1 //===- MachineFunction.cpp ------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // Collect native machine code information for a function. This allows 10 // target-specific information about the generated code to be stored with each 11 // function. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "llvm/CodeGen/MachineFunction.h" 16 #include "llvm/ADT/BitVector.h" 17 #include "llvm/ADT/DenseMap.h" 18 #include "llvm/ADT/DenseSet.h" 19 #include "llvm/ADT/STLExtras.h" 20 #include "llvm/ADT/SmallString.h" 21 #include "llvm/ADT/SmallVector.h" 22 #include "llvm/ADT/StringRef.h" 23 #include "llvm/ADT/Twine.h" 24 #include "llvm/Analysis/ConstantFolding.h" 25 #include "llvm/Analysis/ProfileSummaryInfo.h" 26 #include "llvm/CodeGen/MachineBasicBlock.h" 27 #include "llvm/CodeGen/MachineConstantPool.h" 28 #include "llvm/CodeGen/MachineFrameInfo.h" 29 #include "llvm/CodeGen/MachineInstr.h" 30 #include "llvm/CodeGen/MachineJumpTableInfo.h" 31 #include "llvm/CodeGen/MachineMemOperand.h" 32 #include "llvm/CodeGen/MachineModuleInfo.h" 33 #include "llvm/CodeGen/MachineRegisterInfo.h" 34 #include "llvm/CodeGen/PseudoSourceValue.h" 35 #include "llvm/CodeGen/TargetFrameLowering.h" 36 #include "llvm/CodeGen/TargetInstrInfo.h" 37 #include "llvm/CodeGen/TargetLowering.h" 38 #include "llvm/CodeGen/TargetRegisterInfo.h" 39 #include "llvm/CodeGen/TargetSubtargetInfo.h" 40 #include "llvm/CodeGen/WasmEHFuncInfo.h" 41 #include "llvm/CodeGen/WinEHFuncInfo.h" 42 #include "llvm/Config/llvm-config.h" 43 #include "llvm/IR/Attributes.h" 44 #include "llvm/IR/BasicBlock.h" 45 #include "llvm/IR/Constant.h" 46 #include "llvm/IR/DataLayout.h" 47 #include "llvm/IR/DerivedTypes.h" 48 #include "llvm/IR/EHPersonalities.h" 49 #include "llvm/IR/Function.h" 50 #include "llvm/IR/GlobalValue.h" 51 #include "llvm/IR/Instruction.h" 52 #include "llvm/IR/Instructions.h" 53 #include "llvm/IR/Metadata.h" 54 #include "llvm/IR/Module.h" 55 #include "llvm/IR/ModuleSlotTracker.h" 56 #include "llvm/IR/Value.h" 57 #include "llvm/MC/MCContext.h" 58 #include "llvm/MC/MCSymbol.h" 59 #include "llvm/MC/SectionKind.h" 60 #include "llvm/Support/Casting.h" 61 #include "llvm/Support/CommandLine.h" 62 #include "llvm/Support/Compiler.h" 63 #include "llvm/Support/DOTGraphTraits.h" 64 #include "llvm/Support/ErrorHandling.h" 65 #include "llvm/Support/GraphWriter.h" 66 #include "llvm/Support/raw_ostream.h" 67 #include "llvm/Target/TargetMachine.h" 68 #include <algorithm> 69 #include <cassert> 70 #include <cstddef> 71 #include <cstdint> 72 #include <iterator> 73 #include <string> 74 #include <type_traits> 75 #include <utility> 76 #include <vector> 77 78 #include "LiveDebugValues/LiveDebugValues.h" 79 80 using namespace llvm; 81 82 #define DEBUG_TYPE "codegen" 83 84 static cl::opt<unsigned> AlignAllFunctions( 85 "align-all-functions", 86 cl::desc("Force the alignment of all functions in log2 format (e.g. 4 " 87 "means align on 16B boundaries)."), 88 cl::init(0), cl::Hidden); 89 90 static const char *getPropertyName(MachineFunctionProperties::Property Prop) { 91 using P = MachineFunctionProperties::Property; 92 93 // clang-format off 94 switch(Prop) { 95 case P::FailedISel: return "FailedISel"; 96 case P::IsSSA: return "IsSSA"; 97 case P::Legalized: return "Legalized"; 98 case P::NoPHIs: return "NoPHIs"; 99 case P::NoVRegs: return "NoVRegs"; 100 case P::RegBankSelected: return "RegBankSelected"; 101 case P::Selected: return "Selected"; 102 case P::TracksLiveness: return "TracksLiveness"; 103 case P::TiedOpsRewritten: return "TiedOpsRewritten"; 104 case P::FailsVerification: return "FailsVerification"; 105 case P::TracksDebugUserValues: return "TracksDebugUserValues"; 106 } 107 // clang-format on 108 llvm_unreachable("Invalid machine function property"); 109 } 110 111 void setUnsafeStackSize(const Function &F, MachineFrameInfo &FrameInfo) { 112 if (!F.hasFnAttribute(Attribute::SafeStack)) 113 return; 114 115 auto *Existing = 116 dyn_cast_or_null<MDTuple>(F.getMetadata(LLVMContext::MD_annotation)); 117 118 if (!Existing || Existing->getNumOperands() != 2) 119 return; 120 121 auto *MetadataName = "unsafe-stack-size"; 122 if (auto &N = Existing->getOperand(0)) { 123 if (N.equalsStr(MetadataName)) { 124 if (auto &Op = Existing->getOperand(1)) { 125 auto Val = mdconst::extract<ConstantInt>(Op)->getZExtValue(); 126 FrameInfo.setUnsafeStackSize(Val); 127 } 128 } 129 } 130 } 131 132 // Pin the vtable to this file. 133 void MachineFunction::Delegate::anchor() {} 134 135 void MachineFunctionProperties::print(raw_ostream &OS) const { 136 const char *Separator = ""; 137 for (BitVector::size_type I = 0; I < Properties.size(); ++I) { 138 if (!Properties[I]) 139 continue; 140 OS << Separator << getPropertyName(static_cast<Property>(I)); 141 Separator = ", "; 142 } 143 } 144 145 //===----------------------------------------------------------------------===// 146 // MachineFunction implementation 147 //===----------------------------------------------------------------------===// 148 149 // Out-of-line virtual method. 150 MachineFunctionInfo::~MachineFunctionInfo() = default; 151 152 void ilist_alloc_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) { 153 MBB->getParent()->deleteMachineBasicBlock(MBB); 154 } 155 156 static inline Align getFnStackAlignment(const TargetSubtargetInfo *STI, 157 const Function &F) { 158 if (auto MA = F.getFnStackAlign()) 159 return *MA; 160 return STI->getFrameLowering()->getStackAlign(); 161 } 162 163 MachineFunction::MachineFunction(Function &F, const LLVMTargetMachine &Target, 164 const TargetSubtargetInfo &STI, 165 unsigned FunctionNum, MachineModuleInfo &mmi) 166 : F(F), Target(Target), STI(&STI), Ctx(mmi.getContext()), MMI(mmi) { 167 FunctionNumber = FunctionNum; 168 init(); 169 } 170 171 void MachineFunction::handleInsertion(MachineInstr &MI) { 172 if (TheDelegate) 173 TheDelegate->MF_HandleInsertion(MI); 174 } 175 176 void MachineFunction::handleRemoval(MachineInstr &MI) { 177 if (TheDelegate) 178 TheDelegate->MF_HandleRemoval(MI); 179 } 180 181 void MachineFunction::handleChangeDesc(MachineInstr &MI, 182 const MCInstrDesc &TID) { 183 if (TheDelegate) 184 TheDelegate->MF_HandleChangeDesc(MI, TID); 185 } 186 187 void MachineFunction::init() { 188 // Assume the function starts in SSA form with correct liveness. 189 Properties.set(MachineFunctionProperties::Property::IsSSA); 190 Properties.set(MachineFunctionProperties::Property::TracksLiveness); 191 if (STI->getRegisterInfo()) 192 RegInfo = new (Allocator) MachineRegisterInfo(this); 193 else 194 RegInfo = nullptr; 195 196 MFInfo = nullptr; 197 198 // We can realign the stack if the target supports it and the user hasn't 199 // explicitly asked us not to. 200 bool CanRealignSP = STI->getFrameLowering()->isStackRealignable() && 201 !F.hasFnAttribute("no-realign-stack"); 202 FrameInfo = new (Allocator) MachineFrameInfo( 203 getFnStackAlignment(STI, F), /*StackRealignable=*/CanRealignSP, 204 /*ForcedRealign=*/CanRealignSP && 205 F.hasFnAttribute(Attribute::StackAlignment)); 206 207 setUnsafeStackSize(F, *FrameInfo); 208 209 if (F.hasFnAttribute(Attribute::StackAlignment)) 210 FrameInfo->ensureMaxAlignment(*F.getFnStackAlign()); 211 212 ConstantPool = new (Allocator) MachineConstantPool(getDataLayout()); 213 Alignment = STI->getTargetLowering()->getMinFunctionAlignment(); 214 215 // FIXME: Shouldn't use pref alignment if explicit alignment is set on F. 216 // FIXME: Use Function::hasOptSize(). 