llvm/lib/Bitcode/Writer/BitcodeWriter.cpp

   1 //===- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // Bitcode writer implementation.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/Bitcode/BitcodeWriter.h"
  14 #include "ValueEnumerator.h"
  15 #include "llvm/ADT/APFloat.h"
  16 #include "llvm/ADT/APInt.h"
  17 #include "llvm/ADT/ArrayRef.h"
  18 #include "llvm/ADT/DenseMap.h"
  19 #include "llvm/ADT/STLExtras.h"
  20 #include "llvm/ADT/SetVector.h"
  21 #include "llvm/ADT/SmallPtrSet.h"
  22 #include "llvm/ADT/SmallString.h"
  23 #include "llvm/ADT/SmallVector.h"
  24 #include "llvm/ADT/StringMap.h"
  25 #include "llvm/ADT/StringRef.h"
  26 #include "llvm/Bitcode/BitcodeCommon.h"
  27 #include "llvm/Bitcode/BitcodeReader.h"
  28 #include "llvm/Bitcode/LLVMBitCodes.h"
  29 #include "llvm/Bitstream/BitCodes.h"
  30 #include "llvm/Bitstream/BitstreamWriter.h"
  31 #include "llvm/Config/llvm-config.h"
  32 #include "llvm/IR/Attributes.h"
  33 #include "llvm/IR/BasicBlock.h"
  34 #include "llvm/IR/Comdat.h"
  35 #include "llvm/IR/Constant.h"
  36 #include "llvm/IR/Constants.h"
  37 #include "llvm/IR/DebugInfoMetadata.h"
  38 #include "llvm/IR/DebugLoc.h"
  39 #include "llvm/IR/DerivedTypes.h"
  40 #include "llvm/IR/Function.h"
  41 #include "llvm/IR/GlobalAlias.h"
  42 #include "llvm/IR/GlobalIFunc.h"
  43 #include "llvm/IR/GlobalObject.h"
  44 #include "llvm/IR/GlobalValue.h"
  45 #include "llvm/IR/GlobalVariable.h"
  46 #include "llvm/IR/InlineAsm.h"
  47 #include "llvm/IR/InstrTypes.h"
  48 #include "llvm/IR/Instruction.h"
  49 #include "llvm/IR/Instructions.h"
  50 #include "llvm/IR/LLVMContext.h"
  51 #include "llvm/IR/Metadata.h"
  52 #include "llvm/IR/Module.h"
  53 #include "llvm/IR/ModuleSummaryIndex.h"
  54 #include "llvm/IR/Operator.h"
  55 #include "llvm/IR/Type.h"
  56 #include "llvm/IR/UseListOrder.h"
  57 #include "llvm/IR/Value.h"
  58 #include "llvm/IR/ValueSymbolTable.h"
  59 #include "llvm/MC/StringTableBuilder.h"
  60 #include "llvm/MC/TargetRegistry.h"
  61 #include "llvm/Object/IRSymtab.h"
  62 #include "llvm/Support/AtomicOrdering.h"
  63 #include "llvm/Support/Casting.h"
  64 #include "llvm/Support/CommandLine.h"
  65 #include "llvm/Support/Endian.h"
  66 #include "llvm/Support/Error.h"
  67 #include "llvm/Support/ErrorHandling.h"
  68 #include "llvm/Support/MathExtras.h"
  69 #include "llvm/Support/SHA1.h"
  70 #include "llvm/Support/raw_ostream.h"
  71 #include "llvm/TargetParser/Triple.h"
  72 #include <algorithm>
  73 #include <cassert>
  74 #include <cstddef>
  75 #include <cstdint>
  76 #include <iterator>
  77 #include <map>
  78 #include <memory>
  79 #include <optional>
  80 #include <string>
  81 #include <utility>
  82 #include <vector>
  83
  84 using namespace llvm;
  85
  86 static cl::opt<unsigned>
  87     IndexThreshold("bitcode-mdindex-threshold", cl::Hidden, cl::init(25),
  88                    cl::desc("Number of metadatas above which we emit an index "
  89                             "to enable lazy-loading"));
  90 static cl::opt<uint32_t> FlushThreshold(
  91     "bitcode-flush-threshold", cl::Hidden, cl::init(512),
  92     cl::desc("The threshold (unit M) for flushing LLVM bitcode."));
  93
  94 static cl::opt<bool> WriteRelBFToSummary(
  95     "write-relbf-to-summary", cl::Hidden, cl::init(false),
  96     cl::desc("Write relative block frequency to function summary "));
  97
  98 namespace llvm {
  99 extern FunctionSummary::ForceSummaryHotnessType ForceSummaryEdgesCold;
 100 }
 101
 102 extern bool WriteNewDbgInfoFormatToBitcode;
 103 extern llvm::cl::opt<bool> UseNewDbgInfoFormat;
 104
 105 namespace {
 106
 107 /// These are manifest constants used by the bitcode writer. They do not need to
 108 /// be kept in sync with the reader, but need to be consistent within this file.
 109 enum {
 110   // VALUE_SYMTAB_BLOCK abbrev id's.
 111   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
 112   VST_ENTRY_7_ABBREV,
 113   VST_ENTRY_6_ABBREV,
 114   VST_BBENTRY_6_ABBREV,
 115
 116   // CONSTANTS_BLOCK abbrev id's.
 117   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
 118   CONSTANTS_INTEGER_ABBREV,
 119   CONSTANTS_CE_CAST_Abbrev,
 120   CONSTANTS_NULL_Abbrev,
 121
 122   // FUNCTION_BLOCK abbrev id's.
 123   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
 124   FUNCTION_INST_UNOP_ABBREV,
 125   FUNCTION_INST_UNOP_FLAGS_ABBREV,
 126   FUNCTION_INST_BINOP_ABBREV,
 127   FUNCTION_INST_BINOP_FLAGS_ABBREV,
 128   FUNCTION_INST_CAST_ABBREV,
 129   FUNCTION_INST_CAST_FLAGS_ABBREV,
 130   FUNCTION_INST_RET_VOID_ABBREV,
 131   FUNCTION_INST_RET_VAL_ABBREV,
 132   FUNCTION_INST_UNREACHABLE_ABBREV,
 133   FUNCTION_INST_GEP_ABBREV,
 134   FUNCTION_DEBUG_RECORD_VALUE_ABBREV,
 135 };
 136
 137 /// Abstract class to manage the bitcode writing, subclassed for each bitcode
 138 /// file type.
 139 class BitcodeWriterBase {
 140 protected:
 141   /// The stream created and owned by the client.
 142   BitstreamWriter &Stream;
 143
 144   StringTableBuilder &StrtabBuilder;
 145
 146 public:
 147   /// Constructs a BitcodeWriterBase object that writes to the provided
 148   /// \p Stream.
 149   BitcodeWriterBase(BitstreamWriter &Stream, StringTableBuilder &StrtabBuilder)
 150       : Stream(Stream), StrtabBuilder(StrtabBuilder) {}
 151
 152 protected:
 153   void writeModuleVersion();
 154 };
 155
 156 void BitcodeWriterBase::writeModuleVersion() {
 157   // VERSION: [version#]
 158   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, ArrayRef<uint64_t>{2});
 159 }
 160
 161 /// Base class to manage the module bitcode writing, currently subclassed for
 162 /// ModuleBitcodeWriter and ThinLinkBitcodeWriter.
 163 class ModuleBitcodeWriterBase : public BitcodeWriterBase {
 164 protected:
 165   /// The Module to write to bitcode.
 166   const Module &M;
 167
 168   /// Enumerates ids for all values in the module.
 169   ValueEnumerator VE;
 170
 171   /// Optional per-module index to write for ThinLTO.
 172   const ModuleSummaryIndex *Index;
 173
 174   /// Map that holds the correspondence between GUIDs in the summary index,
 175   /// that came from indirect call profiles, and a value id generated by this
 176   /// class to use in the VST and summary block records.
 177   std::map<GlobalValue::GUID, unsigned> GUIDToValueIdMap;
 178
 179   /// Tracks the last value id recorded in the GUIDToValueMap.
 180   unsigned GlobalValueId;
 181
 182   /// Saves the offset of the VSTOffset record that must eventually be
 183   /// backpatched with the offset of the actual VST.
 184   uint64_t VSTOffsetPlaceholder = 0;
 185
 186 public:
 187   /// Constructs a ModuleBitcodeWriterBase object for the given Module,
 188   /// writing to the provided \p Buffer.
 189   ModuleBitcodeWriterBase(const Module &M, StringTableBuilder &StrtabBuilder,
 190                           BitstreamWriter &Stream,
 191                           bool ShouldPreserveUseListOrder,
 192                           const ModuleSummaryIndex *Index)
 193       : BitcodeWriterBase(Stream, StrtabBuilder), M(M),
 194         VE(M, ShouldPreserveUseListOrder), Index(Index) {
 195     // Assign ValueIds to any callee values in the index that came from
 196     // indirect call profiles and were recorded as a GUID not a Value*
 197     // (which would have been assigned an ID by the ValueEnumerator).
 198     // The starting ValueId is just after the number of values in the
 199     // ValueEnumerator, so that they can be emitted in the VST.
 200     GlobalValueId = VE.getValues().size();
 201     if (!Index)
 202       return;
 203     for (const auto &GUIDSummaryLists : *Index)
 204       // Examine all summaries for this GUID.
 205       for (auto &Summary : GUIDSummaryLists.second.SummaryList)
 206         if (auto FS = dyn_cast<FunctionSummary>(Summary.get())) {
 207           // For each call in the function summary, see if the call
 208           // is to a GUID (which means it is for an indirect call,
 209           // otherwise we would have a Value for it). If so, synthesize
 210           // a value id.
 211           for (auto &CallEdge : FS->calls())
 212             if (!CallEdge.first.haveGVs() || !CallEdge.first.getValue())
 213               assignValueId(CallEdge.first.getGUID());
 214
 215           // For each referenced variables in the function summary, see if the
 216           // variable is represented by a GUID (as opposed to a symbol to
 217           // declarations or definitions in the module). If so, synthesize a
 218           // value id.
 219           for (auto &RefEdge : FS->refs())
 220             if (!RefEdge.haveGVs() || !RefEdge.getValue())
 221               assignValueId(RefEdge.getGUID());
 222         }
 223   }
 224
 225 protected:
 226   void writePerModuleGlobalValueSummary();
 227
 228 private:
 229   void writePerModuleFunctionSummaryRecord(
 230       SmallVector<uint64_t, 64> &NameVals, GlobalValueSummary *Summary,
 231       unsigned ValueID, unsigned FSCallsAbbrev, unsigned FSCallsProfileAbbrev,
 232       unsigned CallsiteAbbrev, unsigned AllocAbbrev, const Function &F);
 233   void writeModuleLevelReferences(const GlobalVariable &V,
 234                                   SmallVector<uint64_t, 64> &NameVals,
 235                                   unsigned FSModRefsAbbrev,
 236                                   unsigned FSModVTableRefsAbbrev);
 237
 238   void assignValueId(GlobalValue::GUID ValGUID) {
 239     GUIDToValueIdMap[ValGUID] = ++GlobalValueId;
 240   }
 241
 242   unsigned getValueId(GlobalValue::GUID ValGUID) {
 243     const auto &VMI = GUIDToValueIdMap.find(ValGUID);
 244     // Expect that any GUID value had a value Id assigned by an
 245     // earlier call to assignValueId.
 246     assert(VMI != GUIDToValueIdMap.end() &&
 247            "GUID does not have assigned value Id");
 248     return VMI->second;
 249   }
 250
 251   // Helper to get the valueId for the type of value recorded in VI.
 252   unsigned getValueId(ValueInfo VI) {
 253     if (!VI.haveGVs() || !VI.getValue())
 254       return getValueId(VI.getGUID());
 255     return VE.getValueID(VI.getValue());
 256   }
 257
 258   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
 259 };
 260
 261 /// Class to manage the bitcode writing for a module.
 262 class ModuleBitcodeWriter : public ModuleBitcodeWriterBase {
 263   /// Pointer to the buffer allocated by caller for bitcode writing.
 264   const SmallVectorImpl<char> &Buffer;
 265
 266   /// True if a module hash record should be written.
 267   bool GenerateHash;
 268
 269   /// If non-null, when GenerateHash is true, the resulting hash is written
 270   /// into ModHash.
 271   ModuleHash *ModHash;
 272
 273   SHA1 Hasher;
 274
 275   /// The start bit of the identification block.
 276   uint64_t BitcodeStartBit;
 277
 278 public:
 279   /// Constructs a ModuleBitcodeWriter object for the given Module,
 280   /// writing to the provided \p Buffer.
 281   ModuleBitcodeWriter(const Module &M, SmallVectorImpl<char> &Buffer,
 282                       StringTableBuilder &StrtabBuilder,
 283                       BitstreamWriter &Stream, bool ShouldPreserveUseListOrder,
 284                       const ModuleSummaryIndex *Index, bool GenerateHash,
 285                       ModuleHash *ModHash = nullptr)
 286       : ModuleBitcodeWriterBase(M, StrtabBuilder, Stream,
 287                                 ShouldPreserveUseListOrder, Index),
 288         Buffer(Buffer), GenerateHash(GenerateHash), ModHash(ModHash),
 289         BitcodeStartBit(Stream.GetCurrentBitNo()) {}
 290
 291   /// Emit the current module to the bitstream.
 292   void write();
 293
 294 private:
 295   uint64_t bitcodeStartBit() { return BitcodeStartBit; }
 296
 297   size_t addToStrtab(StringRef Str);
 298
 299   void writeAttributeGroupTable();
 300   void writeAttributeTable();
 301   void writeTypeTable();
 302   void writeComdats();
 303   void writeValueSymbolTableForwardDecl();
 304   void writeModuleInfo();
 305   void writeValueAsMetadata(const ValueAsMetadata *MD,
 306                             SmallVectorImpl<uint64_t> &Record);
 307   void writeMDTuple(const MDTuple *N, SmallVectorImpl<uint64_t> &Record,
 308                     unsigned Abbrev);
 309   unsigned createDILocationAbbrev();
 310   void writeDILocation(const DILocation *N, SmallVectorImpl<uint64_t> &Record,
 311                        unsigned &Abbrev);
 312   unsigned createGenericDINodeAbbrev();
 313   void writeGenericDINode(const GenericDINode *N,
 314                           SmallVectorImpl<uint64_t> &Record, unsigned &Abbrev);
 315   void writeDISubrange(const DISubrange *N, SmallVectorImpl<uint64_t> &Record,
 316                        unsigned Abbrev);
 317   void writeDIGenericSubrange(const DIGenericSubrange *N,
 318                               SmallVectorImpl<uint64_t> &Record,
 319                               unsigned Abbrev);
 320   void writeDIEnumerator(const DIEnumerator *N,
 321                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
 322   void writeDIBasicType(const DIBasicType *N, SmallVectorImpl<uint64_t> &Record,
 323                         unsigned Abbrev);
 324   void writeDIStringType(const DIStringType *N,
 325                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
 326   void writeDIDerivedType(const DIDerivedType *N,
 327                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
 328   void writeDICompositeType(const DICompositeType *N,
 329                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
 330   void writeDISubroutineType(const DISubroutineType *N,
 331                              SmallVectorImpl<uint64_t> &Record,
 332                              unsigned Abbrev);
 333   void writeDIFile(const DIFile *N, SmallVectorImpl<uint64_t> &Record,
 334                    unsigned Abbrev);
 335   void writeDICompileUnit(const DICompileUnit *N,
 336                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
 337   void writeDISubprogram(const DISubprogram *N,
 338                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
 339   void writeDILexicalBlock(const DILexicalBlock *N,
 340                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
 341   void writeDILexicalBlockFile(const DILexicalBlockFile *N,
 342                                SmallVectorImpl<uint64_t> &Record,
 343                                unsigned Abbrev);
 344   void writeDICommonBlock(const DICommonBlock *N,
 345                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
 346   void writeDINamespace(const DINamespace *N, SmallVectorImpl<uint64_t> &Record,
 347                         unsigned Abbrev);
 348   void writeDIMacro(const DIMacro *N, SmallVectorImpl<uint64_t> &Record,
 349                     unsigned Abbrev);
 350   void writeDIMacroFile(const DIMacroFile *N, SmallVectorImpl<uint64_t> &Record,
 351                         unsigned Abbrev);
 352   void writeDIArgList(const DIArgList *N, SmallVectorImpl<uint64_t> &Record);
 353   void writeDIModule(const DIModule *N, SmallVectorImpl<uint64_t> &Record,
 354                      unsigned Abbrev);
 355   void writeDIAssignID(const DIAssignID *N, SmallVectorImpl<uint64_t> &Record,
 356                        unsigned Abbrev);
 357   void writeDITemplateTypeParameter(const DITemplateTypeParameter *N,
 358                                     SmallVectorImpl<uint64_t> &Record,
 359                                     unsigned Abbrev);
 360   void writeDITemplateValueParameter(const DITemplateValueParameter *N,
 361                                      SmallVectorImpl<uint64_t> &Record,
 362                                      unsigned Abbrev);
 363   void writeDIGlobalVariable(const DIGlobalVariable *N,
 364                              SmallVectorImpl<uint64_t> &Record,
 365                              unsigned Abbrev);
 366   void writeDILocalVariable(const DILocalVariable *N,
 367                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
 368   void writeDILabel(const DILabel *N,
 369                     SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
 370   void writeDIExpression(const DIExpression *N,
 371                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
 372   void writeDIGlobalVariableExpression(const DIGlobalVariableExpression *N,
 373                                        SmallVectorImpl<uint64_t> &Record,
 374                                        unsigned Abbrev);
 375   void writeDIObjCProperty(const DIObjCProperty *N,
 376                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
 377   void writeDIImportedEntity(const DIImportedEntity *N,
 378                              SmallVectorImpl<uint64_t> &Record,
 379                              unsigned Abbrev);
 380   unsigned createNamedMetadataAbbrev();
 381   void writeNamedMetadata(SmallVectorImpl<uint64_t> &Record);
 382   unsigned createMetadataStringsAbbrev();
 383   void writeMetadataStrings(ArrayRef<const Metadata *> Strings,
 384                             SmallVectorImpl<uint64_t> &Record);
 385   void writeMetadataRecords(ArrayRef<const Metadata *> MDs,
 386                             SmallVectorImpl<uint64_t> &Record,
 387                             std::vector<unsigned> *MDAbbrevs = nullptr,
 388                             std::vector<uint64_t> *IndexPos = nullptr);
 389   void writeModuleMetadata();
 390   void writeFunctionMetadata(const Function &F);
 391   void writeFunctionMetadataAttachment(const Function &F);
 392   void pushGlobalMetadataAttachment(SmallVectorImpl<uint64_t> &Record,
 393                                     const GlobalObject &GO);
 394   void writeModuleMetadataKinds();
 395   void writeOperandBundleTags();
 396   void writeSyncScopeNames();
 397   void writeConstants(unsigned FirstVal, unsigned LastVal, bool isGlobal);
 398   void writeModuleConstants();
 399   bool pushValueAndType(const Value *V, unsigned InstID,
 400                         SmallVectorImpl<unsigned> &Vals);
 401   void writeOperandBundles(const CallBase &CB, unsigned InstID);
 402   void pushValue(const Value *V, unsigned InstID,
 403                  SmallVectorImpl<unsigned> &Vals);
 404   void pushValueSigned(const Value *V, unsigned InstID,
 405                        SmallVectorImpl<uint64_t> &Vals);
 406   void writeInstruction(const Instruction &I, unsigned InstID,
 407                         SmallVectorImpl<unsigned> &Vals);
 408   void writeFunctionLevelValueSymbolTable(const ValueSymbolTable &VST);
 409   void writeGlobalValueSymbolTable(
 410       DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
 411   void writeUseList(UseListOrder &&Order);
 412   void writeUseListBlock(const Function *F);
 413   void
 414   writeFunction(const Function &F,
 415                 DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
 416   void writeBlockInfo();
 417   void writeModuleHash(size_t BlockStartPos);
 418
 419   unsigned getEncodedSyncScopeID(SyncScope::ID SSID) {
 420     return unsigned(SSID);
 421   }
 422
 423   unsigned getEncodedAlign(MaybeAlign Alignment) { return encode(Alignment); }
 424 };
 425
 426 /// Class to manage the bitcode writing for a combined index.
 427 class IndexBitcodeWriter : public BitcodeWriterBase {
 428   /// The combined index to write to bitcode.
 429   const ModuleSummaryIndex &Index;
 430
 431   /// When writing a subset of the index for distributed backends, client
 432   /// provides a map of modules to the corresponding GUIDs/summaries to write.
 433   const std::map<std::string, GVSummaryMapTy> *ModuleToSummariesForIndex;
 434
 435   /// Map that holds the correspondence between the GUID used in the combined
 436   /// index and a value id generated by this class to use in references.
 437   std::map<GlobalValue::GUID, unsigned> GUIDToValueIdMap;
 438
 439   // The sorted stack id indices actually used in the summary entries being
 440   // written, which will be a subset of those in the full index in the case of
 441   // distributed indexes.
 442   std::vector<unsigned> StackIdIndices;
 443
 444   /// Tracks the last value id recorded in the GUIDToValueMap.
 445   unsigned GlobalValueId = 0;
 446
 447   /// Tracks the assignment of module paths in the module path string table to
 448   /// an id assigned for use in summary references to the module path.
 449   DenseMap<StringRef, uint64_t> ModuleIdMap;
 450
 451 public:
 452   /// Constructs a IndexBitcodeWriter object for the given combined index,
 453   /// writing to the provided \p Buffer. When writing a subset of the index
 454   /// for a distributed backend, provide a \p ModuleToSummariesForIndex map.
 455   IndexBitcodeWriter(BitstreamWriter &Stream, StringTableBuilder &StrtabBuilder,
 456                      const ModuleSummaryIndex &Index,
 457                      const std::map<std::string, GVSummaryMapTy>
 458                          *ModuleToSummariesForIndex = nullptr)
 459       : BitcodeWriterBase(Stream, StrtabBuilder), Index(Index),
 460         ModuleToSummariesForIndex(ModuleToSummariesForIndex) {
 461     // Assign unique value ids to all summaries to be written, for use
 462     // in writing out the call graph edges. Save the mapping from GUID
 463     // to the new global value id to use when writing those edges, which
 464     // are currently saved in the index in terms of GUID.
 465     forEachSummary([&](GVInfo I, bool IsAliasee) {
 466       GUIDToValueIdMap[I.first] = ++GlobalValueId;
 467       if (IsAliasee)
 468         return;
 469       auto *FS = dyn_cast<FunctionSummary>(I.second);
 470       if (!FS)
 471         return;
 472       // Record all stack id indices actually used in the summary entries being
 473       // written, so that we can compact them in the case of distributed ThinLTO
 474       // indexes.
 475       for (auto &CI : FS->callsites()) {
 476         // If the stack id list is empty, this callsite info was synthesized for
 477         // a missing tail call frame. Ensure that the callee's GUID gets a value
 478         // id. Normally we only generate these for defined summaries, which in
 479         // the case of distributed ThinLTO is only the functions already defined
 480         // in the module or that we want to import. We don't bother to include
 481         // all the callee symbols as they aren't normally needed in the backend.
 482         // However, for the synthesized callsite infos we do need the callee
 483         // GUID in the backend so that we can correlate the identified callee
 484         // with this callsite info (which for non-tail calls is done by the
 485         // ordering of the callsite infos and verified via stack ids).
 486         if (CI.StackIdIndices.empty()) {
 487           GUIDToValueIdMap[CI.Callee.getGUID()] = ++GlobalValueId;
 488           continue;
 489         }
 490         for (auto Idx : CI.StackIdIndices)
 491           StackIdIndices.push_back(Idx);
 492       }
 493       for (auto &AI : FS->allocs())
 494         for (auto &MIB : AI.MIBs)
 495           for (auto Idx : MIB.StackIdIndices)
 496             StackIdIndices.push_back(Idx);
 497     });
 498     llvm::sort(StackIdIndices);
 499     StackIdIndices.erase(
 500         std::unique(StackIdIndices.begin(), StackIdIndices.end()),
 501         StackIdIndices.end());
 502   }
 503
 504   /// The below iterator returns the GUID and associated summary.
 505   using GVInfo = std::pair<GlobalValue::GUID, GlobalValueSummary *>;
 506
 507   /// Calls the callback for each value GUID and summary to be written to
 508   /// bitcode. This hides the details of whether they are being pulled from the
 509   /// entire index or just those in a provided ModuleToSummariesForIndex map.
 510   template<typename Functor>
 511   void forEachSummary(Functor Callback) {
 512     if (ModuleToSummariesForIndex) {
 513       for (auto &M : *ModuleToSummariesForIndex)
 514         for (auto &Summary : M.second) {
 515           Callback(Summary, false);
 516           // Ensure aliasee is handled, e.g. for assigning a valueId,
 517           // even if we are not importing the aliasee directly (the
 518           // imported alias will contain a copy of aliasee).
 519           if (auto *AS = dyn_cast<AliasSummary>(Summary.getSecond()))
 520             Callback({AS->getAliaseeGUID(), &AS->getAliasee()}, true);
 521         }
 522     } else {
 523       for (auto &Summaries : Index)
 524         for (auto &Summary : Summaries.second.SummaryList)
 525           Callback({Summaries.first, Summary.get()}, false);
 526     }
 527   }
 528
 529   /// Calls the callback for each entry in the modulePaths StringMap that
 530   /// should be written to the module path string table. This hides the details
 531   /// of whether they are being pulled from the entire index or just those in a
 532   /// provided ModuleToSummariesForIndex map.
 533   template <typename Functor> void forEachModule(Functor Callback) {
 534     if (ModuleToSummariesForIndex) {
 535       for (const auto &M : *ModuleToSummariesForIndex) {
 536         const auto &MPI = Index.modulePaths().find(M.first);
 537         if (MPI == Index.modulePaths().end()) {
 538           // This should only happen if the bitcode file was empty, in which
 539           // case we shouldn't be importing (the ModuleToSummariesForIndex
 540           // would only include the module we are writing and index for).
 541           assert(ModuleToSummariesForIndex->size() == 1);
 542           continue;
 543         }
 544         Callback(*MPI);
 545       }
 546     } else {
 547       // Since StringMap iteration order isn't guaranteed, order by path string
 548       // first.
 549       // FIXME: Make this a vector of StringMapEntry instead to avoid the later
 550       // map lookup.
 551       std::vector<StringRef> ModulePaths;
 552       for (auto &[ModPath, _] : Index.modulePaths())
 553         ModulePaths.push_back(ModPath);
 554       llvm::sort(ModulePaths.begin(), ModulePaths.end());
 555       for (auto &ModPath : ModulePaths)
 556         Callback(*Index.modulePaths().find(ModPath));
 557     }
 558   }
 559
 560   /// Main entry point for writing a combined index to bitcode.
