xref: /llvm-project/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp (revision 5d9de5f446601d80ebbe5e281f783912b3585bad)
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/None.h"
20 #include "llvm/ADT/Optional.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/SetVector.h"
23 #include "llvm/ADT/SmallPtrSet.h"
24 #include "llvm/ADT/SmallString.h"
25 #include "llvm/ADT/SmallVector.h"
26 #include "llvm/ADT/StringMap.h"
27 #include "llvm/ADT/StringRef.h"
28 #include "llvm/ADT/Triple.h"
29 #include "llvm/Bitcode/BitcodeCommon.h"
30 #include "llvm/Bitcode/BitcodeReader.h"
31 #include "llvm/Bitcode/LLVMBitCodes.h"
32 #include "llvm/Bitstream/BitCodes.h"
33 #include "llvm/Bitstream/BitstreamWriter.h"
34 #include "llvm/Config/llvm-config.h"
35 #include "llvm/IR/Attributes.h"
36 #include "llvm/IR/BasicBlock.h"
37 #include "llvm/IR/Comdat.h"
38 #include "llvm/IR/Constant.h"
39 #include "llvm/IR/Constants.h"
40 #include "llvm/IR/DebugInfoMetadata.h"
41 #include "llvm/IR/DebugLoc.h"
42 #include "llvm/IR/DerivedTypes.h"
43 #include "llvm/IR/Function.h"
44 #include "llvm/IR/GlobalAlias.h"
45 #include "llvm/IR/GlobalIFunc.h"
46 #include "llvm/IR/GlobalObject.h"
47 #include "llvm/IR/GlobalValue.h"
48 #include "llvm/IR/GlobalVariable.h"
49 #include "llvm/IR/InlineAsm.h"
50 #include "llvm/IR/InstrTypes.h"
51 #include "llvm/IR/Instruction.h"
52 #include "llvm/IR/Instructions.h"
53 #include "llvm/IR/LLVMContext.h"
54 #include "llvm/IR/Metadata.h"
55 #include "llvm/IR/Module.h"
56 #include "llvm/IR/ModuleSummaryIndex.h"
57 #include "llvm/IR/Operator.h"
58 #include "llvm/IR/Type.h"
59 #include "llvm/IR/UseListOrder.h"
60 #include "llvm/IR/Value.h"
61 #include "llvm/IR/ValueSymbolTable.h"
62 #include "llvm/MC/StringTableBuilder.h"
63 #include "llvm/MC/TargetRegistry.h"
64 #include "llvm/Object/IRSymtab.h"
65 #include "llvm/Support/AtomicOrdering.h"
66 #include "llvm/Support/Casting.h"
67 #include "llvm/Support/CommandLine.h"
68 #include "llvm/Support/Endian.h"
69 #include "llvm/Support/Error.h"
70 #include "llvm/Support/ErrorHandling.h"
71 #include "llvm/Support/MathExtras.h"
72 #include "llvm/Support/SHA1.h"
73 #include "llvm/Support/raw_ostream.h"
74 #include <algorithm>
75 #include <cassert>
76 #include <cstddef>
77 #include <cstdint>
78 #include <iterator>
79 #include <map>
80 #include <memory>
81 #include <string>
82 #include <utility>
83 #include <vector>
84 
85 using namespace llvm;
86 
87 static cl::opt<unsigned>
88     IndexThreshold("bitcode-mdindex-threshold", cl::Hidden, cl::init(25),
89                    cl::desc("Number of metadatas above which we emit an index "
90                             "to enable lazy-loading"));
91 static cl::opt<uint32_t> FlushThreshold(
92     "bitcode-flush-threshold", cl::Hidden, cl::init(512),
93     cl::desc("The threshold (unit M) for flushing LLVM bitcode."));
94 
95 static cl::opt<bool> WriteRelBFToSummary(
96     "write-relbf-to-summary", cl::Hidden, cl::init(false),
97     cl::desc("Write relative block frequency to function summary "));
98 
99 extern FunctionSummary::ForceSummaryHotnessType ForceSummaryEdgesCold;
100 
101 namespace {
102 
103 /// These are manifest constants used by the bitcode writer. They do not need to
104 /// be kept in sync with the reader, but need to be consistent within this file.
105 enum {
106   // VALUE_SYMTAB_BLOCK abbrev id's.
107   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
108   VST_ENTRY_7_ABBREV,
109   VST_ENTRY_6_ABBREV,
110   VST_BBENTRY_6_ABBREV,
111 
112   // CONSTANTS_BLOCK abbrev id's.
113   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
114   CONSTANTS_INTEGER_ABBREV,
115   CONSTANTS_CE_CAST_Abbrev,
116   CONSTANTS_NULL_Abbrev,
117 
118   // FUNCTION_BLOCK abbrev id's.
119   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
120   FUNCTION_INST_UNOP_ABBREV,
121   FUNCTION_INST_UNOP_FLAGS_ABBREV,
122   FUNCTION_INST_BINOP_ABBREV,
123   FUNCTION_INST_BINOP_FLAGS_ABBREV,
124   FUNCTION_INST_CAST_ABBREV,
125   FUNCTION_INST_RET_VOID_ABBREV,
126   FUNCTION_INST_RET_VAL_ABBREV,
127   FUNCTION_INST_UNREACHABLE_ABBREV,
128   FUNCTION_INST_GEP_ABBREV,
129 };
130 
131 /// Abstract class to manage the bitcode writing, subclassed for each bitcode
132 /// file type.
133 class BitcodeWriterBase {
134 protected:
135   /// The stream created and owned by the client.
136   BitstreamWriter &Stream;
137 
138   StringTableBuilder &StrtabBuilder;
139 
140 public:
141   /// Constructs a BitcodeWriterBase object that writes to the provided
142   /// \p Stream.
143   BitcodeWriterBase(BitstreamWriter &Stream, StringTableBuilder &StrtabBuilder)
144       : Stream(Stream), StrtabBuilder(StrtabBuilder) {}
145 
146 protected:
147   void writeModuleVersion();
148 };
149 
150 void BitcodeWriterBase::writeModuleVersion() {
151   // VERSION: [version#]
152   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, ArrayRef<uint64_t>{2});
153 }
154 
155 /// Base class to manage the module bitcode writing, currently subclassed for
156 /// ModuleBitcodeWriter and ThinLinkBitcodeWriter.
157 class ModuleBitcodeWriterBase : public BitcodeWriterBase {
158 protected:
159   /// The Module to write to bitcode.
160   const Module &M;
161 
162   /// Enumerates ids for all values in the module.
163   ValueEnumerator VE;
164 
165   /// Optional per-module index to write for ThinLTO.
166   const ModuleSummaryIndex *Index;
167 
168   /// Map that holds the correspondence between GUIDs in the summary index,
169   /// that came from indirect call profiles, and a value id generated by this
170   /// class to use in the VST and summary block records.
171   std::map<GlobalValue::GUID, unsigned> GUIDToValueIdMap;
172 
173   /// Tracks the last value id recorded in the GUIDToValueMap.
174   unsigned GlobalValueId;
175 
176   /// Saves the offset of the VSTOffset record that must eventually be
177   /// backpatched with the offset of the actual VST.
178   uint64_t VSTOffsetPlaceholder = 0;
179 
180 public:
181   /// Constructs a ModuleBitcodeWriterBase object for the given Module,
182   /// writing to the provided \p Buffer.
183   ModuleBitcodeWriterBase(const Module &M, StringTableBuilder &StrtabBuilder,
184                           BitstreamWriter &Stream,
185                           bool ShouldPreserveUseListOrder,
186                           const ModuleSummaryIndex *Index)
187       : BitcodeWriterBase(Stream, StrtabBuilder), M(M),
188         VE(M, ShouldPreserveUseListOrder), Index(Index) {
189     // Assign ValueIds to any callee values in the index that came from
190     // indirect call profiles and were recorded as a GUID not a Value*
191     // (which would have been assigned an ID by the ValueEnumerator).
192     // The starting ValueId is just after the number of values in the
193     // ValueEnumerator, so that they can be emitted in the VST.
194     GlobalValueId = VE.getValues().size();
195     if (!Index)
196       return;
197     for (const auto &GUIDSummaryLists : *Index)
198       // Examine all summaries for this GUID.
199       for (auto &Summary : GUIDSummaryLists.second.SummaryList)
200         if (auto FS = dyn_cast<FunctionSummary>(Summary.get()))
201           // For each call in the function summary, see if the call
202           // is to a GUID (which means it is for an indirect call,
203           // otherwise we would have a Value for it). If so, synthesize
204           // a value id.
205           for (auto &CallEdge : FS->calls())
206             if (!CallEdge.first.haveGVs() || !CallEdge.first.getValue())
207               assignValueId(CallEdge.first.getGUID());
208   }
209 
210 protected:
211   void writePerModuleGlobalValueSummary();
212 
213 private:
214   void writePerModuleFunctionSummaryRecord(SmallVector<uint64_t, 64> &NameVals,
215                                            GlobalValueSummary *Summary,
216                                            unsigned ValueID,
217                                            unsigned FSCallsAbbrev,
218                                            unsigned FSCallsProfileAbbrev,
219                                            const Function &F);
220   void writeModuleLevelReferences(const GlobalVariable &V,
221                                   SmallVector<uint64_t, 64> &NameVals,
222                                   unsigned FSModRefsAbbrev,
223                                   unsigned FSModVTableRefsAbbrev);
224 
225   void assignValueId(GlobalValue::GUID ValGUID) {
226     GUIDToValueIdMap[ValGUID] = ++GlobalValueId;
227   }
228 
229   unsigned getValueId(GlobalValue::GUID ValGUID) {
230     const auto &VMI = GUIDToValueIdMap.find(ValGUID);
231     // Expect that any GUID value had a value Id assigned by an
232     // earlier call to assignValueId.
233     assert(VMI != GUIDToValueIdMap.end() &&
234            "GUID does not have assigned value Id");
235     return VMI->second;
236   }
237 
238   // Helper to get the valueId for the type of value recorded in VI.
239   unsigned getValueId(ValueInfo VI) {
240     if (!VI.haveGVs() || !VI.getValue())
241       return getValueId(VI.getGUID());
242     return VE.getValueID(VI.getValue());
243   }
244 
245   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
246 };
247 
248 /// Class to manage the bitcode writing for a module.
249 class ModuleBitcodeWriter : public ModuleBitcodeWriterBase {
250   /// Pointer to the buffer allocated by caller for bitcode writing.
251   const SmallVectorImpl<char> &Buffer;
252 
253   /// True if a module hash record should be written.
254   bool GenerateHash;
255 
256   /// If non-null, when GenerateHash is true, the resulting hash is written
257   /// into ModHash.
258   ModuleHash *ModHash;
259 
260   SHA1 Hasher;
261 
262   /// The start bit of the identification block.
263   uint64_t BitcodeStartBit;
264 
265 public:
266   /// Constructs a ModuleBitcodeWriter object for the given Module,
267   /// writing to the provided \p Buffer.
268   ModuleBitcodeWriter(const Module &M, SmallVectorImpl<char> &Buffer,
269                       StringTableBuilder &StrtabBuilder,
270                       BitstreamWriter &Stream, bool ShouldPreserveUseListOrder,
271                       const ModuleSummaryIndex *Index, bool GenerateHash,
272                       ModuleHash *ModHash = nullptr)
273       : ModuleBitcodeWriterBase(M, StrtabBuilder, Stream,
274                                 ShouldPreserveUseListOrder, Index),
275         Buffer(Buffer), GenerateHash(GenerateHash), ModHash(ModHash),
276         BitcodeStartBit(Stream.GetCurrentBitNo()) {}
277 
278   /// Emit the current module to the bitstream.
279   void write();
280 
281 private:
282   uint64_t bitcodeStartBit() { return BitcodeStartBit; }
283 
284   size_t addToStrtab(StringRef Str);
285 
286   void writeAttributeGroupTable();
287   void writeAttributeTable();
288   void writeTypeTable();
289   void writeComdats();
290   void writeValueSymbolTableForwardDecl();
291   void writeModuleInfo();
292   void writeValueAsMetadata(const ValueAsMetadata *MD,
293                             SmallVectorImpl<uint64_t> &Record);
294   void writeMDTuple(const MDTuple *N, SmallVectorImpl<uint64_t> &Record,
295                     unsigned Abbrev);
296   unsigned createDILocationAbbrev();
297   void writeDILocation(const DILocation *N, SmallVectorImpl<uint64_t> &Record,
298                        unsigned &Abbrev);
299   unsigned createGenericDINodeAbbrev();
300   void writeGenericDINode(const GenericDINode *N,
301                           SmallVectorImpl<uint64_t> &Record, unsigned &Abbrev);
302   void writeDISubrange(const DISubrange *N, SmallVectorImpl<uint64_t> &Record,
303                        unsigned Abbrev);
304   void writeDIGenericSubrange(const DIGenericSubrange *N,
305                               SmallVectorImpl<uint64_t> &Record,
306                               unsigned Abbrev);
307   void writeDIEnumerator(const DIEnumerator *N,
308                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
309   void writeDIBasicType(const DIBasicType *N, SmallVectorImpl<uint64_t> &Record,
310                         unsigned Abbrev);
311   void writeDIStringType(const DIStringType *N,
312                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
313   void writeDIDerivedType(const DIDerivedType *N,
314                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
315   void writeDICompositeType(const DICompositeType *N,
316                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
317   void writeDISubroutineType(const DISubroutineType *N,
318                              SmallVectorImpl<uint64_t> &Record,
319                              unsigned Abbrev);
320   void writeDIFile(const DIFile *N, SmallVectorImpl<uint64_t> &Record,
321                    unsigned Abbrev);
322   void writeDICompileUnit(const DICompileUnit *N,
323                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
324   void writeDISubprogram(const DISubprogram *N,
325                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
326   void writeDILexicalBlock(const DILexicalBlock *N,
327                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
328   void writeDILexicalBlockFile(const DILexicalBlockFile *N,
329                                SmallVectorImpl<uint64_t> &Record,
330                                unsigned Abbrev);
331   void writeDICommonBlock(const DICommonBlock *N,
332                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
333   void writeDINamespace(const DINamespace *N, SmallVectorImpl<uint64_t> &Record,
334                         unsigned Abbrev);
335   void writeDIMacro(const DIMacro *N, SmallVectorImpl<uint64_t> &Record,
336                     unsigned Abbrev);
337   void writeDIMacroFile(const DIMacroFile *N, SmallVectorImpl<uint64_t> &Record,
338                         unsigned Abbrev);
339   void writeDIArgList(const DIArgList *N, SmallVectorImpl<uint64_t> &Record,
340                       unsigned Abbrev);
341   void writeDIModule(const DIModule *N, SmallVectorImpl<uint64_t> &Record,
342                      unsigned Abbrev);
343   void writeDITemplateTypeParameter(const DITemplateTypeParameter *N,
344                                     SmallVectorImpl<uint64_t> &Record,
345                                     unsigned Abbrev);
346   void writeDITemplateValueParameter(const DITemplateValueParameter *N,
347                                      SmallVectorImpl<uint64_t> &Record,
348                                      unsigned Abbrev);
349   void writeDIGlobalVariable(const DIGlobalVariable *N,
350                              SmallVectorImpl<uint64_t> &Record,
351                              unsigned Abbrev);
352   void writeDILocalVariable(const DILocalVariable *N,
353                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
354   void writeDILabel(const DILabel *N,
355                     SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
356   void writeDIExpression(const DIExpression *N,
357                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
358   void writeDIGlobalVariableExpression(const DIGlobalVariableExpression *N,
359                                        SmallVectorImpl<uint64_t> &Record,
360                                        unsigned Abbrev);
361   void writeDIObjCProperty(const DIObjCProperty *N,
362                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
363   void writeDIImportedEntity(const DIImportedEntity *N,
364                              SmallVectorImpl<uint64_t> &Record,
365                              unsigned Abbrev);
366   unsigned createNamedMetadataAbbrev();
367   void writeNamedMetadata(SmallVectorImpl<uint64_t> &Record);
368   unsigned createMetadataStringsAbbrev();
369   void writeMetadataStrings(ArrayRef<const Metadata *> Strings,
370                             SmallVectorImpl<uint64_t> &Record);
371   void writeMetadataRecords(ArrayRef<const Metadata *> MDs,
372                             SmallVectorImpl<uint64_t> &Record,
373                             std::vector<unsigned> *MDAbbrevs = nullptr,
374                             std::vector<uint64_t> *IndexPos = nullptr);
375   void writeModuleMetadata();
376   void writeFunctionMetadata(const Function &F);
377   void writeFunctionMetadataAttachment(const Function &F);
378   void pushGlobalMetadataAttachment(SmallVectorImpl<uint64_t> &Record,
379                                     const GlobalObject &GO);
380   void writeModuleMetadataKinds();
381   void writeOperandBundleTags();
382   void writeSyncScopeNames();
383   void writeConstants(unsigned FirstVal, unsigned LastVal, bool isGlobal);
384   void writeModuleConstants();
385   bool pushValueAndType(const Value *V, unsigned InstID,
386                         SmallVectorImpl<unsigned> &Vals);
387   void writeOperandBundles(const CallBase &CB, unsigned InstID);
388   void pushValue(const Value *V, unsigned InstID,
389                  SmallVectorImpl<unsigned> &Vals);
390   void pushValueSigned(const Value *V, unsigned InstID,
391                        SmallVectorImpl<uint64_t> &Vals);
392   void writeInstruction(const Instruction &I, unsigned InstID,
393                         SmallVectorImpl<unsigned> &Vals);
394   void writeFunctionLevelValueSymbolTable(const ValueSymbolTable &VST);
395   void writeGlobalValueSymbolTable(
396       DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
397   void writeUseList(UseListOrder &&Order);
398   void writeUseListBlock(const Function *F);
399   void
400   writeFunction(const Function &F,
401                 DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
402   void writeBlockInfo();
403   void writeModuleHash(size_t BlockStartPos);
404 
405   unsigned getEncodedSyncScopeID(SyncScope::ID SSID) {
406     return unsigned(SSID);
407   }
408 
409   unsigned getEncodedAlign(MaybeAlign Alignment) { return encode(Alignment); }
410 };
411 
412 /// Class to manage the bitcode writing for a combined index.
413 class IndexBitcodeWriter : public BitcodeWriterBase {
414   /// The combined index to write to bitcode.
415   const ModuleSummaryIndex &Index;
416 
417   /// When writing a subset of the index for distributed backends, client
418   /// provides a map of modules to the corresponding GUIDs/summaries to write.
419   const std::map<std::string, GVSummaryMapTy> *ModuleToSummariesForIndex;
420 
421   /// Map that holds the correspondence between the GUID used in the combined
422   /// index and a value id generated by this class to use in references.
423   std::map<GlobalValue::GUID, unsigned> GUIDToValueIdMap;
424 
425   /// Tracks the last value id recorded in the GUIDToValueMap.
426   unsigned GlobalValueId = 0;
427 
428 public:
429   /// Constructs a IndexBitcodeWriter object for the given combined index,
430   /// writing to the provided \p Buffer. When writing a subset of the index
431   /// for a distributed backend, provide a \p ModuleToSummariesForIndex map.
432   IndexBitcodeWriter(BitstreamWriter &Stream, StringTableBuilder &StrtabBuilder,
433                      const ModuleSummaryIndex &Index,
434                      const std::map<std::string, GVSummaryMapTy>
435                          *ModuleToSummariesForIndex = nullptr)
436       : BitcodeWriterBase(Stream, StrtabBuilder), Index(Index),
437         ModuleToSummariesForIndex(ModuleToSummariesForIndex) {
438     // Assign unique value ids to all summaries to be written, for use
439     // in writing out the call graph edges. Save the mapping from GUID
440     // to the new global value id to use when writing those edges, which
441     // are currently saved in the index in terms of GUID.
442     forEachSummary([&](GVInfo I, bool) {
443       GUIDToValueIdMap[I.first] = ++GlobalValueId;
444     });
445   }
446 
447   /// The below iterator returns the GUID and associated summary.
448   using GVInfo = std::pair<GlobalValue::GUID, GlobalValueSummary *>;
449 
450   /// Calls the callback for each value GUID and summary to be written to
451   /// bitcode. This hides the details of whether they are being pulled from the
452   /// entire index or just those in a provided ModuleToSummariesForIndex map.
453   template<typename Functor>
454   void forEachSummary(Functor Callback) {
455     if (ModuleToSummariesForIndex) {
456       for (auto &M : *ModuleToSummariesForIndex)
457         for (auto &Summary : M.second) {
458           Callback(Summary, false);
459           // Ensure aliasee is handled, e.g. for assigning a valueId,
460           // even if we are not importing the aliasee directly (the
461           // imported alias will contain a copy of aliasee).
462           if (auto *AS = dyn_cast<AliasSummary>(Summary.getSecond()))
463             Callback({AS->getAliaseeGUID(), &AS->getAliasee()}, true);
464         }
465     } else {
466       for (auto &Summaries : Index)
467         for (auto &Summary : Summaries.second.SummaryList)
468           Callback({Summaries.first, Summary.get()}, false);
469     }
470   }
471 
472   /// Calls the callback for each entry in the modulePaths StringMap that
473   /// should be written to the module path string table. This hides the details
474   /// of whether they are being pulled from the entire index or just those in a
475   /// provided ModuleToSummariesForIndex map.
476   template <typename Functor> void forEachModule(Functor Callback) {
477     if (ModuleToSummariesForIndex) {
478       for (const auto &M : *ModuleToSummariesForIndex) {
479         const auto &MPI = Index.modulePaths().find(M.first);
480         if (MPI == Index.modulePaths().end()) {
481           // This should only happen if the bitcode file was empty, in which
482           // case we shouldn't be importing (the ModuleToSummariesForIndex
483           // would only include the module we are writing and index for).
484           assert(ModuleToSummariesForIndex->size() == 1);
485           continue;
486         }
487         Callback(*MPI);
488       }
489     } else {
490       for (const auto &MPSE : Index.modulePaths())
491         Callback(MPSE);
492     }
493   }
494 
495   /// Main entry point for writing a combined index to bitcode.
496   void write();
497 
498 private:
499   void writeModStrings();
500   void writeCombinedGlobalValueSummary();
501 
502   Optional<unsigned> getValueId(GlobalValue::GUID ValGUID) {
503     auto VMI = GUIDToValueIdMap.find(ValGUID);
504     if (VMI == GUIDToValueIdMap.end())
505       return None;
506     return VMI->second;
507   }
508 
509   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
510 };
511 
512 } // end anonymous namespace
513 
514 static unsigned getEncodedCastOpcode(unsigned Opcode) {
515   switch (Opcode) {
516   default: llvm_unreachable("Unknown cast instruction!");
517   case Instruction::Trunc   : return bitc::CAST_TRUNC;
518   case Instruction::ZExt    : return bitc::CAST_ZEXT;
519   case Instruction::SExt    : return bitc::CAST_SEXT;
520   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
521   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
522   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
523   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
524   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
525   case Instruction::FPExt   : return bitc::CAST_FPEXT;
526   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
527   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
528   case Instruction::BitCast : return bitc::CAST_BITCAST;
529   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
530   }
531 }
532 
533 static unsigned getEncodedUnaryOpcode(unsigned Opcode) {
534   switch (Opcode) {
535   default: llvm_unreachable("Unknown binary instruction!");
536   case Instruction::FNeg: return bitc::UNOP_FNEG;
537   }
538 }
539 
540 static unsigned getEncodedBinaryOpcode(unsigned Opcode) {
541   switch (Opcode) {
542   default: llvm_unreachable("Unknown binary instruction!");
543   case Instruction::Add:
544   case Instruction::FAdd: return bitc::BINOP_ADD;
545   case Instruction::Sub:
546   case Instruction::FSub: return bitc::BINOP_SUB;
547   case Instruction::Mul:
548   case Instruction::FMul: return bitc::BINOP_MUL;
549   case Instruction::UDiv: return bitc::BINOP_UDIV;
550   case Instruction::FDiv:
551   case Instruction::SDiv: return bitc::BINOP_SDIV;
552   case Instruction::URem: return bitc::BINOP_UREM;
553   case Instruction::FRem:
554   case Instruction::SRem: return bitc::BINOP_SREM;
555   case Instruction::Shl:  return bitc::BINOP_SHL;
556   case Instruction::LShr: return bitc::BINOP_LSHR;
557   case Instruction::AShr: return bitc::BINOP_ASHR;
558   case Instruction::And:  return bitc::BINOP_AND;
559   case Instruction::Or:   return bitc::BINOP_OR;
560   case Instruction::Xor:  return bitc::BINOP_XOR;
561   }
562 }
563 
564 static unsigned getEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
565   switch (Op) {
566   default: llvm_unreachable("Unknown RMW operation!");
567   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
568   case AtomicRMWInst::Add: return bitc::RMW_ADD;
569   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
570   case AtomicRMWInst::And: return bitc::RMW_AND;
571   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
572   case AtomicRMWInst::Or: return bitc::RMW_OR;
573   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
574   case AtomicRMWInst::Max: return bitc::RMW_MAX;
575   case AtomicRMWInst::Min: return bitc::RMW_MIN;
576   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
577   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
578   case AtomicRMWInst::FAdd: return bitc::RMW_FADD;
579   case AtomicRMWInst::FSub: return bitc::RMW_FSUB;
580   }
581 }
582 
583 static unsigned getEncodedOrdering(AtomicOrdering Ordering) {
584   switch (Ordering) {
585   case AtomicOrdering::NotAtomic: return bitc::ORDERING_NOTATOMIC;
586   case AtomicOrdering::Unordered: return bitc::ORDERING_UNORDERED;
587   case AtomicOrdering::Monotonic: return bitc::ORDERING_MONOTONIC;
588   case AtomicOrdering::Acquire: return bitc::ORDERING_ACQUIRE;
589   case AtomicOrdering::Release: return bitc::ORDERING_RELEASE;
590   case AtomicOrdering::AcquireRelease: return bitc::ORDERING_ACQREL;
591   case AtomicOrdering::SequentiallyConsistent: return bitc::ORDERING_SEQCST;
592   }
593   llvm_unreachable("Invalid ordering");
594 }
595 
596 static void writeStringRecord(BitstreamWriter &Stream, unsigned Code,
597                               StringRef Str, unsigned AbbrevToUse) {
598   SmallVector<unsigned, 64> Vals;
599 
600   // Code: [strchar x N]
601   for (char C : Str) {
602     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(C))
603       AbbrevToUse = 0;
604     Vals.push_back(C);
605   }
606 
607   // Emit the finished record.
