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      1 //===-- SparcISelLowering.cpp - Sparc DAG Lowering Implementation ---------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file implements the interfaces that Sparc uses to lower LLVM code into a
     11 // selection DAG.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #include "SparcISelLowering.h"
     16 #include "SparcTargetMachine.h"
     17 #include "SparcMachineFunctionInfo.h"
     18 #include "llvm/DerivedTypes.h"
     19 #include "llvm/Function.h"
     20 #include "llvm/Module.h"
     21 #include "llvm/CodeGen/CallingConvLower.h"
     22 #include "llvm/CodeGen/MachineFrameInfo.h"
     23 #include "llvm/CodeGen/MachineFunction.h"
     24 #include "llvm/CodeGen/MachineInstrBuilder.h"
     25 #include "llvm/CodeGen/MachineRegisterInfo.h"
     26 #include "llvm/CodeGen/SelectionDAG.h"
     27 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
     28 #include "llvm/Support/ErrorHandling.h"
     29 using namespace llvm;
     30 
     31 
     32 //===----------------------------------------------------------------------===//
     33 // Calling Convention Implementation
     34 //===----------------------------------------------------------------------===//
     35 
     36 static bool CC_Sparc_Assign_SRet(unsigned &ValNo, MVT &ValVT,
     37                                  MVT &LocVT, CCValAssign::LocInfo &LocInfo,
     38                                  ISD::ArgFlagsTy &ArgFlags, CCState &State)
     39 {
     40   assert (ArgFlags.isSRet());
     41 
     42   //Assign SRet argument
     43   State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT,
     44                                          0,
     45                                          LocVT, LocInfo));
     46   return true;
     47 }
     48 
     49 static bool CC_Sparc_Assign_f64(unsigned &ValNo, MVT &ValVT,
     50                                 MVT &LocVT, CCValAssign::LocInfo &LocInfo,
     51                                 ISD::ArgFlagsTy &ArgFlags, CCState &State)
     52 {
     53   static const uint16_t RegList[] = {
     54     SP::I0, SP::I1, SP::I2, SP::I3, SP::I4, SP::I5
     55   };
     56   //Try to get first reg
     57   if (unsigned Reg = State.AllocateReg(RegList, 6)) {
     58     State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
     59   } else {
     60     //Assign whole thing in stack
     61     State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT,
     62                                            State.AllocateStack(8,4),
     63                                            LocVT, LocInfo));
     64     return true;
     65   }
     66 
     67   //Try to get second reg
     68   if (unsigned Reg = State.AllocateReg(RegList, 6))
     69     State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
     70   else
     71     State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT,
     72                                            State.AllocateStack(4,4),
     73                                            LocVT, LocInfo));
     74   return true;
     75 }
     76 
     77 #include "SparcGenCallingConv.inc"
     78 
     79 SDValue
     80 SparcTargetLowering::LowerReturn(SDValue Chain,
     81                                  CallingConv::ID CallConv, bool isVarArg,
     82                                  const SmallVectorImpl<ISD::OutputArg> &Outs,
     83                                  const SmallVectorImpl<SDValue> &OutVals,
     84                                  DebugLoc dl, SelectionDAG &DAG) const {
     85 
     86   MachineFunction &MF = DAG.getMachineFunction();
     87 
     88   // CCValAssign - represent the assignment of the return value to locations.
     89   SmallVector<CCValAssign, 16> RVLocs;
     90 
     91   // CCState - Info about the registers and stack slot.
     92   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
     93 		 DAG.getTarget(), RVLocs, *DAG.getContext());
     94 
     95   // Analize return values.
     96   CCInfo.AnalyzeReturn(Outs, RetCC_Sparc32);
     97 
     98   // If this is the first return lowered for this function, add the regs to the
     99   // liveout set for the function.
    100   if (MF.getRegInfo().liveout_empty()) {
    101     for (unsigned i = 0; i != RVLocs.size(); ++i)
    102       if (RVLocs[i].isRegLoc())
    103         MF.getRegInfo().addLiveOut(RVLocs[i].getLocReg());
    104   }
    105 
    106   SDValue Flag;
    107 
    108   // Copy the result values into the output registers.
    109   for (unsigned i = 0; i != RVLocs.size(); ++i) {
    110     CCValAssign &VA = RVLocs[i];
    111     assert(VA.isRegLoc() && "Can only return in registers!");
    112 
    113     Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
    114                              OutVals[i], Flag);
    115 
    116     // Guarantee that all emitted copies are stuck together with flags.
    117     Flag = Chain.getValue(1);
    118   }
    119 
    120   unsigned RetAddrOffset = 8; //Call Inst + Delay Slot
    121   // If the function returns a struct, copy the SRetReturnReg to I0
    122   if (MF.getFunction()->hasStructRetAttr()) {
    123     SparcMachineFunctionInfo *SFI = MF.getInfo<SparcMachineFunctionInfo>();
    124     unsigned Reg = SFI->getSRetReturnReg();
    125     if (!Reg)
    126       llvm_unreachable("sret virtual register not created in the entry block");
    127     SDValue Val = DAG.getCopyFromReg(Chain, dl, Reg, getPointerTy());
    128     Chain = DAG.getCopyToReg(Chain, dl, SP::I0, Val, Flag);
    129     Flag = Chain.getValue(1);
    130     if (MF.getRegInfo().liveout_empty())
    131       MF.getRegInfo().addLiveOut(SP::I0);
    132     RetAddrOffset = 12; // CallInst + Delay Slot + Unimp
    133   }
    134 
    135   SDValue RetAddrOffsetNode = DAG.getConstant(RetAddrOffset, MVT::i32);
    136 
    137   if (Flag.getNode())
    138     return DAG.getNode(SPISD::RET_FLAG, dl, MVT::Other, Chain,
    139                        RetAddrOffsetNode, Flag);
    140   return DAG.getNode(SPISD::RET_FLAG, dl, MVT::Other, Chain,
    141                      RetAddrOffsetNode);
    142 }
    143 
    144 /// LowerFormalArguments - V8 uses a very simple ABI, where all values are
    145 /// passed in either one or two GPRs, including FP values.  TODO: we should
    146 /// pass FP values in FP registers for fastcc functions.
    147 SDValue
    148 SparcTargetLowering::LowerFormalArguments(SDValue Chain,
    149                                           CallingConv::ID CallConv, bool isVarArg,
    150                                           const SmallVectorImpl<ISD::InputArg>
    151                                             &Ins,
    152                                           DebugLoc dl, SelectionDAG &DAG,
    153                                           SmallVectorImpl<SDValue> &InVals)
    154                                             const {
    155 
    156   MachineFunction &MF = DAG.getMachineFunction();
    157   MachineRegisterInfo &RegInfo = MF.getRegInfo();
    158   SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();
    159 
    160   // Assign locations to all of the incoming arguments.
