Esempio n. 1
0
// Select - Convert the specified operand from a target-independent to a
// target-specific node if it hasn't already been changed.
SDNode *IA64DAGToDAGISel::Select(SDValue Op) {
    SDNode *N = Op.getNode();
    if (N->isMachineOpcode())
        return NULL;   // Already selected.
    DebugLoc dl = Op.getDebugLoc();

    switch (N->getOpcode()) {
    default:
        break;

    case IA64ISD::BRCALL: { // XXX: this is also a hack!
        SDValue Chain = N->getOperand(0);
        SDValue InFlag;  // Null incoming flag value.

        if(N->getNumOperands()==3) { // we have an incoming chain, callee and flag
            InFlag = N->getOperand(2);
        }

        unsigned CallOpcode;
        SDValue CallOperand;

        // if we can call directly, do so
        if (GlobalAddressSDNode *GASD =
                    dyn_cast<GlobalAddressSDNode>(N->getOperand(1))) {
            CallOpcode = IA64::BRCALL_IPREL_GA;
            CallOperand = CurDAG->getTargetGlobalAddress(GASD->getGlobal(), MVT::i64);
        } else if (isa<ExternalSymbolSDNode>(N->getOperand(1))) {
            // FIXME: we currently NEED this case for correctness, to avoid
            // "non-pic code with imm reloc.n against dynamic symbol" errors
            CallOpcode = IA64::BRCALL_IPREL_ES;
            CallOperand = N->getOperand(1);
        } else {
            // otherwise we need to load the function descriptor,
            // load the branch target (function)'s entry point and GP,
            // branch (call) then restore the GP
            SDValue FnDescriptor = N->getOperand(1);

            // load the branch target's entry point [mem] and
            // GP value [mem+8]
            SDValue targetEntryPoint=
                SDValue(CurDAG->getTargetNode(IA64::LD8, dl, MVT::i64, MVT::Other,
                                              FnDescriptor, CurDAG->getEntryNode()), 0);
            Chain = targetEntryPoint.getValue(1);
            SDValue targetGPAddr=
                SDValue(CurDAG->getTargetNode(IA64::ADDS, dl, MVT::i64,
                                              FnDescriptor,
                                              CurDAG->getConstant(8, MVT::i64)), 0);
            Chain = targetGPAddr.getValue(1);
            SDValue targetGP =
                SDValue(CurDAG->getTargetNode(IA64::LD8, dl, MVT::i64,MVT::Other,
                                              targetGPAddr, CurDAG->getEntryNode()), 0);
            Chain = targetGP.getValue(1);

            Chain = CurDAG->getCopyToReg(Chain, dl, IA64::r1, targetGP, InFlag);
            InFlag = Chain.getValue(1);
            Chain = CurDAG->getCopyToReg(Chain, dl, IA64::B6,
                                         targetEntryPoint, InFlag); // FLAG these?
            InFlag = Chain.getValue(1);

            CallOperand = CurDAG->getRegister(IA64::B6, MVT::i64);
            CallOpcode = IA64::BRCALL_INDIRECT;
        }

        // Finally, once everything is setup, emit the call itself
        if (InFlag.getNode())
            Chain = SDValue(CurDAG->getTargetNode(CallOpcode, dl, MVT::Other,
                                                  MVT::Flag, CallOperand, InFlag), 0);
        else // there might be no arguments
            Chain = SDValue(CurDAG->getTargetNode(CallOpcode, dl, MVT::Other,
                                                  MVT::Flag, CallOperand, Chain), 0);
        InFlag = Chain.getValue(1);

        std::vector<SDValue> CallResults;

        CallResults.push_back(Chain);
        CallResults.push_back(InFlag);

        for (unsigned i = 0, e = CallResults.size(); i != e; ++i)
            ReplaceUses(Op.getValue(i), CallResults[i]);
        return NULL;
    }

    case IA64ISD::GETFD: {
        SDValue Input = N->getOperand(0);
        return CurDAG->getTargetNode(IA64::GETFD, dl, MVT::i64, Input);
    }

    case ISD::FDIV:
    case ISD::SDIV:
    case ISD::UDIV:
    case ISD::SREM:
    case ISD::UREM:
        return SelectDIV(Op);

    case ISD::TargetConstantFP: {
        SDValue Chain = CurDAG->getEntryNode(); // this is a constant, so..

