Update aosp/master llvm for rebase to r233350

Change-Id: I07d935f8793ee8ec6b7da003f6483046594bca49

4 files changed, 432 insertions, 395 deletions

diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 92af0f8..84753ff 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -8,34 +8,375 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Bitcode/ReaderWriter.h"
-#include "BitcodeReader.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Triple.h"
+#include "llvm/Bitcode/BitstreamReader.h"
 #include "llvm/Bitcode/LLVMBitCodes.h"
 #include "llvm/IR/AutoUpgrade.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/DiagnosticPrinter.h"
+#include "llvm/IR/GVMaterializer.h"
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/OperandTraits.h"
 #include "llvm/IR/Operator.h"
+#include "llvm/IR/ValueHandle.h"
 #include "llvm/Support/DataStream.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/raw_ostream.h"
-
+#include <deque>
 using namespace llvm;
 
+namespace {
 enum {
   SWITCH_INST_MAGIC = 0x4B5 // May 2012 => 1205 => Hex
 };
 
+class BitcodeReaderValueList {
+  std::vector<WeakVH> ValuePtrs;
+
+  /// ResolveConstants - As we resolve forward-referenced constants, we add
+  /// information about them to this vector.  This allows us to resolve them in
+  /// bulk instead of resolving each reference at a time.  See the code in
+  /// ResolveConstantForwardRefs for more information about this.
+  ///
+  /// The key of this vector is the placeholder constant, the value is the slot
+  /// number that holds the resolved value.
+  typedef std::vector<std::pair<Constant*, unsigned> > ResolveConstantsTy;
+  ResolveConstantsTy ResolveConstants;
+  LLVMContext &Context;
+public:
+  BitcodeReaderValueList(LLVMContext &C) : Context(C) {}
+  ~BitcodeReaderValueList() {
+    assert(ResolveConstants.empty() && "Constants not resolved?");
+  }
+
+  // vector compatibility methods
+  unsigned size() const { return ValuePtrs.size(); }
+  void resize(unsigned N) { ValuePtrs.resize(N); }
+  void push_back(Value *V) {
+    ValuePtrs.push_back(V);
+  }
+
+  void clear() {
+    assert(ResolveConstants.empty() && "Constants not resolved?");
+    ValuePtrs.clear();
+  }
+
+  Value *operator[](unsigned i) const {
+    assert(i < ValuePtrs.size());
+    return ValuePtrs[i];
+  }
+
+  Value *back() const { return ValuePtrs.back(); }
+    void pop_back() { ValuePtrs.pop_back(); }
+  bool empty() const { return ValuePtrs.empty(); }
+  void shrinkTo(unsigned N) {
+    assert(N <= size() && "Invalid shrinkTo request!");
+    ValuePtrs.resize(N);
+  }
+
+  Constant *getConstantFwdRef(unsigned Idx, Type *Ty);
+  Value *getValueFwdRef(unsigned Idx, Type *Ty);
+
+  void AssignValue(Value *V, unsigned Idx);
+
+  /// ResolveConstantForwardRefs - Once all constants are read, this method bulk
+  /// resolves any forward references.
+  void ResolveConstantForwardRefs();
+};
+
+class BitcodeReaderMDValueList {
+  unsigned NumFwdRefs;
+  bool AnyFwdRefs;
+  unsigned MinFwdRef;
+  unsigned MaxFwdRef;
+  std::vector<TrackingMDRef> MDValuePtrs;
+
+  LLVMContext &Context;
+public:
+  BitcodeReaderMDValueList(LLVMContext &C)
+      : NumFwdRefs(0), AnyFwdRefs(false), Context(C) {}
+
+  // vector compatibility methods
+  unsigned size() const       { return MDValuePtrs.size(); }
+  void resize(unsigned N)     { MDValuePtrs.resize(N); }
+  void push_back(Metadata *MD) { MDValuePtrs.emplace_back(MD); }
+  void clear()                { MDValuePtrs.clear();  }
+  Metadata *back() const      { return MDValuePtrs.back(); }
+  void pop_back()             { MDValuePtrs.pop_back(); }
+  bool empty() const          { return MDValuePtrs.empty(); }
+
+  Metadata *operator[](unsigned i) const {
+    assert(i < MDValuePtrs.size());
+    return MDValuePtrs[i];
+  }
+
+  void shrinkTo(unsigned N) {
+    assert(N <= size() && "Invalid shrinkTo request!");
+    MDValuePtrs.resize(N);
+  }
+
+  Metadata *getValueFwdRef(unsigned Idx);
+  void AssignValue(Metadata *MD, unsigned Idx);
+  void tryToResolveCycles();
+};
+
+class BitcodeReader : public GVMaterializer {
+  LLVMContext &Context;
+  DiagnosticHandlerFunction DiagnosticHandler;
+  Module *TheModule;
+  std::unique_ptr<MemoryBuffer> Buffer;
+  std::unique_ptr<BitstreamReader> StreamFile;
+  BitstreamCursor Stream;
+  DataStreamer *LazyStreamer;
+  uint64_t NextUnreadBit;
+  bool SeenValueSymbolTable;
+
+  std::vector<Type*> TypeList;
+  BitcodeReaderValueList ValueList;
+  BitcodeReaderMDValueList MDValueList;
+  std::vector<Comdat *> ComdatList;
+  SmallVector<Instruction *, 64> InstructionList;
+
+  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
+  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInits;
+  std::vector<std::pair<Function*, unsigned> > FunctionPrefixes;
+  std::vector<std::pair<Function*, unsigned> > FunctionPrologues;
+
+  SmallVector<Instruction*, 64> InstsWithTBAATag;
+
+  /// MAttributes - The set of attributes by index.  Index zero in the
