C++ IRGenFunction类代码示例

void
irgen::emitTypeLayoutVerifier(IRGenFunction &IGF,
                              ArrayRef<CanType> formalTypes) {
  llvm::Type *verifierArgTys[] = {
    IGF.IGM.TypeMetadataPtrTy,
    IGF.IGM.Int8PtrTy,
    IGF.IGM.Int8PtrTy,
    IGF.IGM.SizeTy,
    IGF.IGM.Int8PtrTy,
  };
  auto verifierFnTy = llvm::FunctionType::get(IGF.IGM.VoidTy,
                                              verifierArgTys,
                                              /*var arg*/ false);
  auto verifierFn = IGF.IGM.Module.getOrInsertFunction(
                                       "_swift_debug_verifyTypeLayoutAttribute",
                                       verifierFnTy);
  struct VerifierArgumentBuffers {
    Address runtimeBuf, staticBuf;
  };
  llvm::DenseMap<llvm::Type *, VerifierArgumentBuffers>
    verifierArgBufs;
  
  auto getSizeConstant = [&](Size sz) -> llvm::Constant * {
    return llvm::ConstantInt::get(IGF.IGM.SizeTy, sz.getValue());
  };
  auto getAlignmentMaskConstant = [&](Alignment a) -> llvm::Constant * {
    return llvm::ConstantInt::get(IGF.IGM.SizeTy, a.getValue() - 1);
  };
  auto getBoolConstant = [&](bool b) -> llvm::Constant * {
    return llvm::ConstantInt::get(IGF.IGM.Int1Ty, b);
  };

  SmallString<20> numberBuf;

  for (auto formalType : formalTypes) {
    // Runtime type metadata always represents the maximal abstraction level of
    // the type.
    auto anyTy = ProtocolCompositionType::get(IGF.IGM.Context, {});
    auto openedAnyTy = ArchetypeType::getOpened(anyTy);
    auto maxAbstraction = AbstractionPattern(openedAnyTy);
    auto &ti = IGF.getTypeInfoForUnlowered(maxAbstraction, formalType);
    
    // If there's no fixed type info, we rely on the runtime anyway, so there's
    // nothing to verify.
    // TODO: There are some traits of partially-fixed layouts we could check too.
    auto *fixedTI = dyn_cast<FixedTypeInfo>(&ti);
    if (!fixedTI)
      return;
    
    auto metadata = IGF.emitTypeMetadataRef(formalType);
    
    auto verify = [&](llvm::Value *runtimeVal,
                      llvm::Value *staticVal,
                      const llvm::Twine &description) {
      assert(runtimeVal->getType() == staticVal->getType());
      // Get or create buffers for the arguments.
      VerifierArgumentBuffers bufs;
      auto foundBufs = verifierArgBufs.find(runtimeVal->getType());
      if (foundBufs != verifierArgBufs.end()) {
        bufs = foundBufs->second;
      } else {
        Address runtimeBuf = IGF.createAlloca(runtimeVal->getType(),
                                              IGF.IGM.getPointerAlignment(),
                                              "runtime");
        Address staticBuf = IGF.createAlloca(staticVal->getType(),
                                             IGF.IGM.getPointerAlignment(),
                                             "static");
        bufs = {runtimeBuf, staticBuf};
        verifierArgBufs[runtimeVal->getType()] = bufs;
      }
      
      IGF.Builder.CreateStore(runtimeVal, bufs.runtimeBuf);
      IGF.Builder.CreateStore(staticVal, bufs.staticBuf);
      
      auto runtimePtr = IGF.Builder.CreateBitCast(bufs.runtimeBuf.getAddress(),
                                                  IGF.IGM.Int8PtrTy);
      auto staticPtr = IGF.Builder.CreateBitCast(bufs.staticBuf.getAddress(),
                                                 IGF.IGM.Int8PtrTy);
      auto count = llvm::ConstantInt::get(IGF.IGM.SizeTy,
                    IGF.IGM.DataLayout.getTypeStoreSize(runtimeVal->getType()));
      auto msg
        = IGF.IGM.getAddrOfGlobalString(description.str());
      