 561   void write();
 562
 563 private:
 564   void writeModStrings();
 565   void writeCombinedGlobalValueSummary();
 566
 567   std::optional<unsigned> getValueId(GlobalValue::GUID ValGUID) {
 568     auto VMI = GUIDToValueIdMap.find(ValGUID);
 569     if (VMI == GUIDToValueIdMap.end())
 570       return std::nullopt;
 571     return VMI->second;
 572   }
 573
 574   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
 575 };
 576
 577 } // end anonymous namespace
 578
 579 static unsigned getEncodedCastOpcode(unsigned Opcode) {
 580   switch (Opcode) {
 581   default: llvm_unreachable("Unknown cast instruction!");
 582   case Instruction::Trunc   : return bitc::CAST_TRUNC;
 583   case Instruction::ZExt    : return bitc::CAST_ZEXT;
 584   case Instruction::SExt    : return bitc::CAST_SEXT;
 585   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
 586   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
 587   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
 588   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
 589   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
 590   case Instruction::FPExt   : return bitc::CAST_FPEXT;
 591   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
 592   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
 593   case Instruction::BitCast : return bitc::CAST_BITCAST;
 594   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
 595   }
 596 }
 597
 598 static unsigned getEncodedUnaryOpcode(unsigned Opcode) {
 599   switch (Opcode) {
 600   default: llvm_unreachable("Unknown binary instruction!");
 601   case Instruction::FNeg: return bitc::UNOP_FNEG;
 602   }
 603 }
 604
 605 static unsigned getEncodedBinaryOpcode(unsigned Opcode) {
 606   switch (Opcode) {
 607   default: llvm_unreachable("Unknown binary instruction!");
 608   case Instruction::Add:
 609   case Instruction::FAdd: return bitc::BINOP_ADD;
 610   case Instruction::Sub:
 611   case Instruction::FSub: return bitc::BINOP_SUB;
 612   case Instruction::Mul:
 613   case Instruction::FMul: return bitc::BINOP_MUL;
 614   case Instruction::UDiv: return bitc::BINOP_UDIV;
 615   case Instruction::FDiv:
 616   case Instruction::SDiv: return bitc::BINOP_SDIV;
 617   case Instruction::URem: return bitc::BINOP_UREM;
 618   case Instruction::FRem:
 619   case Instruction::SRem: return bitc::BINOP_SREM;
 620   case Instruction::Shl:  return bitc::BINOP_SHL;
 621   case Instruction::LShr: return bitc::BINOP_LSHR;
 622   case Instruction::AShr: return bitc::BINOP_ASHR;
 623   case Instruction::And:  return bitc::BINOP_AND;
 624   case Instruction::Or:   return bitc::BINOP_OR;
 625   case Instruction::Xor:  return bitc::BINOP_XOR;
 626   }
 627 }
 628
 629 static unsigned getEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
 630   switch (Op) {
 631   default: llvm_unreachable("Unknown RMW operation!");
 632   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
 633   case AtomicRMWInst::Add: return bitc::RMW_ADD;
 634   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
 635   case AtomicRMWInst::And: return bitc::RMW_AND;
 636   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
 637   case AtomicRMWInst::Or: return bitc::RMW_OR;
 638   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
 639   case AtomicRMWInst::Max: return bitc::RMW_MAX;
 640   case AtomicRMWInst::Min: return bitc::RMW_MIN;
 641   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
 642   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
 643   case AtomicRMWInst::FAdd: return bitc::RMW_FADD;
 644   case AtomicRMWInst::FSub: return bitc::RMW_FSUB;
 645   case AtomicRMWInst::FMax: return bitc::RMW_FMAX;
 646   case AtomicRMWInst::FMin: return bitc::RMW_FMIN;
 647   case AtomicRMWInst::UIncWrap:
 648     return bitc::RMW_UINC_WRAP;
 649   case AtomicRMWInst::UDecWrap:
 650     return bitc::RMW_UDEC_WRAP;
 651   }
 652 }
 653
 654 static unsigned getEncodedOrdering(AtomicOrdering Ordering) {
 655   switch (Ordering) {
 656   case AtomicOrdering::NotAtomic: return bitc::ORDERING_NOTATOMIC;
 657   case AtomicOrdering::Unordered: return bitc::ORDERING_UNORDERED;
 658   case AtomicOrdering::Monotonic: return bitc::ORDERING_MONOTONIC;
 659   case AtomicOrdering::Acquire: return bitc::ORDERING_ACQUIRE;
 660   case AtomicOrdering::Release: return bitc::ORDERING_RELEASE;
 661   case AtomicOrdering::AcquireRelease: return bitc::ORDERING_ACQREL;
 662   case AtomicOrdering::SequentiallyConsistent: return bitc::ORDERING_SEQCST;
 663   }
 664   llvm_unreachable("Invalid ordering");
 665 }
 666
 667 static void writeStringRecord(BitstreamWriter &Stream, unsigned Code,
 668                               StringRef Str, unsigned AbbrevToUse) {
 669   SmallVector<unsigned, 64> Vals;
 670
 671   // Code: [strchar x N]
 672   for (char C : Str) {
 673     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(C))
 674       AbbrevToUse = 0;
 675     Vals.push_back(C);
 676   }
 677
 678   // Emit the finished record.
 679   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 680 }
 681
 682 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
 683   switch (Kind) {
 684   case Attribute::Alignment:
 685     return bitc::ATTR_KIND_ALIGNMENT;
 686   case Attribute::AllocAlign:
 687     return bitc::ATTR_KIND_ALLOC_ALIGN;
 688   case Attribute::AllocSize:
 689     return bitc::ATTR_KIND_ALLOC_SIZE;
 690   case Attribute::AlwaysInline:
 691     return bitc::ATTR_KIND_ALWAYS_INLINE;
 692   case Attribute::Builtin:
 693     return bitc::ATTR_KIND_BUILTIN;
 694   case Attribute::ByVal:
 695     return bitc::ATTR_KIND_BY_VAL;
 696   case Attribute::Convergent:
 697     return bitc::ATTR_KIND_CONVERGENT;
 698   case Attribute::InAlloca:
 699     return bitc::ATTR_KIND_IN_ALLOCA;
 700   case Attribute::Cold:
 701     return bitc::ATTR_KIND_COLD;
 702   case Attribute::DisableSanitizerInstrumentation:
 703     return bitc::ATTR_KIND_DISABLE_SANITIZER_INSTRUMENTATION;
 704   case Attribute::FnRetThunkExtern:
 705     return bitc::ATTR_KIND_FNRETTHUNK_EXTERN;
 706   case Attribute::Hot:
 707     return bitc::ATTR_KIND_HOT;
 708   case Attribute::ElementType:
 709     return bitc::ATTR_KIND_ELEMENTTYPE;
 710   case Attribute::InlineHint:
 711     return bitc::ATTR_KIND_INLINE_HINT;
 712   case Attribute::InReg:
 713     return bitc::ATTR_KIND_IN_REG;
 714   case Attribute::JumpTable:
 715     return bitc::ATTR_KIND_JUMP_TABLE;
 716   case Attribute::MinSize:
 717     return bitc::ATTR_KIND_MIN_SIZE;
 718   case Attribute::AllocatedPointer:
 719     return bitc::ATTR_KIND_ALLOCATED_POINTER;
 720   case Attribute::AllocKind:
 721     return bitc::ATTR_KIND_ALLOC_KIND;
 722   case Attribute::Memory:
 723     return bitc::ATTR_KIND_MEMORY;
 724   case Attribute::NoFPClass:
 725     return bitc::ATTR_KIND_NOFPCLASS;
 726   case Attribute::Naked:
 727     return bitc::ATTR_KIND_NAKED;
 728   case Attribute::Nest:
 729     return bitc::ATTR_KIND_NEST;
 730   case Attribute::NoAlias:
 731     return bitc::ATTR_KIND_NO_ALIAS;
 732   case Attribute::NoBuiltin:
 733     return bitc::ATTR_KIND_NO_BUILTIN;
 734   case Attribute::NoCallback:
 735     return bitc::ATTR_KIND_NO_CALLBACK;
 736   case Attribute::NoCapture:
 737     return bitc::ATTR_KIND_NO_CAPTURE;
 738   case Attribute::NoDuplicate:
 739     return bitc::ATTR_KIND_NO_DUPLICATE;
 740   case Attribute::NoFree:
 741     return bitc::ATTR_KIND_NOFREE;
 742   case Attribute::NoImplicitFloat:
 743     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
 744   case Attribute::NoInline:
 745     return bitc::ATTR_KIND_NO_INLINE;
 746   case Attribute::NoRecurse:
 747     return bitc::ATTR_KIND_NO_RECURSE;
 748   case Attribute::NoMerge:
 749     return bitc::ATTR_KIND_NO_MERGE;
 750   case Attribute::NonLazyBind:
 751     return bitc::ATTR_KIND_NON_LAZY_BIND;
 752   case Attribute::NonNull:
 753     return bitc::ATTR_KIND_NON_NULL;
 754   case Attribute::Dereferenceable:
 755     return bitc::ATTR_KIND_DEREFERENCEABLE;
 756   case Attribute::DereferenceableOrNull:
 757     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
 758   case Attribute::NoRedZone:
 759     return bitc::ATTR_KIND_NO_RED_ZONE;
 760   case Attribute::NoReturn:
 761     return bitc::ATTR_KIND_NO_RETURN;
 762   case Attribute::NoSync:
 763     return bitc::ATTR_KIND_NOSYNC;
 764   case Attribute::NoCfCheck:
 765     return bitc::ATTR_KIND_NOCF_CHECK;
 766   case Attribute::NoProfile:
 767     return bitc::ATTR_KIND_NO_PROFILE;
 768   case Attribute::SkipProfile:
 769     return bitc::ATTR_KIND_SKIP_PROFILE;
 770   case Attribute::NoUnwind:
 771     return bitc::ATTR_KIND_NO_UNWIND;
 772   case Attribute::NoSanitizeBounds:
 773     return bitc::ATTR_KIND_NO_SANITIZE_BOUNDS;
 774   case Attribute::NoSanitizeCoverage:
 775     return bitc::ATTR_KIND_NO_SANITIZE_COVERAGE;
 776   case Attribute::NullPointerIsValid:
 777     return bitc::ATTR_KIND_NULL_POINTER_IS_VALID;
 778   case Attribute::OptimizeForDebugging:
 779     return bitc::ATTR_KIND_OPTIMIZE_FOR_DEBUGGING;
 780   case Attribute::OptForFuzzing:
 781     return bitc::ATTR_KIND_OPT_FOR_FUZZING;
 782   case Attribute::OptimizeForSize:
 783     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
 784   case Attribute::OptimizeNone:
 785     return bitc::ATTR_KIND_OPTIMIZE_NONE;
 786   case Attribute::ReadNone:
 787     return bitc::ATTR_KIND_READ_NONE;
 788   case Attribute::ReadOnly:
 789     return bitc::ATTR_KIND_READ_ONLY;
 790   case Attribute::Returned:
 791     return bitc::ATTR_KIND_RETURNED;
 792   case Attribute::ReturnsTwice:
 793     return bitc::ATTR_KIND_RETURNS_TWICE;
 794   case Attribute::SExt:
 795     return bitc::ATTR_KIND_S_EXT;
 796   case Attribute::Speculatable:
 797     return bitc::ATTR_KIND_SPECULATABLE;
 798   case Attribute::StackAlignment:
 799     return bitc::ATTR_KIND_STACK_ALIGNMENT;
 800   case Attribute::StackProtect:
 801     return bitc::ATTR_KIND_STACK_PROTECT;
 802   case Attribute::StackProtectReq:
 803     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
 804   case Attribute::StackProtectStrong:
 805     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
 806   case Attribute::SafeStack:
 807     return bitc::ATTR_KIND_SAFESTACK;
 808   case Attribute::ShadowCallStack:
 809     return bitc::ATTR_KIND_SHADOWCALLSTACK;
 810   case Attribute::StrictFP:
 811     return bitc::ATTR_KIND_STRICT_FP;
 812   case Attribute::StructRet:
 813     return bitc::ATTR_KIND_STRUCT_RET;
 814   case Attribute::SanitizeAddress:
 815     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
 816   case Attribute::SanitizeHWAddress:
 817     return bitc::ATTR_KIND_SANITIZE_HWADDRESS;
 818   case Attribute::SanitizeThread:
 819     return bitc::ATTR_KIND_SANITIZE_THREAD;
 820   case Attribute::SanitizeMemory:
 821     return bitc::ATTR_KIND_SANITIZE_MEMORY;
 822   case Attribute::SpeculativeLoadHardening:
 823     return bitc::ATTR_KIND_SPECULATIVE_LOAD_HARDENING;
 824   case Attribute::SwiftError:
 825     return bitc::ATTR_KIND_SWIFT_ERROR;
 826   case Attribute::SwiftSelf:
 827     return bitc::ATTR_KIND_SWIFT_SELF;
 828   case Attribute::SwiftAsync:
 829     return bitc::ATTR_KIND_SWIFT_ASYNC;
 830   case Attribute::UWTable:
 831     return bitc::ATTR_KIND_UW_TABLE;
 832   case Attribute::VScaleRange:
 833     return bitc::ATTR_KIND_VSCALE_RANGE;
 834   case Attribute::WillReturn:
 835     return bitc::ATTR_KIND_WILLRETURN;
 836   case Attribute::WriteOnly:
 837     return bitc::ATTR_KIND_WRITEONLY;
 838   case Attribute::ZExt:
 839     return bitc::ATTR_KIND_Z_EXT;
 840   case Attribute::ImmArg:
 841     return bitc::ATTR_KIND_IMMARG;
 842   case Attribute::SanitizeMemTag:
 843     return bitc::ATTR_KIND_SANITIZE_MEMTAG;
 844   case Attribute::Preallocated:
 845     return bitc::ATTR_KIND_PREALLOCATED;
 846   case Attribute::NoUndef:
 847     return bitc::ATTR_KIND_NOUNDEF;
 848   case Attribute::ByRef:
 849     return bitc::ATTR_KIND_BYREF;
 850   case Attribute::MustProgress:
 851     return bitc::ATTR_KIND_MUSTPROGRESS;
 852   case Attribute::PresplitCoroutine:
 853     return bitc::ATTR_KIND_PRESPLIT_COROUTINE;
 854   case Attribute::Writable:
 855     return bitc::ATTR_KIND_WRITABLE;
 856   case Attribute::CoroDestroyOnlyWhenComplete:
 857     return bitc::ATTR_KIND_CORO_ONLY_DESTROY_WHEN_COMPLETE;
 858   case Attribute::DeadOnUnwind:
 859     return bitc::ATTR_KIND_DEAD_ON_UNWIND;
 860   case Attribute::Range:
 861     return bitc::ATTR_KIND_RANGE;
 862   case Attribute::EndAttrKinds:
 863     llvm_unreachable("Can not encode end-attribute kinds marker.");
 864   case Attribute::None:
 865     llvm_unreachable("Can not encode none-attribute.");
 866   case Attribute::EmptyKey:
 867   case Attribute::TombstoneKey:
 868     llvm_unreachable("Trying to encode EmptyKey/TombstoneKey");
 869   }
 870
 871   llvm_unreachable("Trying to encode unknown attribute");
 872 }
 873
 874 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
 875   if ((int64_t)V >= 0)
 876     Vals.push_back(V << 1);
 877   else
 878     Vals.push_back((-V << 1) | 1);
 879 }
 880
 881 static void emitWideAPInt(SmallVectorImpl<uint64_t> &Vals, const APInt &A) {
 882   // We have an arbitrary precision integer value to write whose
 883   // bit width is > 64. However, in canonical unsigned integer
 884   // format it is likely that the high bits are going to be zero.
 885   // So, we only write the number of active words.
 886   unsigned NumWords = A.getActiveWords();
 887   const uint64_t *RawData = A.getRawData();
 888   for (unsigned i = 0; i < NumWords; i++)
 889     emitSignedInt64(Vals, RawData[i]);
 890 }
 891
 892 static void emitConstantRange(SmallVectorImpl<uint64_t> &Record,
 893                               const ConstantRange &CR) {
 894   unsigned BitWidth = CR.getBitWidth();
 895   Record.push_back(BitWidth);
 896   if (BitWidth > 64) {
 897     Record.push_back(CR.getLower().getActiveWords() |
 898                      (uint64_t(CR.getUpper().getActiveWords()) << 32));
 899     emitWideAPInt(Record, CR.getLower());
 900     emitWideAPInt(Record, CR.getUpper());
 901   } else {
 902     emitSignedInt64(Record, CR.getLower().getSExtValue());
 903     emitSignedInt64(Record, CR.getUpper().getSExtValue());
 904   }
 905 }
 906
 907 void ModuleBitcodeWriter::writeAttributeGroupTable() {
 908   const std::vector<ValueEnumerator::IndexAndAttrSet> &AttrGrps =
 909       VE.getAttributeGroups();
 910   if (AttrGrps.empty()) return;
 911
 912   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
 913
 914   SmallVector<uint64_t, 64> Record;
 915   for (ValueEnumerator::IndexAndAttrSet Pair : AttrGrps) {
 916     unsigned AttrListIndex = Pair.first;
 917     AttributeSet AS = Pair.second;
 918     Record.push_back(VE.getAttributeGroupID(Pair));
 919     Record.push_back(AttrListIndex);
 920
 921     for (Attribute Attr : AS) {
 922       if (Attr.isEnumAttribute()) {
 923         Record.push_back(0);
 924         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 925       } else if (Attr.isIntAttribute()) {
 926         Record.push_back(1);
 927         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 928         Record.push_back(Attr.getValueAsInt());
 929       } else if (Attr.isStringAttribute()) {
 930         StringRef Kind = Attr.getKindAsString();
 931         StringRef Val = Attr.getValueAsString();
 932
 933         Record.push_back(Val.empty() ? 3 : 4);
 934         Record.append(Kind.begin(), Kind.end());
 935         Record.push_back(0);
 936         if (!Val.empty()) {
 937           Record.append(Val.begin(), Val.end());
 938           Record.push_back(0);
 939         }
 940       } else if (Attr.isTypeAttribute()) {
 941         Type *Ty = Attr.getValueAsType();
 942         Record.push_back(Ty ? 6 : 5);
 943         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 944         if (Ty)
 945           Record.push_back(VE.getTypeID(Attr.getValueAsType()));
 946       } else {
 947         assert(Attr.isConstantRangeAttribute());
 948         Record.push_back(7);
 949         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 950         emitConstantRange(Record, Attr.getValueAsConstantRange());
 951       }
 952     }
 953
 954     Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
 955     Record.clear();
 956   }
 957
 958   Stream.ExitBlock();
 959 }
 960
 961 void ModuleBitcodeWriter::writeAttributeTable() {
 962   const std::vector<AttributeList> &Attrs = VE.getAttributeLists();
 963   if (Attrs.empty()) return;
 964
 965   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 966
 967   SmallVector<uint64_t, 64> Record;
 968   for (const AttributeList &AL : Attrs) {
 969     for (unsigned i : AL.indexes()) {
 970       AttributeSet AS = AL.getAttributes(i);
 971       if (AS.hasAttributes())
 972         Record.push_back(VE.getAttributeGroupID({i, AS}));
 973     }
 974
 975     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 976     Record.clear();
 977   }
 978
 979   Stream.ExitBlock();
 980 }
 981
 982 /// WriteTypeTable - Write out the type table for a module.
 983 void ModuleBitcodeWriter::writeTypeTable() {
 984   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 985
 986   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
 987   SmallVector<uint64_t, 64> TypeVals;
 988
 989   uint64_t NumBits = VE.computeBitsRequiredForTypeIndicies();
 990
 991   // Abbrev for TYPE_CODE_OPAQUE_POINTER.
 992   auto Abbv = std::make_shared<BitCodeAbbrev>();
 993   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_OPAQUE_POINTER));
 994   Abbv->Add(BitCodeAbbrevOp(0)); // Addrspace = 0
 995   unsigned OpaquePtrAbbrev = Stream.EmitAbbrev(std::move(Abbv));
 996
 997   // Abbrev for TYPE_CODE_FUNCTION.
 998   Abbv = std::make_shared<BitCodeAbbrev>();
 999   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
1000   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
1001   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1002   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1003   unsigned FunctionAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1004
1005   // Abbrev for TYPE_CODE_STRUCT_ANON.
1006   Abbv = std::make_shared<BitCodeAbbrev>();
1007   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
1008   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
1009   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1010   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1011   unsigned StructAnonAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1012
1013   // Abbrev for TYPE_CODE_STRUCT_NAME.
1014   Abbv = std::make_shared<BitCodeAbbrev>();
1015   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
1016   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1017   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1018   unsigned StructNameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1019
1020   // Abbrev for TYPE_CODE_STRUCT_NAMED.
1021   Abbv = std::make_shared<BitCodeAbbrev>();
1022   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
1023   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
1024   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1025   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1026   unsigned StructNamedAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1027
1028   // Abbrev for TYPE_CODE_ARRAY.
1029   Abbv = std::make_shared<BitCodeAbbrev>();
1030   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
1031   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
1032   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1033   unsigned ArrayAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1034
1035   // Emit an entry count so the reader can reserve space.
1036   TypeVals.push_back(TypeList.size());
1037   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
1038   TypeVals.clear();
1039
1040   // Loop over all of the types, emitting each in turn.
1041   for (Type *T : TypeList) {
1042     int AbbrevToUse = 0;
1043     unsigned Code = 0;
1044
1045     switch (T->getTypeID()) {
1046     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
1047     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
1048     case Type::BFloatTyID:    Code = bitc::TYPE_CODE_BFLOAT;    break;
1049     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
1050     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
1051     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
1052     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
1053     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
1054     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
1055     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
1056     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
1057     case Type::X86_AMXTyID:   Code = bitc::TYPE_CODE_X86_AMX;   break;
1058     case Type::TokenTyID:     Code = bitc::TYPE_CODE_TOKEN;     break;
1059     case Type::IntegerTyID:
1060       // INTEGER: [width]
1061       Code = bitc::TYPE_CODE_INTEGER;
1062       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
1063       break;
1064     case Type::PointerTyID: {
1065       PointerType *PTy = cast<PointerType>(T);
1066       unsigned AddressSpace = PTy->getAddressSpace();
1067       // OPAQUE_POINTER: [address space]
1068       Code = bitc::TYPE_CODE_OPAQUE_POINTER;
1069       TypeVals.push_back(AddressSpace);
1070       if (AddressSpace == 0)
1071         AbbrevToUse = OpaquePtrAbbrev;
1072       break;
1073     }
1074     case Type::FunctionTyID: {
1075       FunctionType *FT = cast<FunctionType>(T);
1076       // FUNCTION: [isvararg, retty, paramty x N]
1077       Code = bitc::TYPE_CODE_FUNCTION;
1078       TypeVals.push_back(FT->isVarArg());
1079       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
1080       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
1081         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
1082       AbbrevToUse = FunctionAbbrev;
1083       break;
1084     }
1085     case Type::StructTyID: {
1086       StructType *ST = cast<StructType>(T);
1087       // STRUCT: [ispacked, eltty x N]
1088       TypeVals.push_back(ST->isPacked());
1089       // Output all of the element types.
1090       for (Type *ET : ST->elements())
1091         TypeVals.push_back(VE.getTypeID(ET));
1092
1093       if (ST->isLiteral()) {
1094         Code = bitc::TYPE_CODE_STRUCT_ANON;
1095         AbbrevToUse = StructAnonAbbrev;
1096       } else {
1097         if (ST->isOpaque()) {
1098           Code = bitc::TYPE_CODE_OPAQUE;
1099         } else {
1100           Code = bitc::TYPE_CODE_STRUCT_NAMED;
1101           AbbrevToUse = StructNamedAbbrev;
1102         }
1103
1104         // Emit the name if it is present.
1105         if (!ST->getName().empty())
1106           writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
1107                             StructNameAbbrev);
1108       }
1109       break;
1110     }
1111     case Type::ArrayTyID: {
1112       ArrayType *AT = cast<ArrayType>(T);
1113       // ARRAY: [numelts, eltty]
1114       Code = bitc::TYPE_CODE_ARRAY;
1115       TypeVals.push_back(AT->getNumElements());
1116       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
1117       AbbrevToUse = ArrayAbbrev;
1118       break;
1119     }
1120     case Type::FixedVectorTyID:
1121     case Type::ScalableVectorTyID: {
1122       VectorType *VT = cast<VectorType>(T);
1123       // VECTOR [numelts, eltty] or
1124       //        [numelts, eltty, scalable]
1125       Code = bitc::TYPE_CODE_VECTOR;
1126       TypeVals.push_back(VT->getElementCount().getKnownMinValue());
1127       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
1128       if (isa<ScalableVectorType>(VT))
1129         TypeVals.push_back(true);
1130       break;
1131     }
1132     case Type::TargetExtTyID: {
1133       TargetExtType *TET = cast<TargetExtType>(T);
1134       Code = bitc::TYPE_CODE_TARGET_TYPE;
1135       writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, TET->getName(),
1136                         StructNameAbbrev);
1137       TypeVals.push_back(TET->getNumTypeParameters());
1138       for (Type *InnerTy : TET->type_params())
1139         TypeVals.push_back(VE.getTypeID(InnerTy));
1140       for (unsigned IntParam : TET->int_params())
1141         TypeVals.push_back(IntParam);
1142       break;
1143     }
1144     case Type::TypedPointerTyID:
1145       llvm_unreachable("Typed pointers cannot be added to IR modules");
1146     }
1147
1148     // Emit the finished record.
1149     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
1150     TypeVals.clear();
1151   }
1152
1153   Stream.ExitBlock();
1154 }
1155
1156 static unsigned getEncodedLinkage(const GlobalValue::LinkageTypes Linkage) {
1157   switch (Linkage) {
1158   case GlobalValue::ExternalLinkage:
1159     return 0;
1160   case GlobalValue::WeakAnyLinkage:
1161     return 16;
1162   case GlobalValue::AppendingLinkage:
1163     return 2;
1164   case GlobalValue::InternalLinkage:
1165     return 3;
1166   case GlobalValue::LinkOnceAnyLinkage:
1167     return 18;
1168   case GlobalValue::ExternalWeakLinkage:
1169     return 7;
1170   case GlobalValue::CommonLinkage:
1171     return 8;
1172   case GlobalValue::PrivateLinkage:
1173     return 9;
1174   case GlobalValue::WeakODRLinkage:
1175     return 17;
1176   case GlobalValue::LinkOnceODRLinkage:
1177     return 19;
1178   case GlobalValue::AvailableExternallyLinkage:
1179     return 12;
1180   }
1181   llvm_unreachable("Invalid linkage");
1182 }
1183
1184 static unsigned getEncodedLinkage(const GlobalValue &GV) {
1185   return getEncodedLinkage(GV.getLinkage());
1186 }
1187
1188 static uint64_t getEncodedFFlags(FunctionSummary::FFlags Flags) {
1189   uint64_t RawFlags = 0;
1190   RawFlags |= Flags.ReadNone;
1191   RawFlags |= (Flags.ReadOnly << 1);
1192   RawFlags |= (Flags.NoRecurse << 2);
1193   RawFlags |= (Flags.ReturnDoesNotAlias << 3);
1194   RawFlags |= (Flags.NoInline << 4);
1195   RawFlags |= (Flags.AlwaysInline << 5);
1196   RawFlags |= (Flags.NoUnwind << 6);
1197   RawFlags |= (Flags.MayThrow << 7);
1198   RawFlags |= (Flags.HasUnknownCall << 8);
1199   RawFlags |= (Flags.MustBeUnreachable << 9);
1200   return RawFlags;
1201 }
1202
1203 // Decode the flags for GlobalValue in the summary. See getDecodedGVSummaryFlags
1204 // in BitcodeReader.cpp.
1205 static uint64_t getEncodedGVSummaryFlags(GlobalValueSummary::GVFlags Flags) {
1206   uint64_t RawFlags = 0;
1207
1208   RawFlags |= Flags.NotEligibleToImport; // bool
1209   RawFlags |= (Flags.Live << 1);
1210   RawFlags |= (Flags.DSOLocal << 2);
1211   RawFlags |= (Flags.CanAutoHide << 3);
1212
1213   // Linkage don't need to be remapped at that time for the summary. Any future
1214   // change to the getEncodedLinkage() function will need to be taken into
1215   // account here as well.