+  /// file is for null, and is thus not represented here.  As such all indices
+  /// are off by one.
+  std::vector<AttributeSet> MAttributes;
+
+  /// \brief The set of attribute groups.
+  std::map<unsigned, AttributeSet> MAttributeGroups;
+
+  /// FunctionBBs - While parsing a function body, this is a list of the basic
+  /// blocks for the function.
+  std::vector<BasicBlock*> FunctionBBs;
+
+  // When reading the module header, this list is populated with functions that
+  // have bodies later in the file.
+  std::vector<Function*> FunctionsWithBodies;
+
+  // When intrinsic functions are encountered which require upgrading they are
+  // stored here with their replacement function.
+  typedef std::vector<std::pair<Function*, Function*> > UpgradedIntrinsicMap;
+  UpgradedIntrinsicMap UpgradedIntrinsics;
+
+  // Map the bitcode's custom MDKind ID to the Module's MDKind ID.
+  DenseMap<unsigned, unsigned> MDKindMap;
+
+  // Several operations happen after the module header has been read, but
+  // before function bodies are processed. This keeps track of whether
+  // we've done this yet.
+  bool SeenFirstFunctionBody;
+
+  /// DeferredFunctionInfo - When function bodies are initially scanned, this
+  /// map contains info about where to find deferred function body in the
+  /// stream.
+  DenseMap<Function*, uint64_t> DeferredFunctionInfo;
+
+  /// When Metadata block is initially scanned when parsing the module, we may
+  /// choose to defer parsing of the metadata. This vector contains info about
+  /// which Metadata blocks are deferred.
+  std::vector<uint64_t> DeferredMetadataInfo;
+
+  /// These are basic blocks forward-referenced by block addresses.  They are
+  /// inserted lazily into functions when they're loaded.  The basic block ID is
+  /// its index into the vector.
+  DenseMap<Function *, std::vector<BasicBlock *>> BasicBlockFwdRefs;
+  std::deque<Function *> BasicBlockFwdRefQueue;
+
+  /// UseRelativeIDs - Indicates that we are using a new encoding for
+  /// instruction operands where most operands in the current
+  /// FUNCTION_BLOCK are encoded relative to the instruction number,
+  /// for a more compact encoding.  Some instruction operands are not
+  /// relative to the instruction ID: basic block numbers, and types.
+  /// Once the old style function blocks have been phased out, we would
+  /// not need this flag.
+  bool UseRelativeIDs;
+
+  /// True if all functions will be materialized, negating the need to process
+  /// (e.g.) blockaddress forward references.
+  bool WillMaterializeAllForwardRefs;
+
+  /// Functions that have block addresses taken.  This is usually empty.
+  SmallPtrSet<const Function *, 4> BlockAddressesTaken;
+
+  /// True if any Metadata block has been materialized.
+  bool IsMetadataMaterialized;
+
+public:
+  std::error_code Error(BitcodeError E, const Twine &Message);
+  std::error_code Error(BitcodeError E);
+  std::error_code Error(const Twine &Message);
+
+  explicit BitcodeReader(MemoryBuffer *buffer, LLVMContext &C,
+                         DiagnosticHandlerFunction DiagnosticHandler);
+  explicit BitcodeReader(DataStreamer *streamer, LLVMContext &C,
+                         DiagnosticHandlerFunction DiagnosticHandler);
+  ~BitcodeReader() { FreeState(); }
+
+  std::error_code materializeForwardReferencedFunctions();
+
+  void FreeState();
+
+  void releaseBuffer();
+
+  bool isDematerializable(const GlobalValue *GV) const override;
+  std::error_code materialize(GlobalValue *GV) override;
+  std::error_code MaterializeModule(Module *M) override;
+  std::vector<StructType *> getIdentifiedStructTypes() const override;
+  void Dematerialize(GlobalValue *GV) override;
+
+  /// @brief Main interface to parsing a bitcode buffer.
+  /// @returns true if an error occurred.
+  std::error_code ParseBitcodeInto(Module *M,
+                                   bool ShouldLazyLoadMetadata = false);
+
+  /// @brief Cheap mechanism to just extract module triple
+  /// @returns true if an error occurred.
+  ErrorOr<std::string> parseTriple();
+
+  static uint64_t decodeSignRotatedValue(uint64_t V);
+
+  /// Materialize any deferred Metadata block.
+  std::error_code materializeMetadata() override;
+
+private:
+  std::vector<StructType *> IdentifiedStructTypes;
+  StructType *createIdentifiedStructType(LLVMContext &Context, StringRef Name);
+  StructType *createIdentifiedStructType(LLVMContext &Context);
+
+  Type *getTypeByID(unsigned ID);
+  Value *getFnValueByID(unsigned ID, Type *Ty) {
+    if (Ty && Ty->isMetadataTy())
+      return MetadataAsValue::get(Ty->getContext(), getFnMetadataByID(ID));
+    return ValueList.getValueFwdRef(ID, Ty);
+  }
+  Metadata *getFnMetadataByID(unsigned ID) {
+    return MDValueList.getValueFwdRef(ID);
+  }
+  BasicBlock *getBasicBlock(unsigned ID) const {
+    if (ID >= FunctionBBs.size()) return nullptr; // Invalid ID
+    return FunctionBBs[ID];
