xref: /llvm-project/llvm/lib/CodeGen/MachineInstr.cpp (revision 55e2f5963aa146c8726650d33df0de072a2eba4c)
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/IR/Constants.h"
37 #include "llvm/IR/DebugInfoMetadata.h"
38 #include "llvm/IR/DebugLoc.h"
39 #include "llvm/IR/DerivedTypes.h"
40 #include "llvm/IR/Function.h"
41 #include "llvm/IR/InlineAsm.h"
42 #include "llvm/IR/InstrTypes.h"
43 #include "llvm/IR/Intrinsics.h"
44 #include "llvm/IR/LLVMContext.h"
45 #include "llvm/IR/Metadata.h"
46 #include "llvm/IR/Module.h"
47 #include "llvm/IR/ModuleSlotTracker.h"
48 #include "llvm/IR/Type.h"
49 #include "llvm/IR/Value.h"
50 #include "llvm/MC/MCInstrDesc.h"
51 #include "llvm/MC/MCRegisterInfo.h"
52 #include "llvm/MC/MCSymbol.h"
53 #include "llvm/Support/Casting.h"
54 #include "llvm/Support/CommandLine.h"
55 #include "llvm/Support/Compiler.h"
56 #include "llvm/Support/Debug.h"
57 #include "llvm/Support/ErrorHandling.h"
58 #include "llvm/Support/LowLevelTypeImpl.h"
59 #include "llvm/Support/MathExtras.h"
60 #include "llvm/Support/raw_ostream.h"
61 #include "llvm/Target/TargetInstrInfo.h"
62 #include "llvm/Target/TargetIntrinsicInfo.h"
63 #include "llvm/Target/TargetMachine.h"
64 #include "llvm/Target/TargetRegisterInfo.h"
65 #include "llvm/Target/TargetSubtargetInfo.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<bool> PrintWholeRegMask(
77     "print-whole-regmask",
78     cl::desc("Print the full contents of regmask operands in IR dumps"),
79     cl::init(true), cl::Hidden);
80 
81 //===----------------------------------------------------------------------===//
82 // MachineOperand Implementation
83 //===----------------------------------------------------------------------===//
84 
85 void MachineOperand::setReg(unsigned Reg) {
86   if (getReg() == Reg) return; // No change.
87 
88   // Otherwise, we have to change the register.  If this operand is embedded
89   // into a machine function, we need to update the old and new register's
90   // use/def lists.
91   if (MachineInstr *MI = getParent())
92     if (MachineBasicBlock *MBB = MI->getParent())
93       if (MachineFunction *MF = MBB->getParent()) {
94         MachineRegisterInfo &MRI = MF->getRegInfo();
95         MRI.removeRegOperandFromUseList(this);
96         SmallContents.RegNo = Reg;
97         MRI.addRegOperandToUseList(this);
98         return;
99       }
100 
101   // Otherwise, just change the register, no problem.  :)
102   SmallContents.RegNo = Reg;
103 }
104 
105 void MachineOperand::substVirtReg(unsigned Reg, unsigned SubIdx,
106                                   const TargetRegisterInfo &TRI) {
107   assert(TargetRegisterInfo::isVirtualRegister(Reg));
108   if (SubIdx && getSubReg())
109     SubIdx = TRI.composeSubRegIndices(SubIdx, getSubReg());
110   setReg(Reg);
111   if (SubIdx)
112     setSubReg(SubIdx);
113 }
114 
115 void MachineOperand::substPhysReg(unsigned Reg, const TargetRegisterInfo &TRI) {
116   assert(TargetRegisterInfo::isPhysicalRegister(Reg));
117   if (getSubReg()) {
118     Reg = TRI.getSubReg(Reg, getSubReg());
119     // Note that getSubReg() may return 0 if the sub-register doesn't exist.
120     // That won't happen in legal code.
121     setSubReg(0);
122     if (isDef())
123       setIsUndef(false);
124   }
125   setReg(Reg);
126 }
127 
128 /// Change a def to a use, or a use to a def.
129 void MachineOperand::setIsDef(bool Val) {
130   assert(isReg() && "Wrong MachineOperand accessor");
131   assert((!Val || !isDebug()) && "Marking a debug operation as def");
132   if (IsDef == Val)
133     return;
134   // MRI may keep uses and defs in different list positions.
135   if (MachineInstr *MI = getParent())
136     if (MachineBasicBlock *MBB = MI->getParent())
137       if (MachineFunction *MF = MBB->getParent()) {
138         MachineRegisterInfo &MRI = MF->getRegInfo();
139         MRI.removeRegOperandFromUseList(this);
140         IsDef = Val;
141         MRI.addRegOperandToUseList(this);
142         return;
143       }
144   IsDef = Val;
145 }
146 
147 // If this operand is currently a register operand, and if this is in a
148 // function, deregister the operand from the register's use/def list.
149 void MachineOperand::removeRegFromUses() {
150   if (!isReg() || !isOnRegUseList())
151     return;
152 
153   if (MachineInstr *MI = getParent()) {
154     if (MachineBasicBlock *MBB = MI->getParent()) {
155       if (MachineFunction *MF = MBB->getParent())
156         MF->getRegInfo().removeRegOperandFromUseList(this);
157     }
158   }
159 }
160 
161 /// ChangeToImmediate - Replace this operand with a new immediate operand of
162 /// the specified value.  If an operand is known to be an immediate already,
163 /// the setImm method should be used.
164 void MachineOperand::ChangeToImmediate(int64_t ImmVal) {
165   assert((!isReg() || !isTied()) && "Cannot change a tied operand into an imm");
166 
167   removeRegFromUses();
168 
169   OpKind = MO_Immediate;
170   Contents.ImmVal = ImmVal;
171 }
172 
173 void MachineOperand::ChangeToFPImmediate(const ConstantFP *FPImm) {
174   assert((!isReg() || !isTied()) && "Cannot change a tied operand into an imm");
175 
176   removeRegFromUses();
177 
178   OpKind = MO_FPImmediate;
179   Contents.CFP = FPImm;
180 }
181 
182 void MachineOperand::ChangeToES(const char *SymName, unsigned char TargetFlags) {
183   assert((!isReg() || !isTied()) &&
184          "Cannot change a tied operand into an external symbol");
185 
186   removeRegFromUses();
187 
188   OpKind = MO_ExternalSymbol;
189   Contents.OffsetedInfo.Val.SymbolName = SymName;
190   setOffset(0); // Offset is always 0.
191   setTargetFlags(TargetFlags);
192 }
193 
194 void MachineOperand::ChangeToMCSymbol(MCSymbol *Sym) {
195   assert((!isReg() || !isTied()) &&
196          "Cannot change a tied operand into an MCSymbol");
197 
198   removeRegFromUses();
199 
200   OpKind = MO_MCSymbol;
201   Contents.Sym = Sym;
202 }
203 
204 void MachineOperand::ChangeToFrameIndex(int Idx) {
205   assert((!isReg() || !isTied()) &&
206          "Cannot change a tied operand into a FrameIndex");
207 
208   removeRegFromUses();
209 
210   OpKind = MO_FrameIndex;
211   setIndex(Idx);
212 }
213 
214 /// ChangeToRegister - Replace this operand with a new register operand of
215 /// the specified value.  If an operand is known to be an register already,
216 /// the setReg method should be used.
217 void MachineOperand::ChangeToRegister(unsigned Reg, bool isDef, bool isImp,
218                                       bool isKill, bool isDead, bool isUndef,
219                                       bool isDebug) {
220   MachineRegisterInfo *RegInfo = nullptr;
221   if (MachineInstr *MI = getParent())
222     if (MachineBasicBlock *MBB = MI->getParent())
223       if (MachineFunction *MF = MBB->getParent())
224         RegInfo = &MF->getRegInfo();
225   // If this operand is already a register operand, remove it from the
226   // register's use/def lists.
227   bool WasReg = isReg();
228   if (RegInfo && WasReg)
229     RegInfo->removeRegOperandFromUseList(this);
230 
231   // Change this to a register and set the reg#.
232   OpKind = MO_Register;
233   SmallContents.RegNo = Reg;
234   SubReg_TargetFlags = 0;
235   IsDef = isDef;
236   IsImp = isImp;
237   IsKill = isKill;
238   IsDead = isDead;
239   IsUndef = isUndef;
240   IsInternalRead = false;
241   IsEarlyClobber = false;
242   IsDebug = isDebug;
243   // Ensure isOnRegUseList() returns false.
244   Contents.Reg.Prev = nullptr;
245   // Preserve the tie when the operand was already a register.
246   if (!WasReg)
247     TiedTo = 0;
248 
249   // If this operand is embedded in a function, add the operand to the
250   // register's use/def list.
251   if (RegInfo)
252     RegInfo->addRegOperandToUseList(this);
253 }
254 
255 /// isIdenticalTo - Return true if this operand is identical to the specified
256 /// operand. Note that this should stay in sync with the hash_value overload
257 /// below.
258 bool MachineOperand::isIdenticalTo(const MachineOperand &Other) const {
259   if (getType() != Other.getType() ||
260       getTargetFlags() != Other.getTargetFlags())
261     return false;
262 
263   switch (getType()) {
264   case MachineOperand::MO_Register:
265     return getReg() == Other.getReg() && isDef() == Other.isDef() &&
266            getSubReg() == Other.getSubReg();
267   case MachineOperand::MO_Immediate:
268     return getImm() == Other.getImm();
269   case MachineOperand::MO_CImmediate:
270     return getCImm() == Other.getCImm();
271   case MachineOperand::MO_FPImmediate:
272     return getFPImm() == Other.getFPImm();
273   case MachineOperand::MO_MachineBasicBlock:
274     return getMBB() == Other.getMBB();
275   case MachineOperand::MO_FrameIndex:
276     return getIndex() == Other.getIndex();
277   case MachineOperand::MO_ConstantPoolIndex:
278   case MachineOperand::MO_TargetIndex:
279     return getIndex() == Other.getIndex() && getOffset() == Other.getOffset();
280   case MachineOperand::MO_JumpTableIndex:
281     return getIndex() == Other.getIndex();
282   case MachineOperand::MO_GlobalAddress:
283     return getGlobal() == Other.getGlobal() && getOffset() == Other.getOffset();
284   case MachineOperand::MO_ExternalSymbol:
285     return strcmp(getSymbolName(), Other.getSymbolName()) == 0 &&
286            getOffset() == Other.getOffset();
287   case MachineOperand::MO_BlockAddress:
288     return getBlockAddress() == Other.getBlockAddress() &&
289            getOffset() == Other.getOffset();
290   case MachineOperand::MO_RegisterMask:
291   case MachineOperand::MO_RegisterLiveOut: {
292     // Shallow compare of the two RegMasks
293     const uint32_t *RegMask = getRegMask();
294     const uint32_t *OtherRegMask = Other.getRegMask();
295     if (RegMask == OtherRegMask)
296       return true;
297 
298     // Calculate the size of the RegMask
299     const MachineFunction *MF = getParent()->getParent()->getParent();
300     const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
301     unsigned RegMaskSize = (TRI->getNumRegs() + 31) / 32;
302 
303     // Deep compare of the two RegMasks
304     return std::equal(RegMask, RegMask + RegMaskSize, OtherRegMask);
305   }
306   case MachineOperand::MO_MCSymbol:
307     return getMCSymbol() == Other.getMCSymbol();
308   case MachineOperand::MO_CFIIndex:
309     return getCFIIndex() == Other.getCFIIndex();
310   case MachineOperand::MO_Metadata:
311     return getMetadata() == Other.getMetadata();
312   case MachineOperand::MO_IntrinsicID:
313     return getIntrinsicID() == Other.getIntrinsicID();
314   case MachineOperand::MO_Predicate:
315     return getPredicate() == Other.getPredicate();
316   }
317   llvm_unreachable("Invalid machine operand type");
318 }
319 
320 // Note: this must stay exactly in sync with isIdenticalTo above.
321 hash_code llvm::hash_value(const MachineOperand &MO) {
322   switch (MO.getType()) {
323   case MachineOperand::MO_Register:
324     // Register operands don't have target flags.
