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      1 //===-- PPCISelDAGToDAG.cpp - PPC --pattern matching inst selector --------===//
      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 defines a pattern matching instruction selector for PowerPC,
     11 // converting from a legalized dag to a PPC dag.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #include "PPC.h"
     16 #include "MCTargetDesc/PPCPredicates.h"
     17 #include "PPCTargetMachine.h"
     18 #include "llvm/CodeGen/MachineFunction.h"
     19 #include "llvm/CodeGen/MachineInstrBuilder.h"
     20 #include "llvm/CodeGen/MachineRegisterInfo.h"
     21 #include "llvm/CodeGen/SelectionDAG.h"
     22 #include "llvm/CodeGen/SelectionDAGISel.h"
     23 #include "llvm/IR/Constants.h"
     24 #include "llvm/IR/Function.h"
     25 #include "llvm/IR/GlobalAlias.h"
     26 #include "llvm/IR/GlobalValue.h"
     27 #include "llvm/IR/GlobalVariable.h"
     28 #include "llvm/IR/Intrinsics.h"
     29 #include "llvm/Support/CommandLine.h"
     30 #include "llvm/Support/Debug.h"
     31 #include "llvm/Support/ErrorHandling.h"
     32 #include "llvm/Support/MathExtras.h"
     33 #include "llvm/Support/raw_ostream.h"
     34 #include "llvm/Target/TargetOptions.h"
     35 using namespace llvm;
     36 
     37 #define DEBUG_TYPE "ppc-codegen"
     38 
     39 // FIXME: Remove this once the bug has been fixed!
     40 cl::opt<bool> ANDIGlueBug("expose-ppc-andi-glue-bug",
     41 cl::desc("expose the ANDI glue bug on PPC"), cl::Hidden);
     42 
     43 namespace llvm {
     44   void initializePPCDAGToDAGISelPass(PassRegistry&);
     45 }
     46 
     47 namespace {
     48   //===--------------------------------------------------------------------===//
     49   /// PPCDAGToDAGISel - PPC specific code to select PPC machine
     50   /// instructions for SelectionDAG operations.
     51   ///
     52   class PPCDAGToDAGISel : public SelectionDAGISel {
     53     const PPCTargetMachine &TM;
     54     const PPCTargetLowering *PPCLowering;
     55     const PPCSubtarget *PPCSubTarget;
     56     unsigned GlobalBaseReg;
     57   public:
     58     explicit PPCDAGToDAGISel(PPCTargetMachine &tm)
     59       : SelectionDAGISel(tm), TM(tm),
     60         PPCLowering(TM.getTargetLowering()),
     61         PPCSubTarget(TM.getSubtargetImpl()) {
     62       initializePPCDAGToDAGISelPass(*PassRegistry::getPassRegistry());
     63     }
     64 
     65     bool runOnMachineFunction(MachineFunction &MF) override {
     66       // Make sure we re-emit a set of the global base reg if necessary
     67       GlobalBaseReg = 0;
     68       PPCLowering = TM.getTargetLowering();
     69       PPCSubTarget = TM.getSubtargetImpl();
     70       SelectionDAGISel::runOnMachineFunction(MF);
     71 
     72       if (!PPCSubTarget->isSVR4ABI())
     73         InsertVRSaveCode(MF);
     74 
     75       return true;
     76     }
     77 
     78     void PostprocessISelDAG() override;
     79 
     80     /// getI32Imm - Return a target constant with the specified value, of type
     81     /// i32.
     82     inline SDValue getI32Imm(unsigned Imm) {
     83       return CurDAG->getTargetConstant(Imm, MVT::i32);
     84     }
     85 
     86     /// getI64Imm - Return a target constant with the specified value, of type
     87     /// i64.
     88     inline SDValue getI64Imm(uint64_t Imm) {
     89       return CurDAG->getTargetConstant(Imm, MVT::i64);
     90     }
     91 
     92     /// getSmallIPtrImm - Return a target constant of pointer type.
     93     inline SDValue getSmallIPtrImm(unsigned Imm) {
     94       return CurDAG->getTargetConstant(Imm, PPCLowering->getPointerTy());
     95     }
     96 
     97     /// isRunOfOnes - Returns true iff Val consists of one contiguous run of 1s
     98     /// with any number of 0s on either side.  The 1s are allowed to wrap from
     99     /// LSB to MSB, so 0x000FFF0, 0x0000FFFF, and 0xFF0000FF are all runs.
    100     /// 0x0F0F0000 is not, since all 1s are not contiguous.
    101     static bool isRunOfOnes(unsigned Val, unsigned &MB, unsigned &ME);
    102 
    103 
    104     /// isRotateAndMask - Returns true if Mask and Shift can be folded into a
    105     /// rotate and mask opcode and mask operation.
    106     static bool isRotateAndMask(SDNode *N, unsigned Mask, bool isShiftMask,
    107                                 unsigned &SH, unsigned &MB, unsigned &ME);
    108 
    109     /// getGlobalBaseReg - insert code into the entry mbb to materialize the PIC
    110     /// base register.  Return the virtual register that holds this value.
    111     SDNode *getGlobalBaseReg();
    112 
    113     // Select - Convert the specified operand from a target-independent to a
    114     // target-specific node if it hasn't already been changed.
    115     SDNode *Select(SDNode *N) override;
    116 
    117     SDNode *SelectBitfieldInsert(SDNode *N);
    118 
    119     /// SelectCC - Select a comparison of the specified values with the
    120     /// specified condition code, returning the CR# of the expression.
    121     SDValue SelectCC(SDValue LHS, SDValue RHS, ISD::CondCode CC, SDLoc dl);
    122 
    123     /// SelectAddrImm - Returns true if the address N can be represented by
    124     /// a base register plus a signed 16-bit displacement [r+imm].
    125     bool SelectAddrImm(SDValue N, SDValue &Disp,
    126                        SDValue &Base) {
    127       return PPCLowering->SelectAddressRegImm(N, Disp, Base, *CurDAG, false);
    128     }
    129 
    130     /// SelectAddrImmOffs - Return true if the operand is valid for a preinc
    131     /// immediate field.  Note that the operand at this point is already the
    132     /// result of a prior SelectAddressRegImm call.
    133     bool SelectAddrImmOffs(SDValue N, SDValue &Out) const {
    134       if (N.getOpcode() == ISD::TargetConstant ||
    135           N.getOpcode() == ISD::TargetGlobalAddress) {
    136         Out = N;
    137         return true;
    138       }
    139 
    140       return false;
    141     }
    142 
    143     /// SelectAddrIdx - Given the specified addressed, check to see if it can be
    144     /// represented as an indexed [r+r] operation.  Returns false if it can
    145     /// be represented by [r+imm], which are preferred.
    146     bool SelectAddrIdx(SDValue N, SDValue &Base, SDValue &Index) {
    147       return PPCLowering->SelectAddressRegReg(N, Base, Index, *CurDAG);
    148     }
    149 
    150     /// SelectAddrIdxOnly - Given the specified addressed, force it to be
    151     /// represented as an indexed [r+r] operation.
    152     bool SelectAddrIdxOnly(SDValue N, SDValue &Base, SDValue &Index) {
    153       return PPCLowering->SelectAddressRegRegOnly(N, Base, Index, *CurDAG);
    154     }
    155 
    156     /// SelectAddrImmX4 - Returns true if the address N can be represented by
    157     /// a base register plus a signed 16-bit displacement that is a multiple of 4.
    158     /// Suitable for use by STD and friends.
    159     bool SelectAddrImmX4(SDValue N, SDValue &Disp, SDValue &Base) {
    160       return PPCLowering->SelectAddressRegImm(N, Disp, Base, *CurDAG, true);
    161     }
    162 
    163     // Select an address into a single register.
    164     bool SelectAddr(SDValue N, SDValue &Base) {
    165       Base = N;
    166       return true;
    167     }
    168 
    169     /// SelectInlineAsmMemoryOperand - Implement addressing mode selection for
    170     /// inline asm expressions.  It is always correct to compute the value into
    171     /// a register.  The case of adding a (possibly relocatable) constant to a
    172     /// register can be improved, but it is wrong to substitute Reg+Reg for
    173     /// Reg in an asm, because the load or store opcode would have to change.
    174    bool SelectInlineAsmMemoryOperand(const SDValue &Op,
    175                                       char ConstraintCode,
    176                                       std::vector<SDValue> &OutOps) override {
    177       OutOps.push_back(Op);
    178       return false;
    179     }
    180 
    181     void InsertVRSaveCode(MachineFunction &MF);
    182 
    183     const char *getPassName() const override {
    184       return "PowerPC DAG->DAG Pattern Instruction Selection";
    185     }
    186 
    187 // Include the pieces autogenerated from the target description.
    188 #include "PPCGenDAGISel.inc"
    189 
    190 private:
    191     SDNode *SelectSETCC(SDNode *N);
    192 
    193     void PeepholePPC64();
    194     void PeepholeCROps();
    195 
    196     bool AllUsersSelectZero(SDNode *N);
    197     void SwapAllSelectUsers(SDNode *N);
    198   };
    199 }
    200 
    201 /// InsertVRSaveCode - Once the entire function has been instruction selected,
    202 /// all virtual registers are created and all machine instructions are built,
    203 /// check to see if we need to save/restore VRSAVE.  If so, do it.
    204 void PPCDAGToDAGISel::InsertVRSaveCode(MachineFunction &Fn) {
    205   // Check to see if this function uses vector registers, which means we have to
    206   // save and restore the VRSAVE register and update it with the regs we use.
    207   //
    208   // In this case, there will be virtual registers of vector type created
    209   // by the scheduler.  Detect them now.
    210   bool HasVectorVReg = false;
    211   for (unsigned i = 0, e = RegInfo->getNumVirtRegs(); i != e; ++i) {
    212     unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
    213     if (RegInfo->getRegClass(Reg) == &PPC::VRRCRegClass) {
    214       HasVectorVReg = true;
    215       break;
    216     }
    217   }
    218   if (!HasVectorVReg) return;  // nothing to do.
    219 
    220   // If we have a vector register, we want to emit code into the entry and exit
    221   // blocks to save and restore the VRSAVE register.  We do this here (instead
    222   // of marking all vector instructions as clobbering VRSAVE) for two reasons:
    223   //
    224   // 1. This (trivially) reduces the load on the register allocator, by not
    225   //    having to represent the live range of the VRSAVE register.
    226   // 2. This (more significantly) allows us to create a temporary virtual
    227   //    register to hold the saved VRSAVE value, allowing this temporary to be
    228   //    register allocated, instead of forcing it to be spilled to the stack.
    229 
    230   // Create two vregs - one to hold the VRSAVE register that is live-in to the
    231   // function and one for the value after having bits or'd into it.
    232   unsigned InVRSAVE = RegInfo->createVirtualRegister(&PPC::GPRCRegClass);
    233   unsigned UpdatedVRSAVE = RegInfo->createVirtualRegister(&PPC::GPRCRegClass);
    234 
    235   const TargetInstrInfo &TII = *TM.getInstrInfo();
    236   MachineBasicBlock &EntryBB = *Fn.begin();
    237   DebugLoc dl;
    238   // Emit the following code into the entry block:
    239   // InVRSAVE = MFVRSAVE
    240   // UpdatedVRSAVE = UPDATE_VRSAVE InVRSAVE
    241   // MTVRSAVE UpdatedVRSAVE
    242   MachineBasicBlock::iterator IP = EntryBB.begin();  // Insert Point
    243   BuildMI(EntryBB, IP, dl, TII.get(PPC::MFVRSAVE), InVRSAVE);
    244   BuildMI(EntryBB, IP, dl, TII.get(PPC::UPDATE_VRSAVE),
    245           UpdatedVRSAVE).addReg(InVRSAVE);
    246   BuildMI(EntryBB, IP, dl, TII.get(PPC::MTVRSAVE)).addReg(UpdatedVRSAVE);
    247 
    248   // Find all return blocks, outputting a restore in each epilog.
    249   for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) {
    250     if (!BB->empty() && BB->back().isReturn()) {
    251       IP = BB->end(); --IP;
    252 
    253       // Skip over all terminator instructions, which are part of the return
    254       // sequence.
    255       MachineBasicBlock::iterator I2 = IP;
    256       while (I2 != BB->begin() && (--I2)->isTerminator())
    257         IP = I2;
    258 
    259       // Emit: MTVRSAVE InVRSave
    260       BuildMI(*BB, IP, dl, TII.get(PPC::MTVRSAVE)).addReg(InVRSAVE);
    261     }
    262   }
    263 }
    264 
    265 
    266 /// getGlobalBaseReg - Output the instructions required to put the
    267 /// base address to use for accessing globals into a register.
    268 ///
    269 SDNode *PPCDAGToDAGISel::getGlobalBaseReg() {
    270   if (!GlobalBaseReg) {
    271     const TargetInstrInfo &TII = *TM.getInstrInfo();
    272     // Insert the set of GlobalBaseReg into the first MBB of the function
    273     MachineBasicBlock &FirstMBB = MF->front();
    274     MachineBasicBlock::iterator MBBI = FirstMBB.begin();
    275     DebugLoc dl;
    276 
    277     if (PPCLowering->getPointerTy() == MVT::i32) {
    278       GlobalBaseReg = RegInfo->createVirtualRegister(&PPC::GPRC_NOR0RegClass);
    279       BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR));
    280       BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR), GlobalBaseReg);
    281     } else {
    282       GlobalBaseReg = RegInfo->createVirtualRegister(&PPC::G8RC_NOX0RegClass);
    283       BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR8));
    284       BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR8), GlobalBaseReg);
    285     }
    286   }
    287   return CurDAG->getRegister(GlobalBaseReg,
    288                              PPCLowering->getPointerTy()).getNode();
    289 }
    290 
    291 /// isIntS16Immediate - This method tests to see if the node is either a 32-bit
    292 /// or 64-bit immediate, and if the value can be accurately represented as a
    293 /// sign extension from a 16-bit value.  If so, this returns true and the
    294 /// immediate.
