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      1 //===-- lib/CodeGen/MachineInstr.cpp --------------------------------------===//
      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 // Methods common to all machine instructions.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "llvm/CodeGen/MachineInstr.h"
     15 #include "llvm/ADT/FoldingSet.h"
     16 #include "llvm/ADT/Hashing.h"
     17 #include "llvm/Analysis/AliasAnalysis.h"
     18 #include "llvm/CodeGen/MachineConstantPool.h"
     19 #include "llvm/CodeGen/MachineFunction.h"
     20 #include "llvm/CodeGen/MachineMemOperand.h"
     21 #include "llvm/CodeGen/MachineModuleInfo.h"
     22 #include "llvm/CodeGen/MachineRegisterInfo.h"
     23 #include "llvm/CodeGen/PseudoSourceValue.h"
     24 #include "llvm/IR/Constants.h"
     25 #include "llvm/IR/DebugInfo.h"
     26 #include "llvm/IR/Function.h"
     27 #include "llvm/IR/InlineAsm.h"
     28 #include "llvm/IR/LLVMContext.h"
     29 #include "llvm/IR/Metadata.h"
     30 #include "llvm/IR/Module.h"
     31 #include "llvm/IR/Type.h"
     32 #include "llvm/IR/Value.h"
     33 #include "llvm/MC/MCInstrDesc.h"
     34 #include "llvm/MC/MCSymbol.h"
     35 #include "llvm/Support/Debug.h"
     36 #include "llvm/Support/ErrorHandling.h"
     37 #include "llvm/Support/MathExtras.h"
     38 #include "llvm/Support/raw_ostream.h"
     39 #include "llvm/Target/TargetInstrInfo.h"
     40 #include "llvm/Target/TargetMachine.h"
     41 #include "llvm/Target/TargetRegisterInfo.h"
     42 using namespace llvm;
     43 
     44 //===----------------------------------------------------------------------===//
     45 // MachineOperand Implementation
     46 //===----------------------------------------------------------------------===//
     47 
     48 void MachineOperand::setReg(unsigned Reg) {
     49   if (getReg() == Reg) return; // No change.
     50 
     51   // Otherwise, we have to change the register.  If this operand is embedded
     52   // into a machine function, we need to update the old and new register's
     53   // use/def lists.
     54   if (MachineInstr *MI = getParent())
     55     if (MachineBasicBlock *MBB = MI->getParent())
     56       if (MachineFunction *MF = MBB->getParent()) {
     57         MachineRegisterInfo &MRI = MF->getRegInfo();
     58         MRI.removeRegOperandFromUseList(this);
     59         SmallContents.RegNo = Reg;
     60         MRI.addRegOperandToUseList(this);
     61         return;
     62       }
     63 
     64   // Otherwise, just change the register, no problem.  :)
     65   SmallContents.RegNo = Reg;
     66 }
     67 
     68 void MachineOperand::substVirtReg(unsigned Reg, unsigned SubIdx,
     69                                   const TargetRegisterInfo &TRI) {
     70   assert(TargetRegisterInfo::isVirtualRegister(Reg));
     71   if (SubIdx && getSubReg())
     72     SubIdx = TRI.composeSubRegIndices(SubIdx, getSubReg());
     73   setReg(Reg);
     74   if (SubIdx)
     75     setSubReg(SubIdx);
     76 }
     77 
     78 void MachineOperand::substPhysReg(unsigned Reg, const TargetRegisterInfo &TRI) {
     79   assert(TargetRegisterInfo::isPhysicalRegister(Reg));
     80   if (getSubReg()) {
     81     Reg = TRI.getSubReg(Reg, getSubReg());
     82     // Note that getSubReg() may return 0 if the sub-register doesn't exist.
     83     // That won't happen in legal code.
     84     setSubReg(0);
     85   }
     86   setReg(Reg);
     87 }
     88 
     89 /// Change a def to a use, or a use to a def.
     90 void MachineOperand::setIsDef(bool Val) {
     91   assert(isReg() && "Wrong MachineOperand accessor");
     92   assert((!Val || !isDebug()) && "Marking a debug operation as def");
     93   if (IsDef == Val)
     94     return;
     95   // MRI may keep uses and defs in different list positions.
     96   if (MachineInstr *MI = getParent())
     97     if (MachineBasicBlock *MBB = MI->getParent())
     98       if (MachineFunction *MF = MBB->getParent()) {
     99         MachineRegisterInfo &MRI = MF->getRegInfo();
    100         MRI.removeRegOperandFromUseList(this);
    101         IsDef = Val;
    102         MRI.addRegOperandToUseList(this);
    103         return;
    104       }
    105   IsDef = Val;
    106 }
    107 
    108 /// ChangeToImmediate - Replace this operand with a new immediate operand of
    109 /// the specified value.  If an operand is known to be an immediate already,
    110 /// the setImm method should be used.
    111 void MachineOperand::ChangeToImmediate(int64_t ImmVal) {
    112   assert((!isReg() || !isTied()) && "Cannot change a tied operand into an imm");
    113   // If this operand is currently a register operand, and if this is in a
    114   // function, deregister the operand from the register's use/def list.
    115   if (isReg() && isOnRegUseList())
    116     if (MachineInstr *MI = getParent())
    117       if (MachineBasicBlock *MBB = MI->getParent())
    118         if (MachineFunction *MF = MBB->getParent())
    119           MF->getRegInfo().removeRegOperandFromUseList(this);
    120 
    121   OpKind = MO_Immediate;
    122   Contents.ImmVal = ImmVal;
    123 }
    124 
    125 /// ChangeToRegister - Replace this operand with a new register operand of
    126 /// the specified value.  If an operand is known to be an register already,
    127 /// the setReg method should be used.
    128 void MachineOperand::ChangeToRegister(unsigned Reg, bool isDef, bool isImp,
    129                                       bool isKill, bool isDead, bool isUndef,
    130                                       bool isDebug) {
    131   MachineRegisterInfo *RegInfo = nullptr;
    132   if (MachineInstr *MI = getParent())
    133     if (MachineBasicBlock *MBB = MI->getParent())
    134       if (MachineFunction *MF = MBB->getParent())
    135         RegInfo = &MF->getRegInfo();
    136   // If this operand is already a register operand, remove it from the
    137   // register's use/def lists.
    138   bool WasReg = isReg();
    139   if (RegInfo && WasReg)
    140     RegInfo->removeRegOperandFromUseList(this);
    141 
    142   // Change this to a register and set the reg#.
    143   OpKind = MO_Register;
    144   SmallContents.RegNo = Reg;
    145   SubReg_TargetFlags = 0;
    146   IsDef = isDef;
    147   IsImp = isImp;
    148   IsKill = isKill;
    149   IsDead = isDead;
    150   IsUndef = isUndef;
    151   IsInternalRead = false;
    152   IsEarlyClobber = false;
    153   IsDebug = isDebug;
    154   // Ensure isOnRegUseList() returns false.
    155   Contents.Reg.Prev = nullptr;
    156   // Preserve the tie when the operand was already a register.
    157   if (!WasReg)
    158     TiedTo = 0;
    159 
    160   // If this operand is embedded in a function, add the operand to the
    161   // register's use/def list.
    162   if (RegInfo)
    163     RegInfo->addRegOperandToUseList(this);
    164 }
    165 
    166 /// isIdenticalTo - Return true if this operand is identical to the specified
    167 /// operand. Note that this should stay in sync with the hash_value overload
    168 /// below.
    169 bool MachineOperand::isIdenticalTo(const MachineOperand &Other) const {
    170   if (getType() != Other.getType() ||
    171       getTargetFlags() != Other.getTargetFlags())
    172     return false;
    173 
    174   switch (getType()) {
    175   case MachineOperand::MO_Register:
    176     return getReg() == Other.getReg() && isDef() == Other.isDef() &&
    177            getSubReg() == Other.getSubReg();
    178   case MachineOperand::MO_Immediate:
    179     return getImm() == Other.getImm();
    180   case MachineOperand::MO_CImmediate:
    181     return getCImm() == Other.getCImm();
    182   case MachineOperand::MO_FPImmediate:
    183     return getFPImm() == Other.getFPImm();
    184   case MachineOperand::MO_MachineBasicBlock:
    185     return getMBB() == Other.getMBB();
    186   case MachineOperand::MO_FrameIndex:
    187     return getIndex() == Other.getIndex();
    188   case MachineOperand::MO_ConstantPoolIndex:
    189   case MachineOperand::MO_TargetIndex:
    190     return getIndex() == Other.getIndex() && getOffset() == Other.getOffset();
    191   case MachineOperand::MO_JumpTableIndex:
    192     return getIndex() == Other.getIndex();
    193   case MachineOperand::MO_GlobalAddress:
    194     return getGlobal() == Other.getGlobal() && getOffset() == Other.getOffset();
    195   case MachineOperand::MO_ExternalSymbol:
    196     return !strcmp(getSymbolName(), Other.getSymbolName()) &&
    197            getOffset() == Other.getOffset();
    198   case MachineOperand::MO_BlockAddress:
    199     return getBlockAddress() == Other.getBlockAddress() &&
    200            getOffset() == Other.getOffset();
    201   case MachineOperand::MO_RegisterMask:
    202   case MachineOperand::MO_RegisterLiveOut:
    203     return getRegMask() == Other.getRegMask();
    204   case MachineOperand::MO_MCSymbol:
    205     return getMCSymbol() == Other.getMCSymbol();
    206   case MachineOperand::MO_CFIIndex:
    207     return getCFIIndex() == Other.getCFIIndex();
    208   case MachineOperand::MO_Metadata:
    209     return getMetadata() == Other.getMetadata();
    210   }
    211   llvm_unreachable("Invalid machine operand type");
    212 }
    213 
    214 // Note: this must stay exactly in sync with isIdenticalTo above.
    215 hash_code llvm::hash_value(const MachineOperand &MO) {
    216   switch (MO.getType()) {
    217   case MachineOperand::MO_Register:
    218     // Register operands don't have target flags.
