xref: /llvm-project/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp (revision 776476c282bca71d5b856e80e0a88fbd6f3ccdd2)
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/ProfileData/MemProf.h"
64 #include "llvm/Support/AtomicOrdering.h"
65 #include "llvm/Support/Casting.h"
66 #include "llvm/Support/CommandLine.h"
67 #include "llvm/Support/Endian.h"
68 #include "llvm/Support/Error.h"
69 #include "llvm/Support/ErrorHandling.h"
70 #include "llvm/Support/MathExtras.h"
71 #include "llvm/Support/SHA1.h"
72 #include "llvm/Support/raw_ostream.h"
73 #include "llvm/TargetParser/Triple.h"
74 #include <algorithm>
75 #include <cassert>
76 #include <cstddef>
77 #include <cstdint>
78 #include <iterator>
79 #include <map>
80 #include <memory>
81 #include <optional>
82 #include <string>
83 #include <utility>
84 #include <vector>
85 
86 using namespace llvm;
87 using namespace llvm::memprof;
88 
89 static cl::opt<unsigned>
90     IndexThreshold("bitcode-mdindex-threshold", cl::Hidden, cl::init(25),
91                    cl::desc("Number of metadatas above which we emit an index "
92                             "to enable lazy-loading"));
93 static cl::opt<uint32_t> FlushThreshold(
94     "bitcode-flush-threshold", cl::Hidden, cl::init(512),
95     cl::desc("The threshold (unit M) for flushing LLVM bitcode."));
96 
97 static cl::opt<bool> WriteRelBFToSummary(
98     "write-relbf-to-summary", cl::Hidden, cl::init(false),
99     cl::desc("Write relative block frequency to function summary "));
100 
101 namespace llvm {
102 extern FunctionSummary::ForceSummaryHotnessType ForceSummaryEdgesCold;
103 }
104 
105 extern bool WriteNewDbgInfoFormatToBitcode;
106 extern llvm::cl::opt<bool> UseNewDbgInfoFormat;
107 
108 namespace {
109 
110 /// These are manifest constants used by the bitcode writer. They do not need to
111 /// be kept in sync with the reader, but need to be consistent within this file.
112 enum {
113   // VALUE_SYMTAB_BLOCK abbrev id's.
114   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
115   VST_ENTRY_7_ABBREV,
116   VST_ENTRY_6_ABBREV,
117   VST_BBENTRY_6_ABBREV,
118 
119   // CONSTANTS_BLOCK abbrev id's.
120   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
121   CONSTANTS_INTEGER_ABBREV,
122   CONSTANTS_CE_CAST_Abbrev,
123   CONSTANTS_NULL_Abbrev,
124 
125   // FUNCTION_BLOCK abbrev id's.
126   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
127   FUNCTION_INST_UNOP_ABBREV,
128   FUNCTION_INST_UNOP_FLAGS_ABBREV,
129   FUNCTION_INST_BINOP_ABBREV,
130   FUNCTION_INST_BINOP_FLAGS_ABBREV,
131   FUNCTION_INST_CAST_ABBREV,
132   FUNCTION_INST_CAST_FLAGS_ABBREV,
133   FUNCTION_INST_RET_VOID_ABBREV,
134   FUNCTION_INST_RET_VAL_ABBREV,
135   FUNCTION_INST_UNREACHABLE_ABBREV,
136   FUNCTION_INST_GEP_ABBREV,
137   FUNCTION_DEBUG_RECORD_VALUE_ABBREV,
138 };
139 
140 /// Abstract class to manage the bitcode writing, subclassed for each bitcode
141 /// file type.
142 class BitcodeWriterBase {
143 protected:
144   /// The stream created and owned by the client.
145   BitstreamWriter &Stream;
146 
147   StringTableBuilder &StrtabBuilder;
148 
149 public:
150   /// Constructs a BitcodeWriterBase object that writes to the provided
151   /// \p Stream.
152   BitcodeWriterBase(BitstreamWriter &Stream, StringTableBuilder &StrtabBuilder)
153       : Stream(Stream), StrtabBuilder(StrtabBuilder) {}
154 
155 protected:
156   void writeModuleVersion();
157 };
158 
159 void BitcodeWriterBase::writeModuleVersion() {
160   // VERSION: [version#]
161   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, ArrayRef<uint64_t>{2});
162 }
163 
164 /// Base class to manage the module bitcode writing, currently subclassed for
165 /// ModuleBitcodeWriter and ThinLinkBitcodeWriter.
166 class ModuleBitcodeWriterBase : public BitcodeWriterBase {
167 protected:
168   /// The Module to write to bitcode.
169   const Module &M;
170 
171   /// Enumerates ids for all values in the module.
172   ValueEnumerator VE;
173 
174   /// Optional per-module index to write for ThinLTO.
175   const ModuleSummaryIndex *Index;
176 
177   /// Map that holds the correspondence between GUIDs in the summary index,
178   /// that came from indirect call profiles, and a value id generated by this
179   /// class to use in the VST and summary block records.
180   std::map<GlobalValue::GUID, unsigned> GUIDToValueIdMap;
181 
182   /// Tracks the last value id recorded in the GUIDToValueMap.
183   unsigned GlobalValueId;
184 
185   /// Saves the offset of the VSTOffset record that must eventually be
186   /// backpatched with the offset of the actual VST.
187   uint64_t VSTOffsetPlaceholder = 0;
188 
189 public:
190   /// Constructs a ModuleBitcodeWriterBase object for the given Module,
191   /// writing to the provided \p Buffer.
192   ModuleBitcodeWriterBase(const Module &M, StringTableBuilder &StrtabBuilder,
193                           BitstreamWriter &Stream,
194                           bool ShouldPreserveUseListOrder,
195                           const ModuleSummaryIndex *Index)
196       : BitcodeWriterBase(Stream, StrtabBuilder), M(M),
197         VE(M, ShouldPreserveUseListOrder), Index(Index) {
198     // Assign ValueIds to any callee values in the index that came from
199     // indirect call profiles and were recorded as a GUID not a Value*
200     // (which would have been assigned an ID by the ValueEnumerator).
201     // The starting ValueId is just after the number of values in the
202     // ValueEnumerator, so that they can be emitted in the VST.
203     GlobalValueId = VE.getValues().size();
204     if (!Index)
205       return;
206     for (const auto &GUIDSummaryLists : *Index)
207       // Examine all summaries for this GUID.
208       for (auto &Summary : GUIDSummaryLists.second.SummaryList)
209         if (auto FS = dyn_cast<FunctionSummary>(Summary.get())) {
210           // For each call in the function summary, see if the call
211           // is to a GUID (which means it is for an indirect call,
212           // otherwise we would have a Value for it). If so, synthesize
213           // a value id.
214           for (auto &CallEdge : FS->calls())
215             if (!CallEdge.first.haveGVs() || !CallEdge.first.getValue())
216               assignValueId(CallEdge.first.getGUID());
217 
218           // For each referenced variables in the function summary, see if the
219           // variable is represented by a GUID (as opposed to a symbol to
220           // declarations or definitions in the module). If so, synthesize a
221           // value id.
222           for (auto &RefEdge : FS->refs())
223             if (!RefEdge.haveGVs() || !RefEdge.getValue())
224               assignValueId(RefEdge.getGUID());
225         }
226   }
227 
228 protected:
229   void writePerModuleGlobalValueSummary();
230 
231 private:
232   void writePerModuleFunctionSummaryRecord(
233       SmallVector<uint64_t, 64> &NameVals, GlobalValueSummary *Summary,
234       unsigned ValueID, unsigned FSCallsAbbrev, unsigned FSCallsProfileAbbrev,
235       unsigned CallsiteAbbrev, unsigned AllocAbbrev, unsigned ContextIdAbbvId,
236       const Function &F, DenseMap<CallStackId, LinearCallStackId> &CallStackPos,
237       CallStackId &CallStackCount);
238   void writeModuleLevelReferences(const GlobalVariable &V,
239                                   SmallVector<uint64_t, 64> &NameVals,
240                                   unsigned FSModRefsAbbrev,
241                                   unsigned FSModVTableRefsAbbrev);
242 
243   void assignValueId(GlobalValue::GUID ValGUID) {
244     GUIDToValueIdMap[ValGUID] = ++GlobalValueId;
245   }
246 
247   unsigned getValueId(GlobalValue::GUID ValGUID) {
248     const auto &VMI = GUIDToValueIdMap.find(ValGUID);
249     // Expect that any GUID value had a value Id assigned by an
250     // earlier call to assignValueId.
251     assert(VMI != GUIDToValueIdMap.end() &&
252            "GUID does not have assigned value Id");
253     return VMI->second;
254   }
255 
256   // Helper to get the valueId for the type of value recorded in VI.
257   unsigned getValueId(ValueInfo VI) {
258     if (!VI.haveGVs() || !VI.getValue())
259       return getValueId(VI.getGUID());
260     return VE.getValueID(VI.getValue());
261   }
262 
263   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
264 };
265 
266 /// Class to manage the bitcode writing for a module.
267 class ModuleBitcodeWriter : public ModuleBitcodeWriterBase {
268   /// True if a module hash record should be written.
269   bool GenerateHash;
270 
271   /// If non-null, when GenerateHash is true, the resulting hash is written
272   /// into ModHash.
273   ModuleHash *ModHash;
274 
275   SHA1 Hasher;
276 
277   /// The start bit of the identification block.
278   uint64_t BitcodeStartBit;
279 
280 public:
281   /// Constructs a ModuleBitcodeWriter object for the given Module,
282   /// writing to the provided \p Buffer.
283   ModuleBitcodeWriter(const Module &M, StringTableBuilder &StrtabBuilder,
284                       BitstreamWriter &Stream, bool ShouldPreserveUseListOrder,
285                       const ModuleSummaryIndex *Index, bool GenerateHash,
286                       ModuleHash *ModHash = nullptr)
287       : ModuleBitcodeWriterBase(M, StrtabBuilder, Stream,
288                                 ShouldPreserveUseListOrder, Index),
289         GenerateHash(GenerateHash), ModHash(ModHash),
290         BitcodeStartBit(Stream.GetCurrentBitNo()) {}
291 
292   /// Emit the current module to the bitstream.
293   void write();
294 
295 private:
296   uint64_t bitcodeStartBit() { return BitcodeStartBit; }
297 
298   size_t addToStrtab(StringRef Str);
299 
300   void writeAttributeGroupTable();
301   void writeAttributeTable();
302   void writeTypeTable();
303   void writeComdats();
304   void writeValueSymbolTableForwardDecl();
305   void writeModuleInfo();
306   void writeValueAsMetadata(const ValueAsMetadata *MD,
307                             SmallVectorImpl<uint64_t> &Record);
308   void writeMDTuple(const MDTuple *N, SmallVectorImpl<uint64_t> &Record,
309                     unsigned Abbrev);
310   unsigned createDILocationAbbrev();
311   void writeDILocation(const DILocation *N, SmallVectorImpl<uint64_t> &Record,
312                        unsigned &Abbrev);
313   unsigned createGenericDINodeAbbrev();
314   void writeGenericDINode(const GenericDINode *N,
315                           SmallVectorImpl<uint64_t> &Record, unsigned &Abbrev);
316   void writeDISubrange(const DISubrange *N, SmallVectorImpl<uint64_t> &Record,
317                        unsigned Abbrev);
318   void writeDIGenericSubrange(const DIGenericSubrange *N,
319                               SmallVectorImpl<uint64_t> &Record,
320                               unsigned Abbrev);
321   void writeDIEnumerator(const DIEnumerator *N,
322                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
323   void writeDIBasicType(const DIBasicType *N, SmallVectorImpl<uint64_t> &Record,
324                         unsigned Abbrev);
325   void writeDIStringType(const DIStringType *N,
326                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
327   void writeDIDerivedType(const DIDerivedType *N,
328                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
329   void writeDICompositeType(const DICompositeType *N,
330                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
331   void writeDISubroutineType(const DISubroutineType *N,
332                              SmallVectorImpl<uint64_t> &Record,
333                              unsigned Abbrev);
334   void writeDIFile(const DIFile *N, SmallVectorImpl<uint64_t> &Record,
335                    unsigned Abbrev);
336   void writeDICompileUnit(const DICompileUnit *N,
337                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
338   void writeDISubprogram(const DISubprogram *N,
339                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
340   void writeDILexicalBlock(const DILexicalBlock *N,
341                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
342   void writeDILexicalBlockFile(const DILexicalBlockFile *N,
343                                SmallVectorImpl<uint64_t> &Record,
344                                unsigned Abbrev);
345   void writeDICommonBlock(const DICommonBlock *N,
346                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
347   void writeDINamespace(const DINamespace *N, SmallVectorImpl<uint64_t> &Record,
348                         unsigned Abbrev);
349   void writeDIMacro(const DIMacro *N, SmallVectorImpl<uint64_t> &Record,
350                     unsigned Abbrev);
351   void writeDIMacroFile(const DIMacroFile *N, SmallVectorImpl<uint64_t> &Record,
352                         unsigned Abbrev);
353   void writeDIArgList(const DIArgList *N, SmallVectorImpl<uint64_t> &Record);
354   void writeDIModule(const DIModule *N, SmallVectorImpl<uint64_t> &Record,
355                      unsigned Abbrev);
356   void writeDIAssignID(const DIAssignID *N, SmallVectorImpl<uint64_t> &Record,
357                        unsigned Abbrev);
358   void writeDITemplateTypeParameter(const DITemplateTypeParameter *N,
359                                     SmallVectorImpl<uint64_t> &Record,
360                                     unsigned Abbrev);
361   void writeDITemplateValueParameter(const DITemplateValueParameter *N,
362                                      SmallVectorImpl<uint64_t> &Record,
363                                      unsigned Abbrev);
364   void writeDIGlobalVariable(const DIGlobalVariable *N,
365                              SmallVectorImpl<uint64_t> &Record,
366                              unsigned Abbrev);
367   void writeDILocalVariable(const DILocalVariable *N,
368                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
369   void writeDILabel(const DILabel *N,
370                     SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
371   void writeDIExpression(const DIExpression *N,
372                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
373   void writeDIGlobalVariableExpression(const DIGlobalVariableExpression *N,
374                                        SmallVectorImpl<uint64_t> &Record,
375                                        unsigned Abbrev);
376   void writeDIObjCProperty(const DIObjCProperty *N,
377                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
378   void writeDIImportedEntity(const DIImportedEntity *N,
379                              SmallVectorImpl<uint64_t> &Record,
380                              unsigned Abbrev);
381   unsigned createNamedMetadataAbbrev();
382   void writeNamedMetadata(SmallVectorImpl<uint64_t> &Record);
383   unsigned createMetadataStringsAbbrev();
384   void writeMetadataStrings(ArrayRef<const Metadata *> Strings,
385                             SmallVectorImpl<uint64_t> &Record);
386   void writeMetadataRecords(ArrayRef<const Metadata *> MDs,
387                             SmallVectorImpl<uint64_t> &Record,
388                             std::vector<unsigned> *MDAbbrevs = nullptr,
389                             std::vector<uint64_t> *IndexPos = nullptr);
390   void writeModuleMetadata();
391   void writeFunctionMetadata(const Function &F);
392   void writeFunctionMetadataAttachment(const Function &F);
393   void pushGlobalMetadataAttachment(SmallVectorImpl<uint64_t> &Record,
394                                     const GlobalObject &GO);
395   void writeModuleMetadataKinds();
396   void writeOperandBundleTags();
397   void writeSyncScopeNames();
398   void writeConstants(unsigned FirstVal, unsigned LastVal, bool isGlobal);
399   void writeModuleConstants();
400   bool pushValueAndType(const Value *V, unsigned InstID,
401                         SmallVectorImpl<unsigned> &Vals);
402   bool pushValueOrMetadata(const Value *V, unsigned InstID,
403                            SmallVectorImpl<unsigned> &Vals);
404   void writeOperandBundles(const CallBase &CB, unsigned InstID);
405   void pushValue(const Value *V, unsigned InstID,
406                  SmallVectorImpl<unsigned> &Vals);
407   void pushValueSigned(const Value *V, unsigned InstID,
408                        SmallVectorImpl<uint64_t> &Vals);
409   void writeInstruction(const Instruction &I, unsigned InstID,
410                         SmallVectorImpl<unsigned> &Vals);
411   void writeFunctionLevelValueSymbolTable(const ValueSymbolTable &VST);
412   void writeGlobalValueSymbolTable(
413       DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
414   void writeUseList(UseListOrder &&Order);
415   void writeUseListBlock(const Function *F);
416   void
417   writeFunction(const Function &F,
418                 DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
419   void writeBlockInfo();
420   void writeModuleHash(StringRef View);
421 
422   unsigned getEncodedSyncScopeID(SyncScope::ID SSID) {
423     return unsigned(SSID);
424   }
425 
426   unsigned getEncodedAlign(MaybeAlign Alignment) { return encode(Alignment); }
427 };
428 
429 /// Class to manage the bitcode writing for a combined index.
430 class IndexBitcodeWriter : public BitcodeWriterBase {
431   /// The combined index to write to bitcode.
432   const ModuleSummaryIndex &Index;
433 
434   /// When writing combined summaries, provides the set of global value
435   /// summaries for which the value (function, function alias, etc) should be
436   /// imported as a declaration.
437   const GVSummaryPtrSet *DecSummaries = nullptr;
438 
439   /// When writing a subset of the index for distributed backends, client
440   /// provides a map of modules to the corresponding GUIDs/summaries to write.
441   const ModuleToSummariesForIndexTy *ModuleToSummariesForIndex;
442 
443   /// Map that holds the correspondence between the GUID used in the combined
444   /// index and a value id generated by this class to use in references.
445   std::map<GlobalValue::GUID, unsigned> GUIDToValueIdMap;
446 
447   // The stack ids used by this index, which will be a subset of those in
448   // the full index in the case of distributed indexes.
449   std::vector<uint64_t> StackIds;
450 
451   // Keep a map of the stack id indices used by records being written for this
452   // index to the index of the corresponding stack id in the above StackIds
453   // vector. Ensures we write each referenced stack id once.
454   DenseMap<unsigned, unsigned> StackIdIndicesToIndex;
455 
456   /// Tracks the last value id recorded in the GUIDToValueMap.
457   unsigned GlobalValueId = 0;
458 
459   /// Tracks the assignment of module paths in the module path string table to
460   /// an id assigned for use in summary references to the module path.
461   DenseMap<StringRef, uint64_t> ModuleIdMap;
462 
463 public:
464   /// Constructs a IndexBitcodeWriter object for the given combined index,
465   /// writing to the provided \p Buffer. When writing a subset of the index
466   /// for a distributed backend, provide a \p ModuleToSummariesForIndex map.
467   /// If provided, \p DecSummaries specifies the set of summaries for which
468   /// the corresponding functions or aliased functions should be imported as a
469   /// declaration (but not definition) for each module.
470   IndexBitcodeWriter(
471       BitstreamWriter &Stream, StringTableBuilder &StrtabBuilder,
472       const ModuleSummaryIndex &Index,
473       const GVSummaryPtrSet *DecSummaries = nullptr,
474       const ModuleToSummariesForIndexTy *ModuleToSummariesForIndex = nullptr)
475       : BitcodeWriterBase(Stream, StrtabBuilder), Index(Index),
476         DecSummaries(DecSummaries),
477         ModuleToSummariesForIndex(ModuleToSummariesForIndex) {
478 
479     // See if the StackIdIndex was already added to the StackId map and
480     // vector. If not, record it.
481     auto RecordStackIdReference = [&](unsigned StackIdIndex) {
482       // If the StackIdIndex is not yet in the map, the below insert ensures
483       // that it will point to the new StackIds vector entry we push to just
484       // below.
485       auto Inserted =
486           StackIdIndicesToIndex.insert({StackIdIndex, StackIds.size()});
487       if (Inserted.second)
488         StackIds.push_back(Index.getStackIdAtIndex(StackIdIndex));
489     };
490 
491     // Assign unique value ids to all summaries to be written, for use
492     // in writing out the call graph edges. Save the mapping from GUID
493     // to the new global value id to use when writing those edges, which
494     // are currently saved in the index in terms of GUID.
495     forEachSummary([&](GVInfo I, bool IsAliasee) {
496       GUIDToValueIdMap[I.first] = ++GlobalValueId;
497       if (IsAliasee)
498         return;
499       auto *FS = dyn_cast<FunctionSummary>(I.second);
500       if (!FS)
501         return;
502       // Record all stack id indices actually used in the summary entries being
503       // written, so that we can compact them in the case of distributed ThinLTO
504       // indexes.
505       for (auto &CI : FS->callsites()) {
506         // If the stack id list is empty, this callsite info was synthesized for
507         // a missing tail call frame. Ensure that the callee's GUID gets a value
508         // id. Normally we only generate these for defined summaries, which in
509         // the case of distributed ThinLTO is only the functions already defined
510         // in the module or that we want to import. We don't bother to include
511         // all the callee symbols as they aren't normally needed in the backend.
512         // However, for the synthesized callsite infos we do need the callee
513         // GUID in the backend so that we can correlate the identified callee
514         // with this callsite info (which for non-tail calls is done by the
515         // ordering of the callsite infos and verified via stack ids).
516         if (CI.StackIdIndices.empty()) {
517           GUIDToValueIdMap[CI.Callee.getGUID()] = ++GlobalValueId;
518           continue;
519         }
520         for (auto Idx : CI.StackIdIndices)
521           RecordStackIdReference(Idx);
522       }
523       for (auto &AI : FS->allocs())
524         for (auto &MIB : AI.MIBs)
525           for (auto Idx : MIB.StackIdIndices)
526             RecordStackIdReference(Idx);
527     });
528   }
529 
530   /// The below iterator returns the GUID and associated summary.
531   using GVInfo = std::pair<GlobalValue::GUID, GlobalValueSummary *>;
532 
533   /// Calls the callback for each value GUID and summary to be written to
534   /// bitcode. This hides the details of whether they are being pulled from the
535   /// entire index or just those in a provided ModuleToSummariesForIndex map.
536   template<typename Functor>
537   void forEachSummary(Functor Callback) {
538     if (ModuleToSummariesForIndex) {
539       for (auto &M : *ModuleToSummariesForIndex)
540         for (auto &Summary : M.second) {
541           Callback(Summary, false);
542           // Ensure aliasee is handled, e.g. for assigning a valueId,
543           // even if we are not importing the aliasee directly (the
544           // imported alias will contain a copy of aliasee).
545           if (auto *AS = dyn_cast<AliasSummary>(Summary.getSecond()))
546             Callback({AS->getAliaseeGUID(), &AS->getAliasee()}, true);
547         }
548     } else {
549       for (auto &Summaries : Index)
550         for (auto &Summary : Summaries.second.SummaryList)
551           Callback({Summaries.first, Summary.get()}, false);
552     }
553   }
554 
555   /// Calls the callback for each entry in the modulePaths StringMap that
556   /// should be written to the module path string table. This hides the details
557   /// of whether they are being pulled from the entire index or just those in a
558   /// provided ModuleToSummariesForIndex map.
559   template <typename Functor> void forEachModule(Functor Callback) {
560     if (ModuleToSummariesForIndex) {
561       for (const auto &M : *ModuleToSummariesForIndex) {
562         const auto &MPI = Index.modulePaths().find(M.first);
563         if (MPI == Index.modulePaths().end()) {
564           // This should only happen if the bitcode file was empty, in which
565           // case we shouldn't be importing (the ModuleToSummariesForIndex
566           // would only include the module we are writing and index for).
567           assert(ModuleToSummariesForIndex->size() == 1);
568           continue;
569         }
570         Callback(*MPI);
571       }
572     } else {
573       // Since StringMap iteration order isn't guaranteed, order by path string
574       // first.
575       // FIXME: Make this a vector of StringMapEntry instead to avoid the later
576       // map lookup.
577       std::vector<StringRef> ModulePaths;
578       for (auto &[ModPath, _] : Index.modulePaths())
579         ModulePaths.push_back(ModPath);
580       llvm::sort(ModulePaths.begin(), ModulePaths.end());
581       for (auto &ModPath : ModulePaths)
582         Callback(*Index.modulePaths().find(ModPath));
583     }
584   }
585 
586   /// Main entry point for writing a combined index to bitcode.
587   void write();
588 
589 private:
590   void writeModStrings();
591   void writeCombinedGlobalValueSummary();
592 
593   std::optional<unsigned> getValueId(GlobalValue::GUID ValGUID) {
594     auto VMI = GUIDToValueIdMap.find(ValGUID);
595     if (VMI == GUIDToValueIdMap.end())
596       return std::nullopt;
597     return VMI->second;
598   }
599 
600   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
601 };
602 
603 } // end anonymous namespace
604 
605 static unsigned getEncodedCastOpcode(unsigned Opcode) {
606   switch (Opcode) {
607   default: llvm_unreachable("Unknown cast instruction!");
608   case Instruction::Trunc   : return bitc::CAST_TRUNC;
609   case Instruction::ZExt    : return bitc::CAST_ZEXT;
610   case Instruction::SExt    : return bitc::CAST_SEXT;
611   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
612   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
613   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
614   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
615   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
616   case Instruction::FPExt   : return bitc::CAST_FPEXT;
617   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
618   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
619   case Instruction::BitCast : return bitc::CAST_BITCAST;
620   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
621   }
622 }
623 
624 static unsigned getEncodedUnaryOpcode(unsigned Opcode) {
625   switch (Opcode) {
626   default: llvm_unreachable("Unknown binary instruction!");
627   case Instruction::FNeg: return bitc::UNOP_FNEG;
628   }
629 }
630 
631 static unsigned getEncodedBinaryOpcode(unsigned Opcode) {
632   switch (Opcode) {
633   default: llvm_unreachable("Unknown binary instruction!");
634   case Instruction::Add:
635   case Instruction::FAdd: return bitc::BINOP_ADD;
636   case Instruction::Sub:
637   case Instruction::FSub: return bitc::BINOP_SUB;
638   case Instruction::Mul:
639   case Instruction::FMul: return bitc::BINOP_MUL;
640   case Instruction::UDiv: return bitc::BINOP_UDIV;
641   case Instruction::FDiv:
642   case Instruction::SDiv: return bitc::BINOP_SDIV;
643   case Instruction::URem: return bitc::BINOP_UREM;
644   case Instruction::FRem:
645   case Instruction::SRem: return bitc::BINOP_SREM;
646   case Instruction::Shl:  return bitc::BINOP_SHL;
647   case Instruction::LShr: return bitc::BINOP_LSHR;
648   case Instruction::AShr: return bitc::BINOP_ASHR;
649   case Instruction::And:  return bitc::BINOP_AND;
650   case Instruction::Or:   return bitc::BINOP_OR;
651   case Instruction::Xor:  return bitc::BINOP_XOR;
652   }
653 }
654 
655 static unsigned getEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
656   switch (Op) {
657   default: llvm_unreachable("Unknown RMW operation!");
658   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
659   case AtomicRMWInst::Add: return bitc::RMW_ADD;
660   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
661   case AtomicRMWInst::And: return bitc::RMW_AND;
662   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
663   case AtomicRMWInst::Or: return bitc::RMW_OR;
664   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
665   case AtomicRMWInst::Max: return bitc::RMW_MAX;
666   case AtomicRMWInst::Min: return bitc::RMW_MIN;
667   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
668   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
669   case AtomicRMWInst::FAdd: return bitc::RMW_FADD;
670   case AtomicRMWInst::FSub: return bitc::RMW_FSUB;
671   case AtomicRMWInst::FMax: return bitc::RMW_FMAX;
672   case AtomicRMWInst::FMin: return bitc::RMW_FMIN;
673   case AtomicRMWInst::UIncWrap:
674     return bitc::RMW_UINC_WRAP;
675   case AtomicRMWInst::UDecWrap:
676     return bitc::RMW_UDEC_WRAP;
677   case AtomicRMWInst::USubCond:
678     return bitc::RMW_USUB_COND;
679   case AtomicRMWInst::USubSat:
680     return bitc::RMW_USUB_SAT;
681   }
682 }
683 
684 static unsigned getEncodedOrdering(AtomicOrdering Ordering) {
685   switch (Ordering) {
686   case AtomicOrdering::NotAtomic: return bitc::ORDERING_NOTATOMIC;
687   case AtomicOrdering::Unordered: return bitc::ORDERING_UNORDERED;
688   case AtomicOrdering::Monotonic: return bitc::ORDERING_MONOTONIC;
689   case AtomicOrdering::Acquire: return bitc::ORDERING_ACQUIRE;
690   case AtomicOrdering::Release: return bitc::ORDERING_RELEASE;
691   case AtomicOrdering::AcquireRelease: return bitc::ORDERING_ACQREL;
692   case AtomicOrdering::SequentiallyConsistent: return bitc::ORDERING_SEQCST;
693   }
694   llvm_unreachable("Invalid ordering");
695 }
696 
697 static void writeStringRecord(BitstreamWriter &Stream, unsigned Code,
698                               StringRef Str, unsigned AbbrevToUse) {
699   SmallVector<unsigned, 64> Vals;
700 
701   // Code: [strchar x N]
702   for (char C : Str) {
703     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(C))
704       AbbrevToUse = 0;
705     Vals.push_back(C);
706   }
707 
708   // Emit the finished record.