    295 static bool isIntS16Immediate(SDNode *N, short &Imm) {
    296   if (N->getOpcode() != ISD::Constant)
    297     return false;
    298 
    299   Imm = (short)cast<ConstantSDNode>(N)->getZExtValue();
    300   if (N->getValueType(0) == MVT::i32)
    301     return Imm == (int32_t)cast<ConstantSDNode>(N)->getZExtValue();
    302   else
    303     return Imm == (int64_t)cast<ConstantSDNode>(N)->getZExtValue();
    304 }
    305 
    306 static bool isIntS16Immediate(SDValue Op, short &Imm) {
    307   return isIntS16Immediate(Op.getNode(), Imm);
    308 }
    309 
    310 
    311 /// isInt32Immediate - This method tests to see if the node is a 32-bit constant
    312 /// operand. If so Imm will receive the 32-bit value.
    313 static bool isInt32Immediate(SDNode *N, unsigned &Imm) {
    314   if (N->getOpcode() == ISD::Constant && N->getValueType(0) == MVT::i32) {
    315     Imm = cast<ConstantSDNode>(N)->getZExtValue();
    316     return true;
    317   }
    318   return false;
    319 }
    320 
    321 /// isInt64Immediate - This method tests to see if the node is a 64-bit constant
    322 /// operand.  If so Imm will receive the 64-bit value.
    323 static bool isInt64Immediate(SDNode *N, uint64_t &Imm) {
    324   if (N->getOpcode() == ISD::Constant && N->getValueType(0) == MVT::i64) {
    325     Imm = cast<ConstantSDNode>(N)->getZExtValue();
    326     return true;
    327   }
    328   return false;
    329 }
    330 
    331 // isInt32Immediate - This method tests to see if a constant operand.
    332 // If so Imm will receive the 32 bit value.
    333 static bool isInt32Immediate(SDValue N, unsigned &Imm) {
    334   return isInt32Immediate(N.getNode(), Imm);
    335 }
    336 
    337 
    338 // isOpcWithIntImmediate - This method tests to see if the node is a specific
    339 // opcode and that it has a immediate integer right operand.
    340 // If so Imm will receive the 32 bit value.
    341 static bool isOpcWithIntImmediate(SDNode *N, unsigned Opc, unsigned& Imm) {
    342   return N->getOpcode() == Opc
    343          && isInt32Immediate(N->getOperand(1).getNode(), Imm);
    344 }
    345 
    346 bool PPCDAGToDAGISel::isRunOfOnes(unsigned Val, unsigned &MB, unsigned &ME) {
    347   if (!Val)
    348     return false;
    349 
    350   if (isShiftedMask_32(Val)) {
    351     // look for the first non-zero bit
    352     MB = countLeadingZeros(Val);
    353     // look for the first zero bit after the run of ones
    354     ME = countLeadingZeros((Val - 1) ^ Val);
    355     return true;
    356   } else {
    357     Val = ~Val; // invert mask
    358     if (isShiftedMask_32(Val)) {
    359       // effectively look for the first zero bit
    360       ME = countLeadingZeros(Val) - 1;
    361       // effectively look for the first one bit after the run of zeros
    362       MB = countLeadingZeros((Val - 1) ^ Val) + 1;
    363       return true;
    364     }
    365   }
    366   // no run present
    367   return false;
    368 }
    369 
    370 bool PPCDAGToDAGISel::isRotateAndMask(SDNode *N, unsigned Mask,
    371                                       bool isShiftMask, unsigned &SH,
    372                                       unsigned &MB, unsigned &ME) {
    373   // Don't even go down this path for i64, since different logic will be
    374   // necessary for rldicl/rldicr/rldimi.
    375   if (N->getValueType(0) != MVT::i32)
    376     return false;
    377 
    378   unsigned Shift  = 32;
    379   unsigned Indeterminant = ~0;  // bit mask marking indeterminant results
    380   unsigned Opcode = N->getOpcode();
    381   if (N->getNumOperands() != 2 ||
    382       !isInt32Immediate(N->getOperand(1).getNode(), Shift) || (Shift > 31))
    383     return false;
    384 
    385   if (Opcode == ISD::SHL) {
    386     // apply shift left to mask if it comes first
    387     if (isShiftMask) Mask = Mask << Shift;
    388     // determine which bits are made indeterminant by shift
    389     Indeterminant = ~(0xFFFFFFFFu << Shift);
    390   } else if (Opcode == ISD::SRL) {
    391     // apply shift right to mask if it comes first
    392     if (isShiftMask) Mask = Mask >> Shift;
    393     // determine which bits are made indeterminant by shift
    394     Indeterminant = ~(0xFFFFFFFFu >> Shift);
    395     // adjust for the left rotate
    396     Shift = 32 - Shift;
    397   } else if (Opcode == ISD::ROTL) {
    398     Indeterminant = 0;
    399   } else {
    400     return false;
    401   }
    402 
    403   // if the mask doesn't intersect any Indeterminant bits
    404   if (Mask && !(Mask & Indeterminant)) {
    405     SH = Shift & 31;
    406     // make sure the mask is still a mask (wrap arounds may not be)
    407     return isRunOfOnes(Mask, MB, ME);
    408   }
    409   return false;
    410 }
    411 
    412 /// SelectBitfieldInsert - turn an or of two masked values into
    413 /// the rotate left word immediate then mask insert (rlwimi) instruction.
    414 SDNode *PPCDAGToDAGISel::SelectBitfieldInsert(SDNode *N) {
    415   SDValue Op0 = N->getOperand(0);
    416   SDValue Op1 = N->getOperand(1);
    417   SDLoc dl(N);
    418 
    419   APInt LKZ, LKO, RKZ, RKO;
    420   CurDAG->computeKnownBits(Op0, LKZ, LKO);
    421   CurDAG->computeKnownBits(Op1, RKZ, RKO);
    422 
    423   unsigned TargetMask = LKZ.getZExtValue();
    424   unsigned InsertMask = RKZ.getZExtValue();
    425 
    426   if ((TargetMask | InsertMask) == 0xFFFFFFFF) {
    427     unsigned Op0Opc = Op0.getOpcode();
    428     unsigned Op1Opc = Op1.getOpcode();
    429     unsigned Value, SH = 0;
    430     TargetMask = ~TargetMask;
    431     InsertMask = ~InsertMask;
    432 
    433     // If the LHS has a foldable shift and the RHS does not, then swap it to the
    434     // RHS so that we can fold the shift into the insert.
    435     if (Op0Opc == ISD::AND && Op1Opc == ISD::AND) {
    436       if (Op0.getOperand(0).getOpcode() == ISD::SHL ||
    437           Op0.getOperand(0).getOpcode() == ISD::SRL) {
    438         if (Op1.getOperand(0).getOpcode() != ISD::SHL &&
    439             Op1.getOperand(0).getOpcode() != ISD::SRL) {
    440           std::swap(Op0, Op1);
    441           std::swap(Op0Opc, Op1Opc);
    442           std::swap(TargetMask, InsertMask);
    443         }
    444       }
    445     } else if (Op0Opc == ISD::SHL || Op0Opc == ISD::SRL) {
    446       if (Op1Opc == ISD::AND && Op1.getOperand(0).getOpcode() != ISD::SHL &&
    447           Op1.getOperand(0).getOpcode() != ISD::SRL) {
    448         std::swap(Op0, Op1);
    449         std::swap(Op0Opc, Op1Opc);
    450         std::swap(TargetMask, InsertMask);
    451       }
    452     }
    453 
    454     unsigned MB, ME;
    455     if (isRunOfOnes(InsertMask, MB, ME)) {
    456       SDValue Tmp1, Tmp2;
    457 
    458       if ((Op1Opc == ISD::SHL || Op1Opc == ISD::SRL) &&
    459           isInt32Immediate(Op1.getOperand(1), Value)) {
    460         Op1 = Op1.getOperand(0);
    461         SH  = (Op1Opc == ISD::SHL) ? Value : 32 - Value;
    462       }
    463       if (Op1Opc == ISD::AND) {
    464        // The AND mask might not be a constant, and we need to make sure that
    465        // if we're going to fold the masking with the insert, all bits not
    466        // know to be zero in the mask are known to be one.
    467         APInt MKZ, MKO;
    468         CurDAG->computeKnownBits(Op1.getOperand(1), MKZ, MKO);
    469         bool CanFoldMask = InsertMask == MKO.getZExtValue();
    470 
    471         unsigned SHOpc = Op1.getOperand(0).getOpcode();
    472         if ((SHOpc == ISD::SHL || SHOpc == ISD::SRL) && CanFoldMask &&
    473             isInt32Immediate(Op1.getOperand(0).getOperand(1), Value)) {
    474           // Note that Value must be in range here (less than 32) because
    475           // otherwise there would not be any bits set in InsertMask.
    476           Op1 = Op1.getOperand(0).getOperand(0);
    477           SH  = (SHOpc == ISD::SHL) ? Value : 32 - Value;
    478         }
    479       }
    480 
    481       SH &= 31;
    482       SDValue Ops[] = { Op0, Op1, getI32Imm(SH), getI32Imm(MB),
    483                           getI32Imm(ME) };
    484       return CurDAG->getMachineNode(PPC::RLWIMI, dl, MVT::i32, Ops);
    485     }
    486   }
    487   return nullptr;
    488 }
    489 
    490 /// SelectCC - Select a comparison of the specified values with the specified
    491 /// condition code, returning the CR# of the expression.
    492 SDValue PPCDAGToDAGISel::SelectCC(SDValue LHS, SDValue RHS,
    493                                     ISD::CondCode CC, SDLoc dl) {
    494   // Always select the LHS.
    495   unsigned Opc;
    496 
    497   if (LHS.getValueType() == MVT::i32) {
    498     unsigned Imm;
    499     if (CC == ISD::SETEQ || CC == ISD::SETNE) {
    500       if (isInt32Immediate(RHS, Imm)) {
    501         // SETEQ/SETNE comparison with 16-bit immediate, fold it.
    502         if (isUInt<16>(Imm))
    503           return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, LHS,
    504                                                 getI32Imm(Imm & 0xFFFF)), 0);
    505         // If this is a 16-bit signed immediate, fold it.
    506         if (isInt<16>((int)Imm))
    507           return SDValue(CurDAG->getMachineNode(PPC::CMPWI, dl, MVT::i32, LHS,
    508                                                 getI32Imm(Imm & 0xFFFF)), 0);
    509 
    510         // For non-equality comparisons, the default code would materialize the
    511         // constant, then compare against it, like this:
    512         //   lis r2, 4660
    513         //   ori r2, r2, 22136
    514         //   cmpw cr0, r3, r2
    515         // Since we are just comparing for equality, we can emit this instead:
    516         //   xoris r0,r3,0x1234
    517         //   cmplwi cr0,r0,0x5678
    518         //   beq cr0,L6
    519         SDValue Xor(CurDAG->getMachineNode(PPC::XORIS, dl, MVT::i32, LHS,
    520                                            getI32Imm(Imm >> 16)), 0);
    521         return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, Xor,
    522                                               getI32Imm(Imm & 0xFFFF)), 0);
    523       }
    524       Opc = PPC::CMPLW;
    525     } else if (ISD::isUnsignedIntSetCC(CC)) {
    526       if (isInt32Immediate(RHS, Imm) && isUInt<16>(Imm))
    527         return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, LHS,
    528                                               getI32Imm(Imm & 0xFFFF)), 0);
    529       Opc = PPC::CMPLW;
    530     } else {
    531       short SImm;
    532       if (isIntS16Immediate(RHS, SImm))
    533         return SDValue(CurDAG->getMachineNode(PPC::CMPWI, dl, MVT::i32, LHS,
    534                                               getI32Imm((int)SImm & 0xFFFF)),
    535                          0);
    536       Opc = PPC::CMPW;
    537     }
    538   } else if (LHS.getValueType() == MVT::i64) {
    539     uint64_t Imm;
    540     if (CC == ISD::SETEQ || CC == ISD::SETNE) {
    541       if (isInt64Immediate(RHS.getNode(), Imm)) {
    542         // SETEQ/SETNE comparison with 16-bit immediate, fold it.
    543         if (isUInt<16>(Imm))
    544           return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, LHS,
    545                                                 getI32Imm(Imm & 0xFFFF)), 0);
    546         // If this is a 16-bit signed immediate, fold it.