    161   SmallVector<CCValAssign, 16> ArgLocs;
    162   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
    163 		 getTargetMachine(), ArgLocs, *DAG.getContext());
    164   CCInfo.AnalyzeFormalArguments(Ins, CC_Sparc32);
    165 
    166   const unsigned StackOffset = 92;
    167 
    168   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
    169     CCValAssign &VA = ArgLocs[i];
    170 
    171     if (i == 0  && Ins[i].Flags.isSRet()) {
    172       //Get SRet from [%fp+64]
    173       int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, 64, true);
    174       SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
    175       SDValue Arg = DAG.getLoad(MVT::i32, dl, Chain, FIPtr,
    176                                 MachinePointerInfo(),
    177                                 false, false, false, 0);
    178       InVals.push_back(Arg);
    179       continue;
    180     }
    181 
    182     if (VA.isRegLoc()) {
    183       if (VA.needsCustom()) {
    184         assert(VA.getLocVT() == MVT::f64);
    185         unsigned VRegHi = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
    186         MF.getRegInfo().addLiveIn(VA.getLocReg(), VRegHi);
    187         SDValue HiVal = DAG.getCopyFromReg(Chain, dl, VRegHi, MVT::i32);
    188 
    189         assert(i+1 < e);
    190         CCValAssign &NextVA = ArgLocs[++i];
    191 
    192         SDValue LoVal;
    193         if (NextVA.isMemLoc()) {
    194           int FrameIdx = MF.getFrameInfo()->
    195             CreateFixedObject(4, StackOffset+NextVA.getLocMemOffset(),true);
    196           SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
    197           LoVal = DAG.getLoad(MVT::i32, dl, Chain, FIPtr,
    198                               MachinePointerInfo(),
    199                               false, false, false, 0);
    200         } else {
    201           unsigned loReg = MF.addLiveIn(NextVA.getLocReg(),
    202                                         &SP::IntRegsRegClass);
    203           LoVal = DAG.getCopyFromReg(Chain, dl, loReg, MVT::i32);
    204         }
    205         SDValue WholeValue =
    206           DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, LoVal, HiVal);
    207         WholeValue = DAG.getNode(ISD::BITCAST, dl, MVT::f64, WholeValue);
    208         InVals.push_back(WholeValue);
    209         continue;
    210       }
    211       unsigned VReg = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
    212       MF.getRegInfo().addLiveIn(VA.getLocReg(), VReg);
    213       SDValue Arg = DAG.getCopyFromReg(Chain, dl, VReg, MVT::i32);
    214       if (VA.getLocVT() == MVT::f32)
    215         Arg = DAG.getNode(ISD::BITCAST, dl, MVT::f32, Arg);
    216       else if (VA.getLocVT() != MVT::i32) {
    217         Arg = DAG.getNode(ISD::AssertSext, dl, MVT::i32, Arg,
    218                           DAG.getValueType(VA.getLocVT()));
    219         Arg = DAG.getNode(ISD::TRUNCATE, dl, VA.getLocVT(), Arg);
    220       }
    221       InVals.push_back(Arg);
    222       continue;
    223     }
    224 
    225     assert(VA.isMemLoc());
    226 
    227     unsigned Offset = VA.getLocMemOffset()+StackOffset;
    228 
    229     if (VA.needsCustom()) {
    230       assert(VA.getValVT() == MVT::f64);
    231       //If it is double-word aligned, just load.
    232       if (Offset % 8 == 0) {
    233         int FI = MF.getFrameInfo()->CreateFixedObject(8,
    234                                                       Offset,
    235                                                       true);
    236         SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy());
    237         SDValue Load = DAG.getLoad(VA.getValVT(), dl, Chain, FIPtr,
    238                                    MachinePointerInfo(),
    239                                    false,false, false, 0);
    240         InVals.push_back(Load);
    241         continue;
    242       }
    243 
    244       int FI = MF.getFrameInfo()->CreateFixedObject(4,
    245                                                     Offset,
    246                                                     true);
    247       SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy());
    248       SDValue HiVal = DAG.getLoad(MVT::i32, dl, Chain, FIPtr,
    249                                   MachinePointerInfo(),
    250                                   false, false, false, 0);
    251       int FI2 = MF.getFrameInfo()->CreateFixedObject(4,
    252                                                      Offset+4,
    253                                                      true);
    254       SDValue FIPtr2 = DAG.getFrameIndex(FI2, getPointerTy());
    255 
    256       SDValue LoVal = DAG.getLoad(MVT::i32, dl, Chain, FIPtr2,
    257                                   MachinePointerInfo(),
    258                                   false, false, false, 0);
    259 
    260       SDValue WholeValue =
    261         DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, LoVal, HiVal);
    262       WholeValue = DAG.getNode(ISD::BITCAST, dl, MVT::f64, WholeValue);
    263       InVals.push_back(WholeValue);
    264       continue;
    265     }
    266 
    267     int FI = MF.getFrameInfo()->CreateFixedObject(4,
    268                                                   Offset,
    269                                                   true);
    270     SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy());
    271     SDValue Load ;
    272     if (VA.getValVT() == MVT::i32 || VA.getValVT() == MVT::f32) {
    273       Load = DAG.getLoad(VA.getValVT(), dl, Chain, FIPtr,
    274                          MachinePointerInfo(),
    275                          false, false, false, 0);
    276     } else {
    277       ISD::LoadExtType LoadOp = ISD::SEXTLOAD;
    278       // Sparc is big endian, so add an offset based on the ObjectVT.
    279       unsigned Offset = 4-std::max(1U, VA.getValVT().getSizeInBits()/8);
    280       FIPtr = DAG.getNode(ISD::ADD, dl, MVT::i32, FIPtr,
    281                           DAG.getConstant(Offset, MVT::i32));
    282       Load = DAG.getExtLoad(LoadOp, dl, MVT::i32, Chain, FIPtr,
    283                             MachinePointerInfo(),
    284                             VA.getValVT(), false, false,0);
    285       Load = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), Load);
    286     }
    287     InVals.push_back(Load);
    288   }
    289 
    290   if (MF.getFunction()->hasStructRetAttr()) {
    291     //Copy the SRet Argument to SRetReturnReg
    292     SparcMachineFunctionInfo *SFI = MF.getInfo<SparcMachineFunctionInfo>();
    293     unsigned Reg = SFI->getSRetReturnReg();
    294     if (!Reg) {
    295       Reg = MF.getRegInfo().createVirtualRegister(&SP::IntRegsRegClass);
    296       SFI->setSRetReturnReg(Reg);
    297     }
    298     SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), dl, Reg, InVals[0]);
    299     Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Copy, Chain);
    300   }
    301 
    302   // Store remaining ArgRegs to the stack if this is a varargs function.
    303   if (isVarArg) {
    304     static const uint16_t ArgRegs[] = {
    305       SP::I0, SP::I1, SP::I2, SP::I3, SP::I4, SP::I5
    306     };
    307     unsigned NumAllocated = CCInfo.getFirstUnallocated(ArgRegs, 6);
    308     const uint16_t *CurArgReg = ArgRegs+NumAllocated, *ArgRegEnd = ArgRegs+6;
    309     unsigned ArgOffset = CCInfo.getNextStackOffset();
    310     if (NumAllocated == 6)
    311       ArgOffset += StackOffset;
    312     else {
    313       assert(!ArgOffset);
    314       ArgOffset = 68+4*NumAllocated;
    315     }
    316 
    317     // Remember the vararg offset for the va_start implementation.
    318     FuncInfo->setVarArgsFrameOffset(ArgOffset);
    319 
    320     std::vector<SDValue> OutChains;
    321 
    322     for (; CurArgReg != ArgRegEnd; ++CurArgReg) {
    323       unsigned VReg = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
    324       MF.getRegInfo().addLiveIn(*CurArgReg, VReg);
    325       SDValue Arg = DAG.getCopyFromReg(DAG.getRoot(), dl, VReg, MVT::i32);
    326 
    327       int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset,
    328                                                           true);
    329       SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
    330 
    331       OutChains.push_back(DAG.getStore(DAG.getRoot(), dl, Arg, FIPtr,
    332                                        MachinePointerInfo(),
    333                                        false, false, 0));
    334       ArgOffset += 4;
    335     }
    336 
    337     if (!OutChains.empty()) {
    338       OutChains.push_back(Chain);
    339       Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
    340                           &OutChains[0], OutChains.size());
    341     }
    342   }
    343 
    344   return Chain;
    345 }
    346 
    347 SDValue
    348 SparcTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
    349                                CallingConv::ID CallConv, bool isVarArg,
    350                                bool doesNotRet, bool &isTailCall,
    351                                const SmallVectorImpl<ISD::OutputArg> &Outs,
    352                                const SmallVectorImpl<SDValue> &OutVals,
    353                                const SmallVectorImpl<ISD::InputArg> &Ins,
    354                                DebugLoc dl, SelectionDAG &DAG,
    355                                SmallVectorImpl<SDValue> &InVals) const {
    356   // Sparc target does not yet support tail call optimization.