1216   RawFlags = (RawFlags << 4) | Flags.Linkage; // 4 bits
1217
1218   RawFlags |= (Flags.Visibility << 8); // 2 bits
1219
1220   RawFlags |= (Flags.ImportType << 10); // 1 bit
1221
1222   return RawFlags;
1223 }
1224
1225 static uint64_t getEncodedGVarFlags(GlobalVarSummary::GVarFlags Flags) {
1226   uint64_t RawFlags = Flags.MaybeReadOnly | (Flags.MaybeWriteOnly << 1) |
1227                       (Flags.Constant << 2) | Flags.VCallVisibility << 3;
1228   return RawFlags;
1229 }
1230
1231 static uint64_t getEncodedHotnessCallEdgeInfo(const CalleeInfo &CI) {
1232   uint64_t RawFlags = 0;
1233
1234   RawFlags |= CI.Hotness;            // 3 bits
1235   RawFlags |= (CI.HasTailCall << 3); // 1 bit
1236
1237   return RawFlags;
1238 }
1239
1240 static uint64_t getEncodedRelBFCallEdgeInfo(const CalleeInfo &CI) {
1241   uint64_t RawFlags = 0;
1242
1243   RawFlags |= CI.RelBlockFreq; // CalleeInfo::RelBlockFreqBits bits
1244   RawFlags |= (CI.HasTailCall << CalleeInfo::RelBlockFreqBits); // 1 bit
1245
1246   return RawFlags;
1247 }
1248
1249 static unsigned getEncodedVisibility(const GlobalValue &GV) {
1250   switch (GV.getVisibility()) {
1251   case GlobalValue::DefaultVisibility:   return 0;
1252   case GlobalValue::HiddenVisibility:    return 1;
1253   case GlobalValue::ProtectedVisibility: return 2;
1254   }
1255   llvm_unreachable("Invalid visibility");
1256 }
1257
1258 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
1259   switch (GV.getDLLStorageClass()) {
1260   case GlobalValue::DefaultStorageClass:   return 0;
1261   case GlobalValue::DLLImportStorageClass: return 1;
1262   case GlobalValue::DLLExportStorageClass: return 2;
1263   }
1264   llvm_unreachable("Invalid DLL storage class");
1265 }
1266
1267 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
1268   switch (GV.getThreadLocalMode()) {
1269     case GlobalVariable::NotThreadLocal:         return 0;
1270     case GlobalVariable::GeneralDynamicTLSModel: return 1;
1271     case GlobalVariable::LocalDynamicTLSModel:   return 2;
1272     case GlobalVariable::InitialExecTLSModel:    return 3;
1273     case GlobalVariable::LocalExecTLSModel:      return 4;
1274   }
1275   llvm_unreachable("Invalid TLS model");
1276 }
1277
1278 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
1279   switch (C.getSelectionKind()) {
1280   case Comdat::Any:
1281     return bitc::COMDAT_SELECTION_KIND_ANY;
1282   case Comdat::ExactMatch:
1283     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
1284   case Comdat::Largest:
1285     return bitc::COMDAT_SELECTION_KIND_LARGEST;
1286   case Comdat::NoDeduplicate:
1287     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
1288   case Comdat::SameSize:
1289     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
1290   }
1291   llvm_unreachable("Invalid selection kind");
1292 }
1293
1294 static unsigned getEncodedUnnamedAddr(const GlobalValue &GV) {
1295   switch (GV.getUnnamedAddr()) {
1296   case GlobalValue::UnnamedAddr::None:   return 0;
1297   case GlobalValue::UnnamedAddr::Local:  return 2;
1298   case GlobalValue::UnnamedAddr::Global: return 1;
1299   }
1300   llvm_unreachable("Invalid unnamed_addr");
1301 }
1302
1303 size_t ModuleBitcodeWriter::addToStrtab(StringRef Str) {
1304   if (GenerateHash)
1305     Hasher.update(Str);
1306   return StrtabBuilder.add(Str);
1307 }
1308
1309 void ModuleBitcodeWriter::writeComdats() {
1310   SmallVector<unsigned, 64> Vals;
1311   for (const Comdat *C : VE.getComdats()) {
1312     // COMDAT: [strtab offset, strtab size, selection_kind]
1313     Vals.push_back(addToStrtab(C->getName()));
1314     Vals.push_back(C->getName().size());
1315     Vals.push_back(getEncodedComdatSelectionKind(*C));
1316     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
1317     Vals.clear();
1318   }
1319 }
1320
1321 /// Write a record that will eventually hold the word offset of the
1322 /// module-level VST. For now the offset is 0, which will be backpatched
1323 /// after the real VST is written. Saves the bit offset to backpatch.
1324 void ModuleBitcodeWriter::writeValueSymbolTableForwardDecl() {
1325   // Write a placeholder value in for the offset of the real VST,
1326   // which is written after the function blocks so that it can include
1327   // the offset of each function. The placeholder offset will be
1328   // updated when the real VST is written.
1329   auto Abbv = std::make_shared<BitCodeAbbrev>();
1330   Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_VSTOFFSET));
1331   // Blocks are 32-bit aligned, so we can use a 32-bit word offset to
1332   // hold the real VST offset. Must use fixed instead of VBR as we don't
1333   // know how many VBR chunks to reserve ahead of time.
1334   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1335   unsigned VSTOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1336
1337   // Emit the placeholder
1338   uint64_t Vals[] = {bitc::MODULE_CODE_VSTOFFSET, 0};
1339   Stream.EmitRecordWithAbbrev(VSTOffsetAbbrev, Vals);
1340
1341   // Compute and save the bit offset to the placeholder, which will be
1342   // patched when the real VST is written. We can simply subtract the 32-bit
1343   // fixed size from the current bit number to get the location to backpatch.
1344   VSTOffsetPlaceholder = Stream.GetCurrentBitNo() - 32;
1345 }
1346
1347 enum StringEncoding { SE_Char6, SE_Fixed7, SE_Fixed8 };
1348
1349 /// Determine the encoding to use for the given string name and length.
1350 static StringEncoding getStringEncoding(StringRef Str) {
1351   bool isChar6 = true;
1352   for (char C : Str) {
1353     if (isChar6)
1354       isChar6 = BitCodeAbbrevOp::isChar6(C);
1355     if ((unsigned char)C & 128)
1356       // don't bother scanning the rest.
1357       return SE_Fixed8;
1358   }
1359   if (isChar6)
1360     return SE_Char6;
1361   return SE_Fixed7;
1362 }
1363
1364 static_assert(sizeof(GlobalValue::SanitizerMetadata) <= sizeof(unsigned),
1365               "Sanitizer Metadata is too large for naive serialization.");
1366 static unsigned
1367 serializeSanitizerMetadata(const GlobalValue::SanitizerMetadata &Meta) {
1368   return Meta.NoAddress | (Meta.NoHWAddress << 1) |
1369          (Meta.Memtag << 2) | (Meta.IsDynInit << 3);
1370 }
1371
1372 /// Emit top-level description of module, including target triple, inline asm,
1373 /// descriptors for global variables, and function prototype info.
1374 /// Returns the bit offset to backpatch with the location of the real VST.
1375 void ModuleBitcodeWriter::writeModuleInfo() {
1376   // Emit various pieces of data attached to a module.
1377   if (!M.getTargetTriple().empty())
1378     writeStringRecord(Stream, bitc::MODULE_CODE_TRIPLE, M.getTargetTriple(),
1379                       0 /*TODO*/);
1380   const std::string &DL = M.getDataLayoutStr();
1381   if (!DL.empty())
1382     writeStringRecord(Stream, bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/);
1383   if (!M.getModuleInlineAsm().empty())
1384     writeStringRecord(Stream, bitc::MODULE_CODE_ASM, M.getModuleInlineAsm(),
1385                       0 /*TODO*/);
1386
1387   // Emit information about sections and GC, computing how many there are. Also
1388   // compute the maximum alignment value.
1389   std::map<std::string, unsigned> SectionMap;
1390   std::map<std::string, unsigned> GCMap;
1391   MaybeAlign MaxAlignment;
1392   unsigned MaxGlobalType = 0;
1393   const auto UpdateMaxAlignment = [&MaxAlignment](const MaybeAlign A) {
1394     if (A)
1395       MaxAlignment = !MaxAlignment ? *A : std::max(*MaxAlignment, *A);
1396   };
1397   for (const GlobalVariable &GV : M.globals()) {
1398     UpdateMaxAlignment(GV.getAlign());
1399     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
1400     if (GV.hasSection()) {
1401       // Give section names unique ID's.
1402       unsigned &Entry = SectionMap[std::string(GV.getSection())];
1403       if (!Entry) {
1404         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
1405                           0 /*TODO*/);
1406         Entry = SectionMap.size();
1407       }
1408     }
1409   }
1410   for (const Function &F : M) {
1411     UpdateMaxAlignment(F.getAlign());
1412     if (F.hasSection()) {
1413       // Give section names unique ID's.
1414       unsigned &Entry = SectionMap[std::string(F.getSection())];
1415       if (!Entry) {
1416         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
1417                           0 /*TODO*/);
1418         Entry = SectionMap.size();
1419       }
1420     }
1421     if (F.hasGC()) {
1422       // Same for GC names.
1423       unsigned &Entry = GCMap[F.getGC()];
1424       if (!Entry) {
1425         writeStringRecord(Stream, bitc::MODULE_CODE_GCNAME, F.getGC(),
1426                           0 /*TODO*/);
1427         Entry = GCMap.size();
1428       }
1429     }
1430   }
1431
1432   // Emit abbrev for globals, now that we know # sections and max alignment.
1433   unsigned SimpleGVarAbbrev = 0;
1434   if (!M.global_empty()) {
1435     // Add an abbrev for common globals with no visibility or thread localness.
1436     auto Abbv = std::make_shared<BitCodeAbbrev>();
1437     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
1438     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1439     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1440     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1441                               Log2_32_Ceil(MaxGlobalType+1)));
1442     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
1443                                                            //| explicitType << 1
1444                                                            //| constant
1445     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
1446     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
1447     if (!MaxAlignment)                                     // Alignment.
1448       Abbv->Add(BitCodeAbbrevOp(0));
1449     else {
1450       unsigned MaxEncAlignment = getEncodedAlign(MaxAlignment);
1451       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1452                                Log2_32_Ceil(MaxEncAlignment+1)));
1453     }
1454     if (SectionMap.empty())                                    // Section.
1455       Abbv->Add(BitCodeAbbrevOp(0));
1456     else
1457       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1458                                Log2_32_Ceil(SectionMap.size()+1)));
1459     // Don't bother emitting vis + thread local.
1460     SimpleGVarAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1461   }
1462
1463   SmallVector<unsigned, 64> Vals;
1464   // Emit the module's source file name.
1465   {
1466     StringEncoding Bits = getStringEncoding(M.getSourceFileName());
1467     BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
1468     if (Bits == SE_Char6)
1469       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
1470     else if (Bits == SE_Fixed7)
1471       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
1472
1473     // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
1474     auto Abbv = std::make_shared<BitCodeAbbrev>();
1475     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
1476     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1477     Abbv->Add(AbbrevOpToUse);
1478     unsigned FilenameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1479
1480     for (const auto P : M.getSourceFileName())
1481       Vals.push_back((unsigned char)P);
1482
1483     // Emit the finished record.
1484     Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
1485     Vals.clear();
1486   }
1487
1488   // Emit the global variable information.
1489   for (const GlobalVariable &GV : M.globals()) {
1490     unsigned AbbrevToUse = 0;
1491
1492     // GLOBALVAR: [strtab offset, strtab size, type, isconst, initid,
1493     //             linkage, alignment, section, visibility, threadlocal,
1494     //             unnamed_addr, externally_initialized, dllstorageclass,
1495     //             comdat, attributes, DSO_Local, GlobalSanitizer, code_model]
1496     Vals.push_back(addToStrtab(GV.getName()));
1497     Vals.push_back(GV.getName().size());
1498     Vals.push_back(VE.getTypeID(GV.getValueType()));
1499     Vals.push_back(GV.getType()->getAddressSpace() << 2 | 2 | GV.isConstant());
1500     Vals.push_back(GV.isDeclaration() ? 0 :
1501                    (VE.getValueID(GV.getInitializer()) + 1));
1502     Vals.push_back(getEncodedLinkage(GV));
1503     Vals.push_back(getEncodedAlign(GV.getAlign()));
1504     Vals.push_back(GV.hasSection() ? SectionMap[std::string(GV.getSection())]
1505                                    : 0);
1506     if (GV.isThreadLocal() ||
1507         GV.getVisibility() != GlobalValue::DefaultVisibility ||
1508         GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None ||
1509         GV.isExternallyInitialized() ||
1510         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
1511         GV.hasComdat() || GV.hasAttributes() || GV.isDSOLocal() ||
1512         GV.hasPartition() || GV.hasSanitizerMetadata() || GV.getCodeModel()) {
1513       Vals.push_back(getEncodedVisibility(GV));
1514       Vals.push_back(getEncodedThreadLocalMode(GV));
1515       Vals.push_back(getEncodedUnnamedAddr(GV));
1516       Vals.push_back(GV.isExternallyInitialized());
1517       Vals.push_back(getEncodedDLLStorageClass(GV));
1518       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
1519
1520       auto AL = GV.getAttributesAsList(AttributeList::FunctionIndex);
1521       Vals.push_back(VE.getAttributeListID(AL));
1522
1523       Vals.push_back(GV.isDSOLocal());
1524       Vals.push_back(addToStrtab(GV.getPartition()));
1525       Vals.push_back(GV.getPartition().size());
1526
1527       Vals.push_back((GV.hasSanitizerMetadata() ? serializeSanitizerMetadata(
1528                                                       GV.getSanitizerMetadata())
1529                                                 : 0));
1530       Vals.push_back(GV.getCodeModelRaw());
1531     } else {
1532       AbbrevToUse = SimpleGVarAbbrev;
1533     }
1534
1535     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
1536     Vals.clear();
1537   }
1538
1539   // Emit the function proto information.
1540   for (const Function &F : M) {
1541     // FUNCTION:  [strtab offset, strtab size, type, callingconv, isproto,
1542     //             linkage, paramattrs, alignment, section, visibility, gc,
1543     //             unnamed_addr, prologuedata, dllstorageclass, comdat,
1544     //             prefixdata, personalityfn, DSO_Local, addrspace]
1545     Vals.push_back(addToStrtab(F.getName()));
1546     Vals.push_back(F.getName().size());
1547     Vals.push_back(VE.getTypeID(F.getFunctionType()));
1548     Vals.push_back(F.getCallingConv());
1549     Vals.push_back(F.isDeclaration());
1550     Vals.push_back(getEncodedLinkage(F));
1551     Vals.push_back(VE.getAttributeListID(F.getAttributes()));
1552     Vals.push_back(getEncodedAlign(F.getAlign()));
1553     Vals.push_back(F.hasSection() ? SectionMap[std::string(F.getSection())]
1554                                   : 0);
1555     Vals.push_back(getEncodedVisibility(F));
1556     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
1557     Vals.push_back(getEncodedUnnamedAddr(F));
1558     Vals.push_back(F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1)
1559                                        : 0);
1560     Vals.push_back(getEncodedDLLStorageClass(F));
1561     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
1562     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
1563                                      : 0);
1564     Vals.push_back(
1565         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
1566
1567     Vals.push_back(F.isDSOLocal());
1568     Vals.push_back(F.getAddressSpace());
1569     Vals.push_back(addToStrtab(F.getPartition()));
1570     Vals.push_back(F.getPartition().size());
1571
1572     unsigned AbbrevToUse = 0;
1573     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
1574     Vals.clear();
1575   }
1576
1577   // Emit the alias information.
1578   for (const GlobalAlias &A : M.aliases()) {
1579     // ALIAS: [strtab offset, strtab size, alias type, aliasee val#, linkage,
1580     //         visibility, dllstorageclass, threadlocal, unnamed_addr,
1581     //         DSO_Local]
1582     Vals.push_back(addToStrtab(A.getName()));
1583     Vals.push_back(A.getName().size());
1584     Vals.push_back(VE.getTypeID(A.getValueType()));
1585     Vals.push_back(A.getType()->getAddressSpace());
1586     Vals.push_back(VE.getValueID(A.getAliasee()));
1587     Vals.push_back(getEncodedLinkage(A));
1588     Vals.push_back(getEncodedVisibility(A));
1589     Vals.push_back(getEncodedDLLStorageClass(A));
1590     Vals.push_back(getEncodedThreadLocalMode(A));
1591     Vals.push_back(getEncodedUnnamedAddr(A));
1592     Vals.push_back(A.isDSOLocal());
1593     Vals.push_back(addToStrtab(A.getPartition()));
1594     Vals.push_back(A.getPartition().size());
1595
1596     unsigned AbbrevToUse = 0;
1597     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
1598     Vals.clear();
1599   }
1600
1601   // Emit the ifunc information.
1602   for (const GlobalIFunc &I : M.ifuncs()) {
1603     // IFUNC: [strtab offset, strtab size, ifunc type, address space, resolver
1604     //         val#, linkage, visibility, DSO_Local]
1605     Vals.push_back(addToStrtab(I.getName()));
1606     Vals.push_back(I.getName().size());
1607     Vals.push_back(VE.getTypeID(I.getValueType()));
1608     Vals.push_back(I.getType()->getAddressSpace());
1609     Vals.push_back(VE.getValueID(I.getResolver()));
1610     Vals.push_back(getEncodedLinkage(I));
1611     Vals.push_back(getEncodedVisibility(I));
1612     Vals.push_back(I.isDSOLocal());
1613     Vals.push_back(addToStrtab(I.getPartition()));
1614     Vals.push_back(I.getPartition().size());
1615     Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
1616     Vals.clear();
1617   }
1618
1619   writeValueSymbolTableForwardDecl();
1620 }
1621
1622 static uint64_t getOptimizationFlags(const Value *V) {
1623   uint64_t Flags = 0;
1624
1625   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
1626     if (OBO->hasNoSignedWrap())
1627       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
1628     if (OBO->hasNoUnsignedWrap())
1629       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
1630   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
1631     if (PEO->isExact())
1632       Flags |= 1 << bitc::PEO_EXACT;
1633   } else if (const auto *PDI = dyn_cast<PossiblyDisjointInst>(V)) {
1634     if (PDI->isDisjoint())
1635       Flags |= 1 << bitc::PDI_DISJOINT;
1636   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
1637     if (FPMO->hasAllowReassoc())
1638       Flags |= bitc::AllowReassoc;
1639     if (FPMO->hasNoNaNs())
1640       Flags |= bitc::NoNaNs;
1641     if (FPMO->hasNoInfs())
1642       Flags |= bitc::NoInfs;
1643     if (FPMO->hasNoSignedZeros())
1644       Flags |= bitc::NoSignedZeros;
1645     if (FPMO->hasAllowReciprocal())
1646       Flags |= bitc::AllowReciprocal;
1647     if (FPMO->hasAllowContract())
1648       Flags |= bitc::AllowContract;
1649     if (FPMO->hasApproxFunc())
1650       Flags |= bitc::ApproxFunc;
1651   } else if (const auto *NNI = dyn_cast<PossiblyNonNegInst>(V)) {
1652     if (NNI->hasNonNeg())
1653       Flags |= 1 << bitc::PNNI_NON_NEG;
1654   } else if (const auto *TI = dyn_cast<TruncInst>(V)) {
1655     if (TI->hasNoSignedWrap())
1656       Flags |= 1 << bitc::TIO_NO_SIGNED_WRAP;
1657     if (TI->hasNoUnsignedWrap())
1658       Flags |= 1 << bitc::TIO_NO_UNSIGNED_WRAP;
1659   }
1660
1661   return Flags;
1662 }
1663
1664 void ModuleBitcodeWriter::writeValueAsMetadata(
1665     const ValueAsMetadata *MD, SmallVectorImpl<uint64_t> &Record) {
1666   // Mimic an MDNode with a value as one operand.
1667   Value *V = MD->getValue();
1668   Record.push_back(VE.getTypeID(V->getType()));
1669   Record.push_back(VE.getValueID(V));
1670   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
1671   Record.clear();
1672 }
1673
1674 void ModuleBitcodeWriter::writeMDTuple(const MDTuple *N,
1675                                        SmallVectorImpl<uint64_t> &Record,
1676                                        unsigned Abbrev) {
1677   for (const MDOperand &MDO : N->operands()) {
1678     Metadata *MD = MDO;
1679     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
1680            "Unexpected function-local metadata");
1681     Record.push_back(VE.getMetadataOrNullID(MD));
1682   }
1683   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
1684                                     : bitc::METADATA_NODE,
1685                     Record, Abbrev);
1686   Record.clear();
1687 }
1688
1689 unsigned ModuleBitcodeWriter::createDILocationAbbrev() {
1690   // Assume the column is usually under 128, and always output the inlined-at
1691   // location (it's never more expensive than building an array size 1).
1692   auto Abbv = std::make_shared<BitCodeAbbrev>();
1693   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1694   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1695   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1696   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1697   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1698   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1699   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1700   return Stream.EmitAbbrev(std::move(Abbv));
1701 }
1702
1703 void ModuleBitcodeWriter::writeDILocation(const DILocation *N,
1704                                           SmallVectorImpl<uint64_t> &Record,
1705                                           unsigned &Abbrev) {
1706   if (!Abbrev)
1707     Abbrev = createDILocationAbbrev();
1708
1709   Record.push_back(N->isDistinct());
1710   Record.push_back(N->getLine());
1711   Record.push_back(N->getColumn());
1712   Record.push_back(VE.getMetadataID(N->getScope()));
1713   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
1714   Record.push_back(N->isImplicitCode());
1715
1716   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
1717   Record.clear();
1718 }
1719
1720 unsigned ModuleBitcodeWriter::createGenericDINodeAbbrev() {
1721   // Assume the column is usually under 128, and always output the inlined-at
1722   // location (it's never more expensive than building an array size 1).
1723   auto Abbv = std::make_shared<BitCodeAbbrev>();
1724   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1725   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1726   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1727   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1728   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1729   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1730   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1731   return Stream.EmitAbbrev(std::move(Abbv));
1732 }
1733
1734 void ModuleBitcodeWriter::writeGenericDINode(const GenericDINode *N,
1735                                              SmallVectorImpl<uint64_t> &Record,
1736                                              unsigned &Abbrev) {
1737   if (!Abbrev)
1738     Abbrev = createGenericDINodeAbbrev();
1739
1740   Record.push_back(N->isDistinct());
1741   Record.push_back(N->getTag());
1742   Record.push_back(0); // Per-tag version field; unused for now.
1743
1744   for (auto &I : N->operands())
1745     Record.push_back(VE.getMetadataOrNullID(I));
1746
1747   Stream.EmitRecord(bitc::METADATA_GENERIC_DEBUG, Record, Abbrev);
1748   Record.clear();
1749 }
1750
1751 void ModuleBitcodeWriter::writeDISubrange(const DISubrange *N,
1752                                           SmallVectorImpl<uint64_t> &Record,
1753                                           unsigned Abbrev) {
1754   const uint64_t Version = 2 << 1;
1755   Record.push_back((uint64_t)N->isDistinct() | Version);
1756   Record.push_back(VE.getMetadataOrNullID(N->getRawCountNode()));
1757   Record.push_back(VE.getMetadataOrNullID(N->getRawLowerBound()));
1758   Record.push_back(VE.getMetadataOrNullID(N->getRawUpperBound()));
1759   Record.push_back(VE.getMetadataOrNullID(N->getRawStride()));
1760
1761   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
1762   Record.clear();
1763 }
1764
1765 void ModuleBitcodeWriter::writeDIGenericSubrange(
1766     const DIGenericSubrange *N, SmallVectorImpl<uint64_t> &Record,
1767     unsigned Abbrev) {
1768   Record.push_back((uint64_t)N->isDistinct());
1769   Record.push_back(VE.getMetadataOrNullID(N->getRawCountNode()));
1770   Record.push_back(VE.getMetadataOrNullID(N->getRawLowerBound()));
1771   Record.push_back(VE.getMetadataOrNullID(N->getRawUpperBound()));
1772   Record.push_back(VE.getMetadataOrNullID(N->getRawStride()));
1773
1774   Stream.EmitRecord(bitc::METADATA_GENERIC_SUBRANGE, Record, Abbrev);
1775   Record.clear();
1776 }
1777
1778 void ModuleBitcodeWriter::writeDIEnumerator(const DIEnumerator *N,
1779                                             SmallVectorImpl<uint64_t> &Record,
1780                                             unsigned Abbrev) {
1781   const uint64_t IsBigInt = 1 << 2;
1782   Record.push_back(IsBigInt | (N->isUnsigned() << 1) | N->isDistinct());
1783   Record.push_back(N->getValue().getBitWidth());
1784   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1785   emitWideAPInt(Record, N->getValue());
1786
1787   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
1788   Record.clear();
1789 }
1790
1791 void ModuleBitcodeWriter::writeDIBasicType(const DIBasicType *N,
1792                                            SmallVectorImpl<uint64_t> &Record,
1793                                            unsigned Abbrev) {
1794   Record.push_back(N->isDistinct());
1795   Record.push_back(N->getTag());
1796   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1797   Record.push_back(N->getSizeInBits());
1798   Record.push_back(N->getAlignInBits());
1799   Record.push_back(N->getEncoding());
1800   Record.push_back(N->getFlags());
1801
1802   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
1803   Record.clear();
1804 }
1805
1806 void ModuleBitcodeWriter::writeDIStringType(const DIStringType *N,
1807                                             SmallVectorImpl<uint64_t> &Record,
1808                                             unsigned Abbrev) {
1809   Record.push_back(N->isDistinct());
1810   Record.push_back(N->getTag());
1811   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1812   Record.push_back(VE.getMetadataOrNullID(N->getStringLength()));
1813   Record.push_back(VE.getMetadataOrNullID(N->getStringLengthExp()));
1814   Record.push_back(VE.getMetadataOrNullID(N->getStringLocationExp()));
1815   Record.push_back(N->getSizeInBits());
1816   Record.push_back(N->getAlignInBits());
1817   Record.push_back(N->getEncoding());
1818
1819   Stream.EmitRecord(bitc::METADATA_STRING_TYPE, Record, Abbrev);
1820   Record.clear();
1821 }
1822
1823 void ModuleBitcodeWriter::writeDIDerivedType(const DIDerivedType *N,
1824                                              SmallVectorImpl<uint64_t> &Record,
1825                                              unsigned Abbrev) {
1826   Record.push_back(N->isDistinct());
1827   Record.push_back(N->getTag());
1828   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1829   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1830   Record.push_back(N->getLine());
1831   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1832   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1833   Record.push_back(N->getSizeInBits());
1834   Record.push_back(N->getAlignInBits());
1835   Record.push_back(N->getOffsetInBits());
1836   Record.push_back(N->getFlags());
1837   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
1838
1839   // DWARF address space is encoded as N->getDWARFAddressSpace() + 1. 0 means
1840   // that there is no DWARF address space associated with DIDerivedType.
1841   if (const auto &DWARFAddressSpace = N->getDWARFAddressSpace())
1842     Record.push_back(*DWARFAddressSpace + 1);
1843   else
1844     Record.push_back(0);
1845
1846   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
1847
1848   if (auto PtrAuthData = N->getPtrAuthData())
1849     Record.push_back(PtrAuthData->RawData);
1850   else
1851     Record.push_back(0);
1852
1853   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
1854   Record.clear();
1855 }
1856
1857 void ModuleBitcodeWriter::writeDICompositeType(
1858     const DICompositeType *N, SmallVectorImpl<uint64_t> &Record,
1859     unsigned Abbrev) {
1860   const unsigned IsNotUsedInOldTypeRef = 0x2;
1861   Record.push_back(IsNotUsedInOldTypeRef | (unsigned)N->isDistinct());
1862   Record.push_back(N->getTag());
1863   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1864   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1865   Record.push_back(N->getLine());
1866   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1867   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1868   Record.push_back(N->getSizeInBits());
1869   Record.push_back(N->getAlignInBits());
1870   Record.push_back(N->getOffsetInBits());
1871   Record.push_back(N->getFlags());
1872   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1873   Record.push_back(N->getRuntimeLang());
1874   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
1875   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1876   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
1877   Record.push_back(VE.getMetadataOrNullID(N->getDiscriminator()));
1878   Record.push_back(VE.getMetadataOrNullID(N->getRawDataLocation()));
1879   Record.push_back(VE.getMetadataOrNullID(N->getRawAssociated()));
1880   Record.push_back(VE.getMetadataOrNullID(N->getRawAllocated()));
1881   Record.push_back(VE.getMetadataOrNullID(N->getRawRank()));
1882   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
1883
1884   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
1885   Record.clear();
1886 }
1887
1888 void ModuleBitcodeWriter::writeDISubroutineType(
1889     const DISubroutineType *N, SmallVectorImpl<uint64_t> &Record,
1890     unsigned Abbrev) {
1891   const unsigned HasNoOldTypeRefs = 0x2;
1892   Record.push_back(HasNoOldTypeRefs | (unsigned)N->isDistinct());
1893   Record.push_back(N->getFlags());
1894   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
1895   Record.push_back(N->getCC());
1896
1897   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
1898   Record.clear();
1899 }
1900
1901 void ModuleBitcodeWriter::writeDIFile(const DIFile *N,
1902                                       SmallVectorImpl<uint64_t> &Record,
1903                                       unsigned Abbrev) {
1904   Record.push_back(N->isDistinct());
1905   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
1906   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
1907   if (N->getRawChecksum()) {
1908     Record.push_back(N->getRawChecksum()->Kind);
1909     Record.push_back(VE.getMetadataOrNullID(N->getRawChecksum()->Value));
1910   } else {
1911     // Maintain backwards compatibility with the old internal representation of
1912     // CSK_None in ChecksumKind by writing nulls here when Checksum is None.
