xref: /llvm-project/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp (revision 76007138f4ffd4e0f510d12b5e8cad529c21f24d)
1 //===- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Bitcode writer implementation.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/Bitcode/BitcodeWriter.h"
14 #include "ValueEnumerator.h"
15 #include "llvm/ADT/APFloat.h"
16 #include "llvm/ADT/APInt.h"
17 #include "llvm/ADT/ArrayRef.h"
18 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/STLExtras.h"
20 #include "llvm/ADT/SetVector.h"
21 #include "llvm/ADT/SmallPtrSet.h"
22 #include "llvm/ADT/SmallString.h"
23 #include "llvm/ADT/SmallVector.h"
24 #include "llvm/ADT/StringMap.h"
25 #include "llvm/ADT/StringRef.h"
26 #include "llvm/Bitcode/BitcodeCommon.h"
27 #include "llvm/Bitcode/BitcodeReader.h"
28 #include "llvm/Bitcode/LLVMBitCodes.h"
29 #include "llvm/Bitstream/BitCodes.h"
30 #include "llvm/Bitstream/BitstreamWriter.h"
31 #include "llvm/Config/llvm-config.h"
32 #include "llvm/IR/Attributes.h"
33 #include "llvm/IR/BasicBlock.h"
34 #include "llvm/IR/Comdat.h"
35 #include "llvm/IR/Constant.h"
36 #include "llvm/IR/ConstantRangeList.h"
37 #include "llvm/IR/Constants.h"
38 #include "llvm/IR/DebugInfoMetadata.h"
39 #include "llvm/IR/DebugLoc.h"
40 #include "llvm/IR/DerivedTypes.h"
41 #include "llvm/IR/Function.h"
42 #include "llvm/IR/GlobalAlias.h"
43 #include "llvm/IR/GlobalIFunc.h"
44 #include "llvm/IR/GlobalObject.h"
45 #include "llvm/IR/GlobalValue.h"
46 #include "llvm/IR/GlobalVariable.h"
47 #include "llvm/IR/InlineAsm.h"
48 #include "llvm/IR/InstrTypes.h"
49 #include "llvm/IR/Instruction.h"
50 #include "llvm/IR/Instructions.h"
51 #include "llvm/IR/LLVMContext.h"
52 #include "llvm/IR/Metadata.h"
53 #include "llvm/IR/Module.h"
54 #include "llvm/IR/ModuleSummaryIndex.h"
55 #include "llvm/IR/Operator.h"
56 #include "llvm/IR/Type.h"
57 #include "llvm/IR/UseListOrder.h"
58 #include "llvm/IR/Value.h"
59 #include "llvm/IR/ValueSymbolTable.h"
60 #include "llvm/MC/StringTableBuilder.h"
61 #include "llvm/MC/TargetRegistry.h"
62 #include "llvm/Object/IRSymtab.h"
63 #include "llvm/Support/AtomicOrdering.h"
64 #include "llvm/Support/Casting.h"
65 #include "llvm/Support/CommandLine.h"
66 #include "llvm/Support/Endian.h"
67 #include "llvm/Support/Error.h"
68 #include "llvm/Support/ErrorHandling.h"
69 #include "llvm/Support/MathExtras.h"
70 #include "llvm/Support/SHA1.h"
71 #include "llvm/Support/raw_ostream.h"
72 #include "llvm/TargetParser/Triple.h"
73 #include <algorithm>
74 #include <cassert>
75 #include <cstddef>
76 #include <cstdint>
77 #include <iterator>
78 #include <map>
79 #include <memory>
80 #include <optional>
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 namespace llvm {
100 extern FunctionSummary::ForceSummaryHotnessType ForceSummaryEdgesCold;
101 }
102 
103 extern bool WriteNewDbgInfoFormatToBitcode;
104 extern llvm::cl::opt<bool> UseNewDbgInfoFormat;
105 
106 namespace {
107 
108 /// These are manifest constants used by the bitcode writer. They do not need to
109 /// be kept in sync with the reader, but need to be consistent within this file.
110 enum {
111   // VALUE_SYMTAB_BLOCK abbrev id's.
112   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
113   VST_ENTRY_7_ABBREV,
114   VST_ENTRY_6_ABBREV,
115   VST_BBENTRY_6_ABBREV,
116 
117   // CONSTANTS_BLOCK abbrev id's.
118   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
119   CONSTANTS_INTEGER_ABBREV,
120   CONSTANTS_CE_CAST_Abbrev,
121   CONSTANTS_NULL_Abbrev,
122 
123   // FUNCTION_BLOCK abbrev id's.
124   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
125   FUNCTION_INST_UNOP_ABBREV,
126   FUNCTION_INST_UNOP_FLAGS_ABBREV,
127   FUNCTION_INST_BINOP_ABBREV,
128   FUNCTION_INST_BINOP_FLAGS_ABBREV,
129   FUNCTION_INST_CAST_ABBREV,
130   FUNCTION_INST_CAST_FLAGS_ABBREV,
131   FUNCTION_INST_RET_VOID_ABBREV,
132   FUNCTION_INST_RET_VAL_ABBREV,
133   FUNCTION_INST_UNREACHABLE_ABBREV,
134   FUNCTION_INST_GEP_ABBREV,
135   FUNCTION_DEBUG_RECORD_VALUE_ABBREV,
136 };
137 
138 /// Abstract class to manage the bitcode writing, subclassed for each bitcode
139 /// file type.
140 class BitcodeWriterBase {
141 protected:
142   /// The stream created and owned by the client.
143   BitstreamWriter &Stream;
144 
145   StringTableBuilder &StrtabBuilder;
146 
147 public:
148   /// Constructs a BitcodeWriterBase object that writes to the provided
149   /// \p Stream.
150   BitcodeWriterBase(BitstreamWriter &Stream, StringTableBuilder &StrtabBuilder)
151       : Stream(Stream), StrtabBuilder(StrtabBuilder) {}
152 
153 protected:
154   void writeModuleVersion();
155 };
156 
157 void BitcodeWriterBase::writeModuleVersion() {
158   // VERSION: [version#]
159   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, ArrayRef<uint64_t>{2});
160 }
161 
162 /// Base class to manage the module bitcode writing, currently subclassed for
163 /// ModuleBitcodeWriter and ThinLinkBitcodeWriter.
164 class ModuleBitcodeWriterBase : public BitcodeWriterBase {
165 protected:
166   /// The Module to write to bitcode.
167   const Module &M;
168 
169   /// Enumerates ids for all values in the module.
170   ValueEnumerator VE;
171 
172   /// Optional per-module index to write for ThinLTO.
173   const ModuleSummaryIndex *Index;
174 
175   /// Map that holds the correspondence between GUIDs in the summary index,
176   /// that came from indirect call profiles, and a value id generated by this
177   /// class to use in the VST and summary block records.
178   std::map<GlobalValue::GUID, unsigned> GUIDToValueIdMap;
179 
180   /// Tracks the last value id recorded in the GUIDToValueMap.
181   unsigned GlobalValueId;
182 
183   /// Saves the offset of the VSTOffset record that must eventually be
184   /// backpatched with the offset of the actual VST.
185   uint64_t VSTOffsetPlaceholder = 0;
186 
187 public:
188   /// Constructs a ModuleBitcodeWriterBase object for the given Module,
189   /// writing to the provided \p Buffer.
190   ModuleBitcodeWriterBase(const Module &M, StringTableBuilder &StrtabBuilder,
191                           BitstreamWriter &Stream,
192                           bool ShouldPreserveUseListOrder,
193                           const ModuleSummaryIndex *Index)
194       : BitcodeWriterBase(Stream, StrtabBuilder), M(M),
195         VE(M, ShouldPreserveUseListOrder), Index(Index) {
196     // Assign ValueIds to any callee values in the index that came from
197     // indirect call profiles and were recorded as a GUID not a Value*
198     // (which would have been assigned an ID by the ValueEnumerator).
199     // The starting ValueId is just after the number of values in the
200     // ValueEnumerator, so that they can be emitted in the VST.
201     GlobalValueId = VE.getValues().size();
202     if (!Index)
203       return;
204     for (const auto &GUIDSummaryLists : *Index)
205       // Examine all summaries for this GUID.
206       for (auto &Summary : GUIDSummaryLists.second.SummaryList)
207         if (auto FS = dyn_cast<FunctionSummary>(Summary.get())) {
208           // For each call in the function summary, see if the call
209           // is to a GUID (which means it is for an indirect call,
210           // otherwise we would have a Value for it). If so, synthesize
211           // a value id.
212           for (auto &CallEdge : FS->calls())
213             if (!CallEdge.first.haveGVs() || !CallEdge.first.getValue())
214               assignValueId(CallEdge.first.getGUID());
215 
216           // For each referenced variables in the function summary, see if the
217           // variable is represented by a GUID (as opposed to a symbol to
218           // declarations or definitions in the module). If so, synthesize a
219           // value id.
220           for (auto &RefEdge : FS->refs())
221             if (!RefEdge.haveGVs() || !RefEdge.getValue())
222               assignValueId(RefEdge.getGUID());
223         }
224   }
225 
226 protected:
227   void writePerModuleGlobalValueSummary();
228 
229 private:
230   void writePerModuleFunctionSummaryRecord(
231       SmallVector<uint64_t, 64> &NameVals, GlobalValueSummary *Summary,
232       unsigned ValueID, unsigned FSCallsAbbrev, unsigned FSCallsProfileAbbrev,
233       unsigned CallsiteAbbrev, unsigned AllocAbbrev, const Function &F);
234   void writeModuleLevelReferences(const GlobalVariable &V,
235                                   SmallVector<uint64_t, 64> &NameVals,
236                                   unsigned FSModRefsAbbrev,
237                                   unsigned FSModVTableRefsAbbrev);
238 
239   void assignValueId(GlobalValue::GUID ValGUID) {
240     GUIDToValueIdMap[ValGUID] = ++GlobalValueId;
241   }
242 
243   unsigned getValueId(GlobalValue::GUID ValGUID) {
244     const auto &VMI = GUIDToValueIdMap.find(ValGUID);
245     // Expect that any GUID value had a value Id assigned by an
246     // earlier call to assignValueId.
247     assert(VMI != GUIDToValueIdMap.end() &&
248            "GUID does not have assigned value Id");
249     return VMI->second;
250   }
251 
252   // Helper to get the valueId for the type of value recorded in VI.
253   unsigned getValueId(ValueInfo VI) {
254     if (!VI.haveGVs() || !VI.getValue())
255       return getValueId(VI.getGUID());
256     return VE.getValueID(VI.getValue());
257   }
258 
259   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
260 };
261 
262 /// Class to manage the bitcode writing for a module.
263 class ModuleBitcodeWriter : public ModuleBitcodeWriterBase {
264   /// True if a module hash record should be written.
265   bool GenerateHash;
266 
267   /// If non-null, when GenerateHash is true, the resulting hash is written
268   /// into ModHash.
269   ModuleHash *ModHash;
270 
271   SHA1 Hasher;
272 
273   /// The start bit of the identification block.
274   uint64_t BitcodeStartBit;
275 
276 public:
277   /// Constructs a ModuleBitcodeWriter object for the given Module,
278   /// writing to the provided \p Buffer.
279   ModuleBitcodeWriter(const Module &M, StringTableBuilder &StrtabBuilder,
280                       BitstreamWriter &Stream, bool ShouldPreserveUseListOrder,
281                       const ModuleSummaryIndex *Index, bool GenerateHash,
282                       ModuleHash *ModHash = nullptr)
283       : ModuleBitcodeWriterBase(M, StrtabBuilder, Stream,
284                                 ShouldPreserveUseListOrder, Index),
285         GenerateHash(GenerateHash), ModHash(ModHash),
286         BitcodeStartBit(Stream.GetCurrentBitNo()) {}
287 
288   /// Emit the current module to the bitstream.
289   void write();
290 
291 private:
292   uint64_t bitcodeStartBit() { return BitcodeStartBit; }
293 
294   size_t addToStrtab(StringRef Str);
295 
296   void writeAttributeGroupTable();
297   void writeAttributeTable();
298   void writeTypeTable();
299   void writeComdats();
300   void writeValueSymbolTableForwardDecl();
301   void writeModuleInfo();
302   void writeValueAsMetadata(const ValueAsMetadata *MD,
303                             SmallVectorImpl<uint64_t> &Record);
304   void writeMDTuple(const MDTuple *N, SmallVectorImpl<uint64_t> &Record,
305                     unsigned Abbrev);
306   unsigned createDILocationAbbrev();
307   void writeDILocation(const DILocation *N, SmallVectorImpl<uint64_t> &Record,
308                        unsigned &Abbrev);
309   unsigned createGenericDINodeAbbrev();
310   void writeGenericDINode(const GenericDINode *N,
311                           SmallVectorImpl<uint64_t> &Record, unsigned &Abbrev);
312   void writeDISubrange(const DISubrange *N, SmallVectorImpl<uint64_t> &Record,
313                        unsigned Abbrev);
314   void writeDIGenericSubrange(const DIGenericSubrange *N,
315                               SmallVectorImpl<uint64_t> &Record,
316                               unsigned Abbrev);
317   void writeDIEnumerator(const DIEnumerator *N,
318                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
319   void writeDIBasicType(const DIBasicType *N, SmallVectorImpl<uint64_t> &Record,
320                         unsigned Abbrev);
321   void writeDIStringType(const DIStringType *N,
322                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
323   void writeDIDerivedType(const DIDerivedType *N,
324                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
325   void writeDICompositeType(const DICompositeType *N,
326                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
327   void writeDISubroutineType(const DISubroutineType *N,
328                              SmallVectorImpl<uint64_t> &Record,
329                              unsigned Abbrev);
330   void writeDIFile(const DIFile *N, SmallVectorImpl<uint64_t> &Record,
331                    unsigned Abbrev);
332   void writeDICompileUnit(const DICompileUnit *N,
333                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
334   void writeDISubprogram(const DISubprogram *N,
335                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
336   void writeDILexicalBlock(const DILexicalBlock *N,
337                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
338   void writeDILexicalBlockFile(const DILexicalBlockFile *N,
339                                SmallVectorImpl<uint64_t> &Record,
340                                unsigned Abbrev);
341   void writeDICommonBlock(const DICommonBlock *N,
342                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
343   void writeDINamespace(const DINamespace *N, SmallVectorImpl<uint64_t> &Record,
344                         unsigned Abbrev);
345   void writeDIMacro(const DIMacro *N, SmallVectorImpl<uint64_t> &Record,
346                     unsigned Abbrev);
347   void writeDIMacroFile(const DIMacroFile *N, SmallVectorImpl<uint64_t> &Record,
348                         unsigned Abbrev);
349   void writeDIArgList(const DIArgList *N, SmallVectorImpl<uint64_t> &Record);
350   void writeDIModule(const DIModule *N, SmallVectorImpl<uint64_t> &Record,
351                      unsigned Abbrev);
352   void writeDIAssignID(const DIAssignID *N, SmallVectorImpl<uint64_t> &Record,
353                        unsigned Abbrev);
354   void writeDITemplateTypeParameter(const DITemplateTypeParameter *N,
355                                     SmallVectorImpl<uint64_t> &Record,
356                                     unsigned Abbrev);
357   void writeDITemplateValueParameter(const DITemplateValueParameter *N,
358                                      SmallVectorImpl<uint64_t> &Record,
359                                      unsigned Abbrev);
360   void writeDIGlobalVariable(const DIGlobalVariable *N,
361                              SmallVectorImpl<uint64_t> &Record,
362                              unsigned Abbrev);
363   void writeDILocalVariable(const DILocalVariable *N,
364                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
365   void writeDILabel(const DILabel *N,
366                     SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
367   void writeDIExpression(const DIExpression *N,
368                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
369   void writeDIGlobalVariableExpression(const DIGlobalVariableExpression *N,
370                                        SmallVectorImpl<uint64_t> &Record,
371                                        unsigned Abbrev);
372   void writeDIObjCProperty(const DIObjCProperty *N,
373                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
374   void writeDIImportedEntity(const DIImportedEntity *N,
375                              SmallVectorImpl<uint64_t> &Record,
376                              unsigned Abbrev);
377   unsigned createNamedMetadataAbbrev();
378   void writeNamedMetadata(SmallVectorImpl<uint64_t> &Record);
379   unsigned createMetadataStringsAbbrev();
380   void writeMetadataStrings(ArrayRef<const Metadata *> Strings,
381                             SmallVectorImpl<uint64_t> &Record);
382   void writeMetadataRecords(ArrayRef<const Metadata *> MDs,
383                             SmallVectorImpl<uint64_t> &Record,
384                             std::vector<unsigned> *MDAbbrevs = nullptr,
385                             std::vector<uint64_t> *IndexPos = nullptr);
386   void writeModuleMetadata();
387   void writeFunctionMetadata(const Function &F);
388   void writeFunctionMetadataAttachment(const Function &F);
389   void pushGlobalMetadataAttachment(SmallVectorImpl<uint64_t> &Record,
390                                     const GlobalObject &GO);
391   void writeModuleMetadataKinds();
392   void writeOperandBundleTags();
393   void writeSyncScopeNames();
394   void writeConstants(unsigned FirstVal, unsigned LastVal, bool isGlobal);
395   void writeModuleConstants();
396   bool pushValueAndType(const Value *V, unsigned InstID,
397                         SmallVectorImpl<unsigned> &Vals);
398   bool pushValueOrMetadata(const Value *V, unsigned InstID,
399                            SmallVectorImpl<unsigned> &Vals);
400   void writeOperandBundles(const CallBase &CB, unsigned InstID);
401   void pushValue(const Value *V, unsigned InstID,
402                  SmallVectorImpl<unsigned> &Vals);
403   void pushValueSigned(const Value *V, unsigned InstID,
404                        SmallVectorImpl<uint64_t> &Vals);
405   void writeInstruction(const Instruction &I, unsigned InstID,
406                         SmallVectorImpl<unsigned> &Vals);
407   void writeFunctionLevelValueSymbolTable(const ValueSymbolTable &VST);
408   void writeGlobalValueSymbolTable(
409       DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
410   void writeUseList(UseListOrder &&Order);
411   void writeUseListBlock(const Function *F);
412   void
413   writeFunction(const Function &F,
414                 DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
415   void writeBlockInfo();
416   void writeModuleHash(StringRef View);
417 
418   unsigned getEncodedSyncScopeID(SyncScope::ID SSID) {
419     return unsigned(SSID);
420   }
421 
422   unsigned getEncodedAlign(MaybeAlign Alignment) { return encode(Alignment); }
423 };
424 
425 /// Class to manage the bitcode writing for a combined index.
426 class IndexBitcodeWriter : public BitcodeWriterBase {
427   /// The combined index to write to bitcode.
428   const ModuleSummaryIndex &Index;
429 
430   /// When writing combined summaries, provides the set of global value
431   /// summaries for which the value (function, function alias, etc) should be
432   /// imported as a declaration.
433   const GVSummaryPtrSet *DecSummaries = nullptr;
434 
435   /// When writing a subset of the index for distributed backends, client
436   /// provides a map of modules to the corresponding GUIDs/summaries to write.
437   const ModuleToSummariesForIndexTy *ModuleToSummariesForIndex;
438 
439   /// Map that holds the correspondence between the GUID used in the combined
440   /// index and a value id generated by this class to use in references.
441   std::map<GlobalValue::GUID, unsigned> GUIDToValueIdMap;
442 
443   // The stack ids used by this index, which will be a subset of those in
444   // the full index in the case of distributed indexes.
445   std::vector<uint64_t> StackIds;
446 
447   // Keep a map of the stack id indices used by records being written for this
448   // index to the index of the corresponding stack id in the above StackIds
449   // vector. Ensures we write each referenced stack id once.
450   DenseMap<unsigned, unsigned> StackIdIndicesToIndex;
451 
452   /// Tracks the last value id recorded in the GUIDToValueMap.
453   unsigned GlobalValueId = 0;
454 
455   /// Tracks the assignment of module paths in the module path string table to
456   /// an id assigned for use in summary references to the module path.
457   DenseMap<StringRef, uint64_t> ModuleIdMap;
458 
459 public:
460   /// Constructs a IndexBitcodeWriter object for the given combined index,
461   /// writing to the provided \p Buffer. When writing a subset of the index
462   /// for a distributed backend, provide a \p ModuleToSummariesForIndex map.
463   /// If provided, \p DecSummaries specifies the set of summaries for which
464   /// the corresponding functions or aliased functions should be imported as a
465   /// declaration (but not definition) for each module.
466   IndexBitcodeWriter(
467       BitstreamWriter &Stream, StringTableBuilder &StrtabBuilder,
468       const ModuleSummaryIndex &Index,
469       const GVSummaryPtrSet *DecSummaries = nullptr,
470       const ModuleToSummariesForIndexTy *ModuleToSummariesForIndex = nullptr)
471       : BitcodeWriterBase(Stream, StrtabBuilder), Index(Index),
472         DecSummaries(DecSummaries),
473         ModuleToSummariesForIndex(ModuleToSummariesForIndex) {
474 
475     // See if the StackIdIndex was already added to the StackId map and
476     // vector. If not, record it.
477     auto RecordStackIdReference = [&](unsigned StackIdIndex) {
478       // If the StackIdIndex is not yet in the map, the below insert ensures
479       // that it will point to the new StackIds vector entry we push to just
480       // below.
481       auto Inserted =
482           StackIdIndicesToIndex.insert({StackIdIndex, StackIds.size()});
483       if (Inserted.second)
484         StackIds.push_back(Index.getStackIdAtIndex(StackIdIndex));
485     };
486 
487     // Assign unique value ids to all summaries to be written, for use
488     // in writing out the call graph edges. Save the mapping from GUID
489     // to the new global value id to use when writing those edges, which
490     // are currently saved in the index in terms of GUID.
491     forEachSummary([&](GVInfo I, bool IsAliasee) {
492       GUIDToValueIdMap[I.first] = ++GlobalValueId;
493       if (IsAliasee)
494         return;
495       auto *FS = dyn_cast<FunctionSummary>(I.second);
496       if (!FS)
497         return;
498       // Record all stack id indices actually used in the summary entries being
499       // written, so that we can compact them in the case of distributed ThinLTO
500       // indexes.
501       for (auto &CI : FS->callsites()) {
502         // If the stack id list is empty, this callsite info was synthesized for
503         // a missing tail call frame. Ensure that the callee's GUID gets a value
504         // id. Normally we only generate these for defined summaries, which in
505         // the case of distributed ThinLTO is only the functions already defined
506         // in the module or that we want to import. We don't bother to include
507         // all the callee symbols as they aren't normally needed in the backend.
508         // However, for the synthesized callsite infos we do need the callee
509         // GUID in the backend so that we can correlate the identified callee
510         // with this callsite info (which for non-tail calls is done by the
511         // ordering of the callsite infos and verified via stack ids).
512         if (CI.StackIdIndices.empty()) {
513           GUIDToValueIdMap[CI.Callee.getGUID()] = ++GlobalValueId;
514           continue;
515         }
516         for (auto Idx : CI.StackIdIndices)
517           RecordStackIdReference(Idx);
518       }
519       for (auto &AI : FS->allocs())
520         for (auto &MIB : AI.MIBs)
521           for (auto Idx : MIB.StackIdIndices)
522             RecordStackIdReference(Idx);
523     });
524   }
525 
526   /// The below iterator returns the GUID and associated summary.
527   using GVInfo = std::pair<GlobalValue::GUID, GlobalValueSummary *>;
528 
529   /// Calls the callback for each value GUID and summary to be written to
530   /// bitcode. This hides the details of whether they are being pulled from the
531   /// entire index or just those in a provided ModuleToSummariesForIndex map.
532   template<typename Functor>
533   void forEachSummary(Functor Callback) {
534     if (ModuleToSummariesForIndex) {
535       for (auto &M : *ModuleToSummariesForIndex)
536         for (auto &Summary : M.second) {
537           Callback(Summary, false);
538           // Ensure aliasee is handled, e.g. for assigning a valueId,
539           // even if we are not importing the aliasee directly (the
540           // imported alias will contain a copy of aliasee).
541           if (auto *AS = dyn_cast<AliasSummary>(Summary.getSecond()))
542             Callback({AS->getAliaseeGUID(), &AS->getAliasee()}, true);
543         }
544     } else {
545       for (auto &Summaries : Index)
546         for (auto &Summary : Summaries.second.SummaryList)
547           Callback({Summaries.first, Summary.get()}, false);
548     }
549   }
550 
551   /// Calls the callback for each entry in the modulePaths StringMap that
552   /// should be written to the module path string table. This hides the details
553   /// of whether they are being pulled from the entire index or just those in a
554   /// provided ModuleToSummariesForIndex map.
555   template <typename Functor> void forEachModule(Functor Callback) {
556     if (ModuleToSummariesForIndex) {
557       for (const auto &M : *ModuleToSummariesForIndex) {
558         const auto &MPI = Index.modulePaths().find(M.first);
559         if (MPI == Index.modulePaths().end()) {
560           // This should only happen if the bitcode file was empty, in which
561           // case we shouldn't be importing (the ModuleToSummariesForIndex
562           // would only include the module we are writing and index for).
563           assert(ModuleToSummariesForIndex->size() == 1);
564           continue;
565         }
566         Callback(*MPI);
567       }
568     } else {
569       // Since StringMap iteration order isn't guaranteed, order by path string
570       // first.
571       // FIXME: Make this a vector of StringMapEntry instead to avoid the later
572       // map lookup.
573       std::vector<StringRef> ModulePaths;
574       for (auto &[ModPath, _] : Index.modulePaths())
575         ModulePaths.push_back(ModPath);
576       llvm::sort(ModulePaths.begin(), ModulePaths.end());
577       for (auto &ModPath : ModulePaths)
578         Callback(*Index.modulePaths().find(ModPath));
579     }
580   }
581 
582   /// Main entry point for writing a combined index to bitcode.
583   void write();
584 
585 private:
586   void writeModStrings();
587   void writeCombinedGlobalValueSummary();
588 
589   std::optional<unsigned> getValueId(GlobalValue::GUID ValGUID) {
590     auto VMI = GUIDToValueIdMap.find(ValGUID);
591     if (VMI == GUIDToValueIdMap.end())
592       return std::nullopt;
593     return VMI->second;
594   }
595 
596   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
597 };
598 
599 } // end anonymous namespace
600 
601 static unsigned getEncodedCastOpcode(unsigned Opcode) {
602   switch (Opcode) {
603   default: llvm_unreachable("Unknown cast instruction!");
604   case Instruction::Trunc   : return bitc::CAST_TRUNC;
605   case Instruction::ZExt    : return bitc::CAST_ZEXT;
606   case Instruction::SExt    : return bitc::CAST_SEXT;
607   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
608   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
609   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
610   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
611   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
612   case Instruction::FPExt   : return bitc::CAST_FPEXT;
613   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
614   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
615   case Instruction::BitCast : return bitc::CAST_BITCAST;
616   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
617   }
618 }
619 
620 static unsigned getEncodedUnaryOpcode(unsigned Opcode) {
621   switch (Opcode) {
622   default: llvm_unreachable("Unknown binary instruction!");
623   case Instruction::FNeg: return bitc::UNOP_FNEG;
624   }
625 }
626 
627 static unsigned getEncodedBinaryOpcode(unsigned Opcode) {
628   switch (Opcode) {
629   default: llvm_unreachable("Unknown binary instruction!");
630   case Instruction::Add:
631   case Instruction::FAdd: return bitc::BINOP_ADD;
632   case Instruction::Sub:
633   case Instruction::FSub: return bitc::BINOP_SUB;
634   case Instruction::Mul:
635   case Instruction::FMul: return bitc::BINOP_MUL;
636   case Instruction::UDiv: return bitc::BINOP_UDIV;
637   case Instruction::FDiv:
638   case Instruction::SDiv: return bitc::BINOP_SDIV;
639   case Instruction::URem: return bitc::BINOP_UREM;
640   case Instruction::FRem:
641   case Instruction::SRem: return bitc::BINOP_SREM;
642   case Instruction::Shl:  return bitc::BINOP_SHL;
643   case Instruction::LShr: return bitc::BINOP_LSHR;
644   case Instruction::AShr: return bitc::BINOP_ASHR;
645   case Instruction::And:  return bitc::BINOP_AND;
646   case Instruction::Or:   return bitc::BINOP_OR;
647   case Instruction::Xor:  return bitc::BINOP_XOR;
648   }
649 }
650 
651 static unsigned getEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
652   switch (Op) {
653   default: llvm_unreachable("Unknown RMW operation!");
654   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
655   case AtomicRMWInst::Add: return bitc::RMW_ADD;
656   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
657   case AtomicRMWInst::And: return bitc::RMW_AND;
658   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
659   case AtomicRMWInst::Or: return bitc::RMW_OR;
660   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
661   case AtomicRMWInst::Max: return bitc::RMW_MAX;
662   case AtomicRMWInst::Min: return bitc::RMW_MIN;
663   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
664   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
665   case AtomicRMWInst::FAdd: return bitc::RMW_FADD;
666   case AtomicRMWInst::FSub: return bitc::RMW_FSUB;
667   case AtomicRMWInst::FMax: return bitc::RMW_FMAX;
668   case AtomicRMWInst::FMin: return bitc::RMW_FMIN;
669   case AtomicRMWInst::UIncWrap:
670     return bitc::RMW_UINC_WRAP;
671   case AtomicRMWInst::UDecWrap:
672     return bitc::RMW_UDEC_WRAP;
673   case AtomicRMWInst::USubCond:
674     return bitc::RMW_USUB_COND;
675   case AtomicRMWInst::USubSat:
676     return bitc::RMW_USUB_SAT;
677   }
678 }
679 
680 static unsigned getEncodedOrdering(AtomicOrdering Ordering) {
681   switch (Ordering) {
682   case AtomicOrdering::NotAtomic: return bitc::ORDERING_NOTATOMIC;
683   case AtomicOrdering::Unordered: return bitc::ORDERING_UNORDERED;
684   case AtomicOrdering::Monotonic: return bitc::ORDERING_MONOTONIC;
685   case AtomicOrdering::Acquire: return bitc::ORDERING_ACQUIRE;
686   case AtomicOrdering::Release: return bitc::ORDERING_RELEASE;
687   case AtomicOrdering::AcquireRelease: return bitc::ORDERING_ACQREL;
688   case AtomicOrdering::SequentiallyConsistent: return bitc::ORDERING_SEQCST;
689   }
690   llvm_unreachable("Invalid ordering");
691 }
692 
693 static void writeStringRecord(BitstreamWriter &Stream, unsigned Code,
694                               StringRef Str, unsigned AbbrevToUse) {
695   SmallVector<unsigned, 64> Vals;
696 
697   // Code: [strchar x N]
698   for (char C : Str) {
699     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(C))
700       AbbrevToUse = 0;
701     Vals.push_back(C);
702   }
703 
704   // Emit the finished record.
