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      1 //===-- SystemZInstrInfo.cpp - SystemZ instruction information ------------===//
      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 contains the SystemZ implementation of the TargetInstrInfo class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "SystemZInstrInfo.h"
     15 #include "SystemZInstrBuilder.h"
     16 #include "SystemZTargetMachine.h"
     17 #include "llvm/CodeGen/LiveVariables.h"
     18 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
     19 #include "llvm/CodeGen/MachineRegisterInfo.h"
     20 
     21 using namespace llvm;
     22 
     23 #define GET_INSTRINFO_CTOR_DTOR
     24 #define GET_INSTRMAP_INFO
     25 #include "SystemZGenInstrInfo.inc"
     26 
     27 // Return a mask with Count low bits set.
     28 static uint64_t allOnes(unsigned int Count) {
     29   return Count == 0 ? 0 : (uint64_t(1) << (Count - 1) << 1) - 1;
     30 }
     31 
     32 // Reg should be a 32-bit GPR.  Return true if it is a high register rather
     33 // than a low register.
     34 static bool isHighReg(unsigned int Reg) {
     35   if (SystemZ::GRH32BitRegClass.contains(Reg))
     36     return true;
     37   assert(SystemZ::GR32BitRegClass.contains(Reg) && "Invalid GRX32");
     38   return false;
     39 }
     40 
     41 // Pin the vtable to this file.
     42 void SystemZInstrInfo::anchor() {}
     43 
     44 SystemZInstrInfo::SystemZInstrInfo(SystemZSubtarget &sti)
     45   : SystemZGenInstrInfo(SystemZ::ADJCALLSTACKDOWN, SystemZ::ADJCALLSTACKUP),
     46     RI(), STI(sti) {
     47 }
     48 
     49 // MI is a 128-bit load or store.  Split it into two 64-bit loads or stores,
     50 // each having the opcode given by NewOpcode.
     51 void SystemZInstrInfo::splitMove(MachineBasicBlock::iterator MI,
     52                                  unsigned NewOpcode) const {
     53   MachineBasicBlock *MBB = MI->getParent();
     54   MachineFunction &MF = *MBB->getParent();
     55 
     56   // Get two load or store instructions.  Use the original instruction for one
     57   // of them (arbitrarily the second here) and create a clone for the other.
     58   MachineInstr *EarlierMI = MF.CloneMachineInstr(&*MI);
     59   MBB->insert(MI, EarlierMI);
     60 
     61   // Set up the two 64-bit registers.
     62   MachineOperand &HighRegOp = EarlierMI->getOperand(0);
     63   MachineOperand &LowRegOp = MI->getOperand(0);
     64   HighRegOp.setReg(RI.getSubReg(HighRegOp.getReg(), SystemZ::subreg_h64));
     65   LowRegOp.setReg(RI.getSubReg(LowRegOp.getReg(), SystemZ::subreg_l64));
     66 
     67   // The address in the first (high) instruction is already correct.
     68   // Adjust the offset in the second (low) instruction.
     69   MachineOperand &HighOffsetOp = EarlierMI->getOperand(2);
     70   MachineOperand &LowOffsetOp = MI->getOperand(2);
     71   LowOffsetOp.setImm(LowOffsetOp.getImm() + 8);
     72 
     73   // Clear the kill flags for the base and index registers in the first
     74   // instruction.
     75   EarlierMI->getOperand(1).setIsKill(false);
     76   EarlierMI->getOperand(3).setIsKill(false);
     77 
     78   // Set the opcodes.
     79   unsigned HighOpcode = getOpcodeForOffset(NewOpcode, HighOffsetOp.getImm());
     80   unsigned LowOpcode = getOpcodeForOffset(NewOpcode, LowOffsetOp.getImm());
     81   assert(HighOpcode && LowOpcode && "Both offsets should be in range");
     82 
     83   EarlierMI->setDesc(get(HighOpcode));
     84   MI->setDesc(get(LowOpcode));
     85 }
     86 
     87 // Split ADJDYNALLOC instruction MI.
     88 void SystemZInstrInfo::splitAdjDynAlloc(MachineBasicBlock::iterator MI) const {
     89   MachineBasicBlock *MBB = MI->getParent();
     90   MachineFunction &MF = *MBB->getParent();
     91   MachineFrameInfo *MFFrame = MF.getFrameInfo();
     92   MachineOperand &OffsetMO = MI->getOperand(2);
     93 
     94   uint64_t Offset = (MFFrame->getMaxCallFrameSize() +
     95                      SystemZMC::CallFrameSize +
     96                      OffsetMO.getImm());
     97   unsigned NewOpcode = getOpcodeForOffset(SystemZ::LA, Offset);
     98   assert(NewOpcode && "No support for huge argument lists yet");
     99   MI->setDesc(get(NewOpcode));
    100   OffsetMO.setImm(Offset);
    101 }
    102 
    103 // MI is an RI-style pseudo instruction.  Replace it with LowOpcode
    104 // if the first operand is a low GR32 and HighOpcode if the first operand
    105 // is a high GR32.  ConvertHigh is true if LowOpcode takes a signed operand
    106 // and HighOpcode takes an unsigned 32-bit operand.  In those cases,
    107 // MI has the same kind of operand as LowOpcode, so needs to be converted
    108 // if HighOpcode is used.
    109 void SystemZInstrInfo::expandRIPseudo(MachineInstr &MI, unsigned LowOpcode,
    110                                       unsigned HighOpcode,
    111                                       bool ConvertHigh) const {
    112   unsigned Reg = MI.getOperand(0).getReg();
    113   bool IsHigh = isHighReg(Reg);
    114   MI.setDesc(get(IsHigh ? HighOpcode : LowOpcode));
    115   if (IsHigh && ConvertHigh)
    116     MI.getOperand(1).setImm(uint32_t(MI.getOperand(1).getImm()));
    117 }
    118 
    119 // MI is a three-operand RIE-style pseudo instruction.  Replace it with
    120 // LowOpcodeK if the registers are both low GR32s, otherwise use a move
    121 // followed by HighOpcode or LowOpcode, depending on whether the target
    122 // is a high or low GR32.
    123 void SystemZInstrInfo::expandRIEPseudo(MachineInstr &MI, unsigned LowOpcode,
    124                                        unsigned LowOpcodeK,
    125                                        unsigned HighOpcode) const {
    126   unsigned DestReg = MI.getOperand(0).getReg();
    127   unsigned SrcReg = MI.getOperand(1).getReg();
    128   bool DestIsHigh = isHighReg(DestReg);
    129   bool SrcIsHigh = isHighReg(SrcReg);
    130   if (!DestIsHigh && !SrcIsHigh)
    131     MI.setDesc(get(LowOpcodeK));
    132   else {
    133     emitGRX32Move(*MI.getParent(), MI, MI.getDebugLoc(), DestReg, SrcReg,
    134                   SystemZ::LR, 32, MI.getOperand(1).isKill());
    135     MI.setDesc(get(DestIsHigh ? HighOpcode : LowOpcode));
    136     MI.getOperand(1).setReg(DestReg);
    137     MI.tieOperands(0, 1);
    138   }
    139 }
    140 
    141 // MI is an RXY-style pseudo instruction.  Replace it with LowOpcode
    142 // if the first operand is a low GR32 and HighOpcode if the first operand
    143 // is a high GR32.
    144 void SystemZInstrInfo::expandRXYPseudo(MachineInstr &MI, unsigned LowOpcode,
    145                                        unsigned HighOpcode) const {
    146   unsigned Reg = MI.getOperand(0).getReg();
    147   unsigned Opcode = getOpcodeForOffset(isHighReg(Reg) ? HighOpcode : LowOpcode,
    148                                        MI.getOperand(2).getImm());
    149   MI.setDesc(get(Opcode));
    150 }
    151 
    152 // MI is an RR-style pseudo instruction that zero-extends the low Size bits
    153 // of one GRX32 into another.  Replace it with LowOpcode if both operands
    154 // are low registers, otherwise use RISB[LH]G.
    155 void SystemZInstrInfo::expandZExtPseudo(MachineInstr &MI, unsigned LowOpcode,
    156                                         unsigned Size) const {
    157   emitGRX32Move(*MI.getParent(), MI, MI.getDebugLoc(),
    158                 MI.getOperand(0).getReg(), MI.getOperand(1).getReg(), LowOpcode,
    159                 Size, MI.getOperand(1).isKill());
    160   MI.eraseFromParent();
    161 }
    162 
    163 void SystemZInstrInfo::expandLoadStackGuard(MachineInstr *MI) const {
    164   MachineBasicBlock *MBB = MI->getParent();
    165   MachineFunction &MF = *MBB->getParent();
    166   const unsigned Reg = MI->getOperand(0).getReg();
    167 
    168   // Conveniently, all 4 instructions are cloned from LOAD_STACK_GUARD,
    169   // so they already have operand 0 set to reg.