709   Stream.EmitRecord(Code, Vals, AbbrevToUse);
710 }
711 
712 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
713   switch (Kind) {
714   case Attribute::Alignment:
715     return bitc::ATTR_KIND_ALIGNMENT;
716   case Attribute::AllocAlign:
717     return bitc::ATTR_KIND_ALLOC_ALIGN;
718   case Attribute::AllocSize:
719     return bitc::ATTR_KIND_ALLOC_SIZE;
720   case Attribute::AlwaysInline:
721     return bitc::ATTR_KIND_ALWAYS_INLINE;
722   case Attribute::Builtin:
723     return bitc::ATTR_KIND_BUILTIN;
724   case Attribute::ByVal:
725     return bitc::ATTR_KIND_BY_VAL;
726   case Attribute::Convergent:
727     return bitc::ATTR_KIND_CONVERGENT;
728   case Attribute::InAlloca:
729     return bitc::ATTR_KIND_IN_ALLOCA;
730   case Attribute::Cold:
731     return bitc::ATTR_KIND_COLD;
732   case Attribute::DisableSanitizerInstrumentation:
733     return bitc::ATTR_KIND_DISABLE_SANITIZER_INSTRUMENTATION;
734   case Attribute::FnRetThunkExtern:
735     return bitc::ATTR_KIND_FNRETTHUNK_EXTERN;
736   case Attribute::Hot:
737     return bitc::ATTR_KIND_HOT;
738   case Attribute::ElementType:
739     return bitc::ATTR_KIND_ELEMENTTYPE;
740   case Attribute::HybridPatchable:
741     return bitc::ATTR_KIND_HYBRID_PATCHABLE;
742   case Attribute::InlineHint:
743     return bitc::ATTR_KIND_INLINE_HINT;
744   case Attribute::InReg:
745     return bitc::ATTR_KIND_IN_REG;
746   case Attribute::JumpTable:
747     return bitc::ATTR_KIND_JUMP_TABLE;
748   case Attribute::MinSize:
749     return bitc::ATTR_KIND_MIN_SIZE;
750   case Attribute::AllocatedPointer:
751     return bitc::ATTR_KIND_ALLOCATED_POINTER;
752   case Attribute::AllocKind:
753     return bitc::ATTR_KIND_ALLOC_KIND;
754   case Attribute::Memory:
755     return bitc::ATTR_KIND_MEMORY;
756   case Attribute::NoFPClass:
757     return bitc::ATTR_KIND_NOFPCLASS;
758   case Attribute::Naked:
759     return bitc::ATTR_KIND_NAKED;
760   case Attribute::Nest:
761     return bitc::ATTR_KIND_NEST;
762   case Attribute::NoAlias:
763     return bitc::ATTR_KIND_NO_ALIAS;
764   case Attribute::NoBuiltin:
765     return bitc::ATTR_KIND_NO_BUILTIN;
766   case Attribute::NoCallback:
767     return bitc::ATTR_KIND_NO_CALLBACK;
768   case Attribute::NoCapture:
769     return bitc::ATTR_KIND_NO_CAPTURE;
770   case Attribute::NoDivergenceSource:
771     return bitc::ATTR_KIND_NO_DIVERGENCE_SOURCE;
772   case Attribute::NoDuplicate:
773     return bitc::ATTR_KIND_NO_DUPLICATE;
774   case Attribute::NoFree:
775     return bitc::ATTR_KIND_NOFREE;
776   case Attribute::NoImplicitFloat:
777     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
778   case Attribute::NoInline:
779     return bitc::ATTR_KIND_NO_INLINE;
780   case Attribute::NoRecurse:
781     return bitc::ATTR_KIND_NO_RECURSE;
782   case Attribute::NoMerge:
783     return bitc::ATTR_KIND_NO_MERGE;
784   case Attribute::NonLazyBind:
785     return bitc::ATTR_KIND_NON_LAZY_BIND;
786   case Attribute::NonNull:
787     return bitc::ATTR_KIND_NON_NULL;
788   case Attribute::Dereferenceable:
789     return bitc::ATTR_KIND_DEREFERENCEABLE;
790   case Attribute::DereferenceableOrNull:
791     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
792   case Attribute::NoRedZone:
793     return bitc::ATTR_KIND_NO_RED_ZONE;
794   case Attribute::NoReturn:
795     return bitc::ATTR_KIND_NO_RETURN;
796   case Attribute::NoSync:
797     return bitc::ATTR_KIND_NOSYNC;
798   case Attribute::NoCfCheck:
799     return bitc::ATTR_KIND_NOCF_CHECK;
800   case Attribute::NoProfile:
801     return bitc::ATTR_KIND_NO_PROFILE;
802   case Attribute::SkipProfile:
803     return bitc::ATTR_KIND_SKIP_PROFILE;
804   case Attribute::NoUnwind:
805     return bitc::ATTR_KIND_NO_UNWIND;
806   case Attribute::NoSanitizeBounds:
807     return bitc::ATTR_KIND_NO_SANITIZE_BOUNDS;
808   case Attribute::NoSanitizeCoverage:
809     return bitc::ATTR_KIND_NO_SANITIZE_COVERAGE;
810   case Attribute::NullPointerIsValid:
811     return bitc::ATTR_KIND_NULL_POINTER_IS_VALID;
812   case Attribute::OptimizeForDebugging:
813     return bitc::ATTR_KIND_OPTIMIZE_FOR_DEBUGGING;
814   case Attribute::OptForFuzzing:
815     return bitc::ATTR_KIND_OPT_FOR_FUZZING;
816   case Attribute::OptimizeForSize:
817     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
818   case Attribute::OptimizeNone:
819     return bitc::ATTR_KIND_OPTIMIZE_NONE;
820   case Attribute::ReadNone:
821     return bitc::ATTR_KIND_READ_NONE;
822   case Attribute::ReadOnly:
823     return bitc::ATTR_KIND_READ_ONLY;
824   case Attribute::Returned:
825     return bitc::ATTR_KIND_RETURNED;
826   case Attribute::ReturnsTwice:
827     return bitc::ATTR_KIND_RETURNS_TWICE;
828   case Attribute::SExt:
829     return bitc::ATTR_KIND_S_EXT;
830   case Attribute::Speculatable:
831     return bitc::ATTR_KIND_SPECULATABLE;
832   case Attribute::StackAlignment:
833     return bitc::ATTR_KIND_STACK_ALIGNMENT;
834   case Attribute::StackProtect:
835     return bitc::ATTR_KIND_STACK_PROTECT;
836   case Attribute::StackProtectReq:
837     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
838   case Attribute::StackProtectStrong:
839     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
840   case Attribute::SafeStack:
841     return bitc::ATTR_KIND_SAFESTACK;
842   case Attribute::ShadowCallStack:
843     return bitc::ATTR_KIND_SHADOWCALLSTACK;
844   case Attribute::StrictFP:
845     return bitc::ATTR_KIND_STRICT_FP;
846   case Attribute::StructRet:
847     return bitc::ATTR_KIND_STRUCT_RET;
848   case Attribute::SanitizeAddress:
849     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
850   case Attribute::SanitizeHWAddress:
851     return bitc::ATTR_KIND_SANITIZE_HWADDRESS;
852   case Attribute::SanitizeThread:
853     return bitc::ATTR_KIND_SANITIZE_THREAD;
854   case Attribute::SanitizeMemory:
855     return bitc::ATTR_KIND_SANITIZE_MEMORY;
856   case Attribute::SanitizeNumericalStability:
857     return bitc::ATTR_KIND_SANITIZE_NUMERICAL_STABILITY;
858   case Attribute::SanitizeRealtime:
859     return bitc::ATTR_KIND_SANITIZE_REALTIME;
860   case Attribute::SanitizeRealtimeBlocking:
861     return bitc::ATTR_KIND_SANITIZE_REALTIME_BLOCKING;
862   case Attribute::SpeculativeLoadHardening:
863     return bitc::ATTR_KIND_SPECULATIVE_LOAD_HARDENING;
864   case Attribute::SwiftError:
865     return bitc::ATTR_KIND_SWIFT_ERROR;
866   case Attribute::SwiftSelf:
867     return bitc::ATTR_KIND_SWIFT_SELF;
868   case Attribute::SwiftAsync:
869     return bitc::ATTR_KIND_SWIFT_ASYNC;
870   case Attribute::UWTable:
871     return bitc::ATTR_KIND_UW_TABLE;
872   case Attribute::VScaleRange:
873     return bitc::ATTR_KIND_VSCALE_RANGE;
874   case Attribute::WillReturn:
875     return bitc::ATTR_KIND_WILLRETURN;
876   case Attribute::WriteOnly:
877     return bitc::ATTR_KIND_WRITEONLY;
878   case Attribute::ZExt:
879     return bitc::ATTR_KIND_Z_EXT;
880   case Attribute::ImmArg:
881     return bitc::ATTR_KIND_IMMARG;
882   case Attribute::SanitizeMemTag:
883     return bitc::ATTR_KIND_SANITIZE_MEMTAG;
884   case Attribute::Preallocated:
885     return bitc::ATTR_KIND_PREALLOCATED;
886   case Attribute::NoUndef:
887     return bitc::ATTR_KIND_NOUNDEF;
888   case Attribute::ByRef:
889     return bitc::ATTR_KIND_BYREF;
890   case Attribute::MustProgress:
891     return bitc::ATTR_KIND_MUSTPROGRESS;
892   case Attribute::PresplitCoroutine:
893     return bitc::ATTR_KIND_PRESPLIT_COROUTINE;
894   case Attribute::Writable:
895     return bitc::ATTR_KIND_WRITABLE;
896   case Attribute::CoroDestroyOnlyWhenComplete:
897     return bitc::ATTR_KIND_CORO_ONLY_DESTROY_WHEN_COMPLETE;
898   case Attribute::CoroElideSafe:
899     return bitc::ATTR_KIND_CORO_ELIDE_SAFE;
900   case Attribute::DeadOnUnwind:
901     return bitc::ATTR_KIND_DEAD_ON_UNWIND;
902   case Attribute::Range:
903     return bitc::ATTR_KIND_RANGE;
904   case Attribute::Initializes:
905     return bitc::ATTR_KIND_INITIALIZES;
906   case Attribute::NoExt:
907     return bitc::ATTR_KIND_NO_EXT;
908   case Attribute::EndAttrKinds:
909     llvm_unreachable("Can not encode end-attribute kinds marker.");
910   case Attribute::None:
911     llvm_unreachable("Can not encode none-attribute.");
912   case Attribute::EmptyKey:
913   case Attribute::TombstoneKey:
914     llvm_unreachable("Trying to encode EmptyKey/TombstoneKey");
915   }
916 
917   llvm_unreachable("Trying to encode unknown attribute");
918 }
919 
920 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
921   if ((int64_t)V >= 0)
922     Vals.push_back(V << 1);
923   else
924     Vals.push_back((-V << 1) | 1);
925 }
926 
927 static void emitWideAPInt(SmallVectorImpl<uint64_t> &Vals, const APInt &A) {
928   // We have an arbitrary precision integer value to write whose
929   // bit width is > 64. However, in canonical unsigned integer
930   // format it is likely that the high bits are going to be zero.
931   // So, we only write the number of active words.
932   unsigned NumWords = A.getActiveWords();
933   const uint64_t *RawData = A.getRawData();
934   for (unsigned i = 0; i < NumWords; i++)
935     emitSignedInt64(Vals, RawData[i]);
936 }
937 
938 static void emitConstantRange(SmallVectorImpl<uint64_t> &Record,
939                               const ConstantRange &CR, bool EmitBitWidth) {
940   unsigned BitWidth = CR.getBitWidth();
941   if (EmitBitWidth)
942     Record.push_back(BitWidth);
943   if (BitWidth > 64) {
944     Record.push_back(CR.getLower().getActiveWords() |
945                      (uint64_t(CR.getUpper().getActiveWords()) << 32));
946     emitWideAPInt(Record, CR.getLower());
947     emitWideAPInt(Record, CR.getUpper());
948   } else {
949     emitSignedInt64(Record, CR.getLower().getSExtValue());
950     emitSignedInt64(Record, CR.getUpper().getSExtValue());
951   }
952 }
953 
954 void ModuleBitcodeWriter::writeAttributeGroupTable() {
955   const std::vector<ValueEnumerator::IndexAndAttrSet> &AttrGrps =
956       VE.getAttributeGroups();
957   if (AttrGrps.empty()) return;
958 
959   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
960 
961   SmallVector<uint64_t, 64> Record;
962   for (ValueEnumerator::IndexAndAttrSet Pair : AttrGrps) {
963     unsigned AttrListIndex = Pair.first;
964     AttributeSet AS = Pair.second;
965     Record.push_back(VE.getAttributeGroupID(Pair));
966     Record.push_back(AttrListIndex);
967 
968     for (Attribute Attr : AS) {
969       if (Attr.isEnumAttribute()) {
970         Record.push_back(0);
971         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
972       } else if (Attr.isIntAttribute()) {
973         Record.push_back(1);
974         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
975         Record.push_back(Attr.getValueAsInt());
976       } else if (Attr.isStringAttribute()) {
977         StringRef Kind = Attr.getKindAsString();
978         StringRef Val = Attr.getValueAsString();
979 
980         Record.push_back(Val.empty() ? 3 : 4);
981         Record.append(Kind.begin(), Kind.end());
982         Record.push_back(0);
983         if (!Val.empty()) {
984           Record.append(Val.begin(), Val.end());
985           Record.push_back(0);
986         }
987       } else if (Attr.isTypeAttribute()) {
988         Type *Ty = Attr.getValueAsType();
989         Record.push_back(Ty ? 6 : 5);
990         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
991         if (Ty)
992           Record.push_back(VE.getTypeID(Attr.getValueAsType()));
993       } else if (Attr.isConstantRangeAttribute()) {
994         Record.push_back(7);
995         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
996         emitConstantRange(Record, Attr.getValueAsConstantRange(),
997                           /*EmitBitWidth=*/true);
998       } else {
999         assert(Attr.isConstantRangeListAttribute());
1000         Record.push_back(8);
1001         Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
1002         ArrayRef<ConstantRange> Val = Attr.getValueAsConstantRangeList();
1003         Record.push_back(Val.size());
1004         Record.push_back(Val[0].getBitWidth());
1005         for (auto &CR : Val)
1006           emitConstantRange(Record, CR, /*EmitBitWidth=*/false);
1007       }
1008     }
1009 
1010     Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
1011     Record.clear();
1012   }
1013 
1014   Stream.ExitBlock();
1015 }
1016 
1017 void ModuleBitcodeWriter::writeAttributeTable() {
1018   const std::vector<AttributeList> &Attrs = VE.getAttributeLists();
1019   if (Attrs.empty()) return;
1020 
1021   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
1022 
1023   SmallVector<uint64_t, 64> Record;
1024   for (const AttributeList &AL : Attrs) {
1025     for (unsigned i : AL.indexes()) {
1026       AttributeSet AS = AL.getAttributes(i);
1027       if (AS.hasAttributes())
1028         Record.push_back(VE.getAttributeGroupID({i, AS}));
1029     }
1030 
1031     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
1032     Record.clear();
1033   }
1034 
1035   Stream.ExitBlock();
1036 }
1037 
1038 /// WriteTypeTable - Write out the type table for a module.
1039 void ModuleBitcodeWriter::writeTypeTable() {
1040   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
1041 
1042   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
1043   SmallVector<uint64_t, 64> TypeVals;
1044 
1045   uint64_t NumBits = VE.computeBitsRequiredForTypeIndices();
1046 
1047   // Abbrev for TYPE_CODE_OPAQUE_POINTER.
1048   auto Abbv = std::make_shared<BitCodeAbbrev>();
1049   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_OPAQUE_POINTER));
1050   Abbv->Add(BitCodeAbbrevOp(0)); // Addrspace = 0
1051   unsigned OpaquePtrAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1052 
1053   // Abbrev for TYPE_CODE_FUNCTION.
1054   Abbv = std::make_shared<BitCodeAbbrev>();
1055   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
1056   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
1057   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1058   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1059   unsigned FunctionAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1060 
1061   // Abbrev for TYPE_CODE_STRUCT_ANON.
1062   Abbv = std::make_shared<BitCodeAbbrev>();
1063   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
1064   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
1065   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1066   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1067   unsigned StructAnonAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1068 
1069   // Abbrev for TYPE_CODE_STRUCT_NAME.
1070   Abbv = std::make_shared<BitCodeAbbrev>();
1071   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
1072   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1073   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1074   unsigned StructNameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1075 
1076   // Abbrev for TYPE_CODE_STRUCT_NAMED.
1077   Abbv = std::make_shared<BitCodeAbbrev>();
1078   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
1079   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
1080   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1081   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1082   unsigned StructNamedAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1083 
1084   // Abbrev for TYPE_CODE_ARRAY.
1085   Abbv = std::make_shared<BitCodeAbbrev>();
1086   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
1087   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
1088   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1089   unsigned ArrayAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1090 
1091   // Emit an entry count so the reader can reserve space.
1092   TypeVals.push_back(TypeList.size());
1093   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
1094   TypeVals.clear();
1095 
1096   // Loop over all of the types, emitting each in turn.
1097   for (Type *T : TypeList) {
1098     int AbbrevToUse = 0;
1099     unsigned Code = 0;
1100 
1101     switch (T->getTypeID()) {
1102     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
1103     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
1104     case Type::BFloatTyID:    Code = bitc::TYPE_CODE_BFLOAT;    break;
1105     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
1106     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
1107     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
1108     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
1109     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
1110     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
1111     case Type::MetadataTyID:
1112       Code = bitc::TYPE_CODE_METADATA;
1113       break;
1114     case Type::X86_AMXTyID:   Code = bitc::TYPE_CODE_X86_AMX;   break;
1115     case Type::TokenTyID:     Code = bitc::TYPE_CODE_TOKEN;     break;
1116     case Type::IntegerTyID:
1117       // INTEGER: [width]
1118       Code = bitc::TYPE_CODE_INTEGER;
1119       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
1120       break;
1121     case Type::PointerTyID: {
1122       PointerType *PTy = cast<PointerType>(T);
1123       unsigned AddressSpace = PTy->getAddressSpace();
1124       // OPAQUE_POINTER: [address space]
1125       Code = bitc::TYPE_CODE_OPAQUE_POINTER;
1126       TypeVals.push_back(AddressSpace);
1127       if (AddressSpace == 0)
1128         AbbrevToUse = OpaquePtrAbbrev;
1129       break;
1130     }
1131     case Type::FunctionTyID: {
1132       FunctionType *FT = cast<FunctionType>(T);
1133       // FUNCTION: [isvararg, retty, paramty x N]
1134       Code = bitc::TYPE_CODE_FUNCTION;
1135       TypeVals.push_back(FT->isVarArg());
1136       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
1137       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
1138         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
1139       AbbrevToUse = FunctionAbbrev;
1140       break;
1141     }
1142     case Type::StructTyID: {
1143       StructType *ST = cast<StructType>(T);
1144       // STRUCT: [ispacked, eltty x N]
1145       TypeVals.push_back(ST->isPacked());
1146       // Output all of the element types.
1147       for (Type *ET : ST->elements())
1148         TypeVals.push_back(VE.getTypeID(ET));
1149 
1150       if (ST->isLiteral()) {
1151         Code = bitc::TYPE_CODE_STRUCT_ANON;
1152         AbbrevToUse = StructAnonAbbrev;
1153       } else {
1154         if (ST->isOpaque()) {
1155           Code = bitc::TYPE_CODE_OPAQUE;
1156         } else {
1157           Code = bitc::TYPE_CODE_STRUCT_NAMED;
1158           AbbrevToUse = StructNamedAbbrev;
1159         }
1160 
1161         // Emit the name if it is present.
1162         if (!ST->getName().empty())
1163           writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
1164                             StructNameAbbrev);
1165       }
1166       break;
1167     }
1168     case Type::ArrayTyID: {
1169       ArrayType *AT = cast<ArrayType>(T);
1170       // ARRAY: [numelts, eltty]
1171       Code = bitc::TYPE_CODE_ARRAY;
1172       TypeVals.push_back(AT->getNumElements());
1173       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
1174       AbbrevToUse = ArrayAbbrev;
1175       break;
1176     }
1177     case Type::FixedVectorTyID:
1178     case Type::ScalableVectorTyID: {
1179       VectorType *VT = cast<VectorType>(T);
1180       // VECTOR [numelts, eltty] or
1181       //        [numelts, eltty, scalable]
1182       Code = bitc::TYPE_CODE_VECTOR;
1183       TypeVals.push_back(VT->getElementCount().getKnownMinValue());
1184       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
1185       if (isa<ScalableVectorType>(VT))
1186         TypeVals.push_back(true);
1187       break;
1188     }
1189     case Type::TargetExtTyID: {
1190       TargetExtType *TET = cast<TargetExtType>(T);
1191       Code = bitc::TYPE_CODE_TARGET_TYPE;
1192       writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, TET->getName(),
1193                         StructNameAbbrev);
1194       TypeVals.push_back(TET->getNumTypeParameters());
1195       for (Type *InnerTy : TET->type_params())
1196         TypeVals.push_back(VE.getTypeID(InnerTy));
1197       for (unsigned IntParam : TET->int_params())
1198         TypeVals.push_back(IntParam);
1199       break;
1200     }
1201     case Type::TypedPointerTyID:
1202       llvm_unreachable("Typed pointers cannot be added to IR modules");
1203     }
1204 
1205     // Emit the finished record.
1206     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
1207     TypeVals.clear();
1208   }
1209 
1210   Stream.ExitBlock();
1211 }
1212 
1213 static unsigned getEncodedLinkage(const GlobalValue::LinkageTypes Linkage) {
1214   switch (Linkage) {
1215   case GlobalValue::ExternalLinkage:
1216     return 0;
1217   case GlobalValue::WeakAnyLinkage:
1218     return 16;
1219   case GlobalValue::AppendingLinkage:
1220     return 2;
1221   case GlobalValue::InternalLinkage:
1222     return 3;
1223   case GlobalValue::LinkOnceAnyLinkage:
1224     return 18;
1225   case GlobalValue::ExternalWeakLinkage:
1226     return 7;
1227   case GlobalValue::CommonLinkage:
1228     return 8;
1229   case GlobalValue::PrivateLinkage:
1230     return 9;
1231   case GlobalValue::WeakODRLinkage:
1232     return 17;
1233   case GlobalValue::LinkOnceODRLinkage:
1234     return 19;
1235   case GlobalValue::AvailableExternallyLinkage:
1236     return 12;
1237   }
1238   llvm_unreachable("Invalid linkage");
1239 }
1240 
1241 static unsigned getEncodedLinkage(const GlobalValue &GV) {
1242   return getEncodedLinkage(GV.getLinkage());
1243 }
1244 
1245 static uint64_t getEncodedFFlags(FunctionSummary::FFlags Flags) {
1246   uint64_t RawFlags = 0;
1247   RawFlags |= Flags.ReadNone;
1248   RawFlags |= (Flags.ReadOnly << 1);
1249   RawFlags |= (Flags.NoRecurse << 2);
1250   RawFlags |= (Flags.ReturnDoesNotAlias << 3);
1251   RawFlags |= (Flags.NoInline << 4);
1252   RawFlags |= (Flags.AlwaysInline << 5);
1253   RawFlags |= (Flags.NoUnwind << 6);
1254   RawFlags |= (Flags.MayThrow << 7);
1255   RawFlags |= (Flags.HasUnknownCall << 8);
1256   RawFlags |= (Flags.MustBeUnreachable << 9);
1257   return RawFlags;
1258 }
1259 
1260 // Decode the flags for GlobalValue in the summary. See getDecodedGVSummaryFlags
1261 // in BitcodeReader.cpp.
1262 static uint64_t getEncodedGVSummaryFlags(GlobalValueSummary::GVFlags Flags,
1263                                          bool ImportAsDecl = false) {
1264   uint64_t RawFlags = 0;
1265 
1266   RawFlags |= Flags.NotEligibleToImport; // bool
1267   RawFlags |= (Flags.Live << 1);
1268   RawFlags |= (Flags.DSOLocal << 2);
1269   RawFlags |= (Flags.CanAutoHide << 3);
1270 
1271   // Linkage don't need to be remapped at that time for the summary. Any future
1272   // change to the getEncodedLinkage() function will need to be taken into
1273   // account here as well.