608   Stream.EmitRecord(Code, Vals, AbbrevToUse);
609 }
610 
611 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
612   switch (Kind) {
613   case Attribute::Alignment:
614     return bitc::ATTR_KIND_ALIGNMENT;
615   case Attribute::AllocAlign:
616     return bitc::ATTR_KIND_ALLOC_ALIGN;
617   case Attribute::AllocSize:
618     return bitc::ATTR_KIND_ALLOC_SIZE;
619   case Attribute::AlwaysInline:
620     return bitc::ATTR_KIND_ALWAYS_INLINE;
621   case Attribute::ArgMemOnly:
622     return bitc::ATTR_KIND_ARGMEMONLY;
623   case Attribute::Builtin:
624     return bitc::ATTR_KIND_BUILTIN;
625   case Attribute::ByVal:
626     return bitc::ATTR_KIND_BY_VAL;
627   case Attribute::Convergent:
628     return bitc::ATTR_KIND_CONVERGENT;
629   case Attribute::InAlloca:
630     return bitc::ATTR_KIND_IN_ALLOCA;
631   case Attribute::Cold:
632     return bitc::ATTR_KIND_COLD;
633   case Attribute::DisableSanitizerInstrumentation:
634     return bitc::ATTR_KIND_DISABLE_SANITIZER_INSTRUMENTATION;
635   case Attribute::Hot:
636     return bitc::ATTR_KIND_HOT;
637   case Attribute::ElementType:
638     return bitc::ATTR_KIND_ELEMENTTYPE;
639   case Attribute::InaccessibleMemOnly:
640     return bitc::ATTR_KIND_INACCESSIBLEMEM_ONLY;
641   case Attribute::InaccessibleMemOrArgMemOnly:
642     return bitc::ATTR_KIND_INACCESSIBLEMEM_OR_ARGMEMONLY;
643   case Attribute::InlineHint:
644     return bitc::ATTR_KIND_INLINE_HINT;
645   case Attribute::InReg:
646     return bitc::ATTR_KIND_IN_REG;
647   case Attribute::JumpTable:
648     return bitc::ATTR_KIND_JUMP_TABLE;
649   case Attribute::MinSize:
650     return bitc::ATTR_KIND_MIN_SIZE;
651   case Attribute::AllocatedPointer:
652     return bitc::ATTR_KIND_ALLOCATED_POINTER;
653   case Attribute::AllocKind:
654     return bitc::ATTR_KIND_ALLOC_KIND;
655   case Attribute::Naked:
656     return bitc::ATTR_KIND_NAKED;
657   case Attribute::Nest:
658     return bitc::ATTR_KIND_NEST;
659   case Attribute::NoAlias:
660     return bitc::ATTR_KIND_NO_ALIAS;
661   case Attribute::NoBuiltin:
662     return bitc::ATTR_KIND_NO_BUILTIN;
663   case Attribute::NoCallback:
664     return bitc::ATTR_KIND_NO_CALLBACK;
665   case Attribute::NoCapture:
666     return bitc::ATTR_KIND_NO_CAPTURE;
667   case Attribute::NoDuplicate:
668     return bitc::ATTR_KIND_NO_DUPLICATE;
669   case Attribute::NoFree:
670     return bitc::ATTR_KIND_NOFREE;
671   case Attribute::NoImplicitFloat:
672     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
673   case Attribute::NoInline:
674     return bitc::ATTR_KIND_NO_INLINE;
675   case Attribute::NoRecurse:
676     return bitc::ATTR_KIND_NO_RECURSE;
677   case Attribute::NoMerge:
678     return bitc::ATTR_KIND_NO_MERGE;
679   case Attribute::NonLazyBind:
680     return bitc::ATTR_KIND_NON_LAZY_BIND;
681   case Attribute::NonNull:
682     return bitc::ATTR_KIND_NON_NULL;
683   case Attribute::Dereferenceable:
684     return bitc::ATTR_KIND_DEREFERENCEABLE;
685   case Attribute::DereferenceableOrNull:
686     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
687   case Attribute::NoRedZone:
688     return bitc::ATTR_KIND_NO_RED_ZONE;
689   case Attribute::NoReturn:
690     return bitc::ATTR_KIND_NO_RETURN;
691   case Attribute::NoSync:
692     return bitc::ATTR_KIND_NOSYNC;
693   case Attribute::NoCfCheck:
694     return bitc::ATTR_KIND_NOCF_CHECK;
695   case Attribute::NoProfile:
696     return bitc::ATTR_KIND_NO_PROFILE;
697   case Attribute::NoUnwind:
698     return bitc::ATTR_KIND_NO_UNWIND;
699   case Attribute::NoSanitizeBounds:
700     return bitc::ATTR_KIND_NO_SANITIZE_BOUNDS;
701   case Attribute::NoSanitizeCoverage:
702     return bitc::ATTR_KIND_NO_SANITIZE_COVERAGE;
703   case Attribute::NullPointerIsValid:
704     return bitc::ATTR_KIND_NULL_POINTER_IS_VALID;
705   case Attribute::OptForFuzzing:
706     return bitc::ATTR_KIND_OPT_FOR_FUZZING;
707   case Attribute::OptimizeForSize:
708     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
709   case Attribute::OptimizeNone:
710     return bitc::ATTR_KIND_OPTIMIZE_NONE;
711   case Attribute::ReadNone:
712     return bitc::ATTR_KIND_READ_NONE;
713   case Attribute::ReadOnly:
714     return bitc::ATTR_KIND_READ_ONLY;
715   case Attribute::Returned:
716     return bitc::ATTR_KIND_RETURNED;
717   case Attribute::ReturnsTwice:
718     return bitc::ATTR_KIND_RETURNS_TWICE;
719   case Attribute::SExt:
720     return bitc::ATTR_KIND_S_EXT;
721   case Attribute::Speculatable:
722     return bitc::ATTR_KIND_SPECULATABLE;
723   case Attribute::StackAlignment:
724     return bitc::ATTR_KIND_STACK_ALIGNMENT;
725   case Attribute::StackProtect:
726     return bitc::ATTR_KIND_STACK_PROTECT;
727   case Attribute::StackProtectReq:
728     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
729   case Attribute::StackProtectStrong:
730     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
731   case Attribute::SafeStack:
732     return bitc::ATTR_KIND_SAFESTACK;
733   case Attribute::ShadowCallStack:
734     return bitc::ATTR_KIND_SHADOWCALLSTACK;
735   case Attribute::StrictFP:
736     return bitc::ATTR_KIND_STRICT_FP;
737   case Attribute::StructRet:
738     return bitc::ATTR_KIND_STRUCT_RET;
739   case Attribute::SanitizeAddress:
740     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
741   case Attribute::SanitizeHWAddress:
742     return bitc::ATTR_KIND_SANITIZE_HWADDRESS;
743   case Attribute::SanitizeThread:
744     return bitc::ATTR_KIND_SANITIZE_THREAD;
745   case Attribute::SanitizeMemory:
746     return bitc::ATTR_KIND_SANITIZE_MEMORY;
747   case Attribute::SpeculativeLoadHardening:
748     return bitc::ATTR_KIND_SPECULATIVE_LOAD_HARDENING;
749   case Attribute::SwiftError:
750     return bitc::ATTR_KIND_SWIFT_ERROR;
751   case Attribute::SwiftSelf:
752     return bitc::ATTR_KIND_SWIFT_SELF;
753   case Attribute::SwiftAsync:
754     return bitc::ATTR_KIND_SWIFT_ASYNC;
755   case Attribute::UWTable:
756     return bitc::ATTR_KIND_UW_TABLE;
757   case Attribute::VScaleRange:
758     return bitc::ATTR_KIND_VSCALE_RANGE;
759   case Attribute::WillReturn:
760     return bitc::ATTR_KIND_WILLRETURN;
761   case Attribute::WriteOnly:
762     return bitc::ATTR_KIND_WRITEONLY;
763   case Attribute::ZExt:
764     return bitc::ATTR_KIND_Z_EXT;
765   case Attribute::ImmArg:
766     return bitc::ATTR_KIND_IMMARG;
767   case Attribute::SanitizeMemTag:
768     return bitc::ATTR_KIND_SANITIZE_MEMTAG;
769   case Attribute::Preallocated:
770     return bitc::ATTR_KIND_PREALLOCATED;
771   case Attribute::NoUndef:
772     return bitc::ATTR_KIND_NOUNDEF;
773   case Attribute::ByRef:
774     return bitc::ATTR_KIND_BYREF;
775   case Attribute::MustProgress:
776     return bitc::ATTR_KIND_MUSTPROGRESS;
777   case Attribute::EndAttrKinds:
778     llvm_unreachable("Can not encode end-attribute kinds marker.");
779   case Attribute::None:
780     llvm_unreachable("Can not encode none-attribute.");
781   case Attribute::EmptyKey:
782   case Attribute::TombstoneKey:
783     llvm_unreachable("Trying to encode EmptyKey/TombstoneKey");
784   }
785 
786   llvm_unreachable("Trying to encode unknown attribute");
787 }
788 
789 void ModuleBitcodeWriter::writeAttributeGroupTable() {
790   const std::vector<ValueEnumerator::IndexAndAttrSet> &AttrGrps =
791       VE.getAttributeGroups();
792   if (AttrGrps.empty()) return;
793 
794   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
795 
796   SmallVector<uint64_t, 64> Record;
797   for (ValueEnumerator::IndexAndAttrSet Pair : AttrGrps) {
798     unsigned AttrListIndex = Pair.first;
799     AttributeSet AS = Pair.second;
800     Record.push_back(VE.getAttributeGroupID(Pair));
801     Record.push_back(AttrListIndex);
802 
803     for (Attribute Attr : AS) {
804       if (Attr.isEnumAttribute()) {
805         Record.push_back(0);
806         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
807       } else if (Attr.isIntAttribute()) {
808         Record.push_back(1);
809         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
810         Record.push_back(Attr.getValueAsInt());
811       } else if (Attr.isStringAttribute()) {
812         StringRef Kind = Attr.getKindAsString();
813         StringRef Val = Attr.getValueAsString();
814 
815         Record.push_back(Val.empty() ? 3 : 4);
816         Record.append(Kind.begin(), Kind.end());
817         Record.push_back(0);
818         if (!Val.empty()) {
819           Record.append(Val.begin(), Val.end());
820           Record.push_back(0);
821         }
822       } else {
823         assert(Attr.isTypeAttribute());
824         Type *Ty = Attr.getValueAsType();
825         Record.push_back(Ty ? 6 : 5);
826         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
827         if (Ty)
828           Record.push_back(VE.getTypeID(Attr.getValueAsType()));
829       }
830     }
831 
832     Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
833     Record.clear();
834   }
835 
836   Stream.ExitBlock();
837 }
838 
839 void ModuleBitcodeWriter::writeAttributeTable() {
840   const std::vector<AttributeList> &Attrs = VE.getAttributeLists();
841   if (Attrs.empty()) return;
842 
843   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
844 
845   SmallVector<uint64_t, 64> Record;
846   for (const AttributeList &AL : Attrs) {
847     for (unsigned i : AL.indexes()) {
848       AttributeSet AS = AL.getAttributes(i);
849       if (AS.hasAttributes())
850         Record.push_back(VE.getAttributeGroupID({i, AS}));
851     }
852 
853     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
854     Record.clear();
855   }
856 
857   Stream.ExitBlock();
858 }
859 
860 /// WriteTypeTable - Write out the type table for a module.
861 void ModuleBitcodeWriter::writeTypeTable() {
862   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
863 
864   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
865   SmallVector<uint64_t, 64> TypeVals;
866 
867   uint64_t NumBits = VE.computeBitsRequiredForTypeIndicies();
868 
869   // Abbrev for TYPE_CODE_POINTER.
870   auto Abbv = std::make_shared<BitCodeAbbrev>();
871   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
872   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
873   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
874   unsigned PtrAbbrev = Stream.EmitAbbrev(std::move(Abbv));
875 
876   // Abbrev for TYPE_CODE_OPAQUE_POINTER.
877   Abbv = std::make_shared<BitCodeAbbrev>();
878   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_OPAQUE_POINTER));
879   Abbv->Add(BitCodeAbbrevOp(0)); // Addrspace = 0
880   unsigned OpaquePtrAbbrev = Stream.EmitAbbrev(std::move(Abbv));
881 
882   // Abbrev for TYPE_CODE_FUNCTION.
883   Abbv = std::make_shared<BitCodeAbbrev>();
884   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
885   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
886   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
887   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
888   unsigned FunctionAbbrev = Stream.EmitAbbrev(std::move(Abbv));
889 
890   // Abbrev for TYPE_CODE_STRUCT_ANON.
891   Abbv = std::make_shared<BitCodeAbbrev>();
892   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
893   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
894   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
895   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
896   unsigned StructAnonAbbrev = Stream.EmitAbbrev(std::move(Abbv));
897 
898   // Abbrev for TYPE_CODE_STRUCT_NAME.
899   Abbv = std::make_shared<BitCodeAbbrev>();
900   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
901   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
902   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
903   unsigned StructNameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
904 
905   // Abbrev for TYPE_CODE_STRUCT_NAMED.
906   Abbv = std::make_shared<BitCodeAbbrev>();
907   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
908   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
909   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
910   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
911   unsigned StructNamedAbbrev = Stream.EmitAbbrev(std::move(Abbv));
912 
913   // Abbrev for TYPE_CODE_ARRAY.
914   Abbv = std::make_shared<BitCodeAbbrev>();
915   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
916   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
917   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
918   unsigned ArrayAbbrev = Stream.EmitAbbrev(std::move(Abbv));
919 
920   // Emit an entry count so the reader can reserve space.
921   TypeVals.push_back(TypeList.size());
922   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
923   TypeVals.clear();
924 
925   // Loop over all of the types, emitting each in turn.
926   for (Type *T : TypeList) {
927     int AbbrevToUse = 0;
928     unsigned Code = 0;
929 
930     switch (T->getTypeID()) {
931     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
932     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
933     case Type::BFloatTyID:    Code = bitc::TYPE_CODE_BFLOAT;    break;
934     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
935     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
936     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
937     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
938     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
939     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
940     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
941     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
942     case Type::X86_AMXTyID:   Code = bitc::TYPE_CODE_X86_AMX;   break;
943     case Type::TokenTyID:     Code = bitc::TYPE_CODE_TOKEN;     break;
944     case Type::IntegerTyID:
945       // INTEGER: [width]
946       Code = bitc::TYPE_CODE_INTEGER;
947       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
948       break;
949     case Type::PointerTyID: {
950       PointerType *PTy = cast<PointerType>(T);
951       unsigned AddressSpace = PTy->getAddressSpace();
952       if (PTy->isOpaque()) {
953         // OPAQUE_POINTER: [address space]
954         Code = bitc::TYPE_CODE_OPAQUE_POINTER;
955         TypeVals.push_back(AddressSpace);
956         if (AddressSpace == 0)
957           AbbrevToUse = OpaquePtrAbbrev;
958       } else {
959         // POINTER: [pointee type, address space]
960         Code = bitc::TYPE_CODE_POINTER;
961         TypeVals.push_back(VE.getTypeID(PTy->getNonOpaquePointerElementType()));
962         TypeVals.push_back(AddressSpace);
963         if (AddressSpace == 0)
964           AbbrevToUse = PtrAbbrev;
965       }
966       break;
967     }
968     case Type::FunctionTyID: {
969       FunctionType *FT = cast<FunctionType>(T);
970       // FUNCTION: [isvararg, retty, paramty x N]
971       Code = bitc::TYPE_CODE_FUNCTION;
972       TypeVals.push_back(FT->isVarArg());
973       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
974       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
975         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
976       AbbrevToUse = FunctionAbbrev;
977       break;
978     }
979     case Type::StructTyID: {
980       StructType *ST = cast<StructType>(T);
981       // STRUCT: [ispacked, eltty x N]
982       TypeVals.push_back(ST->isPacked());
983       // Output all of the element types.
984       for (Type *ET : ST->elements())
985         TypeVals.push_back(VE.getTypeID(ET));
986 
987       if (ST->isLiteral()) {
988         Code = bitc::TYPE_CODE_STRUCT_ANON;
989         AbbrevToUse = StructAnonAbbrev;
990       } else {
991         if (ST->isOpaque()) {
992           Code = bitc::TYPE_CODE_OPAQUE;
993         } else {
994           Code = bitc::TYPE_CODE_STRUCT_NAMED;
995           AbbrevToUse = StructNamedAbbrev;
996         }
997 
998         // Emit the name if it is present.
999         if (!ST->getName().empty())
1000           writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
1001                             StructNameAbbrev);
1002       }
1003       break;
1004     }
1005     case Type::ArrayTyID: {
1006       ArrayType *AT = cast<ArrayType>(T);
1007       // ARRAY: [numelts, eltty]
1008       Code = bitc::TYPE_CODE_ARRAY;
1009       TypeVals.push_back(AT->getNumElements());
1010       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
1011       AbbrevToUse = ArrayAbbrev;
1012       break;
1013     }
1014     case Type::FixedVectorTyID:
1015     case Type::ScalableVectorTyID: {
1016       VectorType *VT = cast<VectorType>(T);
1017       // VECTOR [numelts, eltty] or
1018       //        [numelts, eltty, scalable]
1019       Code = bitc::TYPE_CODE_VECTOR;
1020       TypeVals.push_back(VT->getElementCount().getKnownMinValue());
1021       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
1022       if (isa<ScalableVectorType>(VT))
1023         TypeVals.push_back(true);
1024       break;
1025     }
1026     case Type::DXILPointerTyID:
1027       llvm_unreachable("DXIL pointers cannot be added to IR modules");
1028     }
1029 
1030     // Emit the finished record.
1031     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
1032     TypeVals.clear();
1033   }
1034 
1035   Stream.ExitBlock();
1036 }
1037 
1038 static unsigned getEncodedLinkage(const GlobalValue::LinkageTypes Linkage) {
1039   switch (Linkage) {
1040   case GlobalValue::ExternalLinkage:
1041     return 0;
1042   case GlobalValue::WeakAnyLinkage:
1043     return 16;
1044   case GlobalValue::AppendingLinkage:
1045     return 2;
1046   case GlobalValue::InternalLinkage:
1047     return 3;
1048   case GlobalValue::LinkOnceAnyLinkage:
1049     return 18;
1050   case GlobalValue::ExternalWeakLinkage:
1051     return 7;
1052   case GlobalValue::CommonLinkage:
1053     return 8;
1054   case GlobalValue::PrivateLinkage:
1055     return 9;
1056   case GlobalValue::WeakODRLinkage:
1057     return 17;
1058   case GlobalValue::LinkOnceODRLinkage:
1059     return 19;
1060   case GlobalValue::AvailableExternallyLinkage:
1061     return 12;
1062   }
1063   llvm_unreachable("Invalid linkage");
1064 }
1065 
1066 static unsigned getEncodedLinkage(const GlobalValue &GV) {
1067   return getEncodedLinkage(GV.getLinkage());
1068 }
1069 
1070 static uint64_t getEncodedFFlags(FunctionSummary::FFlags Flags) {
1071   uint64_t RawFlags = 0;
1072   RawFlags |= Flags.ReadNone;
1073   RawFlags |= (Flags.ReadOnly << 1);
1074   RawFlags |= (Flags.NoRecurse << 2);
1075   RawFlags |= (Flags.ReturnDoesNotAlias << 3);
1076   RawFlags |= (Flags.NoInline << 4);
1077   RawFlags |= (Flags.AlwaysInline << 5);
1078   RawFlags |= (Flags.NoUnwind << 6);
1079   RawFlags |= (Flags.MayThrow << 7);
1080   RawFlags |= (Flags.HasUnknownCall << 8);
1081   RawFlags |= (Flags.MustBeUnreachable << 9);
1082   return RawFlags;
1083 }
1084 
1085 // Decode the flags for GlobalValue in the summary. See getDecodedGVSummaryFlags
1086 // in BitcodeReader.cpp.
1087 static uint64_t getEncodedGVSummaryFlags(GlobalValueSummary::GVFlags Flags) {
1088   uint64_t RawFlags = 0;
1089 
1090   RawFlags |= Flags.NotEligibleToImport; // bool
1091   RawFlags |= (Flags.Live << 1);
1092   RawFlags |= (Flags.DSOLocal << 2);
1093   RawFlags |= (Flags.CanAutoHide << 3);
1094 
1095   // Linkage don't need to be remapped at that time for the summary. Any future
1096   // change to the getEncodedLinkage() function will need to be taken into
1097   // account here as well.
1098   RawFlags = (RawFlags << 4) | Flags.Linkage; // 4 bits
1099 
1100   RawFlags |= (Flags.Visibility << 8); // 2 bits
1101 
1102   return RawFlags;
1103 }
1104 
1105 static uint64_t getEncodedGVarFlags(GlobalVarSummary::GVarFlags Flags) {
1106   uint64_t RawFlags = Flags.MaybeReadOnly | (Flags.MaybeWriteOnly << 1) |
1107                       (Flags.Constant << 2) | Flags.VCallVisibility << 3;
1108   return RawFlags;
1109 }
1110 
1111 static unsigned getEncodedVisibility(const GlobalValue &GV) {
1112   switch (GV.getVisibility()) {
1113   case GlobalValue::DefaultVisibility:   return 0;
1114   case GlobalValue::HiddenVisibility:    return 1;
1115   case GlobalValue::ProtectedVisibility: return 2;
1116   }
1117   llvm_unreachable("Invalid visibility");
1118 }
1119 
1120 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
1121   switch (GV.getDLLStorageClass()) {
1122   case GlobalValue::DefaultStorageClass:   return 0;
1123   case GlobalValue::DLLImportStorageClass: return 1;
1124   case GlobalValue::DLLExportStorageClass: return 2;
1125   }
1126   llvm_unreachable("Invalid DLL storage class");
1127 }
1128 
1129 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
1130   switch (GV.getThreadLocalMode()) {
1131     case GlobalVariable::NotThreadLocal:         return 0;
1132     case GlobalVariable::GeneralDynamicTLSModel: return 1;
1133     case GlobalVariable::LocalDynamicTLSModel:   return 2;
1134     case GlobalVariable::InitialExecTLSModel:    return 3;
1135     case GlobalVariable::LocalExecTLSModel:      return 4;
1136   }
1137   llvm_unreachable("Invalid TLS model");
1138 }
1139 
1140 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
1141   switch (C.getSelectionKind()) {
1142   case Comdat::Any:
1143     return bitc::COMDAT_SELECTION_KIND_ANY;
1144   case Comdat::ExactMatch:
1145     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
1146   case Comdat::Largest:
1147     return bitc::COMDAT_SELECTION_KIND_LARGEST;
1148   case Comdat::NoDeduplicate:
1149     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
1150   case Comdat::SameSize:
1151     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
1152   }
1153   llvm_unreachable("Invalid selection kind");
1154 }
1155 
1156 static unsigned getEncodedUnnamedAddr(const GlobalValue &GV) {
1157   switch (GV.getUnnamedAddr()) {
1158   case GlobalValue::UnnamedAddr::None:   return 0;
1159   case GlobalValue::UnnamedAddr::Local:  return 2;
1160   case GlobalValue::UnnamedAddr::Global: return 1;
1161   }
1162   llvm_unreachable("Invalid unnamed_addr");
1163 }
1164 
1165 size_t ModuleBitcodeWriter::addToStrtab(StringRef Str) {
1166   if (GenerateHash)
1167     Hasher.update(Str);
1168   return StrtabBuilder.add(Str);
1169 }
1170 
1171 void ModuleBitcodeWriter::writeComdats() {
1172   SmallVector<unsigned, 64> Vals;
1173   for (const Comdat *C : VE.getComdats()) {
1174     // COMDAT: [strtab offset, strtab size, selection_kind]
1175     Vals.push_back(addToStrtab(C->getName()));
1176     Vals.push_back(C->getName().size());
1177     Vals.push_back(getEncodedComdatSelectionKind(*C));
1178     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
1179     Vals.clear();
1180   }
1181 }
1182 
1183 /// Write a record that will eventually hold the word offset of the
1184 /// module-level VST. For now the offset is 0, which will be backpatched
1185 /// after the real VST is written. Saves the bit offset to backpatch.
1186 void ModuleBitcodeWriter::writeValueSymbolTableForwardDecl() {
1187   // Write a placeholder value in for the offset of the real VST,
1188   // which is written after the function blocks so that it can include
1189   // the offset of each function. The placeholder offset will be
1190   // updated when the real VST is written.
1191   auto Abbv = std::make_shared<BitCodeAbbrev>();
1192   Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_VSTOFFSET));
1193   // Blocks are 32-bit aligned, so we can use a 32-bit word offset to
1194   // hold the real VST offset. Must use fixed instead of VBR as we don't
1195   // know how many VBR chunks to reserve ahead of time.
1196   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1197   unsigned VSTOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1198 
1199   // Emit the placeholder
1200   uint64_t Vals[] = {bitc::MODULE_CODE_VSTOFFSET, 0};
1201   Stream.EmitRecordWithAbbrev(VSTOffsetAbbrev, Vals);
1202 
1203   // Compute and save the bit offset to the placeholder, which will be
1204   // patched when the real VST is written. We can simply subtract the 32-bit
1205   // fixed size from the current bit number to get the location to backpatch.
1206   VSTOffsetPlaceholder = Stream.GetCurrentBitNo() - 32;
1207 }
1208 
1209 enum StringEncoding { SE_Char6, SE_Fixed7, SE_Fixed8 };
1210 
1211 /// Determine the encoding to use for the given string name and length.
1212 static StringEncoding getStringEncoding(StringRef Str) {
1213   bool isChar6 = true;
1214   for (char C : Str) {
1215     if (isChar6)
1216       isChar6 = BitCodeAbbrevOp::isChar6(C);
1217     if ((unsigned char)C & 128)
1218       // don't bother scanning the rest.