217 if (!F.hasFnAttribute(Attribute::OptimizeForSize)) 218 Alignment = std::max(Alignment, 219 STI->getTargetLowering()->getPrefFunctionAlignment()); 220 221 // -fsanitize=function and -fsanitize=kcfi instrument indirect function calls 222 // to load a type hash before the function label. Ensure functions are aligned 223 // by a least 4 to avoid unaligned access, which is especially important for 224 // -mno-unaligned-access. 225 if (F.hasMetadata(LLVMContext::MD_func_sanitize) || 226 F.getMetadata(LLVMContext::MD_kcfi_type)) 227 Alignment = std::max(Alignment, Align(4)); 228 229 if (AlignAllFunctions) 230 Alignment = Align(1ULL << AlignAllFunctions); 231 232 JumpTableInfo = nullptr; 233 234 if (isFuncletEHPersonality(classifyEHPersonality( 235 F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) { 236 WinEHInfo = new (Allocator) WinEHFuncInfo(); 237 } 238 239 if (isScopedEHPersonality(classifyEHPersonality( 240 F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) { 241 WasmEHInfo = new (Allocator) WasmEHFuncInfo(); 242 } 243 244 assert(Target.isCompatibleDataLayout(getDataLayout()) && 245 "Can't create a MachineFunction using a Module with a " 246 "Target-incompatible DataLayout attached\n"); 247 248 PSVManager = std::make_unique<PseudoSourceValueManager>(getTarget()); 249 } 250 251 void MachineFunction::initTargetMachineFunctionInfo( 252 const TargetSubtargetInfo &STI) { 253 assert(!MFInfo && "MachineFunctionInfo already set"); 254 MFInfo = Target.createMachineFunctionInfo(Allocator, F, &STI); 255 } 256 257 MachineFunction::~MachineFunction() { 258 clear(); 259 } 260 261 void MachineFunction::clear() { 262 Properties.reset(); 263 // Don't call destructors on MachineInstr and MachineOperand. All of their 264 // memory comes from the BumpPtrAllocator which is about to be purged. 265 // 266 // Do call MachineBasicBlock destructors, it contains std::vectors. 267 for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I)) 268 I->Insts.clearAndLeakNodesUnsafely(); 269 MBBNumbering.clear(); 270 271 InstructionRecycler.clear(Allocator); 272 OperandRecycler.clear(Allocator); 273 BasicBlockRecycler.clear(Allocator); 274 CodeViewAnnotations.clear(); 275 VariableDbgInfos.clear(); 276 if (RegInfo) { 277 RegInfo->~MachineRegisterInfo(); 278 Allocator.Deallocate(RegInfo); 279 } 280 if (MFInfo) { 281 MFInfo->~MachineFunctionInfo(); 282 Allocator.Deallocate(MFInfo); 283 } 284 285 FrameInfo->~MachineFrameInfo(); 286 Allocator.Deallocate(FrameInfo); 287 288 ConstantPool->~MachineConstantPool(); 289 Allocator.Deallocate(ConstantPool); 290 291 if (JumpTableInfo) { 292 JumpTableInfo->~MachineJumpTableInfo(); 293 Allocator.Deallocate(JumpTableInfo); 294 } 295 296 if (WinEHInfo) { 297 WinEHInfo->~WinEHFuncInfo(); 298 Allocator.Deallocate(WinEHInfo); 299 } 300 301 if (WasmEHInfo) { 302 WasmEHInfo->~WasmEHFuncInfo(); 303 Allocator.Deallocate(WasmEHInfo); 304 } 305 } 306 307 const DataLayout &MachineFunction::getDataLayout() const { 308 return F.getParent()->getDataLayout(); 309 } 310 311 /// Get the JumpTableInfo for this function. 312 /// If it does not already exist, allocate one. 313 MachineJumpTableInfo *MachineFunction:: 314 getOrCreateJumpTableInfo(unsigned EntryKind) { 315 if (JumpTableInfo) return JumpTableInfo; 316 317 JumpTableInfo = new (Allocator) 318 MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind); 319 return JumpTableInfo; 320 } 321 322 DenormalMode MachineFunction::getDenormalMode(const fltSemantics &FPType) const { 323 return F.getDenormalMode(FPType); 324 } 325 326 /// Should we be emitting segmented stack stuff for the function 327 bool MachineFunction::shouldSplitStack() const { 328 return getFunction().hasFnAttribute("split-stack"); 329 } 330 331 [[nodiscard]] unsigned 332 MachineFunction::addFrameInst(const MCCFIInstruction &Inst) { 333 FrameInstructions.push_back(Inst); 334 return FrameInstructions.size() - 1; 335 } 336 337 /// This discards all of the MachineBasicBlock numbers and recomputes them. 338 /// This guarantees that the MBB numbers are sequential, dense, and match the 339 /// ordering of the blocks within the function. If a specific MachineBasicBlock 340 /// is specified, only that block and those after it are renumbered. 341 void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) { 342 if (empty()) { MBBNumbering.clear(); return; } 343 MachineFunction::iterator MBBI, E = end(); 344 if (MBB == nullptr) 345 MBBI = begin(); 346 else 347 MBBI = MBB->getIterator(); 348 349 // Figure out the block number this should have. 350 unsigned BlockNo = 0; 351 if (MBBI != begin()) 352 BlockNo = std::prev(MBBI)->getNumber() + 1; 353 354 for (; MBBI != E; ++MBBI, ++BlockNo) { 355 if (MBBI->getNumber() != (int)BlockNo) { 356 // Remove use of the old number. 357 if (MBBI->getNumber() != -1) { 358 assert(MBBNumbering[MBBI->getNumber()] == &*MBBI && 359 "MBB number mismatch!"); 360 MBBNumbering[MBBI->getNumber()] = nullptr; 361 } 362 363 // If BlockNo is already taken, set that block's number to -1. 364 if (MBBNumbering[BlockNo]) 365 MBBNumbering[BlockNo]->setNumber(-1); 366 367 MBBNumbering[BlockNo] = &*MBBI; 368 MBBI->setNumber(BlockNo); 369 } 370 } 371 372 // Okay, all the blocks are renumbered. If we have compactified the block 373 // numbering, shrink MBBNumbering now. 374 assert(BlockNo <= MBBNumbering.size() && "Mismatch!"); 375 MBBNumbering.resize(BlockNo); 376 } 377 378 /// This method iterates over the basic blocks and assigns their IsBeginSection 379 /// and IsEndSection fields. This must be called after MBB layout is finalized 380 /// and the SectionID's are assigned to MBBs. 381 void MachineFunction::assignBeginEndSections() { 382 front().setIsBeginSection(); 383 auto CurrentSectionID = front().getSectionID(); 384 for (auto MBBI = std::next(begin()), E = end(); MBBI != E; ++MBBI) { 385 if (MBBI->getSectionID() == CurrentSectionID) 386 continue; 387 MBBI->setIsBeginSection(); 388 std::prev(MBBI)->setIsEndSection(); 389 CurrentSectionID = MBBI->getSectionID(); 390 } 391 back().setIsEndSection(); 392 } 393 394 /// Allocate a new MachineInstr. Use this instead of `new MachineInstr'. 