      IGF.Builder.CreateCall(
          verifierFn, {metadata, runtimePtr, staticPtr, count, msg});
    };

    // Check that the fixed layout matches the runtime layout.
    SILType layoutType = SILType::getPrimitiveObjectType(formalType);
    verify(emitLoadOfSize(IGF, layoutType),
           getSizeConstant(fixedTI->getFixedSize()),
           "size");
    verify(emitLoadOfAlignmentMask(IGF, layoutType),
           getAlignmentMaskConstant(fixedTI->getFixedAlignment()),
           "alignment mask");
    verify(emitLoadOfStride(IGF, layoutType),
           getSizeConstant(fixedTI->getFixedStride()),
           "stride");
    verify(emitLoadOfIsInline(IGF, layoutType),
           getBoolConstant(fixedTI->getFixedPacking(IGF.IGM)
//.........这里部分代码省略.........

void LocalTypeDataCache::
addAbstractForFulfillments(IRGenFunction &IGF, FulfillmentMap &&fulfillments,
                           llvm::function_ref<AbstractSource()> createSource) {
  // Add the source lazily.
  Optional<unsigned> sourceIndex;
  auto getSourceIndex = [&]() -> unsigned {
    if (!sourceIndex) {
      AbstractSources.emplace_back(createSource());
      sourceIndex = AbstractSources.size() - 1;
    }
    return *sourceIndex;
  };

  for (auto &fulfillment : fulfillments) {
    CanType type = CanType(fulfillment.first.first);
    LocalTypeDataKind localDataKind;

    // For now, ignore witness-table fulfillments when they're not for
    // archetypes.
    if (ProtocolDecl *protocol = fulfillment.first.second) {
      if (auto archetype = dyn_cast<ArchetypeType>(type)) {
        auto conformsTo = archetype->getConformsTo();
        auto it = std::find(conformsTo.begin(), conformsTo.end(), protocol);
        if (it == conformsTo.end()) continue;
        localDataKind = LocalTypeDataKind::forAbstractProtocolWitnessTable(*it);
      } else {
        continue;
      }

    } else {
      // Ignore type metadata fulfillments for non-dependent types that
      // we can produce very cheaply.  We don't want to end up emitting
      // the type metadata for Int by chasing through N layers of metadata
      // just because that path happens to be in the cache.
      if (!type->hasArchetype() &&
          getTypeMetadataAccessStrategy(IGF.IGM, type, /*preferDirect*/ true)
            == MetadataAccessStrategy::Direct) {
        continue;
      }

      localDataKind = LocalTypeDataKind::forTypeMetadata();
    }

    // Find the chain for the key.
    auto key = getKey(type, localDataKind);
    auto &chain = Map[key];

    // Check whether there's already an entry that's at least as good as the
    // fulfillment.
    Optional<unsigned> fulfillmentCost;
    auto getFulfillmentCost = [&]() -> unsigned {
      if (!fulfillmentCost)
        fulfillmentCost = fulfillment.second.Path.cost();
      return *fulfillmentCost;
    };

    bool isConditional = IGF.isConditionalDominancePoint();

    bool foundBetter = false;
    for (CacheEntry *cur = chain.Root, *last = nullptr; cur;
         last = cur, cur = cur->getNext()) {
      // Ensure the entry is acceptable.
      if (!IGF.isActiveDominancePointDominatedBy(cur->DefinitionPoint))
        continue;

      // Ensure that the entry isn't better than the fulfillment.
      auto curCost = cur->cost();
      if (curCost == 0 || curCost <= getFulfillmentCost()) {
        foundBetter = true;
        break;
      }

      // If the entry is defined at the current point, (1) we know there
      // won't be a better entry and (2) we should remove it.
      if (cur->DefinitionPoint == IGF.getActiveDominancePoint() &&
          !isConditional) {
        // Splice it out of the chain.
        assert(!cur->isConditional());
        chain.eraseEntry(last, cur);
        break;
      }
    }
    if (foundBetter) continue;

    // Okay, make a new entry.