    219     return hash_combine(MO.getType(), MO.getReg(), MO.getSubReg(), MO.isDef());
    220   case MachineOperand::MO_Immediate:
    221     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getImm());
    222   case MachineOperand::MO_CImmediate:
    223     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getCImm());
    224   case MachineOperand::MO_FPImmediate:
    225     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getFPImm());
    226   case MachineOperand::MO_MachineBasicBlock:
    227     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getMBB());
    228   case MachineOperand::MO_FrameIndex:
    229     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIndex());
    230   case MachineOperand::MO_ConstantPoolIndex:
    231   case MachineOperand::MO_TargetIndex:
    232     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIndex(),
    233                         MO.getOffset());
    234   case MachineOperand::MO_JumpTableIndex:
    235     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIndex());
    236   case MachineOperand::MO_ExternalSymbol:
    237     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getOffset(),
    238                         MO.getSymbolName());
    239   case MachineOperand::MO_GlobalAddress:
    240     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getGlobal(),
    241                         MO.getOffset());
    242   case MachineOperand::MO_BlockAddress:
    243     return hash_combine(MO.getType(), MO.getTargetFlags(),
    244                         MO.getBlockAddress(), MO.getOffset());
    245   case MachineOperand::MO_RegisterMask:
    246   case MachineOperand::MO_RegisterLiveOut:
    247     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getRegMask());
    248   case MachineOperand::MO_Metadata:
    249     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getMetadata());
    250   case MachineOperand::MO_MCSymbol:
    251     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getMCSymbol());
    252   case MachineOperand::MO_CFIIndex:
    253     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getCFIIndex());
    254   }
    255   llvm_unreachable("Invalid machine operand type");
    256 }
    257 
    258 /// print - Print the specified machine operand.
    259 ///
    260 void MachineOperand::print(raw_ostream &OS, const TargetMachine *TM) const {
    261   // If the instruction is embedded into a basic block, we can find the
    262   // target info for the instruction.
    263   if (!TM)
    264     if (const MachineInstr *MI = getParent())
    265       if (const MachineBasicBlock *MBB = MI->getParent())
    266         if (const MachineFunction *MF = MBB->getParent())
    267           TM = &MF->getTarget();
    268   const TargetRegisterInfo *TRI = TM ? TM->getRegisterInfo() : nullptr;
    269 
    270   switch (getType()) {
    271   case MachineOperand::MO_Register:
    272     OS << PrintReg(getReg(), TRI, getSubReg());
    273 
    274     if (isDef() || isKill() || isDead() || isImplicit() || isUndef() ||
    275         isInternalRead() || isEarlyClobber() || isTied()) {
    276       OS << '<';
    277       bool NeedComma = false;
    278       if (isDef()) {
    279         if (NeedComma) OS << ',';
    280         if (isEarlyClobber())
    281           OS << "earlyclobber,";
    282         if (isImplicit())
    283           OS << "imp-";
    284         OS << "def";
    285         NeedComma = true;
    286         // <def,read-undef> only makes sense when getSubReg() is set.
    287         // Don't clutter the output otherwise.
    288         if (isUndef() && getSubReg())
    289           OS << ",read-undef";
    290       } else if (isImplicit()) {
    291           OS << "imp-use";
    292           NeedComma = true;
    293       }
    294 
    295       if (isKill()) {
    296         if (NeedComma) OS << ',';
    297         OS << "kill";
    298         NeedComma = true;
    299       }
    300       if (isDead()) {
    301         if (NeedComma) OS << ',';
    302         OS << "dead";
    303         NeedComma = true;
    304       }
    305       if (isUndef() && isUse()) {
    306         if (NeedComma) OS << ',';
    307         OS << "undef";
    308         NeedComma = true;
    309       }
    310       if (isInternalRead()) {
    311         if (NeedComma) OS << ',';
    312         OS << "internal";
    313         NeedComma = true;
    314       }
    315       if (isTied()) {
    316         if (NeedComma) OS << ',';
    317         OS << "tied";
    318         if (TiedTo != 15)
    319           OS << unsigned(TiedTo - 1);
    320       }
    321       OS << '>';
    322     }
    323     break;
    324   case MachineOperand::MO_Immediate:
    325     OS << getImm();
    326     break;
    327   case MachineOperand::MO_CImmediate:
    328     getCImm()->getValue().print(OS, false);
    329     break;
    330   case MachineOperand::MO_FPImmediate:
    331     if (getFPImm()->getType()->isFloatTy())
    332       OS << getFPImm()->getValueAPF().convertToFloat();
    333     else
    334       OS << getFPImm()->getValueAPF().convertToDouble();
    335     break;
    336   case MachineOperand::MO_MachineBasicBlock:
    337     OS << "<BB#" << getMBB()->getNumber() << ">";
    338     break;
    339   case MachineOperand::MO_FrameIndex:
    340     OS << "<fi#" << getIndex() << '>';
    341     break;
    342   case MachineOperand::MO_ConstantPoolIndex:
    343     OS << "<cp#" << getIndex();
    344     if (getOffset()) OS << "+" << getOffset();
    345     OS << '>';
    346     break;
    347   case MachineOperand::MO_TargetIndex:
    348     OS << "<ti#" << getIndex();
    349     if (getOffset()) OS << "+" << getOffset();
    350     OS << '>';
    351     break;
    352   case MachineOperand::MO_JumpTableIndex:
    353     OS << "<jt#" << getIndex() << '>';
    354     break;
    355   case MachineOperand::MO_GlobalAddress:
    356     OS << "<ga:";
    357     getGlobal()->printAsOperand(OS, /*PrintType=*/false);
    358     if (getOffset()) OS << "+" << getOffset();
    359     OS << '>';
    360     break;
    361   case MachineOperand::MO_ExternalSymbol:
    362     OS << "<es:" << getSymbolName();
    363     if (getOffset()) OS << "+" << getOffset();
    364     OS << '>';
    365     break;
    366   case MachineOperand::MO_BlockAddress:
    367     OS << '<';
    368     getBlockAddress()->printAsOperand(OS, /*PrintType=*/false);
    369     if (getOffset()) OS << "+" << getOffset();
    370     OS << '>';
    371     break;
    372   case MachineOperand::MO_RegisterMask:
    373     OS << "<regmask>";
    374     break;
    375   case MachineOperand::MO_RegisterLiveOut:
    376     OS << "<regliveout>";
    377     break;
    378   case MachineOperand::MO_Metadata:
    379     OS << '<';
    380     getMetadata()->printAsOperand(OS, /*PrintType=*/false);
    381     OS << '>';
    382     break;
    383   case MachineOperand::MO_MCSymbol:
    384     OS << "<MCSym=" << *getMCSymbol() << '>';
    385     break;
    386   case MachineOperand::MO_CFIIndex:
    387     OS << "<call frame instruction>";
    388     break;
    389   }
    390 
    391   if (unsigned TF = getTargetFlags())
    392     OS << "[TF=" << TF << ']';
    393 }
    394 
    395 //===----------------------------------------------------------------------===//
    396 // MachineMemOperand Implementation
    397 //===----------------------------------------------------------------------===//
    398 
    399 /// getAddrSpace - Return the LLVM IR address space number that this pointer
    400 /// points into.
    401 unsigned MachinePointerInfo::getAddrSpace() const {
    402   if (V.isNull() || V.is<const PseudoSourceValue*>()) return 0;
    403   return cast<PointerType>(V.get<const Value*>()->getType())->getAddressSpace();
    404 }
    405 
    406 /// getConstantPool - Return a MachinePointerInfo record that refers to the
    407 /// constant pool.
    408 MachinePointerInfo MachinePointerInfo::getConstantPool() {
    409   return MachinePointerInfo(PseudoSourceValue::getConstantPool());
    410 }
    411 
    412 /// getFixedStack - Return a MachinePointerInfo record that refers to the
    413 /// the specified FrameIndex.
    414 MachinePointerInfo MachinePointerInfo::getFixedStack(int FI, int64_t offset) {
    415   return MachinePointerInfo(PseudoSourceValue::getFixedStack(FI), offset);
    416 }
    417 
    418 MachinePointerInfo MachinePointerInfo::getJumpTable() {
    419   return MachinePointerInfo(PseudoSourceValue::getJumpTable());
    420 }
    421 
    422 MachinePointerInfo MachinePointerInfo::getGOT() {
    423   return MachinePointerInfo(PseudoSourceValue::getGOT());
    424 }
    425 
    426 MachinePointerInfo MachinePointerInfo::getStack(int64_t Offset) {
    427   return MachinePointerInfo(PseudoSourceValue::getStack(), Offset);
    428 }
    429 
    430 MachineMemOperand::MachineMemOperand(MachinePointerInfo ptrinfo, unsigned f,
    431                                      uint64_t s, unsigned int a,
    432                                      const MDNode *TBAAInfo,
    433                                      const MDNode *Ranges)
    434   : PtrInfo(ptrinfo), Size(s),
    435     Flags((f & ((1 << MOMaxBits) - 1)) | ((Log2_32(a) + 1) << MOMaxBits)),
    436     TBAAInfo(TBAAInfo), Ranges(Ranges) {
    437   assert((PtrInfo.V.isNull() || PtrInfo.V.is<const PseudoSourceValue*>() ||
    438           isa<PointerType>(PtrInfo.V.get<const Value*>()->getType())) &&
    439          "invalid pointer value");
    440   assert(getBaseAlignment() == a && "Alignment is not a power of 2!");
    441   assert((isLoad() || isStore()) && "Not a load/store!");
    442 }
    443 
    444 /// Profile - Gather unique data for the object.
    445 ///
    446 void MachineMemOperand::Profile(FoldingSetNodeID &ID) const {
    447   ID.AddInteger(getOffset());
    448   ID.AddInteger(Size);
    449   ID.AddPointer(getOpaqueValue());
    450   ID.AddInteger(Flags);
    451 }
    452 
    453 void MachineMemOperand::refineAlignment(const MachineMemOperand *MMO) {
    454   // The Value and Offset may differ due to CSE. But the flags and size
    455   // should be the same.
    456   assert(MMO->getFlags() == getFlags() && "Flags mismatch!");
    457   assert(MMO->getSize() == getSize() && "Size mismatch!");
    458 
    459   if (MMO->getBaseAlignment() >= getBaseAlignment()) {
    460     // Update the alignment value.
    461     Flags = (Flags & ((1 << MOMaxBits) - 1)) |
    462       ((Log2_32(MMO->getBaseAlignment()) + 1) << MOMaxBits);
    463     // Also update the base and offset, because the new alignment may
    464     // not be applicable with the old ones.
    465     PtrInfo = MMO->PtrInfo;
    466   }
    467 }
    468 
    469 /// getAlignment - Return the minimum known alignment in bytes of the
    470 /// actual memory reference.
    471 uint64_t MachineMemOperand::getAlignment() const {
    472   return MinAlign(getBaseAlignment(), getOffset());
    473 }
    474 
    475 raw_ostream &llvm::operator<<(raw_ostream &OS, const MachineMemOperand &MMO) {
    476   assert((MMO.isLoad() || MMO.isStore()) &&
    477          "SV has to be a load, store or both.");
    478 
    479   if (MMO.isVolatile())
    480     OS << "Volatile ";
    481 
    482   if (MMO.isLoad())
    483     OS << "LD";
    484   if (MMO.isStore())
    485     OS << "ST";
    486   OS << MMO.getSize();
    487 
    488   // Print the address information.