705   Stream.EmitRecord(Code, Vals, AbbrevToUse);
706 }
707 
708 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
709   switch (Kind) {
710   case Attribute::Alignment:
711     return bitc::ATTR_KIND_ALIGNMENT;
712   case Attribute::AllocAlign:
713     return bitc::ATTR_KIND_ALLOC_ALIGN;
714   case Attribute::AllocSize:
715     return bitc::ATTR_KIND_ALLOC_SIZE;
716   case Attribute::AlwaysInline:
717     return bitc::ATTR_KIND_ALWAYS_INLINE;
718   case Attribute::Builtin:
719     return bitc::ATTR_KIND_BUILTIN;
720   case Attribute::ByVal:
721     return bitc::ATTR_KIND_BY_VAL;
722   case Attribute::Convergent:
723     return bitc::ATTR_KIND_CONVERGENT;
724   case Attribute::InAlloca:
725     return bitc::ATTR_KIND_IN_ALLOCA;
726   case Attribute::Cold:
727     return bitc::ATTR_KIND_COLD;
728   case Attribute::DisableSanitizerInstrumentation:
729     return bitc::ATTR_KIND_DISABLE_SANITIZER_INSTRUMENTATION;
730   case Attribute::FnRetThunkExtern:
731     return bitc::ATTR_KIND_FNRETTHUNK_EXTERN;
732   case Attribute::Hot:
733     return bitc::ATTR_KIND_HOT;
734   case Attribute::ElementType:
735     return bitc::ATTR_KIND_ELEMENTTYPE;
736   case Attribute::HybridPatchable:
737     return bitc::ATTR_KIND_HYBRID_PATCHABLE;
738   case Attribute::InlineHint:
739     return bitc::ATTR_KIND_INLINE_HINT;
740   case Attribute::InReg:
741     return bitc::ATTR_KIND_IN_REG;
742   case Attribute::JumpTable:
743     return bitc::ATTR_KIND_JUMP_TABLE;
744   case Attribute::MinSize:
745     return bitc::ATTR_KIND_MIN_SIZE;
746   case Attribute::AllocatedPointer:
747     return bitc::ATTR_KIND_ALLOCATED_POINTER;
748   case Attribute::AllocKind:
749     return bitc::ATTR_KIND_ALLOC_KIND;
750   case Attribute::Memory:
751     return bitc::ATTR_KIND_MEMORY;
752   case Attribute::NoFPClass:
753     return bitc::ATTR_KIND_NOFPCLASS;
754   case Attribute::Naked:
755     return bitc::ATTR_KIND_NAKED;
756   case Attribute::Nest:
757     return bitc::ATTR_KIND_NEST;
758   case Attribute::NoAlias:
759     return bitc::ATTR_KIND_NO_ALIAS;
760   case Attribute::NoBuiltin:
761     return bitc::ATTR_KIND_NO_BUILTIN;
762   case Attribute::NoCallback:
763     return bitc::ATTR_KIND_NO_CALLBACK;
764   case Attribute::NoCapture:
765     return bitc::ATTR_KIND_NO_CAPTURE;
766   case Attribute::NoDivergenceSource:
767     return bitc::ATTR_KIND_NO_DIVERGENCE_SOURCE;
768   case Attribute::NoDuplicate:
769     return bitc::ATTR_KIND_NO_DUPLICATE;
770   case Attribute::NoFree:
771     return bitc::ATTR_KIND_NOFREE;
772   case Attribute::NoImplicitFloat:
773     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
774   case Attribute::NoInline:
775     return bitc::ATTR_KIND_NO_INLINE;
776   case Attribute::NoRecurse:
777     return bitc::ATTR_KIND_NO_RECURSE;
778   case Attribute::NoMerge:
779     return bitc::ATTR_KIND_NO_MERGE;
780   case Attribute::NonLazyBind:
781     return bitc::ATTR_KIND_NON_LAZY_BIND;
782   case Attribute::NonNull:
783     return bitc::ATTR_KIND_NON_NULL;
784   case Attribute::Dereferenceable:
785     return bitc::ATTR_KIND_DEREFERENCEABLE;
786   case Attribute::DereferenceableOrNull:
787     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
788   case Attribute::NoRedZone:
789     return bitc::ATTR_KIND_NO_RED_ZONE;
790   case Attribute::NoReturn:
791     return bitc::ATTR_KIND_NO_RETURN;
792   case Attribute::NoSync:
793     return bitc::ATTR_KIND_NOSYNC;
794   case Attribute::NoCfCheck:
795     return bitc::ATTR_KIND_NOCF_CHECK;
796   case Attribute::NoProfile:
797     return bitc::ATTR_KIND_NO_PROFILE;
798   case Attribute::SkipProfile:
799     return bitc::ATTR_KIND_SKIP_PROFILE;
800   case Attribute::NoUnwind:
801     return bitc::ATTR_KIND_NO_UNWIND;
802   case Attribute::NoSanitizeBounds:
803     return bitc::ATTR_KIND_NO_SANITIZE_BOUNDS;
804   case Attribute::NoSanitizeCoverage:
805     return bitc::ATTR_KIND_NO_SANITIZE_COVERAGE;
806   case Attribute::NullPointerIsValid:
807     return bitc::ATTR_KIND_NULL_POINTER_IS_VALID;
808   case Attribute::OptimizeForDebugging:
809     return bitc::ATTR_KIND_OPTIMIZE_FOR_DEBUGGING;
810   case Attribute::OptForFuzzing:
811     return bitc::ATTR_KIND_OPT_FOR_FUZZING;
812   case Attribute::OptimizeForSize:
813     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
814   case Attribute::OptimizeNone:
815     return bitc::ATTR_KIND_OPTIMIZE_NONE;
816   case Attribute::ReadNone:
817     return bitc::ATTR_KIND_READ_NONE;
818   case Attribute::ReadOnly:
819     return bitc::ATTR_KIND_READ_ONLY;
820   case Attribute::Returned:
821     return bitc::ATTR_KIND_RETURNED;
822   case Attribute::ReturnsTwice:
823     return bitc::ATTR_KIND_RETURNS_TWICE;
824   case Attribute::SExt:
825     return bitc::ATTR_KIND_S_EXT;
826   case Attribute::Speculatable:
827     return bitc::ATTR_KIND_SPECULATABLE;
828   case Attribute::StackAlignment:
829     return bitc::ATTR_KIND_STACK_ALIGNMENT;
830   case Attribute::StackProtect:
831     return bitc::ATTR_KIND_STACK_PROTECT;
832   case Attribute::StackProtectReq:
833     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
834   case Attribute::StackProtectStrong:
835     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
836   case Attribute::SafeStack:
837     return bitc::ATTR_KIND_SAFESTACK;
838   case Attribute::ShadowCallStack:
839     return bitc::ATTR_KIND_SHADOWCALLSTACK;
840   case Attribute::StrictFP:
841     return bitc::ATTR_KIND_STRICT_FP;
842   case Attribute::StructRet:
843     return bitc::ATTR_KIND_STRUCT_RET;
844   case Attribute::SanitizeAddress:
845     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
846   case Attribute::SanitizeHWAddress:
847     return bitc::ATTR_KIND_SANITIZE_HWADDRESS;
848   case Attribute::SanitizeThread:
849     return bitc::ATTR_KIND_SANITIZE_THREAD;
850   case Attribute::SanitizeMemory:
851     return bitc::ATTR_KIND_SANITIZE_MEMORY;
852   case Attribute::SanitizeNumericalStability:
853     return bitc::ATTR_KIND_SANITIZE_NUMERICAL_STABILITY;
854   case Attribute::SanitizeRealtime:
855     return bitc::ATTR_KIND_SANITIZE_REALTIME;
856   case Attribute::SanitizeRealtimeUnsafe:
857     return bitc::ATTR_KIND_SANITIZE_REALTIME_UNSAFE;
858   case Attribute::SpeculativeLoadHardening:
859     return bitc::ATTR_KIND_SPECULATIVE_LOAD_HARDENING;
860   case Attribute::SwiftError:
861     return bitc::ATTR_KIND_SWIFT_ERROR;
862   case Attribute::SwiftSelf:
863     return bitc::ATTR_KIND_SWIFT_SELF;
864   case Attribute::SwiftAsync:
865     return bitc::ATTR_KIND_SWIFT_ASYNC;
866   case Attribute::UWTable:
867     return bitc::ATTR_KIND_UW_TABLE;
868   case Attribute::VScaleRange:
869     return bitc::ATTR_KIND_VSCALE_RANGE;
870   case Attribute::WillReturn:
871     return bitc::ATTR_KIND_WILLRETURN;
872   case Attribute::WriteOnly:
873     return bitc::ATTR_KIND_WRITEONLY;
874   case Attribute::ZExt:
875     return bitc::ATTR_KIND_Z_EXT;
876   case Attribute::ImmArg:
877     return bitc::ATTR_KIND_IMMARG;
878   case Attribute::SanitizeMemTag:
879     return bitc::ATTR_KIND_SANITIZE_MEMTAG;
880   case Attribute::Preallocated:
881     return bitc::ATTR_KIND_PREALLOCATED;
882   case Attribute::NoUndef:
883     return bitc::ATTR_KIND_NOUNDEF;
884   case Attribute::ByRef:
885     return bitc::ATTR_KIND_BYREF;
886   case Attribute::MustProgress:
887     return bitc::ATTR_KIND_MUSTPROGRESS;
888   case Attribute::PresplitCoroutine:
889     return bitc::ATTR_KIND_PRESPLIT_COROUTINE;
890   case Attribute::Writable:
891     return bitc::ATTR_KIND_WRITABLE;
892   case Attribute::CoroDestroyOnlyWhenComplete:
893     return bitc::ATTR_KIND_CORO_ONLY_DESTROY_WHEN_COMPLETE;
894   case Attribute::CoroElideSafe:
895     return bitc::ATTR_KIND_CORO_ELIDE_SAFE;
896   case Attribute::DeadOnUnwind:
897     return bitc::ATTR_KIND_DEAD_ON_UNWIND;
898   case Attribute::Range:
899     return bitc::ATTR_KIND_RANGE;
900   case Attribute::Initializes:
901     return bitc::ATTR_KIND_INITIALIZES;
902   case Attribute::NoExt:
903     return bitc::ATTR_KIND_NO_EXT;
904   case Attribute::EndAttrKinds:
905     llvm_unreachable("Can not encode end-attribute kinds marker.");
906   case Attribute::None:
907     llvm_unreachable("Can not encode none-attribute.");
908   case Attribute::EmptyKey:
909   case Attribute::TombstoneKey:
910     llvm_unreachable("Trying to encode EmptyKey/TombstoneKey");
911   }
912 
913   llvm_unreachable("Trying to encode unknown attribute");
914 }
915 
916 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
917   if ((int64_t)V >= 0)
918     Vals.push_back(V << 1);
919   else
920     Vals.push_back((-V << 1) | 1);
921 }
922 
923 static void emitWideAPInt(SmallVectorImpl<uint64_t> &Vals, const APInt &A) {
924   // We have an arbitrary precision integer value to write whose
925   // bit width is > 64. However, in canonical unsigned integer
926   // format it is likely that the high bits are going to be zero.
927   // So, we only write the number of active words.
928   unsigned NumWords = A.getActiveWords();
929   const uint64_t *RawData = A.getRawData();
930   for (unsigned i = 0; i < NumWords; i++)
931     emitSignedInt64(Vals, RawData[i]);
932 }
933 
934 static void emitConstantRange(SmallVectorImpl<uint64_t> &Record,
935                               const ConstantRange &CR, bool EmitBitWidth) {
936   unsigned BitWidth = CR.getBitWidth();
937   if (EmitBitWidth)
938     Record.push_back(BitWidth);
939   if (BitWidth > 64) {
940     Record.push_back(CR.getLower().getActiveWords() |
941                      (uint64_t(CR.getUpper().getActiveWords()) << 32));
942     emitWideAPInt(Record, CR.getLower());
943     emitWideAPInt(Record, CR.getUpper());
944   } else {
945     emitSignedInt64(Record, CR.getLower().getSExtValue());
946     emitSignedInt64(Record, CR.getUpper().getSExtValue());
947   }
948 }
949 
950 void ModuleBitcodeWriter::writeAttributeGroupTable() {
951   const std::vector<ValueEnumerator::IndexAndAttrSet> &AttrGrps =
952       VE.getAttributeGroups();
953   if (AttrGrps.empty()) return;
954 
955   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
956 
957   SmallVector<uint64_t, 64> Record;
958   for (ValueEnumerator::IndexAndAttrSet Pair : AttrGrps) {
959     unsigned AttrListIndex = Pair.first;
960     AttributeSet AS = Pair.second;
961     Record.push_back(VE.getAttributeGroupID(Pair));
962     Record.push_back(AttrListIndex);
963 
964     for (Attribute Attr : AS) {
965       if (Attr.isEnumAttribute()) {
966         Record.push_back(0);
967         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
968       } else if (Attr.isIntAttribute()) {
969         Record.push_back(1);
970         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
971         Record.push_back(Attr.getValueAsInt());
972       } else if (Attr.isStringAttribute()) {
973         StringRef Kind = Attr.getKindAsString();
974         StringRef Val = Attr.getValueAsString();
975 
976         Record.push_back(Val.empty() ? 3 : 4);
977         Record.append(Kind.begin(), Kind.end());
978         Record.push_back(0);
979         if (!Val.empty()) {
980           Record.append(Val.begin(), Val.end());
981           Record.push_back(0);
982         }
983       } else if (Attr.isTypeAttribute()) {
984         Type *Ty = Attr.getValueAsType();
985         Record.push_back(Ty ? 6 : 5);
986         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
987         if (Ty)
988           Record.push_back(VE.getTypeID(Attr.getValueAsType()));
989       } else if (Attr.isConstantRangeAttribute()) {
990         Record.push_back(7);
991         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
992         emitConstantRange(Record, Attr.getValueAsConstantRange(),
993                           /*EmitBitWidth=*/true);
994       } else {
995         assert(Attr.isConstantRangeListAttribute());
996         Record.push_back(8);
997         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
998         ArrayRef<ConstantRange> Val = Attr.getValueAsConstantRangeList();
999         Record.push_back(Val.size());
1000         Record.push_back(Val[0].getBitWidth());
1001         for (auto &CR : Val)
1002           emitConstantRange(Record, CR, /*EmitBitWidth=*/false);
1003       }
1004     }
1005 
1006     Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
1007     Record.clear();
1008   }
1009 
1010   Stream.ExitBlock();
1011 }
1012 
1013 void ModuleBitcodeWriter::writeAttributeTable() {
1014   const std::vector<AttributeList> &Attrs = VE.getAttributeLists();
1015   if (Attrs.empty()) return;
1016 
1017   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
1018 
1019   SmallVector<uint64_t, 64> Record;
1020   for (const AttributeList &AL : Attrs) {
1021     for (unsigned i : AL.indexes()) {
1022       AttributeSet AS = AL.getAttributes(i);
1023       if (AS.hasAttributes())
1024         Record.push_back(VE.getAttributeGroupID({i, AS}));
1025     }
1026 
1027     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
1028     Record.clear();
1029   }
1030 
1031   Stream.ExitBlock();
1032 }
1033 
1034 /// WriteTypeTable - Write out the type table for a module.
1035 void ModuleBitcodeWriter::writeTypeTable() {
1036   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
1037 
1038   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
1039   SmallVector<uint64_t, 64> TypeVals;
1040 
1041   uint64_t NumBits = VE.computeBitsRequiredForTypeIndices();
1042 
1043   // Abbrev for TYPE_CODE_OPAQUE_POINTER.
1044   auto Abbv = std::make_shared<BitCodeAbbrev>();
1045   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_OPAQUE_POINTER));
1046   Abbv->Add(BitCodeAbbrevOp(0)); // Addrspace = 0
1047   unsigned OpaquePtrAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1048 
1049   // Abbrev for TYPE_CODE_FUNCTION.
1050   Abbv = std::make_shared<BitCodeAbbrev>();
1051   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
1052   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
1053   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1054   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1055   unsigned FunctionAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1056 
1057   // Abbrev for TYPE_CODE_STRUCT_ANON.
1058   Abbv = std::make_shared<BitCodeAbbrev>();
1059   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
1060   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
1061   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1062   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1063   unsigned StructAnonAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1064 
1065   // Abbrev for TYPE_CODE_STRUCT_NAME.
1066   Abbv = std::make_shared<BitCodeAbbrev>();
1067   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
1068   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1069   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1070   unsigned StructNameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1071 
1072   // Abbrev for TYPE_CODE_STRUCT_NAMED.
1073   Abbv = std::make_shared<BitCodeAbbrev>();
1074   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
1075   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
1076   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1077   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1078   unsigned StructNamedAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1079 
1080   // Abbrev for TYPE_CODE_ARRAY.
1081   Abbv = std::make_shared<BitCodeAbbrev>();
1082   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
1083   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
1084   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1085   unsigned ArrayAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1086 
1087   // Emit an entry count so the reader can reserve space.
1088   TypeVals.push_back(TypeList.size());
1089   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
1090   TypeVals.clear();
1091 
1092   // Loop over all of the types, emitting each in turn.
1093   for (Type *T : TypeList) {
1094     int AbbrevToUse = 0;
1095     unsigned Code = 0;
1096 
1097     switch (T->getTypeID()) {
1098     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
1099     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
1100     case Type::BFloatTyID:    Code = bitc::TYPE_CODE_BFLOAT;    break;
1101     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
1102     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
1103     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
1104     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
1105     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
1106     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
1107     case Type::MetadataTyID:
1108       Code = bitc::TYPE_CODE_METADATA;
1109       break;
1110     case Type::X86_AMXTyID:   Code = bitc::TYPE_CODE_X86_AMX;   break;
1111     case Type::TokenTyID:     Code = bitc::TYPE_CODE_TOKEN;     break;
1112     case Type::IntegerTyID:
1113       // INTEGER: [width]
1114       Code = bitc::TYPE_CODE_INTEGER;
1115       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
1116       break;
1117     case Type::PointerTyID: {
1118       PointerType *PTy = cast<PointerType>(T);
1119       unsigned AddressSpace = PTy->getAddressSpace();
1120       // OPAQUE_POINTER: [address space]
1121       Code = bitc::TYPE_CODE_OPAQUE_POINTER;
1122       TypeVals.push_back(AddressSpace);
1123       if (AddressSpace == 0)
1124         AbbrevToUse = OpaquePtrAbbrev;
1125       break;
1126     }
1127     case Type::FunctionTyID: {
1128       FunctionType *FT = cast<FunctionType>(T);
1129       // FUNCTION: [isvararg, retty, paramty x N]
1130       Code = bitc::TYPE_CODE_FUNCTION;
1131       TypeVals.push_back(FT->isVarArg());
1132       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
1133       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
1134         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
1135       AbbrevToUse = FunctionAbbrev;
1136       break;
1137     }
1138     case Type::StructTyID: {
1139       StructType *ST = cast<StructType>(T);
1140       // STRUCT: [ispacked, eltty x N]
1141       TypeVals.push_back(ST->isPacked());
1142       // Output all of the element types.
1143       for (Type *ET : ST->elements())
1144         TypeVals.push_back(VE.getTypeID(ET));
1145 
1146       if (ST->isLiteral()) {
1147         Code = bitc::TYPE_CODE_STRUCT_ANON;
1148         AbbrevToUse = StructAnonAbbrev;
1149       } else {
1150         if (ST->isOpaque()) {
1151           Code = bitc::TYPE_CODE_OPAQUE;
1152         } else {
1153           Code = bitc::TYPE_CODE_STRUCT_NAMED;
1154           AbbrevToUse = StructNamedAbbrev;
1155         }
1156 
1157         // Emit the name if it is present.
1158         if (!ST->getName().empty())
1159           writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
1160                             StructNameAbbrev);
1161       }
1162       break;
1163     }
1164     case Type::ArrayTyID: {
1165       ArrayType *AT = cast<ArrayType>(T);
1166       // ARRAY: [numelts, eltty]
1167       Code = bitc::TYPE_CODE_ARRAY;
1168       TypeVals.push_back(AT->getNumElements());
1169       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
1170       AbbrevToUse = ArrayAbbrev;
1171       break;
1172     }
1173     case Type::FixedVectorTyID:
1174     case Type::ScalableVectorTyID: {
1175       VectorType *VT = cast<VectorType>(T);
1176       // VECTOR [numelts, eltty] or
1177       //        [numelts, eltty, scalable]
1178       Code = bitc::TYPE_CODE_VECTOR;
1179       TypeVals.push_back(VT->getElementCount().getKnownMinValue());
1180       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
1181       if (isa<ScalableVectorType>(VT))
1182         TypeVals.push_back(true);
1183       break;
1184     }
1185     case Type::TargetExtTyID: {
1186       TargetExtType *TET = cast<TargetExtType>(T);
1187       Code = bitc::TYPE_CODE_TARGET_TYPE;
1188       writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, TET->getName(),
1189                         StructNameAbbrev);
1190       TypeVals.push_back(TET->getNumTypeParameters());
1191       for (Type *InnerTy : TET->type_params())
1192         TypeVals.push_back(VE.getTypeID(InnerTy));
1193       for (unsigned IntParam : TET->int_params())
1194         TypeVals.push_back(IntParam);
1195       break;
1196     }
1197     case Type::TypedPointerTyID:
1198       llvm_unreachable("Typed pointers cannot be added to IR modules");
1199     }
1200 
1201     // Emit the finished record.
1202     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
1203     TypeVals.clear();
1204   }
1205 
1206   Stream.ExitBlock();
1207 }
1208 
1209 static unsigned getEncodedLinkage(const GlobalValue::LinkageTypes Linkage) {
1210   switch (Linkage) {
1211   case GlobalValue::ExternalLinkage:
1212     return 0;
1213   case GlobalValue::WeakAnyLinkage:
1214     return 16;
1215   case GlobalValue::AppendingLinkage:
1216     return 2;
1217   case GlobalValue::InternalLinkage:
1218     return 3;
1219   case GlobalValue::LinkOnceAnyLinkage:
1220     return 18;
1221   case GlobalValue::ExternalWeakLinkage:
1222     return 7;
1223   case GlobalValue::CommonLinkage:
1224     return 8;
1225   case GlobalValue::PrivateLinkage:
1226     return 9;
1227   case GlobalValue::WeakODRLinkage:
1228     return 17;
1229   case GlobalValue::LinkOnceODRLinkage:
1230     return 19;
1231   case GlobalValue::AvailableExternallyLinkage:
1232     return 12;
1233   }
1234   llvm_unreachable("Invalid linkage");
1235 }
1236 
1237 static unsigned getEncodedLinkage(const GlobalValue &GV) {
1238   return getEncodedLinkage(GV.getLinkage());
1239 }
1240 
1241 static uint64_t getEncodedFFlags(FunctionSummary::FFlags Flags) {
1242   uint64_t RawFlags = 0;
1243   RawFlags |= Flags.ReadNone;
1244   RawFlags |= (Flags.ReadOnly << 1);
1245   RawFlags |= (Flags.NoRecurse << 2);
1246   RawFlags |= (Flags.ReturnDoesNotAlias << 3);
1247   RawFlags |= (Flags.NoInline << 4);
1248   RawFlags |= (Flags.AlwaysInline << 5);
1249   RawFlags |= (Flags.NoUnwind << 6);
1250   RawFlags |= (Flags.MayThrow << 7);
1251   RawFlags |= (Flags.HasUnknownCall << 8);
1252   RawFlags |= (Flags.MustBeUnreachable << 9);
1253   return RawFlags;
1254 }
1255 
1256 // Decode the flags for GlobalValue in the summary. See getDecodedGVSummaryFlags
1257 // in BitcodeReader.cpp.
1258 static uint64_t getEncodedGVSummaryFlags(GlobalValueSummary::GVFlags Flags,
1259                                          bool ImportAsDecl = false) {
1260   uint64_t RawFlags = 0;
1261 
1262   RawFlags |= Flags.NotEligibleToImport; // bool
1263   RawFlags |= (Flags.Live << 1);
1264   RawFlags |= (Flags.DSOLocal << 2);
1265   RawFlags |= (Flags.CanAutoHide << 3);
1266 
1267   // Linkage don't need to be remapped at that time for the summary. Any future
1268   // change to the getEncodedLinkage() function will need to be taken into
1269   // account here as well.
1270   RawFlags = (RawFlags << 4) | Flags.Linkage; // 4 bits
1271 
1272   RawFlags |= (Flags.Visibility << 8); // 2 bits
1273 
1274   unsigned ImportType = Flags.ImportType | ImportAsDecl;
1275   RawFlags |= (ImportType << 10); // 1 bit
1276 
1277   return RawFlags;
1278 }
1279 
1280 static uint64_t getEncodedGVarFlags(GlobalVarSummary::GVarFlags Flags) {
1281   uint64_t RawFlags = Flags.MaybeReadOnly | (Flags.MaybeWriteOnly << 1) |
1282                       (Flags.Constant << 2) | Flags.VCallVisibility << 3;
1283   return RawFlags;
1284 }
1285 
1286 static uint64_t getEncodedHotnessCallEdgeInfo(const CalleeInfo &CI) {
1287   uint64_t RawFlags = 0;
1288 
1289   RawFlags |= CI.Hotness;            // 3 bits
1290   RawFlags |= (CI.HasTailCall << 3); // 1 bit
1291 
1292   return RawFlags;
1293 }
1294 
1295 static uint64_t getEncodedRelBFCallEdgeInfo(const CalleeInfo &CI) {
1296   uint64_t RawFlags = 0;
1297 
1298   RawFlags |= CI.RelBlockFreq; // CalleeInfo::RelBlockFreqBits bits
1299   RawFlags |= (CI.HasTailCall << CalleeInfo::RelBlockFreqBits); // 1 bit
1300 
1301   return RawFlags;
1302 }
1303 
1304 static unsigned getEncodedVisibility(const GlobalValue &GV) {
1305   switch (GV.getVisibility()) {
1306   case GlobalValue::DefaultVisibility:   return 0;
1307   case GlobalValue::HiddenVisibility:    return 1;
1308   case GlobalValue::ProtectedVisibility: return 2;
1309   }
1310   llvm_unreachable("Invalid visibility");
1311 }
1312 
1313 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
1314   switch (GV.getDLLStorageClass()) {
1315   case GlobalValue::DefaultStorageClass:   return 0;
1316   case GlobalValue::DLLImportStorageClass: return 1;
1317   case GlobalValue::DLLExportStorageClass: return 2;
1318   }
1319   llvm_unreachable("Invalid DLL storage class");
1320 }
1321 
1322 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
1323   switch (GV.getThreadLocalMode()) {
1324     case GlobalVariable::NotThreadLocal:         return 0;
1325     case GlobalVariable::GeneralDynamicTLSModel: return 1;
1326     case GlobalVariable::LocalDynamicTLSModel:   return 2;
1327     case GlobalVariable::InitialExecTLSModel:    return 3;
1328     case GlobalVariable::LocalExecTLSModel:      return 4;
1329   }
1330   llvm_unreachable("Invalid TLS model");
1331 }
1332 
1333 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
1334   switch (C.getSelectionKind()) {
1335   case Comdat::Any:
1336     return bitc::COMDAT_SELECTION_KIND_ANY;
1337   case Comdat::ExactMatch:
1338     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
1339   case Comdat::Largest:
1340     return bitc::COMDAT_SELECTION_KIND_LARGEST;
1341   case Comdat::NoDeduplicate:
1342     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
1343   case Comdat::SameSize:
1344     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
1345   }
1346   llvm_unreachable("Invalid selection kind");
1347 }
1348 
1349 static unsigned getEncodedUnnamedAddr(const GlobalValue &GV) {
1350   switch (GV.getUnnamedAddr()) {
1351   case GlobalValue::UnnamedAddr::None:   return 0;
1352   case GlobalValue::UnnamedAddr::Local:  return 2;
1353   case GlobalValue::UnnamedAddr::Global: return 1;
1354   }
1355   llvm_unreachable("Invalid unnamed_addr");
1356 }
1357 
1358 size_t ModuleBitcodeWriter::addToStrtab(StringRef Str) {
1359   if (GenerateHash)
1360     Hasher.update(Str);
1361   return StrtabBuilder.add(Str);
1362 }
1363 
1364 void ModuleBitcodeWriter::writeComdats() {
1365   SmallVector<unsigned, 64> Vals;
1366   for (const Comdat *C : VE.getComdats()) {
1367     // COMDAT: [strtab offset, strtab size, selection_kind]
1368     Vals.push_back(addToStrtab(C->getName()));
1369     Vals.push_back(C->getName().size());
1370     Vals.push_back(getEncodedComdatSelectionKind(*C));
1371     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
1372     Vals.clear();
1373   }
1374 }
1375 
1376 /// Write a record that will eventually hold the word offset of the
1377 /// module-level VST. For now the offset is 0, which will be backpatched
1378 /// after the real VST is written. Saves the bit offset to backpatch.