325     return hash_combine(MO.getType(), MO.getReg(), MO.getSubReg(), MO.isDef());
326   case MachineOperand::MO_Immediate:
327     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getImm());
328   case MachineOperand::MO_CImmediate:
329     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getCImm());
330   case MachineOperand::MO_FPImmediate:
331     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getFPImm());
332   case MachineOperand::MO_MachineBasicBlock:
333     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getMBB());
334   case MachineOperand::MO_FrameIndex:
335     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIndex());
336   case MachineOperand::MO_ConstantPoolIndex:
337   case MachineOperand::MO_TargetIndex:
338     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIndex(),
339                         MO.getOffset());
340   case MachineOperand::MO_JumpTableIndex:
341     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIndex());
342   case MachineOperand::MO_ExternalSymbol:
343     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getOffset(),
344                         MO.getSymbolName());
345   case MachineOperand::MO_GlobalAddress:
346     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getGlobal(),
347                         MO.getOffset());
348   case MachineOperand::MO_BlockAddress:
349     return hash_combine(MO.getType(), MO.getTargetFlags(),
350                         MO.getBlockAddress(), MO.getOffset());
351   case MachineOperand::MO_RegisterMask:
352   case MachineOperand::MO_RegisterLiveOut:
353     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getRegMask());
354   case MachineOperand::MO_Metadata:
355     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getMetadata());
356   case MachineOperand::MO_MCSymbol:
357     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getMCSymbol());
358   case MachineOperand::MO_CFIIndex:
359     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getCFIIndex());
360   case MachineOperand::MO_IntrinsicID:
361     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIntrinsicID());
362   case MachineOperand::MO_Predicate:
363     return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getPredicate());
364   }
365   llvm_unreachable("Invalid machine operand type");
366 }
367 
368 void MachineOperand::print(raw_ostream &OS, const TargetRegisterInfo *TRI,
369                            const TargetIntrinsicInfo *IntrinsicInfo) const {
370   ModuleSlotTracker DummyMST(nullptr);
371   print(OS, DummyMST, TRI, IntrinsicInfo);
372 }
373 
374 void MachineOperand::print(raw_ostream &OS, ModuleSlotTracker &MST,
375                            const TargetRegisterInfo *TRI,
376                            const TargetIntrinsicInfo *IntrinsicInfo) const {
377   switch (getType()) {
378   case MachineOperand::MO_Register:
379     OS << PrintReg(getReg(), TRI, getSubReg());
380 
381     if (isDef() || isKill() || isDead() || isImplicit() || isUndef() ||
382         isInternalRead() || isEarlyClobber() || isTied()) {
383       OS << '<';
384       bool NeedComma = false;
385       if (isDef()) {
386         if (NeedComma) OS << ',';
387         if (isEarlyClobber())
388           OS << "earlyclobber,";
389         if (isImplicit())
390           OS << "imp-";
391         OS << "def";
392         NeedComma = true;
393         // <def,read-undef> only makes sense when getSubReg() is set.
394         // Don't clutter the output otherwise.
395         if (isUndef() && getSubReg())
396           OS << ",read-undef";
397       } else if (isImplicit()) {
398         OS << "imp-use";
399         NeedComma = true;
400       }
401 
402       if (isKill()) {
403         if (NeedComma) OS << ',';
404         OS << "kill";
405         NeedComma = true;
406       }
407       if (isDead()) {
408         if (NeedComma) OS << ',';
409         OS << "dead";
410         NeedComma = true;
411       }
412       if (isUndef() && isUse()) {
413         if (NeedComma) OS << ',';
414         OS << "undef";
415         NeedComma = true;
416       }
417       if (isInternalRead()) {
418         if (NeedComma) OS << ',';
419         OS << "internal";
420         NeedComma = true;
421       }
422       if (isTied()) {
423         if (NeedComma) OS << ',';
424         OS << "tied";
425         if (TiedTo != 15)
426           OS << unsigned(TiedTo - 1);
427       }
428       OS << '>';
429     }
430     break;
431   case MachineOperand::MO_Immediate:
432     OS << getImm();
433     break;
434   case MachineOperand::MO_CImmediate:
435     getCImm()->getValue().print(OS, false);
436     break;
437   case MachineOperand::MO_FPImmediate:
438     if (getFPImm()->getType()->isFloatTy()) {
439       OS << getFPImm()->getValueAPF().convertToFloat();
440     } else if (getFPImm()->getType()->isHalfTy()) {
441       APFloat APF = getFPImm()->getValueAPF();
442       bool Unused;
443       APF.convert(APFloat::IEEEsingle(), APFloat::rmNearestTiesToEven, &Unused);
444       OS << "half " << APF.convertToFloat();
445     } else if (getFPImm()->getType()->isFP128Ty()) {
446       APFloat APF = getFPImm()->getValueAPF();
447       SmallString<16> Str;
448       getFPImm()->getValueAPF().toString(Str);
449       OS << "quad " << Str;
450     } else if (getFPImm()->getType()->isX86_FP80Ty()) {
451       APFloat APF = getFPImm()->getValueAPF();
452       OS << "x86_fp80 0xK";
453       APInt API = APF.bitcastToAPInt();
454       OS << format_hex_no_prefix(API.getHiBits(16).getZExtValue(), 4,
455                                  /*Upper=*/true);
456       OS << format_hex_no_prefix(API.getLoBits(64).getZExtValue(), 16,
457                                  /*Upper=*/true);
458     } else {
459       OS << getFPImm()->getValueAPF().convertToDouble();
460     }
461     break;
462   case MachineOperand::MO_MachineBasicBlock:
463     OS << "<BB#" << getMBB()->getNumber() << ">";
464     break;
465   case MachineOperand::MO_FrameIndex:
466     OS << "<fi#" << getIndex() << '>';
467     break;
468   case MachineOperand::MO_ConstantPoolIndex:
469     OS << "<cp#" << getIndex();
470     if (getOffset()) OS << "+" << getOffset();
471     OS << '>';
472     break;
473   case MachineOperand::MO_TargetIndex:
474     OS << "<ti#" << getIndex();
475     if (getOffset()) OS << "+" << getOffset();
476     OS << '>';
477     break;
478   case MachineOperand::MO_JumpTableIndex:
479     OS << "<jt#" << getIndex() << '>';
480     break;
481   case MachineOperand::MO_GlobalAddress:
482     OS << "<ga:";
483     getGlobal()->printAsOperand(OS, /*PrintType=*/false, MST);
484     if (getOffset()) OS << "+" << getOffset();
485     OS << '>';
486     break;
487   case MachineOperand::MO_ExternalSymbol:
488     OS << "<es:" << getSymbolName();
489     if (getOffset()) OS << "+" << getOffset();
490     OS << '>';
491     break;
492   case MachineOperand::MO_BlockAddress:
493     OS << '<';
494     getBlockAddress()->printAsOperand(OS, /*PrintType=*/false, MST);
495     if (getOffset()) OS << "+" << getOffset();
496     OS << '>';
497     break;
498   case MachineOperand::MO_RegisterMask: {
499     unsigned NumRegsInMask = 0;
500     unsigned NumRegsEmitted = 0;
501     OS << "<regmask";
502     for (unsigned i = 0; i < TRI->getNumRegs(); ++i) {
503       unsigned MaskWord = i / 32;
504       unsigned MaskBit = i % 32;
505       if (getRegMask()[MaskWord] & (1 << MaskBit)) {
506         if (PrintWholeRegMask || NumRegsEmitted <= 10) {
507           OS << " " << PrintReg(i, TRI);
508           NumRegsEmitted++;
509         }
510         NumRegsInMask++;
511       }
512     }
513     if (NumRegsEmitted != NumRegsInMask)
514       OS << " and " << (NumRegsInMask - NumRegsEmitted) << " more...";
515     OS << ">";
516     break;
517   }
518   case MachineOperand::MO_RegisterLiveOut:
519     OS << "<regliveout>";
520     break;
521   case MachineOperand::MO_Metadata:
522     OS << '<';
523     getMetadata()->printAsOperand(OS, MST);
524     OS << '>';
525     break;
526   case MachineOperand::MO_MCSymbol:
527     OS << "<MCSym=" << *getMCSymbol() << '>';
528     break;
529   case MachineOperand::MO_CFIIndex:
530     OS << "<call frame instruction>";
531     break;
532   case MachineOperand::MO_IntrinsicID: {
533     Intrinsic::ID ID = getIntrinsicID();
534     if (ID < Intrinsic::num_intrinsics)
535       OS << "<intrinsic:@" << Intrinsic::getName(ID, None) << '>';
536     else if (IntrinsicInfo)
537       OS << "<intrinsic:@" << IntrinsicInfo->getName(ID) << '>';
538     else
539       OS << "<intrinsic:" << ID << '>';
540     break;
541   }
542   case MachineOperand::MO_Predicate: {
543     auto Pred = static_cast<CmpInst::Predicate>(getPredicate());
544     OS << '<' << (CmpInst::isIntPredicate(Pred) ? "intpred" : "floatpred")
545        << CmpInst::getPredicateName(Pred) << '>';
546     break;
547   }
548   }
549   if (unsigned TF = getTargetFlags())
550     OS << "[TF=" << TF << ']';
551 }
552 
553 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
554 LLVM_DUMP_METHOD void MachineOperand::dump() const {
555   dbgs() << *this << '\n';
556 }
557 #endif
558 
559 //===----------------------------------------------------------------------===//
560 // MachineMemOperand Implementation
561 //===----------------------------------------------------------------------===//
562 
563 /// getAddrSpace - Return the LLVM IR address space number that this pointer
564 /// points into.
565 unsigned MachinePointerInfo::getAddrSpace() const {
566   if (V.isNull() || V.is<const PseudoSourceValue*>()) return 0;
567   return cast<PointerType>(V.get<const Value*>()->getType())->getAddressSpace();
568 }
569 
570 /// isDereferenceable - Return true if V is always dereferenceable for
571 /// Offset + Size byte.
572 bool MachinePointerInfo::isDereferenceable(unsigned Size, LLVMContext &C,
573                                            const DataLayout &DL) const {
574   if (!V.is<const Value*>())
575     return false;
576 
577   const Value *BasePtr = V.get<const Value*>();
578   if (BasePtr == nullptr)
579     return false;
580 
581   return isDereferenceableAndAlignedPointer(BasePtr, 1,
582                                             APInt(DL.getPointerSize(),
583                                                   Offset + Size),
584                                             DL);
585 }
586 
587 /// getConstantPool - Return a MachinePointerInfo record that refers to the
588 /// constant pool.
589 MachinePointerInfo MachinePointerInfo::getConstantPool(MachineFunction &MF) {
590   return MachinePointerInfo(MF.getPSVManager().getConstantPool());
591 }
592 
593 /// getFixedStack - Return a MachinePointerInfo record that refers to the
594 /// the specified FrameIndex.
595 MachinePointerInfo MachinePointerInfo::getFixedStack(MachineFunction &MF,
596                                                      int FI, int64_t Offset) {
597   return MachinePointerInfo(MF.getPSVManager().getFixedStack(FI), Offset);
598 }
599 
600 MachinePointerInfo MachinePointerInfo::getJumpTable(MachineFunction &MF) {
601   return MachinePointerInfo(MF.getPSVManager().getJumpTable());
602 }
603 
604 MachinePointerInfo MachinePointerInfo::getGOT(MachineFunction &MF) {
605   return MachinePointerInfo(MF.getPSVManager().getGOT());
606 }
607 
608 MachinePointerInfo MachinePointerInfo::getStack(MachineFunction &MF,
609                                                 int64_t Offset) {
610   return MachinePointerInfo(MF.getPSVManager().getStack(), Offset);
611 }
612 
613 MachineMemOperand::MachineMemOperand(MachinePointerInfo ptrinfo, Flags f,
614                                      uint64_t s, unsigned int a,
615                                      const AAMDNodes &AAInfo,
616                                      const MDNode *Ranges,
617                                      SynchronizationScope SynchScope,
618                                      AtomicOrdering Ordering,
619                                      AtomicOrdering FailureOrdering)
620     : PtrInfo(ptrinfo), Size(s), FlagVals(f), BaseAlignLog2(Log2_32(a) + 1),
621       AAInfo(AAInfo), Ranges(Ranges) {
622   assert((PtrInfo.V.isNull() || PtrInfo.V.is<const PseudoSourceValue*>() ||
623           isa<PointerType>(PtrInfo.V.get<const Value*>()->getType())) &&
624          "invalid pointer value");
625   assert(getBaseAlignment() == a && "Alignment is not a power of 2!");
626   assert((isLoad() || isStore()) && "Not a load/store!");
627 
628   AtomicInfo.SynchScope = static_cast<unsigned>(SynchScope);
629   assert(getSynchScope() == SynchScope && "Value truncated");
630   AtomicInfo.Ordering = static_cast<unsigned>(Ordering);
631   assert(getOrdering() == Ordering && "Value truncated");
632   AtomicInfo.FailureOrdering = static_cast<unsigned>(FailureOrdering);
633   assert(getFailureOrdering() == FailureOrdering && "Value truncated");
634 }
635 
636 /// Profile - Gather unique data for the object.
637 ///
638 void MachineMemOperand::Profile(FoldingSetNodeID &ID) const {
639   ID.AddInteger(getOffset());
640   ID.AddInteger(Size);
641   ID.AddPointer(getOpaqueValue());
642   ID.AddInteger(getFlags());
643   ID.AddInteger(getBaseAlignment());
644 }
645 
646 void MachineMemOperand::refineAlignment(const MachineMemOperand *MMO) {
647   // The Value and Offset may differ due to CSE. But the flags and size
648   // should be the same.