        SDValue V;
        ConstantFPSDNode* N2 = cast<ConstantFPSDNode>(N);
        if (N2->getValueAPF().isPosZero()) {
            V = CurDAG->getCopyFromReg(Chain, dl, IA64::F0, MVT::f64);
        } else if (N2->isExactlyValue(N2->getValueType(0) == MVT::f32 ?
                                      APFloat(+1.0f) : APFloat(+1.0))) {
            V = CurDAG->getCopyFromReg(Chain, dl, IA64::F1, MVT::f64);
        } else
            assert(0 && "Unexpected FP constant!");

        ReplaceUses(SDValue(N, 0), V);
        return 0;
    }

    case ISD::FrameIndex: { // TODO: reduce creepyness
        int FI = cast<FrameIndexSDNode>(N)->getIndex();
        if (N->hasOneUse())
            return CurDAG->SelectNodeTo(N, IA64::MOV, MVT::i64,
                                        CurDAG->getTargetFrameIndex(FI, MVT::i64));
        else
            return CurDAG->getTargetNode(IA64::MOV, dl, MVT::i64,
                                         CurDAG->getTargetFrameIndex(FI, MVT::i64));
    }

    case ISD::ConstantPool: { // TODO: nuke the constant pool
        // (ia64 doesn't need one)
        ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(N);
        Constant *C = CP->getConstVal();
        SDValue CPI = CurDAG->getTargetConstantPool(C, MVT::i64,
                      CP->getAlignment());
        return CurDAG->getTargetNode(IA64::ADDL_GA, dl, MVT::i64, // ?
                                     CurDAG->getRegister(IA64::r1, MVT::i64), CPI);
    }

    case ISD::GlobalAddress: {
        GlobalValue *GV = cast<GlobalAddressSDNode>(N)->getGlobal();
        SDValue GA = CurDAG->getTargetGlobalAddress(GV, MVT::i64);
        SDValue Tmp =
            SDValue(CurDAG->getTargetNode(IA64::ADDL_GA, dl, MVT::i64,
                                          CurDAG->getRegister(IA64::r1,
                                                  MVT::i64), GA), 0);
        return CurDAG->getTargetNode(IA64::LD8, dl, MVT::i64, MVT::Other, Tmp,
                                     CurDAG->getEntryNode());
    }

    /* XXX
       case ISD::ExternalSymbol: {
         SDValue EA = CurDAG->getTargetExternalSymbol(
           cast<ExternalSymbolSDNode>(N)->getSymbol(),
           MVT::i64);
         SDValue Tmp = CurDAG->getTargetNode(IA64::ADDL_EA, dl, MVT::i64,
                                               CurDAG->getRegister(IA64::r1,
                                                                   MVT::i64),
                                               EA);
         return CurDAG->getTargetNode(IA64::LD8, dl, MVT::i64, Tmp);
       }
    */

    case ISD::LOAD: { // FIXME: load -1, not 1, for bools?
        LoadSDNode *LD = cast<LoadSDNode>(N);
        SDValue Chain = LD->getChain();
        SDValue Address = LD->getBasePtr();