395 MachineInstr *MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID, 396 DebugLoc DL, 397 bool NoImplicit) { 398 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) 399 MachineInstr(*this, MCID, std::move(DL), NoImplicit); 400 } 401 402 /// Create a new MachineInstr which is a copy of the 'Orig' instruction, 403 /// identical in all ways except the instruction has no parent, prev, or next. 404 MachineInstr * 405 MachineFunction::CloneMachineInstr(const MachineInstr *Orig) { 406 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) 407 MachineInstr(*this, *Orig); 408 } 409 410 MachineInstr &MachineFunction::cloneMachineInstrBundle( 411 MachineBasicBlock &MBB, MachineBasicBlock::iterator InsertBefore, 412 const MachineInstr &Orig) { 413 MachineInstr *FirstClone = nullptr; 414 MachineBasicBlock::const_instr_iterator I = Orig.getIterator(); 415 while (true) { 416 MachineInstr *Cloned = CloneMachineInstr(&*I); 417 MBB.insert(InsertBefore, Cloned); 418 if (FirstClone == nullptr) { 419 FirstClone = Cloned; 420 } else { 421 Cloned->bundleWithPred(); 422 } 423 424 if (!I->isBundledWithSucc()) 425 break; 426 ++I; 427 } 428 // Copy over call site info to the cloned instruction if needed. If Orig is in 429 // a bundle, copyCallSiteInfo takes care of finding the call instruction in 430 // the bundle. 431 if (Orig.shouldUpdateCallSiteInfo()) 432 copyCallSiteInfo(&Orig, FirstClone); 433 return *FirstClone; 434 } 435 436 /// Delete the given MachineInstr. 437 /// 438 /// This function also serves as the MachineInstr destructor - the real 439 /// ~MachineInstr() destructor must be empty. 440 void MachineFunction::deleteMachineInstr(MachineInstr *MI) { 441 // Verify that a call site info is at valid state. This assertion should 442 // be triggered during the implementation of support for the 443 // call site info of a new architecture. If the assertion is triggered, 444 // back trace will tell where to insert a call to updateCallSiteInfo(). 445 assert((!MI->isCandidateForCallSiteEntry() || !CallSitesInfo.contains(MI)) && 446 "Call site info was not updated!"); 447 // Strip it for parts. The operand array and the MI object itself are 448 // independently recyclable. 449 if (MI->Operands) 450 deallocateOperandArray(MI->CapOperands, MI->Operands); 451 // Don't call ~MachineInstr() which must be trivial anyway because 452 // ~MachineFunction drops whole lists of MachineInstrs wihout calling their 453 // destructors. 454 InstructionRecycler.Deallocate(Allocator, MI); 455 } 456 457 /// Allocate a new MachineBasicBlock. Use this instead of 458 /// `new MachineBasicBlock'. 459 MachineBasicBlock * 460 MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) { 461 MachineBasicBlock *MBB = 462 new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator)) 463 MachineBasicBlock(*this, bb); 464 // Set BBID for `-basic-block=sections=labels` and 465 // `-basic-block-sections=list` to allow robust mapping of profiles to basic 466 // blocks. 467 if (Target.getBBSectionsType() == BasicBlockSection::Labels || 468 Target.getBBSectionsType() == BasicBlockSection::List) 469 MBB->setBBID(NextBBID++); 470 return MBB; 471 } 472 473 /// Delete the given MachineBasicBlock. 474 void MachineFunction::deleteMachineBasicBlock(MachineBasicBlock *MBB) { 475 assert(MBB->getParent() == this && "MBB parent mismatch!"); 476 // Clean up any references to MBB in jump tables before deleting it. 477 if (JumpTableInfo) 478 JumpTableInfo->RemoveMBBFromJumpTables(MBB); 479 MBB->~MachineBasicBlock(); 480 BasicBlockRecycler.Deallocate(Allocator, MBB); 481 } 482 483 MachineMemOperand *MachineFunction::getMachineMemOperand( 484 MachinePointerInfo PtrInfo, MachineMemOperand::Flags f, uint64_t s, 485 Align base_alignment, const AAMDNodes &AAInfo, const MDNode *Ranges, 486 SyncScope::ID SSID, AtomicOrdering Ordering, 487 AtomicOrdering FailureOrdering) { 488 return new (Allocator) 489 MachineMemOperand(PtrInfo, f, s, base_alignment, AAInfo, Ranges, 490 SSID, Ordering, FailureOrdering); 491 } 492 493 MachineMemOperand *MachineFunction::getMachineMemOperand( 494 MachinePointerInfo PtrInfo, MachineMemOperand::Flags f, LLT MemTy, 495 Align base_alignment, const AAMDNodes &AAInfo, const MDNode *Ranges, 496 SyncScope::ID SSID, AtomicOrdering Ordering, 497 AtomicOrdering FailureOrdering) { 498 return new (Allocator) 499 MachineMemOperand(PtrInfo, f, MemTy, base_alignment, AAInfo, Ranges, SSID, 500 Ordering, FailureOrdering); 501 } 502 503 MachineMemOperand *MachineFunction::getMachineMemOperand( 504 const MachineMemOperand *MMO, const MachinePointerInfo &PtrInfo, uint64_t Size) { 505 return new (Allocator) 506 MachineMemOperand(PtrInfo, MMO->getFlags(), Size, MMO->getBaseAlign(), 507 AAMDNodes(), nullptr, MMO->getSyncScopeID(), 508 MMO->getSuccessOrdering(), MMO->getFailureOrdering()); 509 } 510 511 MachineMemOperand *MachineFunction::getMachineMemOperand( 512 const MachineMemOperand *MMO, const MachinePointerInfo &PtrInfo, LLT Ty) { 513 return new (Allocator) 514 MachineMemOperand(PtrInfo, MMO->getFlags(), Ty, MMO->getBaseAlign(), 515 AAMDNodes(), nullptr, MMO->getSyncScopeID(), 516 MMO->getSuccessOrdering(), MMO->getFailureOrdering()); 517 } 518 519 MachineMemOperand * 520 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO, 521 int64_t Offset, LLT Ty) { 522 const MachinePointerInfo &PtrInfo = MMO->getPointerInfo(); 523 524 // If there is no pointer value, the offset isn't tracked so we need to adjust 525 // the base alignment. 526 Align Alignment = PtrInfo.V.isNull() 527 ? commonAlignment(MMO->getBaseAlign(), Offset) 528 : MMO->getBaseAlign(); 529 530 // Do not preserve ranges, since we don't necessarily know what the high bits 531 // are anymore. 532 return new (Allocator) MachineMemOperand( 533 PtrInfo.getWithOffset(Offset), MMO->getFlags(), Ty, Alignment, 534 MMO->getAAInfo(), nullptr, MMO->getSyncScopeID(), 535 MMO->getSuccessOrdering(), MMO->getFailureOrdering()); 536 } 537 538 MachineMemOperand * 539 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO, 540 const AAMDNodes &AAInfo) { 541 MachinePointerInfo MPI = MMO->getValue() ? 542 MachinePointerInfo(MMO->getValue(), MMO->getOffset()) : 543 MachinePointerInfo(MMO->getPseudoValue(), MMO->getOffset()); 544 545 return new (Allocator) MachineMemOperand( 546 MPI, MMO->getFlags(), MMO->getSize(), MMO->getBaseAlign(), AAInfo, 547 MMO->getRanges(), MMO->getSyncScopeID(), MMO->getSuccessOrdering(), 548 MMO->getFailureOrdering()); 549 } 550 551 MachineMemOperand * 552 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO, 553 MachineMemOperand::Flags Flags) { 554 return new (Allocator) MachineMemOperand( 555 MMO->getPointerInfo(), Flags, MMO->getSize(), MMO->getBaseAlign(), 556 MMO->getAAInfo(), MMO->getRanges(), MMO->getSyncScopeID(), 557 MMO->getSuccessOrdering(), MMO->getFailureOrdering()); 558 } 559 560 MachineInstr::ExtraInfo *MachineFunction::createMIExtraInfo( 561 ArrayRef<MachineMemOperand *> MMOs, MCSymbol *PreInstrSymbol, 562 MCSymbol *PostInstrSymbol, MDNode *HeapAllocMarker, MDNode *PCSections, 563 uint32_t CFIType) { 564 return MachineInstr::ExtraInfo::create(Allocator, MMOs, PreInstrSymbol, 565 PostInstrSymbol, HeapAllocMarker, 566 PCSections, CFIType); 567 } 568 569 const char *MachineFunction::createExternalSymbolName(StringRef Name) { 570 char *Dest = Allocator.Allocate<char>(Name.size() + 1); 571 