1274   RawFlags = (RawFlags << 4) | Flags.Linkage; // 4 bits
1275 
1276   RawFlags |= (Flags.Visibility << 8); // 2 bits
1277 
1278   unsigned ImportType = Flags.ImportType | ImportAsDecl;
1279   RawFlags |= (ImportType << 10); // 1 bit
1280 
1281   return RawFlags;
1282 }
1283 
1284 static uint64_t getEncodedGVarFlags(GlobalVarSummary::GVarFlags Flags) {
1285   uint64_t RawFlags = Flags.MaybeReadOnly | (Flags.MaybeWriteOnly << 1) |
1286                       (Flags.Constant << 2) | Flags.VCallVisibility << 3;
1287   return RawFlags;
1288 }
1289 
1290 static uint64_t getEncodedHotnessCallEdgeInfo(const CalleeInfo &CI) {
1291   uint64_t RawFlags = 0;
1292 
1293   RawFlags |= CI.Hotness;            // 3 bits
1294   RawFlags |= (CI.HasTailCall << 3); // 1 bit
1295 
1296   return RawFlags;
1297 }
1298 
1299 static uint64_t getEncodedRelBFCallEdgeInfo(const CalleeInfo &CI) {
1300   uint64_t RawFlags = 0;
1301 
1302   RawFlags |= CI.RelBlockFreq; // CalleeInfo::RelBlockFreqBits bits
1303   RawFlags |= (CI.HasTailCall << CalleeInfo::RelBlockFreqBits); // 1 bit
1304 
1305   return RawFlags;
1306 }
1307 
1308 static unsigned getEncodedVisibility(const GlobalValue &GV) {
1309   switch (GV.getVisibility()) {
1310   case GlobalValue::DefaultVisibility:   return 0;
1311   case GlobalValue::HiddenVisibility:    return 1;
1312   case GlobalValue::ProtectedVisibility: return 2;
1313   }
1314   llvm_unreachable("Invalid visibility");
1315 }
1316 
1317 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
1318   switch (GV.getDLLStorageClass()) {
1319   case GlobalValue::DefaultStorageClass:   return 0;
1320   case GlobalValue::DLLImportStorageClass: return 1;
1321   case GlobalValue::DLLExportStorageClass: return 2;
1322   }
1323   llvm_unreachable("Invalid DLL storage class");
1324 }
1325 
1326 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
1327   switch (GV.getThreadLocalMode()) {
1328     case GlobalVariable::NotThreadLocal:         return 0;
1329     case GlobalVariable::GeneralDynamicTLSModel: return 1;
1330     case GlobalVariable::LocalDynamicTLSModel:   return 2;
1331     case GlobalVariable::InitialExecTLSModel:    return 3;
1332     case GlobalVariable::LocalExecTLSModel:      return 4;
1333   }
1334   llvm_unreachable("Invalid TLS model");
1335 }
1336 
1337 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
1338   switch (C.getSelectionKind()) {
1339   case Comdat::Any:
1340     return bitc::COMDAT_SELECTION_KIND_ANY;
1341   case Comdat::ExactMatch:
1342     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
1343   case Comdat::Largest:
1344     return bitc::COMDAT_SELECTION_KIND_LARGEST;
1345   case Comdat::NoDeduplicate:
1346     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
1347   case Comdat::SameSize:
1348     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
1349   }
1350   llvm_unreachable("Invalid selection kind");
1351 }
1352 
1353 static unsigned getEncodedUnnamedAddr(const GlobalValue &GV) {
1354   switch (GV.getUnnamedAddr()) {
1355   case GlobalValue::UnnamedAddr::None:   return 0;
1356   case GlobalValue::UnnamedAddr::Local:  return 2;
1357   case GlobalValue::UnnamedAddr::Global: return 1;
1358   }
1359   llvm_unreachable("Invalid unnamed_addr");
1360 }
1361 
1362 size_t ModuleBitcodeWriter::addToStrtab(StringRef Str) {
1363   if (GenerateHash)
1364     Hasher.update(Str);
1365   return StrtabBuilder.add(Str);
1366 }
1367 
1368 void ModuleBitcodeWriter::writeComdats() {
1369   SmallVector<unsigned, 64> Vals;
1370   for (const Comdat *C : VE.getComdats()) {
1371     // COMDAT: [strtab offset, strtab size, selection_kind]
1372     Vals.push_back(addToStrtab(C->getName()));
1373     Vals.push_back(C->getName().size());
1374     Vals.push_back(getEncodedComdatSelectionKind(*C));
1375     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
1376     Vals.clear();
1377   }
1378 }
1379 
1380 /// Write a record that will eventually hold the word offset of the
1381 /// module-level VST. For now the offset is 0, which will be backpatched
1382 /// after the real VST is written. Saves the bit offset to backpatch.
1383 void ModuleBitcodeWriter::writeValueSymbolTableForwardDecl() {
1384   // Write a placeholder value in for the offset of the real VST,
1385   // which is written after the function blocks so that it can include
1386   // the offset of each function. The placeholder offset will be
1387   // updated when the real VST is written.
1388   auto Abbv = std::make_shared<BitCodeAbbrev>();
1389   Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_VSTOFFSET));
1390   // Blocks are 32-bit aligned, so we can use a 32-bit word offset to
1391   // hold the real VST offset. Must use fixed instead of VBR as we don't
1392   // know how many VBR chunks to reserve ahead of time.
1393   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1394   unsigned VSTOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1395 
1396   // Emit the placeholder
1397   uint64_t Vals[] = {bitc::MODULE_CODE_VSTOFFSET, 0};
1398   Stream.EmitRecordWithAbbrev(VSTOffsetAbbrev, Vals);
1399 
1400   // Compute and save the bit offset to the placeholder, which will be
1401   // patched when the real VST is written. We can simply subtract the 32-bit
1402   // fixed size from the current bit number to get the location to backpatch.
1403   VSTOffsetPlaceholder = Stream.GetCurrentBitNo() - 32;
1404 }
1405 
1406 enum StringEncoding { SE_Char6, SE_Fixed7, SE_Fixed8 };
1407 
1408 /// Determine the encoding to use for the given string name and length.
1409 static StringEncoding getStringEncoding(StringRef Str) {
1410   bool isChar6 = true;
1411   for (char C : Str) {
1412     if (isChar6)
1413       isChar6 = BitCodeAbbrevOp::isChar6(C);
1414     if ((unsigned char)C & 128)
1415       // don't bother scanning the rest.
1416       return SE_Fixed8;
1417   }
1418   if (isChar6)
1419     return SE_Char6;
1420   return SE_Fixed7;
1421 }
1422 
1423 static_assert(sizeof(GlobalValue::SanitizerMetadata) <= sizeof(unsigned),
1424               "Sanitizer Metadata is too large for naive serialization.");
1425 static unsigned
1426 serializeSanitizerMetadata(const GlobalValue::SanitizerMetadata &Meta) {
1427   return Meta.NoAddress | (Meta.NoHWAddress << 1) |
1428          (Meta.Memtag << 2) | (Meta.IsDynInit << 3);
1429 }
1430 
1431 /// Emit top-level description of module, including target triple, inline asm,
1432 /// descriptors for global variables, and function prototype info.
1433 /// Returns the bit offset to backpatch with the location of the real VST.
1434 void ModuleBitcodeWriter::writeModuleInfo() {
1435   // Emit various pieces of data attached to a module.
1436   if (!M.getTargetTriple().empty())
1437     writeStringRecord(Stream, bitc::MODULE_CODE_TRIPLE, M.getTargetTriple(),
1438                       0 /*TODO*/);
1439   const std::string &DL = M.getDataLayoutStr();
1440   if (!DL.empty())
1441     writeStringRecord(Stream, bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/);
1442   if (!M.getModuleInlineAsm().empty())
1443     writeStringRecord(Stream, bitc::MODULE_CODE_ASM, M.getModuleInlineAsm(),
1444                       0 /*TODO*/);
1445 
1446   // Emit information about sections and GC, computing how many there are. Also
1447   // compute the maximum alignment value.
1448   std::map<std::string, unsigned> SectionMap;
1449   std::map<std::string, unsigned> GCMap;
1450   MaybeAlign MaxAlignment;
1451   unsigned MaxGlobalType = 0;
1452   const auto UpdateMaxAlignment = [&MaxAlignment](const MaybeAlign A) {
1453     if (A)
1454       MaxAlignment = !MaxAlignment ? *A : std::max(*MaxAlignment, *A);
1455   };
1456   for (const GlobalVariable &GV : M.globals()) {
1457     UpdateMaxAlignment(GV.getAlign());
1458     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
1459     if (GV.hasSection()) {
1460       // Give section names unique ID's.
1461       unsigned &Entry = SectionMap[std::string(GV.getSection())];
1462       if (!Entry) {
1463         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
1464                           0 /*TODO*/);
1465         Entry = SectionMap.size();
1466       }
1467     }
1468   }
1469   for (const Function &F : M) {
1470     UpdateMaxAlignment(F.getAlign());
1471     if (F.hasSection()) {
1472       // Give section names unique ID's.
1473       unsigned &Entry = SectionMap[std::string(F.getSection())];
1474       if (!Entry) {
1475         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
1476                           0 /*TODO*/);
1477         Entry = SectionMap.size();
1478       }
1479     }
1480     if (F.hasGC()) {
1481       // Same for GC names.
1482       unsigned &Entry = GCMap[F.getGC()];
1483       if (!Entry) {
1484         writeStringRecord(Stream, bitc::MODULE_CODE_GCNAME, F.getGC(),
1485                           0 /*TODO*/);
1486         Entry = GCMap.size();
1487       }
1488     }
1489   }
1490 
1491   // Emit abbrev for globals, now that we know # sections and max alignment.
1492   unsigned SimpleGVarAbbrev = 0;
1493   if (!M.global_empty()) {
1494     // Add an abbrev for common globals with no visibility or thread localness.
1495     auto Abbv = std::make_shared<BitCodeAbbrev>();
1496     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
1497     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1498     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1499     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1500                               Log2_32_Ceil(MaxGlobalType+1)));
1501     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
1502                                                            //| explicitType << 1
1503                                                            //| constant
1504     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
1505     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
1506     if (!MaxAlignment)                                     // Alignment.
1507       Abbv->Add(BitCodeAbbrevOp(0));
1508     else {
1509       unsigned MaxEncAlignment = getEncodedAlign(MaxAlignment);
1510       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1511                                Log2_32_Ceil(MaxEncAlignment+1)));
1512     }
1513     if (SectionMap.empty())                                    // Section.
1514       Abbv->Add(BitCodeAbbrevOp(0));
1515     else
1516       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1517                                Log2_32_Ceil(SectionMap.size()+1)));
1518     // Don't bother emitting vis + thread local.
1519     SimpleGVarAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1520   }
1521 
1522   SmallVector<unsigned, 64> Vals;
1523   // Emit the module's source file name.
1524   {
1525     StringEncoding Bits = getStringEncoding(M.getSourceFileName());
1526     BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
1527     if (Bits == SE_Char6)
1528       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
1529     else if (Bits == SE_Fixed7)
1530       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
1531 
1532     // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
1533     auto Abbv = std::make_shared<BitCodeAbbrev>();
1534     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
1535     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1536     Abbv->Add(AbbrevOpToUse);
1537     unsigned FilenameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1538 
1539     for (const auto P : M.getSourceFileName())
1540       Vals.push_back((unsigned char)P);
1541 
1542     // Emit the finished record.
1543     Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
1544     Vals.clear();
1545   }
1546 
1547   // Emit the global variable information.
1548   for (const GlobalVariable &GV : M.globals()) {
1549     unsigned AbbrevToUse = 0;
1550 
1551     // GLOBALVAR: [strtab offset, strtab size, type, isconst, initid,
1552     //             linkage, alignment, section, visibility, threadlocal,
1553     //             unnamed_addr, externally_initialized, dllstorageclass,
1554     //             comdat, attributes, DSO_Local, GlobalSanitizer, code_model]
1555     Vals.push_back(addToStrtab(GV.getName()));
1556     Vals.push_back(GV.getName().size());
1557     Vals.push_back(VE.getTypeID(GV.getValueType()));
1558     Vals.push_back(GV.getType()->getAddressSpace() << 2 | 2 | GV.isConstant());
1559     Vals.push_back(GV.isDeclaration() ? 0 :
1560                    (VE.getValueID(GV.getInitializer()) + 1));
1561     Vals.push_back(getEncodedLinkage(GV));
1562     Vals.push_back(getEncodedAlign(GV.getAlign()));
1563     Vals.push_back(GV.hasSection() ? SectionMap[std::string(GV.getSection())]
1564                                    : 0);
1565     if (GV.isThreadLocal() ||
1566         GV.getVisibility() != GlobalValue::DefaultVisibility ||
1567         GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None ||
1568         GV.isExternallyInitialized() ||
1569         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
1570         GV.hasComdat() || GV.hasAttributes() || GV.isDSOLocal() ||
1571         GV.hasPartition() || GV.hasSanitizerMetadata() || GV.getCodeModel()) {
1572       Vals.push_back(getEncodedVisibility(GV));
1573       Vals.push_back(getEncodedThreadLocalMode(GV));
1574       Vals.push_back(getEncodedUnnamedAddr(GV));
1575       Vals.push_back(GV.isExternallyInitialized());
1576       Vals.push_back(getEncodedDLLStorageClass(GV));
1577       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
1578 
1579       auto AL = GV.getAttributesAsList(AttributeList::FunctionIndex);
1580       Vals.push_back(VE.getAttributeListID(AL));
1581 
1582       Vals.push_back(GV.isDSOLocal());
1583       Vals.push_back(addToStrtab(GV.getPartition()));
1584       Vals.push_back(GV.getPartition().size());
1585 
1586       Vals.push_back((GV.hasSanitizerMetadata() ? serializeSanitizerMetadata(
1587                                                       GV.getSanitizerMetadata())
1588                                                 : 0));
1589       Vals.push_back(GV.getCodeModelRaw());
1590     } else {
1591       AbbrevToUse = SimpleGVarAbbrev;
1592     }
1593 
1594     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
1595     Vals.clear();
1596   }
1597 
1598   // Emit the function proto information.
1599   for (const Function &F : M) {
1600     // FUNCTION:  [strtab offset, strtab size, type, callingconv, isproto,
1601     //             linkage, paramattrs, alignment, section, visibility, gc,
1602     //             unnamed_addr, prologuedata, dllstorageclass, comdat,
1603     //             prefixdata, personalityfn, DSO_Local, addrspace]
1604     Vals.push_back(addToStrtab(F.getName()));
1605     Vals.push_back(F.getName().size());
1606     Vals.push_back(VE.getTypeID(F.getFunctionType()));
1607     Vals.push_back(F.getCallingConv());
1608     Vals.push_back(F.isDeclaration());
1609     Vals.push_back(getEncodedLinkage(F));
1610     Vals.push_back(VE.getAttributeListID(F.getAttributes()));
1611     Vals.push_back(getEncodedAlign(F.getAlign()));
1612     Vals.push_back(F.hasSection() ? SectionMap[std::string(F.getSection())]
1613                                   : 0);
1614     Vals.push_back(getEncodedVisibility(F));
1615     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
1616     Vals.push_back(getEncodedUnnamedAddr(F));
1617     Vals.push_back(F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1)
1618                                        : 0);
1619     Vals.push_back(getEncodedDLLStorageClass(F));
1620     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
1621     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
1622                                      : 0);
1623     Vals.push_back(
1624         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
1625 
1626     Vals.push_back(F.isDSOLocal());
1627     Vals.push_back(F.getAddressSpace());
1628     Vals.push_back(addToStrtab(F.getPartition()));
1629     Vals.push_back(F.getPartition().size());
1630 
1631     unsigned AbbrevToUse = 0;
1632     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
1633     Vals.clear();
1634   }
1635 
1636   // Emit the alias information.
1637   for (const GlobalAlias &A : M.aliases()) {
1638     // ALIAS: [strtab offset, strtab size, alias type, aliasee val#, linkage,
1639     //         visibility, dllstorageclass, threadlocal, unnamed_addr,
1640     //         DSO_Local]
1641     Vals.push_back(addToStrtab(A.getName()));
1642     Vals.push_back(A.getName().size());
1643     Vals.push_back(VE.getTypeID(A.getValueType()));
1644     Vals.push_back(A.getType()->getAddressSpace());
1645     Vals.push_back(VE.getValueID(A.getAliasee()));
1646     Vals.push_back(getEncodedLinkage(A));
1647     Vals.push_back(getEncodedVisibility(A));
1648     Vals.push_back(getEncodedDLLStorageClass(A));
1649     Vals.push_back(getEncodedThreadLocalMode(A));
1650     Vals.push_back(getEncodedUnnamedAddr(A));
1651     Vals.push_back(A.isDSOLocal());
1652     Vals.push_back(addToStrtab(A.getPartition()));
1653     Vals.push_back(A.getPartition().size());
1654 
1655     unsigned AbbrevToUse = 0;
1656     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
1657     Vals.clear();
1658   }
1659 
1660   // Emit the ifunc information.
1661   for (const GlobalIFunc &I : M.ifuncs()) {
1662     // IFUNC: [strtab offset, strtab size, ifunc type, address space, resolver
1663     //         val#, linkage, visibility, DSO_Local]
1664     Vals.push_back(addToStrtab(I.getName()));
1665     Vals.push_back(I.getName().size());
1666     Vals.push_back(VE.getTypeID(I.getValueType()));
1667     Vals.push_back(I.getType()->getAddressSpace());
1668     Vals.push_back(VE.getValueID(I.getResolver()));
1669     Vals.push_back(getEncodedLinkage(I));
1670     Vals.push_back(getEncodedVisibility(I));
1671     Vals.push_back(I.isDSOLocal());
1672     Vals.push_back(addToStrtab(I.getPartition()));
1673     Vals.push_back(I.getPartition().size());
1674     Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
1675     Vals.clear();
1676   }
1677 
1678   writeValueSymbolTableForwardDecl();
1679 }
1680 
1681 static uint64_t getOptimizationFlags(const Value *V) {
1682   uint64_t Flags = 0;
1683 
1684   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
1685     if (OBO->hasNoSignedWrap())
1686       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
1687     if (OBO->hasNoUnsignedWrap())
1688       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
1689   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
1690     if (PEO->isExact())
1691       Flags |= 1 << bitc::PEO_EXACT;
1692   } else if (const auto *PDI = dyn_cast<PossiblyDisjointInst>(V)) {
1693     if (PDI->isDisjoint())
1694       Flags |= 1 << bitc::PDI_DISJOINT;
1695   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
1696     if (FPMO->hasAllowReassoc())
1697       Flags |= bitc::AllowReassoc;
1698     if (FPMO->hasNoNaNs())
1699       Flags |= bitc::NoNaNs;
1700     if (FPMO->hasNoInfs())
1701       Flags |= bitc::NoInfs;
1702     if (FPMO->hasNoSignedZeros())
1703       Flags |= bitc::NoSignedZeros;
1704     if (FPMO->hasAllowReciprocal())
1705       Flags |= bitc::AllowReciprocal;
1706     if (FPMO->hasAllowContract())
1707       Flags |= bitc::AllowContract;
1708     if (FPMO->hasApproxFunc())
1709       Flags |= bitc::ApproxFunc;
1710   } else if (const auto *NNI = dyn_cast<PossiblyNonNegInst>(V)) {
1711     if (NNI->hasNonNeg())
1712       Flags |= 1 << bitc::PNNI_NON_NEG;
1713   } else if (const auto *TI = dyn_cast<TruncInst>(V)) {
1714     if (TI->hasNoSignedWrap())
1715       Flags |= 1 << bitc::TIO_NO_SIGNED_WRAP;
1716     if (TI->hasNoUnsignedWrap())
1717       Flags |= 1 << bitc::TIO_NO_UNSIGNED_WRAP;
1718   } else if (const auto *GEP = dyn_cast<GEPOperator>(V)) {
1719     if (GEP->isInBounds())
1720       Flags |= 1 << bitc::GEP_INBOUNDS;
1721     if (GEP->hasNoUnsignedSignedWrap())
1722       Flags |= 1 << bitc::GEP_NUSW;
1723     if (GEP->hasNoUnsignedWrap())
1724       Flags |= 1 << bitc::GEP_NUW;
1725   } else if (const auto *ICmp = dyn_cast<ICmpInst>(V)) {
1726     if (ICmp->hasSameSign())
1727       Flags |= 1 << bitc::ICMP_SAME_SIGN;
1728   }
1729 
1730   return Flags;
1731 }
1732 
1733 void ModuleBitcodeWriter::writeValueAsMetadata(
1734     const ValueAsMetadata *MD, SmallVectorImpl<uint64_t> &Record) {
1735   // Mimic an MDNode with a value as one operand.
1736   Value *V = MD->getValue();
1737   Record.push_back(VE.getTypeID(V->getType()));
1738   Record.push_back(VE.getValueID(V));
1739   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
1740   Record.clear();
1741 }
1742 
1743 void ModuleBitcodeWriter::writeMDTuple(const MDTuple *N,
1744                                        SmallVectorImpl<uint64_t> &Record,
1745                                        unsigned Abbrev) {
1746   for (const MDOperand &MDO : N->operands()) {
1747     Metadata *MD = MDO;
1748     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
1749            "Unexpected function-local metadata");
1750     Record.push_back(VE.getMetadataOrNullID(MD));
1751   }
1752   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
1753                                     : bitc::METADATA_NODE,
1754                     Record, Abbrev);
1755   Record.clear();
1756 }
1757 
1758 unsigned ModuleBitcodeWriter::createDILocationAbbrev() {
1759   // Assume the column is usually under 128, and always output the inlined-at
1760   // location (it's never more expensive than building an array size 1).
1761   auto Abbv = std::make_shared<BitCodeAbbrev>();
1762   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1763   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1764   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1765   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1766   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1767   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1768   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1769   return Stream.EmitAbbrev(std::move(Abbv));
1770 }
1771 
1772 void ModuleBitcodeWriter::writeDILocation(const DILocation *N,
1773                                           SmallVectorImpl<uint64_t> &Record,
1774                                           unsigned &Abbrev) {
1775   if (!Abbrev)
1776     Abbrev = createDILocationAbbrev();
1777 
1778   Record.push_back(N->isDistinct());
1779   Record.push_back(N->getLine());
1780   Record.push_back(N->getColumn());
1781   Record.push_back(VE.getMetadataID(N->getScope()));
1782   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
1783   Record.push_back(N->isImplicitCode());
1784 
1785   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
1786   Record.clear();
1787 }
1788 
1789 unsigned ModuleBitcodeWriter::createGenericDINodeAbbrev() {
1790   // Assume the column is usually under 128, and always output the inlined-at
1791   // location (it's never more expensive than building an array size 1).
1792   auto Abbv = std::make_shared<BitCodeAbbrev>();
1793   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1794   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1795   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1796   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1797   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1798   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1799   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1800   return Stream.EmitAbbrev(std::move(Abbv));
1801 }
1802 
1803 void ModuleBitcodeWriter::writeGenericDINode(const GenericDINode *N,
1804                                              SmallVectorImpl<uint64_t> &Record,
1805                                              unsigned &Abbrev) {
1806   if (!Abbrev)
1807     Abbrev = createGenericDINodeAbbrev();
1808 
1809   Record.push_back(N->isDistinct());
1810   Record.push_back(N->getTag());
1811   Record.push_back(0); // Per-tag version field; unused for now.
1812 
1813   for (auto &I : N->operands())
1814     Record.push_back(VE.getMetadataOrNullID(I));
1815 
1816   Stream.EmitRecord(bitc::METADATA_GENERIC_DEBUG, Record, Abbrev);
1817   Record.clear();
1818 }
1819 
1820 void ModuleBitcodeWriter::writeDISubrange(const DISubrange *N,
1821                                           SmallVectorImpl<uint64_t> &Record,
1822                                           unsigned Abbrev) {
1823   const uint64_t Version = 2 << 1;
1824   Record.push_back((uint64_t)N->isDistinct() | Version);
1825   Record.push_back(VE.getMetadataOrNullID(N->getRawCountNode()));
1826   Record.push_back(VE.getMetadataOrNullID(N->getRawLowerBound()));
1827   Record.push_back(VE.getMetadataOrNullID(N->getRawUpperBound()));
1828   Record.push_back(VE.getMetadataOrNullID(N->getRawStride()));
1829 
1830   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
1831   Record.clear();
1832 }
1833 
1834 void ModuleBitcodeWriter::writeDIGenericSubrange(
1835     const DIGenericSubrange *N, SmallVectorImpl<uint64_t> &Record,
1836     unsigned Abbrev) {
1837   Record.push_back((uint64_t)N->isDistinct());
1838   Record.push_back(VE.getMetadataOrNullID(N->getRawCountNode()));
1839   Record.push_back(VE.getMetadataOrNullID(N->getRawLowerBound()));
1840   Record.push_back(VE.getMetadataOrNullID(N->getRawUpperBound()));
1841   Record.push_back(VE.getMetadataOrNullID(N->getRawStride()));
1842 
1843   Stream.EmitRecord(bitc::METADATA_GENERIC_SUBRANGE, Record, Abbrev);
1844   Record.clear();
1845 }
1846 
1847 void ModuleBitcodeWriter::writeDIEnumerator(const DIEnumerator *N,
1848                                             SmallVectorImpl<uint64_t> &Record,
1849                                             unsigned Abbrev) {
1850   const uint64_t IsBigInt = 1 << 2;
1851   Record.push_back(IsBigInt | (N->isUnsigned() << 1) | N->isDistinct());
1852   Record.push_back(N->getValue().getBitWidth());
1853   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1854   emitWideAPInt(Record, N->getValue());
1855 
1856   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
1857   Record.clear();
1858 }
1859 
1860 void ModuleBitcodeWriter::writeDIBasicType(const DIBasicType *N,
1861                                            SmallVectorImpl<uint64_t> &Record,
1862                                            unsigned Abbrev) {
1863   Record.push_back(N->isDistinct());
1864   Record.push_back(N->getTag());
1865   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1866   Record.push_back(N->getSizeInBits());
1867   Record.push_back(N->getAlignInBits());
1868   Record.push_back(N->getEncoding());
1869   Record.push_back(N->getFlags());
1870   Record.push_back(N->getNumExtraInhabitants());
1871 
1872   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
1873   Record.clear();
1874 }
1875 
1876 void ModuleBitcodeWriter::writeDIStringType(const DIStringType *N,
1877                                             SmallVectorImpl<uint64_t> &Record,
1878                                             unsigned Abbrev) {
1879   Record.push_back(N->isDistinct());
1880   Record.push_back(N->getTag());
1881   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1882   Record.push_back(VE.getMetadataOrNullID(N->getStringLength()));
1883   Record.push_back(VE.getMetadataOrNullID(N->getStringLengthExp()));
1884   Record.push_back(VE.getMetadataOrNullID(N->getStringLocationExp()));
1885   Record.push_back(N->getSizeInBits());
1886   Record.push_back(N->getAlignInBits());
1887   Record.push_back(N->getEncoding());
1888 
1889   Stream.EmitRecord(bitc::METADATA_STRING_TYPE, Record, Abbrev);
1890   Record.clear();
1891 }
1892 
1893 void ModuleBitcodeWriter::writeDIDerivedType(const DIDerivedType *N,
1894                                              SmallVectorImpl<uint64_t> &Record,
1895                                              unsigned Abbrev) {
1896   Record.push_back(N->isDistinct());
1897   Record.push_back(N->getTag());
1898   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1899   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1900   Record.push_back(N->getLine());
1901   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1902   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1903   Record.push_back(N->getSizeInBits());
1904   Record.push_back(N->getAlignInBits());
1905   Record.push_back(N->getOffsetInBits());
1906   Record.push_back(N->getFlags());
1907   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
1908 
1909   // DWARF address space is encoded as N->getDWARFAddressSpace() + 1. 0 means
1910   // that there is no DWARF address space associated with DIDerivedType.
