C++ SmallVectorImpl::end方法代码示例

void ConformanceLookupTable::getAllConformances(
       NominalTypeDecl *nominal,
       LazyResolver *resolver,
       bool sorted,
       SmallVectorImpl<ProtocolConformance *> &scratch) {
  // We need to expand and resolve all conformances to enumerate them.
  updateLookupTable(nominal, ConformanceStage::Resolved, resolver);

  // Gather all of the protocols.
  for (const auto &conformance : AllConformances) {
    for (auto entry : conformance.second) {
      if (auto conformance = getConformance(nominal, resolver, entry))
        scratch.push_back(conformance);
    }
  }

  // If requested, sort the results.
  if (sorted) {
    llvm::array_pod_sort(scratch.begin(), scratch.end(),
                         &compareProtocolConformances);
  }
}

void Sema::EraseUnwantedCUDAMatches(
    const FunctionDecl *Caller,
    SmallVectorImpl<std::pair<DeclAccessPair, FunctionDecl *>> &Matches) {
  if (Matches.size() <= 1)
    return;

  using Pair = std::pair<DeclAccessPair, FunctionDecl*>;

  // Gets the CUDA function preference for a call from Caller to Match.
  auto GetCFP = [&](const Pair &Match) {
    return IdentifyCUDAPreference(Caller, Match.second);
  };

  // Find the best call preference among the functions in Matches.
  CUDAFunctionPreference BestCFP = GetCFP(*std::max_element(
      Matches.begin(), Matches.end(),
      [&](const Pair &M1, const Pair &M2) { return GetCFP(M1) < GetCFP(M2); }));

  // Erase all functions with lower priority.
  llvm::erase_if(Matches,
                 [&](const Pair &Match) { return GetCFP(Match) < BestCFP; });
}

void AArch64CallLowering::splitToValueTypes(
    const ArgInfo &OrigArg, SmallVectorImpl<ArgInfo> &SplitArgs,
    const DataLayout &DL, MachineRegisterInfo &MRI,
    const SplitArgTy &PerformArgSplit) const {
  const AArch64TargetLowering &TLI = *getTLI<AArch64TargetLowering>();
  LLVMContext &Ctx = OrigArg.Ty->getContext();

  SmallVector<EVT, 4> SplitVTs;
  SmallVector<uint64_t, 4> Offsets;
  ComputeValueVTs(TLI, DL, OrigArg.Ty, SplitVTs, &Offsets, 0);

  if (SplitVTs.size() == 1) {
    // No splitting to do, but we want to replace the original type (e.g. [1 x
    // double] -> double).
    SplitArgs.emplace_back(OrigArg.Reg, SplitVTs[0].getTypeForEVT(Ctx),
                           OrigArg.Flags, OrigArg.IsFixed);
    return;
  }

  unsigned FirstRegIdx = SplitArgs.size();
  for (auto SplitVT : SplitVTs) {
    // FIXME: set split flags if they're actually used (e.g. i128 on AAPCS).
    Type *SplitTy = SplitVT.getTypeForEVT(Ctx);
    SplitArgs.push_back(
        ArgInfo{MRI.createGenericVirtualRegister(LLT{*SplitTy, DL}), SplitTy,
                OrigArg.Flags, OrigArg.IsFixed});
  }

  SmallVector<uint64_t, 4> BitOffsets;
  for (auto Offset : Offsets)
    BitOffsets.push_back(Offset * 8);

  SmallVector<unsigned, 8> SplitRegs;
  for (auto I = &SplitArgs[FirstRegIdx]; I != SplitArgs.end(); ++I)
    SplitRegs.push_back(I->Reg);

  PerformArgSplit(SplitRegs, BitOffsets);
}

void Instruction::getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned,
                                       MDNode*> > &Result) const {
  Result.clear();
  
  // Handle 'dbg' as a special case since it is not stored in the hash table.
  if (!DbgLoc.isUnknown()) {
    Result.push_back(std::make_pair((unsigned)LLVMContext::MD_dbg,
                                    DbgLoc.getAsMDNode(getContext())));
    if (!hasMetadataHashEntry()) return;
  }
  
  assert(hasMetadataHashEntry() &&
         getContext().pImpl->MetadataStore.count(this) &&
         "Shouldn't have called this");
  const LLVMContextImpl::MDMapTy &Info =
    getContext().pImpl->MetadataStore.find(this)->second;
  assert(!Info.empty() && "Shouldn't have called this");