1379 void ModuleBitcodeWriter::writeValueSymbolTableForwardDecl() {
1380   // Write a placeholder value in for the offset of the real VST,
1381   // which is written after the function blocks so that it can include
1382   // the offset of each function. The placeholder offset will be
1383   // updated when the real VST is written.
1384   auto Abbv = std::make_shared<BitCodeAbbrev>();
1385   Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_VSTOFFSET));
1386   // Blocks are 32-bit aligned, so we can use a 32-bit word offset to
1387   // hold the real VST offset. Must use fixed instead of VBR as we don't
1388   // know how many VBR chunks to reserve ahead of time.
1389   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1390   unsigned VSTOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1391 
1392   // Emit the placeholder
1393   uint64_t Vals[] = {bitc::MODULE_CODE_VSTOFFSET, 0};
1394   Stream.EmitRecordWithAbbrev(VSTOffsetAbbrev, Vals);
1395 
1396   // Compute and save the bit offset to the placeholder, which will be
1397   // patched when the real VST is written. We can simply subtract the 32-bit
1398   // fixed size from the current bit number to get the location to backpatch.
1399   VSTOffsetPlaceholder = Stream.GetCurrentBitNo() - 32;
1400 }
1401 
1402 enum StringEncoding { SE_Char6, SE_Fixed7, SE_Fixed8 };
1403 
1404 /// Determine the encoding to use for the given string name and length.
1405 static StringEncoding getStringEncoding(StringRef Str) {
1406   bool isChar6 = true;
1407   for (char C : Str) {
1408     if (isChar6)
1409       isChar6 = BitCodeAbbrevOp::isChar6(C);
1410     if ((unsigned char)C & 128)
1411       // don't bother scanning the rest.
1412       return SE_Fixed8;
1413   }
1414   if (isChar6)
1415     return SE_Char6;
1416   return SE_Fixed7;
1417 }
1418 
1419 static_assert(sizeof(GlobalValue::SanitizerMetadata) <= sizeof(unsigned),
1420               "Sanitizer Metadata is too large for naive serialization.");
1421 static unsigned
1422 serializeSanitizerMetadata(const GlobalValue::SanitizerMetadata &Meta) {
1423   return Meta.NoAddress | (Meta.NoHWAddress << 1) |
1424          (Meta.Memtag << 2) | (Meta.IsDynInit << 3);
1425 }
1426 
1427 /// Emit top-level description of module, including target triple, inline asm,
1428 /// descriptors for global variables, and function prototype info.
1429 /// Returns the bit offset to backpatch with the location of the real VST.
1430 void ModuleBitcodeWriter::writeModuleInfo() {
1431   // Emit various pieces of data attached to a module.
1432   if (!M.getTargetTriple().empty())
1433     writeStringRecord(Stream, bitc::MODULE_CODE_TRIPLE, M.getTargetTriple(),
1434                       0 /*TODO*/);
1435   const std::string &DL = M.getDataLayoutStr();
1436   if (!DL.empty())
1437     writeStringRecord(Stream, bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/);
1438   if (!M.getModuleInlineAsm().empty())
1439     writeStringRecord(Stream, bitc::MODULE_CODE_ASM, M.getModuleInlineAsm(),
1440                       0 /*TODO*/);
1441 
1442   // Emit information about sections and GC, computing how many there are. Also
1443   // compute the maximum alignment value.
1444   std::map<std::string, unsigned> SectionMap;
1445   std::map<std::string, unsigned> GCMap;
1446   MaybeAlign MaxAlignment;
1447   unsigned MaxGlobalType = 0;
1448   const auto UpdateMaxAlignment = [&MaxAlignment](const MaybeAlign A) {
1449     if (A)
1450       MaxAlignment = !MaxAlignment ? *A : std::max(*MaxAlignment, *A);
1451   };
1452   for (const GlobalVariable &GV : M.globals()) {
1453     UpdateMaxAlignment(GV.getAlign());
1454     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
1455     if (GV.hasSection()) {
1456       // Give section names unique ID's.
1457       unsigned &Entry = SectionMap[std::string(GV.getSection())];
1458       if (!Entry) {
1459         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
1460                           0 /*TODO*/);
1461         Entry = SectionMap.size();
1462       }
1463     }
1464   }
1465   for (const Function &F : M) {
1466     UpdateMaxAlignment(F.getAlign());
1467     if (F.hasSection()) {
1468       // Give section names unique ID's.
1469       unsigned &Entry = SectionMap[std::string(F.getSection())];
1470       if (!Entry) {
1471         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
1472                           0 /*TODO*/);
1473         Entry = SectionMap.size();
1474       }
1475     }
1476     if (F.hasGC()) {
1477       // Same for GC names.
1478       unsigned &Entry = GCMap[F.getGC()];
1479       if (!Entry) {
1480         writeStringRecord(Stream, bitc::MODULE_CODE_GCNAME, F.getGC(),
1481                           0 /*TODO*/);
1482         Entry = GCMap.size();
1483       }
1484     }
1485   }
1486 
1487   // Emit abbrev for globals, now that we know # sections and max alignment.
1488   unsigned SimpleGVarAbbrev = 0;
1489   if (!M.global_empty()) {
1490     // Add an abbrev for common globals with no visibility or thread localness.
1491     auto Abbv = std::make_shared<BitCodeAbbrev>();
1492     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
1493     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1494     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1495     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1496                               Log2_32_Ceil(MaxGlobalType+1)));
1497     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
1498                                                            //| explicitType << 1
1499                                                            //| constant
1500     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
1501     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
1502     if (!MaxAlignment)                                     // Alignment.
1503       Abbv->Add(BitCodeAbbrevOp(0));
1504     else {
1505       unsigned MaxEncAlignment = getEncodedAlign(MaxAlignment);
1506       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1507                                Log2_32_Ceil(MaxEncAlignment+1)));
1508     }
1509     if (SectionMap.empty())                                    // Section.
1510       Abbv->Add(BitCodeAbbrevOp(0));
1511     else
1512       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1513                                Log2_32_Ceil(SectionMap.size()+1)));
1514     // Don't bother emitting vis + thread local.
1515     SimpleGVarAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1516   }
1517 
1518   SmallVector<unsigned, 64> Vals;
1519   // Emit the module's source file name.
1520   {
1521     StringEncoding Bits = getStringEncoding(M.getSourceFileName());
1522     BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
1523     if (Bits == SE_Char6)
1524       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
1525     else if (Bits == SE_Fixed7)
1526       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
1527 
1528     // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
1529     auto Abbv = std::make_shared<BitCodeAbbrev>();
1530     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
1531     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1532     Abbv->Add(AbbrevOpToUse);
1533     unsigned FilenameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1534 
1535     for (const auto P : M.getSourceFileName())
1536       Vals.push_back((unsigned char)P);
1537 
1538     // Emit the finished record.
1539     Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
1540     Vals.clear();
1541   }
1542 
1543   // Emit the global variable information.
1544   for (const GlobalVariable &GV : M.globals()) {
1545     unsigned AbbrevToUse = 0;
1546 
1547     // GLOBALVAR: [strtab offset, strtab size, type, isconst, initid,
1548     //             linkage, alignment, section, visibility, threadlocal,
1549     //             unnamed_addr, externally_initialized, dllstorageclass,
1550     //             comdat, attributes, DSO_Local, GlobalSanitizer, code_model]
1551     Vals.push_back(addToStrtab(GV.getName()));
1552     Vals.push_back(GV.getName().size());
1553     Vals.push_back(VE.getTypeID(GV.getValueType()));
1554     Vals.push_back(GV.getType()->getAddressSpace() << 2 | 2 | GV.isConstant());
1555     Vals.push_back(GV.isDeclaration() ? 0 :
1556                    (VE.getValueID(GV.getInitializer()) + 1));
1557     Vals.push_back(getEncodedLinkage(GV));
1558     Vals.push_back(getEncodedAlign(GV.getAlign()));
1559     Vals.push_back(GV.hasSection() ? SectionMap[std::string(GV.getSection())]
1560                                    : 0);
1561     if (GV.isThreadLocal() ||
1562         GV.getVisibility() != GlobalValue::DefaultVisibility ||
1563         GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None ||
1564         GV.isExternallyInitialized() ||
1565         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
1566         GV.hasComdat() || GV.hasAttributes() || GV.isDSOLocal() ||
1567         GV.hasPartition() || GV.hasSanitizerMetadata() || GV.getCodeModel()) {
1568       Vals.push_back(getEncodedVisibility(GV));
1569       Vals.push_back(getEncodedThreadLocalMode(GV));
1570       Vals.push_back(getEncodedUnnamedAddr(GV));
1571       Vals.push_back(GV.isExternallyInitialized());
1572       Vals.push_back(getEncodedDLLStorageClass(GV));
1573       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
1574 
1575       auto AL = GV.getAttributesAsList(AttributeList::FunctionIndex);
1576       Vals.push_back(VE.getAttributeListID(AL));
1577 
1578       Vals.push_back(GV.isDSOLocal());
1579       Vals.push_back(addToStrtab(GV.getPartition()));
1580       Vals.push_back(GV.getPartition().size());
1581 
1582       Vals.push_back((GV.hasSanitizerMetadata() ? serializeSanitizerMetadata(
1583                                                       GV.getSanitizerMetadata())
1584                                                 : 0));
1585       Vals.push_back(GV.getCodeModelRaw());
1586     } else {
1587       AbbrevToUse = SimpleGVarAbbrev;
1588     }
1589 
1590     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
1591     Vals.clear();
1592   }
1593 
1594   // Emit the function proto information.
1595   for (const Function &F : M) {
1596     // FUNCTION:  [strtab offset, strtab size, type, callingconv, isproto,
1597     //             linkage, paramattrs, alignment, section, visibility, gc,
1598     //             unnamed_addr, prologuedata, dllstorageclass, comdat,
1599     //             prefixdata, personalityfn, DSO_Local, addrspace]
1600     Vals.push_back(addToStrtab(F.getName()));
1601     Vals.push_back(F.getName().size());
1602     Vals.push_back(VE.getTypeID(F.getFunctionType()));
1603     Vals.push_back(F.getCallingConv());
1604     Vals.push_back(F.isDeclaration());
1605     Vals.push_back(getEncodedLinkage(F));
1606     Vals.push_back(VE.getAttributeListID(F.getAttributes()));
1607     Vals.push_back(getEncodedAlign(F.getAlign()));
1608     Vals.push_back(F.hasSection() ? SectionMap[std::string(F.getSection())]
1609                                   : 0);
1610     Vals.push_back(getEncodedVisibility(F));
1611     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
1612     Vals.push_back(getEncodedUnnamedAddr(F));
1613     Vals.push_back(F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1)
1614                                        : 0);
1615     Vals.push_back(getEncodedDLLStorageClass(F));
1616     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
1617     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
1618                                      : 0);
1619     Vals.push_back(
1620         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
1621 
1622     Vals.push_back(F.isDSOLocal());
1623     Vals.push_back(F.getAddressSpace());
1624     Vals.push_back(addToStrtab(F.getPartition()));
1625     Vals.push_back(F.getPartition().size());
1626 
1627     unsigned AbbrevToUse = 0;
1628     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
1629     Vals.clear();
1630   }
1631 
1632   // Emit the alias information.
1633   for (const GlobalAlias &A : M.aliases()) {
1634     // ALIAS: [strtab offset, strtab size, alias type, aliasee val#, linkage,
1635     //         visibility, dllstorageclass, threadlocal, unnamed_addr,
1636     //         DSO_Local]
1637     Vals.push_back(addToStrtab(A.getName()));
1638     Vals.push_back(A.getName().size());
1639     Vals.push_back(VE.getTypeID(A.getValueType()));
1640     Vals.push_back(A.getType()->getAddressSpace());
1641     Vals.push_back(VE.getValueID(A.getAliasee()));
1642     Vals.push_back(getEncodedLinkage(A));
1643     Vals.push_back(getEncodedVisibility(A));
1644     Vals.push_back(getEncodedDLLStorageClass(A));
1645     Vals.push_back(getEncodedThreadLocalMode(A));
1646     Vals.push_back(getEncodedUnnamedAddr(A));
1647     Vals.push_back(A.isDSOLocal());
1648     Vals.push_back(addToStrtab(A.getPartition()));
1649     Vals.push_back(A.getPartition().size());
1650 
1651     unsigned AbbrevToUse = 0;
1652     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
1653     Vals.clear();
1654   }
1655 
1656   // Emit the ifunc information.
1657   for (const GlobalIFunc &I : M.ifuncs()) {
1658     // IFUNC: [strtab offset, strtab size, ifunc type, address space, resolver
1659     //         val#, linkage, visibility, DSO_Local]
1660     Vals.push_back(addToStrtab(I.getName()));
1661     Vals.push_back(I.getName().size());
1662     Vals.push_back(VE.getTypeID(I.getValueType()));
1663     Vals.push_back(I.getType()->getAddressSpace());
1664     Vals.push_back(VE.getValueID(I.getResolver()));
1665     Vals.push_back(getEncodedLinkage(I));
1666     Vals.push_back(getEncodedVisibility(I));
1667     Vals.push_back(I.isDSOLocal());
1668     Vals.push_back(addToStrtab(I.getPartition()));
1669     Vals.push_back(I.getPartition().size());
1670     Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
1671     Vals.clear();
1672   }
1673 
1674   writeValueSymbolTableForwardDecl();
1675 }
1676 
1677 static uint64_t getOptimizationFlags(const Value *V) {
1678   uint64_t Flags = 0;
1679 
1680   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
1681     if (OBO->hasNoSignedWrap())
1682       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
1683     if (OBO->hasNoUnsignedWrap())
1684       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
1685   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
1686     if (PEO->isExact())
1687       Flags |= 1 << bitc::PEO_EXACT;
1688   } else if (const auto *PDI = dyn_cast<PossiblyDisjointInst>(V)) {
1689     if (PDI->isDisjoint())
1690       Flags |= 1 << bitc::PDI_DISJOINT;
1691   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
1692     if (FPMO->hasAllowReassoc())
1693       Flags |= bitc::AllowReassoc;
1694     if (FPMO->hasNoNaNs())
1695       Flags |= bitc::NoNaNs;
1696     if (FPMO->hasNoInfs())
1697       Flags |= bitc::NoInfs;
1698     if (FPMO->hasNoSignedZeros())
1699       Flags |= bitc::NoSignedZeros;
1700     if (FPMO->hasAllowReciprocal())
1701       Flags |= bitc::AllowReciprocal;
1702     if (FPMO->hasAllowContract())
1703       Flags |= bitc::AllowContract;
1704     if (FPMO->hasApproxFunc())
1705       Flags |= bitc::ApproxFunc;
1706   } else if (const auto *NNI = dyn_cast<PossiblyNonNegInst>(V)) {
1707     if (NNI->hasNonNeg())
1708       Flags |= 1 << bitc::PNNI_NON_NEG;
1709   } else if (const auto *TI = dyn_cast<TruncInst>(V)) {
1710     if (TI->hasNoSignedWrap())
1711       Flags |= 1 << bitc::TIO_NO_SIGNED_WRAP;
1712     if (TI->hasNoUnsignedWrap())
1713       Flags |= 1 << bitc::TIO_NO_UNSIGNED_WRAP;
1714   } else if (const auto *GEP = dyn_cast<GEPOperator>(V)) {
1715     if (GEP->isInBounds())
1716       Flags |= 1 << bitc::GEP_INBOUNDS;
1717     if (GEP->hasNoUnsignedSignedWrap())
1718       Flags |= 1 << bitc::GEP_NUSW;
1719     if (GEP->hasNoUnsignedWrap())
1720       Flags |= 1 << bitc::GEP_NUW;
1721   }
1722 
1723   return Flags;
1724 }
1725 
1726 void ModuleBitcodeWriter::writeValueAsMetadata(
1727     const ValueAsMetadata *MD, SmallVectorImpl<uint64_t> &Record) {
1728   // Mimic an MDNode with a value as one operand.
1729   Value *V = MD->getValue();
1730   Record.push_back(VE.getTypeID(V->getType()));
1731   Record.push_back(VE.getValueID(V));
1732   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
1733   Record.clear();
1734 }
1735 
1736 void ModuleBitcodeWriter::writeMDTuple(const MDTuple *N,
1737                                        SmallVectorImpl<uint64_t> &Record,
1738                                        unsigned Abbrev) {
1739   for (const MDOperand &MDO : N->operands()) {
1740     Metadata *MD = MDO;
1741     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
1742            "Unexpected function-local metadata");
1743     Record.push_back(VE.getMetadataOrNullID(MD));
1744   }
1745   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
1746                                     : bitc::METADATA_NODE,
1747                     Record, Abbrev);
1748   Record.clear();
1749 }
1750 
1751 unsigned ModuleBitcodeWriter::createDILocationAbbrev() {
1752   // Assume the column is usually under 128, and always output the inlined-at
1753   // location (it's never more expensive than building an array size 1).
1754   auto Abbv = std::make_shared<BitCodeAbbrev>();
1755   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1756   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1757   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1758   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1759   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1760   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1761   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1762   return Stream.EmitAbbrev(std::move(Abbv));
1763 }
1764 
1765 void ModuleBitcodeWriter::writeDILocation(const DILocation *N,
1766                                           SmallVectorImpl<uint64_t> &Record,
1767                                           unsigned &Abbrev) {
1768   if (!Abbrev)
1769     Abbrev = createDILocationAbbrev();
1770 
1771   Record.push_back(N->isDistinct());
1772   Record.push_back(N->getLine());
1773   Record.push_back(N->getColumn());
1774   Record.push_back(VE.getMetadataID(N->getScope()));
1775   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
1776   Record.push_back(N->isImplicitCode());
1777 
1778   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
1779   Record.clear();
1780 }
1781 
1782 unsigned ModuleBitcodeWriter::createGenericDINodeAbbrev() {
1783   // Assume the column is usually under 128, and always output the inlined-at
1784   // location (it's never more expensive than building an array size 1).
1785   auto Abbv = std::make_shared<BitCodeAbbrev>();
1786   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1787   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1788   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1789   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1790   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1791   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1792   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1793   return Stream.EmitAbbrev(std::move(Abbv));
1794 }
1795 
1796 void ModuleBitcodeWriter::writeGenericDINode(const GenericDINode *N,
1797                                              SmallVectorImpl<uint64_t> &Record,
1798                                              unsigned &Abbrev) {
1799   if (!Abbrev)
1800     Abbrev = createGenericDINodeAbbrev();
1801 
1802   Record.push_back(N->isDistinct());
1803   Record.push_back(N->getTag());
1804   Record.push_back(0); // Per-tag version field; unused for now.
1805 
1806   for (auto &I : N->operands())
1807     Record.push_back(VE.getMetadataOrNullID(I));
1808 
1809   Stream.EmitRecord(bitc::METADATA_GENERIC_DEBUG, Record, Abbrev);
1810   Record.clear();
1811 }
1812 
1813 void ModuleBitcodeWriter::writeDISubrange(const DISubrange *N,
1814                                           SmallVectorImpl<uint64_t> &Record,
1815                                           unsigned Abbrev) {
1816   const uint64_t Version = 2 << 1;
1817   Record.push_back((uint64_t)N->isDistinct() | Version);
1818   Record.push_back(VE.getMetadataOrNullID(N->getRawCountNode()));
1819   Record.push_back(VE.getMetadataOrNullID(N->getRawLowerBound()));
1820   Record.push_back(VE.getMetadataOrNullID(N->getRawUpperBound()));
1821   Record.push_back(VE.getMetadataOrNullID(N->getRawStride()));
1822 
1823   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
1824   Record.clear();
1825 }
1826 
1827 void ModuleBitcodeWriter::writeDIGenericSubrange(
1828     const DIGenericSubrange *N, SmallVectorImpl<uint64_t> &Record,
1829     unsigned Abbrev) {
1830   Record.push_back((uint64_t)N->isDistinct());
1831   Record.push_back(VE.getMetadataOrNullID(N->getRawCountNode()));
1832   Record.push_back(VE.getMetadataOrNullID(N->getRawLowerBound()));
1833   Record.push_back(VE.getMetadataOrNullID(N->getRawUpperBound()));
1834   Record.push_back(VE.getMetadataOrNullID(N->getRawStride()));
1835 
1836   Stream.EmitRecord(bitc::METADATA_GENERIC_SUBRANGE, Record, Abbrev);
1837   Record.clear();
1838 }
1839 
1840 void ModuleBitcodeWriter::writeDIEnumerator(const DIEnumerator *N,
1841                                             SmallVectorImpl<uint64_t> &Record,
1842                                             unsigned Abbrev) {
1843   const uint64_t IsBigInt = 1 << 2;
1844   Record.push_back(IsBigInt | (N->isUnsigned() << 1) | N->isDistinct());
1845   Record.push_back(N->getValue().getBitWidth());
1846   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1847   emitWideAPInt(Record, N->getValue());
1848 
1849   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
1850   Record.clear();
1851 }
1852 
1853 void ModuleBitcodeWriter::writeDIBasicType(const DIBasicType *N,
1854                                            SmallVectorImpl<uint64_t> &Record,
1855                                            unsigned Abbrev) {
1856   Record.push_back(N->isDistinct());
1857   Record.push_back(N->getTag());
1858   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1859   Record.push_back(N->getSizeInBits());
1860   Record.push_back(N->getAlignInBits());
1861   Record.push_back(N->getEncoding());
1862   Record.push_back(N->getFlags());
1863 
1864   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
1865   Record.clear();
1866 }
1867 
1868 void ModuleBitcodeWriter::writeDIStringType(const DIStringType *N,
1869                                             SmallVectorImpl<uint64_t> &Record,
1870                                             unsigned Abbrev) {
1871   Record.push_back(N->isDistinct());
1872   Record.push_back(N->getTag());
1873   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1874   Record.push_back(VE.getMetadataOrNullID(N->getStringLength()));
1875   Record.push_back(VE.getMetadataOrNullID(N->getStringLengthExp()));
1876   Record.push_back(VE.getMetadataOrNullID(N->getStringLocationExp()));
1877   Record.push_back(N->getSizeInBits());
1878   Record.push_back(N->getAlignInBits());
1879   Record.push_back(N->getEncoding());
1880 
1881   Stream.EmitRecord(bitc::METADATA_STRING_TYPE, Record, Abbrev);
1882   Record.clear();
1883 }
1884 
1885 void ModuleBitcodeWriter::writeDIDerivedType(const DIDerivedType *N,
1886                                              SmallVectorImpl<uint64_t> &Record,
1887                                              unsigned Abbrev) {
1888   Record.push_back(N->isDistinct());
1889   Record.push_back(N->getTag());
1890   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1891   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1892   Record.push_back(N->getLine());
1893   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1894   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1895   Record.push_back(N->getSizeInBits());
1896   Record.push_back(N->getAlignInBits());
1897   Record.push_back(N->getOffsetInBits());
1898   Record.push_back(N->getFlags());
1899   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
1900 
1901   // DWARF address space is encoded as N->getDWARFAddressSpace() + 1. 0 means
1902   // that there is no DWARF address space associated with DIDerivedType.
1903   if (const auto &DWARFAddressSpace = N->getDWARFAddressSpace())
1904     Record.push_back(*DWARFAddressSpace + 1);
1905   else
1906     Record.push_back(0);
1907 
1908   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
1909 
1910   if (auto PtrAuthData = N->getPtrAuthData())
1911     Record.push_back(PtrAuthData->RawData);
1912   else
1913     Record.push_back(0);
1914 
1915   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
1916   Record.clear();
1917 }
1918 
1919 void ModuleBitcodeWriter::writeDICompositeType(
1920     const DICompositeType *N, SmallVectorImpl<uint64_t> &Record,
1921     unsigned Abbrev) {
1922   const unsigned IsNotUsedInOldTypeRef = 0x2;
1923   Record.push_back(IsNotUsedInOldTypeRef | (unsigned)N->isDistinct());
1924   Record.push_back(N->getTag());
1925   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1926   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1927   Record.push_back(N->getLine());
1928   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1929   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1930   Record.push_back(N->getSizeInBits());
1931   Record.push_back(N->getAlignInBits());
1932   Record.push_back(N->getOffsetInBits());
1933   Record.push_back(N->getFlags());
1934   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1935   Record.push_back(N->getRuntimeLang());
1936   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
1937   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1938   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
1939   Record.push_back(VE.getMetadataOrNullID(N->getDiscriminator()));
1940   Record.push_back(VE.getMetadataOrNullID(N->getRawDataLocation()));
1941   Record.push_back(VE.getMetadataOrNullID(N->getRawAssociated()));
1942   Record.push_back(VE.getMetadataOrNullID(N->getRawAllocated()));
1943   Record.push_back(VE.getMetadataOrNullID(N->getRawRank()));
1944   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
1945 
1946   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
1947   Record.clear();
1948 }
1949 
1950 void ModuleBitcodeWriter::writeDISubroutineType(
1951     const DISubroutineType *N, SmallVectorImpl<uint64_t> &Record,
1952     unsigned Abbrev) {
1953   const unsigned HasNoOldTypeRefs = 0x2;
1954   Record.push_back(HasNoOldTypeRefs | (unsigned)N->isDistinct());
1955   Record.push_back(N->getFlags());
1956   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
1957   Record.push_back(N->getCC());
1958 
1959   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
1960   Record.clear();
1961 }
1962 
1963 void ModuleBitcodeWriter::writeDIFile(const DIFile *N,
1964                                       SmallVectorImpl<uint64_t> &Record,
1965                                       unsigned Abbrev) {
1966   Record.push_back(N->isDistinct());
1967   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
1968   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
1969   if (N->getRawChecksum()) {
1970     Record.push_back(N->getRawChecksum()->Kind);
1971     Record.push_back(VE.getMetadataOrNullID(N->getRawChecksum()->Value));
1972   } else {
1973     // Maintain backwards compatibility with the old internal representation of
1974     // CSK_None in ChecksumKind by writing nulls here when Checksum is None.