    170 
    171   // ear <reg>, %a0
    172   MachineInstr *Ear1MI = MF.CloneMachineInstr(MI);
    173   MBB->insert(MI, Ear1MI);
    174   Ear1MI->setDesc(get(SystemZ::EAR));
    175   MachineInstrBuilder(MF, Ear1MI).addImm(0);
    176 
    177   // sllg <reg>, <reg>, 32
    178   MachineInstr *SllgMI = MF.CloneMachineInstr(MI);
    179   MBB->insert(MI, SllgMI);
    180   SllgMI->setDesc(get(SystemZ::SLLG));
    181   MachineInstrBuilder(MF, SllgMI).addReg(Reg).addReg(0).addImm(32);
    182 
    183   // ear <reg>, %a1
    184   MachineInstr *Ear2MI = MF.CloneMachineInstr(MI);
    185   MBB->insert(MI, Ear2MI);
    186   Ear2MI->setDesc(get(SystemZ::EAR));
    187   MachineInstrBuilder(MF, Ear2MI).addImm(1);
    188 
    189   // lg <reg>, 40(<reg>)
    190   MI->setDesc(get(SystemZ::LG));
    191   MachineInstrBuilder(MF, MI).addReg(Reg).addImm(40).addReg(0);
    192 }
    193 
    194 // Emit a zero-extending move from 32-bit GPR SrcReg to 32-bit GPR
    195 // DestReg before MBBI in MBB.  Use LowLowOpcode when both DestReg and SrcReg
    196 // are low registers, otherwise use RISB[LH]G.  Size is the number of bits
    197 // taken from the low end of SrcReg (8 for LLCR, 16 for LLHR and 32 for LR).
    198 // KillSrc is true if this move is the last use of SrcReg.
    199 void SystemZInstrInfo::emitGRX32Move(MachineBasicBlock &MBB,
    200                                      MachineBasicBlock::iterator MBBI,
    201                                      const DebugLoc &DL, unsigned DestReg,
    202                                      unsigned SrcReg, unsigned LowLowOpcode,
    203                                      unsigned Size, bool KillSrc) const {
    204   unsigned Opcode;
    205   bool DestIsHigh = isHighReg(DestReg);
    206   bool SrcIsHigh = isHighReg(SrcReg);
    207   if (DestIsHigh && SrcIsHigh)
    208     Opcode = SystemZ::RISBHH;
    209   else if (DestIsHigh && !SrcIsHigh)
    210     Opcode = SystemZ::RISBHL;
    211   else if (!DestIsHigh && SrcIsHigh)
    212     Opcode = SystemZ::RISBLH;
    213   else {
    214     BuildMI(MBB, MBBI, DL, get(LowLowOpcode), DestReg)
    215       .addReg(SrcReg, getKillRegState(KillSrc));
    216     return;
    217   }
    218   unsigned Rotate = (DestIsHigh != SrcIsHigh ? 32 : 0);
    219   BuildMI(MBB, MBBI, DL, get(Opcode), DestReg)
    220     .addReg(DestReg, RegState::Undef)
    221     .addReg(SrcReg, getKillRegState(KillSrc))
    222     .addImm(32 - Size).addImm(128 + 31).addImm(Rotate);
    223 }
    224 
    225 // If MI is a simple load or store for a frame object, return the register
    226 // it loads or stores and set FrameIndex to the index of the frame object.
    227 // Return 0 otherwise.
    228 //
    229 // Flag is SimpleBDXLoad for loads and SimpleBDXStore for stores.
    230 static int isSimpleMove(const MachineInstr &MI, int &FrameIndex,
    231                         unsigned Flag) {
    232   const MCInstrDesc &MCID = MI.getDesc();
    233   if ((MCID.TSFlags & Flag) && MI.getOperand(1).isFI() &&
    234       MI.getOperand(2).getImm() == 0 && MI.getOperand(3).getReg() == 0) {
    235     FrameIndex = MI.getOperand(1).getIndex();
    236     return MI.getOperand(0).getReg();
    237   }
    238   return 0;
    239 }
    240 
    241 unsigned SystemZInstrInfo::isLoadFromStackSlot(const MachineInstr &MI,
    242                                                int &FrameIndex) const {
    243   return isSimpleMove(MI, FrameIndex, SystemZII::SimpleBDXLoad);
    244 }
    245 
    246 unsigned SystemZInstrInfo::isStoreToStackSlot(const MachineInstr &MI,
    247                                               int &FrameIndex) const {
    248   return isSimpleMove(MI, FrameIndex, SystemZII::SimpleBDXStore);
    249 }
    250 
    251 bool SystemZInstrInfo::isStackSlotCopy(const MachineInstr &MI,
    252                                        int &DestFrameIndex,
    253                                        int &SrcFrameIndex) const {
    254   // Check for MVC 0(Length,FI1),0(FI2)
    255   const MachineFrameInfo *MFI = MI.getParent()->getParent()->getFrameInfo();
    256   if (MI.getOpcode() != SystemZ::MVC || !MI.getOperand(0).isFI() ||
    257       MI.getOperand(1).getImm() != 0 || !MI.getOperand(3).isFI() ||
    258       MI.getOperand(4).getImm() != 0)
    259     return false;
    260 
    261   // Check that Length covers the full slots.
    262   int64_t Length = MI.getOperand(2).getImm();
    263   unsigned FI1 = MI.getOperand(0).getIndex();
    264   unsigned FI2 = MI.getOperand(3).getIndex();
    265   if (MFI->getObjectSize(FI1) != Length ||
    266       MFI->getObjectSize(FI2) != Length)
    267     return false;
    268 
    269   DestFrameIndex = FI1;
    270   SrcFrameIndex = FI2;
    271   return true;
    272 }
    273 
    274 bool SystemZInstrInfo::analyzeBranch(MachineBasicBlock &MBB,
    275                                      MachineBasicBlock *&TBB,
    276                                      MachineBasicBlock *&FBB,
    277                                      SmallVectorImpl<MachineOperand> &Cond,
    278                                      bool AllowModify) const {
    279   // Most of the code and comments here are boilerplate.
    280 
    281   // Start from the bottom of the block and work up, examining the
    282   // terminator instructions.
    283   MachineBasicBlock::iterator I = MBB.end();
    284   while (I != MBB.begin()) {
    285     --I;
    286     if (I->isDebugValue())
    287       continue;
    288 
    289     // Working from the bottom, when we see a non-terminator instruction, we're
    290     // done.
    291     if (!isUnpredicatedTerminator(*I))
    292       break;
    293 
    294     // A terminator that isn't a branch can't easily be handled by this
    295     // analysis.
    296     if (!I->isBranch())
    297       return true;
    298 
    299     // Can't handle indirect branches.
    300     SystemZII::Branch Branch(getBranchInfo(*I));
    301     if (!Branch.Target->isMBB())
    302       return true;
    303 
    304     // Punt on compound branches.
    305     if (Branch.Type != SystemZII::BranchNormal)
    306       return true;
    307 
    308     if (Branch.CCMask == SystemZ::CCMASK_ANY) {
    309       // Handle unconditional branches.
    310       if (!AllowModify) {
    311         TBB = Branch.Target->getMBB();
    312         continue;
    313       }
    314 
    315       // If the block has any instructions after a JMP, delete them.
    316       while (std::next(I) != MBB.end())
    317         std::next(I)->eraseFromParent();
    318 
    319       Cond.clear();
    320       FBB = nullptr;
    321 
    322       // Delete the JMP if it's equivalent to a fall-through.
    323       if (MBB.isLayoutSuccessor(Branch.Target->getMBB())) {
    324         TBB = nullptr;
    325         I->eraseFromParent();
    326         I = MBB.end();
    327         continue;
    328       }
    329 
    330       // TBB is used to indicate the unconditinal destination.
    331       TBB = Branch.Target->getMBB();
    332       continue;
    333     }
    334 
    335     // Working from the bottom, handle the first conditional branch.
    336     if (Cond.empty()) {
    337       // FIXME: add X86-style branch swap
    338       FBB = TBB;
    339       TBB = Branch.Target->getMBB();
    340       Cond.push_back(MachineOperand::CreateImm(Branch.CCValid));
    341       Cond.push_back(MachineOperand::CreateImm(Branch.CCMask));
    342       continue;
    343     }
    344 
    345     // Handle subsequent conditional branches.
    346     assert(Cond.size() == 2 && TBB && "Should have seen a conditional branch");
    347 
    348     // Only handle the case where all conditional branches branch to the same
    349     // destination.
    350     if (TBB != Branch.Target->getMBB())
    351       return true;
    352 
    353     // If the conditions are the same, we can leave them alone.
    354     unsigned OldCCValid = Cond[0].getImm();
    355     unsigned OldCCMask = Cond[1].getImm();
    356     if (OldCCValid == Branch.CCValid && OldCCMask == Branch.CCMask)
    357       continue;
    358 
    359     // FIXME: Try combining conditions like X86 does.  Should be easy on Z!
    360     return false;
    361   }
    362 
    363   return false;
    364 }
    365 
    366 unsigned SystemZInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
    367   // Most of the code and comments here are boilerplate.
    368   MachineBasicBlock::iterator I = MBB.end();
    369   unsigned Count = 0;
    370 
    371   while (I != MBB.begin()) {
    372     --I;
    373     if (I->isDebugValue())
    374       continue;
    375     if (!I->isBranch())
    376       break;
    377     if (!getBranchInfo(*I).Target->isMBB())
    378       break;
    379     // Remove the branch.
