C++ SmallVector::reserve方法代码示例

void llvm::appendToGlobalCtors(Module &M, Function *F, int Priority) {
  IRBuilder<> IRB(M.getContext());
  FunctionType *FnTy = FunctionType::get(IRB.getVoidTy(), false);
  StructType *Ty = StructType::get(
      IRB.getInt32Ty(), PointerType::getUnqual(FnTy), NULL);

  Constant *RuntimeCtorInit = ConstantStruct::get(
      Ty, IRB.getInt32(Priority), F, NULL);

  // Get the current set of static global constructors and add the new ctor
  // to the list.
  SmallVector<Constant *, 16> CurrentCtors;
  if (GlobalVariable * GVCtor = M.getNamedGlobal("llvm.global_ctors")) {
    if (Constant *Init = GVCtor->getInitializer()) {
      unsigned n = Init->getNumOperands();
      CurrentCtors.reserve(n + 1);
      for (unsigned i = 0; i != n; ++i)
        CurrentCtors.push_back(cast<Constant>(Init->getOperand(i)));
    }
    GVCtor->eraseFromParent();
  }

  CurrentCtors.push_back(RuntimeCtorInit);

  // Create a new initializer.
  ArrayType *AT = ArrayType::get(RuntimeCtorInit->getType(),
                                 CurrentCtors.size());
  Constant *NewInit = ConstantArray::get(AT, CurrentCtors);

  // Create the new global variable and replace all uses of
  // the old global variable with the new one.
  (void)new GlobalVariable(M, NewInit->getType(), false,
                           GlobalValue::AppendingLinkage, NewInit,
                           "llvm.global_ctors");
}

void RenameIndependentSubregs::distribute(const IntEqClasses &Classes,
    const SmallVectorImpl<SubRangeInfo> &SubRangeInfos,
    const SmallVectorImpl<LiveInterval*> &Intervals) const {
  unsigned NumClasses = Classes.getNumClasses();
  SmallVector<unsigned, 8> VNIMapping;
  SmallVector<LiveInterval::SubRange*, 8> SubRanges;
  BumpPtrAllocator &Allocator = LIS->getVNInfoAllocator();
  for (const SubRangeInfo &SRInfo : SubRangeInfos) {
    LiveInterval::SubRange &SR = *SRInfo.SR;
    unsigned NumValNos = SR.valnos.size();
    VNIMapping.clear();
    VNIMapping.reserve(NumValNos);
    SubRanges.clear();
    SubRanges.resize(NumClasses-1, nullptr);
    for (unsigned I = 0; I < NumValNos; ++I) {
      const VNInfo &VNI = *SR.valnos[I];
      unsigned LocalID = SRInfo.ConEQ.getEqClass(&VNI);
      unsigned ID = Classes[LocalID + SRInfo.Index];
      VNIMapping.push_back(ID);
      if (ID > 0 && SubRanges[ID-1] == nullptr)
        SubRanges[ID-1] = Intervals[ID]->createSubRange(Allocator, SR.LaneMask);
    }
    DistributeRange(SR, SubRanges.data(), VNIMapping);
  }
}

// Propagate existing explicit probabilities from either profile data or
// 'expect' intrinsic processing.
bool BranchProbabilityAnalysis::calcMetadataWeights(BasicBlock *BB) {
  TerminatorInst *TI = BB->getTerminator();
  if (TI->getNumSuccessors() == 1)
    return false;
  if (!isa<BranchInst>(TI) && !isa<SwitchInst>(TI))
    return false;

  MDNode *WeightsNode = TI->getMetadata(LLVMContext::MD_prof);
  if (!WeightsNode)
    return false;

  // Ensure there are weights for all of the successors. Note that the first
  // operand to the metadata node is a name, not a weight.
  if (WeightsNode->getNumOperands() != TI->getNumSuccessors() + 1)
    return false;