1913     Record.push_back(0);
1914     Record.push_back(VE.getMetadataOrNullID(nullptr));
1915   }
1916   auto Source = N->getRawSource();
1917   if (Source)
1918     Record.push_back(VE.getMetadataOrNullID(Source));
1919
1920   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
1921   Record.clear();
1922 }
1923
1924 void ModuleBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
1925                                              SmallVectorImpl<uint64_t> &Record,
1926                                              unsigned Abbrev) {
1927   assert(N->isDistinct() && "Expected distinct compile units");
1928   Record.push_back(/* IsDistinct */ true);
1929   Record.push_back(N->getSourceLanguage());
1930   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1931   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
1932   Record.push_back(N->isOptimized());
1933   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
1934   Record.push_back(N->getRuntimeVersion());
1935   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
1936   Record.push_back(N->getEmissionKind());
1937   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
1938   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
1939   Record.push_back(/* subprograms */ 0);
1940   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
1941   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
1942   Record.push_back(N->getDWOId());
1943   Record.push_back(VE.getMetadataOrNullID(N->getMacros().get()));
1944   Record.push_back(N->getSplitDebugInlining());
1945   Record.push_back(N->getDebugInfoForProfiling());
1946   Record.push_back((unsigned)N->getNameTableKind());
1947   Record.push_back(N->getRangesBaseAddress());
1948   Record.push_back(VE.getMetadataOrNullID(N->getRawSysRoot()));
1949   Record.push_back(VE.getMetadataOrNullID(N->getRawSDK()));
1950
1951   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
1952   Record.clear();
1953 }
1954
1955 void ModuleBitcodeWriter::writeDISubprogram(const DISubprogram *N,
1956                                             SmallVectorImpl<uint64_t> &Record,
1957                                             unsigned Abbrev) {
1958   const uint64_t HasUnitFlag = 1 << 1;
1959   const uint64_t HasSPFlagsFlag = 1 << 2;
1960   Record.push_back(uint64_t(N->isDistinct()) | HasUnitFlag | HasSPFlagsFlag);
1961   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1962   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1963   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1964   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1965   Record.push_back(N->getLine());
1966   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1967   Record.push_back(N->getScopeLine());
1968   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
1969   Record.push_back(N->getSPFlags());
1970   Record.push_back(N->getVirtualIndex());
1971   Record.push_back(N->getFlags());
1972   Record.push_back(VE.getMetadataOrNullID(N->getRawUnit()));
1973   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1974   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
1975   Record.push_back(VE.getMetadataOrNullID(N->getRetainedNodes().get()));
1976   Record.push_back(N->getThisAdjustment());
1977   Record.push_back(VE.getMetadataOrNullID(N->getThrownTypes().get()));
1978   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
1979   Record.push_back(VE.getMetadataOrNullID(N->getRawTargetFuncName()));
1980
1981   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
1982   Record.clear();
1983 }
1984
1985 void ModuleBitcodeWriter::writeDILexicalBlock(const DILexicalBlock *N,
1986                                               SmallVectorImpl<uint64_t> &Record,
1987                                               unsigned Abbrev) {
1988   Record.push_back(N->isDistinct());
1989   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1990   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1991   Record.push_back(N->getLine());
1992   Record.push_back(N->getColumn());
1993
1994   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
1995   Record.clear();
1996 }
1997
1998 void ModuleBitcodeWriter::writeDILexicalBlockFile(
1999     const DILexicalBlockFile *N, SmallVectorImpl<uint64_t> &Record,
2000     unsigned Abbrev) {
2001   Record.push_back(N->isDistinct());
2002   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2003   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2004   Record.push_back(N->getDiscriminator());
2005
2006   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
2007   Record.clear();
2008 }
2009
2010 void ModuleBitcodeWriter::writeDICommonBlock(const DICommonBlock *N,
2011                                              SmallVectorImpl<uint64_t> &Record,
2012                                              unsigned Abbrev) {
2013   Record.push_back(N->isDistinct());
2014   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2015   Record.push_back(VE.getMetadataOrNullID(N->getDecl()));
2016   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2017   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2018   Record.push_back(N->getLineNo());
2019
2020   Stream.EmitRecord(bitc::METADATA_COMMON_BLOCK, Record, Abbrev);
2021   Record.clear();
2022 }
2023
2024 void ModuleBitcodeWriter::writeDINamespace(const DINamespace *N,
2025                                            SmallVectorImpl<uint64_t> &Record,
2026                                            unsigned Abbrev) {
2027   Record.push_back(N->isDistinct() | N->getExportSymbols() << 1);
2028   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2029   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2030
2031   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
2032   Record.clear();
2033 }
2034
2035 void ModuleBitcodeWriter::writeDIMacro(const DIMacro *N,
2036                                        SmallVectorImpl<uint64_t> &Record,
2037                                        unsigned Abbrev) {
2038   Record.push_back(N->isDistinct());
2039   Record.push_back(N->getMacinfoType());
2040   Record.push_back(N->getLine());
2041   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2042   Record.push_back(VE.getMetadataOrNullID(N->getRawValue()));
2043
2044   Stream.EmitRecord(bitc::METADATA_MACRO, Record, Abbrev);
2045   Record.clear();
2046 }
2047
2048 void ModuleBitcodeWriter::writeDIMacroFile(const DIMacroFile *N,
2049                                            SmallVectorImpl<uint64_t> &Record,
2050                                            unsigned Abbrev) {
2051   Record.push_back(N->isDistinct());
2052   Record.push_back(N->getMacinfoType());
2053   Record.push_back(N->getLine());
2054   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2055   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
2056
2057   Stream.EmitRecord(bitc::METADATA_MACRO_FILE, Record, Abbrev);
2058   Record.clear();
2059 }
2060
2061 void ModuleBitcodeWriter::writeDIArgList(const DIArgList *N,
2062                                          SmallVectorImpl<uint64_t> &Record) {
2063   Record.reserve(N->getArgs().size());
2064   for (ValueAsMetadata *MD : N->getArgs())
2065     Record.push_back(VE.getMetadataID(MD));
2066
2067   Stream.EmitRecord(bitc::METADATA_ARG_LIST, Record);
2068   Record.clear();
2069 }
2070
2071 void ModuleBitcodeWriter::writeDIModule(const DIModule *N,
2072                                         SmallVectorImpl<uint64_t> &Record,
2073                                         unsigned Abbrev) {
2074   Record.push_back(N->isDistinct());
2075   for (auto &I : N->operands())
2076     Record.push_back(VE.getMetadataOrNullID(I));
2077   Record.push_back(N->getLineNo());
2078   Record.push_back(N->getIsDecl());
2079
2080   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
2081   Record.clear();
2082 }
2083
2084 void ModuleBitcodeWriter::writeDIAssignID(const DIAssignID *N,
2085                                           SmallVectorImpl<uint64_t> &Record,
2086                                           unsigned Abbrev) {
2087   // There are no arguments for this metadata type.
2088   Record.push_back(N->isDistinct());
2089   Stream.EmitRecord(bitc::METADATA_ASSIGN_ID, Record, Abbrev);
2090   Record.clear();
2091 }
2092
2093 void ModuleBitcodeWriter::writeDITemplateTypeParameter(
2094     const DITemplateTypeParameter *N, SmallVectorImpl<uint64_t> &Record,
2095     unsigned Abbrev) {
2096   Record.push_back(N->isDistinct());
2097   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2098   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2099   Record.push_back(N->isDefault());
2100
2101   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
2102   Record.clear();
2103 }
2104
2105 void ModuleBitcodeWriter::writeDITemplateValueParameter(
2106     const DITemplateValueParameter *N, SmallVectorImpl<uint64_t> &Record,
2107     unsigned Abbrev) {
2108   Record.push_back(N->isDistinct());
2109   Record.push_back(N->getTag());
2110   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2111   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2112   Record.push_back(N->isDefault());
2113   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
2114
2115   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
2116   Record.clear();
2117 }
2118
2119 void ModuleBitcodeWriter::writeDIGlobalVariable(
2120     const DIGlobalVariable *N, SmallVectorImpl<uint64_t> &Record,
2121     unsigned Abbrev) {
2122   const uint64_t Version = 2 << 1;
2123   Record.push_back((uint64_t)N->isDistinct() | Version);
2124   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2125   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2126   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
2127   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2128   Record.push_back(N->getLine());
2129   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2130   Record.push_back(N->isLocalToUnit());
2131   Record.push_back(N->isDefinition());
2132   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
2133   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams()));
2134   Record.push_back(N->getAlignInBits());
2135   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
2136
2137   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
2138   Record.clear();
2139 }
2140
2141 void ModuleBitcodeWriter::writeDILocalVariable(
2142     const DILocalVariable *N, SmallVectorImpl<uint64_t> &Record,
2143     unsigned Abbrev) {
2144   // In order to support all possible bitcode formats in BitcodeReader we need
2145   // to distinguish the following cases:
2146   // 1) Record has no artificial tag (Record[1]),
2147   //   has no obsolete inlinedAt field (Record[9]).
2148   //   In this case Record size will be 8, HasAlignment flag is false.
2149   // 2) Record has artificial tag (Record[1]),
2150   //   has no obsolete inlignedAt field (Record[9]).
2151   //   In this case Record size will be 9, HasAlignment flag is false.
2152   // 3) Record has both artificial tag (Record[1]) and
2153   //   obsolete inlignedAt field (Record[9]).
2154   //   In this case Record size will be 10, HasAlignment flag is false.
2155   // 4) Record has neither artificial tag, nor inlignedAt field, but
2156   //   HasAlignment flag is true and Record[8] contains alignment value.
2157   const uint64_t HasAlignmentFlag = 1 << 1;
2158   Record.push_back((uint64_t)N->isDistinct() | HasAlignmentFlag);
2159   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2160   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2161   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2162   Record.push_back(N->getLine());
2163   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2164   Record.push_back(N->getArg());
2165   Record.push_back(N->getFlags());
2166   Record.push_back(N->getAlignInBits());
2167   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
2168
2169   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
2170   Record.clear();
2171 }
2172
2173 void ModuleBitcodeWriter::writeDILabel(
2174     const DILabel *N, SmallVectorImpl<uint64_t> &Record,
2175     unsigned Abbrev) {
2176   Record.push_back((uint64_t)N->isDistinct());
2177   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2178   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2179   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2180   Record.push_back(N->getLine());
2181
2182   Stream.EmitRecord(bitc::METADATA_LABEL, Record, Abbrev);
2183   Record.clear();
2184 }
2185
2186 void ModuleBitcodeWriter::writeDIExpression(const DIExpression *N,
2187                                             SmallVectorImpl<uint64_t> &Record,
2188                                             unsigned Abbrev) {
2189   Record.reserve(N->getElements().size() + 1);
2190   const uint64_t Version = 3 << 1;
2191   Record.push_back((uint64_t)N->isDistinct() | Version);
2192   Record.append(N->elements_begin(), N->elements_end());
2193
2194   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
2195   Record.clear();
2196 }
2197
2198 void ModuleBitcodeWriter::writeDIGlobalVariableExpression(
2199     const DIGlobalVariableExpression *N, SmallVectorImpl<uint64_t> &Record,
2200     unsigned Abbrev) {
2201   Record.push_back(N->isDistinct());
2202   Record.push_back(VE.getMetadataOrNullID(N->getVariable()));
2203   Record.push_back(VE.getMetadataOrNullID(N->getExpression()));
2204
2205   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR_EXPR, Record, Abbrev);
2206   Record.clear();
2207 }
2208
2209 void ModuleBitcodeWriter::writeDIObjCProperty(const DIObjCProperty *N,
2210                                               SmallVectorImpl<uint64_t> &Record,
2211                                               unsigned Abbrev) {
2212   Record.push_back(N->isDistinct());
2213   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2214   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2215   Record.push_back(N->getLine());
2216   Record.push_back(VE.getMetadataOrNullID(N->getRawSetterName()));
2217   Record.push_back(VE.getMetadataOrNullID(N->getRawGetterName()));
2218   Record.push_back(N->getAttributes());
2219   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2220
2221   Stream.EmitRecord(bitc::METADATA_OBJC_PROPERTY, Record, Abbrev);
2222   Record.clear();
2223 }
2224
2225 void ModuleBitcodeWriter::writeDIImportedEntity(
2226     const DIImportedEntity *N, SmallVectorImpl<uint64_t> &Record,
2227     unsigned Abbrev) {
2228   Record.push_back(N->isDistinct());
2229   Record.push_back(N->getTag());
2230   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2231   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
2232   Record.push_back(N->getLine());
2233   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2234   Record.push_back(VE.getMetadataOrNullID(N->getRawFile()));
2235   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
2236
2237   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
2238   Record.clear();
2239 }
2240
2241 unsigned ModuleBitcodeWriter::createNamedMetadataAbbrev() {
2242   auto Abbv = std::make_shared<BitCodeAbbrev>();
2243   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
2244   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2245   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2246   return Stream.EmitAbbrev(std::move(Abbv));
2247 }
2248
2249 void ModuleBitcodeWriter::writeNamedMetadata(
2250     SmallVectorImpl<uint64_t> &Record) {
2251   if (M.named_metadata_empty())
2252     return;
2253
2254   unsigned Abbrev = createNamedMetadataAbbrev();
2255   for (const NamedMDNode &NMD : M.named_metadata()) {
2256     // Write name.
2257     StringRef Str = NMD.getName();
2258     Record.append(Str.bytes_begin(), Str.bytes_end());
2259     Stream.EmitRecord(bitc::METADATA_NAME, Record, Abbrev);
2260     Record.clear();
2261
2262     // Write named metadata operands.
2263     for (const MDNode *N : NMD.operands())
2264       Record.push_back(VE.getMetadataID(N));
2265     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
2266     Record.clear();
2267   }
2268 }
2269
2270 unsigned ModuleBitcodeWriter::createMetadataStringsAbbrev() {
2271   auto Abbv = std::make_shared<BitCodeAbbrev>();
2272   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRINGS));
2273   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of strings
2274   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // offset to chars
2275   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2276   return Stream.EmitAbbrev(std::move(Abbv));
2277 }
2278
2279 /// Write out a record for MDString.
2280 ///
2281 /// All the metadata strings in a metadata block are emitted in a single
2282 /// record.  The sizes and strings themselves are shoved into a blob.
2283 void ModuleBitcodeWriter::writeMetadataStrings(
2284     ArrayRef<const Metadata *> Strings, SmallVectorImpl<uint64_t> &Record) {
2285   if (Strings.empty())
2286     return;
2287
2288   // Start the record with the number of strings.
2289   Record.push_back(bitc::METADATA_STRINGS);
2290   Record.push_back(Strings.size());
2291
2292   // Emit the sizes of the strings in the blob.
2293   SmallString<256> Blob;
2294   {
2295     BitstreamWriter W(Blob);
2296     for (const Metadata *MD : Strings)
2297       W.EmitVBR(cast<MDString>(MD)->getLength(), 6);
2298     W.FlushToWord();
2299   }
2300
2301   // Add the offset to the strings to the record.
2302   Record.push_back(Blob.size());
2303
2304   // Add the strings to the blob.
2305   for (const Metadata *MD : Strings)
2306     Blob.append(cast<MDString>(MD)->getString());
2307
2308   // Emit the final record.
2309   Stream.EmitRecordWithBlob(createMetadataStringsAbbrev(), Record, Blob);
2310   Record.clear();
2311 }
2312
2313 // Generates an enum to use as an index in the Abbrev array of Metadata record.
2314 enum MetadataAbbrev : unsigned {
2315 #define HANDLE_MDNODE_LEAF(CLASS) CLASS##AbbrevID,
2316 #include "llvm/IR/Metadata.def"
2317   LastPlusOne
2318 };
2319
2320 void ModuleBitcodeWriter::writeMetadataRecords(
2321     ArrayRef<const Metadata *> MDs, SmallVectorImpl<uint64_t> &Record,
2322     std::vector<unsigned> *MDAbbrevs, std::vector<uint64_t> *IndexPos) {
2323   if (MDs.empty())
2324     return;
2325
2326   // Initialize MDNode abbreviations.
2327 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
2328 #include "llvm/IR/Metadata.def"
2329
2330   for (const Metadata *MD : MDs) {
2331     if (IndexPos)
2332       IndexPos->push_back(Stream.GetCurrentBitNo());
2333     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
2334       assert(N->isResolved() && "Expected forward references to be resolved");
2335
2336       switch (N->getMetadataID()) {
2337       default:
2338         llvm_unreachable("Invalid MDNode subclass");
2339 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
2340   case Metadata::CLASS##Kind:                                                  \
2341     if (MDAbbrevs)                                                             \
2342       write##CLASS(cast<CLASS>(N), Record,                                     \
2343                    (*MDAbbrevs)[MetadataAbbrev::CLASS##AbbrevID]);             \
2344     else                                                                       \
2345       write##CLASS(cast<CLASS>(N), Record, CLASS##Abbrev);                     \
2346     continue;
2347 #include "llvm/IR/Metadata.def"
2348       }
2349     }
2350     if (auto *AL = dyn_cast<DIArgList>(MD)) {
2351       writeDIArgList(AL, Record);
2352       continue;
2353     }
2354     writeValueAsMetadata(cast<ValueAsMetadata>(MD), Record);
2355   }
2356 }
2357
2358 void ModuleBitcodeWriter::writeModuleMetadata() {
2359   if (!VE.hasMDs() && M.named_metadata_empty())
2360     return;
2361
2362   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 4);
2363   SmallVector<uint64_t, 64> Record;
2364
2365   // Emit all abbrevs upfront, so that the reader can jump in the middle of the
2366   // block and load any metadata.
2367   std::vector<unsigned> MDAbbrevs;
2368
2369   MDAbbrevs.resize(MetadataAbbrev::LastPlusOne);
2370   MDAbbrevs[MetadataAbbrev::DILocationAbbrevID] = createDILocationAbbrev();
2371   MDAbbrevs[MetadataAbbrev::GenericDINodeAbbrevID] =
2372       createGenericDINodeAbbrev();
2373
2374   auto Abbv = std::make_shared<BitCodeAbbrev>();
2375   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_INDEX_OFFSET));
2376   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2377   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2378   unsigned OffsetAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2379
2380   Abbv = std::make_shared<BitCodeAbbrev>();
2381   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_INDEX));
2382   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2383   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2384   unsigned IndexAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2385
2386   // Emit MDStrings together upfront.
2387   writeMetadataStrings(VE.getMDStrings(), Record);
2388
2389   // We only emit an index for the metadata record if we have more than a given
2390   // (naive) threshold of metadatas, otherwise it is not worth it.
2391   if (VE.getNonMDStrings().size() > IndexThreshold) {
2392     // Write a placeholder value in for the offset of the metadata index,
2393     // which is written after the records, so that it can include
2394     // the offset of each entry. The placeholder offset will be
2395     // updated after all records are emitted.
2396     uint64_t Vals[] = {0, 0};
2397     Stream.EmitRecord(bitc::METADATA_INDEX_OFFSET, Vals, OffsetAbbrev);
2398   }
2399
2400   // Compute and save the bit offset to the current position, which will be
2401   // patched when we emit the index later. We can simply subtract the 64-bit
2402   // fixed size from the current bit number to get the location to backpatch.
2403   uint64_t IndexOffsetRecordBitPos = Stream.GetCurrentBitNo();
2404
2405   // This index will contain the bitpos for each individual record.
2406   std::vector<uint64_t> IndexPos;
2407   IndexPos.reserve(VE.getNonMDStrings().size());
2408
2409   // Write all the records
2410   writeMetadataRecords(VE.getNonMDStrings(), Record, &MDAbbrevs, &IndexPos);
2411
2412   if (VE.getNonMDStrings().size() > IndexThreshold) {
2413     // Now that we have emitted all the records we will emit the index. But
2414     // first
2415     // backpatch the forward reference so that the reader can skip the records
2416     // efficiently.
2417     Stream.BackpatchWord64(IndexOffsetRecordBitPos - 64,
2418                            Stream.GetCurrentBitNo() - IndexOffsetRecordBitPos);
2419
2420     // Delta encode the index.
2421     uint64_t PreviousValue = IndexOffsetRecordBitPos;
2422     for (auto &Elt : IndexPos) {
2423       auto EltDelta = Elt - PreviousValue;
2424       PreviousValue = Elt;
2425       Elt = EltDelta;
2426     }
2427     // Emit the index record.
2428     Stream.EmitRecord(bitc::METADATA_INDEX, IndexPos, IndexAbbrev);
2429     IndexPos.clear();
2430   }
2431
2432   // Write the named metadata now.
2433   writeNamedMetadata(Record);
2434
2435   auto AddDeclAttachedMetadata = [&](const GlobalObject &GO) {
2436     SmallVector<uint64_t, 4> Record;
2437     Record.push_back(VE.getValueID(&GO));
2438     pushGlobalMetadataAttachment(Record, GO);
2439     Stream.EmitRecord(bitc::METADATA_GLOBAL_DECL_ATTACHMENT, Record);
2440   };
2441   for (const Function &F : M)
2442     if (F.isDeclaration() && F.hasMetadata())
2443       AddDeclAttachedMetadata(F);
2444   // FIXME: Only store metadata for declarations here, and move data for global
2445   // variable definitions to a separate block (PR28134).
2446   for (const GlobalVariable &GV : M.globals())
2447     if (GV.hasMetadata())
2448       AddDeclAttachedMetadata(GV);
2449
2450   Stream.ExitBlock();
2451 }
2452
2453 void ModuleBitcodeWriter::writeFunctionMetadata(const Function &F) {
2454   if (!VE.hasMDs())
2455     return;
2456
2457   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
2458   SmallVector<uint64_t, 64> Record;
2459   writeMetadataStrings(VE.getMDStrings(), Record);
2460   writeMetadataRecords(VE.getNonMDStrings(), Record);
2461   Stream.ExitBlock();
2462 }
2463
2464 void ModuleBitcodeWriter::pushGlobalMetadataAttachment(
2465     SmallVectorImpl<uint64_t> &Record, const GlobalObject &GO) {
2466   // [n x [id, mdnode]]
2467   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
2468   GO.getAllMetadata(MDs);
2469   for (const auto &I : MDs) {
2470     Record.push_back(I.first);
2471     Record.push_back(VE.getMetadataID(I.second));
2472   }
2473 }
2474
2475 void ModuleBitcodeWriter::writeFunctionMetadataAttachment(const Function &F) {
2476   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
2477
2478   SmallVector<uint64_t, 64> Record;
2479
2480   if (F.hasMetadata()) {
2481     pushGlobalMetadataAttachment(Record, F);
2482     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
2483     Record.clear();
2484   }
2485
2486   // Write metadata attachments
2487   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
2488   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
2489   for (const BasicBlock &BB : F)
2490     for (const Instruction &I : BB) {
2491       MDs.clear();
2492       I.getAllMetadataOtherThanDebugLoc(MDs);
2493
2494       // If no metadata, ignore instruction.
2495       if (MDs.empty()) continue;
2496
2497       Record.push_back(VE.getInstructionID(&I));
2498
2499       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
2500         Record.push_back(MDs[i].first);
2501         Record.push_back(VE.getMetadataID(MDs[i].second));
2502       }
2503       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
2504       Record.clear();
2505     }
2506
2507   Stream.ExitBlock();
2508 }
2509
2510 void ModuleBitcodeWriter::writeModuleMetadataKinds() {
2511   SmallVector<uint64_t, 64> Record;
2512
2513   // Write metadata kinds
2514   // METADATA_KIND - [n x [id, name]]
2515   SmallVector<StringRef, 8> Names;
2516   M.getMDKindNames(Names);
2517
2518   if (Names.empty()) return;
2519
2520   Stream.EnterSubblock(bitc::METADATA_KIND_BLOCK_ID, 3);
2521
2522   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
2523     Record.push_back(MDKindID);
2524     StringRef KName = Names[MDKindID];
2525     Record.append(KName.begin(), KName.end());
2526
2527     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
2528     Record.clear();
2529   }
2530
2531   Stream.ExitBlock();
2532 }
2533
2534 void ModuleBitcodeWriter::writeOperandBundleTags() {
2535   // Write metadata kinds
2536   //
2537   // OPERAND_BUNDLE_TAGS_BLOCK_ID : N x OPERAND_BUNDLE_TAG
2538   //
2539   // OPERAND_BUNDLE_TAG - [strchr x N]
2540
2541   SmallVector<StringRef, 8> Tags;
2542   M.getOperandBundleTags(Tags);
2543
2544   if (Tags.empty())
2545     return;
2546
2547   Stream.EnterSubblock(bitc::OPERAND_BUNDLE_TAGS_BLOCK_ID, 3);
2548
2549   SmallVector<uint64_t, 64> Record;
2550
2551   for (auto Tag : Tags) {
2552     Record.append(Tag.begin(), Tag.end());
2553
2554     Stream.EmitRecord(bitc::OPERAND_BUNDLE_TAG, Record, 0);
2555     Record.clear();
2556   }
2557
2558   Stream.ExitBlock();
2559 }
2560
2561 void ModuleBitcodeWriter::writeSyncScopeNames() {
2562   SmallVector<StringRef, 8> SSNs;
2563   M.getContext().getSyncScopeNames(SSNs);
2564   if (SSNs.empty())
2565     return;
2566
2567   Stream.EnterSubblock(bitc::SYNC_SCOPE_NAMES_BLOCK_ID, 2);
2568
2569   SmallVector<uint64_t, 64> Record;
2570   for (auto SSN : SSNs) {
2571     Record.append(SSN.begin(), SSN.end());
2572     Stream.EmitRecord(bitc::SYNC_SCOPE_NAME, Record, 0);
2573     Record.clear();
2574   }
2575
2576   Stream.ExitBlock();
2577 }
2578
2579 void ModuleBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
2580                                          bool isGlobal) {
2581   if (FirstVal == LastVal) return;
2582
2583   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
2584
2585   unsigned AggregateAbbrev = 0;
2586   unsigned String8Abbrev = 0;
2587   unsigned CString7Abbrev = 0;
2588   unsigned CString6Abbrev = 0;
2589   // If this is a constant pool for the module, emit module-specific abbrevs.
2590   if (isGlobal) {
2591     // Abbrev for CST_CODE_AGGREGATE.
2592     auto Abbv = std::make_shared<BitCodeAbbrev>();
2593     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
2594     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2595     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
2596     AggregateAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2597
2598     // Abbrev for CST_CODE_STRING.
2599     Abbv = std::make_shared<BitCodeAbbrev>();
2600     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
2601     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2602     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2603     String8Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2604     // Abbrev for CST_CODE_CSTRING.
2605     Abbv = std::make_shared<BitCodeAbbrev>();
2606     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
2607     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2608     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2609     CString7Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2610     // Abbrev for CST_CODE_CSTRING.
2611     Abbv = std::make_shared<BitCodeAbbrev>();
2612     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
2613     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2614     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2615     CString6Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2616   }
2617
2618   SmallVector<uint64_t, 64> Record;
2619
2620   const ValueEnumerator::ValueList &Vals = VE.getValues();
2621   Type *LastTy = nullptr;
2622   for (unsigned i = FirstVal; i != LastVal; ++i) {
2623     const Value *V = Vals[i].first;
2624     // If we need to switch types, do so now.
2625     if (V->getType() != LastTy) {
2626       LastTy = V->getType();
2627       Record.push_back(VE.getTypeID(LastTy));
2628       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
2629                         CONSTANTS_SETTYPE_ABBREV);
2630       Record.clear();
2631     }
2632
2633     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
2634       Record.push_back(VE.getTypeID(IA->getFunctionType()));
2635       Record.push_back(
2636           unsigned(IA->hasSideEffects()) | unsigned(IA->isAlignStack()) << 1 |
2637           unsigned(IA->getDialect() & 1) << 2 | unsigned(IA->canThrow()) << 3);
2638
2639       // Add the asm string.
2640       const std::string &AsmStr = IA->getAsmString();
2641       Record.push_back(AsmStr.size());
2642       Record.append(AsmStr.begin(), AsmStr.end());
2643
2644       // Add the constraint string.
2645       const std::string &ConstraintStr = IA->getConstraintString();
2646       Record.push_back(ConstraintStr.size());
2647       Record.append(ConstraintStr.begin(), ConstraintStr.end());
2648       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
2649       Record.clear();
2650       continue;
2651     }
2652     const Constant *C = cast<Constant>(V);
2653     unsigned Code = -1U;
2654     unsigned AbbrevToUse = 0;
2655     if (C->isNullValue()) {
2656       Code = bitc::CST_CODE_NULL;
2657     } else if (isa<PoisonValue>(C)) {
2658       Code = bitc::CST_CODE_POISON;
2659     } else if (isa<UndefValue>(C)) {
2660       Code = bitc::CST_CODE_UNDEF;
2661     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
2662       if (IV->getBitWidth() <= 64) {
2663         uint64_t V = IV->getSExtValue();
2664         emitSignedInt64(Record, V);
2665         Code = bitc::CST_CODE_INTEGER;
2666         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
2667       } else {                             // Wide integers, > 64 bits in size.
2668         emitWideAPInt(Record, IV->getValue());
2669         Code = bitc::CST_CODE_WIDE_INTEGER;
2670       }
2671     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
2672       Code = bitc::CST_CODE_FLOAT;
2673       Type *Ty = CFP->getType()->getScalarType();
2674       if (Ty->isHalfTy() || Ty->isBFloatTy() || Ty->isFloatTy() ||
2675           Ty->isDoubleTy()) {
2676         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
2677       } else if (Ty->isX86_FP80Ty()) {
2678         // api needed to prevent premature destruction
2679         // bits are not in the same order as a normal i80 APInt, compensate.