1975     Record.push_back(0);
1976     Record.push_back(VE.getMetadataOrNullID(nullptr));
1977   }
1978   auto Source = N->getRawSource();
1979   if (Source)
1980     Record.push_back(VE.getMetadataOrNullID(Source));
1981 
1982   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
1983   Record.clear();
1984 }
1985 
1986 void ModuleBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
1987                                              SmallVectorImpl<uint64_t> &Record,
1988                                              unsigned Abbrev) {
1989   assert(N->isDistinct() && "Expected distinct compile units");
1990   Record.push_back(/* IsDistinct */ true);
1991   Record.push_back(N->getSourceLanguage());
1992   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1993   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
1994   Record.push_back(N->isOptimized());
1995   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
1996   Record.push_back(N->getRuntimeVersion());
1997   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
1998   Record.push_back(N->getEmissionKind());
1999   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
2000   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
2001   Record.push_back(/* subprograms */ 0);
2002   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
2003   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
2004   Record.push_back(N->getDWOId());
2005   Record.push_back(VE.getMetadataOrNullID(N->getMacros().get()));
2006   Record.push_back(N->getSplitDebugInlining());
2007   Record.push_back(N->getDebugInfoForProfiling());
2008   Record.push_back((unsigned)N->getNameTableKind());
2009   Record.push_back(N->getRangesBaseAddress());
2010   Record.push_back(VE.getMetadataOrNullID(N->getRawSysRoot()));
2011   Record.push_back(VE.getMetadataOrNullID(N->getRawSDK()));
2012 
2013   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
2014   Record.clear();
2015 }
2016 
2017 void ModuleBitcodeWriter::writeDISubprogram(const DISubprogram *N,
2018                                             SmallVectorImpl<uint64_t> &Record,
2019                                             unsigned Abbrev) {
2020   const uint64_t HasUnitFlag = 1 << 1;
2021   const uint64_t HasSPFlagsFlag = 1 << 2;
2022   Record.push_back(uint64_t(N->isDistinct()) | HasUnitFlag | HasSPFlagsFlag);
2023   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2024   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2025   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
2026   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2027   Record.push_back(N->getLine());
2028   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2029   Record.push_back(N->getScopeLine());
2030   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
2031   Record.push_back(N->getSPFlags());
2032   Record.push_back(N->getVirtualIndex());
2033   Record.push_back(N->getFlags());
2034   Record.push_back(VE.getMetadataOrNullID(N->getRawUnit()));
2035   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
2036   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
2037   Record.push_back(VE.getMetadataOrNullID(N->getRetainedNodes().get()));
2038   Record.push_back(N->getThisAdjustment());
2039   Record.push_back(VE.getMetadataOrNullID(N->getThrownTypes().get()));
2040   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
2041   Record.push_back(VE.getMetadataOrNullID(N->getRawTargetFuncName()));
2042 
2043   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
2044   Record.clear();
2045 }
2046 
2047 void ModuleBitcodeWriter::writeDILexicalBlock(const DILexicalBlock *N,
2048                                               SmallVectorImpl<uint64_t> &Record,
2049                                               unsigned Abbrev) {
2050   Record.push_back(N->isDistinct());
2051   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2052   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2053   Record.push_back(N->getLine());
2054   Record.push_back(N->getColumn());
2055 
2056   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
2057   Record.clear();
2058 }
2059 
2060 void ModuleBitcodeWriter::writeDILexicalBlockFile(
2061     const DILexicalBlockFile *N, SmallVectorImpl<uint64_t> &Record,
2062     unsigned Abbrev) {
2063   Record.push_back(N->isDistinct());
2064   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2065   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2066   Record.push_back(N->getDiscriminator());
2067 
2068   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
2069   Record.clear();
2070 }
2071 
2072 void ModuleBitcodeWriter::writeDICommonBlock(const DICommonBlock *N,
2073                                              SmallVectorImpl<uint64_t> &Record,
2074                                              unsigned Abbrev) {
2075   Record.push_back(N->isDistinct());
2076   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2077   Record.push_back(VE.getMetadataOrNullID(N->getDecl()));
2078   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2079   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2080   Record.push_back(N->getLineNo());
2081 
2082   Stream.EmitRecord(bitc::METADATA_COMMON_BLOCK, Record, Abbrev);
2083   Record.clear();
2084 }
2085 
2086 void ModuleBitcodeWriter::writeDINamespace(const DINamespace *N,
2087                                            SmallVectorImpl<uint64_t> &Record,
2088                                            unsigned Abbrev) {
2089   Record.push_back(N->isDistinct() | N->getExportSymbols() << 1);
2090   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2091   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2092 
2093   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
2094   Record.clear();
2095 }
2096 
2097 void ModuleBitcodeWriter::writeDIMacro(const DIMacro *N,
2098                                        SmallVectorImpl<uint64_t> &Record,
2099                                        unsigned Abbrev) {
2100   Record.push_back(N->isDistinct());
2101   Record.push_back(N->getMacinfoType());
2102   Record.push_back(N->getLine());
2103   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2104   Record.push_back(VE.getMetadataOrNullID(N->getRawValue()));
2105 
2106   Stream.EmitRecord(bitc::METADATA_MACRO, Record, Abbrev);
2107   Record.clear();
2108 }
2109 
2110 void ModuleBitcodeWriter::writeDIMacroFile(const DIMacroFile *N,
2111                                            SmallVectorImpl<uint64_t> &Record,
2112                                            unsigned Abbrev) {
2113   Record.push_back(N->isDistinct());
2114   Record.push_back(N->getMacinfoType());
2115   Record.push_back(N->getLine());
2116   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2117   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
2118 
2119   Stream.EmitRecord(bitc::METADATA_MACRO_FILE, Record, Abbrev);
2120   Record.clear();
2121 }
2122 
2123 void ModuleBitcodeWriter::writeDIArgList(const DIArgList *N,
2124                                          SmallVectorImpl<uint64_t> &Record) {
2125   Record.reserve(N->getArgs().size());
2126   for (ValueAsMetadata *MD : N->getArgs())
2127     Record.push_back(VE.getMetadataID(MD));
2128 
2129   Stream.EmitRecord(bitc::METADATA_ARG_LIST, Record);
2130   Record.clear();
2131 }
2132 
2133 void ModuleBitcodeWriter::writeDIModule(const DIModule *N,
2134                                         SmallVectorImpl<uint64_t> &Record,
2135                                         unsigned Abbrev) {
2136   Record.push_back(N->isDistinct());
2137   for (auto &I : N->operands())
2138     Record.push_back(VE.getMetadataOrNullID(I));
2139   Record.push_back(N->getLineNo());
2140   Record.push_back(N->getIsDecl());
2141 
2142   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
2143   Record.clear();
2144 }
2145 
2146 void ModuleBitcodeWriter::writeDIAssignID(const DIAssignID *N,
2147                                           SmallVectorImpl<uint64_t> &Record,
2148                                           unsigned Abbrev) {
2149   // There are no arguments for this metadata type.
2150   Record.push_back(N->isDistinct());
2151   Stream.EmitRecord(bitc::METADATA_ASSIGN_ID, Record, Abbrev);
2152   Record.clear();
2153 }
2154 
2155 void ModuleBitcodeWriter::writeDITemplateTypeParameter(
2156     const DITemplateTypeParameter *N, SmallVectorImpl<uint64_t> &Record,
2157     unsigned Abbrev) {
2158   Record.push_back(N->isDistinct());
2159   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2160   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2161   Record.push_back(N->isDefault());
2162 
2163   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
2164   Record.clear();
2165 }
2166 
2167 void ModuleBitcodeWriter::writeDITemplateValueParameter(
2168     const DITemplateValueParameter *N, SmallVectorImpl<uint64_t> &Record,
2169     unsigned Abbrev) {
2170   Record.push_back(N->isDistinct());
2171   Record.push_back(N->getTag());
2172   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2173   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2174   Record.push_back(N->isDefault());
2175   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
2176 
2177   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
2178   Record.clear();
2179 }
2180 
2181 void ModuleBitcodeWriter::writeDIGlobalVariable(
2182     const DIGlobalVariable *N, SmallVectorImpl<uint64_t> &Record,
2183     unsigned Abbrev) {
2184   const uint64_t Version = 2 << 1;
2185   Record.push_back((uint64_t)N->isDistinct() | Version);
2186   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2187   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2188   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
2189   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2190   Record.push_back(N->getLine());
2191   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2192   Record.push_back(N->isLocalToUnit());
2193   Record.push_back(N->isDefinition());
2194   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
2195   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams()));
2196   Record.push_back(N->getAlignInBits());
2197   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
2198 
2199   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
2200   Record.clear();
2201 }
2202 
2203 void ModuleBitcodeWriter::writeDILocalVariable(
2204     const DILocalVariable *N, SmallVectorImpl<uint64_t> &Record,
2205     unsigned Abbrev) {
2206   // In order to support all possible bitcode formats in BitcodeReader we need
2207   // to distinguish the following cases:
2208   // 1) Record has no artificial tag (Record[1]),
2209   //   has no obsolete inlinedAt field (Record[9]).
2210   //   In this case Record size will be 8, HasAlignment flag is false.
2211   // 2) Record has artificial tag (Record[1]),
2212   //   has no obsolete inlignedAt field (Record[9]).
2213   //   In this case Record size will be 9, HasAlignment flag is false.
2214   // 3) Record has both artificial tag (Record[1]) and
2215   //   obsolete inlignedAt field (Record[9]).
2216   //   In this case Record size will be 10, HasAlignment flag is false.
2217   // 4) Record has neither artificial tag, nor inlignedAt field, but
2218   //   HasAlignment flag is true and Record[8] contains alignment value.
2219   const uint64_t HasAlignmentFlag = 1 << 1;
2220   Record.push_back((uint64_t)N->isDistinct() | HasAlignmentFlag);
2221   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2222   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2223   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2224   Record.push_back(N->getLine());
2225   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2226   Record.push_back(N->getArg());
2227   Record.push_back(N->getFlags());
2228   Record.push_back(N->getAlignInBits());
2229   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
2230 
2231   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
2232   Record.clear();
2233 }
2234 
2235 void ModuleBitcodeWriter::writeDILabel(
2236     const DILabel *N, SmallVectorImpl<uint64_t> &Record,
2237     unsigned Abbrev) {
2238   Record.push_back((uint64_t)N->isDistinct());
2239   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2240   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2241   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2242   Record.push_back(N->getLine());
2243 
2244   Stream.EmitRecord(bitc::METADATA_LABEL, Record, Abbrev);
2245   Record.clear();
2246 }
2247 
2248 void ModuleBitcodeWriter::writeDIExpression(const DIExpression *N,
2249                                             SmallVectorImpl<uint64_t> &Record,
2250                                             unsigned Abbrev) {
2251   Record.reserve(N->getElements().size() + 1);
2252   const uint64_t Version = 3 << 1;
2253   Record.push_back((uint64_t)N->isDistinct() | Version);
2254   Record.append(N->elements_begin(), N->elements_end());
2255 
2256   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
2257   Record.clear();
2258 }
2259 
2260 void ModuleBitcodeWriter::writeDIGlobalVariableExpression(
2261     const DIGlobalVariableExpression *N, SmallVectorImpl<uint64_t> &Record,
2262     unsigned Abbrev) {
2263   Record.push_back(N->isDistinct());
2264   Record.push_back(VE.getMetadataOrNullID(N->getVariable()));
2265   Record.push_back(VE.getMetadataOrNullID(N->getExpression()));
2266 
2267   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR_EXPR, Record, Abbrev);
2268   Record.clear();
2269 }
2270 
2271 void ModuleBitcodeWriter::writeDIObjCProperty(const DIObjCProperty *N,
2272                                               SmallVectorImpl<uint64_t> &Record,
2273                                               unsigned Abbrev) {
2274   Record.push_back(N->isDistinct());
2275   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2276   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2277   Record.push_back(N->getLine());
2278   Record.push_back(VE.getMetadataOrNullID(N->getRawSetterName()));
2279   Record.push_back(VE.getMetadataOrNullID(N->getRawGetterName()));
2280   Record.push_back(N->getAttributes());
2281   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2282 
2283   Stream.EmitRecord(bitc::METADATA_OBJC_PROPERTY, Record, Abbrev);
2284   Record.clear();
2285 }
2286 
2287 void ModuleBitcodeWriter::writeDIImportedEntity(
2288     const DIImportedEntity *N, SmallVectorImpl<uint64_t> &Record,
2289     unsigned Abbrev) {
2290   Record.push_back(N->isDistinct());
2291   Record.push_back(N->getTag());
2292   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2293   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
2294   Record.push_back(N->getLine());
2295   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2296   Record.push_back(VE.getMetadataOrNullID(N->getRawFile()));
2297   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
2298 
2299   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
2300   Record.clear();
2301 }
2302 
2303 unsigned ModuleBitcodeWriter::createNamedMetadataAbbrev() {
2304   auto Abbv = std::make_shared<BitCodeAbbrev>();
2305   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
2306   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2307   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2308   return Stream.EmitAbbrev(std::move(Abbv));
2309 }
2310 
2311 void ModuleBitcodeWriter::writeNamedMetadata(
2312     SmallVectorImpl<uint64_t> &Record) {
2313   if (M.named_metadata_empty())
2314     return;
2315 
2316   unsigned Abbrev = createNamedMetadataAbbrev();
2317   for (const NamedMDNode &NMD : M.named_metadata()) {
2318     // Write name.
2319     StringRef Str = NMD.getName();
2320     Record.append(Str.bytes_begin(), Str.bytes_end());
2321     Stream.EmitRecord(bitc::METADATA_NAME, Record, Abbrev);
2322     Record.clear();
2323 
2324     // Write named metadata operands.
2325     for (const MDNode *N : NMD.operands())
2326       Record.push_back(VE.getMetadataID(N));
2327     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
2328     Record.clear();
2329   }
2330 }
2331 
2332 unsigned ModuleBitcodeWriter::createMetadataStringsAbbrev() {
2333   auto Abbv = std::make_shared<BitCodeAbbrev>();
2334   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRINGS));
2335   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of strings
2336   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // offset to chars
2337   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2338   return Stream.EmitAbbrev(std::move(Abbv));
2339 }
2340 
2341 /// Write out a record for MDString.
2342 ///
2343 /// All the metadata strings in a metadata block are emitted in a single
2344 /// record.  The sizes and strings themselves are shoved into a blob.
2345 void ModuleBitcodeWriter::writeMetadataStrings(
2346     ArrayRef<const Metadata *> Strings, SmallVectorImpl<uint64_t> &Record) {
2347   if (Strings.empty())
2348     return;
2349 
2350   // Start the record with the number of strings.
2351   Record.push_back(bitc::METADATA_STRINGS);
2352   Record.push_back(Strings.size());
2353 
2354   // Emit the sizes of the strings in the blob.
2355   SmallString<256> Blob;
2356   {
2357     BitstreamWriter W(Blob);
2358     for (const Metadata *MD : Strings)
2359       W.EmitVBR(cast<MDString>(MD)->getLength(), 6);
2360     W.FlushToWord();
2361   }
2362 
2363   // Add the offset to the strings to the record.
2364   Record.push_back(Blob.size());
2365 
2366   // Add the strings to the blob.
2367   for (const Metadata *MD : Strings)
2368     Blob.append(cast<MDString>(MD)->getString());
2369 
2370   // Emit the final record.
2371   Stream.EmitRecordWithBlob(createMetadataStringsAbbrev(), Record, Blob);
2372   Record.clear();
2373 }
2374 
2375 // Generates an enum to use as an index in the Abbrev array of Metadata record.
2376 enum MetadataAbbrev : unsigned {
2377 #define HANDLE_MDNODE_LEAF(CLASS) CLASS##AbbrevID,
2378 #include "llvm/IR/Metadata.def"
2379   LastPlusOne
2380 };
2381 
2382 void ModuleBitcodeWriter::writeMetadataRecords(
2383     ArrayRef<const Metadata *> MDs, SmallVectorImpl<uint64_t> &Record,
2384     std::vector<unsigned> *MDAbbrevs, std::vector<uint64_t> *IndexPos) {
2385   if (MDs.empty())
2386     return;
2387 
2388   // Initialize MDNode abbreviations.
2389 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
2390 #include "llvm/IR/Metadata.def"
2391 
2392   for (const Metadata *MD : MDs) {
2393     if (IndexPos)
2394       IndexPos->push_back(Stream.GetCurrentBitNo());
2395     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
2396       assert(N->isResolved() && "Expected forward references to be resolved");
2397 
2398       switch (N->getMetadataID()) {
2399       default:
2400         llvm_unreachable("Invalid MDNode subclass");
2401 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
2402   case Metadata::CLASS##Kind:                                                  \
2403     if (MDAbbrevs)                                                             \
2404       write##CLASS(cast<CLASS>(N), Record,                                     \
2405                    (*MDAbbrevs)[MetadataAbbrev::CLASS##AbbrevID]);             \
2406     else                                                                       \
2407       write##CLASS(cast<CLASS>(N), Record, CLASS##Abbrev);                     \
2408     continue;
2409 #include "llvm/IR/Metadata.def"
2410       }
2411     }
2412     if (auto *AL = dyn_cast<DIArgList>(MD)) {
2413       writeDIArgList(AL, Record);
2414       continue;
2415     }
2416     writeValueAsMetadata(cast<ValueAsMetadata>(MD), Record);
2417   }
2418 }
2419 
2420 void ModuleBitcodeWriter::writeModuleMetadata() {
2421   if (!VE.hasMDs() && M.named_metadata_empty())
2422     return;
2423 
2424   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 4);
2425   SmallVector<uint64_t, 64> Record;
2426 
2427   // Emit all abbrevs upfront, so that the reader can jump in the middle of the
2428   // block and load any metadata.
2429   std::vector<unsigned> MDAbbrevs;
2430 
2431   MDAbbrevs.resize(MetadataAbbrev::LastPlusOne);
2432   MDAbbrevs[MetadataAbbrev::DILocationAbbrevID] = createDILocationAbbrev();
2433   MDAbbrevs[MetadataAbbrev::GenericDINodeAbbrevID] =
2434       createGenericDINodeAbbrev();
2435 
2436   auto Abbv = std::make_shared<BitCodeAbbrev>();
2437   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_INDEX_OFFSET));
2438   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2439   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2440   unsigned OffsetAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2441 
2442   Abbv = std::make_shared<BitCodeAbbrev>();
2443   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_INDEX));
2444   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2445   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2446   unsigned IndexAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2447 
2448   // Emit MDStrings together upfront.
2449   writeMetadataStrings(VE.getMDStrings(), Record);
2450 
2451   // We only emit an index for the metadata record if we have more than a given
2452   // (naive) threshold of metadatas, otherwise it is not worth it.
2453   if (VE.getNonMDStrings().size() > IndexThreshold) {
2454     // Write a placeholder value in for the offset of the metadata index,
2455     // which is written after the records, so that it can include
2456     // the offset of each entry. The placeholder offset will be
2457     // updated after all records are emitted.
2458     uint64_t Vals[] = {0, 0};
2459     Stream.EmitRecord(bitc::METADATA_INDEX_OFFSET, Vals, OffsetAbbrev);
2460   }
2461 
2462   // Compute and save the bit offset to the current position, which will be
2463   // patched when we emit the index later. We can simply subtract the 64-bit
2464   // fixed size from the current bit number to get the location to backpatch.
2465   uint64_t IndexOffsetRecordBitPos = Stream.GetCurrentBitNo();
2466 
2467   // This index will contain the bitpos for each individual record.
2468   std::vector<uint64_t> IndexPos;
2469   IndexPos.reserve(VE.getNonMDStrings().size());
2470 
2471   // Write all the records
2472   writeMetadataRecords(VE.getNonMDStrings(), Record, &MDAbbrevs, &IndexPos);
2473 
2474   if (VE.getNonMDStrings().size() > IndexThreshold) {
2475     // Now that we have emitted all the records we will emit the index. But
2476     // first
2477     // backpatch the forward reference so that the reader can skip the records
2478     // efficiently.
2479     Stream.BackpatchWord64(IndexOffsetRecordBitPos - 64,
2480                            Stream.GetCurrentBitNo() - IndexOffsetRecordBitPos);
2481 
2482     // Delta encode the index.
2483     uint64_t PreviousValue = IndexOffsetRecordBitPos;
2484     for (auto &Elt : IndexPos) {
2485       auto EltDelta = Elt - PreviousValue;
2486       PreviousValue = Elt;
2487       Elt = EltDelta;
2488     }
2489     // Emit the index record.
2490     Stream.EmitRecord(bitc::METADATA_INDEX, IndexPos, IndexAbbrev);
2491     IndexPos.clear();
2492   }
2493 
2494   // Write the named metadata now.
2495   writeNamedMetadata(Record);
2496 
2497   auto AddDeclAttachedMetadata = [&](const GlobalObject &GO) {
2498     SmallVector<uint64_t, 4> Record;
2499     Record.push_back(VE.getValueID(&GO));
2500     pushGlobalMetadataAttachment(Record, GO);
2501     Stream.EmitRecord(bitc::METADATA_GLOBAL_DECL_ATTACHMENT, Record);
2502   };
2503   for (const Function &F : M)
2504     if (F.isDeclaration() && F.hasMetadata())
2505       AddDeclAttachedMetadata(F);
2506   // FIXME: Only store metadata for declarations here, and move data for global
2507   // variable definitions to a separate block (PR28134).
2508   for (const GlobalVariable &GV : M.globals())
2509     if (GV.hasMetadata())
2510       AddDeclAttachedMetadata(GV);
2511 
2512   Stream.ExitBlock();
2513 }
2514 
2515 void ModuleBitcodeWriter::writeFunctionMetadata(const Function &F) {
2516   if (!VE.hasMDs())
2517     return;
2518 
2519   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
2520   SmallVector<uint64_t, 64> Record;
2521   writeMetadataStrings(VE.getMDStrings(), Record);
2522   writeMetadataRecords(VE.getNonMDStrings(), Record);
2523   Stream.ExitBlock();
2524 }
2525 
2526 void ModuleBitcodeWriter::pushGlobalMetadataAttachment(
2527     SmallVectorImpl<uint64_t> &Record, const GlobalObject &GO) {
2528   // [n x [id, mdnode]]
2529   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
2530   GO.getAllMetadata(MDs);
2531   for (const auto &I : MDs) {
2532     Record.push_back(I.first);
2533     Record.push_back(VE.getMetadataID(I.second));
2534   }
2535 }
2536 
2537 void ModuleBitcodeWriter::writeFunctionMetadataAttachment(const Function &F) {
2538   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
2539 
2540   SmallVector<uint64_t, 64> Record;
2541 
2542   if (F.hasMetadata()) {
2543     pushGlobalMetadataAttachment(Record, F);
2544     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
2545     Record.clear();
2546   }
2547 
2548   // Write metadata attachments
2549   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
2550   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
2551   for (const BasicBlock &BB : F)
2552     for (const Instruction &I : BB) {
2553       MDs.clear();
2554       I.getAllMetadataOtherThanDebugLoc(MDs);
2555 
2556       // If no metadata, ignore instruction.
2557       if (MDs.empty()) continue;
2558 
2559       Record.push_back(VE.getInstructionID(&I));
2560 
2561       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
2562         Record.push_back(MDs[i].first);
2563         Record.push_back(VE.getMetadataID(MDs[i].second));
2564       }
2565       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
2566       Record.clear();
2567     }
2568 
2569   Stream.ExitBlock();
2570 }
2571 
2572 void ModuleBitcodeWriter::writeModuleMetadataKinds() {
2573   SmallVector<uint64_t, 64> Record;
2574 
2575   // Write metadata kinds
2576   // METADATA_KIND - [n x [id, name]]
2577   SmallVector<StringRef, 8> Names;
2578   M.getMDKindNames(Names);
2579 
2580   if (Names.empty()) return;
2581 
2582   Stream.EnterSubblock(bitc::METADATA_KIND_BLOCK_ID, 3);
2583 
2584   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
2585     Record.push_back(MDKindID);
2586     StringRef KName = Names[MDKindID];
2587     Record.append(KName.begin(), KName.end());
2588 
2589     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
2590     Record.clear();
2591   }
2592 
2593   Stream.ExitBlock();
2594 }
2595 
2596 void ModuleBitcodeWriter::writeOperandBundleTags() {
2597   // Write metadata kinds
2598   //
2599   // OPERAND_BUNDLE_TAGS_BLOCK_ID : N x OPERAND_BUNDLE_TAG
2600   //
2601   // OPERAND_BUNDLE_TAG - [strchr x N]
2602 
2603   SmallVector<StringRef, 8> Tags;
2604   M.getOperandBundleTags(Tags);
2605 
2606   if (Tags.empty())
2607     return;
2608 
2609   Stream.EnterSubblock(bitc::OPERAND_BUNDLE_TAGS_BLOCK_ID, 3);
2610 
2611   SmallVector<uint64_t, 64> Record;
2612 
2613   for (auto Tag : Tags) {
2614     Record.append(Tag.begin(), Tag.end());
2615 
2616     Stream.EmitRecord(bitc::OPERAND_BUNDLE_TAG, Record, 0);
2617     Record.clear();
2618   }
2619 
2620   Stream.ExitBlock();
2621 }
2622 
2623 void ModuleBitcodeWriter::writeSyncScopeNames() {
2624   SmallVector<StringRef, 8> SSNs;
2625   M.getContext().getSyncScopeNames(SSNs);
2626   if (SSNs.empty())
2627     return;
2628 
2629   Stream.EnterSubblock(bitc::SYNC_SCOPE_NAMES_BLOCK_ID, 2);
2630 
2631   SmallVector<uint64_t, 64> Record;
2632   for (auto SSN : SSNs) {
2633     Record.append(SSN.begin(), SSN.end());
2634     Stream.EmitRecord(bitc::SYNC_SCOPE_NAME, Record, 0);
2635     Record.clear();
2636   }
2637 
2638   Stream.ExitBlock();
2639 }
2640 
2641 void ModuleBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
2642                                          bool isGlobal) {
2643   if (FirstVal == LastVal) return;
2644 
2645   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
2646 
2647   unsigned AggregateAbbrev = 0;
2648   unsigned String8Abbrev = 0;
2649   unsigned CString7Abbrev = 0;
2650   unsigned CString6Abbrev = 0;
2651   // If this is a constant pool for the module, emit module-specific abbrevs.
2652   if (isGlobal) {
2653     // Abbrev for CST_CODE_AGGREGATE.
2654     auto Abbv = std::make_shared<BitCodeAbbrev>();
2655     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
2656     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2657     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
2658     AggregateAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2659 
2660     // Abbrev for CST_CODE_STRING.
2661     Abbv = std::make_shared<BitCodeAbbrev>();
2662     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
2663     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2664     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2665     String8Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2666     // Abbrev for CST_CODE_CSTRING.
2667     Abbv = std::make_shared<BitCodeAbbrev>();
2668     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
2669     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2670     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2671     CString7Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2672     // Abbrev for CST_CODE_CSTRING.
2673     Abbv = std::make_shared<BitCodeAbbrev>();
2674     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
2675     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2676     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2677     CString6Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2678   }
2679 
2680   SmallVector<uint64_t, 64> Record;
2681 
2682   const ValueEnumerator::ValueList &Vals = VE.getValues();
2683   Type *LastTy = nullptr;
2684   for (unsigned i = FirstVal; i != LastVal; ++i) {
2685     const Value *V = Vals[i].first;
2686     // If we need to switch types, do so now.
2687     if (V->getType() != LastTy) {
2688       LastTy = V->getType();
2689       Record.push_back(VE.getTypeID(LastTy));
2690       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
2691                         CONSTANTS_SETTYPE_ABBREV);
2692       Record.clear();
2693     }
2694 
2695     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
2696       Record.push_back(VE.getTypeID(IA->getFunctionType()));
2697       Record.push_back(
2698           unsigned(IA->hasSideEffects()) | unsigned(IA->isAlignStack()) << 1 |
2699           unsigned(IA->getDialect() & 1) << 2 | unsigned(IA->canThrow()) << 3);
2700 
2701       // Add the asm string.
2702       const std::string &AsmStr = IA->getAsmString();
2703       Record.push_back(AsmStr.size());
2704       Record.append(AsmStr.begin(), AsmStr.end());
2705 
2706       // Add the constraint string.
2707       const std::string &ConstraintStr = IA->getConstraintString();
2708       Record.push_back(ConstraintStr.size());
2709       Record.append(ConstraintStr.begin(), ConstraintStr.end());
2710       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
2711       Record.clear();
2712       continue;
2713     }
2714     const Constant *C = cast<Constant>(V);
2715     unsigned Code = -1U;
2716     unsigned AbbrevToUse = 0;
2717     if (C->isNullValue()) {
2718       Code = bitc::CST_CODE_NULL;
2719     } else if (isa<PoisonValue>(C)) {
2720       Code = bitc::CST_CODE_POISON;
2721     } else if (isa<UndefValue>(C)) {
2722       Code = bitc::CST_CODE_UNDEF;
2723     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
2724       if (IV->getBitWidth() <= 64) {
2725         uint64_t V = IV->getSExtValue();
2726         emitSignedInt64(Record, V);
2727         Code = bitc::CST_CODE_INTEGER;
2728         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
2729       } else {                             // Wide integers, > 64 bits in size.
2730         emitWideAPInt(Record, IV->getValue());
2731         Code = bitc::CST_CODE_WIDE_INTEGER;
2732       }
2733     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
2734       Code = bitc::CST_CODE_FLOAT;
2735       Type *Ty = CFP->getType()->getScalarType();
2736       if (Ty->isHalfTy() || Ty->isBFloatTy() || Ty->isFloatTy() ||
2737           Ty->isDoubleTy()) {
2738         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
2739       } else if (Ty->isX86_FP80Ty()) {
2740         // api needed to prevent premature destruction
2741         // bits are not in the same order as a normal i80 APInt, compensate.
2742         APInt api = CFP->getValueAPF().bitcastToAPInt();
2743         const uint64_t *p = api.getRawData();
2744         Record.push_back((p[1] << 48) | (p[0] >> 16));
2745         Record.push_back(p[0] & 0xffffLL);
2746       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
2747         APInt api = CFP->getValueAPF().bitcastToAPInt();
2748         const uint64_t *p = api.getRawData();
2749         Record.push_back(p[0]);
2750         Record.push_back(p[1]);
2751       } else {
2752         assert(0 && "Unknown FP type!");
2753       }
2754     } else if (isa<ConstantDataSequential>(C) &&
2755                cast<ConstantDataSequential>(C)->isString()) {
2756       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
2757       // Emit constant strings specially.
2758       unsigned NumElts = Str->getNumElements();
2759       // If this is a null-terminated string, use the denser CSTRING encoding.
2760       if (Str->isCString()) {
2761         Code = bitc::CST_CODE_CSTRING;
2762         --NumElts;  // Don't encode the null, which isn't allowed by char6.