    // Register with the conditional dominance scope if necessary.
    if (isConditional) {
      IGF.registerConditionalLocalTypeDataKey(key);
    }

    // Allocate the new entry.
    auto newEntry = new AbstractCacheEntry(IGF.getActiveDominancePoint(),
                                           isConditional,
                                           getSourceIndex(),
                                           std::move(fulfillment.second.Path));

    // Add it to the front of the chain.
    chain.push_front(newEntry);
  }
//.........这里部分代码省略.........

MetadataResponse
LocalTypeDataCache::tryGet(IRGenFunction &IGF, LocalTypeDataKey key,
                           bool allowAbstract, DynamicMetadataRequest request) {
  // Use the caching key.
  key = key.getCachingKey();

  auto it = Map.find(key);
  if (it == Map.end()) return MetadataResponse();
  auto &chain = it->second;

  CacheEntry *best = nullptr;
  Optional<OperationCost> bestCost;

  CacheEntry *next = chain.Root;
  while (next) {
    CacheEntry *cur = next;
    next = cur->getNext();

    // Ignore abstract entries if so requested.
    if (!allowAbstract && !isa<ConcreteCacheEntry>(cur))
      continue;

    // Ignore unacceptable entries.
    if (!IGF.isActiveDominancePointDominatedBy(cur->DefinitionPoint))
      continue;

    // If there's a collision, compare by cost, ignoring higher-cost entries.
    if (best) {
      // Compute the cost of the best entry if we haven't done so already.
      // If that's zero, go ahead and short-circuit out.
      if (!bestCost) {
        bestCost = best->costForRequest(key, request);
        if (*bestCost == OperationCost::Free) break;
      }

      auto curCost = cur->costForRequest(key, request);
      if (curCost >= *bestCost) continue;

      // Replace the best cost and fall through.
      bestCost = curCost;
    }
    best = cur;
  }

  // If we didn't find anything, we're done.
  if (!best) return MetadataResponse();

  // Okay, we've found the best entry available.
  switch (best->getKind()) {

  // For concrete caches, this is easy.
  case CacheEntry::Kind::Concrete: {
    auto entry = cast<ConcreteCacheEntry>(best);

    if (entry->immediatelySatisfies(key, request))
      return entry->Value;

    assert(key.Kind.isAnyTypeMetadata());

    // Emit a dynamic check that the type metadata matches the request.
    // TODO: we could potentially end up calling this redundantly with a
    //   dynamic request.  Fortunately, those are used only in very narrow
    //   circumstances.
    auto response = emitCheckTypeMetadataState(IGF, request, entry->Value);

    // Add a concrete entry for the checked result.
    IGF.setScopedLocalTypeData(key, response);

    return response;
  }

  // For abstract caches, we need to follow a path.
  case CacheEntry::Kind::Abstract: {
    auto entry = cast<AbstractCacheEntry>(best);

    // Follow the path.
    auto &source = AbstractSources[entry->SourceIndex];
    auto response = entry->follow(IGF, source, request);

    // Following the path automatically caches at every point along it,
    // including the end.
    assert(chain.Root->DefinitionPoint == IGF.getActiveDominancePoint());
    assert(isa<ConcreteCacheEntry>(chain.Root));

    return response;
  }

  }
  llvm_unreachable("bad cache entry kind");
}

/// Emit a checked cast to a protocol or protocol composition.
void irgen::emitScalarExistentialDowncast(IRGenFunction &IGF,
                                  llvm::Value *value,
                                  SILType srcType,
                                  SILType destType,
                                  CheckedCastMode mode,
                                  Optional<MetatypeRepresentation> metatypeKind,
                                  Explosion &ex) {
  SmallVector<ProtocolDecl*, 4> allProtos;
  destType.getSwiftRValueType().getAnyExistentialTypeProtocols(allProtos);