2680         APInt api = CFP->getValueAPF().bitcastToAPInt();
2681         const uint64_t *p = api.getRawData();
2682         Record.push_back((p[1] << 48) | (p[0] >> 16));
2683         Record.push_back(p[0] & 0xffffLL);
2684       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
2685         APInt api = CFP->getValueAPF().bitcastToAPInt();
2686         const uint64_t *p = api.getRawData();
2687         Record.push_back(p[0]);
2688         Record.push_back(p[1]);
2689       } else {
2690         assert(0 && "Unknown FP type!");
2691       }
2692     } else if (isa<ConstantDataSequential>(C) &&
2693                cast<ConstantDataSequential>(C)->isString()) {
2694       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
2695       // Emit constant strings specially.
2696       unsigned NumElts = Str->getNumElements();
2697       // If this is a null-terminated string, use the denser CSTRING encoding.
2698       if (Str->isCString()) {
2699         Code = bitc::CST_CODE_CSTRING;
2700         --NumElts;  // Don't encode the null, which isn't allowed by char6.
2701       } else {
2702         Code = bitc::CST_CODE_STRING;
2703         AbbrevToUse = String8Abbrev;
2704       }
2705       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
2706       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
2707       for (unsigned i = 0; i != NumElts; ++i) {
2708         unsigned char V = Str->getElementAsInteger(i);
2709         Record.push_back(V);
2710         isCStr7 &= (V & 128) == 0;
2711         if (isCStrChar6)
2712           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
2713       }
2714
2715       if (isCStrChar6)
2716         AbbrevToUse = CString6Abbrev;
2717       else if (isCStr7)
2718         AbbrevToUse = CString7Abbrev;
2719     } else if (const ConstantDataSequential *CDS =
2720                   dyn_cast<ConstantDataSequential>(C)) {
2721       Code = bitc::CST_CODE_DATA;
2722       Type *EltTy = CDS->getElementType();
2723       if (isa<IntegerType>(EltTy)) {
2724         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2725           Record.push_back(CDS->getElementAsInteger(i));
2726       } else {
2727         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2728           Record.push_back(
2729               CDS->getElementAsAPFloat(i).bitcastToAPInt().getLimitedValue());
2730       }
2731     } else if (isa<ConstantAggregate>(C)) {
2732       Code = bitc::CST_CODE_AGGREGATE;
2733       for (const Value *Op : C->operands())
2734         Record.push_back(VE.getValueID(Op));
2735       AbbrevToUse = AggregateAbbrev;
2736     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
2737       switch (CE->getOpcode()) {
2738       default:
2739         if (Instruction::isCast(CE->getOpcode())) {
2740           Code = bitc::CST_CODE_CE_CAST;
2741           Record.push_back(getEncodedCastOpcode(CE->getOpcode()));
2742           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2743           Record.push_back(VE.getValueID(C->getOperand(0)));
2744           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
2745         } else {
2746           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
2747           Code = bitc::CST_CODE_CE_BINOP;
2748           Record.push_back(getEncodedBinaryOpcode(CE->getOpcode()));
2749           Record.push_back(VE.getValueID(C->getOperand(0)));
2750           Record.push_back(VE.getValueID(C->getOperand(1)));
2751           uint64_t Flags = getOptimizationFlags(CE);
2752           if (Flags != 0)
2753             Record.push_back(Flags);
2754         }
2755         break;
2756       case Instruction::FNeg: {
2757         assert(CE->getNumOperands() == 1 && "Unknown constant expr!");
2758         Code = bitc::CST_CODE_CE_UNOP;
2759         Record.push_back(getEncodedUnaryOpcode(CE->getOpcode()));
2760         Record.push_back(VE.getValueID(C->getOperand(0)));
2761         uint64_t Flags = getOptimizationFlags(CE);
2762         if (Flags != 0)
2763           Record.push_back(Flags);
2764         break;
2765       }
2766       case Instruction::GetElementPtr: {
2767         Code = bitc::CST_CODE_CE_GEP;
2768         const auto *GO = cast<GEPOperator>(C);
2769         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
2770         if (std::optional<ConstantRange> Range = GO->getInRange()) {
2771           Code = bitc::CST_CODE_CE_GEP_WITH_INRANGE;
2772           Record.push_back(GO->isInBounds());
2773           emitConstantRange(Record, *Range);
2774         } else if (GO->isInBounds())
2775           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
2776         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
2777           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
2778           Record.push_back(VE.getValueID(C->getOperand(i)));
2779         }
2780         break;
2781       }
2782       case Instruction::ExtractElement:
2783         Code = bitc::CST_CODE_CE_EXTRACTELT;
2784         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2785         Record.push_back(VE.getValueID(C->getOperand(0)));
2786         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
2787         Record.push_back(VE.getValueID(C->getOperand(1)));
2788         break;
2789       case Instruction::InsertElement:
2790         Code = bitc::CST_CODE_CE_INSERTELT;
2791         Record.push_back(VE.getValueID(C->getOperand(0)));
2792         Record.push_back(VE.getValueID(C->getOperand(1)));
2793         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
2794         Record.push_back(VE.getValueID(C->getOperand(2)));
2795         break;
2796       case Instruction::ShuffleVector:
2797         // If the return type and argument types are the same, this is a
2798         // standard shufflevector instruction.  If the types are different,
2799         // then the shuffle is widening or truncating the input vectors, and
2800         // the argument type must also be encoded.
2801         if (C->getType() == C->getOperand(0)->getType()) {
2802           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
2803         } else {
2804           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
2805           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2806         }
2807         Record.push_back(VE.getValueID(C->getOperand(0)));
2808         Record.push_back(VE.getValueID(C->getOperand(1)));
2809         Record.push_back(VE.getValueID(CE->getShuffleMaskForBitcode()));
2810         break;
2811       case Instruction::ICmp:
2812       case Instruction::FCmp:
2813         Code = bitc::CST_CODE_CE_CMP;
2814         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2815         Record.push_back(VE.getValueID(C->getOperand(0)));
2816         Record.push_back(VE.getValueID(C->getOperand(1)));
2817         Record.push_back(CE->getPredicate());
2818         break;
2819       }
2820     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
2821       Code = bitc::CST_CODE_BLOCKADDRESS;
2822       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
2823       Record.push_back(VE.getValueID(BA->getFunction()));
2824       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
2825     } else if (const auto *Equiv = dyn_cast<DSOLocalEquivalent>(C)) {
2826       Code = bitc::CST_CODE_DSO_LOCAL_EQUIVALENT;
2827       Record.push_back(VE.getTypeID(Equiv->getGlobalValue()->getType()));
2828       Record.push_back(VE.getValueID(Equiv->getGlobalValue()));
2829     } else if (const auto *NC = dyn_cast<NoCFIValue>(C)) {
2830       Code = bitc::CST_CODE_NO_CFI_VALUE;
2831       Record.push_back(VE.getTypeID(NC->getGlobalValue()->getType()));
2832       Record.push_back(VE.getValueID(NC->getGlobalValue()));
2833     } else {
2834 #ifndef NDEBUG
2835       C->dump();
2836 #endif
2837       llvm_unreachable("Unknown constant!");
2838     }
2839     Stream.EmitRecord(Code, Record, AbbrevToUse);
2840     Record.clear();
2841   }
2842
2843   Stream.ExitBlock();
2844 }
2845
2846 void ModuleBitcodeWriter::writeModuleConstants() {
2847   const ValueEnumerator::ValueList &Vals = VE.getValues();
2848
2849   // Find the first constant to emit, which is the first non-globalvalue value.
2850   // We know globalvalues have been emitted by WriteModuleInfo.
2851   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
2852     if (!isa<GlobalValue>(Vals[i].first)) {
2853       writeConstants(i, Vals.size(), true);
2854       return;
2855     }
2856   }
2857 }
2858
2859 /// pushValueAndType - The file has to encode both the value and type id for
2860 /// many values, because we need to know what type to create for forward
2861 /// references.  However, most operands are not forward references, so this type
2862 /// field is not needed.
2863 ///
2864 /// This function adds V's value ID to Vals.  If the value ID is higher than the
2865 /// instruction ID, then it is a forward reference, and it also includes the
2866 /// type ID.  The value ID that is written is encoded relative to the InstID.
2867 bool ModuleBitcodeWriter::pushValueAndType(const Value *V, unsigned InstID,
2868                                            SmallVectorImpl<unsigned> &Vals) {
2869   unsigned ValID = VE.getValueID(V);
2870   // Make encoding relative to the InstID.
2871   Vals.push_back(InstID - ValID);
2872   if (ValID >= InstID) {
2873     Vals.push_back(VE.getTypeID(V->getType()));
2874     return true;
2875   }
2876   return false;
2877 }
2878
2879 void ModuleBitcodeWriter::writeOperandBundles(const CallBase &CS,
2880                                               unsigned InstID) {
2881   SmallVector<unsigned, 64> Record;
2882   LLVMContext &C = CS.getContext();
2883
2884   for (unsigned i = 0, e = CS.getNumOperandBundles(); i != e; ++i) {
2885     const auto &Bundle = CS.getOperandBundleAt(i);
2886     Record.push_back(C.getOperandBundleTagID(Bundle.getTagName()));
2887
2888     for (auto &Input : Bundle.Inputs)
2889       pushValueAndType(Input, InstID, Record);
2890
2891     Stream.EmitRecord(bitc::FUNC_CODE_OPERAND_BUNDLE, Record);
2892     Record.clear();
2893   }
2894 }
2895
2896 /// pushValue - Like pushValueAndType, but where the type of the value is
2897 /// omitted (perhaps it was already encoded in an earlier operand).
2898 void ModuleBitcodeWriter::pushValue(const Value *V, unsigned InstID,
2899                                     SmallVectorImpl<unsigned> &Vals) {
2900   unsigned ValID = VE.getValueID(V);
2901   Vals.push_back(InstID - ValID);
2902 }
2903
2904 void ModuleBitcodeWriter::pushValueSigned(const Value *V, unsigned InstID,
2905                                           SmallVectorImpl<uint64_t> &Vals) {
2906   unsigned ValID = VE.getValueID(V);
2907   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
2908   emitSignedInt64(Vals, diff);
2909 }
2910
2911 /// WriteInstruction - Emit an instruction to the specified stream.
2912 void ModuleBitcodeWriter::writeInstruction(const Instruction &I,
2913                                            unsigned InstID,
2914                                            SmallVectorImpl<unsigned> &Vals) {
2915   unsigned Code = 0;
2916   unsigned AbbrevToUse = 0;
2917   VE.setInstructionID(&I);
2918   switch (I.getOpcode()) {
2919   default:
2920     if (Instruction::isCast(I.getOpcode())) {
2921       Code = bitc::FUNC_CODE_INST_CAST;
2922       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2923         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
2924       Vals.push_back(VE.getTypeID(I.getType()));
2925       Vals.push_back(getEncodedCastOpcode(I.getOpcode()));
2926       uint64_t Flags = getOptimizationFlags(&I);
2927       if (Flags != 0) {
2928         if (AbbrevToUse == FUNCTION_INST_CAST_ABBREV)
2929           AbbrevToUse = FUNCTION_INST_CAST_FLAGS_ABBREV;
2930         Vals.push_back(Flags);
2931       }
2932     } else {
2933       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
2934       Code = bitc::FUNC_CODE_INST_BINOP;
2935       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2936         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
2937       pushValue(I.getOperand(1), InstID, Vals);
2938       Vals.push_back(getEncodedBinaryOpcode(I.getOpcode()));
2939       uint64_t Flags = getOptimizationFlags(&I);
2940       if (Flags != 0) {
2941         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
2942           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
2943         Vals.push_back(Flags);
2944       }
2945     }
2946     break;
2947   case Instruction::FNeg: {
2948     Code = bitc::FUNC_CODE_INST_UNOP;
2949     if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2950       AbbrevToUse = FUNCTION_INST_UNOP_ABBREV;
2951     Vals.push_back(getEncodedUnaryOpcode(I.getOpcode()));
2952     uint64_t Flags = getOptimizationFlags(&I);
2953     if (Flags != 0) {
2954       if (AbbrevToUse == FUNCTION_INST_UNOP_ABBREV)
2955         AbbrevToUse = FUNCTION_INST_UNOP_FLAGS_ABBREV;
2956       Vals.push_back(Flags);
2957     }
2958     break;
2959   }
2960   case Instruction::GetElementPtr: {
2961     Code = bitc::FUNC_CODE_INST_GEP;
2962     AbbrevToUse = FUNCTION_INST_GEP_ABBREV;
2963     auto &GEPInst = cast<GetElementPtrInst>(I);
2964     Vals.push_back(GEPInst.isInBounds());
2965     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
2966     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
2967       pushValueAndType(I.getOperand(i), InstID, Vals);
2968     break;
2969   }
2970   case Instruction::ExtractValue: {
2971     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
2972     pushValueAndType(I.getOperand(0), InstID, Vals);
2973     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
2974     Vals.append(EVI->idx_begin(), EVI->idx_end());
2975     break;
2976   }
2977   case Instruction::InsertValue: {
2978     Code = bitc::FUNC_CODE_INST_INSERTVAL;
2979     pushValueAndType(I.getOperand(0), InstID, Vals);
2980     pushValueAndType(I.getOperand(1), InstID, Vals);
2981     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
2982     Vals.append(IVI->idx_begin(), IVI->idx_end());
2983     break;
2984   }
2985   case Instruction::Select: {
2986     Code = bitc::FUNC_CODE_INST_VSELECT;
2987     pushValueAndType(I.getOperand(1), InstID, Vals);
2988     pushValue(I.getOperand(2), InstID, Vals);
2989     pushValueAndType(I.getOperand(0), InstID, Vals);
2990     uint64_t Flags = getOptimizationFlags(&I);
2991     if (Flags != 0)
2992       Vals.push_back(Flags);
2993     break;
2994   }
2995   case Instruction::ExtractElement:
2996     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
2997     pushValueAndType(I.getOperand(0), InstID, Vals);
2998     pushValueAndType(I.getOperand(1), InstID, Vals);
2999     break;
3000   case Instruction::InsertElement:
3001     Code = bitc::FUNC_CODE_INST_INSERTELT;
3002     pushValueAndType(I.getOperand(0), InstID, Vals);
3003     pushValue(I.getOperand(1), InstID, Vals);
3004     pushValueAndType(I.getOperand(2), InstID, Vals);
3005     break;
3006   case Instruction::ShuffleVector:
3007     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
3008     pushValueAndType(I.getOperand(0), InstID, Vals);
3009     pushValue(I.getOperand(1), InstID, Vals);
3010     pushValue(cast<ShuffleVectorInst>(I).getShuffleMaskForBitcode(), InstID,
3011               Vals);
3012     break;
3013   case Instruction::ICmp:
3014   case Instruction::FCmp: {
3015     // compare returning Int1Ty or vector of Int1Ty
3016     Code = bitc::FUNC_CODE_INST_CMP2;
3017     pushValueAndType(I.getOperand(0), InstID, Vals);
3018     pushValue(I.getOperand(1), InstID, Vals);
3019     Vals.push_back(cast<CmpInst>(I).getPredicate());
3020     uint64_t Flags = getOptimizationFlags(&I);
3021     if (Flags != 0)
3022       Vals.push_back(Flags);
3023     break;
3024   }
3025
3026   case Instruction::Ret:
3027     {
3028       Code = bitc::FUNC_CODE_INST_RET;
3029       unsigned NumOperands = I.getNumOperands();
3030       if (NumOperands == 0)
3031         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
3032       else if (NumOperands == 1) {
3033         if (!pushValueAndType(I.getOperand(0), InstID, Vals))
3034           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
3035       } else {
3036         for (unsigned i = 0, e = NumOperands; i != e; ++i)
3037           pushValueAndType(I.getOperand(i), InstID, Vals);
3038       }
3039     }
3040     break;
3041   case Instruction::Br:
3042     {
3043       Code = bitc::FUNC_CODE_INST_BR;
3044       const BranchInst &II = cast<BranchInst>(I);
3045       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
3046       if (II.isConditional()) {
3047         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
3048         pushValue(II.getCondition(), InstID, Vals);
3049       }
3050     }
3051     break;
3052   case Instruction::Switch:
3053     {
3054       Code = bitc::FUNC_CODE_INST_SWITCH;
3055       const SwitchInst &SI = cast<SwitchInst>(I);
3056       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
3057       pushValue(SI.getCondition(), InstID, Vals);
3058       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
3059       for (auto Case : SI.cases()) {
3060         Vals.push_back(VE.getValueID(Case.getCaseValue()));
3061         Vals.push_back(VE.getValueID(Case.getCaseSuccessor()));
3062       }
3063     }
3064     break;
3065   case Instruction::IndirectBr:
3066     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
3067     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
3068     // Encode the address operand as relative, but not the basic blocks.
3069     pushValue(I.getOperand(0), InstID, Vals);
3070     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
3071       Vals.push_back(VE.getValueID(I.getOperand(i)));
3072     break;
3073
3074   case Instruction::Invoke: {
3075     const InvokeInst *II = cast<InvokeInst>(&I);
3076     const Value *Callee = II->getCalledOperand();
3077     FunctionType *FTy = II->getFunctionType();
3078
3079     if (II->hasOperandBundles())
3080       writeOperandBundles(*II, InstID);
3081
3082     Code = bitc::FUNC_CODE_INST_INVOKE;
3083
3084     Vals.push_back(VE.getAttributeListID(II->getAttributes()));
3085     Vals.push_back(II->getCallingConv() | 1 << 13);
3086     Vals.push_back(VE.getValueID(II->getNormalDest()));
3087     Vals.push_back(VE.getValueID(II->getUnwindDest()));
3088     Vals.push_back(VE.getTypeID(FTy));
3089     pushValueAndType(Callee, InstID, Vals);
3090
3091     // Emit value #'s for the fixed parameters.
3092     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
3093       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
3094
3095     // Emit type/value pairs for varargs params.
3096     if (FTy->isVarArg()) {
3097       for (unsigned i = FTy->getNumParams(), e = II->arg_size(); i != e; ++i)
3098         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
3099     }
3100     break;
3101   }
3102   case Instruction::Resume:
3103     Code = bitc::FUNC_CODE_INST_RESUME;
3104     pushValueAndType(I.getOperand(0), InstID, Vals);
3105     break;
3106   case Instruction::CleanupRet: {
3107     Code = bitc::FUNC_CODE_INST_CLEANUPRET;
3108     const auto &CRI = cast<CleanupReturnInst>(I);
3109     pushValue(CRI.getCleanupPad(), InstID, Vals);
3110     if (CRI.hasUnwindDest())
3111       Vals.push_back(VE.getValueID(CRI.getUnwindDest()));
3112     break;
3113   }
3114   case Instruction::CatchRet: {
3115     Code = bitc::FUNC_CODE_INST_CATCHRET;
3116     const auto &CRI = cast<CatchReturnInst>(I);
3117     pushValue(CRI.getCatchPad(), InstID, Vals);
3118     Vals.push_back(VE.getValueID(CRI.getSuccessor()));
3119     break;
3120   }
3121   case Instruction::CleanupPad:
3122   case Instruction::CatchPad: {
3123     const auto &FuncletPad = cast<FuncletPadInst>(I);
3124     Code = isa<CatchPadInst>(FuncletPad) ? bitc::FUNC_CODE_INST_CATCHPAD
3125                                          : bitc::FUNC_CODE_INST_CLEANUPPAD;
3126     pushValue(FuncletPad.getParentPad(), InstID, Vals);
3127
3128     unsigned NumArgOperands = FuncletPad.arg_size();
3129     Vals.push_back(NumArgOperands);
3130     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
3131       pushValueAndType(FuncletPad.getArgOperand(Op), InstID, Vals);
3132     break;
3133   }
3134   case Instruction::CatchSwitch: {
3135     Code = bitc::FUNC_CODE_INST_CATCHSWITCH;
3136     const auto &CatchSwitch = cast<CatchSwitchInst>(I);
3137
3138     pushValue(CatchSwitch.getParentPad(), InstID, Vals);
3139
3140     unsigned NumHandlers = CatchSwitch.getNumHandlers();
3141     Vals.push_back(NumHandlers);
3142     for (const BasicBlock *CatchPadBB : CatchSwitch.handlers())
3143       Vals.push_back(VE.getValueID(CatchPadBB));
3144
3145     if (CatchSwitch.hasUnwindDest())
3146       Vals.push_back(VE.getValueID(CatchSwitch.getUnwindDest()));
3147     break;
3148   }
3149   case Instruction::CallBr: {
3150     const CallBrInst *CBI = cast<CallBrInst>(&I);
3151     const Value *Callee = CBI->getCalledOperand();
3152     FunctionType *FTy = CBI->getFunctionType();
3153
3154     if (CBI->hasOperandBundles())
3155       writeOperandBundles(*CBI, InstID);
3156
3157     Code = bitc::FUNC_CODE_INST_CALLBR;
3158
3159     Vals.push_back(VE.getAttributeListID(CBI->getAttributes()));
3160
3161     Vals.push_back(CBI->getCallingConv() << bitc::CALL_CCONV |
3162                    1 << bitc::CALL_EXPLICIT_TYPE);
3163
3164     Vals.push_back(VE.getValueID(CBI->getDefaultDest()));
3165     Vals.push_back(CBI->getNumIndirectDests());
3166     for (unsigned i = 0, e = CBI->getNumIndirectDests(); i != e; ++i)
3167       Vals.push_back(VE.getValueID(CBI->getIndirectDest(i)));
3168
3169     Vals.push_back(VE.getTypeID(FTy));
3170     pushValueAndType(Callee, InstID, Vals);
3171
3172     // Emit value #'s for the fixed parameters.
3173     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
3174       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
3175
3176     // Emit type/value pairs for varargs params.
3177     if (FTy->isVarArg()) {
3178       for (unsigned i = FTy->getNumParams(), e = CBI->arg_size(); i != e; ++i)
3179         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
3180     }
3181     break;
3182   }
3183   case Instruction::Unreachable:
3184     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
3185     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
3186     break;
3187
3188   case Instruction::PHI: {
3189     const PHINode &PN = cast<PHINode>(I);
3190     Code = bitc::FUNC_CODE_INST_PHI;
3191     // With the newer instruction encoding, forward references could give
3192     // negative valued IDs.  This is most common for PHIs, so we use
3193     // signed VBRs.
3194     SmallVector<uint64_t, 128> Vals64;
3195     Vals64.push_back(VE.getTypeID(PN.getType()));
3196     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
3197       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64);
3198       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
3199     }
3200
3201     uint64_t Flags = getOptimizationFlags(&I);
3202     if (Flags != 0)
3203       Vals64.push_back(Flags);
3204
3205     // Emit a Vals64 vector and exit.
3206     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
3207     Vals64.clear();
3208     return;
3209   }
3210
3211   case Instruction::LandingPad: {
3212     const LandingPadInst &LP = cast<LandingPadInst>(I);
3213     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
3214     Vals.push_back(VE.getTypeID(LP.getType()));
3215     Vals.push_back(LP.isCleanup());
3216     Vals.push_back(LP.getNumClauses());
3217     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
3218       if (LP.isCatch(I))
3219         Vals.push_back(LandingPadInst::Catch);
3220       else
3221         Vals.push_back(LandingPadInst::Filter);
3222       pushValueAndType(LP.getClause(I), InstID, Vals);
3223     }
3224     break;
3225   }
3226
3227   case Instruction::Alloca: {
3228     Code = bitc::FUNC_CODE_INST_ALLOCA;
3229     const AllocaInst &AI = cast<AllocaInst>(I);
3230     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
3231     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
3232     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
3233     using APV = AllocaPackedValues;
3234     unsigned Record = 0;
3235     unsigned EncodedAlign = getEncodedAlign(AI.getAlign());
3236     Bitfield::set<APV::AlignLower>(
3237         Record, EncodedAlign & ((1 << APV::AlignLower::Bits) - 1));
3238     Bitfield::set<APV::AlignUpper>(Record,
3239                                    EncodedAlign >> APV::AlignLower::Bits);
3240     Bitfield::set<APV::UsedWithInAlloca>(Record, AI.isUsedWithInAlloca());
3241     Bitfield::set<APV::ExplicitType>(Record, true);
3242     Bitfield::set<APV::SwiftError>(Record, AI.isSwiftError());
3243     Vals.push_back(Record);
3244
3245     unsigned AS = AI.getAddressSpace();
3246     if (AS != M.getDataLayout().getAllocaAddrSpace())
3247       Vals.push_back(AS);
3248     break;
3249   }
3250
3251   case Instruction::Load:
3252     if (cast<LoadInst>(I).isAtomic()) {
3253       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
3254       pushValueAndType(I.getOperand(0), InstID, Vals);
3255     } else {
3256       Code = bitc::FUNC_CODE_INST_LOAD;
3257       if (!pushValueAndType(I.getOperand(0), InstID, Vals)) // ptr
3258         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
3259     }
3260     Vals.push_back(VE.getTypeID(I.getType()));
3261     Vals.push_back(getEncodedAlign(cast<LoadInst>(I).getAlign()));
3262     Vals.push_back(cast<LoadInst>(I).isVolatile());
3263     if (cast<LoadInst>(I).isAtomic()) {
3264       Vals.push_back(getEncodedOrdering(cast<LoadInst>(I).getOrdering()));
3265       Vals.push_back(getEncodedSyncScopeID(cast<LoadInst>(I).getSyncScopeID()));
3266     }
3267     break;
3268   case Instruction::Store:
3269     if (cast<StoreInst>(I).isAtomic())
3270       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
3271     else
3272       Code = bitc::FUNC_CODE_INST_STORE;
3273     pushValueAndType(I.getOperand(1), InstID, Vals); // ptrty + ptr
3274     pushValueAndType(I.getOperand(0), InstID, Vals); // valty + val
3275     Vals.push_back(getEncodedAlign(cast<StoreInst>(I).getAlign()));
3276     Vals.push_back(cast<StoreInst>(I).isVolatile());
3277     if (cast<StoreInst>(I).isAtomic()) {
3278       Vals.push_back(getEncodedOrdering(cast<StoreInst>(I).getOrdering()));
3279       Vals.push_back(
3280           getEncodedSyncScopeID(cast<StoreInst>(I).getSyncScopeID()));
3281     }
3282     break;
3283   case Instruction::AtomicCmpXchg:
3284     Code = bitc::FUNC_CODE_INST_CMPXCHG;
3285     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
3286     pushValueAndType(I.getOperand(1), InstID, Vals); // cmp.
3287     pushValue(I.getOperand(2), InstID, Vals);        // newval.
3288     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
3289     Vals.push_back(
3290         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
3291     Vals.push_back(
3292         getEncodedSyncScopeID(cast<AtomicCmpXchgInst>(I).getSyncScopeID()));
3293     Vals.push_back(
3294         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
3295     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
3296     Vals.push_back(getEncodedAlign(cast<AtomicCmpXchgInst>(I).getAlign()));
3297     break;
3298   case Instruction::AtomicRMW:
3299     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
3300     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
3301     pushValueAndType(I.getOperand(1), InstID, Vals); // valty + val
3302     Vals.push_back(
3303         getEncodedRMWOperation(cast<AtomicRMWInst>(I).getOperation()));
3304     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
3305     Vals.push_back(getEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
3306     Vals.push_back(
3307         getEncodedSyncScopeID(cast<AtomicRMWInst>(I).getSyncScopeID()));
3308     Vals.push_back(getEncodedAlign(cast<AtomicRMWInst>(I).getAlign()));
3309     break;
3310   case Instruction::Fence:
3311     Code = bitc::FUNC_CODE_INST_FENCE;
3312     Vals.push_back(getEncodedOrdering(cast<FenceInst>(I).getOrdering()));
3313     Vals.push_back(getEncodedSyncScopeID(cast<FenceInst>(I).getSyncScopeID()));
3314     break;
3315   case Instruction::Call: {
3316     const CallInst &CI = cast<CallInst>(I);
3317     FunctionType *FTy = CI.getFunctionType();
3318
3319     if (CI.hasOperandBundles())
3320       writeOperandBundles(CI, InstID);
3321
3322     Code = bitc::FUNC_CODE_INST_CALL;
3323
3324     Vals.push_back(VE.getAttributeListID(CI.getAttributes()));
3325
3326     unsigned Flags = getOptimizationFlags(&I);
3327     Vals.push_back(CI.getCallingConv() << bitc::CALL_CCONV |
3328                    unsigned(CI.isTailCall()) << bitc::CALL_TAIL |
3329                    unsigned(CI.isMustTailCall()) << bitc::CALL_MUSTTAIL |
3330                    1 << bitc::CALL_EXPLICIT_TYPE |
3331                    unsigned(CI.isNoTailCall()) << bitc::CALL_NOTAIL |
3332                    unsigned(Flags != 0) << bitc::CALL_FMF);
3333     if (Flags != 0)
3334       Vals.push_back(Flags);
3335
3336     Vals.push_back(VE.getTypeID(FTy));
3337     pushValueAndType(CI.getCalledOperand(), InstID, Vals); // Callee
3338
3339     // Emit value #'s for the fixed parameters.