llvm::copy(Name, Dest); 572 Dest[Name.size()] = 0; 573 return Dest; 574 } 575 576 uint32_t *MachineFunction::allocateRegMask() { 577 unsigned NumRegs = getSubtarget().getRegisterInfo()->getNumRegs(); 578 unsigned Size = MachineOperand::getRegMaskSize(NumRegs); 579 uint32_t *Mask = Allocator.Allocate<uint32_t>(Size); 580 memset(Mask, 0, Size * sizeof(Mask[0])); 581 return Mask; 582 } 583 584 ArrayRef<int> MachineFunction::allocateShuffleMask(ArrayRef<int> Mask) { 585 int* AllocMask = Allocator.Allocate<int>(Mask.size()); 586 copy(Mask, AllocMask); 587 return {AllocMask, Mask.size()}; 588 } 589 590 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 591 LLVM_DUMP_METHOD void MachineFunction::dump() const { 592 print(dbgs()); 593 } 594 #endif 595 596 StringRef MachineFunction::getName() const { 597 return getFunction().getName(); 598 } 599 600 void MachineFunction::print(raw_ostream &OS, const SlotIndexes *Indexes) const { 601 OS << "# Machine code for function " << getName() << ": "; 602 getProperties().print(OS); 603 OS << '\n'; 604 605 // Print Frame Information 606 FrameInfo->print(*this, OS); 607 608 // Print JumpTable Information 609 if (JumpTableInfo) 610 JumpTableInfo->print(OS); 611 612 // Print Constant Pool 613 ConstantPool->print(OS); 614 615 const TargetRegisterInfo *TRI = getSubtarget().getRegisterInfo(); 616 617 if (RegInfo && !RegInfo->livein_empty()) { 618 OS << "Function Live Ins: "; 619 for (MachineRegisterInfo::livein_iterator 620 I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) { 621 OS << printReg(I->first, TRI); 622 if (I->second) 623 OS << " in " << printReg(I->second, TRI); 624 if (std::next(I) != E) 625 OS << ", "; 626 } 627 OS << '\n'; 628 } 629 630 ModuleSlotTracker MST(getFunction().getParent()); 631 MST.incorporateFunction(getFunction()); 632 for (const auto &BB : *this) { 633 OS << '\n'; 634 // If we print the whole function, print it at its most verbose level. 635 BB.print(OS, MST, Indexes, /*IsStandalone=*/true); 636 } 637 638 OS << "\n# End machine code for function " << getName() << ".\n\n"; 639 } 640 641 /// True if this function needs frame moves for debug or exceptions. 642 bool MachineFunction::needsFrameMoves() const { 643 return getMMI().hasDebugInfo() || 644 getTarget().Options.ForceDwarfFrameSection || 645 F.needsUnwindTableEntry(); 646 } 647 648 namespace llvm { 649 650 template<> 651 struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits { 652 DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {} 653 654 static std::string getGraphName(const MachineFunction *F) { 655 return ("CFG for '" + F->getName() + "' function").str(); 656 } 657 658 std::string getNodeLabel(const MachineBasicBlock *Node, 659 const MachineFunction *Graph) { 660 std::string OutStr; 661 { 662 raw_string_ostream OSS(OutStr); 663 664 if (isSimple()) { 665 OSS << printMBBReference(*Node); 666 if (const BasicBlock *BB = Node->getBasicBlock()) 667 OSS << ": " << BB->getName(); 668 } else 669 Node->print(OSS); 670 } 671 672 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin()); 673 674 // Process string output to make it nicer... 675 for (unsigned i = 0; i != OutStr.length(); ++i) 676 if (OutStr[i] == '\n') { // Left justify 677 OutStr[i] = '\\'; 678 OutStr.insert(OutStr.begin()+i+1, 'l'); 679 } 680 return OutStr; 681 } 682 }; 683 684 } // end namespace llvm 685 686 void MachineFunction::viewCFG() const 687 { 688 #ifndef NDEBUG 689 ViewGraph(this, "mf" + getName()); 690 #else 691 errs() << "MachineFunction::viewCFG is only available in debug builds on " 692 << "systems with Graphviz or gv!\n"; 693 #endif // NDEBUG 694 } 695 696 void MachineFunction::viewCFGOnly() const 697 { 698 #ifndef NDEBUG 699 ViewGraph(this, "mf" + getName(), true); 700 #else 701 errs() << "MachineFunction::viewCFGOnly is only available in debug builds on " 702 << "systems with Graphviz or gv!\n"; 703 #endif // NDEBUG 704 } 705 706 /// Add the specified physical register as a live-in value and 707 /// create a corresponding virtual register for it. 708 Register MachineFunction::addLiveIn(MCRegister PReg, 709 const TargetRegisterClass *RC) { 710 MachineRegisterInfo &MRI = getRegInfo(); 711 Register VReg = MRI.getLiveInVirtReg(PReg); 712 if (VReg) { 713 const TargetRegisterClass *VRegRC = MRI.getRegClass(VReg); 714 (void)VRegRC; 715 // A physical register can be added several times. 716 // Between two calls, the register class of the related virtual register 717 // may have been constrained to match some operation constraints. 718 // In that case, check that the current register class includes the 719 // physical register and is a sub class of the specified RC. 720 assert((VRegRC == RC || (VRegRC->contains(PReg) && 721 RC->hasSubClassEq(VRegRC))) && 722 "Register class mismatch!"); 723 return VReg; 724 } 725 VReg = MRI.createVirtualRegister(RC); 726 MRI.addLiveIn(PReg, VReg); 727 return VReg; 728 } 729 730 /// Return the MCSymbol for the specified non-empty jump table. 731 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a 732 /// normal 'L' label is returned. 733 MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx, 734 bool isLinkerPrivate) const { 735 const DataLayout &DL = getDataLayout(); 736 assert(JumpTableInfo && "No jump tables"); 737 assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!"); 738 739 StringRef Prefix = isLinkerPrivate ? DL.getLinkerPrivateGlobalPrefix() 740 : DL.getPrivateGlobalPrefix(); 741 SmallString<60> Name; 742 raw_svector_ostream(Name) 743 << Prefix << "JTI" << getFunctionNumber() << '_' << JTI; 744 return Ctx.getOrCreateSymbol(Name); 745 } 746 747 /// Return a function-local symbol to represent the PIC base. 748 MCSymbol *MachineFunction::getPICBaseSymbol() const { 749 const DataLayout &DL = getDataLayout(); 750 return Ctx.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) + 751 Twine(getFunctionNumber()) + "$pb"); 752 } 753 754 /// \name Exception Handling 755 /// \{ 756 757 LandingPadInfo & 758 MachineFunction::getOrCreateLandingPadInfo(MachineBasicBlock *LandingPad) { 759 unsigned N = LandingPads.size(); 760 for (unsigned i = 0; i < N; ++i) { 761 LandingPadInfo &LP = LandingPads[i]; 762 if (LP.LandingPadBlock == LandingPad) 763 return LP; 764 } 765 766 LandingPads.push_back(LandingPadInfo(LandingPad)); 767 return LandingPads[N]; 768 } 769 770 void MachineFunction::addInvoke(MachineBasicBlock *LandingPad, 771 MCSymbol *BeginLabel, MCSymbol *EndLabel) { 772 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 773 LP.BeginLabels.push_back(BeginLabel); 774 LP.EndLabels.push_back(EndLabel); 775 } 776 777 MCSymbol *MachineFunction::addLandingPad(MachineBasicBlock *LandingPad) { 778 MCSymbol *LandingPadLabel = Ctx.createTempSymbol(); 779 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 780 LP.LandingPadLabel = LandingPadLabel; 781 782 const Instruction *FirstI = LandingPad->getBasicBlock()->getFirstNonPHI(); 783 if (const auto *LPI = dyn_cast<LandingPadInst>(FirstI)) { 784 // If there's no typeid list specified, then "cleanup" is implicit. 