  // Look up witness tables for the protocols that need them and get
  // references to the ObjC Protocol* values for the objc protocols.
  SmallVector<llvm::Value*, 4> objcProtos;
  SmallVector<llvm::Value*, 4> witnessTableProtos;

  bool hasClassConstraint = false;
  bool hasClassConstraintByProtocol = false;

  for (auto proto : allProtos) {
    // If the protocol introduces a class constraint, track whether we need
    // to check for it independent of protocol witnesses.
    if (proto->requiresClass()) {
      hasClassConstraint = true;
      if (proto->getKnownProtocolKind()
          && *proto->getKnownProtocolKind() == KnownProtocolKind::AnyObject) {
        // AnyObject only requires that the type be a class.
        continue;
      }
      
      // If this protocol is class-constrained but not AnyObject, checking its
      // conformance will check the class constraint too.
      hasClassConstraintByProtocol = true;
    }

    if (Lowering::TypeConverter::protocolRequiresWitnessTable(proto)) {
      auto descriptor = emitProtocolDescriptorRef(IGF, proto);
      witnessTableProtos.push_back(descriptor);
    }

    if (!proto->isObjC())
      continue;

    objcProtos.push_back(emitReferenceToObjCProtocol(IGF, proto));
  }
  
  llvm::Type *resultType;
  if (metatypeKind) {
    switch (*metatypeKind) {
    case MetatypeRepresentation::Thin:
      llvm_unreachable("can't cast to thin metatype");
    case MetatypeRepresentation::Thick:
      resultType = IGF.IGM.TypeMetadataPtrTy;
      break;
    case MetatypeRepresentation::ObjC:
      resultType = IGF.IGM.ObjCClassPtrTy;
      break;
    }
  } else {
    auto schema = IGF.getTypeInfo(destType).getSchema();
    resultType = schema[0].getScalarType();
  }
  // We only need to check the class constraint for metatype casts where
  // no protocol conformance indirectly requires the constraint for us.
  bool checkClassConstraint =
    (bool)metatypeKind && hasClassConstraint && !hasClassConstraintByProtocol;

  llvm::Value *resultValue = value;

  // If we don't have anything we really need to check, then trivially succeed.
  if (objcProtos.empty() && witnessTableProtos.empty() &&
      !checkClassConstraint) {
    resultValue = IGF.Builder.CreateBitCast(value, resultType);
    ex.add(resultValue);
    return;
  }

  // Check the ObjC protocol conformances if there were any.
  llvm::Value *objcCast = nullptr;
  if (!objcProtos.empty()) {
    // Get the ObjC instance or class object to check for these conformances.
    llvm::Value *objcObject;
    if (metatypeKind) {
      switch (*metatypeKind) {
      case MetatypeRepresentation::Thin:
        llvm_unreachable("can't cast to thin metatype");
      case MetatypeRepresentation::Thick: {
        // The metadata might be for a non-class type, which wouldn't have
        // an ObjC class object.
        objcObject = nullptr;
        break;
      }
      case MetatypeRepresentation::ObjC:
        // Metatype is already an ObjC object.
        objcObject = value;
        break;
      }
    } else {
      // Class instance is already an ObjC object.
      objcObject = value;
//.........这里部分代码省略.........

static void emitSubSwitch(IRGenFunction &IGF,
                    MutableArrayRef<EnumPayload::LazyValue> values,
                    APInt mask,
                    MutableArrayRef<std::pair<APInt, llvm::BasicBlock *>> cases,
                    SwitchDefaultDest dflt) {
recur:
  assert(!values.empty() && "didn't exit out when exhausting all values?!");
  
  assert(!cases.empty() && "switching with no cases?!");
  
  auto &DL = IGF.IGM.DataLayout;
  auto &pv = values.front();
  values = values.slice(1);
  auto payloadTy = getPayloadType(pv);
  unsigned size = DL.getTypeSizeInBits(payloadTy);
  