2763       } else {
2764         Code = bitc::CST_CODE_STRING;
2765         AbbrevToUse = String8Abbrev;
2766       }
2767       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
2768       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
2769       for (unsigned i = 0; i != NumElts; ++i) {
2770         unsigned char V = Str->getElementAsInteger(i);
2771         Record.push_back(V);
2772         isCStr7 &= (V & 128) == 0;
2773         if (isCStrChar6)
2774           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
2775       }
2776 
2777       if (isCStrChar6)
2778         AbbrevToUse = CString6Abbrev;
2779       else if (isCStr7)
2780         AbbrevToUse = CString7Abbrev;
2781     } else if (const ConstantDataSequential *CDS =
2782                   dyn_cast<ConstantDataSequential>(C)) {
2783       Code = bitc::CST_CODE_DATA;
2784       Type *EltTy = CDS->getElementType();
2785       if (isa<IntegerType>(EltTy)) {
2786         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2787           Record.push_back(CDS->getElementAsInteger(i));
2788       } else {
2789         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2790           Record.push_back(
2791               CDS->getElementAsAPFloat(i).bitcastToAPInt().getLimitedValue());
2792       }
2793     } else if (isa<ConstantAggregate>(C)) {
2794       Code = bitc::CST_CODE_AGGREGATE;
2795       for (const Value *Op : C->operands())
2796         Record.push_back(VE.getValueID(Op));
2797       AbbrevToUse = AggregateAbbrev;
2798     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
2799       switch (CE->getOpcode()) {
2800       default:
2801         if (Instruction::isCast(CE->getOpcode())) {
2802           Code = bitc::CST_CODE_CE_CAST;
2803           Record.push_back(getEncodedCastOpcode(CE->getOpcode()));
2804           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2805           Record.push_back(VE.getValueID(C->getOperand(0)));
2806           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
2807         } else {
2808           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
2809           Code = bitc::CST_CODE_CE_BINOP;
2810           Record.push_back(getEncodedBinaryOpcode(CE->getOpcode()));
2811           Record.push_back(VE.getValueID(C->getOperand(0)));
2812           Record.push_back(VE.getValueID(C->getOperand(1)));
2813           uint64_t Flags = getOptimizationFlags(CE);
2814           if (Flags != 0)
2815             Record.push_back(Flags);
2816         }
2817         break;
2818       case Instruction::FNeg: {
2819         assert(CE->getNumOperands() == 1 && "Unknown constant expr!");
2820         Code = bitc::CST_CODE_CE_UNOP;
2821         Record.push_back(getEncodedUnaryOpcode(CE->getOpcode()));
2822         Record.push_back(VE.getValueID(C->getOperand(0)));
2823         uint64_t Flags = getOptimizationFlags(CE);
2824         if (Flags != 0)
2825           Record.push_back(Flags);
2826         break;
2827       }
2828       case Instruction::GetElementPtr: {
2829         Code = bitc::CST_CODE_CE_GEP;
2830         const auto *GO = cast<GEPOperator>(C);
2831         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
2832         Record.push_back(getOptimizationFlags(GO));
2833         if (std::optional<ConstantRange> Range = GO->getInRange()) {
2834           Code = bitc::CST_CODE_CE_GEP_WITH_INRANGE;
2835           emitConstantRange(Record, *Range, /*EmitBitWidth=*/true);
2836         }
2837         for (const Value *Op : CE->operands()) {
2838           Record.push_back(VE.getTypeID(Op->getType()));
2839           Record.push_back(VE.getValueID(Op));
2840         }
2841         break;
2842       }
2843       case Instruction::ExtractElement:
2844         Code = bitc::CST_CODE_CE_EXTRACTELT;
2845         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2846         Record.push_back(VE.getValueID(C->getOperand(0)));
2847         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
2848         Record.push_back(VE.getValueID(C->getOperand(1)));
2849         break;
2850       case Instruction::InsertElement:
2851         Code = bitc::CST_CODE_CE_INSERTELT;
2852         Record.push_back(VE.getValueID(C->getOperand(0)));
2853         Record.push_back(VE.getValueID(C->getOperand(1)));
2854         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
2855         Record.push_back(VE.getValueID(C->getOperand(2)));
2856         break;
2857       case Instruction::ShuffleVector:
2858         // If the return type and argument types are the same, this is a
2859         // standard shufflevector instruction.  If the types are different,
2860         // then the shuffle is widening or truncating the input vectors, and
2861         // the argument type must also be encoded.
2862         if (C->getType() == C->getOperand(0)->getType()) {
2863           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
2864         } else {
2865           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
2866           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2867         }
2868         Record.push_back(VE.getValueID(C->getOperand(0)));
2869         Record.push_back(VE.getValueID(C->getOperand(1)));
2870         Record.push_back(VE.getValueID(CE->getShuffleMaskForBitcode()));
2871         break;
2872       }
2873     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
2874       Code = bitc::CST_CODE_BLOCKADDRESS;
2875       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
2876       Record.push_back(VE.getValueID(BA->getFunction()));
2877       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
2878     } else if (const auto *Equiv = dyn_cast<DSOLocalEquivalent>(C)) {
2879       Code = bitc::CST_CODE_DSO_LOCAL_EQUIVALENT;
2880       Record.push_back(VE.getTypeID(Equiv->getGlobalValue()->getType()));
2881       Record.push_back(VE.getValueID(Equiv->getGlobalValue()));
2882     } else if (const auto *NC = dyn_cast<NoCFIValue>(C)) {
2883       Code = bitc::CST_CODE_NO_CFI_VALUE;
2884       Record.push_back(VE.getTypeID(NC->getGlobalValue()->getType()));
2885       Record.push_back(VE.getValueID(NC->getGlobalValue()));
2886     } else if (const auto *CPA = dyn_cast<ConstantPtrAuth>(C)) {
2887       Code = bitc::CST_CODE_PTRAUTH;
2888       Record.push_back(VE.getValueID(CPA->getPointer()));
2889       Record.push_back(VE.getValueID(CPA->getKey()));
2890       Record.push_back(VE.getValueID(CPA->getDiscriminator()));
2891       Record.push_back(VE.getValueID(CPA->getAddrDiscriminator()));
2892     } else {
2893 #ifndef NDEBUG
2894       C->dump();
2895 #endif
2896       llvm_unreachable("Unknown constant!");
2897     }
2898     Stream.EmitRecord(Code, Record, AbbrevToUse);
2899     Record.clear();
2900   }
2901 
2902   Stream.ExitBlock();
2903 }
2904 
2905 void ModuleBitcodeWriter::writeModuleConstants() {
2906   const ValueEnumerator::ValueList &Vals = VE.getValues();
2907 
2908   // Find the first constant to emit, which is the first non-globalvalue value.
2909   // We know globalvalues have been emitted by WriteModuleInfo.
2910   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
2911     if (!isa<GlobalValue>(Vals[i].first)) {
2912       writeConstants(i, Vals.size(), true);
2913       return;
2914     }
2915   }
2916 }
2917 
2918 /// pushValueAndType - The file has to encode both the value and type id for
2919 /// many values, because we need to know what type to create for forward
2920 /// references.  However, most operands are not forward references, so this type
2921 /// field is not needed.
2922 ///
2923 /// This function adds V's value ID to Vals.  If the value ID is higher than the
2924 /// instruction ID, then it is a forward reference, and it also includes the
2925 /// type ID.  The value ID that is written is encoded relative to the InstID.
2926 bool ModuleBitcodeWriter::pushValueAndType(const Value *V, unsigned InstID,
2927                                            SmallVectorImpl<unsigned> &Vals) {
2928   unsigned ValID = VE.getValueID(V);
2929   // Make encoding relative to the InstID.
2930   Vals.push_back(InstID - ValID);
2931   if (ValID >= InstID) {
2932     Vals.push_back(VE.getTypeID(V->getType()));
2933     return true;
2934   }
2935   return false;
2936 }
2937 
2938 bool ModuleBitcodeWriter::pushValueOrMetadata(const Value *V, unsigned InstID,
2939                                               SmallVectorImpl<unsigned> &Vals) {
2940   bool IsMetadata = V->getType()->isMetadataTy();
2941   if (IsMetadata) {
2942     Vals.push_back(bitc::OB_METADATA);
2943     Metadata *MD = cast<MetadataAsValue>(V)->getMetadata();
2944     unsigned ValID = VE.getMetadataID(MD);
2945     Vals.push_back(InstID - ValID);
2946     return false;
2947   }
2948   return pushValueAndType(V, InstID, Vals);
2949 }
2950 
2951 void ModuleBitcodeWriter::writeOperandBundles(const CallBase &CS,
2952                                               unsigned InstID) {
2953   SmallVector<unsigned, 64> Record;
2954   LLVMContext &C = CS.getContext();
2955 
2956   for (unsigned i = 0, e = CS.getNumOperandBundles(); i != e; ++i) {
2957     const auto &Bundle = CS.getOperandBundleAt(i);
2958     Record.push_back(C.getOperandBundleTagID(Bundle.getTagName()));
2959 
2960     for (auto &Input : Bundle.Inputs)
2961       pushValueOrMetadata(Input, InstID, Record);
2962 
2963     Stream.EmitRecord(bitc::FUNC_CODE_OPERAND_BUNDLE, Record);
2964     Record.clear();
2965   }
2966 }
2967 
2968 /// pushValue - Like pushValueAndType, but where the type of the value is
2969 /// omitted (perhaps it was already encoded in an earlier operand).
2970 void ModuleBitcodeWriter::pushValue(const Value *V, unsigned InstID,
2971                                     SmallVectorImpl<unsigned> &Vals) {
2972   unsigned ValID = VE.getValueID(V);
2973   Vals.push_back(InstID - ValID);
2974 }
2975 
2976 void ModuleBitcodeWriter::pushValueSigned(const Value *V, unsigned InstID,
2977                                           SmallVectorImpl<uint64_t> &Vals) {
2978   unsigned ValID = VE.getValueID(V);
2979   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
2980   emitSignedInt64(Vals, diff);
2981 }
2982 
2983 /// WriteInstruction - Emit an instruction to the specified stream.
2984 void ModuleBitcodeWriter::writeInstruction(const Instruction &I,
2985                                            unsigned InstID,
2986                                            SmallVectorImpl<unsigned> &Vals) {
2987   unsigned Code = 0;
2988   unsigned AbbrevToUse = 0;
2989   VE.setInstructionID(&I);
2990   switch (I.getOpcode()) {
2991   default:
2992     if (Instruction::isCast(I.getOpcode())) {
2993       Code = bitc::FUNC_CODE_INST_CAST;
2994       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2995         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
2996       Vals.push_back(VE.getTypeID(I.getType()));
2997       Vals.push_back(getEncodedCastOpcode(I.getOpcode()));
2998       uint64_t Flags = getOptimizationFlags(&I);
2999       if (Flags != 0) {
3000         if (AbbrevToUse == FUNCTION_INST_CAST_ABBREV)
3001           AbbrevToUse = FUNCTION_INST_CAST_FLAGS_ABBREV;
3002         Vals.push_back(Flags);
3003       }
3004     } else {
3005       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
3006       Code = bitc::FUNC_CODE_INST_BINOP;
3007       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
3008         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
3009       pushValue(I.getOperand(1), InstID, Vals);
3010       Vals.push_back(getEncodedBinaryOpcode(I.getOpcode()));
3011       uint64_t Flags = getOptimizationFlags(&I);
3012       if (Flags != 0) {
3013         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
3014           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
3015         Vals.push_back(Flags);
3016       }
3017     }
3018     break;
3019   case Instruction::FNeg: {
3020     Code = bitc::FUNC_CODE_INST_UNOP;
3021     if (!pushValueAndType(I.getOperand(0), InstID, Vals))
3022       AbbrevToUse = FUNCTION_INST_UNOP_ABBREV;
3023     Vals.push_back(getEncodedUnaryOpcode(I.getOpcode()));
3024     uint64_t Flags = getOptimizationFlags(&I);
3025     if (Flags != 0) {
3026       if (AbbrevToUse == FUNCTION_INST_UNOP_ABBREV)
3027         AbbrevToUse = FUNCTION_INST_UNOP_FLAGS_ABBREV;
3028       Vals.push_back(Flags);
3029     }
3030     break;
3031   }
3032   case Instruction::GetElementPtr: {
3033     Code = bitc::FUNC_CODE_INST_GEP;
3034     AbbrevToUse = FUNCTION_INST_GEP_ABBREV;
3035     auto &GEPInst = cast<GetElementPtrInst>(I);
3036     Vals.push_back(getOptimizationFlags(&I));
3037     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
3038     for (const Value *Op : I.operands())
3039       pushValueAndType(Op, InstID, Vals);
3040     break;
3041   }
3042   case Instruction::ExtractValue: {
3043     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
3044     pushValueAndType(I.getOperand(0), InstID, Vals);
3045     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
3046     Vals.append(EVI->idx_begin(), EVI->idx_end());
3047     break;
3048   }
3049   case Instruction::InsertValue: {
3050     Code = bitc::FUNC_CODE_INST_INSERTVAL;
3051     pushValueAndType(I.getOperand(0), InstID, Vals);
3052     pushValueAndType(I.getOperand(1), InstID, Vals);
3053     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
3054     Vals.append(IVI->idx_begin(), IVI->idx_end());
3055     break;
3056   }
3057   case Instruction::Select: {
3058     Code = bitc::FUNC_CODE_INST_VSELECT;
3059     pushValueAndType(I.getOperand(1), InstID, Vals);
3060     pushValue(I.getOperand(2), InstID, Vals);
3061     pushValueAndType(I.getOperand(0), InstID, Vals);
3062     uint64_t Flags = getOptimizationFlags(&I);
3063     if (Flags != 0)
3064       Vals.push_back(Flags);
3065     break;
3066   }
3067   case Instruction::ExtractElement:
3068     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
3069     pushValueAndType(I.getOperand(0), InstID, Vals);
3070     pushValueAndType(I.getOperand(1), InstID, Vals);
3071     break;
3072   case Instruction::InsertElement:
3073     Code = bitc::FUNC_CODE_INST_INSERTELT;
3074     pushValueAndType(I.getOperand(0), InstID, Vals);
3075     pushValue(I.getOperand(1), InstID, Vals);
3076     pushValueAndType(I.getOperand(2), InstID, Vals);
3077     break;
3078   case Instruction::ShuffleVector:
3079     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
3080     pushValueAndType(I.getOperand(0), InstID, Vals);
3081     pushValue(I.getOperand(1), InstID, Vals);
3082     pushValue(cast<ShuffleVectorInst>(I).getShuffleMaskForBitcode(), InstID,
3083               Vals);
3084     break;
3085   case Instruction::ICmp:
3086   case Instruction::FCmp: {
3087     // compare returning Int1Ty or vector of Int1Ty
3088     Code = bitc::FUNC_CODE_INST_CMP2;
3089     pushValueAndType(I.getOperand(0), InstID, Vals);
3090     pushValue(I.getOperand(1), InstID, Vals);
3091     Vals.push_back(cast<CmpInst>(I).getPredicate());
3092     uint64_t Flags = getOptimizationFlags(&I);
3093     if (Flags != 0)
3094       Vals.push_back(Flags);
3095     break;
3096   }
3097 
3098   case Instruction::Ret:
3099     {
3100       Code = bitc::FUNC_CODE_INST_RET;
3101       unsigned NumOperands = I.getNumOperands();
3102       if (NumOperands == 0)
3103         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
3104       else if (NumOperands == 1) {
3105         if (!pushValueAndType(I.getOperand(0), InstID, Vals))
3106           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
3107       } else {
3108         for (const Value *Op : I.operands())
3109           pushValueAndType(Op, InstID, Vals);
3110       }
3111     }
3112     break;
3113   case Instruction::Br:
3114     {
3115       Code = bitc::FUNC_CODE_INST_BR;
3116       const BranchInst &II = cast<BranchInst>(I);
3117       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
3118       if (II.isConditional()) {
3119         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
3120         pushValue(II.getCondition(), InstID, Vals);
3121       }
3122     }
3123     break;
3124   case Instruction::Switch:
3125     {
3126       Code = bitc::FUNC_CODE_INST_SWITCH;
3127       const SwitchInst &SI = cast<SwitchInst>(I);
3128       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
3129       pushValue(SI.getCondition(), InstID, Vals);
3130       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
3131       for (auto Case : SI.cases()) {
3132         Vals.push_back(VE.getValueID(Case.getCaseValue()));
3133         Vals.push_back(VE.getValueID(Case.getCaseSuccessor()));
3134       }
3135     }
3136     break;
3137   case Instruction::IndirectBr:
3138     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
3139     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
3140     // Encode the address operand as relative, but not the basic blocks.
3141     pushValue(I.getOperand(0), InstID, Vals);
3142     for (const Value *Op : drop_begin(I.operands()))
3143       Vals.push_back(VE.getValueID(Op));
3144     break;
3145 
3146   case Instruction::Invoke: {
3147     const InvokeInst *II = cast<InvokeInst>(&I);
3148     const Value *Callee = II->getCalledOperand();
3149     FunctionType *FTy = II->getFunctionType();
3150 
3151     if (II->hasOperandBundles())
3152       writeOperandBundles(*II, InstID);
3153 
3154     Code = bitc::FUNC_CODE_INST_INVOKE;
3155 
3156     Vals.push_back(VE.getAttributeListID(II->getAttributes()));
3157     Vals.push_back(II->getCallingConv() | 1 << 13);
3158     Vals.push_back(VE.getValueID(II->getNormalDest()));
3159     Vals.push_back(VE.getValueID(II->getUnwindDest()));
3160     Vals.push_back(VE.getTypeID(FTy));
3161     pushValueAndType(Callee, InstID, Vals);
3162 
3163     // Emit value #'s for the fixed parameters.
3164     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
3165       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
3166 
3167     // Emit type/value pairs for varargs params.
3168     if (FTy->isVarArg()) {
3169       for (unsigned i = FTy->getNumParams(), e = II->arg_size(); i != e; ++i)
3170         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
3171     }
3172     break;
3173   }
3174   case Instruction::Resume:
3175     Code = bitc::FUNC_CODE_INST_RESUME;
3176     pushValueAndType(I.getOperand(0), InstID, Vals);
3177     break;
3178   case Instruction::CleanupRet: {
3179     Code = bitc::FUNC_CODE_INST_CLEANUPRET;
3180     const auto &CRI = cast<CleanupReturnInst>(I);
3181     pushValue(CRI.getCleanupPad(), InstID, Vals);
3182     if (CRI.hasUnwindDest())
3183       Vals.push_back(VE.getValueID(CRI.getUnwindDest()));
3184     break;
3185   }
3186   case Instruction::CatchRet: {
3187     Code = bitc::FUNC_CODE_INST_CATCHRET;
3188     const auto &CRI = cast<CatchReturnInst>(I);
3189     pushValue(CRI.getCatchPad(), InstID, Vals);
3190     Vals.push_back(VE.getValueID(CRI.getSuccessor()));
3191     break;
3192   }
3193   case Instruction::CleanupPad:
3194   case Instruction::CatchPad: {
3195     const auto &FuncletPad = cast<FuncletPadInst>(I);
3196     Code = isa<CatchPadInst>(FuncletPad) ? bitc::FUNC_CODE_INST_CATCHPAD
3197                                          : bitc::FUNC_CODE_INST_CLEANUPPAD;
3198     pushValue(FuncletPad.getParentPad(), InstID, Vals);
3199 
3200     unsigned NumArgOperands = FuncletPad.arg_size();
3201     Vals.push_back(NumArgOperands);
3202     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
3203       pushValueAndType(FuncletPad.getArgOperand(Op), InstID, Vals);
3204     break;
3205   }
3206   case Instruction::CatchSwitch: {
3207     Code = bitc::FUNC_CODE_INST_CATCHSWITCH;
3208     const auto &CatchSwitch = cast<CatchSwitchInst>(I);
3209 
3210     pushValue(CatchSwitch.getParentPad(), InstID, Vals);
3211 
3212     unsigned NumHandlers = CatchSwitch.getNumHandlers();
3213     Vals.push_back(NumHandlers);
3214     for (const BasicBlock *CatchPadBB : CatchSwitch.handlers())
3215       Vals.push_back(VE.getValueID(CatchPadBB));
3216 
3217     if (CatchSwitch.hasUnwindDest())
3218       Vals.push_back(VE.getValueID(CatchSwitch.getUnwindDest()));
3219     break;
3220   }
3221   case Instruction::CallBr: {
3222     const CallBrInst *CBI = cast<CallBrInst>(&I);
3223     const Value *Callee = CBI->getCalledOperand();
3224     FunctionType *FTy = CBI->getFunctionType();
3225 
3226     if (CBI->hasOperandBundles())
3227       writeOperandBundles(*CBI, InstID);
3228 
3229     Code = bitc::FUNC_CODE_INST_CALLBR;
3230 
3231     Vals.push_back(VE.getAttributeListID(CBI->getAttributes()));
3232 
3233     Vals.push_back(CBI->getCallingConv() << bitc::CALL_CCONV |
3234                    1 << bitc::CALL_EXPLICIT_TYPE);
3235 
3236     Vals.push_back(VE.getValueID(CBI->getDefaultDest()));
3237     Vals.push_back(CBI->getNumIndirectDests());
3238     for (unsigned i = 0, e = CBI->getNumIndirectDests(); i != e; ++i)
3239       Vals.push_back(VE.getValueID(CBI->getIndirectDest(i)));
3240 
3241     Vals.push_back(VE.getTypeID(FTy));
3242     pushValueAndType(Callee, InstID, Vals);
3243 
3244     // Emit value #'s for the fixed parameters.
3245     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
3246       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
3247 
3248     // Emit type/value pairs for varargs params.
3249     if (FTy->isVarArg()) {
3250       for (unsigned i = FTy->getNumParams(), e = CBI->arg_size(); i != e; ++i)
3251         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
3252     }
3253     break;
3254   }
3255   case Instruction::Unreachable:
3256     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
3257     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
3258     break;
3259 
3260   case Instruction::PHI: {
3261     const PHINode &PN = cast<PHINode>(I);
3262     Code = bitc::FUNC_CODE_INST_PHI;
3263     // With the newer instruction encoding, forward references could give
3264     // negative valued IDs.  This is most common for PHIs, so we use
3265     // signed VBRs.
3266     SmallVector<uint64_t, 128> Vals64;
3267     Vals64.push_back(VE.getTypeID(PN.getType()));
3268     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
3269       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64);
3270       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
3271     }
3272 
3273     uint64_t Flags = getOptimizationFlags(&I);
3274     if (Flags != 0)
3275       Vals64.push_back(Flags);
3276 
3277     // Emit a Vals64 vector and exit.
3278     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
3279     Vals64.clear();
3280     return;
3281   }
3282 
3283   case Instruction::LandingPad: {
3284     const LandingPadInst &LP = cast<LandingPadInst>(I);
3285     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
3286     Vals.push_back(VE.getTypeID(LP.getType()));
3287     Vals.push_back(LP.isCleanup());
3288     Vals.push_back(LP.getNumClauses());
3289     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
3290       if (LP.isCatch(I))
3291         Vals.push_back(LandingPadInst::Catch);
3292       else
3293         Vals.push_back(LandingPadInst::Filter);
3294       pushValueAndType(LP.getClause(I), InstID, Vals);
3295     }
3296     break;
3297   }
3298 
3299   case Instruction::Alloca: {
3300     Code = bitc::FUNC_CODE_INST_ALLOCA;
3301     const AllocaInst &AI = cast<AllocaInst>(I);
3302     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
3303     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
3304     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
3305     using APV = AllocaPackedValues;
3306     unsigned Record = 0;
3307     unsigned EncodedAlign = getEncodedAlign(AI.getAlign());
3308     Bitfield::set<APV::AlignLower>(
3309         Record, EncodedAlign & ((1 << APV::AlignLower::Bits) - 1));
3310     Bitfield::set<APV::AlignUpper>(Record,
3311                                    EncodedAlign >> APV::AlignLower::Bits);
3312     Bitfield::set<APV::UsedWithInAlloca>(Record, AI.isUsedWithInAlloca());
3313     Bitfield::set<APV::ExplicitType>(Record, true);
3314     Bitfield::set<APV::SwiftError>(Record, AI.isSwiftError());
3315     Vals.push_back(Record);
3316 
3317     unsigned AS = AI.getAddressSpace();
3318     if (AS != M.getDataLayout().getAllocaAddrSpace())
3319       Vals.push_back(AS);
3320     break;
3321   }
3322 
3323   case Instruction::Load:
3324     if (cast<LoadInst>(I).isAtomic()) {
3325       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
3326       pushValueAndType(I.getOperand(0), InstID, Vals);
3327     } else {
3328       Code = bitc::FUNC_CODE_INST_LOAD;
3329       if (!pushValueAndType(I.getOperand(0), InstID, Vals)) // ptr
3330         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
3331     }
3332     Vals.push_back(VE.getTypeID(I.getType()));
3333     Vals.push_back(getEncodedAlign(cast<LoadInst>(I).getAlign()));
3334     Vals.push_back(cast<LoadInst>(I).isVolatile());
3335     if (cast<LoadInst>(I).isAtomic()) {
3336       Vals.push_back(getEncodedOrdering(cast<LoadInst>(I).getOrdering()));
3337       Vals.push_back(getEncodedSyncScopeID(cast<LoadInst>(I).getSyncScopeID()));
3338     }
3339     break;
3340   case Instruction::Store:
3341     if (cast<StoreInst>(I).isAtomic())
3342       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
3343     else
3344       Code = bitc::FUNC_CODE_INST_STORE;
3345     pushValueAndType(I.getOperand(1), InstID, Vals); // ptrty + ptr
3346     pushValueAndType(I.getOperand(0), InstID, Vals); // valty + val
3347     Vals.push_back(getEncodedAlign(cast<StoreInst>(I).getAlign()));
3348     Vals.push_back(cast<StoreInst>(I).isVolatile());
3349     if (cast<StoreInst>(I).isAtomic()) {
3350       Vals.push_back(getEncodedOrdering(cast<StoreInst>(I).getOrdering()));
3351       Vals.push_back(
3352           getEncodedSyncScopeID(cast<StoreInst>(I).getSyncScopeID()));
3353     }
3354     break;
3355   case Instruction::AtomicCmpXchg:
3356     Code = bitc::FUNC_CODE_INST_CMPXCHG;
3357     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
3358     pushValueAndType(I.getOperand(1), InstID, Vals); // cmp.
3359     pushValue(I.getOperand(2), InstID, Vals);        // newval.
3360     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
3361     Vals.push_back(
3362         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
3363     Vals.push_back(
3364         getEncodedSyncScopeID(cast<AtomicCmpXchgInst>(I).getSyncScopeID()));
3365     Vals.push_back(
3366         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
3367     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
3368     Vals.push_back(getEncodedAlign(cast<AtomicCmpXchgInst>(I).getAlign()));
3369     break;
3370   case Instruction::AtomicRMW:
3371     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
3372     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
3373     pushValueAndType(I.getOperand(1), InstID, Vals); // valty + val
3374     Vals.push_back(
3375         getEncodedRMWOperation(cast<AtomicRMWInst>(I).getOperation()));
3376     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
3377     Vals.push_back(getEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
3378     Vals.push_back(
3379         getEncodedSyncScopeID(cast<AtomicRMWInst>(I).getSyncScopeID()));
3380     Vals.push_back(getEncodedAlign(cast<AtomicRMWInst>(I).getAlign()));
3381     break;
3382   case Instruction::Fence:
3383     Code = bitc::FUNC_CODE_INST_FENCE;
3384     Vals.push_back(getEncodedOrdering(cast<FenceInst>(I).getOrdering()));
3385     Vals.push_back(getEncodedSyncScopeID(cast<FenceInst>(I).getSyncScopeID()));
3386     break;
3387   case Instruction::Call: {
3388     const CallInst &CI = cast<CallInst>(I);
3389     FunctionType *FTy = CI.getFunctionType();
3390 
3391     if (CI.hasOperandBundles())
3392       writeOperandBundles(CI, InstID);
3393 
3394     Code = bitc::FUNC_CODE_INST_CALL;
3395 
3396     Vals.push_back(VE.getAttributeListID(CI.getAttributes()));
3397 
3398     unsigned Flags = getOptimizationFlags(&I);
3399     Vals.push_back(CI.getCallingConv() << bitc::CALL_CCONV |
3400                    unsigned(CI.isTailCall()) << bitc::CALL_TAIL |
3401                    unsigned(CI.isMustTailCall()) << bitc::CALL_MUSTTAIL |
3402                    1 << bitc::CALL_EXPLICIT_TYPE |
3403                    unsigned(CI.isNoTailCall()) << bitc::CALL_NOTAIL |
3404                    unsigned(Flags != 0) << bitc::CALL_FMF);
3405     if (Flags != 0)
3406       Vals.push_back(Flags);
3407 
3408     Vals.push_back(VE.getTypeID(FTy));
3409     pushValueAndType(CI.getCalledOperand(), InstID, Vals); // Callee
3410 
3411     // Emit value #'s for the fixed parameters.
3412     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
3413       // Check for labels (can happen with asm labels).
3414       if (FTy->getParamType(i)->isLabelTy())
3415         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
3416       else
3417         pushValue(CI.getArgOperand(i), InstID, Vals); // fixed param.
3418     }
3419 
3420     // Emit type/value pairs for varargs params.
3421     if (FTy->isVarArg()) {
3422       for (unsigned i = FTy->getNumParams(), e = CI.arg_size(); i != e; ++i)
3423         pushValueAndType(CI.getArgOperand(i), InstID, Vals); // varargs
3424     }
3425     break;
3426   }
3427   case Instruction::VAArg:
3428     Code = bitc::FUNC_CODE_INST_VAARG;
3429     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
3430     pushValue(I.getOperand(0), InstID, Vals);                   // valist.