        MVT TypeBeingLoaded = LD->getMemoryVT();
        unsigned Opc;
        switch (TypeBeingLoaded.getSimpleVT()) {
        default:
#ifndef NDEBUG
            N->dump(CurDAG);
#endif
            assert(0 && "Cannot load this type!");
        case MVT::i1: { // this is a bool
            Opc = IA64::LD1; // first we load a byte, then compare for != 0
            if(N->getValueType(0) == MVT::i1) { // XXX: early exit!
                return CurDAG->SelectNodeTo(N, IA64::CMPNE, MVT::i1, MVT::Other,
                                            SDValue(CurDAG->getTargetNode(Opc, dl,
                                                    MVT::i64,
                                                    Address), 0),
                                            CurDAG->getRegister(IA64::r0, MVT::i64),
                                            Chain);
            }
            /* otherwise, we want to load a bool into something bigger: LD1
               will do that for us, so we just fall through */
        }
        case MVT::i8:
            Opc = IA64::LD1;
            break;
        case MVT::i16:
            Opc = IA64::LD2;
            break;
        case MVT::i32:
            Opc = IA64::LD4;
            break;
        case MVT::i64:
            Opc = IA64::LD8;
            break;

        case MVT::f32:
            Opc = IA64::LDF4;
            break;
        case MVT::f64:
            Opc = IA64::LDF8;
            break;
        }

        // TODO: comment this
        return CurDAG->SelectNodeTo(N, Opc, N->getValueType(0), MVT::Other,
                                    Address, Chain);
    }

    case ISD::STORE: {
        StoreSDNode *ST = cast<StoreSDNode>(N);
        SDValue Address = ST->getBasePtr();
        SDValue Chain = ST->getChain();

        unsigned Opc;
        if (ISD::isNON_TRUNCStore(N)) {
            switch (N->getOperand(1).getValueType().getSimpleVT()) {
            default:
                assert(0 && "unknown type in store");
            case MVT::i1: { // this is a bool
                Opc = IA64::ST1; // we store either 0 or 1 as a byte
                // first load zero!
                SDValue Initial = CurDAG->getCopyFromReg(Chain, dl, IA64::r0, MVT::i64);
                Chain = Initial.getValue(1);
                // then load 1 into the same reg iff the predicate to store is 1
                SDValue Tmp = ST->getValue();
                Tmp =
                    SDValue(CurDAG->getTargetNode(IA64::TPCADDS, dl, MVT::i64, Initial,
                                                  CurDAG->getTargetConstant(1,
                                                          MVT::i64),
                                                  Tmp), 0);
                return CurDAG->SelectNodeTo(N, Opc, MVT::Other, Address, Tmp, Chain);
            }
            case MVT::i64:
                Opc = IA64::ST8;
                break;
            case MVT::f64:
                Opc = IA64::STF8;
                break;
            }
        } else { // Truncating store
            switch(ST->getMemoryVT().getSimpleVT()) {
            default:
                assert(0 && "unknown type in truncstore");
            case MVT::i8:
                Opc = IA64::ST1;
                break;
            case MVT::i16:
                Opc = IA64::ST2;
                break;
            case MVT::i32:
                Opc = IA64::ST4;
                break;
            case MVT::f32:
                Opc = IA64::STF4;
                break;
            }
        }

        SDValue N1 = N->getOperand(1);
        SDValue N2 = N->getOperand(2);
        return CurDAG->SelectNodeTo(N, Opc, MVT::Other, N2, N1, Chain);
    }

    case ISD::BRCOND: {
        SDValue Chain = N->getOperand(0);
        SDValue CC = N->getOperand(1);
        MachineBasicBlock *Dest =
            cast<BasicBlockSDNode>(N->getOperand(2))->getBasicBlock();
        //FIXME - we do NOT need long branches all the time
        return CurDAG->SelectNodeTo(N, IA64::BRLCOND_NOTCALL, MVT::Other, CC,
                                    CurDAG->getBasicBlock(Dest), Chain);
    }

    case ISD::CALLSEQ_START:
    case ISD::CALLSEQ_END: {
        int64_t Amt = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
        unsigned Opc = N->getOpcode() == ISD::CALLSEQ_START ?
                       IA64::ADJUSTCALLSTACKDOWN : IA64::ADJUSTCALLSTACKUP;
        SDValue N0 = N->getOperand(0);
        return CurDAG->SelectNodeTo(N, Opc, MVT::Other, getI64Imm(Amt), N0);
    }

