xref: /llvm-project/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp (revision b35f40688e3079d888932e0a35caa0b02d90db97)
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, unsigned ContextIdAbbvId,
234       const Function &F);
235   void writeModuleLevelReferences(const GlobalVariable &V,
236                                   SmallVector<uint64_t, 64> &NameVals,
237                                   unsigned FSModRefsAbbrev,
238                                   unsigned FSModVTableRefsAbbrev);
239 
240   void assignValueId(GlobalValue::GUID ValGUID) {
241     GUIDToValueIdMap[ValGUID] = ++GlobalValueId;
242   }
243 
244   unsigned getValueId(GlobalValue::GUID ValGUID) {
245     const auto &VMI = GUIDToValueIdMap.find(ValGUID);
246     // Expect that any GUID value had a value Id assigned by an
247     // earlier call to assignValueId.
248     assert(VMI != GUIDToValueIdMap.end() &&
249            "GUID does not have assigned value Id");
250     return VMI->second;
251   }
252 
253   // Helper to get the valueId for the type of value recorded in VI.
254   unsigned getValueId(ValueInfo VI) {
255     if (!VI.haveGVs() || !VI.getValue())
256       return getValueId(VI.getGUID());
257     return VE.getValueID(VI.getValue());
258   }
259 
260   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
261 };
262 
263 /// Class to manage the bitcode writing for a module.
264 class ModuleBitcodeWriter : public ModuleBitcodeWriterBase {
265   /// True if a module hash record should be written.
266   bool GenerateHash;
267 
268   /// If non-null, when GenerateHash is true, the resulting hash is written
269   /// into ModHash.
270   ModuleHash *ModHash;
271 
272   SHA1 Hasher;
273 
274   /// The start bit of the identification block.
275   uint64_t BitcodeStartBit;
276 
277 public:
278   /// Constructs a ModuleBitcodeWriter object for the given Module,
279   /// writing to the provided \p Buffer.
280   ModuleBitcodeWriter(const Module &M, StringTableBuilder &StrtabBuilder,
281                       BitstreamWriter &Stream, bool ShouldPreserveUseListOrder,
282                       const ModuleSummaryIndex *Index, bool GenerateHash,
283                       ModuleHash *ModHash = nullptr)
284       : ModuleBitcodeWriterBase(M, StrtabBuilder, Stream,
285                                 ShouldPreserveUseListOrder, Index),
286         GenerateHash(GenerateHash), ModHash(ModHash),
287         BitcodeStartBit(Stream.GetCurrentBitNo()) {}
288 
289   /// Emit the current module to the bitstream.
290   void write();
291 
292 private:
293   uint64_t bitcodeStartBit() { return BitcodeStartBit; }
294 
295   size_t addToStrtab(StringRef Str);
296 
297   void writeAttributeGroupTable();
298   void writeAttributeTable();
299   void writeTypeTable();
300   void writeComdats();
301   void writeValueSymbolTableForwardDecl();
302   void writeModuleInfo();
303   void writeValueAsMetadata(const ValueAsMetadata *MD,
304                             SmallVectorImpl<uint64_t> &Record);
305   void writeMDTuple(const MDTuple *N, SmallVectorImpl<uint64_t> &Record,
306                     unsigned Abbrev);
307   unsigned createDILocationAbbrev();
308   void writeDILocation(const DILocation *N, SmallVectorImpl<uint64_t> &Record,
309                        unsigned &Abbrev);
310   unsigned createGenericDINodeAbbrev();
311   void writeGenericDINode(const GenericDINode *N,
312                           SmallVectorImpl<uint64_t> &Record, unsigned &Abbrev);
313   void writeDISubrange(const DISubrange *N, SmallVectorImpl<uint64_t> &Record,
314                        unsigned Abbrev);
315   void writeDIGenericSubrange(const DIGenericSubrange *N,
316                               SmallVectorImpl<uint64_t> &Record,
317                               unsigned Abbrev);
318   void writeDIEnumerator(const DIEnumerator *N,
319                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
320   void writeDIBasicType(const DIBasicType *N, SmallVectorImpl<uint64_t> &Record,
321                         unsigned Abbrev);
322   void writeDIStringType(const DIStringType *N,
323                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
324   void writeDIDerivedType(const DIDerivedType *N,
325                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
326   void writeDICompositeType(const DICompositeType *N,
327                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
328   void writeDISubroutineType(const DISubroutineType *N,
329                              SmallVectorImpl<uint64_t> &Record,
330                              unsigned Abbrev);
331   void writeDIFile(const DIFile *N, SmallVectorImpl<uint64_t> &Record,
332                    unsigned Abbrev);
333   void writeDICompileUnit(const DICompileUnit *N,
334                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
335   void writeDISubprogram(const DISubprogram *N,
336                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
337   void writeDILexicalBlock(const DILexicalBlock *N,
338                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
339   void writeDILexicalBlockFile(const DILexicalBlockFile *N,
340                                SmallVectorImpl<uint64_t> &Record,
341                                unsigned Abbrev);
342   void writeDICommonBlock(const DICommonBlock *N,
343                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
344   void writeDINamespace(const DINamespace *N, SmallVectorImpl<uint64_t> &Record,
345                         unsigned Abbrev);
346   void writeDIMacro(const DIMacro *N, SmallVectorImpl<uint64_t> &Record,
347                     unsigned Abbrev);
348   void writeDIMacroFile(const DIMacroFile *N, SmallVectorImpl<uint64_t> &Record,
349                         unsigned Abbrev);
350   void writeDIArgList(const DIArgList *N, SmallVectorImpl<uint64_t> &Record);
351   void writeDIModule(const DIModule *N, SmallVectorImpl<uint64_t> &Record,
352                      unsigned Abbrev);
353   void writeDIAssignID(const DIAssignID *N, SmallVectorImpl<uint64_t> &Record,
354                        unsigned Abbrev);
355   void writeDITemplateTypeParameter(const DITemplateTypeParameter *N,
356                                     SmallVectorImpl<uint64_t> &Record,
357                                     unsigned Abbrev);
358   void writeDITemplateValueParameter(const DITemplateValueParameter *N,
359                                      SmallVectorImpl<uint64_t> &Record,
360                                      unsigned Abbrev);
361   void writeDIGlobalVariable(const DIGlobalVariable *N,
362                              SmallVectorImpl<uint64_t> &Record,
363                              unsigned Abbrev);
364   void writeDILocalVariable(const DILocalVariable *N,
365                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
366   void writeDILabel(const DILabel *N,
367                     SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
368   void writeDIExpression(const DIExpression *N,
369                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
370   void writeDIGlobalVariableExpression(const DIGlobalVariableExpression *N,
371                                        SmallVectorImpl<uint64_t> &Record,
372                                        unsigned Abbrev);
373   void writeDIObjCProperty(const DIObjCProperty *N,
374                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
375   void writeDIImportedEntity(const DIImportedEntity *N,
376                              SmallVectorImpl<uint64_t> &Record,
377                              unsigned Abbrev);
378   unsigned createNamedMetadataAbbrev();
379   void writeNamedMetadata(SmallVectorImpl<uint64_t> &Record);
380   unsigned createMetadataStringsAbbrev();
381   void writeMetadataStrings(ArrayRef<const Metadata *> Strings,
382                             SmallVectorImpl<uint64_t> &Record);
383   void writeMetadataRecords(ArrayRef<const Metadata *> MDs,
384                             SmallVectorImpl<uint64_t> &Record,
385                             std::vector<unsigned> *MDAbbrevs = nullptr,
386                             std::vector<uint64_t> *IndexPos = nullptr);
387   void writeModuleMetadata();
388   void writeFunctionMetadata(const Function &F);
389   void writeFunctionMetadataAttachment(const Function &F);
390   void pushGlobalMetadataAttachment(SmallVectorImpl<uint64_t> &Record,
391                                     const GlobalObject &GO);
392   void writeModuleMetadataKinds();
393   void writeOperandBundleTags();
394   void writeSyncScopeNames();
395   void writeConstants(unsigned FirstVal, unsigned LastVal, bool isGlobal);
396   void writeModuleConstants();
397   bool pushValueAndType(const Value *V, unsigned InstID,
398                         SmallVectorImpl<unsigned> &Vals);
399   bool pushValueOrMetadata(const Value *V, unsigned InstID,
400                            SmallVectorImpl<unsigned> &Vals);
401   void writeOperandBundles(const CallBase &CB, unsigned InstID);
402   void pushValue(const Value *V, unsigned InstID,
403                  SmallVectorImpl<unsigned> &Vals);
404   void pushValueSigned(const Value *V, unsigned InstID,
405                        SmallVectorImpl<uint64_t> &Vals);
406   void writeInstruction(const Instruction &I, unsigned InstID,
407                         SmallVectorImpl<unsigned> &Vals);
408   void writeFunctionLevelValueSymbolTable(const ValueSymbolTable &VST);
409   void writeGlobalValueSymbolTable(
410       DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
411   void writeUseList(UseListOrder &&Order);
412   void writeUseListBlock(const Function *F);
413   void
414   writeFunction(const Function &F,
415                 DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
416   void writeBlockInfo();
417   void writeModuleHash(StringRef View);
418 
419   unsigned getEncodedSyncScopeID(SyncScope::ID SSID) {
420     return unsigned(SSID);
421   }
422 
423   unsigned getEncodedAlign(MaybeAlign Alignment) { return encode(Alignment); }
424 };
425 
426 /// Class to manage the bitcode writing for a combined index.
427 class IndexBitcodeWriter : public BitcodeWriterBase {
428   /// The combined index to write to bitcode.
429   const ModuleSummaryIndex &Index;
430 
431   /// When writing combined summaries, provides the set of global value
432   /// summaries for which the value (function, function alias, etc) should be
433   /// imported as a declaration.
434   const GVSummaryPtrSet *DecSummaries = nullptr;
435 
436   /// When writing a subset of the index for distributed backends, client
437   /// provides a map of modules to the corresponding GUIDs/summaries to write.
438   const ModuleToSummariesForIndexTy *ModuleToSummariesForIndex;
439 
440   /// Map that holds the correspondence between the GUID used in the combined
441   /// index and a value id generated by this class to use in references.
442   std::map<GlobalValue::GUID, unsigned> GUIDToValueIdMap;
443 
444   // The stack ids used by this index, which will be a subset of those in
445   // the full index in the case of distributed indexes.
446   std::vector<uint64_t> StackIds;
447 
448   // Keep a map of the stack id indices used by records being written for this
449   // index to the index of the corresponding stack id in the above StackIds
450   // vector. Ensures we write each referenced stack id once.
451   DenseMap<unsigned, unsigned> StackIdIndicesToIndex;
452 
453   /// Tracks the last value id recorded in the GUIDToValueMap.
454   unsigned GlobalValueId = 0;
455 
456   /// Tracks the assignment of module paths in the module path string table to
457   /// an id assigned for use in summary references to the module path.
458   DenseMap<StringRef, uint64_t> ModuleIdMap;
459 
460 public:
461   /// Constructs a IndexBitcodeWriter object for the given combined index,
462   /// writing to the provided \p Buffer. When writing a subset of the index
463   /// for a distributed backend, provide a \p ModuleToSummariesForIndex map.
464   /// If provided, \p DecSummaries specifies the set of summaries for which
465   /// the corresponding functions or aliased functions should be imported as a
466   /// declaration (but not definition) for each module.
467   IndexBitcodeWriter(
468       BitstreamWriter &Stream, StringTableBuilder &StrtabBuilder,
469       const ModuleSummaryIndex &Index,
470       const GVSummaryPtrSet *DecSummaries = nullptr,
471       const ModuleToSummariesForIndexTy *ModuleToSummariesForIndex = nullptr)
472       : BitcodeWriterBase(Stream, StrtabBuilder), Index(Index),
473         DecSummaries(DecSummaries),
474         ModuleToSummariesForIndex(ModuleToSummariesForIndex) {
475 
476     // See if the StackIdIndex was already added to the StackId map and
477     // vector. If not, record it.
478     auto RecordStackIdReference = [&](unsigned StackIdIndex) {
479       // If the StackIdIndex is not yet in the map, the below insert ensures
480       // that it will point to the new StackIds vector entry we push to just
481       // below.
482       auto Inserted =
483           StackIdIndicesToIndex.insert({StackIdIndex, StackIds.size()});
484       if (Inserted.second)
485         StackIds.push_back(Index.getStackIdAtIndex(StackIdIndex));
486     };
487 
488     // Assign unique value ids to all summaries to be written, for use
489     // in writing out the call graph edges. Save the mapping from GUID
490     // to the new global value id to use when writing those edges, which
491     // are currently saved in the index in terms of GUID.
492     forEachSummary([&](GVInfo I, bool IsAliasee) {
493       GUIDToValueIdMap[I.first] = ++GlobalValueId;
494       if (IsAliasee)
495         return;
496       auto *FS = dyn_cast<FunctionSummary>(I.second);
497       if (!FS)
498         return;
499       // Record all stack id indices actually used in the summary entries being
500       // written, so that we can compact them in the case of distributed ThinLTO
501       // indexes.
502       for (auto &CI : FS->callsites()) {
503         // If the stack id list is empty, this callsite info was synthesized for
504         // a missing tail call frame. Ensure that the callee's GUID gets a value
505         // id. Normally we only generate these for defined summaries, which in
506         // the case of distributed ThinLTO is only the functions already defined
507         // in the module or that we want to import. We don't bother to include
508         // all the callee symbols as they aren't normally needed in the backend.
509         // However, for the synthesized callsite infos we do need the callee
510         // GUID in the backend so that we can correlate the identified callee
511         // with this callsite info (which for non-tail calls is done by the
512         // ordering of the callsite infos and verified via stack ids).
513         if (CI.StackIdIndices.empty()) {
514           GUIDToValueIdMap[CI.Callee.getGUID()] = ++GlobalValueId;
515           continue;
516         }
517         for (auto Idx : CI.StackIdIndices)
518           RecordStackIdReference(Idx);
519       }
520       for (auto &AI : FS->allocs())
521         for (auto &MIB : AI.MIBs)
522           for (auto Idx : MIB.StackIdIndices)
523             RecordStackIdReference(Idx);
524     });
525   }
526 
527   /// The below iterator returns the GUID and associated summary.
528   using GVInfo = std::pair<GlobalValue::GUID, GlobalValueSummary *>;
529 
530   /// Calls the callback for each value GUID and summary to be written to
531   /// bitcode. This hides the details of whether they are being pulled from the
532   /// entire index or just those in a provided ModuleToSummariesForIndex map.
533   template<typename Functor>
534   void forEachSummary(Functor Callback) {
535     if (ModuleToSummariesForIndex) {
536       for (auto &M : *ModuleToSummariesForIndex)
537         for (auto &Summary : M.second) {
538           Callback(Summary, false);
539           // Ensure aliasee is handled, e.g. for assigning a valueId,
540           // even if we are not importing the aliasee directly (the
541           // imported alias will contain a copy of aliasee).
542           if (auto *AS = dyn_cast<AliasSummary>(Summary.getSecond()))
543             Callback({AS->getAliaseeGUID(), &AS->getAliasee()}, true);
544         }
545     } else {
546       for (auto &Summaries : Index)
547         for (auto &Summary : Summaries.second.SummaryList)
548           Callback({Summaries.first, Summary.get()}, false);
549     }
550   }
551 
552   /// Calls the callback for each entry in the modulePaths StringMap that
553   /// should be written to the module path string table. This hides the details
554   /// of whether they are being pulled from the entire index or just those in a
555   /// provided ModuleToSummariesForIndex map.
556   template <typename Functor> void forEachModule(Functor Callback) {
557     if (ModuleToSummariesForIndex) {
558       for (const auto &M : *ModuleToSummariesForIndex) {
559         const auto &MPI = Index.modulePaths().find(M.first);
560         if (MPI == Index.modulePaths().end()) {
561           // This should only happen if the bitcode file was empty, in which
562           // case we shouldn't be importing (the ModuleToSummariesForIndex
563           // would only include the module we are writing and index for).
564           assert(ModuleToSummariesForIndex->size() == 1);
565           continue;
566         }
567         Callback(*MPI);
568       }
569     } else {
570       // Since StringMap iteration order isn't guaranteed, order by path string
571       // first.
572       // FIXME: Make this a vector of StringMapEntry instead to avoid the later
573       // map lookup.
574       std::vector<StringRef> ModulePaths;
575       for (auto &[ModPath, _] : Index.modulePaths())
576         ModulePaths.push_back(ModPath);
577       llvm::sort(ModulePaths.begin(), ModulePaths.end());
578       for (auto &ModPath : ModulePaths)
579         Callback(*Index.modulePaths().find(ModPath));
580     }
581   }
582 
583   /// Main entry point for writing a combined index to bitcode.
584   void write();
585 
586 private:
587   void writeModStrings();
588   void writeCombinedGlobalValueSummary();
589 
590   std::optional<unsigned> getValueId(GlobalValue::GUID ValGUID) {
591     auto VMI = GUIDToValueIdMap.find(ValGUID);
592     if (VMI == GUIDToValueIdMap.end())
593       return std::nullopt;
594     return VMI->second;
595   }
596 
597   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
598 };
599 
600 } // end anonymous namespace
601 
602 static unsigned getEncodedCastOpcode(unsigned Opcode) {
603   switch (Opcode) {
604   default: llvm_unreachable("Unknown cast instruction!");
605   case Instruction::Trunc   : return bitc::CAST_TRUNC;
606   case Instruction::ZExt    : return bitc::CAST_ZEXT;
607   case Instruction::SExt    : return bitc::CAST_SEXT;
608   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
609   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
610   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
611   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
612   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
613   case Instruction::FPExt   : return bitc::CAST_FPEXT;
614   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
615   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
616   case Instruction::BitCast : return bitc::CAST_BITCAST;
617   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
618   }
619 }
620 
621 static unsigned getEncodedUnaryOpcode(unsigned Opcode) {
622   switch (Opcode) {
623   default: llvm_unreachable("Unknown binary instruction!");
624   case Instruction::FNeg: return bitc::UNOP_FNEG;
625   }
626 }
627 
628 static unsigned getEncodedBinaryOpcode(unsigned Opcode) {
629   switch (Opcode) {
630   default: llvm_unreachable("Unknown binary instruction!");
631   case Instruction::Add:
632   case Instruction::FAdd: return bitc::BINOP_ADD;
633   case Instruction::Sub:
634   case Instruction::FSub: return bitc::BINOP_SUB;
635   case Instruction::Mul:
636   case Instruction::FMul: return bitc::BINOP_MUL;
637   case Instruction::UDiv: return bitc::BINOP_UDIV;
638   case Instruction::FDiv:
639   case Instruction::SDiv: return bitc::BINOP_SDIV;
640   case Instruction::URem: return bitc::BINOP_UREM;
641   case Instruction::FRem:
642   case Instruction::SRem: return bitc::BINOP_SREM;
643   case Instruction::Shl:  return bitc::BINOP_SHL;
644   case Instruction::LShr: return bitc::BINOP_LSHR;
645   case Instruction::AShr: return bitc::BINOP_ASHR;
646   case Instruction::And:  return bitc::BINOP_AND;
647   case Instruction::Or:   return bitc::BINOP_OR;
648   case Instruction::Xor:  return bitc::BINOP_XOR;
649   }
650 }
651 
652 static unsigned getEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
653   switch (Op) {
654   default: llvm_unreachable("Unknown RMW operation!");
655   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
656   case AtomicRMWInst::Add: return bitc::RMW_ADD;
657   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
658   case AtomicRMWInst::And: return bitc::RMW_AND;
659   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
660   case AtomicRMWInst::Or: return bitc::RMW_OR;
661   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
662   case AtomicRMWInst::Max: return bitc::RMW_MAX;
663   case AtomicRMWInst::Min: return bitc::RMW_MIN;
664   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
665   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
666   case AtomicRMWInst::FAdd: return bitc::RMW_FADD;
667   case AtomicRMWInst::FSub: return bitc::RMW_FSUB;
668   case AtomicRMWInst::FMax: return bitc::RMW_FMAX;
669   case AtomicRMWInst::FMin: return bitc::RMW_FMIN;
670   case AtomicRMWInst::UIncWrap:
671     return bitc::RMW_UINC_WRAP;
672   case AtomicRMWInst::UDecWrap:
673     return bitc::RMW_UDEC_WRAP;
674   case AtomicRMWInst::USubCond:
675     return bitc::RMW_USUB_COND;
676   case AtomicRMWInst::USubSat:
677     return bitc::RMW_USUB_SAT;
678   }
679 }
680 
681 static unsigned getEncodedOrdering(AtomicOrdering Ordering) {
682   switch (Ordering) {
683   case AtomicOrdering::NotAtomic: return bitc::ORDERING_NOTATOMIC;
684   case AtomicOrdering::Unordered: return bitc::ORDERING_UNORDERED;
685   case AtomicOrdering::Monotonic: return bitc::ORDERING_MONOTONIC;
686   case AtomicOrdering::Acquire: return bitc::ORDERING_ACQUIRE;
687   case AtomicOrdering::Release: return bitc::ORDERING_RELEASE;
688   case AtomicOrdering::AcquireRelease: return bitc::ORDERING_ACQREL;
689   case AtomicOrdering::SequentiallyConsistent: return bitc::ORDERING_SEQCST;
690   }
691   llvm_unreachable("Invalid ordering");
692 }
693 
694 static void writeStringRecord(BitstreamWriter &Stream, unsigned Code,
695                               StringRef Str, unsigned AbbrevToUse) {
696   SmallVector<unsigned, 64> Vals;
697 
698   // Code: [strchar x N]
699   for (char C : Str) {
700     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(C))
701       AbbrevToUse = 0;
702     Vals.push_back(C);
703   }
704 
705   // Emit the finished record.
706   Stream.EmitRecord(Code, Vals, AbbrevToUse);
707 }
708 
709 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
710   switch (Kind) {
711   case Attribute::Alignment:
712     return bitc::ATTR_KIND_ALIGNMENT;
713   case Attribute::AllocAlign:
714     return bitc::ATTR_KIND_ALLOC_ALIGN;
715   case Attribute::AllocSize:
716     return bitc::ATTR_KIND_ALLOC_SIZE;
717   case Attribute::AlwaysInline:
718     return bitc::ATTR_KIND_ALWAYS_INLINE;
719   case Attribute::Builtin:
720     return bitc::ATTR_KIND_BUILTIN;
721   case Attribute::ByVal:
722     return bitc::ATTR_KIND_BY_VAL;
723   case Attribute::Convergent:
724     return bitc::ATTR_KIND_CONVERGENT;
725   case Attribute::InAlloca:
726     return bitc::ATTR_KIND_IN_ALLOCA;
727   case Attribute::Cold:
728     return bitc::ATTR_KIND_COLD;
729   case Attribute::DisableSanitizerInstrumentation:
730     return bitc::ATTR_KIND_DISABLE_SANITIZER_INSTRUMENTATION;
731   case Attribute::FnRetThunkExtern:
732     return bitc::ATTR_KIND_FNRETTHUNK_EXTERN;
733   case Attribute::Hot:
734     return bitc::ATTR_KIND_HOT;
735   case Attribute::ElementType:
736     return bitc::ATTR_KIND_ELEMENTTYPE;
737   case Attribute::HybridPatchable:
738     return bitc::ATTR_KIND_HYBRID_PATCHABLE;
739   case Attribute::InlineHint:
740     return bitc::ATTR_KIND_INLINE_HINT;
741   case Attribute::InReg:
742     return bitc::ATTR_KIND_IN_REG;
743   case Attribute::JumpTable:
744     return bitc::ATTR_KIND_JUMP_TABLE;
745   case Attribute::MinSize:
746     return bitc::ATTR_KIND_MIN_SIZE;
747   case Attribute::AllocatedPointer:
748     return bitc::ATTR_KIND_ALLOCATED_POINTER;
749   case Attribute::AllocKind:
750     return bitc::ATTR_KIND_ALLOC_KIND;
751   case Attribute::Memory:
752     return bitc::ATTR_KIND_MEMORY;
753   case Attribute::NoFPClass:
754     return bitc::ATTR_KIND_NOFPCLASS;
755   case Attribute::Naked:
756     return bitc::ATTR_KIND_NAKED;
757   case Attribute::Nest:
758     return bitc::ATTR_KIND_NEST;
759   case Attribute::NoAlias:
760     return bitc::ATTR_KIND_NO_ALIAS;
761   case Attribute::NoBuiltin:
762     return bitc::ATTR_KIND_NO_BUILTIN;
763   case Attribute::NoCallback:
764     return bitc::ATTR_KIND_NO_CALLBACK;
765   case Attribute::NoCapture:
766     return bitc::ATTR_KIND_NO_CAPTURE;
767   case Attribute::NoDivergenceSource:
768     return bitc::ATTR_KIND_NO_DIVERGENCE_SOURCE;
769   case Attribute::NoDuplicate:
770     return bitc::ATTR_KIND_NO_DUPLICATE;
771   case Attribute::NoFree:
772     return bitc::ATTR_KIND_NOFREE;
773   case Attribute::NoImplicitFloat:
774     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
775   case Attribute::NoInline:
776     return bitc::ATTR_KIND_NO_INLINE;
777   case Attribute::NoRecurse:
778     return bitc::ATTR_KIND_NO_RECURSE;
779   case Attribute::NoMerge:
780     return bitc::ATTR_KIND_NO_MERGE;
781   case Attribute::NonLazyBind:
782     return bitc::ATTR_KIND_NON_LAZY_BIND;
783   case Attribute::NonNull:
784     return bitc::ATTR_KIND_NON_NULL;
785   case Attribute::Dereferenceable:
786     return bitc::ATTR_KIND_DEREFERENCEABLE;
787   case Attribute::DereferenceableOrNull:
788     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
789   case Attribute::NoRedZone:
790     return bitc::ATTR_KIND_NO_RED_ZONE;
791   case Attribute::NoReturn:
792     return bitc::ATTR_KIND_NO_RETURN;
793   case Attribute::NoSync:
794     return bitc::ATTR_KIND_NOSYNC;
795   case Attribute::NoCfCheck:
796     return bitc::ATTR_KIND_NOCF_CHECK;
797   case Attribute::NoProfile:
798     return bitc::ATTR_KIND_NO_PROFILE;
799   case Attribute::SkipProfile:
800     return bitc::ATTR_KIND_SKIP_PROFILE;
801   case Attribute::NoUnwind:
802     return bitc::ATTR_KIND_NO_UNWIND;
803   case Attribute::NoSanitizeBounds:
804     return bitc::ATTR_KIND_NO_SANITIZE_BOUNDS;
805   case Attribute::NoSanitizeCoverage:
806     return bitc::ATTR_KIND_NO_SANITIZE_COVERAGE;
807   case Attribute::NullPointerIsValid:
808     return bitc::ATTR_KIND_NULL_POINTER_IS_VALID;
809   case Attribute::OptimizeForDebugging:
810     return bitc::ATTR_KIND_OPTIMIZE_FOR_DEBUGGING;
811   case Attribute::OptForFuzzing:
812     return bitc::ATTR_KIND_OPT_FOR_FUZZING;
813   case Attribute::OptimizeForSize:
814     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
815   case Attribute::OptimizeNone:
816     return bitc::ATTR_KIND_OPTIMIZE_NONE;
817   case Attribute::ReadNone:
818     return bitc::ATTR_KIND_READ_NONE;
819   case Attribute::ReadOnly:
820     return bitc::ATTR_KIND_READ_ONLY;
821   case Attribute::Returned:
822     return bitc::ATTR_KIND_RETURNED;
823   case Attribute::ReturnsTwice:
824     return bitc::ATTR_KIND_RETURNS_TWICE;
825   case Attribute::SExt:
826     return bitc::ATTR_KIND_S_EXT;
827   case Attribute::Speculatable:
828     return bitc::ATTR_KIND_SPECULATABLE;
829   case Attribute::StackAlignment:
830     return bitc::ATTR_KIND_STACK_ALIGNMENT;
831   case Attribute::StackProtect:
832     return bitc::ATTR_KIND_STACK_PROTECT;
833   case Attribute::StackProtectReq:
834     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
835   case Attribute::StackProtectStrong:
836     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
837   case Attribute::SafeStack:
838     return bitc::ATTR_KIND_SAFESTACK;
839   case Attribute::ShadowCallStack:
840     return bitc::ATTR_KIND_SHADOWCALLSTACK;
841   case Attribute::StrictFP:
842     return bitc::ATTR_KIND_STRICT_FP;
843   case Attribute::StructRet:
844     return bitc::ATTR_KIND_STRUCT_RET;
845   case Attribute::SanitizeAddress:
846     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
847   case Attribute::SanitizeHWAddress:
848     return bitc::ATTR_KIND_SANITIZE_HWADDRESS;
849   case Attribute::SanitizeThread:
850     return bitc::ATTR_KIND_SANITIZE_THREAD;
851   case Attribute::SanitizeMemory:
852     return bitc::ATTR_KIND_SANITIZE_MEMORY;
853   case Attribute::SanitizeNumericalStability:
854     return bitc::ATTR_KIND_SANITIZE_NUMERICAL_STABILITY;
855   case Attribute::SanitizeRealtime:
856     return bitc::ATTR_KIND_SANITIZE_REALTIME;
857   case Attribute::SanitizeRealtimeBlocking:
858     return bitc::ATTR_KIND_SANITIZE_REALTIME_BLOCKING;
859   case Attribute::SpeculativeLoadHardening:
860     return bitc::ATTR_KIND_SPECULATIVE_LOAD_HARDENING;
861   case Attribute::SwiftError:
862     return bitc::ATTR_KIND_SWIFT_ERROR;
863   case Attribute::SwiftSelf:
864     return bitc::ATTR_KIND_SWIFT_SELF;
865   case Attribute::SwiftAsync:
866     return bitc::ATTR_KIND_SWIFT_ASYNC;
867   case Attribute::UWTable:
868     return bitc::ATTR_KIND_UW_TABLE;
869   case Attribute::VScaleRange:
870     return bitc::ATTR_KIND_VSCALE_RANGE;
871   case Attribute::WillReturn:
872     return bitc::ATTR_KIND_WILLRETURN;
873   case Attribute::WriteOnly:
874     return bitc::ATTR_KIND_WRITEONLY;
875   case Attribute::ZExt:
876     return bitc::ATTR_KIND_Z_EXT;
877   case Attribute::ImmArg:
878     return bitc::ATTR_KIND_IMMARG;
879   case Attribute::SanitizeMemTag:
880     return bitc::ATTR_KIND_SANITIZE_MEMTAG;
881   case Attribute::Preallocated:
882     return bitc::ATTR_KIND_PREALLOCATED;
883   case Attribute::NoUndef:
884     return bitc::ATTR_KIND_NOUNDEF;
885   case Attribute::ByRef:
886     return bitc::ATTR_KIND_BYREF;
887   case Attribute::MustProgress:
888     return bitc::ATTR_KIND_MUSTPROGRESS;
889   case Attribute::PresplitCoroutine:
890     return bitc::ATTR_KIND_PRESPLIT_COROUTINE;
891   case Attribute::Writable:
892     return bitc::ATTR_KIND_WRITABLE;
893   case Attribute::CoroDestroyOnlyWhenComplete:
894     return bitc::ATTR_KIND_CORO_ONLY_DESTROY_WHEN_COMPLETE;
895   case Attribute::CoroElideSafe:
896     return bitc::ATTR_KIND_CORO_ELIDE_SAFE;
897   case Attribute::DeadOnUnwind:
898     return bitc::ATTR_KIND_DEAD_ON_UNWIND;
899   case Attribute::Range:
900     return bitc::ATTR_KIND_RANGE;
901   case Attribute::Initializes:
902     return bitc::ATTR_KIND_INITIALIZES;
903   case Attribute::NoExt:
904     return bitc::ATTR_KIND_NO_EXT;
905   case Attribute::EndAttrKinds:
906     llvm_unreachable("Can not encode end-attribute kinds marker.");
907   case Attribute::None:
908     llvm_unreachable("Can not encode none-attribute.");
909   case Attribute::EmptyKey:
910   case Attribute::TombstoneKey:
911     llvm_unreachable("Trying to encode EmptyKey/TombstoneKey");
912   }
913 
914   llvm_unreachable("Trying to encode unknown attribute");
915 }
916 
917 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
918   if ((int64_t)V >= 0)
919     Vals.push_back(V << 1);
920   else
921     Vals.push_back((-V << 1) | 1);
922 }
923 
924 static void emitWideAPInt(SmallVectorImpl<uint64_t> &Vals, const APInt &A) {
925   // We have an arbitrary precision integer value to write whose
926   // bit width is > 64. However, in canonical unsigned integer
927   // format it is likely that the high bits are going to be zero.