  Result.append(Info.begin(), Info.end());

  // Sort the resulting array so it is stable.
  if (Result.size() > 1)
    array_pod_sort(Result.begin(), Result.end());
}

// OutputPossibleOverflows - We've found a possible overflow earlier,
// now check whether Body might contain a comparison which might be
// preventing the overflow.
// This doesn't do flow analysis, range analysis, or points-to analysis; it's
// just a dumb "is there a comparison" scan.  The aim here is to
// detect the most blatent cases of overflow and educate the
// programmer.
void MallocOverflowSecurityChecker::OutputPossibleOverflows(
  SmallVectorImpl<MallocOverflowCheck> &PossibleMallocOverflows,
  const Decl *D, BugReporter &BR, AnalysisManager &mgr) const {
  // By far the most common case: nothing to check.
  if (PossibleMallocOverflows.empty())
    return;

  // Delete any possible overflows which have a comparison.
  CheckOverflowOps c(PossibleMallocOverflows, BR.getContext());
  c.Visit(mgr.getAnalysisDeclContext(D)->getBody());

  // Output warnings for all overflows that are left.
  for (CheckOverflowOps::theVecType::iterator
       i = PossibleMallocOverflows.begin(),
       e = PossibleMallocOverflows.end();
       i != e;
       ++i) {
    SourceRange R = i->mulop->getSourceRange();
    BR.EmitBasicReport(D, "malloc() size overflow", categories::UnixAPI,
      "the computation of the size of the memory allocation may overflow",
      PathDiagnosticLocation::createOperatorLoc(i->mulop,
                                                BR.getSourceManager()), &R, 1);
  }
}

/// ComputeActionsTable - Compute the actions table and gather the first action
/// index for each landing pad site.
unsigned DwarfException::
ComputeActionsTable(const SmallVectorImpl<const LandingPadInfo*> &LandingPads,
                    SmallVectorImpl<ActionEntry> &Actions,
                    SmallVectorImpl<unsigned> &FirstActions) {

  // The action table follows the call-site table in the LSDA. The individual
  // records are of two types:
  //
  //   * Catch clause
  //   * Exception specification
  //
  // The two record kinds have the same format, with only small differences.
  // They are distinguished by the "switch value" field: Catch clauses
  // (TypeInfos) have strictly positive switch values, and exception
  // specifications (FilterIds) have strictly negative switch values. Value 0
  // indicates a catch-all clause.
  //
  // Negative type IDs index into FilterIds. Positive type IDs index into
  // TypeInfos.  The value written for a positive type ID is just the type ID
  // itself.  For a negative type ID, however, the value written is the
  // (negative) byte offset of the corresponding FilterIds entry.  The byte
  // offset is usually equal to the type ID (because the FilterIds entries are
  // written using a variable width encoding, which outputs one byte per entry
  // as long as the value written is not too large) but can differ.  This kind
  // of complication does not occur for positive type IDs because type infos are
  // output using a fixed width encoding.  FilterOffsets[i] holds the byte
  // offset corresponding to FilterIds[i].

  const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
  SmallVector<int, 16> FilterOffsets;
  FilterOffsets.reserve(FilterIds.size());
  int Offset = -1;

  for (std::vector<unsigned>::const_iterator
         I = FilterIds.begin(), E = FilterIds.end(); I != E; ++I) {
    FilterOffsets.push_back(Offset);
    Offset -= MCAsmInfo::getULEB128Size(*I);
  }

