG.getContext());

  RVInfo.AnalyzeCallResult(Ins, RetCC_Sparc32);

  // Copy all of the result registers out of their specified physreg.
  for (unsigned i = 0; i != RVLocs.size(); ++i) {
    unsigned Reg = RVLocs[i].getLocReg();

    // Remap I0->I7 -> O0->O7.
    if (Reg >= SP::I0 && Reg <= SP::I7)
      Reg = Reg-SP::I0+SP::O0;

    Chain = DAG.getCopyFromReg(Chain, dl, Reg,
                               RVLocs[i].getValVT(), InFlag).getValue(1);
    InFlag = Chain.getValue(2);
    InVals.push_back(Chain.getValue(0));
  }

  return Chain;
}
SDValue
SparcTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
                               CallingConv::ID CallConv, bool isVarArg,
                               bool &isTailCall,
                               const SmallVectorImpl<ISD::OutputArg> &Outs,
                               const SmallVectorImpl<SDValue> &OutVals,
                               const SmallVectorImpl<ISD::InputArg> &Ins,
                               DebugLoc dl, SelectionDAG &DAG,
                               SmallVectorImpl<SDValue> &InVals) const {
  // Sparc target does not yet support tail call optimization.
  isTailCall = false;

  // Analyze operands of the call, assigning locations to each operand.
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CallConv, isVarArg, DAG.getTarget(), ArgLocs,
                 *DAG.getContext());
  CCInfo.AnalyzeCallOperands(Outs, CC_Sparc32);

  // Get the size of the outgoing arguments stack space requirement.
  unsigned ArgsSize = CCInfo.getNextStackOffset();

  // Keep stack frames 8-byte aligned.
  ArgsSize = (ArgsSize+7) & ~7;

  MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();

  //Create local copies for byval args.
  SmallVector<SDValue, 8> ByValArgs;
  for (unsigned i = 0,  e = Outs.size(); i != e; ++i) {
    ISD::ArgFlagsTy Flags = Outs[i].Flags;
    if (!Flags.isByVal())
      continue;

    SDValue Arg = OutVals[i];
    unsigned Size = Flags.getByValSize();
    unsigned Align = Flags.getByValAlign();

    int FI = MFI->CreateStackObject(Size, Align, false);
    SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy());
    SDValue SizeNode = DAG.getConstant(Size, MVT::i32);

    Chain = DAG.getMemcpy(Chain, dl, FIPtr, Arg, SizeNode, Align,
                          false,        //isVolatile,
                          (Size <= 32), //AlwaysInline if size <= 32
                          MachinePointerInfo(), MachinePointerInfo());
    ByValArgs.push_back(FIPtr);
  }

  Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(ArgsSize, true));

  SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
  SmallVector<SDValue, 8> MemOpChains;

  const unsigned StackOffset = 92;
  bool hasStructRetAttr = false;
  // Walk the register/memloc assignments, inserting copies/loads.
  for (unsigned i = 0, realArgIdx = 0, byvalArgIdx = 0, e = ArgLocs.size();
       i != e;
       ++i, ++realArgIdx) {
    CCValAssign &VA = ArgLocs[i];
    SDValue Arg = OutVals[realArgIdx];

    ISD::ArgFlagsTy Flags = Outs[realArgIdx].Flags;

    //Use local copy if it is a byval arg.
    if (Flags.isByVal())
      Arg = ByValArgs[byvalArgIdx++];

    // Promote the value if needed.
    switch (VA.getLocInfo()) {
    default: llvm_unreachable("Unknown loc info!");
    case CCValAssign::Full: break;
    case CCValAssign::SExt:
      Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
      break;
    case CCValAssign::ZExt:
      Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
      break;
    case CCValAssign::AExt:
      Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg);
      break;
    case CCValAssign::BCvt:
      Arg = DAG.getNode(ISD::BITCAST, dl, VA.getLocVT(), Arg);
      break;
    }

    if (Flags.isSRet()) {
      assert(VA.needsCustom());
      // store SRet argument in %sp+64
      SDValue StackPtr = DAG.getRegister(SP::O6, MVT::i32);
      SDValue PtrOff = DAG.getIntPtrConstant(64);
      PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
      MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
                                         MachinePointerInfo(),
                                         false, false, 0));
      hasStructRetAttr = true;
      continue;
    }

    if (VA.needsCustom()) {
      assert(VA.getLocVT() == MVT::f64);

      if (VA.isMemLoc()) {
        unsigned Offset = VA.getLocMemOffset() + StackOffset;
        //if it is double-word aligned, just store.
        if (Offset % 8 == 0) {
          SDValue StackPtr = DAG.getRegister(SP::O6, MVT::i32);
          SDValue PtrOff = DAG.getIntPtrConstant(Offset);
          PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
          MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
                                             MachinePointerInfo(),
                                             false, false, 0));
          continue;
        }
      }