928   // So, we only write the number of active words.
929   unsigned NumWords = A.getActiveWords();
930   const uint64_t *RawData = A.getRawData();
931   for (unsigned i = 0; i < NumWords; i++)
932     emitSignedInt64(Vals, RawData[i]);
933 }
934 
935 static void emitConstantRange(SmallVectorImpl<uint64_t> &Record,
936                               const ConstantRange &CR, bool EmitBitWidth) {
937   unsigned BitWidth = CR.getBitWidth();
938   if (EmitBitWidth)
939     Record.push_back(BitWidth);
940   if (BitWidth > 64) {
941     Record.push_back(CR.getLower().getActiveWords() |
942                      (uint64_t(CR.getUpper().getActiveWords()) << 32));
943     emitWideAPInt(Record, CR.getLower());
944     emitWideAPInt(Record, CR.getUpper());
945   } else {
946     emitSignedInt64(Record, CR.getLower().getSExtValue());
947     emitSignedInt64(Record, CR.getUpper().getSExtValue());
948   }
949 }
950 
951 void ModuleBitcodeWriter::writeAttributeGroupTable() {
952   const std::vector<ValueEnumerator::IndexAndAttrSet> &AttrGrps =
953       VE.getAttributeGroups();
954   if (AttrGrps.empty()) return;
955 
956   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
957 
958   SmallVector<uint64_t, 64> Record;
959   for (ValueEnumerator::IndexAndAttrSet Pair : AttrGrps) {
960     unsigned AttrListIndex = Pair.first;
961     AttributeSet AS = Pair.second;
962     Record.push_back(VE.getAttributeGroupID(Pair));
963     Record.push_back(AttrListIndex);
964 
965     for (Attribute Attr : AS) {
966       if (Attr.isEnumAttribute()) {
967         Record.push_back(0);
968         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
969       } else if (Attr.isIntAttribute()) {
970         Record.push_back(1);
971         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
972         Record.push_back(Attr.getValueAsInt());
973       } else if (Attr.isStringAttribute()) {
974         StringRef Kind = Attr.getKindAsString();
975         StringRef Val = Attr.getValueAsString();
976 
977         Record.push_back(Val.empty() ? 3 : 4);
978         Record.append(Kind.begin(), Kind.end());
979         Record.push_back(0);
980         if (!Val.empty()) {
981           Record.append(Val.begin(), Val.end());
982           Record.push_back(0);
983         }
984       } else if (Attr.isTypeAttribute()) {
985         Type *Ty = Attr.getValueAsType();
986         Record.push_back(Ty ? 6 : 5);
987         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
988         if (Ty)
989           Record.push_back(VE.getTypeID(Attr.getValueAsType()));
990       } else if (Attr.isConstantRangeAttribute()) {
991         Record.push_back(7);
992         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
993         emitConstantRange(Record, Attr.getValueAsConstantRange(),
994                           /*EmitBitWidth=*/true);
995       } else {
996         assert(Attr.isConstantRangeListAttribute());
997         Record.push_back(8);
998         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
999         ArrayRef<ConstantRange> Val = Attr.getValueAsConstantRangeList();
1000         Record.push_back(Val.size());
1001         Record.push_back(Val[0].getBitWidth());
1002         for (auto &CR : Val)
1003           emitConstantRange(Record, CR, /*EmitBitWidth=*/false);
1004       }
1005     }
1006 
1007     Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
1008     Record.clear();
1009   }
1010 
1011   Stream.ExitBlock();
1012 }
1013 
1014 void ModuleBitcodeWriter::writeAttributeTable() {
1015   const std::vector<AttributeList> &Attrs = VE.getAttributeLists();
1016   if (Attrs.empty()) return;
1017 
1018   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
1019 
1020   SmallVector<uint64_t, 64> Record;
1021   for (const AttributeList &AL : Attrs) {
1022     for (unsigned i : AL.indexes()) {
1023       AttributeSet AS = AL.getAttributes(i);
1024       if (AS.hasAttributes())
1025         Record.push_back(VE.getAttributeGroupID({i, AS}));
1026     }
1027 
1028     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
1029     Record.clear();
1030   }
1031 
1032   Stream.ExitBlock();
1033 }
1034 
1035 /// WriteTypeTable - Write out the type table for a module.
1036 void ModuleBitcodeWriter::writeTypeTable() {
1037   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
1038 
1039   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
1040   SmallVector<uint64_t, 64> TypeVals;
1041 
1042   uint64_t NumBits = VE.computeBitsRequiredForTypeIndices();
1043 
1044   // Abbrev for TYPE_CODE_OPAQUE_POINTER.
1045   auto Abbv = std::make_shared<BitCodeAbbrev>();
1046   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_OPAQUE_POINTER));
1047   Abbv->Add(BitCodeAbbrevOp(0)); // Addrspace = 0
1048   unsigned OpaquePtrAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1049 
1050   // Abbrev for TYPE_CODE_FUNCTION.
1051   Abbv = std::make_shared<BitCodeAbbrev>();
1052   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
1053   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
1054   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1055   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1056   unsigned FunctionAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1057 
1058   // Abbrev for TYPE_CODE_STRUCT_ANON.
1059   Abbv = std::make_shared<BitCodeAbbrev>();
1060   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
1061   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
1062   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1063   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1064   unsigned StructAnonAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1065 
1066   // Abbrev for TYPE_CODE_STRUCT_NAME.
1067   Abbv = std::make_shared<BitCodeAbbrev>();
1068   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
1069   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1070   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1071   unsigned StructNameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1072 
1073   // Abbrev for TYPE_CODE_STRUCT_NAMED.
1074   Abbv = std::make_shared<BitCodeAbbrev>();
1075   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
1076   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
1077   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1078   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1079   unsigned StructNamedAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1080 
1081   // Abbrev for TYPE_CODE_ARRAY.
1082   Abbv = std::make_shared<BitCodeAbbrev>();
1083   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
1084   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
1085   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1086   unsigned ArrayAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1087 
1088   // Emit an entry count so the reader can reserve space.
1089   TypeVals.push_back(TypeList.size());
1090   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
1091   TypeVals.clear();
1092 
1093   // Loop over all of the types, emitting each in turn.
1094   for (Type *T : TypeList) {
1095     int AbbrevToUse = 0;
1096     unsigned Code = 0;
1097 
1098     switch (T->getTypeID()) {
1099     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
1100     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
1101     case Type::BFloatTyID:    Code = bitc::TYPE_CODE_BFLOAT;    break;
1102     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
1103     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
1104     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
1105     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
1106     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
1107     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
1108     case Type::MetadataTyID:
1109       Code = bitc::TYPE_CODE_METADATA;
1110       break;
1111     case Type::X86_AMXTyID:   Code = bitc::TYPE_CODE_X86_AMX;   break;
1112     case Type::TokenTyID:     Code = bitc::TYPE_CODE_TOKEN;     break;
1113     case Type::IntegerTyID:
1114       // INTEGER: [width]
1115       Code = bitc::TYPE_CODE_INTEGER;
1116       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
1117       break;
1118     case Type::PointerTyID: {
1119       PointerType *PTy = cast<PointerType>(T);
1120       unsigned AddressSpace = PTy->getAddressSpace();
1121       // OPAQUE_POINTER: [address space]
1122       Code = bitc::TYPE_CODE_OPAQUE_POINTER;
1123       TypeVals.push_back(AddressSpace);
1124       if (AddressSpace == 0)
1125         AbbrevToUse = OpaquePtrAbbrev;
1126       break;
1127     }
1128     case Type::FunctionTyID: {
1129       FunctionType *FT = cast<FunctionType>(T);
1130       // FUNCTION: [isvararg, retty, paramty x N]
1131       Code = bitc::TYPE_CODE_FUNCTION;
1132       TypeVals.push_back(FT->isVarArg());
1133       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
1134       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
1135         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
1136       AbbrevToUse = FunctionAbbrev;
1137       break;
1138     }
1139     case Type::StructTyID: {
1140       StructType *ST = cast<StructType>(T);
1141       // STRUCT: [ispacked, eltty x N]
1142       TypeVals.push_back(ST->isPacked());
1143       // Output all of the element types.
1144       for (Type *ET : ST->elements())
1145         TypeVals.push_back(VE.getTypeID(ET));
1146 
1147       if (ST->isLiteral()) {
1148         Code = bitc::TYPE_CODE_STRUCT_ANON;
1149         AbbrevToUse = StructAnonAbbrev;
1150       } else {
1151         if (ST->isOpaque()) {
1152           Code = bitc::TYPE_CODE_OPAQUE;
1153         } else {
1154           Code = bitc::TYPE_CODE_STRUCT_NAMED;
1155           AbbrevToUse = StructNamedAbbrev;
1156         }
1157 
1158         // Emit the name if it is present.
1159         if (!ST->getName().empty())
1160           writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
1161                             StructNameAbbrev);
1162       }
1163       break;
1164     }
1165     case Type::ArrayTyID: {
1166       ArrayType *AT = cast<ArrayType>(T);
1167       // ARRAY: [numelts, eltty]
1168       Code = bitc::TYPE_CODE_ARRAY;
1169       TypeVals.push_back(AT->getNumElements());
1170       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
1171       AbbrevToUse = ArrayAbbrev;
1172       break;
1173     }
1174     case Type::FixedVectorTyID:
1175     case Type::ScalableVectorTyID: {
1176       VectorType *VT = cast<VectorType>(T);
1177       // VECTOR [numelts, eltty] or
1178       //        [numelts, eltty, scalable]
1179       Code = bitc::TYPE_CODE_VECTOR;
1180       TypeVals.push_back(VT->getElementCount().getKnownMinValue());
1181       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
1182       if (isa<ScalableVectorType>(VT))
1183         TypeVals.push_back(true);
1184       break;
1185     }
1186     case Type::TargetExtTyID: {
1187       TargetExtType *TET = cast<TargetExtType>(T);
1188       Code = bitc::TYPE_CODE_TARGET_TYPE;
1189       writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, TET->getName(),
1190                         StructNameAbbrev);
1191       TypeVals.push_back(TET->getNumTypeParameters());
1192       for (Type *InnerTy : TET->type_params())
1193         TypeVals.push_back(VE.getTypeID(InnerTy));
1194       for (unsigned IntParam : TET->int_params())
1195         TypeVals.push_back(IntParam);
1196       break;
1197     }
1198     case Type::TypedPointerTyID:
1199       llvm_unreachable("Typed pointers cannot be added to IR modules");
1200     }
1201 
1202     // Emit the finished record.
1203     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
1204     TypeVals.clear();
1205   }
1206 
1207   Stream.ExitBlock();
1208 }
1209 
1210 static unsigned getEncodedLinkage(const GlobalValue::LinkageTypes Linkage) {
1211   switch (Linkage) {
1212   case GlobalValue::ExternalLinkage:
1213     return 0;
1214   case GlobalValue::WeakAnyLinkage:
1215     return 16;
1216   case GlobalValue::AppendingLinkage:
1217     return 2;
1218   case GlobalValue::InternalLinkage:
1219     return 3;
1220   case GlobalValue::LinkOnceAnyLinkage:
1221     return 18;
1222   case GlobalValue::ExternalWeakLinkage:
1223     return 7;
1224   case GlobalValue::CommonLinkage:
1225     return 8;
1226   case GlobalValue::PrivateLinkage:
1227     return 9;
1228   case GlobalValue::WeakODRLinkage:
1229     return 17;
1230   case GlobalValue::LinkOnceODRLinkage:
1231     return 19;
1232   case GlobalValue::AvailableExternallyLinkage:
1233     return 12;
1234   }
1235   llvm_unreachable("Invalid linkage");
1236 }
1237 
1238 static unsigned getEncodedLinkage(const GlobalValue &GV) {
1239   return getEncodedLinkage(GV.getLinkage());
1240 }
1241 
1242 static uint64_t getEncodedFFlags(FunctionSummary::FFlags Flags) {
1243   uint64_t RawFlags = 0;
1244   RawFlags |= Flags.ReadNone;
1245   RawFlags |= (Flags.ReadOnly << 1);
1246   RawFlags |= (Flags.NoRecurse << 2);
1247   RawFlags |= (Flags.ReturnDoesNotAlias << 3);
1248   RawFlags |= (Flags.NoInline << 4);
1249   RawFlags |= (Flags.AlwaysInline << 5);
1250   RawFlags |= (Flags.NoUnwind << 6);
1251   RawFlags |= (Flags.MayThrow << 7);
1252   RawFlags |= (Flags.HasUnknownCall << 8);
1253   RawFlags |= (Flags.MustBeUnreachable << 9);
1254   return RawFlags;
1255 }
1256 
1257 // Decode the flags for GlobalValue in the summary. See getDecodedGVSummaryFlags
1258 // in BitcodeReader.cpp.
1259 static uint64_t getEncodedGVSummaryFlags(GlobalValueSummary::GVFlags Flags,
1260                                          bool ImportAsDecl = false) {
1261   uint64_t RawFlags = 0;
1262 
1263   RawFlags |= Flags.NotEligibleToImport; // bool
1264   RawFlags |= (Flags.Live << 1);
1265   RawFlags |= (Flags.DSOLocal << 2);
1266   RawFlags |= (Flags.CanAutoHide << 3);
1267 
1268   // Linkage don't need to be remapped at that time for the summary. Any future
1269   // change to the getEncodedLinkage() function will need to be taken into
1270   // account here as well.
1271   RawFlags = (RawFlags << 4) | Flags.Linkage; // 4 bits
1272 
1273   RawFlags |= (Flags.Visibility << 8); // 2 bits
1274 
1275   unsigned ImportType = Flags.ImportType | ImportAsDecl;
1276   RawFlags |= (ImportType << 10); // 1 bit
1277 
1278   return RawFlags;
1279 }
1280 
1281 static uint64_t getEncodedGVarFlags(GlobalVarSummary::GVarFlags Flags) {
1282   uint64_t RawFlags = Flags.MaybeReadOnly | (Flags.MaybeWriteOnly << 1) |
1283                       (Flags.Constant << 2) | Flags.VCallVisibility << 3;
1284   return RawFlags;
1285 }
1286 
1287 static uint64_t getEncodedHotnessCallEdgeInfo(const CalleeInfo &CI) {
1288   uint64_t RawFlags = 0;
1289 
1290   RawFlags |= CI.Hotness;            // 3 bits
1291   RawFlags |= (CI.HasTailCall << 3); // 1 bit
1292 
1293   return RawFlags;
1294 }
1295 
1296 static uint64_t getEncodedRelBFCallEdgeInfo(const CalleeInfo &CI) {
1297   uint64_t RawFlags = 0;
1298 
1299   RawFlags |= CI.RelBlockFreq; // CalleeInfo::RelBlockFreqBits bits
1300   RawFlags |= (CI.HasTailCall << CalleeInfo::RelBlockFreqBits); // 1 bit
1301 
1302   return RawFlags;
1303 }
1304 
1305 static unsigned getEncodedVisibility(const GlobalValue &GV) {
1306   switch (GV.getVisibility()) {
1307   case GlobalValue::DefaultVisibility:   return 0;
1308   case GlobalValue::HiddenVisibility:    return 1;
1309   case GlobalValue::ProtectedVisibility: return 2;
1310   }
1311   llvm_unreachable("Invalid visibility");
1312 }
1313 
1314 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
1315   switch (GV.getDLLStorageClass()) {
1316   case GlobalValue::DefaultStorageClass:   return 0;
1317   case GlobalValue::DLLImportStorageClass: return 1;
1318   case GlobalValue::DLLExportStorageClass: return 2;
1319   }
1320   llvm_unreachable("Invalid DLL storage class");
1321 }
1322 
1323 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
1324   switch (GV.getThreadLocalMode()) {
1325     case GlobalVariable::NotThreadLocal:         return 0;
1326     case GlobalVariable::GeneralDynamicTLSModel: return 1;
1327     case GlobalVariable::LocalDynamicTLSModel:   return 2;
1328     case GlobalVariable::InitialExecTLSModel:    return 3;
1329     case GlobalVariable::LocalExecTLSModel:      return 4;
1330   }
1331   llvm_unreachable("Invalid TLS model");
1332 }
1333 
1334 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
1335   switch (C.getSelectionKind()) {
1336   case Comdat::Any:
1337     return bitc::COMDAT_SELECTION_KIND_ANY;
1338   case Comdat::ExactMatch:
1339     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
1340   case Comdat::Largest:
1341     return bitc::COMDAT_SELECTION_KIND_LARGEST;
1342   case Comdat::NoDeduplicate:
1343     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
1344   case Comdat::SameSize:
1345     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
1346   }
1347   llvm_unreachable("Invalid selection kind");
1348 }
1349 
1350 static unsigned getEncodedUnnamedAddr(const GlobalValue &GV) {
1351   switch (GV.getUnnamedAddr()) {
1352   case GlobalValue::UnnamedAddr::None:   return 0;
1353   case GlobalValue::UnnamedAddr::Local:  return 2;
1354   case GlobalValue::UnnamedAddr::Global: return 1;
1355   }
1356   llvm_unreachable("Invalid unnamed_addr");
1357 }
1358 
1359 size_t ModuleBitcodeWriter::addToStrtab(StringRef Str) {
1360   if (GenerateHash)
1361     Hasher.update(Str);
1362   return StrtabBuilder.add(Str);
1363 }
1364 
1365 void ModuleBitcodeWriter::writeComdats() {
1366   SmallVector<unsigned, 64> Vals;
1367   for (const Comdat *C : VE.getComdats()) {
1368     // COMDAT: [strtab offset, strtab size, selection_kind]
1369     Vals.push_back(addToStrtab(C->getName()));
1370     Vals.push_back(C->getName().size());
1371     Vals.push_back(getEncodedComdatSelectionKind(*C));
1372     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
1373     Vals.clear();
1374   }
1375 }
1376 
1377 /// Write a record that will eventually hold the word offset of the
1378 /// module-level VST. For now the offset is 0, which will be backpatched
1379 /// after the real VST is written. Saves the bit offset to backpatch.
1380 void ModuleBitcodeWriter::writeValueSymbolTableForwardDecl() {
1381   // Write a placeholder value in for the offset of the real VST,
1382   // which is written after the function blocks so that it can include
1383   // the offset of each function. The placeholder offset will be
1384   // updated when the real VST is written.
1385   auto Abbv = std::make_shared<BitCodeAbbrev>();
1386   Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_VSTOFFSET));
1387   // Blocks are 32-bit aligned, so we can use a 32-bit word offset to
1388   // hold the real VST offset. Must use fixed instead of VBR as we don't
1389   // know how many VBR chunks to reserve ahead of time.
1390   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1391   unsigned VSTOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1392 
1393   // Emit the placeholder
1394   uint64_t Vals[] = {bitc::MODULE_CODE_VSTOFFSET, 0};
1395   Stream.EmitRecordWithAbbrev(VSTOffsetAbbrev, Vals);
1396 
1397   // Compute and save the bit offset to the placeholder, which will be
1398   // patched when the real VST is written. We can simply subtract the 32-bit
1399   // fixed size from the current bit number to get the location to backpatch.
1400   VSTOffsetPlaceholder = Stream.GetCurrentBitNo() - 32;
1401 }
1402 
1403 enum StringEncoding { SE_Char6, SE_Fixed7, SE_Fixed8 };
1404 
1405 /// Determine the encoding to use for the given string name and length.
1406 static StringEncoding getStringEncoding(StringRef Str) {
1407   bool isChar6 = true;
1408   for (char C : Str) {
1409     if (isChar6)
1410       isChar6 = BitCodeAbbrevOp::isChar6(C);
1411     if ((unsigned char)C & 128)
1412       // don't bother scanning the rest.
1413       return SE_Fixed8;
1414   }
1415   if (isChar6)
1416     return SE_Char6;
1417   return SE_Fixed7;
1418 }
1419 
1420 static_assert(sizeof(GlobalValue::SanitizerMetadata) <= sizeof(unsigned),
1421               "Sanitizer Metadata is too large for naive serialization.");
1422 static unsigned
1423 serializeSanitizerMetadata(const GlobalValue::SanitizerMetadata &Meta) {
1424   return Meta.NoAddress | (Meta.NoHWAddress << 1) |
1425          (Meta.Memtag << 2) | (Meta.IsDynInit << 3);
1426 }
1427 
1428 /// Emit top-level description of module, including target triple, inline asm,
1429 /// descriptors for global variables, and function prototype info.
1430 /// Returns the bit offset to backpatch with the location of the real VST.
1431 void ModuleBitcodeWriter::writeModuleInfo() {
1432   // Emit various pieces of data attached to a module.
1433   if (!M.getTargetTriple().empty())
1434     writeStringRecord(Stream, bitc::MODULE_CODE_TRIPLE, M.getTargetTriple(),
1435                       0 /*TODO*/);
1436   const std::string &DL = M.getDataLayoutStr();
1437   if (!DL.empty())
1438     writeStringRecord(Stream, bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/);
1439   if (!M.getModuleInlineAsm().empty())
1440     writeStringRecord(Stream, bitc::MODULE_CODE_ASM, M.getModuleInlineAsm(),
1441                       0 /*TODO*/);
1442 
1443   // Emit information about sections and GC, computing how many there are. Also
1444   // compute the maximum alignment value.
1445   std::map<std::string, unsigned> SectionMap;
1446   std::map<std::string, unsigned> GCMap;
1447   MaybeAlign MaxAlignment;
1448   unsigned MaxGlobalType = 0;
1449   const auto UpdateMaxAlignment = [&MaxAlignment](const MaybeAlign A) {
1450     if (A)
1451       MaxAlignment = !MaxAlignment ? *A : std::max(*MaxAlignment, *A);
1452   };
1453   for (const GlobalVariable &GV : M.globals()) {
1454     UpdateMaxAlignment(GV.getAlign());
1455     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
1456     if (GV.hasSection()) {
1457       // Give section names unique ID's.
1458       unsigned &Entry = SectionMap[std::string(GV.getSection())];
1459       if (!Entry) {
1460         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
1461                           0 /*TODO*/);
1462         Entry = SectionMap.size();
1463       }
1464     }
1465   }
1466   for (const Function &F : M) {
1467     UpdateMaxAlignment(F.getAlign());
1468     if (F.hasSection()) {
1469       // Give section names unique ID's.
1470       unsigned &Entry = SectionMap[std::string(F.getSection())];
1471       if (!Entry) {
1472         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
1473                           0 /*TODO*/);
1474         Entry = SectionMap.size();
1475       }
1476     }
1477     if (F.hasGC()) {
1478       // Same for GC names.
1479       unsigned &Entry = GCMap[F.getGC()];
1480       if (!Entry) {
1481         writeStringRecord(Stream, bitc::MODULE_CODE_GCNAME, F.getGC(),
1482                           0 /*TODO*/);
1483         Entry = GCMap.size();
1484       }
1485     }
1486   }
1487 
1488   // Emit abbrev for globals, now that we know # sections and max alignment.
1489   unsigned SimpleGVarAbbrev = 0;
1490   if (!M.global_empty()) {
1491     // Add an abbrev for common globals with no visibility or thread localness.
1492     auto Abbv = std::make_shared<BitCodeAbbrev>();
1493     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
1494     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1495     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1496     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1497                               Log2_32_Ceil(MaxGlobalType+1)));
1498     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
1499                                                            //| explicitType << 1
1500                                                            //| constant
1501     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
1502     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
1503     if (!MaxAlignment)                                     // Alignment.
1504       Abbv->Add(BitCodeAbbrevOp(0));
1505     else {
1506       unsigned MaxEncAlignment = getEncodedAlign(MaxAlignment);
1507       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1508                                Log2_32_Ceil(MaxEncAlignment+1)));
1509     }
1510     if (SectionMap.empty())                                    // Section.
1511       Abbv->Add(BitCodeAbbrevOp(0));
1512     else
1513       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1514                                Log2_32_Ceil(SectionMap.size()+1)));
1515     // Don't bother emitting vis + thread local.
1516     SimpleGVarAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1517   }
1518 
1519   SmallVector<unsigned, 64> Vals;
1520   // Emit the module's source file name.
1521   {
1522     StringEncoding Bits = getStringEncoding(M.getSourceFileName());
1523     BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
1524     if (Bits == SE_Char6)
1525       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
1526     else if (Bits == SE_Fixed7)
1527       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
1528 
1529     // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
1530     auto Abbv = std::make_shared<BitCodeAbbrev>();
1531     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
1532     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1533     Abbv->Add(AbbrevOpToUse);
1534     unsigned FilenameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1535 
1536     for (const auto P : M.getSourceFileName())
1537       Vals.push_back((unsigned char)P);
1538 
1539     // Emit the finished record.