    547         if (isInt<16>(Imm))
    548           return SDValue(CurDAG->getMachineNode(PPC::CMPDI, dl, MVT::i64, LHS,
    549                                                 getI32Imm(Imm & 0xFFFF)), 0);
    550 
    551         // For non-equality comparisons, the default code would materialize the
    552         // constant, then compare against it, like this:
    553         //   lis r2, 4660
    554         //   ori r2, r2, 22136
    555         //   cmpd cr0, r3, r2
    556         // Since we are just comparing for equality, we can emit this instead:
    557         //   xoris r0,r3,0x1234
    558         //   cmpldi cr0,r0,0x5678
    559         //   beq cr0,L6
    560         if (isUInt<32>(Imm)) {
    561           SDValue Xor(CurDAG->getMachineNode(PPC::XORIS8, dl, MVT::i64, LHS,
    562                                              getI64Imm(Imm >> 16)), 0);
    563           return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, Xor,
    564                                                 getI64Imm(Imm & 0xFFFF)), 0);
    565         }
    566       }
    567       Opc = PPC::CMPLD;
    568     } else if (ISD::isUnsignedIntSetCC(CC)) {
    569       if (isInt64Immediate(RHS.getNode(), Imm) && isUInt<16>(Imm))
    570         return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, LHS,
    571                                               getI64Imm(Imm & 0xFFFF)), 0);
    572       Opc = PPC::CMPLD;
    573     } else {
    574       short SImm;
    575       if (isIntS16Immediate(RHS, SImm))
    576         return SDValue(CurDAG->getMachineNode(PPC::CMPDI, dl, MVT::i64, LHS,
    577                                               getI64Imm(SImm & 0xFFFF)),
    578                          0);
    579       Opc = PPC::CMPD;
    580     }
    581   } else if (LHS.getValueType() == MVT::f32) {
    582     Opc = PPC::FCMPUS;
    583   } else {
    584     assert(LHS.getValueType() == MVT::f64 && "Unknown vt!");
    585     Opc = PPCSubTarget->hasVSX() ? PPC::XSCMPUDP : PPC::FCMPUD;
    586   }
    587   return SDValue(CurDAG->getMachineNode(Opc, dl, MVT::i32, LHS, RHS), 0);
    588 }
    589 
    590 static PPC::Predicate getPredicateForSetCC(ISD::CondCode CC) {
    591   switch (CC) {
    592   case ISD::SETUEQ:
    593   case ISD::SETONE:
    594   case ISD::SETOLE:
    595   case ISD::SETOGE:
    596     llvm_unreachable("Should be lowered by legalize!");
    597   default: llvm_unreachable("Unknown condition!");
    598   case ISD::SETOEQ:
    599   case ISD::SETEQ:  return PPC::PRED_EQ;
    600   case ISD::SETUNE:
    601   case ISD::SETNE:  return PPC::PRED_NE;
    602   case ISD::SETOLT:
    603   case ISD::SETLT:  return PPC::PRED_LT;
    604   case ISD::SETULE:
    605   case ISD::SETLE:  return PPC::PRED_LE;
    606   case ISD::SETOGT:
    607   case ISD::SETGT:  return PPC::PRED_GT;
    608   case ISD::SETUGE:
    609   case ISD::SETGE:  return PPC::PRED_GE;
    610   case ISD::SETO:   return PPC::PRED_NU;
    611   case ISD::SETUO:  return PPC::PRED_UN;
    612     // These two are invalid for floating point.  Assume we have int.
    613   case ISD::SETULT: return PPC::PRED_LT;
    614   case ISD::SETUGT: return PPC::PRED_GT;
    615   }
    616 }
    617 
    618 /// getCRIdxForSetCC - Return the index of the condition register field
    619 /// associated with the SetCC condition, and whether or not the field is
    620 /// treated as inverted.  That is, lt = 0; ge = 0 inverted.
    621 static unsigned getCRIdxForSetCC(ISD::CondCode CC, bool &Invert) {
    622   Invert = false;
    623   switch (CC) {
    624   default: llvm_unreachable("Unknown condition!");
    625   case ISD::SETOLT:
    626   case ISD::SETLT:  return 0;                  // Bit #0 = SETOLT
    627   case ISD::SETOGT:
    628   case ISD::SETGT:  return 1;                  // Bit #1 = SETOGT
    629   case ISD::SETOEQ:
    630   case ISD::SETEQ:  return 2;                  // Bit #2 = SETOEQ
    631   case ISD::SETUO:  return 3;                  // Bit #3 = SETUO
    632   case ISD::SETUGE:
    633   case ISD::SETGE:  Invert = true; return 0;   // !Bit #0 = SETUGE
    634   case ISD::SETULE:
    635   case ISD::SETLE:  Invert = true; return 1;   // !Bit #1 = SETULE
    636   case ISD::SETUNE:
    637   case ISD::SETNE:  Invert = true; return 2;   // !Bit #2 = SETUNE
    638   case ISD::SETO:   Invert = true; return 3;   // !Bit #3 = SETO
    639   case ISD::SETUEQ:
    640   case ISD::SETOGE:
    641   case ISD::SETOLE:
    642   case ISD::SETONE:
    643     llvm_unreachable("Invalid branch code: should be expanded by legalize");
    644   // These are invalid for floating point.  Assume integer.
    645   case ISD::SETULT: return 0;
    646   case ISD::SETUGT: return 1;
    647   }
    648 }
    649 
    650 // getVCmpInst: return the vector compare instruction for the specified
    651 // vector type and condition code. Since this is for altivec specific code,
    652 // only support the altivec types (v16i8, v8i16, v4i32, and v4f32).
    653 static unsigned int getVCmpInst(MVT::SimpleValueType VecVT, ISD::CondCode CC,
    654                                 bool HasVSX) {
    655   switch (CC) {
    656     case ISD::SETEQ:
    657     case ISD::SETUEQ:
    658     case ISD::SETNE:
    659     case ISD::SETUNE:
    660       if (VecVT == MVT::v16i8)
    661         return PPC::VCMPEQUB;
    662       else if (VecVT == MVT::v8i16)
    663         return PPC::VCMPEQUH;
    664       else if (VecVT == MVT::v4i32)
    665         return PPC::VCMPEQUW;
    666       // v4f32 != v4f32 could be translate to unordered not equal
    667       else if (VecVT == MVT::v4f32)
    668         return HasVSX ? PPC::XVCMPEQSP : PPC::VCMPEQFP;
    669       else if (VecVT == MVT::v2f64)
    670         return PPC::XVCMPEQDP;
    671       break;
    672     case ISD::SETLT:
    673     case ISD::SETGT:
    674     case ISD::SETLE:
    675     case ISD::SETGE:
    676       if (VecVT == MVT::v16i8)
    677         return PPC::VCMPGTSB;
    678       else if (VecVT == MVT::v8i16)
    679         return PPC::VCMPGTSH;
    680       else if (VecVT == MVT::v4i32)
    681         return PPC::VCMPGTSW;
    682       else if (VecVT == MVT::v4f32)
    683         return HasVSX ? PPC::XVCMPGTSP : PPC::VCMPGTFP;
    684       else if (VecVT == MVT::v2f64)
    685         return PPC::XVCMPGTDP;
    686       break;
    687     case ISD::SETULT:
    688     case ISD::SETUGT:
    689     case ISD::SETUGE:
    690     case ISD::SETULE:
    691       if (VecVT == MVT::v16i8)
    692         return PPC::VCMPGTUB;
    693       else if (VecVT == MVT::v8i16)
    694         return PPC::VCMPGTUH;
    695       else if (VecVT == MVT::v4i32)
    696         return PPC::VCMPGTUW;
    697       break;
    698     case ISD::SETOEQ:
    699       if (VecVT == MVT::v4f32)
    700         return HasVSX ? PPC::XVCMPEQSP : PPC::VCMPEQFP;
    701       else if (VecVT == MVT::v2f64)
    702         return PPC::XVCMPEQDP;
    703       break;
    704     case ISD::SETOLT:
    705     case ISD::SETOGT:
    706     case ISD::SETOLE:
    707       if (VecVT == MVT::v4f32)
    708         return HasVSX ? PPC::XVCMPGTSP : PPC::VCMPGTFP;
    709       else if (VecVT == MVT::v2f64)
    710         return PPC::XVCMPGTDP;
    711       break;
    712     case ISD::SETOGE:
    713       if (VecVT == MVT::v4f32)
    714         return HasVSX ? PPC::XVCMPGESP : PPC::VCMPGEFP;
    715       else if (VecVT == MVT::v2f64)
    716         return PPC::XVCMPGEDP;
    717       break;
    718     default:
    719       break;
    720   }
    721   llvm_unreachable("Invalid integer vector compare condition");
    722 }
    723 
    724 // getVCmpEQInst: return the equal compare instruction for the specified vector
    725 // type. Since this is for altivec specific code, only support the altivec
    726 // types (v16i8, v8i16, v4i32, and v4f32).
    727 static unsigned int getVCmpEQInst(MVT::SimpleValueType VecVT, bool HasVSX) {
    728   switch (VecVT) {
    729     case MVT::v16i8:
    730       return PPC::VCMPEQUB;
    731     case MVT::v8i16:
    732       return PPC::VCMPEQUH;
    733     case MVT::v4i32:
    734       return PPC::VCMPEQUW;
    735     case MVT::v4f32:
    736       return HasVSX ? PPC::XVCMPEQSP : PPC::VCMPEQFP;
    737     case MVT::v2f64:
    738       return PPC::XVCMPEQDP;
    739     default:
    740       llvm_unreachable("Invalid integer vector compare condition");
    741   }
    742 }
    743 
    744 SDNode *PPCDAGToDAGISel::SelectSETCC(SDNode *N) {
    745   SDLoc dl(N);
    746   unsigned Imm;
    747   ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
    748   EVT PtrVT = CurDAG->getTargetLoweringInfo().getPointerTy();
    749   bool isPPC64 = (PtrVT == MVT::i64);
    750 
    751   if (!PPCSubTarget->useCRBits() &&
    752       isInt32Immediate(N->getOperand(1), Imm)) {
    753     // We can codegen setcc op, imm very efficiently compared to a brcond.
    754     // Check for those cases here.
    755     // setcc op, 0
    756     if (Imm == 0) {
    757       SDValue Op = N->getOperand(0);
    758       switch (CC) {
    759       default: break;
    760       case ISD::SETEQ: {
    761         Op = SDValue(CurDAG->getMachineNode(PPC::CNTLZW, dl, MVT::i32, Op), 0);
    762         SDValue Ops[] = { Op, getI32Imm(27), getI32Imm(5), getI32Imm(31) };
    763         return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
    764       }
    765       case ISD::SETNE: {
    766         if (isPPC64) break;
    767         SDValue AD =
    768           SDValue(CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
    769                                          Op, getI32Imm(~0U)), 0);
    770         return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, AD, Op,
    771                                     AD.getValue(1));
    772       }
    773       case ISD::SETLT: {
    774         SDValue Ops[] = { Op, getI32Imm(1), getI32Imm(31), getI32Imm(31) };
    775         return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
    776       }
    777       case ISD::SETGT: {
    778         SDValue T =
    779           SDValue(CurDAG->getMachineNode(PPC::NEG, dl, MVT::i32, Op), 0);
    780         T = SDValue(CurDAG->getMachineNode(PPC::ANDC, dl, MVT::i32, T, Op), 0);
    781         SDValue Ops[] = { T, getI32Imm(1), getI32Imm(31), getI32Imm(31) };
    782         return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
    783       }
    784       }
    785     } else if (Imm == ~0U) {        // setcc op, -1
    786       SDValue Op = N->getOperand(0);
    787       switch (CC) {
    788       default: break;
    789       case ISD::SETEQ:
    790         if (isPPC64) break;
    791         Op = SDValue(CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
    792                                             Op, getI32Imm(1)), 0);
    793         return CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32,
    794                               SDValue(CurDAG->getMachineNode(PPC::LI, dl,
    795                                                              MVT::i32,
    796                                                              getI32Imm(0)), 0),
    797                                       Op.getValue(1));
    798       case ISD::SETNE: {
    799         if (isPPC64) break;
    800         Op = SDValue(CurDAG->getMachineNode(PPC::NOR, dl, MVT::i32, Op, Op), 0);
    801         SDNode *AD = CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
    802                                             Op, getI32Imm(~0U));
    803         return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, SDValue(AD, 0),
    804                                     Op, SDValue(AD, 1));
    805       }
    806       case ISD::SETLT: {
    807         SDValue AD = SDValue(CurDAG->getMachineNode(PPC::ADDI, dl, MVT::i32, Op,
    808                                                     getI32Imm(1)), 0);
    809         SDValue AN = SDValue(CurDAG->getMachineNode(PPC::AND, dl, MVT::i32, AD,
    810                                                     Op), 0);
    811         SDValue Ops[] = { AN, getI32Imm(1), getI32Imm(31), getI32Imm(31) };
    812         return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
    813       }
    814       case ISD::SETGT: {
    815         SDValue Ops[] = { Op, getI32Imm(1), getI32Imm(31), getI32Imm(31) };
    816         Op = SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops),
    817                      0);
    818         return CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Op,
    819                                     getI32Imm(1));
    820       }
    821       }
    822     }
    823   }
    824 
    825   SDValue LHS = N->getOperand(0);
    826   SDValue RHS = N->getOperand(1);
    827 
    828   // Altivec Vector compare instructions do not set any CR register by default and
    829   // vector compare operations return the same type as the operands.
