lib/Target/Sparc/SparcISelDAGToDAG.cpp - fp2-dev/platform/external/llvm - Gitiles

 //===-- SparcV8ISelDAGToDAG.cpp - A dag to dag inst selector for SparcV8 --===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file was developed by Chris Lattner and is distributed under
 // the University of Illinois Open Source License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines an instruction selector for the V8 target
 //
 //===----------------------------------------------------------------------===//

 #include "SparcV8.h"
 #include "SparcV8TargetMachine.h"
 #include "llvm/Function.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/SelectionDAG.h"
 #include "llvm/CodeGen/SelectionDAGISel.h"
 #include "llvm/CodeGen/SSARegMap.h"
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Support/Debug.h"
 #include <iostream>
 using namespace llvm;

 //===----------------------------------------------------------------------===//
 // TargetLowering Implementation
 //===----------------------------------------------------------------------===//

 namespace V8ISD {
   enum {
     FIRST_NUMBER = ISD::BUILTIN_OP_END+V8::INSTRUCTION_LIST_END,
     CMPICC,   // Compare two GPR operands, set icc.
     CMPFCC,   // Compare two FP operands, set fcc.
     BRICC,    // Branch to dest on icc condition
     BRFCC,    // Branch to dest on fcc condition
   };
 }

 namespace {
   class SparcV8TargetLowering : public TargetLowering {
   public:
     SparcV8TargetLowering(TargetMachine &TM);
     virtual SDOperand LowerOperation(SDOperand Op, SelectionDAG &DAG);
     virtual std::vector<SDOperand>
       LowerArguments(Function &F, SelectionDAG &DAG);
     virtual std::pair<SDOperand, SDOperand>
       LowerCallTo(SDOperand Chain, const Type *RetTy, bool isVarArg,
                   unsigned CC,
                   bool isTailCall, SDOperand Callee, ArgListTy &Args,
                   SelectionDAG &DAG);

     virtual SDOperand LowerReturnTo(SDOperand Chain, SDOperand Op,
                                     SelectionDAG &DAG);
     virtual SDOperand LowerVAStart(SDOperand Chain, SDOperand VAListP,
                                    Value *VAListV, SelectionDAG &DAG);
     virtual std::pair<SDOperand,SDOperand>
       LowerVAArg(SDOperand Chain, SDOperand VAListP, Value *VAListV,
                  const Type *ArgTy, SelectionDAG &DAG);
     virtual std::pair<SDOperand, SDOperand>
       LowerFrameReturnAddress(bool isFrameAddr, SDOperand Chain, unsigned Depth,
                               SelectionDAG &DAG);
   };
 }

 SparcV8TargetLowering::SparcV8TargetLowering(TargetMachine &TM)
   : TargetLowering(TM) {

   // Set up the register classes.
   addRegisterClass(MVT::i32, V8::IntRegsRegisterClass);
   addRegisterClass(MVT::f32, V8::FPRegsRegisterClass);
   addRegisterClass(MVT::f64, V8::DFPRegsRegisterClass);

   // Sparc doesn't have sext_inreg, replace them with shl/sra
   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16  , Expand);
   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8   , Expand);
   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1   , Expand);

   // Sparc has no REM operation.
   setOperationAction(ISD::UREM, MVT::i32, Expand);
   setOperationAction(ISD::SREM, MVT::i32, Expand);

   // Sparc has no select or setcc: expand to SELECT_CC.
   setOperationAction(ISD::SELECT, MVT::i32, Expand);
   setOperationAction(ISD::SELECT, MVT::f32, Expand);
   setOperationAction(ISD::SELECT, MVT::f64, Expand);
   setOperationAction(ISD::SETCC, MVT::i32, Expand);
   setOperationAction(ISD::SETCC, MVT::f32, Expand);
   setOperationAction(ISD::SETCC, MVT::f64, Expand);

   // Sparc doesn't have BRCOND either, it has BR_CC.
   setOperationAction(ISD::BRCOND, MVT::Other, Expand);
   setOperationAction(ISD::BRCONDTWOWAY, MVT::Other, Expand);
   setOperationAction(ISD::BRTWOWAY_CC, MVT::Other, Expand);
   setOperationAction(ISD::BR_CC, MVT::i32, Custom);
   setOperationAction(ISD::BR_CC, MVT::f32, Custom);
   setOperationAction(ISD::BR_CC, MVT::f64, Custom);

   computeRegisterProperties();
 }

 std::vector<SDOperand>
 SparcV8TargetLowering::LowerArguments(Function &F, SelectionDAG &DAG) {
   MachineFunction &MF = DAG.getMachineFunction();
   SSARegMap *RegMap = MF.getSSARegMap();
   std::vector<SDOperand> ArgValues;

   static const unsigned GPR[] = {
     V8::I0, V8::I1, V8::I2, V8::I3, V8::I4, V8::I5
   };
   unsigned ArgNo = 0;
   for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I) {
     MVT::ValueType ObjectVT = getValueType(I->getType());
     assert(ArgNo < 6 && "Only args in regs for now");