1540     Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
1541     Vals.clear();
1542   }
1543 
1544   // Emit the global variable information.
1545   for (const GlobalVariable &GV : M.globals()) {
1546     unsigned AbbrevToUse = 0;
1547 
1548     // GLOBALVAR: [strtab offset, strtab size, type, isconst, initid,
1549     //             linkage, alignment, section, visibility, threadlocal,
1550     //             unnamed_addr, externally_initialized, dllstorageclass,
1551     //             comdat, attributes, DSO_Local, GlobalSanitizer, code_model]
1552     Vals.push_back(addToStrtab(GV.getName()));
1553     Vals.push_back(GV.getName().size());
1554     Vals.push_back(VE.getTypeID(GV.getValueType()));
1555     Vals.push_back(GV.getType()->getAddressSpace() << 2 | 2 | GV.isConstant());
1556     Vals.push_back(GV.isDeclaration() ? 0 :
1557                    (VE.getValueID(GV.getInitializer()) + 1));
1558     Vals.push_back(getEncodedLinkage(GV));
1559     Vals.push_back(getEncodedAlign(GV.getAlign()));
1560     Vals.push_back(GV.hasSection() ? SectionMap[std::string(GV.getSection())]
1561                                    : 0);
1562     if (GV.isThreadLocal() ||
1563         GV.getVisibility() != GlobalValue::DefaultVisibility ||
1564         GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None ||
1565         GV.isExternallyInitialized() ||
1566         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
1567         GV.hasComdat() || GV.hasAttributes() || GV.isDSOLocal() ||
1568         GV.hasPartition() || GV.hasSanitizerMetadata() || GV.getCodeModel()) {
1569       Vals.push_back(getEncodedVisibility(GV));
1570       Vals.push_back(getEncodedThreadLocalMode(GV));
1571       Vals.push_back(getEncodedUnnamedAddr(GV));
1572       Vals.push_back(GV.isExternallyInitialized());
1573       Vals.push_back(getEncodedDLLStorageClass(GV));
1574       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
1575 
1576       auto AL = GV.getAttributesAsList(AttributeList::FunctionIndex);
1577       Vals.push_back(VE.getAttributeListID(AL));
1578 
1579       Vals.push_back(GV.isDSOLocal());
1580       Vals.push_back(addToStrtab(GV.getPartition()));
1581       Vals.push_back(GV.getPartition().size());
1582 
1583       Vals.push_back((GV.hasSanitizerMetadata() ? serializeSanitizerMetadata(
1584                                                       GV.getSanitizerMetadata())
1585                                                 : 0));
1586       Vals.push_back(GV.getCodeModelRaw());
1587     } else {
1588       AbbrevToUse = SimpleGVarAbbrev;
1589     }
1590 
1591     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
1592     Vals.clear();
1593   }
1594 
1595   // Emit the function proto information.
1596   for (const Function &F : M) {
1597     // FUNCTION:  [strtab offset, strtab size, type, callingconv, isproto,
1598     //             linkage, paramattrs, alignment, section, visibility, gc,
1599     //             unnamed_addr, prologuedata, dllstorageclass, comdat,
1600     //             prefixdata, personalityfn, DSO_Local, addrspace]
1601     Vals.push_back(addToStrtab(F.getName()));
1602     Vals.push_back(F.getName().size());
1603     Vals.push_back(VE.getTypeID(F.getFunctionType()));
1604     Vals.push_back(F.getCallingConv());
1605     Vals.push_back(F.isDeclaration());
1606     Vals.push_back(getEncodedLinkage(F));
1607     Vals.push_back(VE.getAttributeListID(F.getAttributes()));
1608     Vals.push_back(getEncodedAlign(F.getAlign()));
1609     Vals.push_back(F.hasSection() ? SectionMap[std::string(F.getSection())]
1610                                   : 0);
1611     Vals.push_back(getEncodedVisibility(F));
1612     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
1613     Vals.push_back(getEncodedUnnamedAddr(F));
1614     Vals.push_back(F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1)
1615                                        : 0);
1616     Vals.push_back(getEncodedDLLStorageClass(F));
1617     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
1618     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
1619                                      : 0);
1620     Vals.push_back(
1621         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
1622 
1623     Vals.push_back(F.isDSOLocal());
1624     Vals.push_back(F.getAddressSpace());
1625     Vals.push_back(addToStrtab(F.getPartition()));
1626     Vals.push_back(F.getPartition().size());
1627 
1628     unsigned AbbrevToUse = 0;
1629     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
1630     Vals.clear();
1631   }
1632 
1633   // Emit the alias information.
1634   for (const GlobalAlias &A : M.aliases()) {
1635     // ALIAS: [strtab offset, strtab size, alias type, aliasee val#, linkage,
1636     //         visibility, dllstorageclass, threadlocal, unnamed_addr,
1637     //         DSO_Local]
1638     Vals.push_back(addToStrtab(A.getName()));
1639     Vals.push_back(A.getName().size());
1640     Vals.push_back(VE.getTypeID(A.getValueType()));
1641     Vals.push_back(A.getType()->getAddressSpace());
1642     Vals.push_back(VE.getValueID(A.getAliasee()));
1643     Vals.push_back(getEncodedLinkage(A));
1644     Vals.push_back(getEncodedVisibility(A));
1645     Vals.push_back(getEncodedDLLStorageClass(A));
1646     Vals.push_back(getEncodedThreadLocalMode(A));
1647     Vals.push_back(getEncodedUnnamedAddr(A));
1648     Vals.push_back(A.isDSOLocal());
1649     Vals.push_back(addToStrtab(A.getPartition()));
1650     Vals.push_back(A.getPartition().size());
1651 
1652     unsigned AbbrevToUse = 0;
1653     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
1654     Vals.clear();
1655   }
1656 
1657   // Emit the ifunc information.
1658   for (const GlobalIFunc &I : M.ifuncs()) {
1659     // IFUNC: [strtab offset, strtab size, ifunc type, address space, resolver
1660     //         val#, linkage, visibility, DSO_Local]
1661     Vals.push_back(addToStrtab(I.getName()));
1662     Vals.push_back(I.getName().size());
1663     Vals.push_back(VE.getTypeID(I.getValueType()));
1664     Vals.push_back(I.getType()->getAddressSpace());
1665     Vals.push_back(VE.getValueID(I.getResolver()));
1666     Vals.push_back(getEncodedLinkage(I));
1667     Vals.push_back(getEncodedVisibility(I));
1668     Vals.push_back(I.isDSOLocal());
1669     Vals.push_back(addToStrtab(I.getPartition()));
1670     Vals.push_back(I.getPartition().size());
1671     Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
1672     Vals.clear();
1673   }
1674 
1675   writeValueSymbolTableForwardDecl();
1676 }
1677 
1678 static uint64_t getOptimizationFlags(const Value *V) {
1679   uint64_t Flags = 0;
1680 
1681   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
1682     if (OBO->hasNoSignedWrap())
1683       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
1684     if (OBO->hasNoUnsignedWrap())
1685       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
1686   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
1687     if (PEO->isExact())
1688       Flags |= 1 << bitc::PEO_EXACT;
1689   } else if (const auto *PDI = dyn_cast<PossiblyDisjointInst>(V)) {
1690     if (PDI->isDisjoint())
1691       Flags |= 1 << bitc::PDI_DISJOINT;
1692   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
1693     if (FPMO->hasAllowReassoc())
1694       Flags |= bitc::AllowReassoc;
1695     if (FPMO->hasNoNaNs())
1696       Flags |= bitc::NoNaNs;
1697     if (FPMO->hasNoInfs())
1698       Flags |= bitc::NoInfs;
1699     if (FPMO->hasNoSignedZeros())
1700       Flags |= bitc::NoSignedZeros;
1701     if (FPMO->hasAllowReciprocal())
1702       Flags |= bitc::AllowReciprocal;
1703     if (FPMO->hasAllowContract())
1704       Flags |= bitc::AllowContract;
1705     if (FPMO->hasApproxFunc())
1706       Flags |= bitc::ApproxFunc;
1707   } else if (const auto *NNI = dyn_cast<PossiblyNonNegInst>(V)) {
1708     if (NNI->hasNonNeg())
1709       Flags |= 1 << bitc::PNNI_NON_NEG;
1710   } else if (const auto *TI = dyn_cast<TruncInst>(V)) {
1711     if (TI->hasNoSignedWrap())
1712       Flags |= 1 << bitc::TIO_NO_SIGNED_WRAP;
1713     if (TI->hasNoUnsignedWrap())
1714       Flags |= 1 << bitc::TIO_NO_UNSIGNED_WRAP;
1715   } else if (const auto *GEP = dyn_cast<GEPOperator>(V)) {
1716     if (GEP->isInBounds())
1717       Flags |= 1 << bitc::GEP_INBOUNDS;
1718     if (GEP->hasNoUnsignedSignedWrap())
1719       Flags |= 1 << bitc::GEP_NUSW;
1720     if (GEP->hasNoUnsignedWrap())
1721       Flags |= 1 << bitc::GEP_NUW;
1722   } else if (const auto *ICmp = dyn_cast<ICmpInst>(V)) {
1723     if (ICmp->hasSameSign())
1724       Flags |= 1 << bitc::ICMP_SAME_SIGN;
1725   }
1726 
1727   return Flags;
1728 }
1729 
1730 void ModuleBitcodeWriter::writeValueAsMetadata(
1731     const ValueAsMetadata *MD, SmallVectorImpl<uint64_t> &Record) {
1732   // Mimic an MDNode with a value as one operand.
1733   Value *V = MD->getValue();
1734   Record.push_back(VE.getTypeID(V->getType()));
1735   Record.push_back(VE.getValueID(V));
1736   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
1737   Record.clear();
1738 }
1739 
1740 void ModuleBitcodeWriter::writeMDTuple(const MDTuple *N,
1741                                        SmallVectorImpl<uint64_t> &Record,
1742                                        unsigned Abbrev) {
1743   for (const MDOperand &MDO : N->operands()) {
1744     Metadata *MD = MDO;
1745     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
1746            "Unexpected function-local metadata");
1747     Record.push_back(VE.getMetadataOrNullID(MD));
1748   }
1749   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
1750                                     : bitc::METADATA_NODE,
1751                     Record, Abbrev);
1752   Record.clear();
1753 }
1754 
1755 unsigned ModuleBitcodeWriter::createDILocationAbbrev() {
1756   // Assume the column is usually under 128, and always output the inlined-at
1757   // location (it's never more expensive than building an array size 1).
1758   auto Abbv = std::make_shared<BitCodeAbbrev>();
1759   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1760   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1761   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1762   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1763   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1764   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1765   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1766   return Stream.EmitAbbrev(std::move(Abbv));
1767 }
1768 
1769 void ModuleBitcodeWriter::writeDILocation(const DILocation *N,
1770                                           SmallVectorImpl<uint64_t> &Record,
1771                                           unsigned &Abbrev) {
1772   if (!Abbrev)
1773     Abbrev = createDILocationAbbrev();
1774 
1775   Record.push_back(N->isDistinct());
1776   Record.push_back(N->getLine());
1777   Record.push_back(N->getColumn());
1778   Record.push_back(VE.getMetadataID(N->getScope()));
1779   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
1780   Record.push_back(N->isImplicitCode());
1781 
1782   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
1783   Record.clear();
1784 }
1785 
1786 unsigned ModuleBitcodeWriter::createGenericDINodeAbbrev() {
1787   // Assume the column is usually under 128, and always output the inlined-at
1788   // location (it's never more expensive than building an array size 1).
1789   auto Abbv = std::make_shared<BitCodeAbbrev>();
1790   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1791   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1792   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1793   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1794   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1795   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1796   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1797   return Stream.EmitAbbrev(std::move(Abbv));
1798 }
1799 
1800 void ModuleBitcodeWriter::writeGenericDINode(const GenericDINode *N,
1801                                              SmallVectorImpl<uint64_t> &Record,
1802                                              unsigned &Abbrev) {
1803   if (!Abbrev)
1804     Abbrev = createGenericDINodeAbbrev();
1805 
1806   Record.push_back(N->isDistinct());
1807   Record.push_back(N->getTag());
1808   Record.push_back(0); // Per-tag version field; unused for now.
1809 
1810   for (auto &I : N->operands())
1811     Record.push_back(VE.getMetadataOrNullID(I));
1812 
1813   Stream.EmitRecord(bitc::METADATA_GENERIC_DEBUG, Record, Abbrev);
1814   Record.clear();
1815 }
1816 
1817 void ModuleBitcodeWriter::writeDISubrange(const DISubrange *N,
1818                                           SmallVectorImpl<uint64_t> &Record,
1819                                           unsigned Abbrev) {
1820   const uint64_t Version = 2 << 1;
1821   Record.push_back((uint64_t)N->isDistinct() | Version);
1822   Record.push_back(VE.getMetadataOrNullID(N->getRawCountNode()));
1823   Record.push_back(VE.getMetadataOrNullID(N->getRawLowerBound()));
1824   Record.push_back(VE.getMetadataOrNullID(N->getRawUpperBound()));
1825   Record.push_back(VE.getMetadataOrNullID(N->getRawStride()));
1826 
1827   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
1828   Record.clear();
1829 }
1830 
1831 void ModuleBitcodeWriter::writeDIGenericSubrange(
1832     const DIGenericSubrange *N, SmallVectorImpl<uint64_t> &Record,
1833     unsigned Abbrev) {
1834   Record.push_back((uint64_t)N->isDistinct());
1835   Record.push_back(VE.getMetadataOrNullID(N->getRawCountNode()));
1836   Record.push_back(VE.getMetadataOrNullID(N->getRawLowerBound()));
1837   Record.push_back(VE.getMetadataOrNullID(N->getRawUpperBound()));
1838   Record.push_back(VE.getMetadataOrNullID(N->getRawStride()));
1839 
1840   Stream.EmitRecord(bitc::METADATA_GENERIC_SUBRANGE, Record, Abbrev);
1841   Record.clear();
1842 }
1843 
1844 void ModuleBitcodeWriter::writeDIEnumerator(const DIEnumerator *N,
1845                                             SmallVectorImpl<uint64_t> &Record,
1846                                             unsigned Abbrev) {
1847   const uint64_t IsBigInt = 1 << 2;
1848   Record.push_back(IsBigInt | (N->isUnsigned() << 1) | N->isDistinct());
1849   Record.push_back(N->getValue().getBitWidth());
1850   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1851   emitWideAPInt(Record, N->getValue());
1852 
1853   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
1854   Record.clear();
1855 }
1856 
1857 void ModuleBitcodeWriter::writeDIBasicType(const DIBasicType *N,
1858                                            SmallVectorImpl<uint64_t> &Record,
1859                                            unsigned Abbrev) {
1860   Record.push_back(N->isDistinct());
1861   Record.push_back(N->getTag());
1862   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1863   Record.push_back(N->getSizeInBits());
1864   Record.push_back(N->getAlignInBits());
1865   Record.push_back(N->getEncoding());
1866   Record.push_back(N->getFlags());
1867   Record.push_back(N->getNumExtraInhabitants());
1868 
1869   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
1870   Record.clear();
1871 }
1872 
1873 void ModuleBitcodeWriter::writeDIStringType(const DIStringType *N,
1874                                             SmallVectorImpl<uint64_t> &Record,
1875                                             unsigned Abbrev) {
1876   Record.push_back(N->isDistinct());
1877   Record.push_back(N->getTag());
1878   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1879   Record.push_back(VE.getMetadataOrNullID(N->getStringLength()));
1880   Record.push_back(VE.getMetadataOrNullID(N->getStringLengthExp()));
1881   Record.push_back(VE.getMetadataOrNullID(N->getStringLocationExp()));
1882   Record.push_back(N->getSizeInBits());
1883   Record.push_back(N->getAlignInBits());
1884   Record.push_back(N->getEncoding());
1885 
1886   Stream.EmitRecord(bitc::METADATA_STRING_TYPE, Record, Abbrev);
1887   Record.clear();
1888 }
1889 
1890 void ModuleBitcodeWriter::writeDIDerivedType(const DIDerivedType *N,
1891                                              SmallVectorImpl<uint64_t> &Record,
1892                                              unsigned Abbrev) {
1893   Record.push_back(N->isDistinct());
1894   Record.push_back(N->getTag());
1895   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1896   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1897   Record.push_back(N->getLine());
1898   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1899   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1900   Record.push_back(N->getSizeInBits());
1901   Record.push_back(N->getAlignInBits());
1902   Record.push_back(N->getOffsetInBits());
1903   Record.push_back(N->getFlags());
1904   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
1905 
1906   // DWARF address space is encoded as N->getDWARFAddressSpace() + 1. 0 means
1907   // that there is no DWARF address space associated with DIDerivedType.
1908   if (const auto &DWARFAddressSpace = N->getDWARFAddressSpace())
1909     Record.push_back(*DWARFAddressSpace + 1);
1910   else
1911     Record.push_back(0);
1912 
1913   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
1914 
1915   if (auto PtrAuthData = N->getPtrAuthData())
1916     Record.push_back(PtrAuthData->RawData);
1917   else
1918     Record.push_back(0);
1919 
1920   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
1921   Record.clear();
1922 }
1923 
1924 void ModuleBitcodeWriter::writeDICompositeType(
1925     const DICompositeType *N, SmallVectorImpl<uint64_t> &Record,
1926     unsigned Abbrev) {
1927   const unsigned IsNotUsedInOldTypeRef = 0x2;
1928   Record.push_back(IsNotUsedInOldTypeRef | (unsigned)N->isDistinct());
1929   Record.push_back(N->getTag());
1930   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1931   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1932   Record.push_back(N->getLine());
1933   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1934   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1935   Record.push_back(N->getSizeInBits());
1936   Record.push_back(N->getAlignInBits());
1937   Record.push_back(N->getOffsetInBits());
1938   Record.push_back(N->getFlags());
1939   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1940   Record.push_back(N->getRuntimeLang());
1941   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
1942   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1943   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
1944   Record.push_back(VE.getMetadataOrNullID(N->getDiscriminator()));
1945   Record.push_back(VE.getMetadataOrNullID(N->getRawDataLocation()));
1946   Record.push_back(VE.getMetadataOrNullID(N->getRawAssociated()));
1947   Record.push_back(VE.getMetadataOrNullID(N->getRawAllocated()));
1948   Record.push_back(VE.getMetadataOrNullID(N->getRawRank()));
1949   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
1950   Record.push_back(N->getNumExtraInhabitants());
1951   Record.push_back(VE.getMetadataOrNullID(N->getRawSpecification()));
1952 
1953   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
1954   Record.clear();
1955 }
1956 
1957 void ModuleBitcodeWriter::writeDISubroutineType(
1958     const DISubroutineType *N, SmallVectorImpl<uint64_t> &Record,
1959     unsigned Abbrev) {
1960   const unsigned HasNoOldTypeRefs = 0x2;
1961   Record.push_back(HasNoOldTypeRefs | (unsigned)N->isDistinct());
1962   Record.push_back(N->getFlags());
1963   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
1964   Record.push_back(N->getCC());
1965 
1966   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
1967   Record.clear();
1968 }
1969 
1970 void ModuleBitcodeWriter::writeDIFile(const DIFile *N,
1971                                       SmallVectorImpl<uint64_t> &Record,
1972                                       unsigned Abbrev) {
1973   Record.push_back(N->isDistinct());
1974   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
1975   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
1976   if (N->getRawChecksum()) {
1977     Record.push_back(N->getRawChecksum()->Kind);
1978     Record.push_back(VE.getMetadataOrNullID(N->getRawChecksum()->Value));
1979   } else {
1980     // Maintain backwards compatibility with the old internal representation of
1981     // CSK_None in ChecksumKind by writing nulls here when Checksum is None.
1982     Record.push_back(0);
1983     Record.push_back(VE.getMetadataOrNullID(nullptr));
1984   }
1985   auto Source = N->getRawSource();
1986   if (Source)
1987     Record.push_back(VE.getMetadataOrNullID(Source));
1988 
1989   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
1990   Record.clear();
1991 }
1992 
1993 void ModuleBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
1994                                              SmallVectorImpl<uint64_t> &Record,
1995                                              unsigned Abbrev) {
1996   assert(N->isDistinct() && "Expected distinct compile units");
1997   Record.push_back(/* IsDistinct */ true);
1998   Record.push_back(N->getSourceLanguage());
1999   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2000   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
2001   Record.push_back(N->isOptimized());
2002   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
2003   Record.push_back(N->getRuntimeVersion());
2004   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
2005   Record.push_back(N->getEmissionKind());
2006   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
2007   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
2008   Record.push_back(/* subprograms */ 0);
2009   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
2010   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
2011   Record.push_back(N->getDWOId());
2012   Record.push_back(VE.getMetadataOrNullID(N->getMacros().get()));
2013   Record.push_back(N->getSplitDebugInlining());
2014   Record.push_back(N->getDebugInfoForProfiling());
2015   Record.push_back((unsigned)N->getNameTableKind());
2016   Record.push_back(N->getRangesBaseAddress());
2017   Record.push_back(VE.getMetadataOrNullID(N->getRawSysRoot()));
2018   Record.push_back(VE.getMetadataOrNullID(N->getRawSDK()));
2019 
2020   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
2021   Record.clear();
2022 }
2023 
2024 void ModuleBitcodeWriter::writeDISubprogram(const DISubprogram *N,
2025                                             SmallVectorImpl<uint64_t> &Record,
2026                                             unsigned Abbrev) {
2027   const uint64_t HasUnitFlag = 1 << 1;
2028   const uint64_t HasSPFlagsFlag = 1 << 2;
2029   Record.push_back(uint64_t(N->isDistinct()) | HasUnitFlag | HasSPFlagsFlag);
2030   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2031   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2032   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
2033   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2034   Record.push_back(N->getLine());
2035   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2036   Record.push_back(N->getScopeLine());
2037   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
2038   Record.push_back(N->getSPFlags());
2039   Record.push_back(N->getVirtualIndex());
2040   Record.push_back(N->getFlags());
2041   Record.push_back(VE.getMetadataOrNullID(N->getRawUnit()));
2042   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
2043   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
2044   Record.push_back(VE.getMetadataOrNullID(N->getRetainedNodes().get()));
2045   Record.push_back(N->getThisAdjustment());
2046   Record.push_back(VE.getMetadataOrNullID(N->getThrownTypes().get()));
2047   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
2048   Record.push_back(VE.getMetadataOrNullID(N->getRawTargetFuncName()));
2049 
2050   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
2051   Record.clear();
2052 }
2053 
2054 void ModuleBitcodeWriter::writeDILexicalBlock(const DILexicalBlock *N,
2055                                               SmallVectorImpl<uint64_t> &Record,
2056                                               unsigned Abbrev) {
2057   Record.push_back(N->isDistinct());
2058   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2059   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2060   Record.push_back(N->getLine());
2061   Record.push_back(N->getColumn());
2062 
2063   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
2064   Record.clear();
2065 }
2066 
2067 void ModuleBitcodeWriter::writeDILexicalBlockFile(
2068     const DILexicalBlockFile *N, SmallVectorImpl<uint64_t> &Record,
2069     unsigned Abbrev) {
2070   Record.push_back(N->isDistinct());
2071   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2072   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2073   Record.push_back(N->getDiscriminator());
2074 
2075   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
2076   Record.clear();
2077 }
2078 
2079 void ModuleBitcodeWriter::writeDICommonBlock(const DICommonBlock *N,
2080                                              SmallVectorImpl<uint64_t> &Record,
2081                                              unsigned Abbrev) {
2082   Record.push_back(N->isDistinct());
2083   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2084   Record.push_back(VE.getMetadataOrNullID(N->getDecl()));
2085   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2086   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2087   Record.push_back(N->getLineNo());
2088 
2089   Stream.EmitRecord(bitc::METADATA_COMMON_BLOCK, Record, Abbrev);
2090   Record.clear();
2091 }
2092 
2093 void ModuleBitcodeWriter::writeDINamespace(const DINamespace *N,
2094                                            SmallVectorImpl<uint64_t> &Record,
2095                                            unsigned Abbrev) {
2096   Record.push_back(N->isDistinct() | N->getExportSymbols() << 1);
2097   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2098   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2099 
2100   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
2101   Record.clear();
2102 }
2103 
2104 void ModuleBitcodeWriter::writeDIMacro(const DIMacro *N,
2105                                        SmallVectorImpl<uint64_t> &Record,
2106                                        unsigned Abbrev) {
2107   Record.push_back(N->isDistinct());
2108   Record.push_back(N->getMacinfoType());
2109   Record.push_back(N->getLine());
2110   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2111   Record.push_back(VE.getMetadataOrNullID(N->getRawValue()));
2112 
2113   Stream.EmitRecord(bitc::METADATA_MACRO, Record, Abbrev);
2114   Record.clear();
2115 }
2116 
2117 void ModuleBitcodeWriter::writeDIMacroFile(const DIMacroFile *N,
2118                                            SmallVectorImpl<uint64_t> &Record,
2119                                            unsigned Abbrev) {
2120   Record.push_back(N->isDistinct());
2121   Record.push_back(N->getMacinfoType());
2122   Record.push_back(N->getLine());
2123   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2124   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
2125 
2126   Stream.EmitRecord(bitc::METADATA_MACRO_FILE, Record, Abbrev);
2127   Record.clear();
2128 }
2129 
2130 void ModuleBitcodeWriter::writeDIArgList(const DIArgList *N,
2131                                          SmallVectorImpl<uint64_t> &Record) {
2132   Record.reserve(N->getArgs().size());
2133   for (ValueAsMetadata *MD : N->getArgs())
2134     Record.push_back(VE.getMetadataID(MD));
2135 
2136   Stream.EmitRecord(bitc::METADATA_ARG_LIST, Record);
2137   Record.clear();
2138 }
2139 
2140 void ModuleBitcodeWriter::writeDIModule(const DIModule *N,
2141                                         SmallVectorImpl<uint64_t> &Record,
2142                                         unsigned Abbrev) {
2143   Record.push_back(N->isDistinct());
2144   for (auto &I : N->operands())
2145     Record.push_back(VE.getMetadataOrNullID(I));
2146   Record.push_back(N->getLineNo());
2147   Record.push_back(N->getIsDecl());
2148 
2149   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
2150   Record.clear();
2151 }
2152 
2153 void ModuleBitcodeWriter::writeDIAssignID(const DIAssignID *N,
2154                                           SmallVectorImpl<uint64_t> &Record,
2155                                           unsigned Abbrev) {
2156   // There are no arguments for this metadata type.
2157   Record.push_back(N->isDistinct());
2158   Stream.EmitRecord(bitc::METADATA_ASSIGN_ID, Record, Abbrev);
2159   Record.clear();
2160 }
2161 
2162 void ModuleBitcodeWriter::writeDITemplateTypeParameter(
2163     const DITemplateTypeParameter *N, SmallVectorImpl<uint64_t> &Record,
2164     unsigned Abbrev) {
2165   Record.push_back(N->isDistinct());
2166   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2167   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2168   Record.push_back(N->isDefault());
2169 
2170   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
2171   Record.clear();
2172 }
2173 
2174 void ModuleBitcodeWriter::writeDITemplateValueParameter(
2175     const DITemplateValueParameter *N, SmallVectorImpl<uint64_t> &Record,
2176     unsigned Abbrev) {
2177   Record.push_back(N->isDistinct());
2178   Record.push_back(N->getTag());
2179   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2180   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2181   Record.push_back(N->isDefault());
2182   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
2183 
2184   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
2185   Record.clear();
2186 }
2187 
2188 void ModuleBitcodeWriter::writeDIGlobalVariable(
2189     const DIGlobalVariable *N, SmallVectorImpl<uint64_t> &Record,
2190     unsigned Abbrev) {
2191   const uint64_t Version = 2 << 1;
2192   Record.push_back((uint64_t)N->isDistinct() | Version);
2193   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2194   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2195   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
2196   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2197   Record.push_back(N->getLine());
2198   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2199   Record.push_back(N->isLocalToUnit());
2200   Record.push_back(N->isDefinition());
2201   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
2202   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams()));
2203   Record.push_back(N->getAlignInBits());
2204   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
2205 
2206   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
2207   Record.clear();
2208 }
2209 
2210 void ModuleBitcodeWriter::writeDILocalVariable(
2211     const DILocalVariable *N, SmallVectorImpl<uint64_t> &Record,
2212     unsigned Abbrev) {
2213   // In order to support all possible bitcode formats in BitcodeReader we need
2214   // to distinguish the following cases:
2215   // 1) Record has no artificial tag (Record[1]),
2216   //   has no obsolete inlinedAt field (Record[9]).