1219       return SE_Fixed8;
1220   }
1221   if (isChar6)
1222     return SE_Char6;
1223   return SE_Fixed7;
1224 }
1225 
1226 /// Emit top-level description of module, including target triple, inline asm,
1227 /// descriptors for global variables, and function prototype info.
1228 /// Returns the bit offset to backpatch with the location of the real VST.
1229 void ModuleBitcodeWriter::writeModuleInfo() {
1230   // Emit various pieces of data attached to a module.
1231   if (!M.getTargetTriple().empty())
1232     writeStringRecord(Stream, bitc::MODULE_CODE_TRIPLE, M.getTargetTriple(),
1233                       0 /*TODO*/);
1234   const std::string &DL = M.getDataLayoutStr();
1235   if (!DL.empty())
1236     writeStringRecord(Stream, bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/);
1237   if (!M.getModuleInlineAsm().empty())
1238     writeStringRecord(Stream, bitc::MODULE_CODE_ASM, M.getModuleInlineAsm(),
1239                       0 /*TODO*/);
1240 
1241   // Emit information about sections and GC, computing how many there are. Also
1242   // compute the maximum alignment value.
1243   std::map<std::string, unsigned> SectionMap;
1244   std::map<std::string, unsigned> GCMap;
1245   MaybeAlign MaxAlignment;
1246   unsigned MaxGlobalType = 0;
1247   const auto UpdateMaxAlignment = [&MaxAlignment](const MaybeAlign A) {
1248     if (A)
1249       MaxAlignment = !MaxAlignment ? *A : std::max(*MaxAlignment, *A);
1250   };
1251   for (const GlobalVariable &GV : M.globals()) {
1252     UpdateMaxAlignment(GV.getAlign());
1253     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
1254     if (GV.hasSection()) {
1255       // Give section names unique ID's.
1256       unsigned &Entry = SectionMap[std::string(GV.getSection())];
1257       if (!Entry) {
1258         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
1259                           0 /*TODO*/);
1260         Entry = SectionMap.size();
1261       }
1262     }
1263   }
1264   for (const Function &F : M) {
1265     UpdateMaxAlignment(F.getAlign());
1266     if (F.hasSection()) {
1267       // Give section names unique ID's.
1268       unsigned &Entry = SectionMap[std::string(F.getSection())];
1269       if (!Entry) {
1270         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
1271                           0 /*TODO*/);
1272         Entry = SectionMap.size();
1273       }
1274     }
1275     if (F.hasGC()) {
1276       // Same for GC names.
1277       unsigned &Entry = GCMap[F.getGC()];
1278       if (!Entry) {
1279         writeStringRecord(Stream, bitc::MODULE_CODE_GCNAME, F.getGC(),
1280                           0 /*TODO*/);
1281         Entry = GCMap.size();
1282       }
1283     }
1284   }
1285 
1286   // Emit abbrev for globals, now that we know # sections and max alignment.
1287   unsigned SimpleGVarAbbrev = 0;
1288   if (!M.global_empty()) {
1289     // Add an abbrev for common globals with no visibility or thread localness.
1290     auto Abbv = std::make_shared<BitCodeAbbrev>();
1291     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
1292     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1293     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1294     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1295                               Log2_32_Ceil(MaxGlobalType+1)));
1296     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
1297                                                            //| explicitType << 1
1298                                                            //| constant
1299     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
1300     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
1301     if (!MaxAlignment)                                     // Alignment.
1302       Abbv->Add(BitCodeAbbrevOp(0));
1303     else {
1304       unsigned MaxEncAlignment = getEncodedAlign(MaxAlignment);
1305       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1306                                Log2_32_Ceil(MaxEncAlignment+1)));
1307     }
1308     if (SectionMap.empty())                                    // Section.
1309       Abbv->Add(BitCodeAbbrevOp(0));
1310     else
1311       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1312                                Log2_32_Ceil(SectionMap.size()+1)));
1313     // Don't bother emitting vis + thread local.
1314     SimpleGVarAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1315   }
1316 
1317   SmallVector<unsigned, 64> Vals;
1318   // Emit the module's source file name.
1319   {
1320     StringEncoding Bits = getStringEncoding(M.getSourceFileName());
1321     BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
1322     if (Bits == SE_Char6)
1323       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
1324     else if (Bits == SE_Fixed7)
1325       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
1326 
1327     // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
1328     auto Abbv = std::make_shared<BitCodeAbbrev>();
1329     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
1330     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1331     Abbv->Add(AbbrevOpToUse);
1332     unsigned FilenameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1333 
1334     for (const auto P : M.getSourceFileName())
1335       Vals.push_back((unsigned char)P);
1336 
1337     // Emit the finished record.
1338     Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
1339     Vals.clear();
1340   }
1341 
1342   // Emit the global variable information.
1343   for (const GlobalVariable &GV : M.globals()) {
1344     unsigned AbbrevToUse = 0;
1345 
1346     // GLOBALVAR: [strtab offset, strtab size, type, isconst, initid,
1347     //             linkage, alignment, section, visibility, threadlocal,
1348     //             unnamed_addr, externally_initialized, dllstorageclass,
1349     //             comdat, attributes, DSO_Local]
1350     Vals.push_back(addToStrtab(GV.getName()));
1351     Vals.push_back(GV.getName().size());
1352     Vals.push_back(VE.getTypeID(GV.getValueType()));
1353     Vals.push_back(GV.getType()->getAddressSpace() << 2 | 2 | GV.isConstant());
1354     Vals.push_back(GV.isDeclaration() ? 0 :
1355                    (VE.getValueID(GV.getInitializer()) + 1));
1356     Vals.push_back(getEncodedLinkage(GV));
1357     Vals.push_back(getEncodedAlign(GV.getAlign()));
1358     Vals.push_back(GV.hasSection() ? SectionMap[std::string(GV.getSection())]
1359                                    : 0);
1360     if (GV.isThreadLocal() ||
1361         GV.getVisibility() != GlobalValue::DefaultVisibility ||
1362         GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None ||
1363         GV.isExternallyInitialized() ||
1364         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
1365         GV.hasComdat() || GV.hasAttributes() || GV.isDSOLocal() ||
1366         GV.hasPartition()) {
1367       Vals.push_back(getEncodedVisibility(GV));
1368       Vals.push_back(getEncodedThreadLocalMode(GV));
1369       Vals.push_back(getEncodedUnnamedAddr(GV));
1370       Vals.push_back(GV.isExternallyInitialized());
1371       Vals.push_back(getEncodedDLLStorageClass(GV));
1372       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
1373 
1374       auto AL = GV.getAttributesAsList(AttributeList::FunctionIndex);
1375       Vals.push_back(VE.getAttributeListID(AL));
1376 
1377       Vals.push_back(GV.isDSOLocal());
1378       Vals.push_back(addToStrtab(GV.getPartition()));
1379       Vals.push_back(GV.getPartition().size());
1380     } else {
1381       AbbrevToUse = SimpleGVarAbbrev;
1382     }
1383 
1384     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
1385     Vals.clear();
1386   }
1387 
1388   // Emit the function proto information.
1389   for (const Function &F : M) {
1390     // FUNCTION:  [strtab offset, strtab size, type, callingconv, isproto,
1391     //             linkage, paramattrs, alignment, section, visibility, gc,
1392     //             unnamed_addr, prologuedata, dllstorageclass, comdat,
1393     //             prefixdata, personalityfn, DSO_Local, addrspace]
1394     Vals.push_back(addToStrtab(F.getName()));
1395     Vals.push_back(F.getName().size());
1396     Vals.push_back(VE.getTypeID(F.getFunctionType()));
1397     Vals.push_back(F.getCallingConv());
1398     Vals.push_back(F.isDeclaration());
1399     Vals.push_back(getEncodedLinkage(F));
1400     Vals.push_back(VE.getAttributeListID(F.getAttributes()));
1401     Vals.push_back(getEncodedAlign(F.getAlign()));
1402     Vals.push_back(F.hasSection() ? SectionMap[std::string(F.getSection())]
1403                                   : 0);
1404     Vals.push_back(getEncodedVisibility(F));
1405     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
1406     Vals.push_back(getEncodedUnnamedAddr(F));
1407     Vals.push_back(F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1)
1408                                        : 0);
1409     Vals.push_back(getEncodedDLLStorageClass(F));
1410     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
1411     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
1412                                      : 0);
1413     Vals.push_back(
1414         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
1415 
1416     Vals.push_back(F.isDSOLocal());
1417     Vals.push_back(F.getAddressSpace());
1418     Vals.push_back(addToStrtab(F.getPartition()));
1419     Vals.push_back(F.getPartition().size());
1420 
1421     unsigned AbbrevToUse = 0;
1422     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
1423     Vals.clear();
1424   }
1425 
1426   // Emit the alias information.
1427   for (const GlobalAlias &A : M.aliases()) {
1428     // ALIAS: [strtab offset, strtab size, alias type, aliasee val#, linkage,
1429     //         visibility, dllstorageclass, threadlocal, unnamed_addr,
1430     //         DSO_Local]
1431     Vals.push_back(addToStrtab(A.getName()));
1432     Vals.push_back(A.getName().size());
1433     Vals.push_back(VE.getTypeID(A.getValueType()));
1434     Vals.push_back(A.getType()->getAddressSpace());
1435     Vals.push_back(VE.getValueID(A.getAliasee()));
1436     Vals.push_back(getEncodedLinkage(A));
1437     Vals.push_back(getEncodedVisibility(A));
1438     Vals.push_back(getEncodedDLLStorageClass(A));
1439     Vals.push_back(getEncodedThreadLocalMode(A));
1440     Vals.push_back(getEncodedUnnamedAddr(A));
1441     Vals.push_back(A.isDSOLocal());
1442     Vals.push_back(addToStrtab(A.getPartition()));
1443     Vals.push_back(A.getPartition().size());
1444 
1445     unsigned AbbrevToUse = 0;
1446     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
1447     Vals.clear();
1448   }
1449 
1450   // Emit the ifunc information.
1451   for (const GlobalIFunc &I : M.ifuncs()) {
1452     // IFUNC: [strtab offset, strtab size, ifunc type, address space, resolver
1453     //         val#, linkage, visibility, DSO_Local]
1454     Vals.push_back(addToStrtab(I.getName()));
1455     Vals.push_back(I.getName().size());
1456     Vals.push_back(VE.getTypeID(I.getValueType()));
1457     Vals.push_back(I.getType()->getAddressSpace());
1458     Vals.push_back(VE.getValueID(I.getResolver()));
1459     Vals.push_back(getEncodedLinkage(I));
1460     Vals.push_back(getEncodedVisibility(I));
1461     Vals.push_back(I.isDSOLocal());
1462     Vals.push_back(addToStrtab(I.getPartition()));
1463     Vals.push_back(I.getPartition().size());
1464     Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
1465     Vals.clear();
1466   }
1467 
1468   writeValueSymbolTableForwardDecl();
1469 }
1470 
1471 static uint64_t getOptimizationFlags(const Value *V) {
1472   uint64_t Flags = 0;
1473 
1474   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
1475     if (OBO->hasNoSignedWrap())
1476       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
1477     if (OBO->hasNoUnsignedWrap())
1478       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
1479   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
1480     if (PEO->isExact())
1481       Flags |= 1 << bitc::PEO_EXACT;
1482   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
1483     if (FPMO->hasAllowReassoc())
1484       Flags |= bitc::AllowReassoc;
1485     if (FPMO->hasNoNaNs())
1486       Flags |= bitc::NoNaNs;
1487     if (FPMO->hasNoInfs())
1488       Flags |= bitc::NoInfs;
1489     if (FPMO->hasNoSignedZeros())
1490       Flags |= bitc::NoSignedZeros;
1491     if (FPMO->hasAllowReciprocal())
1492       Flags |= bitc::AllowReciprocal;
1493     if (FPMO->hasAllowContract())
1494       Flags |= bitc::AllowContract;
1495     if (FPMO->hasApproxFunc())
1496       Flags |= bitc::ApproxFunc;
1497   }
1498 
1499   return Flags;
1500 }
1501 
1502 void ModuleBitcodeWriter::writeValueAsMetadata(
1503     const ValueAsMetadata *MD, SmallVectorImpl<uint64_t> &Record) {
1504   // Mimic an MDNode with a value as one operand.
1505   Value *V = MD->getValue();
1506   Record.push_back(VE.getTypeID(V->getType()));
1507   Record.push_back(VE.getValueID(V));
1508   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
1509   Record.clear();
1510 }
1511 
1512 void ModuleBitcodeWriter::writeMDTuple(const MDTuple *N,
1513                                        SmallVectorImpl<uint64_t> &Record,
1514                                        unsigned Abbrev) {
1515   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
1516     Metadata *MD = N->getOperand(i);
1517     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
1518            "Unexpected function-local metadata");
1519     Record.push_back(VE.getMetadataOrNullID(MD));
1520   }
1521   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
1522                                     : bitc::METADATA_NODE,
1523                     Record, Abbrev);
1524   Record.clear();
1525 }
1526 
1527 unsigned ModuleBitcodeWriter::createDILocationAbbrev() {
1528   // Assume the column is usually under 128, and always output the inlined-at
1529   // location (it's never more expensive than building an array size 1).
1530   auto Abbv = std::make_shared<BitCodeAbbrev>();
1531   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1532   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1533   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1534   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1535   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1536   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1537   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1538   return Stream.EmitAbbrev(std::move(Abbv));
1539 }
1540 
1541 void ModuleBitcodeWriter::writeDILocation(const DILocation *N,
1542                                           SmallVectorImpl<uint64_t> &Record,
1543                                           unsigned &Abbrev) {
1544   if (!Abbrev)
1545     Abbrev = createDILocationAbbrev();
1546 
1547   Record.push_back(N->isDistinct());
1548   Record.push_back(N->getLine());
1549   Record.push_back(N->getColumn());
1550   Record.push_back(VE.getMetadataID(N->getScope()));
1551   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
1552   Record.push_back(N->isImplicitCode());
1553 
1554   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
1555   Record.clear();
1556 }
1557 
1558 unsigned ModuleBitcodeWriter::createGenericDINodeAbbrev() {
1559   // Assume the column is usually under 128, and always output the inlined-at
1560   // location (it's never more expensive than building an array size 1).
1561   auto Abbv = std::make_shared<BitCodeAbbrev>();
1562   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1563   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1564   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1565   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1566   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1567   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1568   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1569   return Stream.EmitAbbrev(std::move(Abbv));
1570 }
1571 
1572 void ModuleBitcodeWriter::writeGenericDINode(const GenericDINode *N,
1573                                              SmallVectorImpl<uint64_t> &Record,
1574                                              unsigned &Abbrev) {
1575   if (!Abbrev)
1576     Abbrev = createGenericDINodeAbbrev();
1577 
1578   Record.push_back(N->isDistinct());
1579   Record.push_back(N->getTag());
1580   Record.push_back(0); // Per-tag version field; unused for now.
1581 
1582   for (auto &I : N->operands())
1583     Record.push_back(VE.getMetadataOrNullID(I));
1584 
1585   Stream.EmitRecord(bitc::METADATA_GENERIC_DEBUG, Record, Abbrev);
1586   Record.clear();
1587 }
1588 
1589 void ModuleBitcodeWriter::writeDISubrange(const DISubrange *N,
1590                                           SmallVectorImpl<uint64_t> &Record,
1591                                           unsigned Abbrev) {
1592   const uint64_t Version = 2 << 1;
1593   Record.push_back((uint64_t)N->isDistinct() | Version);
1594   Record.push_back(VE.getMetadataOrNullID(N->getRawCountNode()));
1595   Record.push_back(VE.getMetadataOrNullID(N->getRawLowerBound()));
1596   Record.push_back(VE.getMetadataOrNullID(N->getRawUpperBound()));
1597   Record.push_back(VE.getMetadataOrNullID(N->getRawStride()));
1598 
1599   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
1600   Record.clear();
1601 }
1602 
1603 void ModuleBitcodeWriter::writeDIGenericSubrange(
1604     const DIGenericSubrange *N, SmallVectorImpl<uint64_t> &Record,
1605     unsigned Abbrev) {
1606   Record.push_back((uint64_t)N->isDistinct());
1607   Record.push_back(VE.getMetadataOrNullID(N->getRawCountNode()));
1608   Record.push_back(VE.getMetadataOrNullID(N->getRawLowerBound()));
1609   Record.push_back(VE.getMetadataOrNullID(N->getRawUpperBound()));
1610   Record.push_back(VE.getMetadataOrNullID(N->getRawStride()));
1611 
1612   Stream.EmitRecord(bitc::METADATA_GENERIC_SUBRANGE, Record, Abbrev);
1613   Record.clear();
1614 }
1615 
1616 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
1617   if ((int64_t)V >= 0)
1618     Vals.push_back(V << 1);
1619   else
1620     Vals.push_back((-V << 1) | 1);
1621 }
1622 
1623 static void emitWideAPInt(SmallVectorImpl<uint64_t> &Vals, const APInt &A) {
1624   // We have an arbitrary precision integer value to write whose
1625   // bit width is > 64. However, in canonical unsigned integer
1626   // format it is likely that the high bits are going to be zero.
1627   // So, we only write the number of active words.
1628   unsigned NumWords = A.getActiveWords();
1629   const uint64_t *RawData = A.getRawData();
1630   for (unsigned i = 0; i < NumWords; i++)
1631     emitSignedInt64(Vals, RawData[i]);
1632 }
1633 
1634 void ModuleBitcodeWriter::writeDIEnumerator(const DIEnumerator *N,
1635                                             SmallVectorImpl<uint64_t> &Record,
1636                                             unsigned Abbrev) {
1637   const uint64_t IsBigInt = 1 << 2;
1638   Record.push_back(IsBigInt | (N->isUnsigned() << 1) | N->isDistinct());
1639   Record.push_back(N->getValue().getBitWidth());
1640   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1641   emitWideAPInt(Record, N->getValue());
1642 
1643   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
1644   Record.clear();
1645 }
1646 
1647 void ModuleBitcodeWriter::writeDIBasicType(const DIBasicType *N,
1648                                            SmallVectorImpl<uint64_t> &Record,
1649                                            unsigned Abbrev) {
1650   Record.push_back(N->isDistinct());
1651   Record.push_back(N->getTag());
1652   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1653   Record.push_back(N->getSizeInBits());
1654   Record.push_back(N->getAlignInBits());
1655   Record.push_back(N->getEncoding());
1656   Record.push_back(N->getFlags());
1657 
1658   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
1659   Record.clear();
1660 }
1661 
1662 void ModuleBitcodeWriter::writeDIStringType(const DIStringType *N,
1663                                             SmallVectorImpl<uint64_t> &Record,
1664                                             unsigned Abbrev) {
1665   Record.push_back(N->isDistinct());
1666   Record.push_back(N->getTag());
1667   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1668   Record.push_back(VE.getMetadataOrNullID(N->getStringLength()));
1669   Record.push_back(VE.getMetadataOrNullID(N->getStringLengthExp()));
1670   Record.push_back(VE.getMetadataOrNullID(N->getStringLocationExp()));
1671   Record.push_back(N->getSizeInBits());
1672   Record.push_back(N->getAlignInBits());
1673   Record.push_back(N->getEncoding());
1674 
1675   Stream.EmitRecord(bitc::METADATA_STRING_TYPE, Record, Abbrev);
1676   Record.clear();
1677 }
1678 
1679 void ModuleBitcodeWriter::writeDIDerivedType(const DIDerivedType *N,
1680                                              SmallVectorImpl<uint64_t> &Record,
1681                                              unsigned Abbrev) {
1682   Record.push_back(N->isDistinct());
1683   Record.push_back(N->getTag());
1684   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1685   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1686   Record.push_back(N->getLine());
1687   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1688   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1689   Record.push_back(N->getSizeInBits());
1690   Record.push_back(N->getAlignInBits());
1691   Record.push_back(N->getOffsetInBits());
1692   Record.push_back(N->getFlags());
1693   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
1694 
1695   // DWARF address space is encoded as N->getDWARFAddressSpace() + 1. 0 means
1696   // that there is no DWARF address space associated with DIDerivedType.
1697   if (const auto &DWARFAddressSpace = N->getDWARFAddressSpace())
1698     Record.push_back(*DWARFAddressSpace + 1);
1699   else
1700     Record.push_back(0);
1701 
1702   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
1703 
1704   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
1705   Record.clear();
1706 }
1707 
1708 void ModuleBitcodeWriter::writeDICompositeType(
1709     const DICompositeType *N, SmallVectorImpl<uint64_t> &Record,
1710     unsigned Abbrev) {
1711   const unsigned IsNotUsedInOldTypeRef = 0x2;
1712   Record.push_back(IsNotUsedInOldTypeRef | (unsigned)N->isDistinct());
1713   Record.push_back(N->getTag());
1714   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1715   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1716   Record.push_back(N->getLine());
1717   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1718   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1719   Record.push_back(N->getSizeInBits());
1720   Record.push_back(N->getAlignInBits());
1721   Record.push_back(N->getOffsetInBits());
1722   Record.push_back(N->getFlags());
1723   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1724   Record.push_back(N->getRuntimeLang());
1725   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
1726   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1727   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
1728   Record.push_back(VE.getMetadataOrNullID(N->getDiscriminator()));
1729   Record.push_back(VE.getMetadataOrNullID(N->getRawDataLocation()));
1730   Record.push_back(VE.getMetadataOrNullID(N->getRawAssociated()));
1731   Record.push_back(VE.getMetadataOrNullID(N->getRawAllocated()));
1732   Record.push_back(VE.getMetadataOrNullID(N->getRawRank()));
1733   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
1734 
1735   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
1736   Record.clear();
1737 }
1738 
1739 void ModuleBitcodeWriter::writeDISubroutineType(
1740     const DISubroutineType *N, SmallVectorImpl<uint64_t> &Record,
1741     unsigned Abbrev) {
1742   const unsigned HasNoOldTypeRefs = 0x2;
1743   Record.push_back(HasNoOldTypeRefs | (unsigned)N->isDistinct());
1744   Record.push_back(N->getFlags());
1745   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
1746   Record.push_back(N->getCC());
1747 
1748   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
1749   Record.clear();
1750 }
1751 
1752 void ModuleBitcodeWriter::writeDIFile(const DIFile *N,
1753                                       SmallVectorImpl<uint64_t> &Record,
1754                                       unsigned Abbrev) {
1755   Record.push_back(N->isDistinct());
1756   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
1757   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
1758   if (N->getRawChecksum()) {
1759     Record.push_back(N->getRawChecksum()->Kind);
1760     Record.push_back(VE.getMetadataOrNullID(N->getRawChecksum()->Value));
1761   } else {
1762     // Maintain backwards compatibility with the old internal representation of
1763     // CSK_None in ChecksumKind by writing nulls here when Checksum is None.