    357   isTailCall = false;
    358 
    359   // Analyze operands of the call, assigning locations to each operand.
    360   SmallVector<CCValAssign, 16> ArgLocs;
    361   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
    362 		 DAG.getTarget(), ArgLocs, *DAG.getContext());
    363   CCInfo.AnalyzeCallOperands(Outs, CC_Sparc32);
    364 
    365   // Get the size of the outgoing arguments stack space requirement.
    366   unsigned ArgsSize = CCInfo.getNextStackOffset();
    367 
    368   // Keep stack frames 8-byte aligned.
    369   ArgsSize = (ArgsSize+7) & ~7;
    370 
    371   MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
    372 
    373   //Create local copies for byval args.
    374   SmallVector<SDValue, 8> ByValArgs;
    375   for (unsigned i = 0,  e = Outs.size(); i != e; ++i) {
    376     ISD::ArgFlagsTy Flags = Outs[i].Flags;
    377     if (!Flags.isByVal())
    378       continue;
    379 
    380     SDValue Arg = OutVals[i];
    381     unsigned Size = Flags.getByValSize();
    382     unsigned Align = Flags.getByValAlign();
    383 
    384     int FI = MFI->CreateStackObject(Size, Align, false);
    385     SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy());
    386     SDValue SizeNode = DAG.getConstant(Size, MVT::i32);
    387 
    388     Chain = DAG.getMemcpy(Chain, dl, FIPtr, Arg, SizeNode, Align,
    389                           false,        //isVolatile,
    390                           (Size <= 32), //AlwaysInline if size <= 32
    391                           MachinePointerInfo(), MachinePointerInfo());
    392     ByValArgs.push_back(FIPtr);
    393   }
    394 
    395   Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(ArgsSize, true));
    396 
    397   SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
    398   SmallVector<SDValue, 8> MemOpChains;
    399 
    400   const unsigned StackOffset = 92;
    401   bool hasStructRetAttr = false;
    402   // Walk the register/memloc assignments, inserting copies/loads.
    403   for (unsigned i = 0, realArgIdx = 0, byvalArgIdx = 0, e = ArgLocs.size();
    404        i != e;
    405        ++i, ++realArgIdx) {
    406     CCValAssign &VA = ArgLocs[i];
    407     SDValue Arg = OutVals[realArgIdx];
    408 
    409     ISD::ArgFlagsTy Flags = Outs[realArgIdx].Flags;
    410 
    411     //Use local copy if it is a byval arg.
    412     if (Flags.isByVal())
    413       Arg = ByValArgs[byvalArgIdx++];
    414 
    415     // Promote the value if needed.
    416     switch (VA.getLocInfo()) {
    417     default: llvm_unreachable("Unknown loc info!");
    418     case CCValAssign::Full: break;
    419     case CCValAssign::SExt:
    420       Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
    421       break;
    422     case CCValAssign::ZExt:
    423       Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
    424       break;
    425     case CCValAssign::AExt:
    426       Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg);
    427       break;
    428     case CCValAssign::BCvt:
    429       Arg = DAG.getNode(ISD::BITCAST, dl, VA.getLocVT(), Arg);
    430       break;
    431     }
    432 
    433     if (Flags.isSRet()) {
    434       assert(VA.needsCustom());
    435       // store SRet argument in %sp+64
    436       SDValue StackPtr = DAG.getRegister(SP::O6, MVT::i32);
    437       SDValue PtrOff = DAG.getIntPtrConstant(64);
    438       PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
    439       MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
    440                                          MachinePointerInfo(),
    441                                          false, false, 0));
    442       hasStructRetAttr = true;
    443       continue;
    444     }
    445 
    446     if (VA.needsCustom()) {
    447       assert(VA.getLocVT() == MVT::f64);
    448 
    449       if (VA.isMemLoc()) {
    450         unsigned Offset = VA.getLocMemOffset() + StackOffset;
    451         //if it is double-word aligned, just store.
    452         if (Offset % 8 == 0) {
    453           SDValue StackPtr = DAG.getRegister(SP::O6, MVT::i32);
    454           SDValue PtrOff = DAG.getIntPtrConstant(Offset);
    455           PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
    456           MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
    457                                              MachinePointerInfo(),
    458                                              false, false, 0));
    459           continue;
    460         }
    461       }
    462 
    463       SDValue StackPtr = DAG.CreateStackTemporary(MVT::f64, MVT::i32);
    464       SDValue Store = DAG.getStore(DAG.getEntryNode(), dl,
    465                                    Arg, StackPtr, MachinePointerInfo(),
    466                                    false, false, 0);
    467       // Sparc is big-endian, so the high part comes first.
    468       SDValue Hi = DAG.getLoad(MVT::i32, dl, Store, StackPtr,
    469                                MachinePointerInfo(), false, false, false, 0);
    470       // Increment the pointer to the other half.
    471       StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
    472                              DAG.getIntPtrConstant(4));
    473       // Load the low part.
    474       SDValue Lo = DAG.getLoad(MVT::i32, dl, Store, StackPtr,
    475                                MachinePointerInfo(), false, false, false, 0);
    476 
    477       if (VA.isRegLoc()) {
    478         RegsToPass.push_back(std::make_pair(VA.getLocReg(), Hi));
    479         assert(i+1 != e);
    480         CCValAssign &NextVA = ArgLocs[++i];
    481         if (NextVA.isRegLoc()) {
    482           RegsToPass.push_back(std::make_pair(NextVA.getLocReg(), Lo));
    483         } else {
    484           //Store the low part in stack.
    485           unsigned Offset = NextVA.getLocMemOffset() + StackOffset;
    486           SDValue StackPtr = DAG.getRegister(SP::O6, MVT::i32);
    487           SDValue PtrOff = DAG.getIntPtrConstant(Offset);
    488           PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
    489           MemOpChains.push_back(DAG.getStore(Chain, dl, Lo, PtrOff,
    490                                              MachinePointerInfo(),
    491                                              false, false, 0));
    492         }
    493       } else {
    494         unsigned Offset = VA.getLocMemOffset() + StackOffset;
    495         // Store the high part.
    496         SDValue StackPtr = DAG.getRegister(SP::O6, MVT::i32);
    497         SDValue PtrOff = DAG.getIntPtrConstant(Offset);
    498         PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
    499         MemOpChains.push_back(DAG.getStore(Chain, dl, Hi, PtrOff,
    500                                            MachinePointerInfo(),
    501                                            false, false, 0));
    502         // Store the low part.
    503         PtrOff = DAG.getIntPtrConstant(Offset+4);
    504         PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
    505         MemOpChains.push_back(DAG.getStore(Chain, dl, Lo, PtrOff,
    506                                            MachinePointerInfo(),
    507                                            false, false, 0));
    508       }
    509       continue;
    510     }
    511 
    512     // Arguments that can be passed on register must be kept at
    513     // RegsToPass vector
    514     if (VA.isRegLoc()) {
    515       if (VA.getLocVT() != MVT::f32) {
    516         RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
    517         continue;
    518       }
    519       Arg = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Arg);
    520       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
    521       continue;
    522     }
    523 
    524     assert(VA.isMemLoc());
    525 
    526     // Create a store off the stack pointer for this argument.