      SDValue StackPtr = DAG.CreateStackTemporary(MVT::f64, MVT::i32);
      SDValue Store = DAG.getStore(DAG.getEntryNode(), dl,
                                   Arg, StackPtr, MachinePointerInfo(),
                                   false, false, 0);
      // Sparc is big-endian, so the high part comes first.
      SDValue Hi = DAG.getLoad(MVT::i32, dl, Store, StackPtr,
                               MachinePointerInfo(), false, false, 0);
      // Increment the pointer to the other half.
      StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
                             DAG.getIntPtrConstant(4));
      // Load the low part.
      SDValue Lo = DAG.getLoad(MVT::i32, dl, Store, StackPtr,
                               MachinePointerInfo(), false, false, 0);

      if (VA.isRegLoc()) {
        RegsToPass.push_back(std::make_pair(VA.getLocReg(), Hi));
        assert(i+1 != e);
        CCValAssign &NextVA = ArgLocs[++i];
        if (NextVA.isRegLoc()) {
          RegsToPass.push_back(std::make_pair(NextVA.getLocReg(), Lo));
        } else {
          //Store the low part in stack.
          unsigned Offset = NextVA.getLocMemOffset() + StackOffset;
          SDValue StackPtr = DAG.getRegister(SP::O6, MVT::i32);
          SDValue PtrOff = DAG.getIntPtrConstant(Offset);
          PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
          MemOpChains.push_back(DAG.getStore(Chain, dl, Lo, PtrOff,
                                             MachinePointerInfo(),
                                             false, false, 0));
        }
      } else {
        unsigned Offset = VA.getLocMemOffset() + StackOffset;
        // Store the high part.
        SDValue StackPtr = DAG.getRegister(SP::O6, MVT::i32);
        SDValue PtrOff = DAG.getIntPtrConstant(Offset);
        PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
        MemOpChains.push_back(DAG.getStore(Chain, dl, Hi, PtrOff,
                                           MachinePointerInfo(),
                                           false, false, 0));
        // Store the low part.
        PtrOff = DAG.getIntPtrConstant(Offset+4);
        PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
        MemOpChains.push_back(DAG.getStore(Chain, dl, Lo, PtrOff,
                                           MachinePointerInfo(),
                                           false, false, 0));
      }
      continue;
    }

    // Arguments that can be passed on register must be kept at
    // RegsToPass vector
    if (VA.isRegLoc()) {
      if (VA.getLocVT() != MVT::f32) {
        RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
        continue;
      }
      Arg = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Arg);
      RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
      continue;
    }

    assert(VA.isMemLoc());

    // Create a store off the stack pointer for this argument.
    SDValue StackPtr = DAG.getRegister(SP::O6, MVT::i32);
    SDValue PtrOff = DAG.getIntPtrConstant(VA.getLocMemOffset()+StackOffset);
    PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
    MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
                                       MachinePointerInfo(),
                                       false, false, 0));
  }


  // Emit all stores, make sure the occur before any copies into physregs.
  if (!MemOpChains.empty())
    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
                        &MemOpChains[0], MemOpChains.size());

  // Build a sequence of copy-to-reg nodes chained together with token
  // chain and flag operands which copy the outgoing args into registers.
  // The InFlag in necessary since all emitted instructions must be
  // stuck together.
  SDValue InFlag;
  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
    unsigned Reg = RegsToPass[i].first;
    // Remap I0->I7 -> O0->O7.
    if (Reg >= SP::I0 && Reg <= SP::I7)
      Reg = Reg-SP::I0+SP::O0;

    Chain = DAG.getCopyToReg(Chain, dl, Reg, RegsToPass[i].second, InFlag);
    InFlag = Chain.getValue(1);
  }

  unsigned SRetArgSize = (hasStructRetAttr)? getSRetArgSize(DAG, Callee):0;