  // Build up the final weights that will be used in a temporary buffer, but
  // don't add them until all weihts are present. Each weight value is clamped
  // to [1, getMaxWeightFor(BB)].
  uint32_t WeightLimit = getMaxWeightFor(BB);
  SmallVector<uint32_t, 2> Weights;
  Weights.reserve(TI->getNumSuccessors());
  for (unsigned i = 1, e = WeightsNode->getNumOperands(); i != e; ++i) {
    ConstantInt *Weight = dyn_cast<ConstantInt>(WeightsNode->getOperand(i));
    if (!Weight)
      return false;
    Weights.push_back(
      std::max<uint32_t>(1, Weight->getLimitedValue(WeightLimit)));
  }
  assert(Weights.size() == TI->getNumSuccessors() && "Checked above");
  for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
    BP->setEdgeWeight(BB, TI->getSuccessor(i), Weights[i]);

  return true;
}

void CallGraph::print(raw_ostream &OS) const {
  OS << "CallGraph Root is: ";
  if (Function *F = Root->getFunction())
    OS << F->getName() << "\n";
  else {
    OS << "<<null function: 0x" << Root << ">>\n";
  }

  // Print in a deterministic order by sorting CallGraphNodes by name.  We do
  // this here to avoid slowing down the non-printing fast path.

  SmallVector<CallGraphNode *, 16> Nodes;
  Nodes.reserve(FunctionMap.size());

  for (auto I = begin(), E = end(); I != E; ++I)
    Nodes.push_back(I->second.get());

  std::sort(Nodes.begin(), Nodes.end(),
            [](CallGraphNode *LHS, CallGraphNode *RHS) {
    if (Function *LF = LHS->getFunction())
      if (Function *RF = RHS->getFunction())
        return LF->getName() < RF->getName();

    return RHS->getFunction() != nullptr;
  });

  for (CallGraphNode *CN : Nodes)
    CN->print(OS);
}

/// \brief Try to simplify a call site.
///
/// Takes a concrete function and callsite and tries to actually simplify it by
/// analyzing the arguments and call itself with instsimplify. Returns true if
/// it has simplified the callsite to some other entity (a constant), making it
/// free.
bool CallAnalyzer::simplifyCallSite(Function *F, CallSite CS) {
  // FIXME: Using the instsimplify logic directly for this is inefficient
  // because we have to continually rebuild the argument list even when no
  // simplifications can be performed. Until that is fixed with remapping
  // inside of instsimplify, directly constant fold calls here.
  if (!canConstantFoldCallTo(F))
    return false;

  // Try to re-map the arguments to constants.
  SmallVector<Constant *, 4> ConstantArgs;
  ConstantArgs.reserve(CS.arg_size());
  for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
       I != E; ++I) {
    Constant *C = dyn_cast<Constant>(*I);
    if (!C)
      C = dyn_cast_or_null<Constant>(SimplifiedValues.lookup(*I));
    if (!C)
      return false; // This argument doesn't map to a constant.

    ConstantArgs.push_back(C);
  }
  if (Constant *C = ConstantFoldCall(F, ConstantArgs)) {
    SimplifiedValues[CS.getInstruction()] = C;
    return true;
  }

  return false;
}

void ExprEngine::evalArguments(ConstExprIterator AI, ConstExprIterator AE,
                                 const FunctionProtoType *FnType, 
                                 ExplodedNode *Pred, ExplodedNodeSet &Dst,
                                 bool FstArgAsLValue) {


  SmallVector<CallExprWLItem, 20> WorkList;
  WorkList.reserve(AE - AI);
  WorkList.push_back(CallExprWLItem(AI, Pred));

  while (!WorkList.empty()) {
    CallExprWLItem Item = WorkList.back();
    WorkList.pop_back();

    if (Item.I == AE) {
      Dst.insert(Item.N);
      continue;
    }

    // Evaluate the argument.
    ExplodedNodeSet Tmp;
    if (FstArgAsLValue) {
      FstArgAsLValue = false;
    }