649   assert(MMO->getFlags() == getFlags() && "Flags mismatch!");
650   assert(MMO->getSize() == getSize() && "Size mismatch!");
651 
652   if (MMO->getBaseAlignment() >= getBaseAlignment()) {
653     // Update the alignment value.
654     BaseAlignLog2 = Log2_32(MMO->getBaseAlignment()) + 1;
655     // Also update the base and offset, because the new alignment may
656     // not be applicable with the old ones.
657     PtrInfo = MMO->PtrInfo;
658   }
659 }
660 
661 /// getAlignment - Return the minimum known alignment in bytes of the
662 /// actual memory reference.
663 uint64_t MachineMemOperand::getAlignment() const {
664   return MinAlign(getBaseAlignment(), getOffset());
665 }
666 
667 void MachineMemOperand::print(raw_ostream &OS) const {
668   ModuleSlotTracker DummyMST(nullptr);
669   print(OS, DummyMST);
670 }
671 void MachineMemOperand::print(raw_ostream &OS, ModuleSlotTracker &MST) const {
672   assert((isLoad() || isStore()) &&
673          "SV has to be a load, store or both.");
674 
675   if (isVolatile())
676     OS << "Volatile ";
677 
678   if (isLoad())
679     OS << "LD";
680   if (isStore())
681     OS << "ST";
682   OS << getSize();
683 
684   // Print the address information.
685   OS << "[";
686   if (const Value *V = getValue())
687     V->printAsOperand(OS, /*PrintType=*/false, MST);
688   else if (const PseudoSourceValue *PSV = getPseudoValue())
689     PSV->printCustom(OS);
690   else
691     OS << "<unknown>";
692 
693   unsigned AS = getAddrSpace();
694   if (AS != 0)
695     OS << "(addrspace=" << AS << ')';
696 
697   // If the alignment of the memory reference itself differs from the alignment
698   // of the base pointer, print the base alignment explicitly, next to the base
699   // pointer.
700   if (getBaseAlignment() != getAlignment())
701     OS << "(align=" << getBaseAlignment() << ")";
702 
703   if (getOffset() != 0)
704     OS << "+" << getOffset();
705   OS << "]";
706 
707   // Print the alignment of the reference.
708   if (getBaseAlignment() != getAlignment() || getBaseAlignment() != getSize())
709     OS << "(align=" << getAlignment() << ")";
710 
711   // Print TBAA info.
712   if (const MDNode *TBAAInfo = getAAInfo().TBAA) {
713     OS << "(tbaa=";
714     if (TBAAInfo->getNumOperands() > 0)
715       TBAAInfo->getOperand(0)->printAsOperand(OS, MST);
716     else
717       OS << "<unknown>";
718     OS << ")";
719   }
720 
721   // Print AA scope info.
722   if (const MDNode *ScopeInfo = getAAInfo().Scope) {
723     OS << "(alias.scope=";
724     if (ScopeInfo->getNumOperands() > 0)
725       for (unsigned i = 0, ie = ScopeInfo->getNumOperands(); i != ie; ++i) {
726         ScopeInfo->getOperand(i)->printAsOperand(OS, MST);
727         if (i != ie-1)
728           OS << ",";
729       }
730     else
731       OS << "<unknown>";
732     OS << ")";
733   }
734 
735   // Print AA noalias scope info.
736   if (const MDNode *NoAliasInfo = getAAInfo().NoAlias) {
737     OS << "(noalias=";
738     if (NoAliasInfo->getNumOperands() > 0)
739       for (unsigned i = 0, ie = NoAliasInfo->getNumOperands(); i != ie; ++i) {
740         NoAliasInfo->getOperand(i)->printAsOperand(OS, MST);
741         if (i != ie-1)
742           OS << ",";
743       }
744     else
745       OS << "<unknown>";
746     OS << ")";
747   }
748 
749   if (isNonTemporal())
750     OS << "(nontemporal)";
751   if (isDereferenceable())
752     OS << "(dereferenceable)";
753   if (isInvariant())
754     OS << "(invariant)";
755 }
756 
757 //===----------------------------------------------------------------------===//
758 // MachineInstr Implementation
759 //===----------------------------------------------------------------------===//
760 
761 void MachineInstr::addImplicitDefUseOperands(MachineFunction &MF) {
762   if (MCID->ImplicitDefs)
763     for (const MCPhysReg *ImpDefs = MCID->getImplicitDefs(); *ImpDefs;
764            ++ImpDefs)
765       addOperand(MF, MachineOperand::CreateReg(*ImpDefs, true, true));
766   if (MCID->ImplicitUses)
767     for (const MCPhysReg *ImpUses = MCID->getImplicitUses(); *ImpUses;
768            ++ImpUses)
769       addOperand(MF, MachineOperand::CreateReg(*ImpUses, false, true));
770 }
771 
772 /// MachineInstr ctor - This constructor creates a MachineInstr and adds the
773 /// implicit operands. It reserves space for the number of operands specified by
774 /// the MCInstrDesc.
775 MachineInstr::MachineInstr(MachineFunction &MF, const MCInstrDesc &tid,
776                            DebugLoc dl, bool NoImp)
777     : MCID(&tid), debugLoc(std::move(dl)) {
778   assert(debugLoc.hasTrivialDestructor() && "Expected trivial destructor");
779 
780   // Reserve space for the expected number of operands.
781   if (unsigned NumOps = MCID->getNumOperands() +
782     MCID->getNumImplicitDefs() + MCID->getNumImplicitUses()) {
783     CapOperands = OperandCapacity::get(NumOps);
784     Operands = MF.allocateOperandArray(CapOperands);
785   }
786 
787   if (!NoImp)
788     addImplicitDefUseOperands(MF);
789 }
790 
791 /// MachineInstr ctor - Copies MachineInstr arg exactly
792 ///
793 MachineInstr::MachineInstr(MachineFunction &MF, const MachineInstr &MI)
794     : MCID(&MI.getDesc()), NumMemRefs(MI.NumMemRefs), MemRefs(MI.MemRefs),
795       debugLoc(MI.getDebugLoc()) {
796   assert(debugLoc.hasTrivialDestructor() && "Expected trivial destructor");
797 
798   CapOperands = OperandCapacity::get(MI.getNumOperands());
799   Operands = MF.allocateOperandArray(CapOperands);
800 
801   // Copy operands.
802   for (const MachineOperand &MO : MI.operands())
803     addOperand(MF, MO);
804 
805   // Copy all the sensible flags.
806   setFlags(MI.Flags);
807 }
808 
809 /// getRegInfo - If this instruction is embedded into a MachineFunction,
810 /// return the MachineRegisterInfo object for the current function, otherwise
811 /// return null.
812 MachineRegisterInfo *MachineInstr::getRegInfo() {
813   if (MachineBasicBlock *MBB = getParent())
814     return &MBB->getParent()->getRegInfo();
815   return nullptr;
816 }
817 
818 /// RemoveRegOperandsFromUseLists - Unlink all of the register operands in
819 /// this instruction from their respective use lists.  This requires that the
820 /// operands already be on their use lists.
821 void MachineInstr::RemoveRegOperandsFromUseLists(MachineRegisterInfo &MRI) {
822   for (MachineOperand &MO : operands())
823     if (MO.isReg())
824       MRI.removeRegOperandFromUseList(&MO);
825 }
826 
827 /// AddRegOperandsToUseLists - Add all of the register operands in
828 /// this instruction from their respective use lists.  This requires that the
829 /// operands not be on their use lists yet.
830 void MachineInstr::AddRegOperandsToUseLists(MachineRegisterInfo &MRI) {
831   for (MachineOperand &MO : operands())
832     if (MO.isReg())
833       MRI.addRegOperandToUseList(&MO);
834 }
835 
836 void MachineInstr::addOperand(const MachineOperand &Op) {
837   MachineBasicBlock *MBB = getParent();
838   assert(MBB && "Use MachineInstrBuilder to add operands to dangling instrs");
839   MachineFunction *MF = MBB->getParent();
840   assert(MF && "Use MachineInstrBuilder to add operands to dangling instrs");
841   addOperand(*MF, Op);
842 }
843 
844 /// Move NumOps MachineOperands from Src to Dst, with support for overlapping
845 /// ranges. If MRI is non-null also update use-def chains.
846 static void moveOperands(MachineOperand *Dst, MachineOperand *Src,
847                          unsigned NumOps, MachineRegisterInfo *MRI) {
848   if (MRI)
849     return MRI->moveOperands(Dst, Src, NumOps);
850 
851   // MachineOperand is a trivially copyable type so we can just use memmove.
852   std::memmove(Dst, Src, NumOps * sizeof(MachineOperand));
853 }
854 
855 /// addOperand - Add the specified operand to the instruction.  If it is an
856 /// implicit operand, it is added to the end of the operand list.  If it is
857 /// an explicit operand it is added at the end of the explicit operand list
858 /// (before the first implicit operand).
859 void MachineInstr::addOperand(MachineFunction &MF, const MachineOperand &Op) {
860   assert(MCID && "Cannot add operands before providing an instr descriptor");
861 
862   // Check if we're adding one of our existing operands.
863   if (&Op >= Operands && &Op < Operands + NumOperands) {
864     // This is unusual: MI->addOperand(MI->getOperand(i)).
865     // If adding Op requires reallocating or moving existing operands around,
866     // the Op reference could go stale. Support it by copying Op.
867     MachineOperand CopyOp(Op);
868     return addOperand(MF, CopyOp);
869   }
870 
871   // Find the insert location for the new operand.  Implicit registers go at
872   // the end, everything else goes before the implicit regs.
873   //
874   // FIXME: Allow mixed explicit and implicit operands on inline asm.
875   // InstrEmitter::EmitSpecialNode() is marking inline asm clobbers as
876   // implicit-defs, but they must not be moved around.  See the FIXME in
877   // InstrEmitter.cpp.
878   unsigned OpNo = getNumOperands();
879   bool isImpReg = Op.isReg() && Op.isImplicit();
880   if (!isImpReg && !isInlineAsm()) {
881     while (OpNo && Operands[OpNo-1].isReg() && Operands[OpNo-1].isImplicit()) {
882       --OpNo;
883       assert(!Operands[OpNo].isTied() && "Cannot move tied operands");
884     }
885   }
886 
887 #ifndef NDEBUG
888   bool isMetaDataOp = Op.getType() == MachineOperand::MO_Metadata;
889   // OpNo now points as the desired insertion point.  Unless this is a variadic
890   // instruction, only implicit regs are allowed beyond MCID->getNumOperands().
891   // RegMask operands go between the explicit and implicit operands.
892   assert((isImpReg || Op.isRegMask() || MCID->isVariadic() ||
893           OpNo < MCID->getNumOperands() || isMetaDataOp) &&
894          "Trying to add an operand to a machine instr that is already done!");
895 #endif
896 
897   MachineRegisterInfo *MRI = getRegInfo();
898 
899   // Determine if the Operands array needs to be reallocated.
900   // Save the old capacity and operand array.
901   OperandCapacity OldCap = CapOperands;
902   MachineOperand *OldOperands = Operands;
903   if (!OldOperands || OldCap.getSize() == getNumOperands()) {
904     CapOperands = OldOperands ? OldCap.getNext() : OldCap.get(1);
905     Operands = MF.allocateOperandArray(CapOperands);
906     // Move the operands before the insertion point.
907     if (OpNo)
908       moveOperands(Operands, OldOperands, OpNo, MRI);
909   }
910 
911   // Move the operands following the insertion point.
912   if (OpNo != NumOperands)
913     moveOperands(Operands + OpNo + 1, OldOperands + OpNo, NumOperands - OpNo,
914                  MRI);
915   ++NumOperands;
916 
917   // Deallocate the old operand array.
918   if (OldOperands != Operands && OldOperands)
919     MF.deallocateOperandArray(OldCap, OldOperands);
920 
921   // Copy Op into place. It still needs to be inserted into the MRI use lists.
922   MachineOperand *NewMO = new (Operands + OpNo) MachineOperand(Op);
923   NewMO->ParentMI = this;
924 
925   // When adding a register operand, tell MRI about it.
926   if (NewMO->isReg()) {
927     // Ensure isOnRegUseList() returns false, regardless of Op's status.
928     NewMO->Contents.Reg.Prev = nullptr;
929     // Ignore existing ties. This is not a property that can be copied.
930     NewMO->TiedTo = 0;
931     // Add the new operand to MRI, but only for instructions in an MBB.
932     if (MRI)
933       MRI->addRegOperandToUseList(NewMO);
934     // The MCID operand information isn't accurate until we start adding
935     // explicit operands. The implicit operands are added first, then the
936     // explicits are inserted before them.
937     if (!isImpReg) {
938       // Tie uses to defs as indicated in MCInstrDesc.
939       if (NewMO->isUse()) {
940         int DefIdx = MCID->getOperandConstraint(OpNo, MCOI::TIED_TO);
941         if (DefIdx != -1)
942           tieOperands(DefIdx, OpNo);
943       }
944       // If the register operand is flagged as early, mark the operand as such.