+  }
+  AttributeSet getAttributes(unsigned i) const {
+    if (i-1 < MAttributes.size())
+      return MAttributes[i-1];
+    return AttributeSet();
+  }
+
+  /// getValueTypePair - Read a value/type pair out of the specified record from
+  /// slot 'Slot'.  Increment Slot past the number of slots used in the record.
+  /// Return true on failure.
+  bool getValueTypePair(SmallVectorImpl<uint64_t> &Record, unsigned &Slot,
+                        unsigned InstNum, Value *&ResVal) {
+    if (Slot == Record.size()) return true;
+    unsigned ValNo = (unsigned)Record[Slot++];
+    // Adjust the ValNo, if it was encoded relative to the InstNum.
+    if (UseRelativeIDs)
+      ValNo = InstNum - ValNo;
+    if (ValNo < InstNum) {
+      // If this is not a forward reference, just return the value we already
+      // have.
+      ResVal = getFnValueByID(ValNo, nullptr);
+      return ResVal == nullptr;
+    } else if (Slot == Record.size()) {
+      return true;
+    }
+
+    unsigned TypeNo = (unsigned)Record[Slot++];
+    ResVal = getFnValueByID(ValNo, getTypeByID(TypeNo));
+    return ResVal == nullptr;
+  }
+
+  /// popValue - Read a value out of the specified record from slot 'Slot'.
+  /// Increment Slot past the number of slots used by the value in the record.
+  /// Return true if there is an error.
+  bool popValue(SmallVectorImpl<uint64_t> &Record, unsigned &Slot,
+                unsigned InstNum, Type *Ty, Value *&ResVal) {
+    if (getValue(Record, Slot, InstNum, Ty, ResVal))
+      return true;
+    // All values currently take a single record slot.
+    ++Slot;
+    return false;
+  }
+
+  /// getValue -- Like popValue, but does not increment the Slot number.
+  bool getValue(SmallVectorImpl<uint64_t> &Record, unsigned Slot,
+                unsigned InstNum, Type *Ty, Value *&ResVal) {
+    ResVal = getValue(Record, Slot, InstNum, Ty);
+    return ResVal == nullptr;
+  }
+
+  /// getValue -- Version of getValue that returns ResVal directly,
+  /// or 0 if there is an error.
+  Value *getValue(SmallVectorImpl<uint64_t> &Record, unsigned Slot,
+                  unsigned InstNum, Type *Ty) {
+    if (Slot == Record.size()) return nullptr;
+    unsigned ValNo = (unsigned)Record[Slot];
+    // Adjust the ValNo, if it was encoded relative to the InstNum.
+    if (UseRelativeIDs)
+      ValNo = InstNum - ValNo;
+    return getFnValueByID(ValNo, Ty);
+  }
+
+  /// getValueSigned -- Like getValue, but decodes signed VBRs.
+  Value *getValueSigned(SmallVectorImpl<uint64_t> &Record, unsigned Slot,
+                        unsigned InstNum, Type *Ty) {
+    if (Slot == Record.size()) return nullptr;
+    unsigned ValNo = (unsigned)decodeSignRotatedValue(Record[Slot]);
+    // Adjust the ValNo, if it was encoded relative to the InstNum.
+    if (UseRelativeIDs)
+      ValNo = InstNum - ValNo;
+    return getFnValueByID(ValNo, Ty);
+  }
+
+  /// Converts alignment exponent (i.e. power of two (or zero)) to the
+  /// corresponding alignment to use. If alignment is too large, returns
+  /// a corresponding error code.
+  std::error_code parseAlignmentValue(uint64_t Exponent, unsigned &Alignment);
+  std::error_code ParseAttrKind(uint64_t Code, Attribute::AttrKind *Kind);
+  std::error_code ParseModule(bool Resume, bool ShouldLazyLoadMetadata = false);
+  std::error_code ParseAttributeBlock();
+  std::error_code ParseAttributeGroupBlock();
+  std::error_code ParseTypeTable();
+  std::error_code ParseTypeTableBody();
+
+  std::error_code ParseValueSymbolTable();
+  std::error_code ParseConstants();
+  std::error_code RememberAndSkipFunctionBody();
+  /// Save the positions of the Metadata blocks and skip parsing the blocks.
+  std::error_code rememberAndSkipMetadata();
+  std::error_code ParseFunctionBody(Function *F);
+  std::error_code GlobalCleanup();
+  std::error_code ResolveGlobalAndAliasInits();
+  std::error_code ParseMetadata();
+  std::error_code ParseMetadataAttachment();
+  ErrorOr<std::string> parseModuleTriple();
+  std::error_code ParseUseLists();
+  std::error_code InitStream();
+  std::error_code InitStreamFromBuffer();
+  std::error_code InitLazyStream();
+  std::error_code FindFunctionInStream(
+      Function *F,
+      DenseMap<Function *, uint64_t>::iterator DeferredFunctionInfoIterator);
+};
+} // namespace
+
 BitcodeDiagnosticInfo::BitcodeDiagnosticInfo(std::error_code EC,
                                              DiagnosticSeverity Severity,
                                              const Twine &Msg)
@@ -81,7 +422,7 @@ BitcodeReader::BitcodeReader(MemoryBuffer *buffer, LLVMContext &C,
       TheModule(nullptr), Buffer(buffer), LazyStreamer(nullptr),
       NextUnreadBit(0), SeenValueSymbolTable(false), ValueList(C),
       MDValueList(C), SeenFirstFunctionBody(false), UseRelativeIDs(false),
-      WillMaterializeAllForwardRefs(false) {}
+      WillMaterializeAllForwardRefs(false), IsMetadataMaterialized(false) {}
 