    case ISD::BR:
        // FIXME: we don't need long branches all the time!
        SDValue N0 = N->getOperand(0);
        return CurDAG->SelectNodeTo(N, IA64::BRL_NOTCALL, MVT::Other,
                                    N->getOperand(1), N0);
    }

    return SelectCode(Op);
}
Esempio n. 2
0
/// LowerArguments - V8 uses a very simple ABI, where all values are passed in
/// either one or two GPRs, including FP values.  TODO: we should pass FP values
/// in FP registers for fastcc functions.
void
SparcTargetLowering::LowerArguments(Function &F, SelectionDAG &DAG,
                                    SmallVectorImpl<SDValue> &ArgValues,
                                    DebugLoc dl) {
  MachineFunction &MF = DAG.getMachineFunction();
  MachineRegisterInfo &RegInfo = MF.getRegInfo();

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

  const unsigned *CurArgReg = ArgRegs, *ArgRegEnd = ArgRegs+6;
  unsigned ArgOffset = 68;

  SDValue Root = DAG.getRoot();
  std::vector<SDValue> OutChains;

  for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I) {
    MVT ObjectVT = getValueType(I->getType());

    switch (ObjectVT.getSimpleVT()) {
    default: assert(0 && "Unhandled argument type!");
    case MVT::i1:
    case MVT::i8:
    case MVT::i16:
    case MVT::i32:
      if (I->use_empty()) {                // Argument is dead.
        if (CurArgReg < ArgRegEnd) ++CurArgReg;
        ArgValues.push_back(DAG.getUNDEF(ObjectVT));
      } else if (CurArgReg < ArgRegEnd) {  // Lives in an incoming GPR
        unsigned VReg = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
        MF.getRegInfo().addLiveIn(*CurArgReg++, VReg);
        SDValue Arg = DAG.getCopyFromReg(Root, dl, VReg, MVT::i32);
        if (ObjectVT != MVT::i32) {
          unsigned AssertOp = ISD::AssertSext;
          Arg = DAG.getNode(AssertOp, dl, MVT::i32, Arg,
                            DAG.getValueType(ObjectVT));
          Arg = DAG.getNode(ISD::TRUNCATE, dl, ObjectVT, Arg);
        }
        ArgValues.push_back(Arg);
      } else {
        int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset);
        SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
        SDValue Load;
        if (ObjectVT == MVT::i32) {
          Load = DAG.getLoad(MVT::i32, dl, Root, FIPtr, NULL, 0);
        } else {
          ISD::LoadExtType LoadOp = ISD::SEXTLOAD;

          // Sparc is big endian, so add an offset based on the ObjectVT.
          unsigned Offset = 4-std::max(1U, ObjectVT.getSizeInBits()/8);
          FIPtr = DAG.getNode(ISD::ADD, dl, MVT::i32, FIPtr,
                              DAG.getConstant(Offset, MVT::i32));
          Load = DAG.getExtLoad(LoadOp, dl, MVT::i32, Root, FIPtr,
                                NULL, 0, ObjectVT);
          Load = DAG.getNode(ISD::TRUNCATE, dl, ObjectVT, Load);
        }
        ArgValues.push_back(Load);
      }

      ArgOffset += 4;
      break;
    case MVT::f32:
      if (I->use_empty()) {                // Argument is dead.
        if (CurArgReg < ArgRegEnd) ++CurArgReg;
        ArgValues.push_back(DAG.getUNDEF(ObjectVT));
      } else if (CurArgReg < ArgRegEnd) {  // Lives in an incoming GPR
        // FP value is passed in an integer register.
        unsigned VReg = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
        MF.getRegInfo().addLiveIn(*CurArgReg++, VReg);
        SDValue Arg = DAG.getCopyFromReg(Root, dl, VReg, MVT::i32);