  // Grab a chunk of the mask.
  auto maskPiece = mask.zextOrTrunc(size);
  mask = mask.lshr(size);
  
  // If the piece is zero, this doesn't affect the switch. We can just move
  // forward and recur.
  if (maskPiece == 0) {
    for (auto &casePair : cases)
      casePair.first = casePair.first.lshr(size);
    goto recur;
  }
  
  // Force the value we will test.
  auto v = forcePayloadValue(pv);
  auto payloadIntTy = llvm::IntegerType::get(IGF.IGM.getLLVMContext(), size);
  
  // Need to coerce to integer for 'icmp eq' if it's not already an integer
  // or pointer. (Switching or masking will also require a cast to integer.)
  if (!isa<llvm::IntegerType>(v->getType())
      && !isa<llvm::PointerType>(v->getType()))
    v = IGF.Builder.CreateBitOrPointerCast(v, payloadIntTy);
  
  // Apply the mask if it's interesting.
  if (!maskPiece.isAllOnesValue()) {
    v = IGF.Builder.CreateBitOrPointerCast(v, payloadIntTy);
    auto maskConstant = llvm::ConstantInt::get(payloadIntTy, maskPiece);
    v = IGF.Builder.CreateAnd(v, maskConstant);
  }
  
  // Gather the values we will switch over for this payload chunk.
  // FIXME: std::map is lame. Should hash APInts.
  std::map<APInt, SmallVector<std::pair<APInt, llvm::BasicBlock*>, 2>, ult>
    subCases;
  
  for (auto casePair : cases) {
    // Grab a chunk of the value.
    auto valuePiece = casePair.first.zextOrTrunc(size);
    // Index the case according to this chunk.
    subCases[valuePiece].push_back({std::move(casePair.first).lshr(size),
                                    casePair.second});
  }
  
  bool needsAdditionalCases = !values.empty() && mask != 0;
  SmallVector<std::pair<llvm::BasicBlock *, decltype(cases)>, 2> recursiveCases;
  
  auto blockForCases
    = [&](MutableArrayRef<std::pair<APInt, llvm::BasicBlock*>> cases)
        -> llvm::BasicBlock *
    {
      // If we need to recur, emit a new block.
      if (needsAdditionalCases) {
        auto newBB = IGF.createBasicBlock("");
        recursiveCases.push_back({newBB, cases});
        return newBB;
      }
      // Otherwise, we can jump directly to the ultimate destination.
      assert(cases.size() == 1 && "more than one case for final destination?!");
      return cases.front().second;
    };
  
  // If there's only one case, do a cond_br.
  if (subCases.size() == 1) {
    auto &subCase = *subCases.begin();
    llvm::BasicBlock *block = blockForCases(subCase.second);
    // If the default case is unreachable, we don't need to conditionally
    // branch.
    if (dflt.getInt()) {
      IGF.Builder.CreateBr(block);
      goto next;
    }
  
    auto &valuePiece = subCase.first;
    llvm::Value *valueConstant = llvm::ConstantInt::get(payloadIntTy,
                                                        valuePiece);
    valueConstant = IGF.Builder.CreateBitOrPointerCast(valueConstant,
                                                       v->getType());
    auto cmp = IGF.Builder.CreateICmpEQ(v, valueConstant);
    IGF.Builder.CreateCondBr(cmp, block, dflt.getPointer());
    goto next;
  }
  
  // Otherwise, do a switch.
  {
    v = IGF.Builder.CreateBitOrPointerCast(v, payloadIntTy);
//.........这里部分代码省略.........