945       if (MCID->getOperandConstraint(OpNo, MCOI::EARLY_CLOBBER) != -1)
946         NewMO->setIsEarlyClobber(true);
947     }
948   }
949 }
950 
951 /// RemoveOperand - Erase an operand  from an instruction, leaving it with one
952 /// fewer operand than it started with.
953 ///
954 void MachineInstr::RemoveOperand(unsigned OpNo) {
955   assert(OpNo < getNumOperands() && "Invalid operand number");
956   untieRegOperand(OpNo);
957 
958 #ifndef NDEBUG
959   // Moving tied operands would break the ties.
960   for (unsigned i = OpNo + 1, e = getNumOperands(); i != e; ++i)
961     if (Operands[i].isReg())
962       assert(!Operands[i].isTied() && "Cannot move tied operands");
963 #endif
964 
965   MachineRegisterInfo *MRI = getRegInfo();
966   if (MRI && Operands[OpNo].isReg())
967     MRI->removeRegOperandFromUseList(Operands + OpNo);
968 
969   // Don't call the MachineOperand destructor. A lot of this code depends on
970   // MachineOperand having a trivial destructor anyway, and adding a call here
971   // wouldn't make it 'destructor-correct'.
972 
973   if (unsigned N = NumOperands - 1 - OpNo)
974     moveOperands(Operands + OpNo, Operands + OpNo + 1, N, MRI);
975   --NumOperands;
976 }
977 
978 /// addMemOperand - Add a MachineMemOperand to the machine instruction.
979 /// This function should be used only occasionally. The setMemRefs function
980 /// is the primary method for setting up a MachineInstr's MemRefs list.
981 void MachineInstr::addMemOperand(MachineFunction &MF,
982                                  MachineMemOperand *MO) {
983   mmo_iterator OldMemRefs = MemRefs;
984   unsigned OldNumMemRefs = NumMemRefs;
985 
986   unsigned NewNum = NumMemRefs + 1;
987   mmo_iterator NewMemRefs = MF.allocateMemRefsArray(NewNum);
988 
989   std::copy(OldMemRefs, OldMemRefs + OldNumMemRefs, NewMemRefs);
990   NewMemRefs[NewNum - 1] = MO;
991   setMemRefs(NewMemRefs, NewMemRefs + NewNum);
992 }
993 
994 /// Check to see if the MMOs pointed to by the two MemRefs arrays are
995 /// identical.
996 static bool hasIdenticalMMOs(const MachineInstr &MI1, const MachineInstr &MI2) {
997   auto I1 = MI1.memoperands_begin(), E1 = MI1.memoperands_end();
998   auto I2 = MI2.memoperands_begin(), E2 = MI2.memoperands_end();
999   if ((E1 - I1) != (E2 - I2))
1000     return false;
1001   for (; I1 != E1; ++I1, ++I2) {
1002     if (**I1 != **I2)
1003       return false;
1004   }
1005   return true;
1006 }
1007 
1008 std::pair<MachineInstr::mmo_iterator, unsigned>
1009 MachineInstr::mergeMemRefsWith(const MachineInstr& Other) {
1010 
1011   // If either of the incoming memrefs are empty, we must be conservative and
1012   // treat this as if we've exhausted our space for memrefs and dropped them.
1013   if (memoperands_empty() || Other.memoperands_empty())
1014     return std::make_pair(nullptr, 0);
1015 
1016   // If both instructions have identical memrefs, we don't need to merge them.
1017   // Since many instructions have a single memref, and we tend to merge things
1018   // like pairs of loads from the same location, this catches a large number of
1019   // cases in practice.
1020   if (hasIdenticalMMOs(*this, Other))
1021     return std::make_pair(MemRefs, NumMemRefs);
1022 
1023   // TODO: consider uniquing elements within the operand lists to reduce
1024   // space usage and fall back to conservative information less often.
1025   size_t CombinedNumMemRefs = NumMemRefs + Other.NumMemRefs;
1026 
1027   // If we don't have enough room to store this many memrefs, be conservative
1028   // and drop them.  Otherwise, we'd fail asserts when trying to add them to
1029   // the new instruction.
1030   if (CombinedNumMemRefs != uint8_t(CombinedNumMemRefs))
1031     return std::make_pair(nullptr, 0);
1032 
1033   MachineFunction *MF = getParent()->getParent();
1034   mmo_iterator MemBegin = MF->allocateMemRefsArray(CombinedNumMemRefs);
1035   mmo_iterator MemEnd = std::copy(memoperands_begin(), memoperands_end(),
1036                                   MemBegin);
1037   MemEnd = std::copy(Other.memoperands_begin(), Other.memoperands_end(),
1038                      MemEnd);
1039   assert(MemEnd - MemBegin == (ptrdiff_t)CombinedNumMemRefs &&
1040          "missing memrefs");
1041 
1042   return std::make_pair(MemBegin, CombinedNumMemRefs);
1043 }
1044 
1045 bool MachineInstr::hasPropertyInBundle(unsigned Mask, QueryType Type) const {
1046   assert(!isBundledWithPred() && "Must be called on bundle header");
1047   for (MachineBasicBlock::const_instr_iterator MII = getIterator();; ++MII) {
1048     if (MII->getDesc().getFlags() & Mask) {
1049       if (Type == AnyInBundle)
1050         return true;
1051     } else {
1052       if (Type == AllInBundle && !MII->isBundle())
1053         return false;
1054     }
1055     // This was the last instruction in the bundle.
1056     if (!MII->isBundledWithSucc())
1057       return Type == AllInBundle;
1058   }
1059 }
1060 
1061 bool MachineInstr::isIdenticalTo(const MachineInstr &Other,
1062                                  MICheckType Check) const {
1063   // If opcodes or number of operands are not the same then the two
1064   // instructions are obviously not identical.
1065   if (Other.getOpcode() != getOpcode() ||
1066       Other.getNumOperands() != getNumOperands())
1067     return false;
1068 
1069   if (isBundle()) {
1070     // We have passed the test above that both instructions have the same
1071     // opcode, so we know that both instructions are bundles here. Let's compare
1072     // MIs inside the bundle.
1073     assert(Other.isBundle() && "Expected that both instructions are bundles.");
1074     MachineBasicBlock::const_instr_iterator I1 = getIterator();
1075     MachineBasicBlock::const_instr_iterator I2 = Other.getIterator();
1076     // Loop until we analysed the last intruction inside at least one of the
1077     // bundles.
1078     while (I1->isBundledWithSucc() && I2->isBundledWithSucc()) {
1079       ++I1;
1080       ++I2;
1081       if (!I1->isIdenticalTo(*I2, Check))
1082         return false;
1083     }
1084     // If we've reached the end of just one of the two bundles, but not both,
1085     // the instructions are not identical.
1086     if (I1->isBundledWithSucc() || I2->isBundledWithSucc())
1087       return false;
1088   }
1089 
1090   // Check operands to make sure they match.
1091   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
1092     const MachineOperand &MO = getOperand(i);
1093     const MachineOperand &OMO = Other.getOperand(i);
1094     if (!MO.isReg()) {
1095       if (!MO.isIdenticalTo(OMO))
1096         return false;
1097       continue;
1098     }
1099 
1100     // Clients may or may not want to ignore defs when testing for equality.
1101     // For example, machine CSE pass only cares about finding common
1102     // subexpressions, so it's safe to ignore virtual register defs.
1103     if (MO.isDef()) {
1104       if (Check == IgnoreDefs)
1105         continue;
1106       else if (Check == IgnoreVRegDefs) {
1107         if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()) ||
1108             TargetRegisterInfo::isPhysicalRegister(OMO.getReg()))
1109           if (MO.getReg() != OMO.getReg())
1110             return false;
1111       } else {
1112         if (!MO.isIdenticalTo(OMO))
1113           return false;
1114         if (Check == CheckKillDead && MO.isDead() != OMO.isDead())
1115           return false;
1116       }
1117     } else {
1118       if (!MO.isIdenticalTo(OMO))
1119         return false;
1120       if (Check == CheckKillDead && MO.isKill() != OMO.isKill())
1121         return false;
1122     }
1123   }
1124   // If DebugLoc does not match then two dbg.values are not identical.
1125   if (isDebugValue())
1126     if (getDebugLoc() && Other.getDebugLoc() &&
1127         getDebugLoc() != Other.getDebugLoc())
1128       return false;
1129   return true;
1130 }
1131 
1132 MachineInstr *MachineInstr::removeFromParent() {
1133   assert(getParent() && "Not embedded in a basic block!");
1134   return getParent()->remove(this);
1135 }
1136 
1137 MachineInstr *MachineInstr::removeFromBundle() {
1138   assert(getParent() && "Not embedded in a basic block!");
1139   return getParent()->remove_instr(this);
1140 }
1141 
1142 void MachineInstr::eraseFromParent() {
1143   assert(getParent() && "Not embedded in a basic block!");
1144   getParent()->erase(this);
1145 }
1146 
1147 void MachineInstr::eraseFromParentAndMarkDBGValuesForRemoval() {
1148   assert(getParent() && "Not embedded in a basic block!");
1149   MachineBasicBlock *MBB = getParent();
1150   MachineFunction *MF = MBB->getParent();
1151   assert(MF && "Not embedded in a function!");
1152 
1153   MachineInstr *MI = (MachineInstr *)this;
1154   MachineRegisterInfo &MRI = MF->getRegInfo();
1155 
1156   for (const MachineOperand &MO : MI->operands()) {
1157     if (!MO.isReg() || !MO.isDef())
1158       continue;
1159     unsigned Reg = MO.getReg();
1160     if (!TargetRegisterInfo::isVirtualRegister(Reg))
1161       continue;
1162     MRI.markUsesInDebugValueAsUndef(Reg);
1163   }
1164   MI->eraseFromParent();
1165 }
1166 
1167 void MachineInstr::eraseFromBundle() {
1168   assert(getParent() && "Not embedded in a basic block!");
1169   getParent()->erase_instr(this);
1170 }
1171 
1172 /// getNumExplicitOperands - Returns the number of non-implicit operands.
1173 ///
1174 unsigned MachineInstr::getNumExplicitOperands() const {
1175   unsigned NumOperands = MCID->getNumOperands();
1176   if (!MCID->isVariadic())
1177     return NumOperands;
1178 
1179   for (unsigned i = NumOperands, e = getNumOperands(); i != e; ++i) {
1180     const MachineOperand &MO = getOperand(i);
1181     if (!MO.isReg() || !MO.isImplicit())
1182       NumOperands++;
1183   }
1184   return NumOperands;
1185 }
1186 
1187 void MachineInstr::bundleWithPred() {
1188   assert(!isBundledWithPred() && "MI is already bundled with its predecessor");
1189   setFlag(BundledPred);
1190   MachineBasicBlock::instr_iterator Pred = getIterator();
1191   --Pred;
1192   assert(!Pred->isBundledWithSucc() && "Inconsistent bundle flags");
1193   Pred->setFlag(BundledSucc);
1194 }
1195 
1196 void MachineInstr::bundleWithSucc() {
1197   assert(!isBundledWithSucc() && "MI is already bundled with its successor");
1198   setFlag(BundledSucc);
1199   MachineBasicBlock::instr_iterator Succ = getIterator();
1200   ++Succ;
1201   assert(!Succ->isBundledWithPred() && "Inconsistent bundle flags");
1202   Succ->setFlag(BundledPred);
1203 }
1204 
1205 void MachineInstr::unbundleFromPred() {
1206   assert(isBundledWithPred() && "MI isn't bundled with its predecessor");
1207   clearFlag(BundledPred);
1208   MachineBasicBlock::instr_iterator Pred = getIterator();
1209   --Pred;
1210   assert(Pred->isBundledWithSucc() && "Inconsistent bundle flags");
1211   Pred->clearFlag(BundledSucc);
1212 }
1213 
1214 void MachineInstr::unbundleFromSucc() {
1215   assert(isBundledWithSucc() && "MI isn't bundled with its successor");
1216   clearFlag(BundledSucc);
1217   MachineBasicBlock::instr_iterator Succ = getIterator();
1218   ++Succ;
1219   assert(Succ->isBundledWithPred() && "Inconsistent bundle flags");
1220   Succ->clearFlag(BundledPred);
1221 }
1222 
1223 bool MachineInstr::isStackAligningInlineAsm() const {
1224   if (isInlineAsm()) {
1225     unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
1226     if (ExtraInfo & InlineAsm::Extra_IsAlignStack)
1227       return true;
1228   }
1229   return false;
1230 }
1231 
1232 InlineAsm::AsmDialect MachineInstr::getInlineAsmDialect() const {
1233   assert(isInlineAsm() && "getInlineAsmDialect() only works for inline asms!");
1234   unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
1235   return InlineAsm::AsmDialect((ExtraInfo & InlineAsm::Extra_AsmDialect) != 0);
1236 }
1237 
1238 int MachineInstr::findInlineAsmFlagIdx(unsigned OpIdx,
1239                                        unsigned *GroupNo) const {
1240   assert(isInlineAsm() && "Expected an inline asm instruction");
1241   assert(OpIdx < getNumOperands() && "OpIdx out of range");
1242 
1243   // Ignore queries about the initial operands.
