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/APFloat.h"
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/FoldingSet.h"
18 #include "llvm/ADT/Hashing.h"
19 #include "llvm/ADT/None.h"
20 #include "llvm/ADT/STLExtras.h"
21 #include "llvm/ADT/SmallString.h"
22 #include "llvm/ADT/SmallVector.h"
23 #include "llvm/Analysis/AliasAnalysis.h"
24 #include "llvm/Analysis/Loads.h"
25 #include "llvm/Analysis/MemoryLocation.h"
26 #include "llvm/CodeGen/GlobalISel/RegisterBank.h"
27 #include "llvm/CodeGen/MachineBasicBlock.h"
28 #include "llvm/CodeGen/MachineFunction.h"
29 #include "llvm/CodeGen/MachineInstrBuilder.h"
30 #include "llvm/CodeGen/MachineInstrBundle.h"
31 #include "llvm/CodeGen/MachineMemOperand.h"
32 #include "llvm/CodeGen/MachineModuleInfo.h"
33 #include "llvm/CodeGen/MachineOperand.h"
34 #include "llvm/CodeGen/MachineRegisterInfo.h"
35 #include "llvm/CodeGen/PseudoSourceValue.h"
36 #include "llvm/CodeGen/TargetInstrInfo.h"
37 #include "llvm/CodeGen/TargetRegisterInfo.h"
38 #include "llvm/CodeGen/TargetSubtargetInfo.h"
39 #include "llvm/IR/Constants.h"
40 #include "llvm/IR/DebugInfoMetadata.h"
41 #include "llvm/IR/DebugLoc.h"
42 #include "llvm/IR/DerivedTypes.h"
43 #include "llvm/IR/Function.h"
44 #include "llvm/IR/InlineAsm.h"
45 #include "llvm/IR/InstrTypes.h"
46 #include "llvm/IR/Intrinsics.h"
47 #include "llvm/IR/LLVMContext.h"
48 #include "llvm/IR/Metadata.h"
49 #include "llvm/IR/Module.h"
50 #include "llvm/IR/ModuleSlotTracker.h"
51 #include "llvm/IR/Type.h"
52 #include "llvm/IR/Value.h"
53 #include "llvm/MC/MCInstrDesc.h"
54 #include "llvm/MC/MCRegisterInfo.h"
55 #include "llvm/MC/MCSymbol.h"
56 #include "llvm/Support/Casting.h"
57 #include "llvm/Support/CommandLine.h"
58 #include "llvm/Support/Compiler.h"
59 #include "llvm/Support/Debug.h"
60 #include "llvm/Support/ErrorHandling.h"
61 #include "llvm/Support/LowLevelTypeImpl.h"
62 #include "llvm/Support/MathExtras.h"
63 #include "llvm/Support/raw_ostream.h"
64 #include "llvm/Target/TargetIntrinsicInfo.h"
65 #include "llvm/Target/TargetMachine.h"
66 #include <algorithm>
67 #include <cassert>
68 #include <cstddef>
69 #include <cstdint>
70 #include <cstring>
71 #include <iterator>
72 #include <utility>
73 
74 using namespace llvm;
75 
76 static cl::opt<int> PrintRegMaskNumRegs(
77     "print-regmask-num-regs",
78     cl::desc("Number of registers to limit to when "
79              "printing regmask operands in IR dumps. "
80              "unlimited = -1"),
81     cl::init(32), cl::Hidden);
82 
83 //===----------------------------------------------------------------------===//
84 // MachineOperand Implementation
85 //===----------------------------------------------------------------------===//
86 
87 void MachineOperand::setReg(unsigned Reg) {
88   if (getReg() == Reg) return; // No change.
89 
90   // Otherwise, we have to change the register.  If this operand is embedded
91   // into a machine function, we need to update the old and new register's
92   // use/def lists.
93   if (MachineInstr *MI = getParent())
94     if (MachineBasicBlock *MBB = MI->getParent())
95       if (MachineFunction *MF = MBB->getParent()) {
96         MachineRegisterInfo &MRI = MF->getRegInfo();
97         MRI.removeRegOperandFromUseList(this);
98         SmallContents.RegNo = Reg;
99         MRI.addRegOperandToUseList(this);
100         return;
101       }
102 
103   // Otherwise, just change the register, no problem.  :)
104   SmallContents.RegNo = Reg;
105 }
106 
107 void MachineOperand::substVirtReg(unsigned Reg, unsigned SubIdx,
108                                   const TargetRegisterInfo &TRI) {
109   assert(TargetRegisterInfo::isVirtualRegister(Reg));
110   if (SubIdx && getSubReg())
111     SubIdx = TRI.composeSubRegIndices(SubIdx, getSubReg());
112   setReg(Reg);
113   if (SubIdx)
114     setSubReg(SubIdx);
115 }
116 
117 void MachineOperand::substPhysReg(unsigned Reg, const TargetRegisterInfo &TRI) {
118   assert(TargetRegisterInfo::isPhysicalRegister(Reg));
119   if (getSubReg()) {
120     Reg = TRI.getSubReg(Reg, getSubReg());
121     // Note that getSubReg() may return 0 if the sub-register doesn't exist.
122     // That won't happen in legal code.
123     setSubReg(0);
124     if (isDef())
125       setIsUndef(false);
126   }
127   setReg(Reg);
128 }
129 
130 void MachineOperand::setIsDef(bool Val) {
131   assert(isReg() && "Wrong MachineOperand accessor");
132   assert((!Val || !isDebug()) && "Marking a debug operation as def");
133   if (IsDef == Val)
134     return;
135   // MRI may keep uses and defs in different list positions.
136   if (MachineInstr *MI = getParent())
137     if (MachineBasicBlock *MBB = MI->getParent())
138       if (MachineFunction *MF = MBB->getParent()) {
139         MachineRegisterInfo &MRI = MF->getRegInfo();
140         MRI.removeRegOperandFromUseList(this);
141         IsDef = Val;
142         MRI.addRegOperandToUseList(this);
143         return;
144       }
145   IsDef = Val;
146 }
147 
148 void MachineOperand::removeRegFromUses() {
149   if (!isReg() || !isOnRegUseList())
150     return;
151 
152   if (MachineInstr *MI = getParent()) {
153     if (MachineBasicBlock *MBB = MI->getParent()) {
154       if (MachineFunction *MF = MBB->getParent())
155         MF->getRegInfo().removeRegOperandFromUseList(this);
156     }
157   }
158 }
159 
160 void MachineOperand::ChangeToImmediate(int64_t ImmVal) {
161   assert((!isReg() || !isTied()) && "Cannot change a tied operand into an imm");
162 
163   removeRegFromUses();
164 
165   OpKind = MO_Immediate;
166   Contents.ImmVal = ImmVal;
167 }
168 
169 void MachineOperand::ChangeToFPImmediate(const ConstantFP *FPImm) {
170   assert((!isReg() || !isTied()) && "Cannot change a tied operand into an imm");
171 
172   removeRegFromUses();
173 
174   OpKind = MO_FPImmediate;
175   Contents.CFP = FPImm;
176 }
177 
178 void MachineOperand::ChangeToES(const char *SymName, unsigned char TargetFlags) {
179   assert((!isReg() || !isTied()) &&
180          "Cannot change a tied operand into an external symbol");
181 
182   removeRegFromUses();
183 
184   OpKind = MO_ExternalSymbol;
185   Contents.OffsetedInfo.Val.SymbolName = SymName;
186   setOffset(0); // Offset is always 0.
187   setTargetFlags(TargetFlags);
188 }
189 
190 void MachineOperand::ChangeToMCSymbol(MCSymbol *Sym) {
191   assert((!isReg() || !isTied()) &&
192          "Cannot change a tied operand into an MCSymbol");
193 
194   removeRegFromUses();
195 
196   OpKind = MO_MCSymbol;
197   Contents.Sym = Sym;
198 }
199 
200 void MachineOperand::ChangeToFrameIndex(int Idx) {
201   assert((!isReg() || !isTied()) &&
202          "Cannot change a tied operand into a FrameIndex");
203 
204   removeRegFromUses();
205 
206   OpKind = MO_FrameIndex;
207   setIndex(Idx);
208 }
209 
210 void MachineOperand::ChangeToTargetIndex(unsigned Idx, int64_t Offset,
211                                          unsigned char TargetFlags) {
212   assert((!isReg() || !isTied()) &&
213          "Cannot change a tied operand into a FrameIndex");
214 
215   removeRegFromUses();
216 
217   OpKind = MO_TargetIndex;
218   setIndex(Idx);
219   setOffset(Offset);
220   setTargetFlags(TargetFlags);
221 }
222 
223 void MachineOperand::ChangeToRegister(unsigned Reg, bool isDef, bool isImp,
224                                       bool isKill, bool isDead, bool isUndef,
225                                       bool isDebug) {
226   MachineRegisterInfo *RegInfo = nullptr;
227   if (MachineInstr *MI = getParent())
228     if (MachineBasicBlock *MBB = MI->getParent())
229       if (MachineFunction *MF = MBB->getParent())
230         RegInfo = &MF->getRegInfo();
231   // If this operand is already a register operand, remove it from the
232   // register's use/def lists.
233   bool WasReg = isReg();
234   if (RegInfo && WasReg)
235     RegInfo->removeRegOperandFromUseList(this);
236 
237   // Change this to a register and set the reg#.
238   OpKind = MO_Register;
239   SmallContents.RegNo = Reg;
240   SubReg_TargetFlags = 0;
241   IsDef = isDef;
242   IsImp = isImp;
243   IsKill = isKill;
244   IsDead = isDead;
245   IsUndef = isUndef;
246   IsInternalRead = false;
247   IsEarlyClobber = false;
248   IsDebug = isDebug;
249   // Ensure isOnRegUseList() returns false.
250   Contents.Reg.Prev = nullptr;
251   // Preserve the tie when the operand was already a register.
252   if (!WasReg)
253     TiedTo = 0;
254 
255   // If this operand is embedded in a function, add the operand to the
256   // register's use/def list.
257   if (RegInfo)
258     RegInfo->addRegOperandToUseList(this);
259 }
260 
261 bool MachineOperand::isIdenticalTo(const MachineOperand &Other) const {
262   if (getType() != Other.getType() ||
263       getTargetFlags() != Other.getTargetFlags())
264     return false;
265 
266   switch (getType()) {
267   case MachineOperand::MO_Register:
268     return getReg() == Other.getReg() && isDef() == Other.isDef() &&
269            getSubReg() == Other.getSubReg();
270   case MachineOperand::MO_Immediate:
271     return getImm() == Other.getImm();
272   case MachineOperand::MO_CImmediate:
273     return getCImm() == Other.getCImm();
274   case MachineOperand::MO_FPImmediate:
275     return getFPImm() == Other.getFPImm();
276   case MachineOperand::MO_MachineBasicBlock:
277     return getMBB() == Other.getMBB();
278   case MachineOperand::MO_FrameIndex:
279     return getIndex() == Other.getIndex();
280   case MachineOperand::MO_ConstantPoolIndex:
281   case MachineOperand::MO_TargetIndex:
282     return getIndex() == Other.getIndex() && getOffset() == Other.getOffset();
283   case MachineOperand::MO_JumpTableIndex:
284     return getIndex() == Other.getIndex();
285   case MachineOperand::MO_GlobalAddress:
286     return getGlobal() == Other.getGlobal() && getOffset() == Other.getOffset();
287   case MachineOperand::MO_ExternalSymbol:
288     return strcmp(getSymbolName(), Other.getSymbolName()) == 0 &&
289            getOffset() == Other.getOffset();
290   case MachineOperand::MO_BlockAddress:
291     return getBlockAddress() == Other.getBlockAddress() &&
292            getOffset() == Other.getOffset();
293   case MachineOperand::MO_RegisterMask:
294   case MachineOperand::MO_RegisterLiveOut: {
295     // Shallow compare of the two RegMasks
296     const uint32_t *RegMask = getRegMask();
297     const uint32_t *OtherRegMask = Other.getRegMask();
298     if (RegMask == OtherRegMask)
299       return true;
300 
301     // Calculate the size of the RegMask
302     const MachineFunction *MF = getParent()->getMF();
303     const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
304     unsigned RegMaskSize = (TRI->getNumRegs() + 31) / 32;
305 
306     // Deep compare of the two RegMasks
307     return std::equal(RegMask, RegMask + RegMaskSize, OtherRegMask);
308   }
309   case MachineOperand::MO_MCSymbol:
310     return getMCSymbol() == Other.getMCSymbol();
311   case MachineOperand::MO_CFIIndex:
312     return getCFIIndex() == Other.getCFIIndex();
313   case MachineOperand::MO_Metadata:
314     return getMetadata() == Other.getMetadata();
315   case MachineOperand::MO_IntrinsicID:
316     return getIntrinsicID() == Other.getIntrinsicID();
317   case MachineOperand::MO_Predicate:
318     return getPredicate() == Other.getPredicate();
319   }
320   llvm_unreachable("Invalid machine operand type");
321 }
322 
323 // Note: this must stay exactly in sync with isIdenticalTo above.
324 hash_code llvm::hash_value(const MachineOperand &MO) {
325   switch (MO.getType()) {
326   case MachineOperand::MO_Register:
327     // Register operands don't have target flags.