    380     I->eraseFromParent();
    381     I = MBB.end();
    382     ++Count;
    383   }
    384 
    385   return Count;
    386 }
    387 
    388 bool SystemZInstrInfo::
    389 ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
    390   assert(Cond.size() == 2 && "Invalid condition");
    391   Cond[1].setImm(Cond[1].getImm() ^ Cond[0].getImm());
    392   return false;
    393 }
    394 
    395 unsigned SystemZInstrInfo::InsertBranch(MachineBasicBlock &MBB,
    396                                         MachineBasicBlock *TBB,
    397                                         MachineBasicBlock *FBB,
    398                                         ArrayRef<MachineOperand> Cond,
    399                                         const DebugLoc &DL) const {
    400   // In this function we output 32-bit branches, which should always
    401   // have enough range.  They can be shortened and relaxed by later code
    402   // in the pipeline, if desired.
    403 
    404   // Shouldn't be a fall through.
    405   assert(TBB && "InsertBranch must not be told to insert a fallthrough");
    406   assert((Cond.size() == 2 || Cond.size() == 0) &&
    407          "SystemZ branch conditions have one component!");
    408 
    409   if (Cond.empty()) {
    410     // Unconditional branch?
    411     assert(!FBB && "Unconditional branch with multiple successors!");
    412     BuildMI(&MBB, DL, get(SystemZ::J)).addMBB(TBB);
    413     return 1;
    414   }
    415 
    416   // Conditional branch.
    417   unsigned Count = 0;
    418   unsigned CCValid = Cond[0].getImm();
    419   unsigned CCMask = Cond[1].getImm();
    420   BuildMI(&MBB, DL, get(SystemZ::BRC))
    421     .addImm(CCValid).addImm(CCMask).addMBB(TBB);
    422   ++Count;
    423 
    424   if (FBB) {
    425     // Two-way Conditional branch. Insert the second branch.
    426     BuildMI(&MBB, DL, get(SystemZ::J)).addMBB(FBB);
    427     ++Count;
    428   }
    429   return Count;
    430 }
    431 
    432 bool SystemZInstrInfo::analyzeCompare(const MachineInstr &MI, unsigned &SrcReg,
    433                                       unsigned &SrcReg2, int &Mask,
    434                                       int &Value) const {
    435   assert(MI.isCompare() && "Caller should have checked for a comparison");
    436 
    437   if (MI.getNumExplicitOperands() == 2 && MI.getOperand(0).isReg() &&
    438       MI.getOperand(1).isImm()) {
    439     SrcReg = MI.getOperand(0).getReg();
    440     SrcReg2 = 0;
    441     Value = MI.getOperand(1).getImm();
    442     Mask = ~0;
    443     return true;
    444   }
    445 
    446   return false;
    447 }
    448 
    449 // If Reg is a virtual register, return its definition, otherwise return null.
    450 static MachineInstr *getDef(unsigned Reg,
    451                             const MachineRegisterInfo *MRI) {
    452   if (TargetRegisterInfo::isPhysicalRegister(Reg))
    453     return nullptr;
    454   return MRI->getUniqueVRegDef(Reg);
    455 }
    456 
    457 // Return true if MI is a shift of type Opcode by Imm bits.
    458 static bool isShift(MachineInstr *MI, unsigned Opcode, int64_t Imm) {
    459   return (MI->getOpcode() == Opcode &&
    460           !MI->getOperand(2).getReg() &&
    461           MI->getOperand(3).getImm() == Imm);
    462 }
    463 
    464 // If the destination of MI has no uses, delete it as dead.
    465 static void eraseIfDead(MachineInstr *MI, const MachineRegisterInfo *MRI) {
    466   if (MRI->use_nodbg_empty(MI->getOperand(0).getReg()))
    467     MI->eraseFromParent();
    468 }
    469 
    470 // Compare compares SrcReg against zero.  Check whether SrcReg contains
    471 // the result of an IPM sequence whose input CC survives until Compare,
    472 // and whether Compare is therefore redundant.  Delete it and return
    473 // true if so.
    474 static bool removeIPMBasedCompare(MachineInstr &Compare, unsigned SrcReg,
    475                                   const MachineRegisterInfo *MRI,
    476                                   const TargetRegisterInfo *TRI) {
    477   MachineInstr *LGFR = nullptr;
    478   MachineInstr *RLL = getDef(SrcReg, MRI);
    479   if (RLL && RLL->getOpcode() == SystemZ::LGFR) {
    480     LGFR = RLL;
    481     RLL = getDef(LGFR->getOperand(1).getReg(), MRI);
    482   }
    483   if (!RLL || !isShift(RLL, SystemZ::RLL, 31))
    484     return false;
    485 
    486   MachineInstr *SRL = getDef(RLL->getOperand(1).getReg(), MRI);
    487   if (!SRL || !isShift(SRL, SystemZ::SRL, SystemZ::IPM_CC))
    488     return false;
    489 
    490   MachineInstr *IPM = getDef(SRL->getOperand(1).getReg(), MRI);
    491   if (!IPM || IPM->getOpcode() != SystemZ::IPM)
    492     return false;
    493 
    494   // Check that there are no assignments to CC between the IPM and Compare,
    495   if (IPM->getParent() != Compare.getParent())
    496     return false;
    497   MachineBasicBlock::iterator MBBI = IPM, MBBE = Compare.getIterator();
    498   for (++MBBI; MBBI != MBBE; ++MBBI) {
    499     MachineInstr &MI = *MBBI;
    500     if (MI.modifiesRegister(SystemZ::CC, TRI))
    501       return false;
    502   }
    503 
    504   Compare.eraseFromParent();
    505   if (LGFR)
    506     eraseIfDead(LGFR, MRI);
    507   eraseIfDead(RLL, MRI);
    508   eraseIfDead(SRL, MRI);
    509   eraseIfDead(IPM, MRI);
    510 
    511   return true;
    512 }
    513 
    514 bool SystemZInstrInfo::optimizeCompareInstr(
    515     MachineInstr &Compare, unsigned SrcReg, unsigned SrcReg2, int Mask,
    516     int Value, const MachineRegisterInfo *MRI) const {
    517   assert(!SrcReg2 && "Only optimizing constant comparisons so far");
    518   bool IsLogical = (Compare.getDesc().TSFlags & SystemZII::IsLogical) != 0;
    519   return Value == 0 && !IsLogical &&
    520          removeIPMBasedCompare(Compare, SrcReg, MRI, &RI);
    521 }
    522 
    523 // If Opcode is a move that has a conditional variant, return that variant,
    524 // otherwise return 0.
    525 static unsigned getConditionalMove(unsigned Opcode) {
    526   switch (Opcode) {
    527   case SystemZ::LR:  return SystemZ::LOCR;
    528   case SystemZ::LGR: return SystemZ::LOCGR;
    529   default:           return 0;
    530   }
    531 }
    532 
    533 static unsigned getConditionalLoadImmediate(unsigned Opcode) {
    534   switch (Opcode) {
    535   case SystemZ::LHI:  return SystemZ::LOCHI;
    536   case SystemZ::LGHI: return SystemZ::LOCGHI;
    537   default:           return 0;
    538   }
    539 }
    540 
    541 bool SystemZInstrInfo::isPredicable(MachineInstr &MI) const {
    542   unsigned Opcode = MI.getOpcode();
    543   if (STI.hasLoadStoreOnCond() && getConditionalMove(Opcode))
    544     return true;
    545   if (STI.hasLoadStoreOnCond2() && getConditionalLoadImmediate(Opcode))
    546     return true;
    547   if (Opcode == SystemZ::Return ||
    548       Opcode == SystemZ::Trap ||
    549       Opcode == SystemZ::CallJG ||
    550       Opcode == SystemZ::CallBR)
    551     return true;
    552   return false;
    553 }
    554 
    555 bool SystemZInstrInfo::
    556 isProfitableToIfCvt(MachineBasicBlock &MBB,
    557                     unsigned NumCycles, unsigned ExtraPredCycles,
    558                     BranchProbability Probability) const {
    559   // Avoid using conditional returns at the end of a loop (since then
    560   // we'd need to emit an unconditional branch to the beginning anyway,
    561   // making the loop body longer).  This doesn't apply for low-probability
    562   // loops (eg. compare-and-swap retry), so just decide based on branch
    563   // probability instead of looping structure.
    564   // However, since Compare and Trap instructions cost the same as a regular
    565   // Compare instruction, we should allow the if conversion to convert this
    566   // into a Conditional Compare regardless of the branch probability.
    567   if (MBB.getLastNonDebugInstr()->getOpcode() != SystemZ::Trap &&
    568       MBB.succ_empty() && Probability < BranchProbability(1, 8))
    569     return false;
    570   // For now only convert single instructions.
    571   return NumCycles == 1;
    572 }
    573 
    574 bool SystemZInstrInfo::
    575 isProfitableToIfCvt(MachineBasicBlock &TMBB,
    576                     unsigned NumCyclesT, unsigned ExtraPredCyclesT,
    577                     MachineBasicBlock &FMBB,
    578                     unsigned NumCyclesF, unsigned ExtraPredCyclesF,
    579                     BranchProbability Probability) const {
    580   // For now avoid converting mutually-exclusive cases.