3431     Vals.push_back(VE.getTypeID(I.getType())); // restype.
3432     break;
3433   case Instruction::Freeze:
3434     Code = bitc::FUNC_CODE_INST_FREEZE;
3435     pushValueAndType(I.getOperand(0), InstID, Vals);
3436     break;
3437   }
3438 
3439   Stream.EmitRecord(Code, Vals, AbbrevToUse);
3440   Vals.clear();
3441 }
3442 
3443 /// Write a GlobalValue VST to the module. The purpose of this data structure is
3444 /// to allow clients to efficiently find the function body.
3445 void ModuleBitcodeWriter::writeGlobalValueSymbolTable(
3446   DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex) {
3447   // Get the offset of the VST we are writing, and backpatch it into
3448   // the VST forward declaration record.
3449   uint64_t VSTOffset = Stream.GetCurrentBitNo();
3450   // The BitcodeStartBit was the stream offset of the identification block.
3451   VSTOffset -= bitcodeStartBit();
3452   assert((VSTOffset & 31) == 0 && "VST block not 32-bit aligned");
3453   // Note that we add 1 here because the offset is relative to one word
3454   // before the start of the identification block, which was historically
3455   // always the start of the regular bitcode header.
3456   Stream.BackpatchWord(VSTOffsetPlaceholder, VSTOffset / 32 + 1);
3457 
3458   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
3459 
3460   auto Abbv = std::make_shared<BitCodeAbbrev>();
3461   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
3462   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
3463   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
3464   unsigned FnEntryAbbrev = Stream.EmitAbbrev(std::move(Abbv));
3465 
3466   for (const Function &F : M) {
3467     uint64_t Record[2];
3468 
3469     if (F.isDeclaration())
3470       continue;
3471 
3472     Record[0] = VE.getValueID(&F);
3473 
3474     // Save the word offset of the function (from the start of the
3475     // actual bitcode written to the stream).
3476     uint64_t BitcodeIndex = FunctionToBitcodeIndex[&F] - bitcodeStartBit();
3477     assert((BitcodeIndex & 31) == 0 && "function block not 32-bit aligned");
3478     // Note that we add 1 here because the offset is relative to one word
3479     // before the start of the identification block, which was historically
3480     // always the start of the regular bitcode header.
3481     Record[1] = BitcodeIndex / 32 + 1;
3482 
3483     Stream.EmitRecord(bitc::VST_CODE_FNENTRY, Record, FnEntryAbbrev);
3484   }
3485 
3486   Stream.ExitBlock();
3487 }
3488 
3489 /// Emit names for arguments, instructions and basic blocks in a function.
3490 void ModuleBitcodeWriter::writeFunctionLevelValueSymbolTable(
3491     const ValueSymbolTable &VST) {
3492   if (VST.empty())
3493     return;
3494 
3495   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
3496 
3497   // FIXME: Set up the abbrev, we know how many values there are!
3498   // FIXME: We know if the type names can use 7-bit ascii.
3499   SmallVector<uint64_t, 64> NameVals;
3500 
3501   for (const ValueName &Name : VST) {
3502     // Figure out the encoding to use for the name.
3503     StringEncoding Bits = getStringEncoding(Name.getKey());
3504 
3505     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
3506     NameVals.push_back(VE.getValueID(Name.getValue()));
3507 
3508     // VST_CODE_ENTRY:   [valueid, namechar x N]
3509     // VST_CODE_BBENTRY: [bbid, namechar x N]
3510     unsigned Code;
3511     if (isa<BasicBlock>(Name.getValue())) {
3512       Code = bitc::VST_CODE_BBENTRY;
3513       if (Bits == SE_Char6)
3514         AbbrevToUse = VST_BBENTRY_6_ABBREV;
3515     } else {
3516       Code = bitc::VST_CODE_ENTRY;
3517       if (Bits == SE_Char6)
3518         AbbrevToUse = VST_ENTRY_6_ABBREV;
3519       else if (Bits == SE_Fixed7)
3520         AbbrevToUse = VST_ENTRY_7_ABBREV;
3521     }
3522 
3523     for (const auto P : Name.getKey())
3524       NameVals.push_back((unsigned char)P);
3525 
3526     // Emit the finished record.
3527     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
3528     NameVals.clear();
3529   }
3530 
3531   Stream.ExitBlock();
3532 }
3533 
3534 void ModuleBitcodeWriter::writeUseList(UseListOrder &&Order) {
3535   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
3536   unsigned Code;
3537   if (isa<BasicBlock>(Order.V))
3538     Code = bitc::USELIST_CODE_BB;
3539   else
3540     Code = bitc::USELIST_CODE_DEFAULT;
3541 
3542   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
3543   Record.push_back(VE.getValueID(Order.V));
3544   Stream.EmitRecord(Code, Record);
3545 }
3546 
3547 void ModuleBitcodeWriter::writeUseListBlock(const Function *F) {
3548   assert(VE.shouldPreserveUseListOrder() &&
3549          "Expected to be preserving use-list order");
3550 
3551   auto hasMore = [&]() {
3552     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
3553   };
3554   if (!hasMore())
3555     // Nothing to do.
3556     return;
3557 
3558   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
3559   while (hasMore()) {
3560     writeUseList(std::move(VE.UseListOrders.back()));
3561     VE.UseListOrders.pop_back();
3562   }
3563   Stream.ExitBlock();
3564 }
3565 
3566 /// Emit a function body to the module stream.
3567 void ModuleBitcodeWriter::writeFunction(
3568     const Function &F,
3569     DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex) {
3570   // Save the bitcode index of the start of this function block for recording
3571   // in the VST.
3572   FunctionToBitcodeIndex[&F] = Stream.GetCurrentBitNo();
3573 
3574   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
3575   VE.incorporateFunction(F);
3576 
3577   SmallVector<unsigned, 64> Vals;
3578 
3579   // Emit the number of basic blocks, so the reader can create them ahead of
3580   // time.
3581   Vals.push_back(VE.getBasicBlocks().size());
3582   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
3583   Vals.clear();
3584 
3585   // If there are function-local constants, emit them now.
3586   unsigned CstStart, CstEnd;
3587   VE.getFunctionConstantRange(CstStart, CstEnd);
3588   writeConstants(CstStart, CstEnd, false);
3589 
3590   // If there is function-local metadata, emit it now.
3591   writeFunctionMetadata(F);
3592 
3593   // Keep a running idea of what the instruction ID is.
3594   unsigned InstID = CstEnd;
3595 
3596   bool NeedsMetadataAttachment = F.hasMetadata();
3597 
3598   DILocation *LastDL = nullptr;
3599   SmallSetVector<Function *, 4> BlockAddressUsers;
3600 
3601   // Finally, emit all the instructions, in order.
3602   for (const BasicBlock &BB : F) {
3603     for (const Instruction &I : BB) {
3604       writeInstruction(I, InstID, Vals);
3605 
3606       if (!I.getType()->isVoidTy())
3607         ++InstID;
3608 
3609       // If the instruction has metadata, write a metadata attachment later.
3610       NeedsMetadataAttachment |= I.hasMetadataOtherThanDebugLoc();
3611 
3612       // If the instruction has a debug location, emit it.
3613       if (DILocation *DL = I.getDebugLoc()) {
3614         if (DL == LastDL) {
3615           // Just repeat the same debug loc as last time.
3616           Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
3617         } else {
3618           Vals.push_back(DL->getLine());
3619           Vals.push_back(DL->getColumn());
3620           Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
3621           Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
3622           Vals.push_back(DL->isImplicitCode());
3623           Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
3624           Vals.clear();
3625           LastDL = DL;
3626         }
3627       }
3628 
3629       // If the instruction has DbgRecords attached to it, emit them. Note that
3630       // they come after the instruction so that it's easy to attach them again
3631       // when reading the bitcode, even though conceptually the debug locations
3632       // start "before" the instruction.
3633       if (I.hasDbgRecords() && WriteNewDbgInfoFormatToBitcode) {
3634         /// Try to push the value only (unwrapped), otherwise push the
3635         /// metadata wrapped value. Returns true if the value was pushed
3636         /// without the ValueAsMetadata wrapper.
3637         auto PushValueOrMetadata = [&Vals, InstID,
3638                                     this](Metadata *RawLocation) {
3639           assert(RawLocation &&
3640                  "RawLocation unexpectedly null in DbgVariableRecord");
3641           if (ValueAsMetadata *VAM = dyn_cast<ValueAsMetadata>(RawLocation)) {
3642             SmallVector<unsigned, 2> ValAndType;
3643             // If the value is a fwd-ref the type is also pushed. We don't
3644             // want the type, so fwd-refs are kept wrapped (pushValueAndType
3645             // returns false if the value is pushed without type).
3646             if (!pushValueAndType(VAM->getValue(), InstID, ValAndType)) {
3647               Vals.push_back(ValAndType[0]);
3648               return true;
3649             }
3650           }
3651           // The metadata is a DIArgList, or ValueAsMetadata wrapping a
3652           // fwd-ref. Push the metadata ID.
3653           Vals.push_back(VE.getMetadataID(RawLocation));
3654           return false;
3655         };
3656 
3657         // Write out non-instruction debug information attached to this
3658         // instruction. Write it after the instruction so that it's easy to
3659         // re-attach to the instruction reading the records in.
3660         for (DbgRecord &DR : I.DebugMarker->getDbgRecordRange()) {
3661           if (DbgLabelRecord *DLR = dyn_cast<DbgLabelRecord>(&DR)) {
3662             Vals.push_back(VE.getMetadataID(&*DLR->getDebugLoc()));
3663             Vals.push_back(VE.getMetadataID(DLR->getLabel()));
3664             Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_LABEL, Vals);
3665             Vals.clear();
3666             continue;
3667           }
3668 
3669           // First 3 fields are common to all kinds:
3670           //   DILocation, DILocalVariable, DIExpression
3671           // dbg_value (FUNC_CODE_DEBUG_RECORD_VALUE)
3672           //   ..., LocationMetadata
3673           // dbg_value (FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE - abbrev'd)
3674           //   ..., Value
3675           // dbg_declare (FUNC_CODE_DEBUG_RECORD_DECLARE)
3676           //   ..., LocationMetadata
3677           // dbg_assign (FUNC_CODE_DEBUG_RECORD_ASSIGN)
3678           //   ..., LocationMetadata, DIAssignID, DIExpression, LocationMetadata
3679           DbgVariableRecord &DVR = cast<DbgVariableRecord>(DR);
3680           Vals.push_back(VE.getMetadataID(&*DVR.getDebugLoc()));
3681           Vals.push_back(VE.getMetadataID(DVR.getVariable()));
3682           Vals.push_back(VE.getMetadataID(DVR.getExpression()));
3683           if (DVR.isDbgValue()) {
3684             if (PushValueOrMetadata(DVR.getRawLocation()))
3685               Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE, Vals,
3686                                 FUNCTION_DEBUG_RECORD_VALUE_ABBREV);
3687             else
3688               Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_VALUE, Vals);
3689           } else if (DVR.isDbgDeclare()) {
3690             Vals.push_back(VE.getMetadataID(DVR.getRawLocation()));
3691             Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_DECLARE, Vals);
3692           } else {
3693             assert(DVR.isDbgAssign() && "Unexpected DbgRecord kind");
3694             Vals.push_back(VE.getMetadataID(DVR.getRawLocation()));
3695             Vals.push_back(VE.getMetadataID(DVR.getAssignID()));
3696             Vals.push_back(VE.getMetadataID(DVR.getAddressExpression()));
3697             Vals.push_back(VE.getMetadataID(DVR.getRawAddress()));
3698             Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_ASSIGN, Vals);
3699           }
3700           Vals.clear();
3701         }
3702       }
3703     }
3704 
3705     if (BlockAddress *BA = BlockAddress::lookup(&BB)) {
3706       SmallVector<Value *> Worklist{BA};
3707       SmallPtrSet<Value *, 8> Visited{BA};
3708       while (!Worklist.empty()) {
3709         Value *V = Worklist.pop_back_val();
3710         for (User *U : V->users()) {
3711           if (auto *I = dyn_cast<Instruction>(U)) {
3712             Function *P = I->getFunction();
3713             if (P != &F)
3714               BlockAddressUsers.insert(P);
3715           } else if (isa<Constant>(U) && !isa<GlobalValue>(U) &&
3716                      Visited.insert(U).second)
3717             Worklist.push_back(U);
3718         }
3719       }
3720     }
3721   }
3722 
3723   if (!BlockAddressUsers.empty()) {
3724     Vals.resize(BlockAddressUsers.size());
3725     for (auto I : llvm::enumerate(BlockAddressUsers))
3726       Vals[I.index()] = VE.getValueID(I.value());
3727     Stream.EmitRecord(bitc::FUNC_CODE_BLOCKADDR_USERS, Vals);
3728     Vals.clear();
3729   }
3730 
3731   // Emit names for all the instructions etc.
3732   if (auto *Symtab = F.getValueSymbolTable())
3733     writeFunctionLevelValueSymbolTable(*Symtab);
3734 
3735   if (NeedsMetadataAttachment)
3736     writeFunctionMetadataAttachment(F);
3737   if (VE.shouldPreserveUseListOrder())
3738     writeUseListBlock(&F);
3739   VE.purgeFunction();
3740   Stream.ExitBlock();
3741 }
3742 
3743 // Emit blockinfo, which defines the standard abbreviations etc.
3744 void ModuleBitcodeWriter::writeBlockInfo() {
3745   // We only want to emit block info records for blocks that have multiple
3746   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
3747   // Other blocks can define their abbrevs inline.
3748   Stream.EnterBlockInfoBlock();
3749 
3750   { // 8-bit fixed-width VST_CODE_ENTRY/VST_CODE_BBENTRY strings.
3751     auto Abbv = std::make_shared<BitCodeAbbrev>();
3752     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
3753     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3754     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3755     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
3756     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3757         VST_ENTRY_8_ABBREV)
3758       llvm_unreachable("Unexpected abbrev ordering!");
3759   }
3760 
3761   { // 7-bit fixed width VST_CODE_ENTRY strings.
3762     auto Abbv = std::make_shared<BitCodeAbbrev>();
3763     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
3764     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3765     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3766     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
3767     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3768         VST_ENTRY_7_ABBREV)
3769       llvm_unreachable("Unexpected abbrev ordering!");
3770   }
3771   { // 6-bit char6 VST_CODE_ENTRY strings.
3772     auto Abbv = std::make_shared<BitCodeAbbrev>();
3773     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
3774     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3775     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3776     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3777     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3778         VST_ENTRY_6_ABBREV)
3779       llvm_unreachable("Unexpected abbrev ordering!");
3780   }
3781   { // 6-bit char6 VST_CODE_BBENTRY strings.
3782     auto Abbv = std::make_shared<BitCodeAbbrev>();
3783     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
3784     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3785     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3786     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3787     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3788         VST_BBENTRY_6_ABBREV)
3789       llvm_unreachable("Unexpected abbrev ordering!");
3790   }
3791 
3792   { // SETTYPE abbrev for CONSTANTS_BLOCK.
3793     auto Abbv = std::make_shared<BitCodeAbbrev>();
3794     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
3795     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
3796                               VE.computeBitsRequiredForTypeIndices()));
3797     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3798         CONSTANTS_SETTYPE_ABBREV)
3799       llvm_unreachable("Unexpected abbrev ordering!");
3800   }
3801 
3802   { // INTEGER abbrev for CONSTANTS_BLOCK.
3803     auto Abbv = std::make_shared<BitCodeAbbrev>();
3804     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
3805     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3806     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3807         CONSTANTS_INTEGER_ABBREV)
3808       llvm_unreachable("Unexpected abbrev ordering!");
3809   }
3810 
3811   { // CE_CAST abbrev for CONSTANTS_BLOCK.
3812     auto Abbv = std::make_shared<BitCodeAbbrev>();
3813     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
3814     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
3815     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
3816                               VE.computeBitsRequiredForTypeIndices()));
3817     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
3818 
3819     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3820         CONSTANTS_CE_CAST_Abbrev)
3821       llvm_unreachable("Unexpected abbrev ordering!");
3822   }
3823   { // NULL abbrev for CONSTANTS_BLOCK.
3824     auto Abbv = std::make_shared<BitCodeAbbrev>();
3825     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
3826     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3827         CONSTANTS_NULL_Abbrev)
3828       llvm_unreachable("Unexpected abbrev ordering!");
3829   }
3830 
3831   // FIXME: This should only use space for first class types!
3832 
3833   { // INST_LOAD abbrev for FUNCTION_BLOCK.
3834     auto Abbv = std::make_shared<BitCodeAbbrev>();
3835     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
3836     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
3837     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
3838                               VE.computeBitsRequiredForTypeIndices()));
3839     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
3840     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
3841     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3842         FUNCTION_INST_LOAD_ABBREV)
3843       llvm_unreachable("Unexpected abbrev ordering!");
3844   }
3845   { // INST_UNOP abbrev for FUNCTION_BLOCK.
3846     auto Abbv = std::make_shared<BitCodeAbbrev>();
3847     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNOP));
3848     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3849     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3850     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3851         FUNCTION_INST_UNOP_ABBREV)
3852       llvm_unreachable("Unexpected abbrev ordering!");
3853   }
3854   { // INST_UNOP_FLAGS abbrev for FUNCTION_BLOCK.
3855     auto Abbv = std::make_shared<BitCodeAbbrev>();
3856     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNOP));
3857     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3858     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3859     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3860     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3861         FUNCTION_INST_UNOP_FLAGS_ABBREV)
3862       llvm_unreachable("Unexpected abbrev ordering!");
3863   }
3864   { // INST_BINOP abbrev for FUNCTION_BLOCK.
3865     auto Abbv = std::make_shared<BitCodeAbbrev>();
3866     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
3867     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3868     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
3869     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3870     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3871         FUNCTION_INST_BINOP_ABBREV)
3872       llvm_unreachable("Unexpected abbrev ordering!");
3873   }
3874   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
3875     auto Abbv = std::make_shared<BitCodeAbbrev>();
3876     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
3877     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3878     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
3879     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3880     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3881     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3882         FUNCTION_INST_BINOP_FLAGS_ABBREV)
3883       llvm_unreachable("Unexpected abbrev ordering!");
3884   }
3885   { // INST_CAST abbrev for FUNCTION_BLOCK.
3886     auto Abbv = std::make_shared<BitCodeAbbrev>();
3887     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
3888     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
3889     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
3890                               VE.computeBitsRequiredForTypeIndices()));
3891     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
3892     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3893         FUNCTION_INST_CAST_ABBREV)
3894       llvm_unreachable("Unexpected abbrev ordering!");
3895   }
3896   { // INST_CAST_FLAGS abbrev for FUNCTION_BLOCK.
3897     auto Abbv = std::make_shared<BitCodeAbbrev>();
3898     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
3899     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // OpVal
3900     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
3901                               VE.computeBitsRequiredForTypeIndices()));
3902     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3903     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3904     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3905         FUNCTION_INST_CAST_FLAGS_ABBREV)
3906       llvm_unreachable("Unexpected abbrev ordering!");
3907   }
3908 
3909   { // INST_RET abbrev for FUNCTION_BLOCK.
3910     auto Abbv = std::make_shared<BitCodeAbbrev>();
3911     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
3912     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3913         FUNCTION_INST_RET_VOID_ABBREV)
3914       llvm_unreachable("Unexpected abbrev ordering!");
3915   }
3916   { // INST_RET abbrev for FUNCTION_BLOCK.
3917     auto Abbv = std::make_shared<BitCodeAbbrev>();
3918     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
3919     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
3920     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3921         FUNCTION_INST_RET_VAL_ABBREV)
3922       llvm_unreachable("Unexpected abbrev ordering!");
3923   }
3924   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
3925     auto Abbv = std::make_shared<BitCodeAbbrev>();
3926     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
3927     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3928         FUNCTION_INST_UNREACHABLE_ABBREV)
3929       llvm_unreachable("Unexpected abbrev ordering!");
3930   }
3931   {
3932     auto Abbv = std::make_shared<BitCodeAbbrev>();
3933     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
3934     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
3935     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
3936                               Log2_32_Ceil(VE.getTypes().size() + 1)));
3937     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3938     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
3939     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3940         FUNCTION_INST_GEP_ABBREV)
3941       llvm_unreachable("Unexpected abbrev ordering!");
3942   }
3943   {
3944     auto Abbv = std::make_shared<BitCodeAbbrev>();
3945     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE));
3946     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 7)); // dbgloc
3947     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 7)); // var
3948     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 7)); // expr
3949     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // val
3950     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3951         FUNCTION_DEBUG_RECORD_VALUE_ABBREV)
3952       llvm_unreachable("Unexpected abbrev ordering! 1");
3953   }
3954   Stream.ExitBlock();
3955 }
3956 
3957 /// Write the module path strings, currently only used when generating
3958 /// a combined index file.
3959 void IndexBitcodeWriter::writeModStrings() {
3960   Stream.EnterSubblock(bitc::MODULE_STRTAB_BLOCK_ID, 3);
3961 
3962   // TODO: See which abbrev sizes we actually need to emit
3963 
3964   // 8-bit fixed-width MST_ENTRY strings.
3965   auto Abbv = std::make_shared<BitCodeAbbrev>();
3966   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3967   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3968   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3969   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
3970   unsigned Abbrev8Bit = Stream.EmitAbbrev(std::move(Abbv));
3971 
3972   // 7-bit fixed width MST_ENTRY strings.
3973   Abbv = std::make_shared<BitCodeAbbrev>();
3974   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3975   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3976   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3977   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
3978   unsigned Abbrev7Bit = Stream.EmitAbbrev(std::move(Abbv));
3979 
3980   // 6-bit char6 MST_ENTRY strings.
3981   Abbv = std::make_shared<BitCodeAbbrev>();
3982   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3983   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3984   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3985   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3986   unsigned Abbrev6Bit = Stream.EmitAbbrev(std::move(Abbv));
3987 
3988   // Module Hash, 160 bits SHA1. Optionally, emitted after each MST_CODE_ENTRY.
3989   Abbv = std::make_shared<BitCodeAbbrev>();
3990   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_HASH));
3991   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3992   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3993   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3994   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3995   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3996   unsigned AbbrevHash = Stream.EmitAbbrev(std::move(Abbv));
3997 
3998   SmallVector<unsigned, 64> Vals;
3999   forEachModule([&](const StringMapEntry<ModuleHash> &MPSE) {
4000     StringRef Key = MPSE.getKey();
4001     const auto &Hash = MPSE.getValue();
4002     StringEncoding Bits = getStringEncoding(Key);
4003     unsigned AbbrevToUse = Abbrev8Bit;
4004     if (Bits == SE_Char6)
4005       AbbrevToUse = Abbrev6Bit;
4006     else if (Bits == SE_Fixed7)
4007       AbbrevToUse = Abbrev7Bit;
4008 
4009     auto ModuleId = ModuleIdMap.size();
4010     ModuleIdMap[Key] = ModuleId;
4011     Vals.push_back(ModuleId);
4012     Vals.append(Key.begin(), Key.end());
4013 
4014     // Emit the finished record.
4015     Stream.EmitRecord(bitc::MST_CODE_ENTRY, Vals, AbbrevToUse);
4016 
4017     // Emit an optional hash for the module now
4018     if (llvm::any_of(Hash, [](uint32_t H) { return H; })) {
4019       Vals.assign(Hash.begin(), Hash.end());
4020       // Emit the hash record.
4021       Stream.EmitRecord(bitc::MST_CODE_HASH, Vals, AbbrevHash);
4022     }
4023 
4024     Vals.clear();
4025   });
4026   Stream.ExitBlock();
4027 }
4028 
4029 /// Write the function type metadata related records that need to appear before
4030 /// a function summary entry (whether per-module or combined).
4031 template <typename Fn>
4032 static void writeFunctionTypeMetadataRecords(BitstreamWriter &Stream,
4033                                              FunctionSummary *FS,
4034                                              Fn GetValueID) {
4035   if (!FS->type_tests().empty())
4036     Stream.EmitRecord(bitc::FS_TYPE_TESTS, FS->type_tests());
4037 
4038   SmallVector<uint64_t, 64> Record;
4039 
4040   auto WriteVFuncIdVec = [&](uint64_t Ty,
4041                              ArrayRef<FunctionSummary::VFuncId> VFs) {
4042     if (VFs.empty())
4043       return;
4044     Record.clear();
4045     for (auto &VF : VFs) {
4046       Record.push_back(VF.GUID);
4047       Record.push_back(VF.Offset);
4048     }
4049     Stream.EmitRecord(Ty, Record);
4050   };
4051 
4052   WriteVFuncIdVec(bitc::FS_TYPE_TEST_ASSUME_VCALLS,
4053                   FS->type_test_assume_vcalls());
4054   WriteVFuncIdVec(bitc::FS_TYPE_CHECKED_LOAD_VCALLS,
4055                   FS->type_checked_load_vcalls());
4056 
4057   auto WriteConstVCallVec = [&](uint64_t Ty,
4058                                 ArrayRef<FunctionSummary::ConstVCall> VCs) {
4059     for (auto &VC : VCs) {
4060       Record.clear();
4061       Record.push_back(VC.VFunc.GUID);
4062       Record.push_back(VC.VFunc.Offset);
4063       llvm::append_range(Record, VC.Args);
4064       Stream.EmitRecord(Ty, Record);
4065     }
4066   };
4067 
4068   WriteConstVCallVec(bitc::FS_TYPE_TEST_ASSUME_CONST_VCALL,
4069                      FS->type_test_assume_const_vcalls());
4070   WriteConstVCallVec(bitc::FS_TYPE_CHECKED_LOAD_CONST_VCALL,
4071                      FS->type_checked_load_const_vcalls());
4072 
4073   auto WriteRange = [&](ConstantRange Range) {
4074     Range = Range.sextOrTrunc(FunctionSummary::ParamAccess::RangeWidth);
4075     assert(Range.getLower().getNumWords() == 1);
4076     assert(Range.getUpper().getNumWords() == 1);
4077     emitSignedInt64(Record, *Range.getLower().getRawData());
4078     emitSignedInt64(Record, *Range.getUpper().getRawData());
4079   };
4080 
4081   if (!FS->paramAccesses().empty()) {
4082     Record.clear();
4083     for (auto &Arg : FS->paramAccesses()) {
4084       size_t UndoSize = Record.size();
4085       Record.push_back(Arg.ParamNo);
4086       WriteRange(Arg.Use);
4087       Record.push_back(Arg.Calls.size());
4088       for (auto &Call : Arg.Calls) {
4089         Record.push_back(Call.ParamNo);
4090         std::optional<unsigned> ValueID = GetValueID(Call.Callee);
4091         if (!ValueID) {
4092           // If ValueID is unknown we can't drop just this call, we must drop
4093           // entire parameter.
4094           Record.resize(UndoSize);
4095           break;
4096         }
4097         Record.push_back(*ValueID);
4098         WriteRange(Call.Offsets);
4099       }
4100     }
4101     if (!Record.empty())
4102       Stream.EmitRecord(bitc::FS_PARAM_ACCESS, Record);
4103   }
4104 }
4105 
4106 /// Collect type IDs from type tests used by function.