     switch (ObjectVT) {
     default: assert(0 && "Unhandled argument type!");
     // TODO: MVT::i64 & FP
     case MVT::i1:
     case MVT::i8:
     case MVT::i16:
     case MVT::i32: {
       unsigned VReg = RegMap->createVirtualRegister(&V8::IntRegsRegClass);
       MF.addLiveIn(GPR[ArgNo++], VReg);
       SDOperand Arg = DAG.getCopyFromReg(DAG.getRoot(), VReg, MVT::i32);
       DAG.setRoot(Arg.getValue(1));
       if (ObjectVT != MVT::i32) {
         unsigned AssertOp = I->getType()->isSigned() ? ISD::AssertSext
                                                      : ISD::AssertZext;
         Arg = DAG.getNode(AssertOp, MVT::i32, Arg,
                           DAG.getValueType(ObjectVT));
         Arg = DAG.getNode(ISD::TRUNCATE, ObjectVT, Arg);
       }
       ArgValues.push_back(Arg);
       break;
     }
     case MVT::i64: {
       unsigned VRegHi = RegMap->createVirtualRegister(&V8::IntRegsRegClass);
       MF.addLiveIn(GPR[ArgNo++], VRegHi);
       unsigned VRegLo = RegMap->createVirtualRegister(&V8::IntRegsRegClass);
       MF.addLiveIn(GPR[ArgNo++], VRegLo);
       SDOperand ArgLo = DAG.getCopyFromReg(DAG.getRoot(), VRegLo, MVT::i32);
       SDOperand ArgHi = DAG.getCopyFromReg(ArgLo.getValue(1), VRegHi, MVT::i32);
       DAG.setRoot(ArgHi.getValue(1));
       ArgValues.push_back(DAG.getNode(ISD::BUILD_PAIR, MVT::i64, ArgLo, ArgHi));
       break;
     }
     }
   }

   assert(!F.isVarArg() && "Unimp");

   // Finally, inform the code generator which regs we return values in.
   switch (getValueType(F.getReturnType())) {
   default: assert(0 && "Unknown type!");
   case MVT::isVoid: break;
   case MVT::i1:
   case MVT::i8:
   case MVT::i16:
   case MVT::i32:
     MF.addLiveOut(V8::I0);
     break;
   case MVT::i64:
     MF.addLiveOut(V8::I0);
     MF.addLiveOut(V8::I1);
     break;
   case MVT::f32:
     MF.addLiveOut(V8::F0);
     break;
   case MVT::f64:
     MF.addLiveOut(V8::D0);
     break;
   }

   return ArgValues;
 }

 std::pair<SDOperand, SDOperand>
 SparcV8TargetLowering::LowerCallTo(SDOperand Chain, const Type *RetTy,
                                    bool isVarArg, unsigned CC,
                                    bool isTailCall, SDOperand Callee,
                                    ArgListTy &Args, SelectionDAG &DAG) {
   assert(0 && "Unimp");
   abort();
 }

 SDOperand SparcV8TargetLowering::LowerReturnTo(SDOperand Chain, SDOperand Op,
                                                SelectionDAG &DAG) {
   if (Op.getValueType() == MVT::i64) {
     SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op,
                                DAG.getConstant(1, MVT::i32));
     SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op,
                                DAG.getConstant(0, MVT::i32));
     return DAG.getNode(ISD::RET, MVT::Other, Chain, Lo, Hi);
   } else {
     return DAG.getNode(ISD::RET, MVT::Other, Chain, Op);
   }
 }

 SDOperand SparcV8TargetLowering::
 LowerVAStart(SDOperand Chain, SDOperand VAListP, Value *VAListV,
              SelectionDAG &DAG) {

   assert(0 && "Unimp");
   abort();
 }

 std::pair<SDOperand,SDOperand> SparcV8TargetLowering::
 LowerVAArg(SDOperand Chain, SDOperand VAListP, Value *VAListV,
            const Type *ArgTy, SelectionDAG &DAG) {
   assert(0 && "Unimp");
   abort();
 }

 std::pair<SDOperand, SDOperand> SparcV8TargetLowering::
 LowerFrameReturnAddress(bool isFrameAddr, SDOperand Chain, unsigned Depth,
                         SelectionDAG &DAG) {
   assert(0 && "Unimp");
   abort();
 }

 SDOperand SparcV8TargetLowering::
 LowerOperation(SDOperand Op, SelectionDAG &DAG) {
   switch (Op.getOpcode()) {
   default: assert(0 && "Should not custom lower this!");
   case ISD::BR_CC: {
     SDOperand Chain = Op.getOperand(0);
     SDOperand CC = Op.getOperand(1);
     SDOperand LHS = Op.getOperand(2);
     SDOperand RHS = Op.getOperand(3);
     SDOperand Dest = Op.getOperand(4);