1764     Record.push_back(0);
1765     Record.push_back(VE.getMetadataOrNullID(nullptr));
1766   }
1767   auto Source = N->getRawSource();
1768   if (Source)
1769     Record.push_back(VE.getMetadataOrNullID(*Source));
1770 
1771   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
1772   Record.clear();
1773 }
1774 
1775 void ModuleBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
1776                                              SmallVectorImpl<uint64_t> &Record,
1777                                              unsigned Abbrev) {
1778   assert(N->isDistinct() && "Expected distinct compile units");
1779   Record.push_back(/* IsDistinct */ true);
1780   Record.push_back(N->getSourceLanguage());
1781   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1782   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
1783   Record.push_back(N->isOptimized());
1784   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
1785   Record.push_back(N->getRuntimeVersion());
1786   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
1787   Record.push_back(N->getEmissionKind());
1788   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
1789   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
1790   Record.push_back(/* subprograms */ 0);
1791   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
1792   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
1793   Record.push_back(N->getDWOId());
1794   Record.push_back(VE.getMetadataOrNullID(N->getMacros().get()));
1795   Record.push_back(N->getSplitDebugInlining());
1796   Record.push_back(N->getDebugInfoForProfiling());
1797   Record.push_back((unsigned)N->getNameTableKind());
1798   Record.push_back(N->getRangesBaseAddress());
1799   Record.push_back(VE.getMetadataOrNullID(N->getRawSysRoot()));
1800   Record.push_back(VE.getMetadataOrNullID(N->getRawSDK()));
1801 
1802   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
1803   Record.clear();
1804 }
1805 
1806 void ModuleBitcodeWriter::writeDISubprogram(const DISubprogram *N,
1807                                             SmallVectorImpl<uint64_t> &Record,
1808                                             unsigned Abbrev) {
1809   const uint64_t HasUnitFlag = 1 << 1;
1810   const uint64_t HasSPFlagsFlag = 1 << 2;
1811   Record.push_back(uint64_t(N->isDistinct()) | HasUnitFlag | HasSPFlagsFlag);
1812   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1813   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1814   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1815   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1816   Record.push_back(N->getLine());
1817   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1818   Record.push_back(N->getScopeLine());
1819   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
1820   Record.push_back(N->getSPFlags());
1821   Record.push_back(N->getVirtualIndex());
1822   Record.push_back(N->getFlags());
1823   Record.push_back(VE.getMetadataOrNullID(N->getRawUnit()));
1824   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1825   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
1826   Record.push_back(VE.getMetadataOrNullID(N->getRetainedNodes().get()));
1827   Record.push_back(N->getThisAdjustment());
1828   Record.push_back(VE.getMetadataOrNullID(N->getThrownTypes().get()));
1829   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
1830   Record.push_back(VE.getMetadataOrNullID(N->getRawTargetFuncName()));
1831 
1832   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
1833   Record.clear();
1834 }
1835 
1836 void ModuleBitcodeWriter::writeDILexicalBlock(const DILexicalBlock *N,
1837                                               SmallVectorImpl<uint64_t> &Record,
1838                                               unsigned Abbrev) {
1839   Record.push_back(N->isDistinct());
1840   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1841   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1842   Record.push_back(N->getLine());
1843   Record.push_back(N->getColumn());
1844 
1845   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
1846   Record.clear();
1847 }
1848 
1849 void ModuleBitcodeWriter::writeDILexicalBlockFile(
1850     const DILexicalBlockFile *N, SmallVectorImpl<uint64_t> &Record,
1851     unsigned Abbrev) {
1852   Record.push_back(N->isDistinct());
1853   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1854   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1855   Record.push_back(N->getDiscriminator());
1856 
1857   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
1858   Record.clear();
1859 }
1860 
1861 void ModuleBitcodeWriter::writeDICommonBlock(const DICommonBlock *N,
1862                                              SmallVectorImpl<uint64_t> &Record,
1863                                              unsigned Abbrev) {
1864   Record.push_back(N->isDistinct());
1865   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1866   Record.push_back(VE.getMetadataOrNullID(N->getDecl()));
1867   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1868   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1869   Record.push_back(N->getLineNo());
1870 
1871   Stream.EmitRecord(bitc::METADATA_COMMON_BLOCK, Record, Abbrev);
1872   Record.clear();
1873 }
1874 
1875 void ModuleBitcodeWriter::writeDINamespace(const DINamespace *N,
1876                                            SmallVectorImpl<uint64_t> &Record,
1877                                            unsigned Abbrev) {
1878   Record.push_back(N->isDistinct() | N->getExportSymbols() << 1);
1879   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1880   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1881 
1882   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
1883   Record.clear();
1884 }
1885 
1886 void ModuleBitcodeWriter::writeDIMacro(const DIMacro *N,
1887                                        SmallVectorImpl<uint64_t> &Record,
1888                                        unsigned Abbrev) {
1889   Record.push_back(N->isDistinct());
1890   Record.push_back(N->getMacinfoType());
1891   Record.push_back(N->getLine());
1892   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1893   Record.push_back(VE.getMetadataOrNullID(N->getRawValue()));
1894 
1895   Stream.EmitRecord(bitc::METADATA_MACRO, Record, Abbrev);
1896   Record.clear();
1897 }
1898 
1899 void ModuleBitcodeWriter::writeDIMacroFile(const DIMacroFile *N,
1900                                            SmallVectorImpl<uint64_t> &Record,
1901                                            unsigned Abbrev) {
1902   Record.push_back(N->isDistinct());
1903   Record.push_back(N->getMacinfoType());
1904   Record.push_back(N->getLine());
1905   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1906   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1907 
1908   Stream.EmitRecord(bitc::METADATA_MACRO_FILE, Record, Abbrev);
1909   Record.clear();
1910 }
1911 
1912 void ModuleBitcodeWriter::writeDIArgList(const DIArgList *N,
1913                                          SmallVectorImpl<uint64_t> &Record,
1914                                          unsigned Abbrev) {
1915   Record.reserve(N->getArgs().size());
1916   for (ValueAsMetadata *MD : N->getArgs())
1917     Record.push_back(VE.getMetadataID(MD));
1918 
1919   Stream.EmitRecord(bitc::METADATA_ARG_LIST, Record, Abbrev);
1920   Record.clear();
1921 }
1922 
1923 void ModuleBitcodeWriter::writeDIModule(const DIModule *N,
1924                                         SmallVectorImpl<uint64_t> &Record,
1925                                         unsigned Abbrev) {
1926   Record.push_back(N->isDistinct());
1927   for (auto &I : N->operands())
1928     Record.push_back(VE.getMetadataOrNullID(I));
1929   Record.push_back(N->getLineNo());
1930   Record.push_back(N->getIsDecl());
1931 
1932   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
1933   Record.clear();
1934 }
1935 
1936 void ModuleBitcodeWriter::writeDITemplateTypeParameter(
1937     const DITemplateTypeParameter *N, SmallVectorImpl<uint64_t> &Record,
1938     unsigned Abbrev) {
1939   Record.push_back(N->isDistinct());
1940   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1941   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1942   Record.push_back(N->isDefault());
1943 
1944   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
1945   Record.clear();
1946 }
1947 
1948 void ModuleBitcodeWriter::writeDITemplateValueParameter(
1949     const DITemplateValueParameter *N, SmallVectorImpl<uint64_t> &Record,
1950     unsigned Abbrev) {
1951   Record.push_back(N->isDistinct());
1952   Record.push_back(N->getTag());
1953   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1954   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1955   Record.push_back(N->isDefault());
1956   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
1957 
1958   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
1959   Record.clear();
1960 }
1961 
1962 void ModuleBitcodeWriter::writeDIGlobalVariable(
1963     const DIGlobalVariable *N, SmallVectorImpl<uint64_t> &Record,
1964     unsigned Abbrev) {
1965   const uint64_t Version = 2 << 1;
1966   Record.push_back((uint64_t)N->isDistinct() | Version);
1967   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1968   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1969   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1970   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1971   Record.push_back(N->getLine());
1972   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1973   Record.push_back(N->isLocalToUnit());
1974   Record.push_back(N->isDefinition());
1975   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
1976   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams()));
1977   Record.push_back(N->getAlignInBits());
1978   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
1979 
1980   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
1981   Record.clear();
1982 }
1983 
1984 void ModuleBitcodeWriter::writeDILocalVariable(
1985     const DILocalVariable *N, SmallVectorImpl<uint64_t> &Record,
1986     unsigned Abbrev) {
1987   // In order to support all possible bitcode formats in BitcodeReader we need
1988   // to distinguish the following cases:
1989   // 1) Record has no artificial tag (Record[1]),
1990   //   has no obsolete inlinedAt field (Record[9]).
1991   //   In this case Record size will be 8, HasAlignment flag is false.
1992   // 2) Record has artificial tag (Record[1]),
1993   //   has no obsolete inlignedAt field (Record[9]).
1994   //   In this case Record size will be 9, HasAlignment flag is false.
1995   // 3) Record has both artificial tag (Record[1]) and
1996   //   obsolete inlignedAt field (Record[9]).
1997   //   In this case Record size will be 10, HasAlignment flag is false.
1998   // 4) Record has neither artificial tag, nor inlignedAt field, but
1999   //   HasAlignment flag is true and Record[8] contains alignment value.
2000   const uint64_t HasAlignmentFlag = 1 << 1;
2001   Record.push_back((uint64_t)N->isDistinct() | HasAlignmentFlag);
2002   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2003   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2004   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2005   Record.push_back(N->getLine());
2006   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2007   Record.push_back(N->getArg());
2008   Record.push_back(N->getFlags());
2009   Record.push_back(N->getAlignInBits());
2010   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
2011 
2012   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
2013   Record.clear();
2014 }
2015 
2016 void ModuleBitcodeWriter::writeDILabel(
2017     const DILabel *N, SmallVectorImpl<uint64_t> &Record,
2018     unsigned Abbrev) {
2019   Record.push_back((uint64_t)N->isDistinct());
2020   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2021   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2022   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2023   Record.push_back(N->getLine());
2024 
2025   Stream.EmitRecord(bitc::METADATA_LABEL, Record, Abbrev);
2026   Record.clear();
2027 }
2028 
2029 void ModuleBitcodeWriter::writeDIExpression(const DIExpression *N,
2030                                             SmallVectorImpl<uint64_t> &Record,
2031                                             unsigned Abbrev) {
2032   Record.reserve(N->getElements().size() + 1);
2033   const uint64_t Version = 3 << 1;
2034   Record.push_back((uint64_t)N->isDistinct() | Version);
2035   Record.append(N->elements_begin(), N->elements_end());
2036 
2037   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
2038   Record.clear();
2039 }
2040 
2041 void ModuleBitcodeWriter::writeDIGlobalVariableExpression(
2042     const DIGlobalVariableExpression *N, SmallVectorImpl<uint64_t> &Record,
2043     unsigned Abbrev) {
2044   Record.push_back(N->isDistinct());
2045   Record.push_back(VE.getMetadataOrNullID(N->getVariable()));
2046   Record.push_back(VE.getMetadataOrNullID(N->getExpression()));
2047 
2048   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR_EXPR, Record, Abbrev);
2049   Record.clear();
2050 }
2051 
2052 void ModuleBitcodeWriter::writeDIObjCProperty(const DIObjCProperty *N,
2053                                               SmallVectorImpl<uint64_t> &Record,
2054                                               unsigned Abbrev) {
2055   Record.push_back(N->isDistinct());
2056   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2057   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2058   Record.push_back(N->getLine());
2059   Record.push_back(VE.getMetadataOrNullID(N->getRawSetterName()));
2060   Record.push_back(VE.getMetadataOrNullID(N->getRawGetterName()));
2061   Record.push_back(N->getAttributes());
2062   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2063 
2064   Stream.EmitRecord(bitc::METADATA_OBJC_PROPERTY, Record, Abbrev);
2065   Record.clear();
2066 }
2067 
2068 void ModuleBitcodeWriter::writeDIImportedEntity(
2069     const DIImportedEntity *N, SmallVectorImpl<uint64_t> &Record,
2070     unsigned Abbrev) {
2071   Record.push_back(N->isDistinct());
2072   Record.push_back(N->getTag());
2073   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2074   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
2075   Record.push_back(N->getLine());
2076   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2077   Record.push_back(VE.getMetadataOrNullID(N->getRawFile()));
2078   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
2079 
2080   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
2081   Record.clear();
2082 }
2083 
2084 unsigned ModuleBitcodeWriter::createNamedMetadataAbbrev() {
2085   auto Abbv = std::make_shared<BitCodeAbbrev>();
2086   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
2087   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2088   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2089   return Stream.EmitAbbrev(std::move(Abbv));
2090 }
2091 
2092 void ModuleBitcodeWriter::writeNamedMetadata(
2093     SmallVectorImpl<uint64_t> &Record) {
2094   if (M.named_metadata_empty())
2095     return;
2096 
2097   unsigned Abbrev = createNamedMetadataAbbrev();
2098   for (const NamedMDNode &NMD : M.named_metadata()) {
2099     // Write name.
2100     StringRef Str = NMD.getName();
2101     Record.append(Str.bytes_begin(), Str.bytes_end());
2102     Stream.EmitRecord(bitc::METADATA_NAME, Record, Abbrev);
2103     Record.clear();
2104 
2105     // Write named metadata operands.
2106     for (const MDNode *N : NMD.operands())
2107       Record.push_back(VE.getMetadataID(N));
2108     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
2109     Record.clear();
2110   }
2111 }
2112 
2113 unsigned ModuleBitcodeWriter::createMetadataStringsAbbrev() {
2114   auto Abbv = std::make_shared<BitCodeAbbrev>();
2115   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRINGS));
2116   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of strings
2117   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // offset to chars
2118   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2119   return Stream.EmitAbbrev(std::move(Abbv));
2120 }
2121 
2122 /// Write out a record for MDString.
2123 ///
2124 /// All the metadata strings in a metadata block are emitted in a single
2125 /// record.  The sizes and strings themselves are shoved into a blob.
2126 void ModuleBitcodeWriter::writeMetadataStrings(
2127     ArrayRef<const Metadata *> Strings, SmallVectorImpl<uint64_t> &Record) {
2128   if (Strings.empty())
2129     return;
2130 
2131   // Start the record with the number of strings.
2132   Record.push_back(bitc::METADATA_STRINGS);
2133   Record.push_back(Strings.size());
2134 
2135   // Emit the sizes of the strings in the blob.
2136   SmallString<256> Blob;
2137   {
2138     BitstreamWriter W(Blob);
2139     for (const Metadata *MD : Strings)
2140       W.EmitVBR(cast<MDString>(MD)->getLength(), 6);
2141     W.FlushToWord();
2142   }
2143 
2144   // Add the offset to the strings to the record.
2145   Record.push_back(Blob.size());
2146 
2147   // Add the strings to the blob.
2148   for (const Metadata *MD : Strings)
2149     Blob.append(cast<MDString>(MD)->getString());
2150 
2151   // Emit the final record.
2152   Stream.EmitRecordWithBlob(createMetadataStringsAbbrev(), Record, Blob);
2153   Record.clear();
2154 }
2155 
2156 // Generates an enum to use as an index in the Abbrev array of Metadata record.
2157 enum MetadataAbbrev : unsigned {
2158 #define HANDLE_MDNODE_LEAF(CLASS) CLASS##AbbrevID,
2159 #include "llvm/IR/Metadata.def"
2160   LastPlusOne
2161 };
2162 
2163 void ModuleBitcodeWriter::writeMetadataRecords(
2164     ArrayRef<const Metadata *> MDs, SmallVectorImpl<uint64_t> &Record,
2165     std::vector<unsigned> *MDAbbrevs, std::vector<uint64_t> *IndexPos) {
2166   if (MDs.empty())
2167     return;
2168 
2169   // Initialize MDNode abbreviations.
2170 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
2171 #include "llvm/IR/Metadata.def"
2172 
2173   for (const Metadata *MD : MDs) {
2174     if (IndexPos)
2175       IndexPos->push_back(Stream.GetCurrentBitNo());
2176     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
2177       assert(N->isResolved() && "Expected forward references to be resolved");
2178 
2179       switch (N->getMetadataID()) {
2180       default:
2181         llvm_unreachable("Invalid MDNode subclass");
2182 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
2183   case Metadata::CLASS##Kind:                                                  \
2184     if (MDAbbrevs)                                                             \
2185       write##CLASS(cast<CLASS>(N), Record,                                     \
2186                    (*MDAbbrevs)[MetadataAbbrev::CLASS##AbbrevID]);             \
2187     else                                                                       \
2188       write##CLASS(cast<CLASS>(N), Record, CLASS##Abbrev);                     \
2189     continue;
2190 #include "llvm/IR/Metadata.def"
2191       }
2192     }
2193     writeValueAsMetadata(cast<ValueAsMetadata>(MD), Record);
2194   }
2195 }
2196 
2197 void ModuleBitcodeWriter::writeModuleMetadata() {
2198   if (!VE.hasMDs() && M.named_metadata_empty())
2199     return;
2200 
2201   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 4);
2202   SmallVector<uint64_t, 64> Record;
2203 
2204   // Emit all abbrevs upfront, so that the reader can jump in the middle of the
2205   // block and load any metadata.
2206   std::vector<unsigned> MDAbbrevs;
2207 
2208   MDAbbrevs.resize(MetadataAbbrev::LastPlusOne);
2209   MDAbbrevs[MetadataAbbrev::DILocationAbbrevID] = createDILocationAbbrev();
2210   MDAbbrevs[MetadataAbbrev::GenericDINodeAbbrevID] =
2211       createGenericDINodeAbbrev();
2212 
2213   auto Abbv = std::make_shared<BitCodeAbbrev>();
2214   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_INDEX_OFFSET));
2215   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2216   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2217   unsigned OffsetAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2218 
2219   Abbv = std::make_shared<BitCodeAbbrev>();
2220   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_INDEX));
2221   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2222   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2223   unsigned IndexAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2224 
2225   // Emit MDStrings together upfront.
2226   writeMetadataStrings(VE.getMDStrings(), Record);
2227 
2228   // We only emit an index for the metadata record if we have more than a given
2229   // (naive) threshold of metadatas, otherwise it is not worth it.
2230   if (VE.getNonMDStrings().size() > IndexThreshold) {
2231     // Write a placeholder value in for the offset of the metadata index,
2232     // which is written after the records, so that it can include
2233     // the offset of each entry. The placeholder offset will be
2234     // updated after all records are emitted.
2235     uint64_t Vals[] = {0, 0};
2236     Stream.EmitRecord(bitc::METADATA_INDEX_OFFSET, Vals, OffsetAbbrev);
2237   }
2238 
2239   // Compute and save the bit offset to the current position, which will be
2240   // patched when we emit the index later. We can simply subtract the 64-bit
2241   // fixed size from the current bit number to get the location to backpatch.
2242   uint64_t IndexOffsetRecordBitPos = Stream.GetCurrentBitNo();
2243 
2244   // This index will contain the bitpos for each individual record.
2245   std::vector<uint64_t> IndexPos;
2246   IndexPos.reserve(VE.getNonMDStrings().size());
2247 
2248   // Write all the records
2249   writeMetadataRecords(VE.getNonMDStrings(), Record, &MDAbbrevs, &IndexPos);
2250 
2251   if (VE.getNonMDStrings().size() > IndexThreshold) {
2252     // Now that we have emitted all the records we will emit the index. But
2253     // first
2254     // backpatch the forward reference so that the reader can skip the records
2255     // efficiently.
2256     Stream.BackpatchWord64(IndexOffsetRecordBitPos - 64,
2257                            Stream.GetCurrentBitNo() - IndexOffsetRecordBitPos);
2258 
2259     // Delta encode the index.
2260     uint64_t PreviousValue = IndexOffsetRecordBitPos;
2261     for (auto &Elt : IndexPos) {
2262       auto EltDelta = Elt - PreviousValue;
2263       PreviousValue = Elt;
2264       Elt = EltDelta;
2265     }
2266     // Emit the index record.
2267     Stream.EmitRecord(bitc::METADATA_INDEX, IndexPos, IndexAbbrev);
2268     IndexPos.clear();
2269   }
2270 
2271   // Write the named metadata now.
2272   writeNamedMetadata(Record);
2273 
2274   auto AddDeclAttachedMetadata = [&](const GlobalObject &GO) {
2275     SmallVector<uint64_t, 4> Record;
2276     Record.push_back(VE.getValueID(&GO));
2277     pushGlobalMetadataAttachment(Record, GO);
2278     Stream.EmitRecord(bitc::METADATA_GLOBAL_DECL_ATTACHMENT, Record);
2279   };
2280   for (const Function &F : M)
2281     if (F.isDeclaration() && F.hasMetadata())
2282       AddDeclAttachedMetadata(F);
2283   // FIXME: Only store metadata for declarations here, and move data for global
2284   // variable definitions to a separate block (PR28134).
2285   for (const GlobalVariable &GV : M.globals())
2286     if (GV.hasMetadata())
2287       AddDeclAttachedMetadata(GV);
2288 
2289   Stream.ExitBlock();
2290 }
2291 
2292 void ModuleBitcodeWriter::writeFunctionMetadata(const Function &F) {
2293   if (!VE.hasMDs())
2294     return;
2295 
2296   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
2297   SmallVector<uint64_t, 64> Record;
2298   writeMetadataStrings(VE.getMDStrings(), Record);
2299   writeMetadataRecords(VE.getNonMDStrings(), Record);
2300   Stream.ExitBlock();
2301 }
2302 
2303 void ModuleBitcodeWriter::pushGlobalMetadataAttachment(
2304     SmallVectorImpl<uint64_t> &Record, const GlobalObject &GO) {
2305   // [n x [id, mdnode]]
2306   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
2307   GO.getAllMetadata(MDs);
2308   for (const auto &I : MDs) {
2309     Record.push_back(I.first);
2310     Record.push_back(VE.getMetadataID(I.second));
2311   }
2312 }
2313 
2314 void ModuleBitcodeWriter::writeFunctionMetadataAttachment(const Function &F) {
2315   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
2316 
2317   SmallVector<uint64_t, 64> Record;
2318 
2319   if (F.hasMetadata()) {
2320     pushGlobalMetadataAttachment(Record, F);
2321     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
2322     Record.clear();
2323   }
2324 
2325   // Write metadata attachments
2326   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
2327   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
2328   for (const BasicBlock &BB : F)
2329     for (const Instruction &I : BB) {
2330       MDs.clear();
2331       I.getAllMetadataOtherThanDebugLoc(MDs);
2332 
2333       // If no metadata, ignore instruction.
2334       if (MDs.empty()) continue;
2335 
2336       Record.push_back(VE.getInstructionID(&I));
2337 
2338       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
2339         Record.push_back(MDs[i].first);
2340         Record.push_back(VE.getMetadataID(MDs[i].second));
2341       }
2342       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
2343       Record.clear();
2344     }
2345 
2346   Stream.ExitBlock();
2347 }
2348 
2349 void ModuleBitcodeWriter::writeModuleMetadataKinds() {
2350   SmallVector<uint64_t, 64> Record;
2351 
2352   // Write metadata kinds
2353   // METADATA_KIND - [n x [id, name]]
2354   SmallVector<StringRef, 8> Names;
2355   M.getMDKindNames(Names);
2356 
2357   if (Names.empty()) return;
2358 
2359   Stream.EnterSubblock(bitc::METADATA_KIND_BLOCK_ID, 3);
2360 
2361   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
2362     Record.push_back(MDKindID);
2363     StringRef KName = Names[MDKindID];
2364     Record.append(KName.begin(), KName.end());
2365 
2366     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
2367     Record.clear();
2368   }
2369 
2370   Stream.ExitBlock();
2371 }
2372 
2373 void ModuleBitcodeWriter::writeOperandBundleTags() {
2374   // Write metadata kinds
2375   //
2376   // OPERAND_BUNDLE_TAGS_BLOCK_ID : N x OPERAND_BUNDLE_TAG
2377   //
2378   // OPERAND_BUNDLE_TAG - [strchr x N]
2379 
2380   SmallVector<StringRef, 8> Tags;
2381   M.getOperandBundleTags(Tags);
2382 
2383   if (Tags.empty())
2384     return;
2385 
2386   Stream.EnterSubblock(bitc::OPERAND_BUNDLE_TAGS_BLOCK_ID, 3);
2387 
2388   SmallVector<uint64_t, 64> Record;
2389 
2390   for (auto Tag : Tags) {
2391     Record.append(Tag.begin(), Tag.end());
2392 
2393     Stream.EmitRecord(bitc::OPERAND_BUNDLE_TAG, Record, 0);
2394     Record.clear();
2395   }
2396 
2397   Stream.ExitBlock();
2398 }
2399 
2400 void ModuleBitcodeWriter::writeSyncScopeNames() {
2401   SmallVector<StringRef, 8> SSNs;
2402   M.getContext().getSyncScopeNames(SSNs);
2403   if (SSNs.empty())
2404     return;
2405 
2406   Stream.EnterSubblock(bitc::SYNC_SCOPE_NAMES_BLOCK_ID, 2);
2407 
2408   SmallVector<uint64_t, 64> Record;
2409   for (auto SSN : SSNs) {
2410     Record.append(SSN.begin(), SSN.end());
2411     Stream.EmitRecord(bitc::SYNC_SCOPE_NAME, Record, 0);
2412     Record.clear();
2413   }
2414 
2415   Stream.ExitBlock();
2416 }
2417 
2418 void ModuleBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
2419                                          bool isGlobal) {
2420   if (FirstVal == LastVal) return;
2421 
2422   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
2423 
2424   unsigned AggregateAbbrev = 0;
2425   unsigned String8Abbrev = 0;
2426   unsigned CString7Abbrev = 0;
2427   unsigned CString6Abbrev = 0;
2428   // If this is a constant pool for the module, emit module-specific abbrevs.
2429   if (isGlobal) {
2430     // Abbrev for CST_CODE_AGGREGATE.
2431     auto Abbv = std::make_shared<BitCodeAbbrev>();
2432     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
2433     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2434     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
2435     AggregateAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2436 
2437     // Abbrev for CST_CODE_STRING.
2438     Abbv = std::make_shared<BitCodeAbbrev>();
2439     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
2440     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2441     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2442     String8Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2443     // Abbrev for CST_CODE_CSTRING.
2444     Abbv = std::make_shared<BitCodeAbbrev>();
2445     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
2446     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2447     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2448     CString7Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2449     // Abbrev for CST_CODE_CSTRING.
2450     Abbv = std::make_shared<BitCodeAbbrev>();
2451     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
2452     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2453     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2454     CString6Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2455   }
2456 
2457   SmallVector<uint64_t, 64> Record;
2458 
2459   const ValueEnumerator::ValueList &Vals = VE.getValues();
2460   Type *LastTy = nullptr;
2461   for (unsigned i = FirstVal; i != LastVal; ++i) {
2462     const Value *V = Vals[i].first;
2463     // If we need to switch types, do so now.
2464     if (V->getType() != LastTy) {
2465       LastTy = V->getType();
2466       Record.push_back(VE.getTypeID(LastTy));
2467       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
2468                         CONSTANTS_SETTYPE_ABBREV);
2469       Record.clear();
2470     }
2471 
2472     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
2473       Record.push_back(VE.getTypeID(IA->getFunctionType()));
2474       Record.push_back(
2475           unsigned(IA->hasSideEffects()) | unsigned(IA->isAlignStack()) << 1 |
2476           unsigned(IA->getDialect() & 1) << 2 | unsigned(IA->canThrow()) << 3);
2477 
2478       // Add the asm string.
2479       const std::string &AsmStr = IA->getAsmString();
2480       Record.push_back(AsmStr.size());
2481       Record.append(AsmStr.begin(), AsmStr.end());
2482 
2483       // Add the constraint string.
2484       const std::string &ConstraintStr = IA->getConstraintString();
2485       Record.push_back(ConstraintStr.size());
2486       Record.append(ConstraintStr.begin(), ConstraintStr.end());
2487       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
2488       Record.clear();
2489       continue;
2490     }
2491     const Constant *C = cast<Constant>(V);
2492     unsigned Code = -1U;
2493     unsigned AbbrevToUse = 0;
2494     if (C->isNullValue()) {
2495       Code = bitc::CST_CODE_NULL;
2496     } else if (isa<PoisonValue>(C)) {
2497       Code = bitc::CST_CODE_POISON;
2498     } else if (isa<UndefValue>(C)) {
2499       Code = bitc::CST_CODE_UNDEF;
2500     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
2501       if (IV->getBitWidth() <= 64) {
2502         uint64_t V = IV->getSExtValue();
2503         emitSignedInt64(Record, V);
2504         Code = bitc::CST_CODE_INTEGER;
2505         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
2506       } else {                             // Wide integers, > 64 bits in size.
2507         emitWideAPInt(Record, IV->getValue());
2508         Code = bitc::CST_CODE_WIDE_INTEGER;
2509       }
2510     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
2511       Code = bitc::CST_CODE_FLOAT;
2512       Type *Ty = CFP->getType();
2513       if (Ty->isHalfTy() || Ty->isBFloatTy() || Ty->isFloatTy() ||
2514           Ty->isDoubleTy()) {
2515         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
2516       } else if (Ty->isX86_FP80Ty()) {
2517         // api needed to prevent premature destruction
2518         // bits are not in the same order as a normal i80 APInt, compensate.