    Visit(*Item.I, Item.N, Tmp);
    ++(Item.I);
    for (ExplodedNodeSet::iterator NI=Tmp.begin(), NE=Tmp.end(); NI != NE; ++NI)
      WorkList.push_back(CallExprWLItem(Item.I, *NI));
  }
}

void Mapper::remapInstruction(Instruction *I) {
  // Remap operands.
  for (Use &Op : I->operands()) {
    Value *V = mapValue(Op);
    // If we aren't ignoring missing entries, assert that something happened.
    if (V)
      Op = V;
    else
      assert((Flags & RF_IgnoreMissingLocals) &&
             "Referenced value not in value map!");
  }

  // Remap phi nodes' incoming blocks.
  if (PHINode *PN = dyn_cast<PHINode>(I)) {
    for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
      Value *V = mapValue(PN->getIncomingBlock(i));
      // If we aren't ignoring missing entries, assert that something happened.
      if (V)
        PN->setIncomingBlock(i, cast<BasicBlock>(V));
      else
        assert((Flags & RF_IgnoreMissingLocals) &&
               "Referenced block not in value map!");
    }
  }

  // Remap attached metadata.
  SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
  I->getAllMetadata(MDs);
  for (const auto &MI : MDs) {
    MDNode *Old = MI.second;
    MDNode *New = cast_or_null<MDNode>(mapMetadata(Old));
    if (New != Old)
      I->setMetadata(MI.first, New);
  }

  if (!TypeMapper)
    return;

  // If the instruction's type is being remapped, do so now.
  if (auto CS = CallSite(I)) {
    SmallVector<Type *, 3> Tys;
    FunctionType *FTy = CS.getFunctionType();
    Tys.reserve(FTy->getNumParams());
    for (Type *Ty : FTy->params())
      Tys.push_back(TypeMapper->remapType(Ty));
    CS.mutateFunctionType(FunctionType::get(
        TypeMapper->remapType(I->getType()), Tys, FTy->isVarArg()));
    return;
  }
  if (auto *AI = dyn_cast<AllocaInst>(I))
    AI->setAllocatedType(TypeMapper->remapType(AI->getAllocatedType()));
  if (auto *GEP = dyn_cast<GetElementPtrInst>(I)) {
    GEP->setSourceElementType(
        TypeMapper->remapType(GEP->getSourceElementType()));
    GEP->setResultElementType(
        TypeMapper->remapType(GEP->getResultElementType()));
  }
  I->mutateType(TypeMapper->remapType(I->getType()));
}

// Add an operand to an existing MDNode. The new operand will be added at the
// back of the operand list.
static void AddOperand(DICompileUnit CU, DIArray SPs, Metadata *NewSP) {
  SmallVector<Metadata *, 16> NewSPs;
  NewSPs.reserve(SPs->getNumOperands() + 1);
  for (unsigned I = 0, E = SPs->getNumOperands(); I != E; ++I)
    NewSPs.push_back(SPs->getOperand(I));
  NewSPs.push_back(NewSP);
  CU.replaceSubprograms(DIArray(MDNode::get(CU->getContext(), NewSPs)));
}

LLVMContextImpl::~LLVMContextImpl() {
  // NOTE: We need to delete the contents of OwnedModules, but we have to
  // duplicate it into a temporary vector, because the destructor of Module
  // will try to remove itself from OwnedModules set.  This would cause
  // iterator invalidation if we iterated on the set directly.
  std::vector<Module*> Modules(OwnedModules.begin(), OwnedModules.end());
  DeleteContainerPointers(Modules);
  
  // Free the constants.  This is important to do here to ensure that they are
  // freed before the LeakDetector is torn down.
  std::for_each(ExprConstants.map_begin(), ExprConstants.map_end(),
                DropReferences());
  std::for_each(ArrayConstants.map_begin(), ArrayConstants.map_end(),
                DropFirst());
  std::for_each(StructConstants.map_begin(), StructConstants.map_end(),
                DropFirst());
  std::for_each(VectorConstants.map_begin(), VectorConstants.map_end(),
                DropFirst());
  ExprConstants.freeConstants();
  ArrayConstants.freeConstants();
  StructConstants.freeConstants();
  VectorConstants.freeConstants();
  DeleteContainerSeconds(CAZConstants);
  DeleteContainerSeconds(CPNConstants);
  DeleteContainerSeconds(UVConstants);
  InlineAsms.freeConstants();
  DeleteContainerSeconds(IntConstants);
  DeleteContainerSeconds(FPConstants);
  
  for (StringMap<ConstantDataSequential*>::iterator I = CDSConstants.begin(),
       E = CDSConstants.end(); I != E; ++I)
    delete I->second;
  CDSConstants.clear();