    527     SDValue StackPtr = DAG.getRegister(SP::O6, MVT::i32);
    528     SDValue PtrOff = DAG.getIntPtrConstant(VA.getLocMemOffset()+StackOffset);
    529     PtrOff = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, PtrOff);
    530     MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
    531                                        MachinePointerInfo(),
    532                                        false, false, 0));
    533   }
    534 
    535 
    536   // Emit all stores, make sure the occur before any copies into physregs.
    537   if (!MemOpChains.empty())
    538     Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
    539                         &MemOpChains[0], MemOpChains.size());
    540 
    541   // Build a sequence of copy-to-reg nodes chained together with token
    542   // chain and flag operands which copy the outgoing args into registers.
    543   // The InFlag in necessary since all emitted instructions must be
    544   // stuck together.
    545   SDValue InFlag;
    546   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
    547     unsigned Reg = RegsToPass[i].first;
    548     // Remap I0->I7 -> O0->O7.
    549     if (Reg >= SP::I0 && Reg <= SP::I7)
    550       Reg = Reg-SP::I0+SP::O0;
    551 
    552     Chain = DAG.getCopyToReg(Chain, dl, Reg, RegsToPass[i].second, InFlag);
    553     InFlag = Chain.getValue(1);
    554   }
    555 
    556   unsigned SRetArgSize = (hasStructRetAttr)? getSRetArgSize(DAG, Callee):0;
    557 
    558   // If the callee is a GlobalAddress node (quite common, every direct call is)
    559   // turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
    560   // Likewise ExternalSymbol -> TargetExternalSymbol.
    561   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
    562     Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, MVT::i32);
    563   else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee))
    564     Callee = DAG.getTargetExternalSymbol(E->getSymbol(), MVT::i32);
    565 
    566   // Returns a chain & a flag for retval copy to use
    567   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
    568   SmallVector<SDValue, 8> Ops;
    569   Ops.push_back(Chain);
    570   Ops.push_back(Callee);
    571   if (hasStructRetAttr)
    572     Ops.push_back(DAG.getTargetConstant(SRetArgSize, MVT::i32));
    573   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
    574     unsigned Reg = RegsToPass[i].first;
    575     if (Reg >= SP::I0 && Reg <= SP::I7)
    576       Reg = Reg-SP::I0+SP::O0;
    577 
    578     Ops.push_back(DAG.getRegister(Reg, RegsToPass[i].second.getValueType()));
    579   }
    580   if (InFlag.getNode())
    581     Ops.push_back(InFlag);
    582 
    583   Chain = DAG.getNode(SPISD::CALL, dl, NodeTys, &Ops[0], Ops.size());
    584   InFlag = Chain.getValue(1);
    585 
    586   Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(ArgsSize, true),
    587                              DAG.getIntPtrConstant(0, true), InFlag);
    588   InFlag = Chain.getValue(1);
    589 
    590   // Assign locations to each value returned by this call.
    591   SmallVector<CCValAssign, 16> RVLocs;
    592   CCState RVInfo(CallConv, isVarArg, DAG.getMachineFunction(),
    593 		 DAG.getTarget(), RVLocs, *DAG.getContext());
    594 
    595   RVInfo.AnalyzeCallResult(Ins, RetCC_Sparc32);
    596 
    597   // Copy all of the result registers out of their specified physreg.
    598   for (unsigned i = 0; i != RVLocs.size(); ++i) {
    599     unsigned Reg = RVLocs[i].getLocReg();
    600 
    601     // Remap I0->I7 -> O0->O7.
    602     if (Reg >= SP::I0 && Reg <= SP::I7)
    603       Reg = Reg-SP::I0+SP::O0;
    604 
    605     Chain = DAG.getCopyFromReg(Chain, dl, Reg,
    606                                RVLocs[i].getValVT(), InFlag).getValue(1);
    607     InFlag = Chain.getValue(2);
    608     InVals.push_back(Chain.getValue(0));
    609   }
    610 
    611   return Chain;
    612 }
    613 
    614 unsigned
    615 SparcTargetLowering::getSRetArgSize(SelectionDAG &DAG, SDValue Callee) const
    616 {
    617   const Function *CalleeFn = 0;
    618   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
    619     CalleeFn = dyn_cast<Function>(G->getGlobal());
    620   } else if (ExternalSymbolSDNode *E =
    621              dyn_cast<ExternalSymbolSDNode>(Callee)) {
    622     const Function *Fn = DAG.getMachineFunction().getFunction();
    623     const Module *M = Fn->getParent();
    624     CalleeFn = M->getFunction(E->getSymbol());
    625   }
    626 
    627   if (!CalleeFn)
    628     return 0;
    629 
    630   assert(CalleeFn->hasStructRetAttr() &&
    631          "Callee does not have the StructRet attribute.");
    632 
    633   PointerType *Ty = cast<PointerType>(CalleeFn->arg_begin()->getType());
    634   Type *ElementTy = Ty->getElementType();
    635   return getTargetData()->getTypeAllocSize(ElementTy);
    636 }
    637 
    638 //===----------------------------------------------------------------------===//
    639 // TargetLowering Implementation
    640 //===----------------------------------------------------------------------===//
    641 
    642 /// IntCondCCodeToICC - Convert a DAG integer condition code to a SPARC ICC
    643 /// condition.
    644 static SPCC::CondCodes IntCondCCodeToICC(ISD::CondCode CC) {
    645   switch (CC) {
    646   default: llvm_unreachable("Unknown integer condition code!");
    647   case ISD::SETEQ:  return SPCC::ICC_E;
    648   case ISD::SETNE:  return SPCC::ICC_NE;
    649   case ISD::SETLT:  return SPCC::ICC_L;
    650   case ISD::SETGT:  return SPCC::ICC_G;
    651   case ISD::SETLE:  return SPCC::ICC_LE;
    652   case ISD::SETGE:  return SPCC::ICC_GE;
    653   case ISD::SETULT: return SPCC::ICC_CS;
    654   case ISD::SETULE: return SPCC::ICC_LEU;
    655   case ISD::SETUGT: return SPCC::ICC_GU;
    656   case ISD::SETUGE: return SPCC::ICC_CC;
    657   }
    658 }
    659 
    660 /// FPCondCCodeToFCC - Convert a DAG floatingp oint condition code to a SPARC
    661 /// FCC condition.
    662 static SPCC::CondCodes FPCondCCodeToFCC(ISD::CondCode CC) {
    663   switch (CC) {
    664   default: llvm_unreachable("Unknown fp condition code!");
    665   case ISD::SETEQ:
    666   case ISD::SETOEQ: return SPCC::FCC_E;
    667   case ISD::SETNE:
    668   case ISD::SETUNE: return SPCC::FCC_NE;
    669   case ISD::SETLT:
    670   case ISD::SETOLT: return SPCC::FCC_L;
    671   case ISD::SETGT:
    672   case ISD::SETOGT: return SPCC::FCC_G;
    673   case ISD::SETLE:
    674   case ISD::SETOLE: return SPCC::FCC_LE;
    675   case ISD::SETGE:
    676   case ISD::SETOGE: return SPCC::FCC_GE;
    677   case ISD::SETULT: return SPCC::FCC_UL;
    678   case ISD::SETULE: return SPCC::FCC_ULE;
    679   case ISD::SETUGT: return SPCC::FCC_UG;
    680   case ISD::SETUGE: return SPCC::FCC_UGE;
    681   case ISD::SETUO:  return SPCC::FCC_U;
    682   case ISD::SETO:   return SPCC::FCC_O;
    683   case ISD::SETONE: return SPCC::FCC_LG;
    684   case ISD::SETUEQ: return SPCC::FCC_UE;
    685   }
    686 }
    687 
    688 SparcTargetLowering::SparcTargetLowering(TargetMachine &TM)
    689   : TargetLowering(TM, new TargetLoweringObjectFileELF()) {
    690 
    691   // Set up the register classes.
