void
SparcRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
                                       int SPAdj, unsigned FIOperandNum,
                                       RegScavenger *RS) const {
  assert(SPAdj == 0 && "Unexpected");

  MachineInstr &MI = *II;
  DebugLoc dl = MI.getDebugLoc();
  int FrameIndex = MI.getOperand(FIOperandNum).getIndex();

  // Addressable stack objects are accessed using neg. offsets from %fp
  MachineFunction &MF = *MI.getParent()->getParent();
  int64_t Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
                   MI.getOperand(FIOperandNum + 1).getImm() +
                   Subtarget.getStackPointerBias();
  SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();
  unsigned FramePtr = SP::I6;
  if (FuncInfo->isLeafProc()) {
    // Use %sp and adjust offset if needed.
    FramePtr = SP::O6;
    int stackSize = MF.getFrameInfo()->getStackSize();
    Offset += (stackSize) ? Subtarget.getAdjustedFrameSize(stackSize) : 0 ;
  }

  if (!Subtarget.isV9() || !Subtarget.hasHardQuad()) {
    if (MI.getOpcode() == SP::STQFri) {
      const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
      unsigned SrcReg = MI.getOperand(2).getReg();
      unsigned SrcEvenReg = getSubReg(SrcReg, SP::sub_even64);
      unsigned SrcOddReg  = getSubReg(SrcReg, SP::sub_odd64);
      MachineInstr *StMI =
        BuildMI(*MI.getParent(), II, dl, TII.get(SP::STDFri))
        .addReg(FramePtr).addImm(0).addReg(SrcEvenReg);
      replaceFI(MF, II, *StMI, dl, 0, Offset, FramePtr);
      MI.setDesc(TII.get(SP::STDFri));
      MI.getOperand(2).setReg(SrcOddReg);
      Offset += 8;
    } else if (MI.getOpcode() == SP::LDQFri) {
      const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
      unsigned DestReg     = MI.getOperand(0).getReg();
      unsigned DestEvenReg = getSubReg(DestReg, SP::sub_even64);
      unsigned DestOddReg  = getSubReg(DestReg, SP::sub_odd64);
      MachineInstr *StMI =
        BuildMI(*MI.getParent(), II, dl, TII.get(SP::LDDFri), DestEvenReg)
        .addReg(FramePtr).addImm(0);
      replaceFI(MF, II, *StMI, dl, 1, Offset, FramePtr);

      MI.setDesc(TII.get(SP::LDDFri));
      MI.getOperand(0).setReg(DestOddReg);
      Offset += 8;
    }
  }

  replaceFI(MF, II, MI, dl, FIOperandNum, Offset, FramePtr);

}
void SparcFrameLowering::processFunctionBeforeCalleeSavedScan
(MachineFunction &MF, RegScavenger *RS) const {

    if (!DisableLeafProc && isLeafProc(MF)) {
        SparcMachineFunctionInfo *MFI = MF.getInfo<SparcMachineFunctionInfo>();
        MFI->setLeafProc(true);

        remapRegsForLeafProc(MF);
    }

}
void SparcFrameLowering::determineCalleeSaves(MachineFunction &MF,
                                              BitVector &SavedRegs,
                                              RegScavenger *RS) const {
  TargetFrameLowering::determineCalleeSaves(MF, SavedRegs, RS);
  if (!DisableLeafProc && isLeafProc(MF)) {
    SparcMachineFunctionInfo *MFI = MF.getInfo<SparcMachineFunctionInfo>();
    MFI->setLeafProc(true);

    remapRegsForLeafProc(MF);
  }

}
void SparcFrameLowering::emitPrologue(MachineFunction &MF,
                                      MachineBasicBlock &MBB) const {
  SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();

  assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
  MachineFrameInfo *MFI = MF.getFrameInfo();
  const SparcInstrInfo &TII =
      *static_cast<const SparcInstrInfo *>(MF.getSubtarget().getInstrInfo());
  MachineBasicBlock::iterator MBBI = MBB.begin();
  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();

  // Get the number of bytes to allocate from the FrameInfo
  int NumBytes = (int) MFI->getStackSize();

  unsigned SAVEri = SP::SAVEri;
  unsigned SAVErr = SP::SAVErr;
  if (FuncInfo->isLeafProc()) {
    if (NumBytes == 0)
      return;
    SAVEri = SP::ADDri;
    SAVErr = SP::ADDrr;
  }
  NumBytes = -MF.getSubtarget<SparcSubtarget>().getAdjustedFrameSize(NumBytes);
  emitSPAdjustment(MF, MBB, MBBI, NumBytes, SAVErr, SAVEri);