     // Get the condition flag.
     if (LHS.getValueType() == MVT::i32) {
       SDOperand Cond = DAG.getNode(V8ISD::CMPICC, MVT::Flag, LHS, RHS);
       return DAG.getNode(V8ISD::BRICC, MVT::Other, Chain, Dest, CC, Cond);
     } else {
       SDOperand Cond = DAG.getNode(V8ISD::CMPFCC, MVT::Flag, LHS, RHS);
       return DAG.getNode(V8ISD::BRFCC, MVT::Other, Chain, Dest, CC, Cond);
     }
   }
   }
 }


 //===----------------------------------------------------------------------===//
 // Instruction Selector Implementation
 //===----------------------------------------------------------------------===//

 //===--------------------------------------------------------------------===//
 /// SparcV8DAGToDAGISel - PPC specific code to select Sparc V8 machine
 /// instructions for SelectionDAG operations.
 ///
 namespace {
 class SparcV8DAGToDAGISel : public SelectionDAGISel {
   SparcV8TargetLowering V8Lowering;
 public:
   SparcV8DAGToDAGISel(TargetMachine &TM)
     : SelectionDAGISel(V8Lowering), V8Lowering(TM) {}

   SDOperand Select(SDOperand Op);

   // Complex Pattern Selectors.
   bool SelectADDRrr(SDOperand N, SDOperand &R1, SDOperand &R2);
   bool SelectADDRri(SDOperand N, SDOperand &Base, SDOperand &Offset);

   /// InstructionSelectBasicBlock - This callback is invoked by
   /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
   virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);

   virtual const char *getPassName() const {
     return "PowerPC DAG->DAG Pattern Instruction Selection";
   }

   // Include the pieces autogenerated from the target description.
 #include "SparcV8GenDAGISel.inc"
 };
 }  // end anonymous namespace

 /// InstructionSelectBasicBlock - This callback is invoked by
 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
 void SparcV8DAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
   DEBUG(BB->dump());

   // Select target instructions for the DAG.
   DAG.setRoot(Select(DAG.getRoot()));
   CodeGenMap.clear();
   DAG.RemoveDeadNodes();

   // Emit machine code to BB.
   ScheduleAndEmitDAG(DAG);
 }

 bool SparcV8DAGToDAGISel::SelectADDRrr(SDOperand Addr, SDOperand &R1,
                                        SDOperand &R2) {
   if (Addr.getOpcode() == ISD::ADD) {
     if (isa<ConstantSDNode>(Addr.getOperand(1)) &&
         Predicate_simm13(Addr.getOperand(1).Val))
       return false;  // Let the reg+imm pattern catch this!
     R1 = Addr.getOperand(0);
     R2 = Addr.getOperand(1);
     return true;
   }

   R1 = Select(Addr);
   R2 = CurDAG->getRegister(V8::G0, MVT::i32);
   return true;
 }

 bool SparcV8DAGToDAGISel::SelectADDRri(SDOperand Addr, SDOperand &Base,
                                        SDOperand &Offset) {
   if (Addr.getOpcode() == ISD::ADD) {
     if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1)))
       if (Predicate_simm13(CN)) {
         Base = Addr.getOperand(0);
         Offset = CurDAG->getTargetConstant(CN->getValue(), MVT::i32);
         return true;
       }
   }
   Base = Select(Addr);
   Offset = CurDAG->getTargetConstant(0, MVT::i32);
   return true;
 }


 SDOperand SparcV8DAGToDAGISel::Select(SDOperand Op) {
   SDNode *N = Op.Val;
   if (N->getOpcode() >= ISD::BUILTIN_OP_END &&
       N->getOpcode() < V8ISD::FIRST_NUMBER)
     return Op;   // Already selected.
                  // If this has already been converted, use it.
   std::map<SDOperand, SDOperand>::iterator CGMI = CodeGenMap.find(Op);
   if (CGMI != CodeGenMap.end()) return CGMI->second;