  // Destroy attributes.
  for (FoldingSetIterator<AttributesImpl> I = AttrsSet.begin(),
         E = AttrsSet.end(); I != E;) {
    FoldingSetIterator<AttributesImpl> Elem = I++;
    delete &*Elem;
  }

  // Destroy MDNodes.  ~MDNode can move and remove nodes between the MDNodeSet
  // and the NonUniquedMDNodes sets, so copy the values out first.
  SmallVector<MDNode*, 8> MDNodes;
  MDNodes.reserve(MDNodeSet.size() + NonUniquedMDNodes.size());
  for (FoldingSetIterator<MDNode> I = MDNodeSet.begin(), E = MDNodeSet.end();
       I != E; ++I)
    MDNodes.push_back(&*I);
  MDNodes.append(NonUniquedMDNodes.begin(), NonUniquedMDNodes.end());
  for (SmallVectorImpl<MDNode *>::iterator I = MDNodes.begin(),
         E = MDNodes.end(); I != E; ++I)
    (*I)->destroy();
  assert(MDNodeSet.empty() && NonUniquedMDNodes.empty() &&
         "Destroying all MDNodes didn't empty the Context's sets.");

  // Destroy MDStrings.
  DeleteContainerSeconds(MDStringCache);
}

TypeRepr *CloneVisitor::visitCompoundIdentTypeRepr(CompoundIdentTypeRepr *T) {
  // Clone the components.
  SmallVector<ComponentIdentTypeRepr*, 8> components;
  components.reserve(T->getComponents().size());
  for (auto &component : T->getComponents()) {
    components.push_back(cast<ComponentIdentTypeRepr>(visit(component)));
  }
  return CompoundIdentTypeRepr::create(Ctx, components);
}

BranchInst *SILBuilder::createBranch(SILLocation Loc,
                                     SILBasicBlock *TargetBlock,
                                     OperandValueArrayRef Args) {
  SmallVector<SILValue, 6> ArgsCopy;
  ArgsCopy.reserve(Args.size());
  for (auto I = Args.begin(), E = Args.end(); I != E; ++I)
    ArgsCopy.push_back(*I);
  return createBranch(Loc, TargetBlock, ArgsCopy);
}

/// InitializeSlots - Process all spill stack slot liveintervals and add them
/// to a sorted (by weight) list.
void StackSlotColoring::InitializeSlots() {
  int LastFI = MFI->getObjectIndexEnd();

  // There is always at least one stack ID.
  AllColors.resize(1);
  UsedColors.resize(1);

  OrigAlignments.resize(LastFI);
  OrigSizes.resize(LastFI);
  AllColors[0].resize(LastFI);
  UsedColors[0].resize(LastFI);
  Assignments.resize(LastFI);

  using Pair = std::iterator_traits<LiveStacks::iterator>::value_type;

  SmallVector<Pair *, 16> Intervals;

  Intervals.reserve(LS->getNumIntervals());
  for (auto &I : *LS)
    Intervals.push_back(&I);
  llvm::sort(Intervals.begin(), Intervals.end(),
             [](Pair *LHS, Pair *RHS) { return LHS->first < RHS->first; });

  // Gather all spill slots into a list.
  LLVM_DEBUG(dbgs() << "Spill slot intervals:\n");
  for (auto *I : Intervals) {
    LiveInterval &li = I->second;
    LLVM_DEBUG(li.dump());
    int FI = TargetRegisterInfo::stackSlot2Index(li.reg);
    if (MFI->isDeadObjectIndex(FI))
      continue;