        Arg = DAG.getNode(ISD::BIT_CONVERT, dl, MVT::f32, Arg);
        ArgValues.push_back(Arg);
      } else {
        int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset);
        SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
        SDValue Load = DAG.getLoad(MVT::f32, dl, Root, FIPtr, NULL, 0);
        ArgValues.push_back(Load);
      }
      ArgOffset += 4;
      break;

    case MVT::i64:
    case MVT::f64:
      if (I->use_empty()) {                // Argument is dead.
        if (CurArgReg < ArgRegEnd) ++CurArgReg;
        if (CurArgReg < ArgRegEnd) ++CurArgReg;
        ArgValues.push_back(DAG.getUNDEF(ObjectVT));
      } else {
        SDValue HiVal;
        if (CurArgReg < ArgRegEnd) {  // Lives in an incoming GPR
          unsigned VRegHi = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
          MF.getRegInfo().addLiveIn(*CurArgReg++, VRegHi);
          HiVal = DAG.getCopyFromReg(Root, dl, VRegHi, MVT::i32);
        } else {
          int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset);
          SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
          HiVal = DAG.getLoad(MVT::i32, dl, Root, FIPtr, NULL, 0);
        }

        SDValue LoVal;
        if (CurArgReg < ArgRegEnd) {  // Lives in an incoming GPR
          unsigned VRegLo = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
          MF.getRegInfo().addLiveIn(*CurArgReg++, VRegLo);
          LoVal = DAG.getCopyFromReg(Root, dl, VRegLo, MVT::i32);
        } else {
          int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset+4);
          SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
          LoVal = DAG.getLoad(MVT::i32, dl, Root, FIPtr, NULL, 0);
        }

        // Compose the two halves together into an i64 unit.
        SDValue WholeValue =
          DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, LoVal, HiVal);

        // If we want a double, do a bit convert.
        if (ObjectVT == MVT::f64)
          WholeValue = DAG.getNode(ISD::BIT_CONVERT, dl, MVT::f64, WholeValue);

        ArgValues.push_back(WholeValue);
      }
      ArgOffset += 8;
      break;
    }
  }

  // Store remaining ArgRegs to the stack if this is a varargs function.
  if (F.isVarArg()) {
    // Remember the vararg offset for the va_start implementation.
    VarArgsFrameOffset = ArgOffset;

    for (; CurArgReg != ArgRegEnd; ++CurArgReg) {
      unsigned VReg = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
      MF.getRegInfo().addLiveIn(*CurArgReg, VReg);
      SDValue Arg = DAG.getCopyFromReg(DAG.getRoot(), dl, VReg, MVT::i32);

      int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset);
      SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);

      OutChains.push_back(DAG.getStore(DAG.getRoot(), dl, Arg, FIPtr, NULL, 0));
      ArgOffset += 4;
    }
  }

  if (!OutChains.empty())
    DAG.setRoot(DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
                            &OutChains[0], OutChains.size()));
}
Esempio n. 3
0
static SDValue LowerCALL(SDValue Op, SelectionDAG &DAG) {
  CallSDNode *TheCall = cast<CallSDNode>(Op.getNode());
  unsigned CallingConv = TheCall->getCallingConv();
  SDValue Chain = TheCall->getChain();
  SDValue Callee = TheCall->getCallee();
  bool isVarArg = TheCall->isVarArg();
  DebugLoc dl = TheCall->getDebugLoc();

#if 0
  // Analyze operands of the call, assigning locations to each operand.
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CallingConv, isVarArg, DAG.getTarget(), ArgLocs);
  CCInfo.AnalyzeCallOperands(Op.getNode(), 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 = TheCall->getNumArgs(); i != e; ++i) {
    switch (TheCall->getArg(i).getValueType().getSimpleVT()) {
      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;
    }
  }
  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];

    // Arguments start after the 5 first operands of ISD::CALL
    SDValue Arg = TheCall->getArg(i);