  MachineModuleInfo &MMI = MF.getMMI();
  const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
  unsigned regFP = MRI->getDwarfRegNum(SP::I6, true);

  // Emit ".cfi_def_cfa_register 30".
  unsigned CFIIndex =
      MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(nullptr, regFP));
  BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
      .addCFIIndex(CFIIndex);

  // Emit ".cfi_window_save".
  CFIIndex = MMI.addFrameInst(MCCFIInstruction::createWindowSave(nullptr));
  BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
      .addCFIIndex(CFIIndex);

  unsigned regInRA = MRI->getDwarfRegNum(SP::I7, true);
  unsigned regOutRA = MRI->getDwarfRegNum(SP::O7, true);
  // Emit ".cfi_register 15, 31".
  CFIIndex = MMI.addFrameInst(
      MCCFIInstruction::createRegister(nullptr, regOutRA, regInRA));
  BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
      .addCFIIndex(CFIIndex);
}
Esempio n. 5
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static SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG,
                            const SparcTargetLowering &TLI) {
  MachineFunction &MF = DAG.getMachineFunction();
  SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();

  // vastart just stores the address of the VarArgsFrameIndex slot into the
  // memory location argument.
  DebugLoc dl = Op.getDebugLoc();
  SDValue Offset =
    DAG.getNode(ISD::ADD, dl, MVT::i32,
                DAG.getRegister(SP::I6, MVT::i32),
                DAG.getConstant(FuncInfo->getVarArgsFrameOffset(),
                                MVT::i32));
  const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
  return DAG.getStore(Op.getOperand(0), dl, Offset, Op.getOperand(1), SV, 0,
                      false, false, 0);
}
void SparcFrameLowering::emitPrologue(MachineFunction &MF) const {
    SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();

    MachineBasicBlock &MBB = MF.front();
    MachineFrameInfo *MFI = MF.getFrameInfo();
    const SparcInstrInfo &TII =
        *static_cast<const SparcInstrInfo*>(MF.getTarget().getInstrInfo());
    MachineBasicBlock::iterator MBBI = MBB.begin();
    DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();

    // Get the number of bytes to allocate from the FrameInfo
    int NumBytes = (int) MFI->getStackSize();

    unsigned SAVEri = SP::SAVEri;
    unsigned SAVErr = SP::SAVErr;
    if (FuncInfo->isLeafProc()) {
        if (NumBytes == 0)
            return;
        SAVEri = SP::ADDri;
        SAVErr = SP::ADDrr;
    }
    NumBytes = - SubTarget.getAdjustedFrameSize(NumBytes);
    emitSPAdjustment(MF, MBB, MBBI, NumBytes, SAVErr, SAVEri);

    MachineModuleInfo &MMI = MF.getMMI();
    const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
    MCSymbol *FrameLabel = MMI.getContext().CreateTempSymbol();
    BuildMI(MBB, MBBI, dl, TII.get(SP::PROLOG_LABEL)).addSym(FrameLabel);

    unsigned regFP = MRI->getDwarfRegNum(SP::I6, true);

    // Emit ".cfi_def_cfa_register 30".
    MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(FrameLabel,
                     regFP));
    // Emit ".cfi_window_save".
    MMI.addFrameInst(MCCFIInstruction::createWindowSave(FrameLabel));

    unsigned regInRA = MRI->getDwarfRegNum(SP::I7, true);
    unsigned regOutRA = MRI->getDwarfRegNum(SP::O7, true);
    // Emit ".cfi_register 15, 31".
    MMI.addFrameInst(MCCFIInstruction::createRegister(FrameLabel,
                     regOutRA,
                     regInRA));
}
Esempio n. 7
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void
SparcRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
                                       int SPAdj, unsigned FIOperandNum,
                                       RegScavenger *RS) const {
  assert(SPAdj == 0 && "Unexpected");

  MachineInstr &MI = *II;
  DebugLoc dl = MI.getDebugLoc();
  int FrameIndex = MI.getOperand(FIOperandNum).getIndex();