785 // Otherwise, id 0 is reserved for the cleanup action. 786 if (LPI->isCleanup() && LPI->getNumClauses() != 0) 787 LP.TypeIds.push_back(0); 788 789 // FIXME: New EH - Add the clauses in reverse order. This isn't 100% 790 // correct, but we need to do it this way because of how the DWARF EH 791 // emitter processes the clauses. 792 for (unsigned I = LPI->getNumClauses(); I != 0; --I) { 793 Value *Val = LPI->getClause(I - 1); 794 if (LPI->isCatch(I - 1)) { 795 LP.TypeIds.push_back( 796 getTypeIDFor(dyn_cast<GlobalValue>(Val->stripPointerCasts()))); 797 } else { 798 // Add filters in a list. 799 auto *CVal = cast<Constant>(Val); 800 SmallVector<unsigned, 4> FilterList; 801 for (const Use &U : CVal->operands()) 802 FilterList.push_back( 803 getTypeIDFor(cast<GlobalValue>(U->stripPointerCasts()))); 804 805 LP.TypeIds.push_back(getFilterIDFor(FilterList)); 806 } 807 } 808 809 } else if (const auto *CPI = dyn_cast<CatchPadInst>(FirstI)) { 810 for (unsigned I = CPI->arg_size(); I != 0; --I) { 811 auto *TypeInfo = 812 dyn_cast<GlobalValue>(CPI->getArgOperand(I - 1)->stripPointerCasts()); 813 LP.TypeIds.push_back(getTypeIDFor(TypeInfo)); 814 } 815 816 } else { 817 assert(isa<CleanupPadInst>(FirstI) && "Invalid landingpad!"); 818 } 819 820 return LandingPadLabel; 821 } 822 823 void MachineFunction::setCallSiteLandingPad(MCSymbol *Sym, 824 ArrayRef<unsigned> Sites) { 825 LPadToCallSiteMap[Sym].append(Sites.begin(), Sites.end()); 826 } 827 828 unsigned MachineFunction::getTypeIDFor(const GlobalValue *TI) { 829 for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i) 830 if (TypeInfos[i] == TI) return i + 1; 831 832 TypeInfos.push_back(TI); 833 return TypeInfos.size(); 834 } 835 836 int MachineFunction::getFilterIDFor(ArrayRef<unsigned> TyIds) { 837 // If the new filter coincides with the tail of an existing filter, then 838 // re-use the existing filter. Folding filters more than this requires 839 // re-ordering filters and/or their elements - probably not worth it. 840 for (unsigned i : FilterEnds) { 841 unsigned j = TyIds.size(); 842 843 while (i && j) 844 if (FilterIds[--i] != TyIds[--j]) 845 goto try_next; 846 847 if (!j) 848 // The new filter coincides with range [i, end) of the existing filter. 849 return -(1 + i); 850 851 try_next:; 852 } 853 854 // Add the new filter. 855 int FilterID = -(1 + FilterIds.size()); 856 FilterIds.reserve(FilterIds.size() + TyIds.size() + 1); 857 llvm::append_range(FilterIds, TyIds); 858 FilterEnds.push_back(FilterIds.size()); 859 FilterIds.push_back(0); // terminator 860 return FilterID; 861 } 862 863 MachineFunction::CallSiteInfoMap::iterator 864 MachineFunction::getCallSiteInfo(const MachineInstr *MI) { 865 assert(MI->isCandidateForCallSiteEntry() && 866 "Call site info refers only to call (MI) candidates"); 867 868 if (!Target.Options.EmitCallSiteInfo) 869 return CallSitesInfo.end(); 870 return CallSitesInfo.find(MI); 871 } 872 873 /// Return the call machine instruction or find a call within bundle. 874 static const MachineInstr *getCallInstr(const MachineInstr *MI) { 875 if (!MI->isBundle()) 876 return MI; 877 878 for (const auto &BMI : make_range(getBundleStart(MI->getIterator()), 879 getBundleEnd(MI->getIterator()))) 880 if (BMI.isCandidateForCallSiteEntry()) 881 return &BMI; 882 883 llvm_unreachable("Unexpected bundle without a call site candidate"); 884 } 885 886 void MachineFunction::eraseCallSiteInfo(const MachineInstr *MI) { 887 assert(MI->shouldUpdateCallSiteInfo() && 888 "Call site info refers only to call (MI) candidates or " 889 "candidates inside bundles"); 890 891 const MachineInstr *CallMI = getCallInstr(MI); 892 CallSiteInfoMap::iterator CSIt = getCallSiteInfo(CallMI); 893 if (CSIt == CallSitesInfo.end()) 894 return; 895 CallSitesInfo.erase(CSIt); 896 } 897 898 void MachineFunction::copyCallSiteInfo(const MachineInstr *Old, 899 const MachineInstr *New) { 900 assert(Old->shouldUpdateCallSiteInfo() && 901 "Call site info refers only to call (MI) candidates or " 902 "candidates inside bundles"); 903 904 if (!New->isCandidateForCallSiteEntry()) 905 return eraseCallSiteInfo(Old); 906 907 const MachineInstr *OldCallMI = getCallInstr(Old); 908 CallSiteInfoMap::iterator CSIt = getCallSiteInfo(OldCallMI); 909 if (CSIt == CallSitesInfo.end()) 910 return; 911 912 CallSiteInfo CSInfo = CSIt->second; 913 CallSitesInfo[New] = CSInfo; 914 } 915 916 void MachineFunction::moveCallSiteInfo(const MachineInstr *Old, 917 const MachineInstr *New) { 918 assert(Old->shouldUpdateCallSiteInfo() && 919 "Call site info refers only to call (MI) candidates or " 920 "candidates inside bundles"); 921 922 if (!New->isCandidateForCallSiteEntry()) 923 return eraseCallSiteInfo(Old); 924 925 const MachineInstr *OldCallMI = getCallInstr(Old); 926 CallSiteInfoMap::iterator CSIt = getCallSiteInfo(OldCallMI); 927 if (CSIt == CallSitesInfo.end()) 928 return; 929 930 CallSiteInfo CSInfo = std::move(CSIt->second); 931 CallSitesInfo.erase(CSIt); 932 CallSitesInfo[New] = CSInfo; 933 } 934 935 void MachineFunction::setDebugInstrNumberingCount(unsigned Num) { 936 DebugInstrNumberingCount = Num; 937 } 938 939 void MachineFunction::makeDebugValueSubstitution(DebugInstrOperandPair A, 940 DebugInstrOperandPair B, 941 unsigned Subreg) { 942 // Catch any accidental self-loops. 943 assert(A.first != B.first); 944 // Don't allow any substitutions _from_ the memory operand number. 945 assert(A.second != DebugOperandMemNumber); 946 947 DebugValueSubstitutions.push_back({A, B, Subreg}); 948 } 949 950 void MachineFunction::substituteDebugValuesForInst(const MachineInstr &Old, 951 MachineInstr &New, 952 unsigned MaxOperand) { 953 // If the Old instruction wasn't tracked at all, there is no work to do. 954 unsigned OldInstrNum = Old.peekDebugInstrNum(); 955 if (!OldInstrNum) 956 return; 957 958 // Iterate over all operands looking for defs to create substitutions for. 959 // Avoid creating new instr numbers unless we create a new substitution. 960 // While this has no functional effect, it risks confusing someone reading 961 // MIR output. 962 // Examine all the operands, or the first N specified by the caller. 