1911   if (const auto &DWARFAddressSpace = N->getDWARFAddressSpace())
1912     Record.push_back(*DWARFAddressSpace + 1);
1913   else
1914     Record.push_back(0);
1915 
1916   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
1917 
1918   if (auto PtrAuthData = N->getPtrAuthData())
1919     Record.push_back(PtrAuthData->RawData);
1920   else
1921     Record.push_back(0);
1922 
1923   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
1924   Record.clear();
1925 }
1926 
1927 void ModuleBitcodeWriter::writeDICompositeType(
1928     const DICompositeType *N, SmallVectorImpl<uint64_t> &Record,
1929     unsigned Abbrev) {
1930   const unsigned IsNotUsedInOldTypeRef = 0x2;
1931   Record.push_back(IsNotUsedInOldTypeRef | (unsigned)N->isDistinct());
1932   Record.push_back(N->getTag());
1933   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1934   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1935   Record.push_back(N->getLine());
1936   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1937   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1938   Record.push_back(N->getSizeInBits());
1939   Record.push_back(N->getAlignInBits());
1940   Record.push_back(N->getOffsetInBits());
1941   Record.push_back(N->getFlags());
1942   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1943   Record.push_back(N->getRuntimeLang());
1944   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
1945   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1946   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
1947   Record.push_back(VE.getMetadataOrNullID(N->getDiscriminator()));
1948   Record.push_back(VE.getMetadataOrNullID(N->getRawDataLocation()));
1949   Record.push_back(VE.getMetadataOrNullID(N->getRawAssociated()));
1950   Record.push_back(VE.getMetadataOrNullID(N->getRawAllocated()));
1951   Record.push_back(VE.getMetadataOrNullID(N->getRawRank()));
1952   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
1953   Record.push_back(N->getNumExtraInhabitants());
1954   Record.push_back(VE.getMetadataOrNullID(N->getRawSpecification()));
1955 
1956   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
1957   Record.clear();
1958 }
1959 
1960 void ModuleBitcodeWriter::writeDISubroutineType(
1961     const DISubroutineType *N, SmallVectorImpl<uint64_t> &Record,
1962     unsigned Abbrev) {
1963   const unsigned HasNoOldTypeRefs = 0x2;
1964   Record.push_back(HasNoOldTypeRefs | (unsigned)N->isDistinct());
1965   Record.push_back(N->getFlags());
1966   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
1967   Record.push_back(N->getCC());
1968 
1969   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
1970   Record.clear();
1971 }
1972 
1973 void ModuleBitcodeWriter::writeDIFile(const DIFile *N,
1974                                       SmallVectorImpl<uint64_t> &Record,
1975                                       unsigned Abbrev) {
1976   Record.push_back(N->isDistinct());
1977   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
1978   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
1979   if (N->getRawChecksum()) {
1980     Record.push_back(N->getRawChecksum()->Kind);
1981     Record.push_back(VE.getMetadataOrNullID(N->getRawChecksum()->Value));
1982   } else {
1983     // Maintain backwards compatibility with the old internal representation of
1984     // CSK_None in ChecksumKind by writing nulls here when Checksum is None.
1985     Record.push_back(0);
1986     Record.push_back(VE.getMetadataOrNullID(nullptr));
1987   }
1988   auto Source = N->getRawSource();
1989   if (Source)
1990     Record.push_back(VE.getMetadataOrNullID(Source));
1991 
1992   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
1993   Record.clear();
1994 }
1995 
1996 void ModuleBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
1997                                              SmallVectorImpl<uint64_t> &Record,
1998                                              unsigned Abbrev) {
1999   assert(N->isDistinct() && "Expected distinct compile units");
2000   Record.push_back(/* IsDistinct */ true);
2001   Record.push_back(N->getSourceLanguage());
2002   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2003   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
2004   Record.push_back(N->isOptimized());
2005   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
2006   Record.push_back(N->getRuntimeVersion());
2007   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
2008   Record.push_back(N->getEmissionKind());
2009   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
2010   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
2011   Record.push_back(/* subprograms */ 0);
2012   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
2013   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
2014   Record.push_back(N->getDWOId());
2015   Record.push_back(VE.getMetadataOrNullID(N->getMacros().get()));
2016   Record.push_back(N->getSplitDebugInlining());
2017   Record.push_back(N->getDebugInfoForProfiling());
2018   Record.push_back((unsigned)N->getNameTableKind());
2019   Record.push_back(N->getRangesBaseAddress());
2020   Record.push_back(VE.getMetadataOrNullID(N->getRawSysRoot()));
2021   Record.push_back(VE.getMetadataOrNullID(N->getRawSDK()));
2022 
2023   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
2024   Record.clear();
2025 }
2026 
2027 void ModuleBitcodeWriter::writeDISubprogram(const DISubprogram *N,
2028                                             SmallVectorImpl<uint64_t> &Record,
2029                                             unsigned Abbrev) {
2030   const uint64_t HasUnitFlag = 1 << 1;
2031   const uint64_t HasSPFlagsFlag = 1 << 2;
2032   Record.push_back(uint64_t(N->isDistinct()) | HasUnitFlag | HasSPFlagsFlag);
2033   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2034   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2035   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
2036   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2037   Record.push_back(N->getLine());
2038   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2039   Record.push_back(N->getScopeLine());
2040   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
2041   Record.push_back(N->getSPFlags());
2042   Record.push_back(N->getVirtualIndex());
2043   Record.push_back(N->getFlags());
2044   Record.push_back(VE.getMetadataOrNullID(N->getRawUnit()));
2045   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
2046   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
2047   Record.push_back(VE.getMetadataOrNullID(N->getRetainedNodes().get()));
2048   Record.push_back(N->getThisAdjustment());
2049   Record.push_back(VE.getMetadataOrNullID(N->getThrownTypes().get()));
2050   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
2051   Record.push_back(VE.getMetadataOrNullID(N->getRawTargetFuncName()));
2052 
2053   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
2054   Record.clear();
2055 }
2056 
2057 void ModuleBitcodeWriter::writeDILexicalBlock(const DILexicalBlock *N,
2058                                               SmallVectorImpl<uint64_t> &Record,
2059                                               unsigned Abbrev) {
2060   Record.push_back(N->isDistinct());
2061   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2062   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2063   Record.push_back(N->getLine());
2064   Record.push_back(N->getColumn());
2065 
2066   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
2067   Record.clear();
2068 }
2069 
2070 void ModuleBitcodeWriter::writeDILexicalBlockFile(
2071     const DILexicalBlockFile *N, SmallVectorImpl<uint64_t> &Record,
2072     unsigned Abbrev) {
2073   Record.push_back(N->isDistinct());
2074   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2075   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2076   Record.push_back(N->getDiscriminator());
2077 
2078   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
2079   Record.clear();
2080 }
2081 
2082 void ModuleBitcodeWriter::writeDICommonBlock(const DICommonBlock *N,
2083                                              SmallVectorImpl<uint64_t> &Record,
2084                                              unsigned Abbrev) {
2085   Record.push_back(N->isDistinct());
2086   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2087   Record.push_back(VE.getMetadataOrNullID(N->getDecl()));
2088   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2089   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2090   Record.push_back(N->getLineNo());
2091 
2092   Stream.EmitRecord(bitc::METADATA_COMMON_BLOCK, Record, Abbrev);
2093   Record.clear();
2094 }
2095 
2096 void ModuleBitcodeWriter::writeDINamespace(const DINamespace *N,
2097                                            SmallVectorImpl<uint64_t> &Record,
2098                                            unsigned Abbrev) {
2099   Record.push_back(N->isDistinct() | N->getExportSymbols() << 1);
2100   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2101   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2102 
2103   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
2104   Record.clear();
2105 }
2106 
2107 void ModuleBitcodeWriter::writeDIMacro(const DIMacro *N,
2108                                        SmallVectorImpl<uint64_t> &Record,
2109                                        unsigned Abbrev) {
2110   Record.push_back(N->isDistinct());
2111   Record.push_back(N->getMacinfoType());
2112   Record.push_back(N->getLine());
2113   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2114   Record.push_back(VE.getMetadataOrNullID(N->getRawValue()));
2115 
2116   Stream.EmitRecord(bitc::METADATA_MACRO, Record, Abbrev);
2117   Record.clear();
2118 }
2119 
2120 void ModuleBitcodeWriter::writeDIMacroFile(const DIMacroFile *N,
2121                                            SmallVectorImpl<uint64_t> &Record,
2122                                            unsigned Abbrev) {
2123   Record.push_back(N->isDistinct());
2124   Record.push_back(N->getMacinfoType());
2125   Record.push_back(N->getLine());
2126   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2127   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
2128 
2129   Stream.EmitRecord(bitc::METADATA_MACRO_FILE, Record, Abbrev);
2130   Record.clear();
2131 }
2132 
2133 void ModuleBitcodeWriter::writeDIArgList(const DIArgList *N,
2134                                          SmallVectorImpl<uint64_t> &Record) {
2135   Record.reserve(N->getArgs().size());
2136   for (ValueAsMetadata *MD : N->getArgs())
2137     Record.push_back(VE.getMetadataID(MD));
2138 
2139   Stream.EmitRecord(bitc::METADATA_ARG_LIST, Record);
2140   Record.clear();
2141 }
2142 
2143 void ModuleBitcodeWriter::writeDIModule(const DIModule *N,
2144                                         SmallVectorImpl<uint64_t> &Record,
2145                                         unsigned Abbrev) {
2146   Record.push_back(N->isDistinct());
2147   for (auto &I : N->operands())
2148     Record.push_back(VE.getMetadataOrNullID(I));
2149   Record.push_back(N->getLineNo());
2150   Record.push_back(N->getIsDecl());
2151 
2152   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
2153   Record.clear();
2154 }
2155 
2156 void ModuleBitcodeWriter::writeDIAssignID(const DIAssignID *N,
2157                                           SmallVectorImpl<uint64_t> &Record,
2158                                           unsigned Abbrev) {
2159   // There are no arguments for this metadata type.
2160   Record.push_back(N->isDistinct());
2161   Stream.EmitRecord(bitc::METADATA_ASSIGN_ID, Record, Abbrev);
2162   Record.clear();
2163 }
2164 
2165 void ModuleBitcodeWriter::writeDITemplateTypeParameter(
2166     const DITemplateTypeParameter *N, SmallVectorImpl<uint64_t> &Record,
2167     unsigned Abbrev) {
2168   Record.push_back(N->isDistinct());
2169   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2170   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2171   Record.push_back(N->isDefault());
2172 
2173   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
2174   Record.clear();
2175 }
2176 
2177 void ModuleBitcodeWriter::writeDITemplateValueParameter(
2178     const DITemplateValueParameter *N, SmallVectorImpl<uint64_t> &Record,
2179     unsigned Abbrev) {
2180   Record.push_back(N->isDistinct());
2181   Record.push_back(N->getTag());
2182   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2183   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2184   Record.push_back(N->isDefault());
2185   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
2186 
2187   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
2188   Record.clear();
2189 }
2190 
2191 void ModuleBitcodeWriter::writeDIGlobalVariable(
2192     const DIGlobalVariable *N, SmallVectorImpl<uint64_t> &Record,
2193     unsigned Abbrev) {
2194   const uint64_t Version = 2 << 1;
2195   Record.push_back((uint64_t)N->isDistinct() | Version);
2196   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2197   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2198   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
2199   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2200   Record.push_back(N->getLine());
2201   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2202   Record.push_back(N->isLocalToUnit());
2203   Record.push_back(N->isDefinition());
2204   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
2205   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams()));
2206   Record.push_back(N->getAlignInBits());
2207   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
2208 
2209   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
2210   Record.clear();
2211 }
2212 
2213 void ModuleBitcodeWriter::writeDILocalVariable(
2214     const DILocalVariable *N, SmallVectorImpl<uint64_t> &Record,
2215     unsigned Abbrev) {
2216   // In order to support all possible bitcode formats in BitcodeReader we need
2217   // to distinguish the following cases:
2218   // 1) Record has no artificial tag (Record[1]),
2219   //   has no obsolete inlinedAt field (Record[9]).
2220   //   In this case Record size will be 8, HasAlignment flag is false.
2221   // 2) Record has artificial tag (Record[1]),
2222   //   has no obsolete inlignedAt field (Record[9]).
2223   //   In this case Record size will be 9, HasAlignment flag is false.
2224   // 3) Record has both artificial tag (Record[1]) and
2225   //   obsolete inlignedAt field (Record[9]).
2226   //   In this case Record size will be 10, HasAlignment flag is false.
2227   // 4) Record has neither artificial tag, nor inlignedAt field, but
2228   //   HasAlignment flag is true and Record[8] contains alignment value.
2229   const uint64_t HasAlignmentFlag = 1 << 1;
2230   Record.push_back((uint64_t)N->isDistinct() | HasAlignmentFlag);
2231   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2232   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2233   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2234   Record.push_back(N->getLine());
2235   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2236   Record.push_back(N->getArg());
2237   Record.push_back(N->getFlags());
2238   Record.push_back(N->getAlignInBits());
2239   Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
2240 
2241   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
2242   Record.clear();
2243 }
2244 
2245 void ModuleBitcodeWriter::writeDILabel(
2246     const DILabel *N, SmallVectorImpl<uint64_t> &Record,
2247     unsigned Abbrev) {
2248   Record.push_back((uint64_t)N->isDistinct());
2249   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2250   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2251   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2252   Record.push_back(N->getLine());
2253 
2254   Stream.EmitRecord(bitc::METADATA_LABEL, Record, Abbrev);
2255   Record.clear();
2256 }
2257 
2258 void ModuleBitcodeWriter::writeDIExpression(const DIExpression *N,
2259                                             SmallVectorImpl<uint64_t> &Record,
2260                                             unsigned Abbrev) {
2261   Record.reserve(N->getElements().size() + 1);
2262   const uint64_t Version = 3 << 1;
2263   Record.push_back((uint64_t)N->isDistinct() | Version);
2264   Record.append(N->elements_begin(), N->elements_end());
2265 
2266   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
2267   Record.clear();
2268 }
2269 
2270 void ModuleBitcodeWriter::writeDIGlobalVariableExpression(
2271     const DIGlobalVariableExpression *N, SmallVectorImpl<uint64_t> &Record,
2272     unsigned Abbrev) {
2273   Record.push_back(N->isDistinct());
2274   Record.push_back(VE.getMetadataOrNullID(N->getVariable()));
2275   Record.push_back(VE.getMetadataOrNullID(N->getExpression()));
2276 
2277   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR_EXPR, Record, Abbrev);
2278   Record.clear();
2279 }
2280 
2281 void ModuleBitcodeWriter::writeDIObjCProperty(const DIObjCProperty *N,
2282                                               SmallVectorImpl<uint64_t> &Record,
2283                                               unsigned Abbrev) {
2284   Record.push_back(N->isDistinct());
2285   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2286   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
2287   Record.push_back(N->getLine());
2288   Record.push_back(VE.getMetadataOrNullID(N->getRawSetterName()));
2289   Record.push_back(VE.getMetadataOrNullID(N->getRawGetterName()));
2290   Record.push_back(N->getAttributes());
2291   Record.push_back(VE.getMetadataOrNullID(N->getType()));
2292 
2293   Stream.EmitRecord(bitc::METADATA_OBJC_PROPERTY, Record, Abbrev);
2294   Record.clear();
2295 }
2296 
2297 void ModuleBitcodeWriter::writeDIImportedEntity(
2298     const DIImportedEntity *N, SmallVectorImpl<uint64_t> &Record,
2299     unsigned Abbrev) {
2300   Record.push_back(N->isDistinct());
2301   Record.push_back(N->getTag());
2302   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
2303   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
2304   Record.push_back(N->getLine());
2305   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
2306   Record.push_back(VE.getMetadataOrNullID(N->getRawFile()));
2307   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
2308 
2309   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
2310   Record.clear();
2311 }
2312 
2313 unsigned ModuleBitcodeWriter::createNamedMetadataAbbrev() {
2314   auto Abbv = std::make_shared<BitCodeAbbrev>();
2315   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
2316   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2317   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2318   return Stream.EmitAbbrev(std::move(Abbv));
2319 }
2320 
2321 void ModuleBitcodeWriter::writeNamedMetadata(
2322     SmallVectorImpl<uint64_t> &Record) {
2323   if (M.named_metadata_empty())
2324     return;
2325 
2326   unsigned Abbrev = createNamedMetadataAbbrev();
2327   for (const NamedMDNode &NMD : M.named_metadata()) {
2328     // Write name.
2329     StringRef Str = NMD.getName();
2330     Record.append(Str.bytes_begin(), Str.bytes_end());
2331     Stream.EmitRecord(bitc::METADATA_NAME, Record, Abbrev);
2332     Record.clear();
2333 
2334     // Write named metadata operands.
2335     for (const MDNode *N : NMD.operands())
2336       Record.push_back(VE.getMetadataID(N));
2337     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
2338     Record.clear();
2339   }
2340 }
2341 
2342 unsigned ModuleBitcodeWriter::createMetadataStringsAbbrev() {
2343   auto Abbv = std::make_shared<BitCodeAbbrev>();
2344   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRINGS));
2345   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of strings
2346   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // offset to chars
2347   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2348   return Stream.EmitAbbrev(std::move(Abbv));
2349 }
2350 
2351 /// Write out a record for MDString.
2352 ///
2353 /// All the metadata strings in a metadata block are emitted in a single
2354 /// record.  The sizes and strings themselves are shoved into a blob.
2355 void ModuleBitcodeWriter::writeMetadataStrings(
2356     ArrayRef<const Metadata *> Strings, SmallVectorImpl<uint64_t> &Record) {
2357   if (Strings.empty())
2358     return;
2359 
2360   // Start the record with the number of strings.
2361   Record.push_back(bitc::METADATA_STRINGS);
2362   Record.push_back(Strings.size());
2363 
2364   // Emit the sizes of the strings in the blob.
2365   SmallString<256> Blob;
2366   {
2367     BitstreamWriter W(Blob);
2368     for (const Metadata *MD : Strings)
2369       W.EmitVBR(cast<MDString>(MD)->getLength(), 6);
2370     W.FlushToWord();
2371   }
2372 
2373   // Add the offset to the strings to the record.
2374   Record.push_back(Blob.size());
2375 
2376   // Add the strings to the blob.
2377   for (const Metadata *MD : Strings)
2378     Blob.append(cast<MDString>(MD)->getString());
2379 
2380   // Emit the final record.
2381   Stream.EmitRecordWithBlob(createMetadataStringsAbbrev(), Record, Blob);
2382   Record.clear();
2383 }
2384 
2385 // Generates an enum to use as an index in the Abbrev array of Metadata record.
2386 enum MetadataAbbrev : unsigned {
2387 #define HANDLE_MDNODE_LEAF(CLASS) CLASS##AbbrevID,
2388 #include "llvm/IR/Metadata.def"
2389   LastPlusOne
2390 };
2391 
2392 void ModuleBitcodeWriter::writeMetadataRecords(
2393     ArrayRef<const Metadata *> MDs, SmallVectorImpl<uint64_t> &Record,
2394     std::vector<unsigned> *MDAbbrevs, std::vector<uint64_t> *IndexPos) {
2395   if (MDs.empty())
2396     return;
2397 
2398   // Initialize MDNode abbreviations.
2399 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
2400 #include "llvm/IR/Metadata.def"
2401 
2402   for (const Metadata *MD : MDs) {
2403     if (IndexPos)
2404       IndexPos->push_back(Stream.GetCurrentBitNo());
2405     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
2406       assert(N->isResolved() && "Expected forward references to be resolved");
2407 
2408       switch (N->getMetadataID()) {
2409       default:
2410         llvm_unreachable("Invalid MDNode subclass");
2411 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
2412   case Metadata::CLASS##Kind:                                                  \
2413     if (MDAbbrevs)                                                             \
2414       write##CLASS(cast<CLASS>(N), Record,                                     \
2415                    (*MDAbbrevs)[MetadataAbbrev::CLASS##AbbrevID]);             \
2416     else                                                                       \
2417       write##CLASS(cast<CLASS>(N), Record, CLASS##Abbrev);                     \
2418     continue;
2419 #include "llvm/IR/Metadata.def"
2420       }
2421     }
2422     if (auto *AL = dyn_cast<DIArgList>(MD)) {
2423       writeDIArgList(AL, Record);
2424       continue;
2425     }
2426     writeValueAsMetadata(cast<ValueAsMetadata>(MD), Record);
2427   }
2428 }
2429 
2430 void ModuleBitcodeWriter::writeModuleMetadata() {
2431   if (!VE.hasMDs() && M.named_metadata_empty())
2432     return;
2433 
2434   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 4);
2435   SmallVector<uint64_t, 64> Record;
2436 
2437   // Emit all abbrevs upfront, so that the reader can jump in the middle of the
2438   // block and load any metadata.
2439   std::vector<unsigned> MDAbbrevs;
2440 
2441   MDAbbrevs.resize(MetadataAbbrev::LastPlusOne);
2442   MDAbbrevs[MetadataAbbrev::DILocationAbbrevID] = createDILocationAbbrev();
2443   MDAbbrevs[MetadataAbbrev::GenericDINodeAbbrevID] =
2444       createGenericDINodeAbbrev();
2445 
2446   auto Abbv = std::make_shared<BitCodeAbbrev>();
2447   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_INDEX_OFFSET));
2448   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2449   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2450   unsigned OffsetAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2451 
2452   Abbv = std::make_shared<BitCodeAbbrev>();
2453   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_INDEX));
2454   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2455   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2456   unsigned IndexAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2457 
2458   // Emit MDStrings together upfront.
2459   writeMetadataStrings(VE.getMDStrings(), Record);
2460 
2461   // We only emit an index for the metadata record if we have more than a given
2462   // (naive) threshold of metadatas, otherwise it is not worth it.
2463   if (VE.getNonMDStrings().size() > IndexThreshold) {
2464     // Write a placeholder value in for the offset of the metadata index,
2465     // which is written after the records, so that it can include
2466     // the offset of each entry. The placeholder offset will be
2467     // updated after all records are emitted.
2468     uint64_t Vals[] = {0, 0};
2469     Stream.EmitRecord(bitc::METADATA_INDEX_OFFSET, Vals, OffsetAbbrev);
2470   }
2471 
2472   // Compute and save the bit offset to the current position, which will be
2473   // patched when we emit the index later. We can simply subtract the 64-bit
2474   // fixed size from the current bit number to get the location to backpatch.
2475   uint64_t IndexOffsetRecordBitPos = Stream.GetCurrentBitNo();
2476 
2477   // This index will contain the bitpos for each individual record.
2478   std::vector<uint64_t> IndexPos;
2479   IndexPos.reserve(VE.getNonMDStrings().size());
2480 
2481   // Write all the records
2482   writeMetadataRecords(VE.getNonMDStrings(), Record, &MDAbbrevs, &IndexPos);
2483 
2484   if (VE.getNonMDStrings().size() > IndexThreshold) {
2485     // Now that we have emitted all the records we will emit the index. But
2486     // first
2487     // backpatch the forward reference so that the reader can skip the records
2488     // efficiently.
2489     Stream.BackpatchWord64(IndexOffsetRecordBitPos - 64,
2490                            Stream.GetCurrentBitNo() - IndexOffsetRecordBitPos);
2491 
2492     // Delta encode the index.
2493     uint64_t PreviousValue = IndexOffsetRecordBitPos;
2494     for (auto &Elt : IndexPos) {
2495       auto EltDelta = Elt - PreviousValue;
2496       PreviousValue = Elt;
2497       Elt = EltDelta;
2498     }
2499     // Emit the index record.
2500     Stream.EmitRecord(bitc::METADATA_INDEX, IndexPos, IndexAbbrev);
2501     IndexPos.clear();
2502   }
2503 
2504   // Write the named metadata now.
2505   writeNamedMetadata(Record);
2506 
2507   auto AddDeclAttachedMetadata = [&](const GlobalObject &GO) {
2508     SmallVector<uint64_t, 4> Record;
2509     Record.push_back(VE.getValueID(&GO));
2510     pushGlobalMetadataAttachment(Record, GO);
2511     Stream.EmitRecord(bitc::METADATA_GLOBAL_DECL_ATTACHMENT, Record);
2512   };
2513   for (const Function &F : M)
2514     if (F.isDeclaration() && F.hasMetadata())
2515       AddDeclAttachedMetadata(F);
2516   // FIXME: Only store metadata for declarations here, and move data for global
2517   // variable definitions to a separate block (PR28134).
2518   for (const GlobalVariable &GV : M.globals())
2519     if (GV.hasMetadata())
2520       AddDeclAttachedMetadata(GV);
2521 
2522   Stream.ExitBlock();
2523 }
2524 
2525 void ModuleBitcodeWriter::writeFunctionMetadata(const Function &F) {
2526   if (!VE.hasMDs())
2527     return;
2528 
2529   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
2530   SmallVector<uint64_t, 64> Record;
2531   writeMetadataStrings(VE.getMDStrings(), Record);
2532   writeMetadataRecords(VE.getNonMDStrings(), Record);
2533   Stream.ExitBlock();
2534 }
2535 
2536 void ModuleBitcodeWriter::pushGlobalMetadataAttachment(
2537     SmallVectorImpl<uint64_t> &Record, const GlobalObject &GO) {
2538   // [n x [id, mdnode]]
2539   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
2540   GO.getAllMetadata(MDs);
2541   for (const auto &I : MDs) {
2542     Record.push_back(I.first);
2543     Record.push_back(VE.getMetadataID(I.second));
2544   }
2545 }
2546 
2547 void ModuleBitcodeWriter::writeFunctionMetadataAttachment(const Function &F) {
2548   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
2549 
2550   SmallVector<uint64_t, 64> Record;
2551 
2552   if (F.hasMetadata()) {
2553     pushGlobalMetadataAttachment(Record, F);
2554     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
2555     Record.clear();
2556   }
2557 
2558   // Write metadata attachments
2559   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
2560   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
2561   for (const BasicBlock &BB : F)
2562     for (const Instruction &I : BB) {
2563       MDs.clear();
2564       I.getAllMetadataOtherThanDebugLoc(MDs);
2565 
2566       // If no metadata, ignore instruction.
2567       if (MDs.empty()) continue;
2568 
2569       Record.push_back(VE.getInstructionID(&I));
2570 
2571       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
2572         Record.push_back(MDs[i].first);
2573         Record.push_back(VE.getMetadataID(MDs[i].second));
2574       }
2575       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
2576       Record.clear();
2577     }
2578 
2579   Stream.ExitBlock();
2580 }
2581 
2582 void ModuleBitcodeWriter::writeModuleMetadataKinds() {
2583   SmallVector<uint64_t, 64> Record;
2584 
2585   // Write metadata kinds
2586   // METADATA_KIND - [n x [id, name]]
2587   SmallVector<StringRef, 8> Names;
2588   M.getMDKindNames(Names);
2589 
2590   if (Names.empty()) return;
2591 
2592   Stream.EnterSubblock(bitc::METADATA_KIND_BLOCK_ID, 3);
2593 
2594   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
2595     Record.push_back(MDKindID);
2596     StringRef KName = Names[MDKindID];
2597     Record.append(KName.begin(), KName.end());
2598 
2599     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
2600     Record.clear();
2601   }
2602 
2603   Stream.ExitBlock();
2604 }
2605 
2606 void ModuleBitcodeWriter::writeOperandBundleTags() {
2607   // Write metadata kinds
2608   //
2609   // OPERAND_BUNDLE_TAGS_BLOCK_ID : N x OPERAND_BUNDLE_TAG
2610   //
2611   // OPERAND_BUNDLE_TAG - [strchr x N]
2612 
2613   SmallVector<StringRef, 8> Tags;
2614   M.getOperandBundleTags(Tags);
2615 
2616   if (Tags.empty())
2617     return;
2618 
2619   Stream.EnterSubblock(bitc::OPERAND_BUNDLE_TAGS_BLOCK_ID, 3);
2620 
2621   SmallVector<uint64_t, 64> Record;
2622 
2623   for (auto Tag : Tags) {
2624     Record.append(Tag.begin(), Tag.end());
2625 
2626     Stream.EmitRecord(bitc::OPERAND_BUNDLE_TAG, Record, 0);
2627     Record.clear();
2628   }
2629 
2630   Stream.ExitBlock();
2631 }
2632 
2633 void ModuleBitcodeWriter::writeSyncScopeNames() {
2634   SmallVector<StringRef, 8> SSNs;
2635   M.getContext().getSyncScopeNames(SSNs);
2636   if (SSNs.empty())
2637     return;
2638 
2639   Stream.EnterSubblock(bitc::SYNC_SCOPE_NAMES_BLOCK_ID, 2);
2640 
2641   SmallVector<uint64_t, 64> Record;
2642   for (auto SSN : SSNs) {
2643     Record.append(SSN.begin(), SSN.end());
2644     Stream.EmitRecord(bitc::SYNC_SCOPE_NAME, Record, 0);
2645     Record.clear();
2646   }
2647 
2648   Stream.ExitBlock();
2649 }
2650 
2651 void ModuleBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
2652                                          bool isGlobal) {
2653   if (FirstVal == LastVal) return;
2654 
2655   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
2656 
2657   unsigned AggregateAbbrev = 0;
2658   unsigned String8Abbrev = 0;
2659   unsigned CString7Abbrev = 0;
2660   unsigned CString6Abbrev = 0;
2661   // If this is a constant pool for the module, emit module-specific abbrevs.