 BitcodeReader::BitcodeReader(DataStreamer *streamer, LLVMContext &C,
                              DiagnosticHandlerFunction DiagnosticHandler)
@@ -89,7 +430,7 @@ BitcodeReader::BitcodeReader(DataStreamer *streamer, LLVMContext &C,
       TheModule(nullptr), Buffer(nullptr), LazyStreamer(streamer),
       NextUnreadBit(0), SeenValueSymbolTable(false), ValueList(C),
       MDValueList(C), SeenFirstFunctionBody(false), UseRelativeIDs(false),
-      WillMaterializeAllForwardRefs(false) {}
+      WillMaterializeAllForwardRefs(false), IsMetadataMaterialized(false) {}
 
 std::error_code BitcodeReader::materializeForwardReferencedFunctions() {
   if (WillMaterializeAllForwardRefs)
@@ -135,6 +476,7 @@ void BitcodeReader::FreeState() {
   std::vector<BasicBlock*>().swap(FunctionBBs);
   std::vector<Function*>().swap(FunctionsWithBodies);
   DeferredFunctionInfo.clear();
+  DeferredMetadataInfo.clear();
   MDKindMap.clear();
 
   assert(BasicBlockFwdRefs.empty() && "Unresolved blockaddress fwd references");
@@ -1198,6 +1540,7 @@ std::error_code BitcodeReader::ParseValueSymbolTable() {
 static int64_t unrotateSign(uint64_t U) { return U & 1 ? ~(U >> 1) : U >> 1; }
 
 std::error_code BitcodeReader::ParseMetadata() {
+  IsMetadataMaterialized = true;
   unsigned NextMDValueNo = MDValueList.size();
 
   if (Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
@@ -1348,14 +1691,15 @@ std::error_code BitcodeReader::ParseMetadata() {
       if (Record.size() != 5)
         return Error("Invalid record");
 
-      auto get = Record[0] ? MDLocation::getDistinct : MDLocation::get;
       unsigned Line = Record[1];
       unsigned Column = Record[2];
       MDNode *Scope = cast<MDNode>(MDValueList.getValueFwdRef(Record[3]));
       Metadata *InlinedAt =
           Record[4] ? MDValueList.getValueFwdRef(Record[4] - 1) : nullptr;
-      MDValueList.AssignValue(get(Context, Line, Column, Scope, InlinedAt),
-                              NextMDValueNo++);
+      MDValueList.AssignValue(
+          GET_OR_DISTINCT(MDLocation, Record[0],
+                          (Context, Line, Column, Scope, InlinedAt)),
+          NextMDValueNo++);
       break;
     }
     case bitc::METADATA_GENERIC_DEBUG: {
@@ -1952,19 +2296,26 @@ std::error_code BitcodeReader::ParseConstants() {
     }
     case bitc::CST_CODE_CE_INBOUNDS_GEP:
     case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
-      if (Record.size() & 1)
-        return Error("Invalid record");
+      unsigned OpNum = 0;
+      Type *PointeeType = nullptr;
+      if (Record.size() % 2)
+        PointeeType = getTypeByID(Record[OpNum++]);
       SmallVector<Constant*, 16> Elts;
-      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
-        Type *ElTy = getTypeByID(Record[i]);
+      while (OpNum != Record.size()) {
+        Type *ElTy = getTypeByID(Record[OpNum++]);
         if (!ElTy)
           return Error("Invalid record");
-        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
+        Elts.push_back(ValueList.getConstantFwdRef(Record[OpNum++], ElTy));
       }
+
       ArrayRef<Constant *> Indices(Elts.begin() + 1, Elts.end());
       V = ConstantExpr::getGetElementPtr(Elts[0], Indices,
                                          BitCode ==
                                            bitc::CST_CODE_CE_INBOUNDS_GEP);
+      if (PointeeType &&
+          PointeeType != cast<GEPOperator>(V)->getSourceElementType())
+        return Error("Explicit gep operator type does not match pointee type "
+                     "of pointer operand");
       break;
     }
     case bitc::CST_CODE_CE_SELECT: {  // CE_SELECT: [opval#, opval#, opval#]
@@ -2234,6 +2585,30 @@ std::error_code BitcodeReader::ParseUseLists() {
   }
 }
 
+/// When we see the block for metadata, remember where it is and then skip it.
+/// This lets us lazily deserialize the metadata.
+std::error_code BitcodeReader::rememberAndSkipMetadata() {
+  // Save the current stream state.
+  uint64_t CurBit = Stream.GetCurrentBitNo();
+  DeferredMetadataInfo.push_back(CurBit);
+
+  // Skip over the block for now.
+  if (Stream.SkipBlock())
+    return Error("Invalid record");
+  return std::error_code();
+}
+
+std::error_code BitcodeReader::materializeMetadata() {
+  for (uint64_t BitPos : DeferredMetadataInfo) {
+    // Move the bit stream to the saved position.
+    Stream.JumpToBit(BitPos);
+    if (std::error_code EC = ParseMetadata())
+      return EC;
+  }
+  DeferredMetadataInfo.clear();
+  return std::error_code();
+}
+
 /// RememberAndSkipFunctionBody - When we see the block for a function body,
 /// remember where it is and then skip it.  This lets us lazily deserialize the
 /// functions.
@@ -2284,7 +2659,8 @@ std::error_code BitcodeReader::GlobalCleanup() {
   return std::error_code();
 }
 
-std::error_code BitcodeReader::ParseModule(bool Resume) {
+std::error_code BitcodeReader::ParseModule(bool Resume,
+                                           bool ShouldLazyLoadMetadata) {
   if (Resume)
     Stream.JumpToBit(NextUnreadBit);
   else if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
@@ -2338,6 +2714,12 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
           return EC;
         break;
       case bitc::METADATA_BLOCK_ID:
+        if (ShouldLazyLoadMetadata && !IsMetadataMaterialized) {
+          if (std::error_code EC = rememberAndSkipMetadata())
+            return EC;
+          break;
+        }
+        assert(DeferredMetadataInfo.empty() && "Unexpected deferred metadata");
         if (std::error_code EC = ParseMetadata())
           return EC;
         break;
@@ -2652,7 +3034,8 @@ std::error_code BitcodeReader::ParseModule(bool Resume) {
   }
 }
 