3340     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
3341       // Check for labels (can happen with asm labels).
3342       if (FTy->getParamType(i)->isLabelTy())
3343         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
3344       else
3345         pushValue(CI.getArgOperand(i), InstID, Vals); // fixed param.
3346     }
3347
3348     // Emit type/value pairs for varargs params.
3349     if (FTy->isVarArg()) {
3350       for (unsigned i = FTy->getNumParams(), e = CI.arg_size(); i != e; ++i)
3351         pushValueAndType(CI.getArgOperand(i), InstID, Vals); // varargs
3352     }
3353     break;
3354   }
3355   case Instruction::VAArg:
3356     Code = bitc::FUNC_CODE_INST_VAARG;
3357     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
3358     pushValue(I.getOperand(0), InstID, Vals);                   // valist.
3359     Vals.push_back(VE.getTypeID(I.getType())); // restype.
3360     break;
3361   case Instruction::Freeze:
3362     Code = bitc::FUNC_CODE_INST_FREEZE;
3363     pushValueAndType(I.getOperand(0), InstID, Vals);
3364     break;
3365   }
3366
3367   Stream.EmitRecord(Code, Vals, AbbrevToUse);
3368   Vals.clear();
3369 }
3370
3371 /// Write a GlobalValue VST to the module. The purpose of this data structure is
3372 /// to allow clients to efficiently find the function body.
3373 void ModuleBitcodeWriter::writeGlobalValueSymbolTable(
3374   DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex) {
3375   // Get the offset of the VST we are writing, and backpatch it into
3376   // the VST forward declaration record.
3377   uint64_t VSTOffset = Stream.GetCurrentBitNo();
3378   // The BitcodeStartBit was the stream offset of the identification block.
3379   VSTOffset -= bitcodeStartBit();
3380   assert((VSTOffset & 31) == 0 && "VST block not 32-bit aligned");
3381   // Note that we add 1 here because the offset is relative to one word
3382   // before the start of the identification block, which was historically
3383   // always the start of the regular bitcode header.
3384   Stream.BackpatchWord(VSTOffsetPlaceholder, VSTOffset / 32 + 1);
3385
3386   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
3387
3388   auto Abbv = std::make_shared<BitCodeAbbrev>();
3389   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
3390   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
3391   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
3392   unsigned FnEntryAbbrev = Stream.EmitAbbrev(std::move(Abbv));
3393
3394   for (const Function &F : M) {
3395     uint64_t Record[2];
3396
3397     if (F.isDeclaration())
3398       continue;
3399
3400     Record[0] = VE.getValueID(&F);
3401
3402     // Save the word offset of the function (from the start of the
3403     // actual bitcode written to the stream).
3404     uint64_t BitcodeIndex = FunctionToBitcodeIndex[&F] - bitcodeStartBit();
3405     assert((BitcodeIndex & 31) == 0 && "function block not 32-bit aligned");
3406     // Note that we add 1 here because the offset is relative to one word
3407     // before the start of the identification block, which was historically
3408     // always the start of the regular bitcode header.
3409     Record[1] = BitcodeIndex / 32 + 1;
3410
3411     Stream.EmitRecord(bitc::VST_CODE_FNENTRY, Record, FnEntryAbbrev);
3412   }
3413
3414   Stream.ExitBlock();
3415 }
3416
3417 /// Emit names for arguments, instructions and basic blocks in a function.
3418 void ModuleBitcodeWriter::writeFunctionLevelValueSymbolTable(
3419     const ValueSymbolTable &VST) {
3420   if (VST.empty())
3421     return;
3422
3423   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
3424
3425   // FIXME: Set up the abbrev, we know how many values there are!
3426   // FIXME: We know if the type names can use 7-bit ascii.
3427   SmallVector<uint64_t, 64> NameVals;
3428
3429   for (const ValueName &Name : VST) {
3430     // Figure out the encoding to use for the name.
3431     StringEncoding Bits = getStringEncoding(Name.getKey());
3432
3433     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
3434     NameVals.push_back(VE.getValueID(Name.getValue()));
3435
3436     // VST_CODE_ENTRY:   [valueid, namechar x N]
3437     // VST_CODE_BBENTRY: [bbid, namechar x N]
3438     unsigned Code;
3439     if (isa<BasicBlock>(Name.getValue())) {
3440       Code = bitc::VST_CODE_BBENTRY;
3441       if (Bits == SE_Char6)
3442         AbbrevToUse = VST_BBENTRY_6_ABBREV;
3443     } else {
3444       Code = bitc::VST_CODE_ENTRY;
3445       if (Bits == SE_Char6)
3446         AbbrevToUse = VST_ENTRY_6_ABBREV;
3447       else if (Bits == SE_Fixed7)
3448         AbbrevToUse = VST_ENTRY_7_ABBREV;
3449     }
3450
3451     for (const auto P : Name.getKey())
3452       NameVals.push_back((unsigned char)P);
3453
3454     // Emit the finished record.
3455     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
3456     NameVals.clear();
3457   }
3458
3459   Stream.ExitBlock();
3460 }
3461
3462 void ModuleBitcodeWriter::writeUseList(UseListOrder &&Order) {
3463   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
3464   unsigned Code;
3465   if (isa<BasicBlock>(Order.V))
3466     Code = bitc::USELIST_CODE_BB;
3467   else
3468     Code = bitc::USELIST_CODE_DEFAULT;
3469
3470   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
3471   Record.push_back(VE.getValueID(Order.V));
3472   Stream.EmitRecord(Code, Record);
3473 }
3474
3475 void ModuleBitcodeWriter::writeUseListBlock(const Function *F) {
3476   assert(VE.shouldPreserveUseListOrder() &&
3477          "Expected to be preserving use-list order");
3478
3479   auto hasMore = [&]() {
3480     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
3481   };
3482   if (!hasMore())
3483     // Nothing to do.
3484     return;
3485
3486   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
3487   while (hasMore()) {
3488     writeUseList(std::move(VE.UseListOrders.back()));
3489     VE.UseListOrders.pop_back();
3490   }
3491   Stream.ExitBlock();
3492 }
3493
3494 /// Emit a function body to the module stream.
3495 void ModuleBitcodeWriter::writeFunction(
3496     const Function &F,
3497     DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex) {
3498   // Save the bitcode index of the start of this function block for recording
3499   // in the VST.
3500   FunctionToBitcodeIndex[&F] = Stream.GetCurrentBitNo();
3501
3502   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
3503   VE.incorporateFunction(F);
3504
3505   SmallVector<unsigned, 64> Vals;
3506
3507   // Emit the number of basic blocks, so the reader can create them ahead of
3508   // time.
3509   Vals.push_back(VE.getBasicBlocks().size());
3510   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
3511   Vals.clear();
3512
3513   // If there are function-local constants, emit them now.
3514   unsigned CstStart, CstEnd;
3515   VE.getFunctionConstantRange(CstStart, CstEnd);
3516   writeConstants(CstStart, CstEnd, false);
3517
3518   // If there is function-local metadata, emit it now.
3519   writeFunctionMetadata(F);
3520
3521   // Keep a running idea of what the instruction ID is.
3522   unsigned InstID = CstEnd;
3523
3524   bool NeedsMetadataAttachment = F.hasMetadata();
3525
3526   DILocation *LastDL = nullptr;
3527   SmallSetVector<Function *, 4> BlockAddressUsers;
3528
3529   // Finally, emit all the instructions, in order.
3530   for (const BasicBlock &BB : F) {
3531     for (const Instruction &I : BB) {
3532       writeInstruction(I, InstID, Vals);
3533
3534       if (!I.getType()->isVoidTy())
3535         ++InstID;
3536
3537       // If the instruction has metadata, write a metadata attachment later.
3538       NeedsMetadataAttachment |= I.hasMetadataOtherThanDebugLoc();
3539
3540       // If the instruction has a debug location, emit it.
3541       if (DILocation *DL = I.getDebugLoc()) {
3542         if (DL == LastDL) {
3543           // Just repeat the same debug loc as last time.
3544           Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
3545         } else {
3546           Vals.push_back(DL->getLine());
3547           Vals.push_back(DL->getColumn());
3548           Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
3549           Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
3550           Vals.push_back(DL->isImplicitCode());
3551           Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
3552           Vals.clear();
3553           LastDL = DL;
3554         }
3555       }
3556
3557       // If the instruction has DbgRecords attached to it, emit them. Note that
3558       // they come after the instruction so that it's easy to attach them again
3559       // when reading the bitcode, even though conceptually the debug locations
3560       // start "before" the instruction.
3561       if (I.hasDbgRecords() && WriteNewDbgInfoFormatToBitcode) {
3562         /// Try to push the value only (unwrapped), otherwise push the
3563         /// metadata wrapped value. Returns true if the value was pushed
3564         /// without the ValueAsMetadata wrapper.
3565         auto PushValueOrMetadata = [&Vals, InstID,
3566                                     this](Metadata *RawLocation) {
3567           assert(RawLocation &&
3568                  "RawLocation unexpectedly null in DbgVariableRecord");
3569           if (ValueAsMetadata *VAM = dyn_cast<ValueAsMetadata>(RawLocation)) {
3570             SmallVector<unsigned, 2> ValAndType;
3571             // If the value is a fwd-ref the type is also pushed. We don't
3572             // want the type, so fwd-refs are kept wrapped (pushValueAndType
3573             // returns false if the value is pushed without type).
3574             if (!pushValueAndType(VAM->getValue(), InstID, ValAndType)) {
3575               Vals.push_back(ValAndType[0]);
3576               return true;
3577             }
3578           }
3579           // The metadata is a DIArgList, or ValueAsMetadata wrapping a
3580           // fwd-ref. Push the metadata ID.
3581           Vals.push_back(VE.getMetadataID(RawLocation));
3582           return false;
3583         };
3584
3585         // Write out non-instruction debug information attached to this
3586         // instruction. Write it after the instruction so that it's easy to
3587         // re-attach to the instruction reading the records in.
3588         for (DbgRecord &DR : I.DebugMarker->getDbgRecordRange()) {
3589           if (DbgLabelRecord *DLR = dyn_cast<DbgLabelRecord>(&DR)) {
3590             Vals.push_back(VE.getMetadataID(&*DLR->getDebugLoc()));
3591             Vals.push_back(VE.getMetadataID(DLR->getLabel()));
3592             Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_LABEL, Vals);
3593             Vals.clear();
3594             continue;
3595           }
3596
3597           // First 3 fields are common to all kinds:
3598           //   DILocation, DILocalVariable, DIExpression
3599           // dbg_value (FUNC_CODE_DEBUG_RECORD_VALUE)
3600           //   ..., LocationMetadata
3601           // dbg_value (FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE - abbrev'd)
3602           //   ..., Value
3603           // dbg_declare (FUNC_CODE_DEBUG_RECORD_DECLARE)
3604           //   ..., LocationMetadata
3605           // dbg_assign (FUNC_CODE_DEBUG_RECORD_ASSIGN)
3606           //   ..., LocationMetadata, DIAssignID, DIExpression, LocationMetadata
3607           DbgVariableRecord &DVR = cast<DbgVariableRecord>(DR);
3608           Vals.push_back(VE.getMetadataID(&*DVR.getDebugLoc()));
3609           Vals.push_back(VE.getMetadataID(DVR.getVariable()));
3610           Vals.push_back(VE.getMetadataID(DVR.getExpression()));
3611           if (DVR.isDbgValue()) {
3612             if (PushValueOrMetadata(DVR.getRawLocation()))
3613               Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE, Vals,
3614                                 FUNCTION_DEBUG_RECORD_VALUE_ABBREV);
3615             else
3616               Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_VALUE, Vals);
3617           } else if (DVR.isDbgDeclare()) {
3618             Vals.push_back(VE.getMetadataID(DVR.getRawLocation()));
3619             Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_DECLARE, Vals);
3620           } else {
3621             assert(DVR.isDbgAssign() && "Unexpected DbgRecord kind");
3622             Vals.push_back(VE.getMetadataID(DVR.getRawLocation()));
3623             Vals.push_back(VE.getMetadataID(DVR.getAssignID()));
3624             Vals.push_back(VE.getMetadataID(DVR.getAddressExpression()));
3625             Vals.push_back(VE.getMetadataID(DVR.getRawAddress()));
3626             Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_ASSIGN, Vals);
3627           }
3628           Vals.clear();
3629         }
3630       }
3631     }
3632
3633     if (BlockAddress *BA = BlockAddress::lookup(&BB)) {
3634       SmallVector<Value *> Worklist{BA};
3635       SmallPtrSet<Value *, 8> Visited{BA};
3636       while (!Worklist.empty()) {
3637         Value *V = Worklist.pop_back_val();
3638         for (User *U : V->users()) {
3639           if (auto *I = dyn_cast<Instruction>(U)) {
3640             Function *P = I->getFunction();
3641             if (P != &F)
3642               BlockAddressUsers.insert(P);
3643           } else if (isa<Constant>(U) && !isa<GlobalValue>(U) &&
3644                      Visited.insert(U).second)
3645             Worklist.push_back(U);
3646         }
3647       }
3648     }
3649   }
3650
3651   if (!BlockAddressUsers.empty()) {
3652     Vals.resize(BlockAddressUsers.size());
3653     for (auto I : llvm::enumerate(BlockAddressUsers))
3654       Vals[I.index()] = VE.getValueID(I.value());
3655     Stream.EmitRecord(bitc::FUNC_CODE_BLOCKADDR_USERS, Vals);
3656     Vals.clear();
3657   }
3658
3659   // Emit names for all the instructions etc.
3660   if (auto *Symtab = F.getValueSymbolTable())
3661     writeFunctionLevelValueSymbolTable(*Symtab);
3662
3663   if (NeedsMetadataAttachment)
3664     writeFunctionMetadataAttachment(F);
3665   if (VE.shouldPreserveUseListOrder())
3666     writeUseListBlock(&F);
3667   VE.purgeFunction();
3668   Stream.ExitBlock();
3669 }
3670
3671 // Emit blockinfo, which defines the standard abbreviations etc.
3672 void ModuleBitcodeWriter::writeBlockInfo() {
3673   // We only want to emit block info records for blocks that have multiple
3674   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
3675   // Other blocks can define their abbrevs inline.
3676   Stream.EnterBlockInfoBlock();
3677
3678   { // 8-bit fixed-width VST_CODE_ENTRY/VST_CODE_BBENTRY strings.
3679     auto Abbv = std::make_shared<BitCodeAbbrev>();
3680     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
3681     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3682     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3683     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
3684     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3685         VST_ENTRY_8_ABBREV)
3686       llvm_unreachable("Unexpected abbrev ordering!");
3687   }
3688
3689   { // 7-bit fixed width VST_CODE_ENTRY strings.
3690     auto Abbv = std::make_shared<BitCodeAbbrev>();
3691     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
3692     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3693     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3694     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
3695     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3696         VST_ENTRY_7_ABBREV)
3697       llvm_unreachable("Unexpected abbrev ordering!");
3698   }
3699   { // 6-bit char6 VST_CODE_ENTRY strings.
3700     auto Abbv = std::make_shared<BitCodeAbbrev>();
3701     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
3702     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3703     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3704     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3705     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3706         VST_ENTRY_6_ABBREV)
3707       llvm_unreachable("Unexpected abbrev ordering!");
3708   }
3709   { // 6-bit char6 VST_CODE_BBENTRY strings.
3710     auto Abbv = std::make_shared<BitCodeAbbrev>();
3711     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
3712     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3713     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3714     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3715     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3716         VST_BBENTRY_6_ABBREV)
3717       llvm_unreachable("Unexpected abbrev ordering!");
3718   }
3719
3720   { // SETTYPE abbrev for CONSTANTS_BLOCK.
3721     auto Abbv = std::make_shared<BitCodeAbbrev>();
3722     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
3723     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
3724                               VE.computeBitsRequiredForTypeIndicies()));
3725     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3726         CONSTANTS_SETTYPE_ABBREV)
3727       llvm_unreachable("Unexpected abbrev ordering!");
3728   }
3729
3730   { // INTEGER abbrev for CONSTANTS_BLOCK.
3731     auto Abbv = std::make_shared<BitCodeAbbrev>();
3732     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
3733     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3734     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3735         CONSTANTS_INTEGER_ABBREV)
3736       llvm_unreachable("Unexpected abbrev ordering!");
3737   }
3738
3739   { // CE_CAST abbrev for CONSTANTS_BLOCK.
3740     auto Abbv = std::make_shared<BitCodeAbbrev>();
3741     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
3742     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
3743     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
3744                               VE.computeBitsRequiredForTypeIndicies()));
3745     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
3746
3747     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3748         CONSTANTS_CE_CAST_Abbrev)
3749       llvm_unreachable("Unexpected abbrev ordering!");
3750   }
3751   { // NULL abbrev for CONSTANTS_BLOCK.
3752     auto Abbv = std::make_shared<BitCodeAbbrev>();
3753     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
3754     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3755         CONSTANTS_NULL_Abbrev)
3756       llvm_unreachable("Unexpected abbrev ordering!");
3757   }
3758
3759   // FIXME: This should only use space for first class types!
3760
3761   { // INST_LOAD abbrev for FUNCTION_BLOCK.
3762     auto Abbv = std::make_shared<BitCodeAbbrev>();
3763     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
3764     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
3765     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
3766                               VE.computeBitsRequiredForTypeIndicies()));
3767     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
3768     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
3769     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3770         FUNCTION_INST_LOAD_ABBREV)
3771       llvm_unreachable("Unexpected abbrev ordering!");
3772   }
3773   { // INST_UNOP abbrev for FUNCTION_BLOCK.
3774     auto Abbv = std::make_shared<BitCodeAbbrev>();
3775     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNOP));
3776     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3777     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3778     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3779         FUNCTION_INST_UNOP_ABBREV)
3780       llvm_unreachable("Unexpected abbrev ordering!");
3781   }
3782   { // INST_UNOP_FLAGS abbrev for FUNCTION_BLOCK.
3783     auto Abbv = std::make_shared<BitCodeAbbrev>();
3784     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNOP));
3785     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3786     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3787     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3788     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3789         FUNCTION_INST_UNOP_FLAGS_ABBREV)
3790       llvm_unreachable("Unexpected abbrev ordering!");
3791   }
3792   { // INST_BINOP abbrev for FUNCTION_BLOCK.
3793     auto Abbv = std::make_shared<BitCodeAbbrev>();
3794     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
3795     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3796     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
3797     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3798     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3799         FUNCTION_INST_BINOP_ABBREV)
3800       llvm_unreachable("Unexpected abbrev ordering!");
3801   }
3802   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
3803     auto Abbv = std::make_shared<BitCodeAbbrev>();
3804     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
3805     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3806     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
3807     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3808     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3809     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3810         FUNCTION_INST_BINOP_FLAGS_ABBREV)
3811       llvm_unreachable("Unexpected abbrev ordering!");
3812   }
3813   { // INST_CAST abbrev for FUNCTION_BLOCK.
3814     auto Abbv = std::make_shared<BitCodeAbbrev>();
3815     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
3816     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
3817     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
3818                               VE.computeBitsRequiredForTypeIndicies()));
3819     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
3820     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3821         FUNCTION_INST_CAST_ABBREV)
3822       llvm_unreachable("Unexpected abbrev ordering!");
3823   }
3824   { // INST_CAST_FLAGS abbrev for FUNCTION_BLOCK.
3825     auto Abbv = std::make_shared<BitCodeAbbrev>();
3826     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
3827     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // OpVal
3828     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
3829                               VE.computeBitsRequiredForTypeIndicies()));
3830     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3831     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3832     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3833         FUNCTION_INST_CAST_FLAGS_ABBREV)
3834       llvm_unreachable("Unexpected abbrev ordering!");
3835   }
3836
3837   { // INST_RET abbrev for FUNCTION_BLOCK.
3838     auto Abbv = std::make_shared<BitCodeAbbrev>();
3839     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
3840     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3841         FUNCTION_INST_RET_VOID_ABBREV)
3842       llvm_unreachable("Unexpected abbrev ordering!");
3843   }
3844   { // INST_RET abbrev for FUNCTION_BLOCK.
3845     auto Abbv = std::make_shared<BitCodeAbbrev>();
3846     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
3847     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
3848     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3849         FUNCTION_INST_RET_VAL_ABBREV)
3850       llvm_unreachable("Unexpected abbrev ordering!");
3851   }
3852   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
3853     auto Abbv = std::make_shared<BitCodeAbbrev>();
3854     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
3855     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3856         FUNCTION_INST_UNREACHABLE_ABBREV)
3857       llvm_unreachable("Unexpected abbrev ordering!");
3858   }
3859   {
3860     auto Abbv = std::make_shared<BitCodeAbbrev>();
3861     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
3862     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
3863     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
3864                               Log2_32_Ceil(VE.getTypes().size() + 1)));
3865     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3866     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
3867     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3868         FUNCTION_INST_GEP_ABBREV)
3869       llvm_unreachable("Unexpected abbrev ordering!");
3870   }
3871   {
3872     auto Abbv = std::make_shared<BitCodeAbbrev>();
3873     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE));
3874     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 7)); // dbgloc
3875     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 7)); // var
3876     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 7)); // expr
3877     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // val
3878     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3879         FUNCTION_DEBUG_RECORD_VALUE_ABBREV)
3880       llvm_unreachable("Unexpected abbrev ordering! 1");
3881   }
3882   Stream.ExitBlock();
3883 }
3884
3885 /// Write the module path strings, currently only used when generating
3886 /// a combined index file.
3887 void IndexBitcodeWriter::writeModStrings() {
3888   Stream.EnterSubblock(bitc::MODULE_STRTAB_BLOCK_ID, 3);
3889
3890   // TODO: See which abbrev sizes we actually need to emit
3891
3892   // 8-bit fixed-width MST_ENTRY strings.
3893   auto Abbv = std::make_shared<BitCodeAbbrev>();
3894   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3895   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3896   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3897   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
3898   unsigned Abbrev8Bit = Stream.EmitAbbrev(std::move(Abbv));
3899
3900   // 7-bit fixed width MST_ENTRY strings.
3901   Abbv = std::make_shared<BitCodeAbbrev>();
3902   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3903   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3904   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3905   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
3906   unsigned Abbrev7Bit = Stream.EmitAbbrev(std::move(Abbv));
3907
3908   // 6-bit char6 MST_ENTRY strings.
3909   Abbv = std::make_shared<BitCodeAbbrev>();
3910   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3911   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3912   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3913   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3914   unsigned Abbrev6Bit = Stream.EmitAbbrev(std::move(Abbv));
3915
3916   // Module Hash, 160 bits SHA1. Optionally, emitted after each MST_CODE_ENTRY.
3917   Abbv = std::make_shared<BitCodeAbbrev>();
3918   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_HASH));
3919   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3920   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3921   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3922   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3923   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3924   unsigned AbbrevHash = Stream.EmitAbbrev(std::move(Abbv));
3925
3926   SmallVector<unsigned, 64> Vals;
3927   forEachModule([&](const StringMapEntry<ModuleHash> &MPSE) {
3928     StringRef Key = MPSE.getKey();
3929     const auto &Hash = MPSE.getValue();
3930     StringEncoding Bits = getStringEncoding(Key);
3931     unsigned AbbrevToUse = Abbrev8Bit;
3932     if (Bits == SE_Char6)
3933       AbbrevToUse = Abbrev6Bit;
3934     else if (Bits == SE_Fixed7)
3935       AbbrevToUse = Abbrev7Bit;
3936
3937     auto ModuleId = ModuleIdMap.size();
3938     ModuleIdMap[Key] = ModuleId;
3939     Vals.push_back(ModuleId);
3940     Vals.append(Key.begin(), Key.end());
3941
3942     // Emit the finished record.
3943     Stream.EmitRecord(bitc::MST_CODE_ENTRY, Vals, AbbrevToUse);
3944
3945     // Emit an optional hash for the module now
3946     if (llvm::any_of(Hash, [](uint32_t H) { return H; })) {
3947       Vals.assign(Hash.begin(), Hash.end());
3948       // Emit the hash record.
3949       Stream.EmitRecord(bitc::MST_CODE_HASH, Vals, AbbrevHash);
3950     }
3951
3952     Vals.clear();
3953   });
3954   Stream.ExitBlock();
3955 }
3956
3957 /// Write the function type metadata related records that need to appear before
3958 /// a function summary entry (whether per-module or combined).
3959 template <typename Fn>
3960 static void writeFunctionTypeMetadataRecords(BitstreamWriter &Stream,
3961                                              FunctionSummary *FS,
3962                                              Fn GetValueID) {
3963   if (!FS->type_tests().empty())
3964     Stream.EmitRecord(bitc::FS_TYPE_TESTS, FS->type_tests());
3965
3966   SmallVector<uint64_t, 64> Record;
3967
3968   auto WriteVFuncIdVec = [&](uint64_t Ty,
3969                              ArrayRef<FunctionSummary::VFuncId> VFs) {
3970     if (VFs.empty())
3971       return;
3972     Record.clear();
3973     for (auto &VF : VFs) {
3974       Record.push_back(VF.GUID);
3975       Record.push_back(VF.Offset);
3976     }
3977     Stream.EmitRecord(Ty, Record);
3978   };
3979
3980   WriteVFuncIdVec(bitc::FS_TYPE_TEST_ASSUME_VCALLS,
3981                   FS->type_test_assume_vcalls());
3982   WriteVFuncIdVec(bitc::FS_TYPE_CHECKED_LOAD_VCALLS,
3983                   FS->type_checked_load_vcalls());
3984
3985   auto WriteConstVCallVec = [&](uint64_t Ty,
3986                                 ArrayRef<FunctionSummary::ConstVCall> VCs) {
3987     for (auto &VC : VCs) {
3988       Record.clear();
3989       Record.push_back(VC.VFunc.GUID);
3990       Record.push_back(VC.VFunc.Offset);
3991       llvm::append_range(Record, VC.Args);
3992       Stream.EmitRecord(Ty, Record);
3993     }
3994   };
3995
3996   WriteConstVCallVec(bitc::FS_TYPE_TEST_ASSUME_CONST_VCALL,
3997                      FS->type_test_assume_const_vcalls());
3998   WriteConstVCallVec(bitc::FS_TYPE_CHECKED_LOAD_CONST_VCALL,
3999                      FS->type_checked_load_const_vcalls());
4000
4001   auto WriteRange = [&](ConstantRange Range) {
4002     Range = Range.sextOrTrunc(FunctionSummary::ParamAccess::RangeWidth);
4003     assert(Range.getLower().getNumWords() == 1);
4004     assert(Range.getUpper().getNumWords() == 1);
4005     emitSignedInt64(Record, *Range.getLower().getRawData());
4006     emitSignedInt64(Record, *Range.getUpper().getRawData());
4007   };
4008
4009   if (!FS->paramAccesses().empty()) {
4010     Record.clear();
4011     for (auto &Arg : FS->paramAccesses()) {
4012       size_t UndoSize = Record.size();
4013       Record.push_back(Arg.ParamNo);
4014       WriteRange(Arg.Use);
4015       Record.push_back(Arg.Calls.size());
4016       for (auto &Call : Arg.Calls) {
4017         Record.push_back(Call.ParamNo);
4018         std::optional<unsigned> ValueID = GetValueID(Call.Callee);
4019         if (!ValueID) {
4020           // If ValueID is unknown we can't drop just this call, we must drop
4021           // entire parameter.
4022           Record.resize(UndoSize);
4023           break;
4024         }
4025         Record.push_back(*ValueID);
4026         WriteRange(Call.Offsets);
4027       }
4028     }
4029     if (!Record.empty())
4030       Stream.EmitRecord(bitc::FS_PARAM_ACCESS, Record);
4031   }
4032 }
4033
4034 /// Collect type IDs from type tests used by function.