  FirstActions.reserve(LandingPads.size());

  int FirstAction = 0;
  unsigned SizeActions = 0;
  const LandingPadInfo *PrevLPI = 0;

  for (SmallVectorImpl<const LandingPadInfo *>::const_iterator
         I = LandingPads.begin(), E = LandingPads.end(); I != E; ++I) {
    const LandingPadInfo *LPI = *I;
    const std::vector<int> &TypeIds = LPI->TypeIds;
    unsigned NumShared = PrevLPI ? SharedTypeIds(LPI, PrevLPI) : 0;
    unsigned SizeSiteActions = 0;

    if (NumShared < TypeIds.size()) {
      unsigned SizeAction = 0;
      unsigned PrevAction = (unsigned)-1;

      if (NumShared) {
        unsigned SizePrevIds = PrevLPI->TypeIds.size();
        assert(Actions.size());
        PrevAction = Actions.size() - 1;
        SizeAction =
          MCAsmInfo::getSLEB128Size(Actions[PrevAction].NextAction) +
          MCAsmInfo::getSLEB128Size(Actions[PrevAction].ValueForTypeID);

        for (unsigned j = NumShared; j != SizePrevIds; ++j) {
          assert(PrevAction != (unsigned)-1 && "PrevAction is invalid!");
          SizeAction -=
            MCAsmInfo::getSLEB128Size(Actions[PrevAction].ValueForTypeID);
          SizeAction += -Actions[PrevAction].NextAction;
          PrevAction = Actions[PrevAction].Previous;
        }
      }

      // Compute the actions.
      for (unsigned J = NumShared, M = TypeIds.size(); J != M; ++J) {
        int TypeID = TypeIds[J];
        assert(-1 - TypeID < (int)FilterOffsets.size() && "Unknown filter id!");
        int ValueForTypeID = TypeID < 0 ? FilterOffsets[-1 - TypeID] : TypeID;
        unsigned SizeTypeID = MCAsmInfo::getSLEB128Size(ValueForTypeID);

        int NextAction = SizeAction ? -(SizeAction + SizeTypeID) : 0;
        SizeAction = SizeTypeID + MCAsmInfo::getSLEB128Size(NextAction);
        SizeSiteActions += SizeAction;

        ActionEntry Action = { ValueForTypeID, NextAction, PrevAction };
        Actions.push_back(Action);
        PrevAction = Actions.size() - 1;
      }

      // Record the first action of the landing pad site.
      FirstAction = SizeActions + SizeSiteActions - SizeAction + 1;
    } // else identical - re-use previous FirstAction

    // Information used when created the call-site table. The action record
    // field of the call site record is the offset of the first associated
    // action record, relative to the start of the actions table. This value is
    // biased by 1 (1 indicating the start of the actions table), and 0
    // indicates that there are no actions.
//.........这里部分代码省略.........

static void populateExternalRelations(
    SmallVectorImpl<ExternalRelation> &ExtRelations, const Function &Fn,
    const SmallVectorImpl<Value *> &RetVals, const ReachabilitySet &ReachSet) {
  // If a function only returns one of its argument X, then X will be both an
  // argument and a return value at the same time. This is an edge case that
  // needs special handling here.
  for (const auto &Arg : Fn.args()) {
    if (is_contained(RetVals, &Arg)) {
      auto ArgVal = InterfaceValue{Arg.getArgNo() + 1, 0};
      auto RetVal = InterfaceValue{0, 0};
      ExtRelations.push_back(ExternalRelation{ArgVal, RetVal, 0});
    }
  }

  // Below is the core summary construction logic.
  // A naive solution of adding only the value aliases that are parameters or
  // return values in ReachSet to the summary won't work: It is possible that a
  // parameter P is written into an intermediate value I, and the function
  // subsequently returns *I. In that case, *I is does not value alias anything
  // in ReachSet, and the naive solution will miss a summary edge from (P, 1) to
  // (I, 1).
  // To account for the aforementioned case, we need to check each non-parameter
  // and non-return value for the possibility of acting as an intermediate.
  // 'ValueMap' here records, for each value, which InterfaceValues read from or
  // write into it. If both the read list and the write list of a given value
  // are non-empty, we know that a particular value is an intermidate and we
  // need to add summary edges from the writes to the reads.
  DenseMap<Value *, ValueSummary> ValueMap;
  for (const auto &OuterMapping : ReachSet.value_mappings()) {
    if (auto Dst = getInterfaceValue(OuterMapping.first, RetVals)) {
      for (const auto &InnerMapping : OuterMapping.second) {
        // If Src is a param/return value, we get a same-level assignment.
        if (auto Src = getInterfaceValue(InnerMapping.first, RetVals)) {
          // This may happen if both Dst and Src are return values
          if (*Dst == *Src)
            continue;