-std::error_code BitcodeReader::ParseBitcodeInto(Module *M) {
+std::error_code BitcodeReader::ParseBitcodeInto(Module *M,
+                                                bool ShouldLazyLoadMetadata) {
   TheModule = nullptr;
 
   if (std::error_code EC = InitStream())
@@ -2693,7 +3076,7 @@ std::error_code BitcodeReader::ParseBitcodeInto(Module *M) {
         if (TheModule)
           return Error("Invalid multiple blocks");
         TheModule = M;
-        if (std::error_code EC = ParseModule(false))
+        if (std::error_code EC = ParseModule(false, ShouldLazyLoadMetadata))
           return EC;
         if (LazyStreamer)
           return std::error_code();
@@ -3082,6 +3465,13 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
         return Error("Invalid record");
 
+      if (Ty &&
+          Ty !=
+              cast<SequentialType>(BasePtr->getType()->getScalarType())
+                  ->getElementType())
+        return Error(
+            "Explicit gep type does not match pointee type of pointer operand");
+
       SmallVector<Value*, 16> GEPIdx;
       while (OpNum != Record.size()) {
         Value *Op;
@@ -3090,8 +3480,8 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
         GEPIdx.push_back(Op);
       }
 
-      I = GetElementPtrInst::Create(BasePtr, GEPIdx);
-      assert(!Ty || Ty == cast<GetElementPtrInst>(I)->getSourceElementType());
+      I = GetElementPtrInst::Create(Ty, BasePtr, GEPIdx);
+
       InstructionList.push_back(I);
       if (InBounds)
         cast<GetElementPtrInst>(I)->setIsInBounds(true);
@@ -3600,8 +3990,9 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
         return EC;
       I = new LoadInst(Op, "", Record[OpNum+1], Align);
 
-      assert((!Ty || Ty == I->getType()) &&
-             "Explicit type doesn't match pointee type of the first operand");
+      if (Ty && Ty != I->getType())
+        return Error("Explicit load type does not match pointee type of "
+                     "pointer operand");
 
       InstructionList.push_back(I);
       break;
@@ -3631,6 +4022,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
         return EC;
       I = new LoadInst(Op, "", Record[OpNum+1], Align, Ordering, SynchScope);
 
+      (void)Ty;
       assert((!Ty || Ty == I->getType()) &&
              "Explicit type doesn't match pointee type of the first operand");
 
@@ -3890,6 +4282,9 @@ std::error_code BitcodeReader::FindFunctionInStream(
 void BitcodeReader::releaseBuffer() { Buffer.release(); }
 
 std::error_code BitcodeReader::materialize(GlobalValue *GV) {
+  if (std::error_code EC = materializeMetadata())
+    return EC;
+
   Function *F = dyn_cast<Function>(GV);
   // If it's not a function or is already material, ignore the request.
   if (!F || !F->isMaterializable())
@@ -3957,6 +4352,9 @@ std::error_code BitcodeReader::MaterializeModule(Module *M) {
   assert(M == TheModule &&
          "Can only Materialize the Module this BitcodeReader is attached to.");
 
+  if (std::error_code EC = materializeMetadata())
+    return EC;
+
   // Promise to materialize all forward references.
   WillMaterializeAllForwardRefs = true;
 
@@ -4097,7 +4495,8 @@ const std::error_category &llvm::BitcodeErrorCategory() {
 static ErrorOr<Module *>
 getLazyBitcodeModuleImpl(std::unique_ptr<MemoryBuffer> &&Buffer,
                          LLVMContext &Context, bool WillMaterializeAll,
-                         DiagnosticHandlerFunction DiagnosticHandler) {
+                         DiagnosticHandlerFunction DiagnosticHandler,
+                         bool ShouldLazyLoadMetadata = false) {
   Module *M = new Module(Buffer->getBufferIdentifier(), Context);
   BitcodeReader *R =
       new BitcodeReader(Buffer.get(), Context, DiagnosticHandler);
@@ -4109,7 +4508,8 @@ getLazyBitcodeModuleImpl(std::unique_ptr<MemoryBuffer> &&Buffer,
     return EC;
   };
 
-  if (std::error_code EC = R->ParseBitcodeInto(M))
+  // Delay parsing Metadata if ShouldLazyLoadMetadata is true.
+  if (std::error_code EC = R->ParseBitcodeInto(M, ShouldLazyLoadMetadata))
     return cleanupOnError(EC);
 
   if (!WillMaterializeAll)
@@ -4124,9 +4524,10 @@ getLazyBitcodeModuleImpl(std::unique_ptr<MemoryBuffer> &&Buffer,
 ErrorOr<Module *>
 llvm::getLazyBitcodeModule(std::unique_ptr<MemoryBuffer> &&Buffer,
                            LLVMContext &Context,
-                           DiagnosticHandlerFunction DiagnosticHandler) {
+                           DiagnosticHandlerFunction DiagnosticHandler,
+                           bool ShouldLazyLoadMetadata) {
   return getLazyBitcodeModuleImpl(std::move(Buffer), Context, false,
-                                  DiagnosticHandler);
+                                  DiagnosticHandler, ShouldLazyLoadMetadata);
 }
 
