C++ MachineBasicBlock::getAlignment方法代码示例

void MIRPrinter::convert(ModuleSlotTracker &MST,
                         yaml::MachineBasicBlock &YamlMBB,
                         const MachineBasicBlock &MBB) {
    assert(MBB.getNumber() >= 0 && "Invalid MBB number");
    YamlMBB.ID = (unsigned)MBB.getNumber();
    // TODO: Serialize unnamed BB references.
    if (const auto *BB = MBB.getBasicBlock())
        YamlMBB.Name.Value = BB->hasName() ? BB->getName() : "<unnamed bb>";
    else
        YamlMBB.Name.Value = "";
    YamlMBB.Alignment = MBB.getAlignment();
    YamlMBB.AddressTaken = MBB.hasAddressTaken();
    YamlMBB.IsLandingPad = MBB.isLandingPad();
    for (const auto *SuccMBB : MBB.successors()) {
        std::string Str;
        raw_string_ostream StrOS(Str);
        MIPrinter(StrOS, MST, RegisterMaskIds).printMBBReference(*SuccMBB);
        YamlMBB.Successors.push_back(StrOS.str());
    }

    // Print the machine instructions.
    YamlMBB.Instructions.reserve(MBB.size());
    std::string Str;
    for (const auto &MI : MBB) {
        raw_string_ostream StrOS(Str);
        MIPrinter(StrOS, MST, RegisterMaskIds).print(MI);
        YamlMBB.Instructions.push_back(StrOS.str());
        Str.clear();
    }
}

void WinException::beginFunclet(const MachineBasicBlock &MBB,
                                MCSymbol *Sym) {
  CurrentFuncletEntry = &MBB;

  const Function *F = Asm->MF->getFunction();
  // If a symbol was not provided for the funclet, invent one.
  if (!Sym) {
    Sym = getMCSymbolForMBB(Asm, &MBB);

    // Describe our funclet symbol as a function with internal linkage.
    Asm->OutStreamer->BeginCOFFSymbolDef(Sym);
    Asm->OutStreamer->EmitCOFFSymbolStorageClass(COFF::IMAGE_SYM_CLASS_STATIC);
    Asm->OutStreamer->EmitCOFFSymbolType(COFF::IMAGE_SYM_DTYPE_FUNCTION
                                         << COFF::SCT_COMPLEX_TYPE_SHIFT);
    Asm->OutStreamer->EndCOFFSymbolDef();

    // We want our funclet's entry point to be aligned such that no nops will be
    // present after the label.
    Asm->EmitAlignment(std::max(Asm->MF->getAlignment(), MBB.getAlignment()),
                       F);

    // Now that we've emitted the alignment directive, point at our funclet.
    Asm->OutStreamer->EmitLabel(Sym);
  }

  // Mark 'Sym' as starting our funclet.
  if (shouldEmitMoves || shouldEmitPersonality)
    Asm->OutStreamer->EmitWinCFIStartProc(Sym);

  if (shouldEmitPersonality) {
    const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
    const Function *PerFn = nullptr;

    // Determine which personality routine we are using for this funclet.
    if (F->hasPersonalityFn())
      PerFn = dyn_cast<Function>(F->getPersonalityFn()->stripPointerCasts());
    const MCSymbol *PersHandlerSym =
        TLOF.getCFIPersonalitySymbol(PerFn, *Asm->Mang, Asm->TM, MMI);

    // Classify the personality routine so that we may reason about it.
    EHPersonality Per = EHPersonality::Unknown;
    if (F->hasPersonalityFn())
      Per = classifyEHPersonality(F->getPersonalityFn());