1244   if (OpIdx < InlineAsm::MIOp_FirstOperand)
1245     return -1;
1246 
1247   unsigned Group = 0;
1248   unsigned NumOps;
1249   for (unsigned i = InlineAsm::MIOp_FirstOperand, e = getNumOperands(); i < e;
1250        i += NumOps) {
1251     const MachineOperand &FlagMO = getOperand(i);
1252     // If we reach the implicit register operands, stop looking.
1253     if (!FlagMO.isImm())
1254       return -1;
1255     NumOps = 1 + InlineAsm::getNumOperandRegisters(FlagMO.getImm());
1256     if (i + NumOps > OpIdx) {
1257       if (GroupNo)
1258         *GroupNo = Group;
1259       return i;
1260     }
1261     ++Group;
1262   }
1263   return -1;
1264 }
1265 
1266 const DILocalVariable *MachineInstr::getDebugVariable() const {
1267   assert(isDebugValue() && "not a DBG_VALUE");
1268   return cast<DILocalVariable>(getOperand(2).getMetadata());
1269 }
1270 
1271 const DIExpression *MachineInstr::getDebugExpression() const {
1272   assert(isDebugValue() && "not a DBG_VALUE");
1273   return cast<DIExpression>(getOperand(3).getMetadata());
1274 }
1275 
1276 const TargetRegisterClass*
1277 MachineInstr::getRegClassConstraint(unsigned OpIdx,
1278                                     const TargetInstrInfo *TII,
1279                                     const TargetRegisterInfo *TRI) const {
1280   assert(getParent() && "Can't have an MBB reference here!");
1281   assert(getParent()->getParent() && "Can't have an MF reference here!");
1282   const MachineFunction &MF = *getParent()->getParent();
1283 
1284   // Most opcodes have fixed constraints in their MCInstrDesc.
1285   if (!isInlineAsm())
1286     return TII->getRegClass(getDesc(), OpIdx, TRI, MF);
1287 
1288   if (!getOperand(OpIdx).isReg())
1289     return nullptr;
1290 
1291   // For tied uses on inline asm, get the constraint from the def.
1292   unsigned DefIdx;
1293   if (getOperand(OpIdx).isUse() && isRegTiedToDefOperand(OpIdx, &DefIdx))
1294     OpIdx = DefIdx;
1295 
1296   // Inline asm stores register class constraints in the flag word.
1297   int FlagIdx = findInlineAsmFlagIdx(OpIdx);
1298   if (FlagIdx < 0)
1299     return nullptr;
1300 
1301   unsigned Flag = getOperand(FlagIdx).getImm();
1302   unsigned RCID;
1303   if ((InlineAsm::getKind(Flag) == InlineAsm::Kind_RegUse ||
1304        InlineAsm::getKind(Flag) == InlineAsm::Kind_RegDef ||
1305        InlineAsm::getKind(Flag) == InlineAsm::Kind_RegDefEarlyClobber) &&
1306       InlineAsm::hasRegClassConstraint(Flag, RCID))
1307     return TRI->getRegClass(RCID);
1308 
1309   // Assume that all registers in a memory operand are pointers.
1310   if (InlineAsm::getKind(Flag) == InlineAsm::Kind_Mem)
1311     return TRI->getPointerRegClass(MF);
1312 
1313   return nullptr;
1314 }
1315 
1316 const TargetRegisterClass *MachineInstr::getRegClassConstraintEffectForVReg(
1317     unsigned Reg, const TargetRegisterClass *CurRC, const TargetInstrInfo *TII,
1318     const TargetRegisterInfo *TRI, bool ExploreBundle) const {
1319   // Check every operands inside the bundle if we have
1320   // been asked to.
1321   if (ExploreBundle)
1322     for (ConstMIBundleOperands OpndIt(*this); OpndIt.isValid() && CurRC;
1323          ++OpndIt)
1324       CurRC = OpndIt->getParent()->getRegClassConstraintEffectForVRegImpl(
1325           OpndIt.getOperandNo(), Reg, CurRC, TII, TRI);
1326   else
1327     // Otherwise, just check the current operands.
1328     for (unsigned i = 0, e = NumOperands; i < e && CurRC; ++i)
1329       CurRC = getRegClassConstraintEffectForVRegImpl(i, Reg, CurRC, TII, TRI);
1330   return CurRC;
1331 }
1332 
1333 const TargetRegisterClass *MachineInstr::getRegClassConstraintEffectForVRegImpl(
1334     unsigned OpIdx, unsigned Reg, const TargetRegisterClass *CurRC,
1335     const TargetInstrInfo *TII, const TargetRegisterInfo *TRI) const {
1336   assert(CurRC && "Invalid initial register class");
1337   // Check if Reg is constrained by some of its use/def from MI.
1338   const MachineOperand &MO = getOperand(OpIdx);
1339   if (!MO.isReg() || MO.getReg() != Reg)
1340     return CurRC;
1341   // If yes, accumulate the constraints through the operand.
1342   return getRegClassConstraintEffect(OpIdx, CurRC, TII, TRI);
1343 }
1344 
1345 const TargetRegisterClass *MachineInstr::getRegClassConstraintEffect(
1346     unsigned OpIdx, const TargetRegisterClass *CurRC,
1347     const TargetInstrInfo *TII, const TargetRegisterInfo *TRI) const {
1348   const TargetRegisterClass *OpRC = getRegClassConstraint(OpIdx, TII, TRI);
1349   const MachineOperand &MO = getOperand(OpIdx);
1350   assert(MO.isReg() &&
1351          "Cannot get register constraints for non-register operand");
1352   assert(CurRC && "Invalid initial register class");
1353   if (unsigned SubIdx = MO.getSubReg()) {
1354     if (OpRC)
1355       CurRC = TRI->getMatchingSuperRegClass(CurRC, OpRC, SubIdx);
1356     else
1357       CurRC = TRI->getSubClassWithSubReg(CurRC, SubIdx);
1358   } else if (OpRC)
1359     CurRC = TRI->getCommonSubClass(CurRC, OpRC);
1360   return CurRC;
1361 }
1362 
1363 /// Return the number of instructions inside the MI bundle, not counting the
1364 /// header instruction.
1365 unsigned MachineInstr::getBundleSize() const {
1366   MachineBasicBlock::const_instr_iterator I = getIterator();
1367   unsigned Size = 0;
1368   while (I->isBundledWithSucc()) {
1369     ++Size;
1370     ++I;
1371   }
1372   return Size;
1373 }
1374 
1375 /// Returns true if the MachineInstr has an implicit-use operand of exactly
1376 /// the given register (not considering sub/super-registers).
1377 bool MachineInstr::hasRegisterImplicitUseOperand(unsigned Reg) const {
1378   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
1379     const MachineOperand &MO = getOperand(i);
1380     if (MO.isReg() && MO.isUse() && MO.isImplicit() && MO.getReg() == Reg)
1381       return true;
1382   }
1383   return false;
1384 }
1385 
1386 /// findRegisterUseOperandIdx() - Returns the MachineOperand that is a use of
1387 /// the specific register or -1 if it is not found. It further tightens
1388 /// the search criteria to a use that kills the register if isKill is true.
1389 int MachineInstr::findRegisterUseOperandIdx(
1390     unsigned Reg, bool isKill, const TargetRegisterInfo *TRI) const {
1391   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
1392     const MachineOperand &MO = getOperand(i);
1393     if (!MO.isReg() || !MO.isUse())
1394       continue;
1395     unsigned MOReg = MO.getReg();
1396     if (!MOReg)
1397       continue;
1398     if (MOReg == Reg || (TRI && TargetRegisterInfo::isPhysicalRegister(MOReg) &&
1399                          TargetRegisterInfo::isPhysicalRegister(Reg) &&
1400                          TRI->isSubRegister(MOReg, Reg)))
1401       if (!isKill || MO.isKill())
1402         return i;
1403   }
1404   return -1;
1405 }
1406 
1407 /// readsWritesVirtualRegister - Return a pair of bools (reads, writes)
1408 /// indicating if this instruction reads or writes Reg. This also considers
1409 /// partial defines.
1410 std::pair<bool,bool>
1411 MachineInstr::readsWritesVirtualRegister(unsigned Reg,
1412                                          SmallVectorImpl<unsigned> *Ops) const {
1413   bool PartDef = false; // Partial redefine.
1414   bool FullDef = false; // Full define.
1415   bool Use = false;
1416 
1417   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
1418     const MachineOperand &MO = getOperand(i);
1419     if (!MO.isReg() || MO.getReg() != Reg)
1420       continue;
1421     if (Ops)
1422       Ops->push_back(i);
1423     if (MO.isUse())
1424       Use |= !MO.isUndef();
1425     else if (MO.getSubReg() && !MO.isUndef())
1426       // A partial <def,undef> doesn't count as reading the register.
1427       PartDef = true;
1428     else
1429       FullDef = true;
1430   }
1431   // A partial redefine uses Reg unless there is also a full define.
1432   return std::make_pair(Use || (PartDef && !FullDef), PartDef || FullDef);
1433 }
1434 
1435 /// findRegisterDefOperandIdx() - Returns the operand index that is a def of
1436 /// the specified register or -1 if it is not found. If isDead is true, defs
1437 /// that are not dead are skipped. If TargetRegisterInfo is non-null, then it
1438 /// also checks if there is a def of a super-register.
1439 int
1440 MachineInstr::findRegisterDefOperandIdx(unsigned Reg, bool isDead, bool Overlap,
1441                                         const TargetRegisterInfo *TRI) const {
1442   bool isPhys = TargetRegisterInfo::isPhysicalRegister(Reg);
1443   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
1444     const MachineOperand &MO = getOperand(i);
1445     // Accept regmask operands when Overlap is set.
1446     // Ignore them when looking for a specific def operand (Overlap == false).
1447     if (isPhys && Overlap && MO.isRegMask() && MO.clobbersPhysReg(Reg))
1448       return i;
1449     if (!MO.isReg() || !MO.isDef())
1450       continue;
1451     unsigned MOReg = MO.getReg();
1452     bool Found = (MOReg == Reg);
1453     if (!Found && TRI && isPhys &&
1454         TargetRegisterInfo::isPhysicalRegister(MOReg)) {
1455       if (Overlap)
1456         Found = TRI->regsOverlap(MOReg, Reg);
1457       else
1458         Found = TRI->isSubRegister(MOReg, Reg);
1459     }
1460     if (Found && (!isDead || MO.isDead()))
1461       return i;
1462   }
1463   return -1;
1464 }
1465 
1466 /// findFirstPredOperandIdx() - Find the index of the first operand in the
1467 /// operand list that is used to represent the predicate. It returns -1 if
1468 /// none is found.
1469 int MachineInstr::findFirstPredOperandIdx() const {
1470   // Don't call MCID.findFirstPredOperandIdx() because this variant
1471   // is sometimes called on an instruction that's not yet complete, and
1472   // so the number of operands is less than the MCID indicates. In
1473   // particular, the PTX target does this.
1474   const MCInstrDesc &MCID = getDesc();
1475   if (MCID.isPredicable()) {
1476     for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
1477       if (MCID.OpInfo[i].isPredicate())
1478         return i;
1479   }
1480 
1481   return -1;
1482 }
1483 
1484 // MachineOperand::TiedTo is 4 bits wide.
1485 const unsigned TiedMax = 15;
1486 
1487 /// tieOperands - Mark operands at DefIdx and UseIdx as tied to each other.
1488 ///
1489 /// Use and def operands can be tied together, indicated by a non-zero TiedTo
1490 /// field. TiedTo can have these values:
1491 ///
1492 /// 0:              Operand is not tied to anything.
1493 /// 1 to TiedMax-1: Tied to getOperand(TiedTo-1).
1494 /// TiedMax:        Tied to an operand >= TiedMax-1.
1495 ///
1496 /// The tied def must be one of the first TiedMax operands on a normal
1497 /// instruction. INLINEASM instructions allow more tied defs.
1498 ///
1499 void MachineInstr::tieOperands(unsigned DefIdx, unsigned UseIdx) {
1500   MachineOperand &DefMO = getOperand(DefIdx);
1501   MachineOperand &UseMO = getOperand(UseIdx);
1502   assert(DefMO.isDef() && "DefIdx must be a def operand");
1503   assert(UseMO.isUse() && "UseIdx must be a use operand");
1504   assert(!DefMO.isTied() && "Def is already tied to another use");
1505   assert(!UseMO.isTied() && "Use is already tied to another def");
1506 
1507   if (DefIdx < TiedMax)
1508     UseMO.TiedTo = DefIdx + 1;
1509   else {
1510     // Inline asm can use the group descriptors to find tied operands, but on
1511     // normal instruction, the tied def must be within the first TiedMax
1512     // operands.