  // If the callee is a GlobalAddress node (quite common, every direct call is)
  // turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
  // Likewise ExternalSymbol -> TargetExternalSymbol.
  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
    Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, MVT::i32);
  else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee))
    Callee = DAG.getTargetExternalSymbol(E->getSymbol(), MVT::i32);

  // Returns a chain & a flag for retval copy to use
  SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
  SmallVector<SDValue, 8> Ops;
  Ops.push_back(Chain);
  Ops.push_back(Callee);
  if (hasStructRetAttr)
    Ops.push_back(DAG.getTargetConstant(SRetArgSize, MVT::i32));
  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
    unsigned Reg = RegsToPass[i].first;
    if (Reg >= SP::I0 && Reg <= SP::I7)
      Reg = Reg-SP::I0+SP::O0;

    Ops.push_back(DAG.getRegister(Reg, RegsToPass[i].second.getValueType()));
  }
  if (InFlag.getNode())
    Ops.push_back(InFlag);

  Chain = DAG.getNode(SPISD::CALL, dl, NodeTys, &Ops[0], Ops.size());
  InFlag = Chain.getValue(1);

  Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(ArgsSize, true),
                             DAG.getIntPtrConstant(0, true), InFlag);
  InFlag = Chain.getValue(1);

  // Assign locations to each value returned by this call.
  SmallVector<CCValAssign, 16> RVLocs;
  CCState RVInfo(CallConv, isVarArg, DAG.getTarget(),
                 RVLocs, *DAG.getContext());

  RVInfo.AnalyzeCallResult(Ins, RetCC_Sparc32);

  // Copy all of the result registers out of their specified physreg.
  for (unsigned i = 0; i != RVLocs.size(); ++i) {
    unsigned Reg = RVLocs[i].getLocReg();

    // Remap I0->I7 -> O0->O7.
    if (Reg >= SP::I0 && Reg <= SP::I7)
      Reg = Reg-SP::I0+SP::O0;

    Chain = DAG.getCopyFromReg(Chain, dl, Reg,
                               RVLocs[i].getValVT(), InFlag).getValue(1);
    InFlag = Chain.getValue(2);
    InVals.push_back(Chain.getValue(0));
  }

  return Chain;
}
std::pair<SDOperand, SDOperand>
IA64TargetLowering::LowerCallTo(SDOperand Chain, const Type *RetTy,
                                bool RetSExt, bool RetZExt,
                                bool isVarArg, unsigned CallingConv, 
                                bool isTailCall, SDOperand Callee, 
                                ArgListTy &Args, SelectionDAG &DAG) {

  MachineFunction &MF = DAG.getMachineFunction();

  unsigned NumBytes = 16;
  unsigned outRegsUsed = 0;

  if (Args.size() > 8) {
    NumBytes += (Args.size() - 8) * 8;
    outRegsUsed = 8;
  } else {
    outRegsUsed = Args.size();
  }

  // FIXME? this WILL fail if we ever try to pass around an arg that
  // consumes more than a single output slot (a 'real' double, int128
  // some sort of aggregate etc.), as we'll underestimate how many 'outX'
  // registers we use. Hopefully, the assembler will notice.
  MF.getInfo<IA64FunctionInfo>()->outRegsUsed=
    std::max(outRegsUsed, MF.getInfo<IA64FunctionInfo>()->outRegsUsed);

  // keep stack frame 16-byte aligned
  // assert(NumBytes==((NumBytes+15) & ~15) && 
  //        "stack frame not 16-byte aligned!");
  NumBytes = (NumBytes+15) & ~15;
  
  Chain = DAG.getCALLSEQ_START(Chain,DAG.getConstant(NumBytes, getPointerTy()));

  SDOperand StackPtr;
  std::vector<SDOperand> Stores;
  std::vector<SDOperand> Converts;
  std::vector<SDOperand> RegValuesToPass;
  unsigned ArgOffset = 16;
  
