1 //===-- lib/CodeGen/MachineInstr.cpp --------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // Methods common to all machine instructions. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/CodeGen/MachineInstr.h" 15 #include "llvm/ADT/FoldingSet.h" 16 #include "llvm/ADT/Hashing.h" 17 #include "llvm/Analysis/AliasAnalysis.h" 18 #include "llvm/CodeGen/MachineConstantPool.h" 19 #include "llvm/CodeGen/MachineFunction.h" 20 #include "llvm/CodeGen/MachineInstrBuilder.h" 21 #include "llvm/CodeGen/MachineMemOperand.h" 22 #include "llvm/CodeGen/MachineModuleInfo.h" 23 #include "llvm/CodeGen/MachineRegisterInfo.h" 24 #include "llvm/CodeGen/PseudoSourceValue.h" 25 #include "llvm/IR/Constants.h" 26 #include "llvm/IR/DebugInfo.h" 27 #include "llvm/IR/Function.h" 28 #include "llvm/IR/InlineAsm.h" 29 #include "llvm/IR/Intrinsics.h" 30 #include "llvm/IR/LLVMContext.h" 31 #include "llvm/IR/Metadata.h" 32 #include "llvm/IR/Module.h" 33 #include "llvm/IR/ModuleSlotTracker.h" 34 #include "llvm/IR/Type.h" 35 #include "llvm/IR/Value.h" 36 #include "llvm/MC/MCInstrDesc.h" 37 #include "llvm/MC/MCSymbol.h" 38 #include "llvm/Support/CommandLine.h" 39 #include "llvm/Support/Debug.h" 40 #include "llvm/Support/ErrorHandling.h" 41 #include "llvm/Support/MathExtras.h" 42 #include "llvm/Support/raw_ostream.h" 43 #include "llvm/Target/TargetInstrInfo.h" 44 #include "llvm/Target/TargetIntrinsicInfo.h" 45 #include "llvm/Target/TargetMachine.h" 46 #include "llvm/Target/TargetRegisterInfo.h" 47 #include "llvm/Target/TargetSubtargetInfo.h" 48 using namespace llvm; 49 50 static cl::opt<bool> PrintWholeRegMask( 51 "print-whole-regmask", 52 cl::desc("Print the full contents of regmask operands in IR dumps"), 53 cl::init(true), cl::Hidden); 54 55 //===----------------------------------------------------------------------===// 56 // MachineOperand Implementation 57 //===----------------------------------------------------------------------===// 58 59 void MachineOperand::setReg(unsigned Reg) { 60 if (getReg() == Reg) return; // No change. 61 62 // Otherwise, we have to change the register. If this operand is embedded 63 // into a machine function, we need to update the old and new register's 64 // use/def lists. 65 if (MachineInstr *MI = getParent()) 66 if (MachineBasicBlock *MBB = MI->getParent()) 67 if (MachineFunction *MF = MBB->getParent()) { 68 MachineRegisterInfo &MRI = MF->getRegInfo(); 69 MRI.removeRegOperandFromUseList(this); 70 SmallContents.RegNo = Reg; 71 MRI.addRegOperandToUseList(this); 72 return; 73 } 74 75 // Otherwise, just change the register, no problem. :) 76 SmallContents.RegNo = Reg; 77 } 78 79 void MachineOperand::substVirtReg(unsigned Reg, unsigned SubIdx, 80 const TargetRegisterInfo &TRI) { 81 assert(TargetRegisterInfo::isVirtualRegister(Reg)); 82 if (SubIdx && getSubReg()) 83 SubIdx = TRI.composeSubRegIndices(SubIdx, getSubReg()); 84 setReg(Reg); 85 if (SubIdx) 86 setSubReg(SubIdx); 87 } 88 89 void MachineOperand::substPhysReg(unsigned Reg, const TargetRegisterInfo &TRI) { 90 assert(TargetRegisterInfo::isPhysicalRegister(Reg)); 91 if (getSubReg()) { 92 Reg = TRI.getSubReg(Reg, getSubReg()); 93 // Note that getSubReg() may return 0 if the sub-register doesn't exist. 94 // That won't happen in legal code. 95 setSubReg(0); 96 if (isDef()) 97 setIsUndef(false); 98 } 99 setReg(Reg); 100 } 101 102 /// Change a def to a use, or a use to a def. 103 void MachineOperand::setIsDef(bool Val) { 104 assert(isReg() && "Wrong MachineOperand accessor"); 105 assert((!Val || !isDebug()) && "Marking a debug operation as def"); 106 if (IsDef == Val) 107 return; 108 // MRI may keep uses and defs in different list positions. 109 if (MachineInstr *MI = getParent()) 110 if (MachineBasicBlock *MBB = MI->getParent()) 111 if (MachineFunction *MF = MBB->getParent()) { 112 MachineRegisterInfo &MRI = MF->getRegInfo(); 113 MRI.removeRegOperandFromUseList(this); 114 IsDef = Val; 115 MRI.addRegOperandToUseList(this); 116 return; 117 } 118 IsDef = Val; 119 } 120 121 // If this operand is currently a register operand, and if this is in a 122 // function, deregister the operand from the register's use/def list. 123 void MachineOperand::removeRegFromUses() { 124 if (!isReg() || !isOnRegUseList()) 125 return; 126 127 if (MachineInstr *MI = getParent()) { 128 if (MachineBasicBlock *MBB = MI->getParent()) { 129 if (MachineFunction *MF = MBB->getParent()) 130 MF->getRegInfo().removeRegOperandFromUseList(this); 131 } 132 } 133 } 134 135 /// ChangeToImmediate - Replace this operand with a new immediate operand of 136 /// the specified value. If an operand is known to be an immediate already, 137 /// the setImm method should be used. 138 void MachineOperand::ChangeToImmediate(int64_t ImmVal) { 139 assert((!isReg() || !isTied()) && "Cannot change a tied operand into an imm"); 140 141 removeRegFromUses(); 142 143 OpKind = MO_Immediate; 144 Contents.ImmVal = ImmVal; 145 } 146 147 void MachineOperand::ChangeToFPImmediate(const ConstantFP *FPImm) { 148 assert((!isReg() || !isTied()) && "Cannot change a tied operand into an imm"); 149 150 removeRegFromUses(); 151 152 OpKind = MO_FPImmediate; 153 Contents.CFP = FPImm; 154 } 155 156 void MachineOperand::ChangeToES(const char *SymName, unsigned char TargetFlags) { 157 assert((!isReg() || !isTied()) && 158 "Cannot change a tied operand into an external symbol"); 159 160 removeRegFromUses(); 161 162 OpKind = MO_ExternalSymbol; 163 Contents.OffsetedInfo.Val.SymbolName = SymName; 164 setOffset(0); // Offset is always 0. 165 setTargetFlags(TargetFlags); 166 } 167 168 void MachineOperand::ChangeToMCSymbol(MCSymbol *Sym) { 169 assert((!isReg() || !isTied()) && 170 "Cannot change a tied operand into an MCSymbol"); 171 172 removeRegFromUses(); 173 174 OpKind = MO_MCSymbol; 175 Contents.Sym = Sym; 176 } 177 178 void MachineOperand::ChangeToFrameIndex(int Idx) { 179 assert((!isReg() || !isTied()) && 180 "Cannot change a tied operand into a FrameIndex"); 181 182 removeRegFromUses(); 183 184 OpKind = MO_FrameIndex; 185 setIndex(Idx); 186 } 187 188 /// ChangeToRegister - Replace this operand with a new register operand of 189 /// the specified value. If an operand is known to be an register already, 190 /// the setReg method should be used. 191 void MachineOperand::ChangeToRegister(unsigned Reg, bool isDef, bool isImp, 192 bool isKill, bool isDead, bool isUndef, 193 bool isDebug) { 194 MachineRegisterInfo *RegInfo = nullptr; 195 if (MachineInstr *MI = getParent()) 196 if (MachineBasicBlock *MBB = MI->getParent()) 197 if (MachineFunction *MF = MBB->getParent()) 198 RegInfo = &MF->getRegInfo(); 199 // If this operand is already a register operand, remove it from the 200 // register's use/def lists. 201 bool WasReg = isReg(); 202 if (RegInfo && WasReg) 203 RegInfo->removeRegOperandFromUseList(this); 204 205 // Change this to a register and set the reg#. 206 OpKind = MO_Register; 207 SmallContents.RegNo = Reg; 208 SubReg_TargetFlags = 0; 209 IsDef = isDef; 210 IsImp = isImp; 211 IsKill = isKill; 212 IsDead = isDead; 213 IsUndef = isUndef; 214 IsInternalRead = false; 215 IsEarlyClobber = false; 216 IsDebug = isDebug; 217 // Ensure isOnRegUseList() returns false. 218 Contents.Reg.Prev = nullptr; 219 // Preserve the tie when the operand was already a register. 220 if (!WasReg) 221 TiedTo = 0; 222 223 // If this operand is embedded in a function, add the operand to the 224 // register's use/def list. 225 if (RegInfo) 226 RegInfo->addRegOperandToUseList(this); 227 } 228 229 /// isIdenticalTo - Return true if this operand is identical to the specified 230 /// operand. Note that this should stay in sync with the hash_value overload 231 /// below. 232 bool MachineOperand::isIdenticalTo(const MachineOperand &Other) const { 233 if (getType() != Other.getType() || 234 getTargetFlags() != Other.getTargetFlags()) 235 return false; 236 237 switch (getType()) { 238 case MachineOperand::MO_Register: 239 return getReg() == Other.getReg() && isDef() == Other.isDef() && 240 getSubReg() == Other.getSubReg(); 241 case MachineOperand::MO_Immediate: 242 return getImm() == Other.getImm(); 243 case MachineOperand::MO_CImmediate: 244 return getCImm() == Other.getCImm(); 245 case MachineOperand::MO_FPImmediate: 246 return getFPImm() == Other.getFPImm(); 247 case MachineOperand::MO_MachineBasicBlock: 248 return getMBB() == Other.getMBB(); 249 case MachineOperand::MO_FrameIndex: 250 return getIndex() == Other.getIndex(); 251 case MachineOperand::MO_ConstantPoolIndex: 252 case MachineOperand::MO_TargetIndex: 253 return getIndex() == Other.getIndex() && getOffset() == Other.getOffset(); 254 case MachineOperand::MO_JumpTableIndex: 255 return getIndex() == Other.getIndex(); 256 case MachineOperand::MO_GlobalAddress: 257 return getGlobal() == Other.getGlobal() && getOffset() == Other.getOffset(); 258 case MachineOperand::MO_ExternalSymbol: 259 return !strcmp(getSymbolName(), Other.getSymbolName()) && 260 getOffset() == Other.getOffset(); 261 case MachineOperand::MO_BlockAddress: 262 return getBlockAddress() == Other.getBlockAddress() && 263 getOffset() == Other.getOffset(); 264 case MachineOperand::MO_RegisterMask: 265 case MachineOperand::MO_RegisterLiveOut: 266 return getRegMask() == Other.getRegMask(); 267 case MachineOperand::MO_MCSymbol: 268 return getMCSymbol() == Other.getMCSymbol(); 269 case MachineOperand::MO_CFIIndex: 270 return getCFIIndex() == Other.getCFIIndex(); 271 case MachineOperand::MO_Metadata: 272 return getMetadata() == Other.getMetadata(); 273 case MachineOperand::MO_IntrinsicID: 274 return getIntrinsicID() == Other.getIntrinsicID(); 275 case MachineOperand::MO_Predicate: 276 return getPredicate() == Other.getPredicate(); 277 } 278 llvm_unreachable("Invalid machine operand type"); 279 } 280 281 // Note: this must stay exactly in sync with isIdenticalTo above. 282 hash_code llvm::hash_value(const MachineOperand &MO) { 283 switch (MO.getType()) { 284 case MachineOperand::MO_Register: 285 // Register operands don't have target flags. 