  // Addressable stack objects are accessed using neg. offsets from %fp
  MachineFunction &MF = *MI.getParent()->getParent();
  int64_t Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
                   MI.getOperand(FIOperandNum + 1).getImm() +
                   Subtarget.getStackPointerBias();
  SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();
  unsigned FramePtr = SP::I6;
  if (FuncInfo->isLeafProc()) {
    // Use %sp and adjust offset if needed.
    FramePtr = SP::O6;
    int stackSize = MF.getFrameInfo()->getStackSize();
    Offset += (stackSize) ? Subtarget.getAdjustedFrameSize(stackSize) : 0 ;
  }

  // Replace frame index with a frame pointer reference.
  if (Offset >= -4096 && Offset <= 4095) {
    // If the offset is small enough to fit in the immediate field, directly
    // encode it.
    MI.getOperand(FIOperandNum).ChangeToRegister(FramePtr, false);
    MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
  } else {
    // Otherwise, emit a G1 = SETHI %hi(offset).  FIXME: it would be better to
    // scavenge a register here instead of reserving G1 all of the time.
    const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
    unsigned OffHi = (unsigned)Offset >> 10U;
    BuildMI(*MI.getParent(), II, dl, TII.get(SP::SETHIi), SP::G1).addImm(OffHi);
    // Emit G1 = G1 + I6
    BuildMI(*MI.getParent(), II, dl, TII.get(SP::ADDrr), SP::G1).addReg(SP::G1)
      .addReg(FramePtr);
    // Insert: G1+%lo(offset) into the user.
    MI.getOperand(FIOperandNum).ChangeToRegister(SP::G1, false);
    MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset & ((1 << 10)-1));
  }
}
Esempio n. 8
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unsigned SparcInstrInfo::getGlobalBaseReg(MachineFunction *MF) const
{
  SparcMachineFunctionInfo *SparcFI = MF->getInfo<SparcMachineFunctionInfo>();
  unsigned GlobalBaseReg = SparcFI->getGlobalBaseReg();
  if (GlobalBaseReg != 0)
    return GlobalBaseReg;

  // Insert the set of GlobalBaseReg into the first MBB of the function
  MachineBasicBlock &FirstMBB = MF->front();
  MachineBasicBlock::iterator MBBI = FirstMBB.begin();
  MachineRegisterInfo &RegInfo = MF->getRegInfo();

  GlobalBaseReg = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);


  DebugLoc dl;

  BuildMI(FirstMBB, MBBI, dl, get(SP::GETPCX), GlobalBaseReg);
  SparcFI->setGlobalBaseReg(GlobalBaseReg);
  return GlobalBaseReg;
}
void SparcFrameLowering::emitEpilogue(MachineFunction &MF,
                                      MachineBasicBlock &MBB) const {
    SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();
    MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
    const SparcInstrInfo &TII =
        *static_cast<const SparcInstrInfo*>(MF.getTarget().getInstrInfo());
    DebugLoc dl = MBBI->getDebugLoc();
    assert(MBBI->getOpcode() == SP::RETL &&
           "Can only put epilog before 'retl' instruction!");
    if (!FuncInfo->isLeafProc()) {
        BuildMI(MBB, MBBI, dl, TII.get(SP::RESTORErr), SP::G0).addReg(SP::G0)
        .addReg(SP::G0);
        return;
    }
    MachineFrameInfo *MFI = MF.getFrameInfo();

    int NumBytes = (int) MFI->getStackSize();
    if (NumBytes == 0)
        return;

    NumBytes = SubTarget.getAdjustedFrameSize(NumBytes);
    emitSPAdjustment(MF, MBB, MBBI, NumBytes, SP::ADDrr, SP::ADDri);
}
Esempio n. 10
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/// LowerFormalArguments - 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.
SDValue
SparcTargetLowering::LowerFormalArguments(SDValue Chain,
                                          CallingConv::ID CallConv, bool isVarArg,
                                          const SmallVectorImpl<ISD::InputArg>
                                            &Ins,
                                          DebugLoc dl, SelectionDAG &DAG,
                                          SmallVectorImpl<SDValue> &InVals)
                                            const {

  MachineFunction &MF = DAG.getMachineFunction();
  MachineRegisterInfo &RegInfo = MF.getRegInfo();
  SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();

  // Assign locations to all of the incoming arguments.
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
                 ArgLocs, *DAG.getContext());
  CCInfo.AnalyzeFormalArguments(Ins, CC_Sparc32);