963 MaxOperand = std::min(MaxOperand, Old.getNumOperands()); 964 for (unsigned int I = 0; I < MaxOperand; ++I) { 965 const auto &OldMO = Old.getOperand(I); 966 auto &NewMO = New.getOperand(I); 967 (void)NewMO; 968 969 if (!OldMO.isReg() || !OldMO.isDef()) 970 continue; 971 assert(NewMO.isDef()); 972 973 unsigned NewInstrNum = New.getDebugInstrNum(); 974 makeDebugValueSubstitution(std::make_pair(OldInstrNum, I), 975 std::make_pair(NewInstrNum, I)); 976 } 977 } 978 979 auto MachineFunction::salvageCopySSA( 980 MachineInstr &MI, DenseMap<Register, DebugInstrOperandPair> &DbgPHICache) 981 -> DebugInstrOperandPair { 982 const TargetInstrInfo &TII = *getSubtarget().getInstrInfo(); 983 984 // Check whether this copy-like instruction has already been salvaged into 985 // an operand pair. 986 Register Dest; 987 if (auto CopyDstSrc = TII.isCopyInstr(MI)) { 988 Dest = CopyDstSrc->Destination->getReg(); 989 } else { 990 assert(MI.isSubregToReg()); 991 Dest = MI.getOperand(0).getReg(); 992 } 993 994 auto CacheIt = DbgPHICache.find(Dest); 995 if (CacheIt != DbgPHICache.end()) 996 return CacheIt->second; 997 998 // Calculate the instruction number to use, or install a DBG_PHI. 999 auto OperandPair = salvageCopySSAImpl(MI); 1000 DbgPHICache.insert({Dest, OperandPair}); 1001 return OperandPair; 1002 } 1003 1004 auto MachineFunction::salvageCopySSAImpl(MachineInstr &MI) 1005 -> DebugInstrOperandPair { 1006 MachineRegisterInfo &MRI = getRegInfo(); 1007 const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo(); 1008 const TargetInstrInfo &TII = *getSubtarget().getInstrInfo(); 1009 1010 // Chase the value read by a copy-like instruction back to the instruction 1011 // that ultimately _defines_ that value. This may pass: 1012 // * Through multiple intermediate copies, including subregister moves / 1013 // copies, 1014 // * Copies from physical registers that must then be traced back to the 1015 // defining instruction, 1016 // * Or, physical registers may be live-in to (only) the entry block, which 1017 // requires a DBG_PHI to be created. 1018 // We can pursue this problem in that order: trace back through copies, 1019 // optionally through a physical register, to a defining instruction. We 1020 // should never move from physreg to vreg. As we're still in SSA form, no need 1021 // to worry about partial definitions of registers. 1022 1023 // Helper lambda to interpret a copy-like instruction. Takes instruction, 1024 // returns the register read and any subregister identifying which part is 1025 // read. 1026 auto GetRegAndSubreg = 1027 [&](const MachineInstr &Cpy) -> std::pair<Register, unsigned> { 1028 Register NewReg, OldReg; 1029 unsigned SubReg; 1030 if (Cpy.isCopy()) { 1031 OldReg = Cpy.getOperand(0).getReg(); 1032 NewReg = Cpy.getOperand(1).getReg(); 1033 SubReg = Cpy.getOperand(1).getSubReg(); 1034 } else if (Cpy.isSubregToReg()) { 1035 OldReg = Cpy.getOperand(0).getReg(); 1036 NewReg = Cpy.getOperand(2).getReg(); 1037 SubReg = Cpy.getOperand(3).getImm(); 1038 } else { 1039 auto CopyDetails = *TII.isCopyInstr(Cpy); 1040 const MachineOperand &Src = *CopyDetails.Source; 1041 const MachineOperand &Dest = *CopyDetails.Destination; 1042 OldReg = Dest.getReg(); 1043 NewReg = Src.getReg(); 1044 SubReg = Src.getSubReg(); 1045 } 1046 1047 return {NewReg, SubReg}; 1048 }; 1049 1050 // First seek either the defining instruction, or a copy from a physreg. 1051 // During search, the current state is the current copy instruction, and which 1052 // register we've read. Accumulate qualifying subregisters into SubregsSeen; 1053 // deal with those later. 1054 auto State = GetRegAndSubreg(MI); 1055 auto CurInst = MI.getIterator(); 1056 SmallVector<unsigned, 4> SubregsSeen; 1057 while (true) { 1058 // If we've found a copy from a physreg, first portion of search is over. 1059 if (!State.first.isVirtual()) 1060 break; 1061 1062 // Record any subregister qualifier. 1063 if (State.second) 1064 SubregsSeen.push_back(State.second); 1065 1066 assert(MRI.hasOneDef(State.first)); 1067 MachineInstr &Inst = *MRI.def_begin(State.first)->getParent(); 1068 CurInst = Inst.getIterator(); 1069 1070 // Any non-copy instruction is the defining instruction we're seeking. 1071 if (!Inst.isCopyLike() && !TII.isCopyInstr(Inst)) 1072 break; 1073 State = GetRegAndSubreg(Inst); 1074 }; 1075 1076 // Helper lambda to apply additional subregister substitutions to a known 1077 // instruction/operand pair. Adds new (fake) substitutions so that we can 1078 // record the subregister. FIXME: this isn't very space efficient if multiple 1079 // values are tracked back through the same copies; cache something later. 1080 auto ApplySubregisters = 1081 [&](DebugInstrOperandPair P) -> DebugInstrOperandPair { 1082 for (unsigned Subreg : reverse(SubregsSeen)) { 1083 // Fetch a new instruction number, not attached to an actual instruction. 1084 unsigned NewInstrNumber = getNewDebugInstrNum(); 1085 // Add a substitution from the "new" number to the known one, with a 1086 // qualifying subreg. 1087 makeDebugValueSubstitution({NewInstrNumber, 0}, P, Subreg); 1088 // Return the new number; to find the underlying value, consumers need to 1089 // deal with the qualifying subreg. 1090 P = {NewInstrNumber, 0}; 1091 } 1092 return P; 1093 }; 1094 1095 // If we managed to find the defining instruction after COPYs, return an 1096 // instruction / operand pair after adding subregister qualifiers. 1097 if (State.first.isVirtual()) { 1098 // Virtual register def -- we can just look up where this happens. 1099 MachineInstr *Inst = MRI.def_begin(State.first)->getParent(); 1100 for (auto &MO : Inst->all_defs()) { 1101 if (MO.getReg() != State.first) 1102 continue; 1103 return ApplySubregisters({Inst->getDebugInstrNum(), MO.getOperandNo()}); 1104 } 1105 1106 llvm_unreachable("Vreg def with no corresponding operand?"); 1107 } 1108 1109 // Our search ended in a copy from a physreg: walk back up the function 1110 // looking for whatever defines the physreg. 1111 assert(CurInst->isCopyLike() || TII.isCopyInstr(*CurInst)); 1112 State = GetRegAndSubreg(*CurInst); 1113 Register RegToSeek = State.first; 1114 1115 auto RMII = CurInst->getReverseIterator(); 1116 auto PrevInstrs = make_range(RMII, CurInst->getParent()->instr_rend()); 1117 for (auto &ToExamine : PrevInstrs) { 1118 for (auto &MO : ToExamine.all_defs()) { 1119 // Test for operand that defines something aliasing RegToSeek. 1120 if (!TRI.regsOverlap(RegToSeek, MO.getReg())) 1121 continue; 1122 1123 return ApplySubregisters( 1124 {ToExamine.getDebugInstrNum(), MO.getOperandNo()}); 1125 } 1126 } 1127 1128 MachineBasicBlock &InsertBB = *CurInst->getParent(); 1129 1130 // We reached the start of the block before finding a defining instruction. 1131 // There are numerous scenarios where this can happen: 1132 // * Constant physical registers, 1133 // * Several intrinsics that allow LLVM-IR to read arbitary registers, 1134 // * Arguments in the entry block, 1135 // * Exception handling landing pads. 1136 // Validating all of them is too difficult, so just insert a DBG_PHI reading 1137 // the variable value at this position, rather than checking it makes sense. 1138 1139 // Create DBG_PHI for specified physreg. 