    489   OS << "[";
    490   if (const Value *V = MMO.getValue())
    491     V->printAsOperand(OS, /*PrintType=*/false);
    492   else if (const PseudoSourceValue *PSV = MMO.getPseudoValue())
    493     PSV->printCustom(OS);
    494   else
    495     OS << "<unknown>";
    496 
    497   unsigned AS = MMO.getAddrSpace();
    498   if (AS != 0)
    499     OS << "(addrspace=" << AS << ')';
    500 
    501   // If the alignment of the memory reference itself differs from the alignment
    502   // of the base pointer, print the base alignment explicitly, next to the base
    503   // pointer.
    504   if (MMO.getBaseAlignment() != MMO.getAlignment())
    505     OS << "(align=" << MMO.getBaseAlignment() << ")";
    506 
    507   if (MMO.getOffset() != 0)
    508     OS << "+" << MMO.getOffset();
    509   OS << "]";
    510 
    511   // Print the alignment of the reference.
    512   if (MMO.getBaseAlignment() != MMO.getAlignment() ||
    513       MMO.getBaseAlignment() != MMO.getSize())
    514     OS << "(align=" << MMO.getAlignment() << ")";
    515 
    516   // Print TBAA info.
    517   if (const MDNode *TBAAInfo = MMO.getTBAAInfo()) {
    518     OS << "(tbaa=";
    519     if (TBAAInfo->getNumOperands() > 0)
    520       TBAAInfo->getOperand(0)->printAsOperand(OS, /*PrintType=*/false);
    521     else
    522       OS << "<unknown>";
    523     OS << ")";
    524   }
    525 
    526   // Print nontemporal info.
    527   if (MMO.isNonTemporal())
    528     OS << "(nontemporal)";
    529 
    530   return OS;
    531 }
    532 
    533 //===----------------------------------------------------------------------===//
    534 // MachineInstr Implementation
    535 //===----------------------------------------------------------------------===//
    536 
    537 void MachineInstr::addImplicitDefUseOperands(MachineFunction &MF) {
    538   if (MCID->ImplicitDefs)
    539     for (const uint16_t *ImpDefs = MCID->getImplicitDefs(); *ImpDefs; ++ImpDefs)
    540       addOperand(MF, MachineOperand::CreateReg(*ImpDefs, true, true));
    541   if (MCID->ImplicitUses)
    542     for (const uint16_t *ImpUses = MCID->getImplicitUses(); *ImpUses; ++ImpUses)
    543       addOperand(MF, MachineOperand::CreateReg(*ImpUses, false, true));
    544 }
    545 
    546 /// MachineInstr ctor - This constructor creates a MachineInstr and adds the
    547 /// implicit operands. It reserves space for the number of operands specified by
    548 /// the MCInstrDesc.
    549 MachineInstr::MachineInstr(MachineFunction &MF, const MCInstrDesc &tid,
    550                            const DebugLoc dl, bool NoImp)
    551   : MCID(&tid), Parent(nullptr), Operands(nullptr), NumOperands(0),
    552     Flags(0), AsmPrinterFlags(0),
    553     NumMemRefs(0), MemRefs(nullptr), debugLoc(dl) {
    554   // Reserve space for the expected number of operands.
    555   if (unsigned NumOps = MCID->getNumOperands() +
    556     MCID->getNumImplicitDefs() + MCID->getNumImplicitUses()) {
    557     CapOperands = OperandCapacity::get(NumOps);
    558     Operands = MF.allocateOperandArray(CapOperands);
    559   }
    560 
    561   if (!NoImp)
    562     addImplicitDefUseOperands(MF);
    563 }
    564 
    565 /// MachineInstr ctor - Copies MachineInstr arg exactly
    566 ///
    567 MachineInstr::MachineInstr(MachineFunction &MF, const MachineInstr &MI)
    568   : MCID(&MI.getDesc()), Parent(nullptr), Operands(nullptr), NumOperands(0),
    569     Flags(0), AsmPrinterFlags(0),
    570     NumMemRefs(MI.NumMemRefs), MemRefs(MI.MemRefs),
    571     debugLoc(MI.getDebugLoc()) {
    572   CapOperands = OperandCapacity::get(MI.getNumOperands());
    573   Operands = MF.allocateOperandArray(CapOperands);
    574 
    575   // Copy operands.
    576   for (unsigned i = 0; i != MI.getNumOperands(); ++i)
    577     addOperand(MF, MI.getOperand(i));
    578 
    579   // Copy all the sensible flags.
    580   setFlags(MI.Flags);
    581 }
    582 
    583 /// getRegInfo - If this instruction is embedded into a MachineFunction,
    584 /// return the MachineRegisterInfo object for the current function, otherwise
    585 /// return null.
    586 MachineRegisterInfo *MachineInstr::getRegInfo() {
    587   if (MachineBasicBlock *MBB = getParent())
    588     return &MBB->getParent()->getRegInfo();
    589   return nullptr;
    590 }
    591 
    592 /// RemoveRegOperandsFromUseLists - Unlink all of the register operands in
    593 /// this instruction from their respective use lists.  This requires that the
    594 /// operands already be on their use lists.
    595 void MachineInstr::RemoveRegOperandsFromUseLists(MachineRegisterInfo &MRI) {
    596   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
    597     if (Operands[i].isReg())
    598       MRI.removeRegOperandFromUseList(&Operands[i]);
    599 }
    600 
    601 /// AddRegOperandsToUseLists - Add all of the register operands in
    602 /// this instruction from their respective use lists.  This requires that the
    603 /// operands not be on their use lists yet.
    604 void MachineInstr::AddRegOperandsToUseLists(MachineRegisterInfo &MRI) {
    605   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
    606     if (Operands[i].isReg())
    607       MRI.addRegOperandToUseList(&Operands[i]);
    608 }
    609 
    610 void MachineInstr::addOperand(const MachineOperand &Op) {
    611   MachineBasicBlock *MBB = getParent();
    612   assert(MBB && "Use MachineInstrBuilder to add operands to dangling instrs");
    613   MachineFunction *MF = MBB->getParent();
    614   assert(MF && "Use MachineInstrBuilder to add operands to dangling instrs");
    615   addOperand(*MF, Op);
    616 }
    617 
    618 /// Move NumOps MachineOperands from Src to Dst, with support for overlapping
    619 /// ranges. If MRI is non-null also update use-def chains.
    620 static void moveOperands(MachineOperand *Dst, MachineOperand *Src,
    621                          unsigned NumOps, MachineRegisterInfo *MRI) {
    622   if (MRI)
    623     return MRI->moveOperands(Dst, Src, NumOps);
    624 
    625   // Here it would be convenient to call memmove, so that isn't allowed because
    626   // MachineOperand has a constructor and so isn't a POD type.
    627   if (Dst < Src)
    628     for (unsigned i = 0; i != NumOps; ++i)
    629       new (Dst + i) MachineOperand(Src[i]);
    630   else
    631     for (unsigned i = NumOps; i ; --i)
    632       new (Dst + i - 1) MachineOperand(Src[i - 1]);
    633 }
    634 
    635 /// addOperand - Add the specified operand to the instruction.  If it is an
    636 /// implicit operand, it is added to the end of the operand list.  If it is
    637 /// an explicit operand it is added at the end of the explicit operand list
    638 /// (before the first implicit operand).
    639 void MachineInstr::addOperand(MachineFunction &MF, const MachineOperand &Op) {
    640   assert(MCID && "Cannot add operands before providing an instr descriptor");
    641 
    642   // Check if we're adding one of our existing operands.
    643   if (&Op >= Operands && &Op < Operands + NumOperands) {
    644     // This is unusual: MI->addOperand(MI->getOperand(i)).
    645     // If adding Op requires reallocating or moving existing operands around,
    646     // the Op reference could go stale. Support it by copying Op.
    647     MachineOperand CopyOp(Op);
    648     return addOperand(MF, CopyOp);
    649   }
    650 
    651   // Find the insert location for the new operand.  Implicit registers go at
    652   // the end, everything else goes before the implicit regs.
    653   //
    654   // FIXME: Allow mixed explicit and implicit operands on inline asm.
    655   // InstrEmitter::EmitSpecialNode() is marking inline asm clobbers as
    656   // implicit-defs, but they must not be moved around.  See the FIXME in
    657   // InstrEmitter.cpp.
    658   unsigned OpNo = getNumOperands();
    659   bool isImpReg = Op.isReg() && Op.isImplicit();
    660   if (!isImpReg && !isInlineAsm()) {
    661     while (OpNo && Operands[OpNo-1].isReg() && Operands[OpNo-1].isImplicit()) {
    662       --OpNo;
    663       assert(!Operands[OpNo].isTied() && "Cannot move tied operands");
    664     }
    665   }
    666 
    667 #ifndef NDEBUG
    668   bool isMetaDataOp = Op.getType() == MachineOperand::MO_Metadata;
    669   // OpNo now points as the desired insertion point.  Unless this is a variadic
    670   // instruction, only implicit regs are allowed beyond MCID->getNumOperands().
    671   // RegMask operands go between the explicit and implicit operands.
    672   assert((isImpReg || Op.isRegMask() || MCID->isVariadic() ||
    673           OpNo < MCID->getNumOperands() || isMetaDataOp) &&
    674          "Trying to add an operand to a machine instr that is already done!");
    675 #endif
    676 
    677   MachineRegisterInfo *MRI = getRegInfo();
    678 
    679   // Determine if the Operands array needs to be reallocated.
    680   // Save the old capacity and operand array.
    681   OperandCapacity OldCap = CapOperands;
    682   MachineOperand *OldOperands = Operands;
    683   if (!OldOperands || OldCap.getSize() == getNumOperands()) {
    684     CapOperands = OldOperands ? OldCap.getNext() : OldCap.get(1);
    685     Operands = MF.allocateOperandArray(CapOperands);
    686     // Move the operands before the insertion point.
    687     if (OpNo)
    688       moveOperands(Operands, OldOperands, OpNo, MRI);
    689   }
    690 
    691   // Move the operands following the insertion point.
    692   if (OpNo != NumOperands)
    693     moveOperands(Operands + OpNo + 1, OldOperands + OpNo, NumOperands - OpNo,
    694                  MRI);
    695   ++NumOperands;
    696 
    697   // Deallocate the old operand array.
    698   if (OldOperands != Operands && OldOperands)
    699     MF.deallocateOperandArray(OldCap, OldOperands);
    700 
    701   // Copy Op into place. It still needs to be inserted into the MRI use lists.
    702   MachineOperand *NewMO = new (Operands + OpNo) MachineOperand(Op);
    703   NewMO->ParentMI = this;
    704 
    705   // When adding a register operand, tell MRI about it.
    706   if (NewMO->isReg()) {
    707     // Ensure isOnRegUseList() returns false, regardless of Op's status.
    708     NewMO->Contents.Reg.Prev = nullptr;
    709     // Ignore existing ties. This is not a property that can be copied.