   switch (N->getOpcode()) {
   default: break;
   case ISD::BasicBlock:         return CodeGenMap[Op] = Op;
   case V8ISD::CMPICC: {
     // FIXME: Handle compare with immediate.
     SDOperand LHS = Select(N->getOperand(0));
     SDOperand RHS = Select(N->getOperand(1));
     SDOperand Result = CurDAG->getTargetNode(V8::SUBCCrr, MVT::i32, MVT::Flag,
                                              LHS, RHS);
     return CodeGenMap[Op] = Result.getValue(1);
   }
   case ISD::ADD_PARTS: {
     SDOperand LHSL = Select(N->getOperand(0));
     SDOperand LHSH = Select(N->getOperand(1));
     SDOperand RHSL = Select(N->getOperand(2));
     SDOperand RHSH = Select(N->getOperand(3));
     // FIXME, handle immediate RHS.
     SDOperand Low = CurDAG->getTargetNode(V8::ADDCCrr, MVT::i32, MVT::Flag,
                                           LHSL, RHSL);
     SDOperand Hi  = CurDAG->getTargetNode(V8::ADDXrr, MVT::i32, LHSH, RHSH,
                                           Low.getValue(1));
     CodeGenMap[SDOperand(N, 0)] = Low;
     CodeGenMap[SDOperand(N, 1)] = Hi;
     return Op.ResNo ? Hi : Low;
   }
   case ISD::SUB_PARTS: {
     SDOperand LHSL = Select(N->getOperand(0));
     SDOperand LHSH = Select(N->getOperand(1));
     SDOperand RHSL = Select(N->getOperand(2));
     SDOperand RHSH = Select(N->getOperand(3));
     // FIXME, handle immediate RHS.
     SDOperand Low = CurDAG->getTargetNode(V8::SUBCCrr, MVT::i32, MVT::Flag,
                                           LHSL, RHSL);
     SDOperand Hi  = CurDAG->getTargetNode(V8::SUBXrr, MVT::i32, LHSH, RHSH,
                                           Low.getValue(1));
     CodeGenMap[SDOperand(N, 0)] = Low;
     CodeGenMap[SDOperand(N, 1)] = Hi;
     return Op.ResNo ? Hi : Low;
   }
   case ISD::SDIV:
   case ISD::UDIV: {
     // FIXME: should use a custom expander to expose the SRA to the dag.
     SDOperand DivLHS = Select(N->getOperand(0));
     SDOperand DivRHS = Select(N->getOperand(1));

     // Set the Y register to the high-part.
     SDOperand TopPart;
     if (N->getOpcode() == ISD::SDIV) {
       TopPart = CurDAG->getTargetNode(V8::SRAri, MVT::i32, DivLHS,
                                       CurDAG->getTargetConstant(31, MVT::i32));
     } else {
       TopPart = CurDAG->getRegister(V8::G0, MVT::i32);
     }
     TopPart = CurDAG->getTargetNode(V8::WRYrr, MVT::Flag, TopPart,
                                     CurDAG->getRegister(V8::G0, MVT::i32));

     // FIXME: Handle div by immediate.
     unsigned Opcode = N->getOpcode() == ISD::SDIV ? V8::SDIVrr : V8::UDIVrr;
     return CurDAG->SelectNodeTo(N, Opcode, MVT::i32, DivLHS, DivRHS, TopPart);
   }
   case ISD::MULHU:
   case ISD::MULHS: {
     // FIXME: Handle mul by immediate.
     SDOperand MulLHS = Select(N->getOperand(0));
     SDOperand MulRHS = Select(N->getOperand(1));
     unsigned Opcode = N->getOpcode() == ISD::MULHU ? V8::UMULrr : V8::SMULrr;
     SDOperand Mul = CurDAG->getTargetNode(Opcode, MVT::i32, MVT::Flag,
                                           MulLHS, MulRHS);
     // The high part is in the Y register.
     return CurDAG->SelectNodeTo(N, V8::RDY, MVT::i32, Mul.getValue(1));
   }

   case ISD::RET: {
     if (N->getNumOperands() == 2) {
       SDOperand Chain = Select(N->getOperand(0));     // Token chain.
       SDOperand Val = Select(N->getOperand(1));
       if (N->getOperand(1).getValueType() == MVT::i32) {
         Chain = CurDAG->getCopyToReg(Chain, V8::I0, Val);
       } else if (N->getOperand(1).getValueType() == MVT::f32) {
         Chain = CurDAG->getCopyToReg(Chain, V8::F0, Val);
       } else {
         assert(N->getOperand(1).getValueType() == MVT::f64);
         Chain = CurDAG->getCopyToReg(Chain, V8::D0, Val);
       }
       return CurDAG->SelectNodeTo(N, V8::RETL, MVT::Other, Chain);
     } else if (N->getNumOperands() > 1) {
       SDOperand Chain = Select(N->getOperand(0));     // Token chain.
       assert(N->getOperand(1).getValueType() == MVT::i32 &&
              N->getOperand(2).getValueType() == MVT::i32 &&
              N->getNumOperands() == 3 && "Unknown two-register ret value!");
       Chain = CurDAG->getCopyToReg(Chain, V8::I1, Select(N->getOperand(1)));
       Chain = CurDAG->getCopyToReg(Chain, V8::I0, Select(N->getOperand(2)));
       return CurDAG->SelectNodeTo(N, V8::RETL, MVT::Other, Chain);
     }
     break;  // Generated code handles the void case.
   }
   }

   return SelectCode(Op);
 }


 /// createPPCISelDag - This pass converts a legalized DAG into a
 /// PowerPC-specific DAG, ready for instruction scheduling.
 ///
 FunctionPass *llvm::createSparcV8ISelDag(TargetMachine &TM) {
   return new SparcV8DAGToDAGISel(TM);
 }
	//===-- SparcV8ISelDAGToDAG.cpp - A dag to dag inst selector for SparcV8 --===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file was developed by Chris Lattner and is distributed under
	// the University of Illinois Open Source License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file defines an instruction selector for the V8 target
	//
	//===----------------------------------------------------------------------===//