286 return hash_combine(MO.getType(), MO.getReg(), MO.getSubReg(), MO.isDef()); 287 case MachineOperand::MO_Immediate: 288 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getImm()); 289 case MachineOperand::MO_CImmediate: 290 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getCImm()); 291 case MachineOperand::MO_FPImmediate: 292 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getFPImm()); 293 case MachineOperand::MO_MachineBasicBlock: 294 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getMBB()); 295 case MachineOperand::MO_FrameIndex: 296 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIndex()); 297 case MachineOperand::MO_ConstantPoolIndex: 298 case MachineOperand::MO_TargetIndex: 299 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIndex(), 300 MO.getOffset()); 301 case MachineOperand::MO_JumpTableIndex: 302 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIndex()); 303 case MachineOperand::MO_ExternalSymbol: 304 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getOffset(), 305 MO.getSymbolName()); 306 case MachineOperand::MO_GlobalAddress: 307 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getGlobal(), 308 MO.getOffset()); 309 case MachineOperand::MO_BlockAddress: 310 return hash_combine(MO.getType(), MO.getTargetFlags(), 311 MO.getBlockAddress(), MO.getOffset()); 312 case MachineOperand::MO_RegisterMask: 313 case MachineOperand::MO_RegisterLiveOut: 314 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getRegMask()); 315 case MachineOperand::MO_Metadata: 316 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getMetadata()); 317 case MachineOperand::MO_MCSymbol: 318 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getMCSymbol()); 319 case MachineOperand::MO_CFIIndex: 320 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getCFIIndex()); 321 case MachineOperand::MO_IntrinsicID: 322 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getIntrinsicID()); 323 case MachineOperand::MO_Predicate: 324 return hash_combine(MO.getType(), MO.getTargetFlags(), MO.getPredicate()); 325 } 326 llvm_unreachable("Invalid machine operand type"); 327 } 328 329 void MachineOperand::print(raw_ostream &OS, const TargetRegisterInfo *TRI, 330 const TargetIntrinsicInfo *IntrinsicInfo) const { 331 ModuleSlotTracker DummyMST(nullptr); 332 print(OS, DummyMST, TRI, IntrinsicInfo); 333 } 334 335 void MachineOperand::print(raw_ostream &OS, ModuleSlotTracker &MST, 336 const TargetRegisterInfo *TRI, 337 const TargetIntrinsicInfo *IntrinsicInfo) const { 338 switch (getType()) { 339 case MachineOperand::MO_Register: 340 OS << PrintReg(getReg(), TRI, getSubReg()); 341 342 if (isDef() || isKill() || isDead() || isImplicit() || isUndef() || 343 isInternalRead() || isEarlyClobber() || isTied()) { 344 OS << '<'; 345 bool NeedComma = false; 346 if (isDef()) { 347 if (NeedComma) OS << ','; 348 if (isEarlyClobber()) 349 OS << "earlyclobber,"; 350 if (isImplicit()) 351 OS << "imp-"; 352 OS << "def"; 353 NeedComma = true; 354 // <def,read-undef> only makes sense when getSubReg() is set. 355 // Don't clutter the output otherwise. 356 if (isUndef() && getSubReg()) 357 OS << ",read-undef"; 358 } else if (isImplicit()) { 359 OS << "imp-use"; 360 NeedComma = true; 361 } 362 363 if (isKill()) { 364 if (NeedComma) OS << ','; 365 OS << "kill"; 366 NeedComma = true; 367 } 368 if (isDead()) { 369 if (NeedComma) OS << ','; 370 OS << "dead"; 371 NeedComma = true; 372 } 373 if (isUndef() && isUse()) { 374 if (NeedComma) OS << ','; 375 OS << "undef"; 376 NeedComma = true; 377 } 378 if (isInternalRead()) { 379 if (NeedComma) OS << ','; 380 OS << "internal"; 381 NeedComma = true; 382 } 383 if (isTied()) { 384 if (NeedComma) OS << ','; 385 OS << "tied"; 386 if (TiedTo != 15) 387 OS << unsigned(TiedTo - 1); 388 } 389 OS << '>'; 390 } 391 break; 392 case MachineOperand::MO_Immediate: 393 OS << getImm(); 394 break; 395 case MachineOperand::MO_CImmediate: 396 getCImm()->getValue().print(OS, false); 397 break; 398 case MachineOperand::MO_FPImmediate: 399 if (getFPImm()->getType()->isFloatTy()) { 400 OS << getFPImm()->getValueAPF().convertToFloat(); 401 } else if (getFPImm()->getType()->isHalfTy()) { 402 APFloat APF = getFPImm()->getValueAPF(); 403 bool Unused; 404 APF.convert(APFloat::IEEEsingle, APFloat::rmNearestTiesToEven, &Unused); 405 OS << "half " << APF.convertToFloat(); 406 } else { 407 OS << getFPImm()->getValueAPF().convertToDouble(); 408 } 409 break; 410 case MachineOperand::MO_MachineBasicBlock: 411 OS << "<BB#" << getMBB()->getNumber() << ">"; 412 break; 413 case MachineOperand::MO_FrameIndex: 414 OS << "<fi#" << getIndex() << '>'; 415 break; 416 case MachineOperand::MO_ConstantPoolIndex: 417 OS << "<cp#" << getIndex(); 418 if (getOffset()) OS << "+" << getOffset(); 419 OS << '>'; 420 break; 421 case MachineOperand::MO_TargetIndex: 422 OS << "<ti#" << getIndex(); 423 if (getOffset()) OS << "+" << getOffset(); 424 OS << '>'; 425 break; 426 case MachineOperand::MO_JumpTableIndex: 427 OS << "<jt#" << getIndex() << '>'; 428 break; 429 case MachineOperand::MO_GlobalAddress: 430 OS << "<ga:"; 431 getGlobal()->printAsOperand(OS, /*PrintType=*/false, MST); 432 if (getOffset()) OS << "+" << getOffset(); 433 OS << '>'; 434 break; 435 case MachineOperand::MO_ExternalSymbol: 436 OS << "<es:" << getSymbolName(); 437 if (getOffset()) OS << "+" << getOffset(); 438 OS << '>'; 439 break; 440 case MachineOperand::MO_BlockAddress: 441 OS << '<'; 442 getBlockAddress()->printAsOperand(OS, /*PrintType=*/false, MST); 443 if (getOffset()) OS << "+" << getOffset(); 444 OS << '>'; 445 break; 446 case MachineOperand::MO_RegisterMask: { 447 unsigned NumRegsInMask = 0; 448 unsigned NumRegsEmitted = 0; 449 OS << "<regmask"; 450 for (unsigned i = 0; i < TRI->getNumRegs(); ++i) { 451 unsigned MaskWord = i / 32; 452 unsigned MaskBit = i % 32; 453 if (getRegMask()[MaskWord] & (1 << MaskBit)) { 454 if (PrintWholeRegMask || NumRegsEmitted <= 10) { 455 OS << " " << PrintReg(i, TRI); 456 NumRegsEmitted++; 457 } 458 NumRegsInMask++; 459 } 460 } 461 if (NumRegsEmitted != NumRegsInMask) 462 OS << " and " << (NumRegsInMask - NumRegsEmitted) << " more..."; 463 OS << ">"; 464 break; 465 } 466 case MachineOperand::MO_RegisterLiveOut: 467 OS << "<regliveout>"; 468 break; 469 case MachineOperand::MO_Metadata: 470 OS << '<'; 471 getMetadata()->printAsOperand(OS, MST); 472 OS << '>'; 473 break; 474 case MachineOperand::MO_MCSymbol: 475 OS << "<MCSym=" << *getMCSymbol() << '>'; 476 break; 477 case MachineOperand::MO_CFIIndex: 478 OS << "<call frame instruction>"; 479 break; 480 case MachineOperand::MO_IntrinsicID: { 481 Intrinsic::ID ID = getIntrinsicID(); 482 if (ID < Intrinsic::num_intrinsics) 483 OS << "<intrinsic:@" << Intrinsic::getName(ID, None) << '>'; 484 else if (IntrinsicInfo) 485 OS << "<intrinsic:@" << IntrinsicInfo->getName(ID) << '>'; 486 else 487 OS << "<intrinsic:" << ID << '>'; 488 break; 489 } 490 case MachineOperand::MO_Predicate: { 491 auto Pred = static_cast<CmpInst::Predicate>(getPredicate()); 492 OS << '<' << (CmpInst::isIntPredicate(Pred) ? "intpred" : "floatpred") 493 << CmpInst::getPredicateName(Pred) << '>'; 494 } 495 } 496 if (unsigned TF = getTargetFlags()) 497 OS << "[TF=" << TF << ']'; 498 } 499 500 //===----------------------------------------------------------------------===// 501 // MachineMemOperand Implementation 502 //===----------------------------------------------------------------------===// 503 504 /// getAddrSpace - Return the LLVM IR address space number that this pointer 505 /// points into. 506 unsigned MachinePointerInfo::getAddrSpace() const { 507 if (V.isNull() || V.is<const PseudoSourceValue*>()) return 0; 508 return cast<PointerType>(V.get<const Value*>()->getType())->getAddressSpace(); 509 } 510 511 /// getConstantPool - Return a MachinePointerInfo record that refers to the 512 /// constant pool. 513 MachinePointerInfo MachinePointerInfo::getConstantPool(MachineFunction &MF) { 514 return MachinePointerInfo(MF.getPSVManager().getConstantPool()); 515 } 516 517 /// getFixedStack - Return a MachinePointerInfo record that refers to the 518 /// the specified FrameIndex. 519 MachinePointerInfo MachinePointerInfo::getFixedStack(MachineFunction &MF, 520 int FI, int64_t Offset) { 521 return MachinePointerInfo(MF.getPSVManager().getFixedStack(FI), Offset); 522 } 523 524 MachinePointerInfo MachinePointerInfo::getJumpTable(MachineFunction &MF) { 525 return MachinePointerInfo(MF.getPSVManager().getJumpTable()); 526 } 527 528 MachinePointerInfo MachinePointerInfo::getGOT(MachineFunction &MF) { 529 return MachinePointerInfo(MF.getPSVManager().getGOT()); 530 } 531 532 MachinePointerInfo MachinePointerInfo::getStack(MachineFunction &MF, 533 int64_t Offset) { 534 return MachinePointerInfo(MF.getPSVManager().getStack(), Offset); 535 } 536 537 MachineMemOperand::MachineMemOperand(MachinePointerInfo ptrinfo, Flags f, 538 uint64_t s, unsigned int a, 539 const AAMDNodes &AAInfo, 540 const MDNode *Ranges, 541 SynchronizationScope SynchScope, 542 AtomicOrdering Ordering, 543 AtomicOrdering FailureOrdering) 544 : PtrInfo(ptrinfo), Size(s), FlagVals(f), BaseAlignLog2(Log2_32(a) + 1), 545 AAInfo(AAInfo), Ranges(Ranges) { 546 assert((PtrInfo.V.isNull() || PtrInfo.V.is<const PseudoSourceValue*>() || 547 isa<PointerType>(PtrInfo.V.get<const Value*>()->getType())) && 548 "invalid pointer value"); 549 assert(getBaseAlignment() == a && "Alignment is not a power of 2!"); 550 assert((isLoad() || isStore()) && "Not a load/store!"); 551 552 AtomicInfo.SynchScope = static_cast<unsigned>(SynchScope); 553 assert(getSynchScope() == SynchScope && "Value truncated"); 554 AtomicInfo.Ordering = static_cast<unsigned>(Ordering); 555 assert(getOrdering() == Ordering && "Value truncated"); 556 AtomicInfo.FailureOrdering = static_cast<unsigned>(FailureOrdering); 557 assert(getFailureOrdering() == FailureOrdering && "Value truncated"); 558 } 559 560 /// Profile - Gather unique data for the object. 561 /// 562 void MachineMemOperand::Profile(FoldingSetNodeID &ID) const { 563 ID.AddInteger(getOffset()); 564 ID.AddInteger(Size); 565 ID.AddPointer(getOpaqueValue()); 566 ID.AddInteger(getFlags()); 567 ID.AddInteger(getBaseAlignment()); 568 } 569 570 void MachineMemOperand::refineAlignment(const MachineMemOperand *MMO) { 571 // The Value and Offset may differ due to CSE. But the flags and size 572 // should be the same. 573 assert(MMO->getFlags() == getFlags() && "Flags mismatch!"); 574 assert(MMO->getSize() == getSize() && "Size mismatch!"); 575 576 if (MMO->getBaseAlignment() >= getBaseAlignment()) { 577 // Update the alignment value. 