328     return hash_combine(MO.getType(), MO.getReg(), MO.getSubReg(), MO.isDef());
329   case MachineOperand::MO_Immediate:
330     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getImm());
331   case MachineOperand::MO_CImmediate:
332     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getCImm());
333   case MachineOperand::MO_FPImmediate:
334     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getFPImm());
335   case MachineOperand::MO_MachineBasicBlock:
336     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getMBB());
337   case MachineOperand::MO_FrameIndex:
338     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIndex());
339   case MachineOperand::MO_ConstantPoolIndex:
340   case MachineOperand::MO_TargetIndex:
341     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIndex(),
342                         MO.getOffset());
343   case MachineOperand::MO_JumpTableIndex:
344     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIndex());
345   case MachineOperand::MO_ExternalSymbol:
346     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getOffset(),
347                         MO.getSymbolName());
348   case MachineOperand::MO_GlobalAddress:
349     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getGlobal(),
350                         MO.getOffset());
351   case MachineOperand::MO_BlockAddress:
352     return hash_combine(MO.getType(), MO.getTargetFlags(),
353                         MO.getBlockAddress(), MO.getOffset());
354   case MachineOperand::MO_RegisterMask:
355   case MachineOperand::MO_RegisterLiveOut:
356     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getRegMask());
357   case MachineOperand::MO_Metadata:
358     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getMetadata());
359   case MachineOperand::MO_MCSymbol:
360     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getMCSymbol());
361   case MachineOperand::MO_CFIIndex:
362     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getCFIIndex());
363   case MachineOperand::MO_IntrinsicID:
364     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIntrinsicID());
365   case MachineOperand::MO_Predicate:
366     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getPredicate());
367   }
368   llvm_unreachable("Invalid machine operand type");
369 }
370 
371 void MachineOperand::print(raw_ostream &OS, const TargetRegisterInfo *TRI,
372                            const TargetIntrinsicInfo *IntrinsicInfo) const {
373   ModuleSlotTracker DummyMST(nullptr);
374   print(OS, DummyMST, TRI, IntrinsicInfo);
375 }
376 
377 void MachineOperand::print(raw_ostream &OS, ModuleSlotTracker &MST,
378                            const TargetRegisterInfo *TRI,
379                            const TargetIntrinsicInfo *IntrinsicInfo) const {
380   switch (getType()) {
381   case MachineOperand::MO_Register:
382     OS << printReg(getReg(), TRI, getSubReg());
383 
384     if (isDef() || isKill() || isDead() || isImplicit() || isUndef() ||
385         isInternalRead() || isEarlyClobber() || isTied()) {
386       OS << '<';
387       bool NeedComma = false;
388       if (isDef()) {
389         if (NeedComma) OS << ',';
390         if (isEarlyClobber())
391           OS << "earlyclobber,";
392         if (isImplicit())
393           OS << "imp-";
394         OS << "def";
395         NeedComma = true;
396         // <def,read-undef> only makes sense when getSubReg() is set.
397         // Don't clutter the output otherwise.
398         if (isUndef() && getSubReg())
399           OS << ",read-undef";
400       } else if (isImplicit()) {
401         OS << "imp-use";
402         NeedComma = true;
403       }
404 
405       if (isKill()) {
406         if (NeedComma) OS << ',';
407         OS << "kill";
408         NeedComma = true;
409       }
410       if (isDead()) {
411         if (NeedComma) OS << ',';
412         OS << "dead";
413         NeedComma = true;
414       }
415       if (isUndef() && isUse()) {
416         if (NeedComma) OS << ',';
417         OS << "undef";
418         NeedComma = true;
419       }
420       if (isInternalRead()) {
421         if (NeedComma) OS << ',';
422         OS << "internal";
423         NeedComma = true;
424       }
425       if (isTied()) {
426         if (NeedComma) OS << ',';
427         OS << "tied";
428         if (TiedTo != 15)
429           OS << unsigned(TiedTo - 1);
430       }
431       OS << '>';
432     }
433     break;
434   case MachineOperand::MO_Immediate:
435     OS << getImm();
436     break;
437   case MachineOperand::MO_CImmediate:
438     getCImm()->getValue().print(OS, false);
439     break;
440   case MachineOperand::MO_FPImmediate:
441     if (getFPImm()->getType()->isFloatTy()) {
442       OS << getFPImm()->getValueAPF().convertToFloat();
443     } else if (getFPImm()->getType()->isHalfTy()) {
444       APFloat APF = getFPImm()->getValueAPF();
445       bool Unused;
446       APF.convert(APFloat::IEEEsingle(), APFloat::rmNearestTiesToEven, &Unused);
447       OS << "half " << APF.convertToFloat();
448     } else if (getFPImm()->getType()->isFP128Ty()) {
449       APFloat APF = getFPImm()->getValueAPF();
450       SmallString<16> Str;
451       getFPImm()->getValueAPF().toString(Str);
452       OS << "quad " << Str;
453     } else if (getFPImm()->getType()->isX86_FP80Ty()) {
454       APFloat APF = getFPImm()->getValueAPF();
455       OS << "x86_fp80 0xK";
456       APInt API = APF.bitcastToAPInt();
457       OS << format_hex_no_prefix(API.getHiBits(16).getZExtValue(), 4,
458                                  /*Upper=*/true);
459       OS << format_hex_no_prefix(API.getLoBits(64).getZExtValue(), 16,
460                                  /*Upper=*/true);
461     } else {
462       OS << getFPImm()->getValueAPF().convertToDouble();
463     }
464     break;
465   case MachineOperand::MO_MachineBasicBlock:
466     OS << "<BB#" << getMBB()->getNumber() << ">";
467     break;
468   case MachineOperand::MO_FrameIndex:
469     OS << "<fi#" << getIndex() << '>';
470     break;
471   case MachineOperand::MO_ConstantPoolIndex:
472     OS << "<cp#" << getIndex();
473     if (getOffset()) OS << "+" << getOffset();
474     OS << '>';
475     break;
476   case MachineOperand::MO_TargetIndex:
477     OS << "<ti#" << getIndex();
478     if (getOffset()) OS << "+" << getOffset();
479     OS << '>';
480     break;
481   case MachineOperand::MO_JumpTableIndex:
482     OS << "<jt#" << getIndex() << '>';
483     break;
484   case MachineOperand::MO_GlobalAddress:
485     OS << "<ga:";
486     getGlobal()->printAsOperand(OS, /*PrintType=*/false, MST);
487     if (getOffset()) OS << "+" << getOffset();
488     OS << '>';
489     break;
490   case MachineOperand::MO_ExternalSymbol:
491     OS << "<es:" << getSymbolName();
492     if (getOffset()) OS << "+" << getOffset();
493     OS << '>';
494     break;
495   case MachineOperand::MO_BlockAddress:
496     OS << '<';
497     getBlockAddress()->printAsOperand(OS, /*PrintType=*/false, MST);
498     if (getOffset()) OS << "+" << getOffset();
499     OS << '>';
500     break;
501   case MachineOperand::MO_RegisterMask: {
502     unsigned NumRegsInMask = 0;
503     unsigned NumRegsEmitted = 0;
504     OS << "<regmask";
505     for (unsigned i = 0; i < TRI->getNumRegs(); ++i) {
506       unsigned MaskWord = i / 32;
507       unsigned MaskBit = i % 32;
508       if (getRegMask()[MaskWord] & (1 << MaskBit)) {
509         if (PrintRegMaskNumRegs < 0 ||
510             NumRegsEmitted <= static_cast<unsigned>(PrintRegMaskNumRegs)) {
511           OS << " " << printReg(i, TRI);
512           NumRegsEmitted++;
513         }
514         NumRegsInMask++;
515       }
516     }
517     if (NumRegsEmitted != NumRegsInMask)
518       OS << " and " << (NumRegsInMask - NumRegsEmitted) << " more...";
519     OS << ">";
520     break;
521   }
522   case MachineOperand::MO_RegisterLiveOut:
523     OS << "<regliveout>";
524     break;
525   case MachineOperand::MO_Metadata:
526     OS << '<';
527     getMetadata()->printAsOperand(OS, MST);
528     OS << '>';
529     break;
530   case MachineOperand::MO_MCSymbol:
531     OS << "<MCSym=" << *getMCSymbol() << '>';
532     break;
533   case MachineOperand::MO_CFIIndex:
534     OS << "<call frame instruction>";
535     break;
536   case MachineOperand::MO_IntrinsicID: {
537     Intrinsic::ID ID = getIntrinsicID();
538     if (ID < Intrinsic::num_intrinsics)
539       OS << "<intrinsic:@" << Intrinsic::getName(ID, None) << '>';
540     else if (IntrinsicInfo)
541       OS << "<intrinsic:@" << IntrinsicInfo->getName(ID) << '>';
542     else
543       OS << "<intrinsic:" << ID << '>';
544     break;
545   }
546   case MachineOperand::MO_Predicate: {
547     auto Pred = static_cast<CmpInst::Predicate>(getPredicate());
548     OS << '<' << (CmpInst::isIntPredicate(Pred) ? "intpred" : "floatpred")
549        << CmpInst::getPredicateName(Pred) << '>';
550     break;
551   }
552   }
553   if (unsigned TF = getTargetFlags())
554     OS << "[TF=" << TF << ']';
555 }
556 
557 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
558 LLVM_DUMP_METHOD void MachineOperand::dump() const {
559   dbgs() << *this << '\n';
560 }
561 #endif
562 
563 //===----------------------------------------------------------------------===//
564 // MachineMemOperand Implementation
565 //===----------------------------------------------------------------------===//
566 
567 unsigned MachinePointerInfo::getAddrSpace() const {
568   if (V.isNull()) return 0;
569 
570   if (V.is<const PseudoSourceValue*>())
571     return V.get<const PseudoSourceValue*>()->getAddressSpace();
572 
573   return cast<PointerType>(V.get<const Value*>()->getType())->getAddressSpace();
574 }
575 
576 bool MachinePointerInfo::isDereferenceable(unsigned Size, LLVMContext &C,
577                                            const DataLayout &DL) const {
578   if (!V.is<const Value*>())
579     return false;
580 
581   const Value *BasePtr = V.get<const Value*>();
582   if (BasePtr == nullptr)
583     return false;
584 
585   return isDereferenceableAndAlignedPointer(
586       BasePtr, 1, APInt(DL.getPointerSizeInBits(), Offset + Size), DL);
587 }
588 
589 MachinePointerInfo MachinePointerInfo::getConstantPool(MachineFunction &MF) {
590   return MachinePointerInfo(MF.getPSVManager().getConstantPool());
591 }
592 
593 MachinePointerInfo MachinePointerInfo::getFixedStack(MachineFunction &MF,
594                                                      int FI, int64_t Offset) {
595   return MachinePointerInfo(MF.getPSVManager().getFixedStack(FI), Offset);
596 }
597 
598 MachinePointerInfo MachinePointerInfo::getJumpTable(MachineFunction &MF) {
599   return MachinePointerInfo(MF.getPSVManager().getJumpTable());
600 }
601 
602 MachinePointerInfo MachinePointerInfo::getGOT(MachineFunction &MF) {
603   return MachinePointerInfo(MF.getPSVManager().getGOT());
604 }
605 
606 MachinePointerInfo MachinePointerInfo::getStack(MachineFunction &MF,
607                                                 int64_t Offset,
608                                                 uint8_t ID) {
609   return MachinePointerInfo(MF.getPSVManager().getStack(), Offset,ID);
610 }
611 
612 MachineMemOperand::MachineMemOperand(MachinePointerInfo ptrinfo, Flags f,
613                                      uint64_t s, unsigned int a,
614                                      const AAMDNodes &AAInfo,
615                                      const MDNode *Ranges,
616                                      SyncScope::ID SSID,
617                                      AtomicOrdering Ordering,
618                                      AtomicOrdering FailureOrdering)
619     : PtrInfo(ptrinfo), Size(s), FlagVals(f), BaseAlignLog2(Log2_32(a) + 1),
620       AAInfo(AAInfo), Ranges(Ranges) {
621   assert((PtrInfo.V.isNull() || PtrInfo.V.is<const PseudoSourceValue*>() ||
622           isa<PointerType>(PtrInfo.V.get<const Value*>()->getType())) &&
623          "invalid pointer value");
624   assert(getBaseAlignment() == a && "Alignment is not a power of 2!");
625   assert((isLoad() || isStore()) && "Not a load/store!");
626 
627   AtomicInfo.SSID = static_cast<unsigned>(SSID);
628   assert(getSyncScopeID() == SSID && "Value truncated");
629   AtomicInfo.Ordering = static_cast<unsigned>(Ordering);
630   assert(getOrdering() == Ordering && "Value truncated");
631   AtomicInfo.FailureOrdering = static_cast<unsigned>(FailureOrdering);
632   assert(getFailureOrdering() == FailureOrdering && "Value truncated");
633 }
634 
635 void MachineMemOperand::Profile(FoldingSetNodeID &ID) const {
636   ID.AddInteger(getOffset());
637   ID.AddInteger(Size);
638   ID.AddPointer(getOpaqueValue());
639   ID.AddInteger(getFlags());
640   ID.AddInteger(getBaseAlignment());
641 }
642 
643 void MachineMemOperand::refineAlignment(const MachineMemOperand *MMO) {
644   // The Value and Offset may differ due to CSE. But the flags and size
645   // should be the same.