          if (hasReadOnlyState(InnerMapping.second))
            ExtRelations.push_back(ExternalRelation{*Dst, *Src, UnknownOffset});
          // No need to check for WriteOnly state, since ReachSet is symmetric
        } else {
          // If Src is not a param/return, add it to ValueMap
          auto SrcIVal = InnerMapping.first;
          if (hasReadOnlyState(InnerMapping.second))
            ValueMap[SrcIVal.Val].FromRecords.push_back(
                ValueSummary::Record{*Dst, SrcIVal.DerefLevel});
          if (hasWriteOnlyState(InnerMapping.second))
            ValueMap[SrcIVal.Val].ToRecords.push_back(
                ValueSummary::Record{*Dst, SrcIVal.DerefLevel});
        }
      }
    }
  }

  for (const auto &Mapping : ValueMap) {
    for (const auto &FromRecord : Mapping.second.FromRecords) {
      for (const auto &ToRecord : Mapping.second.ToRecords) {
        auto ToLevel = ToRecord.DerefLevel;
        auto FromLevel = FromRecord.DerefLevel;
        // Same-level assignments should have already been processed by now
        if (ToLevel == FromLevel)
          continue;

        auto SrcIndex = FromRecord.IValue.Index;
        auto SrcLevel = FromRecord.IValue.DerefLevel;
        auto DstIndex = ToRecord.IValue.Index;
        auto DstLevel = ToRecord.IValue.DerefLevel;
        if (ToLevel > FromLevel)
          SrcLevel += ToLevel - FromLevel;
        else
          DstLevel += FromLevel - ToLevel;

        ExtRelations.push_back(ExternalRelation{
            InterfaceValue{SrcIndex, SrcLevel},
            InterfaceValue{DstIndex, DstLevel}, UnknownOffset});
      }
    }
  }

  // Remove duplicates in ExtRelations
  llvm::sort(ExtRelations.begin(), ExtRelations.end());
  ExtRelations.erase(std::unique(ExtRelations.begin(), ExtRelations.end()),
                     ExtRelations.end());
}

bool GlobalMerge::doMerge(SmallVectorImpl<GlobalVariable*> &Globals,
                          Module &M, bool isConst, unsigned AddrSpace) const {
  // FIXME: Find better heuristics
  std::stable_sort(Globals.begin(), Globals.end(),
                   [this](const GlobalVariable *GV1, const GlobalVariable *GV2) {
    Type *Ty1 = cast<PointerType>(GV1->getType())->getElementType();
    Type *Ty2 = cast<PointerType>(GV2->getType())->getElementType();

    return (DL->getTypeAllocSize(Ty1) < DL->getTypeAllocSize(Ty2));
  });

  Type *Int32Ty = Type::getInt32Ty(M.getContext());

  assert(Globals.size() > 1);

  // FIXME: This simple solution merges globals all together as maximum as
  // possible. However, with this solution it would be hard to remove dead
  // global symbols at link-time. An alternative solution could be checking
  // global symbols references function by function, and make the symbols
  // being referred in the same function merged and we would probably need
  // to introduce heuristic algorithm to solve the merge conflict from
  // different functions.
  for (size_t i = 0, e = Globals.size(); i != e; ) {
    size_t j = 0;
    uint64_t MergedSize = 0;
    std::vector<Type*> Tys;
    std::vector<Constant*> Inits;

    bool HasExternal = false;
    GlobalVariable *TheFirstExternal = 0;
    for (j = i; j != e; ++j) {
      Type *Ty = Globals[j]->getType()->getElementType();
      MergedSize += DL->getTypeAllocSize(Ty);
      if (MergedSize > MaxOffset) {
        break;
      }
      Tys.push_back(Ty);
      Inits.push_back(Globals[j]->getInitializer());

      if (Globals[j]->hasExternalLinkage() && !HasExternal) {
        HasExternal = true;
        TheFirstExternal = Globals[j];
      }
    }

    // If merged variables doesn't have external linkage, we needn't to expose
    // the symbol after merging.
    GlobalValue::LinkageTypes Linkage = HasExternal
                                            ? GlobalValue::ExternalLinkage
                                            : GlobalValue::InternalLinkage;