2217   //   In this case Record size will be 8, HasAlignment flag is false.
2218   // 2) Record has artificial tag (Record[1]),
2219   //   has no obsolete inlignedAt field (Record[9]).
2220   //   In this case Record size will be 9, HasAlignment flag is false.
2221   // 3) Record has both artificial tag (Record[1]) and
2222   //   obsolete inlignedAt field (Record[9]).
2223   //   In this case Record size will be 10, HasAlignment flag is false.
2224   // 4) Record has neither artificial tag, nor inlignedAt field, but
2225   //   HasAlignment flag is true and Record[8] contains alignment value.
2226   const uint64_t HasAlignmentFlag = 1 << 1;
2227   Record.push_back((uint64_t)N->isDistinct() | HasAlignmentFlag);
2228   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2229   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2230   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2231   Record.push_back(N->getLine());
2232   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2233   Record.push_back(N->getArg());
2234   Record.push_back(N->getFlags());
2235   Record.push_back(N->getAlignInBits());
2236   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
2237 
2238   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
2239   Record.clear();
2240 }
2241 
2242 void ModuleBitcodeWriter::writeDILabel(
2243     const DILabel *N, SmallVectorImpl<uint64_t> &Record,
2244     unsigned Abbrev) {
2245   Record.push_back((uint64_t)N->isDistinct());
2246   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2247   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2248   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2249   Record.push_back(N->getLine());
2250 
2251   Stream.EmitRecord(bitc::METADATA_LABEL, Record, Abbrev);
2252   Record.clear();
2253 }
2254 
2255 void ModuleBitcodeWriter::writeDIExpression(const DIExpression *N,
2256                                             SmallVectorImpl<uint64_t> &Record,
2257                                             unsigned Abbrev) {
2258   Record.reserve(N->getElements().size() + 1);
2259   const uint64_t Version = 3 << 1;
2260   Record.push_back((uint64_t)N->isDistinct() | Version);
2261   Record.append(N->elements_begin(), N->elements_end());
2262 
2263   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
2264   Record.clear();
2265 }
2266 
2267 void ModuleBitcodeWriter::writeDIGlobalVariableExpression(
2268     const DIGlobalVariableExpression *N, SmallVectorImpl<uint64_t> &Record,
2269     unsigned Abbrev) {
2270   Record.push_back(N->isDistinct());
2271   Record.push_back(VE.getMetadataOrNullID(N->getVariable()));
2272   Record.push_back(VE.getMetadataOrNullID(N->getExpression()));
2273 
2274   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR_EXPR, Record, Abbrev);
2275   Record.clear();
2276 }
2277 
2278 void ModuleBitcodeWriter::writeDIObjCProperty(const DIObjCProperty *N,
2279                                               SmallVectorImpl<uint64_t> &Record,
2280                                               unsigned Abbrev) {
2281   Record.push_back(N->isDistinct());
2282   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2283   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2284   Record.push_back(N->getLine());
2285   Record.push_back(VE.getMetadataOrNullID(N->getRawSetterName()));
2286   Record.push_back(VE.getMetadataOrNullID(N->getRawGetterName()));
2287   Record.push_back(N->getAttributes());
2288   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2289 
2290   Stream.EmitRecord(bitc::METADATA_OBJC_PROPERTY, Record, Abbrev);
2291   Record.clear();
2292 }
2293 
2294 void ModuleBitcodeWriter::writeDIImportedEntity(
2295     const DIImportedEntity *N, SmallVectorImpl<uint64_t> &Record,
2296     unsigned Abbrev) {
2297   Record.push_back(N->isDistinct());
2298   Record.push_back(N->getTag());
2299   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2300   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
2301   Record.push_back(N->getLine());
2302   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2303   Record.push_back(VE.getMetadataOrNullID(N->getRawFile()));
2304   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
2305 
2306   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
2307   Record.clear();
2308 }
2309 
2310 unsigned ModuleBitcodeWriter::createNamedMetadataAbbrev() {
2311   auto Abbv = std::make_shared<BitCodeAbbrev>();
2312   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
2313   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2314   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2315   return Stream.EmitAbbrev(std::move(Abbv));
2316 }
2317 
2318 void ModuleBitcodeWriter::writeNamedMetadata(
2319     SmallVectorImpl<uint64_t> &Record) {
2320   if (M.named_metadata_empty())
2321     return;
2322 
2323   unsigned Abbrev = createNamedMetadataAbbrev();
2324   for (const NamedMDNode &NMD : M.named_metadata()) {
2325     // Write name.
2326     StringRef Str = NMD.getName();
2327     Record.append(Str.bytes_begin(), Str.bytes_end());
2328     Stream.EmitRecord(bitc::METADATA_NAME, Record, Abbrev);
2329     Record.clear();
2330 
2331     // Write named metadata operands.
2332     for (const MDNode *N : NMD.operands())
2333       Record.push_back(VE.getMetadataID(N));
2334     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
2335     Record.clear();
2336   }
2337 }
2338 
2339 unsigned ModuleBitcodeWriter::createMetadataStringsAbbrev() {
2340   auto Abbv = std::make_shared<BitCodeAbbrev>();
2341   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRINGS));
2342   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of strings
2343   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // offset to chars
2344   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2345   return Stream.EmitAbbrev(std::move(Abbv));
2346 }
2347 
2348 /// Write out a record for MDString.
2349 ///
2350 /// All the metadata strings in a metadata block are emitted in a single
2351 /// record.  The sizes and strings themselves are shoved into a blob.
2352 void ModuleBitcodeWriter::writeMetadataStrings(
2353     ArrayRef<const Metadata *> Strings, SmallVectorImpl<uint64_t> &Record) {
2354   if (Strings.empty())
2355     return;
2356 
2357   // Start the record with the number of strings.
2358   Record.push_back(bitc::METADATA_STRINGS);
2359   Record.push_back(Strings.size());
2360 
2361   // Emit the sizes of the strings in the blob.
2362   SmallString<256> Blob;
2363   {
2364     BitstreamWriter W(Blob);
2365     for (const Metadata *MD : Strings)
2366       W.EmitVBR(cast<MDString>(MD)->getLength(), 6);
2367     W.FlushToWord();
2368   }
2369 
2370   // Add the offset to the strings to the record.
2371   Record.push_back(Blob.size());
2372 
2373   // Add the strings to the blob.
2374   for (const Metadata *MD : Strings)
2375     Blob.append(cast<MDString>(MD)->getString());
2376 
2377   // Emit the final record.
2378   Stream.EmitRecordWithBlob(createMetadataStringsAbbrev(), Record, Blob);
2379   Record.clear();
2380 }
2381 
2382 // Generates an enum to use as an index in the Abbrev array of Metadata record.
2383 enum MetadataAbbrev : unsigned {
2384 #define HANDLE_MDNODE_LEAF(CLASS) CLASS##AbbrevID,
2385 #include "llvm/IR/Metadata.def"
2386   LastPlusOne
2387 };
2388 
2389 void ModuleBitcodeWriter::writeMetadataRecords(
2390     ArrayRef<const Metadata *> MDs, SmallVectorImpl<uint64_t> &Record,
2391     std::vector<unsigned> *MDAbbrevs, std::vector<uint64_t> *IndexPos) {
2392   if (MDs.empty())
2393     return;
2394 
2395   // Initialize MDNode abbreviations.
2396 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
2397 #include "llvm/IR/Metadata.def"
2398 
2399   for (const Metadata *MD : MDs) {
2400     if (IndexPos)
2401       IndexPos->push_back(Stream.GetCurrentBitNo());
2402     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
2403       assert(N->isResolved() && "Expected forward references to be resolved");
2404 
2405       switch (N->getMetadataID()) {
2406       default:
2407         llvm_unreachable("Invalid MDNode subclass");
2408 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
2409   case Metadata::CLASS##Kind:                                                  \
2410     if (MDAbbrevs)                                                             \
2411       write##CLASS(cast<CLASS>(N), Record,                                     \
2412                    (*MDAbbrevs)[MetadataAbbrev::CLASS##AbbrevID]);             \
2413     else                                                                       \
2414       write##CLASS(cast<CLASS>(N), Record, CLASS##Abbrev);                     \
2415     continue;
2416 #include "llvm/IR/Metadata.def"
2417       }
2418     }
2419     if (auto *AL = dyn_cast<DIArgList>(MD)) {
2420       writeDIArgList(AL, Record);
2421       continue;
2422     }
2423     writeValueAsMetadata(cast<ValueAsMetadata>(MD), Record);
2424   }
2425 }
2426 
2427 void ModuleBitcodeWriter::writeModuleMetadata() {
2428   if (!VE.hasMDs() && M.named_metadata_empty())
2429     return;
2430 
2431   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 4);
2432   SmallVector<uint64_t, 64> Record;
2433 
2434   // Emit all abbrevs upfront, so that the reader can jump in the middle of the
2435   // block and load any metadata.
2436   std::vector<unsigned> MDAbbrevs;
2437 
2438   MDAbbrevs.resize(MetadataAbbrev::LastPlusOne);
2439   MDAbbrevs[MetadataAbbrev::DILocationAbbrevID] = createDILocationAbbrev();
2440   MDAbbrevs[MetadataAbbrev::GenericDINodeAbbrevID] =
2441       createGenericDINodeAbbrev();
2442 
2443   auto Abbv = std::make_shared<BitCodeAbbrev>();
2444   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_INDEX_OFFSET));
2445   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2446   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2447   unsigned OffsetAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2448 
2449   Abbv = std::make_shared<BitCodeAbbrev>();
2450   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_INDEX));
2451   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2452   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2453   unsigned IndexAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2454 
2455   // Emit MDStrings together upfront.
2456   writeMetadataStrings(VE.getMDStrings(), Record);
2457 
2458   // We only emit an index for the metadata record if we have more than a given
2459   // (naive) threshold of metadatas, otherwise it is not worth it.
2460   if (VE.getNonMDStrings().size() > IndexThreshold) {
2461     // Write a placeholder value in for the offset of the metadata index,
2462     // which is written after the records, so that it can include
2463     // the offset of each entry. The placeholder offset will be
2464     // updated after all records are emitted.
2465     uint64_t Vals[] = {0, 0};
2466     Stream.EmitRecord(bitc::METADATA_INDEX_OFFSET, Vals, OffsetAbbrev);
2467   }
2468 
2469   // Compute and save the bit offset to the current position, which will be
2470   // patched when we emit the index later. We can simply subtract the 64-bit
2471   // fixed size from the current bit number to get the location to backpatch.
2472   uint64_t IndexOffsetRecordBitPos = Stream.GetCurrentBitNo();
2473 
2474   // This index will contain the bitpos for each individual record.
2475   std::vector<uint64_t> IndexPos;
2476   IndexPos.reserve(VE.getNonMDStrings().size());
2477 
2478   // Write all the records
2479   writeMetadataRecords(VE.getNonMDStrings(), Record, &MDAbbrevs, &IndexPos);
2480 
2481   if (VE.getNonMDStrings().size() > IndexThreshold) {
2482     // Now that we have emitted all the records we will emit the index. But
2483     // first
2484     // backpatch the forward reference so that the reader can skip the records
2485     // efficiently.
2486     Stream.BackpatchWord64(IndexOffsetRecordBitPos - 64,
2487                            Stream.GetCurrentBitNo() - IndexOffsetRecordBitPos);
2488 
2489     // Delta encode the index.
2490     uint64_t PreviousValue = IndexOffsetRecordBitPos;
2491     for (auto &Elt : IndexPos) {
2492       auto EltDelta = Elt - PreviousValue;
2493       PreviousValue = Elt;
2494       Elt = EltDelta;
2495     }
2496     // Emit the index record.
2497     Stream.EmitRecord(bitc::METADATA_INDEX, IndexPos, IndexAbbrev);
2498     IndexPos.clear();
2499   }
2500 
2501   // Write the named metadata now.
2502   writeNamedMetadata(Record);
2503 
2504   auto AddDeclAttachedMetadata = [&](const GlobalObject &GO) {
2505     SmallVector<uint64_t, 4> Record;
2506     Record.push_back(VE.getValueID(&GO));
2507     pushGlobalMetadataAttachment(Record, GO);
2508     Stream.EmitRecord(bitc::METADATA_GLOBAL_DECL_ATTACHMENT, Record);
2509   };
2510   for (const Function &F : M)
2511     if (F.isDeclaration() && F.hasMetadata())
2512       AddDeclAttachedMetadata(F);
2513   // FIXME: Only store metadata for declarations here, and move data for global
2514   // variable definitions to a separate block (PR28134).
2515   for (const GlobalVariable &GV : M.globals())
2516     if (GV.hasMetadata())
2517       AddDeclAttachedMetadata(GV);
2518 
2519   Stream.ExitBlock();
2520 }
2521 
2522 void ModuleBitcodeWriter::writeFunctionMetadata(const Function &F) {
2523   if (!VE.hasMDs())
2524     return;
2525 
2526   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
2527   SmallVector<uint64_t, 64> Record;
2528   writeMetadataStrings(VE.getMDStrings(), Record);
2529   writeMetadataRecords(VE.getNonMDStrings(), Record);
2530   Stream.ExitBlock();
2531 }
2532 
2533 void ModuleBitcodeWriter::pushGlobalMetadataAttachment(
2534     SmallVectorImpl<uint64_t> &Record, const GlobalObject &GO) {
2535   // [n x [id, mdnode]]
2536   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
2537   GO.getAllMetadata(MDs);
2538   for (const auto &I : MDs) {
2539     Record.push_back(I.first);
2540     Record.push_back(VE.getMetadataID(I.second));
2541   }
2542 }
2543 
2544 void ModuleBitcodeWriter::writeFunctionMetadataAttachment(const Function &F) {
2545   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
2546 
2547   SmallVector<uint64_t, 64> Record;
2548 
2549   if (F.hasMetadata()) {
2550     pushGlobalMetadataAttachment(Record, F);
2551     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
2552     Record.clear();
2553   }
2554 
2555   // Write metadata attachments
2556   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
2557   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
2558   for (const BasicBlock &BB : F)
2559     for (const Instruction &I : BB) {
2560       MDs.clear();
2561       I.getAllMetadataOtherThanDebugLoc(MDs);
2562 
2563       // If no metadata, ignore instruction.
2564       if (MDs.empty()) continue;
2565 
2566       Record.push_back(VE.getInstructionID(&I));
2567 
2568       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
2569         Record.push_back(MDs[i].first);
2570         Record.push_back(VE.getMetadataID(MDs[i].second));
2571       }
2572       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
2573       Record.clear();
2574     }
2575 
2576   Stream.ExitBlock();
2577 }
2578 
2579 void ModuleBitcodeWriter::writeModuleMetadataKinds() {
2580   SmallVector<uint64_t, 64> Record;
2581 
2582   // Write metadata kinds
2583   // METADATA_KIND - [n x [id, name]]
2584   SmallVector<StringRef, 8> Names;
2585   M.getMDKindNames(Names);
2586 
2587   if (Names.empty()) return;
2588 
2589   Stream.EnterSubblock(bitc::METADATA_KIND_BLOCK_ID, 3);
2590 
2591   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
2592     Record.push_back(MDKindID);
2593     StringRef KName = Names[MDKindID];
2594     Record.append(KName.begin(), KName.end());
2595 
2596     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
2597     Record.clear();
2598   }
2599 
2600   Stream.ExitBlock();
2601 }
2602 
2603 void ModuleBitcodeWriter::writeOperandBundleTags() {
2604   // Write metadata kinds
2605   //
2606   // OPERAND_BUNDLE_TAGS_BLOCK_ID : N x OPERAND_BUNDLE_TAG
2607   //
2608   // OPERAND_BUNDLE_TAG - [strchr x N]
2609 
2610   SmallVector<StringRef, 8> Tags;
2611   M.getOperandBundleTags(Tags);
2612 
2613   if (Tags.empty())
2614     return;
2615 
2616   Stream.EnterSubblock(bitc::OPERAND_BUNDLE_TAGS_BLOCK_ID, 3);
2617 
2618   SmallVector<uint64_t, 64> Record;
2619 
2620   for (auto Tag : Tags) {
2621     Record.append(Tag.begin(), Tag.end());
2622 
2623     Stream.EmitRecord(bitc::OPERAND_BUNDLE_TAG, Record, 0);
2624     Record.clear();
2625   }
2626 
2627   Stream.ExitBlock();
2628 }
2629 
2630 void ModuleBitcodeWriter::writeSyncScopeNames() {
2631   SmallVector<StringRef, 8> SSNs;
2632   M.getContext().getSyncScopeNames(SSNs);
2633   if (SSNs.empty())
2634     return;
2635 
2636   Stream.EnterSubblock(bitc::SYNC_SCOPE_NAMES_BLOCK_ID, 2);
2637 
2638   SmallVector<uint64_t, 64> Record;
2639   for (auto SSN : SSNs) {
2640     Record.append(SSN.begin(), SSN.end());
2641     Stream.EmitRecord(bitc::SYNC_SCOPE_NAME, Record, 0);
2642     Record.clear();
2643   }
2644 
2645   Stream.ExitBlock();
2646 }
2647 
2648 void ModuleBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
2649                                          bool isGlobal) {
2650   if (FirstVal == LastVal) return;
2651 
2652   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
2653 
2654   unsigned AggregateAbbrev = 0;
2655   unsigned String8Abbrev = 0;
2656   unsigned CString7Abbrev = 0;
2657   unsigned CString6Abbrev = 0;
2658   // If this is a constant pool for the module, emit module-specific abbrevs.
2659   if (isGlobal) {
2660     // Abbrev for CST_CODE_AGGREGATE.
2661     auto Abbv = std::make_shared<BitCodeAbbrev>();
2662     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
2663     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2664     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
2665     AggregateAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2666 
2667     // Abbrev for CST_CODE_STRING.
2668     Abbv = std::make_shared<BitCodeAbbrev>();
2669     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
2670     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2671     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2672     String8Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2673     // Abbrev for CST_CODE_CSTRING.
2674     Abbv = std::make_shared<BitCodeAbbrev>();
2675     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
2676     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2677     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2678     CString7Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2679     // Abbrev for CST_CODE_CSTRING.
2680     Abbv = std::make_shared<BitCodeAbbrev>();
2681     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
2682     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2683     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2684     CString6Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2685   }
2686 
2687   SmallVector<uint64_t, 64> Record;
2688 
2689   const ValueEnumerator::ValueList &Vals = VE.getValues();
2690   Type *LastTy = nullptr;
2691   for (unsigned i = FirstVal; i != LastVal; ++i) {
2692     const Value *V = Vals[i].first;
2693     // If we need to switch types, do so now.
2694     if (V->getType() != LastTy) {
2695       LastTy = V->getType();
2696       Record.push_back(VE.getTypeID(LastTy));
2697       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
2698                         CONSTANTS_SETTYPE_ABBREV);
2699       Record.clear();
2700     }
2701 
2702     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
2703       Record.push_back(VE.getTypeID(IA->getFunctionType()));
2704       Record.push_back(
2705           unsigned(IA->hasSideEffects()) | unsigned(IA->isAlignStack()) << 1 |
2706           unsigned(IA->getDialect() & 1) << 2 | unsigned(IA->canThrow()) << 3);
2707 
2708       // Add the asm string.
2709       const std::string &AsmStr = IA->getAsmString();
2710       Record.push_back(AsmStr.size());
2711       Record.append(AsmStr.begin(), AsmStr.end());
2712 
2713       // Add the constraint string.
2714       const std::string &ConstraintStr = IA->getConstraintString();
2715       Record.push_back(ConstraintStr.size());
2716       Record.append(ConstraintStr.begin(), ConstraintStr.end());
2717       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
2718       Record.clear();
2719       continue;
2720     }
2721     const Constant *C = cast<Constant>(V);
2722     unsigned Code = -1U;
2723     unsigned AbbrevToUse = 0;
2724     if (C->isNullValue()) {
2725       Code = bitc::CST_CODE_NULL;
2726     } else if (isa<PoisonValue>(C)) {
2727       Code = bitc::CST_CODE_POISON;
2728     } else if (isa<UndefValue>(C)) {
2729       Code = bitc::CST_CODE_UNDEF;
2730     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
2731       if (IV->getBitWidth() <= 64) {
2732         uint64_t V = IV->getSExtValue();
2733         emitSignedInt64(Record, V);
2734         Code = bitc::CST_CODE_INTEGER;
2735         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
2736       } else {                             // Wide integers, > 64 bits in size.
2737         emitWideAPInt(Record, IV->getValue());
2738         Code = bitc::CST_CODE_WIDE_INTEGER;
2739       }
2740     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
2741       Code = bitc::CST_CODE_FLOAT;
2742       Type *Ty = CFP->getType()->getScalarType();
2743       if (Ty->isHalfTy() || Ty->isBFloatTy() || Ty->isFloatTy() ||
2744           Ty->isDoubleTy()) {
2745         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
2746       } else if (Ty->isX86_FP80Ty()) {
2747         // api needed to prevent premature destruction
2748         // bits are not in the same order as a normal i80 APInt, compensate.
2749         APInt api = CFP->getValueAPF().bitcastToAPInt();
2750         const uint64_t *p = api.getRawData();
2751         Record.push_back((p[1] << 48) | (p[0] >> 16));
2752         Record.push_back(p[0] & 0xffffLL);
2753       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
2754         APInt api = CFP->getValueAPF().bitcastToAPInt();
2755         const uint64_t *p = api.getRawData();
2756         Record.push_back(p[0]);
2757         Record.push_back(p[1]);
2758       } else {
2759         assert(0 && "Unknown FP type!");
2760       }
2761     } else if (isa<ConstantDataSequential>(C) &&
2762                cast<ConstantDataSequential>(C)->isString()) {
2763       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
2764       // Emit constant strings specially.
2765       unsigned NumElts = Str->getNumElements();
2766       // If this is a null-terminated string, use the denser CSTRING encoding.
2767       if (Str->isCString()) {
2768         Code = bitc::CST_CODE_CSTRING;
2769         --NumElts;  // Don't encode the null, which isn't allowed by char6.
2770       } else {
2771         Code = bitc::CST_CODE_STRING;
2772         AbbrevToUse = String8Abbrev;
2773       }
2774       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
2775       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
2776       for (unsigned i = 0; i != NumElts; ++i) {
2777         unsigned char V = Str->getElementAsInteger(i);
2778         Record.push_back(V);
2779         isCStr7 &= (V & 128) == 0;
2780         if (isCStrChar6)
2781           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
2782       }
2783 
2784       if (isCStrChar6)
2785         AbbrevToUse = CString6Abbrev;
2786       else if (isCStr7)
2787         AbbrevToUse = CString7Abbrev;
2788     } else if (const ConstantDataSequential *CDS =
2789                   dyn_cast<ConstantDataSequential>(C)) {
2790       Code = bitc::CST_CODE_DATA;
2791       Type *EltTy = CDS->getElementType();
2792       if (isa<IntegerType>(EltTy)) {
2793         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2794           Record.push_back(CDS->getElementAsInteger(i));
2795       } else {
2796         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2797           Record.push_back(
2798               CDS->getElementAsAPFloat(i).bitcastToAPInt().getLimitedValue());
2799       }
2800     } else if (isa<ConstantAggregate>(C)) {
2801       Code = bitc::CST_CODE_AGGREGATE;
2802       for (const Value *Op : C->operands())
2803         Record.push_back(VE.getValueID(Op));
2804       AbbrevToUse = AggregateAbbrev;
2805     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
2806       switch (CE->getOpcode()) {
2807       default:
2808         if (Instruction::isCast(CE->getOpcode())) {
2809           Code = bitc::CST_CODE_CE_CAST;
2810           Record.push_back(getEncodedCastOpcode(CE->getOpcode()));
2811           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2812           Record.push_back(VE.getValueID(C->getOperand(0)));
2813           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
2814         } else {
2815           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
2816           Code = bitc::CST_CODE_CE_BINOP;
2817           Record.push_back(getEncodedBinaryOpcode(CE->getOpcode()));
2818           Record.push_back(VE.getValueID(C->getOperand(0)));
2819           Record.push_back(VE.getValueID(C->getOperand(1)));
2820           uint64_t Flags = getOptimizationFlags(CE);
2821           if (Flags != 0)
2822             Record.push_back(Flags);
2823         }
2824         break;
2825       case Instruction::FNeg: {
2826         assert(CE->getNumOperands() == 1 && "Unknown constant expr!");
2827         Code = bitc::CST_CODE_CE_UNOP;
2828         Record.push_back(getEncodedUnaryOpcode(CE->getOpcode()));
2829         Record.push_back(VE.getValueID(C->getOperand(0)));
2830         uint64_t Flags = getOptimizationFlags(CE);
2831         if (Flags != 0)
2832           Record.push_back(Flags);
2833         break;
2834       }
2835       case Instruction::GetElementPtr: {
2836         Code = bitc::CST_CODE_CE_GEP;
2837         const auto *GO = cast<GEPOperator>(C);
2838         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
2839         Record.push_back(getOptimizationFlags(GO));
2840         if (std::optional<ConstantRange> Range = GO->getInRange()) {
2841           Code = bitc::CST_CODE_CE_GEP_WITH_INRANGE;
2842           emitConstantRange(Record, *Range, /*EmitBitWidth=*/true);
2843         }
2844         for (const Value *Op : CE->operands()) {
2845           Record.push_back(VE.getTypeID(Op->getType()));
2846           Record.push_back(VE.getValueID(Op));
2847         }
2848         break;
2849       }
2850       case Instruction::ExtractElement:
2851         Code = bitc::CST_CODE_CE_EXTRACTELT;
2852         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2853         Record.push_back(VE.getValueID(C->getOperand(0)));
2854         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
2855         Record.push_back(VE.getValueID(C->getOperand(1)));
2856         break;
2857       case Instruction::InsertElement:
2858         Code = bitc::CST_CODE_CE_INSERTELT;
2859         Record.push_back(VE.getValueID(C->getOperand(0)));
2860         Record.push_back(VE.getValueID(C->getOperand(1)));
2861         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
2862         Record.push_back(VE.getValueID(C->getOperand(2)));
2863         break;
2864       case Instruction::ShuffleVector:
2865         // If the return type and argument types are the same, this is a
2866         // standard shufflevector instruction.  If the types are different,
2867         // then the shuffle is widening or truncating the input vectors, and
2868         // the argument type must also be encoded.
2869         if (C->getType() == C->getOperand(0)->getType()) {
2870           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
2871         } else {
2872           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
2873           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2874         }
2875         Record.push_back(VE.getValueID(C->getOperand(0)));
2876         Record.push_back(VE.getValueID(C->getOperand(1)));
2877         Record.push_back(VE.getValueID(CE->getShuffleMaskForBitcode()));
2878         break;
2879       }
2880     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
2881       Code = bitc::CST_CODE_BLOCKADDRESS;
2882       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
2883       Record.push_back(VE.getValueID(BA->getFunction()));
2884       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
2885     } else if (const auto *Equiv = dyn_cast<DSOLocalEquivalent>(C)) {
2886       Code = bitc::CST_CODE_DSO_LOCAL_EQUIVALENT;
2887       Record.push_back(VE.getTypeID(Equiv->getGlobalValue()->getType()));
2888       Record.push_back(VE.getValueID(Equiv->getGlobalValue()));
2889     } else if (const auto *NC = dyn_cast<NoCFIValue>(C)) {
2890       Code = bitc::CST_CODE_NO_CFI_VALUE;
2891       Record.push_back(VE.getTypeID(NC->getGlobalValue()->getType()));
2892       Record.push_back(VE.getValueID(NC->getGlobalValue()));
2893     } else if (const auto *CPA = dyn_cast<ConstantPtrAuth>(C)) {
2894       Code = bitc::CST_CODE_PTRAUTH;
2895       Record.push_back(VE.getValueID(CPA->getPointer()));
2896       Record.push_back(VE.getValueID(CPA->getKey()));
2897       Record.push_back(VE.getValueID(CPA->getDiscriminator()));
2898       Record.push_back(VE.getValueID(CPA->getAddrDiscriminator()));
2899     } else {
2900 #ifndef NDEBUG
2901       C->dump();
2902 #endif
2903       llvm_unreachable("Unknown constant!");
2904     }
2905     Stream.EmitRecord(Code, Record, AbbrevToUse);
2906     Record.clear();
2907   }
2908 
2909   Stream.ExitBlock();
2910 }
2911 
2912 void ModuleBitcodeWriter::writeModuleConstants() {
2913   const ValueEnumerator::ValueList &Vals = VE.getValues();
2914 
2915   // Find the first constant to emit, which is the first non-globalvalue value.