4035 static void
4036 getReferencedTypeIds(FunctionSummary *FS,
4037                      std::set<GlobalValue::GUID> &ReferencedTypeIds) {
4038   if (!FS->type_tests().empty())
4039     for (auto &TT : FS->type_tests())
4040       ReferencedTypeIds.insert(TT);
4041
4042   auto GetReferencedTypesFromVFuncIdVec =
4043       [&](ArrayRef<FunctionSummary::VFuncId> VFs) {
4044         for (auto &VF : VFs)
4045           ReferencedTypeIds.insert(VF.GUID);
4046       };
4047
4048   GetReferencedTypesFromVFuncIdVec(FS->type_test_assume_vcalls());
4049   GetReferencedTypesFromVFuncIdVec(FS->type_checked_load_vcalls());
4050
4051   auto GetReferencedTypesFromConstVCallVec =
4052       [&](ArrayRef<FunctionSummary::ConstVCall> VCs) {
4053         for (auto &VC : VCs)
4054           ReferencedTypeIds.insert(VC.VFunc.GUID);
4055       };
4056
4057   GetReferencedTypesFromConstVCallVec(FS->type_test_assume_const_vcalls());
4058   GetReferencedTypesFromConstVCallVec(FS->type_checked_load_const_vcalls());
4059 }
4060
4061 static void writeWholeProgramDevirtResolutionByArg(
4062     SmallVector<uint64_t, 64> &NameVals, const std::vector<uint64_t> &args,
4063     const WholeProgramDevirtResolution::ByArg &ByArg) {
4064   NameVals.push_back(args.size());
4065   llvm::append_range(NameVals, args);
4066
4067   NameVals.push_back(ByArg.TheKind);
4068   NameVals.push_back(ByArg.Info);
4069   NameVals.push_back(ByArg.Byte);
4070   NameVals.push_back(ByArg.Bit);
4071 }
4072
4073 static void writeWholeProgramDevirtResolution(
4074     SmallVector<uint64_t, 64> &NameVals, StringTableBuilder &StrtabBuilder,
4075     uint64_t Id, const WholeProgramDevirtResolution &Wpd) {
4076   NameVals.push_back(Id);
4077
4078   NameVals.push_back(Wpd.TheKind);
4079   NameVals.push_back(StrtabBuilder.add(Wpd.SingleImplName));
4080   NameVals.push_back(Wpd.SingleImplName.size());
4081
4082   NameVals.push_back(Wpd.ResByArg.size());
4083   for (auto &A : Wpd.ResByArg)
4084     writeWholeProgramDevirtResolutionByArg(NameVals, A.first, A.second);
4085 }
4086
4087 static void writeTypeIdSummaryRecord(SmallVector<uint64_t, 64> &NameVals,
4088                                      StringTableBuilder &StrtabBuilder,
4089                                      const std::string &Id,
4090                                      const TypeIdSummary &Summary) {
4091   NameVals.push_back(StrtabBuilder.add(Id));
4092   NameVals.push_back(Id.size());
4093
4094   NameVals.push_back(Summary.TTRes.TheKind);
4095   NameVals.push_back(Summary.TTRes.SizeM1BitWidth);
4096   NameVals.push_back(Summary.TTRes.AlignLog2);
4097   NameVals.push_back(Summary.TTRes.SizeM1);
4098   NameVals.push_back(Summary.TTRes.BitMask);
4099   NameVals.push_back(Summary.TTRes.InlineBits);
4100
4101   for (auto &W : Summary.WPDRes)
4102     writeWholeProgramDevirtResolution(NameVals, StrtabBuilder, W.first,
4103                                       W.second);
4104 }
4105
4106 static void writeTypeIdCompatibleVtableSummaryRecord(
4107     SmallVector<uint64_t, 64> &NameVals, StringTableBuilder &StrtabBuilder,
4108     const std::string &Id, const TypeIdCompatibleVtableInfo &Summary,
4109     ValueEnumerator &VE) {
4110   NameVals.push_back(StrtabBuilder.add(Id));
4111   NameVals.push_back(Id.size());
4112
4113   for (auto &P : Summary) {
4114     NameVals.push_back(P.AddressPointOffset);
4115     NameVals.push_back(VE.getValueID(P.VTableVI.getValue()));
4116   }
4117 }
4118
4119 static void writeFunctionHeapProfileRecords(
4120     BitstreamWriter &Stream, FunctionSummary *FS, unsigned CallsiteAbbrev,
4121     unsigned AllocAbbrev, bool PerModule,
4122     std::function<unsigned(const ValueInfo &VI)> GetValueID,
4123     std::function<unsigned(unsigned)> GetStackIndex) {
4124   SmallVector<uint64_t> Record;
4125
4126   for (auto &CI : FS->callsites()) {
4127     Record.clear();
4128     // Per module callsite clones should always have a single entry of
4129     // value 0.
4130     assert(!PerModule || (CI.Clones.size() == 1 && CI.Clones[0] == 0));
4131     Record.push_back(GetValueID(CI.Callee));
4132     if (!PerModule) {
4133       Record.push_back(CI.StackIdIndices.size());
4134       Record.push_back(CI.Clones.size());
4135     }
4136     for (auto Id : CI.StackIdIndices)
4137       Record.push_back(GetStackIndex(Id));
4138     if (!PerModule) {
4139       for (auto V : CI.Clones)
4140         Record.push_back(V);
4141     }
4142     Stream.EmitRecord(PerModule ? bitc::FS_PERMODULE_CALLSITE_INFO
4143                                 : bitc::FS_COMBINED_CALLSITE_INFO,
4144                       Record, CallsiteAbbrev);
4145   }
4146
4147   for (auto &AI : FS->allocs()) {
4148     Record.clear();
4149     // Per module alloc versions should always have a single entry of
4150     // value 0.
4151     assert(!PerModule || (AI.Versions.size() == 1 && AI.Versions[0] == 0));
4152     if (!PerModule) {
4153       Record.push_back(AI.MIBs.size());
4154       Record.push_back(AI.Versions.size());
4155     }
4156     for (auto &MIB : AI.MIBs) {
4157       Record.push_back((uint8_t)MIB.AllocType);
4158       Record.push_back(MIB.StackIdIndices.size());
4159       for (auto Id : MIB.StackIdIndices)
4160         Record.push_back(GetStackIndex(Id));
4161     }
4162     if (!PerModule) {
4163       for (auto V : AI.Versions)
4164         Record.push_back(V);
4165     }
4166     Stream.EmitRecord(PerModule ? bitc::FS_PERMODULE_ALLOC_INFO
4167                                 : bitc::FS_COMBINED_ALLOC_INFO,
4168                       Record, AllocAbbrev);
4169   }
4170 }
4171
4172 // Helper to emit a single function summary record.
4173 void ModuleBitcodeWriterBase::writePerModuleFunctionSummaryRecord(
4174     SmallVector<uint64_t, 64> &NameVals, GlobalValueSummary *Summary,
4175     unsigned ValueID, unsigned FSCallsRelBFAbbrev,
4176     unsigned FSCallsProfileAbbrev, unsigned CallsiteAbbrev,
4177     unsigned AllocAbbrev, const Function &F) {
4178   NameVals.push_back(ValueID);
4179
4180   FunctionSummary *FS = cast<FunctionSummary>(Summary);
4181
4182   writeFunctionTypeMetadataRecords(
4183       Stream, FS, [&](const ValueInfo &VI) -> std::optional<unsigned> {
4184         return {VE.getValueID(VI.getValue())};
4185       });
4186
4187   writeFunctionHeapProfileRecords(
4188       Stream, FS, CallsiteAbbrev, AllocAbbrev,
4189       /*PerModule*/ true,
4190       /*GetValueId*/ [&](const ValueInfo &VI) { return getValueId(VI); },
4191       /*GetStackIndex*/ [&](unsigned I) { return I; });
4192
4193   auto SpecialRefCnts = FS->specialRefCounts();
4194   NameVals.push_back(getEncodedGVSummaryFlags(FS->flags()));
4195   NameVals.push_back(FS->instCount());
4196   NameVals.push_back(getEncodedFFlags(FS->fflags()));
4197   NameVals.push_back(FS->refs().size());
4198   NameVals.push_back(SpecialRefCnts.first);  // rorefcnt
4199   NameVals.push_back(SpecialRefCnts.second); // worefcnt
4200
4201   for (auto &RI : FS->refs())
4202     NameVals.push_back(getValueId(RI));
4203
4204   const bool UseRelBFRecord =
4205       WriteRelBFToSummary && !F.hasProfileData() &&
4206       ForceSummaryEdgesCold == FunctionSummary::FSHT_None;
4207   for (auto &ECI : FS->calls()) {
4208     NameVals.push_back(getValueId(ECI.first));
4209     if (UseRelBFRecord)
4210       NameVals.push_back(getEncodedRelBFCallEdgeInfo(ECI.second));
4211     else
4212       NameVals.push_back(getEncodedHotnessCallEdgeInfo(ECI.second));
4213   }
4214
4215   unsigned FSAbbrev =
4216       (UseRelBFRecord ? FSCallsRelBFAbbrev : FSCallsProfileAbbrev);
4217   unsigned Code =
4218       (UseRelBFRecord ? bitc::FS_PERMODULE_RELBF : bitc::FS_PERMODULE_PROFILE);
4219
4220   // Emit the finished record.
4221   Stream.EmitRecord(Code, NameVals, FSAbbrev);
4222   NameVals.clear();
4223 }
4224
4225 // Collect the global value references in the given variable's initializer,
4226 // and emit them in a summary record.
4227 void ModuleBitcodeWriterBase::writeModuleLevelReferences(
4228     const GlobalVariable &V, SmallVector<uint64_t, 64> &NameVals,
4229     unsigned FSModRefsAbbrev, unsigned FSModVTableRefsAbbrev) {
4230   auto VI = Index->getValueInfo(V.getGUID());
4231   if (!VI || VI.getSummaryList().empty()) {
4232     // Only declarations should not have a summary (a declaration might however
4233     // have a summary if the def was in module level asm).
4234     assert(V.isDeclaration());
4235     return;
4236   }
4237   auto *Summary = VI.getSummaryList()[0].get();
4238   NameVals.push_back(VE.getValueID(&V));
4239   GlobalVarSummary *VS = cast<GlobalVarSummary>(Summary);
4240   NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
4241   NameVals.push_back(getEncodedGVarFlags(VS->varflags()));
4242
4243   auto VTableFuncs = VS->vTableFuncs();
4244   if (!VTableFuncs.empty())
4245     NameVals.push_back(VS->refs().size());
4246
4247   unsigned SizeBeforeRefs = NameVals.size();
4248   for (auto &RI : VS->refs())
4249     NameVals.push_back(VE.getValueID(RI.getValue()));
4250   // Sort the refs for determinism output, the vector returned by FS->refs() has
4251   // been initialized from a DenseSet.
4252   llvm::sort(drop_begin(NameVals, SizeBeforeRefs));
4253
4254   if (VTableFuncs.empty())
4255     Stream.EmitRecord(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS, NameVals,
4256                       FSModRefsAbbrev);
4257   else {
4258     // VTableFuncs pairs should already be sorted by offset.
4259     for (auto &P : VTableFuncs) {
4260       NameVals.push_back(VE.getValueID(P.FuncVI.getValue()));
4261       NameVals.push_back(P.VTableOffset);
4262     }
4263
4264     Stream.EmitRecord(bitc::FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS, NameVals,
4265                       FSModVTableRefsAbbrev);
4266   }
4267   NameVals.clear();
4268 }
4269
4270 /// Emit the per-module summary section alongside the rest of
4271 /// the module's bitcode.
4272 void ModuleBitcodeWriterBase::writePerModuleGlobalValueSummary() {
4273   // By default we compile with ThinLTO if the module has a summary, but the
4274   // client can request full LTO with a module flag.
4275   bool IsThinLTO = true;
4276   if (auto *MD =
4277           mdconst::extract_or_null<ConstantInt>(M.getModuleFlag("ThinLTO")))
4278     IsThinLTO = MD->getZExtValue();
4279   Stream.EnterSubblock(IsThinLTO ? bitc::GLOBALVAL_SUMMARY_BLOCK_ID
4280                                  : bitc::FULL_LTO_GLOBALVAL_SUMMARY_BLOCK_ID,
4281                        4);
4282
4283   Stream.EmitRecord(
4284       bitc::FS_VERSION,
4285       ArrayRef<uint64_t>{ModuleSummaryIndex::BitcodeSummaryVersion});
4286
4287   // Write the index flags.
4288   uint64_t Flags = 0;
4289   // Bits 1-3 are set only in the combined index, skip them.
4290   if (Index->enableSplitLTOUnit())
4291     Flags |= 0x8;
4292   if (Index->hasUnifiedLTO())
4293     Flags |= 0x200;
4294
4295   Stream.EmitRecord(bitc::FS_FLAGS, ArrayRef<uint64_t>{Flags});
4296
4297   if (Index->begin() == Index->end()) {
4298     Stream.ExitBlock();
4299     return;
4300   }
4301
4302   for (const auto &GVI : valueIds()) {
4303     Stream.EmitRecord(bitc::FS_VALUE_GUID,
4304                       ArrayRef<uint64_t>{GVI.second, GVI.first});
4305   }
4306
4307   if (!Index->stackIds().empty()) {
4308     auto StackIdAbbv = std::make_shared<BitCodeAbbrev>();
4309     StackIdAbbv->Add(BitCodeAbbrevOp(bitc::FS_STACK_IDS));
4310     // numids x stackid
4311     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4312     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4313     unsigned StackIdAbbvId = Stream.EmitAbbrev(std::move(StackIdAbbv));
4314     Stream.EmitRecord(bitc::FS_STACK_IDS, Index->stackIds(), StackIdAbbvId);
4315   }
4316
4317   // Abbrev for FS_PERMODULE_PROFILE.
4318   auto Abbv = std::make_shared<BitCodeAbbrev>();
4319   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_PROFILE));
4320   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4321   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // flags
4322   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4323   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4324   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4325   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4326   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4327   // numrefs x valueid, n x (valueid, hotness+tailcall flags)
4328   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4329   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4330   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4331
4332   // Abbrev for FS_PERMODULE_RELBF.
4333   Abbv = std::make_shared<BitCodeAbbrev>();
4334   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_RELBF));
4335   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4336   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4337   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4338   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4339   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4340   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4341   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4342   // numrefs x valueid, n x (valueid, rel_block_freq+tailcall])
4343   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4344   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4345   unsigned FSCallsRelBFAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4346
4347   // Abbrev for FS_PERMODULE_GLOBALVAR_INIT_REFS.
4348   Abbv = std::make_shared<BitCodeAbbrev>();
4349   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS));
4350   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4351   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
4352   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));  // valueids
4353   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4354   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4355
4356   // Abbrev for FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS.
4357   Abbv = std::make_shared<BitCodeAbbrev>();
4358   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS));
4359   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4360   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
4361   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numrefs
4362   // numrefs x valueid, n x (valueid , offset)
4363   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4364   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4365   unsigned FSModVTableRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4366
4367   // Abbrev for FS_ALIAS.
4368   Abbv = std::make_shared<BitCodeAbbrev>();
4369   Abbv->Add(BitCodeAbbrevOp(bitc::FS_ALIAS));
4370   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4371   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4372   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4373   unsigned FSAliasAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4374
4375   // Abbrev for FS_TYPE_ID_METADATA
4376   Abbv = std::make_shared<BitCodeAbbrev>();
4377   Abbv->Add(BitCodeAbbrevOp(bitc::FS_TYPE_ID_METADATA));
4378   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // typeid strtab index
4379   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // typeid length
4380   // n x (valueid , offset)
4381   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4382   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4383   unsigned TypeIdCompatibleVtableAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4384
4385   Abbv = std::make_shared<BitCodeAbbrev>();
4386   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_CALLSITE_INFO));
4387   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4388   // n x stackidindex
4389   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4390   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4391   unsigned CallsiteAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4392
4393   Abbv = std::make_shared<BitCodeAbbrev>();
4394   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_ALLOC_INFO));
4395   // n x (alloc type, numstackids, numstackids x stackidindex)
4396   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4397   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4398   unsigned AllocAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4399
4400   SmallVector<uint64_t, 64> NameVals;
4401   // Iterate over the list of functions instead of the Index to
4402   // ensure the ordering is stable.
4403   for (const Function &F : M) {
4404     // Summary emission does not support anonymous functions, they have to
4405     // renamed using the anonymous function renaming pass.
4406     if (!F.hasName())
4407       report_fatal_error("Unexpected anonymous function when writing summary");
4408
4409     ValueInfo VI = Index->getValueInfo(F.getGUID());
4410     if (!VI || VI.getSummaryList().empty()) {
4411       // Only declarations should not have a summary (a declaration might
4412       // however have a summary if the def was in module level asm).
4413       assert(F.isDeclaration());
4414       continue;
4415     }
4416     auto *Summary = VI.getSummaryList()[0].get();
4417     writePerModuleFunctionSummaryRecord(
4418         NameVals, Summary, VE.getValueID(&F), FSCallsRelBFAbbrev,
4419         FSCallsProfileAbbrev, CallsiteAbbrev, AllocAbbrev, F);
4420   }
4421
4422   // Capture references from GlobalVariable initializers, which are outside
4423   // of a function scope.
4424   for (const GlobalVariable &G : M.globals())
4425     writeModuleLevelReferences(G, NameVals, FSModRefsAbbrev,
4426                                FSModVTableRefsAbbrev);
4427
4428   for (const GlobalAlias &A : M.aliases()) {
4429     auto *Aliasee = A.getAliaseeObject();
4430     // Skip ifunc and nameless functions which don't have an entry in the
4431     // summary.
4432     if (!Aliasee->hasName() || isa<GlobalIFunc>(Aliasee))
4433       continue;
4434     auto AliasId = VE.getValueID(&A);
4435     auto AliaseeId = VE.getValueID(Aliasee);
4436     NameVals.push_back(AliasId);
4437     auto *Summary = Index->getGlobalValueSummary(A);
4438     AliasSummary *AS = cast<AliasSummary>(Summary);
4439     NameVals.push_back(getEncodedGVSummaryFlags(AS->flags()));
4440     NameVals.push_back(AliaseeId);
4441     Stream.EmitRecord(bitc::FS_ALIAS, NameVals, FSAliasAbbrev);
4442     NameVals.clear();
4443   }
4444
4445   for (auto &S : Index->typeIdCompatibleVtableMap()) {
4446     writeTypeIdCompatibleVtableSummaryRecord(NameVals, StrtabBuilder, S.first,
4447                                              S.second, VE);
4448     Stream.EmitRecord(bitc::FS_TYPE_ID_METADATA, NameVals,
4449                       TypeIdCompatibleVtableAbbrev);
4450     NameVals.clear();
4451   }
4452
4453   if (Index->getBlockCount())
4454     Stream.EmitRecord(bitc::FS_BLOCK_COUNT,
4455                       ArrayRef<uint64_t>{Index->getBlockCount()});
4456
4457   Stream.ExitBlock();
4458 }
4459
4460 /// Emit the combined summary section into the combined index file.
4461 void IndexBitcodeWriter::writeCombinedGlobalValueSummary() {
4462   Stream.EnterSubblock(bitc::GLOBALVAL_SUMMARY_BLOCK_ID, 4);
4463   Stream.EmitRecord(
4464       bitc::FS_VERSION,
4465       ArrayRef<uint64_t>{ModuleSummaryIndex::BitcodeSummaryVersion});
4466
4467   // Write the index flags.
4468   Stream.EmitRecord(bitc::FS_FLAGS, ArrayRef<uint64_t>{Index.getFlags()});
4469
4470   for (const auto &GVI : valueIds()) {
4471     Stream.EmitRecord(bitc::FS_VALUE_GUID,
4472                       ArrayRef<uint64_t>{GVI.second, GVI.first});
4473   }
4474
4475   if (!StackIdIndices.empty()) {
4476     auto StackIdAbbv = std::make_shared<BitCodeAbbrev>();
4477     StackIdAbbv->Add(BitCodeAbbrevOp(bitc::FS_STACK_IDS));
4478     // numids x stackid
4479     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4480     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4481     unsigned StackIdAbbvId = Stream.EmitAbbrev(std::move(StackIdAbbv));
4482     // Write the stack ids used by this index, which will be a subset of those in
4483     // the full index in the case of distributed indexes.
4484     std::vector<uint64_t> StackIds;
4485     for (auto &I : StackIdIndices)
4486       StackIds.push_back(Index.getStackIdAtIndex(I));
4487     Stream.EmitRecord(bitc::FS_STACK_IDS, StackIds, StackIdAbbvId);
4488   }
4489
4490   // Abbrev for FS_COMBINED_PROFILE.
4491   auto Abbv = std::make_shared<BitCodeAbbrev>();
4492   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_PROFILE));
4493   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4494   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4495   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4496   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4497   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4498   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // entrycount
4499   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4500   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4501   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4502   // numrefs x valueid, n x (valueid, hotness+tailcall flags)
4503   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4504   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4505   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4506
4507   // Abbrev for FS_COMBINED_GLOBALVAR_INIT_REFS.
4508   Abbv = std::make_shared<BitCodeAbbrev>();
4509   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS));
4510   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4511   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4512   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4513   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));    // valueids
4514   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4515   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4516
4517   // Abbrev for FS_COMBINED_ALIAS.
4518   Abbv = std::make_shared<BitCodeAbbrev>();
4519   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_ALIAS));
4520   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4521   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4522   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4523   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4524   unsigned FSAliasAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4525
4526   Abbv = std::make_shared<BitCodeAbbrev>();
4527   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_CALLSITE_INFO));
4528   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4529   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numstackindices
4530   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numver
4531   // numstackindices x stackidindex, numver x version
4532   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4533   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4534   unsigned CallsiteAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4535
4536   Abbv = std::make_shared<BitCodeAbbrev>();
4537   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_ALLOC_INFO));
4538   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // nummib
4539   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numver
4540   // nummib x (alloc type, numstackids, numstackids x stackidindex),
4541   // numver x version
4542   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4543   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4544   unsigned AllocAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4545
4546   // The aliases are emitted as a post-pass, and will point to the value
4547   // id of the aliasee. Save them in a vector for post-processing.
4548   SmallVector<AliasSummary *, 64> Aliases;
4549
4550   // Save the value id for each summary for alias emission.
4551   DenseMap<const GlobalValueSummary *, unsigned> SummaryToValueIdMap;
4552
4553   SmallVector<uint64_t, 64> NameVals;
4554
4555   // Set that will be populated during call to writeFunctionTypeMetadataRecords
4556   // with the type ids referenced by this index file.
4557   std::set<GlobalValue::GUID> ReferencedTypeIds;
4558
4559   // For local linkage, we also emit the original name separately
4560   // immediately after the record.
4561   auto MaybeEmitOriginalName = [&](GlobalValueSummary &S) {
4562     // We don't need to emit the original name if we are writing the index for
4563     // distributed backends (in which case ModuleToSummariesForIndex is
4564     // non-null). The original name is only needed during the thin link, since
4565     // for SamplePGO the indirect call targets for local functions have
4566     // have the original name annotated in profile.
4567     // Continue to emit it when writing out the entire combined index, which is
4568     // used in testing the thin link via llvm-lto.
4569     if (ModuleToSummariesForIndex || !GlobalValue::isLocalLinkage(S.linkage()))
4570       return;
4571     NameVals.push_back(S.getOriginalName());
4572     Stream.EmitRecord(bitc::FS_COMBINED_ORIGINAL_NAME, NameVals);
4573     NameVals.clear();
4574   };
4575
4576   std::set<GlobalValue::GUID> DefOrUseGUIDs;
4577   forEachSummary([&](GVInfo I, bool IsAliasee) {
4578     GlobalValueSummary *S = I.second;
4579     assert(S);
4580     DefOrUseGUIDs.insert(I.first);
4581     for (const ValueInfo &VI : S->refs())
4582       DefOrUseGUIDs.insert(VI.getGUID());
4583
4584     auto ValueId = getValueId(I.first);
4585     assert(ValueId);
4586     SummaryToValueIdMap[S] = *ValueId;
4587
4588     // If this is invoked for an aliasee, we want to record the above
4589     // mapping, but then not emit a summary entry (if the aliasee is
4590     // to be imported, we will invoke this separately with IsAliasee=false).
4591     if (IsAliasee)
4592       return;
4593
4594     if (auto *AS = dyn_cast<AliasSummary>(S)) {
4595       // Will process aliases as a post-pass because the reader wants all
4596       // global to be loaded first.
4597       Aliases.push_back(AS);
4598       return;
4599     }
4600
4601     if (auto *VS = dyn_cast<GlobalVarSummary>(S)) {
4602       NameVals.push_back(*ValueId);
4603       assert(ModuleIdMap.count(VS->modulePath()));
4604       NameVals.push_back(ModuleIdMap[VS->modulePath()]);
4605       NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
4606       NameVals.push_back(getEncodedGVarFlags(VS->varflags()));
4607       for (auto &RI : VS->refs()) {
4608         auto RefValueId = getValueId(RI.getGUID());
4609         if (!RefValueId)
4610           continue;
4611         NameVals.push_back(*RefValueId);
4612       }
4613
4614       // Emit the finished record.
4615       Stream.EmitRecord(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS, NameVals,
4616                         FSModRefsAbbrev);
4617       NameVals.clear();
4618       MaybeEmitOriginalName(*S);
4619       return;
4620     }
4621
4622     auto GetValueId = [&](const ValueInfo &VI) -> std::optional<unsigned> {
4623       if (!VI)
4624         return std::nullopt;
4625       return getValueId(VI.getGUID());
4626     };
4627
4628     auto *FS = cast<FunctionSummary>(S);
4629     writeFunctionTypeMetadataRecords(Stream, FS, GetValueId);
4630     getReferencedTypeIds(FS, ReferencedTypeIds);
4631
4632     writeFunctionHeapProfileRecords(
4633         Stream, FS, CallsiteAbbrev, AllocAbbrev,
4634         /*PerModule*/ false,
4635         /*GetValueId*/ [&](const ValueInfo &VI) -> unsigned {
4636           std::optional<unsigned> ValueID = GetValueId(VI);
4637           // This can happen in shared index files for distributed ThinLTO if
4638           // the callee function summary is not included. Record 0 which we
4639           // will have to deal with conservatively when doing any kind of
4640           // validation in the ThinLTO backends.
4641           if (!ValueID)
4642             return 0;
4643           return *ValueID;
4644         },
4645         /*GetStackIndex*/ [&](unsigned I) {
4646           // Get the corresponding index into the list of StackIdIndices
4647           // actually being written for this combined index (which may be a
4648           // subset in the case of distributed indexes).
4649           auto Lower = llvm::lower_bound(StackIdIndices, I);
4650           return std::distance(StackIdIndices.begin(), Lower);
4651         });
4652
4653     NameVals.push_back(*ValueId);
4654     assert(ModuleIdMap.count(FS->modulePath()));
4655     NameVals.push_back(ModuleIdMap[FS->modulePath()]);
4656     NameVals.push_back(getEncodedGVSummaryFlags(FS->flags()));
4657     NameVals.push_back(FS->instCount());
4658     NameVals.push_back(getEncodedFFlags(FS->fflags()));
4659     NameVals.push_back(FS->entryCount());
4660
4661     // Fill in below
4662     NameVals.push_back(0); // numrefs
4663     NameVals.push_back(0); // rorefcnt
4664     NameVals.push_back(0); // worefcnt
4665
4666     unsigned Count = 0, RORefCnt = 0, WORefCnt = 0;
4667     for (auto &RI : FS->refs()) {
4668       auto RefValueId = getValueId(RI.getGUID());
4669       if (!RefValueId)
4670         continue;
4671       NameVals.push_back(*RefValueId);
4672       if (RI.isReadOnly())
4673         RORefCnt++;
4674       else if (RI.isWriteOnly())
4675         WORefCnt++;
4676       Count++;
4677     }
4678     NameVals[6] = Count;
4679     NameVals[7] = RORefCnt;
4680     NameVals[8] = WORefCnt;
4681
4682     for (auto &EI : FS->calls()) {
4683       // If this GUID doesn't have a value id, it doesn't have a function
4684       // summary and we don't need to record any calls to it.
4685       std::optional<unsigned> CallValueId = GetValueId(EI.first);
4686       if (!CallValueId)
4687         continue;
4688       NameVals.push_back(*CallValueId);
4689       NameVals.push_back(getEncodedHotnessCallEdgeInfo(EI.second));
4690     }
4691
4692     // Emit the finished record.
4693     Stream.EmitRecord(bitc::FS_COMBINED_PROFILE, NameVals,
4694                       FSCallsProfileAbbrev);
4695     NameVals.clear();
4696     MaybeEmitOriginalName(*S);
4697   });
4698
4699   for (auto *AS : Aliases) {
4700     auto AliasValueId = SummaryToValueIdMap[AS];
4701     assert(AliasValueId);
4702     NameVals.push_back(AliasValueId);
4703     assert(ModuleIdMap.count(AS->modulePath()));
4704     NameVals.push_back(ModuleIdMap[AS->modulePath()]);
4705     NameVals.push_back(getEncodedGVSummaryFlags(AS->flags()));
4706     auto AliaseeValueId = SummaryToValueIdMap[&AS->getAliasee()];
4707     assert(AliaseeValueId);
4708     NameVals.push_back(AliaseeValueId);
4709
4710     // Emit the finished record.