    // Do not emit a .seh_handler directive if it is a C++ cleanup funclet.
    if (Per != EHPersonality::MSVC_CXX ||
        !CurrentFuncletEntry->isCleanupFuncletEntry())
      Asm->OutStreamer->EmitWinEHHandler(PersHandlerSym, true, true);
  }
}

void MIRPrinter::convert(ModuleSlotTracker &MST,
                         yaml::MachineBasicBlock &YamlMBB,
                         const MachineBasicBlock &MBB) {
  assert(MBB.getNumber() >= 0 && "Invalid MBB number");
  YamlMBB.ID = (unsigned)MBB.getNumber();
  if (const auto *BB = MBB.getBasicBlock()) {
    if (BB->hasName()) {
      YamlMBB.Name.Value = BB->getName();
    } else {
      int Slot = MST.getLocalSlot(BB);
      if (Slot == -1)
        YamlMBB.IRBlock.Value = "<badref>";
      else
        YamlMBB.IRBlock.Value = (Twine("%ir-block.") + Twine(Slot)).str();
    }
  }
  YamlMBB.Alignment = MBB.getAlignment();
  YamlMBB.AddressTaken = MBB.hasAddressTaken();
  YamlMBB.IsLandingPad = MBB.isLandingPad();
  for (const auto *SuccMBB : MBB.successors()) {
    std::string Str;
    raw_string_ostream StrOS(Str);
    MIPrinter(StrOS, MST, RegisterMaskIds, StackObjectOperandMapping)
        .printMBBReference(*SuccMBB);
    YamlMBB.Successors.push_back(StrOS.str());
  }
  if (MBB.hasSuccessorWeights()) {
    for (auto I = MBB.succ_begin(), E = MBB.succ_end(); I != E; ++I)
      YamlMBB.SuccessorWeights.push_back(
          yaml::UnsignedValue(MBB.getSuccWeight(I)));
  }
  // Print the live in registers.
  const auto *TRI = MBB.getParent()->getSubtarget().getRegisterInfo();
  assert(TRI && "Expected target register info");
  for (auto I = MBB.livein_begin(), E = MBB.livein_end(); I != E; ++I) {
    std::string Str;
    raw_string_ostream StrOS(Str);
    printReg(*I, StrOS, TRI);
    YamlMBB.LiveIns.push_back(StrOS.str());
  }
  // Print the machine instructions.
  YamlMBB.Instructions.reserve(MBB.size());
  std::string Str;
  for (const auto &MI : MBB) {
    raw_string_ostream StrOS(Str);
    MIPrinter(StrOS, MST, RegisterMaskIds, StackObjectOperandMapping).print(MI);
    YamlMBB.Instructions.push_back(StrOS.str());
    Str.clear();
  }
}

/// verify - check BBOffsets, BBSizes, alignment of islands
void ARM64BranchRelaxation::verify() {
#ifndef NDEBUG
  unsigned PrevNum = MF->begin()->getNumber();
  for (MachineFunction::iterator MBBI = MF->begin(), E = MF->end(); MBBI != E;
       ++MBBI) {
    MachineBasicBlock *MBB = MBBI;
    unsigned Align = MBB->getAlignment();
    unsigned Num = MBB->getNumber();
    assert(BlockInfo[Num].Offset % (1u << Align) == 0);
    assert(!Num || BlockInfo[PrevNum].postOffset() <= BlockInfo[Num].Offset);
    PrevNum = Num;
  }
#endif
}

// Fill MBBs and Terminators, setting the addresses on the assumption
// that no branches need relaxation.  Return the size of the function under
// this assumption.
uint64_t SystemZLongBranch::initMBBInfo() {
  MF->RenumberBlocks();
  unsigned NumBlocks = MF->size();

  MBBs.clear();
  MBBs.resize(NumBlocks);

  Terminators.clear();
  Terminators.reserve(NumBlocks);

  BlockPosition Position(MF->getAlignment());
  for (unsigned I = 0; I < NumBlocks; ++I) {
    MachineBasicBlock *MBB = MF->getBlockNumbered(I);
    MBBInfo &Block = MBBs[I];

    // Record the alignment, for quick access.
    Block.Alignment = MBB->getAlignment();