    StructType *MergedTy = StructType::get(M.getContext(), Tys);
    Constant *MergedInit = ConstantStruct::get(MergedTy, Inits);

    // If merged variables have external linkage, we use symbol name of the
    // first variable merged as the suffix of global symbol name. This would
    // be able to avoid the link-time naming conflict for globalm symbols.
    GlobalVariable *MergedGV = new GlobalVariable(
        M, MergedTy, isConst, Linkage, MergedInit,
        HasExternal ? "_MergedGlobals_" + TheFirstExternal->getName()
                    : "_MergedGlobals",
        nullptr, GlobalVariable::NotThreadLocal, AddrSpace);

    for (size_t k = i; k < j; ++k) {
      GlobalValue::LinkageTypes Linkage = Globals[k]->getLinkage();
      std::string Name = Globals[k]->getName();

      Constant *Idx[2] = {
        ConstantInt::get(Int32Ty, 0),
        ConstantInt::get(Int32Ty, k-i)
      };
      Constant *GEP = ConstantExpr::getInBoundsGetElementPtr(MergedGV, Idx);
      Globals[k]->replaceAllUsesWith(GEP);
      Globals[k]->eraseFromParent();

      if (Linkage != GlobalValue::InternalLinkage) {
        // Generate a new alias...
        auto *PTy = cast<PointerType>(GEP->getType());
        GlobalAlias::create(PTy->getElementType(), PTy->getAddressSpace(),
                            Linkage, Name, GEP, &M);
      }

      NumMerged++;
    }
    i = j;
  }

  return true;
}

bool
LoadAndStorePromoter::isInstInList(Instruction *I,
                                   const SmallVectorImpl<Instruction*> &Insts)
                                   const {
  return std::find(Insts.begin(), Insts.end(), I) != Insts.end();
}

/// Return true if the specified block is in the list.
static bool isExitBlock(BasicBlock *BB,
                        const SmallVectorImpl<BasicBlock *> &ExitBlocks) {
  return find(ExitBlocks, BB) != ExitBlocks.end();
}

static void lookupInModule(Module *module, Module::AccessPathTy accessPath,
                           SmallVectorImpl<ValueDecl *> &decls,
                           ResolutionKind resolutionKind, bool canReturnEarly,
                           LazyResolver *typeResolver,
                           ModuleLookupCache &cache,
                           const DeclContext *moduleScopeContext,
                           bool respectAccessControl,
                           ArrayRef<Module::ImportedModule> extraImports,
                           CallbackTy callback) {
  assert(module);
  assert(std::none_of(extraImports.begin(), extraImports.end(),
                      [](Module::ImportedModule import) -> bool {
    return !import.second;
  }));

  ModuleLookupCache::iterator iter;
  bool isNew;
  std::tie(iter, isNew) = cache.insert({{accessPath, module}, {}});
  if (!isNew) {
    decls.append(iter->second.begin(), iter->second.end());
    return;
  }

  size_t initialCount = decls.size();

  SmallVector<ValueDecl *, 4> localDecls;
  callback(module, accessPath, localDecls);
  if (respectAccessControl) {
    auto newEndIter = std::remove_if(localDecls.begin(), localDecls.end(),
                                    [=](ValueDecl *VD) {
      if (typeResolver) {
        typeResolver->resolveAccessibility(VD);
      }
      if (!VD->hasAccessibility())
        return false;
      return !VD->isAccessibleFrom(moduleScopeContext);
    });
    localDecls.erase(newEndIter, localDecls.end());

    // This only applies to immediate imports of the top-level module.
    if (moduleScopeContext && moduleScopeContext->getParentModule() != module)
      moduleScopeContext = nullptr;
  }

  OverloadSetTy overloads;
  resolutionKind = recordImportDecls(typeResolver, decls, localDecls,
                                     overloads, resolutionKind);

  bool foundDecls = decls.size() > initialCount;
  if (!foundDecls || !canReturnEarly ||
      resolutionKind == ResolutionKind::Overloadable) {
    SmallVector<Module::ImportedModule, 8> reexports;
    module->getImportedModulesForLookup(reexports);
    assert(std::none_of(reexports.begin(), reexports.end(),
                        [](Module::ImportedModule import) -> bool {
      return !import.second;
    }));
    reexports.append(extraImports.begin(), extraImports.end());