646   assert(MMO->getFlags() == getFlags() && "Flags mismatch!");
647   assert(MMO->getSize() == getSize() && "Size mismatch!");
648 
649   if (MMO->getBaseAlignment() >= getBaseAlignment()) {
650     // Update the alignment value.
651     BaseAlignLog2 = Log2_32(MMO->getBaseAlignment()) + 1;
652     // Also update the base and offset, because the new alignment may
653     // not be applicable with the old ones.
654     PtrInfo = MMO->PtrInfo;
655   }
656 }
657 
658 uint64_t MachineMemOperand::getAlignment() const {
659   return MinAlign(getBaseAlignment(), getOffset());
660 }
661 
662 void MachineMemOperand::print(raw_ostream &OS) const {
663   ModuleSlotTracker DummyMST(nullptr);
664   print(OS, DummyMST);
665 }
666 void MachineMemOperand::print(raw_ostream &OS, ModuleSlotTracker &MST) const {
667   assert((isLoad() || isStore()) &&
668          "SV has to be a load, store or both.");
669 
670   if (isVolatile())
671     OS << "Volatile ";
672 
673   if (isLoad())
674     OS << "LD";
675   if (isStore())
676     OS << "ST";
677   OS << getSize();
678 
679   // Print the address information.
680   OS << "[";
681   if (const Value *V = getValue())
682     V->printAsOperand(OS, /*PrintType=*/false, MST);
683   else if (const PseudoSourceValue *PSV = getPseudoValue())
684     PSV->printCustom(OS);
685   else
686     OS << "<unknown>";
687 
688   unsigned AS = getAddrSpace();
689   if (AS != 0)
690     OS << "(addrspace=" << AS << ')';
691 
692   // If the alignment of the memory reference itself differs from the alignment
693   // of the base pointer, print the base alignment explicitly, next to the base
694   // pointer.
695   if (getBaseAlignment() != getAlignment())
696     OS << "(align=" << getBaseAlignment() << ")";
697 
698   if (getOffset() != 0)
699     OS << "+" << getOffset();
700   OS << "]";
701 
702   // Print the alignment of the reference.
703   if (getBaseAlignment() != getAlignment() || getBaseAlignment() != getSize())
704     OS << "(align=" << getAlignment() << ")";
705 
706   // Print TBAA info.
707   if (const MDNode *TBAAInfo = getAAInfo().TBAA) {
708     OS << "(tbaa=";
709     if (TBAAInfo->getNumOperands() > 0)
710       TBAAInfo->getOperand(0)->printAsOperand(OS, MST);
711     else
712       OS << "<unknown>";
713     OS << ")";
714   }
715 
716   // Print AA scope info.
717   if (const MDNode *ScopeInfo = getAAInfo().Scope) {
718     OS << "(alias.scope=";
719     if (ScopeInfo->getNumOperands() > 0)
720       for (unsigned i = 0, ie = ScopeInfo->getNumOperands(); i != ie; ++i) {
721         ScopeInfo->getOperand(i)->printAsOperand(OS, MST);
722         if (i != ie-1)
723           OS << ",";
724       }
725     else
726       OS << "<unknown>";
727     OS << ")";
728   }
729 
730   // Print AA noalias scope info.
731   if (const MDNode *NoAliasInfo = getAAInfo().NoAlias) {
732     OS << "(noalias=";
733     if (NoAliasInfo->getNumOperands() > 0)
734       for (unsigned i = 0, ie = NoAliasInfo->getNumOperands(); i != ie; ++i) {
735         NoAliasInfo->getOperand(i)->printAsOperand(OS, MST);
736         if (i != ie-1)
737           OS << ",";
738       }
739     else
740       OS << "<unknown>";
741     OS << ")";
742   }
743 
744   if (const MDNode *Ranges = getRanges()) {
745     unsigned NumRanges = Ranges->getNumOperands();
746     if (NumRanges != 0) {
747       OS << "(ranges=";
748 
749       for (unsigned I = 0; I != NumRanges; ++I) {
750         Ranges->getOperand(I)->printAsOperand(OS, MST);
751         if (I != NumRanges - 1)
752           OS << ',';
753       }
754 
755       OS << ')';
756     }
757   }
758 
759   if (isNonTemporal())
760     OS << "(nontemporal)";
761   if (isDereferenceable())
762     OS << "(dereferenceable)";
763   if (isInvariant())
764     OS << "(invariant)";
765   if (getFlags() & MOTargetFlag1)
766     OS << "(flag1)";
767   if (getFlags() & MOTargetFlag2)
768     OS << "(flag2)";
769   if (getFlags() & MOTargetFlag3)
770     OS << "(flag3)";
771 }
772 
773 //===----------------------------------------------------------------------===//
774 // MachineInstr Implementation
775 //===----------------------------------------------------------------------===//
776 
777 void MachineInstr::addImplicitDefUseOperands(MachineFunction &MF) {
778   if (MCID->ImplicitDefs)
779     for (const MCPhysReg *ImpDefs = MCID->getImplicitDefs(); *ImpDefs;
780            ++ImpDefs)
781       addOperand(MF, MachineOperand::CreateReg(*ImpDefs, true, true));
782   if (MCID->ImplicitUses)
783     for (const MCPhysReg *ImpUses = MCID->getImplicitUses(); *ImpUses;
784            ++ImpUses)
785       addOperand(MF, MachineOperand::CreateReg(*ImpUses, false, true));
786 }
787 
788 /// MachineInstr ctor - This constructor creates a MachineInstr and adds the
789 /// implicit operands. It reserves space for the number of operands specified by
790 /// the MCInstrDesc.
791 MachineInstr::MachineInstr(MachineFunction &MF, const MCInstrDesc &tid,
792                            DebugLoc dl, bool NoImp)
793     : MCID(&tid), debugLoc(std::move(dl)) {
794   assert(debugLoc.hasTrivialDestructor() && "Expected trivial destructor");
795 
796   // Reserve space for the expected number of operands.
797   if (unsigned NumOps = MCID->getNumOperands() +
798     MCID->getNumImplicitDefs() + MCID->getNumImplicitUses()) {
799     CapOperands = OperandCapacity::get(NumOps);
800     Operands = MF.allocateOperandArray(CapOperands);
801   }
802 
803   if (!NoImp)
804     addImplicitDefUseOperands(MF);
805 }
806 
807 /// MachineInstr ctor - Copies MachineInstr arg exactly
808 ///
809 MachineInstr::MachineInstr(MachineFunction &MF, const MachineInstr &MI)
810     : MCID(&MI.getDesc()), NumMemRefs(MI.NumMemRefs), MemRefs(MI.MemRefs),
811       debugLoc(MI.getDebugLoc()) {
812   assert(debugLoc.hasTrivialDestructor() && "Expected trivial destructor");
813 
814   CapOperands = OperandCapacity::get(MI.getNumOperands());
815   Operands = MF.allocateOperandArray(CapOperands);
816 
817   // Copy operands.
818   for (const MachineOperand &MO : MI.operands())
819     addOperand(MF, MO);
820 
821   // Copy all the sensible flags.
822   setFlags(MI.Flags);
823 }
824 
825 /// getRegInfo - If this instruction is embedded into a MachineFunction,
826 /// return the MachineRegisterInfo object for the current function, otherwise
827 /// return null.
828 MachineRegisterInfo *MachineInstr::getRegInfo() {
829   if (MachineBasicBlock *MBB = getParent())
830     return &MBB->getParent()->getRegInfo();
831   return nullptr;
832 }
833 
834 /// RemoveRegOperandsFromUseLists - Unlink all of the register operands in
835 /// this instruction from their respective use lists.  This requires that the
836 /// operands already be on their use lists.
837 void MachineInstr::RemoveRegOperandsFromUseLists(MachineRegisterInfo &MRI) {
838   for (MachineOperand &MO : operands())
839     if (MO.isReg())
840       MRI.removeRegOperandFromUseList(&MO);
841 }
842 
843 /// AddRegOperandsToUseLists - Add all of the register operands in
844 /// this instruction from their respective use lists.  This requires that the
845 /// operands not be on their use lists yet.
846 void MachineInstr::AddRegOperandsToUseLists(MachineRegisterInfo &MRI) {
847   for (MachineOperand &MO : operands())
848     if (MO.isReg())
849       MRI.addRegOperandToUseList(&MO);
850 }
851 
852 void MachineInstr::addOperand(const MachineOperand &Op) {
853   MachineBasicBlock *MBB = getParent();
854   assert(MBB && "Use MachineInstrBuilder to add operands to dangling instrs");
855   MachineFunction *MF = MBB->getParent();
856   assert(MF && "Use MachineInstrBuilder to add operands to dangling instrs");
857   addOperand(*MF, Op);
858 }
859 
860 /// Move NumOps MachineOperands from Src to Dst, with support for overlapping
861 /// ranges. If MRI is non-null also update use-def chains.
862 static void moveOperands(MachineOperand *Dst, MachineOperand *Src,
863                          unsigned NumOps, MachineRegisterInfo *MRI) {
864   if (MRI)
865     return MRI->moveOperands(Dst, Src, NumOps);
866 
867   // MachineOperand is a trivially copyable type so we can just use memmove.
868   std::memmove(Dst, Src, NumOps * sizeof(MachineOperand));
869 }
870 
871 /// addOperand - Add the specified operand to the instruction.  If it is an
872 /// implicit operand, it is added to the end of the operand list.  If it is
873 /// an explicit operand it is added at the end of the explicit operand list
874 /// (before the first implicit operand).
875 void MachineInstr::addOperand(MachineFunction &MF, const MachineOperand &Op) {
876   assert(MCID && "Cannot add operands before providing an instr descriptor");
877 
878   // Check if we're adding one of our existing operands.
879   if (&Op >= Operands && &Op < Operands + NumOperands) {
880     // This is unusual: MI->addOperand(MI->getOperand(i)).
881     // If adding Op requires reallocating or moving existing operands around,
882     // the Op reference could go stale. Support it by copying Op.
883     MachineOperand CopyOp(Op);
884     return addOperand(MF, CopyOp);
885   }
886 
887   // Find the insert location for the new operand.  Implicit registers go at
888   // the end, everything else goes before the implicit regs.
889   //
890   // FIXME: Allow mixed explicit and implicit operands on inline asm.
891   // InstrEmitter::EmitSpecialNode() is marking inline asm clobbers as
892   // implicit-defs, but they must not be moved around.  See the FIXME in
893   // InstrEmitter.cpp.
894   unsigned OpNo = getNumOperands();
895   bool isImpReg = Op.isReg() && Op.isImplicit();
896   if (!isImpReg && !isInlineAsm()) {
897     while (OpNo && Operands[OpNo-1].isReg() && Operands[OpNo-1].isImplicit()) {
898       --OpNo;
899       assert(!Operands[OpNo].isTied() && "Cannot move tied operands");
900     }
901   }
902 
903 #ifndef NDEBUG
904   bool isMetaDataOp = Op.getType() == MachineOperand::MO_Metadata;
905   // OpNo now points as the desired insertion point.  Unless this is a variadic
906   // instruction, only implicit regs are allowed beyond MCID->getNumOperands().
907   // RegMask operands go between the explicit and implicit operands.
908   assert((isImpReg || Op.isRegMask() || MCID->isVariadic() ||
909           OpNo < MCID->getNumOperands() || isMetaDataOp) &&
910          "Trying to add an operand to a machine instr that is already done!");
911 #endif
912 
913   MachineRegisterInfo *MRI = getRegInfo();
914 
915   // Determine if the Operands array needs to be reallocated.
916   // Save the old capacity and operand array.
917   OperandCapacity OldCap = CapOperands;
918   MachineOperand *OldOperands = Operands;
919   if (!OldOperands || OldCap.getSize() == getNumOperands()) {
920     CapOperands = OldOperands ? OldCap.getNext() : OldCap.get(1);
921     Operands = MF.allocateOperandArray(CapOperands);
922     // Move the operands before the insertion point.
923     if (OpNo)
924       moveOperands(Operands, OldOperands, OpNo, MRI);
925   }
926 
927   // Move the operands following the insertion point.
928   if (OpNo != NumOperands)
929     moveOperands(Operands + OpNo + 1, OldOperands + OpNo, NumOperands - OpNo,
930                  MRI);
931   ++NumOperands;
932 
933   // Deallocate the old operand array.
934   if (OldOperands != Operands && OldOperands)
935     MF.deallocateOperandArray(OldCap, OldOperands);
936 
937   // Copy Op into place. It still needs to be inserted into the MRI use lists.
938   MachineOperand *NewMO = new (Operands + OpNo) MachineOperand(Op);
939   NewMO->ParentMI = this;
940 
941   // When adding a register operand, tell MRI about it.
942   if (NewMO->isReg()) {
943     // Ensure isOnRegUseList() returns false, regardless of Op's status.
944     NewMO->Contents.Reg.Prev = nullptr;
945     // Ignore existing ties. This is not a property that can be copied.
946     NewMO->TiedTo = 0;
947     // Add the new operand to MRI, but only for instructions in an MBB.
948     if (MRI)
949       MRI->addRegOperandToUseList(NewMO);
950     // The MCID operand information isn't accurate until we start adding
951     // explicit operands. The implicit operands are added first, then the
952     // explicits are inserted before them.