    581   return false;
    582 }
    583 
    584 bool SystemZInstrInfo::
    585 isProfitableToDupForIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
    586                           BranchProbability Probability) const {
    587   // For now only duplicate single instructions.
    588   return NumCycles == 1;
    589 }
    590 
    591 bool SystemZInstrInfo::PredicateInstruction(
    592     MachineInstr &MI, ArrayRef<MachineOperand> Pred) const {
    593   assert(Pred.size() == 2 && "Invalid condition");
    594   unsigned CCValid = Pred[0].getImm();
    595   unsigned CCMask = Pred[1].getImm();
    596   assert(CCMask > 0 && CCMask < 15 && "Invalid predicate");
    597   unsigned Opcode = MI.getOpcode();
    598   if (STI.hasLoadStoreOnCond()) {
    599     if (unsigned CondOpcode = getConditionalMove(Opcode)) {
    600       MI.setDesc(get(CondOpcode));
    601       MachineInstrBuilder(*MI.getParent()->getParent(), MI)
    602           .addImm(CCValid)
    603           .addImm(CCMask)
    604           .addReg(SystemZ::CC, RegState::Implicit);
    605       return true;
    606     }
    607   }
    608   if (STI.hasLoadStoreOnCond2()) {
    609     if (unsigned CondOpcode = getConditionalLoadImmediate(Opcode)) {
    610       MI.setDesc(get(CondOpcode));
    611       MachineInstrBuilder(*MI.getParent()->getParent(), MI)
    612           .addImm(CCValid)
    613           .addImm(CCMask)
    614           .addReg(SystemZ::CC, RegState::Implicit);
    615       return true;
    616     }
    617   }
    618   if (Opcode == SystemZ::Trap) {
    619     MI.setDesc(get(SystemZ::CondTrap));
    620     MachineInstrBuilder(*MI.getParent()->getParent(), MI)
    621       .addImm(CCValid).addImm(CCMask)
    622       .addReg(SystemZ::CC, RegState::Implicit);
    623     return true;
    624   }
    625   if (Opcode == SystemZ::Return) {
    626     MI.setDesc(get(SystemZ::CondReturn));
    627     MachineInstrBuilder(*MI.getParent()->getParent(), MI)
    628       .addImm(CCValid).addImm(CCMask)
    629       .addReg(SystemZ::CC, RegState::Implicit);
    630     return true;
    631   }
    632   if (Opcode == SystemZ::CallJG) {
    633     MachineOperand FirstOp = MI.getOperand(0);
    634     const uint32_t *RegMask = MI.getOperand(1).getRegMask();
    635     MI.RemoveOperand(1);
    636     MI.RemoveOperand(0);
    637     MI.setDesc(get(SystemZ::CallBRCL));
    638     MachineInstrBuilder(*MI.getParent()->getParent(), MI)
    639       .addImm(CCValid).addImm(CCMask)
    640       .addOperand(FirstOp)
    641       .addRegMask(RegMask)
    642       .addReg(SystemZ::CC, RegState::Implicit);
    643     return true;
    644   }
    645   if (Opcode == SystemZ::CallBR) {
    646     const uint32_t *RegMask = MI.getOperand(0).getRegMask();
    647     MI.RemoveOperand(0);
    648     MI.setDesc(get(SystemZ::CallBCR));
    649     MachineInstrBuilder(*MI.getParent()->getParent(), MI)
    650       .addImm(CCValid).addImm(CCMask)
    651       .addRegMask(RegMask)
    652       .addReg(SystemZ::CC, RegState::Implicit);
    653     return true;
    654   }
    655   return false;
    656 }
    657 
    658 void SystemZInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
    659                                    MachineBasicBlock::iterator MBBI,
    660                                    const DebugLoc &DL, unsigned DestReg,
    661                                    unsigned SrcReg, bool KillSrc) const {
    662   // Split 128-bit GPR moves into two 64-bit moves.  This handles ADDR128 too.
    663   if (SystemZ::GR128BitRegClass.contains(DestReg, SrcReg)) {
    664     copyPhysReg(MBB, MBBI, DL, RI.getSubReg(DestReg, SystemZ::subreg_h64),
    665                 RI.getSubReg(SrcReg, SystemZ::subreg_h64), KillSrc);
    666     copyPhysReg(MBB, MBBI, DL, RI.getSubReg(DestReg, SystemZ::subreg_l64),
    667                 RI.getSubReg(SrcReg, SystemZ::subreg_l64), KillSrc);
    668     return;
    669   }
    670 
    671   if (SystemZ::GRX32BitRegClass.contains(DestReg, SrcReg)) {
    672     emitGRX32Move(MBB, MBBI, DL, DestReg, SrcReg, SystemZ::LR, 32, KillSrc);
    673     return;
    674   }
    675 
    676   // Everything else needs only one instruction.
    677   unsigned Opcode;
    678   if (SystemZ::GR64BitRegClass.contains(DestReg, SrcReg))
    679     Opcode = SystemZ::LGR;
    680   else if (SystemZ::FP32BitRegClass.contains(DestReg, SrcReg))
    681     // For z13 we prefer LDR over LER to avoid partial register dependencies.
    682     Opcode = STI.hasVector() ? SystemZ::LDR32 : SystemZ::LER;
    683   else if (SystemZ::FP64BitRegClass.contains(DestReg, SrcReg))
    684     Opcode = SystemZ::LDR;
    685   else if (SystemZ::FP128BitRegClass.contains(DestReg, SrcReg))
    686     Opcode = SystemZ::LXR;
    687   else if (SystemZ::VR32BitRegClass.contains(DestReg, SrcReg))
    688     Opcode = SystemZ::VLR32;
    689   else if (SystemZ::VR64BitRegClass.contains(DestReg, SrcReg))
    690     Opcode = SystemZ::VLR64;
    691   else if (SystemZ::VR128BitRegClass.contains(DestReg, SrcReg))
    692     Opcode = SystemZ::VLR;
    693   else
    694     llvm_unreachable("Impossible reg-to-reg copy");
    695 
    696   BuildMI(MBB, MBBI, DL, get(Opcode), DestReg)
    697     .addReg(SrcReg, getKillRegState(KillSrc));
    698 }
    699 
    700 void SystemZInstrInfo::storeRegToStackSlot(
    701     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, unsigned SrcReg,
    702     bool isKill, int FrameIdx, const TargetRegisterClass *RC,
    703     const TargetRegisterInfo *TRI) const {
    704   DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
    705 
    706   // Callers may expect a single instruction, so keep 128-bit moves
    707   // together for now and lower them after register allocation.
    708   unsigned LoadOpcode, StoreOpcode;
    709   getLoadStoreOpcodes(RC, LoadOpcode, StoreOpcode);
    710   addFrameReference(BuildMI(MBB, MBBI, DL, get(StoreOpcode))
    711                         .addReg(SrcReg, getKillRegState(isKill)),
    712                     FrameIdx);
    713 }
    714 
    715 void SystemZInstrInfo::loadRegFromStackSlot(
    716     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, unsigned DestReg,
    717     int FrameIdx, const TargetRegisterClass *RC,
    718     const TargetRegisterInfo *TRI) const {
    719   DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
    720 
    721   // Callers may expect a single instruction, so keep 128-bit moves
    722   // together for now and lower them after register allocation.
    723   unsigned LoadOpcode, StoreOpcode;
    724   getLoadStoreOpcodes(RC, LoadOpcode, StoreOpcode);
    725   addFrameReference(BuildMI(MBB, MBBI, DL, get(LoadOpcode), DestReg),
    726                     FrameIdx);
    727 }
    728 
    729 // Return true if MI is a simple load or store with a 12-bit displacement
    730 // and no index.  Flag is SimpleBDXLoad for loads and SimpleBDXStore for stores.
    731 static bool isSimpleBD12Move(const MachineInstr *MI, unsigned Flag) {
    732   const MCInstrDesc &MCID = MI->getDesc();
    733   return ((MCID.TSFlags & Flag) &&
    734           isUInt<12>(MI->getOperand(2).getImm()) &&
    735           MI->getOperand(3).getReg() == 0);
    736 }
    737 
    738 namespace {
    739 struct LogicOp {
    740   LogicOp() : RegSize(0), ImmLSB(0), ImmSize(0) {}
    741   LogicOp(unsigned regSize, unsigned immLSB, unsigned immSize)
    742     : RegSize(regSize), ImmLSB(immLSB), ImmSize(immSize) {}
    743 
    744   explicit operator bool() const { return RegSize; }
    745 
    746   unsigned RegSize, ImmLSB, ImmSize;
    747 };
    748 } // end anonymous namespace
    749 
    750 static LogicOp interpretAndImmediate(unsigned Opcode) {
    751   switch (Opcode) {
    752   case SystemZ::NILMux: return LogicOp(32,  0, 16);
    753   case SystemZ::NIHMux: return LogicOp(32, 16, 16);
    754   case SystemZ::NILL64: return LogicOp(64,  0, 16);
    755   case SystemZ::NILH64: return LogicOp(64, 16, 16);
    756   case SystemZ::NIHL64: return LogicOp(64, 32, 16);
    757   case SystemZ::NIHH64: return LogicOp(64, 48, 16);
    758   case SystemZ::NIFMux: return LogicOp(32,  0, 32);
    759   case SystemZ::NILF64: return LogicOp(64,  0, 32);
    760   case SystemZ::NIHF64: return LogicOp(64, 32, 32);
    761   default:              return LogicOp();
    762   }
    763 }
    764 
    765 static void transferDeadCC(MachineInstr *OldMI, MachineInstr *NewMI) {
    766   if (OldMI->registerDefIsDead(SystemZ::CC)) {
    767     MachineOperand *CCDef = NewMI->findRegisterDefOperand(SystemZ::CC);
    768     if (CCDef != nullptr)
    769       CCDef->setIsDead(true);
    770   }
    771 }
    772 
    773 // Used to return from convertToThreeAddress after replacing two-address
    774 // instruction OldMI with three-address instruction NewMI.