    830   if (LHS.getValueType().isVector()) {
    831     EVT VecVT = LHS.getValueType();
    832     MVT::SimpleValueType VT = VecVT.getSimpleVT().SimpleTy;
    833     unsigned int VCmpInst = getVCmpInst(VT, CC, PPCSubTarget->hasVSX());
    834 
    835     switch (CC) {
    836       case ISD::SETEQ:
    837       case ISD::SETOEQ:
    838       case ISD::SETUEQ:
    839         return CurDAG->SelectNodeTo(N, VCmpInst, VecVT, LHS, RHS);
    840       case ISD::SETNE:
    841       case ISD::SETONE:
    842       case ISD::SETUNE: {
    843         SDValue VCmp(CurDAG->getMachineNode(VCmpInst, dl, VecVT, LHS, RHS), 0);
    844         return CurDAG->SelectNodeTo(N, PPCSubTarget->hasVSX() ? PPC::XXLNOR :
    845                                                                PPC::VNOR,
    846                                     VecVT, VCmp, VCmp);
    847       }
    848       case ISD::SETLT:
    849       case ISD::SETOLT:
    850       case ISD::SETULT:
    851         return CurDAG->SelectNodeTo(N, VCmpInst, VecVT, RHS, LHS);
    852       case ISD::SETGT:
    853       case ISD::SETOGT:
    854       case ISD::SETUGT:
    855         return CurDAG->SelectNodeTo(N, VCmpInst, VecVT, LHS, RHS);
    856       case ISD::SETGE:
    857       case ISD::SETOGE:
    858       case ISD::SETUGE: {
    859         // Small optimization: Altivec provides a 'Vector Compare Greater Than
    860         // or Equal To' instruction (vcmpgefp), so in this case there is no
    861         // need for extra logic for the equal compare.
    862         if (VecVT.getSimpleVT().isFloatingPoint()) {
    863           return CurDAG->SelectNodeTo(N, VCmpInst, VecVT, LHS, RHS);
    864         } else {
    865           SDValue VCmpGT(CurDAG->getMachineNode(VCmpInst, dl, VecVT, LHS, RHS), 0);
    866           unsigned int VCmpEQInst = getVCmpEQInst(VT, PPCSubTarget->hasVSX());
    867           SDValue VCmpEQ(CurDAG->getMachineNode(VCmpEQInst, dl, VecVT, LHS, RHS), 0);
    868           return CurDAG->SelectNodeTo(N, PPCSubTarget->hasVSX() ? PPC::XXLOR :
    869                                                                  PPC::VOR,
    870                                       VecVT, VCmpGT, VCmpEQ);
    871         }
    872       }
    873       case ISD::SETLE:
    874       case ISD::SETOLE:
    875       case ISD::SETULE: {
    876         SDValue VCmpLE(CurDAG->getMachineNode(VCmpInst, dl, VecVT, RHS, LHS), 0);
    877         unsigned int VCmpEQInst = getVCmpEQInst(VT, PPCSubTarget->hasVSX());
    878         SDValue VCmpEQ(CurDAG->getMachineNode(VCmpEQInst, dl, VecVT, LHS, RHS), 0);
    879         return CurDAG->SelectNodeTo(N, PPCSubTarget->hasVSX() ? PPC::XXLOR :
    880                                                                PPC::VOR,
    881                                     VecVT, VCmpLE, VCmpEQ);
    882       }
    883       default:
    884         llvm_unreachable("Invalid vector compare type: should be expanded by legalize");
    885     }
    886   }
    887 
    888   if (PPCSubTarget->useCRBits())
    889     return nullptr;
    890 
    891   bool Inv;
    892   unsigned Idx = getCRIdxForSetCC(CC, Inv);
    893   SDValue CCReg = SelectCC(LHS, RHS, CC, dl);
    894   SDValue IntCR;
    895 
    896   // Force the ccreg into CR7.
    897   SDValue CR7Reg = CurDAG->getRegister(PPC::CR7, MVT::i32);
    898 
    899   SDValue InFlag(nullptr, 0);  // Null incoming flag value.
    900   CCReg = CurDAG->getCopyToReg(CurDAG->getEntryNode(), dl, CR7Reg, CCReg,
    901                                InFlag).getValue(1);
    902 
    903   IntCR = SDValue(CurDAG->getMachineNode(PPC::MFOCRF, dl, MVT::i32, CR7Reg,
    904                                          CCReg), 0);
    905 
    906   SDValue Ops[] = { IntCR, getI32Imm((32-(3-Idx)) & 31),
    907                       getI32Imm(31), getI32Imm(31) };
    908   if (!Inv)
    909     return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
    910 
    911   // Get the specified bit.
    912   SDValue Tmp =
    913     SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops), 0);
    914   return CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Tmp, getI32Imm(1));
    915 }
    916 
    917 
    918 // Select - Convert the specified operand from a target-independent to a
    919 // target-specific node if it hasn't already been changed.
    920 SDNode *PPCDAGToDAGISel::Select(SDNode *N) {
    921   SDLoc dl(N);
    922   if (N->isMachineOpcode()) {
    923     N->setNodeId(-1);
    924     return nullptr;   // Already selected.
    925   }
    926 
    927   switch (N->getOpcode()) {
    928   default: break;
    929 
    930   case ISD::Constant: {
    931     if (N->getValueType(0) == MVT::i64) {
    932       // Get 64 bit value.
    933       int64_t Imm = cast<ConstantSDNode>(N)->getZExtValue();
    934       // Assume no remaining bits.
    935       unsigned Remainder = 0;
    936       // Assume no shift required.
    937       unsigned Shift = 0;
    938 
    939       // If it can't be represented as a 32 bit value.
    940       if (!isInt<32>(Imm)) {
    941         Shift = countTrailingZeros<uint64_t>(Imm);
    942         int64_t ImmSh = static_cast<uint64_t>(Imm) >> Shift;
    943 
    944         // If the shifted value fits 32 bits.
    945         if (isInt<32>(ImmSh)) {
    946           // Go with the shifted value.
    947           Imm = ImmSh;
    948         } else {
    949           // Still stuck with a 64 bit value.
    950           Remainder = Imm;
    951           Shift = 32;
    952           Imm >>= 32;
    953         }
    954       }
    955 
    956       // Intermediate operand.
    957       SDNode *Result;
    958 
    959       // Handle first 32 bits.
    960       unsigned Lo = Imm & 0xFFFF;
    961       unsigned Hi = (Imm >> 16) & 0xFFFF;
    962 
    963       // Simple value.
    964       if (isInt<16>(Imm)) {
    965        // Just the Lo bits.
    966         Result = CurDAG->getMachineNode(PPC::LI8, dl, MVT::i64, getI32Imm(Lo));
    967       } else if (Lo) {
    968         // Handle the Hi bits.
    969         unsigned OpC = Hi ? PPC::LIS8 : PPC::LI8;
    970         Result = CurDAG->getMachineNode(OpC, dl, MVT::i64, getI32Imm(Hi));
    971         // And Lo bits.
    972         Result = CurDAG->getMachineNode(PPC::ORI8, dl, MVT::i64,
    973                                         SDValue(Result, 0), getI32Imm(Lo));
    974       } else {
    975        // Just the Hi bits.
    976         Result = CurDAG->getMachineNode(PPC::LIS8, dl, MVT::i64, getI32Imm(Hi));
    977       }
    978 
    979       // If no shift, we're done.
    980       if (!Shift) return Result;
    981 
    982       // Shift for next step if the upper 32-bits were not zero.
    983       if (Imm) {
    984         Result = CurDAG->getMachineNode(PPC::RLDICR, dl, MVT::i64,
    985                                         SDValue(Result, 0),
    986                                         getI32Imm(Shift),
    987                                         getI32Imm(63 - Shift));
    988       }
    989 
    990       // Add in the last bits as required.
    991       if ((Hi = (Remainder >> 16) & 0xFFFF)) {
    992         Result = CurDAG->getMachineNode(PPC::ORIS8, dl, MVT::i64,
    993                                         SDValue(Result, 0), getI32Imm(Hi));
    994       }
    995       if ((Lo = Remainder & 0xFFFF)) {
    996         Result = CurDAG->getMachineNode(PPC::ORI8, dl, MVT::i64,
    997                                         SDValue(Result, 0), getI32Imm(Lo));
    998       }
    999 
   1000       return Result;
   1001     }
   1002     break;
   1003   }
   1004 
   1005   case ISD::SETCC: {
   1006     SDNode *SN = SelectSETCC(N);
   1007     if (SN)
   1008       return SN;
   1009     break;
   1010   }
   1011   case PPCISD::GlobalBaseReg:
   1012     return getGlobalBaseReg();
   1013 
   1014   case ISD::FrameIndex: {
   1015     int FI = cast<FrameIndexSDNode>(N)->getIndex();
   1016     SDValue TFI = CurDAG->getTargetFrameIndex(FI, N->getValueType(0));
   1017     unsigned Opc = N->getValueType(0) == MVT::i32 ? PPC::ADDI : PPC::ADDI8;
   1018     if (N->hasOneUse())
   1019       return CurDAG->SelectNodeTo(N, Opc, N->getValueType(0), TFI,
   1020                                   getSmallIPtrImm(0));
   1021     return CurDAG->getMachineNode(Opc, dl, N->getValueType(0), TFI,
   1022                                   getSmallIPtrImm(0));
   1023   }
   1024 
   1025   case PPCISD::MFOCRF: {
   1026     SDValue InFlag = N->getOperand(1);
   1027     return CurDAG->getMachineNode(PPC::MFOCRF, dl, MVT::i32,
   1028                                   N->getOperand(0), InFlag);
   1029   }
   1030 
   1031   case ISD::SDIV: {
   1032     // FIXME: since this depends on the setting of the carry flag from the srawi
   1033     //        we should really be making notes about that for the scheduler.
   1034     // FIXME: It sure would be nice if we could cheaply recognize the
   1035     //        srl/add/sra pattern the dag combiner will generate for this as
   1036     //        sra/addze rather than having to handle sdiv ourselves.  oh well.
   1037     unsigned Imm;
   1038     if (isInt32Immediate(N->getOperand(1), Imm)) {
   1039       SDValue N0 = N->getOperand(0);
   1040       if ((signed)Imm > 0 && isPowerOf2_32(Imm)) {
   1041         SDNode *Op =
   1042           CurDAG->getMachineNode(PPC::SRAWI, dl, MVT::i32, MVT::Glue,
   1043                                  N0, getI32Imm(Log2_32(Imm)));
   1044         return CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32,
   1045                                     SDValue(Op, 0), SDValue(Op, 1));
   1046       } else if ((signed)Imm < 0 && isPowerOf2_32(-Imm)) {
   1047         SDNode *Op =
   1048           CurDAG->getMachineNode(PPC::SRAWI, dl, MVT::i32, MVT::Glue,
   1049                                  N0, getI32Imm(Log2_32(-Imm)));
   1050         SDValue PT =
   1051           SDValue(CurDAG->getMachineNode(PPC::ADDZE, dl, MVT::i32,
   1052                                          SDValue(Op, 0), SDValue(Op, 1)),
   1053                     0);
   1054         return CurDAG->SelectNodeTo(N, PPC::NEG, MVT::i32, PT);
   1055       }
   1056     }
   1057 
   1058     // Other cases are autogenerated.
   1059     break;
   1060   }
   1061 
   1062   case ISD::LOAD: {
   1063     // Handle preincrement loads.
   1064     LoadSDNode *LD = cast<LoadSDNode>(N);
   1065     EVT LoadedVT = LD->getMemoryVT();
   1066 
   1067     // Normal loads are handled by code generated from the .td file.
   1068     if (LD->getAddressingMode() != ISD::PRE_INC)
   1069       break;
   1070 
   1071     SDValue Offset = LD->getOffset();
   1072     if (Offset.getOpcode() == ISD::TargetConstant ||
   1073         Offset.getOpcode() == ISD::TargetGlobalAddress) {
   1074 
   1075       unsigned Opcode;
   1076       bool isSExt = LD->getExtensionType() == ISD::SEXTLOAD;
   1077       if (LD->getValueType(0) != MVT::i64) {
   1078         // Handle PPC32 integer and normal FP loads.
   1079         assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
   1080         switch (LoadedVT.getSimpleVT().SimpleTy) {
   1081           default: llvm_unreachable("Invalid PPC load type!");
   1082           case MVT::f64: Opcode = PPC::LFDU; break;
   1083           case MVT::f32: Opcode = PPC::LFSU; break;
   1084           case MVT::i32: Opcode = PPC::LWZU; break;
   1085           case MVT::i16: Opcode = isSExt ? PPC::LHAU : PPC::LHZU; break;
   1086           case MVT::i1:
   1087           case MVT::i8:  Opcode = PPC::LBZU; break;
   1088         }
   1089       } else {
   1090         assert(LD->getValueType(0) == MVT::i64 && "Unknown load result type!");
   1091         assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
   1092         switch (LoadedVT.getSimpleVT().SimpleTy) {
   1093           default: llvm_unreachable("Invalid PPC load type!");
   1094           case MVT::i64: Opcode = PPC::LDU; break;
   1095           case MVT::i32: Opcode = PPC::LWZU8; break;
   1096           case MVT::i16: Opcode = isSExt ? PPC::LHAU8 : PPC::LHZU8; break;
   1097           case MVT::i1:
   1098           case MVT::i8:  Opcode = PPC::LBZU8; break;
   1099         }
   1100       }
   1101 
   1102       SDValue Chain = LD->getChain();
   1103       SDValue Base = LD->getBasePtr();
   1104       SDValue Ops[] = { Offset, Base, Chain };
   1105       return CurDAG->getMachineNode(Opcode, dl, LD->getValueType(0),
   1106                                     PPCLowering->getPointerTy(),
   1107                                     MVT::Other, Ops);
   1108     } else {
   1109       unsigned Opcode;
   1110       bool isSExt = LD->getExtensionType() == ISD::SEXTLOAD;
   1111       if (LD->getValueType(0) != MVT::i64) {
   1112         // Handle PPC32 integer and normal FP loads.