1513     assert(isInlineAsm() && "DefIdx out of range");
1514     UseMO.TiedTo = TiedMax;
1515   }
1516 
1517   // UseIdx can be out of range, we'll search for it in findTiedOperandIdx().
1518   DefMO.TiedTo = std::min(UseIdx + 1, TiedMax);
1519 }
1520 
1521 /// Given the index of a tied register operand, find the operand it is tied to.
1522 /// Defs are tied to uses and vice versa. Returns the index of the tied operand
1523 /// which must exist.
1524 unsigned MachineInstr::findTiedOperandIdx(unsigned OpIdx) const {
1525   const MachineOperand &MO = getOperand(OpIdx);
1526   assert(MO.isTied() && "Operand isn't tied");
1527 
1528   // Normally TiedTo is in range.
1529   if (MO.TiedTo < TiedMax)
1530     return MO.TiedTo - 1;
1531 
1532   // Uses on normal instructions can be out of range.
1533   if (!isInlineAsm()) {
1534     // Normal tied defs must be in the 0..TiedMax-1 range.
1535     if (MO.isUse())
1536       return TiedMax - 1;
1537     // MO is a def. Search for the tied use.
1538     for (unsigned i = TiedMax - 1, e = getNumOperands(); i != e; ++i) {
1539       const MachineOperand &UseMO = getOperand(i);
1540       if (UseMO.isReg() && UseMO.isUse() && UseMO.TiedTo == OpIdx + 1)
1541         return i;
1542     }
1543     llvm_unreachable("Can't find tied use");
1544   }
1545 
1546   // Now deal with inline asm by parsing the operand group descriptor flags.
1547   // Find the beginning of each operand group.
1548   SmallVector<unsigned, 8> GroupIdx;
1549   unsigned OpIdxGroup = ~0u;
1550   unsigned NumOps;
1551   for (unsigned i = InlineAsm::MIOp_FirstOperand, e = getNumOperands(); i < e;
1552        i += NumOps) {
1553     const MachineOperand &FlagMO = getOperand(i);
1554     assert(FlagMO.isImm() && "Invalid tied operand on inline asm");
1555     unsigned CurGroup = GroupIdx.size();
1556     GroupIdx.push_back(i);
1557     NumOps = 1 + InlineAsm::getNumOperandRegisters(FlagMO.getImm());
1558     // OpIdx belongs to this operand group.
1559     if (OpIdx > i && OpIdx < i + NumOps)
1560       OpIdxGroup = CurGroup;
1561     unsigned TiedGroup;
1562     if (!InlineAsm::isUseOperandTiedToDef(FlagMO.getImm(), TiedGroup))
1563       continue;
1564     // Operands in this group are tied to operands in TiedGroup which must be
1565     // earlier. Find the number of operands between the two groups.
1566     unsigned Delta = i - GroupIdx[TiedGroup];
1567 
1568     // OpIdx is a use tied to TiedGroup.
1569     if (OpIdxGroup == CurGroup)
1570       return OpIdx - Delta;
1571 
1572     // OpIdx is a def tied to this use group.
1573     if (OpIdxGroup == TiedGroup)
1574       return OpIdx + Delta;
1575   }
1576   llvm_unreachable("Invalid tied operand on inline asm");
1577 }
1578 
1579 /// clearKillInfo - Clears kill flags on all operands.
1580 ///
1581 void MachineInstr::clearKillInfo() {
1582   for (MachineOperand &MO : operands()) {
1583     if (MO.isReg() && MO.isUse())
1584       MO.setIsKill(false);
1585   }
1586 }
1587 
1588 void MachineInstr::substituteRegister(unsigned FromReg,
1589                                       unsigned ToReg,
1590                                       unsigned SubIdx,
1591                                       const TargetRegisterInfo &RegInfo) {
1592   if (TargetRegisterInfo::isPhysicalRegister(ToReg)) {
1593     if (SubIdx)
1594       ToReg = RegInfo.getSubReg(ToReg, SubIdx);
1595     for (MachineOperand &MO : operands()) {
1596       if (!MO.isReg() || MO.getReg() != FromReg)
1597         continue;
1598       MO.substPhysReg(ToReg, RegInfo);
1599     }
1600   } else {
1601     for (MachineOperand &MO : operands()) {
1602       if (!MO.isReg() || MO.getReg() != FromReg)
1603         continue;
1604       MO.substVirtReg(ToReg, SubIdx, RegInfo);
1605     }
1606   }
1607 }
1608 
1609 /// isSafeToMove - Return true if it is safe to move this instruction. If
1610 /// SawStore is set to true, it means that there is a store (or call) between
1611 /// the instruction's location and its intended destination.
1612 bool MachineInstr::isSafeToMove(AliasAnalysis *AA, bool &SawStore) const {
1613   // Ignore stuff that we obviously can't move.
1614   //
1615   // Treat volatile loads as stores. This is not strictly necessary for
1616   // volatiles, but it is required for atomic loads. It is not allowed to move
1617   // a load across an atomic load with Ordering > Monotonic.
1618   if (mayStore() || isCall() ||
1619       (mayLoad() && hasOrderedMemoryRef())) {
1620     SawStore = true;
1621     return false;
1622   }
1623 
1624   if (isPosition() || isDebugValue() || isTerminator() ||
1625       hasUnmodeledSideEffects())
1626     return false;
1627 
1628   // See if this instruction does a load.  If so, we have to guarantee that the
1629   // loaded value doesn't change between the load and the its intended
1630   // destination. The check for isInvariantLoad gives the targe the chance to
1631   // classify the load as always returning a constant, e.g. a constant pool
1632   // load.
1633   if (mayLoad() && !isDereferenceableInvariantLoad(AA))
1634     // Otherwise, this is a real load.  If there is a store between the load and
1635     // end of block, we can't move it.
1636     return !SawStore;
1637 
1638   return true;
1639 }
1640 
1641 bool MachineInstr::mayAlias(AliasAnalysis *AA, MachineInstr &Other,
1642                             bool UseTBAA) {
1643   const MachineFunction *MF = getParent()->getParent();
1644   const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
1645 
1646   // If neither instruction stores to memory, they can't alias in any
1647   // meaningful way, even if they read from the same address.
1648   if (!mayStore() && !Other.mayStore())
1649     return false;
1650 
1651   // Let the target decide if memory accesses cannot possibly overlap.
1652   if (TII->areMemAccessesTriviallyDisjoint(*this, Other, AA))
1653     return false;
1654 
1655   if (!AA)
1656     return true;
1657 
1658   // FIXME: Need to handle multiple memory operands to support all targets.
1659   if (!hasOneMemOperand() || !Other.hasOneMemOperand())
1660     return true;
1661 
1662   MachineMemOperand *MMOa = *memoperands_begin();
1663   MachineMemOperand *MMOb = *Other.memoperands_begin();
1664 
1665   if (!MMOa->getValue() || !MMOb->getValue())
1666     return true;
1667 
1668   // The following interface to AA is fashioned after DAGCombiner::isAlias
1669   // and operates with MachineMemOperand offset with some important
1670   // assumptions:
1671   //   - LLVM fundamentally assumes flat address spaces.
1672   //   - MachineOperand offset can *only* result from legalization and
1673   //     cannot affect queries other than the trivial case of overlap
1674   //     checking.
1675   //   - These offsets never wrap and never step outside
1676   //     of allocated objects.
1677   //   - There should never be any negative offsets here.
1678   //
1679   // FIXME: Modify API to hide this math from "user"
1680   // FIXME: Even before we go to AA we can reason locally about some
1681   // memory objects. It can save compile time, and possibly catch some
1682   // corner cases not currently covered.
1683 
1684   assert((MMOa->getOffset() >= 0) && "Negative MachineMemOperand offset");
1685   assert((MMOb->getOffset() >= 0) && "Negative MachineMemOperand offset");
1686 
1687   int64_t MinOffset = std::min(MMOa->getOffset(), MMOb->getOffset());
1688   int64_t Overlapa = MMOa->getSize() + MMOa->getOffset() - MinOffset;
1689   int64_t Overlapb = MMOb->getSize() + MMOb->getOffset() - MinOffset;
1690 
1691   AliasResult AAResult =
1692       AA->alias(MemoryLocation(MMOa->getValue(), Overlapa,
1693                                UseTBAA ? MMOa->getAAInfo() : AAMDNodes()),
1694                 MemoryLocation(MMOb->getValue(), Overlapb,
1695                                UseTBAA ? MMOb->getAAInfo() : AAMDNodes()));
1696 
1697   return (AAResult != NoAlias);
1698 }
1699 
1700 /// hasOrderedMemoryRef - Return true if this instruction may have an ordered
1701 /// or volatile memory reference, or if the information describing the memory
1702 /// reference is not available. Return false if it is known to have no ordered
1703 /// memory references.
1704 bool MachineInstr::hasOrderedMemoryRef() const {
1705   // An instruction known never to access memory won't have a volatile access.
1706   if (!mayStore() &&
1707       !mayLoad() &&
1708       !isCall() &&
1709       !hasUnmodeledSideEffects())
1710     return false;
1711 
1712   // Otherwise, if the instruction has no memory reference information,
1713   // conservatively assume it wasn't preserved.
1714   if (memoperands_empty())
1715     return true;
1716 
1717   // Check if any of our memory operands are ordered.
1718   return llvm::any_of(memoperands(), [](const MachineMemOperand *MMO) {
1719     return !MMO->isUnordered();
1720   });
1721 }
1722 
1723 /// isDereferenceableInvariantLoad - Return true if this instruction will never
1724 /// trap and is loading from a location whose value is invariant across a run of
1725 /// this function.
1726 bool MachineInstr::isDereferenceableInvariantLoad(AliasAnalysis *AA) const {
1727   // If the instruction doesn't load at all, it isn't an invariant load.
1728   if (!mayLoad())
1729     return false;
1730 
1731   // If the instruction has lost its memoperands, conservatively assume that
1732   // it may not be an invariant load.
1733   if (memoperands_empty())
1734     return false;
1735 
1736   const MachineFrameInfo &MFI = getParent()->getParent()->getFrameInfo();
1737 
1738   for (MachineMemOperand *MMO : memoperands()) {
1739     if (MMO->isVolatile()) return false;
1740     if (MMO->isStore()) return false;
1741     if (MMO->isInvariant() && MMO->isDereferenceable())
1742       continue;
1743 
1744     // A load from a constant PseudoSourceValue is invariant.
1745     if (const PseudoSourceValue *PSV = MMO->getPseudoValue())
1746       if (PSV->isConstant(&MFI))
1747         continue;
1748 
1749     if (const Value *V = MMO->getValue()) {
1750       // If we have an AliasAnalysis, ask it whether the memory is constant.
1751       if (AA &&
1752           AA->pointsToConstantMemory(
1753               MemoryLocation(V, MMO->getSize(), MMO->getAAInfo())))
1754         continue;
1755     }
1756 
1757     // Otherwise assume conservatively.
1758     return false;
1759   }
1760 
1761   // Everything checks out.
1762   return true;
1763 }
1764 
1765 /// isConstantValuePHI - If the specified instruction is a PHI that always
1766 /// merges together the same virtual register, return the register, otherwise
1767 /// return 0.
1768 unsigned MachineInstr::isConstantValuePHI() const {
1769   if (!isPHI())
1770     return 0;
1771   assert(getNumOperands() >= 3 &&
1772          "It's illegal to have a PHI without source operands");
1773 
1774   unsigned Reg = getOperand(1).getReg();
1775   for (unsigned i = 3, e = getNumOperands(); i < e; i += 2)
1776     if (getOperand(i).getReg() != Reg)
1777       return 0;
1778   return Reg;
1779 }
1780 
1781 bool MachineInstr::hasUnmodeledSideEffects() const {
1782   if (hasProperty(MCID::UnmodeledSideEffects))
1783     return true;
1784   if (isInlineAsm()) {
1785     unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
1786     if (ExtraInfo & InlineAsm::Extra_HasSideEffects)
1787       return true;
1788   }
1789 
1790   return false;
1791 }
1792 
1793 bool MachineInstr::isLoadFoldBarrier() const {
1794   return mayStore() || isCall() || hasUnmodeledSideEffects();
1795 }
1796 
1797 /// allDefsAreDead - Return true if all the defs of this instruction are dead.
1798 ///
1799 bool MachineInstr::allDefsAreDead() const {
1800   for (const MachineOperand &MO : operands()) {
1801     if (!MO.isReg() || MO.isUse())
1802       continue;
1803     if (!MO.isDead())
1804       return false;
1805   }
1806   return true;
1807 }
1808 
1809 /// copyImplicitOps - Copy implicit register operands from specified
1810 /// instruction to this instruction.
