1631 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8//9// Collect native machine code information for a function. This allows10// target-specific information about the generated code to be stored with each11// 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/PseudoSourceValueManager.h"36#include "llvm/CodeGen/TargetFrameLowering.h"37#include "llvm/CodeGen/TargetInstrInfo.h"38#include "llvm/CodeGen/TargetLowering.h"39#include "llvm/CodeGen/TargetRegisterInfo.h"40#include "llvm/CodeGen/TargetSubtargetInfo.h"41#include "llvm/CodeGen/WasmEHFuncInfo.h"42#include "llvm/CodeGen/WinEHFuncInfo.h"43#include "llvm/Config/llvm-config.h"44#include "llvm/IR/Attributes.h"45#include "llvm/IR/BasicBlock.h"46#include "llvm/IR/Constant.h"47#include "llvm/IR/DataLayout.h"48#include "llvm/IR/DerivedTypes.h"49#include "llvm/IR/EHPersonalities.h"50#include "llvm/IR/Function.h"51#include "llvm/IR/GlobalValue.h"52#include "llvm/IR/Instruction.h"53#include "llvm/IR/Instructions.h"54#include "llvm/IR/Metadata.h"55#include "llvm/IR/Module.h"56#include "llvm/IR/ModuleSlotTracker.h"57#include "llvm/IR/Value.h"58#include "llvm/MC/MCContext.h"59#include "llvm/MC/MCSymbol.h"60#include "llvm/MC/SectionKind.h"61#include "llvm/Support/Casting.h"62#include "llvm/Support/CommandLine.h"63#include "llvm/Support/Compiler.h"64#include "llvm/Support/DOTGraphTraits.h"65#include "llvm/Support/ErrorHandling.h"66#include "llvm/Support/GraphWriter.h"67#include "llvm/Support/raw_ostream.h"68#include "llvm/Target/TargetMachine.h"69#include <algorithm>70#include <cassert>71#include <cstddef>72#include <cstdint>73#include <iterator>74#include <string>75#include <utility>76#include <vector>77 78#include "LiveDebugValues/LiveDebugValues.h"79 80using namespace llvm;81 82#define DEBUG_TYPE "codegen"83 84static 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 90static const char *getPropertyName(MachineFunctionProperties::Property Prop) {91 using P = MachineFunctionProperties::Property;92 93 // clang-format off94 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::FailedRegAlloc: return "FailedRegAlloc";106 case P::TracksDebugUserValues: return "TracksDebugUserValues";107 }108 // clang-format on109 llvm_unreachable("Invalid machine function property");110}111 112void setUnsafeStackSize(const Function &F, MachineFrameInfo &FrameInfo) {113 if (!F.hasFnAttribute(Attribute::SafeStack))114 return;115 116 auto *Existing =117 dyn_cast_or_null<MDTuple>(F.getMetadata(LLVMContext::MD_annotation));118 119 if (!Existing || Existing->getNumOperands() != 2)120 return;121 122 auto *MetadataName = "unsafe-stack-size";123 if (auto &N = Existing->getOperand(0)) {124 if (N.equalsStr(MetadataName)) {125 if (auto &Op = Existing->getOperand(1)) {126 auto Val = mdconst::extract<ConstantInt>(Op)->getZExtValue();127 FrameInfo.setUnsafeStackSize(Val);128 }129 }130 }131}132 133// Pin the vtable to this file.134void MachineFunction::Delegate::anchor() {}135 136void MachineFunctionProperties::print(raw_ostream &OS) const {137 const char *Separator = "";138 for (BitVector::size_type I = 0; I < Properties.size(); ++I) {139 if (!Properties[I])140 continue;141 OS << Separator << getPropertyName(static_cast<Property>(I));142 Separator = ", ";143 }144}145 146//===----------------------------------------------------------------------===//147// MachineFunction implementation148//===----------------------------------------------------------------------===//149 150// Out-of-line virtual method.151MachineFunctionInfo::~MachineFunctionInfo() = default;152 153void ilist_alloc_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {154 MBB->getParent()->deleteMachineBasicBlock(MBB);155}156 157static inline Align getFnStackAlignment(const TargetSubtargetInfo &STI,158 const Function &F) {159 if (auto MA = F.getFnStackAlign())160 return *MA;161 return STI.getFrameLowering()->getStackAlign();162}163 164MachineFunction::MachineFunction(Function &F, const TargetMachine &Target,165 const TargetSubtargetInfo &STI, MCContext &Ctx,166 unsigned FunctionNum)167 : F(F), Target(Target), STI(STI), Ctx(Ctx) {168 FunctionNumber = FunctionNum;169 init();170}171 172void MachineFunction::handleInsertion(MachineInstr &MI) {173 if (TheDelegate)174 TheDelegate->MF_HandleInsertion(MI);175}176 177void MachineFunction::handleRemoval(MachineInstr &MI) {178 if (TheDelegate)179 TheDelegate->MF_HandleRemoval(MI);180}181 182void MachineFunction::handleChangeDesc(MachineInstr &MI,183 const MCInstrDesc &TID) {184 if (TheDelegate)185 TheDelegate->MF_HandleChangeDesc(MI, TID);186}187 188void MachineFunction::init() {189 // Assume the function starts in SSA form with correct liveness.190 Properties.setIsSSA();191 Properties.setTracksLiveness();192 RegInfo = new (Allocator) MachineRegisterInfo(this);193 194 MFInfo = nullptr;195 196 // We can realign the stack if the target supports it and the user hasn't197 // explicitly asked us not to.198 bool CanRealignSP = STI.getFrameLowering()->isStackRealignable() &&199 !F.hasFnAttribute("no-realign-stack");200 bool ForceRealignSP = F.hasFnAttribute(Attribute::StackAlignment) ||201 F.hasFnAttribute("stackrealign");202 FrameInfo = new (Allocator) MachineFrameInfo(203 getFnStackAlignment(STI, F), /*StackRealignable=*/CanRealignSP,204 /*ForcedRealign=*/ForceRealignSP && CanRealignSP);205 206 setUnsafeStackSize(F, *FrameInfo);207 208 if (F.hasFnAttribute(Attribute::StackAlignment))209 FrameInfo->ensureMaxAlignment(*F.getFnStackAlign());210 211 ConstantPool = new (Allocator) MachineConstantPool(getDataLayout());212 Alignment = STI.getTargetLowering()->getMinFunctionAlignment();213 214 // FIXME: Shouldn't use pref alignment if explicit alignment is set on F.215 if (!F.hasOptSize())216 Alignment = std::max(Alignment,217 STI.getTargetLowering()->getPrefFunctionAlignment());218 219 // -fsanitize=function and -fsanitize=kcfi instrument indirect function calls220 // to load a type hash before the function label. Ensure functions are aligned221 // by a least 4 to avoid unaligned access, which is especially important for222 // -mno-unaligned-access.223 if (F.hasMetadata(LLVMContext::MD_func_sanitize) ||224 F.getMetadata(LLVMContext::MD_kcfi_type))225 Alignment = std::max(Alignment, Align(4));226 227 if (AlignAllFunctions)228 Alignment = Align(1ULL << AlignAllFunctions);229 230 JumpTableInfo = nullptr;231 232 if (isFuncletEHPersonality(classifyEHPersonality(233 F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) {234 WinEHInfo = new (Allocator) WinEHFuncInfo();235 }236 237 if (isScopedEHPersonality(classifyEHPersonality(238 F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) {239 WasmEHInfo = new (Allocator) WasmEHFuncInfo();240 }241 242 assert(Target.isCompatibleDataLayout(getDataLayout()) &&243 "Can't create a MachineFunction using a Module with a "244 "Target-incompatible DataLayout attached\n");245 246 PSVManager = std::make_unique<PseudoSourceValueManager>(getTarget());247}248 249void MachineFunction::initTargetMachineFunctionInfo(250 const TargetSubtargetInfo &STI) {251 assert(!MFInfo && "MachineFunctionInfo already set");252 MFInfo = Target.createMachineFunctionInfo(Allocator, F, &STI);253}254 255MachineFunction::~MachineFunction() {256 clear();257}258 259void MachineFunction::clear() {260 Properties.reset();261 262 // Clear JumpTableInfo first. Otherwise, every MBB we delete would do a263 // linear search over the jump table entries to find and erase itself.264 if (JumpTableInfo) {265 JumpTableInfo->~MachineJumpTableInfo();266 Allocator.Deallocate(JumpTableInfo);267 JumpTableInfo = nullptr;268 }269 270 // Don't call destructors on MachineInstr and MachineOperand. All of their271 // memory comes from the BumpPtrAllocator which is about to be purged.272 //273 // Do call MachineBasicBlock destructors, it contains std::vectors.274 for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I))275 I->Insts.clearAndLeakNodesUnsafely();276 MBBNumbering.clear();277 278 InstructionRecycler.clear(Allocator);279 OperandRecycler.clear(Allocator);280 BasicBlockRecycler.clear(Allocator);281 CodeViewAnnotations.clear();282 VariableDbgInfos.clear();283 if (RegInfo) {284 RegInfo->~MachineRegisterInfo();285 Allocator.Deallocate(RegInfo);286 }287 if (MFInfo) {288 MFInfo->~MachineFunctionInfo();289 Allocator.Deallocate(MFInfo);290 }291 292 FrameInfo->~MachineFrameInfo();293 Allocator.Deallocate(FrameInfo);294 295 ConstantPool->~MachineConstantPool();296 Allocator.Deallocate(ConstantPool);297 298 if (WinEHInfo) {299 WinEHInfo->~WinEHFuncInfo();300 Allocator.Deallocate(WinEHInfo);301 }302 303 if (WasmEHInfo) {304 WasmEHInfo->~WasmEHFuncInfo();305 Allocator.Deallocate(WasmEHInfo);306 }307}308 309const DataLayout &MachineFunction::getDataLayout() const {310 return F.getDataLayout();311}312 313/// Get the JumpTableInfo for this function.314/// If it does not already exist, allocate one.315MachineJumpTableInfo *MachineFunction::316getOrCreateJumpTableInfo(unsigned EntryKind) {317 if (JumpTableInfo) return JumpTableInfo;318 319 JumpTableInfo = new (Allocator)320 MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);321 return JumpTableInfo;322}323 324DenormalMode MachineFunction::getDenormalMode(const fltSemantics &FPType) const {325 return F.getDenormalMode(FPType);326}327 328/// Should we be emitting segmented stack stuff for the function329bool MachineFunction::shouldSplitStack() const {330 return getFunction().hasFnAttribute("split-stack");331}332 333[[nodiscard]] unsigned334MachineFunction::addFrameInst(const MCCFIInstruction &Inst) {335 FrameInstructions.push_back(Inst);336 return FrameInstructions.size() - 1;337}338 339/// This discards all of the MachineBasicBlock numbers and recomputes them.340/// This guarantees that the MBB numbers are sequential, dense, and match the341/// ordering of the blocks within the function. If a specific MachineBasicBlock342/// is specified, only that block and those after it are renumbered.343void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {344 if (empty()) { MBBNumbering.clear(); return; }345 MachineFunction::iterator MBBI, E = end();346 if (MBB == nullptr)347 MBBI = begin();348 else349 MBBI = MBB->getIterator();350 351 // Figure out the block number this should have.352 unsigned BlockNo = 0;353 if (MBBI != begin())354 BlockNo = std::prev(MBBI)->getNumber() + 1;355 356 for (; MBBI != E; ++MBBI, ++BlockNo) {357 if (MBBI->getNumber() != (int)BlockNo) {358 // Remove use of the old number.359 if (MBBI->getNumber() != -1) {360 assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&361 "MBB number mismatch!");362 MBBNumbering[MBBI->getNumber()] = nullptr;363 }364 365 // If BlockNo is already taken, set that block's number to -1.366 if (MBBNumbering[BlockNo])367 MBBNumbering[BlockNo]->setNumber(-1);368 369 MBBNumbering[BlockNo] = &*MBBI;370 MBBI->setNumber(BlockNo);371 }372 }373 374 // Okay, all the blocks are renumbered. If we have compactified the block375 // numbering, shrink MBBNumbering now.376 assert(BlockNo <= MBBNumbering.size() && "Mismatch!");377 MBBNumbering.resize(BlockNo);378 MBBNumberingEpoch++;379}380 381int64_t MachineFunction::estimateFunctionSizeInBytes() {382 const TargetInstrInfo &TII = *getSubtarget().getInstrInfo();383 const Align FunctionAlignment = getAlignment();384 MachineFunction::iterator MBBI = begin(), E = end();385 /// Offset - Distance from the beginning of the function to the end386 /// of the basic block.387 int64_t Offset = 0;388 389 for (; MBBI != E; ++MBBI) {390 const Align Alignment = MBBI->getAlignment();391 int64_t BlockSize = 0;392 393 for (auto &MI : *MBBI) {394 BlockSize += TII.getInstSizeInBytes(MI);395 }396 397 int64_t OffsetBB;398 if (Alignment <= FunctionAlignment) {399 OffsetBB = alignTo(Offset, Alignment);400 } else {401 // The alignment of this MBB is larger than the function's alignment, so402 // we can't tell whether or not it will insert nops. Assume that it will.403 OffsetBB = alignTo(Offset, Alignment) + Alignment.value() -404 FunctionAlignment.value();405 }406 Offset = OffsetBB + BlockSize;407 }408 409 return Offset;410}411 412/// This method iterates over the basic blocks and assigns their IsBeginSection413/// and IsEndSection fields. This must be called after MBB layout is finalized414/// and the SectionID's are assigned to MBBs.415void MachineFunction::assignBeginEndSections() {416 front().setIsBeginSection();417 auto CurrentSectionID = front().getSectionID();418 for (auto MBBI = std::next(begin()), E = end(); MBBI != E; ++MBBI) {419 if (MBBI->getSectionID() == CurrentSectionID)420 continue;421 MBBI->setIsBeginSection();422 std::prev(MBBI)->setIsEndSection();423 CurrentSectionID = MBBI->getSectionID();424 }425 back().setIsEndSection();426}427 428/// Allocate a new MachineInstr. Use this instead of `new MachineInstr'.429MachineInstr *MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,430 DebugLoc DL,431 bool NoImplicit) {432 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))433 MachineInstr(*this, MCID, std::move(DL), NoImplicit);434}435 436/// Create a new MachineInstr which is a copy of the 'Orig' instruction,437/// identical in all ways except the instruction has no parent, prev, or next.438MachineInstr *439MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {440 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))441 MachineInstr(*this, *Orig);442}443 444MachineInstr &MachineFunction::cloneMachineInstrBundle(445 MachineBasicBlock &MBB, MachineBasicBlock::iterator InsertBefore,446 const MachineInstr &Orig) {447 MachineInstr *FirstClone = nullptr;448 MachineBasicBlock::const_instr_iterator I = Orig.getIterator();449 while (true) {450 MachineInstr *Cloned = CloneMachineInstr(&*I);451 MBB.insert(InsertBefore, Cloned);452 if (FirstClone == nullptr) {453 FirstClone = Cloned;454 } else {455 Cloned->bundleWithPred();456 }457 458 if (!I->isBundledWithSucc())459 break;460 ++I;461 }462 // Copy over call info to the cloned instruction if needed. If Orig is in463 // a bundle, copyAdditionalCallInfo takes care of finding the call instruction464 // in the bundle.465 if (Orig.shouldUpdateAdditionalCallInfo())466 copyAdditionalCallInfo(&Orig, FirstClone);467 return *FirstClone;468}469 470/// Delete the given