    692   addRegisterClass(MVT::i32, SP::IntRegsRegisterClass);
    693   addRegisterClass(MVT::f32, SP::FPRegsRegisterClass);
    694   addRegisterClass(MVT::f64, SP::DFPRegsRegisterClass);
    695 
    696   // Turn FP extload into load/fextend
    697   setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand);
    698   // Sparc doesn't have i1 sign extending load
    699   setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Promote);
    700   // Turn FP truncstore into trunc + store.
    701   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
    702 
    703   // Custom legalize GlobalAddress nodes into LO/HI parts.
    704   setOperationAction(ISD::GlobalAddress, MVT::i32, Custom);
    705   setOperationAction(ISD::GlobalTLSAddress, MVT::i32, Custom);
    706   setOperationAction(ISD::ConstantPool , MVT::i32, Custom);
    707 
    708   // Sparc doesn't have sext_inreg, replace them with shl/sra
    709   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
    710   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8 , Expand);
    711   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1 , Expand);
    712 
    713   // Sparc has no REM or DIVREM operations.
    714   setOperationAction(ISD::UREM, MVT::i32, Expand);
    715   setOperationAction(ISD::SREM, MVT::i32, Expand);
    716   setOperationAction(ISD::SDIVREM, MVT::i32, Expand);
    717   setOperationAction(ISD::UDIVREM, MVT::i32, Expand);
    718 
    719   // Custom expand fp<->sint
    720   setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
    721   setOperationAction(ISD::SINT_TO_FP, MVT::i32, Custom);
    722 
    723   // Expand fp<->uint
    724   setOperationAction(ISD::FP_TO_UINT, MVT::i32, Expand);
    725   setOperationAction(ISD::UINT_TO_FP, MVT::i32, Expand);
    726 
    727   setOperationAction(ISD::BITCAST, MVT::f32, Expand);
    728   setOperationAction(ISD::BITCAST, MVT::i32, Expand);
    729 
    730   // Sparc has no select or setcc: expand to SELECT_CC.
    731   setOperationAction(ISD::SELECT, MVT::i32, Expand);
    732   setOperationAction(ISD::SELECT, MVT::f32, Expand);
    733   setOperationAction(ISD::SELECT, MVT::f64, Expand);
    734   setOperationAction(ISD::SETCC, MVT::i32, Expand);
    735   setOperationAction(ISD::SETCC, MVT::f32, Expand);
    736   setOperationAction(ISD::SETCC, MVT::f64, Expand);
    737 
    738   // Sparc doesn't have BRCOND either, it has BR_CC.
    739   setOperationAction(ISD::BRCOND, MVT::Other, Expand);
    740   setOperationAction(ISD::BRIND, MVT::Other, Expand);
    741   setOperationAction(ISD::BR_JT, MVT::Other, Expand);
    742   setOperationAction(ISD::BR_CC, MVT::i32, Custom);
    743   setOperationAction(ISD::BR_CC, MVT::f32, Custom);
    744   setOperationAction(ISD::BR_CC, MVT::f64, Custom);
    745 
    746   setOperationAction(ISD::SELECT_CC, MVT::i32, Custom);
    747   setOperationAction(ISD::SELECT_CC, MVT::f32, Custom);
    748   setOperationAction(ISD::SELECT_CC, MVT::f64, Custom);
    749 
    750   // FIXME: There are instructions available for ATOMIC_FENCE
    751   // on SparcV8 and later.
    752   setOperationAction(ISD::MEMBARRIER, MVT::Other, Expand);
    753   setOperationAction(ISD::ATOMIC_FENCE, MVT::Other, Expand);
    754 
    755   setOperationAction(ISD::FSIN , MVT::f64, Expand);
    756   setOperationAction(ISD::FCOS , MVT::f64, Expand);
    757   setOperationAction(ISD::FREM , MVT::f64, Expand);
    758   setOperationAction(ISD::FMA  , MVT::f64, Expand);
    759   setOperationAction(ISD::FSIN , MVT::f32, Expand);
    760   setOperationAction(ISD::FCOS , MVT::f32, Expand);
    761   setOperationAction(ISD::FREM , MVT::f32, Expand);
    762   setOperationAction(ISD::FMA  , MVT::f32, Expand);
    763   setOperationAction(ISD::CTPOP, MVT::i32, Expand);
    764   setOperationAction(ISD::CTTZ , MVT::i32, Expand);
    765   setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i32, Expand);
    766   setOperationAction(ISD::CTLZ , MVT::i32, Expand);
    767   setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i32, Expand);
    768   setOperationAction(ISD::ROTL , MVT::i32, Expand);
    769   setOperationAction(ISD::ROTR , MVT::i32, Expand);
    770   setOperationAction(ISD::BSWAP, MVT::i32, Expand);
    771   setOperationAction(ISD::FCOPYSIGN, MVT::f64, Expand);
    772   setOperationAction(ISD::FCOPYSIGN, MVT::f32, Expand);
    773   setOperationAction(ISD::FPOW , MVT::f64, Expand);
    774   setOperationAction(ISD::FPOW , MVT::f32, Expand);
    775 
    776   setOperationAction(ISD::SHL_PARTS, MVT::i32, Expand);
    777   setOperationAction(ISD::SRA_PARTS, MVT::i32, Expand);
    778   setOperationAction(ISD::SRL_PARTS, MVT::i32, Expand);
    779 
    780   // FIXME: Sparc provides these multiplies, but we don't have them yet.
    781   setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
    782   setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand);
    783 
    784   setOperationAction(ISD::EH_LABEL, MVT::Other, Expand);
    785 
    786   // VASTART needs to be custom lowered to use the VarArgsFrameIndex.
    787   setOperationAction(ISD::VASTART           , MVT::Other, Custom);
    788   // VAARG needs to be lowered to not do unaligned accesses for doubles.
    789   setOperationAction(ISD::VAARG             , MVT::Other, Custom);
    790 
    791   // Use the default implementation.
    792   setOperationAction(ISD::VACOPY            , MVT::Other, Expand);
    793   setOperationAction(ISD::VAEND             , MVT::Other, Expand);
    794   setOperationAction(ISD::STACKSAVE         , MVT::Other, Expand);
    795   setOperationAction(ISD::STACKRESTORE      , MVT::Other, Expand);
    796   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32  , Custom);
    797 
    798   // No debug info support yet.
    799   setOperationAction(ISD::EH_LABEL, MVT::Other, Expand);
    800 
    801   setStackPointerRegisterToSaveRestore(SP::O6);
    802 
    803   if (TM.getSubtarget<SparcSubtarget>().isV9())
    804     setOperationAction(ISD::CTPOP, MVT::i32, Legal);
    805 
    806   setMinFunctionAlignment(2);
    807 
    808   computeRegisterProperties();
    809 }
    810 
    811 const char *SparcTargetLowering::getTargetNodeName(unsigned Opcode) const {
    812   switch (Opcode) {
    813   default: return 0;
    814   case SPISD::CMPICC:     return "SPISD::CMPICC";
    815   case SPISD::CMPFCC:     return "SPISD::CMPFCC";
    816   case SPISD::BRICC:      return "SPISD::BRICC";
    817   case SPISD::BRFCC:      return "SPISD::BRFCC";
    818   case SPISD::SELECT_ICC: return "SPISD::SELECT_ICC";
    819   case SPISD::SELECT_FCC: return "SPISD::SELECT_FCC";
    820   case SPISD::Hi:         return "SPISD::Hi";
    821   case SPISD::Lo:         return "SPISD::Lo";
    822   case SPISD::FTOI:       return "SPISD::FTOI";
    823   case SPISD::ITOF:       return "SPISD::ITOF";
    824   case SPISD::CALL:       return "SPISD::CALL";
    825   case SPISD::RET_FLAG:   return "SPISD::RET_FLAG";
    826   case SPISD::GLOBAL_BASE_REG: return "SPISD::GLOBAL_BASE_REG";
    827   case SPISD::FLUSHW:     return "SPISD::FLUSHW";
    828   }
    829 }
    830 
    831 /// isMaskedValueZeroForTargetNode - Return true if 'Op & Mask' is known to
    832 /// be zero. Op is expected to be a target specific node. Used by DAG
    833 /// combiner.