    710     NewMO->TiedTo = 0;
    711     // Add the new operand to MRI, but only for instructions in an MBB.
    712     if (MRI)
    713       MRI->addRegOperandToUseList(NewMO);
    714     // The MCID operand information isn't accurate until we start adding
    715     // explicit operands. The implicit operands are added first, then the
    716     // explicits are inserted before them.
    717     if (!isImpReg) {
    718       // Tie uses to defs as indicated in MCInstrDesc.
    719       if (NewMO->isUse()) {
    720         int DefIdx = MCID->getOperandConstraint(OpNo, MCOI::TIED_TO);
    721         if (DefIdx != -1)
    722           tieOperands(DefIdx, OpNo);
    723       }
    724       // If the register operand is flagged as early, mark the operand as such.
    725       if (MCID->getOperandConstraint(OpNo, MCOI::EARLY_CLOBBER) != -1)
    726         NewMO->setIsEarlyClobber(true);
    727     }
    728   }
    729 }
    730 
    731 /// RemoveOperand - Erase an operand  from an instruction, leaving it with one
    732 /// fewer operand than it started with.
    733 ///
    734 void MachineInstr::RemoveOperand(unsigned OpNo) {
    735   assert(OpNo < getNumOperands() && "Invalid operand number");
    736   untieRegOperand(OpNo);
    737 
    738 #ifndef NDEBUG
    739   // Moving tied operands would break the ties.
    740   for (unsigned i = OpNo + 1, e = getNumOperands(); i != e; ++i)
    741     if (Operands[i].isReg())
    742       assert(!Operands[i].isTied() && "Cannot move tied operands");
    743 #endif
    744 
    745   MachineRegisterInfo *MRI = getRegInfo();
    746   if (MRI && Operands[OpNo].isReg())
    747     MRI->removeRegOperandFromUseList(Operands + OpNo);
    748 
    749   // Don't call the MachineOperand destructor. A lot of this code depends on
    750   // MachineOperand having a trivial destructor anyway, and adding a call here
    751   // wouldn't make it 'destructor-correct'.
    752 
    753   if (unsigned N = NumOperands - 1 - OpNo)
    754     moveOperands(Operands + OpNo, Operands + OpNo + 1, N, MRI);
    755   --NumOperands;
    756 }
    757 
    758 /// addMemOperand - Add a MachineMemOperand to the machine instruction.
    759 /// This function should be used only occasionally. The setMemRefs function
    760 /// is the primary method for setting up a MachineInstr's MemRefs list.
    761 void MachineInstr::addMemOperand(MachineFunction &MF,
    762                                  MachineMemOperand *MO) {
    763   mmo_iterator OldMemRefs = MemRefs;
    764   unsigned OldNumMemRefs = NumMemRefs;
    765 
    766   unsigned NewNum = NumMemRefs + 1;
    767   mmo_iterator NewMemRefs = MF.allocateMemRefsArray(NewNum);
    768 
    769   std::copy(OldMemRefs, OldMemRefs + OldNumMemRefs, NewMemRefs);
    770   NewMemRefs[NewNum - 1] = MO;
    771   setMemRefs(NewMemRefs, NewMemRefs + NewNum);
    772 }
    773 
    774 bool MachineInstr::hasPropertyInBundle(unsigned Mask, QueryType Type) const {
    775   assert(!isBundledWithPred() && "Must be called on bundle header");
    776   for (MachineBasicBlock::const_instr_iterator MII = this;; ++MII) {
    777     if (MII->getDesc().getFlags() & Mask) {
    778       if (Type == AnyInBundle)
    779         return true;
    780     } else {
    781       if (Type == AllInBundle && !MII->isBundle())
    782         return false;
    783     }
    784     // This was the last instruction in the bundle.
    785     if (!MII->isBundledWithSucc())
    786       return Type == AllInBundle;
    787   }
    788 }
    789 
    790 bool MachineInstr::isIdenticalTo(const MachineInstr *Other,
    791                                  MICheckType Check) const {
    792   // If opcodes or number of operands are not the same then the two
    793   // instructions are obviously not identical.
    794   if (Other->getOpcode() != getOpcode() ||
    795       Other->getNumOperands() != getNumOperands())
    796     return false;
    797 
    798   if (isBundle()) {
    799     // Both instructions are bundles, compare MIs inside the bundle.
    800     MachineBasicBlock::const_instr_iterator I1 = *this;
    801     MachineBasicBlock::const_instr_iterator E1 = getParent()->instr_end();
    802     MachineBasicBlock::const_instr_iterator I2 = *Other;
    803     MachineBasicBlock::const_instr_iterator E2= Other->getParent()->instr_end();
    804     while (++I1 != E1 && I1->isInsideBundle()) {
    805       ++I2;
    806       if (I2 == E2 || !I2->isInsideBundle() || !I1->isIdenticalTo(I2, Check))
    807         return false;
    808     }
    809   }
    810 
    811   // Check operands to make sure they match.
    812   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
    813     const MachineOperand &MO = getOperand(i);
    814     const MachineOperand &OMO = Other->getOperand(i);
    815     if (!MO.isReg()) {
    816       if (!MO.isIdenticalTo(OMO))
    817         return false;
    818       continue;
    819     }
    820 
    821     // Clients may or may not want to ignore defs when testing for equality.
    822     // For example, machine CSE pass only cares about finding common
    823     // subexpressions, so it's safe to ignore virtual register defs.
    824     if (MO.isDef()) {
    825       if (Check == IgnoreDefs)
    826         continue;
    827       else if (Check == IgnoreVRegDefs) {
    828         if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()) ||
    829             TargetRegisterInfo::isPhysicalRegister(OMO.getReg()))
    830           if (MO.getReg() != OMO.getReg())
    831             return false;
    832       } else {
    833         if (!MO.isIdenticalTo(OMO))
    834           return false;
    835         if (Check == CheckKillDead && MO.isDead() != OMO.isDead())
    836           return false;
    837       }
    838     } else {
    839       if (!MO.isIdenticalTo(OMO))
    840         return false;
    841       if (Check == CheckKillDead && MO.isKill() != OMO.isKill())
    842         return false;
    843     }
    844   }
    845   // If DebugLoc does not match then two dbg.values are not identical.
    846   if (isDebugValue())
    847     if (!getDebugLoc().isUnknown() && !Other->getDebugLoc().isUnknown()
    848         && getDebugLoc() != Other->getDebugLoc())
    849       return false;
    850   return true;
    851 }
    852 
    853 MachineInstr *MachineInstr::removeFromParent() {
    854   assert(getParent() && "Not embedded in a basic block!");
    855   return getParent()->remove(this);
    856 }
    857 
    858 MachineInstr *MachineInstr::removeFromBundle() {
    859   assert(getParent() && "Not embedded in a basic block!");
    860   return getParent()->remove_instr(this);
    861 }
    862 
    863 void MachineInstr::eraseFromParent() {
    864   assert(getParent() && "Not embedded in a basic block!");
    865   getParent()->erase(this);
    866 }
    867 
    868 void MachineInstr::eraseFromBundle() {
    869   assert(getParent() && "Not embedded in a basic block!");
    870   getParent()->erase_instr(this);
    871 }
    872 
    873 /// getNumExplicitOperands - Returns the number of non-implicit operands.
    874 ///
    875 unsigned MachineInstr::getNumExplicitOperands() const {
    876   unsigned NumOperands = MCID->getNumOperands();
    877   if (!MCID->isVariadic())
    878     return NumOperands;
    879 
    880   for (unsigned i = NumOperands, e = getNumOperands(); i != e; ++i) {
    881     const MachineOperand &MO = getOperand(i);
    882     if (!MO.isReg() || !MO.isImplicit())
    883       NumOperands++;
    884   }
    885   return NumOperands;
    886 }
    887 
    888 void MachineInstr::bundleWithPred() {
    889   assert(!isBundledWithPred() && "MI is already bundled with its predecessor");
    890   setFlag(BundledPred);
    891   MachineBasicBlock::instr_iterator Pred = this;
    892   --Pred;
    893   assert(!Pred->isBundledWithSucc() && "Inconsistent bundle flags");
    894   Pred->setFlag(BundledSucc);
    895 }
    896 
    897 void MachineInstr::bundleWithSucc() {
    898   assert(!isBundledWithSucc() && "MI is already bundled with its successor");
    899   setFlag(BundledSucc);
    900   MachineBasicBlock::instr_iterator Succ = this;
    901   ++Succ;
    902   assert(!Succ->isBundledWithPred() && "Inconsistent bundle flags");
    903   Succ->setFlag(BundledPred);
    904 }
    905 
    906 void MachineInstr::unbundleFromPred() {
    907   assert(isBundledWithPred() && "MI isn't bundled with its predecessor");
    908   clearFlag(BundledPred);
    909   MachineBasicBlock::instr_iterator Pred = this;
    910   --Pred;
    911   assert(Pred->isBundledWithSucc() && "Inconsistent bundle flags");
    912   Pred->clearFlag(BundledSucc);
    913 }
    914 
    915 void MachineInstr::unbundleFromSucc() {
    916   assert(isBundledWithSucc() && "MI isn't bundled with its successor");
    917   clearFlag(BundledSucc);
    918   MachineBasicBlock::instr_iterator Succ = this;
    919   ++Succ;
    920   assert(Succ->isBundledWithPred() && "Inconsistent bundle flags");
    921   Succ->clearFlag(BundledPred);
    922 }
    923 
    924 bool MachineInstr::isStackAligningInlineAsm() const {
    925   if (isInlineAsm()) {
    926     unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
    927     if (ExtraInfo & InlineAsm::Extra_IsAlignStack)
    928       return true;
    929   }
    930   return false;
    931 }
    932 
    933 InlineAsm::AsmDialect MachineInstr::getInlineAsmDialect() const {
    934   assert(isInlineAsm() && "getInlineAsmDialect() only works for inline asms!");
    935   unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
    936   return InlineAsm::AsmDialect((ExtraInfo & InlineAsm::Extra_AsmDialect) != 0);
    937 }
    938 
    939 int MachineInstr::findInlineAsmFlagIdx(unsigned OpIdx,
    940                                        unsigned *GroupNo) const {
    941   assert(isInlineAsm() && "Expected an inline asm instruction");
    942   assert(OpIdx < getNumOperands() && "OpIdx out of range");
    943 
    944   // Ignore queries about the initial operands.
    945   if (OpIdx < InlineAsm::MIOp_FirstOperand)
    946     return -1;
    947 
    948   unsigned Group = 0;
    949   unsigned NumOps;
    950   for (unsigned i = InlineAsm::MIOp_FirstOperand, e = getNumOperands(); i < e;
    951        i += NumOps) {
    952     const MachineOperand &FlagMO = getOperand(i);
    953     // If we reach the implicit register operands, stop looking.