1811 void MachineInstr::copyImplicitOps(MachineFunction &MF,
1812                                    const MachineInstr &MI) {
1813   for (unsigned i = MI.getDesc().getNumOperands(), e = MI.getNumOperands();
1814        i != e; ++i) {
1815     const MachineOperand &MO = MI.getOperand(i);
1816     if ((MO.isReg() && MO.isImplicit()) || MO.isRegMask())
1817       addOperand(MF, MO);
1818   }
1819 }
1820 
1821 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
1822 LLVM_DUMP_METHOD void MachineInstr::dump() const {
1823   dbgs() << "  ";
1824   print(dbgs());
1825 }
1826 #endif
1827 
1828 void MachineInstr::print(raw_ostream &OS, bool SkipOpers, bool SkipDebugLoc,
1829                          const TargetInstrInfo *TII) const {
1830   const Module *M = nullptr;
1831   if (const MachineBasicBlock *MBB = getParent())
1832     if (const MachineFunction *MF = MBB->getParent())
1833       M = MF->getFunction()->getParent();
1834 
1835   ModuleSlotTracker MST(M);
1836   print(OS, MST, SkipOpers, SkipDebugLoc, TII);
1837 }
1838 
1839 void MachineInstr::print(raw_ostream &OS, ModuleSlotTracker &MST,
1840                          bool SkipOpers, bool SkipDebugLoc,
1841                          const TargetInstrInfo *TII) const {
1842   // We can be a bit tidier if we know the MachineFunction.
1843   const MachineFunction *MF = nullptr;
1844   const TargetRegisterInfo *TRI = nullptr;
1845   const MachineRegisterInfo *MRI = nullptr;
1846   const TargetIntrinsicInfo *IntrinsicInfo = nullptr;
1847 
1848   if (const MachineBasicBlock *MBB = getParent()) {
1849     MF = MBB->getParent();
1850     if (MF) {
1851       MRI = &MF->getRegInfo();
1852       TRI = MF->getSubtarget().getRegisterInfo();
1853       if (!TII)
1854         TII = MF->getSubtarget().getInstrInfo();
1855       IntrinsicInfo = MF->getTarget().getIntrinsicInfo();
1856     }
1857   }
1858 
1859   // Save a list of virtual registers.
1860   SmallVector<unsigned, 8> VirtRegs;
1861 
1862   // Print explicitly defined operands on the left of an assignment syntax.
1863   unsigned StartOp = 0, e = getNumOperands();
1864   for (; StartOp < e && getOperand(StartOp).isReg() &&
1865          getOperand(StartOp).isDef() &&
1866          !getOperand(StartOp).isImplicit();
1867        ++StartOp) {
1868     if (StartOp != 0) OS << ", ";
1869     getOperand(StartOp).print(OS, MST, TRI, IntrinsicInfo);
1870     unsigned Reg = getOperand(StartOp).getReg();
1871     if (TargetRegisterInfo::isVirtualRegister(Reg)) {
1872       VirtRegs.push_back(Reg);
1873       LLT Ty = MRI ? MRI->getType(Reg) : LLT{};
1874       if (Ty.isValid())
1875         OS << '(' << Ty << ')';
1876     }
1877   }
1878 
1879   if (StartOp != 0)
1880     OS << " = ";
1881 
1882   // Print the opcode name.
1883   if (TII)
1884     OS << TII->getName(getOpcode());
1885   else
1886     OS << "UNKNOWN";
1887 
1888   if (SkipOpers)
1889     return;
1890 
1891   // Print the rest of the operands.
1892   bool FirstOp = true;
1893   unsigned AsmDescOp = ~0u;
1894   unsigned AsmOpCount = 0;
1895 
1896   if (isInlineAsm() && e >= InlineAsm::MIOp_FirstOperand) {
1897     // Print asm string.
1898     OS << " ";
1899     getOperand(InlineAsm::MIOp_AsmString).print(OS, MST, TRI);
1900 
1901     // Print HasSideEffects, MayLoad, MayStore, IsAlignStack
1902     unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
1903     if (ExtraInfo & InlineAsm::Extra_HasSideEffects)
1904       OS << " [sideeffect]";
1905     if (ExtraInfo & InlineAsm::Extra_MayLoad)
1906       OS << " [mayload]";
1907     if (ExtraInfo & InlineAsm::Extra_MayStore)
1908       OS << " [maystore]";
1909     if (ExtraInfo & InlineAsm::Extra_IsConvergent)
1910       OS << " [isconvergent]";
1911     if (ExtraInfo & InlineAsm::Extra_IsAlignStack)
1912       OS << " [alignstack]";
1913     if (getInlineAsmDialect() == InlineAsm::AD_ATT)
1914       OS << " [attdialect]";
1915     if (getInlineAsmDialect() == InlineAsm::AD_Intel)
1916       OS << " [inteldialect]";
1917 
1918     StartOp = AsmDescOp = InlineAsm::MIOp_FirstOperand;
1919     FirstOp = false;
1920   }
1921 
1922   for (unsigned i = StartOp, e = getNumOperands(); i != e; ++i) {
1923     const MachineOperand &MO = getOperand(i);
1924 
1925     if (MO.isReg() && TargetRegisterInfo::isVirtualRegister(MO.getReg()))
1926       VirtRegs.push_back(MO.getReg());
1927 
1928     if (FirstOp) FirstOp = false; else OS << ",";
1929     OS << " ";
1930     if (i < getDesc().NumOperands) {
1931       const MCOperandInfo &MCOI = getDesc().OpInfo[i];
1932       if (MCOI.isPredicate())
1933         OS << "pred:";
1934       if (MCOI.isOptionalDef())
1935         OS << "opt:";
1936     }
1937     if (isDebugValue() && MO.isMetadata()) {
1938       // Pretty print DBG_VALUE instructions.
1939       auto *DIV = dyn_cast<DILocalVariable>(MO.getMetadata());
1940       if (DIV && !DIV->getName().empty())
1941         OS << "!\"" << DIV->getName() << '\"';
1942       else
1943         MO.print(OS, MST, TRI);
1944     } else if (TRI && (isInsertSubreg() || isRegSequence() ||
1945                        (isSubregToReg() && i == 3)) && MO.isImm()) {
1946       OS << TRI->getSubRegIndexName(MO.getImm());
1947     } else if (i == AsmDescOp && MO.isImm()) {
1948       // Pretty print the inline asm operand descriptor.
1949       OS << '$' << AsmOpCount++;
1950       unsigned Flag = MO.getImm();
1951       switch (InlineAsm::getKind(Flag)) {
1952       case InlineAsm::Kind_RegUse:             OS << ":[reguse"; break;
1953       case InlineAsm::Kind_RegDef:             OS << ":[regdef"; break;
1954       case InlineAsm::Kind_RegDefEarlyClobber: OS << ":[regdef-ec"; break;
1955       case InlineAsm::Kind_Clobber:            OS << ":[clobber"; break;
1956       case InlineAsm::Kind_Imm:                OS << ":[imm"; break;
1957       case InlineAsm::Kind_Mem:                OS << ":[mem"; break;
1958       default: OS << ":[??" << InlineAsm::getKind(Flag); break;
1959       }
1960 
1961       unsigned RCID = 0;
1962       if (!InlineAsm::isImmKind(Flag) && !InlineAsm::isMemKind(Flag) &&
1963           InlineAsm::hasRegClassConstraint(Flag, RCID)) {
1964         if (TRI) {
1965           OS << ':' << TRI->getRegClassName(TRI->getRegClass(RCID));
1966         } else
1967           OS << ":RC" << RCID;
1968       }
1969 
1970       if (InlineAsm::isMemKind(Flag)) {
1971         unsigned MCID = InlineAsm::getMemoryConstraintID(Flag);
1972         switch (MCID) {
1973         case InlineAsm::Constraint_es: OS << ":es"; break;
1974         case InlineAsm::Constraint_i:  OS << ":i"; break;
1975         case InlineAsm::Constraint_m:  OS << ":m"; break;
1976         case InlineAsm::Constraint_o:  OS << ":o"; break;
1977         case InlineAsm::Constraint_v:  OS << ":v"; break;
1978         case InlineAsm::Constraint_Q:  OS << ":Q"; break;
1979         case InlineAsm::Constraint_R:  OS << ":R"; break;
1980         case InlineAsm::Constraint_S:  OS << ":S"; break;
1981         case InlineAsm::Constraint_T:  OS << ":T"; break;
1982         case InlineAsm::Constraint_Um: OS << ":Um"; break;
1983         case InlineAsm::Constraint_Un: OS << ":Un"; break;
1984         case InlineAsm::Constraint_Uq: OS << ":Uq"; break;
1985         case InlineAsm::Constraint_Us: OS << ":Us"; break;
1986         case InlineAsm::Constraint_Ut: OS << ":Ut"; break;
1987         case InlineAsm::Constraint_Uv: OS << ":Uv"; break;
1988         case InlineAsm::Constraint_Uy: OS << ":Uy"; break;
1989         case InlineAsm::Constraint_X:  OS << ":X"; break;
1990         case InlineAsm::Constraint_Z:  OS << ":Z"; break;
1991         case InlineAsm::Constraint_ZC: OS << ":ZC"; break;
1992         case InlineAsm::Constraint_Zy: OS << ":Zy"; break;
1993         default: OS << ":?"; break;
1994         }
1995       }
1996 
1997       unsigned TiedTo = 0;
1998       if (InlineAsm::isUseOperandTiedToDef(Flag, TiedTo))
1999         OS << " tiedto:$" << TiedTo;
2000 
2001       OS << ']';
2002 
2003       // Compute the index of the next operand descriptor.
2004       AsmDescOp += 1 + InlineAsm::getNumOperandRegisters(Flag);
2005     } else
2006       MO.print(OS, MST, TRI);
2007   }
2008 
2009   bool HaveSemi = false;
2010   const unsigned PrintableFlags = FrameSetup | FrameDestroy;
2011   if (Flags & PrintableFlags) {
2012     if (!HaveSemi) {
2013       OS << ";";
2014       HaveSemi = true;
2015     }
2016     OS << " flags: ";
2017 
2018     if (Flags & FrameSetup)
2019       OS << "FrameSetup";
2020 
2021     if (Flags & FrameDestroy)
2022       OS << "FrameDestroy";
2023   }
2024 
2025   if (!memoperands_empty()) {
2026     if (!HaveSemi) {
2027       OS << ";";
2028       HaveSemi = true;
2029     }
2030 
2031     OS << " mem:";
2032     for (mmo_iterator i = memoperands_begin(), e = memoperands_end();
2033          i != e; ++i) {
2034       (*i)->print(OS, MST);
2035       if (std::next(i) != e)
2036         OS << " ";
2037     }
2038   }
2039 
2040   // Print the regclass of any virtual registers encountered.
2041   if (MRI && !VirtRegs.empty()) {
2042     if (!HaveSemi) {
2043       OS << ";";
2044       HaveSemi = true;
2045     }
2046     for (unsigned i = 0; i != VirtRegs.size(); ++i) {
2047       const RegClassOrRegBank &RC = MRI->getRegClassOrRegBank(VirtRegs[i]);
2048       if (!RC)
2049         continue;
2050       // Generic virtual registers do not have register classes.
2051       if (RC.is<const RegisterBank *>())
2052         OS << " " << RC.get<const RegisterBank *>()->getName();
2053       else
2054         OS << " "
2055            << TRI->getRegClassName(RC.get<const TargetRegisterClass *>());
2056       OS << ':' << PrintReg(VirtRegs[i]);
2057       for (unsigned j = i+1; j != VirtRegs.size();) {
2058         if (MRI->getRegClassOrRegBank(VirtRegs[j]) != RC) {
2059           ++j;
2060           continue;
2061         }
2062         if (VirtRegs[i] != VirtRegs[j])
2063           OS << "," << PrintReg(VirtRegs[j]);
2064         VirtRegs.erase(VirtRegs.begin()+j);
2065       }
2066     }
2067   }
2068 
2069   // Print debug location information.
2070   if (isDebugValue() && getOperand(e - 2).isMetadata()) {
2071     if (!HaveSemi)
2072       OS << ";";
2073     auto *DV = cast<DILocalVariable>(getOperand(e - 2).getMetadata());
2074     OS << " line no:" <<  DV->getLine();
2075     if (auto *InlinedAt = debugLoc->getInlinedAt()) {
2076       DebugLoc InlinedAtDL(InlinedAt);
2077       if (InlinedAtDL && MF) {
2078         OS << " inlined @[ ";
2079         InlinedAtDL.print(OS);
2080         OS << " ]";
2081       }
2082     }
2083     if (isIndirectDebugValue())
2084       OS << " indirect";
2085   } else if (SkipDebugLoc) {
2086     return;
2087   } else if (debugLoc && MF) {
2088     if (!HaveSemi)
2089       OS << ";";
2090     OS << " dbg:";
2091     debugLoc.print(OS);
2092   }
2093 
2094   OS << '\n';
2095 }
2096 
2097 bool MachineInstr::addRegisterKilled(unsigned IncomingReg,
2098                                      const TargetRegisterInfo *RegInfo,
2099                                      bool AddIfNotFound) {
2100   bool isPhysReg = TargetRegisterInfo::isPhysicalRegister(IncomingReg);
2101   bool hasAliases = isPhysReg &&
2102     MCRegAliasIterator(IncomingReg, RegInfo, false).isValid();
2103   bool Found = false;
2104   SmallVector<unsigned,4> DeadOps;
2105   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
2106     MachineOperand &MO = getOperand(i);
2107     if (!MO.isReg() || !MO.isUse() || MO.isUndef())
2108       continue;
2109 
2110     // DEBUG_VALUE nodes do not contribute to code generation and should
2111     // always be ignored. Failure to do so may result in trying to modify
2112     // KILL flags on DEBUG_VALUE nodes.