578 BaseAlignLog2 = Log2_32(MMO->getBaseAlignment()) + 1; 579 // Also update the base and offset, because the new alignment may 580 // not be applicable with the old ones. 581 PtrInfo = MMO->PtrInfo; 582 } 583 } 584 585 /// getAlignment - Return the minimum known alignment in bytes of the 586 /// actual memory reference. 587 uint64_t MachineMemOperand::getAlignment() const { 588 return MinAlign(getBaseAlignment(), getOffset()); 589 } 590 591 void MachineMemOperand::print(raw_ostream &OS) const { 592 ModuleSlotTracker DummyMST(nullptr); 593 print(OS, DummyMST); 594 } 595 void MachineMemOperand::print(raw_ostream &OS, ModuleSlotTracker &MST) const { 596 assert((isLoad() || isStore()) && 597 "SV has to be a load, store or both."); 598 599 if (isVolatile()) 600 OS << "Volatile "; 601 602 if (isLoad()) 603 OS << "LD"; 604 if (isStore()) 605 OS << "ST"; 606 OS << getSize(); 607 608 // Print the address information. 609 OS << "["; 610 if (const Value *V = getValue()) 611 V->printAsOperand(OS, /*PrintType=*/false, MST); 612 else if (const PseudoSourceValue *PSV = getPseudoValue()) 613 PSV->printCustom(OS); 614 else 615 OS << "<unknown>"; 616 617 unsigned AS = getAddrSpace(); 618 if (AS != 0) 619 OS << "(addrspace=" << AS << ')'; 620 621 // If the alignment of the memory reference itself differs from the alignment 622 // of the base pointer, print the base alignment explicitly, next to the base 623 // pointer. 624 if (getBaseAlignment() != getAlignment()) 625 OS << "(align=" << getBaseAlignment() << ")"; 626 627 if (getOffset() != 0) 628 OS << "+" << getOffset(); 629 OS << "]"; 630 631 // Print the alignment of the reference. 632 if (getBaseAlignment() != getAlignment() || getBaseAlignment() != getSize()) 633 OS << "(align=" << getAlignment() << ")"; 634 635 // Print TBAA info. 636 if (const MDNode *TBAAInfo = getAAInfo().TBAA) { 637 OS << "(tbaa="; 638 if (TBAAInfo->getNumOperands() > 0) 639 TBAAInfo->getOperand(0)->printAsOperand(OS, MST); 640 else 641 OS << "<unknown>"; 642 OS << ")"; 643 } 644 645 // Print AA scope info. 646 if (const MDNode *ScopeInfo = getAAInfo().Scope) { 647 OS << "(alias.scope="; 648 if (ScopeInfo->getNumOperands() > 0) 649 for (unsigned i = 0, ie = ScopeInfo->getNumOperands(); i != ie; ++i) { 650 ScopeInfo->getOperand(i)->printAsOperand(OS, MST); 651 if (i != ie-1) 652 OS << ","; 653 } 654 else 655 OS << "<unknown>"; 656 OS << ")"; 657 } 658 659 // Print AA noalias scope info. 660 if (const MDNode *NoAliasInfo = getAAInfo().NoAlias) { 661 OS << "(noalias="; 662 if (NoAliasInfo->getNumOperands() > 0) 663 for (unsigned i = 0, ie = NoAliasInfo->getNumOperands(); i != ie; ++i) { 664 NoAliasInfo->getOperand(i)->printAsOperand(OS, MST); 665 if (i != ie-1) 666 OS << ","; 667 } 668 else 669 OS << "<unknown>"; 670 OS << ")"; 671 } 672 673 if (isNonTemporal()) 674 OS << "(nontemporal)"; 675 if (isDereferenceable()) 676 OS << "(dereferenceable)"; 677 if (isInvariant()) 678 OS << "(invariant)"; 679 } 680 681 //===----------------------------------------------------------------------===// 682 // MachineInstr Implementation 683 //===----------------------------------------------------------------------===// 684 685 void MachineInstr::addImplicitDefUseOperands(MachineFunction &MF) { 686 if (MCID->ImplicitDefs) 687 for (const MCPhysReg *ImpDefs = MCID->getImplicitDefs(); *ImpDefs; 688 ++ImpDefs) 689 addOperand(MF, MachineOperand::CreateReg(*ImpDefs, true, true)); 690 if (MCID->ImplicitUses) 691 for (const MCPhysReg *ImpUses = MCID->getImplicitUses(); *ImpUses; 692 ++ImpUses) 693 addOperand(MF, MachineOperand::CreateReg(*ImpUses, false, true)); 694 } 695 696 /// MachineInstr ctor - This constructor creates a MachineInstr and adds the 697 /// implicit operands. It reserves space for the number of operands specified by 698 /// the MCInstrDesc. 699 MachineInstr::MachineInstr(MachineFunction &MF, const MCInstrDesc &tid, 700 DebugLoc dl, bool NoImp) 701 : MCID(&tid), Parent(nullptr), Operands(nullptr), NumOperands(0), Flags(0), 702 AsmPrinterFlags(0), NumMemRefs(0), MemRefs(nullptr), 703 debugLoc(std::move(dl)) { 704 assert(debugLoc.hasTrivialDestructor() && "Expected trivial destructor"); 705 706 // Reserve space for the expected number of operands. 707 if (unsigned NumOps = MCID->getNumOperands() + 708 MCID->getNumImplicitDefs() + MCID->getNumImplicitUses()) { 709 CapOperands = OperandCapacity::get(NumOps); 710 Operands = MF.allocateOperandArray(CapOperands); 711 } 712 713 if (!NoImp) 714 addImplicitDefUseOperands(MF); 715 } 716 717 /// MachineInstr ctor - Copies MachineInstr arg exactly 718 /// 719 MachineInstr::MachineInstr(MachineFunction &MF, const MachineInstr &MI) 720 : MCID(&MI.getDesc()), Parent(nullptr), Operands(nullptr), NumOperands(0), 721 Flags(0), AsmPrinterFlags(0), NumMemRefs(MI.NumMemRefs), 722 MemRefs(MI.MemRefs), debugLoc(MI.getDebugLoc()) { 723 assert(debugLoc.hasTrivialDestructor() && "Expected trivial destructor"); 724 725 CapOperands = OperandCapacity::get(MI.getNumOperands()); 726 Operands = MF.allocateOperandArray(CapOperands); 727 728 // Copy operands. 729 for (const MachineOperand &MO : MI.operands()) 730 addOperand(MF, MO); 731 732 // Copy all the sensible flags. 733 setFlags(MI.Flags); 734 } 735 736 /// getRegInfo - If this instruction is embedded into a MachineFunction, 737 /// return the MachineRegisterInfo object for the current function, otherwise 738 /// return null. 739 MachineRegisterInfo *MachineInstr::getRegInfo() { 740 if (MachineBasicBlock *MBB = getParent()) 741 return &MBB->getParent()->getRegInfo(); 742 return nullptr; 743 } 744 745 /// RemoveRegOperandsFromUseLists - Unlink all of the register operands in 746 /// this instruction from their respective use lists. This requires that the 747 /// operands already be on their use lists. 748 void MachineInstr::RemoveRegOperandsFromUseLists(MachineRegisterInfo &MRI) { 749 for (MachineOperand &MO : operands()) 750 if (MO.isReg()) 751 MRI.removeRegOperandFromUseList(&MO); 752 } 753 754 /// AddRegOperandsToUseLists - Add all of the register operands in 755 /// this instruction from their respective use lists. This requires that the 756 /// operands not be on their use lists yet. 757 void MachineInstr::AddRegOperandsToUseLists(MachineRegisterInfo &MRI) { 758 for (MachineOperand &MO : operands()) 759 if (MO.isReg()) 760 MRI.addRegOperandToUseList(&MO); 761 } 762 763 void MachineInstr::addOperand(const MachineOperand &Op) { 764 MachineBasicBlock *MBB = getParent(); 765 assert(MBB && "Use MachineInstrBuilder to add operands to dangling instrs"); 766 MachineFunction *MF = MBB->getParent(); 767 assert(MF && "Use MachineInstrBuilder to add operands to dangling instrs"); 768 addOperand(*MF, Op); 769 } 770 771 /// Move NumOps MachineOperands from Src to Dst, with support for overlapping 772 /// ranges. If MRI is non-null also update use-def chains. 773 static void moveOperands(MachineOperand *Dst, MachineOperand *Src, 774 unsigned NumOps, MachineRegisterInfo *MRI) { 775 if (MRI) 776 return MRI->moveOperands(Dst, Src, NumOps); 777 778 // MachineOperand is a trivially copyable type so we can just use memmove. 779 std::memmove(Dst, Src, NumOps * sizeof(MachineOperand)); 780 } 781 782 /// addOperand - Add the specified operand to the instruction. If it is an 783 /// implicit operand, it is added to the end of the operand list. If it is 784 /// an explicit operand it is added at the end of the explicit operand list 785 /// (before the first implicit operand). 786 void MachineInstr::addOperand(MachineFunction &MF, const MachineOperand &Op) { 787 assert(MCID && "Cannot add operands before providing an instr descriptor"); 788 789 // Check if we're adding one of our existing operands. 790 if (&Op >= Operands && &Op < Operands + NumOperands) { 791 // This is unusual: MI->addOperand(MI->getOperand(i)). 792 // If adding Op requires reallocating or moving existing operands around, 793 // the Op reference could go stale. Support it by copying Op. 794 MachineOperand CopyOp(Op); 795 return addOperand(MF, CopyOp); 796 } 797 798 // Find the insert location for the new operand. Implicit registers go at 799 // the end, everything else goes before the implicit regs. 800 // 801 // FIXME: Allow mixed explicit and implicit operands on inline asm. 802 // InstrEmitter::EmitSpecialNode() is marking inline asm clobbers as 803 // implicit-defs, but they must not be moved around. See the FIXME in 804 // InstrEmitter.cpp. 805 unsigned OpNo = getNumOperands(); 806 bool isImpReg = Op.isReg() && Op.isImplicit(); 807 if (!isImpReg && !isInlineAsm()) { 808 while (OpNo && Operands[OpNo-1].isReg() && Operands[OpNo-1].isImplicit()) { 809 --OpNo; 810 assert(!Operands[OpNo].isTied() && "Cannot move tied operands"); 811 } 812 } 813 814 #ifndef NDEBUG 815 bool isMetaDataOp = Op.getType() == MachineOperand::MO_Metadata; 816 // OpNo now points as the desired insertion point. Unless this is a variadic 817 // instruction, only implicit regs are allowed beyond MCID->getNumOperands(). 818 // RegMask operands go between the explicit and implicit operands. 819 assert((isImpReg || Op.isRegMask() || MCID->isVariadic() || 820 OpNo < MCID->getNumOperands() || isMetaDataOp) && 821 "Trying to add an operand to a machine instr that is already done!"); 822 #endif 823 824 MachineRegisterInfo *MRI = getRegInfo(); 825 826 // Determine if the Operands array needs to be reallocated. 827 // Save the old capacity and operand array. 828 OperandCapacity OldCap = CapOperands; 829 MachineOperand *OldOperands = Operands; 830 if (!OldOperands || OldCap.getSize() == getNumOperands()) { 831 CapOperands = OldOperands ? OldCap.getNext() : OldCap.get(1); 832 Operands = MF.allocateOperandArray(CapOperands); 833 // Move the operands before the insertion point. 834 if (OpNo) 835 moveOperands(Operands, OldOperands, OpNo, MRI); 836 } 837 838 // Move the operands following the insertion point. 