2519         APInt api = CFP->getValueAPF().bitcastToAPInt();
2520         const uint64_t *p = api.getRawData();
2521         Record.push_back((p[1] << 48) | (p[0] >> 16));
2522         Record.push_back(p[0] & 0xffffLL);
2523       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
2524         APInt api = CFP->getValueAPF().bitcastToAPInt();
2525         const uint64_t *p = api.getRawData();
2526         Record.push_back(p[0]);
2527         Record.push_back(p[1]);
2528       } else {
2529         assert(0 && "Unknown FP type!");
2530       }
2531     } else if (isa<ConstantDataSequential>(C) &&
2532                cast<ConstantDataSequential>(C)->isString()) {
2533       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
2534       // Emit constant strings specially.
2535       unsigned NumElts = Str->getNumElements();
2536       // If this is a null-terminated string, use the denser CSTRING encoding.
2537       if (Str->isCString()) {
2538         Code = bitc::CST_CODE_CSTRING;
2539         --NumElts;  // Don't encode the null, which isn't allowed by char6.
2540       } else {
2541         Code = bitc::CST_CODE_STRING;
2542         AbbrevToUse = String8Abbrev;
2543       }
2544       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
2545       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
2546       for (unsigned i = 0; i != NumElts; ++i) {
2547         unsigned char V = Str->getElementAsInteger(i);
2548         Record.push_back(V);
2549         isCStr7 &= (V & 128) == 0;
2550         if (isCStrChar6)
2551           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
2552       }
2553 
2554       if (isCStrChar6)
2555         AbbrevToUse = CString6Abbrev;
2556       else if (isCStr7)
2557         AbbrevToUse = CString7Abbrev;
2558     } else if (const ConstantDataSequential *CDS =
2559                   dyn_cast<ConstantDataSequential>(C)) {
2560       Code = bitc::CST_CODE_DATA;
2561       Type *EltTy = CDS->getElementType();
2562       if (isa<IntegerType>(EltTy)) {
2563         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2564           Record.push_back(CDS->getElementAsInteger(i));
2565       } else {
2566         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2567           Record.push_back(
2568               CDS->getElementAsAPFloat(i).bitcastToAPInt().getLimitedValue());
2569       }
2570     } else if (isa<ConstantAggregate>(C)) {
2571       Code = bitc::CST_CODE_AGGREGATE;
2572       for (const Value *Op : C->operands())
2573         Record.push_back(VE.getValueID(Op));
2574       AbbrevToUse = AggregateAbbrev;
2575     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
2576       switch (CE->getOpcode()) {
2577       default:
2578         if (Instruction::isCast(CE->getOpcode())) {
2579           Code = bitc::CST_CODE_CE_CAST;
2580           Record.push_back(getEncodedCastOpcode(CE->getOpcode()));
2581           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2582           Record.push_back(VE.getValueID(C->getOperand(0)));
2583           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
2584         } else {
2585           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
2586           Code = bitc::CST_CODE_CE_BINOP;
2587           Record.push_back(getEncodedBinaryOpcode(CE->getOpcode()));
2588           Record.push_back(VE.getValueID(C->getOperand(0)));
2589           Record.push_back(VE.getValueID(C->getOperand(1)));
2590           uint64_t Flags = getOptimizationFlags(CE);
2591           if (Flags != 0)
2592             Record.push_back(Flags);
2593         }
2594         break;
2595       case Instruction::FNeg: {
2596         assert(CE->getNumOperands() == 1 && "Unknown constant expr!");
2597         Code = bitc::CST_CODE_CE_UNOP;
2598         Record.push_back(getEncodedUnaryOpcode(CE->getOpcode()));
2599         Record.push_back(VE.getValueID(C->getOperand(0)));
2600         uint64_t Flags = getOptimizationFlags(CE);
2601         if (Flags != 0)
2602           Record.push_back(Flags);
2603         break;
2604       }
2605       case Instruction::GetElementPtr: {
2606         Code = bitc::CST_CODE_CE_GEP;
2607         const auto *GO = cast<GEPOperator>(C);
2608         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
2609         if (Optional<unsigned> Idx = GO->getInRangeIndex()) {
2610           Code = bitc::CST_CODE_CE_GEP_WITH_INRANGE_INDEX;
2611           Record.push_back((*Idx << 1) | GO->isInBounds());
2612         } else if (GO->isInBounds())
2613           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
2614         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
2615           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
2616           Record.push_back(VE.getValueID(C->getOperand(i)));
2617         }
2618         break;
2619       }
2620       case Instruction::Select:
2621         Code = bitc::CST_CODE_CE_SELECT;
2622         Record.push_back(VE.getValueID(C->getOperand(0)));
2623         Record.push_back(VE.getValueID(C->getOperand(1)));
2624         Record.push_back(VE.getValueID(C->getOperand(2)));
2625         break;
2626       case Instruction::ExtractElement:
2627         Code = bitc::CST_CODE_CE_EXTRACTELT;
2628         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2629         Record.push_back(VE.getValueID(C->getOperand(0)));
2630         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
2631         Record.push_back(VE.getValueID(C->getOperand(1)));
2632         break;
2633       case Instruction::InsertElement:
2634         Code = bitc::CST_CODE_CE_INSERTELT;
2635         Record.push_back(VE.getValueID(C->getOperand(0)));
2636         Record.push_back(VE.getValueID(C->getOperand(1)));
2637         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
2638         Record.push_back(VE.getValueID(C->getOperand(2)));
2639         break;
2640       case Instruction::ShuffleVector:
2641         // If the return type and argument types are the same, this is a
2642         // standard shufflevector instruction.  If the types are different,
2643         // then the shuffle is widening or truncating the input vectors, and
2644         // the argument type must also be encoded.
2645         if (C->getType() == C->getOperand(0)->getType()) {
2646           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
2647         } else {
2648           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
2649           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2650         }
2651         Record.push_back(VE.getValueID(C->getOperand(0)));
2652         Record.push_back(VE.getValueID(C->getOperand(1)));
2653         Record.push_back(VE.getValueID(CE->getShuffleMaskForBitcode()));
2654         break;
2655       case Instruction::ICmp:
2656       case Instruction::FCmp:
2657         Code = bitc::CST_CODE_CE_CMP;
2658         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2659         Record.push_back(VE.getValueID(C->getOperand(0)));
2660         Record.push_back(VE.getValueID(C->getOperand(1)));
2661         Record.push_back(CE->getPredicate());
2662         break;
2663       case Instruction::ExtractValue:
2664       case Instruction::InsertValue:
2665         report_fatal_error("extractvalue/insertvalue constexprs not supported");
2666         break;
2667       }
2668     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
2669       Code = bitc::CST_CODE_BLOCKADDRESS;
2670       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
2671       Record.push_back(VE.getValueID(BA->getFunction()));
2672       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
2673     } else if (const auto *Equiv = dyn_cast<DSOLocalEquivalent>(C)) {
2674       Code = bitc::CST_CODE_DSO_LOCAL_EQUIVALENT;
2675       Record.push_back(VE.getTypeID(Equiv->getGlobalValue()->getType()));
2676       Record.push_back(VE.getValueID(Equiv->getGlobalValue()));
2677     } else if (const auto *NC = dyn_cast<NoCFIValue>(C)) {
2678       Code = bitc::CST_CODE_NO_CFI_VALUE;
2679       Record.push_back(VE.getTypeID(NC->getGlobalValue()->getType()));
2680       Record.push_back(VE.getValueID(NC->getGlobalValue()));
2681     } else {
2682 #ifndef NDEBUG
2683       C->dump();
2684 #endif
2685       llvm_unreachable("Unknown constant!");
2686     }
2687     Stream.EmitRecord(Code, Record, AbbrevToUse);
2688     Record.clear();
2689   }
2690 
2691   Stream.ExitBlock();
2692 }
2693 
2694 void ModuleBitcodeWriter::writeModuleConstants() {
2695   const ValueEnumerator::ValueList &Vals = VE.getValues();
2696 
2697   // Find the first constant to emit, which is the first non-globalvalue value.
2698   // We know globalvalues have been emitted by WriteModuleInfo.
2699   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
2700     if (!isa<GlobalValue>(Vals[i].first)) {
2701       writeConstants(i, Vals.size(), true);
2702       return;
2703     }
2704   }
2705 }
2706 
2707 /// pushValueAndType - The file has to encode both the value and type id for
2708 /// many values, because we need to know what type to create for forward
2709 /// references.  However, most operands are not forward references, so this type
2710 /// field is not needed.
2711 ///
2712 /// This function adds V's value ID to Vals.  If the value ID is higher than the
2713 /// instruction ID, then it is a forward reference, and it also includes the
2714 /// type ID.  The value ID that is written is encoded relative to the InstID.
2715 bool ModuleBitcodeWriter::pushValueAndType(const Value *V, unsigned InstID,
2716                                            SmallVectorImpl<unsigned> &Vals) {
2717   unsigned ValID = VE.getValueID(V);
2718   // Make encoding relative to the InstID.
2719   Vals.push_back(InstID - ValID);
2720   if (ValID >= InstID) {
2721     Vals.push_back(VE.getTypeID(V->getType()));
2722     return true;
2723   }
2724   return false;
2725 }
2726 
2727 void ModuleBitcodeWriter::writeOperandBundles(const CallBase &CS,
2728                                               unsigned InstID) {
2729   SmallVector<unsigned, 64> Record;
2730   LLVMContext &C = CS.getContext();
2731 
2732   for (unsigned i = 0, e = CS.getNumOperandBundles(); i != e; ++i) {
2733     const auto &Bundle = CS.getOperandBundleAt(i);
2734     Record.push_back(C.getOperandBundleTagID(Bundle.getTagName()));
2735 
2736     for (auto &Input : Bundle.Inputs)
2737       pushValueAndType(Input, InstID, Record);
2738 
2739     Stream.EmitRecord(bitc::FUNC_CODE_OPERAND_BUNDLE, Record);
2740     Record.clear();
2741   }
2742 }
2743 
2744 /// pushValue - Like pushValueAndType, but where the type of the value is
2745 /// omitted (perhaps it was already encoded in an earlier operand).
2746 void ModuleBitcodeWriter::pushValue(const Value *V, unsigned InstID,
2747                                     SmallVectorImpl<unsigned> &Vals) {
2748   unsigned ValID = VE.getValueID(V);
2749   Vals.push_back(InstID - ValID);
2750 }
2751 
2752 void ModuleBitcodeWriter::pushValueSigned(const Value *V, unsigned InstID,
2753                                           SmallVectorImpl<uint64_t> &Vals) {
2754   unsigned ValID = VE.getValueID(V);
2755   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
2756   emitSignedInt64(Vals, diff);
2757 }
2758 
2759 /// WriteInstruction - Emit an instruction to the specified stream.
2760 void ModuleBitcodeWriter::writeInstruction(const Instruction &I,
2761                                            unsigned InstID,
2762                                            SmallVectorImpl<unsigned> &Vals) {
2763   unsigned Code = 0;
2764   unsigned AbbrevToUse = 0;
2765   VE.setInstructionID(&I);
2766   switch (I.getOpcode()) {
2767   default:
2768     if (Instruction::isCast(I.getOpcode())) {
2769       Code = bitc::FUNC_CODE_INST_CAST;
2770       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2771         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
2772       Vals.push_back(VE.getTypeID(I.getType()));
2773       Vals.push_back(getEncodedCastOpcode(I.getOpcode()));
2774     } else {
2775       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
2776       Code = bitc::FUNC_CODE_INST_BINOP;
2777       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2778         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
2779       pushValue(I.getOperand(1), InstID, Vals);
2780       Vals.push_back(getEncodedBinaryOpcode(I.getOpcode()));
2781       uint64_t Flags = getOptimizationFlags(&I);
2782       if (Flags != 0) {
2783         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
2784           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
2785         Vals.push_back(Flags);
2786       }
2787     }
2788     break;
2789   case Instruction::FNeg: {
2790     Code = bitc::FUNC_CODE_INST_UNOP;
2791     if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2792       AbbrevToUse = FUNCTION_INST_UNOP_ABBREV;
2793     Vals.push_back(getEncodedUnaryOpcode(I.getOpcode()));
2794     uint64_t Flags = getOptimizationFlags(&I);
2795     if (Flags != 0) {
2796       if (AbbrevToUse == FUNCTION_INST_UNOP_ABBREV)
2797         AbbrevToUse = FUNCTION_INST_UNOP_FLAGS_ABBREV;
2798       Vals.push_back(Flags);
2799     }
2800     break;
2801   }
2802   case Instruction::GetElementPtr: {
2803     Code = bitc::FUNC_CODE_INST_GEP;
2804     AbbrevToUse = FUNCTION_INST_GEP_ABBREV;
2805     auto &GEPInst = cast<GetElementPtrInst>(I);
2806     Vals.push_back(GEPInst.isInBounds());
2807     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
2808     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
2809       pushValueAndType(I.getOperand(i), InstID, Vals);
2810     break;
2811   }
2812   case Instruction::ExtractValue: {
2813     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
2814     pushValueAndType(I.getOperand(0), InstID, Vals);
2815     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
2816     Vals.append(EVI->idx_begin(), EVI->idx_end());
2817     break;
2818   }
2819   case Instruction::InsertValue: {
2820     Code = bitc::FUNC_CODE_INST_INSERTVAL;
2821     pushValueAndType(I.getOperand(0), InstID, Vals);
2822     pushValueAndType(I.getOperand(1), InstID, Vals);
2823     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
2824     Vals.append(IVI->idx_begin(), IVI->idx_end());
2825     break;
2826   }
2827   case Instruction::Select: {
2828     Code = bitc::FUNC_CODE_INST_VSELECT;
2829     pushValueAndType(I.getOperand(1), InstID, Vals);
2830     pushValue(I.getOperand(2), InstID, Vals);
2831     pushValueAndType(I.getOperand(0), InstID, Vals);
2832     uint64_t Flags = getOptimizationFlags(&I);
2833     if (Flags != 0)
2834       Vals.push_back(Flags);
2835     break;
2836   }
2837   case Instruction::ExtractElement:
2838     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
2839     pushValueAndType(I.getOperand(0), InstID, Vals);
2840     pushValueAndType(I.getOperand(1), InstID, Vals);
2841     break;
2842   case Instruction::InsertElement:
2843     Code = bitc::FUNC_CODE_INST_INSERTELT;
2844     pushValueAndType(I.getOperand(0), InstID, Vals);
2845     pushValue(I.getOperand(1), InstID, Vals);
2846     pushValueAndType(I.getOperand(2), InstID, Vals);
2847     break;
2848   case Instruction::ShuffleVector:
2849     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
2850     pushValueAndType(I.getOperand(0), InstID, Vals);
2851     pushValue(I.getOperand(1), InstID, Vals);
2852     pushValue(cast<ShuffleVectorInst>(I).getShuffleMaskForBitcode(), InstID,
2853               Vals);
2854     break;
2855   case Instruction::ICmp:
2856   case Instruction::FCmp: {
2857     // compare returning Int1Ty or vector of Int1Ty
2858     Code = bitc::FUNC_CODE_INST_CMP2;
2859     pushValueAndType(I.getOperand(0), InstID, Vals);
2860     pushValue(I.getOperand(1), InstID, Vals);
2861     Vals.push_back(cast<CmpInst>(I).getPredicate());
2862     uint64_t Flags = getOptimizationFlags(&I);
2863     if (Flags != 0)
2864       Vals.push_back(Flags);
2865     break;
2866   }
2867 
2868   case Instruction::Ret:
2869     {
2870       Code = bitc::FUNC_CODE_INST_RET;
2871       unsigned NumOperands = I.getNumOperands();
2872       if (NumOperands == 0)
2873         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
2874       else if (NumOperands == 1) {
2875         if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2876           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
2877       } else {
2878         for (unsigned i = 0, e = NumOperands; i != e; ++i)
2879           pushValueAndType(I.getOperand(i), InstID, Vals);
2880       }
2881     }
2882     break;
2883   case Instruction::Br:
2884     {
2885       Code = bitc::FUNC_CODE_INST_BR;
2886       const BranchInst &II = cast<BranchInst>(I);
2887       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
2888       if (II.isConditional()) {
2889         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
2890         pushValue(II.getCondition(), InstID, Vals);
2891       }
2892     }
2893     break;
2894   case Instruction::Switch:
2895     {
2896       Code = bitc::FUNC_CODE_INST_SWITCH;
2897       const SwitchInst &SI = cast<SwitchInst>(I);
2898       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
2899       pushValue(SI.getCondition(), InstID, Vals);
2900       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
2901       for (auto Case : SI.cases()) {
2902         Vals.push_back(VE.getValueID(Case.getCaseValue()));
2903         Vals.push_back(VE.getValueID(Case.getCaseSuccessor()));
2904       }
2905     }
2906     break;
2907   case Instruction::IndirectBr:
2908     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
2909     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
2910     // Encode the address operand as relative, but not the basic blocks.
2911     pushValue(I.getOperand(0), InstID, Vals);
2912     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
2913       Vals.push_back(VE.getValueID(I.getOperand(i)));
2914     break;
2915 
2916   case Instruction::Invoke: {
2917     const InvokeInst *II = cast<InvokeInst>(&I);
2918     const Value *Callee = II->getCalledOperand();
2919     FunctionType *FTy = II->getFunctionType();
2920 
2921     if (II->hasOperandBundles())
2922       writeOperandBundles(*II, InstID);
2923 
2924     Code = bitc::FUNC_CODE_INST_INVOKE;
2925 
2926     Vals.push_back(VE.getAttributeListID(II->getAttributes()));
2927     Vals.push_back(II->getCallingConv() | 1 << 13);
2928     Vals.push_back(VE.getValueID(II->getNormalDest()));
2929     Vals.push_back(VE.getValueID(II->getUnwindDest()));
2930     Vals.push_back(VE.getTypeID(FTy));
2931     pushValueAndType(Callee, InstID, Vals);
2932 
2933     // Emit value #'s for the fixed parameters.
2934     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
2935       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
2936 
2937     // Emit type/value pairs for varargs params.
2938     if (FTy->isVarArg()) {
2939       for (unsigned i = FTy->getNumParams(), e = II->arg_size(); i != e; ++i)
2940         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
2941     }
2942     break;
2943   }
2944   case Instruction::Resume:
2945     Code = bitc::FUNC_CODE_INST_RESUME;
2946     pushValueAndType(I.getOperand(0), InstID, Vals);
2947     break;
2948   case Instruction::CleanupRet: {
2949     Code = bitc::FUNC_CODE_INST_CLEANUPRET;
2950     const auto &CRI = cast<CleanupReturnInst>(I);
2951     pushValue(CRI.getCleanupPad(), InstID, Vals);
2952     if (CRI.hasUnwindDest())
2953       Vals.push_back(VE.getValueID(CRI.getUnwindDest()));
2954     break;
2955   }
2956   case Instruction::CatchRet: {
2957     Code = bitc::FUNC_CODE_INST_CATCHRET;
2958     const auto &CRI = cast<CatchReturnInst>(I);
2959     pushValue(CRI.getCatchPad(), InstID, Vals);
2960     Vals.push_back(VE.getValueID(CRI.getSuccessor()));
2961     break;
2962   }
2963   case Instruction::CleanupPad:
2964   case Instruction::CatchPad: {
2965     const auto &FuncletPad = cast<FuncletPadInst>(I);
2966     Code = isa<CatchPadInst>(FuncletPad) ? bitc::FUNC_CODE_INST_CATCHPAD
2967                                          : bitc::FUNC_CODE_INST_CLEANUPPAD;
2968     pushValue(FuncletPad.getParentPad(), InstID, Vals);
2969 
2970     unsigned NumArgOperands = FuncletPad.getNumArgOperands();
2971     Vals.push_back(NumArgOperands);
2972     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
2973       pushValueAndType(FuncletPad.getArgOperand(Op), InstID, Vals);
2974     break;
2975   }
2976   case Instruction::CatchSwitch: {
2977     Code = bitc::FUNC_CODE_INST_CATCHSWITCH;
2978     const auto &CatchSwitch = cast<CatchSwitchInst>(I);
2979 
2980     pushValue(CatchSwitch.getParentPad(), InstID, Vals);
2981 
2982     unsigned NumHandlers = CatchSwitch.getNumHandlers();
2983     Vals.push_back(NumHandlers);
2984     for (const BasicBlock *CatchPadBB : CatchSwitch.handlers())
2985       Vals.push_back(VE.getValueID(CatchPadBB));
2986 
2987     if (CatchSwitch.hasUnwindDest())
2988       Vals.push_back(VE.getValueID(CatchSwitch.getUnwindDest()));
2989     break;
2990   }
2991   case Instruction::CallBr: {
2992     const CallBrInst *CBI = cast<CallBrInst>(&I);
2993     const Value *Callee = CBI->getCalledOperand();
2994     FunctionType *FTy = CBI->getFunctionType();
2995 
2996     if (CBI->hasOperandBundles())
2997       writeOperandBundles(*CBI, InstID);
2998 
2999     Code = bitc::FUNC_CODE_INST_CALLBR;
3000 
3001     Vals.push_back(VE.getAttributeListID(CBI->getAttributes()));
3002 
3003     Vals.push_back(CBI->getCallingConv() << bitc::CALL_CCONV |
3004                    1 << bitc::CALL_EXPLICIT_TYPE);
3005 
3006     Vals.push_back(VE.getValueID(CBI->getDefaultDest()));
3007     Vals.push_back(CBI->getNumIndirectDests());
3008     for (unsigned i = 0, e = CBI->getNumIndirectDests(); i != e; ++i)
3009       Vals.push_back(VE.getValueID(CBI->getIndirectDest(i)));
3010 
3011     Vals.push_back(VE.getTypeID(FTy));
3012     pushValueAndType(Callee, InstID, Vals);
3013 
3014     // Emit value #'s for the fixed parameters.
3015     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
3016       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
3017 
3018     // Emit type/value pairs for varargs params.
3019     if (FTy->isVarArg()) {
3020       for (unsigned i = FTy->getNumParams(), e = CBI->arg_size(); i != e; ++i)
3021         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
3022     }
3023     break;
3024   }
3025   case Instruction::Unreachable:
3026     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
3027     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
3028     break;
3029 
3030   case Instruction::PHI: {
3031     const PHINode &PN = cast<PHINode>(I);
3032     Code = bitc::FUNC_CODE_INST_PHI;
3033     // With the newer instruction encoding, forward references could give
3034     // negative valued IDs.  This is most common for PHIs, so we use
3035     // signed VBRs.
3036     SmallVector<uint64_t, 128> Vals64;
3037     Vals64.push_back(VE.getTypeID(PN.getType()));
3038     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
3039       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64);
3040       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
3041     }
3042 
3043     uint64_t Flags = getOptimizationFlags(&I);
3044     if (Flags != 0)
3045       Vals64.push_back(Flags);
3046 
3047     // Emit a Vals64 vector and exit.
3048     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
3049     Vals64.clear();
3050     return;
3051   }
3052 
3053   case Instruction::LandingPad: {
3054     const LandingPadInst &LP = cast<LandingPadInst>(I);
3055     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
3056     Vals.push_back(VE.getTypeID(LP.getType()));
3057     Vals.push_back(LP.isCleanup());
3058     Vals.push_back(LP.getNumClauses());
3059     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
3060       if (LP.isCatch(I))
3061         Vals.push_back(LandingPadInst::Catch);
3062       else
3063         Vals.push_back(LandingPadInst::Filter);
3064       pushValueAndType(LP.getClause(I), InstID, Vals);
3065     }
3066     break;
3067   }
3068 
3069   case Instruction::Alloca: {
3070     Code = bitc::FUNC_CODE_INST_ALLOCA;
3071     const AllocaInst &AI = cast<AllocaInst>(I);
3072     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
3073     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
3074     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
3075     using APV = AllocaPackedValues;
3076     unsigned Record = 0;
3077     unsigned EncodedAlign = getEncodedAlign(AI.getAlign());
3078     Bitfield::set<APV::AlignLower>(
3079         Record, EncodedAlign & ((1 << APV::AlignLower::Bits) - 1));
3080     Bitfield::set<APV::AlignUpper>(Record,
3081                                    EncodedAlign >> APV::AlignLower::Bits);
3082     Bitfield::set<APV::UsedWithInAlloca>(Record, AI.isUsedWithInAlloca());
3083     Bitfield::set<APV::ExplicitType>(Record, true);
3084     Bitfield::set<APV::SwiftError>(Record, AI.isSwiftError());
3085     Vals.push_back(Record);
3086 
3087     unsigned AS = AI.getAddressSpace();
3088     if (AS != M.getDataLayout().getAllocaAddrSpace())
3089       Vals.push_back(AS);
3090     break;
3091   }
3092 
3093   case Instruction::Load:
3094     if (cast<LoadInst>(I).isAtomic()) {
3095       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
3096       pushValueAndType(I.getOperand(0), InstID, Vals);
3097     } else {
3098       Code = bitc::FUNC_CODE_INST_LOAD;
3099       if (!pushValueAndType(I.getOperand(0), InstID, Vals)) // ptr
3100         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
3101     }
3102     Vals.push_back(VE.getTypeID(I.getType()));
3103     Vals.push_back(getEncodedAlign(cast<LoadInst>(I).getAlign()));
3104     Vals.push_back(cast<LoadInst>(I).isVolatile());
3105     if (cast<LoadInst>(I).isAtomic()) {
3106       Vals.push_back(getEncodedOrdering(cast<LoadInst>(I).getOrdering()));
3107       Vals.push_back(getEncodedSyncScopeID(cast<LoadInst>(I).getSyncScopeID()));
3108     }
3109     break;
3110   case Instruction::Store:
3111     if (cast<StoreInst>(I).isAtomic())
3112       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
3113     else
3114       Code = bitc::FUNC_CODE_INST_STORE;
3115     pushValueAndType(I.getOperand(1), InstID, Vals); // ptrty + ptr
3116     pushValueAndType(I.getOperand(0), InstID, Vals); // valty + val
3117     Vals.push_back(getEncodedAlign(cast<StoreInst>(I).getAlign()));
3118     Vals.push_back(cast<StoreInst>(I).isVolatile());
3119     if (cast<StoreInst>(I).isAtomic()) {
3120       Vals.push_back(getEncodedOrdering(cast<StoreInst>(I).getOrdering()));
3121       Vals.push_back(
3122           getEncodedSyncScopeID(cast<StoreInst>(I).getSyncScopeID()));
3123     }
3124     break;
3125   case Instruction::AtomicCmpXchg:
3126     Code = bitc::FUNC_CODE_INST_CMPXCHG;
3127     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
3128     pushValueAndType(I.getOperand(1), InstID, Vals); // cmp.