4711     Stream.EmitRecord(bitc::FS_COMBINED_ALIAS, NameVals, FSAliasAbbrev);
4712     NameVals.clear();
4713     MaybeEmitOriginalName(*AS);
4714
4715     if (auto *FS = dyn_cast<FunctionSummary>(&AS->getAliasee()))
4716       getReferencedTypeIds(FS, ReferencedTypeIds);
4717   }
4718
4719   if (!Index.cfiFunctionDefs().empty()) {
4720     for (auto &S : Index.cfiFunctionDefs()) {
4721       if (DefOrUseGUIDs.count(
4722               GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(S)))) {
4723         NameVals.push_back(StrtabBuilder.add(S));
4724         NameVals.push_back(S.size());
4725       }
4726     }
4727     if (!NameVals.empty()) {
4728       Stream.EmitRecord(bitc::FS_CFI_FUNCTION_DEFS, NameVals);
4729       NameVals.clear();
4730     }
4731   }
4732
4733   if (!Index.cfiFunctionDecls().empty()) {
4734     for (auto &S : Index.cfiFunctionDecls()) {
4735       if (DefOrUseGUIDs.count(
4736               GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(S)))) {
4737         NameVals.push_back(StrtabBuilder.add(S));
4738         NameVals.push_back(S.size());
4739       }
4740     }
4741     if (!NameVals.empty()) {
4742       Stream.EmitRecord(bitc::FS_CFI_FUNCTION_DECLS, NameVals);
4743       NameVals.clear();
4744     }
4745   }
4746
4747   // Walk the GUIDs that were referenced, and write the
4748   // corresponding type id records.
4749   for (auto &T : ReferencedTypeIds) {
4750     auto TidIter = Index.typeIds().equal_range(T);
4751     for (auto It = TidIter.first; It != TidIter.second; ++It) {
4752       writeTypeIdSummaryRecord(NameVals, StrtabBuilder, It->second.first,
4753                                It->second.second);
4754       Stream.EmitRecord(bitc::FS_TYPE_ID, NameVals);
4755       NameVals.clear();
4756     }
4757   }
4758
4759   if (Index.getBlockCount())
4760     Stream.EmitRecord(bitc::FS_BLOCK_COUNT,
4761                       ArrayRef<uint64_t>{Index.getBlockCount()});
4762
4763   Stream.ExitBlock();
4764 }
4765
4766 /// Create the "IDENTIFICATION_BLOCK_ID" containing a single string with the
4767 /// current llvm version, and a record for the epoch number.
4768 static void writeIdentificationBlock(BitstreamWriter &Stream) {
4769   Stream.EnterSubblock(bitc::IDENTIFICATION_BLOCK_ID, 5);
4770
4771   // Write the "user readable" string identifying the bitcode producer
4772   auto Abbv = std::make_shared<BitCodeAbbrev>();
4773   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_STRING));
4774   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4775   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
4776   auto StringAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4777   writeStringRecord(Stream, bitc::IDENTIFICATION_CODE_STRING,
4778                     "LLVM" LLVM_VERSION_STRING, StringAbbrev);
4779
4780   // Write the epoch version
4781   Abbv = std::make_shared<BitCodeAbbrev>();
4782   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_EPOCH));
4783   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
4784   auto EpochAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4785   constexpr std::array<unsigned, 1> Vals = {{bitc::BITCODE_CURRENT_EPOCH}};
4786   Stream.EmitRecord(bitc::IDENTIFICATION_CODE_EPOCH, Vals, EpochAbbrev);
4787   Stream.ExitBlock();
4788 }
4789
4790 void ModuleBitcodeWriter::writeModuleHash(size_t BlockStartPos) {
4791   // Emit the module's hash.
4792   // MODULE_CODE_HASH: [5*i32]
4793   if (GenerateHash) {
4794     uint32_t Vals[5];
4795     Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&(Buffer)[BlockStartPos],
4796                                     Buffer.size() - BlockStartPos));
4797     std::array<uint8_t, 20> Hash = Hasher.result();
4798     for (int Pos = 0; Pos < 20; Pos += 4) {
4799       Vals[Pos / 4] = support::endian::read32be(Hash.data() + Pos);
4800     }
4801
4802     // Emit the finished record.
4803     Stream.EmitRecord(bitc::MODULE_CODE_HASH, Vals);
4804
4805     if (ModHash)
4806       // Save the written hash value.
4807       llvm::copy(Vals, std::begin(*ModHash));
4808   }
4809 }
4810
4811 void ModuleBitcodeWriter::write() {
4812   writeIdentificationBlock(Stream);
4813
4814   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
4815   size_t BlockStartPos = Buffer.size();
4816
4817   writeModuleVersion();
4818
4819   // Emit blockinfo, which defines the standard abbreviations etc.
4820   writeBlockInfo();
4821
4822   // Emit information describing all of the types in the module.
4823   writeTypeTable();
4824
4825   // Emit information about attribute groups.
4826   writeAttributeGroupTable();
4827
4828   // Emit information about parameter attributes.
4829   writeAttributeTable();
4830
4831   writeComdats();
4832
4833   // Emit top-level description of module, including target triple, inline asm,
4834   // descriptors for global variables, and function prototype info.
4835   writeModuleInfo();
4836
4837   // Emit constants.
4838   writeModuleConstants();
4839
4840   // Emit metadata kind names.
4841   writeModuleMetadataKinds();
4842
4843   // Emit metadata.
4844   writeModuleMetadata();
4845
4846   // Emit module-level use-lists.
4847   if (VE.shouldPreserveUseListOrder())
4848     writeUseListBlock(nullptr);
4849
4850   writeOperandBundleTags();
4851   writeSyncScopeNames();
4852
4853   // Emit function bodies.
4854   DenseMap<const Function *, uint64_t> FunctionToBitcodeIndex;
4855   for (const Function &F : M)
4856     if (!F.isDeclaration())
4857       writeFunction(F, FunctionToBitcodeIndex);
4858
4859   // Need to write after the above call to WriteFunction which populates
4860   // the summary information in the index.
4861   if (Index)
4862     writePerModuleGlobalValueSummary();
4863
4864   writeGlobalValueSymbolTable(FunctionToBitcodeIndex);
4865
4866   writeModuleHash(BlockStartPos);
4867
4868   Stream.ExitBlock();
4869 }
4870
4871 static void writeInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
4872                                uint32_t &Position) {
4873   support::endian::write32le(&Buffer[Position], Value);
4874   Position += 4;
4875 }
4876
4877 /// If generating a bc file on darwin, we have to emit a
4878 /// header and trailer to make it compatible with the system archiver.  To do
4879 /// this we emit the following header, and then emit a trailer that pads the
4880 /// file out to be a multiple of 16 bytes.
4881 ///
4882 /// struct bc_header {
4883 ///   uint32_t Magic;         // 0x0B17C0DE
4884 ///   uint32_t Version;       // Version, currently always 0.
4885 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
4886 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
4887 ///   uint32_t CPUType;       // CPU specifier.
4888 ///   ... potentially more later ...
4889 /// };
4890 static void emitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
4891                                          const Triple &TT) {
4892   unsigned CPUType = ~0U;
4893
4894   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
4895   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
4896   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
4897   // specific constants here because they are implicitly part of the Darwin ABI.
4898   enum {
4899     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
4900     DARWIN_CPU_TYPE_X86        = 7,
4901     DARWIN_CPU_TYPE_ARM        = 12,
4902     DARWIN_CPU_TYPE_POWERPC    = 18
4903   };
4904
4905   Triple::ArchType Arch = TT.getArch();
4906   if (Arch == Triple::x86_64)
4907     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
4908   else if (Arch == Triple::x86)
4909     CPUType = DARWIN_CPU_TYPE_X86;
4910   else if (Arch == Triple::ppc)
4911     CPUType = DARWIN_CPU_TYPE_POWERPC;
4912   else if (Arch == Triple::ppc64)
4913     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
4914   else if (Arch == Triple::arm || Arch == Triple::thumb)
4915     CPUType = DARWIN_CPU_TYPE_ARM;
4916
4917   // Traditional Bitcode starts after header.
4918   assert(Buffer.size() >= BWH_HeaderSize &&
4919          "Expected header size to be reserved");
4920   unsigned BCOffset = BWH_HeaderSize;
4921   unsigned BCSize = Buffer.size() - BWH_HeaderSize;
4922
4923   // Write the magic and version.
4924   unsigned Position = 0;
4925   writeInt32ToBuffer(0x0B17C0DE, Buffer, Position);
4926   writeInt32ToBuffer(0, Buffer, Position); // Version.
4927   writeInt32ToBuffer(BCOffset, Buffer, Position);
4928   writeInt32ToBuffer(BCSize, Buffer, Position);
4929   writeInt32ToBuffer(CPUType, Buffer, Position);
4930
4931   // If the file is not a multiple of 16 bytes, insert dummy padding.
4932   while (Buffer.size() & 15)
4933     Buffer.push_back(0);
4934 }
4935
4936 /// Helper to write the header common to all bitcode files.
4937 static void writeBitcodeHeader(BitstreamWriter &Stream) {
4938   // Emit the file header.
4939   Stream.Emit((unsigned)'B', 8);
4940   Stream.Emit((unsigned)'C', 8);
4941   Stream.Emit(0x0, 4);
4942   Stream.Emit(0xC, 4);
4943   Stream.Emit(0xE, 4);
4944   Stream.Emit(0xD, 4);
4945 }
4946
4947 BitcodeWriter::BitcodeWriter(SmallVectorImpl<char> &Buffer, raw_fd_stream *FS)
4948     : Buffer(Buffer), Stream(new BitstreamWriter(Buffer, FS, FlushThreshold)) {
4949   writeBitcodeHeader(*Stream);
4950 }
4951
4952 BitcodeWriter::~BitcodeWriter() { assert(WroteStrtab); }
4953
4954 void BitcodeWriter::writeBlob(unsigned Block, unsigned Record, StringRef Blob) {
4955   Stream->EnterSubblock(Block, 3);
4956
4957   auto Abbv = std::make_shared<BitCodeAbbrev>();
4958   Abbv->Add(BitCodeAbbrevOp(Record));
4959   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
4960   auto AbbrevNo = Stream->EmitAbbrev(std::move(Abbv));
4961
4962   Stream->EmitRecordWithBlob(AbbrevNo, ArrayRef<uint64_t>{Record}, Blob);
4963
4964   Stream->ExitBlock();
4965 }
4966
4967 void BitcodeWriter::writeSymtab() {
4968   assert(!WroteStrtab && !WroteSymtab);
4969
4970   // If any module has module-level inline asm, we will require a registered asm
4971   // parser for the target so that we can create an accurate symbol table for
4972   // the module.
4973   for (Module *M : Mods) {
4974     if (M->getModuleInlineAsm().empty())
4975       continue;
4976
4977     std::string Err;
4978     const Triple TT(M->getTargetTriple());
4979     const Target *T = TargetRegistry::lookupTarget(TT.str(), Err);
4980     if (!T || !T->hasMCAsmParser())
4981       return;
4982   }
4983
4984   WroteSymtab = true;
4985   SmallVector<char, 0> Symtab;
4986   // The irsymtab::build function may be unable to create a symbol table if the
4987   // module is malformed (e.g. it contains an invalid alias). Writing a symbol
4988   // table is not required for correctness, but we still want to be able to
4989   // write malformed modules to bitcode files, so swallow the error.
4990   if (Error E = irsymtab::build(Mods, Symtab, StrtabBuilder, Alloc)) {
4991     consumeError(std::move(E));
4992     return;
4993   }
4994
4995   writeBlob(bitc::SYMTAB_BLOCK_ID, bitc::SYMTAB_BLOB,
4996             {Symtab.data(), Symtab.size()});
4997 }
4998
4999 void BitcodeWriter::writeStrtab() {
5000   assert(!WroteStrtab);
5001
5002   std::vector<char> Strtab;
5003   StrtabBuilder.finalizeInOrder();
5004   Strtab.resize(StrtabBuilder.getSize());
5005   StrtabBuilder.write((uint8_t *)Strtab.data());
5006
5007   writeBlob(bitc::STRTAB_BLOCK_ID, bitc::STRTAB_BLOB,
5008             {Strtab.data(), Strtab.size()});
5009
5010   WroteStrtab = true;
5011 }
5012
5013 void BitcodeWriter::copyStrtab(StringRef Strtab) {
5014   writeBlob(bitc::STRTAB_BLOCK_ID, bitc::STRTAB_BLOB, Strtab);
5015   WroteStrtab = true;
5016 }
5017
5018 void BitcodeWriter::writeModule(const Module &M,
5019                                 bool ShouldPreserveUseListOrder,
5020                                 const ModuleSummaryIndex *Index,
5021                                 bool GenerateHash, ModuleHash *ModHash) {
5022   assert(!WroteStrtab);
5023
5024   // The Mods vector is used by irsymtab::build, which requires non-const
5025   // Modules in case it needs to materialize metadata. But the bitcode writer
5026   // requires that the module is materialized, so we can cast to non-const here,
5027   // after checking that it is in fact materialized.
5028   assert(M.isMaterialized());
5029   Mods.push_back(const_cast<Module *>(&M));
5030
5031   ModuleBitcodeWriter ModuleWriter(M, Buffer, StrtabBuilder, *Stream,
5032                                    ShouldPreserveUseListOrder, Index,
5033                                    GenerateHash, ModHash);
5034   ModuleWriter.write();
5035 }
5036
5037 void BitcodeWriter::writeIndex(
5038     const ModuleSummaryIndex *Index,
5039     const std::map<std::string, GVSummaryMapTy> *ModuleToSummariesForIndex) {
5040   IndexBitcodeWriter IndexWriter(*Stream, StrtabBuilder, *Index,
5041                                  ModuleToSummariesForIndex);
5042   IndexWriter.write();
5043 }
5044
5045 /// Write the specified module to the specified output stream.
5046 void llvm::WriteBitcodeToFile(const Module &M, raw_ostream &Out,
5047                               bool ShouldPreserveUseListOrder,
5048                               const ModuleSummaryIndex *Index,
5049                               bool GenerateHash, ModuleHash *ModHash) {
5050   SmallVector<char, 0> Buffer;
5051   Buffer.reserve(256*1024);
5052
5053   // If this is darwin or another generic macho target, reserve space for the
5054   // header.
5055   Triple TT(M.getTargetTriple());
5056   if (TT.isOSDarwin() || TT.isOSBinFormatMachO())
5057     Buffer.insert(Buffer.begin(), BWH_HeaderSize, 0);
5058
5059   BitcodeWriter Writer(Buffer, dyn_cast<raw_fd_stream>(&Out));
5060   Writer.writeModule(M, ShouldPreserveUseListOrder, Index, GenerateHash,
5061                      ModHash);
5062   Writer.writeSymtab();
5063   Writer.writeStrtab();
5064
5065   if (TT.isOSDarwin() || TT.isOSBinFormatMachO())
5066     emitDarwinBCHeaderAndTrailer(Buffer, TT);
5067
5068   // Write the generated bitstream to "Out".
5069   if (!Buffer.empty())
5070     Out.write((char *)&Buffer.front(), Buffer.size());
5071 }
5072
5073 void IndexBitcodeWriter::write() {
5074   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
5075
5076   writeModuleVersion();
5077
5078   // Write the module paths in the combined index.
5079   writeModStrings();
5080
5081   // Write the summary combined index records.
5082   writeCombinedGlobalValueSummary();
5083
5084   Stream.ExitBlock();
5085 }
5086
5087 // Write the specified module summary index to the given raw output stream,
5088 // where it will be written in a new bitcode block. This is used when
5089 // writing the combined index file for ThinLTO. When writing a subset of the
5090 // index for a distributed backend, provide a \p ModuleToSummariesForIndex map.
5091 void llvm::writeIndexToFile(
5092     const ModuleSummaryIndex &Index, raw_ostream &Out,
5093     const std::map<std::string, GVSummaryMapTy> *ModuleToSummariesForIndex) {
5094   SmallVector<char, 0> Buffer;
5095   Buffer.reserve(256 * 1024);
5096
5097   BitcodeWriter Writer(Buffer);
5098   Writer.writeIndex(&Index, ModuleToSummariesForIndex);
5099   Writer.writeStrtab();
5100
5101   Out.write((char *)&Buffer.front(), Buffer.size());
5102 }
5103
5104 namespace {
5105
5106 /// Class to manage the bitcode writing for a thin link bitcode file.
5107 class ThinLinkBitcodeWriter : public ModuleBitcodeWriterBase {
5108   /// ModHash is for use in ThinLTO incremental build, generated while writing
5109   /// the module bitcode file.
5110   const ModuleHash *ModHash;
5111
5112 public:
5113   ThinLinkBitcodeWriter(const Module &M, StringTableBuilder &StrtabBuilder,
5114                         BitstreamWriter &Stream,
5115                         const ModuleSummaryIndex &Index,
5116                         const ModuleHash &ModHash)
5117       : ModuleBitcodeWriterBase(M, StrtabBuilder, Stream,
5118                                 /*ShouldPreserveUseListOrder=*/false, &Index),
5119         ModHash(&ModHash) {}
5120
5121   void write();
5122
5123 private:
5124   void writeSimplifiedModuleInfo();
5125 };
5126
5127 } // end anonymous namespace
5128
5129 // This function writes a simpilified module info for thin link bitcode file.
5130 // It only contains the source file name along with the name(the offset and
5131 // size in strtab) and linkage for global values. For the global value info
5132 // entry, in order to keep linkage at offset 5, there are three zeros used
5133 // as padding.
5134 void ThinLinkBitcodeWriter::writeSimplifiedModuleInfo() {
5135   SmallVector<unsigned, 64> Vals;
5136   // Emit the module's source file name.
5137   {
5138     StringEncoding Bits = getStringEncoding(M.getSourceFileName());
5139     BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
5140     if (Bits == SE_Char6)
5141       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
5142     else if (Bits == SE_Fixed7)
5143       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
5144
5145     // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
5146     auto Abbv = std::make_shared<BitCodeAbbrev>();
5147     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
5148     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
5149     Abbv->Add(AbbrevOpToUse);
5150     unsigned FilenameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
5151
5152     for (const auto P : M.getSourceFileName())
5153       Vals.push_back((unsigned char)P);
5154
5155     Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
5156     Vals.clear();
5157   }
5158
5159   // Emit the global variable information.
5160   for (const GlobalVariable &GV : M.globals()) {
5161     // GLOBALVAR: [strtab offset, strtab size, 0, 0, 0, linkage]
5162     Vals.push_back(StrtabBuilder.add(GV.getName()));
5163     Vals.push_back(GV.getName().size());
5164     Vals.push_back(0);
5165     Vals.push_back(0);
5166     Vals.push_back(0);
5167     Vals.push_back(getEncodedLinkage(GV));
5168
5169     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals);
5170     Vals.clear();
5171   }
5172
5173   // Emit the function proto information.
5174   for (const Function &F : M) {
5175     // FUNCTION:  [strtab offset, strtab size, 0, 0, 0, linkage]
5176     Vals.push_back(StrtabBuilder.add(F.getName()));
5177     Vals.push_back(F.getName().size());
5178     Vals.push_back(0);
5179     Vals.push_back(0);
5180     Vals.push_back(0);
5181     Vals.push_back(getEncodedLinkage(F));
5182
5183     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals);
5184     Vals.clear();
5185   }
5186
5187   // Emit the alias information.
5188   for (const GlobalAlias &A : M.aliases()) {
5189     // ALIAS: [strtab offset, strtab size, 0, 0, 0, linkage]
5190     Vals.push_back(StrtabBuilder.add(A.getName()));
5191     Vals.push_back(A.getName().size());
5192     Vals.push_back(0);
5193     Vals.push_back(0);
5194     Vals.push_back(0);
5195     Vals.push_back(getEncodedLinkage(A));
5196
5197     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals);
5198     Vals.clear();
5199   }
5200
5201   // Emit the ifunc information.
5202   for (const GlobalIFunc &I : M.ifuncs()) {
5203     // IFUNC: [strtab offset, strtab size, 0, 0, 0, linkage]
5204     Vals.push_back(StrtabBuilder.add(I.getName()));
5205     Vals.push_back(I.getName().size());
5206     Vals.push_back(0);
5207     Vals.push_back(0);
5208     Vals.push_back(0);
5209     Vals.push_back(getEncodedLinkage(I));
5210
5211     Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
5212     Vals.clear();
5213   }
5214 }
5215
5216 void ThinLinkBitcodeWriter::write() {
5217   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
5218
5219   writeModuleVersion();
5220
5221   writeSimplifiedModuleInfo();
5222
5223   writePerModuleGlobalValueSummary();
5224
5225   // Write module hash.
5226   Stream.EmitRecord(bitc::MODULE_CODE_HASH, ArrayRef<uint32_t>(*ModHash));
5227
5228   Stream.ExitBlock();
5229 }
5230
5231 void BitcodeWriter::writeThinLinkBitcode(const Module &M,
5232                                          const ModuleSummaryIndex &Index,
5233                                          const ModuleHash &ModHash) {
5234   assert(!WroteStrtab);
5235
5236   // The Mods vector is used by irsymtab::build, which requires non-const
5237   // Modules in case it needs to materialize metadata. But the bitcode writer
5238   // requires that the module is materialized, so we can cast to non-const here,
5239   // after checking that it is in fact materialized.
5240   assert(M.isMaterialized());
5241   Mods.push_back(const_cast<Module *>(&M));
5242
5243   ThinLinkBitcodeWriter ThinLinkWriter(M, StrtabBuilder, *Stream, Index,
5244                                        ModHash);
5245   ThinLinkWriter.write();
5246 }
5247
5248 // Write the specified thin link bitcode file to the given raw output stream,
5249 // where it will be written in a new bitcode block. This is used when
5250 // writing the per-module index file for ThinLTO.
5251 void llvm::writeThinLinkBitcodeToFile(const Module &M, raw_ostream &Out,
5252                                       const ModuleSummaryIndex &Index,
5253                                       const ModuleHash &ModHash) {
5254   SmallVector<char, 0> Buffer;
5255   Buffer.reserve(256 * 1024);
5256
5257   BitcodeWriter Writer(Buffer);
5258   Writer.writeThinLinkBitcode(M, Index, ModHash);
5259   Writer.writeSymtab();
5260   Writer.writeStrtab();
5261
5262   Out.write((char *)&Buffer.front(), Buffer.size());
5263 }
5264
5265 static const char *getSectionNameForBitcode(const Triple &T) {
5266   switch (T.getObjectFormat()) {
5267   case Triple::MachO:
5268     return "__LLVM,__bitcode";
5269   case Triple::COFF:
5270   case Triple::ELF:
5271   case Triple::Wasm:
5272   case Triple::UnknownObjectFormat:
5273     return ".llvmbc";
5274   case Triple::GOFF:
5275     llvm_unreachable("GOFF is not yet implemented");
5276     break;
5277   case Triple::SPIRV:
5278     llvm_unreachable("SPIRV is not yet implemented");
5279     break;
5280   case Triple::XCOFF:
5281     llvm_unreachable("XCOFF is not yet implemented");
5282     break;
5283   case Triple::DXContainer:
5284     llvm_unreachable("DXContainer is not yet implemented");
5285     break;
5286   }
5287   llvm_unreachable("Unimplemented ObjectFormatType");
5288 }
5289
5290 static const char *getSectionNameForCommandline(const Triple &T) {
5291   switch (T.getObjectFormat()) {
5292   case Triple::MachO:
5293     return "__LLVM,__cmdline";
5294   case Triple::COFF:
5295   case Triple::ELF:
5296   case Triple::Wasm:
5297   case Triple::UnknownObjectFormat:
5298     return ".llvmcmd";
5299   case Triple::GOFF:
5300     llvm_unreachable("GOFF is not yet implemented");
5301     break;
5302   case Triple::SPIRV:
5303     llvm_unreachable("SPIRV is not yet implemented");
5304     break;
5305   case Triple::XCOFF:
5306     llvm_unreachable("XCOFF is not yet implemented");
5307     break;
5308   case Triple::DXContainer:
5309     llvm_unreachable("DXC is not yet implemented");
5310     break;
5311   }
5312   llvm_unreachable("Unimplemented ObjectFormatType");
5313 }
5314
5315 void llvm::embedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
5316                                 bool EmbedBitcode, bool EmbedCmdline,
5317                                 const std::vector<uint8_t> &CmdArgs) {
5318   // Save llvm.compiler.used and remove it.
5319   SmallVector<Constant *, 2> UsedArray;
5320   SmallVector<GlobalValue *, 4> UsedGlobals;
5321   Type *UsedElementType = PointerType::getUnqual(M.getContext());
5322   GlobalVariable *Used = collectUsedGlobalVariables(M, UsedGlobals, true);
5323   for (auto *GV : UsedGlobals) {
5324     if (GV->getName() != "llvm.embedded.module" &&
5325         GV->getName() != "llvm.cmdline")
5326       UsedArray.push_back(
5327           ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
5328   }
5329   if (Used)
5330     Used->eraseFromParent();
5331
5332   // Embed the bitcode for the llvm module.
5333   std::string Data;
5334   ArrayRef<uint8_t> ModuleData;
5335   Triple T(M.getTargetTriple());
5336
5337   if (EmbedBitcode) {
5338     if (Buf.getBufferSize() == 0 ||
5339         !isBitcode((const unsigned char *)Buf.getBufferStart(),
5340                    (const unsigned char *)Buf.getBufferEnd())) {
5341       // If the input is LLVM Assembly, bitcode is produced by serializing
5342       // the module. Use-lists order need to be preserved in this case.
5343       llvm::raw_string_ostream OS(Data);
5344       llvm::WriteBitcodeToFile(M, OS, /* ShouldPreserveUseListOrder */ true);
5345       ModuleData =
5346           ArrayRef<uint8_t>((const uint8_t *)OS.str().data(), OS.str().size());
5347     } else
5348       // If the input is LLVM bitcode, write the input byte stream directly.
5349       ModuleData = ArrayRef<uint8_t>((const uint8_t *)Buf.getBufferStart(),
5350                                      Buf.getBufferSize());
5351   }
5352   llvm::Constant *ModuleConstant =
5353       llvm::ConstantDataArray::get(M.getContext(), ModuleData);
5354   llvm::GlobalVariable *GV = new llvm::GlobalVariable(
5355       M, ModuleConstant->getType(), true, llvm::GlobalValue::PrivateLinkage,
5356       ModuleConstant);
5357   GV->setSection(getSectionNameForBitcode(T));
5358   // Set alignment to 1 to prevent padding between two contributions from input
5359   // sections after linking.
5360   GV->setAlignment(Align(1));
5361   UsedArray.push_back(
5362       ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
5363   if (llvm::GlobalVariable *Old =
5364           M.getGlobalVariable("llvm.embedded.module", true)) {
5365     assert(Old->hasZeroLiveUses() &&
5366            "llvm.embedded.module can only be used once in llvm.compiler.used");
5367     GV->takeName(Old);
5368     Old->eraseFromParent();
5369   } else {
5370     GV->setName("llvm.embedded.module");
5371   }
5372
5373   // Skip if only bitcode needs to be embedded.
5374   if (EmbedCmdline) {
5375     // Embed command-line options.
5376     ArrayRef<uint8_t> CmdData(const_cast<uint8_t *>(CmdArgs.data()),
5377                               CmdArgs.size());
5378     llvm::Constant *CmdConstant =
5379         llvm::ConstantDataArray::get(M.getContext(), CmdData);
5380     GV = new llvm::GlobalVariable(M, CmdConstant->getType(), true,
5381                                   llvm::GlobalValue::PrivateLinkage,
5382                                   CmdConstant);
5383     GV->setSection(getSectionNameForCommandline(T));
5384     GV->setAlignment(Align(1));
5385     UsedArray.push_back(
5386         ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
5387     if (llvm::GlobalVariable *Old = M.getGlobalVariable("llvm.cmdline", true)) {
5388       assert(Old->hasZeroLiveUses() &&
5389              "llvm.cmdline can only be used once in llvm.compiler.used");
5390       GV->takeName(Old);
5391       Old->eraseFromParent();
5392     } else {
5393       GV->setName("llvm.cmdline");
5394     }
5395   }
5396
5397   if (UsedArray.empty())
5398     return;
5399
5400   // Recreate llvm.compiler.used.
5401   ArrayType *ATy = ArrayType::get(UsedElementType, UsedArray.size());
5402   auto *NewUsed = new GlobalVariable(
5403       M, ATy, false, llvm::GlobalValue::AppendingLinkage,
5404       llvm::ConstantArray::get(ATy, UsedArray), "llvm.compiler.used");
5405   NewUsed->setSection("llvm.metadata");
5406 }