 ErrorOr<std::unique_ptr<Module>>
diff --git a/lib/Bitcode/Reader/BitcodeReader.h b/lib/Bitcode/Reader/BitcodeReader.h
deleted file mode 100644
index 9803e78..0000000
--- a/lib/Bitcode/Reader/BitcodeReader.h
+++ /dev/null
@@ -1,369 +0,0 @@
-//===- BitcodeReader.h - Internal BitcodeReader impl ------------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This header defines the BitcodeReader class.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_LIB_BITCODE_READER_BITCODEREADER_H
-#define LLVM_LIB_BITCODE_READER_BITCODEREADER_H
-
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/Bitcode/BitstreamReader.h"
-#include "llvm/Bitcode/LLVMBitCodes.h"
-#include "llvm/IR/Attributes.h"
-#include "llvm/IR/GVMaterializer.h"
-#include "llvm/IR/Metadata.h"
-#include "llvm/IR/OperandTraits.h"
-#include "llvm/IR/TrackingMDRef.h"
-#include "llvm/IR/Type.h"
-#include "llvm/IR/ValueHandle.h"
-#include <deque>
-#include <system_error>
-#include <vector>
-
-namespace llvm {
-  class Comdat;
-  class MemoryBuffer;
-  class LLVMContext;
-
-//===----------------------------------------------------------------------===//
-//                          BitcodeReaderValueList Class
-//===----------------------------------------------------------------------===//
-
-class BitcodeReaderValueList {
-  std::vector<WeakVH> ValuePtrs;
-
-  /// ResolveConstants - As we resolve forward-referenced constants, we add
-  /// information about them to this vector.  This allows us to resolve them in
-  /// bulk instead of resolving each reference at a time.  See the code in
-  /// ResolveConstantForwardRefs for more information about this.
-  ///
-  /// The key of this vector is the placeholder constant, the value is the slot
-  /// number that holds the resolved value.
-  typedef std::vector<std::pair<Constant*, unsigned> > ResolveConstantsTy;
-  ResolveConstantsTy ResolveConstants;
-  LLVMContext &Context;
-public:
-  BitcodeReaderValueList(LLVMContext &C) : Context(C) {}
-  ~BitcodeReaderValueList() {
-    assert(ResolveConstants.empty() && "Constants not resolved?");
-  }
-
-  // vector compatibility methods
-  unsigned size() const { return ValuePtrs.size(); }
-  void resize(unsigned N) { ValuePtrs.resize(N); }
-  void push_back(Value *V) {
-    ValuePtrs.push_back(V);
-  }
-
-  void clear() {
-    assert(ResolveConstants.empty() && "Constants not resolved?");
-    ValuePtrs.clear();
-  }
-
-  Value *operator[](unsigned i) const {
-    assert(i < ValuePtrs.size());
-    return ValuePtrs[i];
-  }
-
-  Value *back() const { return ValuePtrs.back(); }
-    void pop_back() { ValuePtrs.pop_back(); }
-  bool empty() const { return ValuePtrs.empty(); }
-  void shrinkTo(unsigned N) {
-    assert(N <= size() && "Invalid shrinkTo request!");
-    ValuePtrs.resize(N);
-  }
-
-  Constant *getConstantFwdRef(unsigned Idx, Type *Ty);
-  Value *getValueFwdRef(unsigned Idx, Type *Ty);
-
-  void AssignValue(Value *V, unsigned Idx);
-
-  /// ResolveConstantForwardRefs - Once all constants are read, this method bulk
-  /// resolves any forward references.
-  void ResolveConstantForwardRefs();
-};
-
-
-//===----------------------------------------------------------------------===//
-//                          BitcodeReaderMDValueList Class
-//===----------------------------------------------------------------------===//
-
-class BitcodeReaderMDValueList {
-  unsigned NumFwdRefs;
-  bool AnyFwdRefs;
-  unsigned MinFwdRef;
-  unsigned MaxFwdRef;
-  std::vector<TrackingMDRef> MDValuePtrs;
-
-  LLVMContext &Context;
-public:
-  BitcodeReaderMDValueList(LLVMContext &C)
-      : NumFwdRefs(0), AnyFwdRefs(false), Context(C) {}
-
-  // vector compatibility methods
-  unsigned size() const       { return MDValuePtrs.size(); }
-  void resize(unsigned N)     { MDValuePtrs.resize(N); }
-  void push_back(Metadata *MD) { MDValuePtrs.emplace_back(MD); }
-  void clear()                { MDValuePtrs.clear();  }
-  Metadata *back() const      { return MDValuePtrs.back(); }
-  void pop_back()             { MDValuePtrs.pop_back(); }
-  bool empty() const          { return MDValuePtrs.empty(); }
-
-  Metadata *operator[](unsigned i) const {
-    assert(i < MDValuePtrs.size());
-    return MDValuePtrs[i];
-  }
-
-  void shrinkTo(unsigned N) {
-    assert(N <= size() && "Invalid shrinkTo request!");
-    MDValuePtrs.resize(N);
-  }
-
-  Metadata *getValueFwdRef(unsigned Idx);
-  void AssignValue(Metadata *MD, unsigned Idx);
-  void tryToResolveCycles();
-};
-
-class BitcodeReader : public GVMaterializer {
-  LLVMContext &Context;
-  DiagnosticHandlerFunction DiagnosticHandler;
-  Module *TheModule;
-  std::unique_ptr<MemoryBuffer> Buffer;
-  std::unique_ptr<BitstreamReader> StreamFile;
-  BitstreamCursor Stream;
-  DataStreamer *LazyStreamer;
-  uint64_t NextUnreadBit;
-  bool SeenValueSymbolTable;
-
-  std::vector<Type*> TypeList;
-  BitcodeReaderValueList ValueList;
-  BitcodeReaderMDValueList MDValueList;
-  std::vector<Comdat *> ComdatList;
-  SmallVector<Instruction *, 64> InstructionList;
-
-  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
-  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInits;
-  std::vector<std::pair<Function*, unsigned> > FunctionPrefixes;
-  std::vector<std::pair<Function*, unsigned> > FunctionPrologues;
-