   1113         assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
   1114         switch (LoadedVT.getSimpleVT().SimpleTy) {
   1115           default: llvm_unreachable("Invalid PPC load type!");
   1116           case MVT::f64: Opcode = PPC::LFDUX; break;
   1117           case MVT::f32: Opcode = PPC::LFSUX; break;
   1118           case MVT::i32: Opcode = PPC::LWZUX; break;
   1119           case MVT::i16: Opcode = isSExt ? PPC::LHAUX : PPC::LHZUX; break;
   1120           case MVT::i1:
   1121           case MVT::i8:  Opcode = PPC::LBZUX; break;
   1122         }
   1123       } else {
   1124         assert(LD->getValueType(0) == MVT::i64 && "Unknown load result type!");
   1125         assert((!isSExt || LoadedVT == MVT::i16 || LoadedVT == MVT::i32) &&
   1126                "Invalid sext update load");
   1127         switch (LoadedVT.getSimpleVT().SimpleTy) {
   1128           default: llvm_unreachable("Invalid PPC load type!");
   1129           case MVT::i64: Opcode = PPC::LDUX; break;
   1130           case MVT::i32: Opcode = isSExt ? PPC::LWAUX  : PPC::LWZUX8; break;
   1131           case MVT::i16: Opcode = isSExt ? PPC::LHAUX8 : PPC::LHZUX8; break;
   1132           case MVT::i1:
   1133           case MVT::i8:  Opcode = PPC::LBZUX8; break;
   1134         }
   1135       }
   1136 
   1137       SDValue Chain = LD->getChain();
   1138       SDValue Base = LD->getBasePtr();
   1139       SDValue Ops[] = { Base, Offset, Chain };
   1140       return CurDAG->getMachineNode(Opcode, dl, LD->getValueType(0),
   1141                                     PPCLowering->getPointerTy(),
   1142                                     MVT::Other, Ops);
   1143     }
   1144   }
   1145 
   1146   case ISD::AND: {
   1147     unsigned Imm, Imm2, SH, MB, ME;
   1148     uint64_t Imm64;
   1149 
   1150     // If this is an and of a value rotated between 0 and 31 bits and then and'd
   1151     // with a mask, emit rlwinm
   1152     if (isInt32Immediate(N->getOperand(1), Imm) &&
   1153         isRotateAndMask(N->getOperand(0).getNode(), Imm, false, SH, MB, ME)) {
   1154       SDValue Val = N->getOperand(0).getOperand(0);
   1155       SDValue Ops[] = { Val, getI32Imm(SH), getI32Imm(MB), getI32Imm(ME) };
   1156       return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
   1157     }
   1158     // If this is just a masked value where the input is not handled above, and
   1159     // is not a rotate-left (handled by a pattern in the .td file), emit rlwinm
   1160     if (isInt32Immediate(N->getOperand(1), Imm) &&
   1161         isRunOfOnes(Imm, MB, ME) &&
   1162         N->getOperand(0).getOpcode() != ISD::ROTL) {
   1163       SDValue Val = N->getOperand(0);
   1164       SDValue Ops[] = { Val, getI32Imm(0), getI32Imm(MB), getI32Imm(ME) };
   1165       return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
   1166     }
   1167     // If this is a 64-bit zero-extension mask, emit rldicl.
   1168     if (isInt64Immediate(N->getOperand(1).getNode(), Imm64) &&
   1169         isMask_64(Imm64)) {
   1170       SDValue Val = N->getOperand(0);
   1171       MB = 64 - CountTrailingOnes_64(Imm64);
   1172       SH = 0;
   1173 
   1174       // If the operand is a logical right shift, we can fold it into this
   1175       // instruction: rldicl(rldicl(x, 64-n, n), 0, mb) -> rldicl(x, 64-n, mb)
   1176       // for n <= mb. The right shift is really a left rotate followed by a
   1177       // mask, and this mask is a more-restrictive sub-mask of the mask implied
   1178       // by the shift.
   1179       if (Val.getOpcode() == ISD::SRL &&
   1180           isInt32Immediate(Val.getOperand(1).getNode(), Imm) && Imm <= MB) {
   1181         assert(Imm < 64 && "Illegal shift amount");
   1182         Val = Val.getOperand(0);
   1183         SH = 64 - Imm;
   1184       }
   1185 
   1186       SDValue Ops[] = { Val, getI32Imm(SH), getI32Imm(MB) };
   1187       return CurDAG->SelectNodeTo(N, PPC::RLDICL, MVT::i64, Ops);
   1188     }
   1189     // AND X, 0 -> 0, not "rlwinm 32".
   1190     if (isInt32Immediate(N->getOperand(1), Imm) && (Imm == 0)) {
   1191       ReplaceUses(SDValue(N, 0), N->getOperand(1));
   1192       return nullptr;
   1193     }
   1194     // ISD::OR doesn't get all the bitfield insertion fun.
   1195     // (and (or x, c1), c2) where isRunOfOnes(~(c1^c2)) is a bitfield insert
   1196     if (isInt32Immediate(N->getOperand(1), Imm) &&
   1197         N->getOperand(0).getOpcode() == ISD::OR &&
   1198         isInt32Immediate(N->getOperand(0).getOperand(1), Imm2)) {
   1199       unsigned MB, ME;
   1200       Imm = ~(Imm^Imm2);
   1201       if (isRunOfOnes(Imm, MB, ME)) {
   1202         SDValue Ops[] = { N->getOperand(0).getOperand(0),
   1203                             N->getOperand(0).getOperand(1),
   1204                             getI32Imm(0), getI32Imm(MB),getI32Imm(ME) };
   1205         return CurDAG->getMachineNode(PPC::RLWIMI, dl, MVT::i32, Ops);
   1206       }
   1207     }
   1208 
   1209     // Other cases are autogenerated.
   1210     break;
   1211   }
   1212   case ISD::OR:
   1213     if (N->getValueType(0) == MVT::i32)
   1214       if (SDNode *I = SelectBitfieldInsert(N))
   1215         return I;
   1216 
   1217     // Other cases are autogenerated.
   1218     break;
   1219   case ISD::SHL: {
   1220     unsigned Imm, SH, MB, ME;
   1221     if (isOpcWithIntImmediate(N->getOperand(0).getNode(), ISD::AND, Imm) &&
   1222         isRotateAndMask(N, Imm, true, SH, MB, ME)) {
   1223       SDValue Ops[] = { N->getOperand(0).getOperand(0),
   1224                           getI32Imm(SH), getI32Imm(MB), getI32Imm(ME) };
   1225       return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
   1226     }
   1227 
   1228     // Other cases are autogenerated.
   1229     break;
   1230   }
   1231   case ISD::SRL: {
   1232     unsigned Imm, SH, MB, ME;
   1233     if (isOpcWithIntImmediate(N->getOperand(0).getNode(), ISD::AND, Imm) &&
   1234         isRotateAndMask(N, Imm, true, SH, MB, ME)) {
   1235       SDValue Ops[] = { N->getOperand(0).getOperand(0),
   1236                           getI32Imm(SH), getI32Imm(MB), getI32Imm(ME) };
   1237       return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
   1238     }
   1239 
   1240     // Other cases are autogenerated.
   1241     break;
   1242   }
   1243   // FIXME: Remove this once the ANDI glue bug is fixed:
   1244   case PPCISD::ANDIo_1_EQ_BIT:
   1245   case PPCISD::ANDIo_1_GT_BIT: {
   1246     if (!ANDIGlueBug)
   1247       break;
   1248 
   1249     EVT InVT = N->getOperand(0).getValueType();
   1250     assert((InVT == MVT::i64 || InVT == MVT::i32) &&
   1251            "Invalid input type for ANDIo_1_EQ_BIT");
   1252 
   1253     unsigned Opcode = (InVT == MVT::i64) ? PPC::ANDIo8 : PPC::ANDIo;
   1254     SDValue AndI(CurDAG->getMachineNode(Opcode, dl, InVT, MVT::Glue,
   1255                                         N->getOperand(0),
   1256                                         CurDAG->getTargetConstant(1, InVT)), 0);
   1257     SDValue CR0Reg = CurDAG->getRegister(PPC::CR0, MVT::i32);
   1258     SDValue SRIdxVal =
   1259       CurDAG->getTargetConstant(N->getOpcode() == PPCISD::ANDIo_1_EQ_BIT ?
   1260                                 PPC::sub_eq : PPC::sub_gt, MVT::i32);
   1261 
   1262     return CurDAG->SelectNodeTo(N, TargetOpcode::EXTRACT_SUBREG, MVT::i1,
   1263                                 CR0Reg, SRIdxVal,
   1264                                 SDValue(AndI.getNode(), 1) /* glue */);
   1265   }
   1266   case ISD::SELECT_CC: {
   1267     ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(4))->get();
   1268     EVT PtrVT = CurDAG->getTargetLoweringInfo().getPointerTy();
   1269     bool isPPC64 = (PtrVT == MVT::i64);
   1270 
   1271     // If this is a select of i1 operands, we'll pattern match it.
   1272     if (PPCSubTarget->useCRBits() &&
   1273         N->getOperand(0).getValueType() == MVT::i1)
   1274       break;
   1275 
   1276     // Handle the setcc cases here.  select_cc lhs, 0, 1, 0, cc
   1277     if (!isPPC64)
   1278       if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N->getOperand(1)))
   1279         if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N->getOperand(2)))
   1280           if (ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N->getOperand(3)))
   1281             if (N1C->isNullValue() && N3C->isNullValue() &&
   1282                 N2C->getZExtValue() == 1ULL && CC == ISD::SETNE &&
   1283                 // FIXME: Implement this optzn for PPC64.
   1284                 N->getValueType(0) == MVT::i32) {
   1285               SDNode *Tmp =
   1286                 CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
   1287                                        N->getOperand(0), getI32Imm(~0U));
   1288               return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32,
   1289                                           SDValue(Tmp, 0), N->getOperand(0),
   1290                                           SDValue(Tmp, 1));
   1291             }
   1292 
   1293     SDValue CCReg = SelectCC(N->getOperand(0), N->getOperand(1), CC, dl);
   1294 
   1295     if (N->getValueType(0) == MVT::i1) {
   1296       // An i1 select is: (c & t) | (!c & f).
   1297       bool Inv;
   1298       unsigned Idx = getCRIdxForSetCC(CC, Inv);
   1299 
   1300       unsigned SRI;
   1301       switch (Idx) {
   1302       default: llvm_unreachable("Invalid CC index");
   1303       case 0: SRI = PPC::sub_lt; break;
   1304       case 1: SRI = PPC::sub_gt; break;
   1305       case 2: SRI = PPC::sub_eq; break;
   1306       case 3: SRI = PPC::sub_un; break;
   1307       }
   1308 
   1309       SDValue CCBit = CurDAG->getTargetExtractSubreg(SRI, dl, MVT::i1, CCReg);
   1310 
   1311       SDValue NotCCBit(CurDAG->getMachineNode(PPC::CRNOR, dl, MVT::i1,
   1312                                               CCBit, CCBit), 0);
   1313       SDValue C =    Inv ? NotCCBit : CCBit,
   1314               NotC = Inv ? CCBit    : NotCCBit;
   1315 
   1316       SDValue CAndT(CurDAG->getMachineNode(PPC::CRAND, dl, MVT::i1,
   1317                                            C, N->getOperand(2)), 0);
   1318       SDValue NotCAndF(CurDAG->getMachineNode(PPC::CRAND, dl, MVT::i1,
   1319                                               NotC, N->getOperand(3)), 0);
   1320 
   1321       return CurDAG->SelectNodeTo(N, PPC::CROR, MVT::i1, CAndT, NotCAndF);
   1322     }
   1323 
   1324     unsigned BROpc = getPredicateForSetCC(CC);
   1325 
   1326     unsigned SelectCCOp;
   1327     if (N->getValueType(0) == MVT::i32)
   1328       SelectCCOp = PPC::SELECT_CC_I4;
   1329     else if (N->getValueType(0) == MVT::i64)
   1330       SelectCCOp = PPC::SELECT_CC_I8;
   1331     else if (N->getValueType(0) == MVT::f32)
   1332       SelectCCOp = PPC::SELECT_CC_F4;
   1333     else if (N->getValueType(0) == MVT::f64)
   1334       SelectCCOp = PPC::SELECT_CC_F8;
   1335     else
   1336       SelectCCOp = PPC::SELECT_CC_VRRC;
   1337 
   1338     SDValue Ops[] = { CCReg, N->getOperand(2), N->getOperand(3),
   1339                         getI32Imm(BROpc) };
   1340     return CurDAG->SelectNodeTo(N, SelectCCOp, N->getValueType(0), Ops);
   1341   }
   1342   case ISD::VSELECT:
   1343     if (PPCSubTarget->hasVSX()) {
   1344       SDValue Ops[] = { N->getOperand(2), N->getOperand(1), N->getOperand(0) };
   1345       return CurDAG->SelectNodeTo(N, PPC::XXSEL, N->getValueType(0), Ops);
   1346     }
   1347 
   1348     break;
   1349   case ISD::VECTOR_SHUFFLE:
   1350     if (PPCSubTarget->hasVSX() && (N->getValueType(0) == MVT::v2f64 ||
   1351                                   N->getValueType(0) == MVT::v2i64)) {
   1352       ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
   1353 
   1354       SDValue Op1 = N->getOperand(SVN->getMaskElt(0) < 2 ? 0 : 1),
   1355               Op2 = N->getOperand(SVN->getMaskElt(1) < 2 ? 0 : 1);
   1356       unsigned DM[2];
   1357 
   1358       for (int i = 0; i < 2; ++i)
   1359         if (SVN->getMaskElt(i) <= 0 || SVN->getMaskElt(i) == 2)
   1360           DM[i] = 0;
   1361         else
   1362           DM[i] = 1;
   1363 
   1364       SDValue DMV = CurDAG->getTargetConstant(DM[1] | (DM[0] << 1), MVT::i32);
   1365 
   1366       if (Op1 == Op2 && DM[0] == 0 && DM[1] == 0 &&
   1367           Op1.getOpcode() == ISD::SCALAR_TO_VECTOR &&
   1368           isa<LoadSDNode>(Op1.getOperand(0))) {
   1369         LoadSDNode *LD = cast<LoadSDNode>(Op1.getOperand(0));
   1370         SDValue Base, Offset;
   1371 
   1372         if (LD->isUnindexed() &&
   1373             SelectAddrIdxOnly(LD->getBasePtr(), Base, Offset)) {
   1374           SDValue Chain = LD->getChain();
   1375           SDValue Ops[] = { Base, Offset, Chain };
   1376           return CurDAG->SelectNodeTo(N, PPC::LXVDSX,
   1377                                       N->getValueType(0), Ops);
   1378         }
   1379       }
   1380 
   1381       SDValue Ops[] = { Op1, Op2, DMV };
   1382       return CurDAG->SelectNodeTo(N, PPC::XXPERMDI, N->getValueType(0), Ops);
   1383     }
   1384 
   1385     break;
   1386   case PPCISD::BDNZ:
   1387   case PPCISD::BDZ: {
   1388     bool IsPPC64 = PPCSubTarget->isPPC64();
   1389     SDValue Ops[] = { N->getOperand(1), N->getOperand(0) };
   1390     return CurDAG->SelectNodeTo(N, N->getOpcode() == PPCISD::BDNZ ?