	#include "SparcV8.h"
	#include "SparcV8TargetMachine.h"
	#include "llvm/Function.h"
	#include "llvm/CodeGen/MachineFunction.h"
	#include "llvm/CodeGen/SelectionDAG.h"
	#include "llvm/CodeGen/SelectionDAGISel.h"
	#include "llvm/CodeGen/SSARegMap.h"
	#include "llvm/Target/TargetLowering.h"
	#include "llvm/Support/Debug.h"
	#include <iostream>
	using namespace llvm;

	//===----------------------------------------------------------------------===//
	// TargetLowering Implementation
	//===----------------------------------------------------------------------===//

	namespace V8ISD {
	enum {
	FIRST_NUMBER = ISD::BUILTIN_OP_END+V8::INSTRUCTION_LIST_END,
	CMPICC, // Compare two GPR operands, set icc.
	CMPFCC, // Compare two FP operands, set fcc.
	BRICC, // Branch to dest on icc condition
	BRFCC, // Branch to dest on fcc condition
	};
	}

	namespace {
	class SparcV8TargetLowering : public TargetLowering {
	public:
	SparcV8TargetLowering(TargetMachine &TM);
	virtual SDOperand LowerOperation(SDOperand Op, SelectionDAG &DAG);
	virtual std::vector<SDOperand>
	LowerArguments(Function &F, SelectionDAG &DAG);
	virtual std::pair<SDOperand, SDOperand>
	LowerCallTo(SDOperand Chain, const Type *RetTy, bool isVarArg,
	unsigned CC,
	bool isTailCall, SDOperand Callee, ArgListTy &Args,
	SelectionDAG &DAG);

	virtual SDOperand LowerReturnTo(SDOperand Chain, SDOperand Op,
	SelectionDAG &DAG);
	virtual SDOperand LowerVAStart(SDOperand Chain, SDOperand VAListP,
	Value *VAListV, SelectionDAG &DAG);
	virtual std::pair<SDOperand,SDOperand>
	LowerVAArg(SDOperand Chain, SDOperand VAListP, Value *VAListV,
	const Type *ArgTy, SelectionDAG &DAG);
	virtual std::pair<SDOperand, SDOperand>
	LowerFrameReturnAddress(bool isFrameAddr, SDOperand Chain, unsigned Depth,
	SelectionDAG &DAG);
	};
	}

	SparcV8TargetLowering::SparcV8TargetLowering(TargetMachine &TM)
	: TargetLowering(TM) {

	// Set up the register classes.
	addRegisterClass(MVT::i32, V8::IntRegsRegisterClass);
	addRegisterClass(MVT::f32, V8::FPRegsRegisterClass);
	addRegisterClass(MVT::f64, V8::DFPRegsRegisterClass);

	// Sparc doesn't have sext_inreg, replace them with shl/sra
	setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16 , Expand);
	setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8 , Expand);
	setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1 , Expand);

	// Sparc has no REM operation.
	setOperationAction(ISD::UREM, MVT::i32, Expand);
	setOperationAction(ISD::SREM, MVT::i32, Expand);

	// Sparc has no select or setcc: expand to SELECT_CC.
	setOperationAction(ISD::SELECT, MVT::i32, Expand);
	setOperationAction(ISD::SELECT, MVT::f32, Expand);
	setOperationAction(ISD::SELECT, MVT::f64, Expand);
	setOperationAction(ISD::SETCC, MVT::i32, Expand);
	setOperationAction(ISD::SETCC, MVT::f32, Expand);
	setOperationAction(ISD::SETCC, MVT::f64, Expand);

	// Sparc doesn't have BRCOND either, it has BR_CC.
	setOperationAction(ISD::BRCOND, MVT::Other, Expand);
	setOperationAction(ISD::BRCONDTWOWAY, MVT::Other, Expand);
	setOperationAction(ISD::BRTWOWAY_CC, MVT::Other, Expand);
	setOperationAction(ISD::BR_CC, MVT::i32, Custom);
	setOperationAction(ISD::BR_CC, MVT::f32, Custom);
	setOperationAction(ISD::BR_CC, MVT::f64, Custom);

	computeRegisterProperties();
	}

	std::vector<SDOperand>
	SparcV8TargetLowering::LowerArguments(Function &F, SelectionDAG &DAG) {
	MachineFunction &MF = DAG.getMachineFunction();
	SSARegMap *RegMap = MF.getSSARegMap();
	std::vector<SDOperand> ArgValues;