1140 auto Builder = BuildMI(InsertBB, InsertBB.getFirstNonPHI(), DebugLoc(), 1141 TII.get(TargetOpcode::DBG_PHI)); 1142 Builder.addReg(State.first); 1143 unsigned NewNum = getNewDebugInstrNum(); 1144 Builder.addImm(NewNum); 1145 return ApplySubregisters({NewNum, 0u}); 1146 } 1147 1148 void MachineFunction::finalizeDebugInstrRefs() { 1149 auto *TII = getSubtarget().getInstrInfo(); 1150 1151 auto MakeUndefDbgValue = [&](MachineInstr &MI) { 1152 const MCInstrDesc &RefII = TII->get(TargetOpcode::DBG_VALUE_LIST); 1153 MI.setDesc(RefII); 1154 MI.setDebugValueUndef(); 1155 }; 1156 1157 DenseMap<Register, DebugInstrOperandPair> ArgDbgPHIs; 1158 for (auto &MBB : *this) { 1159 for (auto &MI : MBB) { 1160 if (!MI.isDebugRef()) 1161 continue; 1162 1163 bool IsValidRef = true; 1164 1165 for (MachineOperand &MO : MI.debug_operands()) { 1166 if (!MO.isReg()) 1167 continue; 1168 1169 Register Reg = MO.getReg(); 1170 1171 // Some vregs can be deleted as redundant in the meantime. Mark those 1172 // as DBG_VALUE $noreg. Additionally, some normal instructions are 1173 // quickly deleted, leaving dangling references to vregs with no def. 1174 if (Reg == 0 || !RegInfo->hasOneDef(Reg)) { 1175 IsValidRef = false; 1176 break; 1177 } 1178 1179 assert(Reg.isVirtual()); 1180 MachineInstr &DefMI = *RegInfo->def_instr_begin(Reg); 1181 1182 // If we've found a copy-like instruction, follow it back to the 1183 // instruction that defines the source value, see salvageCopySSA docs 1184 // for why this is important. 1185 if (DefMI.isCopyLike() || TII->isCopyInstr(DefMI)) { 1186 auto Result = salvageCopySSA(DefMI, ArgDbgPHIs); 1187 MO.ChangeToDbgInstrRef(Result.first, Result.second); 1188 } else { 1189 // Otherwise, identify the operand number that the VReg refers to. 1190 unsigned OperandIdx = 0; 1191 for (const auto &DefMO : DefMI.operands()) { 1192 if (DefMO.isReg() && DefMO.isDef() && DefMO.getReg() == Reg) 1193 break; 1194 ++OperandIdx; 1195 } 1196 assert(OperandIdx < DefMI.getNumOperands()); 1197 1198 // Morph this instr ref to point at the given instruction and operand. 1199 unsigned ID = DefMI.getDebugInstrNum(); 1200 MO.ChangeToDbgInstrRef(ID, OperandIdx); 1201 } 1202 } 1203 1204 if (!IsValidRef) 1205 MakeUndefDbgValue(MI); 1206 } 1207 } 1208 } 1209 1210 bool MachineFunction::shouldUseDebugInstrRef() const { 1211 // Disable instr-ref at -O0: it's very slow (in compile time). We can still 1212 // have optimized code inlined into this unoptimized code, however with 1213 // fewer and less aggressive optimizations happening, coverage and accuracy 1214 // should not suffer. 1215 if (getTarget().getOptLevel() == CodeGenOptLevel::None) 1216 return false; 1217 1218 // Don't use instr-ref if this function is marked optnone. 1219 if (F.hasFnAttribute(Attribute::OptimizeNone)) 1220 return false; 1221 1222 if (llvm::debuginfoShouldUseDebugInstrRef(getTarget().getTargetTriple())) 1223 return true; 1224 1225 return false; 1226 } 1227 1228 bool MachineFunction::useDebugInstrRef() const { 1229 return UseDebugInstrRef; 1230 } 1231 1232 void MachineFunction::setUseDebugInstrRef(bool Use) { 1233 UseDebugInstrRef = Use; 1234 } 1235 1236 // Use one million as a high / reserved number. 1237 const unsigned MachineFunction::DebugOperandMemNumber = 1000000; 1238 1239 /// \} 1240 1241 //===----------------------------------------------------------------------===// 1242 // MachineJumpTableInfo implementation 1243 //===----------------------------------------------------------------------===// 1244 1245 /// Return the size of each entry in the jump table. 1246 unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const { 1247 // The size of a jump table entry is 4 bytes unless the entry is just the 1248 // address of a block, in which case it is the pointer size. 1249 switch (getEntryKind()) { 1250 case MachineJumpTableInfo::EK_BlockAddress: 1251 return TD.getPointerSize(); 1252 case MachineJumpTableInfo::EK_GPRel64BlockAddress: 1253 case MachineJumpTableInfo::EK_LabelDifference64: 1254 return 8; 1255 case MachineJumpTableInfo::EK_GPRel32BlockAddress: 1256 case MachineJumpTableInfo::EK_LabelDifference32: 1257 case MachineJumpTableInfo::EK_Custom32: 1258 return 4; 1259 case MachineJumpTableInfo::EK_Inline: 1260 return 0; 1261 } 1262 llvm_unreachable("Unknown jump table encoding!"); 1263 } 1264 1265 /// Return the alignment of each entry in the jump table. 1266 unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const { 1267 // The alignment of a jump table entry is the alignment of int32 unless the 1268 // entry is just the address of a block, in which case it is the pointer 1269 // alignment. 1270 switch (getEntryKind()) { 1271 case MachineJumpTableInfo::EK_BlockAddress: 1272 return TD.getPointerABIAlignment(0).value(); 1273 case MachineJumpTableInfo::EK_GPRel64BlockAddress: 1274 case MachineJumpTableInfo::EK_LabelDifference64: 1275 return TD.getABIIntegerTypeAlignment(64).value(); 1276 case MachineJumpTableInfo::EK_GPRel32BlockAddress: 1277 case MachineJumpTableInfo::EK_LabelDifference32: 1278 case MachineJumpTableInfo::EK_Custom32: 1279 return TD.getABIIntegerTypeAlignment(32).value(); 1280 case MachineJumpTableInfo::EK_Inline: 1281 return 1; 1282 } 1283 llvm_unreachable("Unknown jump table encoding!"); 1284 } 1285 1286 /// Create a new jump table entry in the jump table info. 1287 unsigned MachineJumpTableInfo::createJumpTableIndex( 1288 const std::vector<MachineBasicBlock*> &DestBBs) { 1289 assert(!DestBBs.empty() && "Cannot create an empty jump table!"); 1290 JumpTables.push_back(MachineJumpTableEntry(DestBBs)); 1291 return JumpTables.size()-1; 1292 } 1293 1294 /// If Old is the target of any jump tables, update the jump tables to branch 1295 /// to New instead. 1296 bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old, 1297 MachineBasicBlock *New) { 1298 assert(Old != New && "Not making a change?"); 1299 bool MadeChange = false; 1300 for (size_t i = 0, e = JumpTables.size(); i != e; ++i) 1301 ReplaceMBBInJumpTable(i, Old, New); 1302 return MadeChange; 1303 } 1304 1305 /// If MBB is present in any jump tables, remove it. 1306 bool MachineJumpTableInfo::RemoveMBBFromJumpTables(MachineBasicBlock *MBB) { 1307 bool MadeChange = false; 1308 for (MachineJumpTableEntry &JTE : JumpTables) { 1309 auto removeBeginItr = std::remove(JTE.MBBs.begin(), JTE.MBBs.end(), MBB); 1310 MadeChange |= (removeBeginItr != JTE.MBBs.end()); 1311 JTE.MBBs.erase(removeBeginItr, JTE.MBBs.end()); 1312 } 1313 return MadeChange; 1314 } 1315 1316 /// If Old is a target of the jump tables, update the jump table to branch to 1317 /// New instead. 