  for (unsigned i = 0, e = Args.size(); i != e; ++i)
    {
      SDOperand Val = Args[i].Node;
      MVT::ValueType ObjectVT = Val.getValueType();
      SDOperand ValToStore(0, 0), ValToConvert(0, 0);
      unsigned ObjSize=8;
      switch (ObjectVT) {
      default: assert(0 && "unexpected argument type!");
      case MVT::i1:
      case MVT::i8:
      case MVT::i16:
      case MVT::i32: {
        //promote to 64-bits, sign/zero extending based on type
        //of the argument
        ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
        if (Args[i].isSExt)
          ExtendKind = ISD::SIGN_EXTEND;
        else if (Args[i].isZExt)
          ExtendKind = ISD::ZERO_EXTEND;
        Val = DAG.getNode(ExtendKind, MVT::i64, Val);
        // XXX: fall through
      }
      case MVT::i64:
        //ObjSize = 8;
        if(RegValuesToPass.size() >= 8) {
          ValToStore = Val;
        } else {
          RegValuesToPass.push_back(Val);
        }
        break;
      case MVT::f32:
        //promote to 64-bits
        Val = DAG.getNode(ISD::FP_EXTEND, MVT::f64, Val);
        // XXX: fall through
      case MVT::f64:
        if(RegValuesToPass.size() >= 8) {
          ValToStore = Val;
        } else {
          RegValuesToPass.push_back(Val);
          if(1 /* TODO: if(calling external or varadic function)*/ ) {
            ValToConvert = Val; // additionally pass this FP value as an int
          }
        }
        break;
      }
      
      if(ValToStore.Val) {
        if(!StackPtr.Val) {
          StackPtr = DAG.getRegister(IA64::r12, MVT::i64);
        }
        SDOperand PtrOff = DAG.getConstant(ArgOffset, getPointerTy());
        PtrOff = DAG.getNode(ISD::ADD, MVT::i64, StackPtr, PtrOff);
        Stores.push_back(DAG.getStore(Chain, ValToStore, PtrOff, NULL, 0));
        ArgOffset += ObjSize;
      }

      if(ValToConvert.Val) {
        Converts.push_back(DAG.getNode(IA64ISD::GETFD, MVT::i64, ValToConvert)); 
      }
    }

  // Emit all stores, make sure they occur before any copies into physregs.
  if (!Stores.empty())
    Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, &Stores[0],Stores.size());

  static const unsigned IntArgRegs[] = {
    IA64::out0, IA64::out1, IA64::out2, IA64::out3, 
    IA64::out4, IA64::out5, IA64::out6, IA64::out7
  };

  static const unsigned FPArgRegs[] = {
    IA64::F8,  IA64::F9,  IA64::F10, IA64::F11, 
    IA64::F12, IA64::F13, IA64::F14, IA64::F15
  };

  SDOperand InFlag;
  
  // save the current GP, SP and RP : FIXME: do we need to do all 3 always?
  SDOperand GPBeforeCall = DAG.getCopyFromReg(Chain, IA64::r1, MVT::i64, InFlag);
  Chain = GPBeforeCall.getValue(1);
  InFlag = Chain.getValue(2);
  SDOperand SPBeforeCall = DAG.getCopyFromReg(Chain, IA64::r12, MVT::i64, InFlag);
  Chain = SPBeforeCall.getValue(1);
  InFlag = Chain.getValue(2);
  SDOperand RPBeforeCall = DAG.getCopyFromReg(Chain, IA64::rp, MVT::i64, InFlag);
  Chain = RPBeforeCall.getValue(1);
  InFlag = Chain.getValue(2);

  // Build a sequence of copy-to-reg nodes chained together with token chain
  // and flag operands which copy the outgoing integer args into regs out[0-7]
  // mapped 1:1 and the FP args into regs F8-F15 "lazily"
  // TODO: for performance, we should only copy FP args into int regs when we
  // know this is required (i.e. for varardic or external (unknown) functions)

  // first to the FP->(integer representation) conversions, these are
  // flagged for now, but shouldn't have to be (TODO)
  unsigned seenConverts = 0;
  for (unsigned i = 0, e = RegValuesToPass.size(); i != e; ++i) {
    if(MVT::isFloatingPoint(RegValuesToPass[i].getValueType())) {
      Chain = DAG.getCopyToReg(Chain, IntArgRegs[i], Converts[seenConverts++], 
                               InFlag);
      InFlag = Chain.getValue(1);
    }
  }

  // next copy args into the usual places, these are flagged
  unsigned usedFPArgs = 0;
  for (unsigned i = 0, e = RegValuesToPass.size(); i != e; ++i) {
    Chain = DAG.getCopyToReg(Chain,
      MVT::isInteger(RegValuesToPass[i].getValueType()) ?
        IntArgRegs[i] : FPArgRegs[usedFPArgs++], RegValuesToPass[i], InFlag);
    InFlag = Chain.getValue(1);
  }