    // Calculate the size of the fixed part of the block.
    MachineBasicBlock::iterator MI = MBB->begin();
    MachineBasicBlock::iterator End = MBB->end();
    while (MI != End && !MI->isTerminator()) {
      Block.Size += TII->getInstSizeInBytes(*MI);
      ++MI;
    }
    skipNonTerminators(Position, Block);

    // Add the terminators.
    while (MI != End) {
      if (!MI->isDebugValue()) {
        assert(MI->isTerminator() && "Terminator followed by non-terminator");
        Terminators.push_back(describeTerminator(*MI));
        skipTerminator(Position, Terminators.back(), false);
        ++Block.NumTerminators;
      }
      ++MI;
    }
  }

  return Position.Address;
}

void MIRPrinter::convert(yaml::MachineBasicBlock &YamlMBB,
                         const MachineBasicBlock &MBB) {
  // TODO: Serialize unnamed BB references.
  if (const auto *BB = MBB.getBasicBlock())
    YamlMBB.Name = BB->hasName() ? BB->getName() : "<unnamed bb>";
  else
    YamlMBB.Name = "";
  YamlMBB.Alignment = MBB.getAlignment();
  YamlMBB.AddressTaken = MBB.hasAddressTaken();
  YamlMBB.IsLandingPad = MBB.isLandingPad();

  // Print the machine instructions.
  YamlMBB.Instructions.reserve(MBB.size());
  std::string Str;
  for (const auto &MI : MBB) {
    raw_string_ostream StrOS(Str);
    MIPrinter(StrOS).print(MI);
    YamlMBB.Instructions.push_back(StrOS.str());
    Str.clear();
  }
}

void MIPrinter::print(const MachineBasicBlock &MBB) {
  assert(MBB.getNumber() >= 0 && "Invalid MBB number");
  OS << "bb." << MBB.getNumber();
  bool HasAttributes = false;
  if (const auto *BB = MBB.getBasicBlock()) {
    if (BB->hasName()) {
      OS << "." << BB->getName();
    } else {
      HasAttributes = true;
      OS << " (";
      int Slot = MST.getLocalSlot(BB);
      if (Slot == -1)
        OS << "<ir-block badref>";
      else
        OS << (Twine("%ir-block.") + Twine(Slot)).str();
    }
  }
  if (MBB.hasAddressTaken()) {
    OS << (HasAttributes ? ", " : " (");
    OS << "address-taken";
    HasAttributes = true;
  }
  if (MBB.isEHPad()) {
    OS << (HasAttributes ? ", " : " (");
    OS << "landing-pad";
    HasAttributes = true;
  }
  if (MBB.getAlignment()) {
    OS << (HasAttributes ? ", " : " (");
    OS << "align " << MBB.getAlignment();
    HasAttributes = true;
  }
  if (HasAttributes)
    OS << ")";
  OS << ":\n";

  bool HasLineAttributes = false;
  // Print the successors
  if (!MBB.succ_empty()) {
    OS.indent(2) << "successors: ";
    for (auto I = MBB.succ_begin(), E = MBB.succ_end(); I != E; ++I) {
      if (I != MBB.succ_begin())
        OS << ", ";
      printMBBReference(**I);
      if (MBB.hasSuccessorWeights())
        OS << '(' << MBB.getSuccWeight(I) << ')';
    }
    OS << "\n";
    HasLineAttributes = true;
  }

  // Print the live in registers.
  const auto *TRI = MBB.getParent()->getSubtarget().getRegisterInfo();
  assert(TRI && "Expected target register info");
  if (!MBB.livein_empty()) {
    OS.indent(2) << "liveins: ";
    bool First = true;
    for (unsigned LI : MBB.liveins()) {
      if (!First)
        OS << ", ";
      First = false;
      printReg(LI, OS, TRI);
    }
    OS << "\n";
    HasLineAttributes = true;
  }