1318 bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx, 1319 MachineBasicBlock *Old, 1320 MachineBasicBlock *New) { 1321 assert(Old != New && "Not making a change?"); 1322 bool MadeChange = false; 1323 MachineJumpTableEntry &JTE = JumpTables[Idx]; 1324 for (MachineBasicBlock *&MBB : JTE.MBBs) 1325 if (MBB == Old) { 1326 MBB = New; 1327 MadeChange = true; 1328 } 1329 return MadeChange; 1330 } 1331 1332 void MachineJumpTableInfo::print(raw_ostream &OS) const { 1333 if (JumpTables.empty()) return; 1334 1335 OS << "Jump Tables:\n"; 1336 1337 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) { 1338 OS << printJumpTableEntryReference(i) << ':'; 1339 for (const MachineBasicBlock *MBB : JumpTables[i].MBBs) 1340 OS << ' ' << printMBBReference(*MBB); 1341 if (i != e) 1342 OS << '\n'; 1343 } 1344 1345 OS << '\n'; 1346 } 1347 1348 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 1349 LLVM_DUMP_METHOD void MachineJumpTableInfo::dump() const { print(dbgs()); } 1350 #endif 1351 1352 Printable llvm::printJumpTableEntryReference(unsigned Idx) { 1353 return Printable([Idx](raw_ostream &OS) { OS << "%jump-table." << Idx; }); 1354 } 1355 1356 //===----------------------------------------------------------------------===// 1357 // MachineConstantPool implementation 1358 //===----------------------------------------------------------------------===// 1359 1360 void MachineConstantPoolValue::anchor() {} 1361 1362 unsigned MachineConstantPoolValue::getSizeInBytes(const DataLayout &DL) const { 1363 return DL.getTypeAllocSize(Ty); 1364 } 1365 1366 unsigned MachineConstantPoolEntry::getSizeInBytes(const DataLayout &DL) const { 1367 if (isMachineConstantPoolEntry()) 1368 return Val.MachineCPVal->getSizeInBytes(DL); 1369 return DL.getTypeAllocSize(Val.ConstVal->getType()); 1370 } 1371 1372 bool MachineConstantPoolEntry::needsRelocation() const { 1373 if (isMachineConstantPoolEntry()) 1374 return true; 1375 return Val.ConstVal->needsDynamicRelocation(); 1376 } 1377 1378 SectionKind 1379 MachineConstantPoolEntry::getSectionKind(const DataLayout *DL) const { 1380 if (needsRelocation()) 1381 return SectionKind::getReadOnlyWithRel(); 1382 switch (getSizeInBytes(*DL)) { 1383 case 4: 1384 return SectionKind::getMergeableConst4(); 1385 case 8: 1386 return SectionKind::getMergeableConst8(); 1387 case 16: 1388 return SectionKind::getMergeableConst16(); 1389 case 32: 1390 return SectionKind::getMergeableConst32(); 1391 default: 1392 return SectionKind::getReadOnly(); 1393 } 1394 } 1395 1396 MachineConstantPool::~MachineConstantPool() { 1397 // A constant may be a member of both Constants and MachineCPVsSharingEntries, 1398 // so keep track of which we've deleted to avoid double deletions. 1399 DenseSet<MachineConstantPoolValue*> Deleted; 1400 for (const MachineConstantPoolEntry &C : Constants) 1401 if (C.isMachineConstantPoolEntry()) { 1402 Deleted.insert(C.Val.MachineCPVal); 1403 delete C.Val.MachineCPVal; 1404 } 1405 for (MachineConstantPoolValue *CPV : MachineCPVsSharingEntries) { 1406 if (Deleted.count(CPV) == 0) 1407 delete CPV; 1408 } 1409 } 1410 1411 /// Test whether the given two constants can be allocated the same constant pool 1412 /// entry referenced by \param A. 1413 static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B, 1414 const DataLayout &DL) { 1415 // Handle the trivial case quickly. 1416 if (A == B) return true; 1417 1418 // If they have the same type but weren't the same constant, quickly 1419 // reject them. 1420 if (A->getType() == B->getType()) return false; 1421 1422 // We can't handle structs or arrays. 1423 if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) || 1424 isa<StructType>(B->getType()) || isa<ArrayType>(B->getType())) 1425 return false; 1426 1427 // For now, only support constants with the same size. 1428 uint64_t StoreSize = DL.getTypeStoreSize(A->getType()); 1429 if (StoreSize != DL.getTypeStoreSize(B->getType()) || StoreSize > 128) 1430 return false; 1431 1432 bool ContainsUndefOrPoisonA = A->containsUndefOrPoisonElement(); 1433 1434 Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8); 1435 1436 // Try constant folding a bitcast of both instructions to an integer. If we 1437 // get two identical ConstantInt's, then we are good to share them. We use 1438 // the constant folding APIs to do this so that we get the benefit of 1439 // DataLayout. 1440 if (isa<PointerType>(A->getType())) 1441 A = ConstantFoldCastOperand(Instruction::PtrToInt, 1442 const_cast<Constant *>(A), IntTy, DL); 1443 else if (A->getType() != IntTy) 1444 A = ConstantFoldCastOperand(Instruction::BitCast, const_cast<Constant *>(A), 1445 IntTy, DL); 1446 if (isa<PointerType>(B->getType())) 1447 B = ConstantFoldCastOperand(Instruction::PtrToInt, 1448 const_cast<Constant *>(B), IntTy, DL); 1449 else if (B->getType() != IntTy) 1450 B = ConstantFoldCastOperand(Instruction::BitCast, const_cast<Constant *>(B), 1451 IntTy, DL); 1452 1453 if (A != B) 1454 return false; 1455 1456 // Constants only safely match if A doesn't contain undef/poison. 1457 // As we'll be reusing A, it doesn't matter if B contain undef/poison. 1458 // TODO: Handle cases where A and B have the same undef/poison elements. 1459 // TODO: Merge A and B with mismatching undef/poison elements. 1460 return !ContainsUndefOrPoisonA; 1461 } 1462 1463 /// Create a new entry in the constant pool or return an existing one. 1464 /// User must specify the log2 of the minimum required alignment for the object. 1465 unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C, 1466 Align Alignment) { 1467 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 1468 1469 // Check to see if we already have this constant. 1470 // 1471 // FIXME, this could be made much more efficient for large constant pools. 1472 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 1473 if (!Constants[i].isMachineConstantPoolEntry() && 1474 CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, DL)) { 1475 if (Constants[i].getAlign() < Alignment) 1476 Constants[i].Alignment = Alignment; 1477 return i; 1478 } 1479 1480 Constants.push_back(MachineConstantPoolEntry(C, Alignment)); 1481 return Constants.size()-1; 1482 } 1483 1484 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V, 1485 Align Alignment) { 1486 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 1487 1488 // Check to see if we already have this constant. 1489 // 1490 // FIXME, this could be made much more efficient for large constant pools. 1491 int Idx = V->getExistingMachineCPValue(this, Alignment); 1492 if (Idx != -1) { 1493 MachineCPVsSharingEntries.insert(V); 1494 return (unsigned)Idx; 1495 } 1496 1497 Constants.push_back(MachineConstantPoolEntry(V, Alignment)); 1498 return Constants.size()-1; 1499 } 1500 1501 void MachineConstantPool::print(raw_ostream &OS) const { 1502 if (Constants.empty()) return; 1503 1504 OS << "Constant Pool:\n"; 1505 for (unsigned i = 0, e = Constants.size(); i != e; ++i) { 1506 OS << " cp#" << i << ": "; 1507 if (Constants[i].isMachineConstantPoolEntry()) 1508 Constants[i].Val.MachineCPVal->print(OS); 1509 else 1510 Constants[i].Val.ConstVal->printAsOperand(OS, /*PrintType=*/false); 1511 OS << ", align=" << Constants[i].getAlign().value(); 1512 OS << "\n"; 1513 } 1514 } 1515 1516 //===----------------------------------------------------------------------===// 1517 // Template specialization for MachineFunction implementation of 1518 // ProfileSummaryInfo::getEntryCount(). 1519 //===----------------------------------------------------------------------===// 1520 template <> 1521 std::optional<Function::ProfileCount> 1522 ProfileSummaryInfo::getEntryCount<llvm::MachineFunction>( 1523 const llvm::MachineFunction *F) const { 1524 return F->getFunction().getEntryCount(); 1525 } 1526 1527 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 1528 LLVM_DUMP_METHOD void MachineConstantPool::dump() const { print(dbgs()); } 1529 #endif 1530