    775 static MachineInstr *finishConvertToThreeAddress(MachineInstr *OldMI,
    776                                                  MachineInstr *NewMI,
    777                                                  LiveVariables *LV) {
    778   if (LV) {
    779     unsigned NumOps = OldMI->getNumOperands();
    780     for (unsigned I = 1; I < NumOps; ++I) {
    781       MachineOperand &Op = OldMI->getOperand(I);
    782       if (Op.isReg() && Op.isKill())
    783         LV->replaceKillInstruction(Op.getReg(), *OldMI, *NewMI);
    784     }
    785   }
    786   transferDeadCC(OldMI, NewMI);
    787   return NewMI;
    788 }
    789 
    790 MachineInstr *SystemZInstrInfo::convertToThreeAddress(
    791     MachineFunction::iterator &MFI, MachineInstr &MI, LiveVariables *LV) const {
    792   MachineBasicBlock *MBB = MI.getParent();
    793   MachineFunction *MF = MBB->getParent();
    794   MachineRegisterInfo &MRI = MF->getRegInfo();
    795 
    796   unsigned Opcode = MI.getOpcode();
    797   unsigned NumOps = MI.getNumOperands();
    798 
    799   // Try to convert something like SLL into SLLK, if supported.
    800   // We prefer to keep the two-operand form where possible both
    801   // because it tends to be shorter and because some instructions
    802   // have memory forms that can be used during spilling.
    803   if (STI.hasDistinctOps()) {
    804     MachineOperand &Dest = MI.getOperand(0);
    805     MachineOperand &Src = MI.getOperand(1);
    806     unsigned DestReg = Dest.getReg();
    807     unsigned SrcReg = Src.getReg();
    808     // AHIMux is only really a three-operand instruction when both operands
    809     // are low registers.  Try to constrain both operands to be low if
    810     // possible.
    811     if (Opcode == SystemZ::AHIMux &&
    812         TargetRegisterInfo::isVirtualRegister(DestReg) &&
    813         TargetRegisterInfo::isVirtualRegister(SrcReg) &&
    814         MRI.getRegClass(DestReg)->contains(SystemZ::R1L) &&
    815         MRI.getRegClass(SrcReg)->contains(SystemZ::R1L)) {
    816       MRI.constrainRegClass(DestReg, &SystemZ::GR32BitRegClass);
    817       MRI.constrainRegClass(SrcReg, &SystemZ::GR32BitRegClass);
    818     }
    819     int ThreeOperandOpcode = SystemZ::getThreeOperandOpcode(Opcode);
    820     if (ThreeOperandOpcode >= 0) {
    821       // Create three address instruction without adding the implicit
    822       // operands. Those will instead be copied over from the original
    823       // instruction by the loop below.
    824       MachineInstrBuilder MIB(
    825           *MF, MF->CreateMachineInstr(get(ThreeOperandOpcode), MI.getDebugLoc(),
    826                                       /*NoImplicit=*/true));
    827       MIB.addOperand(Dest);
    828       // Keep the kill state, but drop the tied flag.
    829       MIB.addReg(Src.getReg(), getKillRegState(Src.isKill()), Src.getSubReg());
    830       // Keep the remaining operands as-is.
    831       for (unsigned I = 2; I < NumOps; ++I)
    832         MIB.addOperand(MI.getOperand(I));
    833       MBB->insert(MI, MIB);
    834       return finishConvertToThreeAddress(&MI, MIB, LV);
    835     }
    836   }
    837 
    838   // Try to convert an AND into an RISBG-type instruction.
    839   if (LogicOp And = interpretAndImmediate(Opcode)) {
    840     uint64_t Imm = MI.getOperand(2).getImm() << And.ImmLSB;
    841     // AND IMMEDIATE leaves the other bits of the register unchanged.
    842     Imm |= allOnes(And.RegSize) & ~(allOnes(And.ImmSize) << And.ImmLSB);
    843     unsigned Start, End;
    844     if (isRxSBGMask(Imm, And.RegSize, Start, End)) {
    845       unsigned NewOpcode;
    846       if (And.RegSize == 64) {
    847         NewOpcode = SystemZ::RISBG;
    848         // Prefer RISBGN if available, since it does not clobber CC.
    849         if (STI.hasMiscellaneousExtensions())
    850           NewOpcode = SystemZ::RISBGN;
    851       } else {
    852         NewOpcode = SystemZ::RISBMux;
    853         Start &= 31;
    854         End &= 31;
    855       }
    856       MachineOperand &Dest = MI.getOperand(0);
    857       MachineOperand &Src = MI.getOperand(1);
    858       MachineInstrBuilder MIB =
    859           BuildMI(*MBB, MI, MI.getDebugLoc(), get(NewOpcode))
    860               .addOperand(Dest)
    861               .addReg(0)
    862               .addReg(Src.getReg(), getKillRegState(Src.isKill()),
    863                       Src.getSubReg())
    864               .addImm(Start)
    865               .addImm(End + 128)
    866               .addImm(0);
    867       return finishConvertToThreeAddress(&MI, MIB, LV);
    868     }
    869   }
    870   return nullptr;
    871 }
    872 
    873 MachineInstr *SystemZInstrInfo::foldMemoryOperandImpl(
    874     MachineFunction &MF, MachineInstr &MI, ArrayRef<unsigned> Ops,
    875     MachineBasicBlock::iterator InsertPt, int FrameIndex,
    876     LiveIntervals *LIS) const {
    877   const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
    878   const MachineFrameInfo *MFI = MF.getFrameInfo();
    879   unsigned Size = MFI->getObjectSize(FrameIndex);
    880   unsigned Opcode = MI.getOpcode();
    881 
    882   if (Ops.size() == 2 && Ops[0] == 0 && Ops[1] == 1) {
    883     if (LIS != nullptr && (Opcode == SystemZ::LA || Opcode == SystemZ::LAY) &&
    884         isInt<8>(MI.getOperand(2).getImm()) && !MI.getOperand(3).getReg()) {
    885 
    886       // Check CC liveness, since new instruction introduces a dead
    887       // def of CC.
    888       MCRegUnitIterator CCUnit(SystemZ::CC, TRI);
    889       LiveRange &CCLiveRange = LIS->getRegUnit(*CCUnit);
    890       ++CCUnit;
    891       assert (!CCUnit.isValid() && "CC only has one reg unit.");
    892       SlotIndex MISlot =
    893           LIS->getSlotIndexes()->getInstructionIndex(MI).getRegSlot();
    894       if (!CCLiveRange.liveAt(MISlot)) {
    895         // LA(Y) %reg, CONST(%reg) -> AGSI %mem, CONST
    896         MachineInstr *BuiltMI = BuildMI(*InsertPt->getParent(), InsertPt,
    897                                         MI.getDebugLoc(), get(SystemZ::AGSI))
    898                                     .addFrameIndex(FrameIndex)
    899                                     .addImm(0)
    900                                     .addImm(MI.getOperand(2).getImm());
    901         BuiltMI->findRegisterDefOperand(SystemZ::CC)->setIsDead(true);
    902         CCLiveRange.createDeadDef(MISlot, LIS->getVNInfoAllocator());
    903         return BuiltMI;
    904       }
    905     }
    906     return nullptr;
    907   }
    908 
    909   // All other cases require a single operand.
    910   if (Ops.size() != 1)
    911     return nullptr;
    912 
    913   unsigned OpNum = Ops[0];
    914   assert(Size ==
    915              MF.getRegInfo()
    916                  .getRegClass(MI.getOperand(OpNum).getReg())
    917                  ->getSize() &&
    918          "Invalid size combination");
    919 
    920   if ((Opcode == SystemZ::AHI || Opcode == SystemZ::AGHI) && OpNum == 0 &&
    921       isInt<8>(MI.getOperand(2).getImm())) {
    922     // A(G)HI %reg, CONST -> A(G)SI %mem, CONST
    923     Opcode = (Opcode == SystemZ::AHI ? SystemZ::ASI : SystemZ::AGSI);
    924     MachineInstr *BuiltMI =
    925         BuildMI(*InsertPt->getParent(), InsertPt, MI.getDebugLoc(), get(Opcode))
    926             .addFrameIndex(FrameIndex)
    927             .addImm(0)
    928             .addImm(MI.getOperand(2).getImm());
    929     transferDeadCC(&MI, BuiltMI);
    930     return BuiltMI;
    931   }
    932 
    933   if (Opcode == SystemZ::LGDR || Opcode == SystemZ::LDGR) {
    934     bool Op0IsGPR = (Opcode == SystemZ::LGDR);
    935     bool Op1IsGPR = (Opcode == SystemZ::LDGR);
    936     // If we're spilling the destination of an LDGR or LGDR, store the
    937     // source register instead.