    // Promote the value if needed.
    switch (VA.getLocInfo()) {
    default: assert(0 && "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));
  }

#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 = TheCall->getNumArgs(); i != e; ++i) {
    SDValue Val = TheCall->getArg(i);
    MVT ObjectVT = Val.getValueType();
    SDValue ValToStore(0, 0);
    unsigned ObjSize;
    switch (ObjectVT.getSimpleVT()) {
    default: assert(0 && "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);
      // Sparc is big-endian, so the high part comes first.
      SDValue Hi = DAG.getLoad(MVT::i32, dl, Store, StackPtr, NULL, 0, 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, 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));
    }
    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<MVT> 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(CallingConv, isVarArg, DAG.getTarget(), RVLocs);

  RVInfo.AnalyzeCallResult(TheCall, RetCC_Sparc32);
  SmallVector<SDValue, 8> ResultVals;

  // 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);
    ResultVals.push_back(Chain.getValue(0));
  }

  ResultVals.push_back(Chain);

  // Merge everything together with a MERGE_VALUES node.
  return DAG.getNode(ISD::MERGE_VALUES, dl, 
                     TheCall->getVTList(), &ResultVals[0],
                     ResultVals.size());
}
/// LowerCCCArguments - transform physical registers into virtual registers and
/// generate load operations for arguments places on the stack.
// FIXME: struct return stuff
// FIXME: varargs
SDValue MSP430TargetLowering::LowerCCCArguments(SDValue Op,
        SelectionDAG &DAG) {
    MachineFunction &MF = DAG.getMachineFunction();
    MachineFrameInfo *MFI = MF.getFrameInfo();
    MachineRegisterInfo &RegInfo = MF.getRegInfo();
    SDValue Root = Op.getOperand(0);
    bool isVarArg = cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue() != 0;
    unsigned CC = MF.getFunction()->getCallingConv();
    DebugLoc dl = Op.getDebugLoc();

    // Assign locations to all of the incoming arguments.
    SmallVector<CCValAssign, 16> ArgLocs;
    CCState CCInfo(CC, isVarArg, getTargetMachine(), ArgLocs);
    CCInfo.AnalyzeFormalArguments(Op.getNode(), CC_MSP430);

    assert(!isVarArg && "Varargs not supported yet");

    SmallVector<SDValue, 16> ArgValues;
    for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
        CCValAssign &VA = ArgLocs[i];
        if (VA.isRegLoc()) {
            // Arguments passed in registers
            MVT RegVT = VA.getLocVT();
            switch (RegVT.getSimpleVT()) {
            default:
                cerr << "LowerFORMAL_ARGUMENTS Unhandled argument type: "
                     << RegVT.getSimpleVT()
                     << "\n";
                abort();
            case MVT::i16:
                unsigned VReg =
                    RegInfo.createVirtualRegister(MSP430::GR16RegisterClass);
                RegInfo.addLiveIn(VA.getLocReg(), VReg);
                SDValue ArgValue = DAG.getCopyFromReg(Root, dl, VReg, RegVT);

                // If this is an 8-bit value, it is really passed promoted to 16
                // bits. Insert an assert[sz]ext to capture this, then truncate to the
                // right size.
                if (VA.getLocInfo() == CCValAssign::SExt)
                    ArgValue = DAG.getNode(ISD::AssertSext, dl, RegVT, ArgValue,
                                           DAG.getValueType(VA.getValVT()));
                else if (VA.getLocInfo() == CCValAssign::ZExt)
                    ArgValue = DAG.getNode(ISD::AssertZext, dl, RegVT, ArgValue,
                                           DAG.getValueType(VA.getValVT()));

                if (VA.getLocInfo() != CCValAssign::Full)
                    ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);