    834 void SparcTargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
    835                                                          APInt &KnownZero,
    836                                                          APInt &KnownOne,
    837                                                          const SelectionDAG &DAG,
    838                                                          unsigned Depth) const {
    839   APInt KnownZero2, KnownOne2;
    840   KnownZero = KnownOne = APInt(KnownZero.getBitWidth(), 0);
    841 
    842   switch (Op.getOpcode()) {
    843   default: break;
    844   case SPISD::SELECT_ICC:
    845   case SPISD::SELECT_FCC:
    846     DAG.ComputeMaskedBits(Op.getOperand(1), KnownZero, KnownOne, Depth+1);
    847     DAG.ComputeMaskedBits(Op.getOperand(0), KnownZero2, KnownOne2, Depth+1);
    848     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
    849     assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
    850 
    851     // Only known if known in both the LHS and RHS.
    852     KnownOne &= KnownOne2;
    853     KnownZero &= KnownZero2;
    854     break;
    855   }
    856 }
    857 
    858 // Look at LHS/RHS/CC and see if they are a lowered setcc instruction.  If so
    859 // set LHS/RHS and SPCC to the LHS/RHS of the setcc and SPCC to the condition.
    860 static void LookThroughSetCC(SDValue &LHS, SDValue &RHS,
    861                              ISD::CondCode CC, unsigned &SPCC) {
    862   if (isa<ConstantSDNode>(RHS) &&
    863       cast<ConstantSDNode>(RHS)->isNullValue() &&
    864       CC == ISD::SETNE &&
    865       ((LHS.getOpcode() == SPISD::SELECT_ICC &&
    866         LHS.getOperand(3).getOpcode() == SPISD::CMPICC) ||
    867        (LHS.getOpcode() == SPISD::SELECT_FCC &&
    868         LHS.getOperand(3).getOpcode() == SPISD::CMPFCC)) &&
    869       isa<ConstantSDNode>(LHS.getOperand(0)) &&
    870       isa<ConstantSDNode>(LHS.getOperand(1)) &&
    871       cast<ConstantSDNode>(LHS.getOperand(0))->isOne() &&
    872       cast<ConstantSDNode>(LHS.getOperand(1))->isNullValue()) {
    873     SDValue CMPCC = LHS.getOperand(3);
    874     SPCC = cast<ConstantSDNode>(LHS.getOperand(2))->getZExtValue();
    875     LHS = CMPCC.getOperand(0);
    876     RHS = CMPCC.getOperand(1);
    877   }
    878 }
    879 
    880 SDValue SparcTargetLowering::LowerGlobalAddress(SDValue Op,
    881                                                 SelectionDAG &DAG) const {
    882   const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
    883   // FIXME there isn't really any debug info here
    884   DebugLoc dl = Op.getDebugLoc();
    885   SDValue GA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32);
    886   SDValue Hi = DAG.getNode(SPISD::Hi, dl, MVT::i32, GA);
    887   SDValue Lo = DAG.getNode(SPISD::Lo, dl, MVT::i32, GA);
    888 
    889   if (getTargetMachine().getRelocationModel() != Reloc::PIC_)
    890     return DAG.getNode(ISD::ADD, dl, MVT::i32, Lo, Hi);
    891 
    892   SDValue GlobalBase = DAG.getNode(SPISD::GLOBAL_BASE_REG, dl,
    893                                    getPointerTy());
    894   SDValue RelAddr = DAG.getNode(ISD::ADD, dl, MVT::i32, Lo, Hi);
    895   SDValue AbsAddr = DAG.getNode(ISD::ADD, dl, MVT::i32,
    896                                 GlobalBase, RelAddr);
    897   return DAG.getLoad(getPointerTy(), dl, DAG.getEntryNode(),
    898                      AbsAddr, MachinePointerInfo(), false, false, false, 0);
    899 }
    900 
    901 SDValue SparcTargetLowering::LowerConstantPool(SDValue Op,
    902                                                SelectionDAG &DAG) const {
    903   ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
    904   // FIXME there isn't really any debug info here
    905   DebugLoc dl = Op.getDebugLoc();
    906   const Constant *C = N->getConstVal();
    907   SDValue CP = DAG.getTargetConstantPool(C, MVT::i32, N->getAlignment());
    908   SDValue Hi = DAG.getNode(SPISD::Hi, dl, MVT::i32, CP);
    909   SDValue Lo = DAG.getNode(SPISD::Lo, dl, MVT::i32, CP);
    910   if (getTargetMachine().getRelocationModel() != Reloc::PIC_)
    911     return DAG.getNode(ISD::ADD, dl, MVT::i32, Lo, Hi);
    912 
    913   SDValue GlobalBase = DAG.getNode(SPISD::GLOBAL_BASE_REG, dl,
    914                                    getPointerTy());
    915   SDValue RelAddr = DAG.getNode(ISD::ADD, dl, MVT::i32, Lo, Hi);
    916   SDValue AbsAddr = DAG.getNode(ISD::ADD, dl, MVT::i32,
    917                                 GlobalBase, RelAddr);
    918   return DAG.getLoad(getPointerTy(), dl, DAG.getEntryNode(),
    919                      AbsAddr, MachinePointerInfo(), false, false, false, 0);
    920 }
    921 
    922 static SDValue LowerFP_TO_SINT(SDValue Op, SelectionDAG &DAG) {
    923   DebugLoc dl = Op.getDebugLoc();
    924   // Convert the fp value to integer in an FP register.
    925   assert(Op.getValueType() == MVT::i32);
    926   Op = DAG.getNode(SPISD::FTOI, dl, MVT::f32, Op.getOperand(0));
    927   return DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op);
    928 }
    929 
    930 static SDValue LowerSINT_TO_FP(SDValue Op, SelectionDAG &DAG) {
    931   DebugLoc dl = Op.getDebugLoc();
    932   assert(Op.getOperand(0).getValueType() == MVT::i32);
    933   SDValue Tmp = DAG.getNode(ISD::BITCAST, dl, MVT::f32, Op.getOperand(0));
    934   // Convert the int value to FP in an FP register.
    935   return DAG.getNode(SPISD::ITOF, dl, Op.getValueType(), Tmp);
    936 }
    937 
    938 static SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) {
    939   SDValue Chain = Op.getOperand(0);
    940   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
    941   SDValue LHS = Op.getOperand(2);
    942   SDValue RHS = Op.getOperand(3);
    943   SDValue Dest = Op.getOperand(4);
    944   DebugLoc dl = Op.getDebugLoc();
    945   unsigned Opc, SPCC = ~0U;
    946 
    947   // If this is a br_cc of a "setcc", and if the setcc got lowered into
    948   // an CMP[IF]CC/SELECT_[IF]CC pair, find the original compared values.
    949   LookThroughSetCC(LHS, RHS, CC, SPCC);
    950 
    951   // Get the condition flag.