   1391                                    (IsPPC64 ? PPC::BDNZ8 : PPC::BDNZ) :
   1392                                    (IsPPC64 ? PPC::BDZ8 : PPC::BDZ),
   1393                                 MVT::Other, Ops);
   1394   }
   1395   case PPCISD::COND_BRANCH: {
   1396     // Op #0 is the Chain.
   1397     // Op #1 is the PPC::PRED_* number.
   1398     // Op #2 is the CR#
   1399     // Op #3 is the Dest MBB
   1400     // Op #4 is the Flag.
   1401     // Prevent PPC::PRED_* from being selected into LI.
   1402     SDValue Pred =
   1403       getI32Imm(cast<ConstantSDNode>(N->getOperand(1))->getZExtValue());
   1404     SDValue Ops[] = { Pred, N->getOperand(2), N->getOperand(3),
   1405       N->getOperand(0), N->getOperand(4) };
   1406     return CurDAG->SelectNodeTo(N, PPC::BCC, MVT::Other, Ops);
   1407   }
   1408   case ISD::BR_CC: {
   1409     ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(1))->get();
   1410     unsigned PCC = getPredicateForSetCC(CC);
   1411 
   1412     if (N->getOperand(2).getValueType() == MVT::i1) {
   1413       unsigned Opc;
   1414       bool Swap;
   1415       switch (PCC) {
   1416       default: llvm_unreachable("Unexpected Boolean-operand predicate");
   1417       case PPC::PRED_LT: Opc = PPC::CRANDC; Swap = true;  break;
   1418       case PPC::PRED_LE: Opc = PPC::CRORC;  Swap = true;  break;
   1419       case PPC::PRED_EQ: Opc = PPC::CREQV;  Swap = false; break;
   1420       case PPC::PRED_GE: Opc = PPC::CRORC;  Swap = false; break;
   1421       case PPC::PRED_GT: Opc = PPC::CRANDC; Swap = false; break;
   1422       case PPC::PRED_NE: Opc = PPC::CRXOR;  Swap = false; break;
   1423       }
   1424 
   1425       SDValue BitComp(CurDAG->getMachineNode(Opc, dl, MVT::i1,
   1426                                              N->getOperand(Swap ? 3 : 2),
   1427                                              N->getOperand(Swap ? 2 : 3)), 0);
   1428       return CurDAG->SelectNodeTo(N, PPC::BC, MVT::Other,
   1429                                   BitComp, N->getOperand(4), N->getOperand(0));
   1430     }
   1431 
   1432     SDValue CondCode = SelectCC(N->getOperand(2), N->getOperand(3), CC, dl);
   1433     SDValue Ops[] = { getI32Imm(PCC), CondCode,
   1434                         N->getOperand(4), N->getOperand(0) };
   1435     return CurDAG->SelectNodeTo(N, PPC::BCC, MVT::Other, Ops);
   1436   }
   1437   case ISD::BRIND: {
   1438     // FIXME: Should custom lower this.
   1439     SDValue Chain = N->getOperand(0);
   1440     SDValue Target = N->getOperand(1);
   1441     unsigned Opc = Target.getValueType() == MVT::i32 ? PPC::MTCTR : PPC::MTCTR8;
   1442     unsigned Reg = Target.getValueType() == MVT::i32 ? PPC::BCTR : PPC::BCTR8;
   1443     Chain = SDValue(CurDAG->getMachineNode(Opc, dl, MVT::Glue, Target,
   1444                                            Chain), 0);
   1445     return CurDAG->SelectNodeTo(N, Reg, MVT::Other, Chain);
   1446   }
   1447   case PPCISD::TOC_ENTRY: {
   1448     assert (PPCSubTarget->isPPC64() && "Only supported for 64-bit ABI");
   1449 
   1450     // For medium and large code model, we generate two instructions as
   1451     // described below.  Otherwise we allow SelectCodeCommon to handle this,
   1452     // selecting one of LDtoc, LDtocJTI, and LDtocCPT.
   1453     CodeModel::Model CModel = TM.getCodeModel();
   1454     if (CModel != CodeModel::Medium && CModel != CodeModel::Large)
   1455       break;
   1456 
   1457     // The first source operand is a TargetGlobalAddress or a TargetJumpTable.
   1458     // If it is an externally defined symbol, a symbol with common linkage,
   1459     // a non-local function address, or a jump table address, or if we are
   1460     // generating code for large code model, we generate:
   1461     //   LDtocL(<ga:@sym>, ADDIStocHA(%X2, <ga:@sym>))
   1462     // Otherwise we generate:
   1463     //   ADDItocL(ADDIStocHA(%X2, <ga:@sym>), <ga:@sym>)
   1464     SDValue GA = N->getOperand(0);
   1465     SDValue TOCbase = N->getOperand(1);
   1466     SDNode *Tmp = CurDAG->getMachineNode(PPC::ADDIStocHA, dl, MVT::i64,
   1467                                         TOCbase, GA);
   1468 
   1469     if (isa<JumpTableSDNode>(GA) || CModel == CodeModel::Large)
   1470       return CurDAG->getMachineNode(PPC::LDtocL, dl, MVT::i64, GA,
   1471                                     SDValue(Tmp, 0));
   1472 
   1473     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(GA)) {
   1474       const GlobalValue *GValue = G->getGlobal();
   1475       if ((GValue->getType()->getElementType()->isFunctionTy() &&
   1476            (GValue->isDeclaration() || GValue->isWeakForLinker())) ||
   1477           GValue->isDeclaration() || GValue->hasCommonLinkage() ||
   1478           GValue->hasAvailableExternallyLinkage())
   1479         return CurDAG->getMachineNode(PPC::LDtocL, dl, MVT::i64, GA,
   1480                                       SDValue(Tmp, 0));
   1481     }
   1482 
   1483     return CurDAG->getMachineNode(PPC::ADDItocL, dl, MVT::i64,
   1484                                   SDValue(Tmp, 0), GA);
   1485   }
   1486   case PPCISD::VADD_SPLAT: {
   1487     // This expands into one of three sequences, depending on whether
   1488     // the first operand is odd or even, positive or negative.
   1489     assert(isa<ConstantSDNode>(N->getOperand(0)) &&
   1490            isa<ConstantSDNode>(N->getOperand(1)) &&
   1491            "Invalid operand on VADD_SPLAT!");
   1492 
   1493     int Elt     = N->getConstantOperandVal(0);
   1494     int EltSize = N->getConstantOperandVal(1);
   1495     unsigned Opc1, Opc2, Opc3;
   1496     EVT VT;
   1497 
   1498     if (EltSize == 1) {
   1499       Opc1 = PPC::VSPLTISB;
   1500       Opc2 = PPC::VADDUBM;
   1501       Opc3 = PPC::VSUBUBM;
   1502       VT = MVT::v16i8;
   1503     } else if (EltSize == 2) {
   1504       Opc1 = PPC::VSPLTISH;
   1505       Opc2 = PPC::VADDUHM;
   1506       Opc3 = PPC::VSUBUHM;
   1507       VT = MVT::v8i16;
   1508     } else {
   1509       assert(EltSize == 4 && "Invalid element size on VADD_SPLAT!");
   1510       Opc1 = PPC::VSPLTISW;
   1511       Opc2 = PPC::VADDUWM;
   1512       Opc3 = PPC::VSUBUWM;
   1513       VT = MVT::v4i32;
   1514     }
   1515 
   1516     if ((Elt & 1) == 0) {
   1517       // Elt is even, in the range [-32,-18] + [16,30].
   1518       //
   1519       // Convert: VADD_SPLAT elt, size
   1520       // Into:    tmp = VSPLTIS[BHW] elt
   1521       //          VADDU[BHW]M tmp, tmp
   1522       // Where:   [BHW] = B for size = 1, H for size = 2, W for size = 4
   1523       SDValue EltVal = getI32Imm(Elt >> 1);
   1524       SDNode *Tmp = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
   1525       SDValue TmpVal = SDValue(Tmp, 0);
   1526       return CurDAG->getMachineNode(Opc2, dl, VT, TmpVal, TmpVal);
   1527 
   1528     } else if (Elt > 0) {
   1529       // Elt is odd and positive, in the range [17,31].
   1530       //
   1531       // Convert: VADD_SPLAT elt, size
   1532       // Into:    tmp1 = VSPLTIS[BHW] elt-16
   1533       //          tmp2 = VSPLTIS[BHW] -16
   1534       //          VSUBU[BHW]M tmp1, tmp2
   1535       SDValue EltVal = getI32Imm(Elt - 16);
   1536       SDNode *Tmp1 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
   1537       EltVal = getI32Imm(-16);
   1538       SDNode *Tmp2 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
   1539       return CurDAG->getMachineNode(Opc3, dl, VT, SDValue(Tmp1, 0),
   1540                                     SDValue(Tmp2, 0));
   1541 
   1542     } else {
   1543       // Elt is odd and negative, in the range [-31,-17].
   1544       //
   1545       // Convert: VADD_SPLAT elt, size
   1546       // Into:    tmp1 = VSPLTIS[BHW] elt+16
   1547       //          tmp2 = VSPLTIS[BHW] -16
   1548       //          VADDU[BHW]M tmp1, tmp2
   1549       SDValue EltVal = getI32Imm(Elt + 16);
   1550       SDNode *Tmp1 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
   1551       EltVal = getI32Imm(-16);
   1552       SDNode *Tmp2 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
   1553       return CurDAG->getMachineNode(Opc2, dl, VT, SDValue(Tmp1, 0),
   1554                                     SDValue(Tmp2, 0));
   1555     }
   1556   }
   1557   }
   1558 
   1559   return SelectCode(N);
   1560 }
   1561 
   1562 /// PostprocessISelDAG - Perform some late peephole optimizations
   1563 /// on the DAG representation.
   1564 void PPCDAGToDAGISel::PostprocessISelDAG() {
   1565 
   1566   // Skip peepholes at -O0.
   1567   if (TM.getOptLevel() == CodeGenOpt::None)
   1568     return;
   1569 
   1570   PeepholePPC64();
   1571   PeepholeCROps();
   1572 }
   1573 
   1574 // Check if all users of this node will become isel where the second operand
   1575 // is the constant zero. If this is so, and if we can negate the condition,
   1576 // then we can flip the true and false operands. This will allow the zero to
   1577 // be folded with the isel so that we don't need to materialize a register
   1578 // containing zero.
   1579 bool PPCDAGToDAGISel::AllUsersSelectZero(SDNode *N) {
   1580   // If we're not using isel, then this does not matter.