MachineInstr.471///472/// This function also serves as the MachineInstr destructor - the real473/// ~MachineInstr() destructor must be empty.474void MachineFunction::deleteMachineInstr(MachineInstr *MI) {475 // Verify that a call site info is at valid state. This assertion should476 // be triggered during the implementation of support for the477 // call site info of a new architecture. If the assertion is triggered,478 // back trace will tell where to insert a call to updateCallSiteInfo().479 assert((!MI->isCandidateForAdditionalCallInfo() ||480 !CallSitesInfo.contains(MI)) &&481 "Call site info was not updated!");482 // Verify that the "called globals" info is in a valid state.483 assert((!MI->isCandidateForAdditionalCallInfo() ||484 !CalledGlobalsInfo.contains(MI)) &&485 "Called globals info was not updated!");486 // Strip it for parts. The operand array and the MI object itself are487 // independently recyclable.488 if (MI->Operands)489 deallocateOperandArray(MI->CapOperands, MI->Operands);490 // Don't call ~MachineInstr() which must be trivial anyway because491 // ~MachineFunction drops whole lists of MachineInstrs wihout calling their492 // destructors.493 InstructionRecycler.Deallocate(Allocator, MI);494}495 496/// Allocate a new MachineBasicBlock. Use this instead of497/// `new MachineBasicBlock'.498MachineBasicBlock *499MachineFunction::CreateMachineBasicBlock(const BasicBlock *BB,500 std::optional<UniqueBBID> BBID) {501 MachineBasicBlock *MBB =502 new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))503 MachineBasicBlock(*this, BB);504 // Set BBID for `-basic-block-sections=list` and `-basic-block-address-map` to505 // allow robust mapping of profiles to basic blocks.506 if (Target.Options.BBAddrMap ||507 Target.getBBSectionsType() == BasicBlockSection::List)508 MBB->setBBID(BBID.has_value() ? *BBID : UniqueBBID{NextBBID++, 0});509 return MBB;510}511 512/// Delete the given MachineBasicBlock.513void MachineFunction::deleteMachineBasicBlock(MachineBasicBlock *MBB) {514 assert(MBB->getParent() == this && "MBB parent mismatch!");515 // Clean up any references to MBB in jump tables before deleting it.516 if (JumpTableInfo)517 JumpTableInfo->RemoveMBBFromJumpTables(MBB);518 MBB->~MachineBasicBlock();519 BasicBlockRecycler.Deallocate(Allocator, MBB);520}521 522MachineMemOperand *MachineFunction::getMachineMemOperand(523 MachinePointerInfo PtrInfo, MachineMemOperand::Flags F, LocationSize Size,524 Align BaseAlignment, const AAMDNodes &AAInfo, const MDNode *Ranges,525 SyncScope::ID SSID, AtomicOrdering Ordering,526 AtomicOrdering FailureOrdering) {527 assert((!Size.hasValue() ||528 Size.getValue().getKnownMinValue() != ~UINT64_C(0)) &&529 "Unexpected an unknown size to be represented using "530 "LocationSize::beforeOrAfter()");531 return new (Allocator)532 MachineMemOperand(PtrInfo, F, Size, BaseAlignment, AAInfo, Ranges, SSID,533 Ordering, FailureOrdering);534}535 536MachineMemOperand *MachineFunction::getMachineMemOperand(537 MachinePointerInfo PtrInfo, MachineMemOperand::Flags f, LLT MemTy,538 Align base_alignment, const AAMDNodes &AAInfo, const MDNode *Ranges,539 SyncScope::ID SSID, AtomicOrdering Ordering,540 AtomicOrdering FailureOrdering) {541 return new (Allocator)542 MachineMemOperand(PtrInfo, f, MemTy, base_alignment, AAInfo, Ranges, SSID,543 Ordering, FailureOrdering);544}545 546MachineMemOperand *547MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,548 const MachinePointerInfo &PtrInfo,549 LocationSize Size) {550 assert((!Size.hasValue() ||551 Size.getValue().getKnownMinValue() != ~UINT64_C(0)) &&552 "Unexpected an unknown size to be represented using "553 "LocationSize::beforeOrAfter()");554 return new (Allocator)555 MachineMemOperand(PtrInfo, MMO->getFlags(), Size, MMO->getBaseAlign(),556 AAMDNodes(), nullptr, MMO->getSyncScopeID(),557 MMO->getSuccessOrdering(), MMO->getFailureOrdering());558}559 560MachineMemOperand *MachineFunction::getMachineMemOperand(561 const MachineMemOperand *MMO, const MachinePointerInfo &PtrInfo, LLT Ty) {562 return new (Allocator)563 MachineMemOperand(PtrInfo, MMO->getFlags(), Ty, MMO->getBaseAlign(),564 AAMDNodes(), nullptr, MMO->getSyncScopeID(),565 MMO->getSuccessOrdering(), MMO->getFailureOrdering());566}567 568MachineMemOperand *569MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,570 int64_t Offset, LLT Ty) {571 const MachinePointerInfo &PtrInfo = MMO->getPointerInfo();572 573 // If there is no pointer value, the offset isn't tracked so we need to adjust574 // the base alignment.575 Align Alignment = PtrInfo.V.isNull()576 ? commonAlignment(MMO->getBaseAlign(), Offset)577 : MMO->getBaseAlign();578 579 // Do not preserve ranges, since we don't necessarily know what the high bits580 // are anymore.581 return new (Allocator) MachineMemOperand(582 PtrInfo.getWithOffset(Offset), MMO->getFlags(), Ty, Alignment,583 MMO->getAAInfo(), nullptr, MMO->getSyncScopeID(),584 MMO->getSuccessOrdering(), MMO->getFailureOrdering());585}586 587MachineMemOperand *588MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,589 const AAMDNodes &AAInfo) {590 MachinePointerInfo MPI = MMO->getValue() ?591 MachinePointerInfo(MMO->getValue(), MMO->getOffset()) :592 MachinePointerInfo(MMO->getPseudoValue(), MMO->getOffset());593 594 return new (Allocator) MachineMemOperand(595 MPI, MMO->getFlags(), MMO->getSize(), MMO->getBaseAlign(), AAInfo,596 MMO->getRanges(), MMO->getSyncScopeID(), MMO->getSuccessOrdering(),597 MMO->getFailureOrdering());598}599 600MachineMemOperand *601MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,602 MachineMemOperand::Flags Flags) {603 return new (Allocator) MachineMemOperand(604 MMO->getPointerInfo(), Flags, MMO->getSize(), MMO->getBaseAlign(),605 MMO->getAAInfo(), MMO->getRanges(), MMO->getSyncScopeID(),606 MMO->getSuccessOrdering(), MMO->getFailureOrdering());607}608 609MachineInstr::ExtraInfo *MachineFunction::createMIExtraInfo(610 ArrayRef<MachineMemOperand *> MMOs, MCSymbol *PreInstrSymbol,611 MCSymbol *PostInstrSymbol, MDNode *HeapAllocMarker, MDNode *PCSections,612 uint32_t CFIType, MDNode *MMRAs, Value *DS) {613 return MachineInstr::ExtraInfo::create(Allocator, MMOs, PreInstrSymbol,614 PostInstrSymbol, HeapAllocMarker,615 PCSections, CFIType, MMRAs, DS);616}617 618const char *MachineFunction::createExternalSymbolName(StringRef Name) {619 char *Dest = Allocator.Allocate<char>(Name.size() + 1);620 llvm::copy(Name, Dest);621 Dest[Name.size()] = 0;622 return Dest;623}624 625uint32_t *MachineFunction::allocateRegMask() {626 unsigned NumRegs = getSubtarget().getRegisterInfo()->getNumRegs();627 unsigned Size = MachineOperand::getRegMaskSize(NumRegs);628 uint32_t *Mask = Allocator.Allocate<uint32_t>(Size);629 memset(Mask, 0, Size * sizeof(Mask[0]));630 return Mask;631}632 633ArrayRef<int> MachineFunction::allocateShuffleMask(ArrayRef<int> Mask) {634 int* AllocMask = Allocator.Allocate<int>(Mask.size());635 copy(Mask, AllocMask);636 return {AllocMask, Mask.size()};637}638 639#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)640LLVM_DUMP_METHOD void MachineFunction::dump() const {641 