2916   // We know globalvalues have been emitted by WriteModuleInfo.
2917   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
2918     if (!isa<GlobalValue>(Vals[i].first)) {
2919       writeConstants(i, Vals.size(), true);
2920       return;
2921     }
2922   }
2923 }
2924 
2925 /// pushValueAndType - The file has to encode both the value and type id for
2926 /// many values, because we need to know what type to create for forward
2927 /// references.  However, most operands are not forward references, so this type
2928 /// field is not needed.
2929 ///
2930 /// This function adds V's value ID to Vals.  If the value ID is higher than the
2931 /// instruction ID, then it is a forward reference, and it also includes the
2932 /// type ID.  The value ID that is written is encoded relative to the InstID.
2933 bool ModuleBitcodeWriter::pushValueAndType(const Value *V, unsigned InstID,
2934                                            SmallVectorImpl<unsigned> &Vals) {
2935   unsigned ValID = VE.getValueID(V);
2936   // Make encoding relative to the InstID.
2937   Vals.push_back(InstID - ValID);
2938   if (ValID >= InstID) {
2939     Vals.push_back(VE.getTypeID(V->getType()));
2940     return true;
2941   }
2942   return false;
2943 }
2944 
2945 bool ModuleBitcodeWriter::pushValueOrMetadata(const Value *V, unsigned InstID,
2946                                               SmallVectorImpl<unsigned> &Vals) {
2947   bool IsMetadata = V->getType()->isMetadataTy();
2948   if (IsMetadata) {
2949     Vals.push_back(bitc::OB_METADATA);
2950     Metadata *MD = cast<MetadataAsValue>(V)->getMetadata();
2951     unsigned ValID = VE.getMetadataID(MD);
2952     Vals.push_back(InstID - ValID);
2953     return false;
2954   }
2955   return pushValueAndType(V, InstID, Vals);
2956 }
2957 
2958 void ModuleBitcodeWriter::writeOperandBundles(const CallBase &CS,
2959                                               unsigned InstID) {
2960   SmallVector<unsigned, 64> Record;
2961   LLVMContext &C = CS.getContext();
2962 
2963   for (unsigned i = 0, e = CS.getNumOperandBundles(); i != e; ++i) {
2964     const auto &Bundle = CS.getOperandBundleAt(i);
2965     Record.push_back(C.getOperandBundleTagID(Bundle.getTagName()));
2966 
2967     for (auto &Input : Bundle.Inputs)
2968       pushValueOrMetadata(Input, InstID, Record);
2969 
2970     Stream.EmitRecord(bitc::FUNC_CODE_OPERAND_BUNDLE, Record);
2971     Record.clear();
2972   }
2973 }
2974 
2975 /// pushValue - Like pushValueAndType, but where the type of the value is
2976 /// omitted (perhaps it was already encoded in an earlier operand).
2977 void ModuleBitcodeWriter::pushValue(const Value *V, unsigned InstID,
2978                                     SmallVectorImpl<unsigned> &Vals) {
2979   unsigned ValID = VE.getValueID(V);
2980   Vals.push_back(InstID - ValID);
2981 }
2982 
2983 void ModuleBitcodeWriter::pushValueSigned(const Value *V, unsigned InstID,
2984                                           SmallVectorImpl<uint64_t> &Vals) {
2985   unsigned ValID = VE.getValueID(V);
2986   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
2987   emitSignedInt64(Vals, diff);
2988 }
2989 
2990 /// WriteInstruction - Emit an instruction to the specified stream.
2991 void ModuleBitcodeWriter::writeInstruction(const Instruction &I,
2992                                            unsigned InstID,
2993                                            SmallVectorImpl<unsigned> &Vals) {
2994   unsigned Code = 0;
2995   unsigned AbbrevToUse = 0;
2996   VE.setInstructionID(&I);
2997   switch (I.getOpcode()) {
2998   default:
2999     if (Instruction::isCast(I.getOpcode())) {
3000       Code = bitc::FUNC_CODE_INST_CAST;
3001       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
3002         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
3003       Vals.push_back(VE.getTypeID(I.getType()));
3004       Vals.push_back(getEncodedCastOpcode(I.getOpcode()));
3005       uint64_t Flags = getOptimizationFlags(&I);
3006       if (Flags != 0) {
3007         if (AbbrevToUse == FUNCTION_INST_CAST_ABBREV)
3008           AbbrevToUse = FUNCTION_INST_CAST_FLAGS_ABBREV;
3009         Vals.push_back(Flags);
3010       }
3011     } else {
3012       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
3013       Code = bitc::FUNC_CODE_INST_BINOP;
3014       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
3015         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
3016       pushValue(I.getOperand(1), InstID, Vals);
3017       Vals.push_back(getEncodedBinaryOpcode(I.getOpcode()));
3018       uint64_t Flags = getOptimizationFlags(&I);
3019       if (Flags != 0) {
3020         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
3021           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
3022         Vals.push_back(Flags);
3023       }
3024     }
3025     break;
3026   case Instruction::FNeg: {
3027     Code = bitc::FUNC_CODE_INST_UNOP;
3028     if (!pushValueAndType(I.getOperand(0), InstID, Vals))
3029       AbbrevToUse = FUNCTION_INST_UNOP_ABBREV;
3030     Vals.push_back(getEncodedUnaryOpcode(I.getOpcode()));
3031     uint64_t Flags = getOptimizationFlags(&I);
3032     if (Flags != 0) {
3033       if (AbbrevToUse == FUNCTION_INST_UNOP_ABBREV)
3034         AbbrevToUse = FUNCTION_INST_UNOP_FLAGS_ABBREV;
3035       Vals.push_back(Flags);
3036     }
3037     break;
3038   }
3039   case Instruction::GetElementPtr: {
3040     Code = bitc::FUNC_CODE_INST_GEP;
3041     AbbrevToUse = FUNCTION_INST_GEP_ABBREV;
3042     auto &GEPInst = cast<GetElementPtrInst>(I);
3043     Vals.push_back(getOptimizationFlags(&I));
3044     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
3045     for (const Value *Op : I.operands())
3046       pushValueAndType(Op, InstID, Vals);
3047     break;
3048   }
3049   case Instruction::ExtractValue: {
3050     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
3051     pushValueAndType(I.getOperand(0), InstID, Vals);
3052     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
3053     Vals.append(EVI->idx_begin(), EVI->idx_end());
3054     break;
3055   }
3056   case Instruction::InsertValue: {
3057     Code = bitc::FUNC_CODE_INST_INSERTVAL;
3058     pushValueAndType(I.getOperand(0), InstID, Vals);
3059     pushValueAndType(I.getOperand(1), InstID, Vals);
3060     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
3061     Vals.append(IVI->idx_begin(), IVI->idx_end());
3062     break;
3063   }
3064   case Instruction::Select: {
3065     Code = bitc::FUNC_CODE_INST_VSELECT;
3066     pushValueAndType(I.getOperand(1), InstID, Vals);
3067     pushValue(I.getOperand(2), InstID, Vals);
3068     pushValueAndType(I.getOperand(0), InstID, Vals);
3069     uint64_t Flags = getOptimizationFlags(&I);
3070     if (Flags != 0)
3071       Vals.push_back(Flags);
3072     break;
3073   }
3074   case Instruction::ExtractElement:
3075     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
3076     pushValueAndType(I.getOperand(0), InstID, Vals);
3077     pushValueAndType(I.getOperand(1), InstID, Vals);
3078     break;
3079   case Instruction::InsertElement:
3080     Code = bitc::FUNC_CODE_INST_INSERTELT;
3081     pushValueAndType(I.getOperand(0), InstID, Vals);
3082     pushValue(I.getOperand(1), InstID, Vals);
3083     pushValueAndType(I.getOperand(2), InstID, Vals);
3084     break;
3085   case Instruction::ShuffleVector:
3086     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
3087     pushValueAndType(I.getOperand(0), InstID, Vals);
3088     pushValue(I.getOperand(1), InstID, Vals);
3089     pushValue(cast<ShuffleVectorInst>(I).getShuffleMaskForBitcode(), InstID,
3090               Vals);
3091     break;
3092   case Instruction::ICmp:
3093   case Instruction::FCmp: {
3094     // compare returning Int1Ty or vector of Int1Ty
3095     Code = bitc::FUNC_CODE_INST_CMP2;
3096     pushValueAndType(I.getOperand(0), InstID, Vals);
3097     pushValue(I.getOperand(1), InstID, Vals);
3098     Vals.push_back(cast<CmpInst>(I).getPredicate());
3099     uint64_t Flags = getOptimizationFlags(&I);
3100     if (Flags != 0)
3101       Vals.push_back(Flags);
3102     break;
3103   }
3104 
3105   case Instruction::Ret:
3106     {
3107       Code = bitc::FUNC_CODE_INST_RET;
3108       unsigned NumOperands = I.getNumOperands();
3109       if (NumOperands == 0)
3110         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
3111       else if (NumOperands == 1) {
3112         if (!pushValueAndType(I.getOperand(0), InstID, Vals))
3113           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
3114       } else {
3115         for (const Value *Op : I.operands())
3116           pushValueAndType(Op, InstID, Vals);
3117       }
3118     }
3119     break;
3120   case Instruction::Br:
3121     {
3122       Code = bitc::FUNC_CODE_INST_BR;
3123       const BranchInst &II = cast<BranchInst>(I);
3124       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
3125       if (II.isConditional()) {
3126         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
3127         pushValue(II.getCondition(), InstID, Vals);
3128       }
3129     }
3130     break;
3131   case Instruction::Switch:
3132     {
3133       Code = bitc::FUNC_CODE_INST_SWITCH;
3134       const SwitchInst &SI = cast<SwitchInst>(I);
3135       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
3136       pushValue(SI.getCondition(), InstID, Vals);
3137       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
3138       for (auto Case : SI.cases()) {
3139         Vals.push_back(VE.getValueID(Case.getCaseValue()));
3140         Vals.push_back(VE.getValueID(Case.getCaseSuccessor()));
3141       }
3142     }
3143     break;
3144   case Instruction::IndirectBr:
3145     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
3146     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
3147     // Encode the address operand as relative, but not the basic blocks.
3148     pushValue(I.getOperand(0), InstID, Vals);
3149     for (const Value *Op : drop_begin(I.operands()))
3150       Vals.push_back(VE.getValueID(Op));
3151     break;
3152 
3153   case Instruction::Invoke: {
3154     const InvokeInst *II = cast<InvokeInst>(&I);
3155     const Value *Callee = II->getCalledOperand();
3156     FunctionType *FTy = II->getFunctionType();
3157 
3158     if (II->hasOperandBundles())
3159       writeOperandBundles(*II, InstID);
3160 
3161     Code = bitc::FUNC_CODE_INST_INVOKE;
3162 
3163     Vals.push_back(VE.getAttributeListID(II->getAttributes()));
3164     Vals.push_back(II->getCallingConv() | 1 << 13);
3165     Vals.push_back(VE.getValueID(II->getNormalDest()));
3166     Vals.push_back(VE.getValueID(II->getUnwindDest()));
3167     Vals.push_back(VE.getTypeID(FTy));
3168     pushValueAndType(Callee, InstID, Vals);
3169 
3170     // Emit value #'s for the fixed parameters.
3171     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
3172       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
3173 
3174     // Emit type/value pairs for varargs params.
3175     if (FTy->isVarArg()) {
3176       for (unsigned i = FTy->getNumParams(), e = II->arg_size(); i != e; ++i)
3177         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
3178     }
3179     break;
3180   }
3181   case Instruction::Resume:
3182     Code = bitc::FUNC_CODE_INST_RESUME;
3183     pushValueAndType(I.getOperand(0), InstID, Vals);
3184     break;
3185   case Instruction::CleanupRet: {
3186     Code = bitc::FUNC_CODE_INST_CLEANUPRET;
3187     const auto &CRI = cast<CleanupReturnInst>(I);
3188     pushValue(CRI.getCleanupPad(), InstID, Vals);
3189     if (CRI.hasUnwindDest())
3190       Vals.push_back(VE.getValueID(CRI.getUnwindDest()));
3191     break;
3192   }
3193   case Instruction::CatchRet: {
3194     Code = bitc::FUNC_CODE_INST_CATCHRET;
3195     const auto &CRI = cast<CatchReturnInst>(I);
3196     pushValue(CRI.getCatchPad(), InstID, Vals);
3197     Vals.push_back(VE.getValueID(CRI.getSuccessor()));
3198     break;
3199   }
3200   case Instruction::CleanupPad:
3201   case Instruction::CatchPad: {
3202     const auto &FuncletPad = cast<FuncletPadInst>(I);
3203     Code = isa<CatchPadInst>(FuncletPad) ? bitc::FUNC_CODE_INST_CATCHPAD
3204                                          : bitc::FUNC_CODE_INST_CLEANUPPAD;
3205     pushValue(FuncletPad.getParentPad(), InstID, Vals);
3206 
3207     unsigned NumArgOperands = FuncletPad.arg_size();
3208     Vals.push_back(NumArgOperands);
3209     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
3210       pushValueAndType(FuncletPad.getArgOperand(Op), InstID, Vals);
3211     break;
3212   }
3213   case Instruction::CatchSwitch: {
3214     Code = bitc::FUNC_CODE_INST_CATCHSWITCH;
3215     const auto &CatchSwitch = cast<CatchSwitchInst>(I);
3216 
3217     pushValue(CatchSwitch.getParentPad(), InstID, Vals);
3218 
3219     unsigned NumHandlers = CatchSwitch.getNumHandlers();
3220     Vals.push_back(NumHandlers);
3221     for (const BasicBlock *CatchPadBB : CatchSwitch.handlers())
3222       Vals.push_back(VE.getValueID(CatchPadBB));
3223 
3224     if (CatchSwitch.hasUnwindDest())
3225       Vals.push_back(VE.getValueID(CatchSwitch.getUnwindDest()));
3226     break;
3227   }
3228   case Instruction::CallBr: {
3229     const CallBrInst *CBI = cast<CallBrInst>(&I);
3230     const Value *Callee = CBI->getCalledOperand();
3231     FunctionType *FTy = CBI->getFunctionType();
3232 
3233     if (CBI->hasOperandBundles())
3234       writeOperandBundles(*CBI, InstID);
3235 
3236     Code = bitc::FUNC_CODE_INST_CALLBR;
3237 
3238     Vals.push_back(VE.getAttributeListID(CBI->getAttributes()));
3239 
3240     Vals.push_back(CBI->getCallingConv() << bitc::CALL_CCONV |
3241                    1 << bitc::CALL_EXPLICIT_TYPE);
3242 
3243     Vals.push_back(VE.getValueID(CBI->getDefaultDest()));
3244     Vals.push_back(CBI->getNumIndirectDests());
3245     for (unsigned i = 0, e = CBI->getNumIndirectDests(); i != e; ++i)
3246       Vals.push_back(VE.getValueID(CBI->getIndirectDest(i)));
3247 
3248     Vals.push_back(VE.getTypeID(FTy));
3249     pushValueAndType(Callee, InstID, Vals);
3250 
3251     // Emit value #'s for the fixed parameters.
3252     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
3253       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
3254 
3255     // Emit type/value pairs for varargs params.
3256     if (FTy->isVarArg()) {
3257       for (unsigned i = FTy->getNumParams(), e = CBI->arg_size(); i != e; ++i)
3258         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
3259     }
3260     break;
3261   }
3262   case Instruction::Unreachable:
3263     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
3264     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
3265     break;
3266 
3267   case Instruction::PHI: {
3268     const PHINode &PN = cast<PHINode>(I);
3269     Code = bitc::FUNC_CODE_INST_PHI;
3270     // With the newer instruction encoding, forward references could give
3271     // negative valued IDs.  This is most common for PHIs, so we use
3272     // signed VBRs.
3273     SmallVector<uint64_t, 128> Vals64;
3274     Vals64.push_back(VE.getTypeID(PN.getType()));
3275     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
3276       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64);
3277       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
3278     }
3279 
3280     uint64_t Flags = getOptimizationFlags(&I);
3281     if (Flags != 0)
3282       Vals64.push_back(Flags);
3283 
3284     // Emit a Vals64 vector and exit.
3285     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
3286     Vals64.clear();
3287     return;
3288   }
3289 
3290   case Instruction::LandingPad: {
3291     const LandingPadInst &LP = cast<LandingPadInst>(I);
3292     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
3293     Vals.push_back(VE.getTypeID(LP.getType()));
3294     Vals.push_back(LP.isCleanup());
3295     Vals.push_back(LP.getNumClauses());
3296     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
3297       if (LP.isCatch(I))
3298         Vals.push_back(LandingPadInst::Catch);
3299       else
3300         Vals.push_back(LandingPadInst::Filter);
3301       pushValueAndType(LP.getClause(I), InstID, Vals);
3302     }
3303     break;
3304   }
3305 
3306   case Instruction::Alloca: {
3307     Code = bitc::FUNC_CODE_INST_ALLOCA;
3308     const AllocaInst &AI = cast<AllocaInst>(I);
3309     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
3310     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
3311     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
3312     using APV = AllocaPackedValues;
3313     unsigned Record = 0;
3314     unsigned EncodedAlign = getEncodedAlign(AI.getAlign());
3315     Bitfield::set<APV::AlignLower>(
3316         Record, EncodedAlign & ((1 << APV::AlignLower::Bits) - 1));
3317     Bitfield::set<APV::AlignUpper>(Record,
3318                                    EncodedAlign >> APV::AlignLower::Bits);
3319     Bitfield::set<APV::UsedWithInAlloca>(Record, AI.isUsedWithInAlloca());
3320     Bitfield::set<APV::ExplicitType>(Record, true);
3321     Bitfield::set<APV::SwiftError>(Record, AI.isSwiftError());
3322     Vals.push_back(Record);
3323 
3324     unsigned AS = AI.getAddressSpace();
3325     if (AS != M.getDataLayout().getAllocaAddrSpace())
3326       Vals.push_back(AS);
3327     break;
3328   }
3329 
3330   case Instruction::Load:
3331     if (cast<LoadInst>(I).isAtomic()) {
3332       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
3333       pushValueAndType(I.getOperand(0), InstID, Vals);
3334     } else {
3335       Code = bitc::FUNC_CODE_INST_LOAD;
3336       if (!pushValueAndType(I.getOperand(0), InstID, Vals)) // ptr
3337         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
3338     }
3339     Vals.push_back(VE.getTypeID(I.getType()));
3340     Vals.push_back(getEncodedAlign(cast<LoadInst>(I).getAlign()));
3341     Vals.push_back(cast<LoadInst>(I).isVolatile());
3342     if (cast<LoadInst>(I).isAtomic()) {
3343       Vals.push_back(getEncodedOrdering(cast<LoadInst>(I).getOrdering()));
3344       Vals.push_back(getEncodedSyncScopeID(cast<LoadInst>(I).getSyncScopeID()));
3345     }
3346     break;
3347   case Instruction::Store:
3348     if (cast<StoreInst>(I).isAtomic())
3349       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
3350     else
3351       Code = bitc::FUNC_CODE_INST_STORE;
3352     pushValueAndType(I.getOperand(1), InstID, Vals); // ptrty + ptr
3353     pushValueAndType(I.getOperand(0), InstID, Vals); // valty + val
3354     Vals.push_back(getEncodedAlign(cast<StoreInst>(I).getAlign()));
3355     Vals.push_back(cast<StoreInst>(I).isVolatile());
3356     if (cast<StoreInst>(I).isAtomic()) {
3357       Vals.push_back(getEncodedOrdering(cast<StoreInst>(I).getOrdering()));
3358       Vals.push_back(
3359           getEncodedSyncScopeID(cast<StoreInst>(I).getSyncScopeID()));
3360     }
3361     break;
3362   case Instruction::AtomicCmpXchg:
3363     Code = bitc::FUNC_CODE_INST_CMPXCHG;
3364     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
3365     pushValueAndType(I.getOperand(1), InstID, Vals); // cmp.
3366     pushValue(I.getOperand(2), InstID, Vals);        // newval.
3367     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
3368     Vals.push_back(
3369         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
3370     Vals.push_back(
3371         getEncodedSyncScopeID(cast<AtomicCmpXchgInst>(I).getSyncScopeID()));
3372     Vals.push_back(
3373         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
3374     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
3375     Vals.push_back(getEncodedAlign(cast<AtomicCmpXchgInst>(I).getAlign()));
3376     break;
3377   case Instruction::AtomicRMW:
3378     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
3379     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
3380     pushValueAndType(I.getOperand(1), InstID, Vals); // valty + val
3381     Vals.push_back(
3382         getEncodedRMWOperation(cast<AtomicRMWInst>(I).getOperation()));
3383     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
3384     Vals.push_back(getEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
3385     Vals.push_back(
3386         getEncodedSyncScopeID(cast<AtomicRMWInst>(I).getSyncScopeID()));
3387     Vals.push_back(getEncodedAlign(cast<AtomicRMWInst>(I).getAlign()));
3388     break;
3389   case Instruction::Fence:
3390     Code = bitc::FUNC_CODE_INST_FENCE;
3391     Vals.push_back(getEncodedOrdering(cast<FenceInst>(I).getOrdering()));
3392     Vals.push_back(getEncodedSyncScopeID(cast<FenceInst>(I).getSyncScopeID()));
3393     break;
3394   case Instruction::Call: {
3395     const CallInst &CI = cast<CallInst>(I);
3396     FunctionType *FTy = CI.getFunctionType();
3397 
3398     if (CI.hasOperandBundles())
3399       writeOperandBundles(CI, InstID);
3400 
3401     Code = bitc::FUNC_CODE_INST_CALL;
3402 
3403     Vals.push_back(VE.getAttributeListID(CI.getAttributes()));
3404 
3405     unsigned Flags = getOptimizationFlags(&I);
3406     Vals.push_back(CI.getCallingConv() << bitc::CALL_CCONV |
3407                    unsigned(CI.isTailCall()) << bitc::CALL_TAIL |
3408                    unsigned(CI.isMustTailCall()) << bitc::CALL_MUSTTAIL |
3409                    1 << bitc::CALL_EXPLICIT_TYPE |
3410                    unsigned(CI.isNoTailCall()) << bitc::CALL_NOTAIL |
3411                    unsigned(Flags != 0) << bitc::CALL_FMF);
3412     if (Flags != 0)
3413       Vals.push_back(Flags);
3414 
3415     Vals.push_back(VE.getTypeID(FTy));
3416     pushValueAndType(CI.getCalledOperand(), InstID, Vals); // Callee
3417 
3418     // Emit value #'s for the fixed parameters.
3419     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
3420       // Check for labels (can happen with asm labels).
3421       if (FTy->getParamType(i)->isLabelTy())
3422         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
3423       else
3424         pushValue(CI.getArgOperand(i), InstID, Vals); // fixed param.
3425     }
3426 
3427     // Emit type/value pairs for varargs params.
3428     if (FTy->isVarArg()) {
3429       for (unsigned i = FTy->getNumParams(), e = CI.arg_size(); i != e; ++i)
3430         pushValueAndType(CI.getArgOperand(i), InstID, Vals); // varargs
3431     }
3432     break;
3433   }
3434   case Instruction::VAArg:
3435     Code = bitc::FUNC_CODE_INST_VAARG;
3436     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
3437     pushValue(I.getOperand(0), InstID, Vals);                   // valist.
3438     Vals.push_back(VE.getTypeID(I.getType())); // restype.
3439     break;
3440   case Instruction::Freeze:
3441     Code = bitc::FUNC_CODE_INST_FREEZE;
3442     pushValueAndType(I.getOperand(0), InstID, Vals);
3443     break;
3444   }
3445 
3446   Stream.EmitRecord(Code, Vals, AbbrevToUse);
3447   Vals.clear();
3448 }
3449 
3450 /// Write a GlobalValue VST to the module. The purpose of this data structure is
3451 /// to allow clients to efficiently find the function body.
3452 void ModuleBitcodeWriter::writeGlobalValueSymbolTable(
3453   DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex) {
3454   // Get the offset of the VST we are writing, and backpatch it into
3455   // the VST forward declaration record.
3456   uint64_t VSTOffset = Stream.GetCurrentBitNo();
3457   // The BitcodeStartBit was the stream offset of the identification block.
3458   VSTOffset -= bitcodeStartBit();
3459   assert((VSTOffset & 31) == 0 && "VST block not 32-bit aligned");
3460   // Note that we add 1 here because the offset is relative to one word
3461   // before the start of the identification block, which was historically
3462   // always the start of the regular bitcode header.
3463   Stream.BackpatchWord(VSTOffsetPlaceholder, VSTOffset / 32 + 1);
3464 
3465   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
3466 
3467   auto Abbv = std::make_shared<BitCodeAbbrev>();
3468   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
3469   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
3470   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
3471   unsigned FnEntryAbbrev = Stream.EmitAbbrev(std::move(Abbv));
3472 
3473   for (const Function &F : M) {
3474     uint64_t Record[2];
3475 
3476     if (F.isDeclaration())
3477       continue;
3478 
3479     Record[0] = VE.getValueID(&F);
3480 
3481     // Save the word offset of the function (from the start of the
3482     // actual bitcode written to the stream).
3483     uint64_t BitcodeIndex = FunctionToBitcodeIndex[&F] - bitcodeStartBit();
3484     assert((BitcodeIndex & 31) == 0 && "function block not 32-bit aligned");
3485     // Note that we add 1 here because the offset is relative to one word
3486     // before the start of the identification block, which was historically
3487     // always the start of the regular bitcode header.
3488     Record[1] = BitcodeIndex / 32 + 1;
3489 
3490     Stream.EmitRecord(bitc::VST_CODE_FNENTRY, Record, FnEntryAbbrev);
3491   }
3492 
3493   Stream.ExitBlock();
3494 }
3495 
3496 /// Emit names for arguments, instructions and basic blocks in a function.
3497 void ModuleBitcodeWriter::writeFunctionLevelValueSymbolTable(
3498     const ValueSymbolTable &VST) {
3499   if (VST.empty())
3500     return;
3501 
3502   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
3503 
3504   // FIXME: Set up the abbrev, we know how many values there are!
3505   // FIXME: We know if the type names can use 7-bit ascii.
3506   SmallVector<uint64_t, 64> NameVals;
3507 
3508   for (const ValueName &Name : VST) {
3509     // Figure out the encoding to use for the name.
3510     StringEncoding Bits = getStringEncoding(Name.getKey());
3511 
3512     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
3513     NameVals.push_back(VE.getValueID(Name.getValue()));
3514 
3515     // VST_CODE_ENTRY:   [valueid, namechar x N]
3516     // VST_CODE_BBENTRY: [bbid, namechar x N]
3517     unsigned Code;
3518     if (isa<BasicBlock>(Name.getValue())) {
3519       Code = bitc::VST_CODE_BBENTRY;
3520       if (Bits == SE_Char6)
3521         AbbrevToUse = VST_BBENTRY_6_ABBREV;
3522     } else {
3523       Code = bitc::VST_CODE_ENTRY;
3524       if (Bits == SE_Char6)
3525         AbbrevToUse = VST_ENTRY_6_ABBREV;
3526       else if (Bits == SE_Fixed7)
3527         AbbrevToUse = VST_ENTRY_7_ABBREV;
3528     }
3529 
3530     for (const auto P : Name.getKey())
3531       NameVals.push_back((unsigned char)P);
3532 
3533     // Emit the finished record.
3534     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
3535     NameVals.clear();
3536   }
3537 
3538   Stream.ExitBlock();
3539 }
3540 
3541 void ModuleBitcodeWriter::writeUseList(UseListOrder &&Order) {
3542   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
3543   unsigned Code;
3544   if (isa<BasicBlock>(Order.V))
3545     Code = bitc::USELIST_CODE_BB;
3546   else
3547     Code = bitc::USELIST_CODE_DEFAULT;
3548 
3549   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
3550   Record.push_back(VE.getValueID(Order.V));
3551   Stream.EmitRecord(Code, Record);
3552 }
3553 
3554 void ModuleBitcodeWriter::writeUseListBlock(const Function *F) {
3555   assert(VE.shouldPreserveUseListOrder() &&
3556          "Expected to be preserving use-list order");
3557 
3558   auto hasMore = [&]() {
3559     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
3560   };
3561   if (!hasMore())
3562     // Nothing to do.