  if (HasLineAttributes)
    OS << "\n";
  bool IsInBundle = false;
  for (auto I = MBB.instr_begin(), E = MBB.instr_end(); I != E; ++I) {
    const MachineInstr &MI = *I;
    if (IsInBundle && !MI.isInsideBundle()) {
      OS.indent(2) << "}\n";
      IsInBundle = false;
    }
    OS.indent(IsInBundle ? 4 : 2);
    print(MI);
    if (!IsInBundle && MI.getFlag(MachineInstr::BundledSucc)) {
      OS << " {";
      IsInBundle = true;
    }
    OS << "\n";
  }
  if (IsInBundle)
    OS.indent(2) << "}\n";
}

void MIPrinter::print(const MachineBasicBlock &MBB) {
  assert(MBB.getNumber() >= 0 && "Invalid MBB number");
  OS << "bb." << MBB.getNumber();
  bool HasAttributes = false;
  if (const auto *BB = MBB.getBasicBlock()) {
    if (BB->hasName()) {
      OS << "." << BB->getName();
    } else {
      HasAttributes = true;
      OS << " (";
      int Slot = MST.getLocalSlot(BB);
      if (Slot == -1)
        OS << "<ir-block badref>";
      else
        OS << (Twine("%ir-block.") + Twine(Slot)).str();
    }
  }
  if (MBB.hasAddressTaken()) {
    OS << (HasAttributes ? ", " : " (");
    OS << "address-taken";
    HasAttributes = true;
  }
  if (MBB.isEHPad()) {
    OS << (HasAttributes ? ", " : " (");
    OS << "landing-pad";
    HasAttributes = true;
  }
  if (MBB.getAlignment()) {
    OS << (HasAttributes ? ", " : " (");
    OS << "align " << MBB.getAlignment();
    HasAttributes = true;
  }
  if (HasAttributes)
    OS << ")";
  OS << ":\n";

  bool HasLineAttributes = false;
  // Print the successors
  bool canPredictProbs = canPredictBranchProbabilities(MBB);
  // Even if the list of successors is empty, if we cannot guess it,
  // we need to print it to tell the parser that the list is empty.
  // This is needed, because MI model unreachable as empty blocks
  // with an empty successor list. If the parser would see that
  // without the successor list, it would guess the code would
  // fallthrough.
  if ((!MBB.succ_empty() && !SimplifyMIR) || !canPredictProbs ||
      !canPredictSuccessors(MBB)) {
    OS.indent(2) << "successors: ";
    for (auto I = MBB.succ_begin(), E = MBB.succ_end(); I != E; ++I) {
      if (I != MBB.succ_begin())
        OS << ", ";
      OS << printMBBReference(**I);
      if (!SimplifyMIR || !canPredictProbs)
        OS << '('
           << format("0x%08" PRIx32, MBB.getSuccProbability(I).getNumerator())
           << ')';
    }
    OS << "\n";
    HasLineAttributes = true;
  }

  // Print the live in registers.
  const MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
  if (MRI.tracksLiveness() && !MBB.livein_empty()) {
    const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo();
    OS.indent(2) << "liveins: ";
    bool First = true;
    for (const auto &LI : MBB.liveins()) {
      if (!First)
        OS << ", ";
      First = false;
      OS << printReg(LI.PhysReg, &TRI);
      if (!LI.LaneMask.all())
        OS << ":0x" << PrintLaneMask(LI.LaneMask);
    }
    OS << "\n";
    HasLineAttributes = true;
  }

  if (HasLineAttributes)
    OS << "\n";
  bool IsInBundle = false;
  for (auto I = MBB.instr_begin(), E = MBB.instr_end(); I != E; ++I) {
    const MachineInstr &MI = *I;
    if (IsInBundle && !MI.isInsideBundle()) {
      OS.indent(2) << "}\n";
      IsInBundle = false;
    }
    OS.indent(IsInBundle ? 4 : 2);
    print(MI);
    if (!IsInBundle && MI.getFlag(MachineInstr::BundledSucc)) {
      OS << " {";
      IsInBundle = true;
    }
    OS << "\n";
  }
  if (IsInBundle)
    OS.indent(2) << "}\n";
}