    938     if (OpNum == 0) {
    939       unsigned StoreOpcode = Op1IsGPR ? SystemZ::STG : SystemZ::STD;
    940       return BuildMI(*InsertPt->getParent(), InsertPt, MI.getDebugLoc(),
    941                      get(StoreOpcode))
    942           .addOperand(MI.getOperand(1))
    943           .addFrameIndex(FrameIndex)
    944           .addImm(0)
    945           .addReg(0);
    946     }
    947     // If we're spilling the source of an LDGR or LGDR, load the
    948     // destination register instead.
    949     if (OpNum == 1) {
    950       unsigned LoadOpcode = Op0IsGPR ? SystemZ::LG : SystemZ::LD;
    951       unsigned Dest = MI.getOperand(0).getReg();
    952       return BuildMI(*InsertPt->getParent(), InsertPt, MI.getDebugLoc(),
    953                      get(LoadOpcode), Dest)
    954           .addFrameIndex(FrameIndex)
    955           .addImm(0)
    956           .addReg(0);
    957     }
    958   }
    959 
    960   // Look for cases where the source of a simple store or the destination
    961   // of a simple load is being spilled.  Try to use MVC instead.
    962   //
    963   // Although MVC is in practice a fast choice in these cases, it is still
    964   // logically a bytewise copy.  This means that we cannot use it if the
    965   // load or store is volatile.  We also wouldn't be able to use MVC if
    966   // the two memories partially overlap, but that case cannot occur here,
    967   // because we know that one of the memories is a full frame index.
    968   //
    969   // For performance reasons, we also want to avoid using MVC if the addresses
    970   // might be equal.  We don't worry about that case here, because spill slot
    971   // coloring happens later, and because we have special code to remove
    972   // MVCs that turn out to be redundant.
    973   if (OpNum == 0 && MI.hasOneMemOperand()) {
    974     MachineMemOperand *MMO = *MI.memoperands_begin();
    975     if (MMO->getSize() == Size && !MMO->isVolatile()) {
    976       // Handle conversion of loads.
    977       if (isSimpleBD12Move(&MI, SystemZII::SimpleBDXLoad)) {
    978         return BuildMI(*InsertPt->getParent(), InsertPt, MI.getDebugLoc(),
    979                        get(SystemZ::MVC))
    980             .addFrameIndex(FrameIndex)
    981             .addImm(0)
    982             .addImm(Size)
    983             .addOperand(MI.getOperand(1))
    984             .addImm(MI.getOperand(2).getImm())
    985             .addMemOperand(MMO);
    986       }
    987       // Handle conversion of stores.
    988       if (isSimpleBD12Move(&MI, SystemZII::SimpleBDXStore)) {
    989         return BuildMI(*InsertPt->getParent(), InsertPt, MI.getDebugLoc(),
    990                        get(SystemZ::MVC))
    991             .addOperand(MI.getOperand(1))
    992             .addImm(MI.getOperand(2).getImm())
    993             .addImm(Size)
    994             .addFrameIndex(FrameIndex)
    995             .addImm(0)
    996             .addMemOperand(MMO);
    997       }
    998     }
    999   }
   1000 
   1001   // If the spilled operand is the final one, try to change <INSN>R
   1002   // into <INSN>.
   1003   int MemOpcode = SystemZ::getMemOpcode(Opcode);
   1004   if (MemOpcode >= 0) {
   1005     unsigned NumOps = MI.getNumExplicitOperands();
   1006     if (OpNum == NumOps - 1) {
   1007       const MCInstrDesc &MemDesc = get(MemOpcode);
   1008       uint64_t AccessBytes = SystemZII::getAccessSize(MemDesc.TSFlags);
   1009       assert(AccessBytes != 0 && "Size of access should be known");
   1010       assert(AccessBytes <= Size && "Access outside the frame index");
   1011       uint64_t Offset = Size - AccessBytes;
   1012       MachineInstrBuilder MIB = BuildMI(*InsertPt->getParent(), InsertPt,
   1013                                         MI.getDebugLoc(), get(MemOpcode));
   1014       for (unsigned I = 0; I < OpNum; ++I)
   1015         MIB.addOperand(MI.getOperand(I));
   1016       MIB.addFrameIndex(FrameIndex).addImm(Offset);
   1017       if (MemDesc.TSFlags & SystemZII::HasIndex)
   1018         MIB.addReg(0);
   1019       transferDeadCC(&MI, MIB);
   1020       return MIB;
   1021     }
   1022   }
   1023 
   1024   return nullptr;
   1025 }
   1026 
   1027 MachineInstr *SystemZInstrInfo::foldMemoryOperandImpl(
   1028     MachineFunction &MF, MachineInstr &MI, ArrayRef<unsigned> Ops,
   1029     MachineBasicBlock::iterator InsertPt, MachineInstr &LoadMI,
   1030     LiveIntervals *LIS) const {
   1031   return nullptr;
   1032 }
   1033 
   1034 bool SystemZInstrInfo::expandPostRAPseudo(MachineInstr &MI) const {
   1035   switch (MI.getOpcode()) {
   1036   case SystemZ::L128:
   1037     splitMove(MI, SystemZ::LG);
   1038     return true;
   1039 
   1040   case SystemZ::ST128:
   1041     splitMove(MI, SystemZ::STG);
   1042     return true;
   1043 
   1044   case SystemZ::LX:
   1045     splitMove(MI, SystemZ::LD);
   1046     return true;
   1047 
   1048   case SystemZ::STX:
   1049     splitMove(MI, SystemZ::STD);
   1050     return true;
   1051 
   1052   case SystemZ::LBMux:
   1053     expandRXYPseudo(MI, SystemZ::LB, SystemZ::LBH);
   1054     return true;
   1055 
   1056   case SystemZ::LHMux:
   1057     expandRXYPseudo(MI, SystemZ::LH, SystemZ::LHH);
   1058     return true;
   1059 
   1060   case SystemZ::LLCRMux:
   1061     expandZExtPseudo(MI, SystemZ::LLCR, 8);
   1062     return true;
   1063 
   1064   case SystemZ::LLHRMux:
   1065     expandZExtPseudo(MI, SystemZ::LLHR, 16);
   1066     return true;
   1067 
   1068   case SystemZ::LLCMux:
   1069     expandRXYPseudo(MI, SystemZ::LLC, SystemZ::LLCH);
   1070     return true;
   1071 
   1072   case SystemZ::LLHMux:
   1073     expandRXYPseudo(MI, SystemZ::LLH, SystemZ::LLHH);
   1074     return true;
   1075 
   1076   case SystemZ::LMux:
   1077     expandRXYPseudo(MI, SystemZ::L, SystemZ::LFH);
   1078     return true;
   1079 
   1080   case SystemZ::STCMux:
   1081     expandRXYPseudo(MI, SystemZ::STC, SystemZ::STCH);
   1082     return true;
   1083 
   1084   case SystemZ::STHMux:
   1085     expandRXYPseudo(MI, SystemZ::STH, SystemZ::STHH);
   1086     return true;
   1087 
   1088   case SystemZ::STMux:
   1089     expandRXYPseudo(MI, SystemZ::ST, SystemZ::STFH);
   1090     return true;
   1091 
   1092   case SystemZ::LHIMux:
   1093     expandRIPseudo(MI, SystemZ::LHI, SystemZ::IIHF, true);
   1094     return true;
   1095 
   1096   case SystemZ::IIFMux:
   1097     expandRIPseudo(MI, SystemZ::IILF, SystemZ::IIHF, false);
   1098     return true;
   1099 
   1100   case SystemZ::IILMux:
   1101     expandRIPseudo(MI, SystemZ::IILL, SystemZ::IIHL, false);
   1102     return true;
   1103 
   1104   case SystemZ::IIHMux:
   1105     expandRIPseudo(MI, SystemZ::IILH, SystemZ::IIHH, false);
   1106     return true;
   1107 
   1108   case SystemZ::NIFMux:
   1109     expandRIPseudo(MI, SystemZ::NILF, SystemZ::NIHF, false);
   1110     return true;
   1111 
   1112   case SystemZ::NILMux:
   1113     expandRIPseudo(MI, SystemZ::NILL, SystemZ::NIHL, false);
   1114     return true;
   1115 
   1116   case SystemZ::NIHMux:
   1117     expandRIPseudo(MI, SystemZ::NILH, SystemZ::NIHH, false);
   1118     return true;
   1119 
   1120   case SystemZ::OIFMux:
   1121     expandRIPseudo(MI, SystemZ::OILF, SystemZ::OIHF, false);
   1122     return true;
   1123 
   1124   case SystemZ::OILMux:
   1125     expandRIPseudo(MI, SystemZ::OILL, SystemZ::OIHL, false);