  // If the callee is a GlobalAddress node (quite common, every direct call is)
  // turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
/*
  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
    Callee = DAG.getTargetGlobalAddress(G->getGlobal(), MVT::i64);
  }
*/

  std::vector<MVT::ValueType> NodeTys;
  std::vector<SDOperand> CallOperands;
  NodeTys.push_back(MVT::Other);   // Returns a chain
  NodeTys.push_back(MVT::Flag);    // Returns a flag for retval copy to use.
  CallOperands.push_back(Chain);
  CallOperands.push_back(Callee);

  // emit the call itself
  if (InFlag.Val)
    CallOperands.push_back(InFlag);
  else
    assert(0 && "this should never happen!\n");

  // to make way for a hack:
  Chain = DAG.getNode(IA64ISD::BRCALL, NodeTys,
                      &CallOperands[0], CallOperands.size());
  InFlag = Chain.getValue(1);

  // restore the GP, SP and RP after the call  
  Chain = DAG.getCopyToReg(Chain, IA64::r1, GPBeforeCall, InFlag);
  InFlag = Chain.getValue(1);
  Chain = DAG.getCopyToReg(Chain, IA64::r12, SPBeforeCall, InFlag);
  InFlag = Chain.getValue(1);
  Chain = DAG.getCopyToReg(Chain, IA64::rp, RPBeforeCall, InFlag);
  InFlag = Chain.getValue(1);
 
  std::vector<MVT::ValueType> RetVals;
  RetVals.push_back(MVT::Other);
  RetVals.push_back(MVT::Flag);
 
  MVT::ValueType RetTyVT = getValueType(RetTy);
  SDOperand RetVal;
  if (RetTyVT != MVT::isVoid) {
    switch (RetTyVT) {
    default: assert(0 && "Unknown value type to return!");
    case MVT::i1: { // bools are just like other integers (returned in r8)
      // we *could* fall through to the truncate below, but this saves a
      // few redundant predicate ops
      SDOperand boolInR8 = DAG.getCopyFromReg(Chain, IA64::r8, MVT::i64,InFlag);
      InFlag = boolInR8.getValue(2);
      Chain = boolInR8.getValue(1);
      SDOperand zeroReg = DAG.getCopyFromReg(Chain, IA64::r0, MVT::i64, InFlag);
      InFlag = zeroReg.getValue(2);
      Chain = zeroReg.getValue(1);
      
      RetVal = DAG.getSetCC(MVT::i1, boolInR8, zeroReg, ISD::SETNE);
      break;
    }
    case MVT::i8:
    case MVT::i16:
    case MVT::i32:
      RetVal = DAG.getCopyFromReg(Chain, IA64::r8, MVT::i64, InFlag);
      Chain = RetVal.getValue(1);
      
      // keep track of whether it is sign or zero extended (todo: bools?)
/* XXX
      RetVal = DAG.getNode(RetTy->isSigned() ? ISD::AssertSext :ISD::AssertZext,
                           MVT::i64, RetVal, DAG.getValueType(RetTyVT));
*/
      RetVal = DAG.getNode(ISD::TRUNCATE, RetTyVT, RetVal);
      break;
    case MVT::i64:
      RetVal = DAG.getCopyFromReg(Chain, IA64::r8, MVT::i64, InFlag);
      Chain = RetVal.getValue(1);
      InFlag = RetVal.getValue(2); // XXX dead
      break;
    case MVT::f32:
      RetVal = DAG.getCopyFromReg(Chain, IA64::F8, MVT::f64, InFlag);
      Chain = RetVal.getValue(1);
      RetVal = DAG.getNode(ISD::TRUNCATE, MVT::f32, RetVal);
      break;
    case MVT::f64:
      RetVal = DAG.getCopyFromReg(Chain, IA64::F8, MVT::f64, InFlag);
      Chain = RetVal.getValue(1);
      InFlag = RetVal.getValue(2); // XXX dead
      break;
    }
  }
  
  Chain = DAG.getCALLSEQ_END(Chain,
                             DAG.getConstant(NumBytes, getPointerTy()),
                             DAG.getConstant(0, getPointerTy()),
                             SDOperand());
  return std::make_pair(RetVal, Chain);
}