    954     if (!FlagMO.isImm())
    955       return -1;
    956     NumOps = 1 + InlineAsm::getNumOperandRegisters(FlagMO.getImm());
    957     if (i + NumOps > OpIdx) {
    958       if (GroupNo)
    959         *GroupNo = Group;
    960       return i;
    961     }
    962     ++Group;
    963   }
    964   return -1;
    965 }
    966 
    967 const TargetRegisterClass*
    968 MachineInstr::getRegClassConstraint(unsigned OpIdx,
    969                                     const TargetInstrInfo *TII,
    970                                     const TargetRegisterInfo *TRI) const {
    971   assert(getParent() && "Can't have an MBB reference here!");
    972   assert(getParent()->getParent() && "Can't have an MF reference here!");
    973   const MachineFunction &MF = *getParent()->getParent();
    974 
    975   // Most opcodes have fixed constraints in their MCInstrDesc.
    976   if (!isInlineAsm())
    977     return TII->getRegClass(getDesc(), OpIdx, TRI, MF);
    978 
    979   if (!getOperand(OpIdx).isReg())
    980     return nullptr;
    981 
    982   // For tied uses on inline asm, get the constraint from the def.
    983   unsigned DefIdx;
    984   if (getOperand(OpIdx).isUse() && isRegTiedToDefOperand(OpIdx, &DefIdx))
    985     OpIdx = DefIdx;
    986 
    987   // Inline asm stores register class constraints in the flag word.
    988   int FlagIdx = findInlineAsmFlagIdx(OpIdx);
    989   if (FlagIdx < 0)
    990     return nullptr;
    991 
    992   unsigned Flag = getOperand(FlagIdx).getImm();
    993   unsigned RCID;
    994   if (InlineAsm::hasRegClassConstraint(Flag, RCID))
    995     return TRI->getRegClass(RCID);
    996 
    997   // Assume that all registers in a memory operand are pointers.
    998   if (InlineAsm::getKind(Flag) == InlineAsm::Kind_Mem)
    999     return TRI->getPointerRegClass(MF);
   1000 
   1001   return nullptr;
   1002 }
   1003 
   1004 const TargetRegisterClass *MachineInstr::getRegClassConstraintEffectForVReg(
   1005     unsigned Reg, const TargetRegisterClass *CurRC, const TargetInstrInfo *TII,
   1006     const TargetRegisterInfo *TRI, bool ExploreBundle) const {
   1007   // Check every operands inside the bundle if we have
   1008   // been asked to.
   1009   if (ExploreBundle)
   1010     for (ConstMIBundleOperands OpndIt(this); OpndIt.isValid() && CurRC;
   1011          ++OpndIt)
   1012       CurRC = OpndIt->getParent()->getRegClassConstraintEffectForVRegImpl(
   1013           OpndIt.getOperandNo(), Reg, CurRC, TII, TRI);
   1014   else
   1015     // Otherwise, just check the current operands.
   1016     for (ConstMIOperands OpndIt(this); OpndIt.isValid() && CurRC; ++OpndIt)
   1017       CurRC = getRegClassConstraintEffectForVRegImpl(OpndIt.getOperandNo(), Reg,
   1018                                                      CurRC, TII, TRI);
   1019   return CurRC;
   1020 }
   1021 
   1022 const TargetRegisterClass *MachineInstr::getRegClassConstraintEffectForVRegImpl(
   1023     unsigned OpIdx, unsigned Reg, const TargetRegisterClass *CurRC,
   1024     const TargetInstrInfo *TII, const TargetRegisterInfo *TRI) const {
   1025   assert(CurRC && "Invalid initial register class");
   1026   // Check if Reg is constrained by some of its use/def from MI.
   1027   const MachineOperand &MO = getOperand(OpIdx);
   1028   if (!MO.isReg() || MO.getReg() != Reg)
   1029     return CurRC;
   1030   // If yes, accumulate the constraints through the operand.
   1031   return getRegClassConstraintEffect(OpIdx, CurRC, TII, TRI);
   1032 }
   1033 
   1034 const TargetRegisterClass *MachineInstr::getRegClassConstraintEffect(
   1035     unsigned OpIdx, const TargetRegisterClass *CurRC,
   1036     const TargetInstrInfo *TII, const TargetRegisterInfo *TRI) const {
   1037   const TargetRegisterClass *OpRC = getRegClassConstraint(OpIdx, TII, TRI);
   1038   const MachineOperand &MO = getOperand(OpIdx);
   1039   assert(MO.isReg() &&
   1040          "Cannot get register constraints for non-register operand");
   1041   assert(CurRC && "Invalid initial register class");
   1042   if (unsigned SubIdx = MO.getSubReg()) {
   1043     if (OpRC)
   1044       CurRC = TRI->getMatchingSuperRegClass(CurRC, OpRC, SubIdx);
   1045     else
   1046       CurRC = TRI->getSubClassWithSubReg(CurRC, SubIdx);
   1047   } else if (OpRC)
   1048     CurRC = TRI->getCommonSubClass(CurRC, OpRC);
   1049   return CurRC;
   1050 }
   1051 
   1052 /// Return the number of instructions inside the MI bundle, not counting the
   1053 /// header instruction.
   1054 unsigned MachineInstr::getBundleSize() const {
   1055   MachineBasicBlock::const_instr_iterator I = this;
   1056   unsigned Size = 0;
   1057   while (I->isBundledWithSucc())
   1058     ++Size, ++I;
   1059   return Size;
   1060 }
   1061 
   1062 /// findRegisterUseOperandIdx() - Returns the MachineOperand that is a use of
   1063 /// the specific register or -1 if it is not found. It further tightens
   1064 /// the search criteria to a use that kills the register if isKill is true.
   1065 int MachineInstr::findRegisterUseOperandIdx(unsigned Reg, bool isKill,
   1066                                           const TargetRegisterInfo *TRI) const {
   1067   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
   1068     const MachineOperand &MO = getOperand(i);
   1069     if (!MO.isReg() || !MO.isUse())
   1070       continue;
   1071     unsigned MOReg = MO.getReg();
   1072     if (!MOReg)
   1073       continue;
   1074     if (MOReg == Reg ||
   1075         (TRI &&
   1076          TargetRegisterInfo::isPhysicalRegister(MOReg) &&
   1077          TargetRegisterInfo::isPhysicalRegister(Reg) &&
   1078          TRI->isSubRegister(MOReg, Reg)))
   1079       if (!isKill || MO.isKill())
   1080         return i;
   1081   }
   1082   return -1;
   1083 }
   1084 
   1085 /// readsWritesVirtualRegister - Return a pair of bools (reads, writes)
   1086 /// indicating if this instruction reads or writes Reg. This also considers
   1087 /// partial defines.
   1088 std::pair<bool,bool>
   1089 MachineInstr::readsWritesVirtualRegister(unsigned Reg,
   1090                                          SmallVectorImpl<unsigned> *Ops) const {
   1091   bool PartDef = false; // Partial redefine.
   1092   bool FullDef = false; // Full define.
   1093   bool Use = false;
   1094 
   1095   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
   1096     const MachineOperand &MO = getOperand(i);
   1097     if (!MO.isReg() || MO.getReg() != Reg)
   1098       continue;
   1099     if (Ops)
   1100       Ops->push_back(i);
   1101     if (MO.isUse())
   1102       Use |= !MO.isUndef();
   1103     else if (MO.getSubReg() && !MO.isUndef())
   1104       // A partial <def,undef> doesn't count as reading the register.
   1105       PartDef = true;
   1106     else
   1107       FullDef = true;
   1108   }
   1109   // A partial redefine uses Reg unless there is also a full define.
   1110   return std::make_pair(Use || (PartDef && !FullDef), PartDef || FullDef);
   1111 }
   1112 
   1113 /// findRegisterDefOperandIdx() - Returns the operand index that is a def of
   1114 /// the specified register or -1 if it is not found. If isDead is true, defs
   1115 /// that are not dead are skipped. If TargetRegisterInfo is non-null, then it
   1116 /// also checks if there is a def of a super-register.
   1117 int
   1118 MachineInstr::findRegisterDefOperandIdx(unsigned Reg, bool isDead, bool Overlap,
   1119                                         const TargetRegisterInfo *TRI) const {
   1120   bool isPhys = TargetRegisterInfo::isPhysicalRegister(Reg);
   1121   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
   1122     const MachineOperand &MO = getOperand(i);
   1123     // Accept regmask operands when Overlap is set.
   1124     // Ignore them when looking for a specific def operand (Overlap == false).
   1125     if (isPhys && Overlap && MO.isRegMask() && MO.clobbersPhysReg(Reg))
   1126       return i;
   1127     if (!MO.isReg() || !MO.isDef())
   1128       continue;
   1129     unsigned MOReg = MO.getReg();
   1130     bool Found = (MOReg == Reg);
   1131     if (!Found && TRI && isPhys &&
   1132         TargetRegisterInfo::isPhysicalRegister(MOReg)) {
   1133       if (Overlap)
   1134         Found = TRI->regsOverlap(MOReg, Reg);
   1135       else
   1136         Found = TRI->isSubRegister(MOReg, Reg);
   1137     }
   1138     if (Found && (!isDead || MO.isDead()))
   1139       return i;
   1140   }
   1141   return -1;
   1142 }
   1143 
   1144 /// findFirstPredOperandIdx() - Find the index of the first operand in the
   1145 /// operand list that is used to represent the predicate. It returns -1 if
   1146 /// none is found.
   1147 int MachineInstr::findFirstPredOperandIdx() const {
   1148   // Don't call MCID.findFirstPredOperandIdx() because this variant
   1149   // is sometimes called on an instruction that's not yet complete, and
   1150   // so the number of operands is less than the MCID indicates. In
   1151   // particular, the PTX target does this.
   1152   const MCInstrDesc &MCID = getDesc();
   1153   if (MCID.isPredicable()) {
   1154     for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
   1155       if (MCID.OpInfo[i].isPredicate())
   1156         return i;
   1157   }
   1158 
   1159   return -1;
   1160 }
   1161 
   1162 // MachineOperand::TiedTo is 4 bits wide.
   1163 const unsigned TiedMax = 15;
   1164 
   1165 /// tieOperands - Mark operands at DefIdx and UseIdx as tied to each other.
   1166 ///
   1167 /// Use and def operands can be tied together, indicated by a non-zero TiedTo
   1168 /// field. TiedTo can have these values:
   1169 ///
   1170 /// 0:              Operand is not tied to anything.
   1171 /// 1 to TiedMax-1: Tied to getOperand(TiedTo-1).
   1172 /// TiedMax:        Tied to an operand >= TiedMax-1.
   1173 ///
   1174 /// The tied def must be one of the first TiedMax operands on a normal
   1175 /// instruction. INLINEASM instructions allow more tied defs.