839 if (OpNo != NumOperands) 840 moveOperands(Operands + OpNo + 1, OldOperands + OpNo, NumOperands - OpNo, 841 MRI); 842 ++NumOperands; 843 844 // Deallocate the old operand array. 845 if (OldOperands != Operands && OldOperands) 846 MF.deallocateOperandArray(OldCap, OldOperands); 847 848 // Copy Op into place. It still needs to be inserted into the MRI use lists. 849 MachineOperand *NewMO = new (Operands + OpNo) MachineOperand(Op); 850 NewMO->ParentMI = this; 851 852 // When adding a register operand, tell MRI about it. 853 if (NewMO->isReg()) { 854 // Ensure isOnRegUseList() returns false, regardless of Op's status. 855 NewMO->Contents.Reg.Prev = nullptr; 856 // Ignore existing ties. This is not a property that can be copied. 857 NewMO->TiedTo = 0; 858 // Add the new operand to MRI, but only for instructions in an MBB. 859 if (MRI) 860 MRI->addRegOperandToUseList(NewMO); 861 // The MCID operand information isn't accurate until we start adding 862 // explicit operands. The implicit operands are added first, then the 863 // explicits are inserted before them. 864 if (!isImpReg) { 865 // Tie uses to defs as indicated in MCInstrDesc. 866 if (NewMO->isUse()) { 867 int DefIdx = MCID->getOperandConstraint(OpNo, MCOI::TIED_TO); 868 if (DefIdx != -1) 869 tieOperands(DefIdx, OpNo); 870 } 871 // If the register operand is flagged as early, mark the operand as such. 872 if (MCID->getOperandConstraint(OpNo, MCOI::EARLY_CLOBBER) != -1) 873 NewMO->setIsEarlyClobber(true); 874 } 875 } 876 } 877 878 /// RemoveOperand - Erase an operand from an instruction, leaving it with one 879 /// fewer operand than it started with. 880 /// 881 void MachineInstr::RemoveOperand(unsigned OpNo) { 882 assert(OpNo < getNumOperands() && "Invalid operand number"); 883 untieRegOperand(OpNo); 884 885 #ifndef NDEBUG 886 // Moving tied operands would break the ties. 887 for (unsigned i = OpNo + 1, e = getNumOperands(); i != e; ++i) 888 if (Operands[i].isReg()) 889 assert(!Operands[i].isTied() && "Cannot move tied operands"); 890 #endif 891 892 MachineRegisterInfo *MRI = getRegInfo(); 893 if (MRI && Operands[OpNo].isReg()) 894 MRI->removeRegOperandFromUseList(Operands + OpNo); 895 896 // Don't call the MachineOperand destructor. A lot of this code depends on 897 // MachineOperand having a trivial destructor anyway, and adding a call here 898 // wouldn't make it 'destructor-correct'. 899 900 if (unsigned N = NumOperands - 1 - OpNo) 901 moveOperands(Operands + OpNo, Operands + OpNo + 1, N, MRI); 902 --NumOperands; 903 } 904 905 /// addMemOperand - Add a MachineMemOperand to the machine instruction. 906 /// This function should be used only occasionally. The setMemRefs function 907 /// is the primary method for setting up a MachineInstr's MemRefs list. 908 void MachineInstr::addMemOperand(MachineFunction &MF, 909 MachineMemOperand *MO) { 910 mmo_iterator OldMemRefs = MemRefs; 911 unsigned OldNumMemRefs = NumMemRefs; 912 913 unsigned NewNum = NumMemRefs + 1; 914 mmo_iterator NewMemRefs = MF.allocateMemRefsArray(NewNum); 915 916 std::copy(OldMemRefs, OldMemRefs + OldNumMemRefs, NewMemRefs); 917 NewMemRefs[NewNum - 1] = MO; 918 setMemRefs(NewMemRefs, NewMemRefs + NewNum); 919 } 920 921 /// Check to see if the MMOs pointed to by the two MemRefs arrays are 922 /// identical. 923 static bool hasIdenticalMMOs(const MachineInstr &MI1, const MachineInstr &MI2) { 924 auto I1 = MI1.memoperands_begin(), E1 = MI1.memoperands_end(); 925 auto I2 = MI2.memoperands_begin(), E2 = MI2.memoperands_end(); 926 if ((E1 - I1) != (E2 - I2)) 927 return false; 928 for (; I1 != E1; ++I1, ++I2) { 929 if (**I1 != **I2) 930 return false; 931 } 932 return true; 933 } 934 935 std::pair<MachineInstr::mmo_iterator, unsigned> 936 MachineInstr::mergeMemRefsWith(const MachineInstr& Other) { 937 938 // If either of the incoming memrefs are empty, we must be conservative and 939 // treat this as if we've exhausted our space for memrefs and dropped them. 940 if (memoperands_empty() || Other.memoperands_empty()) 941 return std::make_pair(nullptr, 0); 942 943 // If both instructions have identical memrefs, we don't need to merge them. 944 // Since many instructions have a single memref, and we tend to merge things 945 // like pairs of loads from the same location, this catches a large number of 946 // cases in practice. 947 if (hasIdenticalMMOs(*this, Other)) 948 return std::make_pair(MemRefs, NumMemRefs); 949 950 // TODO: consider uniquing elements within the operand lists to reduce 951 // space usage and fall back to conservative information less often. 952 size_t CombinedNumMemRefs = NumMemRefs + Other.NumMemRefs; 953 954 // If we don't have enough room to store this many memrefs, be conservative 955 // and drop them. Otherwise, we'd fail asserts when trying to add them to 956 // the new instruction. 957 if (CombinedNumMemRefs != uint8_t(CombinedNumMemRefs)) 958 return std::make_pair(nullptr, 0); 959 960 MachineFunction *MF = getParent()->getParent(); 961 mmo_iterator MemBegin = MF->allocateMemRefsArray(CombinedNumMemRefs); 962 mmo_iterator MemEnd = std::copy(memoperands_begin(), memoperands_end(), 963 MemBegin); 964 MemEnd = std::copy(Other.memoperands_begin(), Other.memoperands_end(), 965 MemEnd); 966 assert(MemEnd - MemBegin == (ptrdiff_t)CombinedNumMemRefs && 967 "missing memrefs"); 968 969 return std::make_pair(MemBegin, CombinedNumMemRefs); 970 } 971 972 bool MachineInstr::hasPropertyInBundle(unsigned Mask, QueryType Type) const { 973 assert(!isBundledWithPred() && "Must be called on bundle header"); 974 for (MachineBasicBlock::const_instr_iterator MII = getIterator();; ++MII) { 975 if (MII->getDesc().getFlags() & Mask) { 976 if (Type == AnyInBundle) 977 return true; 978 } else { 979 if (Type == AllInBundle && !MII->isBundle()) 980 return false; 981 } 982 // This was the last instruction in the bundle. 983 if (!MII->isBundledWithSucc()) 984 return Type == AllInBundle; 985 } 986 } 987 988 bool MachineInstr::isIdenticalTo(const MachineInstr &Other, 989 MICheckType Check) const { 990 // If opcodes or number of operands are not the same then the two 991 // instructions are obviously not identical. 992 if (Other.getOpcode() != getOpcode() || 993 Other.getNumOperands() != getNumOperands()) 994 return false; 995 996 if (isBundle()) { 997 // Both instructions are bundles, compare MIs inside the bundle. 998 MachineBasicBlock::const_instr_iterator I1 = getIterator(); 999 MachineBasicBlock::const_instr_iterator E1 = getParent()->instr_end(); 1000 MachineBasicBlock::const_instr_iterator I2 = Other.getIterator(); 1001 MachineBasicBlock::const_instr_iterator E2 = Other.getParent()->instr_end(); 1002 while (++I1 != E1 && I1->isInsideBundle()) { 1003 ++I2; 1004 if (I2 == E2 || !I2->isInsideBundle() || !I1->isIdenticalTo(*I2, Check)) 1005 return false; 1006 } 1007 } 1008 1009 // Check operands to make sure they match. 1010 for (unsigned i = 0, e = getNumOperands(); i != e; ++i) { 1011 const MachineOperand &MO = getOperand(i); 1012 const MachineOperand &OMO = Other.getOperand(i); 1013 if (!MO.isReg()) { 1014 if (!MO.isIdenticalTo(OMO)) 1015 return false; 1016 continue; 1017 } 1018 1019 // Clients may or may not want to ignore defs when testing for equality. 1020 // For example, machine CSE pass only cares about finding common 1021 // subexpressions, so it's safe to ignore virtual register defs. 1022 if (MO.isDef()) { 1023 if (Check == IgnoreDefs) 1024 continue; 1025 else if (Check == IgnoreVRegDefs) { 1026 if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()) || 1027 TargetRegisterInfo::isPhysicalRegister(OMO.getReg())) 1028 if (MO.getReg() != OMO.getReg()) 1029 return false; 1030 } else { 1031 if (!MO.isIdenticalTo(OMO)) 1032 return false; 1033 if (Check == CheckKillDead && MO.isDead() != OMO.isDead()) 1034 return false; 1035 } 1036 } else { 1037 if (!MO.isIdenticalTo(OMO)) 1038 return false; 1039 if (Check == CheckKillDead && MO.isKill() != OMO.isKill()) 1040 return false; 1041 } 1042 } 1043 // If DebugLoc does not match then two dbg.values are not identical. 1044 if (isDebugValue()) 1045 if (getDebugLoc() && Other.getDebugLoc() && 1046 getDebugLoc() != Other.getDebugLoc()) 1047 return false; 1048 return true; 1049 } 1050 1051 MachineInstr *MachineInstr::removeFromParent() { 1052 assert(getParent() && "Not embedded in a basic block!"); 1053 return getParent()->remove(this); 1054 } 1055 1056 MachineInstr *MachineInstr::removeFromBundle() { 1057 assert(getParent() && "Not embedded in a basic block!"); 1058 return getParent()->remove_instr(this); 1059 } 1060 1061 void MachineInstr::eraseFromParent() { 1062 assert(getParent() && "Not embedded in a basic block!"); 1063 getParent()->erase(this); 1064 } 1065 1066 void MachineInstr::eraseFromParentAndMarkDBGValuesForRemoval() { 1067 assert(getParent() && "Not embedded in a basic block!"); 1068 MachineBasicBlock *MBB = getParent(); 1069 MachineFunction *MF = MBB->getParent(); 1070 assert(MF && "Not embedded in a function!"); 1071 1072 MachineInstr *MI = (MachineInstr *)this; 1073 MachineRegisterInfo &MRI = MF->getRegInfo(); 1074 1075 for (const MachineOperand &MO : MI->operands()) { 1076 if (!MO.isReg() || !MO.isDef()) 1077 continue; 1078 unsigned Reg = MO.getReg(); 1079 if (!TargetRegisterInfo::isVirtualRegister(Reg)) 1080 continue; 1081 MRI.markUsesInDebugValueAsUndef(Reg); 1082 } 1083 MI->eraseFromParent(); 1084 } 1085 1086 void MachineInstr::eraseFromBundle() { 1087 assert(getParent() && "Not embedded in a basic block!"); 1088 getParent()->erase_instr(this); 1089 } 1090 1091 /// getNumExplicitOperands - Returns the number of non-implicit operands. 