                ArgValues.push_back(ArgValue);
            }
        } else {
            // Sanity check
            assert(VA.isMemLoc());
            // Load the argument to a virtual register
            unsigned ObjSize = VA.getLocVT().getSizeInBits()/8;
            if (ObjSize > 2) {
                cerr << "LowerFORMAL_ARGUMENTS Unhandled argument type: "
                     << VA.getLocVT().getSimpleVT()
                     << "\n";
            }
            // Create the frame index object for this incoming parameter...
            int FI = MFI->CreateFixedObject(ObjSize, VA.getLocMemOffset());

            // Create the SelectionDAG nodes corresponding to a load
            //from this parameter
            SDValue FIN = DAG.getFrameIndex(FI, MVT::i16);
            ArgValues.push_back(DAG.getLoad(VA.getLocVT(), dl, Root, FIN,
                                            PseudoSourceValue::getFixedStack(FI), 0));
        }
    }

    ArgValues.push_back(Root);

    // Return the new list of results.
    return DAG.getNode(ISD::MERGE_VALUES, dl, Op.getNode()->getVTList(),
                       &ArgValues[0], ArgValues.size()).getValue(Op.getResNo());
}
std::pair<SDValue, SDValue>
IA64TargetLowering::LowerCallTo(SDValue Chain, const Type *RetTy,
                                bool RetSExt, bool RetZExt, bool isVarArg,
                                bool isInreg, unsigned CallingConv, 
                                bool isTailCall, SDValue Callee, 
                                ArgListTy &Args, SelectionDAG &DAG,
                                DebugLoc dl) {

  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.getIntPtrConstant(NumBytes, true));

  SDValue StackPtr;
  std::vector<SDValue> Stores;
  std::vector<SDValue> Converts;
  std::vector<SDValue> RegValuesToPass;
  unsigned ArgOffset = 16;
  
  for (unsigned i = 0, e = Args.size(); i != e; ++i)
    {
      SDValue Val = Args[i].Node;
      MVT ObjectVT = Val.getValueType();
      SDValue ValToStore(0, 0), ValToConvert(0, 0);
      unsigned ObjSize=8;
      switch (ObjectVT.getSimpleVT()) {
      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, dl, 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, dl, 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.getNode()) {
        if(!StackPtr.getNode()) {
          StackPtr = DAG.getRegister(IA64::r12, MVT::i64);
        }
        SDValue PtrOff = DAG.getConstant(ArgOffset, getPointerTy());
        PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i64, StackPtr, PtrOff);
        Stores.push_back(DAG.getStore(Chain, dl, ValToStore, PtrOff, NULL, 0));
        ArgOffset += ObjSize;
      }

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

  // Emit all stores, make sure they occur before any copies into physregs.
  if (!Stores.empty())
    Chain = DAG.getNode(ISD::TokenFactor, dl,
                        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
  };

  SDValue InFlag;
  
  // save the current GP, SP and RP : FIXME: do we need to do all 3 always?
  SDValue GPBeforeCall = DAG.getCopyFromReg(Chain, IA64::r1, MVT::i64, InFlag);
  Chain = GPBeforeCall.getValue(1);
  InFlag = Chain.getValue(2);
  SDValue SPBeforeCall = DAG.getCopyFromReg(Chain, IA64::r12, MVT::i64, InFlag);
  Chain = SPBeforeCall.getValue(1);
  InFlag = Chain.getValue(2);
  SDValue 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(RegValuesToPass[i].getValueType().isFloatingPoint()) {
      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,
      RegValuesToPass[i].getValueType().isInteger() ?
        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> NodeTys;
  std::vector<SDValue> 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.getNode())
    CallOperands.push_back(InFlag);
  else
    assert(0 && "this should never happen!\n");

  // to make way for a hack:
  Chain = DAG.getNode(IA64ISD::BRCALL, dl, 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> RetVals;
  RetVals.push_back(MVT::Other);
  RetVals.push_back(MVT::Flag);
 