3563     return;
3564 
3565   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
3566   while (hasMore()) {
3567     writeUseList(std::move(VE.UseListOrders.back()));
3568     VE.UseListOrders.pop_back();
3569   }
3570   Stream.ExitBlock();
3571 }
3572 
3573 /// Emit a function body to the module stream.
3574 void ModuleBitcodeWriter::writeFunction(
3575     const Function &F,
3576     DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex) {
3577   // Save the bitcode index of the start of this function block for recording
3578   // in the VST.
3579   FunctionToBitcodeIndex[&F] = Stream.GetCurrentBitNo();
3580 
3581   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
3582   VE.incorporateFunction(F);
3583 
3584   SmallVector<unsigned, 64> Vals;
3585 
3586   // Emit the number of basic blocks, so the reader can create them ahead of
3587   // time.
3588   Vals.push_back(VE.getBasicBlocks().size());
3589   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
3590   Vals.clear();
3591 
3592   // If there are function-local constants, emit them now.
3593   unsigned CstStart, CstEnd;
3594   VE.getFunctionConstantRange(CstStart, CstEnd);
3595   writeConstants(CstStart, CstEnd, false);
3596 
3597   // If there is function-local metadata, emit it now.
3598   writeFunctionMetadata(F);
3599 
3600   // Keep a running idea of what the instruction ID is.
3601   unsigned InstID = CstEnd;
3602 
3603   bool NeedsMetadataAttachment = F.hasMetadata();
3604 
3605   DILocation *LastDL = nullptr;
3606   SmallSetVector<Function *, 4> BlockAddressUsers;
3607 
3608   // Finally, emit all the instructions, in order.
3609   for (const BasicBlock &BB : F) {
3610     for (const Instruction &I : BB) {
3611       writeInstruction(I, InstID, Vals);
3612 
3613       if (!I.getType()->isVoidTy())
3614         ++InstID;
3615 
3616       // If the instruction has metadata, write a metadata attachment later.
3617       NeedsMetadataAttachment |= I.hasMetadataOtherThanDebugLoc();
3618 
3619       // If the instruction has a debug location, emit it.
3620       if (DILocation *DL = I.getDebugLoc()) {
3621         if (DL == LastDL) {
3622           // Just repeat the same debug loc as last time.
3623           Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
3624         } else {
3625           Vals.push_back(DL->getLine());
3626           Vals.push_back(DL->getColumn());
3627           Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
3628           Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
3629           Vals.push_back(DL->isImplicitCode());
3630           Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
3631           Vals.clear();
3632           LastDL = DL;
3633         }
3634       }
3635 
3636       // If the instruction has DbgRecords attached to it, emit them. Note that
3637       // they come after the instruction so that it's easy to attach them again
3638       // when reading the bitcode, even though conceptually the debug locations
3639       // start "before" the instruction.
3640       if (I.hasDbgRecords() && WriteNewDbgInfoFormatToBitcode) {
3641         /// Try to push the value only (unwrapped), otherwise push the
3642         /// metadata wrapped value. Returns true if the value was pushed
3643         /// without the ValueAsMetadata wrapper.
3644         auto PushValueOrMetadata = [&Vals, InstID,
3645                                     this](Metadata *RawLocation) {
3646           assert(RawLocation &&
3647                  "RawLocation unexpectedly null in DbgVariableRecord");
3648           if (ValueAsMetadata *VAM = dyn_cast<ValueAsMetadata>(RawLocation)) {
3649             SmallVector<unsigned, 2> ValAndType;
3650             // If the value is a fwd-ref the type is also pushed. We don't
3651             // want the type, so fwd-refs are kept wrapped (pushValueAndType
3652             // returns false if the value is pushed without type).
3653             if (!pushValueAndType(VAM->getValue(), InstID, ValAndType)) {
3654               Vals.push_back(ValAndType[0]);
3655               return true;
3656             }
3657           }
3658           // The metadata is a DIArgList, or ValueAsMetadata wrapping a
3659           // fwd-ref. Push the metadata ID.
3660           Vals.push_back(VE.getMetadataID(RawLocation));
3661           return false;
3662         };
3663 
3664         // Write out non-instruction debug information attached to this
3665         // instruction. Write it after the instruction so that it's easy to
3666         // re-attach to the instruction reading the records in.
3667         for (DbgRecord &DR : I.DebugMarker->getDbgRecordRange()) {
3668           if (DbgLabelRecord *DLR = dyn_cast<DbgLabelRecord>(&DR)) {
3669             Vals.push_back(VE.getMetadataID(&*DLR->getDebugLoc()));
3670             Vals.push_back(VE.getMetadataID(DLR->getLabel()));
3671             Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_LABEL, Vals);
3672             Vals.clear();
3673             continue;
3674           }
3675 
3676           // First 3 fields are common to all kinds:
3677           //   DILocation, DILocalVariable, DIExpression
3678           // dbg_value (FUNC_CODE_DEBUG_RECORD_VALUE)
3679           //   ..., LocationMetadata
3680           // dbg_value (FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE - abbrev'd)
3681           //   ..., Value
3682           // dbg_declare (FUNC_CODE_DEBUG_RECORD_DECLARE)
3683           //   ..., LocationMetadata
3684           // dbg_assign (FUNC_CODE_DEBUG_RECORD_ASSIGN)
3685           //   ..., LocationMetadata, DIAssignID, DIExpression, LocationMetadata
3686           DbgVariableRecord &DVR = cast<DbgVariableRecord>(DR);
3687           Vals.push_back(VE.getMetadataID(&*DVR.getDebugLoc()));
3688           Vals.push_back(VE.getMetadataID(DVR.getVariable()));
3689           Vals.push_back(VE.getMetadataID(DVR.getExpression()));
3690           if (DVR.isDbgValue()) {
3691             if (PushValueOrMetadata(DVR.getRawLocation()))
3692               Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE, Vals,
3693                                 FUNCTION_DEBUG_RECORD_VALUE_ABBREV);
3694             else
3695               Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_VALUE, Vals);
3696           } else if (DVR.isDbgDeclare()) {
3697             Vals.push_back(VE.getMetadataID(DVR.getRawLocation()));
3698             Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_DECLARE, Vals);
3699           } else {
3700             assert(DVR.isDbgAssign() && "Unexpected DbgRecord kind");
3701             Vals.push_back(VE.getMetadataID(DVR.getRawLocation()));
3702             Vals.push_back(VE.getMetadataID(DVR.getAssignID()));
3703             Vals.push_back(VE.getMetadataID(DVR.getAddressExpression()));
3704             Vals.push_back(VE.getMetadataID(DVR.getRawAddress()));
3705             Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_ASSIGN, Vals);
3706           }
3707           Vals.clear();
3708         }
3709       }
3710     }
3711 
3712     if (BlockAddress *BA = BlockAddress::lookup(&BB)) {
3713       SmallVector<Value *> Worklist{BA};
3714       SmallPtrSet<Value *, 8> Visited{BA};
3715       while (!Worklist.empty()) {
3716         Value *V = Worklist.pop_back_val();
3717         for (User *U : V->users()) {
3718           if (auto *I = dyn_cast<Instruction>(U)) {
3719             Function *P = I->getFunction();
3720             if (P != &F)
3721               BlockAddressUsers.insert(P);
3722           } else if (isa<Constant>(U) && !isa<GlobalValue>(U) &&
3723                      Visited.insert(U).second)
3724             Worklist.push_back(U);
3725         }
3726       }
3727     }
3728   }
3729 
3730   if (!BlockAddressUsers.empty()) {
3731     Vals.resize(BlockAddressUsers.size());
3732     for (auto I : llvm::enumerate(BlockAddressUsers))
3733       Vals[I.index()] = VE.getValueID(I.value());
3734     Stream.EmitRecord(bitc::FUNC_CODE_BLOCKADDR_USERS, Vals);
3735     Vals.clear();
3736   }
3737 
3738   // Emit names for all the instructions etc.
3739   if (auto *Symtab = F.getValueSymbolTable())
3740     writeFunctionLevelValueSymbolTable(*Symtab);
3741 
3742   if (NeedsMetadataAttachment)
3743     writeFunctionMetadataAttachment(F);
3744   if (VE.shouldPreserveUseListOrder())
3745     writeUseListBlock(&F);
3746   VE.purgeFunction();
3747   Stream.ExitBlock();
3748 }
3749 
3750 // Emit blockinfo, which defines the standard abbreviations etc.
3751 void ModuleBitcodeWriter::writeBlockInfo() {
3752   // We only want to emit block info records for blocks that have multiple
3753   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
3754   // Other blocks can define their abbrevs inline.
3755   Stream.EnterBlockInfoBlock();
3756 
3757   { // 8-bit fixed-width VST_CODE_ENTRY/VST_CODE_BBENTRY strings.
3758     auto Abbv = std::make_shared<BitCodeAbbrev>();
3759     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
3760     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3761     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3762     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
3763     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3764         VST_ENTRY_8_ABBREV)
3765       llvm_unreachable("Unexpected abbrev ordering!");
3766   }
3767 
3768   { // 7-bit fixed width VST_CODE_ENTRY strings.
3769     auto Abbv = std::make_shared<BitCodeAbbrev>();
3770     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
3771     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3772     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3773     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
3774     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3775         VST_ENTRY_7_ABBREV)
3776       llvm_unreachable("Unexpected abbrev ordering!");
3777   }
3778   { // 6-bit char6 VST_CODE_ENTRY strings.
3779     auto Abbv = std::make_shared<BitCodeAbbrev>();
3780     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
3781     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3782     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3783     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3784     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3785         VST_ENTRY_6_ABBREV)
3786       llvm_unreachable("Unexpected abbrev ordering!");
3787   }
3788   { // 6-bit char6 VST_CODE_BBENTRY strings.
3789     auto Abbv = std::make_shared<BitCodeAbbrev>();
3790     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
3791     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3792     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3793     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3794     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3795         VST_BBENTRY_6_ABBREV)
3796       llvm_unreachable("Unexpected abbrev ordering!");
3797   }
3798 
3799   { // SETTYPE abbrev for CONSTANTS_BLOCK.
3800     auto Abbv = std::make_shared<BitCodeAbbrev>();
3801     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
3802     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
3803                               VE.computeBitsRequiredForTypeIndices()));
3804     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3805         CONSTANTS_SETTYPE_ABBREV)
3806       llvm_unreachable("Unexpected abbrev ordering!");
3807   }
3808 
3809   { // INTEGER abbrev for CONSTANTS_BLOCK.
3810     auto Abbv = std::make_shared<BitCodeAbbrev>();
3811     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
3812     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3813     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3814         CONSTANTS_INTEGER_ABBREV)
3815       llvm_unreachable("Unexpected abbrev ordering!");
3816   }
3817 
3818   { // CE_CAST abbrev for CONSTANTS_BLOCK.
3819     auto Abbv = std::make_shared<BitCodeAbbrev>();
3820     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
3821     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
3822     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
3823                               VE.computeBitsRequiredForTypeIndices()));
3824     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
3825 
3826     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3827         CONSTANTS_CE_CAST_Abbrev)
3828       llvm_unreachable("Unexpected abbrev ordering!");
3829   }
3830   { // NULL abbrev for CONSTANTS_BLOCK.
3831     auto Abbv = std::make_shared<BitCodeAbbrev>();
3832     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
3833     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3834         CONSTANTS_NULL_Abbrev)
3835       llvm_unreachable("Unexpected abbrev ordering!");
3836   }
3837 
3838   // FIXME: This should only use space for first class types!
3839 
3840   { // INST_LOAD abbrev for FUNCTION_BLOCK.
3841     auto Abbv = std::make_shared<BitCodeAbbrev>();
3842     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
3843     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
3844     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
3845                               VE.computeBitsRequiredForTypeIndices()));
3846     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
3847     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
3848     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3849         FUNCTION_INST_LOAD_ABBREV)
3850       llvm_unreachable("Unexpected abbrev ordering!");
3851   }
3852   { // INST_UNOP abbrev for FUNCTION_BLOCK.
3853     auto Abbv = std::make_shared<BitCodeAbbrev>();
3854     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNOP));
3855     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3856     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3857     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3858         FUNCTION_INST_UNOP_ABBREV)
3859       llvm_unreachable("Unexpected abbrev ordering!");
3860   }
3861   { // INST_UNOP_FLAGS abbrev for FUNCTION_BLOCK.
3862     auto Abbv = std::make_shared<BitCodeAbbrev>();
3863     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNOP));
3864     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3865     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3866     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3867     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3868         FUNCTION_INST_UNOP_FLAGS_ABBREV)
3869       llvm_unreachable("Unexpected abbrev ordering!");
3870   }
3871   { // INST_BINOP abbrev for FUNCTION_BLOCK.
3872     auto Abbv = std::make_shared<BitCodeAbbrev>();
3873     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
3874     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3875     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
3876     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3877     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3878         FUNCTION_INST_BINOP_ABBREV)
3879       llvm_unreachable("Unexpected abbrev ordering!");
3880   }
3881   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
3882     auto Abbv = std::make_shared<BitCodeAbbrev>();
3883     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
3884     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3885     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
3886     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3887     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3888     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3889         FUNCTION_INST_BINOP_FLAGS_ABBREV)
3890       llvm_unreachable("Unexpected abbrev ordering!");
3891   }
3892   { // INST_CAST abbrev for FUNCTION_BLOCK.
3893     auto Abbv = std::make_shared<BitCodeAbbrev>();
3894     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
3895     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
3896     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
3897                               VE.computeBitsRequiredForTypeIndices()));
3898     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
3899     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3900         FUNCTION_INST_CAST_ABBREV)
3901       llvm_unreachable("Unexpected abbrev ordering!");
3902   }
3903   { // INST_CAST_FLAGS abbrev for FUNCTION_BLOCK.
3904     auto Abbv = std::make_shared<BitCodeAbbrev>();
3905     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
3906     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // OpVal
3907     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
3908                               VE.computeBitsRequiredForTypeIndices()));
3909     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3910     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3911     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3912         FUNCTION_INST_CAST_FLAGS_ABBREV)
3913       llvm_unreachable("Unexpected abbrev ordering!");
3914   }
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     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3920         FUNCTION_INST_RET_VOID_ABBREV)
3921       llvm_unreachable("Unexpected abbrev ordering!");
3922   }
3923   { // INST_RET abbrev for FUNCTION_BLOCK.
3924     auto Abbv = std::make_shared<BitCodeAbbrev>();
3925     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
3926     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
3927     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3928         FUNCTION_INST_RET_VAL_ABBREV)
3929       llvm_unreachable("Unexpected abbrev ordering!");
3930   }
3931   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
3932     auto Abbv = std::make_shared<BitCodeAbbrev>();
3933     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
3934     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3935         FUNCTION_INST_UNREACHABLE_ABBREV)
3936       llvm_unreachable("Unexpected abbrev ordering!");
3937   }
3938   {
3939     auto Abbv = std::make_shared<BitCodeAbbrev>();
3940     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
3941     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
3942     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
3943                               Log2_32_Ceil(VE.getTypes().size() + 1)));
3944     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3945     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
3946     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3947         FUNCTION_INST_GEP_ABBREV)
3948       llvm_unreachable("Unexpected abbrev ordering!");
3949   }
3950   {
3951     auto Abbv = std::make_shared<BitCodeAbbrev>();
3952     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE));
3953     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 7)); // dbgloc
3954     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 7)); // var
3955     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 7)); // expr
3956     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // val
3957     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3958         FUNCTION_DEBUG_RECORD_VALUE_ABBREV)
3959       llvm_unreachable("Unexpected abbrev ordering! 1");
3960   }
3961   Stream.ExitBlock();
3962 }
3963 
3964 /// Write the module path strings, currently only used when generating
3965 /// a combined index file.
3966 void IndexBitcodeWriter::writeModStrings() {
3967   Stream.EnterSubblock(bitc::MODULE_STRTAB_BLOCK_ID, 3);
3968 
3969   // TODO: See which abbrev sizes we actually need to emit
3970 
3971   // 8-bit fixed-width MST_ENTRY strings.
3972   auto Abbv = std::make_shared<BitCodeAbbrev>();
3973   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3974   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3975   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3976   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
3977   unsigned Abbrev8Bit = Stream.EmitAbbrev(std::move(Abbv));
3978 
3979   // 7-bit fixed width MST_ENTRY strings.
3980   Abbv = std::make_shared<BitCodeAbbrev>();
3981   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3982   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3983   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3984   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
3985   unsigned Abbrev7Bit = Stream.EmitAbbrev(std::move(Abbv));
3986 
3987   // 6-bit char6 MST_ENTRY strings.
3988   Abbv = std::make_shared<BitCodeAbbrev>();
3989   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3990   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3991   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3992   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3993   unsigned Abbrev6Bit = Stream.EmitAbbrev(std::move(Abbv));
3994 
3995   // Module Hash, 160 bits SHA1. Optionally, emitted after each MST_CODE_ENTRY.
3996   Abbv = std::make_shared<BitCodeAbbrev>();
3997   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_HASH));
3998   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3999   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4000   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4001   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4002   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4003   unsigned AbbrevHash = Stream.EmitAbbrev(std::move(Abbv));
4004 
4005   SmallVector<unsigned, 64> Vals;
4006   forEachModule([&](const StringMapEntry<ModuleHash> &MPSE) {
4007     StringRef Key = MPSE.getKey();
4008     const auto &Hash = MPSE.getValue();
4009     StringEncoding Bits = getStringEncoding(Key);
4010     unsigned AbbrevToUse = Abbrev8Bit;
4011     if (Bits == SE_Char6)
4012       AbbrevToUse = Abbrev6Bit;
4013     else if (Bits == SE_Fixed7)
4014       AbbrevToUse = Abbrev7Bit;
4015 
4016     auto ModuleId = ModuleIdMap.size();
4017     ModuleIdMap[Key] = ModuleId;
4018     Vals.push_back(ModuleId);
4019     Vals.append(Key.begin(), Key.end());
4020 
4021     // Emit the finished record.
4022     Stream.EmitRecord(bitc::MST_CODE_ENTRY, Vals, AbbrevToUse);
4023 
4024     // Emit an optional hash for the module now
4025     if (llvm::any_of(Hash, [](uint32_t H) { return H; })) {
4026       Vals.assign(Hash.begin(), Hash.end());
4027       // Emit the hash record.
4028       Stream.EmitRecord(bitc::MST_CODE_HASH, Vals, AbbrevHash);
4029     }
4030 
4031     Vals.clear();
4032   });
4033   Stream.ExitBlock();
4034 }
4035 
4036 /// Write the function type metadata related records that need to appear before
4037 /// a function summary entry (whether per-module or combined).
4038 template <typename Fn>
4039 static void writeFunctionTypeMetadataRecords(BitstreamWriter &Stream,
4040                                              FunctionSummary *FS,
4041                                              Fn GetValueID) {
4042   if (!FS->type_tests().empty())
4043     Stream.EmitRecord(bitc::FS_TYPE_TESTS, FS->type_tests());
4044 
4045   SmallVector<uint64_t, 64> Record;
4046 
4047   auto WriteVFuncIdVec = [&](uint64_t Ty,
4048                              ArrayRef<FunctionSummary::VFuncId> VFs) {
4049     if (VFs.empty())
4050       return;
4051     Record.clear();
4052     for (auto &VF : VFs) {
4053       Record.push_back(VF.GUID);
4054       Record.push_back(VF.Offset);
4055     }
4056     Stream.EmitRecord(Ty, Record);
4057   };
4058 
4059   WriteVFuncIdVec(bitc::FS_TYPE_TEST_ASSUME_VCALLS,
4060                   FS->type_test_assume_vcalls());
4061   WriteVFuncIdVec(bitc::FS_TYPE_CHECKED_LOAD_VCALLS,
4062                   FS->type_checked_load_vcalls());
4063 
4064   auto WriteConstVCallVec = [&](uint64_t Ty,
4065                                 ArrayRef<FunctionSummary::ConstVCall> VCs) {
4066     for (auto &VC : VCs) {
4067       Record.clear();
4068       Record.push_back(VC.VFunc.GUID);
4069       Record.push_back(VC.VFunc.Offset);
4070       llvm::append_range(Record, VC.Args);
4071       Stream.EmitRecord(Ty, Record);
4072     }
4073   };
4074 
4075   WriteConstVCallVec(bitc::FS_TYPE_TEST_ASSUME_CONST_VCALL,
4076                      FS->type_test_assume_const_vcalls());
4077   WriteConstVCallVec(bitc::FS_TYPE_CHECKED_LOAD_CONST_VCALL,
4078                      FS->type_checked_load_const_vcalls());
4079 
4080   auto WriteRange = [&](ConstantRange Range) {
4081     Range = Range.sextOrTrunc(FunctionSummary::ParamAccess::RangeWidth);
4082     assert(Range.getLower().getNumWords() == 1);
4083     assert(Range.getUpper().getNumWords() == 1);
4084     emitSignedInt64(Record, *Range.getLower().getRawData());
4085     emitSignedInt64(Record, *Range.getUpper().getRawData());
4086   };
4087 
4088   if (!FS->paramAccesses().empty()) {
4089     Record.clear();
4090     for (auto &Arg : FS->paramAccesses()) {
4091       size_t UndoSize = Record.size();
4092       Record.push_back(Arg.ParamNo);
4093       WriteRange(Arg.Use);
4094       Record.push_back(Arg.Calls.size());
4095       for (auto &Call : Arg.Calls) {
4096         Record.push_back(Call.ParamNo);
4097         std::optional<unsigned> ValueID = GetValueID(Call.Callee);
4098         if (!ValueID) {
4099           // If ValueID is unknown we can't drop just this call, we must drop
4100           // entire parameter.
4101           Record.resize(UndoSize);
4102           break;
4103         }
4104         Record.push_back(*ValueID);
4105         WriteRange(Call.Offsets);
4106       }
4107     }
4108     if (!Record.empty())
4109       Stream.EmitRecord(bitc::FS_PARAM_ACCESS, Record);
4110   }
4111 }
4112 
4113 /// Collect type IDs from type tests used by function.
4114 static void
4115 getReferencedTypeIds(FunctionSummary *FS,
4116                      std::set<GlobalValue::GUID> &ReferencedTypeIds) {
4117   if (!FS->type_tests().empty())
4118     for (auto &TT : FS->type_tests())
4119       ReferencedTypeIds.insert(TT);
4120 
4121   auto GetReferencedTypesFromVFuncIdVec =
4122       [&](ArrayRef<FunctionSummary::VFuncId> VFs) {
4123         for (auto &VF : VFs)
4124           ReferencedTypeIds.insert(VF.GUID);
4125       };
4126 
4127   GetReferencedTypesFromVFuncIdVec(FS->type_test_assume_vcalls());
4128   GetReferencedTypesFromVFuncIdVec(FS->type_checked_load_vcalls());
4129 
4130   auto GetReferencedTypesFromConstVCallVec =
4131       [&](ArrayRef<FunctionSummary::ConstVCall> VCs) {
4132         for (auto &VC : VCs)
4133           ReferencedTypeIds.insert(VC.VFunc.GUID);
4134       };
4135 
4136   GetReferencedTypesFromConstVCallVec(FS->type_test_assume_const_vcalls());
4137   GetReferencedTypesFromConstVCallVec(FS->type_checked_load_const_vcalls());
4138 }
4139 
4140 static void writeWholeProgramDevirtResolutionByArg(
4141     SmallVector<uint64_t, 64> &NameVals, const std::vector<uint64_t> &args,
4142     const WholeProgramDevirtResolution::ByArg &ByArg) {
4143   NameVals.push_back(args.size());
4144   llvm::append_range(NameVals, args);
4145 
4146   NameVals.push_back(ByArg.TheKind);
4147   NameVals.push_back(ByArg.Info);
4148   NameVals.push_back(ByArg.Byte);
4149   NameVals.push_back(ByArg.Bit);
4150 }
4151 
4152 static void writeWholeProgramDevirtResolution(
4153     SmallVector<uint64_t, 64> &NameVals, StringTableBuilder &StrtabBuilder,
4154     uint64_t Id, const WholeProgramDevirtResolution &Wpd) {
4155   NameVals.push_back(Id);
4156 
4157   NameVals.push_back(Wpd.TheKind);
4158   NameVals.push_back(StrtabBuilder.add(Wpd.SingleImplName));
4159   NameVals.push_back(Wpd.SingleImplName.size());
4160 
4161   NameVals.push_back(Wpd.ResByArg.size());
4162   for (auto &A : Wpd.ResByArg)
4163     writeWholeProgramDevirtResolutionByArg(NameVals, A.first, A.second);
4164 }
4165 
4166 static void writeTypeIdSummaryRecord(SmallVector<uint64_t, 64> &NameVals,
4167                                      StringTableBuilder &StrtabBuilder,
4168                                      const std::string &Id,
4169                                      const TypeIdSummary &Summary) {
4170   NameVals.push_back(StrtabBuilder.add(Id));
4171   NameVals.push_back(Id.size());
4172 
4173   NameVals.push_back(Summary.TTRes.TheKind);
4174   NameVals.push_back(Summary.TTRes.SizeM1BitWidth);
4175   NameVals.push_back(Summary.TTRes.AlignLog2);
4176   NameVals.push_back(Summary.TTRes.SizeM1);
4177   NameVals.push_back(Summary.TTRes.BitMask);
4178   NameVals.push_back(Summary.TTRes.InlineBits);
4179 
4180   for (auto &W : Summary.WPDRes)
4181     writeWholeProgramDevirtResolution(NameVals, StrtabBuilder, W.first,
4182                                       W.second);
4183 }
4184 
4185 static void writeTypeIdCompatibleVtableSummaryRecord(
4186     SmallVector<uint64_t, 64> &NameVals, StringTableBuilder &StrtabBuilder,
4187     const std::string &Id, const TypeIdCompatibleVtableInfo &Summary,
4188     ValueEnumerator &VE) {
4189   NameVals.push_back(StrtabBuilder.add(Id));
4190   NameVals.push_back(Id.size());
4191 
4192   for (auto &P : Summary) {
4193     NameVals.push_back(P.AddressPointOffset);
4194     NameVals.push_back(VE.getValueID(P.VTableVI.getValue()));
4195   }
4196 }
4197 
4198 static void writeFunctionHeapProfileRecords(
4199     BitstreamWriter &Stream, FunctionSummary *FS, unsigned CallsiteAbbrev,
4200     unsigned AllocAbbrev, unsigned ContextIdAbbvId, bool PerModule,
4201     std::function<unsigned(const ValueInfo &VI)> GetValueID,
4202     std::function<unsigned(unsigned)> GetStackIndex,
4203     bool WriteContextSizeInfoIndex) {
4204   SmallVector<uint64_t> Record;
4205 
4206   for (auto &CI : FS->callsites()) {
4207     Record.clear();
4208     // Per module callsite clones should always have a single entry of
4209     // value 0.
4210     assert(!PerModule || (CI.Clones.size() == 1 && CI.Clones[0] == 0));
4211     Record.push_back(GetValueID(CI.Callee));
4212     if (!PerModule) {
4213       Record.push_back(CI.StackIdIndices.size());
4214       Record.push_back(CI.Clones.size());
4215     }
4216     for (auto Id : CI.StackIdIndices)
4217       Record.push_back(GetStackIndex(Id));
4218     if (!PerModule) {
4219       for (auto V : CI.Clones)
4220         Record.push_back(V);
4221     }
4222     Stream.EmitRecord(PerModule ? bitc::FS_PERMODULE_CALLSITE_INFO
4223                                 : bitc::FS_COMBINED_CALLSITE_INFO,
4224                       Record, CallsiteAbbrev);
4225   }
4226 
4227   for (auto &AI : FS->allocs()) {
4228     Record.clear();
4229     // Per module alloc versions should always have a single entry of
4230     // value 0.
4231     assert(!PerModule || (AI.Versions.size() == 1 && AI.Versions[0] == 0));
4232     Record.push_back(AI.MIBs.size());
4233     if (!PerModule)
4234       Record.push_back(AI.Versions.size());
4235     for (auto &MIB : AI.MIBs) {
4236       Record.push_back((uint8_t)MIB.AllocType);
4237       Record.push_back(MIB.StackIdIndices.size());
4238       for (auto Id : MIB.StackIdIndices)
4239         Record.push_back(GetStackIndex(Id));
4240     }
4241     if (!PerModule) {
4242       for (auto V : AI.Versions)
4243         Record.push_back(V);
4244     }
4245     assert(AI.ContextSizeInfos.empty() ||
4246            AI.ContextSizeInfos.size() == AI.MIBs.size());
4247     // Optionally emit the context size information if it exists.
4248     if (WriteContextSizeInfoIndex && !AI.ContextSizeInfos.empty()) {
4249       // The abbreviation id for the context ids record should have been created
4250       // if we are emitting the per-module index, which is where we write this
4251       // info.