    SSIntervals.push_back(&li);
    OrigAlignments[FI] = MFI->getObjectAlignment(FI);
    OrigSizes[FI]      = MFI->getObjectSize(FI);

    auto StackID = MFI->getStackID(FI);
    if (StackID != 0) {
      AllColors.resize(StackID + 1);
      UsedColors.resize(StackID + 1);
      AllColors[StackID].resize(LastFI);
      UsedColors[StackID].resize(LastFI);
    }

    AllColors[StackID].set(FI);
  }
  LLVM_DEBUG(dbgs() << '\n');

  // Sort them by weight.
  std::stable_sort(SSIntervals.begin(), SSIntervals.end(), IntervalSorter());

  NextColors.resize(AllColors.size());

  // Get first "color".
  for (unsigned I = 0, E = AllColors.size(); I != E; ++I)
    NextColors[I] = AllColors[I].find_first();
}

// Add an operand to an existing MDNode. The new operand will be added at the
// back of the operand list.
static void AddOperand(DICompileUnit *CU, DISubprogramArray SPs,
                       Metadata *NewSP) {
  SmallVector<Metadata *, 16> NewSPs;
  NewSPs.reserve(SPs.size() + 1);
  for (auto *SP : SPs)
    NewSPs.push_back(SP);
  NewSPs.push_back(NewSP);
  CU->replaceSubprograms(MDTuple::get(CU->getContext(), NewSPs));
}

void DwarfCompileUnit::attachRangesOrLowHighPC(
    DIE &Die, const SmallVectorImpl<InsnRange> &Ranges) {
  SmallVector<RangeSpan, 2> List;
  List.reserve(Ranges.size());
  for (const InsnRange &R : Ranges)
    List.push_back(RangeSpan(DD->getLabelBeforeInsn(R.first),
                             DD->getLabelAfterInsn(R.second)));
  attachRangesOrLowHighPC(Die, std::move(List));
}

ProtocolConformance *ProtocolConformance::subst(Module *module,
                                      Type substType,
                                      ArrayRef<Substitution> subs,
                                      TypeSubstitutionMap &subMap,
                                      ArchetypeConformanceMap &conformanceMap) {
  if (getType()->isEqual(substType))
    return this;
  
  switch (getKind()) {
  case ProtocolConformanceKind::Normal:
    if (substType->isSpecialized()) {
      assert(getType()->isSpecialized()
             && "substitution mapped non-specialized to specialized?!");
      assert(getType()->getNominalOrBoundGenericNominal()
               == substType->getNominalOrBoundGenericNominal()
             && "substitution mapped to different nominal?!");
      return module->getASTContext()
        .getSpecializedConformance(substType, this,
                           substType->gatherAllSubstitutions(module, nullptr));
    }
    assert(substType->isEqual(getType())
           && "substitution changed non-specialized type?!");
    return this;
      
  case ProtocolConformanceKind::Inherited: {
    // Substitute the base.
    auto inheritedConformance
      = cast<InheritedProtocolConformance>(this)->getInheritedConformance();
    ProtocolConformance *newBase;
    if (inheritedConformance->getType()->isSpecialized()) {
      newBase = inheritedConformance->subst(module, substType, subs, subMap,
                                            conformanceMap);
    } else {
      newBase = inheritedConformance;
    }

    return module->getASTContext()
      .getInheritedConformance(substType, newBase);
  }
  case ProtocolConformanceKind::Specialized: {
    // Substitute the substitutions in the specialized conformance.
    auto spec = cast<SpecializedProtocolConformance>(this);
    SmallVector<Substitution, 8> newSubs;
    newSubs.reserve(spec->getGenericSubstitutions().size());
    for (auto &sub : spec->getGenericSubstitutions())
      newSubs.push_back(sub.subst(module, subs, subMap, conformanceMap));
    
    auto ctxNewSubs = module->getASTContext().AllocateCopy(newSubs);
    
    return module->getASTContext()
      .getSpecializedConformance(substType, spec->getGenericConformance(),
                                 ctxNewSubs);
  }
  }
  llvm_unreachable("bad ProtocolConformanceKind");
}