953     if (!isImpReg) {
954       // Tie uses to defs as indicated in MCInstrDesc.
955       if (NewMO->isUse()) {
956         int DefIdx = MCID->getOperandConstraint(OpNo, MCOI::TIED_TO);
957         if (DefIdx != -1)
958           tieOperands(DefIdx, OpNo);
959       }
960       // If the register operand is flagged as early, mark the operand as such.
961       if (MCID->getOperandConstraint(OpNo, MCOI::EARLY_CLOBBER) != -1)
962         NewMO->setIsEarlyClobber(true);
963     }
964   }
965 }
966 
967 /// RemoveOperand - Erase an operand  from an instruction, leaving it with one
968 /// fewer operand than it started with.
969 ///
970 void MachineInstr::RemoveOperand(unsigned OpNo) {
971   assert(OpNo < getNumOperands() && "Invalid operand number");
972   untieRegOperand(OpNo);
973 
974 #ifndef NDEBUG
975   // Moving tied operands would break the ties.
976   for (unsigned i = OpNo + 1, e = getNumOperands(); i != e; ++i)
977     if (Operands[i].isReg())
978       assert(!Operands[i].isTied() && "Cannot move tied operands");
979 #endif
980 
981   MachineRegisterInfo *MRI = getRegInfo();
982   if (MRI && Operands[OpNo].isReg())
983     MRI->removeRegOperandFromUseList(Operands + OpNo);
984 
985   // Don't call the MachineOperand destructor. A lot of this code depends on
986   // MachineOperand having a trivial destructor anyway, and adding a call here
987   // wouldn't make it 'destructor-correct'.
988 
989   if (unsigned N = NumOperands - 1 - OpNo)
990     moveOperands(Operands + OpNo, Operands + OpNo + 1, N, MRI);
991   --NumOperands;
992 }
993 
994 /// addMemOperand - Add a MachineMemOperand to the machine instruction.
995 /// This function should be used only occasionally. The setMemRefs function
996 /// is the primary method for setting up a MachineInstr's MemRefs list.
997 void MachineInstr::addMemOperand(MachineFunction &MF,
998                                  MachineMemOperand *MO) {
999   mmo_iterator OldMemRefs = MemRefs;
1000   unsigned OldNumMemRefs = NumMemRefs;
1001 
1002   unsigned NewNum = NumMemRefs + 1;
1003   mmo_iterator NewMemRefs = MF.allocateMemRefsArray(NewNum);
1004 
1005   std::copy(OldMemRefs, OldMemRefs + OldNumMemRefs, NewMemRefs);
1006   NewMemRefs[NewNum - 1] = MO;
1007   setMemRefs(NewMemRefs, NewMemRefs + NewNum);
1008 }
1009 
1010 /// Check to see if the MMOs pointed to by the two MemRefs arrays are
1011 /// identical.
1012 static bool hasIdenticalMMOs(const MachineInstr &MI1, const MachineInstr &MI2) {
1013   auto I1 = MI1.memoperands_begin(), E1 = MI1.memoperands_end();
1014   auto I2 = MI2.memoperands_begin(), E2 = MI2.memoperands_end();
1015   if ((E1 - I1) != (E2 - I2))
1016     return false;
1017   for (; I1 != E1; ++I1, ++I2) {
1018     if (**I1 != **I2)
1019       return false;
1020   }
1021   return true;
1022 }
1023 
1024 std::pair<MachineInstr::mmo_iterator, unsigned>
1025 MachineInstr::mergeMemRefsWith(const MachineInstr& Other) {
1026 
1027   // If either of the incoming memrefs are empty, we must be conservative and
1028   // treat this as if we've exhausted our space for memrefs and dropped them.
1029   if (memoperands_empty() || Other.memoperands_empty())
1030     return std::make_pair(nullptr, 0);
1031 
1032   // If both instructions have identical memrefs, we don't need to merge them.
1033   // Since many instructions have a single memref, and we tend to merge things
1034   // like pairs of loads from the same location, this catches a large number of
1035   // cases in practice.
1036   if (hasIdenticalMMOs(*this, Other))
1037     return std::make_pair(MemRefs, NumMemRefs);
1038 
1039   // TODO: consider uniquing elements within the operand lists to reduce
1040   // space usage and fall back to conservative information less often.
1041   size_t CombinedNumMemRefs = NumMemRefs + Other.NumMemRefs;
1042 
1043   // If we don't have enough room to store this many memrefs, be conservative
1044   // and drop them.  Otherwise, we'd fail asserts when trying to add them to
1045   // the new instruction.
1046   if (CombinedNumMemRefs != uint8_t(CombinedNumMemRefs))
1047     return std::make_pair(nullptr, 0);
1048 
1049   MachineFunction *MF = getMF();
1050   mmo_iterator MemBegin = MF->allocateMemRefsArray(CombinedNumMemRefs);
1051   mmo_iterator MemEnd = std::copy(memoperands_begin(), memoperands_end(),
1052                                   MemBegin);
1053   MemEnd = std::copy(Other.memoperands_begin(), Other.memoperands_end(),
1054                      MemEnd);
1055   assert(MemEnd - MemBegin == (ptrdiff_t)CombinedNumMemRefs &&
1056          "missing memrefs");
1057 
1058   return std::make_pair(MemBegin, CombinedNumMemRefs);
1059 }
1060 
1061 bool MachineInstr::hasPropertyInBundle(unsigned Mask, QueryType Type) const {
1062   assert(!isBundledWithPred() && "Must be called on bundle header");
1063   for (MachineBasicBlock::const_instr_iterator MII = getIterator();; ++MII) {
1064     if (MII->getDesc().getFlags() & Mask) {
1065       if (Type == AnyInBundle)
1066         return true;
1067     } else {
1068       if (Type == AllInBundle && !MII->isBundle())
1069         return false;
1070     }
1071     // This was the last instruction in the bundle.
1072     if (!MII->isBundledWithSucc())
1073       return Type == AllInBundle;
1074   }
1075 }
1076 
1077 bool MachineInstr::isIdenticalTo(const MachineInstr &Other,
1078                                  MICheckType Check) const {
1079   // If opcodes or number of operands are not the same then the two
1080   // instructions are obviously not identical.
1081   if (Other.getOpcode() != getOpcode() ||
1082       Other.getNumOperands() != getNumOperands())
1083     return false;
1084 
1085   if (isBundle()) {
1086     // We have passed the test above that both instructions have the same
1087     // opcode, so we know that both instructions are bundles here. Let's compare
1088     // MIs inside the bundle.
1089     assert(Other.isBundle() && "Expected that both instructions are bundles.");
1090     MachineBasicBlock::const_instr_iterator I1 = getIterator();
1091     MachineBasicBlock::const_instr_iterator I2 = Other.getIterator();
1092     // Loop until we analysed the last intruction inside at least one of the
1093     // bundles.
1094     while (I1->isBundledWithSucc() && I2->isBundledWithSucc()) {
1095       ++I1;
1096       ++I2;
1097       if (!I1->isIdenticalTo(*I2, Check))
1098         return false;
1099     }
1100     // If we've reached the end of just one of the two bundles, but not both,
1101     // the instructions are not identical.
1102     if (I1->isBundledWithSucc() || I2->isBundledWithSucc())
1103       return false;
1104   }
1105 
1106   // Check operands to make sure they match.
1107   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
1108     const MachineOperand &MO = getOperand(i);
1109     const MachineOperand &OMO = Other.getOperand(i);
1110     if (!MO.isReg()) {
1111       if (!MO.isIdenticalTo(OMO))
1112         return false;
1113       continue;
1114     }
1115 
1116     // Clients may or may not want to ignore defs when testing for equality.
1117     // For example, machine CSE pass only cares about finding common
1118     // subexpressions, so it's safe to ignore virtual register defs.
1119     if (MO.isDef()) {
1120       if (Check == IgnoreDefs)
1121         continue;
1122       else if (Check == IgnoreVRegDefs) {
1123         if (!TargetRegisterInfo::isVirtualRegister(MO.getReg()) ||
1124             !TargetRegisterInfo::isVirtualRegister(OMO.getReg()))
1125           if (!MO.isIdenticalTo(OMO))
1126             return false;
1127       } else {
1128         if (!MO.isIdenticalTo(OMO))
1129           return false;
1130         if (Check == CheckKillDead && MO.isDead() != OMO.isDead())
1131           return false;
1132       }
1133     } else {
1134       if (!MO.isIdenticalTo(OMO))
1135         return false;
1136       if (Check == CheckKillDead && MO.isKill() != OMO.isKill())
1137         return false;
1138     }
1139   }
1140   // If DebugLoc does not match then two dbg.values are not identical.
1141   if (isDebugValue())
1142     if (getDebugLoc() && Other.getDebugLoc() &&
1143         getDebugLoc() != Other.getDebugLoc())
1144       return false;
1145   return true;
1146 }
1147 
1148 const MachineFunction *MachineInstr::getMF() const {
1149   return getParent()->getParent();
1150 }
1151 
1152 MachineInstr *MachineInstr::removeFromParent() {
1153   assert(getParent() && "Not embedded in a basic block!");
1154   return getParent()->remove(this);
1155 }
1156 
1157 MachineInstr *MachineInstr::removeFromBundle() {
1158   assert(getParent() && "Not embedded in a basic block!");
1159   return getParent()->remove_instr(this);
1160 }
1161 
1162 void MachineInstr::eraseFromParent() {
1163   assert(getParent() && "Not embedded in a basic block!");
1164   getParent()->erase(this);
1165 }
1166 
1167 void MachineInstr::eraseFromParentAndMarkDBGValuesForRemoval() {
1168   assert(getParent() && "Not embedded in a basic block!");
1169   MachineBasicBlock *MBB = getParent();
1170   MachineFunction *MF = MBB->getParent();
1171   assert(MF && "Not embedded in a function!");
1172 
1173   MachineInstr *MI = (MachineInstr *)this;
1174   MachineRegisterInfo &MRI = MF->getRegInfo();
1175 
1176   for (const MachineOperand &MO : MI->operands()) {
1177     if (!MO.isReg() || !MO.isDef())
1178       continue;
1179     unsigned Reg = MO.getReg();
1180     if (!TargetRegisterInfo::isVirtualRegister(Reg))
1181       continue;
1182     MRI.markUsesInDebugValueAsUndef(Reg);
1183   }
1184   MI->eraseFromParent();
1185 }
1186 
1187 void MachineInstr::eraseFromBundle() {
1188   assert(getParent() && "Not embedded in a basic block!");
1189   getParent()->erase_instr(this);
1190 }
1191 
1192 /// getNumExplicitOperands - Returns the number of non-implicit operands.
1193 ///
1194 unsigned MachineInstr::getNumExplicitOperands() const {
1195   unsigned NumOperands = MCID->getNumOperands();
1196   if (!MCID->isVariadic())
1197     return NumOperands;
1198 
1199   for (unsigned i = NumOperands, e = getNumOperands(); i != e; ++i) {
1200     const MachineOperand &MO = getOperand(i);
1201     if (!MO.isReg() || !MO.isImplicit())
1202       NumOperands++;
1203   }
1204   return NumOperands;
1205 }
1206 
1207 void MachineInstr::bundleWithPred() {
1208   assert(!isBundledWithPred() && "MI is already bundled with its predecessor");
1209   setFlag(BundledPred);
1210   MachineBasicBlock::instr_iterator Pred = getIterator();
1211   --Pred;
1212   assert(!Pred->isBundledWithSucc() && "Inconsistent bundle flags");
1213   Pred->setFlag(BundledSucc);
1214 }
1215 
1216 void MachineInstr::bundleWithSucc() {
1217   assert(!isBundledWithSucc() && "MI is already bundled with its successor");
1218   setFlag(BundledSucc);
1219   MachineBasicBlock::instr_iterator Succ = getIterator();
1220   ++Succ;
1221   assert(!Succ->isBundledWithPred() && "Inconsistent bundle flags");
1222   Succ->setFlag(BundledPred);
1223 }
1224 
1225 void MachineInstr::unbundleFromPred() {
1226   assert(isBundledWithPred() && "MI isn't bundled with its predecessor");
1227   clearFlag(BundledPred);
1228   MachineBasicBlock::instr_iterator Pred = getIterator();
1229   --Pred;
1230   assert(Pred->isBundledWithSucc() && "Inconsistent bundle flags");
1231   Pred->clearFlag(BundledSucc);
1232 }
1233 
1234 void MachineInstr::unbundleFromSucc() {
1235   assert(isBundledWithSucc() && "MI isn't bundled with its successor");
1236   clearFlag(BundledSucc);
1237   MachineBasicBlock::instr_iterator Succ = getIterator();
1238   ++Succ;
1239   assert(Succ->isBundledWithPred() && "Inconsistent bundle flags");
1240   Succ->clearFlag(BundledPred);
1241 }
1242 
1243 bool MachineInstr::isStackAligningInlineAsm() const {
1244   if (isInlineAsm()) {
1245     unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
1246     if (ExtraInfo & InlineAsm::Extra_IsAlignStack)
1247       return true;
1248   }
1249   return false;
1250 }
1251 
1252 InlineAsm::AsmDialect MachineInstr::getInlineAsmDialect() const {
1253   assert(isInlineAsm() && "getInlineAsmDialect() only works for inline asms!");
1254   unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
1255   return InlineAsm::AsmDialect((ExtraInfo & InlineAsm::Extra_AsmDialect) != 0);
1256 }
1257 
1258 int MachineInstr::findInlineAsmFlagIdx(unsigned OpIdx,
1259                                        unsigned *GroupNo) const {
1260   assert(isInlineAsm() && "Expected an inline asm instruction");
1261   assert(OpIdx < getNumOperands() && "OpIdx out of range");
1262 
1263   // Ignore queries about the initial operands.