1092 /// 1093 unsigned MachineInstr::getNumExplicitOperands() const { 1094 unsigned NumOperands = MCID->getNumOperands(); 1095 if (!MCID->isVariadic()) 1096 return NumOperands; 1097 1098 for (unsigned i = NumOperands, e = getNumOperands(); i != e; ++i) { 1099 const MachineOperand &MO = getOperand(i); 1100 if (!MO.isReg() || !MO.isImplicit()) 1101 NumOperands++; 1102 } 1103 return NumOperands; 1104 } 1105 1106 void MachineInstr::bundleWithPred() { 1107 assert(!isBundledWithPred() && "MI is already bundled with its predecessor"); 1108 setFlag(BundledPred); 1109 MachineBasicBlock::instr_iterator Pred = getIterator(); 1110 --Pred; 1111 assert(!Pred->isBundledWithSucc() && "Inconsistent bundle flags"); 1112 Pred->setFlag(BundledSucc); 1113 } 1114 1115 void MachineInstr::bundleWithSucc() { 1116 assert(!isBundledWithSucc() && "MI is already bundled with its successor"); 1117 setFlag(BundledSucc); 1118 MachineBasicBlock::instr_iterator Succ = getIterator(); 1119 ++Succ; 1120 assert(!Succ->isBundledWithPred() && "Inconsistent bundle flags"); 1121 Succ->setFlag(BundledPred); 1122 } 1123 1124 void MachineInstr::unbundleFromPred() { 1125 assert(isBundledWithPred() && "MI isn't bundled with its predecessor"); 1126 clearFlag(BundledPred); 1127 MachineBasicBlock::instr_iterator Pred = getIterator(); 1128 --Pred; 1129 assert(Pred->isBundledWithSucc() && "Inconsistent bundle flags"); 1130 Pred->clearFlag(BundledSucc); 1131 } 1132 1133 void MachineInstr::unbundleFromSucc() { 1134 assert(isBundledWithSucc() && "MI isn't bundled with its successor"); 1135 clearFlag(BundledSucc); 1136 MachineBasicBlock::instr_iterator Succ = getIterator(); 1137 ++Succ; 1138 assert(Succ->isBundledWithPred() && "Inconsistent bundle flags"); 1139 Succ->clearFlag(BundledPred); 1140 } 1141 1142 bool MachineInstr::isStackAligningInlineAsm() const { 1143 if (isInlineAsm()) { 1144 unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm(); 1145 if (ExtraInfo & InlineAsm::Extra_IsAlignStack) 1146 return true; 1147 } 1148 return false; 1149 } 1150 1151 InlineAsm::AsmDialect MachineInstr::getInlineAsmDialect() const { 1152 assert(isInlineAsm() && "getInlineAsmDialect() only works for inline asms!"); 1153 unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm(); 1154 return InlineAsm::AsmDialect((ExtraInfo & InlineAsm::Extra_AsmDialect) != 0); 1155 } 1156 1157 int MachineInstr::findInlineAsmFlagIdx(unsigned OpIdx, 1158 unsigned *GroupNo) const { 1159 assert(isInlineAsm() && "Expected an inline asm instruction"); 1160 assert(OpIdx < getNumOperands() && "OpIdx out of range"); 1161 1162 // Ignore queries about the initial operands. 1163 if (OpIdx < InlineAsm::MIOp_FirstOperand) 1164 return -1; 1165 1166 unsigned Group = 0; 1167 unsigned NumOps; 1168 for (unsigned i = InlineAsm::MIOp_FirstOperand, e = getNumOperands(); i < e; 1169 i += NumOps) { 1170 const MachineOperand &FlagMO = getOperand(i); 1171 // If we reach the implicit register operands, stop looking. 1172 if (!FlagMO.isImm()) 1173 return -1; 1174 NumOps = 1 + InlineAsm::getNumOperandRegisters(FlagMO.getImm()); 1175 if (i + NumOps > OpIdx) { 1176 if (GroupNo) 1177 *GroupNo = Group; 1178 return i; 1179 } 1180 ++Group; 1181 } 1182 return -1; 1183 } 1184 1185 const DILocalVariable *MachineInstr::getDebugVariable() const { 1186 assert(isDebugValue() && "not a DBG_VALUE"); 1187 return cast<DILocalVariable>(getOperand(2).getMetadata()); 1188 } 1189 1190 const DIExpression *MachineInstr::getDebugExpression() const { 1191 assert(isDebugValue() && "not a DBG_VALUE"); 1192 return cast<DIExpression>(getOperand(3).getMetadata()); 1193 } 1194 1195 const TargetRegisterClass* 1196 MachineInstr::getRegClassConstraint(unsigned OpIdx, 1197 const TargetInstrInfo *TII, 1198 const TargetRegisterInfo *TRI) const { 1199 assert(getParent() && "Can't have an MBB reference here!"); 1200 assert(getParent()->getParent() && "Can't have an MF reference here!"); 1201 const MachineFunction &MF = *getParent()->getParent(); 1202 1203 // Most opcodes have fixed constraints in their MCInstrDesc. 1204 if (!isInlineAsm()) 1205 return TII->getRegClass(getDesc(), OpIdx, TRI, MF); 1206 1207 if (!getOperand(OpIdx).isReg()) 1208 return nullptr; 1209 1210 // For tied uses on inline asm, get the constraint from the def. 1211 unsigned DefIdx; 1212 if (getOperand(OpIdx).isUse() && isRegTiedToDefOperand(OpIdx, &DefIdx)) 1213 OpIdx = DefIdx; 1214 1215 // Inline asm stores register class constraints in the flag word. 1216 int FlagIdx = findInlineAsmFlagIdx(OpIdx); 1217 if (FlagIdx < 0) 1218 return nullptr; 1219 1220 unsigned Flag = getOperand(FlagIdx).getImm(); 1221 unsigned RCID; 1222 if ((InlineAsm::getKind(Flag) == InlineAsm::Kind_RegUse || 1223 InlineAsm::getKind(Flag) == InlineAsm::Kind_RegDef || 1224 InlineAsm::getKind(Flag) == InlineAsm::Kind_RegDefEarlyClobber) && 1225 InlineAsm::hasRegClassConstraint(Flag, RCID)) 1226 return TRI->getRegClass(RCID); 1227 1228 // Assume that all registers in a memory operand are pointers. 1229 if (InlineAsm::getKind(Flag) == InlineAsm::Kind_Mem) 1230 return TRI->getPointerRegClass(MF); 1231 1232 return nullptr; 1233 } 1234 1235 const TargetRegisterClass *MachineInstr::getRegClassConstraintEffectForVReg( 1236 unsigned Reg, const TargetRegisterClass *CurRC, const TargetInstrInfo *TII, 1237 const TargetRegisterInfo *TRI, bool ExploreBundle) const { 1238 // Check every operands inside the bundle if we have 1239 // been asked to. 1240 if (ExploreBundle) 1241 for (ConstMIBundleOperands OpndIt(*this); OpndIt.isValid() && CurRC; 1242 ++OpndIt) 1243 CurRC = OpndIt->getParent()->getRegClassConstraintEffectForVRegImpl( 1244 OpndIt.getOperandNo(), Reg, CurRC, TII, TRI); 1245 else 1246 // Otherwise, just check the current operands. 1247 for (unsigned i = 0, e = NumOperands; i < e && CurRC; ++i) 1248 CurRC = getRegClassConstraintEffectForVRegImpl(i, Reg, CurRC, TII, TRI); 1249 return CurRC; 1250 } 1251 1252 const TargetRegisterClass *MachineInstr::getRegClassConstraintEffectForVRegImpl( 1253 unsigned OpIdx, unsigned Reg, const TargetRegisterClass *CurRC, 1254 const TargetInstrInfo *TII, const TargetRegisterInfo *TRI) const { 1255 assert(CurRC && "Invalid initial register class"); 1256 // Check if Reg is constrained by some of its use/def from MI. 1257 const MachineOperand &MO = getOperand(OpIdx); 1258 if (!MO.isReg() || MO.getReg() != Reg) 1259 return CurRC; 1260 // If yes, accumulate the constraints through the operand. 1261 return getRegClassConstraintEffect(OpIdx, CurRC, TII, TRI); 1262 } 1263 1264 const TargetRegisterClass *MachineInstr::getRegClassConstraintEffect( 1265 unsigned OpIdx, const TargetRegisterClass *CurRC, 1266 const TargetInstrInfo *TII, const TargetRegisterInfo *TRI) const { 1267 const TargetRegisterClass *OpRC = getRegClassConstraint(OpIdx, TII, TRI); 1268 const MachineOperand &MO = getOperand(OpIdx); 1269 assert(MO.isReg() && 1270 "Cannot get register constraints for non-register operand"); 1271 assert(CurRC && "Invalid initial register class"); 1272 if (unsigned SubIdx = MO.getSubReg()) { 1273 if (OpRC) 1274 CurRC = TRI->getMatchingSuperRegClass(CurRC, OpRC, SubIdx); 1275 else 1276 CurRC = TRI->getSubClassWithSubReg(CurRC, SubIdx); 1277 } else if (OpRC) 1278 CurRC = TRI->getCommonSubClass(CurRC, OpRC); 1279 return CurRC; 1280 } 1281 1282 /// Return the number of instructions inside the MI bundle, not counting the 1283 /// header instruction. 1284 unsigned MachineInstr::getBundleSize() const { 1285 MachineBasicBlock::const_instr_iterator I = getIterator(); 1286 unsigned Size = 0; 1287 while (I->isBundledWithSucc()) { 1288 ++Size; 1289 ++I; 1290 } 1291 return Size; 1292 } 1293 1294 /// Returns true if the MachineInstr has an implicit-use operand of exactly 1295 /// the given register (not considering sub/super-registers). 1296 bool MachineInstr::hasRegisterImplicitUseOperand(unsigned Reg) const { 1297 for (unsigned i = 0, e = getNumOperands(); i != e; ++i) { 1298 const MachineOperand &MO = getOperand(i); 1299 if (MO.isReg() && MO.isUse() && MO.isImplicit() && MO.getReg() == Reg) 1300 return true; 1301 } 1302 return false; 1303 } 1304 1305 /// findRegisterUseOperandIdx() - Returns the MachineOperand that is a use of 1306 /// the specific register or -1 if it is not found. It further tightens 1307 /// the search criteria to a use that kills the register if isKill is true. 1308 int MachineInstr::findRegisterUseOperandIdx( 1309 unsigned Reg, bool isKill, const TargetRegisterInfo *TRI) const { 1310 for (unsigned i = 0, e = getNumOperands(); i != e; ++i) { 1311 const MachineOperand &MO = getOperand(i); 1312 if (!MO.isReg() || !MO.isUse()) 1313 continue; 1314 unsigned MOReg = MO.getReg(); 1315 if (!MOReg) 1316 continue; 1317 if (MOReg == Reg || (TRI && TargetRegisterInfo::isPhysicalRegister(MOReg) && 1318 TargetRegisterInfo::isPhysicalRegister(Reg) && 1319 TRI->isSubRegister(MOReg, Reg))) 1320 if (!isKill || MO.isKill()) 1321 return i; 1322 } 1323 return -1; 1324 } 1325 1326 /// readsWritesVirtualRegister - Return a pair of bools (reads, writes) 1327 /// indicating if this instruction reads or writes Reg. This also considers 1328 /// partial defines. 1329 std::pair<bool,bool> 1330 MachineInstr::readsWritesVirtualRegister(unsigned Reg, 1331 SmallVectorImpl<unsigned> *Ops) const { 1332 bool PartDef = false; // Partial redefine. 1333 bool FullDef = false; // Full define. 1334 bool Use = false; 1335 1336 for (unsigned i = 0, e = getNumOperands(); i != e; ++i) { 1337 const MachineOperand &MO = getOperand(i); 1338 if (!MO.isReg() || MO.getReg() != Reg) 1339 continue; 1340 if (Ops) 1341 Ops->push_back(i); 1342 if (MO.isUse()) 1343 Use |= !MO.isUndef(); 1344 else if (MO.getSubReg() && !MO.isUndef()) 1345 // A partial <def,undef> doesn't count as reading the register. 1346 PartDef = true; 1347 else 1348 FullDef = true; 1349 } 1350 // A partial redefine uses Reg unless there is also a full define. 1351 return std::make_pair(Use || (PartDef && !FullDef), PartDef || FullDef); 1352 } 1353 1354 /// findRegisterDefOperandIdx() - Returns the operand index that is a def of 1355 /// the specified register or -1 if it is not found. If isDead is true, defs 1356 /// that are not dead are skipped. If TargetRegisterInfo is non-null, then it 1357 /// also checks if there is a def of a super-register. 1358 int 1359 MachineInstr::findRegisterDefOperandIdx(unsigned Reg, bool isDead, bool Overlap, 1360 const TargetRegisterInfo *TRI) const { 1361 bool isPhys = TargetRegisterInfo::isPhysicalRegister(Reg); 1362 for (unsigned i = 0, e = getNumOperands(); i != e; ++i) { 1363 const MachineOperand &MO = getOperand(i); 1364 // Accept regmask operands when Overlap is set. 1365 // Ignore them when looking for a specific def operand (Overlap == false). 