    // Prefer scoped imports (import func Swift.max) to whole-module imports.
    SmallVector<ValueDecl *, 8> unscopedValues;
    SmallVector<ValueDecl *, 8> scopedValues;
    for (auto next : reexports) {
      // Filter any whole-module imports, and skip specific-decl imports if the
      // import path doesn't match exactly.
      Module::AccessPathTy combinedAccessPath;
      if (accessPath.empty()) {
        combinedAccessPath = next.first;
      } else if (!next.first.empty() &&
                 !Module::isSameAccessPath(next.first, accessPath)) {
        // If we ever allow importing non-top-level decls, it's possible the
        // rule above isn't what we want.
        assert(next.first.size() == 1 && "import of non-top-level decl");
        continue;
      } else {
        combinedAccessPath = accessPath;
      }

      auto &resultSet = next.first.empty() ? unscopedValues : scopedValues;
      lookupInModule<OverloadSetTy>(next.second, combinedAccessPath,
                                    resultSet, resolutionKind, canReturnEarly,
                                    typeResolver, cache, moduleScopeContext,
                                    respectAccessControl, {}, callback);
    }

    // Add the results from scoped imports.
    resolutionKind = recordImportDecls(typeResolver, decls, scopedValues,
                                       overloads, resolutionKind);

    // Add the results from unscoped imports.
    foundDecls = decls.size() > initialCount;
    if (!foundDecls || !canReturnEarly ||
        resolutionKind == ResolutionKind::Overloadable) {
      resolutionKind = recordImportDecls(typeResolver, decls, unscopedValues,
                                         overloads, resolutionKind);
    }
  }

  // Remove duplicated declarations.
  llvm::SmallPtrSet<ValueDecl *, 4> knownDecls;
//.........这里部分代码省略.........

static void createVectorVariantWrapper(llvm::Function *ScalarFunc,
                                       llvm::Function *VectorFunc,
                                       unsigned VLen,
                                       const SmallVectorImpl<ParamInfo> &Info) {
  assert(ScalarFunc->arg_size() == Info.size() &&
         "Wrong number of parameter infos");
  assert((VLen & (VLen - 1)) == 0 && "VLen must be a power-of-2");

  bool IsMasked = VectorFunc->arg_size() == ScalarFunc->arg_size() + 1;
  llvm::LLVMContext &Context = ScalarFunc->getContext();
  llvm::BasicBlock *Entry
    = llvm::BasicBlock::Create(Context, "entry", VectorFunc);
  llvm::BasicBlock *LoopCond
    = llvm::BasicBlock::Create(Context, "loop.cond", VectorFunc);
  llvm::BasicBlock *LoopBody
    = llvm::BasicBlock::Create(Context, "loop.body", VectorFunc);
  llvm::BasicBlock *MaskOn
    = IsMasked ? llvm::BasicBlock::Create(Context, "mask_on", VectorFunc) : 0;
  llvm::BasicBlock *MaskOff
    = IsMasked ? llvm::BasicBlock::Create(Context, "mask_off", VectorFunc) : 0;
  llvm::BasicBlock *LoopStep
    = llvm::BasicBlock::Create(Context, "loop.step", VectorFunc);
  llvm::BasicBlock *LoopEnd
    = llvm::BasicBlock::Create(Context, "loop.end", VectorFunc);

  llvm::Value *VectorRet = 0;
  SmallVector<llvm::Value*, 4> VectorArgs;

  // The loop counter.
  llvm::Type *IndexTy = llvm::Type::getInt32Ty(Context);
  llvm::Value *Index = 0;
  llvm::Value *Mask = 0;

  // Copy the names from the scalar args to the vector args.
  {
    llvm::Function::arg_iterator SI = ScalarFunc->arg_begin(),
                                 SE = ScalarFunc->arg_end(),
                                 VI = VectorFunc->arg_begin();
    for ( ; SI != SE; ++SI, ++VI)
      VI->setName(SI->getName());
    if (IsMasked)
      VI->setName("mask");
  }

  llvm::IRBuilder<> Builder(Entry);
  {
    if (!VectorFunc->getReturnType()->isVoidTy())
      VectorRet = Builder.CreateAlloca(VectorFunc->getReturnType());