1264   if (OpIdx < InlineAsm::MIOp_FirstOperand)
1265     return -1;
1266 
1267   unsigned Group = 0;
1268   unsigned NumOps;
1269   for (unsigned i = InlineAsm::MIOp_FirstOperand, e = getNumOperands(); i < e;
1270        i += NumOps) {
1271     const MachineOperand &FlagMO = getOperand(i);
1272     // If we reach the implicit register operands, stop looking.
1273     if (!FlagMO.isImm())
1274       return -1;
1275     NumOps = 1 + InlineAsm::getNumOperandRegisters(FlagMO.getImm());
1276     if (i + NumOps > OpIdx) {
1277       if (GroupNo)
1278         *GroupNo = Group;
1279       return i;
1280     }
1281     ++Group;
1282   }
1283   return -1;
1284 }
1285 
1286 const DILocalVariable *MachineInstr::getDebugVariable() const {
1287   assert(isDebugValue() && "not a DBG_VALUE");
1288   return cast<DILocalVariable>(getOperand(2).getMetadata());
1289 }
1290 
1291 const DIExpression *MachineInstr::getDebugExpression() const {
1292   assert(isDebugValue() && "not a DBG_VALUE");
1293   return cast<DIExpression>(getOperand(3).getMetadata());
1294 }
1295 
1296 const TargetRegisterClass*
1297 MachineInstr::getRegClassConstraint(unsigned OpIdx,
1298                                     const TargetInstrInfo *TII,
1299                                     const TargetRegisterInfo *TRI) const {
1300   assert(getParent() && "Can't have an MBB reference here!");
1301   assert(getMF() && "Can't have an MF reference here!");
1302   const MachineFunction &MF = *getMF();
1303 
1304   // Most opcodes have fixed constraints in their MCInstrDesc.
1305   if (!isInlineAsm())
1306     return TII->getRegClass(getDesc(), OpIdx, TRI, MF);
1307 
1308   if (!getOperand(OpIdx).isReg())
1309     return nullptr;
1310 
1311   // For tied uses on inline asm, get the constraint from the def.
1312   unsigned DefIdx;
1313   if (getOperand(OpIdx).isUse() && isRegTiedToDefOperand(OpIdx, &DefIdx))
1314     OpIdx = DefIdx;
1315 
1316   // Inline asm stores register class constraints in the flag word.
1317   int FlagIdx = findInlineAsmFlagIdx(OpIdx);
1318   if (FlagIdx < 0)
1319     return nullptr;
1320 
1321   unsigned Flag = getOperand(FlagIdx).getImm();
1322   unsigned RCID;
1323   if ((InlineAsm::getKind(Flag) == InlineAsm::Kind_RegUse ||
1324        InlineAsm::getKind(Flag) == InlineAsm::Kind_RegDef ||
1325        InlineAsm::getKind(Flag) == InlineAsm::Kind_RegDefEarlyClobber) &&
1326       InlineAsm::hasRegClassConstraint(Flag, RCID))
1327     return TRI->getRegClass(RCID);
1328 
1329   // Assume that all registers in a memory operand are pointers.
1330   if (InlineAsm::getKind(Flag) == InlineAsm::Kind_Mem)
1331     return TRI->getPointerRegClass(MF);
1332 
1333   return nullptr;
1334 }
1335 
1336 const TargetRegisterClass *MachineInstr::getRegClassConstraintEffectForVReg(
1337     unsigned Reg, const TargetRegisterClass *CurRC, const TargetInstrInfo *TII,
1338     const TargetRegisterInfo *TRI, bool ExploreBundle) const {
1339   // Check every operands inside the bundle if we have
1340   // been asked to.
1341   if (ExploreBundle)
1342     for (ConstMIBundleOperands OpndIt(*this); OpndIt.isValid() && CurRC;
1343          ++OpndIt)
1344       CurRC = OpndIt->getParent()->getRegClassConstraintEffectForVRegImpl(
1345           OpndIt.getOperandNo(), Reg, CurRC, TII, TRI);
1346   else
1347     // Otherwise, just check the current operands.
1348     for (unsigned i = 0, e = NumOperands; i < e && CurRC; ++i)
1349       CurRC = getRegClassConstraintEffectForVRegImpl(i, Reg, CurRC, TII, TRI);
1350   return CurRC;
1351 }
1352 
1353 const TargetRegisterClass *MachineInstr::getRegClassConstraintEffectForVRegImpl(
1354     unsigned OpIdx, unsigned Reg, const TargetRegisterClass *CurRC,
1355     const TargetInstrInfo *TII, const TargetRegisterInfo *TRI) const {
1356   assert(CurRC && "Invalid initial register class");
1357   // Check if Reg is constrained by some of its use/def from MI.
1358   const MachineOperand &MO = getOperand(OpIdx);
1359   if (!MO.isReg() || MO.getReg() != Reg)
1360     return CurRC;
1361   // If yes, accumulate the constraints through the operand.
1362   return getRegClassConstraintEffect(OpIdx, CurRC, TII, TRI);
1363 }
1364 
1365 const TargetRegisterClass *MachineInstr::getRegClassConstraintEffect(
1366     unsigned OpIdx, const TargetRegisterClass *CurRC,
1367     const TargetInstrInfo *TII, const TargetRegisterInfo *TRI) const {
1368   const TargetRegisterClass *OpRC = getRegClassConstraint(OpIdx, TII, TRI);
1369   const MachineOperand &MO = getOperand(OpIdx);
1370   assert(MO.isReg() &&
1371          "Cannot get register constraints for non-register operand");
1372   assert(CurRC && "Invalid initial register class");
1373   if (unsigned SubIdx = MO.getSubReg()) {
1374     if (OpRC)
1375       CurRC = TRI->getMatchingSuperRegClass(CurRC, OpRC, SubIdx);
1376     else
1377       CurRC = TRI->getSubClassWithSubReg(CurRC, SubIdx);
1378   } else if (OpRC)
1379     CurRC = TRI->getCommonSubClass(CurRC, OpRC);
1380   return CurRC;
1381 }
1382 
1383 /// Return the number of instructions inside the MI bundle, not counting the
1384 /// header instruction.
1385 unsigned MachineInstr::getBundleSize() const {
1386   MachineBasicBlock::const_instr_iterator I = getIterator();
1387   unsigned Size = 0;
1388   while (I->isBundledWithSucc()) {
1389     ++Size;
1390     ++I;
1391   }
1392   return Size;
1393 }
1394 
1395 /// Returns true if the MachineInstr has an implicit-use operand of exactly
1396 /// the given register (not considering sub/super-registers).
1397 bool MachineInstr::hasRegisterImplicitUseOperand(unsigned Reg) const {
1398   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
1399     const MachineOperand &MO = getOperand(i);
1400     if (MO.isReg() && MO.isUse() && MO.isImplicit() && MO.getReg() == Reg)
1401       return true;
1402   }
1403   return false;
1404 }
1405 
1406 /// findRegisterUseOperandIdx() - Returns the MachineOperand that is a use of
1407 /// the specific register or -1 if it is not found. It further tightens
1408 /// the search criteria to a use that kills the register if isKill is true.
1409 int MachineInstr::findRegisterUseOperandIdx(
1410     unsigned Reg, bool isKill, const TargetRegisterInfo *TRI) const {
1411   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
1412     const MachineOperand &MO = getOperand(i);
1413     if (!MO.isReg() || !MO.isUse())
1414       continue;
1415     unsigned MOReg = MO.getReg();
1416     if (!MOReg)
1417       continue;
1418     if (MOReg == Reg || (TRI && TargetRegisterInfo::isPhysicalRegister(MOReg) &&
1419                          TargetRegisterInfo::isPhysicalRegister(Reg) &&
1420                          TRI->isSubRegister(MOReg, Reg)))
1421       if (!isKill || MO.isKill())
1422         return i;
1423   }
1424   return -1;
1425 }
1426 
1427 /// readsWritesVirtualRegister - Return a pair of bools (reads, writes)
1428 /// indicating if this instruction reads or writes Reg. This also considers
1429 /// partial defines.
1430 std::pair<bool,bool>
1431 MachineInstr::readsWritesVirtualRegister(unsigned Reg,
1432                                          SmallVectorImpl<unsigned> *Ops) const {
1433   bool PartDef = false; // Partial redefine.
1434   bool FullDef = false; // Full define.
1435   bool Use = false;
1436 
1437   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
1438     const MachineOperand &MO = getOperand(i);
1439     if (!MO.isReg() || MO.getReg() != Reg)
1440       continue;
1441     if (Ops)
1442       Ops->push_back(i);
1443     if (MO.isUse())
1444       Use |= !MO.isUndef();
1445     else if (MO.getSubReg() && !MO.isUndef())
1446       // A partial <def,undef> doesn't count as reading the register.
1447       PartDef = true;
1448     else
1449       FullDef = true;
1450   }
1451   // A partial redefine uses Reg unless there is also a full define.
1452   return std::make_pair(Use || (PartDef && !FullDef), PartDef || FullDef);
1453 }
1454 
1455 /// findRegisterDefOperandIdx() - Returns the operand index that is a def of
1456 /// the specified register or -1 if it is not found. If isDead is true, defs
1457 /// that are not dead are skipped. If TargetRegisterInfo is non-null, then it
1458 /// also checks if there is a def of a super-register.
1459 int
1460 MachineInstr::findRegisterDefOperandIdx(unsigned Reg, bool isDead, bool Overlap,
1461                                         const TargetRegisterInfo *TRI) const {
1462   bool isPhys = TargetRegisterInfo::isPhysicalRegister(Reg);
1463   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
1464     const MachineOperand &MO = getOperand(i);
1465     // Accept regmask operands when Overlap is set.
1466     // Ignore them when looking for a specific def operand (Overlap == false).
1467     if (isPhys && Overlap && MO.isRegMask() && MO.clobbersPhysReg(Reg))
1468       return i;
1469     if (!MO.isReg() || !MO.isDef())
1470       continue;
1471     unsigned MOReg = MO.getReg();
1472     bool Found = (MOReg == Reg);
1473     if (!Found && TRI && isPhys &&
1474         TargetRegisterInfo::isPhysicalRegister(MOReg)) {
1475       if (Overlap)
1476         Found = TRI->regsOverlap(MOReg, Reg);
1477       else
1478         Found = TRI->isSubRegister(MOReg, Reg);
1479     }
1480     if (Found && (!isDead || MO.isDead()))
1481       return i;
1482   }
1483   return -1;
1484 }
1485 
1486 /// findFirstPredOperandIdx() - Find the index of the first operand in the
1487 /// operand list that is used to represent the predicate. It returns -1 if
1488 /// none is found.
1489 int MachineInstr::findFirstPredOperandIdx() const {
1490   // Don't call MCID.findFirstPredOperandIdx() because this variant
1491   // is sometimes called on an instruction that's not yet complete, and
1492   // so the number of operands is less than the MCID indicates. In
1493   // particular, the PTX target does this.
1494   const MCInstrDesc &MCID = getDesc();
1495   if (MCID.isPredicable()) {
1496     for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
1497       if (MCID.OpInfo[i].isPredicate())
1498         return i;
1499   }
1500 
1501   return -1;
1502 }
1503 
1504 // MachineOperand::TiedTo is 4 bits wide.
1505 const unsigned TiedMax = 15;
1506 
1507 /// tieOperands - Mark operands at DefIdx and UseIdx as tied to each other.
1508 ///
1509 /// Use and def operands can be tied together, indicated by a non-zero TiedTo
1510 /// field. TiedTo can have these values:
1511 ///
1512 /// 0:              Operand is not tied to anything.
1513 /// 1 to TiedMax-1: Tied to getOperand(TiedTo-1).
1514 /// TiedMax:        Tied to an operand >= TiedMax-1.
1515 ///
1516 /// The tied def must be one of the first TiedMax operands on a normal
1517 /// instruction. INLINEASM instructions allow more tied defs.
1518 ///
1519 void MachineInstr::tieOperands(unsigned DefIdx, unsigned UseIdx) {
1520   MachineOperand &DefMO = getOperand(DefIdx);
1521   MachineOperand &UseMO = getOperand(UseIdx);
1522   assert(DefMO.isDef() && "DefIdx must be a def operand");
1523   assert(UseMO.isUse() && "UseIdx must be a use operand");
1524   assert(!DefMO.isTied() && "Def is already tied to another use");
1525   assert(!UseMO.isTied() && "Use is already tied to another def");
1526 
1527   if (DefIdx < TiedMax)
1528     UseMO.TiedTo = DefIdx + 1;
1529   else {
1530     // Inline asm can use the group descriptors to find tied operands, but on
1531     // normal instruction, the tied def must be within the first TiedMax
1532     // operands.