2113     if (MO.isDebug())
2114       continue;
2115 
2116     unsigned Reg = MO.getReg();
2117     if (!Reg)
2118       continue;
2119 
2120     if (Reg == IncomingReg) {
2121       if (!Found) {
2122         if (MO.isKill())
2123           // The register is already marked kill.
2124           return true;
2125         if (isPhysReg && isRegTiedToDefOperand(i))
2126           // Two-address uses of physregs must not be marked kill.
2127           return true;
2128         MO.setIsKill();
2129         Found = true;
2130       }
2131     } else if (hasAliases && MO.isKill() &&
2132                TargetRegisterInfo::isPhysicalRegister(Reg)) {
2133       // A super-register kill already exists.
2134       if (RegInfo->isSuperRegister(IncomingReg, Reg))
2135         return true;
2136       if (RegInfo->isSubRegister(IncomingReg, Reg))
2137         DeadOps.push_back(i);
2138     }
2139   }
2140 
2141   // Trim unneeded kill operands.
2142   while (!DeadOps.empty()) {
2143     unsigned OpIdx = DeadOps.back();
2144     if (getOperand(OpIdx).isImplicit())
2145       RemoveOperand(OpIdx);
2146     else
2147       getOperand(OpIdx).setIsKill(false);
2148     DeadOps.pop_back();
2149   }
2150 
2151   // If not found, this means an alias of one of the operands is killed. Add a
2152   // new implicit operand if required.
2153   if (!Found && AddIfNotFound) {
2154     addOperand(MachineOperand::CreateReg(IncomingReg,
2155                                          false /*IsDef*/,
2156                                          true  /*IsImp*/,
2157                                          true  /*IsKill*/));
2158     return true;
2159   }
2160   return Found;
2161 }
2162 
2163 void MachineInstr::clearRegisterKills(unsigned Reg,
2164                                       const TargetRegisterInfo *RegInfo) {
2165   if (!TargetRegisterInfo::isPhysicalRegister(Reg))
2166     RegInfo = nullptr;
2167   for (MachineOperand &MO : operands()) {
2168     if (!MO.isReg() || !MO.isUse() || !MO.isKill())
2169       continue;
2170     unsigned OpReg = MO.getReg();
2171     if ((RegInfo && RegInfo->regsOverlap(Reg, OpReg)) || Reg == OpReg)
2172       MO.setIsKill(false);
2173   }
2174 }
2175 
2176 bool MachineInstr::addRegisterDead(unsigned Reg,
2177                                    const TargetRegisterInfo *RegInfo,
2178                                    bool AddIfNotFound) {
2179   bool isPhysReg = TargetRegisterInfo::isPhysicalRegister(Reg);
2180   bool hasAliases = isPhysReg &&
2181     MCRegAliasIterator(Reg, RegInfo, false).isValid();
2182   bool Found = false;
2183   SmallVector<unsigned,4> DeadOps;
2184   for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
2185     MachineOperand &MO = getOperand(i);
2186     if (!MO.isReg() || !MO.isDef())
2187       continue;
2188     unsigned MOReg = MO.getReg();
2189     if (!MOReg)
2190       continue;
2191 
2192     if (MOReg == Reg) {
2193       MO.setIsDead();
2194       Found = true;
2195     } else if (hasAliases && MO.isDead() &&
2196                TargetRegisterInfo::isPhysicalRegister(MOReg)) {
2197       // There exists a super-register that's marked dead.
2198       if (RegInfo->isSuperRegister(Reg, MOReg))
2199         return true;
2200       if (RegInfo->isSubRegister(Reg, MOReg))
2201         DeadOps.push_back(i);
2202     }
2203   }
2204 
2205   // Trim unneeded dead operands.
2206   while (!DeadOps.empty()) {
2207     unsigned OpIdx = DeadOps.back();
2208     if (getOperand(OpIdx).isImplicit())
2209       RemoveOperand(OpIdx);
2210     else
2211       getOperand(OpIdx).setIsDead(false);
2212     DeadOps.pop_back();
2213   }
2214 
2215   // If not found, this means an alias of one of the operands is dead. Add a
2216   // new implicit operand if required.
2217   if (Found || !AddIfNotFound)
2218     return Found;
2219 
2220   addOperand(MachineOperand::CreateReg(Reg,
2221                                        true  /*IsDef*/,
2222                                        true  /*IsImp*/,
2223                                        false /*IsKill*/,
2224                                        true  /*IsDead*/));
2225   return true;
2226 }
2227 
2228 void MachineInstr::clearRegisterDeads(unsigned Reg) {
2229   for (MachineOperand &MO : operands()) {
2230     if (!MO.isReg() || !MO.isDef() || MO.getReg() != Reg)
2231       continue;
2232     MO.setIsDead(false);
2233   }
2234 }
2235 
2236 void MachineInstr::setRegisterDefReadUndef(unsigned Reg, bool IsUndef) {
2237   for (MachineOperand &MO : operands()) {
2238     if (!MO.isReg() || !MO.isDef() || MO.getReg() != Reg || MO.getSubReg() == 0)
2239       continue;
2240     MO.setIsUndef(IsUndef);
2241   }
2242 }
2243 
2244 void MachineInstr::addRegisterDefined(unsigned Reg,
2245                                       const TargetRegisterInfo *RegInfo) {
2246   if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
2247     MachineOperand *MO = findRegisterDefOperand(Reg, false, RegInfo);
2248     if (MO)
2249       return;
2250   } else {
2251     for (const MachineOperand &MO : operands()) {
2252       if (MO.isReg() && MO.getReg() == Reg && MO.isDef() &&
2253           MO.getSubReg() == 0)
2254         return;
2255     }
2256   }
2257   addOperand(MachineOperand::CreateReg(Reg,
2258                                        true  /*IsDef*/,
2259                                        true  /*IsImp*/));
2260 }
2261 
2262 void MachineInstr::setPhysRegsDeadExcept(ArrayRef<unsigned> UsedRegs,
2263                                          const TargetRegisterInfo &TRI) {
2264   bool HasRegMask = false;
2265   for (MachineOperand &MO : operands()) {
2266     if (MO.isRegMask()) {
2267       HasRegMask = true;
2268       continue;
2269     }
2270     if (!MO.isReg() || !MO.isDef()) continue;
2271     unsigned Reg = MO.getReg();
2272     if (!TargetRegisterInfo::isPhysicalRegister(Reg)) continue;
2273     // If there are no uses, including partial uses, the def is dead.
2274     if (llvm::none_of(UsedRegs,
2275                       [&](unsigned Use) { return TRI.regsOverlap(Use, Reg); }))
2276       MO.setIsDead();
2277   }
2278 
2279   // This is a call with a register mask operand.
2280   // Mask clobbers are always dead, so add defs for the non-dead defines.
2281   if (HasRegMask)
2282     for (ArrayRef<unsigned>::iterator I = UsedRegs.begin(), E = UsedRegs.end();
2283          I != E; ++I)
2284       addRegisterDefined(*I, &TRI);
2285 }
2286 
2287 unsigned
2288 MachineInstrExpressionTrait::getHashValue(const MachineInstr* const &MI) {
2289   // Build up a buffer of hash code components.
2290   SmallVector<size_t, 8> HashComponents;
2291   HashComponents.reserve(MI->getNumOperands() + 1);
2292   HashComponents.push_back(MI->getOpcode());
2293   for (const MachineOperand &MO : MI->operands()) {
2294     if (MO.isReg() && MO.isDef() &&
2295         TargetRegisterInfo::isVirtualRegister(MO.getReg()))
2296       continue;  // Skip virtual register defs.
2297 
2298     HashComponents.push_back(hash_value(MO));
2299   }
2300   return hash_combine_range(HashComponents.begin(), HashComponents.end());
2301 }
2302 
2303 void MachineInstr::emitError(StringRef Msg) const {
2304   // Find the source location cookie.
2305   unsigned LocCookie = 0;
2306   const MDNode *LocMD = nullptr;
2307   for (unsigned i = getNumOperands(); i != 0; --i) {
2308     if (getOperand(i-1).isMetadata() &&
2309         (LocMD = getOperand(i-1).getMetadata()) &&
2310         LocMD->getNumOperands() != 0) {
2311       if (const ConstantInt *CI =
2312               mdconst::dyn_extract<ConstantInt>(LocMD->getOperand(0))) {
2313         LocCookie = CI->getZExtValue();
2314         break;
2315       }
2316     }
2317   }
2318 
2319   if (const MachineBasicBlock *MBB = getParent())
2320     if (const MachineFunction *MF = MBB->getParent())
2321       return MF->getMMI().getModule()->getContext().emitError(LocCookie, Msg);
2322   report_fatal_error(Msg);
2323 }
2324 
2325 MachineInstrBuilder llvm::BuildMI(MachineFunction &MF, const DebugLoc &DL,
2326                                   const MCInstrDesc &MCID, bool IsIndirect,
2327                                   unsigned Reg, unsigned Offset,
2328                                   const MDNode *Variable, const MDNode *Expr) {
2329   assert(isa<DILocalVariable>(Variable) && "not a variable");
2330   assert(cast<DIExpression>(Expr)->isValid() && "not an expression");
2331   assert(cast<DILocalVariable>(Variable)->isValidLocationForIntrinsic(DL) &&
2332          "Expected inlined-at fields to agree");
2333   if (IsIndirect)
2334     return BuildMI(MF, DL, MCID)
2335         .addReg(Reg, RegState::Debug)
2336         .addImm(Offset)
2337         .addMetadata(Variable)
2338         .addMetadata(Expr);
2339   else {
2340     assert(Offset == 0 && "A direct address cannot have an offset.");
2341     return BuildMI(MF, DL, MCID)
2342         .addReg(Reg, RegState::Debug)
2343         .addReg(0U, RegState::Debug)
2344         .addMetadata(Variable)
2345         .addMetadata(Expr);
2346   }
2347 }
2348 
2349 MachineInstrBuilder llvm::BuildMI(MachineBasicBlock &BB,
2350                                   MachineBasicBlock::iterator I,
2351                                   const DebugLoc &DL, const MCInstrDesc &MCID,
2352                                   bool IsIndirect, unsigned Reg,
2353                                   unsigned Offset, const MDNode *Variable,
2354                                   const MDNode *Expr) {
2355   assert(isa<DILocalVariable>(Variable) && "not a variable");
2356   assert(cast<DIExpression>(Expr)->isValid() && "not an expression");
2357   MachineFunction &MF = *BB.getParent();
2358   MachineInstr *MI =
2359       BuildMI(MF, DL, MCID, IsIndirect, Reg, Offset, Variable, Expr);
2360   BB.insert(I, MI);
2361   return MachineInstrBuilder(MF, MI);
2362 }
2363 
2364 MachineInstr *llvm::buildDbgValueForSpill(MachineBasicBlock &BB,
2365                                           MachineBasicBlock::iterator I,
2366                                           const MachineInstr &Orig,
2367                                           int FrameIndex) {
2368   const MDNode *Var = Orig.getDebugVariable();
2369   const auto *Expr = cast_or_null<DIExpression>(Orig.getDebugExpression());
2370   bool IsIndirect = Orig.isIndirectDebugValue();
2371   uint64_t Offset = IsIndirect ? Orig.getOperand(1).getImm() : 0;
2372   DebugLoc DL = Orig.getDebugLoc();
2373   assert(cast<DILocalVariable>(Var)->isValidLocationForIntrinsic(DL) &&
2374          "Expected inlined-at fields to agree");
2375   // If the DBG_VALUE already was a memory location, add an extra
2376   // DW_OP_deref. Otherwise just turning this from a register into a
2377   // memory/indirect location is sufficient.
2378   if (IsIndirect)
2379     Expr = DIExpression::prepend(Expr, DIExpression::WithDeref);
2380   return BuildMI(BB, I, DL, Orig.getDesc())
2381       .addFrameIndex(FrameIndex)
2382       .addImm(Offset)
2383       .addMetadata(Var)
2384       .addMetadata(Expr);
2385 }
2386