4252       assert(ContextIdAbbvId);
4253       SmallVector<uint32_t> ContextIds;
4254       // At least one context id per ContextSizeInfos entry (MIB), broken into 2
4255       // halves.
4256       ContextIds.reserve(AI.ContextSizeInfos.size() * 2);
4257       for (auto &Infos : AI.ContextSizeInfos) {
4258         Record.push_back(Infos.size());
4259         for (auto [FullStackId, TotalSize] : Infos) {
4260           // The context ids are emitted separately as a fixed width array,
4261           // which is more efficient than a VBR given that these hashes are
4262           // typically close to 64-bits. The max fixed width entry is 32 bits so
4263           // it is split into 2.
4264           ContextIds.push_back(static_cast<uint32_t>(FullStackId >> 32));
4265           ContextIds.push_back(static_cast<uint32_t>(FullStackId));
4266           Record.push_back(TotalSize);
4267         }
4268       }
4269       // The context ids are expected by the reader to immediately precede the
4270       // associated alloc info record.
4271       Stream.EmitRecord(bitc::FS_ALLOC_CONTEXT_IDS, ContextIds,
4272                         ContextIdAbbvId);
4273     }
4274     Stream.EmitRecord(PerModule ? bitc::FS_PERMODULE_ALLOC_INFO
4275                                 : bitc::FS_COMBINED_ALLOC_INFO,
4276                       Record, AllocAbbrev);
4277   }
4278 }
4279 
4280 // Helper to emit a single function summary record.
4281 void ModuleBitcodeWriterBase::writePerModuleFunctionSummaryRecord(
4282     SmallVector<uint64_t, 64> &NameVals, GlobalValueSummary *Summary,
4283     unsigned ValueID, unsigned FSCallsRelBFAbbrev,
4284     unsigned FSCallsProfileAbbrev, unsigned CallsiteAbbrev,
4285     unsigned AllocAbbrev, unsigned ContextIdAbbvId, const Function &F) {
4286   NameVals.push_back(ValueID);
4287 
4288   FunctionSummary *FS = cast<FunctionSummary>(Summary);
4289 
4290   writeFunctionTypeMetadataRecords(
4291       Stream, FS, [&](const ValueInfo &VI) -> std::optional<unsigned> {
4292         return {VE.getValueID(VI.getValue())};
4293       });
4294 
4295   writeFunctionHeapProfileRecords(
4296       Stream, FS, CallsiteAbbrev, AllocAbbrev, ContextIdAbbvId,
4297       /*PerModule*/ true,
4298       /*GetValueId*/ [&](const ValueInfo &VI) { return getValueId(VI); },
4299       /*GetStackIndex*/ [&](unsigned I) { return I; },
4300       /*WriteContextSizeInfoIndex*/ true);
4301 
4302   auto SpecialRefCnts = FS->specialRefCounts();
4303   NameVals.push_back(getEncodedGVSummaryFlags(FS->flags()));
4304   NameVals.push_back(FS->instCount());
4305   NameVals.push_back(getEncodedFFlags(FS->fflags()));
4306   NameVals.push_back(FS->refs().size());
4307   NameVals.push_back(SpecialRefCnts.first);  // rorefcnt
4308   NameVals.push_back(SpecialRefCnts.second); // worefcnt
4309 
4310   for (auto &RI : FS->refs())
4311     NameVals.push_back(getValueId(RI));
4312 
4313   const bool UseRelBFRecord =
4314       WriteRelBFToSummary && !F.hasProfileData() &&
4315       ForceSummaryEdgesCold == FunctionSummary::FSHT_None;
4316   for (auto &ECI : FS->calls()) {
4317     NameVals.push_back(getValueId(ECI.first));
4318     if (UseRelBFRecord)
4319       NameVals.push_back(getEncodedRelBFCallEdgeInfo(ECI.second));
4320     else
4321       NameVals.push_back(getEncodedHotnessCallEdgeInfo(ECI.second));
4322   }
4323 
4324   unsigned FSAbbrev =
4325       (UseRelBFRecord ? FSCallsRelBFAbbrev : FSCallsProfileAbbrev);
4326   unsigned Code =
4327       (UseRelBFRecord ? bitc::FS_PERMODULE_RELBF : bitc::FS_PERMODULE_PROFILE);
4328 
4329   // Emit the finished record.
4330   Stream.EmitRecord(Code, NameVals, FSAbbrev);
4331   NameVals.clear();
4332 }
4333 
4334 // Collect the global value references in the given variable's initializer,
4335 // and emit them in a summary record.
4336 void ModuleBitcodeWriterBase::writeModuleLevelReferences(
4337     const GlobalVariable &V, SmallVector<uint64_t, 64> &NameVals,
4338     unsigned FSModRefsAbbrev, unsigned FSModVTableRefsAbbrev) {
4339   auto VI = Index->getValueInfo(V.getGUID());
4340   if (!VI || VI.getSummaryList().empty()) {
4341     // Only declarations should not have a summary (a declaration might however
4342     // have a summary if the def was in module level asm).
4343     assert(V.isDeclaration());
4344     return;
4345   }
4346   auto *Summary = VI.getSummaryList()[0].get();
4347   NameVals.push_back(VE.getValueID(&V));
4348   GlobalVarSummary *VS = cast<GlobalVarSummary>(Summary);
4349   NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
4350   NameVals.push_back(getEncodedGVarFlags(VS->varflags()));
4351 
4352   auto VTableFuncs = VS->vTableFuncs();
4353   if (!VTableFuncs.empty())
4354     NameVals.push_back(VS->refs().size());
4355 
4356   unsigned SizeBeforeRefs = NameVals.size();
4357   for (auto &RI : VS->refs())
4358     NameVals.push_back(VE.getValueID(RI.getValue()));
4359   // Sort the refs for determinism output, the vector returned by FS->refs() has
4360   // been initialized from a DenseSet.
4361   llvm::sort(drop_begin(NameVals, SizeBeforeRefs));
4362 
4363   if (VTableFuncs.empty())
4364     Stream.EmitRecord(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS, NameVals,
4365                       FSModRefsAbbrev);
4366   else {
4367     // VTableFuncs pairs should already be sorted by offset.
4368     for (auto &P : VTableFuncs) {
4369       NameVals.push_back(VE.getValueID(P.FuncVI.getValue()));
4370       NameVals.push_back(P.VTableOffset);
4371     }
4372 
4373     Stream.EmitRecord(bitc::FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS, NameVals,
4374                       FSModVTableRefsAbbrev);
4375   }
4376   NameVals.clear();
4377 }
4378 
4379 /// Emit the per-module summary section alongside the rest of
4380 /// the module's bitcode.
4381 void ModuleBitcodeWriterBase::writePerModuleGlobalValueSummary() {
4382   // By default we compile with ThinLTO if the module has a summary, but the
4383   // client can request full LTO with a module flag.
4384   bool IsThinLTO = true;
4385   if (auto *MD =
4386           mdconst::extract_or_null<ConstantInt>(M.getModuleFlag("ThinLTO")))
4387     IsThinLTO = MD->getZExtValue();
4388   Stream.EnterSubblock(IsThinLTO ? bitc::GLOBALVAL_SUMMARY_BLOCK_ID
4389                                  : bitc::FULL_LTO_GLOBALVAL_SUMMARY_BLOCK_ID,
4390                        4);
4391 
4392   Stream.EmitRecord(
4393       bitc::FS_VERSION,
4394       ArrayRef<uint64_t>{ModuleSummaryIndex::BitcodeSummaryVersion});
4395 
4396   // Write the index flags.
4397   uint64_t Flags = 0;
4398   // Bits 1-3 are set only in the combined index, skip them.
4399   if (Index->enableSplitLTOUnit())
4400     Flags |= 0x8;
4401   if (Index->hasUnifiedLTO())
4402     Flags |= 0x200;
4403 
4404   Stream.EmitRecord(bitc::FS_FLAGS, ArrayRef<uint64_t>{Flags});
4405 
4406   if (Index->begin() == Index->end()) {
4407     Stream.ExitBlock();
4408     return;
4409   }
4410 
4411   auto Abbv = std::make_shared<BitCodeAbbrev>();
4412   Abbv->Add(BitCodeAbbrevOp(bitc::FS_VALUE_GUID));
4413   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
4414   // GUIDS often use up most of 64-bits, so encode as two Fixed 32.
4415   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4416   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4417   unsigned ValueGuidAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4418 
4419   for (const auto &GVI : valueIds()) {
4420     Stream.EmitRecord(bitc::FS_VALUE_GUID,
4421                       ArrayRef<uint32_t>{GVI.second,
4422                                          static_cast<uint32_t>(GVI.first >> 32),
4423                                          static_cast<uint32_t>(GVI.first)},
4424                       ValueGuidAbbrev);
4425   }
4426 
4427   if (!Index->stackIds().empty()) {
4428     auto StackIdAbbv = std::make_shared<BitCodeAbbrev>();
4429     StackIdAbbv->Add(BitCodeAbbrevOp(bitc::FS_STACK_IDS));
4430     // numids x stackid
4431     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4432     // The stack ids are hashes that are close to 64 bits in size, so emitting
4433     // as a pair of 32-bit fixed-width values is more efficient than a VBR.
4434     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4435     unsigned StackIdAbbvId = Stream.EmitAbbrev(std::move(StackIdAbbv));
4436     SmallVector<uint32_t> Vals;
4437     Vals.reserve(Index->stackIds().size() * 2);
4438     for (auto Id : Index->stackIds()) {
4439       Vals.push_back(static_cast<uint32_t>(Id >> 32));
4440       Vals.push_back(static_cast<uint32_t>(Id));
4441     }
4442     Stream.EmitRecord(bitc::FS_STACK_IDS, Vals, StackIdAbbvId);
4443   }
4444 
4445   // n x context id
4446   auto ContextIdAbbv = std::make_shared<BitCodeAbbrev>();
4447   ContextIdAbbv->Add(BitCodeAbbrevOp(bitc::FS_ALLOC_CONTEXT_IDS));
4448   ContextIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4449   // The context ids are hashes that are close to 64 bits in size, so emitting
4450   // as a pair of 32-bit fixed-width values is more efficient than a VBR.
4451   ContextIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4452   unsigned ContextIdAbbvId = Stream.EmitAbbrev(std::move(ContextIdAbbv));
4453 
4454   // Abbrev for FS_PERMODULE_PROFILE.
4455   Abbv = std::make_shared<BitCodeAbbrev>();
4456   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_PROFILE));
4457   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4458   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // flags
4459   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4460   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4461   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4462   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4463   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4464   // numrefs x valueid, n x (valueid, hotness+tailcall flags)
4465   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4466   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4467   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4468 
4469   // Abbrev for FS_PERMODULE_RELBF.
4470   Abbv = std::make_shared<BitCodeAbbrev>();
4471   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_RELBF));
4472   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4473   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4474   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4475   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4476   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4477   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4478   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4479   // numrefs x valueid, n x (valueid, rel_block_freq+tailcall])
4480   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4481   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4482   unsigned FSCallsRelBFAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4483 
4484   // Abbrev for FS_PERMODULE_GLOBALVAR_INIT_REFS.
4485   Abbv = std::make_shared<BitCodeAbbrev>();
4486   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS));
4487   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4488   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
4489   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));  // valueids
4490   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4491   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4492 
4493   // Abbrev for FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS.
4494   Abbv = std::make_shared<BitCodeAbbrev>();
4495   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS));
4496   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4497   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
4498   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numrefs
4499   // numrefs x valueid, n x (valueid , offset)
4500   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4501   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4502   unsigned FSModVTableRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4503 
4504   // Abbrev for FS_ALIAS.
4505   Abbv = std::make_shared<BitCodeAbbrev>();
4506   Abbv->Add(BitCodeAbbrevOp(bitc::FS_ALIAS));
4507   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4508   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4509   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4510   unsigned FSAliasAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4511 
4512   // Abbrev for FS_TYPE_ID_METADATA
4513   Abbv = std::make_shared<BitCodeAbbrev>();
4514   Abbv->Add(BitCodeAbbrevOp(bitc::FS_TYPE_ID_METADATA));
4515   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // typeid strtab index
4516   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // typeid length
4517   // n x (valueid , offset)
4518   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4519   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4520   unsigned TypeIdCompatibleVtableAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4521 
4522   Abbv = std::make_shared<BitCodeAbbrev>();
4523   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_CALLSITE_INFO));
4524   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4525   // n x stackidindex
4526   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4527   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4528   unsigned CallsiteAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4529 
4530   Abbv = std::make_shared<BitCodeAbbrev>();
4531   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_ALLOC_INFO));
4532   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // nummib
4533   // n x (alloc type, numstackids, numstackids x stackidindex)
4534   // optional: nummib x (numcontext x total size)
4535   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4536   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4537   unsigned AllocAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4538 
4539   SmallVector<uint64_t, 64> NameVals;
4540   // Iterate over the list of functions instead of the Index to
4541   // ensure the ordering is stable.
4542   for (const Function &F : M) {
4543     // Summary emission does not support anonymous functions, they have to
4544     // renamed using the anonymous function renaming pass.
4545     if (!F.hasName())
4546       report_fatal_error("Unexpected anonymous function when writing summary");
4547 
4548     ValueInfo VI = Index->getValueInfo(F.getGUID());
4549     if (!VI || VI.getSummaryList().empty()) {
4550       // Only declarations should not have a summary (a declaration might
4551       // however have a summary if the def was in module level asm).
4552       assert(F.isDeclaration());
4553       continue;
4554     }
4555     auto *Summary = VI.getSummaryList()[0].get();
4556     writePerModuleFunctionSummaryRecord(
4557         NameVals, Summary, VE.getValueID(&F), FSCallsRelBFAbbrev,
4558         FSCallsProfileAbbrev, CallsiteAbbrev, AllocAbbrev, ContextIdAbbvId, F);
4559   }
4560 
4561   // Capture references from GlobalVariable initializers, which are outside
4562   // of a function scope.
4563   for (const GlobalVariable &G : M.globals())
4564     writeModuleLevelReferences(G, NameVals, FSModRefsAbbrev,
4565                                FSModVTableRefsAbbrev);
4566 
4567   for (const GlobalAlias &A : M.aliases()) {
4568     auto *Aliasee = A.getAliaseeObject();
4569     // Skip ifunc and nameless functions which don't have an entry in the
4570     // summary.
4571     if (!Aliasee->hasName() || isa<GlobalIFunc>(Aliasee))
4572       continue;
4573     auto AliasId = VE.getValueID(&A);
4574     auto AliaseeId = VE.getValueID(Aliasee);
4575     NameVals.push_back(AliasId);
4576     auto *Summary = Index->getGlobalValueSummary(A);
4577     AliasSummary *AS = cast<AliasSummary>(Summary);
4578     NameVals.push_back(getEncodedGVSummaryFlags(AS->flags()));
4579     NameVals.push_back(AliaseeId);
4580     Stream.EmitRecord(bitc::FS_ALIAS, NameVals, FSAliasAbbrev);
4581     NameVals.clear();
4582   }
4583 
4584   for (auto &S : Index->typeIdCompatibleVtableMap()) {
4585     writeTypeIdCompatibleVtableSummaryRecord(NameVals, StrtabBuilder, S.first,
4586                                              S.second, VE);
4587     Stream.EmitRecord(bitc::FS_TYPE_ID_METADATA, NameVals,
4588                       TypeIdCompatibleVtableAbbrev);
4589     NameVals.clear();
4590   }
4591 
4592   if (Index->getBlockCount())
4593     Stream.EmitRecord(bitc::FS_BLOCK_COUNT,
4594                       ArrayRef<uint64_t>{Index->getBlockCount()});
4595 
4596   Stream.ExitBlock();
4597 }
4598 
4599 /// Emit the combined summary section into the combined index file.
4600 void IndexBitcodeWriter::writeCombinedGlobalValueSummary() {
4601   Stream.EnterSubblock(bitc::GLOBALVAL_SUMMARY_BLOCK_ID, 4);
4602   Stream.EmitRecord(
4603       bitc::FS_VERSION,
4604       ArrayRef<uint64_t>{ModuleSummaryIndex::BitcodeSummaryVersion});
4605 
4606   // Write the index flags.
4607   Stream.EmitRecord(bitc::FS_FLAGS, ArrayRef<uint64_t>{Index.getFlags()});
4608 
4609   auto Abbv = std::make_shared<BitCodeAbbrev>();
4610   Abbv->Add(BitCodeAbbrevOp(bitc::FS_VALUE_GUID));
4611   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
4612   // GUIDS often use up most of 64-bits, so encode as two Fixed 32.
4613   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4614   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4615   unsigned ValueGuidAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4616 
4617   for (const auto &GVI : valueIds()) {
4618     Stream.EmitRecord(bitc::FS_VALUE_GUID,
4619                       ArrayRef<uint32_t>{GVI.second,
4620                                          static_cast<uint32_t>(GVI.first >> 32),
4621                                          static_cast<uint32_t>(GVI.first)},
4622                       ValueGuidAbbrev);
4623   }
4624 
4625   // Write the stack ids used by this index, which will be a subset of those in
4626   // the full index in the case of distributed indexes.
4627   if (!StackIds.empty()) {
4628     auto StackIdAbbv = std::make_shared<BitCodeAbbrev>();
4629     StackIdAbbv->Add(BitCodeAbbrevOp(bitc::FS_STACK_IDS));
4630     // numids x stackid
4631     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4632     // The stack ids are hashes that are close to 64 bits in size, so emitting
4633     // as a pair of 32-bit fixed-width values is more efficient than a VBR.
4634     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4635     unsigned StackIdAbbvId = Stream.EmitAbbrev(std::move(StackIdAbbv));
4636     SmallVector<uint32_t> Vals;
4637     Vals.reserve(StackIds.size() * 2);
4638     for (auto Id : StackIds) {
4639       Vals.push_back(static_cast<uint32_t>(Id >> 32));
4640       Vals.push_back(static_cast<uint32_t>(Id));
4641     }
4642     Stream.EmitRecord(bitc::FS_STACK_IDS, Vals, StackIdAbbvId);
4643   }
4644 
4645   // Abbrev for FS_COMBINED_PROFILE.
4646   Abbv = std::make_shared<BitCodeAbbrev>();
4647   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_PROFILE));
4648   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4649   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4650   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4651   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4652   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4653   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // entrycount
4654   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4655   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4656   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4657   // numrefs x valueid, n x (valueid, hotness+tailcall flags)
4658   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4659   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4660   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4661 
4662   // Abbrev for FS_COMBINED_GLOBALVAR_INIT_REFS.
4663   Abbv = std::make_shared<BitCodeAbbrev>();
4664   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS));
4665   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4666   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4667   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4668   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));    // valueids
4669   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4670   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4671 
4672   // Abbrev for FS_COMBINED_ALIAS.
4673   Abbv = std::make_shared<BitCodeAbbrev>();
4674   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_ALIAS));
4675   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4676   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4677   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4678   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4679   unsigned FSAliasAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4680 
4681   Abbv = std::make_shared<BitCodeAbbrev>();
4682   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_CALLSITE_INFO));
4683   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4684   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numstackindices
4685   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numver
4686   // numstackindices x stackidindex, numver x version
4687   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4688   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4689   unsigned CallsiteAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4690 
4691   Abbv = std::make_shared<BitCodeAbbrev>();
4692   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_ALLOC_INFO));
4693   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // nummib
4694   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numver
4695   // nummib x (alloc type, numstackids, numstackids x stackidindex),
4696   // numver x version
4697   // optional: nummib x total size
4698   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4699   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4700   unsigned AllocAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4701 
4702   auto shouldImportValueAsDecl = [&](GlobalValueSummary *GVS) -> bool {
4703     if (DecSummaries == nullptr)
4704       return false;
4705     return DecSummaries->count(GVS);
4706   };
4707 
4708   // The aliases are emitted as a post-pass, and will point to the value
4709   // id of the aliasee. Save them in a vector for post-processing.
4710   SmallVector<AliasSummary *, 64> Aliases;
4711 
4712   // Save the value id for each summary for alias emission.
4713   DenseMap<const GlobalValueSummary *, unsigned> SummaryToValueIdMap;
4714 
4715   SmallVector<uint64_t, 64> NameVals;
4716 
4717   // Set that will be populated during call to writeFunctionTypeMetadataRecords
4718   // with the type ids referenced by this index file.
4719   std::set<GlobalValue::GUID> ReferencedTypeIds;
4720 
4721   // For local linkage, we also emit the original name separately
4722   // immediately after the record.
4723   auto MaybeEmitOriginalName = [&](GlobalValueSummary &S) {
4724     // We don't need to emit the original name if we are writing the index for
4725     // distributed backends (in which case ModuleToSummariesForIndex is
4726     // non-null). The original name is only needed during the thin link, since
4727     // for SamplePGO the indirect call targets for local functions have
4728     // have the original name annotated in profile.
4729     // Continue to emit it when writing out the entire combined index, which is
4730     // used in testing the thin link via llvm-lto.
4731     if (ModuleToSummariesForIndex || !GlobalValue::isLocalLinkage(S.linkage()))
4732       return;
4733     NameVals.push_back(S.getOriginalName());
4734     Stream.EmitRecord(bitc::FS_COMBINED_ORIGINAL_NAME, NameVals);
4735     NameVals.clear();
4736   };
4737 
4738   DenseSet<GlobalValue::GUID> DefOrUseGUIDs;
4739   forEachSummary([&](GVInfo I, bool IsAliasee) {
4740     GlobalValueSummary *S = I.second;
4741     assert(S);
4742     DefOrUseGUIDs.insert(I.first);
4743     for (const ValueInfo &VI : S->refs())
4744       DefOrUseGUIDs.insert(VI.getGUID());
4745 
4746     auto ValueId = getValueId(I.first);
4747     assert(ValueId);
4748     SummaryToValueIdMap[S] = *ValueId;
4749 
4750     // If this is invoked for an aliasee, we want to record the above
4751     // mapping, but then not emit a summary entry (if the aliasee is
4752     // to be imported, we will invoke this separately with IsAliasee=false).
4753     if (IsAliasee)
4754       return;
4755 
4756     if (auto *AS = dyn_cast<AliasSummary>(S)) {
4757       // Will process aliases as a post-pass because the reader wants all
4758       // global to be loaded first.
4759       Aliases.push_back(AS);
4760       return;
4761     }
4762 
4763     if (auto *VS = dyn_cast<GlobalVarSummary>(S)) {
4764       NameVals.push_back(*ValueId);
4765       assert(ModuleIdMap.count(VS->modulePath()));
4766       NameVals.push_back(ModuleIdMap[VS->modulePath()]);
4767       NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
4768       NameVals.push_back(getEncodedGVarFlags(VS->varflags()));
4769       for (auto &RI : VS->refs()) {
4770         auto RefValueId = getValueId(RI.getGUID());
4771         if (!RefValueId)
4772           continue;
4773         NameVals.push_back(*RefValueId);
4774       }
4775 
4776       // Emit the finished record.
4777       Stream.EmitRecord(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS, NameVals,
4778                         FSModRefsAbbrev);
4779       NameVals.clear();
4780       MaybeEmitOriginalName(*S);
4781       return;
4782     }
4783 
4784     auto GetValueId = [&](const ValueInfo &VI) -> std::optional<unsigned> {
4785       if (!VI)
4786         return std::nullopt;
4787       return getValueId(VI.getGUID());
4788     };
4789 
4790     auto *FS = cast<FunctionSummary>(S);
4791     writeFunctionTypeMetadataRecords(Stream, FS, GetValueId);
4792     getReferencedTypeIds(FS, ReferencedTypeIds);
4793 
4794     writeFunctionHeapProfileRecords(
4795         Stream, FS, CallsiteAbbrev, AllocAbbrev, /*ContextIdAbbvId*/ 0,
4796         /*PerModule*/ false,
4797         /*GetValueId*/
4798         [&](const ValueInfo &VI) -> unsigned {
4799           std::optional<unsigned> ValueID = GetValueId(VI);
4800           // This can happen in shared index files for distributed ThinLTO if
4801           // the callee function summary is not included. Record 0 which we
4802           // will have to deal with conservatively when doing any kind of
4803           // validation in the ThinLTO backends.
4804           if (!ValueID)
4805             return 0;
4806           return *ValueID;
4807         },
4808         /*GetStackIndex*/
4809         [&](unsigned I) {
4810           // Get the corresponding index into the list of StackIds actually
4811           // being written for this combined index (which may be a subset in
4812           // the case of distributed indexes).
4813           assert(StackIdIndicesToIndex.contains(I));
4814           return StackIdIndicesToIndex[I];
4815         },
4816         /*WriteContextSizeInfoIndex*/ false);
4817 
4818     NameVals.push_back(*ValueId);
4819     assert(ModuleIdMap.count(FS->modulePath()));
4820     NameVals.push_back(ModuleIdMap[FS->modulePath()]);
4821     NameVals.push_back(
4822         getEncodedGVSummaryFlags(FS->flags(), shouldImportValueAsDecl(FS)));
4823     NameVals.push_back(FS->instCount());
4824     NameVals.push_back(getEncodedFFlags(FS->fflags()));
4825     // TODO: Stop writing entry count and bump bitcode version.
4826     NameVals.push_back(0 /* EntryCount */);
4827 
4828     // Fill in below
4829     NameVals.push_back(0); // numrefs
4830     NameVals.push_back(0); // rorefcnt
4831     NameVals.push_back(0); // worefcnt
4832 
4833     unsigned Count = 0, RORefCnt = 0, WORefCnt = 0;
4834     for (auto &RI : FS->refs()) {
4835       auto RefValueId = getValueId(RI.getGUID());
4836       if (!RefValueId)
4837         continue;
4838       NameVals.push_back(*RefValueId);
4839       if (RI.isReadOnly())
4840         RORefCnt++;
4841       else if (RI.isWriteOnly())
4842         WORefCnt++;
4843       Count++;
4844     }
4845     NameVals[6] = Count;
4846     NameVals[7] = RORefCnt;
4847     NameVals[8] = WORefCnt;
4848 
4849     for (auto &EI : FS->calls()) {
4850       // If this GUID doesn't have a value id, it doesn't have a function
4851       // summary and we don't need to record any calls to it.
4852       std::optional<unsigned> CallValueId = GetValueId(EI.first);
4853       if (!CallValueId)
4854         continue;
4855       NameVals.push_back(*CallValueId);
4856       NameVals.push_back(getEncodedHotnessCallEdgeInfo(EI.second));
4857     }
4858 
4859     // Emit the finished record.
4860     Stream.EmitRecord(bitc::FS_COMBINED_PROFILE, NameVals,
4861                       FSCallsProfileAbbrev);
4862     NameVals.clear();
4863     MaybeEmitOriginalName(*S);
4864   });
4865 
4866   for (auto *AS : Aliases) {
4867     auto AliasValueId = SummaryToValueIdMap[AS];
4868     assert(AliasValueId);
4869     NameVals.push_back(AliasValueId);
4870     assert(ModuleIdMap.count(AS->modulePath()));
4871     NameVals.push_back(ModuleIdMap[AS->modulePath()]);
4872     NameVals.push_back(
4873         getEncodedGVSummaryFlags(AS->flags(), shouldImportValueAsDecl(AS)));
4874     auto AliaseeValueId = SummaryToValueIdMap[&AS->getAliasee()];
4875     assert(AliaseeValueId);
4876     NameVals.push_back(AliaseeValueId);
4877 
4878     // Emit the finished record.
4879     Stream.EmitRecord(bitc::FS_COMBINED_ALIAS, NameVals, FSAliasAbbrev);
4880     NameVals.clear();
4881     MaybeEmitOriginalName(*AS);
4882 
4883     if (auto *FS = dyn_cast<FunctionSummary>(&AS->getAliasee()))
4884       getReferencedTypeIds(FS, ReferencedTypeIds);
4885   }
4886 
4887   if (!Index.cfiFunctionDefs().empty()) {
4888     for (auto &S : Index.cfiFunctionDefs()) {
4889       if (DefOrUseGUIDs.contains(
4890               GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(S)))) {
4891         NameVals.push_back(StrtabBuilder.add(S));
4892         NameVals.push_back(S.size());
4893       }
4894     }
4895     if (!NameVals.empty()) {
4896       Stream.EmitRecord(bitc::FS_CFI_FUNCTION_DEFS, NameVals);
4897       NameVals.clear();
4898     }
4899   }
4900 
4901   if (!Index.cfiFunctionDecls().empty()) {
4902     for (auto &S : Index.cfiFunctionDecls()) {
4903       if (DefOrUseGUIDs.contains(
4904               GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(S)))) {
4905         NameVals.push_back(StrtabBuilder.add(S));
4906         NameVals.push_back(S.size());
4907       }
4908     }
4909     if (!NameVals.empty()) {
4910       Stream.EmitRecord(bitc::FS_CFI_FUNCTION_DECLS, NameVals);
4911       NameVals.clear();
4912     }
4913   }
4914 
4915   // Walk the GUIDs that were referenced, and write the
4916   // corresponding type id records.