3129     pushValue(I.getOperand(2), InstID, Vals);        // newval.
3130     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
3131     Vals.push_back(
3132         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
3133     Vals.push_back(
3134         getEncodedSyncScopeID(cast<AtomicCmpXchgInst>(I).getSyncScopeID()));
3135     Vals.push_back(
3136         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
3137     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
3138     Vals.push_back(getEncodedAlign(cast<AtomicCmpXchgInst>(I).getAlign()));
3139     break;
3140   case Instruction::AtomicRMW:
3141     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
3142     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
3143     pushValueAndType(I.getOperand(1), InstID, Vals); // valty + val
3144     Vals.push_back(
3145         getEncodedRMWOperation(cast<AtomicRMWInst>(I).getOperation()));
3146     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
3147     Vals.push_back(getEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
3148     Vals.push_back(
3149         getEncodedSyncScopeID(cast<AtomicRMWInst>(I).getSyncScopeID()));
3150     Vals.push_back(getEncodedAlign(cast<AtomicRMWInst>(I).getAlign()));
3151     break;
3152   case Instruction::Fence:
3153     Code = bitc::FUNC_CODE_INST_FENCE;
3154     Vals.push_back(getEncodedOrdering(cast<FenceInst>(I).getOrdering()));
3155     Vals.push_back(getEncodedSyncScopeID(cast<FenceInst>(I).getSyncScopeID()));
3156     break;
3157   case Instruction::Call: {
3158     const CallInst &CI = cast<CallInst>(I);
3159     FunctionType *FTy = CI.getFunctionType();
3160 
3161     if (CI.hasOperandBundles())
3162       writeOperandBundles(CI, InstID);
3163 
3164     Code = bitc::FUNC_CODE_INST_CALL;
3165 
3166     Vals.push_back(VE.getAttributeListID(CI.getAttributes()));
3167 
3168     unsigned Flags = getOptimizationFlags(&I);
3169     Vals.push_back(CI.getCallingConv() << bitc::CALL_CCONV |
3170                    unsigned(CI.isTailCall()) << bitc::CALL_TAIL |
3171                    unsigned(CI.isMustTailCall()) << bitc::CALL_MUSTTAIL |
3172                    1 << bitc::CALL_EXPLICIT_TYPE |
3173                    unsigned(CI.isNoTailCall()) << bitc::CALL_NOTAIL |
3174                    unsigned(Flags != 0) << bitc::CALL_FMF);
3175     if (Flags != 0)
3176       Vals.push_back(Flags);
3177 
3178     Vals.push_back(VE.getTypeID(FTy));
3179     pushValueAndType(CI.getCalledOperand(), InstID, Vals); // Callee
3180 
3181     // Emit value #'s for the fixed parameters.
3182     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
3183       // Check for labels (can happen with asm labels).
3184       if (FTy->getParamType(i)->isLabelTy())
3185         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
3186       else
3187         pushValue(CI.getArgOperand(i), InstID, Vals); // fixed param.
3188     }
3189 
3190     // Emit type/value pairs for varargs params.
3191     if (FTy->isVarArg()) {
3192       for (unsigned i = FTy->getNumParams(), e = CI.arg_size(); i != e; ++i)
3193         pushValueAndType(CI.getArgOperand(i), InstID, Vals); // varargs
3194     }
3195     break;
3196   }
3197   case Instruction::VAArg:
3198     Code = bitc::FUNC_CODE_INST_VAARG;
3199     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
3200     pushValue(I.getOperand(0), InstID, Vals);                   // valist.
3201     Vals.push_back(VE.getTypeID(I.getType())); // restype.
3202     break;
3203   case Instruction::Freeze:
3204     Code = bitc::FUNC_CODE_INST_FREEZE;
3205     pushValueAndType(I.getOperand(0), InstID, Vals);
3206     break;
3207   }
3208 
3209   Stream.EmitRecord(Code, Vals, AbbrevToUse);
3210   Vals.clear();
3211 }
3212 
3213 /// Write a GlobalValue VST to the module. The purpose of this data structure is
3214 /// to allow clients to efficiently find the function body.
3215 void ModuleBitcodeWriter::writeGlobalValueSymbolTable(
3216   DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex) {
3217   // Get the offset of the VST we are writing, and backpatch it into
3218   // the VST forward declaration record.
3219   uint64_t VSTOffset = Stream.GetCurrentBitNo();
3220   // The BitcodeStartBit was the stream offset of the identification block.
3221   VSTOffset -= bitcodeStartBit();
3222   assert((VSTOffset & 31) == 0 && "VST block not 32-bit aligned");
3223   // Note that we add 1 here because the offset is relative to one word
3224   // before the start of the identification block, which was historically
3225   // always the start of the regular bitcode header.
3226   Stream.BackpatchWord(VSTOffsetPlaceholder, VSTOffset / 32 + 1);
3227 
3228   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
3229 
3230   auto Abbv = std::make_shared<BitCodeAbbrev>();
3231   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
3232   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
3233   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
3234   unsigned FnEntryAbbrev = Stream.EmitAbbrev(std::move(Abbv));
3235 
3236   for (const Function &F : M) {
3237     uint64_t Record[2];
3238 
3239     if (F.isDeclaration())
3240       continue;
3241 
3242     Record[0] = VE.getValueID(&F);
3243 
3244     // Save the word offset of the function (from the start of the
3245     // actual bitcode written to the stream).
3246     uint64_t BitcodeIndex = FunctionToBitcodeIndex[&F] - bitcodeStartBit();
3247     assert((BitcodeIndex & 31) == 0 && "function block not 32-bit aligned");
3248     // Note that we add 1 here because the offset is relative to one word
3249     // before the start of the identification block, which was historically
3250     // always the start of the regular bitcode header.
3251     Record[1] = BitcodeIndex / 32 + 1;
3252 
3253     Stream.EmitRecord(bitc::VST_CODE_FNENTRY, Record, FnEntryAbbrev);
3254   }
3255 
3256   Stream.ExitBlock();
3257 }
3258 
3259 /// Emit names for arguments, instructions and basic blocks in a function.
3260 void ModuleBitcodeWriter::writeFunctionLevelValueSymbolTable(
3261     const ValueSymbolTable &VST) {
3262   if (VST.empty())
3263     return;
3264 
3265   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
3266 
3267   // FIXME: Set up the abbrev, we know how many values there are!
3268   // FIXME: We know if the type names can use 7-bit ascii.
3269   SmallVector<uint64_t, 64> NameVals;
3270 
3271   for (const ValueName &Name : VST) {
3272     // Figure out the encoding to use for the name.
3273     StringEncoding Bits = getStringEncoding(Name.getKey());
3274 
3275     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
3276     NameVals.push_back(VE.getValueID(Name.getValue()));
3277 
3278     // VST_CODE_ENTRY:   [valueid, namechar x N]
3279     // VST_CODE_BBENTRY: [bbid, namechar x N]
3280     unsigned Code;
3281     if (isa<BasicBlock>(Name.getValue())) {
3282       Code = bitc::VST_CODE_BBENTRY;
3283       if (Bits == SE_Char6)
3284         AbbrevToUse = VST_BBENTRY_6_ABBREV;
3285     } else {
3286       Code = bitc::VST_CODE_ENTRY;
3287       if (Bits == SE_Char6)
3288         AbbrevToUse = VST_ENTRY_6_ABBREV;
3289       else if (Bits == SE_Fixed7)
3290         AbbrevToUse = VST_ENTRY_7_ABBREV;
3291     }
3292 
3293     for (const auto P : Name.getKey())
3294       NameVals.push_back((unsigned char)P);
3295 
3296     // Emit the finished record.
3297     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
3298     NameVals.clear();
3299   }
3300 
3301   Stream.ExitBlock();
3302 }
3303 
3304 void ModuleBitcodeWriter::writeUseList(UseListOrder &&Order) {
3305   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
3306   unsigned Code;
3307   if (isa<BasicBlock>(Order.V))
3308     Code = bitc::USELIST_CODE_BB;
3309   else
3310     Code = bitc::USELIST_CODE_DEFAULT;
3311 
3312   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
3313   Record.push_back(VE.getValueID(Order.V));
3314   Stream.EmitRecord(Code, Record);
3315 }
3316 
3317 void ModuleBitcodeWriter::writeUseListBlock(const Function *F) {
3318   assert(VE.shouldPreserveUseListOrder() &&
3319          "Expected to be preserving use-list order");
3320 
3321   auto hasMore = [&]() {
3322     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
3323   };
3324   if (!hasMore())
3325     // Nothing to do.
3326     return;
3327 
3328   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
3329   while (hasMore()) {
3330     writeUseList(std::move(VE.UseListOrders.back()));
3331     VE.UseListOrders.pop_back();
3332   }
3333   Stream.ExitBlock();
3334 }
3335 
3336 /// Emit a function body to the module stream.
3337 void ModuleBitcodeWriter::writeFunction(
3338     const Function &F,
3339     DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex) {
3340   // Save the bitcode index of the start of this function block for recording
3341   // in the VST.
3342   FunctionToBitcodeIndex[&F] = Stream.GetCurrentBitNo();
3343 
3344   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
3345   VE.incorporateFunction(F);
3346 
3347   SmallVector<unsigned, 64> Vals;
3348 
3349   // Emit the number of basic blocks, so the reader can create them ahead of
3350   // time.
3351   Vals.push_back(VE.getBasicBlocks().size());
3352   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
3353   Vals.clear();
3354 
3355   // If there are function-local constants, emit them now.
3356   unsigned CstStart, CstEnd;
3357   VE.getFunctionConstantRange(CstStart, CstEnd);
3358   writeConstants(CstStart, CstEnd, false);
3359 
3360   // If there is function-local metadata, emit it now.
3361   writeFunctionMetadata(F);
3362 
3363   // Keep a running idea of what the instruction ID is.
3364   unsigned InstID = CstEnd;
3365 
3366   bool NeedsMetadataAttachment = F.hasMetadata();
3367 
3368   DILocation *LastDL = nullptr;
3369   SmallSetVector<Function *, 4> BlockAddressUsers;
3370 
3371   // Finally, emit all the instructions, in order.
3372   for (const BasicBlock &BB : F) {
3373     for (const Instruction &I : BB) {
3374       writeInstruction(I, InstID, Vals);
3375 
3376       if (!I.getType()->isVoidTy())
3377         ++InstID;
3378 
3379       // If the instruction has metadata, write a metadata attachment later.
3380       NeedsMetadataAttachment |= I.hasMetadataOtherThanDebugLoc();
3381 
3382       // If the instruction has a debug location, emit it.
3383       DILocation *DL = I.getDebugLoc();
3384       if (!DL)
3385         continue;
3386 
3387       if (DL == LastDL) {
3388         // Just repeat the same debug loc as last time.
3389         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
3390         continue;
3391       }
3392 
3393       Vals.push_back(DL->getLine());
3394       Vals.push_back(DL->getColumn());
3395       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
3396       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
3397       Vals.push_back(DL->isImplicitCode());
3398       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
3399       Vals.clear();
3400 
3401       LastDL = DL;
3402     }
3403 
3404     if (BlockAddress *BA = BlockAddress::lookup(&BB)) {
3405       SmallVector<Value *> Worklist{BA};
3406       SmallPtrSet<Value *, 8> Visited{BA};
3407       while (!Worklist.empty()) {
3408         Value *V = Worklist.pop_back_val();
3409         for (User *U : V->users()) {
3410           if (auto *I = dyn_cast<Instruction>(U)) {
3411             Function *P = I->getFunction();
3412             if (P != &F)
3413               BlockAddressUsers.insert(P);
3414           } else if (isa<Constant>(U) && !isa<GlobalValue>(U) &&
3415                      Visited.insert(U).second)
3416             Worklist.push_back(U);
3417         }
3418       }
3419     }
3420   }
3421 
3422   if (!BlockAddressUsers.empty()) {
3423     Vals.resize(BlockAddressUsers.size());
3424     for (auto I : llvm::enumerate(BlockAddressUsers))
3425       Vals[I.index()] = VE.getValueID(I.value());
3426     Stream.EmitRecord(bitc::FUNC_CODE_BLOCKADDR_USERS, Vals);
3427     Vals.clear();
3428   }
3429 
3430   // Emit names for all the instructions etc.
3431   if (auto *Symtab = F.getValueSymbolTable())
3432     writeFunctionLevelValueSymbolTable(*Symtab);
3433 
3434   if (NeedsMetadataAttachment)
3435     writeFunctionMetadataAttachment(F);
3436   if (VE.shouldPreserveUseListOrder())
3437     writeUseListBlock(&F);
3438   VE.purgeFunction();
3439   Stream.ExitBlock();
3440 }
3441 
3442 // Emit blockinfo, which defines the standard abbreviations etc.
3443 void ModuleBitcodeWriter::writeBlockInfo() {
3444   // We only want to emit block info records for blocks that have multiple
3445   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
3446   // Other blocks can define their abbrevs inline.
3447   Stream.EnterBlockInfoBlock();
3448 
3449   { // 8-bit fixed-width VST_CODE_ENTRY/VST_CODE_BBENTRY strings.
3450     auto Abbv = std::make_shared<BitCodeAbbrev>();
3451     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
3452     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3453     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3454     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
3455     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3456         VST_ENTRY_8_ABBREV)
3457       llvm_unreachable("Unexpected abbrev ordering!");
3458   }
3459 
3460   { // 7-bit fixed width VST_CODE_ENTRY strings.
3461     auto Abbv = std::make_shared<BitCodeAbbrev>();
3462     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
3463     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3464     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3465     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
3466     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3467         VST_ENTRY_7_ABBREV)
3468       llvm_unreachable("Unexpected abbrev ordering!");
3469   }
3470   { // 6-bit char6 VST_CODE_ENTRY strings.
3471     auto Abbv = std::make_shared<BitCodeAbbrev>();
3472     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
3473     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3474     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3475     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3476     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3477         VST_ENTRY_6_ABBREV)
3478       llvm_unreachable("Unexpected abbrev ordering!");
3479   }
3480   { // 6-bit char6 VST_CODE_BBENTRY strings.
3481     auto Abbv = std::make_shared<BitCodeAbbrev>();
3482     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
3483     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3484     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3485     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3486     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3487         VST_BBENTRY_6_ABBREV)
3488       llvm_unreachable("Unexpected abbrev ordering!");
3489   }
3490 
3491   { // SETTYPE abbrev for CONSTANTS_BLOCK.
3492     auto Abbv = std::make_shared<BitCodeAbbrev>();
3493     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
3494     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
3495                               VE.computeBitsRequiredForTypeIndicies()));
3496     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3497         CONSTANTS_SETTYPE_ABBREV)
3498       llvm_unreachable("Unexpected abbrev ordering!");
3499   }
3500 
3501   { // INTEGER abbrev for CONSTANTS_BLOCK.
3502     auto Abbv = std::make_shared<BitCodeAbbrev>();
3503     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
3504     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3505     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3506         CONSTANTS_INTEGER_ABBREV)
3507       llvm_unreachable("Unexpected abbrev ordering!");
3508   }
3509 
3510   { // CE_CAST abbrev for CONSTANTS_BLOCK.
3511     auto Abbv = std::make_shared<BitCodeAbbrev>();
3512     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
3513     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
3514     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
3515                               VE.computeBitsRequiredForTypeIndicies()));
3516     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
3517 
3518     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3519         CONSTANTS_CE_CAST_Abbrev)
3520       llvm_unreachable("Unexpected abbrev ordering!");
3521   }
3522   { // NULL abbrev for CONSTANTS_BLOCK.
3523     auto Abbv = std::make_shared<BitCodeAbbrev>();
3524     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
3525     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3526         CONSTANTS_NULL_Abbrev)
3527       llvm_unreachable("Unexpected abbrev ordering!");
3528   }
3529 
3530   // FIXME: This should only use space for first class types!
3531 
3532   { // INST_LOAD abbrev for FUNCTION_BLOCK.
3533     auto Abbv = std::make_shared<BitCodeAbbrev>();
3534     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
3535     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
3536     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
3537                               VE.computeBitsRequiredForTypeIndicies()));
3538     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
3539     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
3540     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3541         FUNCTION_INST_LOAD_ABBREV)
3542       llvm_unreachable("Unexpected abbrev ordering!");
3543   }
3544   { // INST_UNOP abbrev for FUNCTION_BLOCK.
3545     auto Abbv = std::make_shared<BitCodeAbbrev>();
3546     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNOP));
3547     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3548     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3549     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3550         FUNCTION_INST_UNOP_ABBREV)
3551       llvm_unreachable("Unexpected abbrev ordering!");
3552   }
3553   { // INST_UNOP_FLAGS abbrev for FUNCTION_BLOCK.
3554     auto Abbv = std::make_shared<BitCodeAbbrev>();
3555     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNOP));
3556     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3557     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3558     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3559     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3560         FUNCTION_INST_UNOP_FLAGS_ABBREV)
3561       llvm_unreachable("Unexpected abbrev ordering!");
3562   }
3563   { // INST_BINOP abbrev for FUNCTION_BLOCK.
3564     auto Abbv = std::make_shared<BitCodeAbbrev>();
3565     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
3566     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3567     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
3568     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3569     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3570         FUNCTION_INST_BINOP_ABBREV)
3571       llvm_unreachable("Unexpected abbrev ordering!");
3572   }
3573   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
3574     auto Abbv = std::make_shared<BitCodeAbbrev>();
3575     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
3576     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3577     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
3578     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3579     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3580     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3581         FUNCTION_INST_BINOP_FLAGS_ABBREV)
3582       llvm_unreachable("Unexpected abbrev ordering!");
3583   }
3584   { // INST_CAST abbrev for FUNCTION_BLOCK.
3585     auto Abbv = std::make_shared<BitCodeAbbrev>();
3586     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
3587     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
3588     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
3589                               VE.computeBitsRequiredForTypeIndicies()));
3590     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
3591     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3592         FUNCTION_INST_CAST_ABBREV)
3593       llvm_unreachable("Unexpected abbrev ordering!");
3594   }
3595 
3596   { // INST_RET abbrev for FUNCTION_BLOCK.
3597     auto Abbv = std::make_shared<BitCodeAbbrev>();
3598     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
3599     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3600         FUNCTION_INST_RET_VOID_ABBREV)
3601       llvm_unreachable("Unexpected abbrev ordering!");
3602   }
3603   { // INST_RET abbrev for FUNCTION_BLOCK.
3604     auto Abbv = std::make_shared<BitCodeAbbrev>();
3605     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
3606     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
3607     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3608         FUNCTION_INST_RET_VAL_ABBREV)
3609       llvm_unreachable("Unexpected abbrev ordering!");
3610   }
3611   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
3612     auto Abbv = std::make_shared<BitCodeAbbrev>();
3613     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
3614     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3615         FUNCTION_INST_UNREACHABLE_ABBREV)
3616       llvm_unreachable("Unexpected abbrev ordering!");
3617   }
3618   {
3619     auto Abbv = std::make_shared<BitCodeAbbrev>();
3620     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
3621     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
3622     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
3623                               Log2_32_Ceil(VE.getTypes().size() + 1)));
3624     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3625     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
3626     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3627         FUNCTION_INST_GEP_ABBREV)
3628       llvm_unreachable("Unexpected abbrev ordering!");
3629   }
3630 
3631   Stream.ExitBlock();
3632 }
3633 
3634 /// Write the module path strings, currently only used when generating
3635 /// a combined index file.
3636 void IndexBitcodeWriter::writeModStrings() {
3637   Stream.EnterSubblock(bitc::MODULE_STRTAB_BLOCK_ID, 3);
3638 
3639   // TODO: See which abbrev sizes we actually need to emit
3640 
3641   // 8-bit fixed-width MST_ENTRY strings.
3642   auto Abbv = std::make_shared<BitCodeAbbrev>();
3643   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3644   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3645   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3646   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
3647   unsigned Abbrev8Bit = Stream.EmitAbbrev(std::move(Abbv));
3648 
3649   // 7-bit fixed width MST_ENTRY strings.
3650   Abbv = std::make_shared<BitCodeAbbrev>();
3651   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3652   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3653   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3654   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
3655   unsigned Abbrev7Bit = Stream.EmitAbbrev(std::move(Abbv));
3656 
3657   // 6-bit char6 MST_ENTRY strings.
3658   Abbv = std::make_shared<BitCodeAbbrev>();
3659   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3660   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3661   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3662   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3663   unsigned Abbrev6Bit = Stream.EmitAbbrev(std::move(Abbv));
3664 
3665   // Module Hash, 160 bits SHA1. Optionally, emitted after each MST_CODE_ENTRY.
3666   Abbv = std::make_shared<BitCodeAbbrev>();
3667   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_HASH));
3668   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3669   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3670   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3671   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3672   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3673   unsigned AbbrevHash = Stream.EmitAbbrev(std::move(Abbv));
3674 
3675   SmallVector<unsigned, 64> Vals;
3676   forEachModule(
3677       [&](const StringMapEntry<std::pair<uint64_t, ModuleHash>> &MPSE) {
3678         StringRef Key = MPSE.getKey();
3679         const auto &Value = MPSE.getValue();
3680         StringEncoding Bits = getStringEncoding(Key);
3681         unsigned AbbrevToUse = Abbrev8Bit;
3682         if (Bits == SE_Char6)
3683           AbbrevToUse = Abbrev6Bit;
3684         else if (Bits == SE_Fixed7)
3685           AbbrevToUse = Abbrev7Bit;
3686 
3687         Vals.push_back(Value.first);
3688         Vals.append(Key.begin(), Key.end());
3689 
3690         // Emit the finished record.
3691         Stream.EmitRecord(bitc::MST_CODE_ENTRY, Vals, AbbrevToUse);
3692 
3693         // Emit an optional hash for the module now
3694         const auto &Hash = Value.second;
3695         if (llvm::any_of(Hash, [](uint32_t H) { return H; })) {
3696           Vals.assign(Hash.begin(), Hash.end());
3697           // Emit the hash record.
3698           Stream.EmitRecord(bitc::MST_CODE_HASH, Vals, AbbrevHash);
3699         }
3700 
3701         Vals.clear();
3702       });
3703   Stream.ExitBlock();
3704 }
3705 
3706 /// Write the function type metadata related records that need to appear before
3707 /// a function summary entry (whether per-module or combined).
3708 template <typename Fn>
3709 static void writeFunctionTypeMetadataRecords(BitstreamWriter &Stream,
3710                                              FunctionSummary *FS,
3711                                              Fn GetValueID) {
3712   if (!FS->type_tests().empty())
3713     Stream.EmitRecord(bitc::FS_TYPE_TESTS, FS->type_tests());
3714 
3715   SmallVector<uint64_t, 64> Record;
3716 
3717   auto WriteVFuncIdVec = [&](uint64_t Ty,
3718                              ArrayRef<FunctionSummary::VFuncId> VFs) {
3719     if (VFs.empty())
3720       return;
3721     Record.clear();
3722     for (auto &VF : VFs) {
3723       Record.push_back(VF.GUID);
3724       Record.push_back(VF.Offset);
3725     }
3726     Stream.EmitRecord(Ty, Record);
3727   };
3728 
3729   WriteVFuncIdVec(bitc::FS_TYPE_TEST_ASSUME_VCALLS,
3730                   FS->type_test_assume_vcalls());
3731   WriteVFuncIdVec(bitc::FS_TYPE_CHECKED_LOAD_VCALLS,
3732                   FS->type_checked_load_vcalls());
3733 
3734   auto WriteConstVCallVec = [&](uint64_t Ty,
3735                                 ArrayRef<FunctionSummary::ConstVCall> VCs) {
3736     for (auto &VC : VCs) {
3737       Record.clear();
3738       Record.push_back(VC.VFunc.GUID);
3739       Record.push_back(VC.VFunc.Offset);
3740       llvm::append_range(Record, VC.Args);
3741       Stream.EmitRecord(Ty, Record);
3742     }
3743   };
3744 
3745   WriteConstVCallVec(bitc::FS_TYPE_TEST_ASSUME_CONST_VCALL,
3746                      FS->type_test_assume_const_vcalls());
3747   WriteConstVCallVec(bitc::FS_TYPE_CHECKED_LOAD_CONST_VCALL,
3748                      FS->type_checked_load_const_vcalls());
3749 
3750   auto WriteRange = [&](ConstantRange Range) {
3751     Range = Range.sextOrTrunc(FunctionSummary::ParamAccess::RangeWidth);
3752     assert(Range.getLower().getNumWords() == 1);
3753     assert(Range.getUpper().getNumWords() == 1);
3754     emitSignedInt64(Record, *Range.getLower().getRawData());
3755     emitSignedInt64(Record, *Range.getUpper().getRawData());
3756   };
3757 
3758   if (!FS->paramAccesses().empty()) {
3759     Record.clear();
3760     for (auto &Arg : FS->paramAccesses()) {
3761       size_t UndoSize = Record.size();
3762       Record.push_back(Arg.ParamNo);
3763       WriteRange(Arg.Use);
3764       Record.push_back(Arg.Calls.size());
3765       for (auto &Call : Arg.Calls) {
3766         Record.push_back(Call.ParamNo);
3767         Optional<unsigned> ValueID = GetValueID(Call.Callee);
3768         if (!ValueID) {
3769           // If ValueID is unknown we can't drop just this call, we must drop
3770           // entire parameter.
3771           Record.resize(UndoSize);
3772           break;
3773         }
3774         Record.push_back(*ValueID);
3775         WriteRange(Call.Offsets);
3776       }
3777     }
3778     if (!Record.empty())
3779       Stream.EmitRecord(bitc::FS_PARAM_ACCESS, Record);
3780   }
3781 }
3782 
3783 /// Collect type IDs from type tests used by function.