1533     assert(isInlineAsm() && "DefIdx out of range");
1534     UseMO.TiedTo = TiedMax;
1535   }
1536 
1537   // UseIdx can be out of range, we'll search for it in findTiedOperandIdx().
1538   DefMO.TiedTo = std::min(UseIdx + 1, TiedMax);
1539 }
1540 
1541 /// Given the index of a tied register operand, find the operand it is tied to.
1542 /// Defs are tied to uses and vice versa. Returns the index of the tied operand
1543 /// which must exist.
1544 unsigned MachineInstr::findTiedOperandIdx(unsigned OpIdx) const {
1545   const MachineOperand &MO = getOperand(OpIdx);
1546   assert(MO.isTied() && "Operand isn't tied");
1547 
1548   // Normally TiedTo is in range.
1549   if (MO.TiedTo < TiedMax)
1550     return MO.TiedTo - 1;
1551 
1552   // Uses on normal instructions can be out of range.
1553   if (!isInlineAsm()) {
1554     // Normal tied defs must be in the 0..TiedMax-1 range.
1555     if (MO.isUse())
1556       return TiedMax - 1;
1557     // MO is a def. Search for the tied use.
1558     for (unsigned i = TiedMax - 1, e = getNumOperands(); i != e; ++i) {
1559       const MachineOperand &UseMO = getOperand(i);
1560       if (UseMO.isReg() && UseMO.isUse() && UseMO.TiedTo == OpIdx + 1)
1561         return i;
1562     }
1563     llvm_unreachable("Can't find tied use");
1564   }
1565 
1566   // Now deal with inline asm by parsing the operand group descriptor flags.
1567   // Find the beginning of each operand group.
1568   SmallVector<unsigned, 8> GroupIdx;
1569   unsigned OpIdxGroup = ~0u;
1570   unsigned NumOps;
1571   for (unsigned i = InlineAsm::MIOp_FirstOperand, e = getNumOperands(); i < e;
1572        i += NumOps) {
1573     const MachineOperand &FlagMO = getOperand(i);
1574     assert(FlagMO.isImm() && "Invalid tied operand on inline asm");
1575     unsigned CurGroup = GroupIdx.size();
1576     GroupIdx.push_back(i);
1577     NumOps = 1 + InlineAsm::getNumOperandRegisters(FlagMO.getImm());
1578     // OpIdx belongs to this operand group.
1579     if (OpIdx > i && OpIdx < i + NumOps)
1580       OpIdxGroup = CurGroup;
1581     unsigned TiedGroup;
1582     if (!InlineAsm::isUseOperandTiedToDef(FlagMO.getImm(), TiedGroup))
1583       continue;
1584     // Operands in this group are tied to operands in TiedGroup which must be
1585     // earlier. Find the number of operands between the two groups.
1586     unsigned Delta = i - GroupIdx[TiedGroup];
1587 
1588     // OpIdx is a use tied to TiedGroup.
1589     if (OpIdxGroup == CurGroup)
1590       return OpIdx - Delta;
1591 
1592     // OpIdx is a def tied to this use group.
1593     if (OpIdxGroup == TiedGroup)
1594       return OpIdx + Delta;
1595   }
1596   llvm_unreachable("Invalid tied operand on inline asm");
1597 }
1598 
1599 /// clearKillInfo - Clears kill flags on all operands.
1600 ///
1601 void MachineInstr::clearKillInfo() {
1602   for (MachineOperand &MO : operands()) {
1603     if (MO.isReg() && MO.isUse())
1604       MO.setIsKill(false);
1605   }
1606 }
1607 
1608 void MachineInstr::substituteRegister(unsigned FromReg,
1609                                       unsigned ToReg,
1610                                       unsigned SubIdx,
1611                                       const TargetRegisterInfo &RegInfo) {
1612   if (TargetRegisterInfo::isPhysicalRegister(ToReg)) {
1613     if (SubIdx)
1614       ToReg = RegInfo.getSubReg(ToReg, SubIdx);
1615     for (MachineOperand &MO : operands()) {
1616       if (!MO.isReg() || MO.getReg() != FromReg)
1617         continue;
1618       MO.substPhysReg(ToReg, RegInfo);
1619     }
1620   } else {
1621     for (MachineOperand &MO : operands()) {
1622       if (!MO.isReg() || MO.getReg() != FromReg)
1623         continue;
1624       MO.substVirtReg(ToReg, SubIdx, RegInfo);
1625     }
1626   }
1627 }
1628 
1629 /// isSafeToMove - Return true if it is safe to move this instruction. If
1630 /// SawStore is set to true, it means that there is a store (or call) between
1631 /// the instruction's location and its intended destination.
1632 bool MachineInstr::isSafeToMove(AliasAnalysis *AA, bool &SawStore) const {
1633   // Ignore stuff that we obviously can't move.
1634   //
1635   // Treat volatile loads as stores. This is not strictly necessary for
1636   // volatiles, but it is required for atomic loads. It is not allowed to move
1637   // a load across an atomic load with Ordering > Monotonic.
1638   if (mayStore() || isCall() || isPHI() ||
1639       (mayLoad() && hasOrderedMemoryRef())) {
1640     SawStore = true;
1641     return false;
1642   }
1643 
1644   if (isPosition() || isDebugValue() || isTerminator() ||
1645       hasUnmodeledSideEffects())
1646     return false;
1647 
1648   // See if this instruction does a load.  If so, we have to guarantee that the
1649   // loaded value doesn't change between the load and the its intended
1650   // destination. The check for isInvariantLoad gives the targe the chance to
1651   // classify the load as always returning a constant, e.g. a constant pool
1652   // load.
1653   if (mayLoad() && !isDereferenceableInvariantLoad(AA))
1654     // Otherwise, this is a real load.  If there is a store between the load and
1655     // end of block, we can't move it.
1656     return !SawStore;
1657 
1658   return true;
1659 }
1660 
1661 bool MachineInstr::mayAlias(AliasAnalysis *AA, MachineInstr &Other,
1662                             bool UseTBAA) {
1663   const MachineFunction *MF = getMF();
1664   const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
1665   const MachineFrameInfo &MFI = MF->getFrameInfo();
1666 
1667   // If neither instruction stores to memory, they can't alias in any
1668   // meaningful way, even if they read from the same address.
1669   if (!mayStore() && !Other.mayStore())
1670     return false;
1671 
1672   // Let the target decide if memory accesses cannot possibly overlap.
1673   if (TII->areMemAccessesTriviallyDisjoint(*this, Other, AA))
1674     return false;
1675 
1676   // FIXME: Need to handle multiple memory operands to support all targets.
1677   if (!hasOneMemOperand() || !Other.hasOneMemOperand())
1678     return true;
1679 
1680   MachineMemOperand *MMOa = *memoperands_begin();
1681   MachineMemOperand *MMOb = *Other.memoperands_begin();
1682 
1683   // The following interface to AA is fashioned after DAGCombiner::isAlias
1684   // and operates with MachineMemOperand offset with some important
1685   // assumptions:
1686   //   - LLVM fundamentally assumes flat address spaces.
1687   //   - MachineOperand offset can *only* result from legalization and
1688   //     cannot affect queries other than the trivial case of overlap
1689   //     checking.
1690   //   - These offsets never wrap and never step outside
1691   //     of allocated objects.
1692   //   - There should never be any negative offsets here.
1693   //
1694   // FIXME: Modify API to hide this math from "user"
1695   // Even before we go to AA we can reason locally about some
1696   // memory objects. It can save compile time, and possibly catch some
1697   // corner cases not currently covered.
1698 
1699   int64_t OffsetA = MMOa->getOffset();
1700   int64_t OffsetB = MMOb->getOffset();
1701 
1702   int64_t MinOffset = std::min(OffsetA, OffsetB);
1703   int64_t WidthA = MMOa->getSize();
1704   int64_t WidthB = MMOb->getSize();
1705   const Value *ValA = MMOa->getValue();
1706   const Value *ValB = MMOb->getValue();
1707   bool SameVal = (ValA && ValB && (ValA == ValB));
1708   if (!SameVal) {
1709     const PseudoSourceValue *PSVa = MMOa->getPseudoValue();
1710     const PseudoSourceValue *PSVb = MMOb->getPseudoValue();
1711     if (PSVa && ValB && !PSVa->mayAlias(&MFI))
1712       return false;
1713     if (PSVb && ValA && !PSVb->mayAlias(&MFI))
1714       return false;
1715     if (PSVa && PSVb && (PSVa == PSVb))
1716       SameVal = true;
1717   }
1718 
1719   if (SameVal) {
1720     int64_t MaxOffset = std::max(OffsetA, OffsetB);
1721     int64_t LowWidth = (MinOffset == OffsetA) ? WidthA : WidthB;
1722     return (MinOffset + LowWidth > MaxOffset);
1723   }
1724 
1725   if (!AA)
1726     return true;
1727 
1728   if (!ValA || !ValB)
1729     return true;
1730 
1731   assert((OffsetA >= 0) && "Negative MachineMemOperand offset");
1732   assert((OffsetB >= 0) && "Negative MachineMemOperand offset");
1733 
1734   int64_t Overlapa = WidthA + OffsetA - MinOffset;
1735   int64_t Overlapb = WidthB + OffsetB - MinOffset;
1736 
1737   AliasResult AAResult = AA->alias(
1738       MemoryLocation(ValA, Overlapa,
1739                      UseTBAA ? MMOa->getAAInfo() : AAMDNodes()),
1740       MemoryLocation(ValB, Overlapb,
1741                      UseTBAA ? MMOb->getAAInfo() : AAMDNodes()));
1742 
1743   return (AAResult != NoAlias);
1744 }
1745 
1746 /// hasOrderedMemoryRef - Return true if this instruction may have an ordered
1747 /// or volatile memory reference, or if the information describing the memory
1748 /// reference is not available. Return false if it is known to have no ordered
1749 /// memory references.
1750 bool MachineInstr::hasOrderedMemoryRef() const {
1751   // An instruction known never to access memory won't have a volatile access.
1752   if (!mayStore() &&
1753       !mayLoad() &&
1754       !isCall() &&
1755       !hasUnmodeledSideEffects())
1756     return false;
1757 
1758   // Otherwise, if the instruction has no memory reference information,
1759   // conservatively assume it wasn't preserved.
1760   if (memoperands_empty())
1761     return true;
1762 
1763   // Check if any of our memory operands are ordered.
1764   return llvm::any_of(memoperands(), [](const MachineMemOperand *MMO) {
1765     return !MMO->isUnordered();
1766   });
1767 }
1768 
1769 /// isDereferenceableInvariantLoad - Return true if this instruction will never
1770 /// trap and is loading from a location whose value is invariant across a run of
1771 /// this function.
1772 bool MachineInstr::isDereferenceableInvariantLoad(AliasAnalysis *AA) const {
1773   // If the instruction doesn't load at all, it isn't an invariant load.
1774   if (!mayLoad())
1775     return false;
1776 
1777   // If the instruction has lost its memoperands, conservatively assume that
1778   // it may not be an invariant load.
1779   if (memoperands_empty())
1780     return false;
1781 
1782   const MachineFrameInfo &MFI = getParent()->getParent()->getFrameInfo();
1783 
1784   for (MachineMemOperand *MMO : memoperands()) {
1785     if (MMO->isVolatile()) return false;
1786     if (MMO->isStore()) return false;
1787     if (MMO->isInvariant() && MMO->isDereferenceable())
1788       continue;
1789 
1790     // A load from a constant PseudoSourceValue is invariant.
1791     if (const PseudoSourceValue *PSV = MMO->getPseudoValue())
1792       if (PSV->isConstant(&MFI))
1793         continue;
1794 
1795     if (const Value *V = MMO->getValue()) {
1796       // If we have an AliasAnalysis, ask it whether the memory is constant.
1797       if (AA &&
1798           AA->pointsToConstantMemory(
1799               MemoryLocation(V, MMO->getSize(), MMO->getAAInfo())))
1800         continue;
1801     }
1802 
1803     // Otherwise assume conservatively.
1804     return false;
1805   }
1806 
1807   // Everything checks out.
1808   return true;
1809 }
1810 
1811 /// isConstantValuePHI - If the specified instruction is a PHI that always
1812 /// merges together the same virtual register, return the register, otherwise
1813 /// return 0.
1814 unsigned MachineInstr::isConstantValuePHI() const {
1815   if (!isPHI())
1816     return 0;
1817   assert(getNumOperands() >= 3 &&
1818          "It's illegal to have a PHI without source operands");
1819 
1820   unsigned Reg = getOperand(1).getReg();
1821   for (unsigned i = 3, e = getNumOperands(); i < e; i += 2)
1822     if (getOperand(i).getReg() != Reg)
1823       return 0;
1824   return Reg;
1825 }
1826 
1827 bool MachineInstr::hasUnmodeledSideEffects() const {
1828   if (hasProperty(MCID::UnmodeledSideEffects))
1829     return true;
1830   if (isInlineAsm()) {
1831     unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
1832     if (ExtraInfo & InlineAsm::Extra_HasSideEffects)
1833       return true;
1834   }
1835 
1836   return false;
1837 }
1838 
1839 bool MachineInstr::isLoadFoldBarrier() const {
1840   return mayStore() || isCall() || hasUnmodeledSideEffects();
1841 }
1842 
1843 /// allDefsAreDead - Return true if all the defs of this instruction are dead.