/// Emit a checked cast to a protocol or protocol composition.
void irgen::emitScalarExistentialDowncast(IRGenFunction &IGF,
                                  llvm::Value *value,
                                  SILType srcType,
                                  SILType destType,
                                  CheckedCastMode mode,
                                  Optional<MetatypeRepresentation> metatypeKind,
                                  Explosion &ex) {
  auto srcInstanceType = srcType.getSwiftRValueType();
  auto destInstanceType = destType.getSwiftRValueType();
  while (auto metatypeType = dyn_cast<ExistentialMetatypeType>(
           destInstanceType)) {
    destInstanceType = metatypeType.getInstanceType();
    srcInstanceType = cast<AnyMetatypeType>(srcInstanceType).getInstanceType();
  }

  auto layout = destInstanceType.getExistentialLayout();

  // Look up witness tables for the protocols that need them and get
  // references to the ObjC Protocol* values for the objc protocols.
  SmallVector<llvm::Value*, 4> objcProtos;
  SmallVector<llvm::Value*, 4> witnessTableProtos;

  bool hasClassConstraint = layout.requiresClass();
  bool hasClassConstraintByProtocol = false;

  bool hasSuperclassConstraint = bool(layout.superclass);

  for (auto protoTy : layout.getProtocols()) {
    auto *protoDecl = protoTy->getDecl();

    // If the protocol introduces a class constraint, track whether we need
    // to check for it independent of protocol witnesses.
    if (protoDecl->requiresClass()) {
      assert(hasClassConstraint);
      hasClassConstraintByProtocol = true;
    }

    if (Lowering::TypeConverter::protocolRequiresWitnessTable(protoDecl)) {
      auto descriptor = emitProtocolDescriptorRef(IGF, protoDecl);
      witnessTableProtos.push_back(descriptor);
    }

    if (protoDecl->isObjC())
      objcProtos.push_back(emitReferenceToObjCProtocol(IGF, protoDecl));
  }
  
  llvm::Type *resultType;
  if (metatypeKind) {
    switch (*metatypeKind) {
    case MetatypeRepresentation::Thin:
      llvm_unreachable("can't cast to thin metatype");
    case MetatypeRepresentation::Thick:
      resultType = IGF.IGM.TypeMetadataPtrTy;
      break;
    case MetatypeRepresentation::ObjC:
      resultType = IGF.IGM.ObjCClassPtrTy;
      break;
    }
  } else {
    auto schema = IGF.getTypeInfo(destType).getSchema();
    resultType = schema[0].getScalarType();
  }

  // The source of a scalar cast is statically known to be a class or a
  // metatype, so we only have to check the class constraint in two cases:
  //
  // 1) The destination type has an explicit superclass constraint that is
  //    more derived than what the source type is known to be.
  //
  // 2) We are casting between metatypes, in which case the source might
  //    be a non-class metatype.
  bool checkClassConstraint = false;
  if ((bool)metatypeKind &&
      hasClassConstraint &&
      !hasClassConstraintByProtocol &&
      !srcInstanceType->mayHaveSuperclass())
    checkClassConstraint = true;

  // If the source has an equal or more derived superclass constraint than
  // the destination, we can elide the superclass check.
  //
  // Note that destInstanceType is always an existential type, so calling
  // getSuperclass() returns the superclass constraint of the existential,
  // not the superclass of some concrete class.
  bool checkSuperclassConstraint =
    hasSuperclassConstraint &&
    !destInstanceType->getSuperclass()->isExactSuperclassOf(srcInstanceType);

  if (checkSuperclassConstraint)
    checkClassConstraint = true;

  llvm::Value *resultValue = value;

  // If we don't have anything we really need to check, then trivially succeed.
  if (objcProtos.empty() && witnessTableProtos.empty() &&
      !checkClassConstraint) {
    resultValue = IGF.Builder.CreateBitCast(value, resultType);
    ex.add(resultValue);
    return;
//.........这里部分代码省略.........