-  SmallVector<Instruction*, 64> InstsWithTBAATag;
-
-  /// MAttributes - The set of attributes by index.  Index zero in the
-  /// file is for null, and is thus not represented here.  As such all indices
-  /// are off by one.
-  std::vector<AttributeSet> MAttributes;
-
-  /// \brief The set of attribute groups.
-  std::map<unsigned, AttributeSet> MAttributeGroups;
-
-  /// FunctionBBs - While parsing a function body, this is a list of the basic
-  /// blocks for the function.
-  std::vector<BasicBlock*> FunctionBBs;
-
-  // When reading the module header, this list is populated with functions that
-  // have bodies later in the file.
-  std::vector<Function*> FunctionsWithBodies;
-
-  // When intrinsic functions are encountered which require upgrading they are
-  // stored here with their replacement function.
-  typedef std::vector<std::pair<Function*, Function*> > UpgradedIntrinsicMap;
-  UpgradedIntrinsicMap UpgradedIntrinsics;
-
-  // Map the bitcode's custom MDKind ID to the Module's MDKind ID.
-  DenseMap<unsigned, unsigned> MDKindMap;
-
-  // Several operations happen after the module header has been read, but
-  // before function bodies are processed. This keeps track of whether
-  // we've done this yet.
-  bool SeenFirstFunctionBody;
-
-  /// DeferredFunctionInfo - When function bodies are initially scanned, this
-  /// map contains info about where to find deferred function body in the
-  /// stream.
-  DenseMap<Function*, uint64_t> DeferredFunctionInfo;
-
-  /// These are basic blocks forward-referenced by block addresses.  They are
-  /// inserted lazily into functions when they're loaded.  The basic block ID is
-  /// its index into the vector.
-  DenseMap<Function *, std::vector<BasicBlock *>> BasicBlockFwdRefs;
-  std::deque<Function *> BasicBlockFwdRefQueue;
-
-  /// UseRelativeIDs - Indicates that we are using a new encoding for
-  /// instruction operands where most operands in the current
-  /// FUNCTION_BLOCK are encoded relative to the instruction number,
-  /// for a more compact encoding.  Some instruction operands are not
-  /// relative to the instruction ID: basic block numbers, and types.
-  /// Once the old style function blocks have been phased out, we would
-  /// not need this flag.
-  bool UseRelativeIDs;
-
-  /// True if all functions will be materialized, negating the need to process
-  /// (e.g.) blockaddress forward references.
-  bool WillMaterializeAllForwardRefs;
-
-  /// Functions that have block addresses taken.  This is usually empty.
-  SmallPtrSet<const Function *, 4> BlockAddressesTaken;
-
-public:
-  std::error_code Error(BitcodeError E, const Twine &Message);
-  std::error_code Error(BitcodeError E);
-  std::error_code Error(const Twine &Message);
-
-  explicit BitcodeReader(MemoryBuffer *buffer, LLVMContext &C,
-                         DiagnosticHandlerFunction DiagnosticHandler);
-  explicit BitcodeReader(DataStreamer *streamer, LLVMContext &C,
-                         DiagnosticHandlerFunction DiagnosticHandler);
-  ~BitcodeReader() { FreeState(); }
-
-  std::error_code materializeForwardReferencedFunctions();
-
-  void FreeState();
-
-  void releaseBuffer();
-
-  bool isDematerializable(const GlobalValue *GV) const override;
-  std::error_code materialize(GlobalValue *GV) override;
-  std::error_code MaterializeModule(Module *M) override;
-  std::vector<StructType *> getIdentifiedStructTypes() const override;
-  void Dematerialize(GlobalValue *GV) override;
-
-  /// @brief Main interface to parsing a bitcode buffer.
-  /// @returns true if an error occurred.
-  std::error_code ParseBitcodeInto(Module *M);
-
-  /// @brief Cheap mechanism to just extract module triple
-  /// @returns true if an error occurred.
-  ErrorOr<std::string> parseTriple();
-
-  static uint64_t decodeSignRotatedValue(uint64_t V);
-
-private:
-  std::vector<StructType *> IdentifiedStructTypes;
-  StructType *createIdentifiedStructType(LLVMContext &Context, StringRef Name);
-  StructType *createIdentifiedStructType(LLVMContext &Context);
-
-  Type *getTypeByID(unsigned ID);
-  Value *getFnValueByID(unsigned ID, Type *Ty) {
-    if (Ty && Ty->isMetadataTy())
-      return MetadataAsValue::get(Ty->getContext(), getFnMetadataByID(ID));
-    return ValueList.getValueFwdRef(ID, Ty);
-  }
-  Metadata *getFnMetadataByID(unsigned ID) {
-    return MDValueList.getValueFwdRef(ID);
-  }
-  BasicBlock *getBasicBlock(unsigned ID) const {
-    if (ID >= FunctionBBs.size()) return nullptr; // Invalid ID
-    return FunctionBBs[ID];
-  }
-  AttributeSet getAttributes(unsigned i) const {
-    if (i-1 < MAttributes.size())
-      return MAttributes[i-1];
-    return AttributeSet();
-  }
-
-  /// getValueTypePair - Read a value/type pair out of the specified record from
-  /// slot 'Slot'.  Increment Slot past the number of slots used in the record.
-  /// Return true on failure.
-  bool getValueTypePair(SmallVectorImpl<uint64_t> &Record, unsigned &Slot,
-                        unsigned InstNum, Value *&ResVal) {
-    if (Slot == Record.size()) return true;
-    unsigned ValNo = (unsigned)Record[Slot++];
-    // Adjust the ValNo, if it was encoded relative to the InstNum.
-    if (UseRelativeIDs)
-      ValNo = InstNum - ValNo;
-    if (ValNo < InstNum) {
-      // If this is not a forward reference, just return the value we already