4107 static void
4108 getReferencedTypeIds(FunctionSummary *FS,
4109                      std::set<GlobalValue::GUID> &ReferencedTypeIds) {
4110   if (!FS->type_tests().empty())
4111     for (auto &TT : FS->type_tests())
4112       ReferencedTypeIds.insert(TT);
4113 
4114   auto GetReferencedTypesFromVFuncIdVec =
4115       [&](ArrayRef<FunctionSummary::VFuncId> VFs) {
4116         for (auto &VF : VFs)
4117           ReferencedTypeIds.insert(VF.GUID);
4118       };
4119 
4120   GetReferencedTypesFromVFuncIdVec(FS->type_test_assume_vcalls());
4121   GetReferencedTypesFromVFuncIdVec(FS->type_checked_load_vcalls());
4122 
4123   auto GetReferencedTypesFromConstVCallVec =
4124       [&](ArrayRef<FunctionSummary::ConstVCall> VCs) {
4125         for (auto &VC : VCs)
4126           ReferencedTypeIds.insert(VC.VFunc.GUID);
4127       };
4128 
4129   GetReferencedTypesFromConstVCallVec(FS->type_test_assume_const_vcalls());
4130   GetReferencedTypesFromConstVCallVec(FS->type_checked_load_const_vcalls());
4131 }
4132 
4133 static void writeWholeProgramDevirtResolutionByArg(
4134     SmallVector<uint64_t, 64> &NameVals, const std::vector<uint64_t> &args,
4135     const WholeProgramDevirtResolution::ByArg &ByArg) {
4136   NameVals.push_back(args.size());
4137   llvm::append_range(NameVals, args);
4138 
4139   NameVals.push_back(ByArg.TheKind);
4140   NameVals.push_back(ByArg.Info);
4141   NameVals.push_back(ByArg.Byte);
4142   NameVals.push_back(ByArg.Bit);
4143 }
4144 
4145 static void writeWholeProgramDevirtResolution(
4146     SmallVector<uint64_t, 64> &NameVals, StringTableBuilder &StrtabBuilder,
4147     uint64_t Id, const WholeProgramDevirtResolution &Wpd) {
4148   NameVals.push_back(Id);
4149 
4150   NameVals.push_back(Wpd.TheKind);
4151   NameVals.push_back(StrtabBuilder.add(Wpd.SingleImplName));
4152   NameVals.push_back(Wpd.SingleImplName.size());
4153 
4154   NameVals.push_back(Wpd.ResByArg.size());
4155   for (auto &A : Wpd.ResByArg)
4156     writeWholeProgramDevirtResolutionByArg(NameVals, A.first, A.second);
4157 }
4158 
4159 static void writeTypeIdSummaryRecord(SmallVector<uint64_t, 64> &NameVals,
4160                                      StringTableBuilder &StrtabBuilder,
4161                                      const std::string &Id,
4162                                      const TypeIdSummary &Summary) {
4163   NameVals.push_back(StrtabBuilder.add(Id));
4164   NameVals.push_back(Id.size());
4165 
4166   NameVals.push_back(Summary.TTRes.TheKind);
4167   NameVals.push_back(Summary.TTRes.SizeM1BitWidth);
4168   NameVals.push_back(Summary.TTRes.AlignLog2);
4169   NameVals.push_back(Summary.TTRes.SizeM1);
4170   NameVals.push_back(Summary.TTRes.BitMask);
4171   NameVals.push_back(Summary.TTRes.InlineBits);
4172 
4173   for (auto &W : Summary.WPDRes)
4174     writeWholeProgramDevirtResolution(NameVals, StrtabBuilder, W.first,
4175                                       W.second);
4176 }
4177 
4178 static void writeTypeIdCompatibleVtableSummaryRecord(
4179     SmallVector<uint64_t, 64> &NameVals, StringTableBuilder &StrtabBuilder,
4180     const std::string &Id, const TypeIdCompatibleVtableInfo &Summary,
4181     ValueEnumerator &VE) {
4182   NameVals.push_back(StrtabBuilder.add(Id));
4183   NameVals.push_back(Id.size());
4184 
4185   for (auto &P : Summary) {
4186     NameVals.push_back(P.AddressPointOffset);
4187     NameVals.push_back(VE.getValueID(P.VTableVI.getValue()));
4188   }
4189 }
4190 
4191 static void writeFunctionHeapProfileRecords(
4192     BitstreamWriter &Stream, FunctionSummary *FS, unsigned CallsiteAbbrev,
4193     unsigned AllocAbbrev, bool PerModule,
4194     std::function<unsigned(const ValueInfo &VI)> GetValueID,
4195     std::function<unsigned(unsigned)> GetStackIndex) {
4196   SmallVector<uint64_t> Record;
4197 
4198   for (auto &CI : FS->callsites()) {
4199     Record.clear();
4200     // Per module callsite clones should always have a single entry of
4201     // value 0.
4202     assert(!PerModule || (CI.Clones.size() == 1 && CI.Clones[0] == 0));
4203     Record.push_back(GetValueID(CI.Callee));
4204     if (!PerModule) {
4205       Record.push_back(CI.StackIdIndices.size());
4206       Record.push_back(CI.Clones.size());
4207     }
4208     for (auto Id : CI.StackIdIndices)
4209       Record.push_back(GetStackIndex(Id));
4210     if (!PerModule) {
4211       for (auto V : CI.Clones)
4212         Record.push_back(V);
4213     }
4214     Stream.EmitRecord(PerModule ? bitc::FS_PERMODULE_CALLSITE_INFO
4215                                 : bitc::FS_COMBINED_CALLSITE_INFO,
4216                       Record, CallsiteAbbrev);
4217   }
4218 
4219   for (auto &AI : FS->allocs()) {
4220     Record.clear();
4221     // Per module alloc versions should always have a single entry of
4222     // value 0.
4223     assert(!PerModule || (AI.Versions.size() == 1 && AI.Versions[0] == 0));
4224     Record.push_back(AI.MIBs.size());
4225     if (!PerModule)
4226       Record.push_back(AI.Versions.size());
4227     for (auto &MIB : AI.MIBs) {
4228       Record.push_back((uint8_t)MIB.AllocType);
4229       Record.push_back(MIB.StackIdIndices.size());
4230       for (auto Id : MIB.StackIdIndices)
4231         Record.push_back(GetStackIndex(Id));
4232     }
4233     if (!PerModule) {
4234       for (auto V : AI.Versions)
4235         Record.push_back(V);
4236     }
4237     assert(AI.TotalSizes.empty() || AI.TotalSizes.size() == AI.MIBs.size());
4238     if (!AI.TotalSizes.empty()) {
4239       for (auto Size : AI.TotalSizes)
4240         Record.push_back(Size);
4241     }
4242     Stream.EmitRecord(PerModule ? bitc::FS_PERMODULE_ALLOC_INFO
4243                                 : bitc::FS_COMBINED_ALLOC_INFO,
4244                       Record, AllocAbbrev);
4245   }
4246 }
4247 
4248 // Helper to emit a single function summary record.
4249 void ModuleBitcodeWriterBase::writePerModuleFunctionSummaryRecord(
4250     SmallVector<uint64_t, 64> &NameVals, GlobalValueSummary *Summary,
4251     unsigned ValueID, unsigned FSCallsRelBFAbbrev,
4252     unsigned FSCallsProfileAbbrev, unsigned CallsiteAbbrev,
4253     unsigned AllocAbbrev, const Function &F) {
4254   NameVals.push_back(ValueID);
4255 
4256   FunctionSummary *FS = cast<FunctionSummary>(Summary);
4257 
4258   writeFunctionTypeMetadataRecords(
4259       Stream, FS, [&](const ValueInfo &VI) -> std::optional<unsigned> {
4260         return {VE.getValueID(VI.getValue())};
4261       });
4262 
4263   writeFunctionHeapProfileRecords(
4264       Stream, FS, CallsiteAbbrev, AllocAbbrev,
4265       /*PerModule*/ true,
4266       /*GetValueId*/ [&](const ValueInfo &VI) { return getValueId(VI); },
4267       /*GetStackIndex*/ [&](unsigned I) { return I; });
4268 
4269   auto SpecialRefCnts = FS->specialRefCounts();
4270   NameVals.push_back(getEncodedGVSummaryFlags(FS->flags()));
4271   NameVals.push_back(FS->instCount());
4272   NameVals.push_back(getEncodedFFlags(FS->fflags()));
4273   NameVals.push_back(FS->refs().size());
4274   NameVals.push_back(SpecialRefCnts.first);  // rorefcnt
4275   NameVals.push_back(SpecialRefCnts.second); // worefcnt
4276 
4277   for (auto &RI : FS->refs())
4278     NameVals.push_back(getValueId(RI));
4279 
4280   const bool UseRelBFRecord =
4281       WriteRelBFToSummary && !F.hasProfileData() &&
4282       ForceSummaryEdgesCold == FunctionSummary::FSHT_None;
4283   for (auto &ECI : FS->calls()) {
4284     NameVals.push_back(getValueId(ECI.first));
4285     if (UseRelBFRecord)
4286       NameVals.push_back(getEncodedRelBFCallEdgeInfo(ECI.second));
4287     else
4288       NameVals.push_back(getEncodedHotnessCallEdgeInfo(ECI.second));
4289   }
4290 
4291   unsigned FSAbbrev =
4292       (UseRelBFRecord ? FSCallsRelBFAbbrev : FSCallsProfileAbbrev);
4293   unsigned Code =
4294       (UseRelBFRecord ? bitc::FS_PERMODULE_RELBF : bitc::FS_PERMODULE_PROFILE);
4295 
4296   // Emit the finished record.
4297   Stream.EmitRecord(Code, NameVals, FSAbbrev);
4298   NameVals.clear();
4299 }
4300 
4301 // Collect the global value references in the given variable's initializer,
4302 // and emit them in a summary record.
4303 void ModuleBitcodeWriterBase::writeModuleLevelReferences(
4304     const GlobalVariable &V, SmallVector<uint64_t, 64> &NameVals,
4305     unsigned FSModRefsAbbrev, unsigned FSModVTableRefsAbbrev) {
4306   auto VI = Index->getValueInfo(V.getGUID());
4307   if (!VI || VI.getSummaryList().empty()) {
4308     // Only declarations should not have a summary (a declaration might however
4309     // have a summary if the def was in module level asm).
4310     assert(V.isDeclaration());
4311     return;
4312   }
4313   auto *Summary = VI.getSummaryList()[0].get();
4314   NameVals.push_back(VE.getValueID(&V));
4315   GlobalVarSummary *VS = cast<GlobalVarSummary>(Summary);
4316   NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
4317   NameVals.push_back(getEncodedGVarFlags(VS->varflags()));
4318 
4319   auto VTableFuncs = VS->vTableFuncs();
4320   if (!VTableFuncs.empty())
4321     NameVals.push_back(VS->refs().size());
4322 
4323   unsigned SizeBeforeRefs = NameVals.size();
4324   for (auto &RI : VS->refs())
4325     NameVals.push_back(VE.getValueID(RI.getValue()));
4326   // Sort the refs for determinism output, the vector returned by FS->refs() has
4327   // been initialized from a DenseSet.
4328   llvm::sort(drop_begin(NameVals, SizeBeforeRefs));
4329 
4330   if (VTableFuncs.empty())
4331     Stream.EmitRecord(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS, NameVals,
4332                       FSModRefsAbbrev);
4333   else {
4334     // VTableFuncs pairs should already be sorted by offset.
4335     for (auto &P : VTableFuncs) {
4336       NameVals.push_back(VE.getValueID(P.FuncVI.getValue()));
4337       NameVals.push_back(P.VTableOffset);
4338     }
4339 
4340     Stream.EmitRecord(bitc::FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS, NameVals,
4341                       FSModVTableRefsAbbrev);
4342   }
4343   NameVals.clear();
4344 }
4345 
4346 /// Emit the per-module summary section alongside the rest of
4347 /// the module's bitcode.
4348 void ModuleBitcodeWriterBase::writePerModuleGlobalValueSummary() {
4349   // By default we compile with ThinLTO if the module has a summary, but the
4350   // client can request full LTO with a module flag.
4351   bool IsThinLTO = true;
4352   if (auto *MD =
4353           mdconst::extract_or_null<ConstantInt>(M.getModuleFlag("ThinLTO")))
4354     IsThinLTO = MD->getZExtValue();
4355   Stream.EnterSubblock(IsThinLTO ? bitc::GLOBALVAL_SUMMARY_BLOCK_ID
4356                                  : bitc::FULL_LTO_GLOBALVAL_SUMMARY_BLOCK_ID,
4357                        4);
4358 
4359   Stream.EmitRecord(
4360       bitc::FS_VERSION,
4361       ArrayRef<uint64_t>{ModuleSummaryIndex::BitcodeSummaryVersion});
4362 
4363   // Write the index flags.
4364   uint64_t Flags = 0;
4365   // Bits 1-3 are set only in the combined index, skip them.
4366   if (Index->enableSplitLTOUnit())
4367     Flags |= 0x8;
4368   if (Index->hasUnifiedLTO())
4369     Flags |= 0x200;
4370 
4371   Stream.EmitRecord(bitc::FS_FLAGS, ArrayRef<uint64_t>{Flags});
4372 
4373   if (Index->begin() == Index->end()) {
4374     Stream.ExitBlock();
4375     return;
4376   }
4377 
4378   auto Abbv = std::make_shared<BitCodeAbbrev>();
4379   Abbv->Add(BitCodeAbbrevOp(bitc::FS_VALUE_GUID));
4380   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
4381   // GUIDS often use up most of 64-bits, so encode as two Fixed 32.
4382   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4383   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4384   unsigned ValueGuidAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4385 
4386   for (const auto &GVI : valueIds()) {
4387     Stream.EmitRecord(bitc::FS_VALUE_GUID,
4388                       ArrayRef<uint32_t>{GVI.second,
4389                                          static_cast<uint32_t>(GVI.first >> 32),
4390                                          static_cast<uint32_t>(GVI.first)},
4391                       ValueGuidAbbrev);
4392   }
4393 
4394   if (!Index->stackIds().empty()) {
4395     auto StackIdAbbv = std::make_shared<BitCodeAbbrev>();
4396     StackIdAbbv->Add(BitCodeAbbrevOp(bitc::FS_STACK_IDS));
4397     // numids x stackid
4398     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4399     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4400     unsigned StackIdAbbvId = Stream.EmitAbbrev(std::move(StackIdAbbv));
4401     Stream.EmitRecord(bitc::FS_STACK_IDS, Index->stackIds(), StackIdAbbvId);
4402   }
4403 
4404   // Abbrev for FS_PERMODULE_PROFILE.
4405   Abbv = std::make_shared<BitCodeAbbrev>();
4406   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_PROFILE));
4407   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4408   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // flags
4409   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4410   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4411   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4412   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4413   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4414   // numrefs x valueid, n x (valueid, hotness+tailcall flags)
4415   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4416   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4417   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4418 
4419   // Abbrev for FS_PERMODULE_RELBF.
4420   Abbv = std::make_shared<BitCodeAbbrev>();
4421   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_RELBF));
4422   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4423   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4424   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4425   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4426   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4427   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4428   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4429   // numrefs x valueid, n x (valueid, rel_block_freq+tailcall])
4430   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4431   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4432   unsigned FSCallsRelBFAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4433 
4434   // Abbrev for FS_PERMODULE_GLOBALVAR_INIT_REFS.
4435   Abbv = std::make_shared<BitCodeAbbrev>();
4436   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS));
4437   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4438   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
4439   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));  // valueids
4440   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4441   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4442 
4443   // Abbrev for FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS.
4444   Abbv = std::make_shared<BitCodeAbbrev>();
4445   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS));
4446   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4447   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
4448   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numrefs
4449   // numrefs x valueid, n x (valueid , offset)
4450   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4451   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4452   unsigned FSModVTableRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4453 
4454   // Abbrev for FS_ALIAS.
4455   Abbv = std::make_shared<BitCodeAbbrev>();
4456   Abbv->Add(BitCodeAbbrevOp(bitc::FS_ALIAS));
4457   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4458   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4459   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4460   unsigned FSAliasAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4461 
4462   // Abbrev for FS_TYPE_ID_METADATA
4463   Abbv = std::make_shared<BitCodeAbbrev>();
4464   Abbv->Add(BitCodeAbbrevOp(bitc::FS_TYPE_ID_METADATA));
4465   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // typeid strtab index
4466   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // typeid length
4467   // n x (valueid , offset)
4468   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4469   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4470   unsigned TypeIdCompatibleVtableAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4471 
4472   Abbv = std::make_shared<BitCodeAbbrev>();
4473   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_CALLSITE_INFO));
4474   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4475   // n x stackidindex
4476   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4477   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4478   unsigned CallsiteAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4479 
4480   Abbv = std::make_shared<BitCodeAbbrev>();
4481   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_ALLOC_INFO));
4482   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // nummib
4483   // n x (alloc type, numstackids, numstackids x stackidindex)
4484   // optional: nummib x total size
4485   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4486   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4487   unsigned AllocAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4488 
4489   SmallVector<uint64_t, 64> NameVals;
4490   // Iterate over the list of functions instead of the Index to
4491   // ensure the ordering is stable.
4492   for (const Function &F : M) {
4493     // Summary emission does not support anonymous functions, they have to
4494     // renamed using the anonymous function renaming pass.
4495     if (!F.hasName())
4496       report_fatal_error("Unexpected anonymous function when writing summary");
4497 
4498     ValueInfo VI = Index->getValueInfo(F.getGUID());
4499     if (!VI || VI.getSummaryList().empty()) {
4500       // Only declarations should not have a summary (a declaration might
4501       // however have a summary if the def was in module level asm).
4502       assert(F.isDeclaration());
4503       continue;
4504     }
4505     auto *Summary = VI.getSummaryList()[0].get();
4506     writePerModuleFunctionSummaryRecord(
4507         NameVals, Summary, VE.getValueID(&F), FSCallsRelBFAbbrev,
4508         FSCallsProfileAbbrev, CallsiteAbbrev, AllocAbbrev, F);
4509   }
4510 
4511   // Capture references from GlobalVariable initializers, which are outside
4512   // of a function scope.
4513   for (const GlobalVariable &G : M.globals())
4514     writeModuleLevelReferences(G, NameVals, FSModRefsAbbrev,
4515                                FSModVTableRefsAbbrev);
4516 
4517   for (const GlobalAlias &A : M.aliases()) {
4518     auto *Aliasee = A.getAliaseeObject();
4519     // Skip ifunc and nameless functions which don't have an entry in the
4520     // summary.
4521     if (!Aliasee->hasName() || isa<GlobalIFunc>(Aliasee))
4522       continue;
4523     auto AliasId = VE.getValueID(&A);
4524     auto AliaseeId = VE.getValueID(Aliasee);
4525     NameVals.push_back(AliasId);
4526     auto *Summary = Index->getGlobalValueSummary(A);
4527     AliasSummary *AS = cast<AliasSummary>(Summary);
4528     NameVals.push_back(getEncodedGVSummaryFlags(AS->flags()));
4529     NameVals.push_back(AliaseeId);
4530     Stream.EmitRecord(bitc::FS_ALIAS, NameVals, FSAliasAbbrev);
4531     NameVals.clear();
4532   }
4533 
4534   for (auto &S : Index->typeIdCompatibleVtableMap()) {
4535     writeTypeIdCompatibleVtableSummaryRecord(NameVals, StrtabBuilder, S.first,
4536                                              S.second, VE);
4537     Stream.EmitRecord(bitc::FS_TYPE_ID_METADATA, NameVals,
4538                       TypeIdCompatibleVtableAbbrev);
4539     NameVals.clear();
4540   }
4541 
4542   if (Index->getBlockCount())
4543     Stream.EmitRecord(bitc::FS_BLOCK_COUNT,
4544                       ArrayRef<uint64_t>{Index->getBlockCount()});
4545 
4546   Stream.ExitBlock();
4547 }
4548 
4549 /// Emit the combined summary section into the combined index file.
4550 void IndexBitcodeWriter::writeCombinedGlobalValueSummary() {
4551   Stream.EnterSubblock(bitc::GLOBALVAL_SUMMARY_BLOCK_ID, 4);
4552   Stream.EmitRecord(
4553       bitc::FS_VERSION,
4554       ArrayRef<uint64_t>{ModuleSummaryIndex::BitcodeSummaryVersion});
4555 
4556   // Write the index flags.
4557   Stream.EmitRecord(bitc::FS_FLAGS, ArrayRef<uint64_t>{Index.getFlags()});
4558 
4559   auto Abbv = std::make_shared<BitCodeAbbrev>();
4560   Abbv->Add(BitCodeAbbrevOp(bitc::FS_VALUE_GUID));
4561   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
4562   // GUIDS often use up most of 64-bits, so encode as two Fixed 32.
4563   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4564   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4565   unsigned ValueGuidAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4566 
4567   for (const auto &GVI : valueIds()) {
4568     Stream.EmitRecord(bitc::FS_VALUE_GUID,
4569                       ArrayRef<uint32_t>{GVI.second,
4570                                          static_cast<uint32_t>(GVI.first >> 32),
4571                                          static_cast<uint32_t>(GVI.first)},
4572                       ValueGuidAbbrev);
4573   }
4574 
4575   // Write the stack ids used by this index, which will be a subset of those in
4576   // the full index in the case of distributed indexes.
4577   if (!StackIds.empty()) {
4578     auto StackIdAbbv = std::make_shared<BitCodeAbbrev>();
4579     StackIdAbbv->Add(BitCodeAbbrevOp(bitc::FS_STACK_IDS));
4580     // numids x stackid
4581     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4582     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4583     unsigned StackIdAbbvId = Stream.EmitAbbrev(std::move(StackIdAbbv));
4584     Stream.EmitRecord(bitc::FS_STACK_IDS, StackIds, StackIdAbbvId);
4585   }
4586 
4587   // Abbrev for FS_COMBINED_PROFILE.
4588   Abbv = std::make_shared<BitCodeAbbrev>();
4589   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_PROFILE));
4590   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4591   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4592   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4593   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4594   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4595   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // entrycount
4596   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4597   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4598   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4599   // numrefs x valueid, n x (valueid, hotness+tailcall flags)
4600   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4601   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4602   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4603 
4604   // Abbrev for FS_COMBINED_GLOBALVAR_INIT_REFS.
4605   Abbv = std::make_shared<BitCodeAbbrev>();
4606   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS));
4607   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4608   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4609   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4610   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));    // valueids
4611   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4612   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4613 
4614   // Abbrev for FS_COMBINED_ALIAS.
4615   Abbv = std::make_shared<BitCodeAbbrev>();
4616   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_ALIAS));
4617   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4618   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4619   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4620   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4621   unsigned FSAliasAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4622 
4623   Abbv = std::make_shared<BitCodeAbbrev>();
4624   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_CALLSITE_INFO));
4625   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4626   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numstackindices
4627   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numver
4628   // numstackindices x stackidindex, numver x version
4629   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4630   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4631   unsigned CallsiteAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4632 
4633   Abbv = std::make_shared<BitCodeAbbrev>();
4634   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_ALLOC_INFO));
4635   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // nummib
4636   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numver
4637   // nummib x (alloc type, numstackids, numstackids x stackidindex),
4638   // numver x version
4639   // optional: nummib x total size
4640   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4641   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4642   unsigned AllocAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4643 
4644   auto shouldImportValueAsDecl = [&](GlobalValueSummary *GVS) -> bool {
4645     if (DecSummaries == nullptr)
4646       return false;
4647     return DecSummaries->count(GVS);
4648   };
4649 
4650   // The aliases are emitted as a post-pass, and will point to the value
4651   // id of the aliasee. Save them in a vector for post-processing.
4652   SmallVector<AliasSummary *, 64> Aliases;
4653 
4654   // Save the value id for each summary for alias emission.
4655   DenseMap<const GlobalValueSummary *, unsigned> SummaryToValueIdMap;
4656 
4657   SmallVector<uint64_t, 64> NameVals;
4658 
4659   // Set that will be populated during call to writeFunctionTypeMetadataRecords
4660   // with the type ids referenced by this index file.
4661   std::set<GlobalValue::GUID> ReferencedTypeIds;
4662 
4663   // For local linkage, we also emit the original name separately
4664   // immediately after the record.
4665   auto MaybeEmitOriginalName = [&](GlobalValueSummary &S) {
4666     // We don't need to emit the original name if we are writing the index for
4667     // distributed backends (in which case ModuleToSummariesForIndex is
4668     // non-null). The original name is only needed during the thin link, since
4669     // for SamplePGO the indirect call targets for local functions have
4670     // have the original name annotated in profile.
4671     // Continue to emit it when writing out the entire combined index, which is
4672     // used in testing the thin link via llvm-lto.
4673     if (ModuleToSummariesForIndex || !GlobalValue::isLocalLinkage(S.linkage()))
4674       return;
4675     NameVals.push_back(S.getOriginalName());
4676     Stream.EmitRecord(bitc::FS_COMBINED_ORIGINAL_NAME, NameVals);
4677     NameVals.clear();
4678   };
4679 
4680   DenseSet<GlobalValue::GUID> DefOrUseGUIDs;
4681   forEachSummary([&](GVInfo I, bool IsAliasee) {
4682     GlobalValueSummary *S = I.second;
4683     assert(S);
4684     DefOrUseGUIDs.insert(I.first);
4685     for (const ValueInfo &VI : S->refs())
4686       DefOrUseGUIDs.insert(VI.getGUID());
4687 
4688     auto ValueId = getValueId(I.first);
4689     assert(ValueId);
4690     SummaryToValueIdMap[S] = *ValueId;
4691 
4692     // If this is invoked for an aliasee, we want to record the above
4693     // mapping, but then not emit a summary entry (if the aliasee is
4694     // to be imported, we will invoke this separately with IsAliasee=false).
4695     if (IsAliasee)
4696       return;
4697 
4698     if (auto *AS = dyn_cast<AliasSummary>(S)) {
4699       // Will process aliases as a post-pass because the reader wants all
4700       // global to be loaded first.
4701       Aliases.push_back(AS);
4702       return;
4703     }
4704 
4705     if (auto *VS = dyn_cast<GlobalVarSummary>(S)) {
4706       NameVals.push_back(*ValueId);
4707       assert(ModuleIdMap.count(VS->modulePath()));
4708       NameVals.push_back(ModuleIdMap[VS->modulePath()]);
4709       NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
4710       NameVals.push_back(getEncodedGVarFlags(VS->varflags()));
4711       for (auto &RI : VS->refs()) {
4712         auto RefValueId = getValueId(RI.getGUID());
4713         if (!RefValueId)
4714           continue;
4715         NameVals.push_back(*RefValueId);
4716       }
4717 
4718       // Emit the finished record.
4719       Stream.EmitRecord(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS, NameVals,
4720                         FSModRefsAbbrev);
4721       NameVals.clear();
4722       MaybeEmitOriginalName(*S);
4723       return;
4724     }
4725 
4726     auto GetValueId = [&](const ValueInfo &VI) -> std::optional<unsigned> {
4727       if (!VI)
4728         return std::nullopt;
4729       return getValueId(VI.getGUID());
4730     };
4731 
4732     auto *FS = cast<FunctionSummary>(S);
4733     writeFunctionTypeMetadataRecords(Stream, FS, GetValueId);
4734     getReferencedTypeIds(FS, ReferencedTypeIds);
4735 
4736     writeFunctionHeapProfileRecords(
4737         Stream, FS, CallsiteAbbrev, AllocAbbrev,
4738         /*PerModule*/ false,
4739         /*GetValueId*/
4740         [&](const ValueInfo &VI) -> unsigned {
4741           std::optional<unsigned> ValueID = GetValueId(VI);
4742           // This can happen in shared index files for distributed ThinLTO if
4743           // the callee function summary is not included. Record 0 which we
4744           // will have to deal with conservatively when doing any kind of
4745           // validation in the ThinLTO backends.
4746           if (!ValueID)
4747             return 0;
4748           return *ValueID;
4749         },
4750         /*GetStackIndex*/
4751         [&](unsigned I) {
4752           // Get the corresponding index into the list of StackIds actually
4753           // being written for this combined index (which may be a subset in
4754           // the case of distributed indexes).
4755           assert(StackIdIndicesToIndex.contains(I));
4756           return StackIdIndicesToIndex[I];
4757         });
4758 
4759     NameVals.push_back(*ValueId);
4760     assert(ModuleIdMap.count(FS->modulePath()));
4761     NameVals.push_back(ModuleIdMap[FS->modulePath()]);
4762     NameVals.push_back(
4763         getEncodedGVSummaryFlags(FS->flags(), shouldImportValueAsDecl(FS)));
4764     NameVals.push_back(FS->instCount());
4765     NameVals.push_back(getEncodedFFlags(FS->fflags()));
4766     // TODO: Stop writing entry count and bump bitcode version.
4767     NameVals.push_back(0 /* EntryCount */);
4768 
4769     // Fill in below
4770     NameVals.push_back(0); // numrefs
4771     NameVals.push_back(0); // rorefcnt
4772     NameVals.push_back(0); // worefcnt
4773 
4774     unsigned Count = 0, RORefCnt = 0, WORefCnt = 0;
4775     for (auto &RI : FS->refs()) {
4776       auto RefValueId = getValueId(RI.getGUID());
4777       if (!RefValueId)
4778         continue;
4779       NameVals.push_back(*RefValueId);
4780       if (RI.isReadOnly())
4781         RORefCnt++;
4782       else if (RI.isWriteOnly())
4783         WORefCnt++;
4784       Count++;
4785     }
4786     NameVals[6] = Count;
4787     NameVals[7] = RORefCnt;
4788     NameVals[8] = WORefCnt;
4789 
4790     for (auto &EI : FS->calls()) {
4791       // If this GUID doesn't have a value id, it doesn't have a function
4792       // summary and we don't need to record any calls to it.
4793       std::optional<unsigned> CallValueId = GetValueId(EI.first);
4794       if (!CallValueId)
4795         continue;
4796       NameVals.push_back(*CallValueId);
4797       NameVals.push_back(getEncodedHotnessCallEdgeInfo(EI.second));
4798     }
4799 
4800     // Emit the finished record.
4801     Stream.EmitRecord(bitc::FS_COMBINED_PROFILE, NameVals,
4802                       FSCallsProfileAbbrev);
4803     NameVals.clear();
4804     MaybeEmitOriginalName(*S);
4805   });
4806 
4807   for (auto *AS : Aliases) {
4808     auto AliasValueId = SummaryToValueIdMap[AS];
4809     assert(AliasValueId);
4810     NameVals.push_back(AliasValueId);
4811     assert(ModuleIdMap.count(AS->modulePath()));
4812     NameVals.push_back(ModuleIdMap[AS->modulePath()]);
4813     NameVals.push_back(
4814         getEncodedGVSummaryFlags(AS->flags(), shouldImportValueAsDecl(AS)));
4815     auto AliaseeValueId = SummaryToValueIdMap[&AS->getAliasee()];
4816     assert(AliaseeValueId);
4817     NameVals.push_back(AliaseeValueId);
4818 
4819     // Emit the finished record.