print(dbgs());642}643#endif644 645StringRef MachineFunction::getName() const {646 return getFunction().getName();647}648 649void MachineFunction::print(raw_ostream &OS, const SlotIndexes *Indexes) const {650 OS << "# Machine code for function " << getName() << ": ";651 getProperties().print(OS);652 OS << '\n';653 654 // Print Frame Information655 FrameInfo->print(*this, OS);656 657 // Print JumpTable Information658 if (JumpTableInfo)659 JumpTableInfo->print(OS);660 661 // Print Constant Pool662 ConstantPool->print(OS);663 664 const TargetRegisterInfo *TRI = getSubtarget().getRegisterInfo();665 666 if (RegInfo && !RegInfo->livein_empty()) {667 OS << "Function Live Ins: ";668 for (MachineRegisterInfo::livein_iterator669 I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {670 OS << printReg(I->first, TRI);671 if (I->second)672 OS << " in " << printReg(I->second, TRI);673 if (std::next(I) != E)674 OS << ", ";675 }676 OS << '\n';677 }678 679 ModuleSlotTracker MST(getFunction().getParent());680 MST.incorporateFunction(getFunction());681 for (const auto &BB : *this) {682 OS << '\n';683 // If we print the whole function, print it at its most verbose level.684 BB.print(OS, MST, Indexes, /*IsStandalone=*/true);685 }686 687 OS << "\n# End machine code for function " << getName() << ".\n\n";688}689 690/// True if this function needs frame moves for debug or exceptions.691bool MachineFunction::needsFrameMoves() const {692 // TODO: Ideally, what we'd like is to have a switch that allows emitting693 // synchronous (precise at call-sites only) CFA into .eh_frame. However, even694 // under this switch, we'd like .debug_frame to be precise when using -g. At695 // this moment, there's no way to specify that some CFI directives go into696 // .eh_frame only, while others go into .debug_frame only.697 return getTarget().Options.ForceDwarfFrameSection ||698 F.needsUnwindTableEntry() ||699 !F.getParent()->debug_compile_units().empty();700}701 702MachineFunction::CallSiteInfo::CallSiteInfo(const CallBase &CB) {703 // Numeric callee_type ids are only for indirect calls.704 if (!CB.isIndirectCall())705 return;706 707 MDNode *CalleeTypeList = CB.getMetadata(LLVMContext::MD_callee_type);708 if (!CalleeTypeList)709 return;710 711 for (const MDOperand &Op : CalleeTypeList->operands()) {712 MDNode *TypeMD = cast<MDNode>(Op);713 MDString *TypeIdStr = cast<MDString>(TypeMD->getOperand(1));714 // Compute numeric type id from generalized type id string715 uint64_t TypeIdVal = MD5Hash(TypeIdStr->getString());716 IntegerType *Int64Ty = Type::getInt64Ty(CB.getContext());717 CalleeTypeIds.push_back(718 ConstantInt::get(Int64Ty, TypeIdVal, /*IsSigned=*/false));719 }720}721 722template <>723struct llvm::DOTGraphTraits<const MachineFunction *>724 : public DefaultDOTGraphTraits {725 DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}726 727 static std::string getGraphName(const MachineFunction *F) {728 return ("CFG for '" + F->getName() + "' function").str();729 }730 731 std::string getNodeLabel(const MachineBasicBlock *Node,732 const MachineFunction *Graph) {733 std::string OutStr;734 {735 raw_string_ostream OSS(OutStr);736 737 if (isSimple()) {738 OSS << printMBBReference(*Node);739 if (const BasicBlock *BB = Node->getBasicBlock())740 OSS << ": " << BB->getName();741 } else742 Node->print(OSS);743 }744 745 if (OutStr[0] == '\n')746 OutStr.erase(OutStr.begin());747 748 // Process string output to make it nicer...749 for (unsigned i = 0; i != OutStr.length(); ++i)750 if (OutStr[i] == '\n') { // Left justify751 OutStr[i] = '\\';752 OutStr.insert(OutStr.begin() + i + 1, 'l');753 }754 return OutStr;755 }756};757 758void MachineFunction::viewCFG() const759{760#ifndef NDEBUG761 ViewGraph(this, "mf" + getName());762#else763 errs() << "MachineFunction::viewCFG is only available in debug builds on "764 << "systems with Graphviz or gv!\n";765#endif // NDEBUG766}767 768void MachineFunction::viewCFGOnly() const769{770#ifndef NDEBUG771 ViewGraph(this, "mf" + getName(), true);772#else773 errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "774 << "systems with Graphviz or gv!\n";775#endif // NDEBUG776}777 778/// Add the specified physical register as a live-in value and779/// create a corresponding virtual register for it.780Register MachineFunction::addLiveIn(MCRegister PReg,781 const TargetRegisterClass *RC) {782 MachineRegisterInfo &MRI = getRegInfo();783 Register VReg = MRI.getLiveInVirtReg(PReg);784 if (VReg) {785 const TargetRegisterClass *VRegRC = MRI.getRegClass(VReg);786 (void)VRegRC;787 // A physical register can be added several times.788 // Between two calls, the register class of the related virtual register789 // may have been constrained to match some operation constraints.790 // In that case, check that the current register class includes the791 // physical register and is a sub class of the specified RC.792 assert((VRegRC == RC || (VRegRC->contains(PReg) &&793 RC->hasSubClassEq(VRegRC))) &&794 "Register class mismatch!");795 return VReg;796 }797 VReg = MRI.createVirtualRegister(RC);798 MRI.addLiveIn(PReg, VReg);799 return VReg;800}801 802/// Return the MCSymbol for the specified non-empty jump table.803/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a804/// normal 'L' label is returned.805MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,806 bool isLinkerPrivate) const {807 const DataLayout &DL = getDataLayout();808 assert(JumpTableInfo && "No jump tables");809 assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");810 811 StringRef Prefix = isLinkerPrivate ? DL.getLinkerPrivateGlobalPrefix()812 : DL.getPrivateGlobalPrefix();813 SmallString<60> Name;814 raw_svector_ostream(Name)815 << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;816 return Ctx.getOrCreateSymbol(Name);817}818 819/// Return a function-local symbol to represent the PIC base.820MCSymbol *MachineFunction::getPICBaseSymbol() const {821 const DataLayout &DL = getDataLayout();822 return Ctx.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +823 Twine(getFunctionNumber()) + "$pb");824}825 826/// \name Exception Handling827/// \{828 829LandingPadInfo &830MachineFunction::getOrCreateLandingPadInfo(MachineBasicBlock *LandingPad) {831 unsigned N = LandingPads.size();832 for (unsigned i = 0; i < N; ++i) {833 LandingPadInfo &LP = LandingPads[i];834 if (LP.LandingPadBlock == LandingPad)835 return LP;836 }837 838 LandingPads.push_back(LandingPadInfo(LandingPad));839 return LandingPads[N];840}841 842void MachineFunction::addInvoke(MachineBasicBlock *LandingPad,843 MCSymbol *BeginLabel, MCSymbol *EndLabel) {844 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);845 LP.BeginLabels.push_back(BeginLabel);846 LP.EndLabels.push_back(EndLabel);847}848 849MCSymbol *MachineFunction::addLandingPad(MachineBasicBlock *LandingPad) {850 MCSymbol *LandingPadLabel = Ctx.createTempSymbol();851 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);852 LP.LandingPadLabel = LandingPadLabel;853 854 BasicBlock::const_iterator FirstI =855 LandingPad->getBasicBlock()->getFirstNonPHIIt();856 if (const auto *LPI = dyn_cast<LandingPadInst>(FirstI)) {857 // If there's no typeid list specified, then "cleanup" is implicit.858 // Otherwise, id 0 is reserved for the cleanup action.859 if (LPI->isCleanup() && LPI->getNumClauses() != 0)860 LP.TypeIds.push_back(0);861 862 // FIXME: New EH - Add the clauses in reverse order. This isn't 100%863 // correct, but we need to do it this way because of how the DWARF EH864 // emitter processes the clauses.865 for (unsigned I = LPI->getNumClauses(); I != 0; --I) {866 Value *Val = LPI->getClause(I - 1);867 if (LPI->isCatch(I - 1)) {868 LP.TypeIds.push_back(869 getTypeIDFor(dyn_cast<GlobalValue>(Val->stripPointerCasts())));870 } else {871 // Add filters in a list.872 auto *CVal = cast<Constant>(Val);873 SmallVector<unsigned, 4> FilterList;874 for (const Use &U : CVal->operands())875 FilterList.push_back(876 getTypeIDFor(cast<GlobalValue>(U->stripPointerCasts())));877 878 LP.TypeIds.push_back(getFilterIDFor(FilterList));879 }880 }881 882 } else if (const auto *CPI = dyn_cast<CatchPadInst>(FirstI)) {883 for (unsigned I = CPI->arg_size(); I != 0; --I) {884 auto *TypeInfo =885 dyn_cast<GlobalValue>(CPI->getArgOperand(I - 1)->stripPointerCasts());886 LP.TypeIds.push_back(getTypeIDFor(TypeInfo));887 }888 889 } else {890 assert(isa<CleanupPadInst>(FirstI) && "Invalid landingpad!");891 }892 893 return LandingPadLabel;894}895 896void MachineFunction::setCallSiteLandingPad(MCSymbol *Sym,897 ArrayRef<unsigned> Sites) {898 LPadToCallSiteMap[Sym].append(Sites.begin(), Sites.end());899}900 901unsigned MachineFunction::getTypeIDFor(const GlobalValue *TI) {902 for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i)903 if (TypeInfos[i] == TI) return i + 1;904 905 TypeInfos.push_back(TI);906 return TypeInfos.size();907}908 909int MachineFunction::getFilterIDFor(ArrayRef<unsigned> TyIds) {910 // If the new filter coincides with the tail of an existing filter, then911 // re-use the existing filter. Folding filters more than this requires912 // re-ordering filters and/or their elements - probably not worth it.913 for (unsigned i : FilterEnds) {914 unsigned j = TyIds.size();915 916 while (i && j)917 if (FilterIds[--i] != TyIds[--j])918 goto try_next;919 920 if (!j)921 // The new filter coincides with range [i, end) of the existing filter.922 return -(1 + i);923 924try_next:;925 }926 927 // Add the new filter.928 int FilterID = -(1 + FilterIds.size());929 FilterIds.reserve(FilterIds.size() + TyIds.size() + 1);930 llvm::append_range(FilterIds, TyIds);931 FilterEnds.push_back(FilterIds.size());932 FilterIds.push_back(0); // terminator933 return FilterID;934}935 936MachineFunction::CallSiteInfoMap::iterator937MachineFunction::getCallSiteInfo(const MachineInstr *MI) {938 assert(MI->isCandidateForAdditionalCallInfo() &&939 "Call site info refers only to call (MI) candidates");940 941 if (!Target.Options.EmitCallSiteInfo && !Target.Options.EmitCallGraphSection)942 return CallSitesInfo.end();943 return CallSitesInfo.find(MI);944}945 946/// Return the call machine instruction or find a call within bundle.947static const MachineInstr *getCallInstr(const MachineInstr *MI) {948 if (!MI->isBundle())949 return MI;950 951 for (const auto &BMI : make_range(getBundleStart(MI->getIterator()),952 getBundleEnd(MI->getIterator())))953 if (BMI.isCandidateForAdditionalCallInfo())954 return &BMI;955 956 llvm_unreachable("Unexpected bundle without a call site candidate");957}958 959void MachineFunction::eraseAdditionalCallInfo(const MachineInstr *MI) {960 assert(MI->shouldUpdateAdditionalCallInfo() &&961 "Call info refers only to call (MI) candidates or "962 "candidates inside bundles");963 964 const MachineInstr *CallMI = getCallInstr(MI);965 966 CallSiteInfoMap::iterator CSIt = getCallSiteInfo(CallMI);967 if (CSIt != CallSitesInfo.end())968 CallSitesInfo.erase(CSIt);969 970 CalledGlobalsInfo.erase(CallMI);971}972 973void MachineFunction::copyAdditionalCallInfo(const MachineInstr *Old,974 const MachineInstr *New) {975 assert(Old->shouldUpdateAdditionalCallInfo() &&976 "Call info refers only to call (MI) candidates or "977 "candidates inside bundles");978 979 if (!New->isCandidateForAdditionalCallInfo())980 return eraseAdditionalCallInfo(Old);981 982 const MachineInstr *OldCallMI = getCallInstr(Old);983 CallSiteInfoMap::iterator CSIt = getCallSiteInfo(OldCallMI);984 if (CSIt != CallSitesInfo.end()) {985 CallSiteInfo CSInfo = CSIt->second;986 CallSitesInfo[New] = std::move(CSInfo);987 }988 989 CalledGlobalsMap::iterator CGIt = CalledGlobalsInfo.find(OldCallMI);990 if (CGIt != CalledGlobalsInfo.end()) {991 CalledGlobalInfo CGInfo = CGIt->second;992 CalledGlobalsInfo[New] = std::move(CGInfo);993 }994}995 996void MachineFunction::moveAdditionalCallInfo(const MachineInstr *Old,997 const MachineInstr *New) {998 assert(Old->shouldUpdateAdditionalCallInfo() &&999 "Call info refers only to call (MI) candidates or "1000 "candidates inside bundles");1001 1002 if (!New->isCandidateForAdditionalCallInfo())1003 return eraseAdditionalCallInfo(Old);1004 1005 const MachineInstr *OldCallMI = getCallInstr(Old);1006 CallSiteInfoMap::iterator CSIt = getCallSiteInfo(OldCallMI);1007 if (CSIt != CallSitesInfo.end()) {1008 CallSiteInfo CSInfo = std::move(CSIt->second);1009 CallSitesInfo.erase(CSIt);1010 CallSitesInfo[New] = std::move(CSInfo);1011 }1012 1013 CalledGlobalsMap::iterator CGIt = CalledGlobalsInfo.find(OldCallMI);1014 if (CGIt != CalledGlobalsInfo.end()) {1015 CalledGlobalInfo CGInfo = std::move(CGIt->second);1016 CalledGlobalsInfo.erase(CGIt);1017 CalledGlobalsInfo[New] = std::move(CGInfo);1018 }1019}1020 1021void MachineFunction::setDebugInstrNumberingCount(unsigned Num) {1022 DebugInstrNumberingCount = Num;1023}1024 1025void MachineFunction::makeDebugValueSubstitution(DebugInstrOperandPair A,1026 DebugInstrOperandPair B,1027 unsigned Subreg) {1028 // Catch any accidental self-loops.1029 assert(A.first != B.first);1030 // Don't allow any substitutions _from_ the memory operand number.1031 assert(A.second != DebugOperandMemNumber);1032 1033 DebugValueSubstitutions.push_back({A, B, Subreg});1034}1035 1036void MachineFunction::substituteDebugValuesForInst(const MachineInstr &Old,1037 MachineInstr &New,1038 unsigned MaxOperand) {1039 // If the Old instruction wasn't tracked at all, there is no work to do.1040 unsigned OldInstrNum = Old.peekDebugInstrNum();1041 if (!OldInstrNum)1042 return;1043 1044 // Iterate over all operands looking for defs to create substitutions for.1045 // Avoid creating new instr numbers unless we create a new substitution.1046 // While this has no functional effect, it risks confusing someone reading1047 // MIR output.1048 // Examine all the operands, or the first N specified by the caller.1049 MaxOperand = std::min(MaxOperand, Old.getNumOperands());1050 for (unsigned int I = 0; I < MaxOperand; ++I) {1051 const auto &OldMO = Old.getOperand(I);1052 auto &NewMO = New.getOperand(I);1053 (void)NewMO;1054 1055 if (!OldMO.isReg() || !OldMO.isDef())1056 continue;1057 assert(NewMO.isDef());1058 1059 unsigned NewInstrNum = New.getDebugInstrNum();1060 makeDebugValueSubstitution(std::make_pair(OldInstrNum, I),1061 