2662   if (isGlobal) {
2663     // Abbrev for CST_CODE_AGGREGATE.
2664     auto Abbv = std::make_shared<BitCodeAbbrev>();
2665     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
2666     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2667     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
2668     AggregateAbbrev = Stream.EmitAbbrev(std::move(Abbv));
2669 
2670     // Abbrev for CST_CODE_STRING.
2671     Abbv = std::make_shared<BitCodeAbbrev>();
2672     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
2673     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2674     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2675     String8Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2676     // Abbrev for CST_CODE_CSTRING.
2677     Abbv = std::make_shared<BitCodeAbbrev>();
2678     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
2679     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2680     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2681     CString7Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2682     // Abbrev for CST_CODE_CSTRING.
2683     Abbv = std::make_shared<BitCodeAbbrev>();
2684     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
2685     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2686     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2687     CString6Abbrev = Stream.EmitAbbrev(std::move(Abbv));
2688   }
2689 
2690   SmallVector<uint64_t, 64> Record;
2691 
2692   const ValueEnumerator::ValueList &Vals = VE.getValues();
2693   Type *LastTy = nullptr;
2694   for (unsigned i = FirstVal; i != LastVal; ++i) {
2695     const Value *V = Vals[i].first;
2696     // If we need to switch types, do so now.
2697     if (V->getType() != LastTy) {
2698       LastTy = V->getType();
2699       Record.push_back(VE.getTypeID(LastTy));
2700       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
2701                         CONSTANTS_SETTYPE_ABBREV);
2702       Record.clear();
2703     }
2704 
2705     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
2706       Record.push_back(VE.getTypeID(IA->getFunctionType()));
2707       Record.push_back(
2708           unsigned(IA->hasSideEffects()) | unsigned(IA->isAlignStack()) << 1 |
2709           unsigned(IA->getDialect() & 1) << 2 | unsigned(IA->canThrow()) << 3);
2710 
2711       // Add the asm string.
2712       const std::string &AsmStr = IA->getAsmString();
2713       Record.push_back(AsmStr.size());
2714       Record.append(AsmStr.begin(), AsmStr.end());
2715 
2716       // Add the constraint string.
2717       const std::string &ConstraintStr = IA->getConstraintString();
2718       Record.push_back(ConstraintStr.size());
2719       Record.append(ConstraintStr.begin(), ConstraintStr.end());
2720       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
2721       Record.clear();
2722       continue;
2723     }
2724     const Constant *C = cast<Constant>(V);
2725     unsigned Code = -1U;
2726     unsigned AbbrevToUse = 0;
2727     if (C->isNullValue()) {
2728       Code = bitc::CST_CODE_NULL;
2729     } else if (isa<PoisonValue>(C)) {
2730       Code = bitc::CST_CODE_POISON;
2731     } else if (isa<UndefValue>(C)) {
2732       Code = bitc::CST_CODE_UNDEF;
2733     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
2734       if (IV->getBitWidth() <= 64) {
2735         uint64_t V = IV->getSExtValue();
2736         emitSignedInt64(Record, V);
2737         Code = bitc::CST_CODE_INTEGER;
2738         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
2739       } else {                             // Wide integers, > 64 bits in size.
2740         emitWideAPInt(Record, IV->getValue());
2741         Code = bitc::CST_CODE_WIDE_INTEGER;
2742       }
2743     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
2744       Code = bitc::CST_CODE_FLOAT;
2745       Type *Ty = CFP->getType()->getScalarType();
2746       if (Ty->isHalfTy() || Ty->isBFloatTy() || Ty->isFloatTy() ||
2747           Ty->isDoubleTy()) {
2748         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
2749       } else if (Ty->isX86_FP80Ty()) {
2750         // api needed to prevent premature destruction
2751         // bits are not in the same order as a normal i80 APInt, compensate.
2752         APInt api = CFP->getValueAPF().bitcastToAPInt();
2753         const uint64_t *p = api.getRawData();
2754         Record.push_back((p[1] << 48) | (p[0] >> 16));
2755         Record.push_back(p[0] & 0xffffLL);
2756       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
2757         APInt api = CFP->getValueAPF().bitcastToAPInt();
2758         const uint64_t *p = api.getRawData();
2759         Record.push_back(p[0]);
2760         Record.push_back(p[1]);
2761       } else {
2762         assert(0 && "Unknown FP type!");
2763       }
2764     } else if (isa<ConstantDataSequential>(C) &&
2765                cast<ConstantDataSequential>(C)->isString()) {
2766       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
2767       // Emit constant strings specially.
2768       unsigned NumElts = Str->getNumElements();
2769       // If this is a null-terminated string, use the denser CSTRING encoding.
2770       if (Str->isCString()) {
2771         Code = bitc::CST_CODE_CSTRING;
2772         --NumElts;  // Don't encode the null, which isn't allowed by char6.
2773       } else {
2774         Code = bitc::CST_CODE_STRING;
2775         AbbrevToUse = String8Abbrev;
2776       }
2777       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
2778       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
2779       for (unsigned i = 0; i != NumElts; ++i) {
2780         unsigned char V = Str->getElementAsInteger(i);
2781         Record.push_back(V);
2782         isCStr7 &= (V & 128) == 0;
2783         if (isCStrChar6)
2784           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
2785       }
2786 
2787       if (isCStrChar6)
2788         AbbrevToUse = CString6Abbrev;
2789       else if (isCStr7)
2790         AbbrevToUse = CString7Abbrev;
2791     } else if (const ConstantDataSequential *CDS =
2792                   dyn_cast<ConstantDataSequential>(C)) {
2793       Code = bitc::CST_CODE_DATA;
2794       Type *EltTy = CDS->getElementType();
2795       if (isa<IntegerType>(EltTy)) {
2796         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2797           Record.push_back(CDS->getElementAsInteger(i));
2798       } else {
2799         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2800           Record.push_back(
2801               CDS->getElementAsAPFloat(i).bitcastToAPInt().getLimitedValue());
2802       }
2803     } else if (isa<ConstantAggregate>(C)) {
2804       Code = bitc::CST_CODE_AGGREGATE;
2805       for (const Value *Op : C->operands())
2806         Record.push_back(VE.getValueID(Op));
2807       AbbrevToUse = AggregateAbbrev;
2808     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
2809       switch (CE->getOpcode()) {
2810       default:
2811         if (Instruction::isCast(CE->getOpcode())) {
2812           Code = bitc::CST_CODE_CE_CAST;
2813           Record.push_back(getEncodedCastOpcode(CE->getOpcode()));
2814           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2815           Record.push_back(VE.getValueID(C->getOperand(0)));
2816           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
2817         } else {
2818           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
2819           Code = bitc::CST_CODE_CE_BINOP;
2820           Record.push_back(getEncodedBinaryOpcode(CE->getOpcode()));
2821           Record.push_back(VE.getValueID(C->getOperand(0)));
2822           Record.push_back(VE.getValueID(C->getOperand(1)));
2823           uint64_t Flags = getOptimizationFlags(CE);
2824           if (Flags != 0)
2825             Record.push_back(Flags);
2826         }
2827         break;
2828       case Instruction::FNeg: {
2829         assert(CE->getNumOperands() == 1 && "Unknown constant expr!");
2830         Code = bitc::CST_CODE_CE_UNOP;
2831         Record.push_back(getEncodedUnaryOpcode(CE->getOpcode()));
2832         Record.push_back(VE.getValueID(C->getOperand(0)));
2833         uint64_t Flags = getOptimizationFlags(CE);
2834         if (Flags != 0)
2835           Record.push_back(Flags);
2836         break;
2837       }
2838       case Instruction::GetElementPtr: {
2839         Code = bitc::CST_CODE_CE_GEP;
2840         const auto *GO = cast<GEPOperator>(C);
2841         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
2842         Record.push_back(getOptimizationFlags(GO));
2843         if (std::optional<ConstantRange> Range = GO->getInRange()) {
2844           Code = bitc::CST_CODE_CE_GEP_WITH_INRANGE;
2845           emitConstantRange(Record, *Range, /*EmitBitWidth=*/true);
2846         }
2847         for (const Value *Op : CE->operands()) {
2848           Record.push_back(VE.getTypeID(Op->getType()));
2849           Record.push_back(VE.getValueID(Op));
2850         }
2851         break;
2852       }
2853       case Instruction::ExtractElement:
2854         Code = bitc::CST_CODE_CE_EXTRACTELT;
2855         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2856         Record.push_back(VE.getValueID(C->getOperand(0)));
2857         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
2858         Record.push_back(VE.getValueID(C->getOperand(1)));
2859         break;
2860       case Instruction::InsertElement:
2861         Code = bitc::CST_CODE_CE_INSERTELT;
2862         Record.push_back(VE.getValueID(C->getOperand(0)));
2863         Record.push_back(VE.getValueID(C->getOperand(1)));
2864         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
2865         Record.push_back(VE.getValueID(C->getOperand(2)));
2866         break;
2867       case Instruction::ShuffleVector:
2868         // If the return type and argument types are the same, this is a
2869         // standard shufflevector instruction.  If the types are different,
2870         // then the shuffle is widening or truncating the input vectors, and
2871         // the argument type must also be encoded.
2872         if (C->getType() == C->getOperand(0)->getType()) {
2873           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
2874         } else {
2875           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
2876           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2877         }
2878         Record.push_back(VE.getValueID(C->getOperand(0)));
2879         Record.push_back(VE.getValueID(C->getOperand(1)));
2880         Record.push_back(VE.getValueID(CE->getShuffleMaskForBitcode()));
2881         break;
2882       }
2883     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
2884       Code = bitc::CST_CODE_BLOCKADDRESS;
2885       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
2886       Record.push_back(VE.getValueID(BA->getFunction()));
2887       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
2888     } else if (const auto *Equiv = dyn_cast<DSOLocalEquivalent>(C)) {
2889       Code = bitc::CST_CODE_DSO_LOCAL_EQUIVALENT;
2890       Record.push_back(VE.getTypeID(Equiv->getGlobalValue()->getType()));
2891       Record.push_back(VE.getValueID(Equiv->getGlobalValue()));
2892     } else if (const auto *NC = dyn_cast<NoCFIValue>(C)) {
2893       Code = bitc::CST_CODE_NO_CFI_VALUE;
2894       Record.push_back(VE.getTypeID(NC->getGlobalValue()->getType()));
2895       Record.push_back(VE.getValueID(NC->getGlobalValue()));
2896     } else if (const auto *CPA = dyn_cast<ConstantPtrAuth>(C)) {
2897       Code = bitc::CST_CODE_PTRAUTH;
2898       Record.push_back(VE.getValueID(CPA->getPointer()));
2899       Record.push_back(VE.getValueID(CPA->getKey()));
2900       Record.push_back(VE.getValueID(CPA->getDiscriminator()));
2901       Record.push_back(VE.getValueID(CPA->getAddrDiscriminator()));
2902     } else {
2903 #ifndef NDEBUG
2904       C->dump();
2905 #endif
2906       llvm_unreachable("Unknown constant!");
2907     }
2908     Stream.EmitRecord(Code, Record, AbbrevToUse);
2909     Record.clear();
2910   }
2911 
2912   Stream.ExitBlock();
2913 }
2914 
2915 void ModuleBitcodeWriter::writeModuleConstants() {
2916   const ValueEnumerator::ValueList &Vals = VE.getValues();
2917 
2918   // Find the first constant to emit, which is the first non-globalvalue value.
2919   // We know globalvalues have been emitted by WriteModuleInfo.
2920   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
2921     if (!isa<GlobalValue>(Vals[i].first)) {
2922       writeConstants(i, Vals.size(), true);
2923       return;
2924     }
2925   }
2926 }
2927 
2928 /// pushValueAndType - The file has to encode both the value and type id for
2929 /// many values, because we need to know what type to create for forward
2930 /// references.  However, most operands are not forward references, so this type
2931 /// field is not needed.
2932 ///
2933 /// This function adds V's value ID to Vals.  If the value ID is higher than the
2934 /// instruction ID, then it is a forward reference, and it also includes the
2935 /// type ID.  The value ID that is written is encoded relative to the InstID.
2936 bool ModuleBitcodeWriter::pushValueAndType(const Value *V, unsigned InstID,
2937                                            SmallVectorImpl<unsigned> &Vals) {
2938   unsigned ValID = VE.getValueID(V);
2939   // Make encoding relative to the InstID.
2940   Vals.push_back(InstID - ValID);
2941   if (ValID >= InstID) {
2942     Vals.push_back(VE.getTypeID(V->getType()));
2943     return true;
2944   }
2945   return false;
2946 }
2947 
2948 bool ModuleBitcodeWriter::pushValueOrMetadata(const Value *V, unsigned InstID,
2949                                               SmallVectorImpl<unsigned> &Vals) {
2950   bool IsMetadata = V->getType()->isMetadataTy();
2951   if (IsMetadata) {
2952     Vals.push_back(bitc::OB_METADATA);
2953     Metadata *MD = cast<MetadataAsValue>(V)->getMetadata();
2954     unsigned ValID = VE.getMetadataID(MD);
2955     Vals.push_back(InstID - ValID);
2956     return false;
2957   }
2958   return pushValueAndType(V, InstID, Vals);
2959 }
2960 
2961 void ModuleBitcodeWriter::writeOperandBundles(const CallBase &CS,
2962                                               unsigned InstID) {
2963   SmallVector<unsigned, 64> Record;
2964   LLVMContext &C = CS.getContext();
2965 
2966   for (unsigned i = 0, e = CS.getNumOperandBundles(); i != e; ++i) {
2967     const auto &Bundle = CS.getOperandBundleAt(i);
2968     Record.push_back(C.getOperandBundleTagID(Bundle.getTagName()));
2969 
2970     for (auto &Input : Bundle.Inputs)
2971       pushValueOrMetadata(Input, InstID, Record);
2972 
2973     Stream.EmitRecord(bitc::FUNC_CODE_OPERAND_BUNDLE, Record);
2974     Record.clear();
2975   }
2976 }
2977 
2978 /// pushValue - Like pushValueAndType, but where the type of the value is
2979 /// omitted (perhaps it was already encoded in an earlier operand).
2980 void ModuleBitcodeWriter::pushValue(const Value *V, unsigned InstID,
2981                                     SmallVectorImpl<unsigned> &Vals) {
2982   unsigned ValID = VE.getValueID(V);
2983   Vals.push_back(InstID - ValID);
2984 }
2985 
2986 void ModuleBitcodeWriter::pushValueSigned(const Value *V, unsigned InstID,
2987                                           SmallVectorImpl<uint64_t> &Vals) {
2988   unsigned ValID = VE.getValueID(V);
2989   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
2990   emitSignedInt64(Vals, diff);
2991 }
2992 
2993 /// WriteInstruction - Emit an instruction to the specified stream.
2994 void ModuleBitcodeWriter::writeInstruction(const Instruction &I,
2995                                            unsigned InstID,
2996                                            SmallVectorImpl<unsigned> &Vals) {
2997   unsigned Code = 0;
2998   unsigned AbbrevToUse = 0;
2999   VE.setInstructionID(&I);
3000   switch (I.getOpcode()) {
3001   default:
3002     if (Instruction::isCast(I.getOpcode())) {
3003       Code = bitc::FUNC_CODE_INST_CAST;
3004       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
3005         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
3006       Vals.push_back(VE.getTypeID(I.getType()));
3007       Vals.push_back(getEncodedCastOpcode(I.getOpcode()));
3008       uint64_t Flags = getOptimizationFlags(&I);
3009       if (Flags != 0) {
3010         if (AbbrevToUse == FUNCTION_INST_CAST_ABBREV)
3011           AbbrevToUse = FUNCTION_INST_CAST_FLAGS_ABBREV;
3012         Vals.push_back(Flags);
3013       }
3014     } else {
3015       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
3016       Code = bitc::FUNC_CODE_INST_BINOP;
3017       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
3018         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
3019       pushValue(I.getOperand(1), InstID, Vals);
3020       Vals.push_back(getEncodedBinaryOpcode(I.getOpcode()));
3021       uint64_t Flags = getOptimizationFlags(&I);
3022       if (Flags != 0) {
3023         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
3024           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
3025         Vals.push_back(Flags);
3026       }
3027     }
3028     break;
3029   case Instruction::FNeg: {
3030     Code = bitc::FUNC_CODE_INST_UNOP;
3031     if (!pushValueAndType(I.getOperand(0), InstID, Vals))
3032       AbbrevToUse = FUNCTION_INST_UNOP_ABBREV;
3033     Vals.push_back(getEncodedUnaryOpcode(I.getOpcode()));
3034     uint64_t Flags = getOptimizationFlags(&I);
3035     if (Flags != 0) {
3036       if (AbbrevToUse == FUNCTION_INST_UNOP_ABBREV)
3037         AbbrevToUse = FUNCTION_INST_UNOP_FLAGS_ABBREV;
3038       Vals.push_back(Flags);
3039     }
3040     break;
3041   }
3042   case Instruction::GetElementPtr: {
3043     Code = bitc::FUNC_CODE_INST_GEP;
3044     AbbrevToUse = FUNCTION_INST_GEP_ABBREV;
3045     auto &GEPInst = cast<GetElementPtrInst>(I);
3046     Vals.push_back(getOptimizationFlags(&I));
3047     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
3048     for (const Value *Op : I.operands())
3049       pushValueAndType(Op, InstID, Vals);
3050     break;
3051   }
3052   case Instruction::ExtractValue: {
3053     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
3054     pushValueAndType(I.getOperand(0), InstID, Vals);
3055     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
3056     Vals.append(EVI->idx_begin(), EVI->idx_end());
3057     break;
3058   }
3059   case Instruction::InsertValue: {
3060     Code = bitc::FUNC_CODE_INST_INSERTVAL;
3061     pushValueAndType(I.getOperand(0), InstID, Vals);
3062     pushValueAndType(I.getOperand(1), InstID, Vals);
3063     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
3064     Vals.append(IVI->idx_begin(), IVI->idx_end());
3065     break;
3066   }
3067   case Instruction::Select: {
3068     Code = bitc::FUNC_CODE_INST_VSELECT;
3069     pushValueAndType(I.getOperand(1), InstID, Vals);
3070     pushValue(I.getOperand(2), InstID, Vals);
3071     pushValueAndType(I.getOperand(0), InstID, Vals);
3072     uint64_t Flags = getOptimizationFlags(&I);
3073     if (Flags != 0)
3074       Vals.push_back(Flags);
3075     break;
3076   }
3077   case Instruction::ExtractElement:
3078     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
3079     pushValueAndType(I.getOperand(0), InstID, Vals);
3080     pushValueAndType(I.getOperand(1), InstID, Vals);
3081     break;
3082   case Instruction::InsertElement:
3083     Code = bitc::FUNC_CODE_INST_INSERTELT;
3084     pushValueAndType(I.getOperand(0), InstID, Vals);
3085     pushValue(I.getOperand(1), InstID, Vals);
3086     pushValueAndType(I.getOperand(2), InstID, Vals);
3087     break;
3088   case Instruction::ShuffleVector:
3089     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
3090     pushValueAndType(I.getOperand(0), InstID, Vals);
3091     pushValue(I.getOperand(1), InstID, Vals);
3092     pushValue(cast<ShuffleVectorInst>(I).getShuffleMaskForBitcode(), InstID,
3093               Vals);
3094     break;
3095   case Instruction::ICmp:
3096   case Instruction::FCmp: {
3097     // compare returning Int1Ty or vector of Int1Ty
3098     Code = bitc::FUNC_CODE_INST_CMP2;
3099     pushValueAndType(I.getOperand(0), InstID, Vals);
3100     pushValue(I.getOperand(1), InstID, Vals);
3101     Vals.push_back(cast<CmpInst>(I).getPredicate());
3102     uint64_t Flags = getOptimizationFlags(&I);
3103     if (Flags != 0)
3104       Vals.push_back(Flags);
3105     break;
3106   }
3107 
3108   case Instruction::Ret:
3109     {
3110       Code = bitc::FUNC_CODE_INST_RET;
3111       unsigned NumOperands = I.getNumOperands();
3112       if (NumOperands == 0)
3113         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
3114       else if (NumOperands == 1) {
3115         if (!pushValueAndType(I.getOperand(0), InstID, Vals))
3116           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
3117       } else {
3118         for (const Value *Op : I.operands())
3119           pushValueAndType(Op, InstID, Vals);
3120       }
3121     }
3122     break;
3123   case Instruction::Br:
3124     {
3125       Code = bitc::FUNC_CODE_INST_BR;
3126       const BranchInst &II = cast<BranchInst>(I);
3127       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
3128       if (II.isConditional()) {
3129         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
3130         pushValue(II.getCondition(), InstID, Vals);
3131       }
3132     }
3133     break;
3134   case Instruction::Switch:
3135     {
3136       Code = bitc::FUNC_CODE_INST_SWITCH;
3137       const SwitchInst &SI = cast<SwitchInst>(I);
3138       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
3139       pushValue(SI.getCondition(), InstID, Vals);
3140       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
3141       for (auto Case : SI.cases()) {
3142         Vals.push_back(VE.getValueID(Case.getCaseValue()));
3143         Vals.push_back(VE.getValueID(Case.getCaseSuccessor()));
3144       }
3145     }
3146     break;
3147   case Instruction::IndirectBr:
3148     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
3149     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
3150     // Encode the address operand as relative, but not the basic blocks.
3151     pushValue(I.getOperand(0), InstID, Vals);
3152     for (const Value *Op : drop_begin(I.operands()))
3153       Vals.push_back(VE.getValueID(Op));
3154     break;
3155 
3156   case Instruction::Invoke: {
3157     const InvokeInst *II = cast<InvokeInst>(&I);
3158     const Value *Callee = II->getCalledOperand();
3159     FunctionType *FTy = II->getFunctionType();
3160 
3161     if (II->hasOperandBundles())
3162       writeOperandBundles(*II, InstID);
3163 
3164     Code = bitc::FUNC_CODE_INST_INVOKE;
3165 
3166     Vals.push_back(VE.getAttributeListID(II->getAttributes()));
3167     Vals.push_back(II->getCallingConv() | 1 << 13);
3168     Vals.push_back(VE.getValueID(II->getNormalDest()));
3169     Vals.push_back(VE.getValueID(II->getUnwindDest()));
3170     Vals.push_back(VE.getTypeID(FTy));
3171     pushValueAndType(Callee, InstID, Vals);
3172 
3173     // Emit value #'s for the fixed parameters.
3174     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
3175       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
3176 
3177     // Emit type/value pairs for varargs params.
3178     if (FTy->isVarArg()) {
3179       for (unsigned i = FTy->getNumParams(), e = II->arg_size(); i != e; ++i)
3180         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
3181     }
3182     break;
3183   }
3184   case Instruction::Resume:
3185     Code = bitc::FUNC_CODE_INST_RESUME;
3186     pushValueAndType(I.getOperand(0), InstID, Vals);
3187     break;
3188   case Instruction::CleanupRet: {
3189     Code = bitc::FUNC_CODE_INST_CLEANUPRET;
3190     const auto &CRI = cast<CleanupReturnInst>(I);
3191     pushValue(CRI.getCleanupPad(), InstID, Vals);
3192     if (CRI.hasUnwindDest())
3193       Vals.push_back(VE.getValueID(CRI.getUnwindDest()));
3194     break;
3195   }
3196   case Instruction::CatchRet: {
3197     Code = bitc::FUNC_CODE_INST_CATCHRET;
3198     const auto &CRI = cast<CatchReturnInst>(I);
3199     pushValue(CRI.getCatchPad(), InstID, Vals);
3200     Vals.push_back(VE.getValueID(CRI.getSuccessor()));
3201     break;
3202   }
3203   case Instruction::CleanupPad:
3204   case Instruction::CatchPad: {
3205     const auto &FuncletPad = cast<FuncletPadInst>(I);
3206     Code = isa<CatchPadInst>(FuncletPad) ? bitc::FUNC_CODE_INST_CATCHPAD
3207                                          : bitc::FUNC_CODE_INST_CLEANUPPAD;
3208     pushValue(FuncletPad.getParentPad(), InstID, Vals);
3209 
3210     unsigned NumArgOperands = FuncletPad.arg_size();
3211     Vals.push_back(NumArgOperands);
3212     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
3213       pushValueAndType(FuncletPad.getArgOperand(Op), InstID, Vals);
3214     break;
3215   }
3216   case Instruction::CatchSwitch: {
3217     Code = bitc::FUNC_CODE_INST_CATCHSWITCH;
3218     const auto &CatchSwitch = cast<CatchSwitchInst>(I);
3219 
3220     pushValue(CatchSwitch.getParentPad(), InstID, Vals);
3221 
3222     unsigned NumHandlers = CatchSwitch.getNumHandlers();
3223     Vals.push_back(NumHandlers);
3224     for (const BasicBlock *CatchPadBB : CatchSwitch.handlers())
3225       Vals.push_back(VE.getValueID(CatchPadBB));
3226 
3227     if (CatchSwitch.hasUnwindDest())
3228       Vals.push_back(VE.getValueID(CatchSwitch.getUnwindDest()));
3229     break;
3230   }
3231   case Instruction::CallBr: {
3232     const CallBrInst *CBI = cast<CallBrInst>(&I);
3233     const Value *Callee = CBI->getCalledOperand();
3234     FunctionType *FTy = CBI->getFunctionType();
3235 
3236     if (CBI->hasOperandBundles())
3237       writeOperandBundles(*CBI, InstID);
3238 
3239     Code = bitc::FUNC_CODE_INST_CALLBR;
3240 
3241     Vals.push_back(VE.getAttributeListID(CBI->getAttributes()));
3242 
3243     Vals.push_back(CBI->getCallingConv() << bitc::CALL_CCONV |
3244                    1 << bitc::CALL_EXPLICIT_TYPE);
3245 
3246     Vals.push_back(VE.getValueID(CBI->getDefaultDest()));
3247     Vals.push_back(CBI->getNumIndirectDests());
3248     for (unsigned i = 0, e = CBI->getNumIndirectDests(); i != e; ++i)
3249       Vals.push_back(VE.getValueID(CBI->getIndirectDest(i)));
3250 
3251     Vals.push_back(VE.getTypeID(FTy));
3252     pushValueAndType(Callee, InstID, Vals);
3253 
3254     // Emit value #'s for the fixed parameters.