-      // have.
-      ResVal = getFnValueByID(ValNo, nullptr);
-      return ResVal == nullptr;
-    } else if (Slot == Record.size()) {
-      return true;
-    }
-
-    unsigned TypeNo = (unsigned)Record[Slot++];
-    ResVal = getFnValueByID(ValNo, getTypeByID(TypeNo));
-    return ResVal == nullptr;
-  }
-
-  /// popValue - Read a value out of the specified record from slot 'Slot'.
-  /// Increment Slot past the number of slots used by the value in the record.
-  /// Return true if there is an error.
-  bool popValue(SmallVectorImpl<uint64_t> &Record, unsigned &Slot,
-                unsigned InstNum, Type *Ty, Value *&ResVal) {
-    if (getValue(Record, Slot, InstNum, Ty, ResVal))
-      return true;
-    // All values currently take a single record slot.
-    ++Slot;
-    return false;
-  }
-
-  /// getValue -- Like popValue, but does not increment the Slot number.
-  bool getValue(SmallVectorImpl<uint64_t> &Record, unsigned Slot,
-                unsigned InstNum, Type *Ty, Value *&ResVal) {
-    ResVal = getValue(Record, Slot, InstNum, Ty);
-    return ResVal == nullptr;
-  }
-
-  /// getValue -- Version of getValue that returns ResVal directly,
-  /// or 0 if there is an error.
-  Value *getValue(SmallVectorImpl<uint64_t> &Record, unsigned Slot,
-                  unsigned InstNum, Type *Ty) {
-    if (Slot == Record.size()) return nullptr;
-    unsigned ValNo = (unsigned)Record[Slot];
-    // Adjust the ValNo, if it was encoded relative to the InstNum.
-    if (UseRelativeIDs)
-      ValNo = InstNum - ValNo;
-    return getFnValueByID(ValNo, Ty);
-  }
-
-  /// getValueSigned -- Like getValue, but decodes signed VBRs.
-  Value *getValueSigned(SmallVectorImpl<uint64_t> &Record, unsigned Slot,
-                        unsigned InstNum, Type *Ty) {
-    if (Slot == Record.size()) return nullptr;
-    unsigned ValNo = (unsigned)decodeSignRotatedValue(Record[Slot]);
-    // Adjust the ValNo, if it was encoded relative to the InstNum.
-    if (UseRelativeIDs)
-      ValNo = InstNum - ValNo;
-    return getFnValueByID(ValNo, Ty);
-  }
-
-  /// Converts alignment exponent (i.e. power of two (or zero)) to the
-  /// corresponding alignment to use. If alignment is too large, returns
-  /// a corresponding error code.
-  std::error_code parseAlignmentValue(uint64_t Exponent, unsigned &Alignment);
-  std::error_code ParseAttrKind(uint64_t Code, Attribute::AttrKind *Kind);
-  std::error_code ParseModule(bool Resume);
-  std::error_code ParseAttributeBlock();
-  std::error_code ParseAttributeGroupBlock();
-  std::error_code ParseTypeTable();
-  std::error_code ParseTypeTableBody();
-
-  std::error_code ParseValueSymbolTable();
-  std::error_code ParseConstants();
-  std::error_code RememberAndSkipFunctionBody();
-  std::error_code ParseFunctionBody(Function *F);
-  std::error_code GlobalCleanup();
-  std::error_code ResolveGlobalAndAliasInits();
-  std::error_code ParseMetadata();
-  std::error_code ParseMetadataAttachment();
-  ErrorOr<std::string> parseModuleTriple();
-  std::error_code ParseUseLists();
-  std::error_code InitStream();
-  std::error_code InitStreamFromBuffer();
-  std::error_code InitLazyStream();
-  std::error_code FindFunctionInStream(
-      Function *F,
-      DenseMap<Function *, uint64_t>::iterator DeferredFunctionInfoIterator);
-};
-
-} // End llvm namespace
-
-#endif
diff --git a/lib/Bitcode/Reader/BitstreamReader.cpp b/lib/Bitcode/Reader/BitstreamReader.cpp
index ca68257..beaaf7a 100644
--- a/lib/Bitcode/Reader/BitstreamReader.cpp
+++ b/lib/Bitcode/Reader/BitstreamReader.cpp
@@ -245,7 +245,7 @@ void BitstreamCursor::ReadAbbrevRecord() {
   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
   unsigned NumOpInfo = ReadVBR(5);
   for (unsigned i = 0; i != NumOpInfo; ++i) {
-    bool IsLiteral = Read(1) ? true : false;
+    bool IsLiteral = Read(1);
     if (IsLiteral) {
       Abbv->Add(BitCodeAbbrevOp(ReadVBR64(8)));
       continue;
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index ecb6f7c..0123fb2 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1205,6 +1205,8 @@ static void WriteModuleMetadata(const Module *M,
   SmallVector<uint64_t, 64> Record;
   for (const Metadata *MD : MDs) {
     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
+      assert(N->isResolved() && "Expected forward references to be resolved");
+
       switch (N->getMetadataID()) {
       default:
         llvm_unreachable("Invalid MDNode subclass");
@@ -1522,15 +1524,18 @@ static void WriteConstants(unsigned FirstVal, unsigned LastVal,
             Record.push_back(Flags);
         }
         break;
-      case Instruction::GetElementPtr:
+      case Instruction::GetElementPtr: {
         Code = bitc::CST_CODE_CE_GEP;
-        if (cast<GEPOperator>(C)->isInBounds())
+        const auto *GO = cast<GEPOperator>(C);
+        if (GO->isInBounds())
           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
+        Record.push_back(VE.getTypeID(GO->getSourceElementType()));
         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
           Record.push_back(VE.getValueID(C->getOperand(i)));
         }
         break;
+      }
       case Instruction::Select:
         Code = bitc::CST_CODE_CE_SELECT;
         Record.push_back(VE.getValueID(C->getOperand(0)));