1366 if (isPhys && Overlap && MO.isRegMask() && MO.clobbersPhysReg(Reg)) 1367 return i; 1368 if (!MO.isReg() || !MO.isDef()) 1369 continue; 1370 unsigned MOReg = MO.getReg(); 1371 bool Found = (MOReg == Reg); 1372 if (!Found && TRI && isPhys && 1373 TargetRegisterInfo::isPhysicalRegister(MOReg)) { 1374 if (Overlap) 1375 Found = TRI->regsOverlap(MOReg, Reg); 1376 else 1377 Found = TRI->isSubRegister(MOReg, Reg); 1378 } 1379 if (Found && (!isDead || MO.isDead())) 1380 return i; 1381 } 1382 return -1; 1383 } 1384 1385 /// findFirstPredOperandIdx() - Find the index of the first operand in the 1386 /// operand list that is used to represent the predicate. It returns -1 if 1387 /// none is found. 1388 int MachineInstr::findFirstPredOperandIdx() const { 1389 // Don't call MCID.findFirstPredOperandIdx() because this variant 1390 // is sometimes called on an instruction that's not yet complete, and 1391 // so the number of operands is less than the MCID indicates. In 1392 // particular, the PTX target does this. 1393 const MCInstrDesc &MCID = getDesc(); 1394 if (MCID.isPredicable()) { 1395 for (unsigned i = 0, e = getNumOperands(); i != e; ++i) 1396 if (MCID.OpInfo[i].isPredicate()) 1397 return i; 1398 } 1399 1400 return -1; 1401 } 1402 1403 // MachineOperand::TiedTo is 4 bits wide. 1404 const unsigned TiedMax = 15; 1405 1406 /// tieOperands - Mark operands at DefIdx and UseIdx as tied to each other. 1407 /// 1408 /// Use and def operands can be tied together, indicated by a non-zero TiedTo 1409 /// field. TiedTo can have these values: 1410 /// 1411 /// 0: Operand is not tied to anything. 1412 /// 1 to TiedMax-1: Tied to getOperand(TiedTo-1). 1413 /// TiedMax: Tied to an operand >= TiedMax-1. 1414 /// 1415 /// The tied def must be one of the first TiedMax operands on a normal 1416 /// instruction. INLINEASM instructions allow more tied defs. 1417 /// 1418 void MachineInstr::tieOperands(unsigned DefIdx, unsigned UseIdx) { 1419 MachineOperand &DefMO = getOperand(DefIdx); 1420 MachineOperand &UseMO = getOperand(UseIdx); 1421 assert(DefMO.isDef() && "DefIdx must be a def operand"); 1422 assert(UseMO.isUse() && "UseIdx must be a use operand"); 1423 assert(!DefMO.isTied() && "Def is already tied to another use"); 1424 assert(!UseMO.isTied() && "Use is already tied to another def"); 1425 1426 if (DefIdx < TiedMax) 1427 UseMO.TiedTo = DefIdx + 1; 1428 else { 1429 // Inline asm can use the group descriptors to find tied operands, but on 1430 // normal instruction, the tied def must be within the first TiedMax 1431 // operands. 1432 assert(isInlineAsm() && "DefIdx out of range"); 1433 UseMO.TiedTo = TiedMax; 1434 } 1435 1436 // UseIdx can be out of range, we'll search for it in findTiedOperandIdx(). 1437 DefMO.TiedTo = std::min(UseIdx + 1, TiedMax); 1438 } 1439 1440 /// Given the index of a tied register operand, find the operand it is tied to. 1441 /// Defs are tied to uses and vice versa. Returns the index of the tied operand 1442 /// which must exist. 1443 unsigned MachineInstr::findTiedOperandIdx(unsigned OpIdx) const { 1444 const MachineOperand &MO = getOperand(OpIdx); 1445 assert(MO.isTied() && "Operand isn't tied"); 1446 1447 // Normally TiedTo is in range. 1448 if (MO.TiedTo < TiedMax) 1449 return MO.TiedTo - 1; 1450 1451 // Uses on normal instructions can be out of range. 1452 if (!isInlineAsm()) { 1453 // Normal tied defs must be in the 0..TiedMax-1 range. 1454 if (MO.isUse()) 1455 return TiedMax - 1; 1456 // MO is a def. Search for the tied use. 1457 for (unsigned i = TiedMax - 1, e = getNumOperands(); i != e; ++i) { 1458 const MachineOperand &UseMO = getOperand(i); 1459 if (UseMO.isReg() && UseMO.isUse() && UseMO.TiedTo == OpIdx + 1) 1460 return i; 1461 } 1462 llvm_unreachable("Can't find tied use"); 1463 } 1464 1465 // Now deal with inline asm by parsing the operand group descriptor flags. 1466 // Find the beginning of each operand group. 1467 SmallVector<unsigned, 8> GroupIdx; 1468 unsigned OpIdxGroup = ~0u; 1469 unsigned NumOps; 1470 for (unsigned i = InlineAsm::MIOp_FirstOperand, e = getNumOperands(); i < e; 1471 i += NumOps) { 1472 const MachineOperand &FlagMO = getOperand(i); 1473 assert(FlagMO.isImm() && "Invalid tied operand on inline asm"); 1474 unsigned CurGroup = GroupIdx.size(); 1475 GroupIdx.push_back(i); 1476 NumOps = 1 + InlineAsm::getNumOperandRegisters(FlagMO.getImm()); 1477 // OpIdx belongs to this operand group. 1478 if (OpIdx > i && OpIdx < i + NumOps) 1479 OpIdxGroup = CurGroup; 1480 unsigned TiedGroup; 1481 if (!InlineAsm::isUseOperandTiedToDef(FlagMO.getImm(), TiedGroup)) 1482 continue; 1483 // Operands in this group are tied to operands in TiedGroup which must be 1484 // earlier. Find the number of operands between the two groups. 1485 unsigned Delta = i - GroupIdx[TiedGroup]; 1486 1487 // OpIdx is a use tied to TiedGroup. 1488 if (OpIdxGroup == CurGroup) 1489 return OpIdx - Delta; 1490 1491 // OpIdx is a def tied to this use group. 1492 if (OpIdxGroup == TiedGroup) 1493 return OpIdx + Delta; 1494 } 1495 llvm_unreachable("Invalid tied operand on inline asm"); 1496 } 1497 1498 /// clearKillInfo - Clears kill flags on all operands. 1499 /// 1500 void MachineInstr::clearKillInfo() { 1501 for (MachineOperand &MO : operands()) { 1502 if (MO.isReg() && MO.isUse()) 1503 MO.setIsKill(false); 1504 } 1505 } 1506 1507 void MachineInstr::substituteRegister(unsigned FromReg, 1508 unsigned ToReg, 1509 unsigned SubIdx, 1510 const TargetRegisterInfo &RegInfo) { 1511 if (TargetRegisterInfo::isPhysicalRegister(ToReg)) { 1512 if (SubIdx) 1513 ToReg = RegInfo.getSubReg(ToReg, SubIdx); 1514 for (MachineOperand &MO : operands()) { 1515 if (!MO.isReg() || MO.getReg() != FromReg) 1516 continue; 1517 MO.substPhysReg(ToReg, RegInfo); 1518 } 1519 } else { 1520 for (MachineOperand &MO : operands()) { 1521 if (!MO.isReg() || MO.getReg() != FromReg) 1522 continue; 1523 MO.substVirtReg(ToReg, SubIdx, RegInfo); 1524 } 1525 } 1526 } 1527 1528 /// isSafeToMove - Return true if it is safe to move this instruction. If 1529 /// SawStore is set to true, it means that there is a store (or call) between 1530 /// the instruction's location and its intended destination. 1531 bool MachineInstr::isSafeToMove(AliasAnalysis *AA, bool &SawStore) const { 1532 // Ignore stuff that we obviously can't move. 1533 // 1534 // Treat volatile loads as stores. This is not strictly necessary for 1535 // volatiles, but it is required for atomic loads. It is not allowed to move 1536 // a load across an atomic load with Ordering > Monotonic. 1537 if (mayStore() || isCall() || 1538 (mayLoad() && hasOrderedMemoryRef())) { 1539 SawStore = true; 1540 return false; 1541 } 1542 1543 if (isPosition() || isDebugValue() || isTerminator() || 1544 hasUnmodeledSideEffects()) 1545 return false; 1546 1547 // See if this instruction does a load. If so, we have to guarantee that the 1548 // loaded value doesn't change between the load and the its intended 1549 // destination. The check for isInvariantLoad gives the targe the chance to 1550 // classify the load as always returning a constant, e.g. a constant pool 1551 // load. 1552 if (mayLoad() && !isDereferenceableInvariantLoad(AA)) 1553 // Otherwise, this is a real load. If there is a store between the load and 1554 // end of block, we can't move it. 1555 return !SawStore; 1556 1557 return true; 1558 } 1559 1560 /// hasOrderedMemoryRef - Return true if this instruction may have an ordered 1561 /// or volatile memory reference, or if the information describing the memory 1562 /// reference is not available. Return false if it is known to have no ordered 1563 /// memory references. 1564 bool MachineInstr::hasOrderedMemoryRef() const { 1565 // An instruction known never to access memory won't have a volatile access. 1566 if (!mayStore() && 1567 !mayLoad() && 1568 !isCall() && 1569 !hasUnmodeledSideEffects()) 1570 return false; 1571 1572 // Otherwise, if the instruction has no memory reference information, 1573 // conservatively assume it wasn't preserved. 1574 if (memoperands_empty()) 1575 return true; 1576 1577 // Check if any of our memory operands are ordered. 1578 return any_of(memoperands(), [](const MachineMemOperand *MMO) { 1579 return !MMO->isUnordered(); 1580 }); 1581 } 1582 1583 /// isDereferenceableInvariantLoad - Return true if this instruction will never 1584 /// trap and is loading from a location whose value is invariant across a run of 1585 /// this function. 1586 bool MachineInstr::isDereferenceableInvariantLoad(AliasAnalysis *AA) const { 1587 // If the instruction doesn't load at all, it isn't an invariant load. 1588 if (!mayLoad()) 1589 return false; 1590 1591 // If the instruction has lost its memoperands, conservatively assume that 1592 // it may not be an invariant load. 1593 if (memoperands_empty()) 1594 return false; 1595 1596 const MachineFrameInfo &MFI = getParent()->getParent()->getFrameInfo(); 1597 1598 for (MachineMemOperand *MMO : memoperands()) { 1599 if (MMO->isVolatile()) return false; 1600 if (MMO->isStore()) return false; 1601 if (MMO->isInvariant() && MMO->isDereferenceable()) 1602 continue; 1603 1604 // A load from a constant PseudoSourceValue is invariant. 1605 if (const PseudoSourceValue *PSV = MMO->getPseudoValue()) 1606 if (PSV->isConstant(&MFI)) 1607 continue; 1608 1609 if (const Value *V = MMO->getValue()) { 1610 // If we have an AliasAnalysis, ask it whether the memory is constant. 1611 if (AA && 1612 AA->pointsToConstantMemory( 1613 MemoryLocation(V, MMO->getSize(), MMO->getAAInfo()))) 1614 continue; 1615 } 1616 1617 // Otherwise assume conservatively. 1618 return false; 1619 } 1620 1621 // Everything checks out. 1622 return true; 1623 } 1624 1625 /// isConstantValuePHI - If the specified instruction is a PHI that always 1626 /// merges together the same virtual register, return the register, otherwise 1627 /// return 0. 