  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;

  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
    SDValue ArgValue;
    CCValAssign &VA = ArgLocs[i];
    // FIXME: We ignore the register assignments of AnalyzeFormalArguments
    // because it doesn't know how to split a double into two i32 registers.
    EVT ObjectVT = VA.getValVT();
    switch (ObjectVT.getSimpleVT().SimpleTy) {
    default: llvm_unreachable("Unhandled argument type!");
    case MVT::i1:
    case MVT::i8:
    case MVT::i16:
    case MVT::i32:
      if (!Ins[i].Used) {                  // Argument is dead.
        if (CurArgReg < ArgRegEnd) ++CurArgReg;
        InVals.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(Chain, 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);
        }
        InVals.push_back(Arg);
      } else {
        int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset,
                                                            true, false);
        SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
        SDValue Load;
        if (ObjectVT == MVT::i32) {
          Load = DAG.getLoad(MVT::i32, dl, Chain, FIPtr, NULL, 0,
                             false, false, 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, Chain, FIPtr,
                                NULL, 0, ObjectVT, false, false, 0);
          Load = DAG.getNode(ISD::TRUNCATE, dl, ObjectVT, Load);
        }
        InVals.push_back(Load);
      }

      ArgOffset += 4;
      break;
    case MVT::f32:
      if (!Ins[i].Used) {                  // Argument is dead.
        if (CurArgReg < ArgRegEnd) ++CurArgReg;
        InVals.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(Chain, dl, VReg, MVT::i32);

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

    case MVT::i64:
    case MVT::f64:
      if (!Ins[i].Used) {                // Argument is dead.
        if (CurArgReg < ArgRegEnd) ++CurArgReg;
        if (CurArgReg < ArgRegEnd) ++CurArgReg;
        InVals.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(Chain, dl, VRegHi, MVT::i32);
        } else {
          int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset,
                                                              true, false);
          SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
          HiVal = DAG.getLoad(MVT::i32, dl, Chain, FIPtr, NULL, 0,
                              false, false, 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(Chain, dl, VRegLo, MVT::i32);
        } else {
          int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset+4,
                                                              true, false);
          SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
          LoVal = DAG.getLoad(MVT::i32, dl, Chain, FIPtr, NULL, 0,
                              false, false, 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);

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

  // Store remaining ArgRegs to the stack if this is a varargs function.
  if (isVarArg) {
    // Remember the vararg offset for the va_start implementation.
    FuncInfo->setVarArgsFrameOffset(ArgOffset);

    std::vector<SDValue> OutChains;

    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,
                                                          true, false);
      SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);

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

    if (!OutChains.empty()) {
      OutChains.push_back(Chain);
      Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
                          &OutChains[0], OutChains.size());
    }
  }

  return Chain;
}
SDValue
SparcTargetLowering::LowerReturn(SDValue Chain,
                                 CallingConv::ID CallConv, bool isVarArg,
                                 const SmallVectorImpl<ISD::OutputArg> &Outs,
                                 const SmallVectorImpl<SDValue> &OutVals,
                                 DebugLoc dl, SelectionDAG &DAG) const {

  MachineFunction &MF = DAG.getMachineFunction();

  // CCValAssign - represent the assignment of the return value to locations.
  SmallVector<CCValAssign, 16> RVLocs;

  // CCState - Info about the registers and stack slot.
  CCState CCInfo(CallConv, isVarArg, DAG.getTarget(),
                 RVLocs, *DAG.getContext());

  // Analize return values.
  CCInfo.AnalyzeReturn(Outs, RetCC_Sparc32);

  // If this is the first return lowered for this function, add the regs to the
  // liveout set for the function.
  if (MF.getRegInfo().liveout_empty()) {
    for (unsigned i = 0; i != RVLocs.size(); ++i)
      if (RVLocs[i].isRegLoc())
        MF.getRegInfo().addLiveOut(RVLocs[i].getLocReg());
  }

  SDValue Flag;

  // Copy the result values into the output registers.
  for (unsigned i = 0; i != RVLocs.size(); ++i) {
    CCValAssign &VA = RVLocs[i];
    assert(VA.isRegLoc() && "Can only return in registers!");

    Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
                             OutVals[i], Flag);