    Index = Builder.CreateAlloca(IndexTy, 0, "index");
    Builder.CreateStore(llvm::ConstantInt::get(IndexTy, 0), Index);

    llvm::Function::arg_iterator VI = VectorFunc->arg_begin();
    for (SmallVectorImpl<ParamInfo>::const_iterator I = Info.begin(),
         IE = Info.end(); I != IE; ++I, ++VI) {
      llvm::Value *Arg = VI;
      switch (I->Kind) {
      case PK_Vector:
        assert(Arg->getType()->isVectorTy() && "Not a vector");
        assert(VLen == Arg->getType()->getVectorNumElements() &&
               "Wrong number of elements");
        break;
      case PK_LinearConst:
        Arg = buildLinearArg(Builder, VLen, Arg,
          cast<llvm::ConstantAsMetadata>(I->Step)->getValue());
        Arg->setName(VI->getName() + ".linear");
        break;
      case PK_Linear: {
        unsigned Number =
          cast<llvm::ConstantInt>(
            cast<llvm::ConstantAsMetadata>(I->Step)->getValue())->getZExtValue();
        llvm::Function::arg_iterator ArgI = VectorFunc->arg_begin();
        std::advance(ArgI, Number);
        llvm::Value *Step = ArgI;
        Arg = buildLinearArg(Builder, VLen, Arg, Step);
        Arg->setName(VI->getName() + ".linear");
      } break;
      case PK_Uniform:
        Arg = Builder.CreateVectorSplat(VLen, Arg);
        Arg->setName(VI->getName() + ".uniform");
        break;
      }
      VectorArgs.push_back(Arg);
    }

    if (IsMasked)
      Mask = buildMask(Builder, VLen, VI);

    Builder.CreateBr(LoopCond);
  }

  Builder.SetInsertPoint(LoopCond);
  {
    llvm::Value *Cond = Builder.CreateICmpULT(
        Builder.CreateLoad(Index), llvm::ConstantInt::get(IndexTy, VLen));
    Builder.CreateCondBr(Cond, LoopBody, LoopEnd);
  }

  llvm::Value *VecIndex = 0;

//.........这里部分代码省略.........

//.........这里部分代码省略.........
        auto secondDecl = collidingDecls.second[secondIdx];
        auto secondModule = secondDecl->getModuleContext();

        // If one declaration is in a protocol or extension thereof and the
        // other is not, prefer the one that is not.
        if ((bool)firstDecl->getDeclContext()
              ->getAsProtocolOrProtocolExtensionContext()
              != (bool)secondDecl->getDeclContext()
                   ->getAsProtocolOrProtocolExtensionContext()) {
          if (firstDecl->getDeclContext()
                ->getAsProtocolOrProtocolExtensionContext()) {
            shadowed.insert(firstDecl);
            break;
          } else {
            shadowed.insert(secondDecl);
            continue;
          }
        }

        // If one declaration is available and the other is not, prefer the
        // available one.
        if (firstDecl->getAttrs().isUnavailable(ctx) !=
              secondDecl->getAttrs().isUnavailable(ctx)) {
         if (firstDecl->getAttrs().isUnavailable(ctx)) {
           shadowed.insert(firstDecl);
           break;
         } else {
           shadowed.insert(secondDecl);
           continue;
         }
        }

        // Don't apply module-shadowing rules to members of protocol types.
        if (isa<ProtocolDecl>(firstDecl->getDeclContext()) ||
            isa<ProtocolDecl>(secondDecl->getDeclContext()))
          continue;

        // Prefer declarations in the current module over those in another
        // module.
        // FIXME: This is a hack. We should query a (lazily-built, cached)
        // module graph to determine shadowing.
        if ((firstModule == curModule) == (secondModule == curModule))
          continue;

        // If the first module is the current module, the second declaration
        // is shadowed by the first.
        if (firstModule == curModule) {
          shadowed.insert(secondDecl);
          continue;
        }

        // Otherwise, the first declaration is shadowed by the second. There is
        // no point in continuing to compare the first declaration to others.
        shadowed.insert(firstDecl);
        break;
      }
    }
  }
  