1628 unsigned MachineInstr::isConstantValuePHI() const { 1629 if (!isPHI()) 1630 return 0; 1631 assert(getNumOperands() >= 3 && 1632 "It's illegal to have a PHI without source operands"); 1633 1634 unsigned Reg = getOperand(1).getReg(); 1635 for (unsigned i = 3, e = getNumOperands(); i < e; i += 2) 1636 if (getOperand(i).getReg() != Reg) 1637 return 0; 1638 return Reg; 1639 } 1640 1641 bool MachineInstr::hasUnmodeledSideEffects() const { 1642 if (hasProperty(MCID::UnmodeledSideEffects)) 1643 return true; 1644 if (isInlineAsm()) { 1645 unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm(); 1646 if (ExtraInfo & InlineAsm::Extra_HasSideEffects) 1647 return true; 1648 } 1649 1650 return false; 1651 } 1652 1653 bool MachineInstr::isLoadFoldBarrier() const { 1654 return mayStore() || isCall() || hasUnmodeledSideEffects(); 1655 } 1656 1657 /// allDefsAreDead - Return true if all the defs of this instruction are dead. 1658 /// 1659 bool MachineInstr::allDefsAreDead() const { 1660 for (const MachineOperand &MO : operands()) { 1661 if (!MO.isReg() || MO.isUse()) 1662 continue; 1663 if (!MO.isDead()) 1664 return false; 1665 } 1666 return true; 1667 } 1668 1669 /// copyImplicitOps - Copy implicit register operands from specified 1670 /// instruction to this instruction. 1671 void MachineInstr::copyImplicitOps(MachineFunction &MF, 1672 const MachineInstr &MI) { 1673 for (unsigned i = MI.getDesc().getNumOperands(), e = MI.getNumOperands(); 1674 i != e; ++i) { 1675 const MachineOperand &MO = MI.getOperand(i); 1676 if ((MO.isReg() && MO.isImplicit()) || MO.isRegMask()) 1677 addOperand(MF, MO); 1678 } 1679 } 1680 1681 LLVM_DUMP_METHOD void MachineInstr::dump() const { 1682 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 1683 dbgs() << " " << *this; 1684 #endif 1685 } 1686 1687 void MachineInstr::print(raw_ostream &OS, bool SkipOpers) const { 1688 const Module *M = nullptr; 1689 if (const MachineBasicBlock *MBB = getParent()) 1690 if (const MachineFunction *MF = MBB->getParent()) 1691 M = MF->getFunction()->getParent(); 1692 1693 ModuleSlotTracker MST(M); 1694 print(OS, MST, SkipOpers); 1695 } 1696 1697 void MachineInstr::print(raw_ostream &OS, ModuleSlotTracker &MST, 1698 bool SkipOpers) const { 1699 // We can be a bit tidier if we know the MachineFunction. 1700 const MachineFunction *MF = nullptr; 1701 const TargetRegisterInfo *TRI = nullptr; 1702 const MachineRegisterInfo *MRI = nullptr; 1703 const TargetInstrInfo *TII = nullptr; 1704 const TargetIntrinsicInfo *IntrinsicInfo = nullptr; 1705 1706 if (const MachineBasicBlock *MBB = getParent()) { 1707 MF = MBB->getParent(); 1708 if (MF) { 1709 MRI = &MF->getRegInfo(); 1710 TRI = MF->getSubtarget().getRegisterInfo(); 1711 TII = MF->getSubtarget().getInstrInfo(); 1712 IntrinsicInfo = MF->getTarget().getIntrinsicInfo(); 1713 } 1714 } 1715 1716 // Save a list of virtual registers. 1717 SmallVector<unsigned, 8> VirtRegs; 1718 1719 // Print explicitly defined operands on the left of an assignment syntax. 1720 unsigned StartOp = 0, e = getNumOperands(); 1721 for (; StartOp < e && getOperand(StartOp).isReg() && 1722 getOperand(StartOp).isDef() && 1723 !getOperand(StartOp).isImplicit(); 1724 ++StartOp) { 1725 if (StartOp != 0) OS << ", "; 1726 getOperand(StartOp).print(OS, MST, TRI, IntrinsicInfo); 1727 unsigned Reg = getOperand(StartOp).getReg(); 1728 if (TargetRegisterInfo::isVirtualRegister(Reg)) { 1729 VirtRegs.push_back(Reg); 1730 LLT Ty = MRI ? MRI->getType(Reg) : LLT{}; 1731 if (Ty.isValid()) 1732 OS << '(' << Ty << ')'; 1733 } 1734 } 1735 1736 if (StartOp != 0) 1737 OS << " = "; 1738 1739 // Print the opcode name. 1740 if (TII) 1741 OS << TII->getName(getOpcode()); 1742 else 1743 OS << "UNKNOWN"; 1744 1745 if (SkipOpers) 1746 return; 1747 1748 // Print the rest of the operands. 1749 bool OmittedAnyCallClobbers = false; 1750 bool FirstOp = true; 1751 unsigned AsmDescOp = ~0u; 1752 unsigned AsmOpCount = 0; 1753 1754 if (isInlineAsm() && e >= InlineAsm::MIOp_FirstOperand) { 1755 // Print asm string. 1756 OS << " "; 1757 getOperand(InlineAsm::MIOp_AsmString).print(OS, MST, TRI); 1758 1759 // Print HasSideEffects, MayLoad, MayStore, IsAlignStack 1760 unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm(); 1761 if (ExtraInfo & InlineAsm::Extra_HasSideEffects) 1762 OS << " [sideeffect]"; 1763 if (ExtraInfo & InlineAsm::Extra_MayLoad) 1764 OS << " [mayload]"; 1765 if (ExtraInfo & InlineAsm::Extra_MayStore) 1766 OS << " [maystore]"; 1767 if (ExtraInfo & InlineAsm::Extra_IsConvergent) 1768 OS << " [isconvergent]"; 1769 if (ExtraInfo & InlineAsm::Extra_IsAlignStack) 1770 OS << " [alignstack]"; 1771 if (getInlineAsmDialect() == InlineAsm::AD_ATT) 1772 OS << " [attdialect]"; 1773 if (getInlineAsmDialect() == InlineAsm::AD_Intel) 1774 OS << " [inteldialect]"; 1775 1776 StartOp = AsmDescOp = InlineAsm::MIOp_FirstOperand; 1777 FirstOp = false; 1778 } 1779 1780 for (unsigned i = StartOp, e = getNumOperands(); i != e; ++i) { 1781 const MachineOperand &MO = getOperand(i); 1782 1783 if (MO.isReg() && TargetRegisterInfo::isVirtualRegister(MO.getReg())) 1784 VirtRegs.push_back(MO.getReg()); 1785 1786 // Omit call-clobbered registers which aren't used anywhere. This makes 1787 // call instructions much less noisy on targets where calls clobber lots 1788 // of registers. Don't rely on MO.isDead() because we may be called before 1789 // LiveVariables is run, or we may be looking at a non-allocatable reg. 1790 if (MRI && isCall() && 1791 MO.isReg() && MO.isImplicit() && MO.isDef()) { 1792 unsigned Reg = MO.getReg(); 1793 if (TargetRegisterInfo::isPhysicalRegister(Reg)) { 1794 if (MRI->use_empty(Reg)) { 1795 bool HasAliasLive = false; 1796 for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI) { 1797 unsigned AliasReg = *AI; 1798 if (!MRI->use_empty(AliasReg)) { 1799 HasAliasLive = true; 1800 break; 1801 } 1802 } 1803 if (!HasAliasLive) { 1804 OmittedAnyCallClobbers = true; 1805 continue; 1806 } 1807 } 1808 } 1809 } 1810 1811 if (FirstOp) FirstOp = false; else OS << ","; 1812 OS << " "; 1813 if (i < getDesc().NumOperands) { 1814 const MCOperandInfo &MCOI = getDesc().OpInfo[i]; 1815 if (MCOI.isPredicate()) 1816 OS << "pred:"; 1817 if (MCOI.isOptionalDef()) 1818 OS << "opt:"; 1819 } 1820 if (isDebugValue() && MO.isMetadata()) { 1821 // Pretty print DBG_VALUE instructions. 1822 auto *DIV = dyn_cast<DILocalVariable>(MO.getMetadata()); 1823 if (DIV && !DIV->getName().empty()) 1824 OS << "!\"" << DIV->getName() << '\"'; 1825 else 1826 MO.print(OS, MST, TRI); 1827 } else if (TRI && (isInsertSubreg() || isRegSequence()) && MO.isImm()) { 1828 OS << TRI->getSubRegIndexName(MO.getImm()); 1829 } else if (i == AsmDescOp && MO.isImm()) { 1830 // Pretty print the inline asm operand descriptor. 1831 OS << '$' << AsmOpCount++; 1832 unsigned Flag = MO.getImm(); 1833 switch (InlineAsm::getKind(Flag)) { 1834 case InlineAsm::Kind_RegUse: OS << ":[reguse"; break; 1835 case InlineAsm::Kind_RegDef: OS << ":[regdef"; break; 1836 case InlineAsm::Kind_RegDefEarlyClobber: OS << ":[regdef-ec"; break; 1837 case InlineAsm::Kind_Clobber: OS << ":[clobber"; break; 1838 case InlineAsm::Kind_Imm: OS << ":[imm"; break; 1839 case InlineAsm::Kind_Mem: OS << ":[mem"; break; 1840 default: OS << ":[??" << InlineAsm::getKind(Flag); break; 1841 } 1842 1843 unsigned RCID = 0; 1844 if (!InlineAsm::isImmKind(Flag) && !InlineAsm::isMemKind(Flag) && 1845 InlineAsm::hasRegClassConstraint(Flag, RCID)) { 1846 if (TRI) { 1847 OS << ':' << TRI->getRegClassName(TRI->getRegClass(RCID)); 1848 } else 1849 OS << ":RC" << RCID; 1850 } 1851 1852 if (InlineAsm::isMemKind(Flag)) { 1853 unsigned MCID = InlineAsm::getMemoryConstraintID(Flag); 1854 switch (MCID) { 1855 case InlineAsm::Constraint_es: OS << ":es"; break; 1856 case InlineAsm::Constraint_i: OS << ":i"; break; 1857 case InlineAsm::Constraint_m: OS << ":m"; break; 1858 case InlineAsm::Constraint_o: OS << ":o"; break; 1859 case InlineAsm::Constraint_v: OS << ":v"; break; 1860 case InlineAsm::Constraint_Q: OS << ":Q"; break; 1861 case InlineAsm::Constraint_R: OS << ":R"; break; 1862 case InlineAsm::Constraint_S: OS << ":S"; break; 1863 case InlineAsm::Constraint_T: OS << ":T"; break; 1864 case InlineAsm::Constraint_Um: OS << ":Um"; break; 1865 case InlineAsm::Constraint_Un: OS << ":Un"; break; 1866 case InlineAsm::Constraint_Uq: OS << ":Uq"; break; 1867 case InlineAsm::Constraint_Us: OS << ":Us"; break; 1868 case InlineAsm::Constraint_Ut: OS << ":Ut"; break; 1869 case InlineAsm::Constraint_Uv: OS << ":Uv"; break; 1870 case InlineAsm::Constraint_Uy: OS << ":Uy"; break; 1871 case InlineAsm::Constraint_X: OS << ":X"; break; 1872 case InlineAsm::Constraint_Z: OS << ":Z"; break; 1873 case InlineAsm::Constraint_ZC: OS << ":ZC"; break; 1874 case InlineAsm::Constraint_Zy: OS << ":Zy"; break; 1875 default: OS << ":?"; break; 1876 } 1877 } 1878 1879 unsigned TiedTo = 0; 1880 if (InlineAsm::isUseOperandTiedToDef(Flag, TiedTo)) 1881 OS << " tiedto:$" << TiedTo; 1882 1883 OS << ']'; 1884 1885 // Compute the index of the next operand descriptor. 1886 AsmDescOp += 1 + InlineAsm::getNumOperandRegisters(Flag); 1887 } else 1888 MO.print(OS, MST, TRI); 1889 } 1890 1891 // Briefly indicate whether any call clobbers were omitted. 1892 if (OmittedAnyCallClobbers) { 1893 if (!FirstOp) OS << ","; 1894 OS << " ..."; 1895 } 1896 1897 bool HaveSemi = false; 1898 const unsigned PrintableFlags = FrameSetup | FrameDestroy; 1899 if (Flags & PrintableFlags) { 1900 if (!HaveSemi) { 1901 OS << ";"; 1902 HaveSemi = true; 1903 } 1904 OS << " flags: "; 1905 1906 if (Flags & FrameSetup) 1907 OS << "FrameSetup"; 1908 1909 if (Flags & FrameDestroy) 1910 OS << "FrameDestroy"; 1911 } 1912 1913 if (!memoperands_empty()) { 1914 if (!HaveSemi) { 1915 OS << ";"; 1916 HaveSemi = true; 1917 } 1918 1919 OS << " mem:"; 1920 for (mmo_iterator i = memoperands_begin(), e = memoperands_end(); 1921 i != e; ++i) { 1922 (*i)->print(OS, MST); 1923 if (std::next(i) != e) 1924 OS << " "; 1925 } 1926 } 1927 1928 // Print the regclass of any virtual registers encountered. 1929 if (MRI && !VirtRegs.empty()) { 1930 if (!HaveSemi) { 1931 OS << ";"; 1932 HaveSemi = true; 1933 } 1934 for (unsigned i = 0; i != VirtRegs.size(); ++i) { 1935 const RegClassOrRegBank &RC = MRI->getRegClassOrRegBank(VirtRegs[i]); 1936 if (!RC) 1937 continue; 1938 // Generic virtual registers do not have register classes. 