   1126     return true;
   1127 
   1128   case SystemZ::OIHMux:
   1129     expandRIPseudo(MI, SystemZ::OILH, SystemZ::OIHH, false);
   1130     return true;
   1131 
   1132   case SystemZ::XIFMux:
   1133     expandRIPseudo(MI, SystemZ::XILF, SystemZ::XIHF, false);
   1134     return true;
   1135 
   1136   case SystemZ::TMLMux:
   1137     expandRIPseudo(MI, SystemZ::TMLL, SystemZ::TMHL, false);
   1138     return true;
   1139 
   1140   case SystemZ::TMHMux:
   1141     expandRIPseudo(MI, SystemZ::TMLH, SystemZ::TMHH, false);
   1142     return true;
   1143 
   1144   case SystemZ::AHIMux:
   1145     expandRIPseudo(MI, SystemZ::AHI, SystemZ::AIH, false);
   1146     return true;
   1147 
   1148   case SystemZ::AHIMuxK:
   1149     expandRIEPseudo(MI, SystemZ::AHI, SystemZ::AHIK, SystemZ::AIH);
   1150     return true;
   1151 
   1152   case SystemZ::AFIMux:
   1153     expandRIPseudo(MI, SystemZ::AFI, SystemZ::AIH, false);
   1154     return true;
   1155 
   1156   case SystemZ::CFIMux:
   1157     expandRIPseudo(MI, SystemZ::CFI, SystemZ::CIH, false);
   1158     return true;
   1159 
   1160   case SystemZ::CLFIMux:
   1161     expandRIPseudo(MI, SystemZ::CLFI, SystemZ::CLIH, false);
   1162     return true;
   1163 
   1164   case SystemZ::CMux:
   1165     expandRXYPseudo(MI, SystemZ::C, SystemZ::CHF);
   1166     return true;
   1167 
   1168   case SystemZ::CLMux:
   1169     expandRXYPseudo(MI, SystemZ::CL, SystemZ::CLHF);
   1170     return true;
   1171 
   1172   case SystemZ::RISBMux: {
   1173     bool DestIsHigh = isHighReg(MI.getOperand(0).getReg());
   1174     bool SrcIsHigh = isHighReg(MI.getOperand(2).getReg());
   1175     if (SrcIsHigh == DestIsHigh)
   1176       MI.setDesc(get(DestIsHigh ? SystemZ::RISBHH : SystemZ::RISBLL));
   1177     else {
   1178       MI.setDesc(get(DestIsHigh ? SystemZ::RISBHL : SystemZ::RISBLH));
   1179       MI.getOperand(5).setImm(MI.getOperand(5).getImm() ^ 32);
   1180     }
   1181     return true;
   1182   }
   1183 
   1184   case SystemZ::ADJDYNALLOC:
   1185     splitAdjDynAlloc(MI);
   1186     return true;
   1187 
   1188   case TargetOpcode::LOAD_STACK_GUARD:
   1189     expandLoadStackGuard(&MI);
   1190     return true;
   1191 
   1192   default:
   1193     return false;
   1194   }
   1195 }
   1196 
   1197 uint64_t SystemZInstrInfo::getInstSizeInBytes(const MachineInstr &MI) const {
   1198   if (MI.getOpcode() == TargetOpcode::INLINEASM) {
   1199     const MachineFunction *MF = MI.getParent()->getParent();
   1200     const char *AsmStr = MI.getOperand(0).getSymbolName();
   1201     return getInlineAsmLength(AsmStr, *MF->getTarget().getMCAsmInfo());
   1202   }
   1203   return MI.getDesc().getSize();
   1204 }
   1205 
   1206 SystemZII::Branch
   1207 SystemZInstrInfo::getBranchInfo(const MachineInstr &MI) const {
   1208   switch (MI.getOpcode()) {
   1209   case SystemZ::BR:
   1210   case SystemZ::J:
   1211   case SystemZ::JG:
   1212     return SystemZII::Branch(SystemZII::BranchNormal, SystemZ::CCMASK_ANY,
   1213                              SystemZ::CCMASK_ANY, &MI.getOperand(0));
   1214 
   1215   case SystemZ::BRC:
   1216   case SystemZ::BRCL:
   1217     return SystemZII::Branch(SystemZII::BranchNormal, MI.getOperand(0).getImm(),
   1218                              MI.getOperand(1).getImm(), &MI.getOperand(2));
   1219 
   1220   case SystemZ::BRCT:
   1221     return SystemZII::Branch(SystemZII::BranchCT, SystemZ::CCMASK_ICMP,
   1222                              SystemZ::CCMASK_CMP_NE, &MI.getOperand(2));
   1223 
   1224   case SystemZ::BRCTG:
   1225     return SystemZII::Branch(SystemZII::BranchCTG, SystemZ::CCMASK_ICMP,
   1226                              SystemZ::CCMASK_CMP_NE, &MI.getOperand(2));
   1227 
   1228   case SystemZ::CIJ:
   1229   case SystemZ::CRJ:
   1230     return SystemZII::Branch(SystemZII::BranchC, SystemZ::CCMASK_ICMP,
   1231                              MI.getOperand(2).getImm(), &MI.getOperand(3));
   1232 
   1233   case SystemZ::CLIJ:
   1234   case SystemZ::CLRJ:
   1235     return SystemZII::Branch(SystemZII::BranchCL, SystemZ::CCMASK_ICMP,
   1236                              MI.getOperand(2).getImm(), &MI.getOperand(3));
   1237 
   1238   case SystemZ::CGIJ:
   1239   case SystemZ::CGRJ:
   1240     return SystemZII::Branch(SystemZII::BranchCG, SystemZ::CCMASK_ICMP,
   1241                              MI.getOperand(2).getImm(), &MI.getOperand(3));
   1242 
   1243   case SystemZ::CLGIJ:
   1244   case SystemZ::CLGRJ:
   1245     return SystemZII::Branch(SystemZII::BranchCLG, SystemZ::CCMASK_ICMP,
   1246                              MI.getOperand(2).getImm(), &MI.getOperand(3));
   1247 
   1248   default:
   1249     llvm_unreachable("Unrecognized branch opcode");
   1250   }
   1251 }
   1252 
   1253 void SystemZInstrInfo::getLoadStoreOpcodes(const TargetRegisterClass *RC,
   1254                                            unsigned &LoadOpcode,
   1255                                            unsigned &StoreOpcode) const {
   1256   if (RC == &SystemZ::GR32BitRegClass || RC == &SystemZ::ADDR32BitRegClass) {
   1257     LoadOpcode = SystemZ::L;
   1258     StoreOpcode = SystemZ::ST;
   1259   } else if (RC == &SystemZ::GRH32BitRegClass) {
   1260     LoadOpcode = SystemZ::LFH;
   1261     StoreOpcode = SystemZ::STFH;
   1262   } else if (RC == &SystemZ::GRX32BitRegClass) {
   1263     LoadOpcode = SystemZ::LMux;
   1264     StoreOpcode = SystemZ::STMux;
   1265   } else if (RC == &SystemZ::GR64BitRegClass ||
   1266              RC == &SystemZ::ADDR64BitRegClass) {
   1267     LoadOpcode = SystemZ::LG;
   1268     StoreOpcode = SystemZ::STG;
   1269   } else if (RC == &SystemZ::GR128BitRegClass ||
   1270              RC == &SystemZ::ADDR128BitRegClass) {
   1271     LoadOpcode = SystemZ::L128;
   1272     StoreOpcode = SystemZ::ST128;
   1273   } else if (RC == &SystemZ::FP32BitRegClass) {
   1274     LoadOpcode = SystemZ::LE;
   1275     StoreOpcode = SystemZ::STE;
   1276   } else if (RC == &SystemZ::FP64BitRegClass) {
   1277     LoadOpcode = SystemZ::LD;
   1278     StoreOpcode = SystemZ::STD;
   1279   } else if (RC == &SystemZ::FP128BitRegClass) {
   1280     LoadOpcode = SystemZ::LX;
   1281     StoreOpcode = SystemZ::STX;
   1282   } else if (RC == &SystemZ::VR32BitRegClass) {
   1283     LoadOpcode = SystemZ::VL32;
   1284     StoreOpcode = SystemZ::VST32;
   1285   } else if (RC == &SystemZ::VR64BitRegClass) {
   1286     LoadOpcode = SystemZ::VL64;
   1287     StoreOpcode = SystemZ::VST64;
   1288   } else if (RC == &SystemZ::VF128BitRegClass ||
   1289              RC == &SystemZ::VR128BitRegClass) {
   1290     LoadOpcode = SystemZ::VL;
   1291     StoreOpcode = SystemZ::VST;
   1292   } else
   1293     llvm_unreachable("Unsupported regclass to load or store");
   1294 }
   1295 
   1296 unsigned SystemZInstrInfo::getOpcodeForOffset(unsigned Opcode,
   1297                                               int64_t Offset) const {
   1298   const MCInstrDesc &MCID = get(Opcode);
   1299   int64_t Offset2 = (MCID.TSFlags & SystemZII::Is128Bit ? Offset + 8 : Offset);
   1300   if (isUInt<12>(Offset) && isUInt<12>(Offset2)) {
   1301     // Get the instruction to use for unsigned 12-bit displacements.
   1302     int Disp12Opcode = SystemZ::getDisp12Opcode(Opcode);
   1303     if (Disp12Opcode >= 0)
   1304       return Disp12Opcode;
   1305 
   1306     // All address-related instructions can use unsigned 12-bit
   1307     // displacements.