3784 static void
3785 getReferencedTypeIds(FunctionSummary *FS,
3786                      std::set<GlobalValue::GUID> &ReferencedTypeIds) {
3787   if (!FS->type_tests().empty())
3788     for (auto &TT : FS->type_tests())
3789       ReferencedTypeIds.insert(TT);
3790 
3791   auto GetReferencedTypesFromVFuncIdVec =
3792       [&](ArrayRef<FunctionSummary::VFuncId> VFs) {
3793         for (auto &VF : VFs)
3794           ReferencedTypeIds.insert(VF.GUID);
3795       };
3796 
3797   GetReferencedTypesFromVFuncIdVec(FS->type_test_assume_vcalls());
3798   GetReferencedTypesFromVFuncIdVec(FS->type_checked_load_vcalls());
3799 
3800   auto GetReferencedTypesFromConstVCallVec =
3801       [&](ArrayRef<FunctionSummary::ConstVCall> VCs) {
3802         for (auto &VC : VCs)
3803           ReferencedTypeIds.insert(VC.VFunc.GUID);
3804       };
3805 
3806   GetReferencedTypesFromConstVCallVec(FS->type_test_assume_const_vcalls());
3807   GetReferencedTypesFromConstVCallVec(FS->type_checked_load_const_vcalls());
3808 }
3809 
3810 static void writeWholeProgramDevirtResolutionByArg(
3811     SmallVector<uint64_t, 64> &NameVals, const std::vector<uint64_t> &args,
3812     const WholeProgramDevirtResolution::ByArg &ByArg) {
3813   NameVals.push_back(args.size());
3814   llvm::append_range(NameVals, args);
3815 
3816   NameVals.push_back(ByArg.TheKind);
3817   NameVals.push_back(ByArg.Info);
3818   NameVals.push_back(ByArg.Byte);
3819   NameVals.push_back(ByArg.Bit);
3820 }
3821 
3822 static void writeWholeProgramDevirtResolution(
3823     SmallVector<uint64_t, 64> &NameVals, StringTableBuilder &StrtabBuilder,
3824     uint64_t Id, const WholeProgramDevirtResolution &Wpd) {
3825   NameVals.push_back(Id);
3826 
3827   NameVals.push_back(Wpd.TheKind);
3828   NameVals.push_back(StrtabBuilder.add(Wpd.SingleImplName));
3829   NameVals.push_back(Wpd.SingleImplName.size());
3830 
3831   NameVals.push_back(Wpd.ResByArg.size());
3832   for (auto &A : Wpd.ResByArg)
3833     writeWholeProgramDevirtResolutionByArg(NameVals, A.first, A.second);
3834 }
3835 
3836 static void writeTypeIdSummaryRecord(SmallVector<uint64_t, 64> &NameVals,
3837                                      StringTableBuilder &StrtabBuilder,
3838                                      const std::string &Id,
3839                                      const TypeIdSummary &Summary) {
3840   NameVals.push_back(StrtabBuilder.add(Id));
3841   NameVals.push_back(Id.size());
3842 
3843   NameVals.push_back(Summary.TTRes.TheKind);
3844   NameVals.push_back(Summary.TTRes.SizeM1BitWidth);
3845   NameVals.push_back(Summary.TTRes.AlignLog2);
3846   NameVals.push_back(Summary.TTRes.SizeM1);
3847   NameVals.push_back(Summary.TTRes.BitMask);
3848   NameVals.push_back(Summary.TTRes.InlineBits);
3849 
3850   for (auto &W : Summary.WPDRes)
3851     writeWholeProgramDevirtResolution(NameVals, StrtabBuilder, W.first,
3852                                       W.second);
3853 }
3854 
3855 static void writeTypeIdCompatibleVtableSummaryRecord(
3856     SmallVector<uint64_t, 64> &NameVals, StringTableBuilder &StrtabBuilder,
3857     const std::string &Id, const TypeIdCompatibleVtableInfo &Summary,
3858     ValueEnumerator &VE) {
3859   NameVals.push_back(StrtabBuilder.add(Id));
3860   NameVals.push_back(Id.size());
3861 
3862   for (auto &P : Summary) {
3863     NameVals.push_back(P.AddressPointOffset);
3864     NameVals.push_back(VE.getValueID(P.VTableVI.getValue()));
3865   }
3866 }
3867 
3868 // Helper to emit a single function summary record.
3869 void ModuleBitcodeWriterBase::writePerModuleFunctionSummaryRecord(
3870     SmallVector<uint64_t, 64> &NameVals, GlobalValueSummary *Summary,
3871     unsigned ValueID, unsigned FSCallsAbbrev, unsigned FSCallsProfileAbbrev,
3872     const Function &F) {
3873   NameVals.push_back(ValueID);
3874 
3875   FunctionSummary *FS = cast<FunctionSummary>(Summary);
3876 
3877   writeFunctionTypeMetadataRecords(
3878       Stream, FS, [&](const ValueInfo &VI) -> Optional<unsigned> {
3879         return {VE.getValueID(VI.getValue())};
3880       });
3881 
3882   auto SpecialRefCnts = FS->specialRefCounts();
3883   NameVals.push_back(getEncodedGVSummaryFlags(FS->flags()));
3884   NameVals.push_back(FS->instCount());
3885   NameVals.push_back(getEncodedFFlags(FS->fflags()));
3886   NameVals.push_back(FS->refs().size());
3887   NameVals.push_back(SpecialRefCnts.first);  // rorefcnt
3888   NameVals.push_back(SpecialRefCnts.second); // worefcnt
3889 
3890   for (auto &RI : FS->refs())
3891     NameVals.push_back(VE.getValueID(RI.getValue()));
3892 
3893   bool HasProfileData =
3894       F.hasProfileData() || ForceSummaryEdgesCold != FunctionSummary::FSHT_None;
3895   for (auto &ECI : FS->calls()) {
3896     NameVals.push_back(getValueId(ECI.first));
3897     if (HasProfileData)
3898       NameVals.push_back(static_cast<uint8_t>(ECI.second.Hotness));
3899     else if (WriteRelBFToSummary)
3900       NameVals.push_back(ECI.second.RelBlockFreq);
3901   }
3902 
3903   unsigned FSAbbrev = (HasProfileData ? FSCallsProfileAbbrev : FSCallsAbbrev);
3904   unsigned Code =
3905       (HasProfileData ? bitc::FS_PERMODULE_PROFILE
3906                       : (WriteRelBFToSummary ? bitc::FS_PERMODULE_RELBF
3907                                              : bitc::FS_PERMODULE));
3908 
3909   // Emit the finished record.
3910   Stream.EmitRecord(Code, NameVals, FSAbbrev);
3911   NameVals.clear();
3912 }
3913 
3914 // Collect the global value references in the given variable's initializer,
3915 // and emit them in a summary record.
3916 void ModuleBitcodeWriterBase::writeModuleLevelReferences(
3917     const GlobalVariable &V, SmallVector<uint64_t, 64> &NameVals,
3918     unsigned FSModRefsAbbrev, unsigned FSModVTableRefsAbbrev) {
3919   auto VI = Index->getValueInfo(V.getGUID());
3920   if (!VI || VI.getSummaryList().empty()) {
3921     // Only declarations should not have a summary (a declaration might however
3922     // have a summary if the def was in module level asm).
3923     assert(V.isDeclaration());
3924     return;
3925   }
3926   auto *Summary = VI.getSummaryList()[0].get();
3927   NameVals.push_back(VE.getValueID(&V));
3928   GlobalVarSummary *VS = cast<GlobalVarSummary>(Summary);
3929   NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
3930   NameVals.push_back(getEncodedGVarFlags(VS->varflags()));
3931 
3932   auto VTableFuncs = VS->vTableFuncs();
3933   if (!VTableFuncs.empty())
3934     NameVals.push_back(VS->refs().size());
3935 
3936   unsigned SizeBeforeRefs = NameVals.size();
3937   for (auto &RI : VS->refs())
3938     NameVals.push_back(VE.getValueID(RI.getValue()));
3939   // Sort the refs for determinism output, the vector returned by FS->refs() has
3940   // been initialized from a DenseSet.
3941   llvm::sort(drop_begin(NameVals, SizeBeforeRefs));
3942 
3943   if (VTableFuncs.empty())
3944     Stream.EmitRecord(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS, NameVals,
3945                       FSModRefsAbbrev);
3946   else {
3947     // VTableFuncs pairs should already be sorted by offset.
3948     for (auto &P : VTableFuncs) {
3949       NameVals.push_back(VE.getValueID(P.FuncVI.getValue()));
3950       NameVals.push_back(P.VTableOffset);
3951     }
3952 
3953     Stream.EmitRecord(bitc::FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS, NameVals,
3954                       FSModVTableRefsAbbrev);
3955   }
3956   NameVals.clear();
3957 }
3958 
3959 /// Emit the per-module summary section alongside the rest of
3960 /// the module's bitcode.
3961 void ModuleBitcodeWriterBase::writePerModuleGlobalValueSummary() {
3962   // By default we compile with ThinLTO if the module has a summary, but the
3963   // client can request full LTO with a module flag.
3964   bool IsThinLTO = true;
3965   if (auto *MD =
3966           mdconst::extract_or_null<ConstantInt>(M.getModuleFlag("ThinLTO")))
3967     IsThinLTO = MD->getZExtValue();
3968   Stream.EnterSubblock(IsThinLTO ? bitc::GLOBALVAL_SUMMARY_BLOCK_ID
3969                                  : bitc::FULL_LTO_GLOBALVAL_SUMMARY_BLOCK_ID,
3970                        4);
3971 
3972   Stream.EmitRecord(
3973       bitc::FS_VERSION,
3974       ArrayRef<uint64_t>{ModuleSummaryIndex::BitcodeSummaryVersion});
3975 
3976   // Write the index flags.
3977   uint64_t Flags = 0;
3978   // Bits 1-3 are set only in the combined index, skip them.
3979   if (Index->enableSplitLTOUnit())
3980     Flags |= 0x8;
3981   Stream.EmitRecord(bitc::FS_FLAGS, ArrayRef<uint64_t>{Flags});
3982 
3983   if (Index->begin() == Index->end()) {
3984     Stream.ExitBlock();
3985     return;
3986   }
3987 
3988   for (const auto &GVI : valueIds()) {
3989     Stream.EmitRecord(bitc::FS_VALUE_GUID,
3990                       ArrayRef<uint64_t>{GVI.second, GVI.first});
3991   }
3992 
3993   // Abbrev for FS_PERMODULE_PROFILE.
3994   auto Abbv = std::make_shared<BitCodeAbbrev>();
3995   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_PROFILE));
3996   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3997   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3998   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
3999   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4000   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4001   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4002   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4003   // numrefs x valueid, n x (valueid, hotness)
4004   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4005   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4006   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4007 
4008   // Abbrev for FS_PERMODULE or FS_PERMODULE_RELBF.
4009   Abbv = std::make_shared<BitCodeAbbrev>();
4010   if (WriteRelBFToSummary)
4011     Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_RELBF));
4012   else
4013     Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE));
4014   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4015   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4016   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4017   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4018   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4019   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4020   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4021   // numrefs x valueid, n x (valueid [, rel_block_freq])
4022   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4023   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4024   unsigned FSCallsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4025 
4026   // Abbrev for FS_PERMODULE_GLOBALVAR_INIT_REFS.
4027   Abbv = std::make_shared<BitCodeAbbrev>();
4028   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS));
4029   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4030   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
4031   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));  // valueids
4032   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4033   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4034 
4035   // Abbrev for FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS.
4036   Abbv = std::make_shared<BitCodeAbbrev>();
4037   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS));
4038   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4039   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
4040   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numrefs
4041   // numrefs x valueid, n x (valueid , offset)
4042   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4043   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4044   unsigned FSModVTableRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4045 
4046   // Abbrev for FS_ALIAS.
4047   Abbv = std::make_shared<BitCodeAbbrev>();
4048   Abbv->Add(BitCodeAbbrevOp(bitc::FS_ALIAS));
4049   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4050   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4051   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4052   unsigned FSAliasAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4053 
4054   // Abbrev for FS_TYPE_ID_METADATA
4055   Abbv = std::make_shared<BitCodeAbbrev>();
4056   Abbv->Add(BitCodeAbbrevOp(bitc::FS_TYPE_ID_METADATA));
4057   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // typeid strtab index
4058   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // typeid length
4059   // n x (valueid , offset)
4060   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4061   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4062   unsigned TypeIdCompatibleVtableAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4063 
4064   SmallVector<uint64_t, 64> NameVals;
4065   // Iterate over the list of functions instead of the Index to
4066   // ensure the ordering is stable.
4067   for (const Function &F : M) {
4068     // Summary emission does not support anonymous functions, they have to
4069     // renamed using the anonymous function renaming pass.
4070     if (!F.hasName())
4071       report_fatal_error("Unexpected anonymous function when writing summary");
4072 
4073     ValueInfo VI = Index->getValueInfo(F.getGUID());
4074     if (!VI || VI.getSummaryList().empty()) {
4075       // Only declarations should not have a summary (a declaration might
4076       // however have a summary if the def was in module level asm).
4077       assert(F.isDeclaration());
4078       continue;
4079     }
4080     auto *Summary = VI.getSummaryList()[0].get();
4081     writePerModuleFunctionSummaryRecord(NameVals, Summary, VE.getValueID(&F),
4082                                         FSCallsAbbrev, FSCallsProfileAbbrev, F);
4083   }
4084 
4085   // Capture references from GlobalVariable initializers, which are outside
4086   // of a function scope.
4087   for (const GlobalVariable &G : M.globals())
4088     writeModuleLevelReferences(G, NameVals, FSModRefsAbbrev,
4089                                FSModVTableRefsAbbrev);
4090 
4091   for (const GlobalAlias &A : M.aliases()) {
4092     auto *Aliasee = A.getAliaseeObject();
4093     if (!Aliasee->hasName())
4094       // Nameless function don't have an entry in the summary, skip it.
4095       continue;
4096     auto AliasId = VE.getValueID(&A);
4097     auto AliaseeId = VE.getValueID(Aliasee);
4098     NameVals.push_back(AliasId);
4099     auto *Summary = Index->getGlobalValueSummary(A);
4100     AliasSummary *AS = cast<AliasSummary>(Summary);
4101     NameVals.push_back(getEncodedGVSummaryFlags(AS->flags()));
4102     NameVals.push_back(AliaseeId);
4103     Stream.EmitRecord(bitc::FS_ALIAS, NameVals, FSAliasAbbrev);
4104     NameVals.clear();
4105   }
4106 
4107   for (auto &S : Index->typeIdCompatibleVtableMap()) {
4108     writeTypeIdCompatibleVtableSummaryRecord(NameVals, StrtabBuilder, S.first,
4109                                              S.second, VE);
4110     Stream.EmitRecord(bitc::FS_TYPE_ID_METADATA, NameVals,
4111                       TypeIdCompatibleVtableAbbrev);
4112     NameVals.clear();
4113   }
4114 
4115   Stream.EmitRecord(bitc::FS_BLOCK_COUNT,
4116                     ArrayRef<uint64_t>{Index->getBlockCount()});
4117 
4118   Stream.ExitBlock();
4119 }
4120 
4121 /// Emit the combined summary section into the combined index file.
4122 void IndexBitcodeWriter::writeCombinedGlobalValueSummary() {
4123   Stream.EnterSubblock(bitc::GLOBALVAL_SUMMARY_BLOCK_ID, 3);
4124   Stream.EmitRecord(
4125       bitc::FS_VERSION,
4126       ArrayRef<uint64_t>{ModuleSummaryIndex::BitcodeSummaryVersion});
4127 
4128   // Write the index flags.
4129   Stream.EmitRecord(bitc::FS_FLAGS, ArrayRef<uint64_t>{Index.getFlags()});
4130 
4131   for (const auto &GVI : valueIds()) {
4132     Stream.EmitRecord(bitc::FS_VALUE_GUID,
4133                       ArrayRef<uint64_t>{GVI.second, GVI.first});
4134   }
4135 
4136   // Abbrev for FS_COMBINED.
4137   auto Abbv = std::make_shared<BitCodeAbbrev>();
4138   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED));
4139   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4140   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4141   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4142   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4143   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4144   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // entrycount
4145   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4146   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4147   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4148   // numrefs x valueid, n x (valueid)
4149   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4150   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4151   unsigned FSCallsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4152 
4153   // Abbrev for FS_COMBINED_PROFILE.
4154   Abbv = std::make_shared<BitCodeAbbrev>();
4155   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_PROFILE));
4156   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4157   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4158   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4159   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4160   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4161   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // entrycount
4162   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4163   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4164   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4165   // numrefs x valueid, n x (valueid, hotness)
4166   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4167   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4168   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4169 
4170   // Abbrev for FS_COMBINED_GLOBALVAR_INIT_REFS.
4171   Abbv = std::make_shared<BitCodeAbbrev>();
4172   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS));
4173   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4174   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4175   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4176   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));    // valueids
4177   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4178   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4179 
4180   // Abbrev for FS_COMBINED_ALIAS.
4181   Abbv = std::make_shared<BitCodeAbbrev>();
4182   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_ALIAS));
4183   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4184   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4185   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4186   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4187   unsigned FSAliasAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4188 
4189   // The aliases are emitted as a post-pass, and will point to the value
4190   // id of the aliasee. Save them in a vector for post-processing.
4191   SmallVector<AliasSummary *, 64> Aliases;
4192 
4193   // Save the value id for each summary for alias emission.
4194   DenseMap<const GlobalValueSummary *, unsigned> SummaryToValueIdMap;
4195 
4196   SmallVector<uint64_t, 64> NameVals;
4197 
4198   // Set that will be populated during call to writeFunctionTypeMetadataRecords
4199   // with the type ids referenced by this index file.
4200   std::set<GlobalValue::GUID> ReferencedTypeIds;
4201 
4202   // For local linkage, we also emit the original name separately
4203   // immediately after the record.
4204   auto MaybeEmitOriginalName = [&](GlobalValueSummary &S) {
4205     // We don't need to emit the original name if we are writing the index for
4206     // distributed backends (in which case ModuleToSummariesForIndex is
4207     // non-null). The original name is only needed during the thin link, since
4208     // for SamplePGO the indirect call targets for local functions have
4209     // have the original name annotated in profile.
4210     // Continue to emit it when writing out the entire combined index, which is
4211     // used in testing the thin link via llvm-lto.
4212     if (ModuleToSummariesForIndex || !GlobalValue::isLocalLinkage(S.linkage()))
4213       return;
4214     NameVals.push_back(S.getOriginalName());
4215     Stream.EmitRecord(bitc::FS_COMBINED_ORIGINAL_NAME, NameVals);
4216     NameVals.clear();
4217   };
4218 
4219   std::set<GlobalValue::GUID> DefOrUseGUIDs;
4220   forEachSummary([&](GVInfo I, bool IsAliasee) {
4221     GlobalValueSummary *S = I.second;
4222     assert(S);
4223     DefOrUseGUIDs.insert(I.first);
4224     for (const ValueInfo &VI : S->refs())
4225       DefOrUseGUIDs.insert(VI.getGUID());
4226 
4227     auto ValueId = getValueId(I.first);
4228     assert(ValueId);
4229     SummaryToValueIdMap[S] = *ValueId;
4230 
4231     // If this is invoked for an aliasee, we want to record the above
4232     // mapping, but then not emit a summary entry (if the aliasee is
4233     // to be imported, we will invoke this separately with IsAliasee=false).
4234     if (IsAliasee)
4235       return;
4236 
4237     if (auto *AS = dyn_cast<AliasSummary>(S)) {
4238       // Will process aliases as a post-pass because the reader wants all
4239       // global to be loaded first.
4240       Aliases.push_back(AS);
4241       return;
4242     }
4243 
4244     if (auto *VS = dyn_cast<GlobalVarSummary>(S)) {
4245       NameVals.push_back(*ValueId);
4246       NameVals.push_back(Index.getModuleId(VS->modulePath()));
4247       NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
4248       NameVals.push_back(getEncodedGVarFlags(VS->varflags()));
4249       for (auto &RI : VS->refs()) {
4250         auto RefValueId = getValueId(RI.getGUID());
4251         if (!RefValueId)
4252           continue;
4253         NameVals.push_back(*RefValueId);
4254       }
4255 
4256       // Emit the finished record.
4257       Stream.EmitRecord(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS, NameVals,
4258                         FSModRefsAbbrev);
4259       NameVals.clear();
4260       MaybeEmitOriginalName(*S);
4261       return;
4262     }
4263 
4264     auto GetValueId = [&](const ValueInfo &VI) -> Optional<unsigned> {
4265       return getValueId(VI.getGUID());
4266     };
4267 
4268     auto *FS = cast<FunctionSummary>(S);
4269     writeFunctionTypeMetadataRecords(Stream, FS, GetValueId);
4270     getReferencedTypeIds(FS, ReferencedTypeIds);
4271 
4272     NameVals.push_back(*ValueId);
4273     NameVals.push_back(Index.getModuleId(FS->modulePath()));
4274     NameVals.push_back(getEncodedGVSummaryFlags(FS->flags()));
4275     NameVals.push_back(FS->instCount());
4276     NameVals.push_back(getEncodedFFlags(FS->fflags()));
4277     NameVals.push_back(FS->entryCount());
4278 
4279     // Fill in below
4280     NameVals.push_back(0); // numrefs
4281     NameVals.push_back(0); // rorefcnt
4282     NameVals.push_back(0); // worefcnt
4283 
4284     unsigned Count = 0, RORefCnt = 0, WORefCnt = 0;
4285     for (auto &RI : FS->refs()) {
4286       auto RefValueId = getValueId(RI.getGUID());
4287       if (!RefValueId)
4288         continue;
4289       NameVals.push_back(*RefValueId);
4290       if (RI.isReadOnly())
4291         RORefCnt++;
4292       else if (RI.isWriteOnly())
4293         WORefCnt++;
4294       Count++;
4295     }
4296     NameVals[6] = Count;
4297     NameVals[7] = RORefCnt;
4298     NameVals[8] = WORefCnt;
4299 
4300     bool HasProfileData = false;
4301     for (auto &EI : FS->calls()) {
4302       HasProfileData |=
4303           EI.second.getHotness() != CalleeInfo::HotnessType::Unknown;
4304       if (HasProfileData)
4305         break;
4306     }
4307 
4308     for (auto &EI : FS->calls()) {
4309       // If this GUID doesn't have a value id, it doesn't have a function
4310       // summary and we don't need to record any calls to it.
4311       Optional<unsigned> CallValueId = GetValueId(EI.first);
4312       if (!CallValueId)
4313         continue;
4314       NameVals.push_back(*CallValueId);
4315       if (HasProfileData)
4316         NameVals.push_back(static_cast<uint8_t>(EI.second.Hotness));
4317     }
4318 
4319     unsigned FSAbbrev = (HasProfileData ? FSCallsProfileAbbrev : FSCallsAbbrev);
4320     unsigned Code =
4321         (HasProfileData ? bitc::FS_COMBINED_PROFILE : bitc::FS_COMBINED);
4322 
4323     // Emit the finished record.
4324     Stream.EmitRecord(Code, NameVals, FSAbbrev);
4325     NameVals.clear();
4326     MaybeEmitOriginalName(*S);
4327   });
4328 
4329   for (auto *AS : Aliases) {
4330     auto AliasValueId = SummaryToValueIdMap[AS];
4331     assert(AliasValueId);
4332     NameVals.push_back(AliasValueId);
4333     NameVals.push_back(Index.getModuleId(AS->modulePath()));
4334     NameVals.push_back(getEncodedGVSummaryFlags(AS->flags()));
4335     auto AliaseeValueId = SummaryToValueIdMap[&AS->getAliasee()];
4336     assert(AliaseeValueId);
4337     NameVals.push_back(AliaseeValueId);
4338 
4339     // Emit the finished record.
4340     Stream.EmitRecord(bitc::FS_COMBINED_ALIAS, NameVals, FSAliasAbbrev);
4341     NameVals.clear();
4342     MaybeEmitOriginalName(*AS);
4343 
4344     if (auto *FS = dyn_cast<FunctionSummary>(&AS->getAliasee()))
4345       getReferencedTypeIds(FS, ReferencedTypeIds);
4346   }
4347 
4348   if (!Index.cfiFunctionDefs().empty()) {
4349     for (auto &S : Index.cfiFunctionDefs()) {
4350       if (DefOrUseGUIDs.count(
4351               GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(S)))) {
4352         NameVals.push_back(StrtabBuilder.add(S));
4353         NameVals.push_back(S.size());
4354       }
4355     }
4356     if (!NameVals.empty()) {
4357       Stream.EmitRecord(bitc::FS_CFI_FUNCTION_DEFS, NameVals);
4358       NameVals.clear();
4359     }
4360   }
4361 
4362   if (!Index.cfiFunctionDecls().empty()) {
4363     for (auto &S : Index.cfiFunctionDecls()) {
4364       if (DefOrUseGUIDs.count(
4365               GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(S)))) {
4366         NameVals.push_back(StrtabBuilder.add(S));
4367         NameVals.push_back(S.size());
4368       }
4369     }
4370     if (!NameVals.empty()) {
4371       Stream.EmitRecord(bitc::FS_CFI_FUNCTION_DECLS, NameVals);
4372       NameVals.clear();
4373     }
4374   }
4375 
4376   // Walk the GUIDs that were referenced, and write the
4377   // corresponding type id records.
4378   for (auto &T : ReferencedTypeIds) {
4379     auto TidIter = Index.typeIds().equal_range(T);
4380     for (auto It = TidIter.first; It != TidIter.second; ++It) {
4381       writeTypeIdSummaryRecord(NameVals, StrtabBuilder, It->second.first,
4382                                It->second.second);
4383       Stream.EmitRecord(bitc::FS_TYPE_ID, NameVals);
4384       NameVals.clear();
4385     }
4386   }
4387 
4388   Stream.EmitRecord(bitc::FS_BLOCK_COUNT,
4389                     ArrayRef<uint64_t>{Index.getBlockCount()});
4390 
4391   Stream.ExitBlock();
4392 }
4393 
4394 /// Create the "IDENTIFICATION_BLOCK_ID" containing a single string with the
4395 /// current llvm version, and a record for the epoch number.