4820     Stream.EmitRecord(bitc::FS_COMBINED_ALIAS, NameVals, FSAliasAbbrev);
4821     NameVals.clear();
4822     MaybeEmitOriginalName(*AS);
4823 
4824     if (auto *FS = dyn_cast<FunctionSummary>(&AS->getAliasee()))
4825       getReferencedTypeIds(FS, ReferencedTypeIds);
4826   }
4827 
4828   if (!Index.cfiFunctionDefs().empty()) {
4829     for (auto &S : Index.cfiFunctionDefs()) {
4830       if (DefOrUseGUIDs.contains(
4831               GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(S)))) {
4832         NameVals.push_back(StrtabBuilder.add(S));
4833         NameVals.push_back(S.size());
4834       }
4835     }
4836     if (!NameVals.empty()) {
4837       Stream.EmitRecord(bitc::FS_CFI_FUNCTION_DEFS, NameVals);
4838       NameVals.clear();
4839     }
4840   }
4841 
4842   if (!Index.cfiFunctionDecls().empty()) {
4843     for (auto &S : Index.cfiFunctionDecls()) {
4844       if (DefOrUseGUIDs.contains(
4845               GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(S)))) {
4846         NameVals.push_back(StrtabBuilder.add(S));
4847         NameVals.push_back(S.size());
4848       }
4849     }
4850     if (!NameVals.empty()) {
4851       Stream.EmitRecord(bitc::FS_CFI_FUNCTION_DECLS, NameVals);
4852       NameVals.clear();
4853     }
4854   }
4855 
4856   // Walk the GUIDs that were referenced, and write the
4857   // corresponding type id records.
4858   for (auto &T : ReferencedTypeIds) {
4859     auto TidIter = Index.typeIds().equal_range(T);
4860     for (const auto &[GUID, TypeIdPair] : make_range(TidIter)) {
4861       writeTypeIdSummaryRecord(NameVals, StrtabBuilder, TypeIdPair.first,
4862                                TypeIdPair.second);
4863       Stream.EmitRecord(bitc::FS_TYPE_ID, NameVals);
4864       NameVals.clear();
4865     }
4866   }
4867 
4868   if (Index.getBlockCount())
4869     Stream.EmitRecord(bitc::FS_BLOCK_COUNT,
4870                       ArrayRef<uint64_t>{Index.getBlockCount()});
4871 
4872   Stream.ExitBlock();
4873 }
4874 
4875 /// Create the "IDENTIFICATION_BLOCK_ID" containing a single string with the
4876 /// current llvm version, and a record for the epoch number.
4877 static void writeIdentificationBlock(BitstreamWriter &Stream) {
4878   Stream.EnterSubblock(bitc::IDENTIFICATION_BLOCK_ID, 5);
4879 
4880   // Write the "user readable" string identifying the bitcode producer
4881   auto Abbv = std::make_shared<BitCodeAbbrev>();
4882   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_STRING));
4883   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4884   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
4885   auto StringAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4886   writeStringRecord(Stream, bitc::IDENTIFICATION_CODE_STRING,
4887                     "LLVM" LLVM_VERSION_STRING, StringAbbrev);
4888 
4889   // Write the epoch version
4890   Abbv = std::make_shared<BitCodeAbbrev>();
4891   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_EPOCH));
4892   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
4893   auto EpochAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4894   constexpr std::array<unsigned, 1> Vals = {{bitc::BITCODE_CURRENT_EPOCH}};
4895   Stream.EmitRecord(bitc::IDENTIFICATION_CODE_EPOCH, Vals, EpochAbbrev);
4896   Stream.ExitBlock();
4897 }
4898 
4899 void ModuleBitcodeWriter::writeModuleHash(StringRef View) {
4900   // Emit the module's hash.
4901   // MODULE_CODE_HASH: [5*i32]
4902   if (GenerateHash) {
4903     uint32_t Vals[5];
4904     Hasher.update(ArrayRef<uint8_t>(
4905         reinterpret_cast<const uint8_t *>(View.data()), View.size()));
4906     std::array<uint8_t, 20> Hash = Hasher.result();
4907     for (int Pos = 0; Pos < 20; Pos += 4) {
4908       Vals[Pos / 4] = support::endian::read32be(Hash.data() + Pos);
4909     }
4910 
4911     // Emit the finished record.
4912     Stream.EmitRecord(bitc::MODULE_CODE_HASH, Vals);
4913 
4914     if (ModHash)
4915       // Save the written hash value.
4916       llvm::copy(Vals, std::begin(*ModHash));
4917   }
4918 }
4919 
4920 void ModuleBitcodeWriter::write() {
4921   writeIdentificationBlock(Stream);
4922 
4923   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
4924   // We will want to write the module hash at this point. Block any flushing so
4925   // we can have access to the whole underlying data later.
4926   Stream.markAndBlockFlushing();
4927 
4928   writeModuleVersion();
4929 
4930   // Emit blockinfo, which defines the standard abbreviations etc.
4931   writeBlockInfo();
4932 
4933   // Emit information describing all of the types in the module.
4934   writeTypeTable();
4935 
4936   // Emit information about attribute groups.
4937   writeAttributeGroupTable();
4938 
4939   // Emit information about parameter attributes.
4940   writeAttributeTable();
4941 
4942   writeComdats();
4943 
4944   // Emit top-level description of module, including target triple, inline asm,
4945   // descriptors for global variables, and function prototype info.
4946   writeModuleInfo();
4947 
4948   // Emit constants.
4949   writeModuleConstants();
4950 
4951   // Emit metadata kind names.
4952   writeModuleMetadataKinds();
4953 
4954   // Emit metadata.
4955   writeModuleMetadata();
4956 
4957   // Emit module-level use-lists.
4958   if (VE.shouldPreserveUseListOrder())
4959     writeUseListBlock(nullptr);
4960 
4961   writeOperandBundleTags();
4962   writeSyncScopeNames();
4963 
4964   // Emit function bodies.
4965   DenseMap<const Function *, uint64_t> FunctionToBitcodeIndex;
4966   for (const Function &F : M)
4967     if (!F.isDeclaration())
4968       writeFunction(F, FunctionToBitcodeIndex);
4969 
4970   // Need to write after the above call to WriteFunction which populates
4971   // the summary information in the index.
4972   if (Index)
4973     writePerModuleGlobalValueSummary();
4974 
4975   writeGlobalValueSymbolTable(FunctionToBitcodeIndex);
4976 
4977   writeModuleHash(Stream.getMarkedBufferAndResumeFlushing());
4978 
4979   Stream.ExitBlock();
4980 }
4981 
4982 static void writeInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
4983                                uint32_t &Position) {
4984   support::endian::write32le(&Buffer[Position], Value);
4985   Position += 4;
4986 }
4987 
4988 /// If generating a bc file on darwin, we have to emit a
4989 /// header and trailer to make it compatible with the system archiver.  To do
4990 /// this we emit the following header, and then emit a trailer that pads the
4991 /// file out to be a multiple of 16 bytes.
4992 ///
4993 /// struct bc_header {
4994 ///   uint32_t Magic;         // 0x0B17C0DE
4995 ///   uint32_t Version;       // Version, currently always 0.
4996 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
4997 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
4998 ///   uint32_t CPUType;       // CPU specifier.
4999 ///   ... potentially more later ...
5000 /// };
5001 static void emitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
5002                                          const Triple &TT) {
5003   unsigned CPUType = ~0U;
5004 
5005   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
5006   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
5007   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
5008   // specific constants here because they are implicitly part of the Darwin ABI.
5009   enum {
5010     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
5011     DARWIN_CPU_TYPE_X86        = 7,
5012     DARWIN_CPU_TYPE_ARM        = 12,
5013     DARWIN_CPU_TYPE_POWERPC    = 18
5014   };
5015 
5016   Triple::ArchType Arch = TT.getArch();
5017   if (Arch == Triple::x86_64)
5018     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
5019   else if (Arch == Triple::x86)
5020     CPUType = DARWIN_CPU_TYPE_X86;
5021   else if (Arch == Triple::ppc)
5022     CPUType = DARWIN_CPU_TYPE_POWERPC;
5023   else if (Arch == Triple::ppc64)
5024     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
5025   else if (Arch == Triple::arm || Arch == Triple::thumb)
5026     CPUType = DARWIN_CPU_TYPE_ARM;
5027 
5028   // Traditional Bitcode starts after header.
5029   assert(Buffer.size() >= BWH_HeaderSize &&
5030          "Expected header size to be reserved");
5031   unsigned BCOffset = BWH_HeaderSize;
5032   unsigned BCSize = Buffer.size() - BWH_HeaderSize;
5033 
5034   // Write the magic and version.
5035   unsigned Position = 0;
5036   writeInt32ToBuffer(0x0B17C0DE, Buffer, Position);
5037   writeInt32ToBuffer(0, Buffer, Position); // Version.
5038   writeInt32ToBuffer(BCOffset, Buffer, Position);
5039   writeInt32ToBuffer(BCSize, Buffer, Position);
5040   writeInt32ToBuffer(CPUType, Buffer, Position);
5041 
5042   // If the file is not a multiple of 16 bytes, insert dummy padding.
5043   while (Buffer.size() & 15)
5044     Buffer.push_back(0);
5045 }
5046 
5047 /// Helper to write the header common to all bitcode files.
5048 static void writeBitcodeHeader(BitstreamWriter &Stream) {
5049   // Emit the file header.
5050   Stream.Emit((unsigned)'B', 8);
5051   Stream.Emit((unsigned)'C', 8);
5052   Stream.Emit(0x0, 4);
5053   Stream.Emit(0xC, 4);
5054   Stream.Emit(0xE, 4);
5055   Stream.Emit(0xD, 4);
5056 }
5057 
5058 BitcodeWriter::BitcodeWriter(SmallVectorImpl<char> &Buffer)
5059     : Stream(new BitstreamWriter(Buffer)) {
5060   writeBitcodeHeader(*Stream);
5061 }
5062 
5063 BitcodeWriter::BitcodeWriter(raw_ostream &FS)
5064     : Stream(new BitstreamWriter(FS, FlushThreshold)) {
5065   writeBitcodeHeader(*Stream);
5066 }
5067 
5068 BitcodeWriter::~BitcodeWriter() { assert(WroteStrtab); }
5069 
5070 void BitcodeWriter::writeBlob(unsigned Block, unsigned Record, StringRef Blob) {
5071   Stream->EnterSubblock(Block, 3);
5072 
5073   auto Abbv = std::make_shared<BitCodeAbbrev>();
5074   Abbv->Add(BitCodeAbbrevOp(Record));
5075   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
5076   auto AbbrevNo = Stream->EmitAbbrev(std::move(Abbv));
5077 
5078   Stream->EmitRecordWithBlob(AbbrevNo, ArrayRef<uint64_t>{Record}, Blob);
5079 
5080   Stream->ExitBlock();
5081 }
5082 
5083 void BitcodeWriter::writeSymtab() {
5084   assert(!WroteStrtab && !WroteSymtab);
5085 
5086   // If any module has module-level inline asm, we will require a registered asm
5087   // parser for the target so that we can create an accurate symbol table for
5088   // the module.
5089   for (Module *M : Mods) {
5090     if (M->getModuleInlineAsm().empty())
5091       continue;
5092 
5093     std::string Err;
5094     const Triple TT(M->getTargetTriple());
5095     const Target *T = TargetRegistry::lookupTarget(TT.str(), Err);
5096     if (!T || !T->hasMCAsmParser())
5097       return;
5098   }
5099 
5100   WroteSymtab = true;
5101   SmallVector<char, 0> Symtab;
5102   // The irsymtab::build function may be unable to create a symbol table if the
5103   // module is malformed (e.g. it contains an invalid alias). Writing a symbol
5104   // table is not required for correctness, but we still want to be able to
5105   // write malformed modules to bitcode files, so swallow the error.
5106   if (Error E = irsymtab::build(Mods, Symtab, StrtabBuilder, Alloc)) {
5107     consumeError(std::move(E));
5108     return;
5109   }
5110 
5111   writeBlob(bitc::SYMTAB_BLOCK_ID, bitc::SYMTAB_BLOB,
5112             {Symtab.data(), Symtab.size()});
5113 }
5114 
5115 void BitcodeWriter::writeStrtab() {
5116   assert(!WroteStrtab);
5117 
5118   std::vector<char> Strtab;
5119   StrtabBuilder.finalizeInOrder();
5120   Strtab.resize(StrtabBuilder.getSize());
5121   StrtabBuilder.write((uint8_t *)Strtab.data());
5122 
5123   writeBlob(bitc::STRTAB_BLOCK_ID, bitc::STRTAB_BLOB,
5124             {Strtab.data(), Strtab.size()});
5125 
5126   WroteStrtab = true;
5127 }
5128 
5129 void BitcodeWriter::copyStrtab(StringRef Strtab) {
5130   writeBlob(bitc::STRTAB_BLOCK_ID, bitc::STRTAB_BLOB, Strtab);
5131   WroteStrtab = true;
5132 }
5133 
5134 void BitcodeWriter::writeModule(const Module &M,
5135                                 bool ShouldPreserveUseListOrder,
5136                                 const ModuleSummaryIndex *Index,
5137                                 bool GenerateHash, ModuleHash *ModHash) {
5138   assert(!WroteStrtab);
5139 
5140   // The Mods vector is used by irsymtab::build, which requires non-const
5141   // Modules in case it needs to materialize metadata. But the bitcode writer
5142   // requires that the module is materialized, so we can cast to non-const here,
5143   // after checking that it is in fact materialized.
5144   assert(M.isMaterialized());
5145   Mods.push_back(const_cast<Module *>(&M));
5146 
5147   ModuleBitcodeWriter ModuleWriter(M, StrtabBuilder, *Stream,
5148                                    ShouldPreserveUseListOrder, Index,
5149                                    GenerateHash, ModHash);
5150   ModuleWriter.write();
5151 }
5152 
5153 void BitcodeWriter::writeIndex(
5154     const ModuleSummaryIndex *Index,
5155     const ModuleToSummariesForIndexTy *ModuleToSummariesForIndex,
5156     const GVSummaryPtrSet *DecSummaries) {
5157   IndexBitcodeWriter IndexWriter(*Stream, StrtabBuilder, *Index, DecSummaries,
5158                                  ModuleToSummariesForIndex);
5159   IndexWriter.write();
5160 }
5161 
5162 /// Write the specified module to the specified output stream.
5163 void llvm::WriteBitcodeToFile(const Module &M, raw_ostream &Out,
5164                               bool ShouldPreserveUseListOrder,
5165                               const ModuleSummaryIndex *Index,
5166                               bool GenerateHash, ModuleHash *ModHash) {
5167   auto Write = [&](BitcodeWriter &Writer) {
5168     Writer.writeModule(M, ShouldPreserveUseListOrder, Index, GenerateHash,
5169                        ModHash);
5170     Writer.writeSymtab();
5171     Writer.writeStrtab();
5172   };
5173   Triple TT(M.getTargetTriple());
5174   if (TT.isOSDarwin() || TT.isOSBinFormatMachO()) {
5175     // If this is darwin or another generic macho target, reserve space for the
5176     // header. Note that the header is computed *after* the output is known, so
5177     // we currently explicitly use a buffer, write to it, and then subsequently
5178     // flush to Out.
5179     SmallVector<char, 0> Buffer;
5180     Buffer.reserve(256 * 1024);
5181     Buffer.insert(Buffer.begin(), BWH_HeaderSize, 0);
5182     BitcodeWriter Writer(Buffer);
5183     Write(Writer);
5184     emitDarwinBCHeaderAndTrailer(Buffer, TT);
5185     Out.write(Buffer.data(), Buffer.size());
5186   } else {
5187     BitcodeWriter Writer(Out);
5188     Write(Writer);
5189   }
5190 }
5191 
5192 void IndexBitcodeWriter::write() {
5193   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
5194 
5195   writeModuleVersion();
5196 
5197   // Write the module paths in the combined index.
5198   writeModStrings();
5199 
5200   // Write the summary combined index records.
5201   writeCombinedGlobalValueSummary();
5202 
5203   Stream.ExitBlock();
5204 }
5205 
5206 // Write the specified module summary index to the given raw output stream,
5207 // where it will be written in a new bitcode block. This is used when
5208 // writing the combined index file for ThinLTO. When writing a subset of the
5209 // index for a distributed backend, provide a \p ModuleToSummariesForIndex map.
5210 void llvm::writeIndexToFile(
5211     const ModuleSummaryIndex &Index, raw_ostream &Out,
5212     const ModuleToSummariesForIndexTy *ModuleToSummariesForIndex,
5213     const GVSummaryPtrSet *DecSummaries) {
5214   SmallVector<char, 0> Buffer;
5215   Buffer.reserve(256 * 1024);
5216 
5217   BitcodeWriter Writer(Buffer);
5218   Writer.writeIndex(&Index, ModuleToSummariesForIndex, DecSummaries);
5219   Writer.writeStrtab();
5220 
5221   Out.write((char *)&Buffer.front(), Buffer.size());
5222 }
5223 
5224 namespace {
5225 
5226 /// Class to manage the bitcode writing for a thin link bitcode file.
5227 class ThinLinkBitcodeWriter : public ModuleBitcodeWriterBase {
5228   /// ModHash is for use in ThinLTO incremental build, generated while writing
5229   /// the module bitcode file.
5230   const ModuleHash *ModHash;
5231 
5232 public:
5233   ThinLinkBitcodeWriter(const Module &M, StringTableBuilder &StrtabBuilder,
5234                         BitstreamWriter &Stream,
5235                         const ModuleSummaryIndex &Index,
5236                         const ModuleHash &ModHash)
5237       : ModuleBitcodeWriterBase(M, StrtabBuilder, Stream,
5238                                 /*ShouldPreserveUseListOrder=*/false, &Index),
5239         ModHash(&ModHash) {}
5240 
5241   void write();
5242 
5243 private:
5244   void writeSimplifiedModuleInfo();
5245 };
5246 
5247 } // end anonymous namespace
5248 
5249 // This function writes a simpilified module info for thin link bitcode file.
5250 // It only contains the source file name along with the name(the offset and
5251 // size in strtab) and linkage for global values. For the global value info
5252 // entry, in order to keep linkage at offset 5, there are three zeros used
5253 // as padding.
5254 void ThinLinkBitcodeWriter::writeSimplifiedModuleInfo() {
5255   SmallVector<unsigned, 64> Vals;
5256   // Emit the module's source file name.
5257   {
5258     StringEncoding Bits = getStringEncoding(M.getSourceFileName());
5259     BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
5260     if (Bits == SE_Char6)
5261       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
5262     else if (Bits == SE_Fixed7)
5263       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
5264 
5265     // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
5266     auto Abbv = std::make_shared<BitCodeAbbrev>();
5267     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
5268     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
5269     Abbv->Add(AbbrevOpToUse);
5270     unsigned FilenameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
5271 
5272     for (const auto P : M.getSourceFileName())
5273       Vals.push_back((unsigned char)P);
5274 
5275     Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
5276     Vals.clear();
5277   }
5278 
5279   // Emit the global variable information.
5280   for (const GlobalVariable &GV : M.globals()) {
5281     // GLOBALVAR: [strtab offset, strtab size, 0, 0, 0, linkage]
5282     Vals.push_back(StrtabBuilder.add(GV.getName()));
5283     Vals.push_back(GV.getName().size());
5284     Vals.push_back(0);
5285     Vals.push_back(0);
5286     Vals.push_back(0);
5287     Vals.push_back(getEncodedLinkage(GV));
5288 
5289     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals);
5290     Vals.clear();
5291   }
5292 
5293   // Emit the function proto information.
5294   for (const Function &F : M) {
5295     // FUNCTION:  [strtab offset, strtab size, 0, 0, 0, linkage]
5296     Vals.push_back(StrtabBuilder.add(F.getName()));
5297     Vals.push_back(F.getName().size());
5298     Vals.push_back(0);
5299     Vals.push_back(0);
5300     Vals.push_back(0);
5301     Vals.push_back(getEncodedLinkage(F));
5302 
5303     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals);
5304     Vals.clear();
5305   }
5306 
5307   // Emit the alias information.
5308   for (const GlobalAlias &A : M.aliases()) {
5309     // ALIAS: [strtab offset, strtab size, 0, 0, 0, linkage]
5310     Vals.push_back(StrtabBuilder.add(A.getName()));
5311     Vals.push_back(A.getName().size());
5312     Vals.push_back(0);
5313     Vals.push_back(0);
5314     Vals.push_back(0);
5315     Vals.push_back(getEncodedLinkage(A));
5316 
5317     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals);
5318     Vals.clear();
5319   }
5320 
5321   // Emit the ifunc information.
5322   for (const GlobalIFunc &I : M.ifuncs()) {
5323     // IFUNC: [strtab offset, strtab size, 0, 0, 0, linkage]
5324     Vals.push_back(StrtabBuilder.add(I.getName()));
5325     Vals.push_back(I.getName().size());
5326     Vals.push_back(0);
5327     Vals.push_back(0);
5328     Vals.push_back(0);
5329     Vals.push_back(getEncodedLinkage(I));
5330 
5331     Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
5332     Vals.clear();
5333   }
5334 }
5335 
5336 void ThinLinkBitcodeWriter::write() {
5337   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
5338 
5339   writeModuleVersion();
5340 
5341   writeSimplifiedModuleInfo();
5342 
5343   writePerModuleGlobalValueSummary();
5344 
5345   // Write module hash.
5346   Stream.EmitRecord(bitc::MODULE_CODE_HASH, ArrayRef<uint32_t>(*ModHash));
5347 
5348   Stream.ExitBlock();
5349 }
5350 
5351 void BitcodeWriter::writeThinLinkBitcode(const Module &M,
5352                                          const ModuleSummaryIndex &Index,
5353                                          const ModuleHash &ModHash) {
5354   assert(!WroteStrtab);
5355 
5356   // The Mods vector is used by irsymtab::build, which requires non-const
5357   // Modules in case it needs to materialize metadata. But the bitcode writer
5358   // requires that the module is materialized, so we can cast to non-const here,
5359   // after checking that it is in fact materialized.
5360   assert(M.isMaterialized());
5361   Mods.push_back(const_cast<Module *>(&M));
5362 
5363   ThinLinkBitcodeWriter ThinLinkWriter(M, StrtabBuilder, *Stream, Index,
5364                                        ModHash);
5365   ThinLinkWriter.write();
5366 }
5367 
5368 // Write the specified thin link bitcode file to the given raw output stream,
5369 // where it will be written in a new bitcode block. This is used when
5370 // writing the per-module index file for ThinLTO.
5371 void llvm::writeThinLinkBitcodeToFile(const Module &M, raw_ostream &Out,
5372                                       const ModuleSummaryIndex &Index,
5373                                       const ModuleHash &ModHash) {
5374   SmallVector<char, 0> Buffer;
5375   Buffer.reserve(256 * 1024);
5376 
5377   BitcodeWriter Writer(Buffer);
5378   Writer.writeThinLinkBitcode(M, Index, ModHash);
5379   Writer.writeSymtab();
5380   Writer.writeStrtab();
5381 
5382   Out.write((char *)&Buffer.front(), Buffer.size());
5383 }
5384 
5385 static const char *getSectionNameForBitcode(const Triple &T) {
5386   switch (T.getObjectFormat()) {
5387   case Triple::MachO:
5388     return "__LLVM,__bitcode";
5389   case Triple::COFF:
5390   case Triple::ELF:
5391   case Triple::Wasm:
5392   case Triple::UnknownObjectFormat:
5393     return ".llvmbc";
5394   case Triple::GOFF:
5395     llvm_unreachable("GOFF is not yet implemented");
5396     break;
5397   case Triple::SPIRV:
5398     if (T.getVendor() == Triple::AMD)
5399       return ".llvmbc";
5400     llvm_unreachable("SPIRV is not yet implemented");
5401     break;
5402   case Triple::XCOFF:
5403     llvm_unreachable("XCOFF is not yet implemented");
5404     break;
5405   case Triple::DXContainer:
5406     llvm_unreachable("DXContainer is not yet implemented");
5407     break;
5408   }
5409   llvm_unreachable("Unimplemented ObjectFormatType");
5410 }
5411 
5412 static const char *getSectionNameForCommandline(const Triple &T) {
5413   switch (T.getObjectFormat()) {
5414   case Triple::MachO:
5415     return "__LLVM,__cmdline";
5416   case Triple::COFF:
5417   case Triple::ELF:
5418   case Triple::Wasm:
5419   case Triple::UnknownObjectFormat:
5420     return ".llvmcmd";
5421   case Triple::GOFF:
5422     llvm_unreachable("GOFF is not yet implemented");
5423     break;
5424   case Triple::SPIRV:
5425     if (T.getVendor() == Triple::AMD)
5426       return ".llvmcmd";
5427     llvm_unreachable("SPIRV is not yet implemented");
5428     break;
5429   case Triple::XCOFF:
5430     llvm_unreachable("XCOFF is not yet implemented");
5431     break;
5432   case Triple::DXContainer:
5433     llvm_unreachable("DXC is not yet implemented");
5434     break;
5435   }
5436   llvm_unreachable("Unimplemented ObjectFormatType");
5437 }
5438 
5439 void llvm::embedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
5440                                 bool EmbedBitcode, bool EmbedCmdline,
5441                                 const std::vector<uint8_t> &CmdArgs) {
5442   // Save llvm.compiler.used and remove it.
5443   SmallVector<Constant *, 2> UsedArray;
5444   SmallVector<GlobalValue *, 4> UsedGlobals;
5445   Type *UsedElementType = PointerType::getUnqual(M.getContext());
5446   GlobalVariable *Used = collectUsedGlobalVariables(M, UsedGlobals, true);
5447   for (auto *GV : UsedGlobals) {
5448     if (GV->getName() != "llvm.embedded.module" &&
5449         GV->getName() != "llvm.cmdline")
5450       UsedArray.push_back(
5451           ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
5452   }
5453   if (Used)
5454     Used->eraseFromParent();
5455 
5456   // Embed the bitcode for the llvm module.
5457   std::string Data;
5458   ArrayRef<uint8_t> ModuleData;
5459   Triple T(M.getTargetTriple());
5460 
5461   if (EmbedBitcode) {
5462     if (Buf.getBufferSize() == 0 ||
5463         !isBitcode((const unsigned char *)Buf.getBufferStart(),
5464                    (const unsigned char *)Buf.getBufferEnd())) {
5465       // If the input is LLVM Assembly, bitcode is produced by serializing
5466       // the module. Use-lists order need to be preserved in this case.
5467       llvm::raw_string_ostream OS(Data);
5468       llvm::WriteBitcodeToFile(M, OS, /* ShouldPreserveUseListOrder */ true);
5469       ModuleData =
5470           ArrayRef<uint8_t>((const uint8_t *)OS.str().data(), OS.str().size());
5471     } else
5472       // If the input is LLVM bitcode, write the input byte stream directly.
5473       ModuleData = ArrayRef<uint8_t>((const uint8_t *)Buf.getBufferStart(),
5474                                      Buf.getBufferSize());
5475   }
5476   llvm::Constant *ModuleConstant =
5477       llvm::ConstantDataArray::get(M.getContext(), ModuleData);
5478   llvm::GlobalVariable *GV = new llvm::GlobalVariable(
5479       M, ModuleConstant->getType(), true, llvm::GlobalValue::PrivateLinkage,
5480       ModuleConstant);
5481   GV->setSection(getSectionNameForBitcode(T));
5482   // Set alignment to 1 to prevent padding between two contributions from input
5483   // sections after linking.
5484   GV->setAlignment(Align(1));
5485   UsedArray.push_back(
5486       ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
5487   if (llvm::GlobalVariable *Old =
5488           M.getGlobalVariable("llvm.embedded.module", true)) {
5489     assert(Old->hasZeroLiveUses() &&
5490            "llvm.embedded.module can only be used once in llvm.compiler.used");
5491     GV->takeName(Old);
5492     Old->eraseFromParent();
5493   } else {
5494     GV->setName("llvm.embedded.module");
5495   }
5496 
5497   // Skip if only bitcode needs to be embedded.
5498   if (EmbedCmdline) {
5499     // Embed command-line options.
5500     ArrayRef<uint8_t> CmdData(const_cast<uint8_t *>(CmdArgs.data()),
5501                               CmdArgs.size());
5502     llvm::Constant *CmdConstant =
5503         llvm::ConstantDataArray::get(M.getContext(), CmdData);
5504     GV = new llvm::GlobalVariable(M, CmdConstant->getType(), true,
5505                                   llvm::GlobalValue::PrivateLinkage,
5506                                   CmdConstant);
5507     GV->setSection(getSectionNameForCommandline(T));
5508     GV->setAlignment(Align(1));
5509     UsedArray.push_back(
5510         ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
5511     if (llvm::GlobalVariable *Old = M.getGlobalVariable("llvm.cmdline", true)) {
5512       assert(Old->hasZeroLiveUses() &&
5513              "llvm.cmdline can only be used once in llvm.compiler.used");
5514       GV->takeName(Old);
5515       Old->eraseFromParent();
5516     } else {
5517       GV->setName("llvm.cmdline");
5518     }
5519   }
5520 
5521   if (UsedArray.empty())
5522     return;
5523 
5524   // Recreate llvm.compiler.used.
5525   ArrayType *ATy = ArrayType::get(UsedElementType, UsedArray.size());
5526   auto *NewUsed = new GlobalVariable(
5527       M, ATy, false, llvm::GlobalValue::AppendingLinkage,
5528       llvm::ConstantArray::get(ATy, UsedArray), "llvm.compiler.used");
5529   NewUsed->setSection("llvm.metadata");
5530 }
5531