4917   for (auto &T : ReferencedTypeIds) {
4918     auto TidIter = Index.typeIds().equal_range(T);
4919     for (const auto &[GUID, TypeIdPair] : make_range(TidIter)) {
4920       writeTypeIdSummaryRecord(NameVals, StrtabBuilder, TypeIdPair.first,
4921                                TypeIdPair.second);
4922       Stream.EmitRecord(bitc::FS_TYPE_ID, NameVals);
4923       NameVals.clear();
4924     }
4925   }
4926 
4927   if (Index.getBlockCount())
4928     Stream.EmitRecord(bitc::FS_BLOCK_COUNT,
4929                       ArrayRef<uint64_t>{Index.getBlockCount()});
4930 
4931   Stream.ExitBlock();
4932 }
4933 
4934 /// Create the "IDENTIFICATION_BLOCK_ID" containing a single string with the
4935 /// current llvm version, and a record for the epoch number.
4936 static void writeIdentificationBlock(BitstreamWriter &Stream) {
4937   Stream.EnterSubblock(bitc::IDENTIFICATION_BLOCK_ID, 5);
4938 
4939   // Write the "user readable" string identifying the bitcode producer
4940   auto Abbv = std::make_shared<BitCodeAbbrev>();
4941   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_STRING));
4942   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4943   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
4944   auto StringAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4945   writeStringRecord(Stream, bitc::IDENTIFICATION_CODE_STRING,
4946                     "LLVM" LLVM_VERSION_STRING, StringAbbrev);
4947 
4948   // Write the epoch version
4949   Abbv = std::make_shared<BitCodeAbbrev>();
4950   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_EPOCH));
4951   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
4952   auto EpochAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4953   constexpr std::array<unsigned, 1> Vals = {{bitc::BITCODE_CURRENT_EPOCH}};
4954   Stream.EmitRecord(bitc::IDENTIFICATION_CODE_EPOCH, Vals, EpochAbbrev);
4955   Stream.ExitBlock();
4956 }
4957 
4958 void ModuleBitcodeWriter::writeModuleHash(StringRef View) {
4959   // Emit the module's hash.
4960   // MODULE_CODE_HASH: [5*i32]
4961   if (GenerateHash) {
4962     uint32_t Vals[5];
4963     Hasher.update(ArrayRef<uint8_t>(
4964         reinterpret_cast<const uint8_t *>(View.data()), View.size()));
4965     std::array<uint8_t, 20> Hash = Hasher.result();
4966     for (int Pos = 0; Pos < 20; Pos += 4) {
4967       Vals[Pos / 4] = support::endian::read32be(Hash.data() + Pos);
4968     }
4969 
4970     // Emit the finished record.
4971     Stream.EmitRecord(bitc::MODULE_CODE_HASH, Vals);
4972 
4973     if (ModHash)
4974       // Save the written hash value.
4975       llvm::copy(Vals, std::begin(*ModHash));
4976   }
4977 }
4978 
4979 void ModuleBitcodeWriter::write() {
4980   writeIdentificationBlock(Stream);
4981 
4982   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
4983   // We will want to write the module hash at this point. Block any flushing so
4984   // we can have access to the whole underlying data later.
4985   Stream.markAndBlockFlushing();
4986 
4987   writeModuleVersion();
4988 
4989   // Emit blockinfo, which defines the standard abbreviations etc.
4990   writeBlockInfo();
4991 
4992   // Emit information describing all of the types in the module.
4993   writeTypeTable();
4994 
4995   // Emit information about attribute groups.
4996   writeAttributeGroupTable();
4997 
4998   // Emit information about parameter attributes.
4999   writeAttributeTable();
5000 
5001   writeComdats();
5002 
5003   // Emit top-level description of module, including target triple, inline asm,
5004   // descriptors for global variables, and function prototype info.
5005   writeModuleInfo();
5006 
5007   // Emit constants.
5008   writeModuleConstants();
5009 
5010   // Emit metadata kind names.
5011   writeModuleMetadataKinds();
5012 
5013   // Emit metadata.
5014   writeModuleMetadata();
5015 
5016   // Emit module-level use-lists.
5017   if (VE.shouldPreserveUseListOrder())
5018     writeUseListBlock(nullptr);
5019 
5020   writeOperandBundleTags();
5021   writeSyncScopeNames();
5022 
5023   // Emit function bodies.
5024   DenseMap<const Function *, uint64_t> FunctionToBitcodeIndex;
5025   for (const Function &F : M)
5026     if (!F.isDeclaration())
5027       writeFunction(F, FunctionToBitcodeIndex);
5028 
5029   // Need to write after the above call to WriteFunction which populates
5030   // the summary information in the index.
5031   if (Index)
5032     writePerModuleGlobalValueSummary();
5033 
5034   writeGlobalValueSymbolTable(FunctionToBitcodeIndex);
5035 
5036   writeModuleHash(Stream.getMarkedBufferAndResumeFlushing());
5037 
5038   Stream.ExitBlock();
5039 }
5040 
5041 static void writeInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
5042                                uint32_t &Position) {
5043   support::endian::write32le(&Buffer[Position], Value);
5044   Position += 4;
5045 }
5046 
5047 /// If generating a bc file on darwin, we have to emit a
5048 /// header and trailer to make it compatible with the system archiver.  To do
5049 /// this we emit the following header, and then emit a trailer that pads the
5050 /// file out to be a multiple of 16 bytes.
5051 ///
5052 /// struct bc_header {
5053 ///   uint32_t Magic;         // 0x0B17C0DE
5054 ///   uint32_t Version;       // Version, currently always 0.
5055 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
5056 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
5057 ///   uint32_t CPUType;       // CPU specifier.
5058 ///   ... potentially more later ...
5059 /// };
5060 static void emitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
5061                                          const Triple &TT) {
5062   unsigned CPUType = ~0U;
5063 
5064   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
5065   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
5066   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
5067   // specific constants here because they are implicitly part of the Darwin ABI.
5068   enum {
5069     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
5070     DARWIN_CPU_TYPE_X86        = 7,
5071     DARWIN_CPU_TYPE_ARM        = 12,
5072     DARWIN_CPU_TYPE_POWERPC    = 18
5073   };
5074 
5075   Triple::ArchType Arch = TT.getArch();
5076   if (Arch == Triple::x86_64)
5077     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
5078   else if (Arch == Triple::x86)
5079     CPUType = DARWIN_CPU_TYPE_X86;
5080   else if (Arch == Triple::ppc)
5081     CPUType = DARWIN_CPU_TYPE_POWERPC;
5082   else if (Arch == Triple::ppc64)
5083     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
5084   else if (Arch == Triple::arm || Arch == Triple::thumb)
5085     CPUType = DARWIN_CPU_TYPE_ARM;
5086 
5087   // Traditional Bitcode starts after header.
5088   assert(Buffer.size() >= BWH_HeaderSize &&
5089          "Expected header size to be reserved");
5090   unsigned BCOffset = BWH_HeaderSize;
5091   unsigned BCSize = Buffer.size() - BWH_HeaderSize;
5092 
5093   // Write the magic and version.
5094   unsigned Position = 0;
5095   writeInt32ToBuffer(0x0B17C0DE, Buffer, Position);
5096   writeInt32ToBuffer(0, Buffer, Position); // Version.
5097   writeInt32ToBuffer(BCOffset, Buffer, Position);
5098   writeInt32ToBuffer(BCSize, Buffer, Position);
5099   writeInt32ToBuffer(CPUType, Buffer, Position);
5100 
5101   // If the file is not a multiple of 16 bytes, insert dummy padding.
5102   while (Buffer.size() & 15)
5103     Buffer.push_back(0);
5104 }
5105 
5106 /// Helper to write the header common to all bitcode files.
5107 static void writeBitcodeHeader(BitstreamWriter &Stream) {
5108   // Emit the file header.
5109   Stream.Emit((unsigned)'B', 8);
5110   Stream.Emit((unsigned)'C', 8);
5111   Stream.Emit(0x0, 4);
5112   Stream.Emit(0xC, 4);
5113   Stream.Emit(0xE, 4);
5114   Stream.Emit(0xD, 4);
5115 }
5116 
5117 BitcodeWriter::BitcodeWriter(SmallVectorImpl<char> &Buffer)
5118     : Stream(new BitstreamWriter(Buffer)) {
5119   writeBitcodeHeader(*Stream);
5120 }
5121 
5122 BitcodeWriter::BitcodeWriter(raw_ostream &FS)
5123     : Stream(new BitstreamWriter(FS, FlushThreshold)) {
5124   writeBitcodeHeader(*Stream);
5125 }
5126 
5127 BitcodeWriter::~BitcodeWriter() { assert(WroteStrtab); }
5128 
5129 void BitcodeWriter::writeBlob(unsigned Block, unsigned Record, StringRef Blob) {
5130   Stream->EnterSubblock(Block, 3);
5131 
5132   auto Abbv = std::make_shared<BitCodeAbbrev>();
5133   Abbv->Add(BitCodeAbbrevOp(Record));
5134   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
5135   auto AbbrevNo = Stream->EmitAbbrev(std::move(Abbv));
5136 
5137   Stream->EmitRecordWithBlob(AbbrevNo, ArrayRef<uint64_t>{Record}, Blob);
5138 
5139   Stream->ExitBlock();
5140 }
5141 
5142 void BitcodeWriter::writeSymtab() {
5143   assert(!WroteStrtab && !WroteSymtab);
5144 
5145   // If any module has module-level inline asm, we will require a registered asm
5146   // parser for the target so that we can create an accurate symbol table for
5147   // the module.
5148   for (Module *M : Mods) {
5149     if (M->getModuleInlineAsm().empty())
5150       continue;
5151 
5152     std::string Err;
5153     const Triple TT(M->getTargetTriple());
5154     const Target *T = TargetRegistry::lookupTarget(TT.str(), Err);
5155     if (!T || !T->hasMCAsmParser())
5156       return;
5157   }
5158 
5159   WroteSymtab = true;
5160   SmallVector<char, 0> Symtab;
5161   // The irsymtab::build function may be unable to create a symbol table if the
5162   // module is malformed (e.g. it contains an invalid alias). Writing a symbol
5163   // table is not required for correctness, but we still want to be able to
5164   // write malformed modules to bitcode files, so swallow the error.
5165   if (Error E = irsymtab::build(Mods, Symtab, StrtabBuilder, Alloc)) {
5166     consumeError(std::move(E));
5167     return;
5168   }
5169 
5170   writeBlob(bitc::SYMTAB_BLOCK_ID, bitc::SYMTAB_BLOB,
5171             {Symtab.data(), Symtab.size()});
5172 }
5173 
5174 void BitcodeWriter::writeStrtab() {
5175   assert(!WroteStrtab);
5176 
5177   std::vector<char> Strtab;
5178   StrtabBuilder.finalizeInOrder();
5179   Strtab.resize(StrtabBuilder.getSize());
5180   StrtabBuilder.write((uint8_t *)Strtab.data());
5181 
5182   writeBlob(bitc::STRTAB_BLOCK_ID, bitc::STRTAB_BLOB,
5183             {Strtab.data(), Strtab.size()});
5184 
5185   WroteStrtab = true;
5186 }
5187 
5188 void BitcodeWriter::copyStrtab(StringRef Strtab) {
5189   writeBlob(bitc::STRTAB_BLOCK_ID, bitc::STRTAB_BLOB, Strtab);
5190   WroteStrtab = true;
5191 }
5192 
5193 void BitcodeWriter::writeModule(const Module &M,
5194                                 bool ShouldPreserveUseListOrder,
5195                                 const ModuleSummaryIndex *Index,
5196                                 bool GenerateHash, ModuleHash *ModHash) {
5197   assert(!WroteStrtab);
5198 
5199   // The Mods vector is used by irsymtab::build, which requires non-const
5200   // Modules in case it needs to materialize metadata. But the bitcode writer
5201   // requires that the module is materialized, so we can cast to non-const here,
5202   // after checking that it is in fact materialized.
5203   assert(M.isMaterialized());
5204   Mods.push_back(const_cast<Module *>(&M));
5205 
5206   ModuleBitcodeWriter ModuleWriter(M, StrtabBuilder, *Stream,
5207                                    ShouldPreserveUseListOrder, Index,
5208                                    GenerateHash, ModHash);
5209   ModuleWriter.write();
5210 }
5211 
5212 void BitcodeWriter::writeIndex(
5213     const ModuleSummaryIndex *Index,
5214     const ModuleToSummariesForIndexTy *ModuleToSummariesForIndex,
5215     const GVSummaryPtrSet *DecSummaries) {
5216   IndexBitcodeWriter IndexWriter(*Stream, StrtabBuilder, *Index, DecSummaries,
5217                                  ModuleToSummariesForIndex);
5218   IndexWriter.write();
5219 }
5220 
5221 /// Write the specified module to the specified output stream.
5222 void llvm::WriteBitcodeToFile(const Module &M, raw_ostream &Out,
5223                               bool ShouldPreserveUseListOrder,
5224                               const ModuleSummaryIndex *Index,
5225                               bool GenerateHash, ModuleHash *ModHash) {
5226   auto Write = [&](BitcodeWriter &Writer) {
5227     Writer.writeModule(M, ShouldPreserveUseListOrder, Index, GenerateHash,
5228                        ModHash);
5229     Writer.writeSymtab();
5230     Writer.writeStrtab();
5231   };
5232   Triple TT(M.getTargetTriple());
5233   if (TT.isOSDarwin() || TT.isOSBinFormatMachO()) {
5234     // If this is darwin or another generic macho target, reserve space for the
5235     // header. Note that the header is computed *after* the output is known, so
5236     // we currently explicitly use a buffer, write to it, and then subsequently
5237     // flush to Out.
5238     SmallVector<char, 0> Buffer;
5239     Buffer.reserve(256 * 1024);
5240     Buffer.insert(Buffer.begin(), BWH_HeaderSize, 0);
5241     BitcodeWriter Writer(Buffer);
5242     Write(Writer);
5243     emitDarwinBCHeaderAndTrailer(Buffer, TT);
5244     Out.write(Buffer.data(), Buffer.size());
5245   } else {
5246     BitcodeWriter Writer(Out);
5247     Write(Writer);
5248   }
5249 }
5250 
5251 void IndexBitcodeWriter::write() {
5252   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
5253 
5254   writeModuleVersion();
5255 
5256   // Write the module paths in the combined index.
5257   writeModStrings();
5258 
5259   // Write the summary combined index records.
5260   writeCombinedGlobalValueSummary();
5261 
5262   Stream.ExitBlock();
5263 }
5264 
5265 // Write the specified module summary index to the given raw output stream,
5266 // where it will be written in a new bitcode block. This is used when
5267 // writing the combined index file for ThinLTO. When writing a subset of the
5268 // index for a distributed backend, provide a \p ModuleToSummariesForIndex map.
5269 void llvm::writeIndexToFile(
5270     const ModuleSummaryIndex &Index, raw_ostream &Out,
5271     const ModuleToSummariesForIndexTy *ModuleToSummariesForIndex,
5272     const GVSummaryPtrSet *DecSummaries) {
5273   SmallVector<char, 0> Buffer;
5274   Buffer.reserve(256 * 1024);
5275 
5276   BitcodeWriter Writer(Buffer);
5277   Writer.writeIndex(&Index, ModuleToSummariesForIndex, DecSummaries);
5278   Writer.writeStrtab();
5279 
5280   Out.write((char *)&Buffer.front(), Buffer.size());
5281 }
5282 
5283 namespace {
5284 
5285 /// Class to manage the bitcode writing for a thin link bitcode file.
5286 class ThinLinkBitcodeWriter : public ModuleBitcodeWriterBase {
5287   /// ModHash is for use in ThinLTO incremental build, generated while writing
5288   /// the module bitcode file.
5289   const ModuleHash *ModHash;
5290 
5291 public:
5292   ThinLinkBitcodeWriter(const Module &M, StringTableBuilder &StrtabBuilder,
5293                         BitstreamWriter &Stream,
5294                         const ModuleSummaryIndex &Index,
5295                         const ModuleHash &ModHash)
5296       : ModuleBitcodeWriterBase(M, StrtabBuilder, Stream,
5297                                 /*ShouldPreserveUseListOrder=*/false, &Index),
5298         ModHash(&ModHash) {}
5299 
5300   void write();
5301 
5302 private:
5303   void writeSimplifiedModuleInfo();
5304 };
5305 
5306 } // end anonymous namespace
5307 
5308 // This function writes a simpilified module info for thin link bitcode file.
5309 // It only contains the source file name along with the name(the offset and
5310 // size in strtab) and linkage for global values. For the global value info
5311 // entry, in order to keep linkage at offset 5, there are three zeros used
5312 // as padding.
5313 void ThinLinkBitcodeWriter::writeSimplifiedModuleInfo() {
5314   SmallVector<unsigned, 64> Vals;
5315   // Emit the module's source file name.
5316   {
5317     StringEncoding Bits = getStringEncoding(M.getSourceFileName());
5318     BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
5319     if (Bits == SE_Char6)
5320       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
5321     else if (Bits == SE_Fixed7)
5322       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
5323 
5324     // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
5325     auto Abbv = std::make_shared<BitCodeAbbrev>();
5326     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
5327     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
5328     Abbv->Add(AbbrevOpToUse);
5329     unsigned FilenameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
5330 
5331     for (const auto P : M.getSourceFileName())
5332       Vals.push_back((unsigned char)P);
5333 
5334     Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
5335     Vals.clear();
5336   }
5337 
5338   // Emit the global variable information.
5339   for (const GlobalVariable &GV : M.globals()) {
5340     // GLOBALVAR: [strtab offset, strtab size, 0, 0, 0, linkage]
5341     Vals.push_back(StrtabBuilder.add(GV.getName()));
5342     Vals.push_back(GV.getName().size());
5343     Vals.push_back(0);
5344     Vals.push_back(0);
5345     Vals.push_back(0);
5346     Vals.push_back(getEncodedLinkage(GV));
5347 
5348     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals);
5349     Vals.clear();
5350   }
5351 
5352   // Emit the function proto information.
5353   for (const Function &F : M) {
5354     // FUNCTION:  [strtab offset, strtab size, 0, 0, 0, linkage]
5355     Vals.push_back(StrtabBuilder.add(F.getName()));
5356     Vals.push_back(F.getName().size());
5357     Vals.push_back(0);
5358     Vals.push_back(0);
5359     Vals.push_back(0);
5360     Vals.push_back(getEncodedLinkage(F));
5361 
5362     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals);
5363     Vals.clear();
5364   }
5365 
5366   // Emit the alias information.
5367   for (const GlobalAlias &A : M.aliases()) {
5368     // ALIAS: [strtab offset, strtab size, 0, 0, 0, linkage]
5369     Vals.push_back(StrtabBuilder.add(A.getName()));
5370     Vals.push_back(A.getName().size());
5371     Vals.push_back(0);
5372     Vals.push_back(0);
5373     Vals.push_back(0);
5374     Vals.push_back(getEncodedLinkage(A));
5375 
5376     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals);
5377     Vals.clear();
5378   }
5379 
5380   // Emit the ifunc information.
5381   for (const GlobalIFunc &I : M.ifuncs()) {
5382     // IFUNC: [strtab offset, strtab size, 0, 0, 0, linkage]
5383     Vals.push_back(StrtabBuilder.add(I.getName()));
5384     Vals.push_back(I.getName().size());
5385     Vals.push_back(0);
5386     Vals.push_back(0);
5387     Vals.push_back(0);
5388     Vals.push_back(getEncodedLinkage(I));
5389 
5390     Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
5391     Vals.clear();
5392   }
5393 }
5394 
5395 void ThinLinkBitcodeWriter::write() {
5396   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
5397 
5398   writeModuleVersion();
5399 
5400   writeSimplifiedModuleInfo();
5401 
5402   writePerModuleGlobalValueSummary();
5403 
5404   // Write module hash.
5405   Stream.EmitRecord(bitc::MODULE_CODE_HASH, ArrayRef<uint32_t>(*ModHash));
5406 
5407   Stream.ExitBlock();
5408 }
5409 
5410 void BitcodeWriter::writeThinLinkBitcode(const Module &M,
5411                                          const ModuleSummaryIndex &Index,
5412                                          const ModuleHash &ModHash) {
5413   assert(!WroteStrtab);
5414 
5415   // The Mods vector is used by irsymtab::build, which requires non-const
5416   // Modules in case it needs to materialize metadata. But the bitcode writer
5417   // requires that the module is materialized, so we can cast to non-const here,
5418   // after checking that it is in fact materialized.
5419   assert(M.isMaterialized());
5420   Mods.push_back(const_cast<Module *>(&M));
5421 
5422   ThinLinkBitcodeWriter ThinLinkWriter(M, StrtabBuilder, *Stream, Index,
5423                                        ModHash);
5424   ThinLinkWriter.write();
5425 }
5426 
5427 // Write the specified thin link bitcode file to the given raw output stream,
5428 // where it will be written in a new bitcode block. This is used when
5429 // writing the per-module index file for ThinLTO.
5430 void llvm::writeThinLinkBitcodeToFile(const Module &M, raw_ostream &Out,
5431                                       const ModuleSummaryIndex &Index,
5432                                       const ModuleHash &ModHash) {
5433   SmallVector<char, 0> Buffer;
5434   Buffer.reserve(256 * 1024);
5435 
5436   BitcodeWriter Writer(Buffer);
5437   Writer.writeThinLinkBitcode(M, Index, ModHash);
5438   Writer.writeSymtab();
5439   Writer.writeStrtab();
5440 
5441   Out.write((char *)&Buffer.front(), Buffer.size());
5442 }
5443 
5444 static const char *getSectionNameForBitcode(const Triple &T) {
5445   switch (T.getObjectFormat()) {
5446   case Triple::MachO:
5447     return "__LLVM,__bitcode";
5448   case Triple::COFF:
5449   case Triple::ELF:
5450   case Triple::Wasm:
5451   case Triple::UnknownObjectFormat:
5452     return ".llvmbc";
5453   case Triple::GOFF:
5454     llvm_unreachable("GOFF is not yet implemented");
5455     break;
5456   case Triple::SPIRV:
5457     if (T.getVendor() == Triple::AMD)
5458       return ".llvmbc";
5459     llvm_unreachable("SPIRV is not yet implemented");
5460     break;
5461   case Triple::XCOFF:
5462     llvm_unreachable("XCOFF is not yet implemented");
5463     break;
5464   case Triple::DXContainer:
5465     llvm_unreachable("DXContainer is not yet implemented");
5466     break;
5467   }
5468   llvm_unreachable("Unimplemented ObjectFormatType");
5469 }
5470 
5471 static const char *getSectionNameForCommandline(const Triple &T) {
5472   switch (T.getObjectFormat()) {
5473   case Triple::MachO:
5474     return "__LLVM,__cmdline";
5475   case Triple::COFF:
5476   case Triple::ELF:
5477   case Triple::Wasm:
5478   case Triple::UnknownObjectFormat:
5479     return ".llvmcmd";
5480   case Triple::GOFF:
5481     llvm_unreachable("GOFF is not yet implemented");
5482     break;
5483   case Triple::SPIRV:
5484     if (T.getVendor() == Triple::AMD)
5485       return ".llvmcmd";
5486     llvm_unreachable("SPIRV is not yet implemented");
5487     break;
5488   case Triple::XCOFF:
5489     llvm_unreachable("XCOFF is not yet implemented");
5490     break;
5491   case Triple::DXContainer:
5492     llvm_unreachable("DXC is not yet implemented");
5493     break;
5494   }
5495   llvm_unreachable("Unimplemented ObjectFormatType");
5496 }
5497 
5498 void llvm::embedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
5499                                 bool EmbedBitcode, bool EmbedCmdline,
5500                                 const std::vector<uint8_t> &CmdArgs) {
5501   // Save llvm.compiler.used and remove it.
5502   SmallVector<Constant *, 2> UsedArray;
5503   SmallVector<GlobalValue *, 4> UsedGlobals;
5504   Type *UsedElementType = PointerType::getUnqual(M.getContext());
5505   GlobalVariable *Used = collectUsedGlobalVariables(M, UsedGlobals, true);
5506   for (auto *GV : UsedGlobals) {
5507     if (GV->getName() != "llvm.embedded.module" &&
5508         GV->getName() != "llvm.cmdline")
5509       UsedArray.push_back(
5510           ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
5511   }
5512   if (Used)
5513     Used->eraseFromParent();
5514 
5515   // Embed the bitcode for the llvm module.
5516   std::string Data;
5517   ArrayRef<uint8_t> ModuleData;
5518   Triple T(M.getTargetTriple());
5519 
5520   if (EmbedBitcode) {
5521     if (Buf.getBufferSize() == 0 ||
5522         !isBitcode((const unsigned char *)Buf.getBufferStart(),
5523                    (const unsigned char *)Buf.getBufferEnd())) {
5524       // If the input is LLVM Assembly, bitcode is produced by serializing
5525       // the module. Use-lists order need to be preserved in this case.
5526       llvm::raw_string_ostream OS(Data);
5527       llvm::WriteBitcodeToFile(M, OS, /* ShouldPreserveUseListOrder */ true);
5528       ModuleData =
5529           ArrayRef<uint8_t>((const uint8_t *)OS.str().data(), OS.str().size());
5530     } else
5531       // If the input is LLVM bitcode, write the input byte stream directly.
5532       ModuleData = ArrayRef<uint8_t>((const uint8_t *)Buf.getBufferStart(),
5533                                      Buf.getBufferSize());
5534   }
5535   llvm::Constant *ModuleConstant =
5536       llvm::ConstantDataArray::get(M.getContext(), ModuleData);
5537   llvm::GlobalVariable *GV = new llvm::GlobalVariable(
5538       M, ModuleConstant->getType(), true, llvm::GlobalValue::PrivateLinkage,
5539       ModuleConstant);
5540   GV->setSection(getSectionNameForBitcode(T));
5541   // Set alignment to 1 to prevent padding between two contributions from input
5542   // sections after linking.
5543   GV->setAlignment(Align(1));
5544   UsedArray.push_back(
5545       ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
5546   if (llvm::GlobalVariable *Old =
5547           M.getGlobalVariable("llvm.embedded.module", true)) {
5548     assert(Old->hasZeroLiveUses() &&
5549            "llvm.embedded.module can only be used once in llvm.compiler.used");
5550     GV->takeName(Old);
5551     Old->eraseFromParent();
5552   } else {
5553     GV->setName("llvm.embedded.module");
5554   }
5555 
5556   // Skip if only bitcode needs to be embedded.
5557   if (EmbedCmdline) {
5558     // Embed command-line options.
5559     ArrayRef<uint8_t> CmdData(const_cast<uint8_t *>(CmdArgs.data()),
5560                               CmdArgs.size());
5561     llvm::Constant *CmdConstant =
5562         llvm::ConstantDataArray::get(M.getContext(), CmdData);
5563     GV = new llvm::GlobalVariable(M, CmdConstant->getType(), true,
5564                                   llvm::GlobalValue::PrivateLinkage,
5565                                   CmdConstant);
5566     GV->setSection(getSectionNameForCommandline(T));
5567     GV->setAlignment(Align(1));
5568     UsedArray.push_back(
5569         ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
5570     if (llvm::GlobalVariable *Old = M.getGlobalVariable("llvm.cmdline", true)) {
5571       assert(Old->hasZeroLiveUses() &&
5572              "llvm.cmdline can only be used once in llvm.compiler.used");
5573       GV->takeName(Old);
5574       Old->eraseFromParent();
5575     } else {
5576       GV->setName("llvm.cmdline");
5577     }
5578   }
5579 
5580   if (UsedArray.empty())
5581     return;
5582 
5583   // Recreate llvm.compiler.used.
5584   ArrayType *ATy = ArrayType::get(UsedElementType, UsedArray.size());
5585   auto *NewUsed = new GlobalVariable(
5586       M, ATy, false, llvm::GlobalValue::AppendingLinkage,
5587       llvm::ConstantArray::get(ATy, UsedArray), "llvm.compiler.used");
5588   NewUsed->setSection("llvm.metadata");
5589 }
5590