    952   SDValue CompareFlag;
    953   if (LHS.getValueType() == MVT::i32) {
    954     std::vector<EVT> VTs;
    955     VTs.push_back(MVT::i32);
    956     VTs.push_back(MVT::Glue);
    957     SDValue Ops[2] = { LHS, RHS };
    958     CompareFlag = DAG.getNode(SPISD::CMPICC, dl, VTs, Ops, 2).getValue(1);
    959     if (SPCC == ~0U) SPCC = IntCondCCodeToICC(CC);
    960     Opc = SPISD::BRICC;
    961   } else {
    962     CompareFlag = DAG.getNode(SPISD::CMPFCC, dl, MVT::Glue, LHS, RHS);
    963     if (SPCC == ~0U) SPCC = FPCondCCodeToFCC(CC);
    964     Opc = SPISD::BRFCC;
    965   }
    966   return DAG.getNode(Opc, dl, MVT::Other, Chain, Dest,
    967                      DAG.getConstant(SPCC, MVT::i32), CompareFlag);
    968 }
    969 
    970 static SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) {
    971   SDValue LHS = Op.getOperand(0);
    972   SDValue RHS = Op.getOperand(1);
    973   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
    974   SDValue TrueVal = Op.getOperand(2);
    975   SDValue FalseVal = Op.getOperand(3);
    976   DebugLoc dl = Op.getDebugLoc();
    977   unsigned Opc, SPCC = ~0U;
    978 
    979   // If this is a select_cc of a "setcc", and if the setcc got lowered into
    980   // an CMP[IF]CC/SELECT_[IF]CC pair, find the original compared values.
    981   LookThroughSetCC(LHS, RHS, CC, SPCC);
    982 
    983   SDValue CompareFlag;
    984   if (LHS.getValueType() == MVT::i32) {
    985     std::vector<EVT> VTs;
    986     VTs.push_back(LHS.getValueType());   // subcc returns a value
    987     VTs.push_back(MVT::Glue);
    988     SDValue Ops[2] = { LHS, RHS };
    989     CompareFlag = DAG.getNode(SPISD::CMPICC, dl, VTs, Ops, 2).getValue(1);
    990     Opc = SPISD::SELECT_ICC;
    991     if (SPCC == ~0U) SPCC = IntCondCCodeToICC(CC);
    992   } else {
    993     CompareFlag = DAG.getNode(SPISD::CMPFCC, dl, MVT::Glue, LHS, RHS);
    994     Opc = SPISD::SELECT_FCC;
    995     if (SPCC == ~0U) SPCC = FPCondCCodeToFCC(CC);
    996   }
    997   return DAG.getNode(Opc, dl, TrueVal.getValueType(), TrueVal, FalseVal,
    998                      DAG.getConstant(SPCC, MVT::i32), CompareFlag);
    999 }
   1000 
   1001 static SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG,
   1002                             const SparcTargetLowering &TLI) {
   1003   MachineFunction &MF = DAG.getMachineFunction();
   1004   SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();
   1005 
   1006   // vastart just stores the address of the VarArgsFrameIndex slot into the
   1007   // memory location argument.
   1008   DebugLoc dl = Op.getDebugLoc();
   1009   SDValue Offset =
   1010     DAG.getNode(ISD::ADD, dl, MVT::i32,
   1011                 DAG.getRegister(SP::I6, MVT::i32),
   1012                 DAG.getConstant(FuncInfo->getVarArgsFrameOffset(),
   1013                                 MVT::i32));
   1014   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
   1015   return DAG.getStore(Op.getOperand(0), dl, Offset, Op.getOperand(1),
   1016                       MachinePointerInfo(SV), false, false, 0);
   1017 }
   1018 
   1019 static SDValue LowerVAARG(SDValue Op, SelectionDAG &DAG) {
   1020   SDNode *Node = Op.getNode();
   1021   EVT VT = Node->getValueType(0);
   1022   SDValue InChain = Node->getOperand(0);
   1023   SDValue VAListPtr = Node->getOperand(1);
   1024   const Value *SV = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
   1025   DebugLoc dl = Node->getDebugLoc();
   1026   SDValue VAList = DAG.getLoad(MVT::i32, dl, InChain, VAListPtr,
   1027                                MachinePointerInfo(SV), false, false, false, 0);
   1028   // Increment the pointer, VAList, to the next vaarg
   1029   SDValue NextPtr = DAG.getNode(ISD::ADD, dl, MVT::i32, VAList,
   1030                                   DAG.getConstant(VT.getSizeInBits()/8,
   1031                                                   MVT::i32));
   1032   // Store the incremented VAList to the legalized pointer
   1033   InChain = DAG.getStore(VAList.getValue(1), dl, NextPtr,
   1034                          VAListPtr, MachinePointerInfo(SV), false, false, 0);
   1035   // Load the actual argument out of the pointer VAList, unless this is an
   1036   // f64 load.
   1037   if (VT != MVT::f64)
   1038     return DAG.getLoad(VT, dl, InChain, VAList, MachinePointerInfo(),
   1039                        false, false, false, 0);
   1040 
   1041   // Otherwise, load it as i64, then do a bitconvert.
   1042   SDValue V = DAG.getLoad(MVT::i64, dl, InChain, VAList, MachinePointerInfo(),
   1043                           false, false, false, 0);
   1044 
   1045   // Bit-Convert the value to f64.
   1046   SDValue Ops[2] = {
   1047     DAG.getNode(ISD::BITCAST, dl, MVT::f64, V),
   1048     V.getValue(1)
   1049   };
   1050   return DAG.getMergeValues(Ops, 2, dl);
   1051 }
   1052 
   1053 static SDValue LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) {
   1054   SDValue Chain = Op.getOperand(0);  // Legalize the chain.
   1055   SDValue Size  = Op.getOperand(1);  // Legalize the size.
   1056   DebugLoc dl = Op.getDebugLoc();
   1057 
   1058   unsigned SPReg = SP::O6;
   1059   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, MVT::i32);
   1060   SDValue NewSP = DAG.getNode(ISD::SUB, dl, MVT::i32, SP, Size); // Value
   1061   Chain = DAG.getCopyToReg(SP.getValue(1), dl, SPReg, NewSP);    // Output chain
   1062 
   1063   // The resultant pointer is actually 16 words from the bottom of the stack,
   1064   // to provide a register spill area.