/// emitBuiltinCall - Emit a call to a builtin function.
void irgen::emitBuiltinCall(IRGenFunction &IGF, Identifier FnId,
                            SILType resultType,
                            Explosion &args, Explosion &out,
                            SubstitutionList substitutions) {
  // Decompose the function's name into a builtin name and type list.
  const BuiltinInfo &Builtin = IGF.getSILModule().getBuiltinInfo(FnId);

  if (Builtin.ID == BuiltinValueKind::UnsafeGuaranteedEnd) {
    // Just consume the incoming argument.
    assert(args.size() == 1 && "Expecting one incoming argument");
    (void)args.claimAll();
    return;
  }

  if (Builtin.ID == BuiltinValueKind::UnsafeGuaranteed) {
    // Just forward the incoming argument.
    assert(args.size() == 1 && "Expecting one incoming argument");
    out = std::move(args);
    // This is a token.
    out.add(llvm::ConstantInt::get(IGF.IGM.Int8Ty, 0));
    return;
  }

  if (Builtin.ID == BuiltinValueKind::OnFastPath) {
    // The onFastPath builtin has only an effect on SIL level, so we lower it
    // to a no-op.
    return;
  }

  // These builtins don't care about their argument:
  if (Builtin.ID == BuiltinValueKind::Sizeof) {
    (void)args.claimAll();
    auto valueTy = getLoweredTypeAndTypeInfo(IGF.IGM,
                                             substitutions[0].getReplacement());
    out.add(valueTy.second.getSize(IGF, valueTy.first));
    return;
  }

  if (Builtin.ID == BuiltinValueKind::Strideof) {
    (void)args.claimAll();
    auto valueTy = getLoweredTypeAndTypeInfo(IGF.IGM,
                                             substitutions[0].getReplacement());
    out.add(valueTy.second.getStride(IGF, valueTy.first));
    return;
  }

  if (Builtin.ID == BuiltinValueKind::Alignof) {
    (void)args.claimAll();
    auto valueTy = getLoweredTypeAndTypeInfo(IGF.IGM,
                                             substitutions[0].getReplacement());
    // The alignof value is one greater than the alignment mask.
    out.add(IGF.Builder.CreateAdd(
                           valueTy.second.getAlignmentMask(IGF, valueTy.first),
                           IGF.IGM.getSize(Size(1))));
    return;
  }

  if (Builtin.ID == BuiltinValueKind::IsPOD) {
    (void)args.claimAll();
    auto valueTy = getLoweredTypeAndTypeInfo(IGF.IGM,
                                             substitutions[0].getReplacement());
    out.add(valueTy.second.getIsPOD(IGF, valueTy.first));
    return;
  }


  // addressof expects an lvalue argument.
  if (Builtin.ID == BuiltinValueKind::AddressOf) {
    llvm::Value *address = args.claimNext();
    llvm::Value *value = IGF.Builder.CreateBitCast(address,
                                                   IGF.IGM.Int8PtrTy);
    out.add(value);
    return;
  }

  // Everything else cares about the (rvalue) argument.

  // If this is an LLVM IR intrinsic, lower it to an intrinsic call.
  const IntrinsicInfo &IInfo = IGF.getSILModule().getIntrinsicInfo(FnId);
  llvm::Intrinsic::ID IID = IInfo.ID;

  // Calls to the int_instrprof_increment intrinsic are emitted during SILGen.
  // At that stage, the function name GV used by the profiling pass is hidden.
  // Fix the intrinsic call here by pointing it to the correct GV.
  if (IID == llvm::Intrinsic::instrprof_increment) {
    // Extract the PGO function name.
    auto *NameGEP = cast<llvm::User>(args.claimNext());
    auto *NameGV = dyn_cast<llvm::GlobalVariable>(NameGEP->stripPointerCasts());
    if (NameGV) {
      auto *NameC = NameGV->getInitializer();
      StringRef Name = cast<llvm::ConstantDataArray>(NameC)->getRawDataValues();
      StringRef PGOFuncName = Name.rtrim(StringRef("\0", 1));

      // Point the increment call to the right function name variable.
      std::string PGOFuncNameVar = llvm::getPGOFuncNameVarName(
          PGOFuncName, llvm::GlobalValue::LinkOnceAnyLinkage);
      auto *FuncNamePtr = IGF.IGM.Module.getNamedGlobal(PGOFuncNameVar);

      if (FuncNamePtr) {
//.........这里部分代码省略.........