1844 ///
1845 bool MachineInstr::allDefsAreDead() const {
1846   for (const MachineOperand &MO : operands()) {
1847     if (!MO.isReg() || MO.isUse())
1848       continue;
1849     if (!MO.isDead())
1850       return false;
1851   }
1852   return true;
1853 }
1854 
1855 /// copyImplicitOps - Copy implicit register operands from specified
1856 /// instruction to this instruction.
1857 void MachineInstr::copyImplicitOps(MachineFunction &MF,
1858                                    const MachineInstr &MI) {
1859   for (unsigned i = MI.getDesc().getNumOperands(), e = MI.getNumOperands();
1860        i != e; ++i) {
1861     const MachineOperand &MO = MI.getOperand(i);
1862     if ((MO.isReg() && MO.isImplicit()) || MO.isRegMask())
1863       addOperand(MF, MO);
1864   }
1865 }
1866 
1867 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1868 LLVM_DUMP_METHOD void MachineInstr::dump() const {
1869   dbgs() << "  ";
1870   print(dbgs());
1871 }
1872 #endif
1873 
1874 void MachineInstr::print(raw_ostream &OS, bool SkipOpers, bool SkipDebugLoc,
1875                          const TargetInstrInfo *TII) const {
1876   const Module *M = nullptr;
1877   if (const MachineBasicBlock *MBB = getParent())
1878     if (const MachineFunction *MF = MBB->getParent())
1879       M = MF->getFunction()->getParent();
1880 
1881   ModuleSlotTracker MST(M);
1882   print(OS, MST, SkipOpers, SkipDebugLoc, TII);
1883 }
1884 
1885 void MachineInstr::print(raw_ostream &OS, ModuleSlotTracker &MST,
1886                          bool SkipOpers, bool SkipDebugLoc,
1887                          const TargetInstrInfo *TII) const {
1888   // We can be a bit tidier if we know the MachineFunction.
1889   const MachineFunction *MF = nullptr;
1890   const TargetRegisterInfo *TRI = nullptr;
1891   const MachineRegisterInfo *MRI = nullptr;
1892   const TargetIntrinsicInfo *IntrinsicInfo = nullptr;
1893 
1894   if (const MachineBasicBlock *MBB = getParent()) {
1895     MF = MBB->getParent();
1896     if (MF) {
1897       MRI = &MF->getRegInfo();
1898       TRI = MF->getSubtarget().getRegisterInfo();
1899       if (!TII)
1900         TII = MF->getSubtarget().getInstrInfo();
1901       IntrinsicInfo = MF->getTarget().getIntrinsicInfo();
1902     }
1903   }
1904 
1905   // Save a list of virtual registers.
1906   SmallVector<unsigned, 8> VirtRegs;
1907 
1908   // Print explicitly defined operands on the left of an assignment syntax.
1909   unsigned StartOp = 0, e = getNumOperands();
1910   for (; StartOp < e && getOperand(StartOp).isReg() &&
1911          getOperand(StartOp).isDef() &&
1912          !getOperand(StartOp).isImplicit();
1913        ++StartOp) {
1914     if (StartOp != 0) OS << ", ";
1915     getOperand(StartOp).print(OS, MST, TRI, IntrinsicInfo);
1916     unsigned Reg = getOperand(StartOp).getReg();
1917     if (TargetRegisterInfo::isVirtualRegister(Reg)) {
1918       VirtRegs.push_back(Reg);
1919       LLT Ty = MRI ? MRI->getType(Reg) : LLT{};
1920       if (Ty.isValid())
1921         OS << '(' << Ty << ')';
1922     }
1923   }
1924 
1925   if (StartOp != 0)
1926     OS << " = ";
1927 
1928   // Print the opcode name.
1929   if (TII)
1930     OS << TII->getName(getOpcode());
1931   else
1932     OS << "UNKNOWN";
1933 
1934   if (SkipOpers)
1935     return;
1936 
1937   // Print the rest of the operands.
1938   bool FirstOp = true;
1939   unsigned AsmDescOp = ~0u;
1940   unsigned AsmOpCount = 0;
1941 
1942   if (isInlineAsm() && e >= InlineAsm::MIOp_FirstOperand) {
1943     // Print asm string.
1944     OS << " ";
1945     getOperand(InlineAsm::MIOp_AsmString).print(OS, MST, TRI);
1946 
1947     // Print HasSideEffects, MayLoad, MayStore, IsAlignStack
1948     unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
1949     if (ExtraInfo & InlineAsm::Extra_HasSideEffects)
1950       OS << " [sideeffect]";
1951     if (ExtraInfo & InlineAsm::Extra_MayLoad)
1952       OS << " [mayload]";
1953     if (ExtraInfo & InlineAsm::Extra_MayStore)
1954       OS << " [maystore]";
1955     if (ExtraInfo & InlineAsm::Extra_IsConvergent)
1956       OS << " [isconvergent]";
1957     if (ExtraInfo & InlineAsm::Extra_IsAlignStack)
1958       OS << " [alignstack]";
1959     if (getInlineAsmDialect() == InlineAsm::AD_ATT)
1960       OS << " [attdialect]";
1961     if (getInlineAsmDialect() == InlineAsm::AD_Intel)
1962       OS << " [inteldialect]";
1963 
1964     StartOp = AsmDescOp = InlineAsm::MIOp_FirstOperand;
1965     FirstOp = false;
1966   }
1967 
1968   for (unsigned i = StartOp, e = getNumOperands(); i != e; ++i) {
1969     const MachineOperand &MO = getOperand(i);
1970 
1971     if (MO.isReg() && TargetRegisterInfo::isVirtualRegister(MO.getReg()))
1972       VirtRegs.push_back(MO.getReg());
1973 
1974     if (FirstOp) FirstOp = false; else OS << ",";
1975     OS << " ";
1976     if (i < getDesc().NumOperands) {
1977       const MCOperandInfo &MCOI = getDesc().OpInfo[i];
1978       if (MCOI.isPredicate())
1979         OS << "pred:";
1980       if (MCOI.isOptionalDef())
1981         OS << "opt:";
1982     }
1983     if (isDebugValue() && MO.isMetadata()) {
1984       // Pretty print DBG_VALUE instructions.
1985       auto *DIV = dyn_cast<DILocalVariable>(MO.getMetadata());
1986       if (DIV && !DIV->getName().empty())
1987         OS << "!\"" << DIV->getName() << '\"';
1988       else
1989         MO.print(OS, MST, TRI);
1990     } else if (TRI && (isInsertSubreg() || isRegSequence() ||
1991                        (isSubregToReg() && i == 3)) && MO.isImm()) {
1992       OS << TRI->getSubRegIndexName(MO.getImm());
1993     } else if (i == AsmDescOp && MO.isImm()) {
1994       // Pretty print the inline asm operand descriptor.
1995       OS << '$' << AsmOpCount++;
1996       unsigned Flag = MO.getImm();
1997       switch (InlineAsm::getKind(Flag)) {
1998       case InlineAsm::Kind_RegUse:             OS << ":[reguse"; break;
1999       case InlineAsm::Kind_RegDef:             OS << ":[regdef"; break;
2000       case InlineAsm::Kind_RegDefEarlyClobber: OS << ":[regdef-ec"; break;
2001       case InlineAsm::Kind_Clobber:            OS << ":[clobber"; break;
2002       case InlineAsm::Kind_Imm:                OS << ":[imm"; break;
2003       case InlineAsm::Kind_Mem:                OS << ":[mem"; break;
2004       default: OS << ":[??" << InlineAsm::getKind(Flag); break;
2005       }
2006 
2007       unsigned RCID = 0;
2008       if (!InlineAsm::isImmKind(Flag) && !InlineAsm::isMemKind(Flag) &&
2009           InlineAsm::hasRegClassConstraint(Flag, RCID)) {
2010         if (TRI) {
2011           OS << ':' << TRI->getRegClassName(TRI->getRegClass(RCID));
2012         } else
2013           OS << ":RC" << RCID;
2014       }
2015 
2016       if (InlineAsm::isMemKind(Flag)) {
2017         unsigned MCID = InlineAsm::getMemoryConstraintID(Flag);
2018         switch (MCID) {
2019         case InlineAsm::Constraint_es: OS << ":es"; break;
2020         case InlineAsm::Constraint_i:  OS << ":i"; break;
2021         case InlineAsm::Constraint_m:  OS << ":m"; break;
2022         case InlineAsm::Constraint_o:  OS << ":o"; break;
2023         case InlineAsm::Constraint_v:  OS << ":v"; break;
2024         case InlineAsm::Constraint_Q:  OS << ":Q"; break;
2025         case InlineAsm::Constraint_R:  OS << ":R"; break;
2026         case InlineAsm::Constraint_S:  OS << ":S"; break;
2027         case InlineAsm::Constraint_T:  OS << ":T"; break;
2028         case InlineAsm::Constraint_Um: OS << ":Um"; break;
2029         case InlineAsm::Constraint_Un: OS << ":Un"; break;
2030         case InlineAsm::Constraint_Uq: OS << ":Uq"; break;
2031         case InlineAsm::Constraint_Us: OS << ":Us"; break;
2032         case InlineAsm::Constraint_Ut: OS << ":Ut"; break;
2033         case InlineAsm::Constraint_Uv: OS << ":Uv"; break;
2034         case InlineAsm::Constraint_Uy: OS << ":Uy"; break;
2035         case InlineAsm::Constraint_X:  OS << ":X"; break;
2036         case InlineAsm::Constraint_Z:  OS << ":Z"; break;
2037         case InlineAsm::Constraint_ZC: OS << ":ZC"; break;
2038         case InlineAsm::Constraint_Zy: OS << ":Zy"; break;
2039         default: OS << ":?"; break;
2040         }
2041       }
2042 
2043       unsigned TiedTo = 0;
2044       if (InlineAsm::isUseOperandTiedToDef(Flag, TiedTo))
2045         OS << " tiedto:$" << TiedTo;
2046 
2047       OS << ']';
2048 
2049       // Compute the index of the next operand descriptor.
2050       AsmDescOp += 1 + InlineAsm::getNumOperandRegisters(Flag);
2051     } else
2052       MO.print(OS, MST, TRI);
2053   }
2054 
2055   bool HaveSemi = false;
2056   const unsigned PrintableFlags = FrameSetup | FrameDestroy;
2057   if (Flags & PrintableFlags) {
2058     if (!HaveSemi) {
2059       OS << ";";
2060       HaveSemi = true;
2061     }
2062     OS << " flags: ";
2063 
2064     if (Flags & FrameSetup)
2065       OS << "FrameSetup";
2066 
2067     if (Flags & FrameDestroy)
2068       OS << "FrameDestroy";
2069   }
2070 
2071   if (!memoperands_empty()) {
2072     if (!HaveSemi) {
2073       OS << ";";
2074       HaveSemi = true;
2075     }
2076 
2077     OS << " mem:";
2078     for (mmo_iterator i = memoperands_begin(), e = memoperands_end();
2079          i != e; ++i) {
2080       (*i)->print(OS, MST);
2081       if (std::next(i) != e)
2082         OS << " ";
2083     }
2084   }
2085 
2086   // Print the regclass of any virtual registers encountered.
2087   if (MRI && !VirtRegs.empty()) {
2088     if (!HaveSemi) {
2089       OS << ";";
2090       HaveSemi = true;
2091     }
2092     for (unsigned i = 0; i != VirtRegs.size(); ++i) {
2093       const RegClassOrRegBank &RC = MRI->getRegClassOrRegBank(VirtRegs[i]);
2094       if (!RC)
2095         continue;
2096       // Generic virtual registers do not have register classes.
2097       if (RC.is<const RegisterBank *>())
2098         OS << " " << RC.get<const RegisterBank *>()->getName();
2099       else
2100         OS << " "
2101            << TRI->getRegClassName(RC.get<const TargetRegisterClass *>());
2102       OS << ':' << printReg(VirtRegs[i]);
2103       for (unsigned j = i+1; j != VirtRegs.size();) {
2104         if (MRI->getRegClassOrRegBank(VirtRegs[j]) != RC) {
2105           ++j;
2106           continue;
2107         }
2108         if (VirtRegs[i] != VirtRegs[j])
2109           OS << "," << printReg(VirtRegs[j]);
2110         VirtRegs.erase(VirtRegs.begin()+j);
2111       }
2112     }
2113   }
2114 
2115   // Print debug location information.
2116   if (isDebugValue() && getOperand(e - 2).isMetadata()) {
2117     if (!HaveSemi)
2118       OS << ";";
2119     auto *DV = cast<DILocalVariable>(getOperand(e - 2).getMetadata());
2120     OS << " line no:" <<  DV->getLine();
2121     if (auto *InlinedAt = debugLoc->getInlinedAt()) {
2122       DebugLoc InlinedAtDL(InlinedAt);
2123       if (InlinedAtDL && MF) {
2124         OS << " inlined @[ ";
2125         InlinedAtDL.print(OS);
2126         OS << " ]";
2127       }
2128     }
2129     if (isIndirectDebugValue())
2130       OS << " indirect";
2131   } else if (SkipDebugLoc) {
2132     return;
2133   } else if (debugLoc && MF) {
2134     if (!HaveSemi)
2135       OS << ";";
2136     OS << " dbg:";
2137     debugLoc.print(OS);
2138   }
2139 
2140   OS << '\n';
2141 }
2142 
2143 bool MachineInstr::addRegisterKilled(unsigned IncomingReg,
2144                                      const TargetRegisterInfo *RegInfo,
2145                                      bool AddIfNotFound) {
2146   bool isPhysReg = TargetRegisterInfo::isPhysicalRegister(IncomingReg);
2147   bool hasAliases = isPhysReg &&
2148     MCRegAliasIterator(IncomingReg, RegInfo, false).isValid();
2149   bool Found = false;
2150   SmallVector<unsigned,4> DeadOps;
2151   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
2152     MachineOperand &MO = getOperand(i);
2153     if (!MO.isReg() || !MO.isUse() || MO.isUndef())
2154       continue;
2155 
2156     // DEBUG_VALUE nodes do not contribute to code generation and should
2157     // always be ignored. Failure to do so may result in trying to modify
2158     // KILL flags on DEBUG_VALUE nodes.