   1065   SDValue NewVal = DAG.getNode(ISD::ADD, dl, MVT::i32, NewSP,
   1066                                  DAG.getConstant(96, MVT::i32));
   1067   SDValue Ops[2] = { NewVal, Chain };
   1068   return DAG.getMergeValues(Ops, 2, dl);
   1069 }
   1070 
   1071 
   1072 static SDValue getFLUSHW(SDValue Op, SelectionDAG &DAG) {
   1073   DebugLoc dl = Op.getDebugLoc();
   1074   SDValue Chain = DAG.getNode(SPISD::FLUSHW,
   1075                               dl, MVT::Other, DAG.getEntryNode());
   1076   return Chain;
   1077 }
   1078 
   1079 static SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) {
   1080   MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
   1081   MFI->setFrameAddressIsTaken(true);
   1082 
   1083   EVT VT = Op.getValueType();
   1084   DebugLoc dl = Op.getDebugLoc();
   1085   unsigned FrameReg = SP::I6;
   1086 
   1087   uint64_t depth = Op.getConstantOperandVal(0);
   1088 
   1089   SDValue FrameAddr;
   1090   if (depth == 0)
   1091     FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl, FrameReg, VT);
   1092   else {
   1093     // flush first to make sure the windowed registers' values are in stack
   1094     SDValue Chain = getFLUSHW(Op, DAG);
   1095     FrameAddr = DAG.getCopyFromReg(Chain, dl, FrameReg, VT);
   1096 
   1097     for (uint64_t i = 0; i != depth; ++i) {
   1098       SDValue Ptr = DAG.getNode(ISD::ADD,
   1099                                 dl, MVT::i32,
   1100                                 FrameAddr, DAG.getIntPtrConstant(56));
   1101       FrameAddr = DAG.getLoad(MVT::i32, dl,
   1102                               Chain,
   1103                               Ptr,
   1104                               MachinePointerInfo(), false, false, false, 0);
   1105     }
   1106   }
   1107   return FrameAddr;
   1108 }
   1109 
   1110 static SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) {
   1111   MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
   1112   MFI->setReturnAddressIsTaken(true);
   1113 
   1114   EVT VT = Op.getValueType();
   1115   DebugLoc dl = Op.getDebugLoc();
   1116   unsigned RetReg = SP::I7;
   1117 
   1118   uint64_t depth = Op.getConstantOperandVal(0);
   1119 
   1120   SDValue RetAddr;
   1121   if (depth == 0)
   1122     RetAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl, RetReg, VT);
   1123   else {
   1124     // flush first to make sure the windowed registers' values are in stack
   1125     SDValue Chain = getFLUSHW(Op, DAG);
   1126     RetAddr = DAG.getCopyFromReg(Chain, dl, SP::I6, VT);
   1127 
   1128     for (uint64_t i = 0; i != depth; ++i) {
   1129       SDValue Ptr = DAG.getNode(ISD::ADD,
   1130                                 dl, MVT::i32,
   1131                                 RetAddr,
   1132                                 DAG.getIntPtrConstant((i == depth-1)?60:56));
   1133       RetAddr = DAG.getLoad(MVT::i32, dl,
   1134                             Chain,
   1135                             Ptr,
   1136                             MachinePointerInfo(), false, false, false, 0);
   1137     }
   1138   }
   1139   return RetAddr;
   1140 }
   1141 
   1142 SDValue SparcTargetLowering::
   1143 LowerOperation(SDValue Op, SelectionDAG &DAG) const {
   1144   switch (Op.getOpcode()) {
   1145   default: llvm_unreachable("Should not custom lower this!");
   1146   case ISD::RETURNADDR:         return LowerRETURNADDR(Op, DAG);
   1147   case ISD::FRAMEADDR:          return LowerFRAMEADDR(Op, DAG);
   1148   case ISD::GlobalTLSAddress:
   1149     llvm_unreachable("TLS not implemented for Sparc.");
   1150   case ISD::GlobalAddress:      return LowerGlobalAddress(Op, DAG);
   1151   case ISD::ConstantPool:       return LowerConstantPool(Op, DAG);
   1152   case ISD::FP_TO_SINT:         return LowerFP_TO_SINT(Op, DAG);
   1153   case ISD::SINT_TO_FP:         return LowerSINT_TO_FP(Op, DAG);
   1154   case ISD::BR_CC:              return LowerBR_CC(Op, DAG);
   1155   case ISD::SELECT_CC:          return LowerSELECT_CC(Op, DAG);
   1156   case ISD::VASTART:            return LowerVASTART(Op, DAG, *this);
   1157   case ISD::VAARG:              return LowerVAARG(Op, DAG);
   1158   case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
   1159   }
   1160 }
   1161 
   1162 MachineBasicBlock *
   1163 SparcTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
   1164                                                  MachineBasicBlock *BB) const {
   1165   const TargetInstrInfo &TII = *getTargetMachine().getInstrInfo();
   1166   unsigned BROpcode;
   1167   unsigned CC;
   1168   DebugLoc dl = MI->getDebugLoc();
   1169   // Figure out the conditional branch opcode to use for this select_cc.
   1170   switch (MI->getOpcode()) {
   1171   default: llvm_unreachable("Unknown SELECT_CC!");
   1172   case SP::SELECT_CC_Int_ICC:
   1173   case SP::SELECT_CC_FP_ICC:
   1174   case SP::SELECT_CC_DFP_ICC:
   1175     BROpcode = SP::BCOND;
   1176     break;
   1177   case SP::SELECT_CC_Int_FCC:
   1178   case SP::SELECT_CC_FP_FCC:
   1179   case SP::SELECT_CC_DFP_FCC:
   1180     BROpcode = SP::FBCOND;
   1181     break;
   1182   }
   1183 
   1184   CC = (SPCC::CondCodes)MI->getOperand(3).getImm();
   1185 
   1186   // To "insert" a SELECT_CC instruction, we actually have to insert the diamond
   1187   // control-flow pattern.  The incoming instruction knows the destination vreg
   1188   // to set, the condition code register to branch on, the true/false values to
   1189   // select between, and a branch opcode to use.
   1190   const BasicBlock *LLVM_BB = BB->getBasicBlock();
   1191   MachineFunction::iterator It = BB;
   1192   ++It;
   1193 
   1194   //  thisMBB:
   1195   //  ...
   1196   //   TrueVal = ...
   1197   //   [f]bCC copy1MBB
   1198   //   fallthrough --> copy0MBB
   1199   MachineBasicBlock *thisMBB = BB;
   1200   MachineFunction *F = BB->getParent();
   1201   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
   1202   MachineBasicBlock *sinkMBB = F->CreateMachineBasicBlock(LLVM_BB);
   1203   F->insert(It, copy0MBB);
   1204   F->insert(It, sinkMBB);
   1205 
   1206   // Transfer the remainder of BB and its successor edges to sinkMBB.
   1207   sinkMBB->splice(sinkMBB->begin(), BB,
   1208                   llvm::next(MachineBasicBlock::iterator(MI)),
   1209                   BB->end());
   1210   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
   1211 
   1212   // Add the true and fallthrough blocks as its successors.
   1213   BB->addSuccessor(copy0MBB);
   1214   BB->addSuccessor(sinkMBB);
   1215 
   1216   BuildMI(BB, dl, TII.get(BROpcode)).addMBB(sinkMBB).addImm(CC);
   1217 
   1218   //  copy0MBB:
   1219   //   %FalseValue = ...
   1220   //   # fallthrough to sinkMBB
   1221   BB = copy0MBB;
   1222 
   1223   // Update machine-CFG edges
   1224   BB->addSuccessor(sinkMBB);
   1225 
   1226   //  sinkMBB:
   1227   //   %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
   1228   //  ...
   1229   BB = sinkMBB;
   1230   BuildMI(*BB, BB->begin(), dl, TII.get(SP::PHI), MI->getOperand(0).getReg())
   1231     .addReg(MI->getOperand(2).getReg()).addMBB(copy0MBB)
   1232     .addReg(MI->getOperand(1).getReg()).addMBB(thisMBB);
   1233 
   1234   MI->eraseFromParent();   // The pseudo instruction is gone now.
   1235   return BB;
   1236 }
   1237 
   1238 //===----------------------------------------------------------------------===//
   1239 //                         Sparc Inline Assembly Support
   1240 //===----------------------------------------------------------------------===//
   1241 
   1242 /// getConstraintType - Given a constraint letter, return the type of
   1243 /// constraint it is for this target.
   1244 SparcTargetLowering::ConstraintType
   1245 SparcTargetLowering::getConstraintType(const std::string &Constraint) const {
   1246   if (Constraint.size() == 1) {
   1247     switch (Constraint[0]) {
   1248     default:  break;
   1249     case 'r': return C_RegisterClass;
   1250     }
   1251   }
   1252 
   1253   return TargetLowering::getConstraintType(Constraint);
   1254 }
   1255 
   1256 std::pair<unsigned, const TargetRegisterClass*>
   1257 SparcTargetLowering::getRegForInlineAsmConstraint(const std::string &Constraint,
   1258                                                   EVT VT) const {
   1259   if (Constraint.size() == 1) {
   1260     switch (Constraint[0]) {
   1261     case 'r':
   1262       return std::make_pair(0U, SP::IntRegsRegisterClass);
   1263     }
   1264   }
   1265 
   1266   return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
   1267 }
   1268 
   1269 bool
   1270 SparcTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
   1271   // The Sparc target isn't yet aware of offsets.
   1272   return false;
   1273 }
   1274