std::make_pair(NewInstrNum, I));1062 }1063}1064 1065auto MachineFunction::salvageCopySSA(1066 MachineInstr &MI, DenseMap<Register, DebugInstrOperandPair> &DbgPHICache)1067 -> DebugInstrOperandPair {1068 const TargetInstrInfo &TII = *getSubtarget().getInstrInfo();1069 1070 // Check whether this copy-like instruction has already been salvaged into1071 // an operand pair.1072 Register Dest;1073 if (auto CopyDstSrc = TII.isCopyLikeInstr(MI)) {1074 Dest = CopyDstSrc->Destination->getReg();1075 } else {1076 assert(MI.isSubregToReg());1077 Dest = MI.getOperand(0).getReg();1078 }1079 1080 auto CacheIt = DbgPHICache.find(Dest);1081 if (CacheIt != DbgPHICache.end())1082 return CacheIt->second;1083 1084 // Calculate the instruction number to use, or install a DBG_PHI.1085 auto OperandPair = salvageCopySSAImpl(MI);1086 DbgPHICache.insert({Dest, OperandPair});1087 return OperandPair;1088}1089 1090auto MachineFunction::salvageCopySSAImpl(MachineInstr &MI)1091 -> DebugInstrOperandPair {1092 MachineRegisterInfo &MRI = getRegInfo();1093 const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo();1094 const TargetInstrInfo &TII = *getSubtarget().getInstrInfo();1095 1096 // Chase the value read by a copy-like instruction back to the instruction1097 // that ultimately _defines_ that value. This may pass:1098 // * Through multiple intermediate copies, including subregister moves /1099 // copies,1100 // * Copies from physical registers that must then be traced back to the1101 // defining instruction,1102 // * Or, physical registers may be live-in to (only) the entry block, which1103 // requires a DBG_PHI to be created.1104 // We can pursue this problem in that order: trace back through copies,1105 // optionally through a physical register, to a defining instruction. We1106 // should never move from physreg to vreg. As we're still in SSA form, no need1107 // to worry about partial definitions of registers.1108 1109 // Helper lambda to interpret a copy-like instruction. Takes instruction,1110 // returns the register read and any subregister identifying which part is1111 // read.1112 auto GetRegAndSubreg =1113 [&](const MachineInstr &Cpy) -> std::pair<Register, unsigned> {1114 Register NewReg, OldReg;1115 unsigned SubReg;1116 if (Cpy.isCopy()) {1117 OldReg = Cpy.getOperand(0).getReg();1118 NewReg = Cpy.getOperand(1).getReg();1119 SubReg = Cpy.getOperand(1).getSubReg();1120 } else if (Cpy.isSubregToReg()) {1121 OldReg = Cpy.getOperand(0).getReg();1122 NewReg = Cpy.getOperand(2).getReg();1123 SubReg = Cpy.getOperand(3).getImm();1124 } else {1125 auto CopyDetails = *TII.isCopyInstr(Cpy);1126 const MachineOperand &Src = *CopyDetails.Source;1127 const MachineOperand &Dest = *CopyDetails.Destination;1128 OldReg = Dest.getReg();1129 NewReg = Src.getReg();1130 SubReg = Src.getSubReg();1131 }1132 1133 return {NewReg, SubReg};1134 };1135 1136 // First seek either the defining instruction, or a copy from a physreg.1137 // During search, the current state is the current copy instruction, and which1138 // register we've read. Accumulate qualifying subregisters into SubregsSeen;1139 // deal with those later.1140 auto State = GetRegAndSubreg(MI);1141 auto CurInst = MI.getIterator();1142 SmallVector<unsigned, 4> SubregsSeen;1143 while (true) {1144 // If we've found a copy from a physreg, first portion of search is over.1145 if (!State.first.isVirtual())1146 break;1147 1148 // Record any subregister qualifier.1149 if (State.second)1150 SubregsSeen.push_back(State.second);1151 1152 assert(MRI.hasOneDef(State.first));1153 MachineInstr &Inst = *MRI.def_begin(State.first)->getParent();1154 CurInst = Inst.getIterator();1155 1156 // Any non-copy instruction is the defining instruction we're seeking.1157 if (!Inst.isCopyLike() && !TII.isCopyLikeInstr(Inst))1158 break;1159 State = GetRegAndSubreg(Inst);1160 };1161 1162 // Helper lambda to apply additional subregister substitutions to a known1163 // instruction/operand pair. Adds new (fake) substitutions so that we can1164 // record the subregister. FIXME: this isn't very space efficient if multiple1165 // values are tracked back through the same copies; cache something later.1166 auto ApplySubregisters =1167 [&](DebugInstrOperandPair P) -> DebugInstrOperandPair {1168 for (unsigned Subreg : reverse(SubregsSeen)) {1169 // Fetch a new instruction number, not attached to an actual instruction.1170 unsigned NewInstrNumber = getNewDebugInstrNum();1171 // Add a substitution from the "new" number to the known one, with a1172 // qualifying subreg.1173 makeDebugValueSubstitution({NewInstrNumber, 0}, P, Subreg);1174 // Return the new number; to find the underlying value, consumers need to1175 // deal with the qualifying subreg.1176 P = {NewInstrNumber, 0};1177 }1178 return P;1179 };1180 1181 // If we managed to find the defining instruction after COPYs, return an1182 // instruction / operand pair after adding subregister qualifiers.1183 if (State.first.isVirtual()) {1184 // Virtual register def -- we can just look up where this happens.1185 MachineInstr *Inst = MRI.def_begin(State.first)->getParent();1186 for (auto &MO : Inst->all_defs()) {1187 if (MO.getReg() != State.first)1188 continue;1189 return ApplySubregisters({Inst->getDebugInstrNum(), MO.getOperandNo()});1190 }1191 1192 llvm_unreachable("Vreg def with no corresponding operand?");1193 }1194 1195 // Our search ended in a copy from a physreg: walk back up the function1196 // looking for whatever defines the physreg.1197 assert(CurInst->isCopyLike() || TII.isCopyInstr(*CurInst));1198 State = GetRegAndSubreg(*CurInst);1199 Register RegToSeek = State.first;1200 1201 auto RMII = CurInst->getReverseIterator();1202 auto PrevInstrs = make_range(RMII, CurInst->getParent()->instr_rend());1203 for (auto &ToExamine : PrevInstrs) {1204 for (auto &MO : ToExamine.all_defs()) {1205 // Test for operand that defines something aliasing RegToSeek.1206 if (!TRI.regsOverlap(RegToSeek, MO.getReg()))1207 continue;1208 1209 return ApplySubregisters(1210 {ToExamine.getDebugInstrNum(), MO.getOperandNo()});1211 }1212 }1213 1214 MachineBasicBlock &InsertBB = *CurInst->getParent();1215 1216 // We reached the start of the block before finding a defining instruction.1217 // There are numerous scenarios where this can happen:1218 // * Constant physical registers,1219 // * Several intrinsics that allow LLVM-IR to read arbitary registers,1220 // * Arguments in the entry block,1221 // * Exception handling landing pads.1222 // Validating all of them is too difficult, so just insert a DBG_PHI reading1223 // the variable value at this position, rather than checking it makes sense.1224 1225 // Create DBG_PHI for specified physreg.1226 auto Builder = BuildMI(InsertBB, InsertBB.getFirstNonPHI(), DebugLoc(),1227 TII.get(TargetOpcode::DBG_PHI));1228 Builder.addReg(State.first);1229 unsigned NewNum = getNewDebugInstrNum();1230 Builder.addImm(NewNum);1231 return ApplySubregisters({NewNum, 0u});1232}1233 1234void MachineFunction::finalizeDebugInstrRefs() {1235 auto *TII = getSubtarget().getInstrInfo();1236 1237 auto MakeUndefDbgValue = [&](MachineInstr &MI) {1238 const MCInstrDesc &RefII = TII->get(TargetOpcode::DBG_VALUE_LIST);1239 MI.setDesc(RefII);1240 MI.setDebugValueUndef();1241 };1242 1243 DenseMap<Register, DebugInstrOperandPair> ArgDbgPHIs;1244 for (auto &MBB : *this) {1245 for (auto &MI : MBB) {1246 if (!MI.isDebugRef())1247 continue;1248 1249 bool IsValidRef = true;1250 1251 for (MachineOperand &MO : MI.debug_operands()) {1252 if (!MO.isReg())1253 continue;1254 1255 Register Reg = MO.getReg();1256 1257 // Some vregs can be deleted as redundant in the meantime. Mark those1258 // as DBG_VALUE $noreg. Additionally, some normal instructions are1259 // quickly deleted, leaving dangling references to vregs with no def.1260 if (Reg == 0 || !RegInfo->hasOneDef(Reg)) {1261 IsValidRef = false;1262 break;1263 }1264 1265 assert(Reg.isVirtual());1266 MachineInstr &DefMI = *RegInfo->def_instr_begin(Reg);1267 1268 // If we've found a copy-like instruction, follow it back to the1269 // instruction that defines the source value, see salvageCopySSA docs1270 // for why this is important.1271 if (DefMI.isCopyLike() || TII->isCopyInstr(DefMI)) {1272 auto Result = salvageCopySSA(DefMI, ArgDbgPHIs);1273 MO.ChangeToDbgInstrRef(Result.first, Result.second);1274 } else {1275 // Otherwise, identify the operand number that the VReg refers to.1276 unsigned OperandIdx = 0;1277 for (const auto &DefMO : DefMI.operands()) {1278 if (DefMO.isReg() && DefMO.isDef() && DefMO.getReg() == Reg)1279 break;1280 ++OperandIdx;1281 }1282 assert(OperandIdx < DefMI.getNumOperands());1283 1284 // Morph this instr ref to point at the given instruction and operand.1285 unsigned ID = DefMI.getDebugInstrNum();1286 MO.ChangeToDbgInstrRef(ID, OperandIdx);1287 }1288 }1289 1290 if (!IsValidRef)1291 MakeUndefDbgValue(MI);1292 }1293 }1294}1295 1296bool MachineFunction::shouldUseDebugInstrRef() const {1297 // Disable instr-ref at -O0: it's very slow (in compile time). We can still1298 // have optimized code inlined into this unoptimized code, however with1299 // fewer and less aggressive optimizations happening, coverage and accuracy1300 // should not suffer.1301 if (getTarget().getOptLevel() == CodeGenOptLevel::None)1302 return false;1303 1304 // Don't use instr-ref if this function is marked optnone.1305 if (F.hasFnAttribute(Attribute::OptimizeNone))1306 return false;1307 1308 if (llvm::debuginfoShouldUseDebugInstrRef(getTarget().getTargetTriple()))1309 return true;1310 1311 return false;1312}1313 1314bool MachineFunction::useDebugInstrRef() const {1315 return UseDebugInstrRef;1316}1317 1318void MachineFunction::setUseDebugInstrRef(bool Use) {1319 UseDebugInstrRef = Use;1320}1321 1322// Use one million as a high / reserved number.1323const unsigned MachineFunction::DebugOperandMemNumber = 1000000;1324 1325/// \}1326 1327//===----------------------------------------------------------------------===//1328// MachineJumpTableInfo implementation1329//===----------------------------------------------------------------------===//1330 1331MachineJumpTableEntry::MachineJumpTableEntry(1332 const std::vector<MachineBasicBlock *> &MBBs)1333 : MBBs(MBBs), Hotness(MachineFunctionDataHotness::Unknown) {}1334 1335/// Return the size of each entry in the jump table.1336unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const {1337 // The size of a jump table entry is 4 bytes unless the entry is just the1338 // address of a block, in which case it is the pointer size.1339 switch (getEntryKind()) {1340 case MachineJumpTableInfo::EK_BlockAddress:1341 return TD.getPointerSize();1342 case MachineJumpTableInfo::EK_GPRel64BlockAddress:1343 case MachineJumpTableInfo::EK_LabelDifference64:1344 return 8;1345 case MachineJumpTableInfo::EK_GPRel32BlockAddress:1346 case MachineJumpTableInfo::EK_LabelDifference32:1347 case MachineJumpTableInfo::EK_Custom32:1348 return 4;1349 case MachineJumpTableInfo::EK_Inline:1350 return 0;1351 }1352 llvm_unreachable("Unknown jump table encoding!");1353}1354 1355/// Return the alignment of each entry in the jump table.1356unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const {1357 // The alignment of a jump table entry is the alignment of int32 unless the1358 // entry is just the address of a block, in which case it is the pointer1359 // alignment.1360 switch (getEntryKind()) {1361 case MachineJumpTableInfo::EK_BlockAddress:1362 return TD.getPointerABIAlignment(0).value();1363 case MachineJumpTableInfo::EK_GPRel64BlockAddress:1364 case MachineJumpTableInfo::EK_LabelDifference64:1365 return TD.getABIIntegerTypeAlignment(64).value();1366 case MachineJumpTableInfo::EK_GPRel32BlockAddress:1367 case MachineJumpTableInfo::EK_LabelDifference32:1368 case MachineJumpTableInfo::EK_Custom32:1369 return TD.getABIIntegerTypeAlignment(32).value();1370 case MachineJumpTableInfo::EK_Inline:1371 return 1;1372 }1373 llvm_unreachable("Unknown jump table encoding!");1374}1375 1376/// Create a new jump table entry in the jump table info.1377unsigned MachineJumpTableInfo::createJumpTableIndex(1378 const std::vector<MachineBasicBlock*> &DestBBs) {1379 assert(!DestBBs.empty() && "Cannot create an empty jump table!");1380 JumpTables.push_back(MachineJumpTableEntry(DestBBs));1381 return JumpTables.size()-1;1382}1383 1384bool MachineJumpTableInfo::updateJumpTableEntryHotness(1385 size_t JTI, MachineFunctionDataHotness Hotness) {1386 assert(JTI < JumpTables.size() && "Invalid JTI!");1387 // Record the largest hotness value.1388 if (Hotness <= JumpTables[JTI].Hotness)1389 return false;1390 1391 JumpTables[JTI].Hotness = Hotness;1392 return true;1393}1394 1395/// If Old is the target of any jump tables, update the jump tables to branch1396/// to New instead.1397bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,1398 MachineBasicBlock *New) {1399 assert(Old != New && "Not making a change?");1400 bool MadeChange = false;1401 for (size_t i = 0, e = JumpTables.size(); i != e; ++i)1402 ReplaceMBBInJumpTable(i, Old, New);1403 return MadeChange;1404}1405 1406/// If MBB is present in any jump tables, remove it.1407bool MachineJumpTableInfo::RemoveMBBFromJumpTables(MachineBasicBlock *MBB) {1408 bool MadeChange = false;1409 for (MachineJumpTableEntry &JTE : JumpTables) {1410 auto removeBeginItr = std::remove(JTE.MBBs.begin(), JTE.MBBs.end(), MBB);1411 MadeChange |= (removeBeginItr != JTE.MBBs.end());1412 JTE.MBBs.erase(removeBeginItr, JTE.MBBs.end());1413 }1414 return MadeChange;1415}1416 1417/// If Old is a target of the jump tables, update the jump table to branch to1418/// New instead.1419bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,1420 MachineBasicBlock *Old,1421 MachineBasicBlock *New) {1422 assert(Old != New && "Not making a change?");1423 bool MadeChange = false;1424 MachineJumpTableEntry &JTE = JumpTables[Idx];1425 for (MachineBasicBlock *&MBB : JTE.MBBs)1426 if (MBB == Old) {1427 MBB = New;1428 MadeChange = true;1429 }1430 return MadeChange;1431}1432 1433void MachineJumpTableInfo::print(raw_ostream &OS) const {1434 if (JumpTables.empty()) return;1435 1436 OS << "Jump Tables:\n";1437 1438 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {1439 