3255     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
3256       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
3257 
3258     // Emit type/value pairs for varargs params.
3259     if (FTy->isVarArg()) {
3260       for (unsigned i = FTy->getNumParams(), e = CBI->arg_size(); i != e; ++i)
3261         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
3262     }
3263     break;
3264   }
3265   case Instruction::Unreachable:
3266     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
3267     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
3268     break;
3269 
3270   case Instruction::PHI: {
3271     const PHINode &PN = cast<PHINode>(I);
3272     Code = bitc::FUNC_CODE_INST_PHI;
3273     // With the newer instruction encoding, forward references could give
3274     // negative valued IDs.  This is most common for PHIs, so we use
3275     // signed VBRs.
3276     SmallVector<uint64_t, 128> Vals64;
3277     Vals64.push_back(VE.getTypeID(PN.getType()));
3278     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
3279       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64);
3280       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
3281     }
3282 
3283     uint64_t Flags = getOptimizationFlags(&I);
3284     if (Flags != 0)
3285       Vals64.push_back(Flags);
3286 
3287     // Emit a Vals64 vector and exit.
3288     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
3289     Vals64.clear();
3290     return;
3291   }
3292 
3293   case Instruction::LandingPad: {
3294     const LandingPadInst &LP = cast<LandingPadInst>(I);
3295     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
3296     Vals.push_back(VE.getTypeID(LP.getType()));
3297     Vals.push_back(LP.isCleanup());
3298     Vals.push_back(LP.getNumClauses());
3299     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
3300       if (LP.isCatch(I))
3301         Vals.push_back(LandingPadInst::Catch);
3302       else
3303         Vals.push_back(LandingPadInst::Filter);
3304       pushValueAndType(LP.getClause(I), InstID, Vals);
3305     }
3306     break;
3307   }
3308 
3309   case Instruction::Alloca: {
3310     Code = bitc::FUNC_CODE_INST_ALLOCA;
3311     const AllocaInst &AI = cast<AllocaInst>(I);
3312     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
3313     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
3314     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
3315     using APV = AllocaPackedValues;
3316     unsigned Record = 0;
3317     unsigned EncodedAlign = getEncodedAlign(AI.getAlign());
3318     Bitfield::set<APV::AlignLower>(
3319         Record, EncodedAlign & ((1 << APV::AlignLower::Bits) - 1));
3320     Bitfield::set<APV::AlignUpper>(Record,
3321                                    EncodedAlign >> APV::AlignLower::Bits);
3322     Bitfield::set<APV::UsedWithInAlloca>(Record, AI.isUsedWithInAlloca());
3323     Bitfield::set<APV::ExplicitType>(Record, true);
3324     Bitfield::set<APV::SwiftError>(Record, AI.isSwiftError());
3325     Vals.push_back(Record);
3326 
3327     unsigned AS = AI.getAddressSpace();
3328     if (AS != M.getDataLayout().getAllocaAddrSpace())
3329       Vals.push_back(AS);
3330     break;
3331   }
3332 
3333   case Instruction::Load:
3334     if (cast<LoadInst>(I).isAtomic()) {
3335       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
3336       pushValueAndType(I.getOperand(0), InstID, Vals);
3337     } else {
3338       Code = bitc::FUNC_CODE_INST_LOAD;
3339       if (!pushValueAndType(I.getOperand(0), InstID, Vals)) // ptr
3340         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
3341     }
3342     Vals.push_back(VE.getTypeID(I.getType()));
3343     Vals.push_back(getEncodedAlign(cast<LoadInst>(I).getAlign()));
3344     Vals.push_back(cast<LoadInst>(I).isVolatile());
3345     if (cast<LoadInst>(I).isAtomic()) {
3346       Vals.push_back(getEncodedOrdering(cast<LoadInst>(I).getOrdering()));
3347       Vals.push_back(getEncodedSyncScopeID(cast<LoadInst>(I).getSyncScopeID()));
3348     }
3349     break;
3350   case Instruction::Store:
3351     if (cast<StoreInst>(I).isAtomic())
3352       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
3353     else
3354       Code = bitc::FUNC_CODE_INST_STORE;
3355     pushValueAndType(I.getOperand(1), InstID, Vals); // ptrty + ptr
3356     pushValueAndType(I.getOperand(0), InstID, Vals); // valty + val
3357     Vals.push_back(getEncodedAlign(cast<StoreInst>(I).getAlign()));
3358     Vals.push_back(cast<StoreInst>(I).isVolatile());
3359     if (cast<StoreInst>(I).isAtomic()) {
3360       Vals.push_back(getEncodedOrdering(cast<StoreInst>(I).getOrdering()));
3361       Vals.push_back(
3362           getEncodedSyncScopeID(cast<StoreInst>(I).getSyncScopeID()));
3363     }
3364     break;
3365   case Instruction::AtomicCmpXchg:
3366     Code = bitc::FUNC_CODE_INST_CMPXCHG;
3367     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
3368     pushValueAndType(I.getOperand(1), InstID, Vals); // cmp.
3369     pushValue(I.getOperand(2), InstID, Vals);        // newval.
3370     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
3371     Vals.push_back(
3372         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
3373     Vals.push_back(
3374         getEncodedSyncScopeID(cast<AtomicCmpXchgInst>(I).getSyncScopeID()));
3375     Vals.push_back(
3376         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
3377     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
3378     Vals.push_back(getEncodedAlign(cast<AtomicCmpXchgInst>(I).getAlign()));
3379     break;
3380   case Instruction::AtomicRMW:
3381     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
3382     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
3383     pushValueAndType(I.getOperand(1), InstID, Vals); // valty + val
3384     Vals.push_back(
3385         getEncodedRMWOperation(cast<AtomicRMWInst>(I).getOperation()));
3386     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
3387     Vals.push_back(getEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
3388     Vals.push_back(
3389         getEncodedSyncScopeID(cast<AtomicRMWInst>(I).getSyncScopeID()));
3390     Vals.push_back(getEncodedAlign(cast<AtomicRMWInst>(I).getAlign()));
3391     break;
3392   case Instruction::Fence:
3393     Code = bitc::FUNC_CODE_INST_FENCE;
3394     Vals.push_back(getEncodedOrdering(cast<FenceInst>(I).getOrdering()));
3395     Vals.push_back(getEncodedSyncScopeID(cast<FenceInst>(I).getSyncScopeID()));
3396     break;
3397   case Instruction::Call: {
3398     const CallInst &CI = cast<CallInst>(I);
3399     FunctionType *FTy = CI.getFunctionType();
3400 
3401     if (CI.hasOperandBundles())
3402       writeOperandBundles(CI, InstID);
3403 
3404     Code = bitc::FUNC_CODE_INST_CALL;
3405 
3406     Vals.push_back(VE.getAttributeListID(CI.getAttributes()));
3407 
3408     unsigned Flags = getOptimizationFlags(&I);
3409     Vals.push_back(CI.getCallingConv() << bitc::CALL_CCONV |
3410                    unsigned(CI.isTailCall()) << bitc::CALL_TAIL |
3411                    unsigned(CI.isMustTailCall()) << bitc::CALL_MUSTTAIL |
3412                    1 << bitc::CALL_EXPLICIT_TYPE |
3413                    unsigned(CI.isNoTailCall()) << bitc::CALL_NOTAIL |
3414                    unsigned(Flags != 0) << bitc::CALL_FMF);
3415     if (Flags != 0)
3416       Vals.push_back(Flags);
3417 
3418     Vals.push_back(VE.getTypeID(FTy));
3419     pushValueAndType(CI.getCalledOperand(), InstID, Vals); // Callee
3420 
3421     // Emit value #'s for the fixed parameters.
3422     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
3423       // Check for labels (can happen with asm labels).
3424       if (FTy->getParamType(i)->isLabelTy())
3425         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
3426       else
3427         pushValue(CI.getArgOperand(i), InstID, Vals); // fixed param.
3428     }
3429 
3430     // Emit type/value pairs for varargs params.
3431     if (FTy->isVarArg()) {
3432       for (unsigned i = FTy->getNumParams(), e = CI.arg_size(); i != e; ++i)
3433         pushValueAndType(CI.getArgOperand(i), InstID, Vals); // varargs
3434     }
3435     break;
3436   }
3437   case Instruction::VAArg:
3438     Code = bitc::FUNC_CODE_INST_VAARG;
3439     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
3440     pushValue(I.getOperand(0), InstID, Vals);                   // valist.
3441     Vals.push_back(VE.getTypeID(I.getType())); // restype.
3442     break;
3443   case Instruction::Freeze:
3444     Code = bitc::FUNC_CODE_INST_FREEZE;
3445     pushValueAndType(I.getOperand(0), InstID, Vals);
3446     break;
3447   }
3448 
3449   Stream.EmitRecord(Code, Vals, AbbrevToUse);
3450   Vals.clear();
3451 }
3452 
3453 /// Write a GlobalValue VST to the module. The purpose of this data structure is
3454 /// to allow clients to efficiently find the function body.
3455 void ModuleBitcodeWriter::writeGlobalValueSymbolTable(
3456   DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex) {
3457   // Get the offset of the VST we are writing, and backpatch it into
3458   // the VST forward declaration record.
3459   uint64_t VSTOffset = Stream.GetCurrentBitNo();
3460   // The BitcodeStartBit was the stream offset of the identification block.
3461   VSTOffset -= bitcodeStartBit();
3462   assert((VSTOffset & 31) == 0 && "VST block not 32-bit aligned");
3463   // Note that we add 1 here because the offset is relative to one word
3464   // before the start of the identification block, which was historically
3465   // always the start of the regular bitcode header.
3466   Stream.BackpatchWord(VSTOffsetPlaceholder, VSTOffset / 32 + 1);
3467 
3468   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
3469 
3470   auto Abbv = std::make_shared<BitCodeAbbrev>();
3471   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
3472   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
3473   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
3474   unsigned FnEntryAbbrev = Stream.EmitAbbrev(std::move(Abbv));
3475 
3476   for (const Function &F : M) {
3477     uint64_t Record[2];
3478 
3479     if (F.isDeclaration())
3480       continue;
3481 
3482     Record[0] = VE.getValueID(&F);
3483 
3484     // Save the word offset of the function (from the start of the
3485     // actual bitcode written to the stream).
3486     uint64_t BitcodeIndex = FunctionToBitcodeIndex[&F] - bitcodeStartBit();
3487     assert((BitcodeIndex & 31) == 0 && "function block not 32-bit aligned");
3488     // Note that we add 1 here because the offset is relative to one word
3489     // before the start of the identification block, which was historically
3490     // always the start of the regular bitcode header.
3491     Record[1] = BitcodeIndex / 32 + 1;
3492 
3493     Stream.EmitRecord(bitc::VST_CODE_FNENTRY, Record, FnEntryAbbrev);
3494   }
3495 
3496   Stream.ExitBlock();
3497 }
3498 
3499 /// Emit names for arguments, instructions and basic blocks in a function.
3500 void ModuleBitcodeWriter::writeFunctionLevelValueSymbolTable(
3501     const ValueSymbolTable &VST) {
3502   if (VST.empty())
3503     return;
3504 
3505   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
3506 
3507   // FIXME: Set up the abbrev, we know how many values there are!
3508   // FIXME: We know if the type names can use 7-bit ascii.
3509   SmallVector<uint64_t, 64> NameVals;
3510 
3511   for (const ValueName &Name : VST) {
3512     // Figure out the encoding to use for the name.
3513     StringEncoding Bits = getStringEncoding(Name.getKey());
3514 
3515     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
3516     NameVals.push_back(VE.getValueID(Name.getValue()));
3517 
3518     // VST_CODE_ENTRY:   [valueid, namechar x N]
3519     // VST_CODE_BBENTRY: [bbid, namechar x N]
3520     unsigned Code;
3521     if (isa<BasicBlock>(Name.getValue())) {
3522       Code = bitc::VST_CODE_BBENTRY;
3523       if (Bits == SE_Char6)
3524         AbbrevToUse = VST_BBENTRY_6_ABBREV;
3525     } else {
3526       Code = bitc::VST_CODE_ENTRY;
3527       if (Bits == SE_Char6)
3528         AbbrevToUse = VST_ENTRY_6_ABBREV;
3529       else if (Bits == SE_Fixed7)
3530         AbbrevToUse = VST_ENTRY_7_ABBREV;
3531     }
3532 
3533     for (const auto P : Name.getKey())
3534       NameVals.push_back((unsigned char)P);
3535 
3536     // Emit the finished record.
3537     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
3538     NameVals.clear();
3539   }
3540 
3541   Stream.ExitBlock();
3542 }
3543 
3544 void ModuleBitcodeWriter::writeUseList(UseListOrder &&Order) {
3545   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
3546   unsigned Code;
3547   if (isa<BasicBlock>(Order.V))
3548     Code = bitc::USELIST_CODE_BB;
3549   else
3550     Code = bitc::USELIST_CODE_DEFAULT;
3551 
3552   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
3553   Record.push_back(VE.getValueID(Order.V));
3554   Stream.EmitRecord(Code, Record);
3555 }
3556 
3557 void ModuleBitcodeWriter::writeUseListBlock(const Function *F) {
3558   assert(VE.shouldPreserveUseListOrder() &&
3559          "Expected to be preserving use-list order");
3560 
3561   auto hasMore = [&]() {
3562     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
3563   };
3564   if (!hasMore())
3565     // Nothing to do.
3566     return;
3567 
3568   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
3569   while (hasMore()) {
3570     writeUseList(std::move(VE.UseListOrders.back()));
3571     VE.UseListOrders.pop_back();
3572   }
3573   Stream.ExitBlock();
3574 }
3575 
3576 /// Emit a function body to the module stream.
3577 void ModuleBitcodeWriter::writeFunction(
3578     const Function &F,
3579     DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex) {
3580   // Save the bitcode index of the start of this function block for recording
3581   // in the VST.
3582   FunctionToBitcodeIndex[&F] = Stream.GetCurrentBitNo();
3583 
3584   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
3585   VE.incorporateFunction(F);
3586 
3587   SmallVector<unsigned, 64> Vals;
3588 
3589   // Emit the number of basic blocks, so the reader can create them ahead of
3590   // time.
3591   Vals.push_back(VE.getBasicBlocks().size());
3592   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
3593   Vals.clear();
3594 
3595   // If there are function-local constants, emit them now.
3596   unsigned CstStart, CstEnd;
3597   VE.getFunctionConstantRange(CstStart, CstEnd);
3598   writeConstants(CstStart, CstEnd, false);
3599 
3600   // If there is function-local metadata, emit it now.
3601   writeFunctionMetadata(F);
3602 
3603   // Keep a running idea of what the instruction ID is.
3604   unsigned InstID = CstEnd;
3605 
3606   bool NeedsMetadataAttachment = F.hasMetadata();
3607 
3608   DILocation *LastDL = nullptr;
3609   SmallSetVector<Function *, 4> BlockAddressUsers;
3610 
3611   // Finally, emit all the instructions, in order.
3612   for (const BasicBlock &BB : F) {
3613     for (const Instruction &I : BB) {
3614       writeInstruction(I, InstID, Vals);
3615 
3616       if (!I.getType()->isVoidTy())
3617         ++InstID;
3618 
3619       // If the instruction has metadata, write a metadata attachment later.
3620       NeedsMetadataAttachment |= I.hasMetadataOtherThanDebugLoc();
3621 
3622       // If the instruction has a debug location, emit it.
3623       if (DILocation *DL = I.getDebugLoc()) {
3624         if (DL == LastDL) {
3625           // Just repeat the same debug loc as last time.
3626           Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
3627         } else {
3628           Vals.push_back(DL->getLine());
3629           Vals.push_back(DL->getColumn());
3630           Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
3631           Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
3632           Vals.push_back(DL->isImplicitCode());
3633           Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
3634           Vals.clear();
3635           LastDL = DL;
3636         }
3637       }
3638 
3639       // If the instruction has DbgRecords attached to it, emit them. Note that
3640       // they come after the instruction so that it's easy to attach them again
3641       // when reading the bitcode, even though conceptually the debug locations
3642       // start "before" the instruction.
3643       if (I.hasDbgRecords() && WriteNewDbgInfoFormatToBitcode) {
3644         /// Try to push the value only (unwrapped), otherwise push the
3645         /// metadata wrapped value. Returns true if the value was pushed
3646         /// without the ValueAsMetadata wrapper.
3647         auto PushValueOrMetadata = [&Vals, InstID,
3648                                     this](Metadata *RawLocation) {
3649           assert(RawLocation &&
3650                  "RawLocation unexpectedly null in DbgVariableRecord");
3651           if (ValueAsMetadata *VAM = dyn_cast<ValueAsMetadata>(RawLocation)) {
3652             SmallVector<unsigned, 2> ValAndType;
3653             // If the value is a fwd-ref the type is also pushed. We don't
3654             // want the type, so fwd-refs are kept wrapped (pushValueAndType
3655             // returns false if the value is pushed without type).
3656             if (!pushValueAndType(VAM->getValue(), InstID, ValAndType)) {
3657               Vals.push_back(ValAndType[0]);
3658               return true;
3659             }
3660           }
3661           // The metadata is a DIArgList, or ValueAsMetadata wrapping a
3662           // fwd-ref. Push the metadata ID.
3663           Vals.push_back(VE.getMetadataID(RawLocation));
3664           return false;
3665         };
3666 
3667         // Write out non-instruction debug information attached to this
3668         // instruction. Write it after the instruction so that it's easy to
3669         // re-attach to the instruction reading the records in.
3670         for (DbgRecord &DR : I.DebugMarker->getDbgRecordRange()) {
3671           if (DbgLabelRecord *DLR = dyn_cast<DbgLabelRecord>(&DR)) {
3672             Vals.push_back(VE.getMetadataID(&*DLR->getDebugLoc()));
3673             Vals.push_back(VE.getMetadataID(DLR->getLabel()));
3674             Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_LABEL, Vals);
3675             Vals.clear();
3676             continue;
3677           }
3678 
3679           // First 3 fields are common to all kinds:
3680           //   DILocation, DILocalVariable, DIExpression
3681           // dbg_value (FUNC_CODE_DEBUG_RECORD_VALUE)
3682           //   ..., LocationMetadata
3683           // dbg_value (FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE - abbrev'd)
3684           //   ..., Value
3685           // dbg_declare (FUNC_CODE_DEBUG_RECORD_DECLARE)
3686           //   ..., LocationMetadata
3687           // dbg_assign (FUNC_CODE_DEBUG_RECORD_ASSIGN)
3688           //   ..., LocationMetadata, DIAssignID, DIExpression, LocationMetadata
3689           DbgVariableRecord &DVR = cast<DbgVariableRecord>(DR);
3690           Vals.push_back(VE.getMetadataID(&*DVR.getDebugLoc()));
3691           Vals.push_back(VE.getMetadataID(DVR.getVariable()));
3692           Vals.push_back(VE.getMetadataID(DVR.getExpression()));
3693           if (DVR.isDbgValue()) {
3694             if (PushValueOrMetadata(DVR.getRawLocation()))
3695               Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE, Vals,
3696                                 FUNCTION_DEBUG_RECORD_VALUE_ABBREV);
3697             else
3698               Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_VALUE, Vals);
3699           } else if (DVR.isDbgDeclare()) {
3700             Vals.push_back(VE.getMetadataID(DVR.getRawLocation()));
3701             Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_DECLARE, Vals);
3702           } else {
3703             assert(DVR.isDbgAssign() && "Unexpected DbgRecord kind");
3704             Vals.push_back(VE.getMetadataID(DVR.getRawLocation()));
3705             Vals.push_back(VE.getMetadataID(DVR.getAssignID()));
3706             Vals.push_back(VE.getMetadataID(DVR.getAddressExpression()));
3707             Vals.push_back(VE.getMetadataID(DVR.getRawAddress()));
3708             Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_RECORD_ASSIGN, Vals);
3709           }
3710           Vals.clear();
3711         }
3712       }
3713     }
3714 
3715     if (BlockAddress *BA = BlockAddress::lookup(&BB)) {
3716       SmallVector<Value *> Worklist{BA};
3717       SmallPtrSet<Value *, 8> Visited{BA};
3718       while (!Worklist.empty()) {
3719         Value *V = Worklist.pop_back_val();
3720         for (User *U : V->users()) {
3721           if (auto *I = dyn_cast<Instruction>(U)) {
3722             Function *P = I->getFunction();
3723             if (P != &F)
3724               BlockAddressUsers.insert(P);
3725           } else if (isa<Constant>(U) && !isa<GlobalValue>(U) &&
3726                      Visited.insert(U).second)
3727             Worklist.push_back(U);
3728         }
3729       }
3730     }
3731   }
3732 
3733   if (!BlockAddressUsers.empty()) {
3734     Vals.resize(BlockAddressUsers.size());
3735     for (auto I : llvm::enumerate(BlockAddressUsers))
3736       Vals[I.index()] = VE.getValueID(I.value());
3737     Stream.EmitRecord(bitc::FUNC_CODE_BLOCKADDR_USERS, Vals);
3738     Vals.clear();
3739   }
3740 
3741   // Emit names for all the instructions etc.
3742   if (auto *Symtab = F.getValueSymbolTable())
3743     writeFunctionLevelValueSymbolTable(*Symtab);
3744 
3745   if (NeedsMetadataAttachment)
3746     writeFunctionMetadataAttachment(F);
3747   if (VE.shouldPreserveUseListOrder())
3748     writeUseListBlock(&F);
3749   VE.purgeFunction();
3750   Stream.ExitBlock();
3751 }
3752 
3753 // Emit blockinfo, which defines the standard abbreviations etc.
3754 void ModuleBitcodeWriter::writeBlockInfo() {
3755   // We only want to emit block info records for blocks that have multiple
3756   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
3757   // Other blocks can define their abbrevs inline.
3758   Stream.EnterBlockInfoBlock();
3759 
3760   { // 8-bit fixed-width VST_CODE_ENTRY/VST_CODE_BBENTRY strings.
3761     auto Abbv = std::make_shared<BitCodeAbbrev>();
3762     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
3763     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3764     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3765     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
3766     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3767         VST_ENTRY_8_ABBREV)
3768       llvm_unreachable("Unexpected abbrev ordering!");
3769   }
3770 
3771   { // 7-bit fixed width VST_CODE_ENTRY strings.
3772     auto Abbv = std::make_shared<BitCodeAbbrev>();
3773     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
3774     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3775     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3776     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
3777     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3778         VST_ENTRY_7_ABBREV)
3779       llvm_unreachable("Unexpected abbrev ordering!");
3780   }
3781   { // 6-bit char6 VST_CODE_ENTRY strings.
3782     auto Abbv = std::make_shared<BitCodeAbbrev>();
3783     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
3784     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3785     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3786     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3787     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3788         VST_ENTRY_6_ABBREV)
3789       llvm_unreachable("Unexpected abbrev ordering!");
3790   }
3791   { // 6-bit char6 VST_CODE_BBENTRY strings.
3792     auto Abbv = std::make_shared<BitCodeAbbrev>();
3793     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
3794     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3795     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3796     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3797     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
3798         VST_BBENTRY_6_ABBREV)
3799       llvm_unreachable("Unexpected abbrev ordering!");
3800   }
3801 
3802   { // SETTYPE abbrev for CONSTANTS_BLOCK.
3803     auto Abbv = std::make_shared<BitCodeAbbrev>();
3804     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
3805     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
3806                               VE.computeBitsRequiredForTypeIndices()));
3807     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3808         CONSTANTS_SETTYPE_ABBREV)
3809       llvm_unreachable("Unexpected abbrev ordering!");
3810   }
3811 
3812   { // INTEGER abbrev for CONSTANTS_BLOCK.
3813     auto Abbv = std::make_shared<BitCodeAbbrev>();
3814     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
3815     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3816     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3817         CONSTANTS_INTEGER_ABBREV)
3818       llvm_unreachable("Unexpected abbrev ordering!");
3819   }
3820 
3821   { // CE_CAST abbrev for CONSTANTS_BLOCK.
3822     auto Abbv = std::make_shared<BitCodeAbbrev>();
3823     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
3824     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
3825     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
3826                               VE.computeBitsRequiredForTypeIndices()));
3827     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
3828 
3829     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3830         CONSTANTS_CE_CAST_Abbrev)
3831       llvm_unreachable("Unexpected abbrev ordering!");
3832   }
3833   { // NULL abbrev for CONSTANTS_BLOCK.
3834     auto Abbv = std::make_shared<BitCodeAbbrev>();
3835     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
3836     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3837         CONSTANTS_NULL_Abbrev)
3838       llvm_unreachable("Unexpected abbrev ordering!");
3839   }
3840 
3841   // FIXME: This should only use space for first class types!
3842 
3843   { // INST_LOAD abbrev for FUNCTION_BLOCK.
3844     auto Abbv = std::make_shared<BitCodeAbbrev>();
3845     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
3846     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
3847     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
3848                               VE.computeBitsRequiredForTypeIndices()));
3849     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
3850     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
3851     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3852         FUNCTION_INST_LOAD_ABBREV)
3853       llvm_unreachable("Unexpected abbrev ordering!");
3854   }
3855   { // INST_UNOP abbrev for FUNCTION_BLOCK.
3856     auto Abbv = std::make_shared<BitCodeAbbrev>();
3857     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNOP));
3858     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3859     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3860     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3861         FUNCTION_INST_UNOP_ABBREV)
3862       llvm_unreachable("Unexpected abbrev ordering!");
3863   }
3864   { // INST_UNOP_FLAGS abbrev for FUNCTION_BLOCK.
3865     auto Abbv = std::make_shared<BitCodeAbbrev>();
3866     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNOP));
3867     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3868     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3869     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3870     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3871         FUNCTION_INST_UNOP_FLAGS_ABBREV)
3872       llvm_unreachable("Unexpected abbrev ordering!");
3873   }
3874   { // INST_BINOP abbrev for FUNCTION_BLOCK.
3875     auto Abbv = std::make_shared<BitCodeAbbrev>();
3876     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
3877     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3878     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
3879     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3880     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3881         FUNCTION_INST_BINOP_ABBREV)
3882       llvm_unreachable("Unexpected abbrev ordering!");
3883   }
3884   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
3885     auto Abbv = std::make_shared<BitCodeAbbrev>();
3886     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
3887     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3888     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
3889     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3890     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3891     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3892         FUNCTION_INST_BINOP_FLAGS_ABBREV)
3893       llvm_unreachable("Unexpected abbrev ordering!");
3894   }
3895   { // INST_CAST abbrev for FUNCTION_BLOCK.
3896     auto Abbv = std::make_shared<BitCodeAbbrev>();
3897     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
3898     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
3899     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
3900                               VE.computeBitsRequiredForTypeIndices()));
3901     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
3902     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3903         FUNCTION_INST_CAST_ABBREV)
3904       llvm_unreachable("Unexpected abbrev ordering!");
3905   }
3906   { // INST_CAST_FLAGS abbrev for FUNCTION_BLOCK.
3907     auto Abbv = std::make_shared<BitCodeAbbrev>();
3908     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
3909     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // OpVal
3910     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
3911                               VE.computeBitsRequiredForTypeIndices()));
3912     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3913     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8)); // flags
3914     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3915         FUNCTION_INST_CAST_FLAGS_ABBREV)
3916       llvm_unreachable("Unexpected abbrev ordering!");
3917   }
3918 
3919   { // INST_RET abbrev for FUNCTION_BLOCK.