2159     if (MO.isDebug())
2160       continue;
2161 
2162     unsigned Reg = MO.getReg();
2163     if (!Reg)
2164       continue;
2165 
2166     if (Reg == IncomingReg) {
2167       if (!Found) {
2168         if (MO.isKill())
2169           // The register is already marked kill.
2170           return true;
2171         if (isPhysReg && isRegTiedToDefOperand(i))
2172           // Two-address uses of physregs must not be marked kill.
2173           return true;
2174         MO.setIsKill();
2175         Found = true;
2176       }
2177     } else if (hasAliases && MO.isKill() &&
2178                TargetRegisterInfo::isPhysicalRegister(Reg)) {
2179       // A super-register kill already exists.
2180       if (RegInfo->isSuperRegister(IncomingReg, Reg))
2181         return true;
2182       if (RegInfo->isSubRegister(IncomingReg, Reg))
2183         DeadOps.push_back(i);
2184     }
2185   }
2186 
2187   // Trim unneeded kill operands.
2188   while (!DeadOps.empty()) {
2189     unsigned OpIdx = DeadOps.back();
2190     if (getOperand(OpIdx).isImplicit())
2191       RemoveOperand(OpIdx);
2192     else
2193       getOperand(OpIdx).setIsKill(false);
2194     DeadOps.pop_back();
2195   }
2196 
2197   // If not found, this means an alias of one of the operands is killed. Add a
2198   // new implicit operand if required.
2199   if (!Found && AddIfNotFound) {
2200     addOperand(MachineOperand::CreateReg(IncomingReg,
2201                                          false /*IsDef*/,
2202                                          true  /*IsImp*/,
2203                                          true  /*IsKill*/));
2204     return true;
2205   }
2206   return Found;
2207 }
2208 
2209 void MachineInstr::clearRegisterKills(unsigned Reg,
2210                                       const TargetRegisterInfo *RegInfo) {
2211   if (!TargetRegisterInfo::isPhysicalRegister(Reg))
2212     RegInfo = nullptr;
2213   for (MachineOperand &MO : operands()) {
2214     if (!MO.isReg() || !MO.isUse() || !MO.isKill())
2215       continue;
2216     unsigned OpReg = MO.getReg();
2217     if ((RegInfo && RegInfo->regsOverlap(Reg, OpReg)) || Reg == OpReg)
2218       MO.setIsKill(false);
2219   }
2220 }
2221 
2222 bool MachineInstr::addRegisterDead(unsigned Reg,
2223                                    const TargetRegisterInfo *RegInfo,
2224                                    bool AddIfNotFound) {
2225   bool isPhysReg = TargetRegisterInfo::isPhysicalRegister(Reg);
2226   bool hasAliases = isPhysReg &&
2227     MCRegAliasIterator(Reg, RegInfo, false).isValid();
2228   bool Found = false;
2229   SmallVector<unsigned,4> DeadOps;
2230   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
2231     MachineOperand &MO = getOperand(i);
2232     if (!MO.isReg() || !MO.isDef())
2233       continue;
2234     unsigned MOReg = MO.getReg();
2235     if (!MOReg)
2236       continue;
2237 
2238     if (MOReg == Reg) {
2239       MO.setIsDead();
2240       Found = true;
2241     } else if (hasAliases && MO.isDead() &&
2242                TargetRegisterInfo::isPhysicalRegister(MOReg)) {
2243       // There exists a super-register that's marked dead.
2244       if (RegInfo->isSuperRegister(Reg, MOReg))
2245         return true;
2246       if (RegInfo->isSubRegister(Reg, MOReg))
2247         DeadOps.push_back(i);
2248     }
2249   }
2250 
2251   // Trim unneeded dead operands.
2252   while (!DeadOps.empty()) {
2253     unsigned OpIdx = DeadOps.back();
2254     if (getOperand(OpIdx).isImplicit())
2255       RemoveOperand(OpIdx);
2256     else
2257       getOperand(OpIdx).setIsDead(false);
2258     DeadOps.pop_back();
2259   }
2260 
2261   // If not found, this means an alias of one of the operands is dead. Add a
2262   // new implicit operand if required.
2263   if (Found || !AddIfNotFound)
2264     return Found;
2265 
2266   addOperand(MachineOperand::CreateReg(Reg,
2267                                        true  /*IsDef*/,
2268                                        true  /*IsImp*/,
2269                                        false /*IsKill*/,
2270                                        true  /*IsDead*/));
2271   return true;
2272 }
2273 
2274 void MachineInstr::clearRegisterDeads(unsigned Reg) {
2275   for (MachineOperand &MO : operands()) {
2276     if (!MO.isReg() || !MO.isDef() || MO.getReg() != Reg)
2277       continue;
2278     MO.setIsDead(false);
2279   }
2280 }
2281 
2282 void MachineInstr::setRegisterDefReadUndef(unsigned Reg, bool IsUndef) {
2283   for (MachineOperand &MO : operands()) {
2284     if (!MO.isReg() || !MO.isDef() || MO.getReg() != Reg || MO.getSubReg() == 0)
2285       continue;
2286     MO.setIsUndef(IsUndef);
2287   }
2288 }
2289 
2290 void MachineInstr::addRegisterDefined(unsigned Reg,
2291                                       const TargetRegisterInfo *RegInfo) {
2292   if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
2293     MachineOperand *MO = findRegisterDefOperand(Reg, false, RegInfo);
2294     if (MO)
2295       return;
2296   } else {
2297     for (const MachineOperand &MO : operands()) {
2298       if (MO.isReg() && MO.getReg() == Reg && MO.isDef() &&
2299           MO.getSubReg() == 0)
2300         return;
2301     }
2302   }
2303   addOperand(MachineOperand::CreateReg(Reg,
2304                                        true  /*IsDef*/,
2305                                        true  /*IsImp*/));
2306 }
2307 
2308 void MachineInstr::setPhysRegsDeadExcept(ArrayRef<unsigned> UsedRegs,
2309                                          const TargetRegisterInfo &TRI) {
2310   bool HasRegMask = false;
2311   for (MachineOperand &MO : operands()) {
2312     if (MO.isRegMask()) {
2313       HasRegMask = true;
2314       continue;
2315     }
2316     if (!MO.isReg() || !MO.isDef()) continue;
2317     unsigned Reg = MO.getReg();
2318     if (!TargetRegisterInfo::isPhysicalRegister(Reg)) continue;
2319     // If there are no uses, including partial uses, the def is dead.
2320     if (llvm::none_of(UsedRegs,
2321                       [&](unsigned Use) { return TRI.regsOverlap(Use, Reg); }))
2322       MO.setIsDead();
2323   }
2324 
2325   // This is a call with a register mask operand.
2326   // Mask clobbers are always dead, so add defs for the non-dead defines.
2327   if (HasRegMask)
2328     for (ArrayRef<unsigned>::iterator I = UsedRegs.begin(), E = UsedRegs.end();
2329          I != E; ++I)
2330       addRegisterDefined(*I, &TRI);
2331 }
2332 
2333 unsigned
2334 MachineInstrExpressionTrait::getHashValue(const MachineInstr* const &MI) {
2335   // Build up a buffer of hash code components.
2336   SmallVector<size_t, 8> HashComponents;
2337   HashComponents.reserve(MI->getNumOperands() + 1);
2338   HashComponents.push_back(MI->getOpcode());
2339   for (const MachineOperand &MO : MI->operands()) {
2340     if (MO.isReg() && MO.isDef() &&
2341         TargetRegisterInfo::isVirtualRegister(MO.getReg()))
2342       continue;  // Skip virtual register defs.
2343 
2344     HashComponents.push_back(hash_value(MO));
2345   }
2346   return hash_combine_range(HashComponents.begin(), HashComponents.end());
2347 }
2348 
2349 void MachineInstr::emitError(StringRef Msg) const {
2350   // Find the source location cookie.
2351   unsigned LocCookie = 0;
2352   const MDNode *LocMD = nullptr;
2353   for (unsigned i = getNumOperands(); i != 0; --i) {
2354     if (getOperand(i-1).isMetadata() &&
2355         (LocMD = getOperand(i-1).getMetadata()) &&
2356         LocMD->getNumOperands() != 0) {
2357       if (const ConstantInt *CI =
2358               mdconst::dyn_extract<ConstantInt>(LocMD->getOperand(0))) {
2359         LocCookie = CI->getZExtValue();
2360         break;
2361       }
2362     }
2363   }
2364 
2365   if (const MachineBasicBlock *MBB = getParent())
2366     if (const MachineFunction *MF = MBB->getParent())
2367       return MF->getMMI().getModule()->getContext().emitError(LocCookie, Msg);
2368   report_fatal_error(Msg);
2369 }
2370 
2371 MachineInstrBuilder llvm::BuildMI(MachineFunction &MF, const DebugLoc &DL,
2372                                   const MCInstrDesc &MCID, bool IsIndirect,
2373                                   unsigned Reg, const MDNode *Variable,
2374                                   const MDNode *Expr) {
2375   assert(isa<DILocalVariable>(Variable) && "not a variable");
2376   assert(cast<DIExpression>(Expr)->isValid() && "not an expression");
2377   assert(cast<DILocalVariable>(Variable)->isValidLocationForIntrinsic(DL) &&
2378          "Expected inlined-at fields to agree");
2379   if (IsIndirect)
2380     return BuildMI(MF, DL, MCID)
2381         .addReg(Reg, RegState::Debug)
2382         .addImm(0U)
2383         .addMetadata(Variable)
2384         .addMetadata(Expr);
2385   else
2386     return BuildMI(MF, DL, MCID)
2387         .addReg(Reg, RegState::Debug)
2388         .addReg(0U, RegState::Debug)
2389         .addMetadata(Variable)
2390         .addMetadata(Expr);
2391 }
2392 
2393 MachineInstrBuilder llvm::BuildMI(MachineBasicBlock &BB,
2394                                   MachineBasicBlock::iterator I,
2395                                   const DebugLoc &DL, const MCInstrDesc &MCID,
2396                                   bool IsIndirect, unsigned Reg,
2397                                   const MDNode *Variable, const MDNode *Expr) {
2398   assert(isa<DILocalVariable>(Variable) && "not a variable");
2399   assert(cast<DIExpression>(Expr)->isValid() && "not an expression");
2400   MachineFunction &MF = *BB.getParent();
2401   MachineInstr *MI = BuildMI(MF, DL, MCID, IsIndirect, Reg, Variable, Expr);
2402   BB.insert(I, MI);
2403   return MachineInstrBuilder(MF, MI);
2404 }
2405 
2406 /// Compute the new DIExpression to use with a DBG_VALUE for a spill slot.
2407 /// This prepends DW_OP_deref when spilling an indirect DBG_VALUE.
2408 static const DIExpression *computeExprForSpill(const MachineInstr &MI) {
2409   assert(MI.getOperand(0).isReg() && "can't spill non-register");
2410   assert(MI.getDebugVariable()->isValidLocationForIntrinsic(MI.getDebugLoc()) &&
2411          "Expected inlined-at fields to agree");
2412 
2413   const DIExpression *Expr = MI.getDebugExpression();
2414   if (MI.isIndirectDebugValue()) {
2415     assert(MI.getOperand(1).getImm() == 0 && "DBG_VALUE with nonzero offset");
2416     Expr = DIExpression::prepend(Expr, DIExpression::WithDeref);
2417   }
2418   return Expr;
2419 }
2420 
2421 MachineInstr *llvm::buildDbgValueForSpill(MachineBasicBlock &BB,
2422                                           MachineBasicBlock::iterator I,
2423                                           const MachineInstr &Orig,
2424                                           int FrameIndex) {
2425   const DIExpression *Expr = computeExprForSpill(Orig);
2426   return BuildMI(BB, I, Orig.getDebugLoc(), Orig.getDesc())
2427       .addFrameIndex(FrameIndex)
2428       .addImm(0U)
2429       .addMetadata(Orig.getDebugVariable())
2430       .addMetadata(Expr);
2431 }
2432 
2433 void llvm::updateDbgValueForSpill(MachineInstr &Orig, int FrameIndex) {
2434   const DIExpression *Expr = computeExprForSpill(Orig);
2435   Orig.getOperand(0).ChangeToFrameIndex(FrameIndex);
2436   Orig.getOperand(1).ChangeToImmediate(0U);
2437   Orig.getOperand(3).setMetadata(Expr);
2438 }
2439