	static const unsigned GPR[] = {
	V8::I0, V8::I1, V8::I2, V8::I3, V8::I4, V8::I5
	};
	unsigned ArgNo = 0;
	for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I) {
	MVT::ValueType ObjectVT = getValueType(I->getType());
	assert(ArgNo < 6 && "Only args in regs for now");

	switch (ObjectVT) {
	default: assert(0 && "Unhandled argument type!");
	// TODO: MVT::i64 & FP
	case MVT::i1:
	case MVT::i8:
	case MVT::i16:
	case MVT::i32: {
	unsigned VReg = RegMap->createVirtualRegister(&V8::IntRegsRegClass);
	MF.addLiveIn(GPR[ArgNo++], VReg);
	SDOperand Arg = DAG.getCopyFromReg(DAG.getRoot(), VReg, MVT::i32);
	DAG.setRoot(Arg.getValue(1));
	if (ObjectVT != MVT::i32) {
	unsigned AssertOp = I->getType()->isSigned() ? ISD::AssertSext
	: ISD::AssertZext;
	Arg = DAG.getNode(AssertOp, MVT::i32, Arg,
	DAG.getValueType(ObjectVT));
	Arg = DAG.getNode(ISD::TRUNCATE, ObjectVT, Arg);
	}
	ArgValues.push_back(Arg);
	break;
	}
	case MVT::i64: {
	unsigned VRegHi = RegMap->createVirtualRegister(&V8::IntRegsRegClass);
	MF.addLiveIn(GPR[ArgNo++], VRegHi);
	unsigned VRegLo = RegMap->createVirtualRegister(&V8::IntRegsRegClass);
	MF.addLiveIn(GPR[ArgNo++], VRegLo);
	SDOperand ArgLo = DAG.getCopyFromReg(DAG.getRoot(), VRegLo, MVT::i32);
	SDOperand ArgHi = DAG.getCopyFromReg(ArgLo.getValue(1), VRegHi, MVT::i32);
	DAG.setRoot(ArgHi.getValue(1));
	ArgValues.push_back(DAG.getNode(ISD::BUILD_PAIR, MVT::i64, ArgLo, ArgHi));
	break;
	}
	}
	}

	assert(!F.isVarArg() && "Unimp");

	// Finally, inform the code generator which regs we return values in.
	switch (getValueType(F.getReturnType())) {
	default: assert(0 && "Unknown type!");
	case MVT::isVoid: break;
	case MVT::i1:
	case MVT::i8:
	case MVT::i16:
	case MVT::i32:
	MF.addLiveOut(V8::I0);
	break;
	case MVT::i64:
	MF.addLiveOut(V8::I0);
	MF.addLiveOut(V8::I1);
	break;
	case MVT::f32:
	MF.addLiveOut(V8::F0);
	break;
	case MVT::f64:
	MF.addLiveOut(V8::D0);
	break;
	}

	return ArgValues;
	}

	std::pair<SDOperand, SDOperand>
	SparcV8TargetLowering::LowerCallTo(SDOperand Chain, const Type *RetTy,
	bool isVarArg, unsigned CC,
	bool isTailCall, SDOperand Callee,
	ArgListTy &Args, SelectionDAG &DAG) {
	assert(0 && "Unimp");
	abort();
	}

	SDOperand SparcV8TargetLowering::LowerReturnTo(SDOperand Chain, SDOperand Op,
	SelectionDAG &DAG) {
	if (Op.getValueType() == MVT::i64) {
	SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op,
	DAG.getConstant(1, MVT::i32));
	SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32, Op,
	DAG.getConstant(0, MVT::i32));
	return DAG.getNode(ISD::RET, MVT::Other, Chain, Lo, Hi);
	} else {
	return DAG.getNode(ISD::RET, MVT::Other, Chain, Op);
	}
	}

	SDOperand SparcV8TargetLowering::
	LowerVAStart(SDOperand Chain, SDOperand VAListP, Value *VAListV,
	SelectionDAG &DAG) {

	assert(0 && "Unimp");
	abort();
	}

	std::pair<SDOperand,SDOperand> SparcV8TargetLowering::
	LowerVAArg(SDOperand Chain, SDOperand VAListP, Value *VAListV,
	const Type *ArgTy, SelectionDAG &DAG) {
	assert(0 && "Unimp");
	abort();
	}

	std::pair<SDOperand, SDOperand> SparcV8TargetLowering::
	LowerFrameReturnAddress(bool isFrameAddr, SDOperand Chain, unsigned Depth,
	SelectionDAG &DAG) {
	assert(0 && "Unimp");
	abort();
	}

	SDOperand SparcV8TargetLowering::
	LowerOperation(SDOperand Op, SelectionDAG &DAG) {
	switch (Op.getOpcode()) {
	default: assert(0 && "Should not custom lower this!");
	case ISD::BR_CC: {
	SDOperand Chain = Op.getOperand(0);
	SDOperand CC = Op.getOperand(1);
	SDOperand LHS = Op.getOperand(2);
	SDOperand RHS = Op.getOperand(3);
	SDOperand Dest = Op.getOperand(4);