   1176 ///
   1177 void MachineInstr::tieOperands(unsigned DefIdx, unsigned UseIdx) {
   1178   MachineOperand &DefMO = getOperand(DefIdx);
   1179   MachineOperand &UseMO = getOperand(UseIdx);
   1180   assert(DefMO.isDef() && "DefIdx must be a def operand");
   1181   assert(UseMO.isUse() && "UseIdx must be a use operand");
   1182   assert(!DefMO.isTied() && "Def is already tied to another use");
   1183   assert(!UseMO.isTied() && "Use is already tied to another def");
   1184 
   1185   if (DefIdx < TiedMax)
   1186     UseMO.TiedTo = DefIdx + 1;
   1187   else {
   1188     // Inline asm can use the group descriptors to find tied operands, but on
   1189     // normal instruction, the tied def must be within the first TiedMax
   1190     // operands.
   1191     assert(isInlineAsm() && "DefIdx out of range");
   1192     UseMO.TiedTo = TiedMax;
   1193   }
   1194 
   1195   // UseIdx can be out of range, we'll search for it in findTiedOperandIdx().
   1196   DefMO.TiedTo = std::min(UseIdx + 1, TiedMax);
   1197 }
   1198 
   1199 /// Given the index of a tied register operand, find the operand it is tied to.
   1200 /// Defs are tied to uses and vice versa. Returns the index of the tied operand
   1201 /// which must exist.
   1202 unsigned MachineInstr::findTiedOperandIdx(unsigned OpIdx) const {
   1203   const MachineOperand &MO = getOperand(OpIdx);
   1204   assert(MO.isTied() && "Operand isn't tied");
   1205 
   1206   // Normally TiedTo is in range.
   1207   if (MO.TiedTo < TiedMax)
   1208     return MO.TiedTo - 1;
   1209 
   1210   // Uses on normal instructions can be out of range.
   1211   if (!isInlineAsm()) {
   1212     // Normal tied defs must be in the 0..TiedMax-1 range.
   1213     if (MO.isUse())
   1214       return TiedMax - 1;
   1215     // MO is a def. Search for the tied use.
   1216     for (unsigned i = TiedMax - 1, e = getNumOperands(); i != e; ++i) {
   1217       const MachineOperand &UseMO = getOperand(i);
   1218       if (UseMO.isReg() && UseMO.isUse() && UseMO.TiedTo == OpIdx + 1)
   1219         return i;
   1220     }
   1221     llvm_unreachable("Can't find tied use");
   1222   }
   1223 
   1224   // Now deal with inline asm by parsing the operand group descriptor flags.
   1225   // Find the beginning of each operand group.
   1226   SmallVector<unsigned, 8> GroupIdx;
   1227   unsigned OpIdxGroup = ~0u;
   1228   unsigned NumOps;
   1229   for (unsigned i = InlineAsm::MIOp_FirstOperand, e = getNumOperands(); i < e;
   1230        i += NumOps) {
   1231     const MachineOperand &FlagMO = getOperand(i);
   1232     assert(FlagMO.isImm() && "Invalid tied operand on inline asm");
   1233     unsigned CurGroup = GroupIdx.size();
   1234     GroupIdx.push_back(i);
   1235     NumOps = 1 + InlineAsm::getNumOperandRegisters(FlagMO.getImm());
   1236     // OpIdx belongs to this operand group.
   1237     if (OpIdx > i && OpIdx < i + NumOps)
   1238       OpIdxGroup = CurGroup;
   1239     unsigned TiedGroup;
   1240     if (!InlineAsm::isUseOperandTiedToDef(FlagMO.getImm(), TiedGroup))
   1241       continue;
   1242     // Operands in this group are tied to operands in TiedGroup which must be
   1243     // earlier. Find the number of operands between the two groups.
   1244     unsigned Delta = i - GroupIdx[TiedGroup];
   1245 
   1246     // OpIdx is a use tied to TiedGroup.
   1247     if (OpIdxGroup == CurGroup)
   1248       return OpIdx - Delta;
   1249 
   1250     // OpIdx is a def tied to this use group.
   1251     if (OpIdxGroup == TiedGroup)
   1252       return OpIdx + Delta;
   1253   }
   1254   llvm_unreachable("Invalid tied operand on inline asm");
   1255 }
   1256 
   1257 /// clearKillInfo - Clears kill flags on all operands.
   1258 ///
   1259 void MachineInstr::clearKillInfo() {
   1260   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
   1261     MachineOperand &MO = getOperand(i);
   1262     if (MO.isReg() && MO.isUse())
   1263       MO.setIsKill(false);
   1264   }
   1265 }
   1266 
   1267 void MachineInstr::substituteRegister(unsigned FromReg,
   1268                                       unsigned ToReg,
   1269                                       unsigned SubIdx,
   1270                                       const TargetRegisterInfo &RegInfo) {
   1271   if (TargetRegisterInfo::isPhysicalRegister(ToReg)) {
   1272     if (SubIdx)
   1273       ToReg = RegInfo.getSubReg(ToReg, SubIdx);
   1274     for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
   1275       MachineOperand &MO = getOperand(i);
   1276       if (!MO.isReg() || MO.getReg() != FromReg)
   1277         continue;
   1278       MO.substPhysReg(ToReg, RegInfo);
   1279     }
   1280   } else {
   1281     for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
   1282       MachineOperand &MO = getOperand(i);
   1283       if (!MO.isReg() || MO.getReg() != FromReg)
   1284         continue;
   1285       MO.substVirtReg(ToReg, SubIdx, RegInfo);
   1286     }
   1287   }
   1288 }
   1289 
   1290 /// isSafeToMove - Return true if it is safe to move this instruction. If
   1291 /// SawStore is set to true, it means that there is a store (or call) between
   1292 /// the instruction's location and its intended destination.
   1293 bool MachineInstr::isSafeToMove(const TargetInstrInfo *TII,
   1294                                 AliasAnalysis *AA,
   1295                                 bool &SawStore) const {
   1296   // Ignore stuff that we obviously can't move.
   1297   //
   1298   // Treat volatile loads as stores. This is not strictly necessary for
   1299   // volatiles, but it is required for atomic loads. It is not allowed to move
   1300   // a load across an atomic load with Ordering > Monotonic.
   1301   if (mayStore() || isCall() ||
   1302       (mayLoad() && hasOrderedMemoryRef())) {
   1303     SawStore = true;
   1304     return false;
   1305   }
   1306 
   1307   if (isPosition() || isDebugValue() || isTerminator() ||
   1308       hasUnmodeledSideEffects())
   1309     return false;
   1310 
   1311   // See if this instruction does a load.  If so, we have to guarantee that the
   1312   // loaded value doesn't change between the load and the its intended
   1313   // destination. The check for isInvariantLoad gives the targe the chance to
   1314   // classify the load as always returning a constant, e.g. a constant pool
   1315   // load.
   1316   if (mayLoad() && !isInvariantLoad(AA))
   1317     // Otherwise, this is a real load.  If there is a store between the load and
   1318     // end of block, we can't move it.
   1319     return !SawStore;
   1320 
   1321   return true;
   1322 }
   1323 
   1324 /// hasOrderedMemoryRef - Return true if this instruction may have an ordered
   1325 /// or volatile memory reference, or if the information describing the memory
   1326 /// reference is not available. Return false if it is known to have no ordered
   1327 /// memory references.
   1328 bool MachineInstr::hasOrderedMemoryRef() const {
   1329   // An instruction known never to access memory won't have a volatile access.
   1330   if (!mayStore() &&
   1331       !mayLoad() &&
   1332       !isCall() &&
   1333       !hasUnmodeledSideEffects())
   1334     return false;
   1335 
   1336   // Otherwise, if the instruction has no memory reference information,
   1337   // conservatively assume it wasn't preserved.
   1338   if (memoperands_empty())
   1339     return true;
   1340 
   1341   // Check the memory reference information for ordered references.
   1342   for (mmo_iterator I = memoperands_begin(), E = memoperands_end(); I != E; ++I)
   1343     if (!(*I)->isUnordered())
   1344       return true;
   1345 
   1346   return false;
   1347 }
   1348 
   1349 /// isInvariantLoad - Return true if this instruction is loading from a
   1350 /// location whose value is invariant across the function.  For example,
   1351 /// loading a value from the constant pool or from the argument area
   1352 /// of a function if it does not change.  This should only return true of
   1353 /// *all* loads the instruction does are invariant (if it does multiple loads).
   1354 bool MachineInstr::isInvariantLoad(AliasAnalysis *AA) const {
   1355   // If the instruction doesn't load at all, it isn't an invariant load.
   1356   if (!mayLoad())
   1357     return false;
   1358 
   1359   // If the instruction has lost its memoperands, conservatively assume that
   1360   // it may not be an invariant load.
   1361   if (memoperands_empty())
   1362     return false;
   1363 
   1364   const MachineFrameInfo *MFI = getParent()->getParent()->getFrameInfo();
   1365 
   1366   for (mmo_iterator I = memoperands_begin(),
   1367        E = memoperands_end(); I != E; ++I) {
   1368     if ((*I)->isVolatile()) return false;
   1369     if ((*I)->isStore()) return false;
   1370     if ((*I)->isInvariant()) return true;
   1371 
   1372 
   1373     // A load from a constant PseudoSourceValue is invariant.
   1374     if (const PseudoSourceValue *PSV = (*I)->getPseudoValue())
   1375       if (PSV->isConstant(MFI))
   1376         continue;
   1377 
   1378     if (const Value *V = (*I)->getValue()) {
   1379       // If we have an AliasAnalysis, ask it whether the memory is constant.
   1380       if (AA && AA->pointsToConstantMemory(
   1381                       AliasAnalysis::Location(V, (*I)->getSize(),
   1382                                               (*I)->getTBAAInfo())))
   1383         continue;
   1384     }
   1385 
   1386     // Otherwise assume conservatively.
   1387     return false;
   1388   }
   1389 
   1390   // Everything checks out.
   1391   return true;
   1392 }
   1393 
   1394 /// isConstantValuePHI - If the specified instruction is a PHI that always
   1395 /// merges together the same virtual register, return the register, otherwise
   1396 /// return 0.
   1397 unsigned MachineInstr::isConstantValuePHI() const {
   1398   if (!isPHI())
   1399     return 0;
   1400   assert(getNumOperands() >= 3 &&
   1401          "It's illegal to have a PHI without source operands");
   1402 
   1403   unsigned Reg = getOperand(1).getReg();
   1404   for (unsigned i = 3, e = getNumOperands(); i < e; i += 2)
   1405     if (getOperand(i).getReg() != Reg)
   1406       return 0;
   1407   return Reg;
   1408 }
   1409 
   1410 bool MachineInstr::hasUnmodeledSideEffects() const {
   1411   if (hasProperty(MCID::UnmodeledSideEffects))
   1412     return true;
   1413   if (isInlineAsm()) {
   1414     unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
   1415     if (ExtraInfo & InlineAsm::Extra_HasSideEffects)
   1416       return true;
   1417   }
   1418 
   1419   return false;
   1420 }
   1421 
   1422 /// allDefsAreDead - Return true if all the defs of this instruction are dead.