OS << printJumpTableEntryReference(i) << ':';1440 for (const MachineBasicBlock *MBB : JumpTables[i].MBBs)1441 OS << ' ' << printMBBReference(*MBB);1442 if (i != e)1443 OS << '\n';1444 }1445 1446 OS << '\n';1447}1448 1449#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)1450LLVM_DUMP_METHOD void MachineJumpTableInfo::dump() const { print(dbgs()); }1451#endif1452 1453Printable llvm::printJumpTableEntryReference(unsigned Idx) {1454 return Printable([Idx](raw_ostream &OS) { OS << "%jump-table." << Idx; });1455}1456 1457//===----------------------------------------------------------------------===//1458// MachineConstantPool implementation1459//===----------------------------------------------------------------------===//1460 1461void MachineConstantPoolValue::anchor() {}1462 1463unsigned MachineConstantPoolValue::getSizeInBytes(const DataLayout &DL) const {1464 return DL.getTypeAllocSize(Ty);1465}1466 1467unsigned MachineConstantPoolEntry::getSizeInBytes(const DataLayout &DL) const {1468 if (isMachineConstantPoolEntry())1469 return Val.MachineCPVal->getSizeInBytes(DL);1470 return DL.getTypeAllocSize(Val.ConstVal->getType());1471}1472 1473bool MachineConstantPoolEntry::needsRelocation() const {1474 if (isMachineConstantPoolEntry())1475 return true;1476 return Val.ConstVal->needsDynamicRelocation();1477}1478 1479SectionKind1480MachineConstantPoolEntry::getSectionKind(const DataLayout *DL) const {1481 if (needsRelocation())1482 return SectionKind::getReadOnlyWithRel();1483 switch (getSizeInBytes(*DL)) {1484 case 4:1485 return SectionKind::getMergeableConst4();1486 case 8:1487 return SectionKind::getMergeableConst8();1488 case 16:1489 return SectionKind::getMergeableConst16();1490 case 32:1491 return SectionKind::getMergeableConst32();1492 default:1493 return SectionKind::getReadOnly();1494 }1495}1496 1497MachineConstantPool::~MachineConstantPool() {1498 // A constant may be a member of both Constants and MachineCPVsSharingEntries,1499 // so keep track of which we've deleted to avoid double deletions.1500 DenseSet<MachineConstantPoolValue*> Deleted;1501 for (const MachineConstantPoolEntry &C : Constants)1502 if (C.isMachineConstantPoolEntry()) {1503 Deleted.insert(C.Val.MachineCPVal);1504 delete C.Val.MachineCPVal;1505 }1506 for (MachineConstantPoolValue *CPV : MachineCPVsSharingEntries) {1507 if (Deleted.count(CPV) == 0)1508 delete CPV;1509 }1510}1511 1512/// Test whether the given two constants can be allocated the same constant pool1513/// entry referenced by \param A.1514static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,1515 const DataLayout &DL) {1516 // Handle the trivial case quickly.1517 if (A == B) return true;1518 1519 // If they have the same type but weren't the same constant, quickly1520 // reject them.1521 if (A->getType() == B->getType()) return false;1522 1523 // We can't handle structs or arrays.1524 if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||1525 isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))1526 return false;1527 1528 // For now, only support constants with the same size.1529 uint64_t StoreSize = DL.getTypeStoreSize(A->getType());1530 if (StoreSize != DL.getTypeStoreSize(B->getType()) || StoreSize > 128)1531 return false;1532 1533 bool ContainsUndefOrPoisonA = A->containsUndefOrPoisonElement();1534 1535 Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);1536 1537 // Try constant folding a bitcast of both instructions to an integer. If we1538 // get two identical ConstantInt's, then we are good to share them. We use1539 // the constant folding APIs to do this so that we get the benefit of1540 // DataLayout.1541 if (isa<PointerType>(A->getType()))1542 A = ConstantFoldCastOperand(Instruction::PtrToInt,1543 const_cast<Constant *>(A), IntTy, DL);1544 else if (A->getType() != IntTy)1545 A = ConstantFoldCastOperand(Instruction::BitCast, const_cast<Constant *>(A),1546 IntTy, DL);1547 if (isa<PointerType>(B->getType()))1548 B = ConstantFoldCastOperand(Instruction::PtrToInt,1549 const_cast<Constant *>(B), IntTy, DL);1550 else if (B->getType() != IntTy)1551 B = ConstantFoldCastOperand(Instruction::BitCast, const_cast<Constant *>(B),1552 IntTy, DL);1553 1554 if (A != B)1555 return false;1556 1557 // Constants only safely match if A doesn't contain undef/poison.1558 // As we'll be reusing A, it doesn't matter if B contain undef/poison.1559 // TODO: Handle cases where A and B have the same undef/poison elements.1560 // TODO: Merge A and B with mismatching undef/poison elements.1561 return !ContainsUndefOrPoisonA;1562}1563 1564/// Create a new entry in the constant pool or return an existing one.1565/// User must specify the log2 of the minimum required alignment for the object.1566unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,1567 Align Alignment) {1568 if (Alignment > PoolAlignment) PoolAlignment = Alignment;1569 1570 // Check to see if we already have this constant.1571 //1572 // FIXME, this could be made much more efficient for large constant pools.1573 for (unsigned i = 0, e = Constants.size(); i != e; ++i)1574 if (!Constants[i].isMachineConstantPoolEntry() &&1575 CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, DL)) {1576 if (Constants[i].getAlign() < Alignment)1577 Constants[i].Alignment = Alignment;1578 return i;1579 }1580 1581 Constants.push_back(MachineConstantPoolEntry(C, Alignment));1582 return Constants.size()-1;1583}1584 1585unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,1586 Align Alignment) {1587 if (Alignment > PoolAlignment) PoolAlignment = Alignment;1588 1589 // Check to see if we already have this constant.1590 //1591 // FIXME, this could be made much more efficient for large constant pools.1592 int Idx = V->getExistingMachineCPValue(this, Alignment);1593 if (Idx != -1) {1594 MachineCPVsSharingEntries.insert(V);1595 return (unsigned)Idx;1596 }1597 1598 Constants.push_back(MachineConstantPoolEntry(V, Alignment));1599 return Constants.size()-1;1600}1601 1602void MachineConstantPool::print(raw_ostream &OS) const {1603 if (Constants.empty()) return;1604 1605 OS << "Constant Pool:\n";1606 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {1607 OS << " cp#" << i << ": ";1608 if (Constants[i].isMachineConstantPoolEntry())1609 Constants[i].Val.MachineCPVal->print(OS);1610 else1611 Constants[i].Val.ConstVal->printAsOperand(OS, /*PrintType=*/false);1612 OS << ", align=" << Constants[i].getAlign().value();1613 OS << "\n";1614 }1615}1616 1617//===----------------------------------------------------------------------===//1618// Template specialization for MachineFunction implementation of1619// ProfileSummaryInfo::getEntryCount().1620//===----------------------------------------------------------------------===//1621template <>1622std::optional<Function::ProfileCount>1623ProfileSummaryInfo::getEntryCount<llvm::MachineFunction>(1624 const llvm::MachineFunction *F) const {1625 return F->getFunction().getEntryCount();1626}1627 1628#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)1629LLVM_DUMP_METHOD void MachineConstantPool::dump() const { print(dbgs()); }1630#endif1631