  MVT RetTyVT = getValueType(RetTy);
  SDValue RetVal;
  if (RetTyVT != MVT::isVoid) {
    switch (RetTyVT.getSimpleVT()) {
    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
      SDValue boolInR8 = DAG.getCopyFromReg(Chain, IA64::r8, MVT::i64,InFlag);
      InFlag = boolInR8.getValue(2);
      Chain = boolInR8.getValue(1);
      SDValue zeroReg = DAG.getCopyFromReg(Chain, IA64::r0, MVT::i64, InFlag);
      InFlag = zeroReg.getValue(2);
      Chain = zeroReg.getValue(1);
      
      RetVal = DAG.getSetCC(dl, 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,
                           dl, MVT::i64, RetVal, DAG.getValueType(RetTyVT));
*/
      RetVal = DAG.getNode(ISD::TRUNCATE, dl, 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::FP_ROUND, dl, MVT::f32, RetVal,
                           DAG.getIntPtrConstant(0));
      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.getIntPtrConstant(NumBytes, true),
                             DAG.getIntPtrConstant(0, true), SDValue());
  return std::make_pair(RetVal, Chain);
}
unsigned getX86SubSuperRegister(unsigned Reg, MVT VT, bool High) {
  switch (VT.getSimpleVT()) {
  default: return Reg;
  case MVT::i8:
    if (High) {
      switch (Reg) {
      default: return 0;
      case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
        return X86::AH;
      case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
        return X86::DH;
      case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
        return X86::CH;
      case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
        return X86::BH;
      }
    } else {
      switch (Reg) {
      default: return 0;
      case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
        return X86::AL;
      case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
        return X86::DL;
      case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
        return X86::CL;
      case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
        return X86::BL;
      case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
        return X86::SIL;
      case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
        return X86::DIL;
      case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
        return X86::BPL;
      case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
        return X86::SPL;
      case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
        return X86::R8B;
      case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
        return X86::R9B;
      case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
        return X86::R10B;
      case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
        return X86::R11B;
      case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
        return X86::R12B;
      case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
        return X86::R13B;
      case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
        return X86::R14B;
      case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
        return X86::R15B;
      }
    }
  case MVT::i16:
    switch (Reg) {
    default: return Reg;
    case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
      return X86::AX;
    case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
      return X86::DX;
    case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
      return X86::CX;
    case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
      return X86::BX;
    case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
      return X86::SI;
    case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
      return X86::DI;
    case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
      return X86::BP;
    case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
      return X86::SP;
    case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
      return X86::R8W;
    case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
      return X86::R9W;
    case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
      return X86::R10W;
    case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
      return X86::R11W;
    case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
      return X86::R12W;
    case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
      return X86::R13W;
    case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
      return X86::R14W;
    case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
      return X86::R15W;
    }
  case MVT::i32:
    switch (Reg) {
    default: return Reg;
    case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
      return X86::EAX;
    case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
      return X86::EDX;
    case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
      return X86::ECX;
    case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
      return X86::EBX;
    case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
      return X86::ESI;
    case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
      return X86::EDI;
    case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
      return X86::EBP;
    case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
      return X86::ESP;
    case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
      return X86::R8D;
    case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
      return X86::R9D;
    case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
      return X86::R10D;
    case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
      return X86::R11D;
    case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
      return X86::R12D;
    case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
      return X86::R13D;
    case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
      return X86::R14D;
    case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
      return X86::R15D;
    }
  case MVT::i64:
    switch (Reg) {
    default: return Reg;
    case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
      return X86::RAX;
    case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
      return X86::RDX;
    case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
      return X86::RCX;
    case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
      return X86::RBX;
    case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
      return X86::RSI;
    case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
      return X86::RDI;
    case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
      return X86::RBP;
    case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
      return X86::RSP;
    case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
      return X86::R8;
    case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
      return X86::R9;
    case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
      return X86::R10;
    case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
      return X86::R11;
    case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
      return X86::R12;
    case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
      return X86::R13;
    case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
      return X86::R14;
    case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
      return X86::R15;
    }
  }

  return Reg;
}