    // Guarantee that all emitted copies are stuck together with flags.
    Flag = Chain.getValue(1);
  }

  unsigned RetAddrOffset = 8; //Call Inst + Delay Slot
  // If the function returns a struct, copy the SRetReturnReg to I0
  if (MF.getFunction()->hasStructRetAttr()) {
    SparcMachineFunctionInfo *SFI = MF.getInfo<SparcMachineFunctionInfo>();
    unsigned Reg = SFI->getSRetReturnReg();
    if (!Reg)
      llvm_unreachable("sret virtual register not created in the entry block");
    SDValue Val = DAG.getCopyFromReg(Chain, dl, Reg, getPointerTy());
    Chain = DAG.getCopyToReg(Chain, dl, SP::I0, Val, Flag);
    Flag = Chain.getValue(1);
    if (MF.getRegInfo().liveout_empty())
      MF.getRegInfo().addLiveOut(SP::I0);
    RetAddrOffset = 12; // CallInst + Delay Slot + Unimp
  }

  SDValue RetAddrOffsetNode = DAG.getConstant(RetAddrOffset, MVT::i32);

  if (Flag.getNode())
    return DAG.getNode(SPISD::RET_FLAG, dl, MVT::Other, Chain,
                       RetAddrOffsetNode, Flag);
  return DAG.getNode(SPISD::RET_FLAG, dl, MVT::Other, Chain, 
                     RetAddrOffsetNode);
}
/// LowerFormalArguments - 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.
SDValue
SparcTargetLowering::LowerFormalArguments(SDValue Chain,
                                          CallingConv::ID CallConv, bool isVarArg,
                                          const SmallVectorImpl<ISD::InputArg>
                                            &Ins,
                                          DebugLoc dl, SelectionDAG &DAG,
                                          SmallVectorImpl<SDValue> &InVals)
                                            const {

  MachineFunction &MF = DAG.getMachineFunction();
  MachineRegisterInfo &RegInfo = MF.getRegInfo();
  SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();

  // Assign locations to all of the incoming arguments.
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
                 ArgLocs, *DAG.getContext());
  CCInfo.AnalyzeFormalArguments(Ins, CC_Sparc32);

  const unsigned StackOffset = 92;

  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
    CCValAssign &VA = ArgLocs[i];

    if (i == 0  && Ins[i].Flags.isSRet()) {
      //Get SRet from [%fp+64]
      int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, 64, true);
      SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
      SDValue Arg = DAG.getLoad(MVT::i32, dl, Chain, FIPtr,
                                MachinePointerInfo(),
                                false, false, 0);
      InVals.push_back(Arg);
      continue;
    }

    if (VA.isRegLoc()) {
      if (VA.needsCustom()) {
        assert(VA.getLocVT() == MVT::f64);
        unsigned VRegHi = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
        MF.getRegInfo().addLiveIn(VA.getLocReg(), VRegHi);
        SDValue HiVal = DAG.getCopyFromReg(Chain, dl, VRegHi, MVT::i32);

        assert(i+1 < e);
        CCValAssign &NextVA = ArgLocs[++i];

        SDValue LoVal;
        if (NextVA.isMemLoc()) {
          int FrameIdx = MF.getFrameInfo()->
            CreateFixedObject(4, StackOffset+NextVA.getLocMemOffset(),true);
          SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
          LoVal = DAG.getLoad(MVT::i32, dl, Chain, FIPtr,
                              MachinePointerInfo(),
                              false, false, 0);
        } else {
          unsigned loReg = MF.addLiveIn(NextVA.getLocReg(),
                                        &SP::IntRegsRegClass);
          LoVal = DAG.getCopyFromReg(Chain, dl, loReg, MVT::i32);
        }
        SDValue WholeValue =
          DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, LoVal, HiVal);
        WholeValue = DAG.getNode(ISD::BITCAST, dl, MVT::f64, WholeValue);
        InVals.push_back(WholeValue);
        continue;
      }
      unsigned VReg = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
      MF.getRegInfo().addLiveIn(VA.getLocReg(), VReg);
      SDValue Arg = DAG.getCopyFromReg(Chain, dl, VReg, MVT::i32);
      if (VA.getLocVT() == MVT::f32)
        Arg = DAG.getNode(ISD::BITCAST, dl, MVT::f32, Arg);
      else if (VA.getLocVT() != MVT::i32) {
        Arg = DAG.getNode(ISD::AssertSext, dl, MVT::i32, Arg,
                          DAG.getValueType(VA.getLocVT()));
        Arg = DAG.getNode(ISD::TRUNCATE, dl, VA.getLocVT(), Arg);
      }
      InVals.push_back(Arg);
      continue;
    }