3920     auto Abbv = std::make_shared<BitCodeAbbrev>();
3921     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
3922     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3923         FUNCTION_INST_RET_VOID_ABBREV)
3924       llvm_unreachable("Unexpected abbrev ordering!");
3925   }
3926   { // INST_RET abbrev for FUNCTION_BLOCK.
3927     auto Abbv = std::make_shared<BitCodeAbbrev>();
3928     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
3929     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
3930     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3931         FUNCTION_INST_RET_VAL_ABBREV)
3932       llvm_unreachable("Unexpected abbrev ordering!");
3933   }
3934   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
3935     auto Abbv = std::make_shared<BitCodeAbbrev>();
3936     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
3937     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3938         FUNCTION_INST_UNREACHABLE_ABBREV)
3939       llvm_unreachable("Unexpected abbrev ordering!");
3940   }
3941   {
3942     auto Abbv = std::make_shared<BitCodeAbbrev>();
3943     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
3944     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
3945     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
3946                               Log2_32_Ceil(VE.getTypes().size() + 1)));
3947     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3948     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
3949     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3950         FUNCTION_INST_GEP_ABBREV)
3951       llvm_unreachable("Unexpected abbrev ordering!");
3952   }
3953   {
3954     auto Abbv = std::make_shared<BitCodeAbbrev>();
3955     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_DEBUG_RECORD_VALUE_SIMPLE));
3956     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 7)); // dbgloc
3957     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 7)); // var
3958     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 7)); // expr
3959     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // val
3960     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3961         FUNCTION_DEBUG_RECORD_VALUE_ABBREV)
3962       llvm_unreachable("Unexpected abbrev ordering! 1");
3963   }
3964   Stream.ExitBlock();
3965 }
3966 
3967 /// Write the module path strings, currently only used when generating
3968 /// a combined index file.
3969 void IndexBitcodeWriter::writeModStrings() {
3970   Stream.EnterSubblock(bitc::MODULE_STRTAB_BLOCK_ID, 3);
3971 
3972   // TODO: See which abbrev sizes we actually need to emit
3973 
3974   // 8-bit fixed-width MST_ENTRY strings.
3975   auto Abbv = std::make_shared<BitCodeAbbrev>();
3976   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3977   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3978   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3979   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
3980   unsigned Abbrev8Bit = Stream.EmitAbbrev(std::move(Abbv));
3981 
3982   // 7-bit fixed width MST_ENTRY strings.
3983   Abbv = std::make_shared<BitCodeAbbrev>();
3984   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3985   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3986   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3987   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
3988   unsigned Abbrev7Bit = Stream.EmitAbbrev(std::move(Abbv));
3989 
3990   // 6-bit char6 MST_ENTRY strings.
3991   Abbv = std::make_shared<BitCodeAbbrev>();
3992   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3993   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3994   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3995   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3996   unsigned Abbrev6Bit = Stream.EmitAbbrev(std::move(Abbv));
3997 
3998   // Module Hash, 160 bits SHA1. Optionally, emitted after each MST_CODE_ENTRY.
3999   Abbv = std::make_shared<BitCodeAbbrev>();
4000   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_HASH));
4001   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4002   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4003   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4004   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4005   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4006   unsigned AbbrevHash = Stream.EmitAbbrev(std::move(Abbv));
4007 
4008   SmallVector<unsigned, 64> Vals;
4009   forEachModule([&](const StringMapEntry<ModuleHash> &MPSE) {
4010     StringRef Key = MPSE.getKey();
4011     const auto &Hash = MPSE.getValue();
4012     StringEncoding Bits = getStringEncoding(Key);
4013     unsigned AbbrevToUse = Abbrev8Bit;
4014     if (Bits == SE_Char6)
4015       AbbrevToUse = Abbrev6Bit;
4016     else if (Bits == SE_Fixed7)
4017       AbbrevToUse = Abbrev7Bit;
4018 
4019     auto ModuleId = ModuleIdMap.size();
4020     ModuleIdMap[Key] = ModuleId;
4021     Vals.push_back(ModuleId);
4022     Vals.append(Key.begin(), Key.end());
4023 
4024     // Emit the finished record.
4025     Stream.EmitRecord(bitc::MST_CODE_ENTRY, Vals, AbbrevToUse);
4026 
4027     // Emit an optional hash for the module now
4028     if (llvm::any_of(Hash, [](uint32_t H) { return H; })) {
4029       Vals.assign(Hash.begin(), Hash.end());
4030       // Emit the hash record.
4031       Stream.EmitRecord(bitc::MST_CODE_HASH, Vals, AbbrevHash);
4032     }
4033 
4034     Vals.clear();
4035   });
4036   Stream.ExitBlock();
4037 }
4038 
4039 /// Write the function type metadata related records that need to appear before
4040 /// a function summary entry (whether per-module or combined).
4041 template <typename Fn>
4042 static void writeFunctionTypeMetadataRecords(BitstreamWriter &Stream,
4043                                              FunctionSummary *FS,
4044                                              Fn GetValueID) {
4045   if (!FS->type_tests().empty())
4046     Stream.EmitRecord(bitc::FS_TYPE_TESTS, FS->type_tests());
4047 
4048   SmallVector<uint64_t, 64> Record;
4049 
4050   auto WriteVFuncIdVec = [&](uint64_t Ty,
4051                              ArrayRef<FunctionSummary::VFuncId> VFs) {
4052     if (VFs.empty())
4053       return;
4054     Record.clear();
4055     for (auto &VF : VFs) {
4056       Record.push_back(VF.GUID);
4057       Record.push_back(VF.Offset);
4058     }
4059     Stream.EmitRecord(Ty, Record);
4060   };
4061 
4062   WriteVFuncIdVec(bitc::FS_TYPE_TEST_ASSUME_VCALLS,
4063                   FS->type_test_assume_vcalls());
4064   WriteVFuncIdVec(bitc::FS_TYPE_CHECKED_LOAD_VCALLS,
4065                   FS->type_checked_load_vcalls());
4066 
4067   auto WriteConstVCallVec = [&](uint64_t Ty,
4068                                 ArrayRef<FunctionSummary::ConstVCall> VCs) {
4069     for (auto &VC : VCs) {
4070       Record.clear();
4071       Record.push_back(VC.VFunc.GUID);
4072       Record.push_back(VC.VFunc.Offset);
4073       llvm::append_range(Record, VC.Args);
4074       Stream.EmitRecord(Ty, Record);
4075     }
4076   };
4077 
4078   WriteConstVCallVec(bitc::FS_TYPE_TEST_ASSUME_CONST_VCALL,
4079                      FS->type_test_assume_const_vcalls());
4080   WriteConstVCallVec(bitc::FS_TYPE_CHECKED_LOAD_CONST_VCALL,
4081                      FS->type_checked_load_const_vcalls());
4082 
4083   auto WriteRange = [&](ConstantRange Range) {
4084     Range = Range.sextOrTrunc(FunctionSummary::ParamAccess::RangeWidth);
4085     assert(Range.getLower().getNumWords() == 1);
4086     assert(Range.getUpper().getNumWords() == 1);
4087     emitSignedInt64(Record, *Range.getLower().getRawData());
4088     emitSignedInt64(Record, *Range.getUpper().getRawData());
4089   };
4090 
4091   if (!FS->paramAccesses().empty()) {
4092     Record.clear();
4093     for (auto &Arg : FS->paramAccesses()) {
4094       size_t UndoSize = Record.size();
4095       Record.push_back(Arg.ParamNo);
4096       WriteRange(Arg.Use);
4097       Record.push_back(Arg.Calls.size());
4098       for (auto &Call : Arg.Calls) {
4099         Record.push_back(Call.ParamNo);
4100         std::optional<unsigned> ValueID = GetValueID(Call.Callee);
4101         if (!ValueID) {
4102           // If ValueID is unknown we can't drop just this call, we must drop
4103           // entire parameter.
4104           Record.resize(UndoSize);
4105           break;
4106         }
4107         Record.push_back(*ValueID);
4108         WriteRange(Call.Offsets);
4109       }
4110     }
4111     if (!Record.empty())
4112       Stream.EmitRecord(bitc::FS_PARAM_ACCESS, Record);
4113   }
4114 }
4115 
4116 /// Collect type IDs from type tests used by function.
4117 static void
4118 getReferencedTypeIds(FunctionSummary *FS,
4119                      std::set<GlobalValue::GUID> &ReferencedTypeIds) {
4120   if (!FS->type_tests().empty())
4121     for (auto &TT : FS->type_tests())
4122       ReferencedTypeIds.insert(TT);
4123 
4124   auto GetReferencedTypesFromVFuncIdVec =
4125       [&](ArrayRef<FunctionSummary::VFuncId> VFs) {
4126         for (auto &VF : VFs)
4127           ReferencedTypeIds.insert(VF.GUID);
4128       };
4129 
4130   GetReferencedTypesFromVFuncIdVec(FS->type_test_assume_vcalls());
4131   GetReferencedTypesFromVFuncIdVec(FS->type_checked_load_vcalls());
4132 
4133   auto GetReferencedTypesFromConstVCallVec =
4134       [&](ArrayRef<FunctionSummary::ConstVCall> VCs) {
4135         for (auto &VC : VCs)
4136           ReferencedTypeIds.insert(VC.VFunc.GUID);
4137       };
4138 
4139   GetReferencedTypesFromConstVCallVec(FS->type_test_assume_const_vcalls());
4140   GetReferencedTypesFromConstVCallVec(FS->type_checked_load_const_vcalls());
4141 }
4142 
4143 static void writeWholeProgramDevirtResolutionByArg(
4144     SmallVector<uint64_t, 64> &NameVals, const std::vector<uint64_t> &args,
4145     const WholeProgramDevirtResolution::ByArg &ByArg) {
4146   NameVals.push_back(args.size());
4147   llvm::append_range(NameVals, args);
4148 
4149   NameVals.push_back(ByArg.TheKind);
4150   NameVals.push_back(ByArg.Info);
4151   NameVals.push_back(ByArg.Byte);
4152   NameVals.push_back(ByArg.Bit);
4153 }
4154 
4155 static void writeWholeProgramDevirtResolution(
4156     SmallVector<uint64_t, 64> &NameVals, StringTableBuilder &StrtabBuilder,
4157     uint64_t Id, const WholeProgramDevirtResolution &Wpd) {
4158   NameVals.push_back(Id);
4159 
4160   NameVals.push_back(Wpd.TheKind);
4161   NameVals.push_back(StrtabBuilder.add(Wpd.SingleImplName));
4162   NameVals.push_back(Wpd.SingleImplName.size());
4163 
4164   NameVals.push_back(Wpd.ResByArg.size());
4165   for (auto &A : Wpd.ResByArg)
4166     writeWholeProgramDevirtResolutionByArg(NameVals, A.first, A.second);
4167 }
4168 
4169 static void writeTypeIdSummaryRecord(SmallVector<uint64_t, 64> &NameVals,
4170                                      StringTableBuilder &StrtabBuilder,
4171                                      StringRef Id,
4172                                      const TypeIdSummary &Summary) {
4173   NameVals.push_back(StrtabBuilder.add(Id));
4174   NameVals.push_back(Id.size());
4175 
4176   NameVals.push_back(Summary.TTRes.TheKind);
4177   NameVals.push_back(Summary.TTRes.SizeM1BitWidth);
4178   NameVals.push_back(Summary.TTRes.AlignLog2);
4179   NameVals.push_back(Summary.TTRes.SizeM1);
4180   NameVals.push_back(Summary.TTRes.BitMask);
4181   NameVals.push_back(Summary.TTRes.InlineBits);
4182 
4183   for (auto &W : Summary.WPDRes)
4184     writeWholeProgramDevirtResolution(NameVals, StrtabBuilder, W.first,
4185                                       W.second);
4186 }
4187 
4188 static void writeTypeIdCompatibleVtableSummaryRecord(
4189     SmallVector<uint64_t, 64> &NameVals, StringTableBuilder &StrtabBuilder,
4190     StringRef Id, const TypeIdCompatibleVtableInfo &Summary,
4191     ValueEnumerator &VE) {
4192   NameVals.push_back(StrtabBuilder.add(Id));
4193   NameVals.push_back(Id.size());
4194 
4195   for (auto &P : Summary) {
4196     NameVals.push_back(P.AddressPointOffset);
4197     NameVals.push_back(VE.getValueID(P.VTableVI.getValue()));
4198   }
4199 }
4200 
4201 // Adds the allocation contexts to the CallStacks map. We simply use the
4202 // size at the time the context was added as the CallStackId. This works because
4203 // when we look up the call stacks later on we process the function summaries
4204 // and their allocation records in the same exact order.
4205 static void collectMemProfCallStacks(
4206     FunctionSummary *FS, std::function<LinearFrameId(unsigned)> GetStackIndex,
4207     MapVector<CallStackId, llvm::SmallVector<LinearFrameId>> &CallStacks) {
4208   // The interfaces in ProfileData/MemProf.h use a type alias for a stack frame
4209   // id offset into the index of the full stack frames. The ModuleSummaryIndex
4210   // currently uses unsigned. Make sure these stay in sync.
4211   static_assert(std::is_same_v<LinearFrameId, unsigned>);
4212   for (auto &AI : FS->allocs()) {
4213     for (auto &MIB : AI.MIBs) {
4214       SmallVector<unsigned> StackIdIndices;
4215       StackIdIndices.reserve(MIB.StackIdIndices.size());
4216       for (auto Id : MIB.StackIdIndices)
4217         StackIdIndices.push_back(GetStackIndex(Id));
4218       // The CallStackId is the size at the time this context was inserted.
4219       CallStacks.insert({CallStacks.size(), StackIdIndices});
4220     }
4221   }
4222 }
4223 
4224 // Build the radix tree from the accumulated CallStacks, write out the resulting
4225 // linearized radix tree array, and return the map of call stack positions into
4226 // this array for use when writing the allocation records. The returned map is
4227 // indexed by a CallStackId which in this case is implicitly determined by the
4228 // order of function summaries and their allocation infos being written.
4229 static DenseMap<CallStackId, LinearCallStackId> writeMemoryProfileRadixTree(
4230     MapVector<CallStackId, llvm::SmallVector<LinearFrameId>> &&CallStacks,
4231     BitstreamWriter &Stream, unsigned RadixAbbrev) {
4232   assert(!CallStacks.empty());
4233   DenseMap<unsigned, FrameStat> FrameHistogram =
4234       computeFrameHistogram<LinearFrameId>(CallStacks);
4235   CallStackRadixTreeBuilder<LinearFrameId> Builder;
4236   // We don't need a MemProfFrameIndexes map as we have already converted the
4237   // full stack id hash to a linear offset into the StackIds array.
4238   Builder.build(std::move(CallStacks), /*MemProfFrameIndexes=*/std::nullopt,
4239                 FrameHistogram);
4240   Stream.EmitRecord(bitc::FS_CONTEXT_RADIX_TREE_ARRAY, Builder.getRadixArray(),
4241                     RadixAbbrev);
4242   return Builder.takeCallStackPos();
4243 }
4244 
4245 static void writeFunctionHeapProfileRecords(
4246     BitstreamWriter &Stream, FunctionSummary *FS, unsigned CallsiteAbbrev,
4247     unsigned AllocAbbrev, unsigned ContextIdAbbvId, bool PerModule,
4248     std::function<unsigned(const ValueInfo &VI)> GetValueID,
4249     std::function<unsigned(unsigned)> GetStackIndex,
4250     bool WriteContextSizeInfoIndex,
4251     DenseMap<CallStackId, LinearCallStackId> &CallStackPos,
4252     CallStackId &CallStackCount) {
4253   SmallVector<uint64_t> Record;
4254 
4255   for (auto &CI : FS->callsites()) {
4256     Record.clear();
4257     // Per module callsite clones should always have a single entry of
4258     // value 0.
4259     assert(!PerModule || (CI.Clones.size() == 1 && CI.Clones[0] == 0));
4260     Record.push_back(GetValueID(CI.Callee));
4261     if (!PerModule) {
4262       Record.push_back(CI.StackIdIndices.size());
4263       Record.push_back(CI.Clones.size());
4264     }
4265     for (auto Id : CI.StackIdIndices)
4266       Record.push_back(GetStackIndex(Id));
4267     if (!PerModule) {
4268       for (auto V : CI.Clones)
4269         Record.push_back(V);
4270     }
4271     Stream.EmitRecord(PerModule ? bitc::FS_PERMODULE_CALLSITE_INFO
4272                                 : bitc::FS_COMBINED_CALLSITE_INFO,
4273                       Record, CallsiteAbbrev);
4274   }
4275 
4276   for (auto &AI : FS->allocs()) {
4277     Record.clear();
4278     // Per module alloc versions should always have a single entry of
4279     // value 0.
4280     assert(!PerModule || (AI.Versions.size() == 1 && AI.Versions[0] == 0));
4281     Record.push_back(AI.MIBs.size());
4282     if (!PerModule)
4283       Record.push_back(AI.Versions.size());
4284     for (auto &MIB : AI.MIBs) {
4285       Record.push_back((uint8_t)MIB.AllocType);
4286       // Record the index into the radix tree array for this context.
4287       assert(CallStackCount <= CallStackPos.size());
4288       Record.push_back(CallStackPos[CallStackCount++]);
4289     }
4290     if (!PerModule) {
4291       for (auto V : AI.Versions)
4292         Record.push_back(V);
4293     }
4294     assert(AI.ContextSizeInfos.empty() ||
4295            AI.ContextSizeInfos.size() == AI.MIBs.size());
4296     // Optionally emit the context size information if it exists.
4297     if (WriteContextSizeInfoIndex && !AI.ContextSizeInfos.empty()) {
4298       // The abbreviation id for the context ids record should have been created
4299       // if we are emitting the per-module index, which is where we write this
4300       // info.
4301       assert(ContextIdAbbvId);
4302       SmallVector<uint32_t> ContextIds;
4303       // At least one context id per ContextSizeInfos entry (MIB), broken into 2
4304       // halves.
4305       ContextIds.reserve(AI.ContextSizeInfos.size() * 2);
4306       for (auto &Infos : AI.ContextSizeInfos) {
4307         Record.push_back(Infos.size());
4308         for (auto [FullStackId, TotalSize] : Infos) {
4309           // The context ids are emitted separately as a fixed width array,
4310           // which is more efficient than a VBR given that these hashes are
4311           // typically close to 64-bits. The max fixed width entry is 32 bits so
4312           // it is split into 2.
4313           ContextIds.push_back(static_cast<uint32_t>(FullStackId >> 32));
4314           ContextIds.push_back(static_cast<uint32_t>(FullStackId));
4315           Record.push_back(TotalSize);
4316         }
4317       }
4318       // The context ids are expected by the reader to immediately precede the
4319       // associated alloc info record.
4320       Stream.EmitRecord(bitc::FS_ALLOC_CONTEXT_IDS, ContextIds,
4321                         ContextIdAbbvId);
4322     }
4323     Stream.EmitRecord(PerModule ? bitc::FS_PERMODULE_ALLOC_INFO
4324                                 : bitc::FS_COMBINED_ALLOC_INFO,
4325                       Record, AllocAbbrev);
4326   }
4327 }
4328 
4329 // Helper to emit a single function summary record.
4330 void ModuleBitcodeWriterBase::writePerModuleFunctionSummaryRecord(
4331     SmallVector<uint64_t, 64> &NameVals, GlobalValueSummary *Summary,
4332     unsigned ValueID, unsigned FSCallsRelBFAbbrev,
4333     unsigned FSCallsProfileAbbrev, unsigned CallsiteAbbrev,
4334     unsigned AllocAbbrev, unsigned ContextIdAbbvId, const Function &F,
4335     DenseMap<CallStackId, LinearCallStackId> &CallStackPos,
4336     CallStackId &CallStackCount) {
4337   NameVals.push_back(ValueID);
4338 
4339   FunctionSummary *FS = cast<FunctionSummary>(Summary);
4340 
4341   writeFunctionTypeMetadataRecords(
4342       Stream, FS, [&](const ValueInfo &VI) -> std::optional<unsigned> {
4343         return {VE.getValueID(VI.getValue())};
4344       });
4345 
4346   writeFunctionHeapProfileRecords(
4347       Stream, FS, CallsiteAbbrev, AllocAbbrev, ContextIdAbbvId,
4348       /*PerModule*/ true,
4349       /*GetValueId*/ [&](const ValueInfo &VI) { return getValueId(VI); },
4350       /*GetStackIndex*/ [&](unsigned I) { return I; },
4351       /*WriteContextSizeInfoIndex*/ true, CallStackPos, CallStackCount);
4352 
4353   auto SpecialRefCnts = FS->specialRefCounts();
4354   NameVals.push_back(getEncodedGVSummaryFlags(FS->flags()));
4355   NameVals.push_back(FS->instCount());
4356   NameVals.push_back(getEncodedFFlags(FS->fflags()));
4357   NameVals.push_back(FS->refs().size());
4358   NameVals.push_back(SpecialRefCnts.first);  // rorefcnt
4359   NameVals.push_back(SpecialRefCnts.second); // worefcnt
4360 
4361   for (auto &RI : FS->refs())
4362     NameVals.push_back(getValueId(RI));
4363 
4364   const bool UseRelBFRecord =
4365       WriteRelBFToSummary && !F.hasProfileData() &&
4366       ForceSummaryEdgesCold == FunctionSummary::FSHT_None;
4367   for (auto &ECI : FS->calls()) {
4368     NameVals.push_back(getValueId(ECI.first));
4369     if (UseRelBFRecord)
4370       NameVals.push_back(getEncodedRelBFCallEdgeInfo(ECI.second));
4371     else
4372       NameVals.push_back(getEncodedHotnessCallEdgeInfo(ECI.second));
4373   }
4374 
4375   unsigned FSAbbrev =
4376       (UseRelBFRecord ? FSCallsRelBFAbbrev : FSCallsProfileAbbrev);
4377   unsigned Code =
4378       (UseRelBFRecord ? bitc::FS_PERMODULE_RELBF : bitc::FS_PERMODULE_PROFILE);
4379 
4380   // Emit the finished record.
4381   Stream.EmitRecord(Code, NameVals, FSAbbrev);
4382   NameVals.clear();
4383 }
4384 
4385 // Collect the global value references in the given variable's initializer,
4386 // and emit them in a summary record.
4387 void ModuleBitcodeWriterBase::writeModuleLevelReferences(
4388     const GlobalVariable &V, SmallVector<uint64_t, 64> &NameVals,
4389     unsigned FSModRefsAbbrev, unsigned FSModVTableRefsAbbrev) {
4390   auto VI = Index->getValueInfo(V.getGUID());
4391   if (!VI || VI.getSummaryList().empty()) {
4392     // Only declarations should not have a summary (a declaration might however
4393     // have a summary if the def was in module level asm).
4394     assert(V.isDeclaration());
4395     return;
4396   }
4397   auto *Summary = VI.getSummaryList()[0].get();
4398   NameVals.push_back(VE.getValueID(&V));
4399   GlobalVarSummary *VS = cast<GlobalVarSummary>(Summary);
4400   NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
4401   NameVals.push_back(getEncodedGVarFlags(VS->varflags()));
4402 
4403   auto VTableFuncs = VS->vTableFuncs();
4404   if (!VTableFuncs.empty())
4405     NameVals.push_back(VS->refs().size());
4406 
4407   unsigned SizeBeforeRefs = NameVals.size();
4408   for (auto &RI : VS->refs())
4409     NameVals.push_back(VE.getValueID(RI.getValue()));
4410   // Sort the refs for determinism output, the vector returned by FS->refs() has
4411   // been initialized from a DenseSet.
4412   llvm::sort(drop_begin(NameVals, SizeBeforeRefs));
4413 
4414   if (VTableFuncs.empty())
4415     Stream.EmitRecord(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS, NameVals,
4416                       FSModRefsAbbrev);
4417   else {
4418     // VTableFuncs pairs should already be sorted by offset.
4419     for (auto &P : VTableFuncs) {
4420       NameVals.push_back(VE.getValueID(P.FuncVI.getValue()));
4421       NameVals.push_back(P.VTableOffset);
4422     }
4423 
4424     Stream.EmitRecord(bitc::FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS, NameVals,
4425                       FSModVTableRefsAbbrev);
4426   }
4427   NameVals.clear();
4428 }
4429 
4430 /// Emit the per-module summary section alongside the rest of
4431 /// the module's bitcode.
4432 void ModuleBitcodeWriterBase::writePerModuleGlobalValueSummary() {
4433   // By default we compile with ThinLTO if the module has a summary, but the
4434   // client can request full LTO with a module flag.
4435   bool IsThinLTO = true;
4436   if (auto *MD =
4437           mdconst::extract_or_null<ConstantInt>(M.getModuleFlag("ThinLTO")))
4438     IsThinLTO = MD->getZExtValue();
4439   Stream.EnterSubblock(IsThinLTO ? bitc::GLOBALVAL_SUMMARY_BLOCK_ID
4440                                  : bitc::FULL_LTO_GLOBALVAL_SUMMARY_BLOCK_ID,
4441                        4);
4442 
4443   Stream.EmitRecord(
4444       bitc::FS_VERSION,
4445       ArrayRef<uint64_t>{ModuleSummaryIndex::BitcodeSummaryVersion});
4446 
4447   // Write the index flags.
4448   uint64_t Flags = 0;
4449   // Bits 1-3 are set only in the combined index, skip them.
4450   if (Index->enableSplitLTOUnit())
4451     Flags |= 0x8;
4452   if (Index->hasUnifiedLTO())
4453     Flags |= 0x200;
4454 
4455   Stream.EmitRecord(bitc::FS_FLAGS, ArrayRef<uint64_t>{Flags});
4456 
4457   if (Index->begin() == Index->end()) {
4458     Stream.ExitBlock();
4459     return;
4460   }
4461 
4462   auto Abbv = std::make_shared<BitCodeAbbrev>();
4463   Abbv->Add(BitCodeAbbrevOp(bitc::FS_VALUE_GUID));
4464   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
4465   // GUIDS often use up most of 64-bits, so encode as two Fixed 32.
4466   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4467   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4468   unsigned ValueGuidAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4469 
4470   for (const auto &GVI : valueIds()) {
4471     Stream.EmitRecord(bitc::FS_VALUE_GUID,
4472                       ArrayRef<uint32_t>{GVI.second,
4473                                          static_cast<uint32_t>(GVI.first >> 32),
4474                                          static_cast<uint32_t>(GVI.first)},
4475                       ValueGuidAbbrev);
4476   }
4477 
4478   if (!Index->stackIds().empty()) {
4479     auto StackIdAbbv = std::make_shared<BitCodeAbbrev>();
4480     StackIdAbbv->Add(BitCodeAbbrevOp(bitc::FS_STACK_IDS));
4481     // numids x stackid
4482     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4483     // The stack ids are hashes that are close to 64 bits in size, so emitting
4484     // as a pair of 32-bit fixed-width values is more efficient than a VBR.