4396 static void writeIdentificationBlock(BitstreamWriter &Stream) {
4397   Stream.EnterSubblock(bitc::IDENTIFICATION_BLOCK_ID, 5);
4398 
4399   // Write the "user readable" string identifying the bitcode producer
4400   auto Abbv = std::make_shared<BitCodeAbbrev>();
4401   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_STRING));
4402   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4403   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
4404   auto StringAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4405   writeStringRecord(Stream, bitc::IDENTIFICATION_CODE_STRING,
4406                     "LLVM" LLVM_VERSION_STRING, StringAbbrev);
4407 
4408   // Write the epoch version
4409   Abbv = std::make_shared<BitCodeAbbrev>();
4410   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_EPOCH));
4411   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
4412   auto EpochAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4413   constexpr std::array<unsigned, 1> Vals = {{bitc::BITCODE_CURRENT_EPOCH}};
4414   Stream.EmitRecord(bitc::IDENTIFICATION_CODE_EPOCH, Vals, EpochAbbrev);
4415   Stream.ExitBlock();
4416 }
4417 
4418 void ModuleBitcodeWriter::writeModuleHash(size_t BlockStartPos) {
4419   // Emit the module's hash.
4420   // MODULE_CODE_HASH: [5*i32]
4421   if (GenerateHash) {
4422     uint32_t Vals[5];
4423     Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&(Buffer)[BlockStartPos],
4424                                     Buffer.size() - BlockStartPos));
4425     std::array<uint8_t, 20> Hash = Hasher.result();
4426     for (int Pos = 0; Pos < 20; Pos += 4) {
4427       Vals[Pos / 4] = support::endian::read32be(Hash.data() + Pos);
4428     }
4429 
4430     // Emit the finished record.
4431     Stream.EmitRecord(bitc::MODULE_CODE_HASH, Vals);
4432 
4433     if (ModHash)
4434       // Save the written hash value.
4435       llvm::copy(Vals, std::begin(*ModHash));
4436   }
4437 }
4438 
4439 void ModuleBitcodeWriter::write() {
4440   writeIdentificationBlock(Stream);
4441 
4442   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
4443   size_t BlockStartPos = Buffer.size();
4444 
4445   writeModuleVersion();
4446 
4447   // Emit blockinfo, which defines the standard abbreviations etc.
4448   writeBlockInfo();
4449 
4450   // Emit information describing all of the types in the module.
4451   writeTypeTable();
4452 
4453   // Emit information about attribute groups.
4454   writeAttributeGroupTable();
4455 
4456   // Emit information about parameter attributes.
4457   writeAttributeTable();
4458 
4459   writeComdats();
4460 
4461   // Emit top-level description of module, including target triple, inline asm,
4462   // descriptors for global variables, and function prototype info.
4463   writeModuleInfo();
4464 
4465   // Emit constants.
4466   writeModuleConstants();
4467 
4468   // Emit metadata kind names.
4469   writeModuleMetadataKinds();
4470 
4471   // Emit metadata.
4472   writeModuleMetadata();
4473 
4474   // Emit module-level use-lists.
4475   if (VE.shouldPreserveUseListOrder())
4476     writeUseListBlock(nullptr);
4477 
4478   writeOperandBundleTags();
4479   writeSyncScopeNames();
4480 
4481   // Emit function bodies.
4482   DenseMap<const Function *, uint64_t> FunctionToBitcodeIndex;
4483   for (const Function &F : M)
4484     if (!F.isDeclaration())
4485       writeFunction(F, FunctionToBitcodeIndex);
4486 
4487   // Need to write after the above call to WriteFunction which populates
4488   // the summary information in the index.
4489   if (Index)
4490     writePerModuleGlobalValueSummary();
4491 
4492   writeGlobalValueSymbolTable(FunctionToBitcodeIndex);
4493 
4494   writeModuleHash(BlockStartPos);
4495 
4496   Stream.ExitBlock();
4497 }
4498 
4499 static void writeInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
4500                                uint32_t &Position) {
4501   support::endian::write32le(&Buffer[Position], Value);
4502   Position += 4;
4503 }
4504 
4505 /// If generating a bc file on darwin, we have to emit a
4506 /// header and trailer to make it compatible with the system archiver.  To do
4507 /// this we emit the following header, and then emit a trailer that pads the
4508 /// file out to be a multiple of 16 bytes.
4509 ///
4510 /// struct bc_header {
4511 ///   uint32_t Magic;         // 0x0B17C0DE
4512 ///   uint32_t Version;       // Version, currently always 0.
4513 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
4514 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
4515 ///   uint32_t CPUType;       // CPU specifier.
4516 ///   ... potentially more later ...
4517 /// };
4518 static void emitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
4519                                          const Triple &TT) {
4520   unsigned CPUType = ~0U;
4521 
4522   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
4523   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
4524   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
4525   // specific constants here because they are implicitly part of the Darwin ABI.
4526   enum {
4527     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
4528     DARWIN_CPU_TYPE_X86        = 7,
4529     DARWIN_CPU_TYPE_ARM        = 12,
4530     DARWIN_CPU_TYPE_POWERPC    = 18
4531   };
4532 
4533   Triple::ArchType Arch = TT.getArch();
4534   if (Arch == Triple::x86_64)
4535     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
4536   else if (Arch == Triple::x86)
4537     CPUType = DARWIN_CPU_TYPE_X86;
4538   else if (Arch == Triple::ppc)
4539     CPUType = DARWIN_CPU_TYPE_POWERPC;
4540   else if (Arch == Triple::ppc64)
4541     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
4542   else if (Arch == Triple::arm || Arch == Triple::thumb)
4543     CPUType = DARWIN_CPU_TYPE_ARM;
4544 
4545   // Traditional Bitcode starts after header.
4546   assert(Buffer.size() >= BWH_HeaderSize &&
4547          "Expected header size to be reserved");
4548   unsigned BCOffset = BWH_HeaderSize;
4549   unsigned BCSize = Buffer.size() - BWH_HeaderSize;
4550 
4551   // Write the magic and version.
4552   unsigned Position = 0;
4553   writeInt32ToBuffer(0x0B17C0DE, Buffer, Position);
4554   writeInt32ToBuffer(0, Buffer, Position); // Version.
4555   writeInt32ToBuffer(BCOffset, Buffer, Position);
4556   writeInt32ToBuffer(BCSize, Buffer, Position);
4557   writeInt32ToBuffer(CPUType, Buffer, Position);
4558 
4559   // If the file is not a multiple of 16 bytes, insert dummy padding.
4560   while (Buffer.size() & 15)
4561     Buffer.push_back(0);
4562 }
4563 
4564 /// Helper to write the header common to all bitcode files.
4565 static void writeBitcodeHeader(BitstreamWriter &Stream) {
4566   // Emit the file header.
4567   Stream.Emit((unsigned)'B', 8);
4568   Stream.Emit((unsigned)'C', 8);
4569   Stream.Emit(0x0, 4);
4570   Stream.Emit(0xC, 4);
4571   Stream.Emit(0xE, 4);
4572   Stream.Emit(0xD, 4);
4573 }
4574 
4575 BitcodeWriter::BitcodeWriter(SmallVectorImpl<char> &Buffer, raw_fd_stream *FS)
4576     : Buffer(Buffer), Stream(new BitstreamWriter(Buffer, FS, FlushThreshold)) {
4577   writeBitcodeHeader(*Stream);
4578 }
4579 
4580 BitcodeWriter::~BitcodeWriter() { assert(WroteStrtab); }
4581 
4582 void BitcodeWriter::writeBlob(unsigned Block, unsigned Record, StringRef Blob) {
4583   Stream->EnterSubblock(Block, 3);
4584 
4585   auto Abbv = std::make_shared<BitCodeAbbrev>();
4586   Abbv->Add(BitCodeAbbrevOp(Record));
4587   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
4588   auto AbbrevNo = Stream->EmitAbbrev(std::move(Abbv));
4589 
4590   Stream->EmitRecordWithBlob(AbbrevNo, ArrayRef<uint64_t>{Record}, Blob);
4591 
4592   Stream->ExitBlock();
4593 }
4594 
4595 void BitcodeWriter::writeSymtab() {
4596   assert(!WroteStrtab && !WroteSymtab);
4597 
4598   // If any module has module-level inline asm, we will require a registered asm
4599   // parser for the target so that we can create an accurate symbol table for
4600   // the module.
4601   for (Module *M : Mods) {
4602     if (M->getModuleInlineAsm().empty())
4603       continue;
4604 
4605     std::string Err;
4606     const Triple TT(M->getTargetTriple());
4607     const Target *T = TargetRegistry::lookupTarget(TT.str(), Err);
4608     if (!T || !T->hasMCAsmParser())
4609       return;
4610   }
4611 
4612   WroteSymtab = true;
4613   SmallVector<char, 0> Symtab;
4614   // The irsymtab::build function may be unable to create a symbol table if the
4615   // module is malformed (e.g. it contains an invalid alias). Writing a symbol
4616   // table is not required for correctness, but we still want to be able to
4617   // write malformed modules to bitcode files, so swallow the error.
4618   if (Error E = irsymtab::build(Mods, Symtab, StrtabBuilder, Alloc)) {
4619     consumeError(std::move(E));
4620     return;
4621   }
4622 
4623   writeBlob(bitc::SYMTAB_BLOCK_ID, bitc::SYMTAB_BLOB,
4624             {Symtab.data(), Symtab.size()});
4625 }
4626 
4627 void BitcodeWriter::writeStrtab() {
4628   assert(!WroteStrtab);
4629 
4630   std::vector<char> Strtab;
4631   StrtabBuilder.finalizeInOrder();
4632   Strtab.resize(StrtabBuilder.getSize());
4633   StrtabBuilder.write((uint8_t *)Strtab.data());
4634 
4635   writeBlob(bitc::STRTAB_BLOCK_ID, bitc::STRTAB_BLOB,
4636             {Strtab.data(), Strtab.size()});
4637 
4638   WroteStrtab = true;
4639 }
4640 
4641 void BitcodeWriter::copyStrtab(StringRef Strtab) {
4642   writeBlob(bitc::STRTAB_BLOCK_ID, bitc::STRTAB_BLOB, Strtab);
4643   WroteStrtab = true;
4644 }
4645 
4646 void BitcodeWriter::writeModule(const Module &M,
4647                                 bool ShouldPreserveUseListOrder,
4648                                 const ModuleSummaryIndex *Index,
4649                                 bool GenerateHash, ModuleHash *ModHash) {
4650   assert(!WroteStrtab);
4651 
4652   // The Mods vector is used by irsymtab::build, which requires non-const
4653   // Modules in case it needs to materialize metadata. But the bitcode writer
4654   // requires that the module is materialized, so we can cast to non-const here,
4655   // after checking that it is in fact materialized.
4656   assert(M.isMaterialized());
4657   Mods.push_back(const_cast<Module *>(&M));
4658 
4659   ModuleBitcodeWriter ModuleWriter(M, Buffer, StrtabBuilder, *Stream,
4660                                    ShouldPreserveUseListOrder, Index,
4661                                    GenerateHash, ModHash);
4662   ModuleWriter.write();
4663 }
4664 
4665 void BitcodeWriter::writeIndex(
4666     const ModuleSummaryIndex *Index,
4667     const std::map<std::string, GVSummaryMapTy> *ModuleToSummariesForIndex) {
4668   IndexBitcodeWriter IndexWriter(*Stream, StrtabBuilder, *Index,
4669                                  ModuleToSummariesForIndex);
4670   IndexWriter.write();
4671 }
4672 
4673 /// Write the specified module to the specified output stream.
4674 void llvm::WriteBitcodeToFile(const Module &M, raw_ostream &Out,
4675                               bool ShouldPreserveUseListOrder,
4676                               const ModuleSummaryIndex *Index,
4677                               bool GenerateHash, ModuleHash *ModHash) {
4678   SmallVector<char, 0> Buffer;
4679   Buffer.reserve(256*1024);
4680 
4681   // If this is darwin or another generic macho target, reserve space for the
4682   // header.
4683   Triple TT(M.getTargetTriple());
4684   if (TT.isOSDarwin() || TT.isOSBinFormatMachO())
4685     Buffer.insert(Buffer.begin(), BWH_HeaderSize, 0);
4686 
4687   BitcodeWriter Writer(Buffer, dyn_cast<raw_fd_stream>(&Out));
4688   Writer.writeModule(M, ShouldPreserveUseListOrder, Index, GenerateHash,
4689                      ModHash);
4690   Writer.writeSymtab();
4691   Writer.writeStrtab();
4692 
4693   if (TT.isOSDarwin() || TT.isOSBinFormatMachO())
4694     emitDarwinBCHeaderAndTrailer(Buffer, TT);
4695 
4696   // Write the generated bitstream to "Out".
4697   if (!Buffer.empty())
4698     Out.write((char *)&Buffer.front(), Buffer.size());
4699 }
4700 
4701 void IndexBitcodeWriter::write() {
4702   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
4703 
4704   writeModuleVersion();
4705 
4706   // Write the module paths in the combined index.
4707   writeModStrings();
4708 
4709   // Write the summary combined index records.
4710   writeCombinedGlobalValueSummary();
4711 
4712   Stream.ExitBlock();
4713 }
4714 
4715 // Write the specified module summary index to the given raw output stream,
4716 // where it will be written in a new bitcode block. This is used when
4717 // writing the combined index file for ThinLTO. When writing a subset of the
4718 // index for a distributed backend, provide a \p ModuleToSummariesForIndex map.
4719 void llvm::writeIndexToFile(
4720     const ModuleSummaryIndex &Index, raw_ostream &Out,
4721     const std::map<std::string, GVSummaryMapTy> *ModuleToSummariesForIndex) {
4722   SmallVector<char, 0> Buffer;
4723   Buffer.reserve(256 * 1024);
4724 
4725   BitcodeWriter Writer(Buffer);
4726   Writer.writeIndex(&Index, ModuleToSummariesForIndex);
4727   Writer.writeStrtab();
4728 
4729   Out.write((char *)&Buffer.front(), Buffer.size());
4730 }
4731 
4732 namespace {
4733 
4734 /// Class to manage the bitcode writing for a thin link bitcode file.
4735 class ThinLinkBitcodeWriter : public ModuleBitcodeWriterBase {
4736   /// ModHash is for use in ThinLTO incremental build, generated while writing
4737   /// the module bitcode file.
4738   const ModuleHash *ModHash;
4739 
4740 public:
4741   ThinLinkBitcodeWriter(const Module &M, StringTableBuilder &StrtabBuilder,
4742                         BitstreamWriter &Stream,
4743                         const ModuleSummaryIndex &Index,
4744                         const ModuleHash &ModHash)
4745       : ModuleBitcodeWriterBase(M, StrtabBuilder, Stream,
4746                                 /*ShouldPreserveUseListOrder=*/false, &Index),
4747         ModHash(&ModHash) {}
4748 
4749   void write();
4750 
4751 private:
4752   void writeSimplifiedModuleInfo();
4753 };
4754 
4755 } // end anonymous namespace
4756 
4757 // This function writes a simpilified module info for thin link bitcode file.
4758 // It only contains the source file name along with the name(the offset and
4759 // size in strtab) and linkage for global values. For the global value info
4760 // entry, in order to keep linkage at offset 5, there are three zeros used
4761 // as padding.
4762 void ThinLinkBitcodeWriter::writeSimplifiedModuleInfo() {
4763   SmallVector<unsigned, 64> Vals;
4764   // Emit the module's source file name.
4765   {
4766     StringEncoding Bits = getStringEncoding(M.getSourceFileName());
4767     BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
4768     if (Bits == SE_Char6)
4769       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
4770     else if (Bits == SE_Fixed7)
4771       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
4772 
4773     // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
4774     auto Abbv = std::make_shared<BitCodeAbbrev>();
4775     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
4776     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4777     Abbv->Add(AbbrevOpToUse);
4778     unsigned FilenameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4779 
4780     for (const auto P : M.getSourceFileName())
4781       Vals.push_back((unsigned char)P);
4782 
4783     Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
4784     Vals.clear();
4785   }
4786 
4787   // Emit the global variable information.
4788   for (const GlobalVariable &GV : M.globals()) {
4789     // GLOBALVAR: [strtab offset, strtab size, 0, 0, 0, linkage]
4790     Vals.push_back(StrtabBuilder.add(GV.getName()));
4791     Vals.push_back(GV.getName().size());
4792     Vals.push_back(0);
4793     Vals.push_back(0);
4794     Vals.push_back(0);
4795     Vals.push_back(getEncodedLinkage(GV));
4796 
4797     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals);
4798     Vals.clear();
4799   }
4800 
4801   // Emit the function proto information.
4802   for (const Function &F : M) {
4803     // FUNCTION:  [strtab offset, strtab size, 0, 0, 0, linkage]
4804     Vals.push_back(StrtabBuilder.add(F.getName()));
4805     Vals.push_back(F.getName().size());
4806     Vals.push_back(0);
4807     Vals.push_back(0);
4808     Vals.push_back(0);
4809     Vals.push_back(getEncodedLinkage(F));
4810 
4811     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals);
4812     Vals.clear();
4813   }
4814 
4815   // Emit the alias information.
4816   for (const GlobalAlias &A : M.aliases()) {
4817     // ALIAS: [strtab offset, strtab size, 0, 0, 0, linkage]
4818     Vals.push_back(StrtabBuilder.add(A.getName()));
4819     Vals.push_back(A.getName().size());
4820     Vals.push_back(0);
4821     Vals.push_back(0);
4822     Vals.push_back(0);
4823     Vals.push_back(getEncodedLinkage(A));
4824 
4825     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals);
4826     Vals.clear();
4827   }
4828 
4829   // Emit the ifunc information.
4830   for (const GlobalIFunc &I : M.ifuncs()) {
4831     // IFUNC: [strtab offset, strtab size, 0, 0, 0, linkage]
4832     Vals.push_back(StrtabBuilder.add(I.getName()));
4833     Vals.push_back(I.getName().size());
4834     Vals.push_back(0);
4835     Vals.push_back(0);
4836     Vals.push_back(0);
4837     Vals.push_back(getEncodedLinkage(I));
4838 
4839     Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
4840     Vals.clear();
4841   }
4842 }
4843 
4844 void ThinLinkBitcodeWriter::write() {
4845   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
4846 
4847   writeModuleVersion();
4848 
4849   writeSimplifiedModuleInfo();
4850 
4851   writePerModuleGlobalValueSummary();
4852 
4853   // Write module hash.
4854   Stream.EmitRecord(bitc::MODULE_CODE_HASH, ArrayRef<uint32_t>(*ModHash));
4855 
4856   Stream.ExitBlock();
4857 }
4858 
4859 void BitcodeWriter::writeThinLinkBitcode(const Module &M,
4860                                          const ModuleSummaryIndex &Index,
4861                                          const ModuleHash &ModHash) {
4862   assert(!WroteStrtab);
4863 
4864   // The Mods vector is used by irsymtab::build, which requires non-const
4865   // Modules in case it needs to materialize metadata. But the bitcode writer
4866   // requires that the module is materialized, so we can cast to non-const here,
4867   // after checking that it is in fact materialized.
4868   assert(M.isMaterialized());
4869   Mods.push_back(const_cast<Module *>(&M));
4870 
4871   ThinLinkBitcodeWriter ThinLinkWriter(M, StrtabBuilder, *Stream, Index,
4872                                        ModHash);
4873   ThinLinkWriter.write();
4874 }
4875 
4876 // Write the specified thin link bitcode file to the given raw output stream,
4877 // where it will be written in a new bitcode block. This is used when
4878 // writing the per-module index file for ThinLTO.
4879 void llvm::writeThinLinkBitcodeToFile(const Module &M, raw_ostream &Out,
4880                                       const ModuleSummaryIndex &Index,
4881                                       const ModuleHash &ModHash) {
4882   SmallVector<char, 0> Buffer;
4883   Buffer.reserve(256 * 1024);
4884 
4885   BitcodeWriter Writer(Buffer);
4886   Writer.writeThinLinkBitcode(M, Index, ModHash);
4887   Writer.writeSymtab();
4888   Writer.writeStrtab();
4889 
4890   Out.write((char *)&Buffer.front(), Buffer.size());
4891 }
4892 
4893 static const char *getSectionNameForBitcode(const Triple &T) {
4894   switch (T.getObjectFormat()) {
4895   case Triple::MachO:
4896     return "__LLVM,__bitcode";
4897   case Triple::COFF:
4898   case Triple::ELF:
4899   case Triple::Wasm:
4900   case Triple::UnknownObjectFormat:
4901     return ".llvmbc";
4902   case Triple::GOFF:
4903     llvm_unreachable("GOFF is not yet implemented");
4904     break;
4905   case Triple::SPIRV:
4906     llvm_unreachable("SPIRV is not yet implemented");
4907     break;
4908   case Triple::XCOFF:
4909     llvm_unreachable("XCOFF is not yet implemented");
4910     break;
4911   case Triple::DXContainer:
4912     llvm_unreachable("DXContainer is not yet implemented");
4913     break;
4914   }
4915   llvm_unreachable("Unimplemented ObjectFormatType");
4916 }
4917 
4918 static const char *getSectionNameForCommandline(const Triple &T) {
4919   switch (T.getObjectFormat()) {
4920   case Triple::MachO:
4921     return "__LLVM,__cmdline";
4922   case Triple::COFF:
4923   case Triple::ELF:
4924   case Triple::Wasm:
4925   case Triple::UnknownObjectFormat:
4926     return ".llvmcmd";
4927   case Triple::GOFF:
4928     llvm_unreachable("GOFF is not yet implemented");
4929     break;
4930   case Triple::SPIRV:
4931     llvm_unreachable("SPIRV is not yet implemented");
4932     break;
4933   case Triple::XCOFF:
4934     llvm_unreachable("XCOFF is not yet implemented");
4935     break;
4936   case Triple::DXContainer:
4937     llvm_unreachable("DXC is not yet implemented");
4938     break;
4939   }
4940   llvm_unreachable("Unimplemented ObjectFormatType");
4941 }
4942 
4943 void llvm::embedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
4944                                 bool EmbedBitcode, bool EmbedCmdline,
4945                                 const std::vector<uint8_t> &CmdArgs) {
4946   // Save llvm.compiler.used and remove it.
4947   SmallVector<Constant *, 2> UsedArray;
4948   SmallVector<GlobalValue *, 4> UsedGlobals;
4949   Type *UsedElementType = Type::getInt8Ty(M.getContext())->getPointerTo(0);
4950   GlobalVariable *Used = collectUsedGlobalVariables(M, UsedGlobals, true);
4951   for (auto *GV : UsedGlobals) {
4952     if (GV->getName() != "llvm.embedded.module" &&
4953         GV->getName() != "llvm.cmdline")
4954       UsedArray.push_back(
4955           ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
4956   }
4957   if (Used)
4958     Used->eraseFromParent();
4959 
4960   // Embed the bitcode for the llvm module.
4961   std::string Data;
4962   ArrayRef<uint8_t> ModuleData;
4963   Triple T(M.getTargetTriple());
4964 
4965   if (EmbedBitcode) {
4966     if (Buf.getBufferSize() == 0 ||
4967         !isBitcode((const unsigned char *)Buf.getBufferStart(),
4968                    (const unsigned char *)Buf.getBufferEnd())) {
4969       // If the input is LLVM Assembly, bitcode is produced by serializing
4970       // the module. Use-lists order need to be preserved in this case.
4971       llvm::raw_string_ostream OS(Data);
4972       llvm::WriteBitcodeToFile(M, OS, /* ShouldPreserveUseListOrder */ true);
4973       ModuleData =
4974           ArrayRef<uint8_t>((const uint8_t *)OS.str().data(), OS.str().size());
4975     } else
4976       // If the input is LLVM bitcode, write the input byte stream directly.
4977       ModuleData = ArrayRef<uint8_t>((const uint8_t *)Buf.getBufferStart(),
4978                                      Buf.getBufferSize());
4979   }
4980   llvm::Constant *ModuleConstant =
4981       llvm::ConstantDataArray::get(M.getContext(), ModuleData);
4982   llvm::GlobalVariable *GV = new llvm::GlobalVariable(
4983       M, ModuleConstant->getType(), true, llvm::GlobalValue::PrivateLinkage,
4984       ModuleConstant);
4985   GV->setSection(getSectionNameForBitcode(T));
4986   // Set alignment to 1 to prevent padding between two contributions from input
4987   // sections after linking.
4988   GV->setAlignment(Align(1));
4989   UsedArray.push_back(
4990       ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
4991   if (llvm::GlobalVariable *Old =
4992           M.getGlobalVariable("llvm.embedded.module", true)) {
4993     assert(Old->hasZeroLiveUses() &&
4994            "llvm.embedded.module can only be used once in llvm.compiler.used");
4995     GV->takeName(Old);
4996     Old->eraseFromParent();
4997   } else {
4998     GV->setName("llvm.embedded.module");
4999   }
5000 
5001   // Skip if only bitcode needs to be embedded.
5002   if (EmbedCmdline) {
5003     // Embed command-line options.
5004     ArrayRef<uint8_t> CmdData(const_cast<uint8_t *>(CmdArgs.data()),
5005                               CmdArgs.size());
5006     llvm::Constant *CmdConstant =
5007         llvm::ConstantDataArray::get(M.getContext(), CmdData);
5008     GV = new llvm::GlobalVariable(M, CmdConstant->getType(), true,
5009                                   llvm::GlobalValue::PrivateLinkage,
5010                                   CmdConstant);
5011     GV->setSection(getSectionNameForCommandline(T));
5012     GV->setAlignment(Align(1));
5013     UsedArray.push_back(
5014         ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
5015     if (llvm::GlobalVariable *Old = M.getGlobalVariable("llvm.cmdline", true)) {
5016       assert(Old->hasZeroLiveUses() &&
5017              "llvm.cmdline can only be used once in llvm.compiler.used");
5018       GV->takeName(Old);
5019       Old->eraseFromParent();
5020     } else {
5021       GV->setName("llvm.cmdline");
5022     }
5023   }
5024 
5025   if (UsedArray.empty())
5026     return;
5027 
5028   // Recreate llvm.compiler.used.
5029   ArrayType *ATy = ArrayType::get(UsedElementType, UsedArray.size());
5030   auto *NewUsed = new GlobalVariable(
5031       M, ATy, false, llvm::GlobalValue::AppendingLinkage,
5032       llvm::ConstantArray::get(ATy, UsedArray), "llvm.compiler.used");
5033   NewUsed->setSection("llvm.metadata");
5034 }
5035