	// Get the condition flag.
	if (LHS.getValueType() == MVT::i32) {
	SDOperand Cond = DAG.getNode(V8ISD::CMPICC, MVT::Flag, LHS, RHS);
	return DAG.getNode(V8ISD::BRICC, MVT::Other, Chain, Dest, CC, Cond);
	} else {
	SDOperand Cond = DAG.getNode(V8ISD::CMPFCC, MVT::Flag, LHS, RHS);
	return DAG.getNode(V8ISD::BRFCC, MVT::Other, Chain, Dest, CC, Cond);
	}
	}
	}
	}


	//===----------------------------------------------------------------------===//
	// Instruction Selector Implementation
	//===----------------------------------------------------------------------===//

	//===--------------------------------------------------------------------===//
	/// SparcV8DAGToDAGISel - PPC specific code to select Sparc V8 machine
	/// instructions for SelectionDAG operations.
	///
	namespace {
	class SparcV8DAGToDAGISel : public SelectionDAGISel {
	SparcV8TargetLowering V8Lowering;
	public:
	SparcV8DAGToDAGISel(TargetMachine &TM)
	: SelectionDAGISel(V8Lowering), V8Lowering(TM) {}

	SDOperand Select(SDOperand Op);

	// Complex Pattern Selectors.
	bool SelectADDRrr(SDOperand N, SDOperand &R1, SDOperand &R2);
	bool SelectADDRri(SDOperand N, SDOperand &Base, SDOperand &Offset);

	/// InstructionSelectBasicBlock - This callback is invoked by
	/// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
	virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);

	virtual const char *getPassName() const {
	return "PowerPC DAG->DAG Pattern Instruction Selection";
	}

	// Include the pieces autogenerated from the target description.
	#include "SparcV8GenDAGISel.inc"
	};
	} // end anonymous namespace

	/// InstructionSelectBasicBlock - This callback is invoked by
	/// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
	void SparcV8DAGToDAGISel::InstructionSelectBasicBlock(SelectionDAG &DAG) {
	DEBUG(BB->dump());

	// Select target instructions for the DAG.
	DAG.setRoot(Select(DAG.getRoot()));
	CodeGenMap.clear();
	DAG.RemoveDeadNodes();

	// Emit machine code to BB.
	ScheduleAndEmitDAG(DAG);
	}

	bool SparcV8DAGToDAGISel::SelectADDRrr(SDOperand Addr, SDOperand &R1,
	SDOperand &R2) {
	if (Addr.getOpcode() == ISD::ADD) {
	if (isa<ConstantSDNode>(Addr.getOperand(1)) &&
	Predicate_simm13(Addr.getOperand(1).Val))
	return false; // Let the reg+imm pattern catch this!
	R1 = Addr.getOperand(0);
	R2 = Addr.getOperand(1);
	return true;
	}

	R1 = Select(Addr);
	R2 = CurDAG->getRegister(V8::G0, MVT::i32);
	return true;
	}

	bool SparcV8DAGToDAGISel::SelectADDRri(SDOperand Addr, SDOperand &Base,
	SDOperand &Offset) {
	if (Addr.getOpcode() == ISD::ADD) {
	if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1)))
	if (Predicate_simm13(CN)) {
	Base = Addr.getOperand(0);
	Offset = CurDAG->getTargetConstant(CN->getValue(), MVT::i32);
	return true;
	}
	}
	Base = Select(Addr);
	Offset = CurDAG->getTargetConstant(0, MVT::i32);
	return true;
	}


	SDOperand SparcV8DAGToDAGISel::Select(SDOperand Op) {
	SDNode *N = Op.Val;
	if (N->getOpcode() >= ISD::BUILTIN_OP_END &&
	N->getOpcode() < V8ISD::FIRST_NUMBER)
	return Op; // Already selected.
	// If this has already been converted, use it.
	std::map<SDOperand, SDOperand>::iterator CGMI = CodeGenMap.find(Op);
	if (CGMI != CodeGenMap.end()) return CGMI->second;