  // Check for collisions among Objective-C initializers. When such collisions
  // exist, we pick the
  for (const auto &colliding : ObjCCollidingConstructors) {
    if (colliding.second.size() == 1)
      continue;

    // Find the "best" constructor with this signature.
    ConstructorDecl *bestCtor = colliding.second[0];
    for (auto ctor : colliding.second) {
      auto comparison = compareConstructors(ctor, bestCtor, ctx);
      if (comparison == ConstructorComparison::Better)
        bestCtor = ctor;
    }

    // Shadow any initializers that are worse.
    for (auto ctor : colliding.second) {
      auto comparison = compareConstructors(ctor, bestCtor, ctx);
      if (comparison == ConstructorComparison::Worse)
        shadowed.insert(ctor);
    }
  }

  // If none of the declarations were shadowed, we're done.
  if (shadowed.empty())
    return false;

  // Remove shadowed declarations from the list of declarations.
  bool anyRemoved = false;
  decls.erase(std::remove_if(decls.begin(), decls.end(),
                             [&](ValueDecl *vd) {
                               if (shadowed.count(vd) > 0) {
                                 anyRemoved = true;
                                 return true;
                               }

                               return false;
                             }),
              decls.end());

  return anyRemoved;
}

bool GlobalMerge::doInitialization(Module &M) {
  if (!EnableGlobalMerge)
    return false;

  auto &DL = M.getDataLayout();
  DenseMap<unsigned, SmallVector<GlobalVariable*, 16> > Globals, ConstGlobals,
                                                        BSSGlobals;
  bool Changed = false;
  setMustKeepGlobalVariables(M);

  // Grab all non-const globals.
  for (Module::global_iterator I = M.global_begin(),
         E = M.global_end(); I != E; ++I) {
    // Merge is safe for "normal" internal or external globals only
    if (I->isDeclaration() || I->isThreadLocal() || I->hasSection())
      continue;

    if (!(EnableGlobalMergeOnExternal && I->hasExternalLinkage()) &&
        !I->hasInternalLinkage())
      continue;

    PointerType *PT = dyn_cast<PointerType>(I->getType());
    assert(PT && "Global variable is not a pointer!");

    unsigned AddressSpace = PT->getAddressSpace();

    // Ignore fancy-aligned globals for now.
    unsigned Alignment = DL.getPreferredAlignment(I);
    Type *Ty = I->getType()->getElementType();
    if (Alignment > DL.getABITypeAlignment(Ty))
      continue;

    // Ignore all 'special' globals.
    if (I->getName().startswith("llvm.") ||
        I->getName().startswith(".llvm."))
      continue;

    // Ignore all "required" globals:
    if (isMustKeepGlobalVariable(I))
      continue;

    if (DL.getTypeAllocSize(Ty) < MaxOffset) {
      if (TargetLoweringObjectFile::getKindForGlobal(I, *TM).isBSSLocal())
        BSSGlobals[AddressSpace].push_back(I);
      else if (I->isConstant())
        ConstGlobals[AddressSpace].push_back(I);
      else
        Globals[AddressSpace].push_back(I);
    }
  }

  for (DenseMap<unsigned, SmallVector<GlobalVariable*, 16> >::iterator
       I = Globals.begin(), E = Globals.end(); I != E; ++I)
    if (I->second.size() > 1)
      Changed |= doMerge(I->second, M, false, I->first);

  for (DenseMap<unsigned, SmallVector<GlobalVariable*, 16> >::iterator
       I = BSSGlobals.begin(), E = BSSGlobals.end(); I != E; ++I)
    if (I->second.size() > 1)
      Changed |= doMerge(I->second, M, false, I->first);

  if (EnableGlobalMergeOnConst)
    for (DenseMap<unsigned, SmallVector<GlobalVariable*, 16> >::iterator
         I = ConstGlobals.begin(), E = ConstGlobals.end(); I != E; ++I)
      if (I->second.size() > 1)
        Changed |= doMerge(I->second, M, true, I->first);

  return Changed;
}

CheckPredicateMatcher::CheckPredicateMatcher(
    const TreePredicateFn &pred, const SmallVectorImpl<unsigned> &Ops)
  : Matcher(CheckPredicate), Pred(pred.getOrigPatFragRecord()),
    Operands(Ops.begin(), Ops.end()) {}