   1581   if (!PPCSubTarget->hasISEL())
   1582     return false;
   1583 
   1584   for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
   1585        UI != UE; ++UI) {
   1586     SDNode *User = *UI;
   1587     if (!User->isMachineOpcode())
   1588       return false;
   1589     if (User->getMachineOpcode() != PPC::SELECT_I4 &&
   1590         User->getMachineOpcode() != PPC::SELECT_I8)
   1591       return false;
   1592 
   1593     SDNode *Op2 = User->getOperand(2).getNode();
   1594     if (!Op2->isMachineOpcode())
   1595       return false;
   1596 
   1597     if (Op2->getMachineOpcode() != PPC::LI &&
   1598         Op2->getMachineOpcode() != PPC::LI8)
   1599       return false;
   1600 
   1601     ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op2->getOperand(0));
   1602     if (!C)
   1603       return false;
   1604 
   1605     if (!C->isNullValue())
   1606       return false;
   1607   }
   1608 
   1609   return true;
   1610 }
   1611 
   1612 void PPCDAGToDAGISel::SwapAllSelectUsers(SDNode *N) {
   1613   SmallVector<SDNode *, 4> ToReplace;
   1614   for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
   1615        UI != UE; ++UI) {
   1616     SDNode *User = *UI;
   1617     assert((User->getMachineOpcode() == PPC::SELECT_I4 ||
   1618             User->getMachineOpcode() == PPC::SELECT_I8) &&
   1619            "Must have all select users");
   1620     ToReplace.push_back(User);
   1621   }
   1622 
   1623   for (SmallVector<SDNode *, 4>::iterator UI = ToReplace.begin(),
   1624        UE = ToReplace.end(); UI != UE; ++UI) {
   1625     SDNode *User = *UI;
   1626     SDNode *ResNode =
   1627       CurDAG->getMachineNode(User->getMachineOpcode(), SDLoc(User),
   1628                              User->getValueType(0), User->getOperand(0),
   1629                              User->getOperand(2),
   1630                              User->getOperand(1));
   1631 
   1632       DEBUG(dbgs() << "CR Peephole replacing:\nOld:    ");
   1633       DEBUG(User->dump(CurDAG));
   1634       DEBUG(dbgs() << "\nNew: ");
   1635       DEBUG(ResNode->dump(CurDAG));
   1636       DEBUG(dbgs() << "\n");
   1637 
   1638       ReplaceUses(User, ResNode);
   1639   }
   1640 }
   1641 
   1642 void PPCDAGToDAGISel::PeepholeCROps() {
   1643   bool IsModified;
   1644   do {
   1645     IsModified = false;
   1646     for (SelectionDAG::allnodes_iterator I = CurDAG->allnodes_begin(),
   1647          E = CurDAG->allnodes_end(); I != E; ++I) {
   1648       MachineSDNode *MachineNode = dyn_cast<MachineSDNode>(I);
   1649       if (!MachineNode || MachineNode->use_empty())
   1650         continue;
   1651       SDNode *ResNode = MachineNode;
   1652 
   1653       bool Op1Set   = false, Op1Unset = false,
   1654            Op1Not   = false,
   1655            Op2Set   = false, Op2Unset = false,
   1656            Op2Not   = false;
   1657 
   1658       unsigned Opcode = MachineNode->getMachineOpcode();
   1659       switch (Opcode) {
   1660       default: break;
   1661       case PPC::CRAND:
   1662       case PPC::CRNAND:
   1663       case PPC::CROR:
   1664       case PPC::CRXOR:
   1665       case PPC::CRNOR:
   1666       case PPC::CREQV:
   1667       case PPC::CRANDC:
   1668       case PPC::CRORC: {
   1669         SDValue Op = MachineNode->getOperand(1);
   1670         if (Op.isMachineOpcode()) {
   1671           if (Op.getMachineOpcode() == PPC::CRSET)
   1672             Op2Set = true;
   1673           else if (Op.getMachineOpcode() == PPC::CRUNSET)
   1674             Op2Unset = true;
   1675           else if (Op.getMachineOpcode() == PPC::CRNOR &&
   1676                    Op.getOperand(0) == Op.getOperand(1))
   1677             Op2Not = true;
   1678         }
   1679         }  // fallthrough
   1680       case PPC::BC:
   1681       case PPC::BCn:
   1682       case PPC::SELECT_I4:
   1683       case PPC::SELECT_I8:
   1684       case PPC::SELECT_F4:
   1685       case PPC::SELECT_F8:
   1686       case PPC::SELECT_VRRC: {
   1687         SDValue Op = MachineNode->getOperand(0);
   1688         if (Op.isMachineOpcode()) {
   1689           if (Op.getMachineOpcode() == PPC::CRSET)
   1690             Op1Set = true;
   1691           else if (Op.getMachineOpcode() == PPC::CRUNSET)
   1692             Op1Unset = true;
   1693           else if (Op.getMachineOpcode() == PPC::CRNOR &&
   1694                    Op.getOperand(0) == Op.getOperand(1))
   1695             Op1Not = true;
   1696         }
   1697         }
   1698         break;
   1699       }
   1700 
   1701       bool SelectSwap = false;
   1702       switch (Opcode) {
   1703       default: break;
   1704       case PPC::CRAND:
   1705         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
   1706           // x & x = x
   1707           ResNode = MachineNode->getOperand(0).getNode();
   1708         else if (Op1Set)
   1709           // 1 & y = y
   1710           ResNode = MachineNode->getOperand(1).getNode();
   1711         else if (Op2Set)
   1712           // x & 1 = x
   1713           ResNode = MachineNode->getOperand(0).getNode();
   1714         else if (Op1Unset || Op2Unset)
   1715           // x & 0 = 0 & y = 0
   1716           ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
   1717                                            MVT::i1);
   1718         else if (Op1Not)
   1719           // ~x & y = andc(y, x)
   1720           ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
   1721                                            MVT::i1, MachineNode->getOperand(1),
   1722                                            MachineNode->getOperand(0).
   1723                                              getOperand(0));
   1724         else if (Op2Not)
   1725           // x & ~y = andc(x, y)
   1726           ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
   1727                                            MVT::i1, MachineNode->getOperand(0),
   1728                                            MachineNode->getOperand(1).
   1729                                              getOperand(0));
   1730         else if (AllUsersSelectZero(MachineNode))
   1731           ResNode = CurDAG->getMachineNode(PPC::CRNAND, SDLoc(MachineNode),
   1732                                            MVT::i1, MachineNode->getOperand(0),
   1733                                            MachineNode->getOperand(1)),
   1734           SelectSwap = true;
   1735         break;
   1736       case PPC::CRNAND:
   1737         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
   1738           // nand(x, x) -> nor(x, x)
   1739           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
   1740                                            MVT::i1, MachineNode->getOperand(0),
   1741                                            MachineNode->getOperand(0));
   1742         else if (Op1Set)
   1743           // nand(1, y) -> nor(y, y)
   1744           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
   1745                                            MVT::i1, MachineNode->getOperand(1),
   1746                                            MachineNode->getOperand(1));
   1747         else if (Op2Set)
   1748           // nand(x, 1) -> nor(x, x)
   1749           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
   1750                                            MVT::i1, MachineNode->getOperand(0),
   1751                                            MachineNode->getOperand(0));
   1752         else if (Op1Unset || Op2Unset)
   1753           // nand(x, 0) = nand(0, y) = 1
   1754           ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
   1755                                            MVT::i1);
   1756         else if (Op1Not)
   1757           // nand(~x, y) = ~(~x & y) = x | ~y = orc(x, y)
   1758           ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
   1759                                            MVT::i1, MachineNode->getOperand(0).
   1760                                                       getOperand(0),
   1761                                            MachineNode->getOperand(1));
   1762         else if (Op2Not)
   1763           // nand(x, ~y) = ~x | y = orc(y, x)
   1764           ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
   1765                                            MVT::i1, MachineNode->getOperand(1).
   1766                                                       getOperand(0),
   1767                                            MachineNode->getOperand(0));
   1768         else if (AllUsersSelectZero(MachineNode))
   1769           ResNode = CurDAG->getMachineNode(PPC::CRAND, SDLoc(MachineNode),
   1770                                            MVT::i1, MachineNode->getOperand(0),
   1771                                            MachineNode->getOperand(1)),
   1772           SelectSwap = true;
   1773         break;
   1774       case PPC::CROR:
   1775         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
   1776           // x | x = x
   1777           ResNode = MachineNode->getOperand(0).getNode();
   1778         else if (Op1Set || Op2Set)
   1779           // x | 1 = 1 | y = 1
   1780           ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
   1781                                            MVT::i1);
   1782         else if (Op1Unset)
   1783           // 0 | y = y
   1784           ResNode = MachineNode->getOperand(1).getNode();
   1785         else if (Op2Unset)
   1786           // x | 0 = x
   1787           ResNode = MachineNode->getOperand(0).getNode();
   1788         else if (Op1Not)
   1789           // ~x | y = orc(y, x)
   1790           ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
   1791                                            MVT::i1, MachineNode->getOperand(1),
   1792                                            MachineNode->getOperand(0).
   1793                                              getOperand(0));
   1794         else if (Op2Not)
   1795           // x | ~y = orc(x, y)
   1796           ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
   1797                                            MVT::i1, MachineNode->getOperand(0),
   1798                                            MachineNode->getOperand(1).
   1799                                              getOperand(0));
   1800         else if (AllUsersSelectZero(MachineNode))
   1801           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
   1802                                            MVT::i1, MachineNode->getOperand(0),
   1803                                            MachineNode->getOperand(1)),
   1804           SelectSwap = true;
   1805         break;
   1806       case PPC::CRXOR:
   1807         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
   1808           // xor(x, x) = 0
   1809           ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
   1810                                            MVT::i1);
   1811         else if (Op1Set)
   1812           // xor(1, y) -> nor(y, y)
   1813           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
   1814                                            MVT::i1, MachineNode->getOperand(1),
   1815                                            MachineNode->getOperand(1));
   1816         else if (Op2Set)
   1817           // xor(x, 1) -> nor(x, x)
   1818           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
   1819                                            MVT::i1, MachineNode->getOperand(0),
   1820                                            MachineNode->getOperand(0));
   1821         else if (Op1Unset)
   1822           // xor(0, y) = y
   1823           ResNode = MachineNode->getOperand(1).getNode();
   1824         else if (Op2Unset)
   1825           // xor(x, 0) = x
   1826           ResNode = MachineNode->getOperand(0).getNode();
   1827         else if (Op1Not)
   1828           // xor(~x, y) = eqv(x, y)
   1829           ResNode = CurDAG->getMachineNode(PPC::CREQV, SDLoc(MachineNode),
   1830                                            MVT::i1, MachineNode->getOperand(0).
   1831                                                       getOperand(0),
   1832                                            MachineNode->getOperand(1));
   1833         else if (Op2Not)
   1834           // xor(x, ~y) = eqv(x, y)
   1835           ResNode = CurDAG->getMachineNode(PPC::CREQV, SDLoc(MachineNode),
   1836                                            MVT::i1, MachineNode->getOperand(0),
   1837                                            MachineNode->getOperand(1).
   1838                                              getOperand(0));
   1839         else if (AllUsersSelectZero(MachineNode))
   1840           ResNode = CurDAG->getMachineNode(PPC::CREQV, SDLoc(MachineNode),
   1841                                            MVT::i1, MachineNode->getOperand(0),
   1842                                            MachineNode->getOperand(1)),
   1843           SelectSwap = true;
   1844         break;
   1845       case PPC::CRNOR:
   1846         if (Op1Set || Op2Set)
   1847           // nor(1, y) -> 0
   1848           ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
   1849                                            MVT::i1);
   1850         else if (Op1Unset)
   1851           // nor(0, y) = ~y -> nor(y, y)
   1852           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
   1853                                            MVT::i1, MachineNode->getOperand(1),
   1854                                            MachineNode->getOperand(1));
   1855         else if (Op2Unset)
   1856           // nor(x, 0) = ~x
   1857           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
   1858                                            MVT::i1, MachineNode->getOperand(0),
   1859                                            MachineNode->getOperand(0));
   1860         else if (Op1Not)
   1861           // nor(~x, y) = andc(x, y)
   1862           ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
   1863                                            MVT::i1, MachineNode->getOperand(0).
   1864                                                       getOperand(0),
   1865                                            MachineNode->getOperand(1));
   1866         else if (Op2Not)
   1867           // nor(x, ~y) = andc(y, x)
   1868           ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
   1869                                            MVT::i1, MachineNode->getOperand(1).
   1870                                                       getOperand(0),
   1871                                            MachineNode->getOperand(0));
   1872         else if (AllUsersSelectZero(MachineNode))
   1873           ResNode = CurDAG->getMachineNode(PPC::CROR, SDLoc(MachineNode),
   1874                                            MVT::i1, MachineNode->getOperand(0),
   1875                                            MachineNode->getOperand(1)),
   1876           SelectSwap = true;
   1877         break;
   1878       case PPC::CREQV:
   1879         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
   1880           // eqv(x, x) = 1
   1881           ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
   1882                                            MVT::i1);
   1883         else if (Op1Set)
   1884           // eqv(1, y) = y
   1885           ResNode = MachineNode->getOperand(1).getNode();
   1886         else if (Op2Set)
   1887           // eqv(x, 1) = x
   1888           ResNode = MachineNode->getOperand(0).getNode();
   1889         else if (Op1Unset)
   1890           // eqv(0, y) = ~y -> nor(y, y)
   1891           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
   1892                                            MVT::i1, MachineNode->getOperand(1),
   1893                                            MachineNode->getOperand(1));
   1894         else if (Op2Unset)
   1895           // eqv(x, 0) = ~x
   1896           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
   1897                                            MVT::i1, MachineNode->getOperand(0),
   1898                                            MachineNode->getOperand(0));
   1899         else if (Op1Not)
   1900           // eqv(~x, y) = xor(x, y)
   1901           ResNode = CurDAG->getMachineNode(PPC::CRXOR, SDLoc(MachineNode),
   1902                                            MVT::i1, MachineNode->getOperand(0).
   1903                                                       getOperand(0),
   1904                                            MachineNode->getOperand(1));
   1905         else if (Op2Not)
   1906           // eqv(x, ~y) = xor(x, y)