1939 if (RC.is<const RegisterBank *>()) 1940 OS << " " << RC.get<const RegisterBank *>()->getName(); 1941 else 1942 OS << " " 1943 << TRI->getRegClassName(RC.get<const TargetRegisterClass *>()); 1944 OS << ':' << PrintReg(VirtRegs[i]); 1945 for (unsigned j = i+1; j != VirtRegs.size();) { 1946 if (MRI->getRegClassOrRegBank(VirtRegs[j]) != RC) { 1947 ++j; 1948 continue; 1949 } 1950 if (VirtRegs[i] != VirtRegs[j]) 1951 OS << "," << PrintReg(VirtRegs[j]); 1952 VirtRegs.erase(VirtRegs.begin()+j); 1953 } 1954 } 1955 } 1956 1957 // Print debug location information. 1958 if (isDebugValue() && getOperand(e - 2).isMetadata()) { 1959 if (!HaveSemi) 1960 OS << ";"; 1961 auto *DV = cast<DILocalVariable>(getOperand(e - 2).getMetadata()); 1962 OS << " line no:" << DV->getLine(); 1963 if (auto *InlinedAt = debugLoc->getInlinedAt()) { 1964 DebugLoc InlinedAtDL(InlinedAt); 1965 if (InlinedAtDL && MF) { 1966 OS << " inlined @[ "; 1967 InlinedAtDL.print(OS); 1968 OS << " ]"; 1969 } 1970 } 1971 if (isIndirectDebugValue()) 1972 OS << " indirect"; 1973 } else if (debugLoc && MF) { 1974 if (!HaveSemi) 1975 OS << ";"; 1976 OS << " dbg:"; 1977 debugLoc.print(OS); 1978 } 1979 1980 OS << '\n'; 1981 } 1982 1983 bool MachineInstr::addRegisterKilled(unsigned IncomingReg, 1984 const TargetRegisterInfo *RegInfo, 1985 bool AddIfNotFound) { 1986 bool isPhysReg = TargetRegisterInfo::isPhysicalRegister(IncomingReg); 1987 bool hasAliases = isPhysReg && 1988 MCRegAliasIterator(IncomingReg, RegInfo, false).isValid(); 1989 bool Found = false; 1990 SmallVector<unsigned,4> DeadOps; 1991 for (unsigned i = 0, e = getNumOperands(); i != e; ++i) { 1992 MachineOperand &MO = getOperand(i); 1993 if (!MO.isReg() || !MO.isUse() || MO.isUndef()) 1994 continue; 1995 1996 // DEBUG_VALUE nodes do not contribute to code generation and should 1997 // always be ignored. Failure to do so may result in trying to modify 1998 // KILL flags on DEBUG_VALUE nodes. 1999 if (MO.isDebug()) 2000 continue; 2001 2002 unsigned Reg = MO.getReg(); 2003 if (!Reg) 2004 continue; 2005 2006 if (Reg == IncomingReg) { 2007 if (!Found) { 2008 if (MO.isKill()) 2009 // The register is already marked kill. 2010 return true; 2011 if (isPhysReg && isRegTiedToDefOperand(i)) 2012 // Two-address uses of physregs must not be marked kill. 2013 return true; 2014 MO.setIsKill(); 2015 Found = true; 2016 } 2017 } else if (hasAliases && MO.isKill() && 2018 TargetRegisterInfo::isPhysicalRegister(Reg)) { 2019 // A super-register kill already exists. 2020 if (RegInfo->isSuperRegister(IncomingReg, Reg)) 2021 return true; 2022 if (RegInfo->isSubRegister(IncomingReg, Reg)) 2023 DeadOps.push_back(i); 2024 } 2025 } 2026 2027 // Trim unneeded kill operands. 2028 while (!DeadOps.empty()) { 2029 unsigned OpIdx = DeadOps.back(); 2030 if (getOperand(OpIdx).isImplicit()) 2031 RemoveOperand(OpIdx); 2032 else 2033 getOperand(OpIdx).setIsKill(false); 2034 DeadOps.pop_back(); 2035 } 2036 2037 // If not found, this means an alias of one of the operands is killed. Add a 2038 // new implicit operand if required. 2039 if (!Found && AddIfNotFound) { 2040 addOperand(MachineOperand::CreateReg(IncomingReg, 2041 false /*IsDef*/, 2042 true /*IsImp*/, 2043 true /*IsKill*/)); 2044 return true; 2045 } 2046 return Found; 2047 } 2048 2049 void MachineInstr::clearRegisterKills(unsigned Reg, 2050 const TargetRegisterInfo *RegInfo) { 2051 if (!TargetRegisterInfo::isPhysicalRegister(Reg)) 2052 RegInfo = nullptr; 2053 for (MachineOperand &MO : operands()) { 2054 if (!MO.isReg() || !MO.isUse() || !MO.isKill()) 2055 continue; 2056 unsigned OpReg = MO.getReg(); 2057 if ((RegInfo && RegInfo->regsOverlap(Reg, OpReg)) || Reg == OpReg) 2058 MO.setIsKill(false); 2059 } 2060 } 2061 2062 bool MachineInstr::addRegisterDead(unsigned Reg, 2063 const TargetRegisterInfo *RegInfo, 2064 bool AddIfNotFound) { 2065 bool isPhysReg = TargetRegisterInfo::isPhysicalRegister(Reg); 2066 bool hasAliases = isPhysReg && 2067 MCRegAliasIterator(Reg, RegInfo, false).isValid(); 2068 bool Found = false; 2069 SmallVector<unsigned,4> DeadOps; 2070 for (unsigned i = 0, e = getNumOperands(); i != e; ++i) { 2071 MachineOperand &MO = getOperand(i); 2072 if (!MO.isReg() || !MO.isDef()) 2073 continue; 2074 unsigned MOReg = MO.getReg(); 2075 if (!MOReg) 2076 continue; 2077 2078 if (MOReg == Reg) { 2079 MO.setIsDead(); 2080 Found = true; 2081 } else if (hasAliases && MO.isDead() && 2082 TargetRegisterInfo::isPhysicalRegister(MOReg)) { 2083 // There exists a super-register that's marked dead. 2084 if (RegInfo->isSuperRegister(Reg, MOReg)) 2085 return true; 2086 if (RegInfo->isSubRegister(Reg, MOReg)) 2087 DeadOps.push_back(i); 2088 } 2089 } 2090 2091 // Trim unneeded dead operands. 2092 while (!DeadOps.empty()) { 2093 unsigned OpIdx = DeadOps.back(); 2094 if (getOperand(OpIdx).isImplicit()) 2095 RemoveOperand(OpIdx); 2096 else 2097 getOperand(OpIdx).setIsDead(false); 2098 DeadOps.pop_back(); 2099 } 2100 2101 // If not found, this means an alias of one of the operands is dead. Add a 2102 // new implicit operand if required. 2103 if (Found || !AddIfNotFound) 2104 return Found; 2105 2106 addOperand(MachineOperand::CreateReg(Reg, 2107 true /*IsDef*/, 2108 true /*IsImp*/, 2109 false /*IsKill*/, 2110 true /*IsDead*/)); 2111 return true; 2112 } 2113 2114 void MachineInstr::clearRegisterDeads(unsigned Reg) { 2115 for (MachineOperand &MO : operands()) { 2116 if (!MO.isReg() || !MO.isDef() || MO.getReg() != Reg) 2117 continue; 2118 MO.setIsDead(false); 2119 } 2120 } 2121 2122 void MachineInstr::setRegisterDefReadUndef(unsigned Reg, bool IsUndef) { 2123 for (MachineOperand &MO : operands()) { 2124 if (!MO.isReg() || !MO.isDef() || MO.getReg() != Reg || MO.getSubReg() == 0) 2125 continue; 2126 MO.setIsUndef(IsUndef); 2127 } 2128 } 2129 2130 void MachineInstr::addRegisterDefined(unsigned Reg, 2131 const TargetRegisterInfo *RegInfo) { 2132 if (TargetRegisterInfo::isPhysicalRegister(Reg)) { 2133 MachineOperand *MO = findRegisterDefOperand(Reg, false, RegInfo); 2134 if (MO) 2135 return; 2136 } else { 2137 for (const MachineOperand &MO : operands()) { 2138 if (MO.isReg() && MO.getReg() == Reg && MO.isDef() && 2139 MO.getSubReg() == 0) 2140 return; 2141 } 2142 } 2143 addOperand(MachineOperand::CreateReg(Reg, 2144 true /*IsDef*/, 2145 true /*IsImp*/)); 2146 } 2147 2148 void MachineInstr::setPhysRegsDeadExcept(ArrayRef<unsigned> UsedRegs, 2149 const TargetRegisterInfo &TRI) { 2150 bool HasRegMask = false; 2151 for (MachineOperand &MO : operands()) { 2152 if (MO.isRegMask()) { 2153 HasRegMask = true; 2154 continue; 2155 } 2156 if (!MO.isReg() || !MO.isDef()) continue; 2157 unsigned Reg = MO.getReg(); 2158 if (!TargetRegisterInfo::isPhysicalRegister(Reg)) continue; 2159 // If there are no uses, including partial uses, the def is dead. 2160 if (none_of(UsedRegs, 2161 [&](unsigned Use) { return TRI.regsOverlap(Use, Reg); })) 2162 MO.setIsDead(); 2163 } 2164 2165 // This is a call with a register mask operand. 2166 // Mask clobbers are always dead, so add defs for the non-dead defines. 2167 if (HasRegMask) 2168 for (ArrayRef<unsigned>::iterator I = UsedRegs.begin(), E = UsedRegs.end(); 2169 I != E; ++I) 2170 addRegisterDefined(*I, &TRI); 2171 } 2172 2173 unsigned 2174 MachineInstrExpressionTrait::getHashValue(const MachineInstr* const &MI) { 2175 // Build up a buffer of hash code components. 2176 SmallVector<size_t, 8> HashComponents; 2177 HashComponents.reserve(MI->getNumOperands() + 1); 2178 HashComponents.push_back(MI->getOpcode()); 2179 for (const MachineOperand &MO : MI->operands()) { 2180 if (MO.isReg() && MO.isDef() && 2181 TargetRegisterInfo::isVirtualRegister(MO.getReg())) 2182 continue; // Skip virtual register defs. 2183 2184 HashComponents.push_back(hash_value(MO)); 2185 } 2186 return hash_combine_range(HashComponents.begin(), HashComponents.end()); 2187 } 2188 2189 void MachineInstr::emitError(StringRef Msg) const { 2190 // Find the source location cookie. 2191 unsigned LocCookie = 0; 2192 const MDNode *LocMD = nullptr; 2193 for (unsigned i = getNumOperands(); i != 0; --i) { 2194 if (getOperand(i-1).isMetadata() && 2195 (LocMD = getOperand(i-1).getMetadata()) && 2196 LocMD->getNumOperands() != 0) { 2197 if (const ConstantInt *CI = 2198 mdconst::dyn_extract<ConstantInt>(LocMD->getOperand(0))) { 2199 LocCookie = CI->getZExtValue(); 2200 break; 2201 } 2202 } 2203 } 2204 2205 if (const MachineBasicBlock *MBB = getParent()) 2206 if (const MachineFunction *MF = MBB->getParent()) 2207 return MF->getMMI().getModule()->getContext().emitError(LocCookie, Msg); 2208 report_fatal_error(Msg); 2209 } 2210 2211 MachineInstrBuilder llvm::BuildMI(MachineFunction &MF, const DebugLoc &DL, 2212 const MCInstrDesc &MCID, bool IsIndirect, 2213 unsigned Reg, unsigned Offset, 2214 const MDNode *Variable, const MDNode *Expr) { 2215 assert(isa<DILocalVariable>(Variable) && "not a variable"); 2216 assert(cast<DIExpression>(Expr)->isValid() && "not an expression"); 2217 assert(cast<DILocalVariable>(Variable)->isValidLocationForIntrinsic(DL) && 2218 "Expected inlined-at fields to agree"); 2219 if (IsIndirect) 2220 return BuildMI(MF, DL, MCID) 2221 .addReg(Reg, RegState::Debug) 2222 .addImm(Offset) 2223 .addMetadata(Variable) 2224 .addMetadata(Expr); 2225 else { 2226 assert(Offset == 0 && "A direct address cannot have an offset."); 2227 return BuildMI(MF, DL, MCID) 2228 .addReg(Reg, RegState::Debug) 2229 .addReg(0U, RegState::Debug) 2230 .addMetadata(Variable) 2231 .addMetadata(Expr); 2232 } 2233 } 2234 2235 MachineInstrBuilder llvm::BuildMI(MachineBasicBlock &BB, 2236 MachineBasicBlock::iterator I, 2237 const DebugLoc &DL, const MCInstrDesc &MCID, 2238 bool IsIndirect, unsigned Reg, 2239 unsigned Offset, const MDNode *Variable, 2240 const MDNode *Expr) { 2241 assert(isa<DILocalVariable>(Variable) && "not a variable"); 2242 assert(cast<DIExpression>(Expr)->isValid() && "not an expression"); 2243 MachineFunction &MF = *BB.getParent(); 2244 MachineInstr *MI = 2245 BuildMI(MF, DL, MCID, IsIndirect, Reg, Offset, Variable, Expr); 2246 BB.insert(I, MI); 2247 return MachineInstrBuilder(MF, MI); 2248 } 2249