   1308     return Opcode;
   1309   }
   1310   if (isInt<20>(Offset) && isInt<20>(Offset2)) {
   1311     // Get the instruction to use for signed 20-bit displacements.
   1312     int Disp20Opcode = SystemZ::getDisp20Opcode(Opcode);
   1313     if (Disp20Opcode >= 0)
   1314       return Disp20Opcode;
   1315 
   1316     // Check whether Opcode allows signed 20-bit displacements.
   1317     if (MCID.TSFlags & SystemZII::Has20BitOffset)
   1318       return Opcode;
   1319   }
   1320   return 0;
   1321 }
   1322 
   1323 unsigned SystemZInstrInfo::getLoadAndTest(unsigned Opcode) const {
   1324   switch (Opcode) {
   1325   case SystemZ::L:      return SystemZ::LT;
   1326   case SystemZ::LY:     return SystemZ::LT;
   1327   case SystemZ::LG:     return SystemZ::LTG;
   1328   case SystemZ::LGF:    return SystemZ::LTGF;
   1329   case SystemZ::LR:     return SystemZ::LTR;
   1330   case SystemZ::LGFR:   return SystemZ::LTGFR;
   1331   case SystemZ::LGR:    return SystemZ::LTGR;
   1332   case SystemZ::LER:    return SystemZ::LTEBR;
   1333   case SystemZ::LDR:    return SystemZ::LTDBR;
   1334   case SystemZ::LXR:    return SystemZ::LTXBR;
   1335   case SystemZ::LCDFR:  return SystemZ::LCDBR;
   1336   case SystemZ::LPDFR:  return SystemZ::LPDBR;
   1337   case SystemZ::LNDFR:  return SystemZ::LNDBR;
   1338   case SystemZ::LCDFR_32:  return SystemZ::LCEBR;
   1339   case SystemZ::LPDFR_32:  return SystemZ::LPEBR;
   1340   case SystemZ::LNDFR_32:  return SystemZ::LNEBR;
   1341   // On zEC12 we prefer to use RISBGN.  But if there is a chance to
   1342   // actually use the condition code, we may turn it back into RISGB.
   1343   // Note that RISBG is not really a "load-and-test" instruction,
   1344   // but sets the same condition code values, so is OK to use here.
   1345   case SystemZ::RISBGN: return SystemZ::RISBG;
   1346   default:              return 0;
   1347   }
   1348 }
   1349 
   1350 // Return true if Mask matches the regexp 0*1+0*, given that zero masks
   1351 // have already been filtered out.  Store the first set bit in LSB and
   1352 // the number of set bits in Length if so.
   1353 static bool isStringOfOnes(uint64_t Mask, unsigned &LSB, unsigned &Length) {
   1354   unsigned First = findFirstSet(Mask);
   1355   uint64_t Top = (Mask >> First) + 1;
   1356   if ((Top & -Top) == Top) {
   1357     LSB = First;
   1358     Length = findFirstSet(Top);
   1359     return true;
   1360   }
   1361   return false;
   1362 }
   1363 
   1364 bool SystemZInstrInfo::isRxSBGMask(uint64_t Mask, unsigned BitSize,
   1365                                    unsigned &Start, unsigned &End) const {
   1366   // Reject trivial all-zero masks.
   1367   Mask &= allOnes(BitSize);
   1368   if (Mask == 0)
   1369     return false;
   1370 
   1371   // Handle the 1+0+ or 0+1+0* cases.  Start then specifies the index of
   1372   // the msb and End specifies the index of the lsb.
   1373   unsigned LSB, Length;
   1374   if (isStringOfOnes(Mask, LSB, Length)) {
   1375     Start = 63 - (LSB + Length - 1);
   1376     End = 63 - LSB;
   1377     return true;
   1378   }
   1379 
   1380   // Handle the wrap-around 1+0+1+ cases.  Start then specifies the msb
   1381   // of the low 1s and End specifies the lsb of the high 1s.
   1382   if (isStringOfOnes(Mask ^ allOnes(BitSize), LSB, Length)) {
   1383     assert(LSB > 0 && "Bottom bit must be set");
   1384     assert(LSB + Length < BitSize && "Top bit must be set");
   1385     Start = 63 - (LSB - 1);
   1386     End = 63 - (LSB + Length);
   1387     return true;
   1388   }
   1389 
   1390   return false;
   1391 }
   1392 
   1393 unsigned SystemZInstrInfo::getFusedCompare(unsigned Opcode,
   1394                                            SystemZII::FusedCompareType Type,
   1395                                            const MachineInstr *MI) const {
   1396   switch (Opcode) {
   1397   case SystemZ::CHI:
   1398   case SystemZ::CGHI:
   1399     if (!(MI && isInt<8>(MI->getOperand(1).getImm())))
   1400       return 0;
   1401     break;
   1402   case SystemZ::CLFI:
   1403   case SystemZ::CLGFI:
   1404     if (!(MI && isUInt<8>(MI->getOperand(1).getImm())))
   1405       return 0;
   1406   }
   1407   switch (Type) {
   1408   case SystemZII::CompareAndBranch:
   1409     switch (Opcode) {
   1410     case SystemZ::CR:
   1411       return SystemZ::CRJ;
   1412     case SystemZ::CGR:
   1413       return SystemZ::CGRJ;
   1414     case SystemZ::CHI:
   1415       return SystemZ::CIJ;
   1416     case SystemZ::CGHI:
   1417       return SystemZ::CGIJ;
   1418     case SystemZ::CLR:
   1419       return SystemZ::CLRJ;
   1420     case SystemZ::CLGR:
   1421       return SystemZ::CLGRJ;
   1422     case SystemZ::CLFI:
   1423       return SystemZ::CLIJ;
   1424     case SystemZ::CLGFI:
   1425       return SystemZ::CLGIJ;
   1426     default:
   1427       return 0;
   1428     }
   1429   case SystemZII::CompareAndReturn:
   1430     switch (Opcode) {
   1431     case SystemZ::CR:
   1432       return SystemZ::CRBReturn;
   1433     case SystemZ::CGR:
   1434       return SystemZ::CGRBReturn;
   1435     case SystemZ::CHI:
   1436       return SystemZ::CIBReturn;
   1437     case SystemZ::CGHI:
   1438       return SystemZ::CGIBReturn;
   1439     case SystemZ::CLR:
   1440       return SystemZ::CLRBReturn;
   1441     case SystemZ::CLGR:
   1442       return SystemZ::CLGRBReturn;
   1443     case SystemZ::CLFI:
   1444       return SystemZ::CLIBReturn;
   1445     case SystemZ::CLGFI:
   1446       return SystemZ::CLGIBReturn;
   1447     default:
   1448       return 0;
   1449     }
   1450   case SystemZII::CompareAndSibcall:
   1451     switch (Opcode) {
   1452     case SystemZ::CR:
   1453       return SystemZ::CRBCall;
   1454     case SystemZ::CGR:
   1455       return SystemZ::CGRBCall;
   1456     case SystemZ::CHI:
   1457       return SystemZ::CIBCall;
   1458     case SystemZ::CGHI:
   1459       return SystemZ::CGIBCall;
   1460     case SystemZ::CLR:
   1461       return SystemZ::CLRBCall;
   1462     case SystemZ::CLGR:
   1463       return SystemZ::CLGRBCall;
   1464     case SystemZ::CLFI:
   1465       return SystemZ::CLIBCall;
   1466     case SystemZ::CLGFI:
   1467       return SystemZ::CLGIBCall;
   1468     default:
   1469       return 0;
   1470     }
   1471   case SystemZII::CompareAndTrap:
   1472     switch (Opcode) {
   1473     case SystemZ::CR:
   1474       return SystemZ::CRT;
   1475     case SystemZ::CGR:
   1476       return SystemZ::CGRT;
   1477     case SystemZ::CHI:
   1478       return SystemZ::CIT;
   1479     case SystemZ::CGHI:
   1480       return SystemZ::CGIT;
   1481     case SystemZ::CLR:
   1482       return SystemZ::CLRT;
   1483     case SystemZ::CLGR:
   1484       return SystemZ::CLGRT;
   1485     case SystemZ::CLFI:
   1486       return SystemZ::CLFIT;
   1487     case SystemZ::CLGFI:
   1488       return SystemZ::CLGIT;
   1489     default:
   1490       return 0;
   1491     }
   1492   }
   1493   return 0;
   1494 }
   1495 
   1496 void SystemZInstrInfo::loadImmediate(MachineBasicBlock &MBB,
   1497                                      MachineBasicBlock::iterator MBBI,
   1498                                      unsigned Reg, uint64_t Value) const {
   1499   DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
   1500   unsigned Opcode;
   1501   if (isInt<16>(Value))
   1502     Opcode = SystemZ::LGHI;
   1503   else if (SystemZ::isImmLL(Value))
   1504     Opcode = SystemZ::LLILL;
   1505   else if (SystemZ::isImmLH(Value)) {
   1506     Opcode = SystemZ::LLILH;
   1507     Value >>= 16;
   1508   } else {
   1509     assert(isInt<32>(Value) && "Huge values not handled yet");
   1510     Opcode = SystemZ::LGFI;
   1511   }
   1512   BuildMI(MBB, MBBI, DL, get(Opcode), Reg).addImm(Value);
   1513 }
   1514