    assert(VA.isMemLoc());

    unsigned Offset = VA.getLocMemOffset()+StackOffset;

    if (VA.needsCustom()) {
      assert(VA.getValVT() == MVT::f64);
      //If it is double-word aligned, just load.
      if (Offset % 8 == 0) {
        int FI = MF.getFrameInfo()->CreateFixedObject(8,
                                                      Offset,
                                                      true);
        SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy());
        SDValue Load = DAG.getLoad(VA.getValVT(), dl, Chain, FIPtr,
                                   MachinePointerInfo(),
                                   false,false, 0);
        InVals.push_back(Load);
        continue;
      }

      int FI = MF.getFrameInfo()->CreateFixedObject(4,
                                                    Offset,
                                                    true);
      SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy());
      SDValue HiVal = DAG.getLoad(MVT::i32, dl, Chain, FIPtr,
                                  MachinePointerInfo(),
                                  false, false, 0);
      int FI2 = MF.getFrameInfo()->CreateFixedObject(4,
                                                     Offset+4,
                                                     true);
      SDValue FIPtr2 = DAG.getFrameIndex(FI2, getPointerTy());

      SDValue LoVal = DAG.getLoad(MVT::i32, dl, Chain, FIPtr2,
                                  MachinePointerInfo(),
                                  false, false, 0);

      SDValue WholeValue =
        DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, LoVal, HiVal);
      WholeValue = DAG.getNode(ISD::BITCAST, dl, MVT::f64, WholeValue);
      InVals.push_back(WholeValue);
      continue;
    }

    int FI = MF.getFrameInfo()->CreateFixedObject(4,
                                                  Offset,
                                                  true);
    SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy());
    SDValue Load ;
    if (VA.getValVT() == MVT::i32 || VA.getValVT() == MVT::f32) {
      Load = DAG.getLoad(VA.getValVT(), dl, Chain, FIPtr,
                         MachinePointerInfo(),
                         false, false, 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, VA.getValVT().getSizeInBits()/8);
      FIPtr = DAG.getNode(ISD::ADD, dl, MVT::i32, FIPtr,
                          DAG.getConstant(Offset, MVT::i32));
      Load = DAG.getExtLoad(LoadOp, dl, MVT::i32, Chain, FIPtr,
                            MachinePointerInfo(),
                            VA.getValVT(), false, false,0);
      Load = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), Load);
    }
    InVals.push_back(Load);
  }

  if (MF.getFunction()->hasStructRetAttr()) {
    //Copy the SRet Argument to SRetReturnReg
    SparcMachineFunctionInfo *SFI = MF.getInfo<SparcMachineFunctionInfo>();
    unsigned Reg = SFI->getSRetReturnReg();
    if (!Reg) {
      Reg = MF.getRegInfo().createVirtualRegister(&SP::IntRegsRegClass);
      SFI->setSRetReturnReg(Reg);
    }
    SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), dl, Reg, InVals[0]);
    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Copy, Chain);
  }

  // Store remaining ArgRegs to the stack if this is a varargs function.
  if (isVarArg) {
    static const unsigned ArgRegs[] = {
      SP::I0, SP::I1, SP::I2, SP::I3, SP::I4, SP::I5
    };
    unsigned NumAllocated = CCInfo.getFirstUnallocated(ArgRegs, 6);
    const unsigned *CurArgReg = ArgRegs+NumAllocated, *ArgRegEnd = ArgRegs+6;
    unsigned ArgOffset = CCInfo.getNextStackOffset();
    if (NumAllocated == 6)
      ArgOffset += StackOffset;
    else {
      assert(!ArgOffset);
      ArgOffset = 68+4*NumAllocated;
    }

    // Remember the vararg offset for the va_start implementation.
    FuncInfo->setVarArgsFrameOffset(ArgOffset);

    std::vector<SDValue> OutChains;

    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,
                                                          true);
      SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);

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

    if (!OutChains.empty()) {
      OutChains.push_back(Chain);
      Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
                          &OutChains[0], OutChains.size());
    }
  }

  return Chain;
}