   1423 ///
   1424 bool MachineInstr::allDefsAreDead() const {
   1425   for (unsigned i = 0, e = getNumOperands(); i < e; ++i) {
   1426     const MachineOperand &MO = getOperand(i);
   1427     if (!MO.isReg() || MO.isUse())
   1428       continue;
   1429     if (!MO.isDead())
   1430       return false;
   1431   }
   1432   return true;
   1433 }
   1434 
   1435 /// copyImplicitOps - Copy implicit register operands from specified
   1436 /// instruction to this instruction.
   1437 void MachineInstr::copyImplicitOps(MachineFunction &MF,
   1438                                    const MachineInstr *MI) {
   1439   for (unsigned i = MI->getDesc().getNumOperands(), e = MI->getNumOperands();
   1440        i != e; ++i) {
   1441     const MachineOperand &MO = MI->getOperand(i);
   1442     if ((MO.isReg() && MO.isImplicit()) || MO.isRegMask())
   1443       addOperand(MF, MO);
   1444   }
   1445 }
   1446 
   1447 void MachineInstr::dump() const {
   1448 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
   1449   dbgs() << "  " << *this;
   1450 #endif
   1451 }
   1452 
   1453 static void printDebugLoc(DebugLoc DL, const MachineFunction *MF,
   1454                          raw_ostream &CommentOS) {
   1455   const LLVMContext &Ctx = MF->getFunction()->getContext();
   1456   DL.print(Ctx, CommentOS);
   1457 }
   1458 
   1459 void MachineInstr::print(raw_ostream &OS, const TargetMachine *TM,
   1460                          bool SkipOpers) const {
   1461   // We can be a bit tidier if we know the TargetMachine and/or MachineFunction.
   1462   const MachineFunction *MF = nullptr;
   1463   const MachineRegisterInfo *MRI = nullptr;
   1464   if (const MachineBasicBlock *MBB = getParent()) {
   1465     MF = MBB->getParent();
   1466     if (!TM && MF)
   1467       TM = &MF->getTarget();
   1468     if (MF)
   1469       MRI = &MF->getRegInfo();
   1470   }
   1471 
   1472   // Save a list of virtual registers.
   1473   SmallVector<unsigned, 8> VirtRegs;
   1474 
   1475   // Print explicitly defined operands on the left of an assignment syntax.
   1476   unsigned StartOp = 0, e = getNumOperands();
   1477   for (; StartOp < e && getOperand(StartOp).isReg() &&
   1478          getOperand(StartOp).isDef() &&
   1479          !getOperand(StartOp).isImplicit();
   1480        ++StartOp) {
   1481     if (StartOp != 0) OS << ", ";
   1482     getOperand(StartOp).print(OS, TM);
   1483     unsigned Reg = getOperand(StartOp).getReg();
   1484     if (TargetRegisterInfo::isVirtualRegister(Reg))
   1485       VirtRegs.push_back(Reg);
   1486   }
   1487 
   1488   if (StartOp != 0)
   1489     OS << " = ";
   1490 
   1491   // Print the opcode name.
   1492   if (TM && TM->getInstrInfo())
   1493     OS << TM->getInstrInfo()->getName(getOpcode());
   1494   else
   1495     OS << "UNKNOWN";
   1496 
   1497   if (SkipOpers)
   1498     return;
   1499 
   1500   // Print the rest of the operands.
   1501   bool OmittedAnyCallClobbers = false;
   1502   bool FirstOp = true;
   1503   unsigned AsmDescOp = ~0u;
   1504   unsigned AsmOpCount = 0;
   1505 
   1506   if (isInlineAsm() && e >= InlineAsm::MIOp_FirstOperand) {
   1507     // Print asm string.
   1508     OS << " ";
   1509     getOperand(InlineAsm::MIOp_AsmString).print(OS, TM);
   1510 
   1511     // Print HasSideEffects, MayLoad, MayStore, IsAlignStack
   1512     unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
   1513     if (ExtraInfo & InlineAsm::Extra_HasSideEffects)
   1514       OS << " [sideeffect]";
   1515     if (ExtraInfo & InlineAsm::Extra_MayLoad)
   1516       OS << " [mayload]";
   1517     if (ExtraInfo & InlineAsm::Extra_MayStore)
   1518       OS << " [maystore]";
   1519     if (ExtraInfo & InlineAsm::Extra_IsAlignStack)
   1520       OS << " [alignstack]";
   1521     if (getInlineAsmDialect() == InlineAsm::AD_ATT)
   1522       OS << " [attdialect]";
   1523     if (getInlineAsmDialect() == InlineAsm::AD_Intel)
   1524       OS << " [inteldialect]";
   1525 
   1526     StartOp = AsmDescOp = InlineAsm::MIOp_FirstOperand;
   1527     FirstOp = false;
   1528   }
   1529 
   1530 
   1531   for (unsigned i = StartOp, e = getNumOperands(); i != e; ++i) {
   1532     const MachineOperand &MO = getOperand(i);
   1533 
   1534     if (MO.isReg() && TargetRegisterInfo::isVirtualRegister(MO.getReg()))
   1535       VirtRegs.push_back(MO.getReg());
   1536 
   1537     // Omit call-clobbered registers which aren't used anywhere. This makes
   1538     // call instructions much less noisy on targets where calls clobber lots
   1539     // of registers. Don't rely on MO.isDead() because we may be called before
   1540     // LiveVariables is run, or we may be looking at a non-allocatable reg.
   1541     if (MF && isCall() &&
   1542         MO.isReg() && MO.isImplicit() && MO.isDef()) {
   1543       unsigned Reg = MO.getReg();
   1544       if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
   1545         const MachineRegisterInfo &MRI = MF->getRegInfo();
   1546         if (MRI.use_empty(Reg)) {
   1547           bool HasAliasLive = false;
   1548           for (MCRegAliasIterator AI(Reg, TM->getRegisterInfo(), true);
   1549                AI.isValid(); ++AI) {
   1550             unsigned AliasReg = *AI;
   1551             if (!MRI.use_empty(AliasReg)) {
   1552               HasAliasLive = true;
   1553               break;
   1554             }
   1555           }
   1556           if (!HasAliasLive) {
   1557             OmittedAnyCallClobbers = true;
   1558             continue;
   1559           }
   1560         }
   1561       }
   1562     }
   1563 
   1564     if (FirstOp) FirstOp = false; else OS << ",";
   1565     OS << " ";
   1566     if (i < getDesc().NumOperands) {
   1567       const MCOperandInfo &MCOI = getDesc().OpInfo[i];
   1568       if (MCOI.isPredicate())
   1569         OS << "pred:";
   1570       if (MCOI.isOptionalDef())
   1571         OS << "opt:";
   1572     }
   1573     if (isDebugValue() && MO.isMetadata()) {
   1574       // Pretty print DBG_VALUE instructions.
   1575       const MDNode *MD = MO.getMetadata();
   1576       if (const MDString *MDS = dyn_cast<MDString>(MD->getOperand(2)))
   1577         OS << "!\"" << MDS->getString() << '\"';
   1578       else
   1579         MO.print(OS, TM);
   1580     } else if (TM && (isInsertSubreg() || isRegSequence()) && MO.isImm()) {
   1581       OS << TM->getRegisterInfo()->getSubRegIndexName(MO.getImm());
   1582     } else if (i == AsmDescOp && MO.isImm()) {
   1583       // Pretty print the inline asm operand descriptor.
   1584       OS << '$' << AsmOpCount++;
   1585       unsigned Flag = MO.getImm();
   1586       switch (InlineAsm::getKind(Flag)) {
   1587       case InlineAsm::Kind_RegUse:             OS << ":[reguse"; break;
   1588       case InlineAsm::Kind_RegDef:             OS << ":[regdef"; break;
   1589       case InlineAsm::Kind_RegDefEarlyClobber: OS << ":[regdef-ec"; break;
   1590       case InlineAsm::Kind_Clobber:            OS << ":[clobber"; break;
   1591       case InlineAsm::Kind_Imm:                OS << ":[imm"; break;
   1592       case InlineAsm::Kind_Mem:                OS << ":[mem"; break;
   1593       default: OS << ":[??" << InlineAsm::getKind(Flag); break;
   1594       }
   1595 
   1596       unsigned RCID = 0;
   1597       if (InlineAsm::hasRegClassConstraint(Flag, RCID)) {
   1598         if (TM)
   1599           OS << ':' << TM->getRegisterInfo()->getRegClass(RCID)->getName();
   1600         else
   1601           OS << ":RC" << RCID;
   1602       }
   1603 
   1604       unsigned TiedTo = 0;
   1605       if (InlineAsm::isUseOperandTiedToDef(Flag, TiedTo))
   1606         OS << " tiedto:$" << TiedTo;
   1607 
   1608       OS << ']';
   1609 
   1610       // Compute the index of the next operand descriptor.
   1611       AsmDescOp += 1 + InlineAsm::getNumOperandRegisters(Flag);
   1612     } else
   1613       MO.print(OS, TM);
   1614   }
   1615 
   1616   // Briefly indicate whether any call clobbers were omitted.
   1617   if (OmittedAnyCallClobbers) {
   1618     if (!FirstOp) OS << ",";
   1619     OS << " ...";
   1620   }
   1621 
   1622   bool HaveSemi = false;
   1623   const unsigned PrintableFlags = FrameSetup;
   1624   if (Flags & PrintableFlags) {
   1625     if (!HaveSemi) OS << ";"; HaveSemi = true;
   1626     OS << " flags: ";
   1627 
   1628     if (Flags & FrameSetup)
   1629       OS << "FrameSetup";
   1630   }
   1631 
   1632   if (!memoperands_empty()) {
   1633     if (!HaveSemi) OS << ";"; HaveSemi = true;
   1634 
   1635     OS << " mem:";
   1636     for (mmo_iterator i = memoperands_begin(), e = memoperands_end();
   1637          i != e; ++i) {
   1638       OS << **i;
   1639       if (std::next(i) != e)
   1640         OS << " ";
   1641     }
   1642   }
   1643 
   1644   // Print the regclass of any virtual registers encountered.