   1907           ResNode = CurDAG->getMachineNode(PPC::CRXOR, SDLoc(MachineNode),
   1908                                            MVT::i1, MachineNode->getOperand(0),
   1909                                            MachineNode->getOperand(1).
   1910                                              getOperand(0));
   1911         else if (AllUsersSelectZero(MachineNode))
   1912           ResNode = CurDAG->getMachineNode(PPC::CRXOR, SDLoc(MachineNode),
   1913                                            MVT::i1, MachineNode->getOperand(0),
   1914                                            MachineNode->getOperand(1)),
   1915           SelectSwap = true;
   1916         break;
   1917       case PPC::CRANDC:
   1918         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
   1919           // andc(x, x) = 0
   1920           ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
   1921                                            MVT::i1);
   1922         else if (Op1Set)
   1923           // andc(1, y) = ~y
   1924           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
   1925                                            MVT::i1, MachineNode->getOperand(1),
   1926                                            MachineNode->getOperand(1));
   1927         else if (Op1Unset || Op2Set)
   1928           // andc(0, y) = andc(x, 1) = 0
   1929           ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
   1930                                            MVT::i1);
   1931         else if (Op2Unset)
   1932           // andc(x, 0) = x
   1933           ResNode = MachineNode->getOperand(0).getNode();
   1934         else if (Op1Not)
   1935           // andc(~x, y) = ~(x | y) = nor(x, y)
   1936           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
   1937                                            MVT::i1, MachineNode->getOperand(0).
   1938                                                       getOperand(0),
   1939                                            MachineNode->getOperand(1));
   1940         else if (Op2Not)
   1941           // andc(x, ~y) = x & y
   1942           ResNode = CurDAG->getMachineNode(PPC::CRAND, SDLoc(MachineNode),
   1943                                            MVT::i1, MachineNode->getOperand(0),
   1944                                            MachineNode->getOperand(1).
   1945                                              getOperand(0));
   1946         else if (AllUsersSelectZero(MachineNode))
   1947           ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
   1948                                            MVT::i1, MachineNode->getOperand(1),
   1949                                            MachineNode->getOperand(0)),
   1950           SelectSwap = true;
   1951         break;
   1952       case PPC::CRORC:
   1953         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
   1954           // orc(x, x) = 1
   1955           ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
   1956                                            MVT::i1);
   1957         else if (Op1Set || Op2Unset)
   1958           // orc(1, y) = orc(x, 0) = 1
   1959           ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
   1960                                            MVT::i1);
   1961         else if (Op2Set)
   1962           // orc(x, 1) = x
   1963           ResNode = MachineNode->getOperand(0).getNode();
   1964         else if (Op1Unset)
   1965           // orc(0, y) = ~y
   1966           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
   1967                                            MVT::i1, MachineNode->getOperand(1),
   1968                                            MachineNode->getOperand(1));
   1969         else if (Op1Not)
   1970           // orc(~x, y) = ~(x & y) = nand(x, y)
   1971           ResNode = CurDAG->getMachineNode(PPC::CRNAND, SDLoc(MachineNode),
   1972                                            MVT::i1, MachineNode->getOperand(0).
   1973                                                       getOperand(0),
   1974                                            MachineNode->getOperand(1));
   1975         else if (Op2Not)
   1976           // orc(x, ~y) = x | y
   1977           ResNode = CurDAG->getMachineNode(PPC::CROR, SDLoc(MachineNode),
   1978                                            MVT::i1, MachineNode->getOperand(0),
   1979                                            MachineNode->getOperand(1).
   1980                                              getOperand(0));
   1981         else if (AllUsersSelectZero(MachineNode))
   1982           ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
   1983                                            MVT::i1, MachineNode->getOperand(1),
   1984                                            MachineNode->getOperand(0)),
   1985           SelectSwap = true;
   1986         break;
   1987       case PPC::SELECT_I4:
   1988       case PPC::SELECT_I8:
   1989       case PPC::SELECT_F4:
   1990       case PPC::SELECT_F8:
   1991       case PPC::SELECT_VRRC:
   1992         if (Op1Set)
   1993           ResNode = MachineNode->getOperand(1).getNode();
   1994         else if (Op1Unset)
   1995           ResNode = MachineNode->getOperand(2).getNode();
   1996         else if (Op1Not)
   1997           ResNode = CurDAG->getMachineNode(MachineNode->getMachineOpcode(),
   1998                                            SDLoc(MachineNode),
   1999                                            MachineNode->getValueType(0),
   2000                                            MachineNode->getOperand(0).
   2001                                              getOperand(0),
   2002                                            MachineNode->getOperand(2),
   2003                                            MachineNode->getOperand(1));
   2004         break;
   2005       case PPC::BC:
   2006       case PPC::BCn:
   2007         if (Op1Not)
   2008           ResNode = CurDAG->getMachineNode(Opcode == PPC::BC ? PPC::BCn :
   2009                                                                PPC::BC,
   2010                                            SDLoc(MachineNode),
   2011                                            MVT::Other,
   2012                                            MachineNode->getOperand(0).
   2013                                              getOperand(0),
   2014                                            MachineNode->getOperand(1),
   2015                                            MachineNode->getOperand(2));
   2016         // FIXME: Handle Op1Set, Op1Unset here too.
   2017         break;
   2018       }
   2019 
   2020       // If we're inverting this node because it is used only by selects that
   2021       // we'd like to swap, then swap the selects before the node replacement.
   2022       if (SelectSwap)
   2023         SwapAllSelectUsers(MachineNode);
   2024 
   2025       if (ResNode != MachineNode) {
   2026         DEBUG(dbgs() << "CR Peephole replacing:\nOld:    ");
   2027         DEBUG(MachineNode->dump(CurDAG));
   2028         DEBUG(dbgs() << "\nNew: ");
   2029         DEBUG(ResNode->dump(CurDAG));
   2030         DEBUG(dbgs() << "\n");
   2031 
   2032         ReplaceUses(MachineNode, ResNode);
   2033         IsModified = true;
   2034       }
   2035     }
   2036     if (IsModified)
   2037       CurDAG->RemoveDeadNodes();
   2038   } while (IsModified);
   2039 }
   2040 
   2041 void PPCDAGToDAGISel::PeepholePPC64() {
   2042   // These optimizations are currently supported only for 64-bit SVR4.
   2043   if (PPCSubTarget->isDarwin() || !PPCSubTarget->isPPC64())
   2044     return;
   2045 
   2046   SelectionDAG::allnodes_iterator Position(CurDAG->getRoot().getNode());
   2047   ++Position;
   2048 
   2049   while (Position != CurDAG->allnodes_begin()) {
   2050     SDNode *N = --Position;
   2051     // Skip dead nodes and any non-machine opcodes.
   2052     if (N->use_empty() || !N->isMachineOpcode())
   2053       continue;
   2054 
   2055     unsigned FirstOp;
   2056     unsigned StorageOpcode = N->getMachineOpcode();
   2057 
   2058     switch (StorageOpcode) {
   2059     default: continue;
   2060 
   2061     case PPC::LBZ:
   2062     case PPC::LBZ8:
   2063     case PPC::LD:
   2064     case PPC::LFD:
   2065     case PPC::LFS:
   2066     case PPC::LHA:
   2067     case PPC::LHA8:
   2068     case PPC::LHZ:
   2069     case PPC::LHZ8:
   2070     case PPC::LWA:
   2071     case PPC::LWZ:
   2072     case PPC::LWZ8:
   2073       FirstOp = 0;
   2074       break;
   2075 
   2076     case PPC::STB:
   2077     case PPC::STB8:
   2078     case PPC::STD:
   2079     case PPC::STFD:
   2080     case PPC::STFS:
   2081     case PPC::STH:
   2082     case PPC::STH8:
   2083     case PPC::STW:
   2084     case PPC::STW8:
   2085       FirstOp = 1;
   2086       break;
   2087     }
   2088 
   2089     // If this is a load or store with a zero offset, we may be able to
   2090     // fold an add-immediate into the memory operation.
   2091     if (!isa<ConstantSDNode>(N->getOperand(FirstOp)) ||
   2092         N->getConstantOperandVal(FirstOp) != 0)
   2093       continue;
   2094 
   2095     SDValue Base = N->getOperand(FirstOp + 1);
   2096     if (!Base.isMachineOpcode())
   2097       continue;
   2098 
   2099     unsigned Flags = 0;
   2100     bool ReplaceFlags = true;
   2101 
   2102     // When the feeding operation is an add-immediate of some sort,
   2103     // determine whether we need to add relocation information to the
   2104     // target flags on the immediate operand when we fold it into the
   2105     // load instruction.
   2106     //
   2107     // For something like ADDItocL, the relocation information is
   2108     // inferred from the opcode; when we process it in the AsmPrinter,
   2109     // we add the necessary relocation there.  A load, though, can receive
   2110     // relocation from various flavors of ADDIxxx, so we need to carry
   2111     // the relocation information in the target flags.
   2112     switch (Base.getMachineOpcode()) {
   2113     default: continue;
   2114 
   2115     case PPC::ADDI8:
   2116     case PPC::ADDI:
   2117       // In some cases (such as TLS) the relocation information
   2118       // is already in place on the operand, so copying the operand
   2119       // is sufficient.
   2120       ReplaceFlags = false;
   2121       // For these cases, the immediate may not be divisible by 4, in
   2122       // which case the fold is illegal for DS-form instructions.  (The
   2123       // other cases provide aligned addresses and are always safe.)
   2124       if ((StorageOpcode == PPC::LWA ||
   2125            StorageOpcode == PPC::LD  ||
   2126            StorageOpcode == PPC::STD) &&
   2127           (!isa<ConstantSDNode>(Base.getOperand(1)) ||
   2128            Base.getConstantOperandVal(1) % 4 != 0))
   2129         continue;
   2130       break;
   2131     case PPC::ADDIdtprelL:
   2132       Flags = PPCII::MO_DTPREL_LO;
   2133       break;
   2134     case PPC::ADDItlsldL:
   2135       Flags = PPCII::MO_TLSLD_LO;
   2136       break;
   2137     case PPC::ADDItocL:
   2138       Flags = PPCII::MO_TOC_LO;
   2139       break;
   2140     }
   2141 
   2142     // We found an opportunity.  Reverse the operands from the add
   2143     // immediate and substitute them into the load or store.  If
   2144     // needed, update the target flags for the immediate operand to
   2145     // reflect the necessary relocation information.
   2146     DEBUG(dbgs() << "Folding add-immediate into mem-op:\nBase:    ");
   2147     DEBUG(Base->dump(CurDAG));
   2148     DEBUG(dbgs() << "\nN: ");
   2149     DEBUG(N->dump(CurDAG));
   2150     DEBUG(dbgs() << "\n");
   2151 
   2152     SDValue ImmOpnd = Base.getOperand(1);
   2153 
   2154     // If the relocation information isn't already present on the
   2155     // immediate operand, add it now.
   2156     if (ReplaceFlags) {
   2157       if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(ImmOpnd)) {
   2158         SDLoc dl(GA);
   2159         const GlobalValue *GV = GA->getGlobal();
   2160         // We can't perform this optimization for data whose alignment
   2161         // is insufficient for the instruction encoding.
   2162         if (GV->getAlignment() < 4 &&
   2163             (StorageOpcode == PPC::LD || StorageOpcode == PPC::STD ||
   2164              StorageOpcode == PPC::LWA)) {
   2165           DEBUG(dbgs() << "Rejected this candidate for alignment.\n\n");
   2166           continue;
   2167         }
   2168         ImmOpnd = CurDAG->getTargetGlobalAddress(GV, dl, MVT::i64, 0, Flags);
   2169       } else if (ConstantPoolSDNode *CP =
   2170                  dyn_cast<ConstantPoolSDNode>(ImmOpnd)) {
   2171         const Constant *C = CP->getConstVal();
   2172         ImmOpnd = CurDAG->getTargetConstantPool(C, MVT::i64,
   2173                                                 CP->getAlignment(),
   2174                                                 0, Flags);
   2175       }
   2176     }
   2177 
   2178     if (FirstOp == 1) // Store
   2179       (void)CurDAG->UpdateNodeOperands(N, N->getOperand(0), ImmOpnd,
   2180                                        Base.getOperand(0), N->getOperand(3));
   2181     else // Load
   2182       (void)CurDAG->UpdateNodeOperands(N, ImmOpnd, Base.getOperand(0),
   2183                                        N->getOperand(2));
   2184 
   2185     // The add-immediate may now be dead, in which case remove it.
   2186     if (Base.getNode()->use_empty())
   2187       CurDAG->RemoveDeadNode(Base.getNode());
   2188   }
   2189 }
   2190 
   2191 
   2192 /// createPPCISelDag - This pass converts a legalized DAG into a
   2193 /// PowerPC-specific DAG, ready for instruction scheduling.
   2194 ///
   2195 FunctionPass *llvm::createPPCISelDag(PPCTargetMachine &TM) {
   2196   return new PPCDAGToDAGISel(TM);
   2197 }
   2198 
   2199 static void initializePassOnce(PassRegistry &Registry) {
   2200   const char *Name = "PowerPC DAG->DAG Pattern Instruction Selection";
   2201   PassInfo *PI = new PassInfo(Name, "ppc-codegen", &SelectionDAGISel::ID,
   2202                               nullptr, false, false);
   2203   Registry.registerPass(*PI, true);
   2204 }
   2205 
   2206 void llvm::initializePPCDAGToDAGISelPass(PassRegistry &Registry) {
   2207   CALL_ONCE_INITIALIZATION(initializePassOnce);
   2208 }
   2209 
   2210