	switch (N->getOpcode()) {
	default: break;
	case ISD::BasicBlock: return CodeGenMap[Op] = Op;
	case V8ISD::CMPICC: {
	// FIXME: Handle compare with immediate.
	SDOperand LHS = Select(N->getOperand(0));
	SDOperand RHS = Select(N->getOperand(1));
	SDOperand Result = CurDAG->getTargetNode(V8::SUBCCrr, MVT::i32, MVT::Flag,
	LHS, RHS);
	return CodeGenMap[Op] = Result.getValue(1);
	}
	case ISD::ADD_PARTS: {
	SDOperand LHSL = Select(N->getOperand(0));
	SDOperand LHSH = Select(N->getOperand(1));
	SDOperand RHSL = Select(N->getOperand(2));
	SDOperand RHSH = Select(N->getOperand(3));
	// FIXME, handle immediate RHS.
	SDOperand Low = CurDAG->getTargetNode(V8::ADDCCrr, MVT::i32, MVT::Flag,
	LHSL, RHSL);
	SDOperand Hi = CurDAG->getTargetNode(V8::ADDXrr, MVT::i32, LHSH, RHSH,
	Low.getValue(1));
	CodeGenMap[SDOperand(N, 0)] = Low;
	CodeGenMap[SDOperand(N, 1)] = Hi;
	return Op.ResNo ? Hi : Low;
	}
	case ISD::SUB_PARTS: {
	SDOperand LHSL = Select(N->getOperand(0));
	SDOperand LHSH = Select(N->getOperand(1));
	SDOperand RHSL = Select(N->getOperand(2));
	SDOperand RHSH = Select(N->getOperand(3));
	// FIXME, handle immediate RHS.
	SDOperand Low = CurDAG->getTargetNode(V8::SUBCCrr, MVT::i32, MVT::Flag,
	LHSL, RHSL);
	SDOperand Hi = CurDAG->getTargetNode(V8::SUBXrr, MVT::i32, LHSH, RHSH,
	Low.getValue(1));
	CodeGenMap[SDOperand(N, 0)] = Low;
	CodeGenMap[SDOperand(N, 1)] = Hi;
	return Op.ResNo ? Hi : Low;
	}
	case ISD::SDIV:
	case ISD::UDIV: {
	// FIXME: should use a custom expander to expose the SRA to the dag.
	SDOperand DivLHS = Select(N->getOperand(0));
	SDOperand DivRHS = Select(N->getOperand(1));

	// Set the Y register to the high-part.
	SDOperand TopPart;
	if (N->getOpcode() == ISD::SDIV) {
	TopPart = CurDAG->getTargetNode(V8::SRAri, MVT::i32, DivLHS,
	CurDAG->getTargetConstant(31, MVT::i32));
	} else {
	TopPart = CurDAG->getRegister(V8::G0, MVT::i32);
	}
	TopPart = CurDAG->getTargetNode(V8::WRYrr, MVT::Flag, TopPart,
	CurDAG->getRegister(V8::G0, MVT::i32));

	// FIXME: Handle div by immediate.
	unsigned Opcode = N->getOpcode() == ISD::SDIV ? V8::SDIVrr : V8::UDIVrr;
	return CurDAG->SelectNodeTo(N, Opcode, MVT::i32, DivLHS, DivRHS, TopPart);
	}
	case ISD::MULHU:
	case ISD::MULHS: {
	// FIXME: Handle mul by immediate.
	SDOperand MulLHS = Select(N->getOperand(0));
	SDOperand MulRHS = Select(N->getOperand(1));
	unsigned Opcode = N->getOpcode() == ISD::MULHU ? V8::UMULrr : V8::SMULrr;
	SDOperand Mul = CurDAG->getTargetNode(Opcode, MVT::i32, MVT::Flag,
	MulLHS, MulRHS);
	// The high part is in the Y register.
	return CurDAG->SelectNodeTo(N, V8::RDY, MVT::i32, Mul.getValue(1));
	}

	case ISD::RET: {
	if (N->getNumOperands() == 2) {
	SDOperand Chain = Select(N->getOperand(0)); // Token chain.
	SDOperand Val = Select(N->getOperand(1));
	if (N->getOperand(1).getValueType() == MVT::i32) {
	Chain = CurDAG->getCopyToReg(Chain, V8::I0, Val);
	} else if (N->getOperand(1).getValueType() == MVT::f32) {
	Chain = CurDAG->getCopyToReg(Chain, V8::F0, Val);
	} else {
	assert(N->getOperand(1).getValueType() == MVT::f64);
	Chain = CurDAG->getCopyToReg(Chain, V8::D0, Val);
	}
	return CurDAG->SelectNodeTo(N, V8::RETL, MVT::Other, Chain);
	} else if (N->getNumOperands() > 1) {
	SDOperand Chain = Select(N->getOperand(0)); // Token chain.
	assert(N->getOperand(1).getValueType() == MVT::i32 &&
	N->getOperand(2).getValueType() == MVT::i32 &&
	N->getNumOperands() == 3 && "Unknown two-register ret value!");
	Chain = CurDAG->getCopyToReg(Chain, V8::I1, Select(N->getOperand(1)));
	Chain = CurDAG->getCopyToReg(Chain, V8::I0, Select(N->getOperand(2)));
	return CurDAG->SelectNodeTo(N, V8::RETL, MVT::Other, Chain);
	}
	break; // Generated code handles the void case.
	}
	}

	return SelectCode(Op);
	}


	/// createPPCISelDag - This pass converts a legalized DAG into a
	/// PowerPC-specific DAG, ready for instruction scheduling.
	///
	FunctionPass *llvm::createSparcV8ISelDag(TargetMachine &TM) {
	return new SparcV8DAGToDAGISel(TM);
	}