   1645   if (MRI && !VirtRegs.empty()) {
   1646     if (!HaveSemi) OS << ";"; HaveSemi = true;
   1647     for (unsigned i = 0; i != VirtRegs.size(); ++i) {
   1648       const TargetRegisterClass *RC = MRI->getRegClass(VirtRegs[i]);
   1649       OS << " " << RC->getName() << ':' << PrintReg(VirtRegs[i]);
   1650       for (unsigned j = i+1; j != VirtRegs.size();) {
   1651         if (MRI->getRegClass(VirtRegs[j]) != RC) {
   1652           ++j;
   1653           continue;
   1654         }
   1655         if (VirtRegs[i] != VirtRegs[j])
   1656           OS << "," << PrintReg(VirtRegs[j]);
   1657         VirtRegs.erase(VirtRegs.begin()+j);
   1658       }
   1659     }
   1660   }
   1661 
   1662   // Print debug location information.
   1663   if (isDebugValue() && getOperand(e - 1).isMetadata()) {
   1664     if (!HaveSemi) OS << ";";
   1665     DIVariable DV(getOperand(e - 1).getMetadata());
   1666     OS << " line no:" <<  DV.getLineNumber();
   1667     if (MDNode *InlinedAt = DV.getInlinedAt()) {
   1668       DebugLoc InlinedAtDL = DebugLoc::getFromDILocation(InlinedAt);
   1669       if (!InlinedAtDL.isUnknown() && MF) {
   1670         OS << " inlined @[ ";
   1671         printDebugLoc(InlinedAtDL, MF, OS);
   1672         OS << " ]";
   1673       }
   1674     }
   1675   } else if (!debugLoc.isUnknown() && MF) {
   1676     if (!HaveSemi) OS << ";";
   1677     OS << " dbg:";
   1678     printDebugLoc(debugLoc, MF, OS);
   1679   }
   1680 
   1681   OS << '\n';
   1682 }
   1683 
   1684 bool MachineInstr::addRegisterKilled(unsigned IncomingReg,
   1685                                      const TargetRegisterInfo *RegInfo,
   1686                                      bool AddIfNotFound) {
   1687   bool isPhysReg = TargetRegisterInfo::isPhysicalRegister(IncomingReg);
   1688   bool hasAliases = isPhysReg &&
   1689     MCRegAliasIterator(IncomingReg, RegInfo, false).isValid();
   1690   bool Found = false;
   1691   SmallVector<unsigned,4> DeadOps;
   1692   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
   1693     MachineOperand &MO = getOperand(i);
   1694     if (!MO.isReg() || !MO.isUse() || MO.isUndef())
   1695       continue;
   1696     unsigned Reg = MO.getReg();
   1697     if (!Reg)
   1698       continue;
   1699 
   1700     if (Reg == IncomingReg) {
   1701       if (!Found) {
   1702         if (MO.isKill())
   1703           // The register is already marked kill.
   1704           return true;
   1705         if (isPhysReg && isRegTiedToDefOperand(i))
   1706           // Two-address uses of physregs must not be marked kill.
   1707           return true;
   1708         MO.setIsKill();
   1709         Found = true;
   1710       }
   1711     } else if (hasAliases && MO.isKill() &&
   1712                TargetRegisterInfo::isPhysicalRegister(Reg)) {
   1713       // A super-register kill already exists.
   1714       if (RegInfo->isSuperRegister(IncomingReg, Reg))
   1715         return true;
   1716       if (RegInfo->isSubRegister(IncomingReg, Reg))
   1717         DeadOps.push_back(i);
   1718     }
   1719   }
   1720 
   1721   // Trim unneeded kill operands.
   1722   while (!DeadOps.empty()) {
   1723     unsigned OpIdx = DeadOps.back();
   1724     if (getOperand(OpIdx).isImplicit())
   1725       RemoveOperand(OpIdx);
   1726     else
   1727       getOperand(OpIdx).setIsKill(false);
   1728     DeadOps.pop_back();
   1729   }
   1730 
   1731   // If not found, this means an alias of one of the operands is killed. Add a
   1732   // new implicit operand if required.
   1733   if (!Found && AddIfNotFound) {
   1734     addOperand(MachineOperand::CreateReg(IncomingReg,
   1735                                          false /*IsDef*/,
   1736                                          true  /*IsImp*/,
   1737                                          true  /*IsKill*/));
   1738     return true;
   1739   }
   1740   return Found;
   1741 }
   1742 
   1743 void MachineInstr::clearRegisterKills(unsigned Reg,
   1744                                       const TargetRegisterInfo *RegInfo) {
   1745   if (!TargetRegisterInfo::isPhysicalRegister(Reg))
   1746     RegInfo = nullptr;
   1747   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
   1748     MachineOperand &MO = getOperand(i);
   1749     if (!MO.isReg() || !MO.isUse() || !MO.isKill())
   1750       continue;
   1751     unsigned OpReg = MO.getReg();
   1752     if (OpReg == Reg || (RegInfo && RegInfo->isSuperRegister(Reg, OpReg)))
   1753       MO.setIsKill(false);
   1754   }
   1755 }
   1756 
   1757 bool MachineInstr::addRegisterDead(unsigned Reg,
   1758                                    const TargetRegisterInfo *RegInfo,
   1759                                    bool AddIfNotFound) {
   1760   bool isPhysReg = TargetRegisterInfo::isPhysicalRegister(Reg);
   1761   bool hasAliases = isPhysReg &&
   1762     MCRegAliasIterator(Reg, RegInfo, false).isValid();
   1763   bool Found = false;
   1764   SmallVector<unsigned,4> DeadOps;
   1765   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
   1766     MachineOperand &MO = getOperand(i);
   1767     if (!MO.isReg() || !MO.isDef())
   1768       continue;
   1769     unsigned MOReg = MO.getReg();
   1770     if (!MOReg)
   1771       continue;
   1772 
   1773     if (MOReg == Reg) {
   1774       MO.setIsDead();
   1775       Found = true;
   1776     } else if (hasAliases && MO.isDead() &&
   1777                TargetRegisterInfo::isPhysicalRegister(MOReg)) {
   1778       // There exists a super-register that's marked dead.
   1779       if (RegInfo->isSuperRegister(Reg, MOReg))
   1780         return true;
   1781       if (RegInfo->isSubRegister(Reg, MOReg))
   1782         DeadOps.push_back(i);
   1783     }
   1784   }
   1785 
   1786   // Trim unneeded dead operands.
   1787   while (!DeadOps.empty()) {
   1788     unsigned OpIdx = DeadOps.back();
   1789     if (getOperand(OpIdx).isImplicit())
   1790       RemoveOperand(OpIdx);
   1791     else
   1792       getOperand(OpIdx).setIsDead(false);
   1793     DeadOps.pop_back();
   1794   }
   1795 
   1796   // If not found, this means an alias of one of the operands is dead. Add a
   1797   // new implicit operand if required.
   1798   if (Found || !AddIfNotFound)
   1799     return Found;
   1800 
   1801   addOperand(MachineOperand::CreateReg(Reg,
   1802                                        true  /*IsDef*/,
   1803                                        true  /*IsImp*/,
   1804                                        false /*IsKill*/,
   1805                                        true  /*IsDead*/));
   1806   return true;
   1807 }
   1808 
   1809 void MachineInstr::addRegisterDefined(unsigned Reg,
   1810                                       const TargetRegisterInfo *RegInfo) {
   1811   if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
   1812     MachineOperand *MO = findRegisterDefOperand(Reg, false, RegInfo);
   1813     if (MO)
   1814       return;
   1815   } else {
   1816     for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
   1817       const MachineOperand &MO = getOperand(i);
   1818       if (MO.isReg() && MO.getReg() == Reg && MO.isDef() &&
   1819           MO.getSubReg() == 0)
   1820         return;
   1821     }
   1822   }
   1823   addOperand(MachineOperand::CreateReg(Reg,
   1824                                        true  /*IsDef*/,
   1825                                        true  /*IsImp*/));
   1826 }
   1827 
   1828 void MachineInstr::setPhysRegsDeadExcept(ArrayRef<unsigned> UsedRegs,
   1829                                          const TargetRegisterInfo &TRI) {
   1830   bool HasRegMask = false;
   1831   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
   1832     MachineOperand &MO = getOperand(i);
   1833     if (MO.isRegMask()) {
   1834       HasRegMask = true;
   1835       continue;
   1836     }
   1837     if (!MO.isReg() || !MO.isDef()) continue;
   1838     unsigned Reg = MO.getReg();
   1839     if (!TargetRegisterInfo::isPhysicalRegister(Reg)) continue;
   1840     bool Dead = true;
   1841     for (ArrayRef<unsigned>::iterator I = UsedRegs.begin(), E = UsedRegs.end();
   1842          I != E; ++I)
   1843       if (TRI.regsOverlap(*I, Reg)) {
   1844         Dead = false;
   1845         break;
   1846       }
   1847     // If there are no uses, including partial uses, the def is dead.
   1848     if (Dead) MO.setIsDead();
   1849   }
   1850 
   1851   // This is a call with a register mask operand.
   1852   // Mask clobbers are always dead, so add defs for the non-dead defines.
   1853   if (HasRegMask)
   1854     for (ArrayRef<unsigned>::iterator I = UsedRegs.begin(), E = UsedRegs.end();
   1855          I != E; ++I)
   1856       addRegisterDefined(*I, &TRI);
   1857 }
   1858 
   1859 unsigned
   1860 MachineInstrExpressionTrait::getHashValue(const MachineInstr* const &MI) {
   1861   // Build up a buffer of hash code components.
   1862   SmallVector<size_t, 8> HashComponents;
   1863   HashComponents.reserve(MI->getNumOperands() + 1);
   1864   HashComponents.push_back(MI->getOpcode());
   1865   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
   1866     const MachineOperand &MO = MI->getOperand(i);
   1867     if (MO.isReg() && MO.isDef() &&
   1868         TargetRegisterInfo::isVirtualRegister(MO.getReg()))
   1869       continue;  // Skip virtual register defs.
   1870 
   1871     HashComponents.push_back(hash_value(MO));
   1872   }
   1873   return hash_combine_range(HashComponents.begin(), HashComponents.end());
   1874 }
   1875 
   1876 void MachineInstr::emitError(StringRef Msg) const {
   1877   // Find the source location cookie.
   1878   unsigned LocCookie = 0;
   1879   const MDNode *LocMD = nullptr;
   1880   for (unsigned i = getNumOperands(); i != 0; --i) {
   1881     if (getOperand(i-1).isMetadata() &&
   1882         (LocMD = getOperand(i-1).getMetadata()) &&
   1883         LocMD->getNumOperands() != 0) {
   1884       if (const ConstantInt *CI = dyn_cast<ConstantInt>(LocMD->getOperand(0))) {
   1885         LocCookie = CI->getZExtValue();
   1886         break;
   1887       }
   1888     }
   1889   }
   1890 
   1891   if (const MachineBasicBlock *MBB = getParent())
   1892     if (const MachineFunction *MF = MBB->getParent())
   1893       return MF->getMMI().getModule()->getContext().emitError(LocCookie, Msg);
   1894   report_fatal_error(Msg);
   1895 }
   1896