4485     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4486     unsigned StackIdAbbvId = Stream.EmitAbbrev(std::move(StackIdAbbv));
4487     SmallVector<uint32_t> Vals;
4488     Vals.reserve(Index->stackIds().size() * 2);
4489     for (auto Id : Index->stackIds()) {
4490       Vals.push_back(static_cast<uint32_t>(Id >> 32));
4491       Vals.push_back(static_cast<uint32_t>(Id));
4492     }
4493     Stream.EmitRecord(bitc::FS_STACK_IDS, Vals, StackIdAbbvId);
4494   }
4495 
4496   // n x context id
4497   auto ContextIdAbbv = std::make_shared<BitCodeAbbrev>();
4498   ContextIdAbbv->Add(BitCodeAbbrevOp(bitc::FS_ALLOC_CONTEXT_IDS));
4499   ContextIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4500   // The context ids are hashes that are close to 64 bits in size, so emitting
4501   // as a pair of 32-bit fixed-width values is more efficient than a VBR.
4502   ContextIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4503   unsigned ContextIdAbbvId = Stream.EmitAbbrev(std::move(ContextIdAbbv));
4504 
4505   // Abbrev for FS_PERMODULE_PROFILE.
4506   Abbv = std::make_shared<BitCodeAbbrev>();
4507   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_PROFILE));
4508   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4509   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // flags
4510   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4511   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4512   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4513   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4514   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4515   // numrefs x valueid, n x (valueid, hotness+tailcall flags)
4516   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4517   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4518   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4519 
4520   // Abbrev for FS_PERMODULE_RELBF.
4521   Abbv = std::make_shared<BitCodeAbbrev>();
4522   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_RELBF));
4523   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4524   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4525   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4526   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4527   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4528   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4529   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4530   // numrefs x valueid, n x (valueid, rel_block_freq+tailcall])
4531   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4532   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4533   unsigned FSCallsRelBFAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4534 
4535   // Abbrev for FS_PERMODULE_GLOBALVAR_INIT_REFS.
4536   Abbv = std::make_shared<BitCodeAbbrev>();
4537   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS));
4538   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4539   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
4540   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));  // valueids
4541   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4542   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4543 
4544   // Abbrev for FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS.
4545   Abbv = std::make_shared<BitCodeAbbrev>();
4546   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_VTABLE_GLOBALVAR_INIT_REFS));
4547   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4548   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
4549   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numrefs
4550   // numrefs x valueid, n x (valueid , offset)
4551   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4552   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4553   unsigned FSModVTableRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4554 
4555   // Abbrev for FS_ALIAS.
4556   Abbv = std::make_shared<BitCodeAbbrev>();
4557   Abbv->Add(BitCodeAbbrevOp(bitc::FS_ALIAS));
4558   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4559   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4560   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4561   unsigned FSAliasAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4562 
4563   // Abbrev for FS_TYPE_ID_METADATA
4564   Abbv = std::make_shared<BitCodeAbbrev>();
4565   Abbv->Add(BitCodeAbbrevOp(bitc::FS_TYPE_ID_METADATA));
4566   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // typeid strtab index
4567   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // typeid length
4568   // n x (valueid , offset)
4569   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4570   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4571   unsigned TypeIdCompatibleVtableAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4572 
4573   Abbv = std::make_shared<BitCodeAbbrev>();
4574   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_CALLSITE_INFO));
4575   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4576   // n x stackidindex
4577   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4578   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4579   unsigned CallsiteAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4580 
4581   Abbv = std::make_shared<BitCodeAbbrev>();
4582   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_ALLOC_INFO));
4583   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // nummib
4584   // n x (alloc type, context radix tree index)
4585   // optional: nummib x (numcontext x total size)
4586   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4587   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4588   unsigned AllocAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4589 
4590   Abbv = std::make_shared<BitCodeAbbrev>();
4591   Abbv->Add(BitCodeAbbrevOp(bitc::FS_CONTEXT_RADIX_TREE_ARRAY));
4592   // n x entry
4593   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4594   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4595   unsigned RadixAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4596 
4597   // First walk through all the functions and collect the allocation contexts in
4598   // their associated summaries, for use in constructing a radix tree of
4599   // contexts. Note that we need to do this in the same order as the functions
4600   // are processed further below since the call stack positions in the resulting
4601   // radix tree array are identified based on this order.
4602   MapVector<CallStackId, llvm::SmallVector<LinearFrameId>> CallStacks;
4603   for (const Function &F : M) {
4604     // Summary emission does not support anonymous functions, they have to be
4605     // renamed using the anonymous function renaming pass.
4606     if (!F.hasName())
4607       report_fatal_error("Unexpected anonymous function when writing summary");
4608 
4609     ValueInfo VI = Index->getValueInfo(F.getGUID());
4610     if (!VI || VI.getSummaryList().empty()) {
4611       // Only declarations should not have a summary (a declaration might
4612       // however have a summary if the def was in module level asm).
4613       assert(F.isDeclaration());
4614       continue;
4615     }
4616     auto *Summary = VI.getSummaryList()[0].get();
4617     FunctionSummary *FS = cast<FunctionSummary>(Summary);
4618     collectMemProfCallStacks(
4619         FS, /*GetStackIndex*/ [](unsigned I) { return I; }, CallStacks);
4620   }
4621   // Finalize the radix tree, write it out, and get the map of positions in the
4622   // linearized tree array.
4623   DenseMap<CallStackId, LinearCallStackId> CallStackPos;
4624   if (!CallStacks.empty()) {
4625     CallStackPos =
4626         writeMemoryProfileRadixTree(std::move(CallStacks), Stream, RadixAbbrev);
4627   }
4628 
4629   // Keep track of the current index into the CallStackPos map.
4630   CallStackId CallStackCount = 0;
4631 
4632   SmallVector<uint64_t, 64> NameVals;
4633   // Iterate over the list of functions instead of the Index to
4634   // ensure the ordering is stable.
4635   for (const Function &F : M) {
4636     // Summary emission does not support anonymous functions, they have to
4637     // renamed using the anonymous function renaming pass.
4638     if (!F.hasName())
4639       report_fatal_error("Unexpected anonymous function when writing summary");
4640 
4641     ValueInfo VI = Index->getValueInfo(F.getGUID());
4642     if (!VI || VI.getSummaryList().empty()) {
4643       // Only declarations should not have a summary (a declaration might
4644       // however have a summary if the def was in module level asm).
4645       assert(F.isDeclaration());
4646       continue;
4647     }
4648     auto *Summary = VI.getSummaryList()[0].get();
4649     writePerModuleFunctionSummaryRecord(
4650         NameVals, Summary, VE.getValueID(&F), FSCallsRelBFAbbrev,
4651         FSCallsProfileAbbrev, CallsiteAbbrev, AllocAbbrev, ContextIdAbbvId, F,
4652         CallStackPos, CallStackCount);
4653   }
4654 
4655   // Capture references from GlobalVariable initializers, which are outside
4656   // of a function scope.
4657   for (const GlobalVariable &G : M.globals())
4658     writeModuleLevelReferences(G, NameVals, FSModRefsAbbrev,
4659                                FSModVTableRefsAbbrev);
4660 
4661   for (const GlobalAlias &A : M.aliases()) {
4662     auto *Aliasee = A.getAliaseeObject();
4663     // Skip ifunc and nameless functions which don't have an entry in the
4664     // summary.
4665     if (!Aliasee->hasName() || isa<GlobalIFunc>(Aliasee))
4666       continue;
4667     auto AliasId = VE.getValueID(&A);
4668     auto AliaseeId = VE.getValueID(Aliasee);
4669     NameVals.push_back(AliasId);
4670     auto *Summary = Index->getGlobalValueSummary(A);
4671     AliasSummary *AS = cast<AliasSummary>(Summary);
4672     NameVals.push_back(getEncodedGVSummaryFlags(AS->flags()));
4673     NameVals.push_back(AliaseeId);
4674     Stream.EmitRecord(bitc::FS_ALIAS, NameVals, FSAliasAbbrev);
4675     NameVals.clear();
4676   }
4677 
4678   for (auto &S : Index->typeIdCompatibleVtableMap()) {
4679     writeTypeIdCompatibleVtableSummaryRecord(NameVals, StrtabBuilder, S.first,
4680                                              S.second, VE);
4681     Stream.EmitRecord(bitc::FS_TYPE_ID_METADATA, NameVals,
4682                       TypeIdCompatibleVtableAbbrev);
4683     NameVals.clear();
4684   }
4685 
4686   if (Index->getBlockCount())
4687     Stream.EmitRecord(bitc::FS_BLOCK_COUNT,
4688                       ArrayRef<uint64_t>{Index->getBlockCount()});
4689 
4690   Stream.ExitBlock();
4691 }
4692 
4693 /// Emit the combined summary section into the combined index file.
4694 void IndexBitcodeWriter::writeCombinedGlobalValueSummary() {
4695   Stream.EnterSubblock(bitc::GLOBALVAL_SUMMARY_BLOCK_ID, 4);
4696   Stream.EmitRecord(
4697       bitc::FS_VERSION,
4698       ArrayRef<uint64_t>{ModuleSummaryIndex::BitcodeSummaryVersion});
4699 
4700   // Write the index flags.
4701   Stream.EmitRecord(bitc::FS_FLAGS, ArrayRef<uint64_t>{Index.getFlags()});
4702 
4703   auto Abbv = std::make_shared<BitCodeAbbrev>();
4704   Abbv->Add(BitCodeAbbrevOp(bitc::FS_VALUE_GUID));
4705   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
4706   // GUIDS often use up most of 64-bits, so encode as two Fixed 32.
4707   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4708   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4709   unsigned ValueGuidAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4710 
4711   for (const auto &GVI : valueIds()) {
4712     Stream.EmitRecord(bitc::FS_VALUE_GUID,
4713                       ArrayRef<uint32_t>{GVI.second,
4714                                          static_cast<uint32_t>(GVI.first >> 32),
4715                                          static_cast<uint32_t>(GVI.first)},
4716                       ValueGuidAbbrev);
4717   }
4718 
4719   // Write the stack ids used by this index, which will be a subset of those in
4720   // the full index in the case of distributed indexes.
4721   if (!StackIds.empty()) {
4722     auto StackIdAbbv = std::make_shared<BitCodeAbbrev>();
4723     StackIdAbbv->Add(BitCodeAbbrevOp(bitc::FS_STACK_IDS));
4724     // numids x stackid
4725     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4726     // The stack ids are hashes that are close to 64 bits in size, so emitting
4727     // as a pair of 32-bit fixed-width values is more efficient than a VBR.
4728     StackIdAbbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
4729     unsigned StackIdAbbvId = Stream.EmitAbbrev(std::move(StackIdAbbv));
4730     SmallVector<uint32_t> Vals;
4731     Vals.reserve(StackIds.size() * 2);
4732     for (auto Id : StackIds) {
4733       Vals.push_back(static_cast<uint32_t>(Id >> 32));
4734       Vals.push_back(static_cast<uint32_t>(Id));
4735     }
4736     Stream.EmitRecord(bitc::FS_STACK_IDS, Vals, StackIdAbbvId);
4737   }
4738 
4739   // Abbrev for FS_COMBINED_PROFILE.
4740   Abbv = std::make_shared<BitCodeAbbrev>();
4741   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_PROFILE));
4742   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4743   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4744   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4745   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
4746   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // fflags
4747   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // entrycount
4748   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
4749   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // rorefcnt
4750   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // worefcnt
4751   // numrefs x valueid, n x (valueid, hotness+tailcall flags)
4752   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4753   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4754   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4755 
4756   // Abbrev for FS_COMBINED_GLOBALVAR_INIT_REFS.
4757   Abbv = std::make_shared<BitCodeAbbrev>();
4758   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS));
4759   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4760   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4761   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4762   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));    // valueids
4763   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4764   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4765 
4766   // Abbrev for FS_COMBINED_ALIAS.
4767   Abbv = std::make_shared<BitCodeAbbrev>();
4768   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_ALIAS));
4769   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4770   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
4771   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
4772   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
4773   unsigned FSAliasAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4774 
4775   Abbv = std::make_shared<BitCodeAbbrev>();
4776   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_CALLSITE_INFO));
4777   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
4778   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numstackindices
4779   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numver
4780   // numstackindices x stackidindex, numver x version
4781   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4782   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4783   unsigned CallsiteAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4784 
4785   Abbv = std::make_shared<BitCodeAbbrev>();
4786   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_ALLOC_INFO));
4787   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // nummib
4788   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // numver
4789   // nummib x (alloc type, context radix tree index),
4790   // numver x version
4791   // optional: nummib x total size
4792   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4793   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4794   unsigned AllocAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4795 
4796   Abbv = std::make_shared<BitCodeAbbrev>();
4797   Abbv->Add(BitCodeAbbrevOp(bitc::FS_CONTEXT_RADIX_TREE_ARRAY));
4798   // n x entry
4799   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
4800   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
4801   unsigned RadixAbbrev = Stream.EmitAbbrev(std::move(Abbv));
4802 
4803   auto shouldImportValueAsDecl = [&](GlobalValueSummary *GVS) -> bool {
4804     if (DecSummaries == nullptr)
4805       return false;
4806     return DecSummaries->count(GVS);
4807   };
4808 
4809   // The aliases are emitted as a post-pass, and will point to the value
4810   // id of the aliasee. Save them in a vector for post-processing.
4811   SmallVector<AliasSummary *, 64> Aliases;
4812 
4813   // Save the value id for each summary for alias emission.
4814   DenseMap<const GlobalValueSummary *, unsigned> SummaryToValueIdMap;
4815 
4816   SmallVector<uint64_t, 64> NameVals;
4817 
4818   // Set that will be populated during call to writeFunctionTypeMetadataRecords
4819   // with the type ids referenced by this index file.
4820   std::set<GlobalValue::GUID> ReferencedTypeIds;
4821 
4822   // For local linkage, we also emit the original name separately
4823   // immediately after the record.
4824   auto MaybeEmitOriginalName = [&](GlobalValueSummary &S) {
4825     // We don't need to emit the original name if we are writing the index for
4826     // distributed backends (in which case ModuleToSummariesForIndex is
4827     // non-null). The original name is only needed during the thin link, since
4828     // for SamplePGO the indirect call targets for local functions have
4829     // have the original name annotated in profile.
4830     // Continue to emit it when writing out the entire combined index, which is
4831     // used in testing the thin link via llvm-lto.
4832     if (ModuleToSummariesForIndex || !GlobalValue::isLocalLinkage(S.linkage()))
4833       return;
4834     NameVals.push_back(S.getOriginalName());
4835     Stream.EmitRecord(bitc::FS_COMBINED_ORIGINAL_NAME, NameVals);
4836     NameVals.clear();
4837   };
4838 
4839   // First walk through all the functions and collect the allocation contexts in
4840   // their associated summaries, for use in constructing a radix tree of
4841   // contexts. Note that we need to do this in the same order as the functions
4842   // are processed further below since the call stack positions in the resulting
4843   // radix tree array are identified based on this order.
4844   MapVector<CallStackId, llvm::SmallVector<LinearFrameId>> CallStacks;
4845   forEachSummary([&](GVInfo I, bool IsAliasee) {
4846     GlobalValueSummary *S = I.second;
4847     assert(S);
4848     auto *FS = dyn_cast<FunctionSummary>(S);
4849     if (!FS)
4850       return;
4851     collectMemProfCallStacks(
4852         FS,
4853         /*GetStackIndex*/
4854         [&](unsigned I) {
4855           // Get the corresponding index into the list of StackIds actually
4856           // being written for this combined index (which may be a subset in
4857           // the case of distributed indexes).
4858           assert(StackIdIndicesToIndex.contains(I));
4859           return StackIdIndicesToIndex[I];
4860         },
4861         CallStacks);
4862   });
4863   // Finalize the radix tree, write it out, and get the map of positions in the
4864   // linearized tree array.
4865   DenseMap<CallStackId, LinearCallStackId> CallStackPos;
4866   if (!CallStacks.empty()) {
4867     CallStackPos =
4868         writeMemoryProfileRadixTree(std::move(CallStacks), Stream, RadixAbbrev);
4869   }
4870 
4871   // Keep track of the current index into the CallStackPos map.
4872   CallStackId CallStackCount = 0;
4873 
4874   DenseSet<GlobalValue::GUID> DefOrUseGUIDs;
4875   forEachSummary([&](GVInfo I, bool IsAliasee) {
4876     GlobalValueSummary *S = I.second;
4877     assert(S);
4878     DefOrUseGUIDs.insert(I.first);
4879     for (const ValueInfo &VI : S->refs())
4880       DefOrUseGUIDs.insert(VI.getGUID());
4881 
4882     auto ValueId = getValueId(I.first);
4883     assert(ValueId);
4884     SummaryToValueIdMap[S] = *ValueId;
4885 
4886     // If this is invoked for an aliasee, we want to record the above
4887     // mapping, but then not emit a summary entry (if the aliasee is
4888     // to be imported, we will invoke this separately with IsAliasee=false).
4889     if (IsAliasee)
4890       return;
4891 
4892     if (auto *AS = dyn_cast<AliasSummary>(S)) {
4893       // Will process aliases as a post-pass because the reader wants all
4894       // global to be loaded first.
4895       Aliases.push_back(AS);
4896       return;
4897     }
4898 
4899     if (auto *VS = dyn_cast<GlobalVarSummary>(S)) {
4900       NameVals.push_back(*ValueId);
4901       assert(ModuleIdMap.count(VS->modulePath()));
4902       NameVals.push_back(ModuleIdMap[VS->modulePath()]);
4903       NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
4904       NameVals.push_back(getEncodedGVarFlags(VS->varflags()));
4905       for (auto &RI : VS->refs()) {
4906         auto RefValueId = getValueId(RI.getGUID());
4907         if (!RefValueId)
4908           continue;
4909         NameVals.push_back(*RefValueId);
4910       }
4911 
4912       // Emit the finished record.
4913       Stream.EmitRecord(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS, NameVals,
4914                         FSModRefsAbbrev);
4915       NameVals.clear();
4916       MaybeEmitOriginalName(*S);
4917       return;
4918     }
4919 
4920     auto GetValueId = [&](const ValueInfo &VI) -> std::optional<unsigned> {
4921       if (!VI)
4922         return std::nullopt;
4923       return getValueId(VI.getGUID());
4924     };
4925 
4926     auto *FS = cast<FunctionSummary>(S);
4927     writeFunctionTypeMetadataRecords(Stream, FS, GetValueId);
4928     getReferencedTypeIds(FS, ReferencedTypeIds);
4929 
4930     writeFunctionHeapProfileRecords(
4931         Stream, FS, CallsiteAbbrev, AllocAbbrev, /*ContextIdAbbvId*/ 0,
4932         /*PerModule*/ false,
4933         /*GetValueId*/
4934         [&](const ValueInfo &VI) -> unsigned {
4935           std::optional<unsigned> ValueID = GetValueId(VI);
4936           // This can happen in shared index files for distributed ThinLTO if
4937           // the callee function summary is not included. Record 0 which we
4938           // will have to deal with conservatively when doing any kind of
4939           // validation in the ThinLTO backends.
4940           if (!ValueID)
4941             return 0;
4942           return *ValueID;
4943         },
4944         /*GetStackIndex*/
4945         [&](unsigned I) {
4946           // Get the corresponding index into the list of StackIds actually
4947           // being written for this combined index (which may be a subset in
4948           // the case of distributed indexes).
4949           assert(StackIdIndicesToIndex.contains(I));
4950           return StackIdIndicesToIndex[I];
4951         },
4952         /*WriteContextSizeInfoIndex*/ false, CallStackPos, CallStackCount);
4953 
4954     NameVals.push_back(*ValueId);
4955     assert(ModuleIdMap.count(FS->modulePath()));
4956     NameVals.push_back(ModuleIdMap[FS->modulePath()]);
4957     NameVals.push_back(
4958         getEncodedGVSummaryFlags(FS->flags(), shouldImportValueAsDecl(FS)));
4959     NameVals.push_back(FS->instCount());
4960     NameVals.push_back(getEncodedFFlags(FS->fflags()));
4961     // TODO: Stop writing entry count and bump bitcode version.
4962     NameVals.push_back(0 /* EntryCount */);
4963 
4964     // Fill in below
4965     NameVals.push_back(0); // numrefs
4966     NameVals.push_back(0); // rorefcnt
4967     NameVals.push_back(0); // worefcnt
4968 
4969     unsigned Count = 0, RORefCnt = 0, WORefCnt = 0;
4970     for (auto &RI : FS->refs()) {
4971       auto RefValueId = getValueId(RI.getGUID());
4972       if (!RefValueId)
4973         continue;
4974       NameVals.push_back(*RefValueId);
4975       if (RI.isReadOnly())
4976         RORefCnt++;
4977       else if (RI.isWriteOnly())
4978         WORefCnt++;
4979       Count++;
4980     }
4981     NameVals[6] = Count;
4982     NameVals[7] = RORefCnt;
4983     NameVals[8] = WORefCnt;
4984 
4985     for (auto &EI : FS->calls()) {
4986       // If this GUID doesn't have a value id, it doesn't have a function
4987       // summary and we don't need to record any calls to it.
4988       std::optional<unsigned> CallValueId = GetValueId(EI.first);
4989       if (!CallValueId)
4990         continue;
4991       NameVals.push_back(*CallValueId);
4992       NameVals.push_back(getEncodedHotnessCallEdgeInfo(EI.second));
4993     }
4994 
4995     // Emit the finished record.
4996     Stream.EmitRecord(bitc::FS_COMBINED_PROFILE, NameVals,
4997                       FSCallsProfileAbbrev);
4998     NameVals.clear();
4999     MaybeEmitOriginalName(*S);
5000   });
5001 
5002   for (auto *AS : Aliases) {
5003     auto AliasValueId = SummaryToValueIdMap[AS];
5004     assert(AliasValueId);
5005     NameVals.push_back(AliasValueId);
5006     assert(ModuleIdMap.count(AS->modulePath()));
5007     NameVals.push_back(ModuleIdMap[AS->modulePath()]);
5008     NameVals.push_back(
5009         getEncodedGVSummaryFlags(AS->flags(), shouldImportValueAsDecl(AS)));
5010     auto AliaseeValueId = SummaryToValueIdMap[&AS->getAliasee()];
5011     assert(AliaseeValueId);
5012     NameVals.push_back(AliaseeValueId);
5013 
5014     // Emit the finished record.
5015     Stream.EmitRecord(bitc::FS_COMBINED_ALIAS, NameVals, FSAliasAbbrev);
5016     NameVals.clear();
5017     MaybeEmitOriginalName(*AS);
5018 
5019     if (auto *FS = dyn_cast<FunctionSummary>(&AS->getAliasee()))
5020       getReferencedTypeIds(FS, ReferencedTypeIds);
5021   }
5022 
5023   if (!Index.cfiFunctionDefs().empty()) {
5024     for (auto &S : Index.cfiFunctionDefs()) {
5025       if (DefOrUseGUIDs.contains(
5026               GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(S)))) {
5027         NameVals.push_back(StrtabBuilder.add(S));
5028         NameVals.push_back(S.size());
5029       }
5030     }
5031     if (!NameVals.empty()) {
5032       Stream.EmitRecord(bitc::FS_CFI_FUNCTION_DEFS, NameVals);
5033       NameVals.clear();
5034     }
5035   }
5036 
5037   if (!Index.cfiFunctionDecls().empty()) {
5038     for (auto &S : Index.cfiFunctionDecls()) {
5039       if (DefOrUseGUIDs.contains(
5040               GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(S)))) {
5041         NameVals.push_back(StrtabBuilder.add(S));
5042         NameVals.push_back(S.size());
5043       }
5044     }
5045     if (!NameVals.empty()) {
5046       Stream.EmitRecord(bitc::FS_CFI_FUNCTION_DECLS, NameVals);
5047       NameVals.clear();
5048     }
5049   }
5050 
5051   // Walk the GUIDs that were referenced, and write the
5052   // corresponding type id records.
5053   for (auto &T : ReferencedTypeIds) {
5054     auto TidIter = Index.typeIds().equal_range(T);
5055     for (const auto &[GUID, TypeIdPair] : make_range(TidIter)) {
5056       writeTypeIdSummaryRecord(NameVals, StrtabBuilder, TypeIdPair.first,
5057                                TypeIdPair.second);
5058       Stream.EmitRecord(bitc::FS_TYPE_ID, NameVals);
5059       NameVals.clear();
5060     }
5061   }
5062 
5063   if (Index.getBlockCount())
5064     Stream.EmitRecord(bitc::FS_BLOCK_COUNT,
5065                       ArrayRef<uint64_t>{Index.getBlockCount()});
5066 
5067   Stream.ExitBlock();
5068 }
5069 
5070 /// Create the "IDENTIFICATION_BLOCK_ID" containing a single string with the
5071 /// current llvm version, and a record for the epoch number.
5072 static void writeIdentificationBlock(BitstreamWriter &Stream) {
5073   Stream.EnterSubblock(bitc::IDENTIFICATION_BLOCK_ID, 5);
5074 
5075   // Write the "user readable" string identifying the bitcode producer
5076   auto Abbv = std::make_shared<BitCodeAbbrev>();
5077   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_STRING));
5078   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
5079   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
5080   auto StringAbbrev = Stream.EmitAbbrev(std::move(Abbv));
5081   writeStringRecord(Stream, bitc::IDENTIFICATION_CODE_STRING,
5082                     "LLVM" LLVM_VERSION_STRING, StringAbbrev);
5083 
5084   // Write the epoch version
5085   Abbv = std::make_shared<BitCodeAbbrev>();
5086   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_EPOCH));
5087   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
5088   auto EpochAbbrev = Stream.EmitAbbrev(std::move(Abbv));
5089   constexpr std::array<unsigned, 1> Vals = {{bitc::BITCODE_CURRENT_EPOCH}};
5090   Stream.EmitRecord(bitc::IDENTIFICATION_CODE_EPOCH, Vals, EpochAbbrev);
5091   Stream.ExitBlock();
5092 }
5093 
5094 void ModuleBitcodeWriter::writeModuleHash(StringRef View) {
5095   // Emit the module's hash.
5096   // MODULE_CODE_HASH: [5*i32]
5097   if (GenerateHash) {
5098     uint32_t Vals[5];
5099     Hasher.update(ArrayRef<uint8_t>(
5100         reinterpret_cast<const uint8_t *>(View.data()), View.size()));
5101     std::array<uint8_t, 20> Hash = Hasher.result();
5102     for (int Pos = 0; Pos < 20; Pos += 4) {
5103       Vals[Pos / 4] = support::endian::read32be(Hash.data() + Pos);
5104     }
5105 
5106     // Emit the finished record.
5107     Stream.EmitRecord(bitc::MODULE_CODE_HASH, Vals);
5108 
5109     if (ModHash)
5110       // Save the written hash value.
5111       llvm::copy(Vals, std::begin(*ModHash));
5112   }
5113 }
5114 
5115 void ModuleBitcodeWriter::write() {
5116   writeIdentificationBlock(Stream);
5117 
5118   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
5119   // We will want to write the module hash at this point. Block any flushing so
5120   // we can have access to the whole underlying data later.
5121   Stream.markAndBlockFlushing();
5122 
5123   writeModuleVersion();
5124 
5125   // Emit blockinfo, which defines the standard abbreviations etc.
5126   writeBlockInfo();
5127 
5128   // Emit information describing all of the types in the module.
5129   writeTypeTable();
5130 
5131   // Emit information about attribute groups.
5132   writeAttributeGroupTable();
5133 
5134   // Emit information about parameter attributes.
5135   writeAttributeTable();
5136 
5137   writeComdats();
5138 
5139   // Emit top-level description of module, including target triple, inline asm,
5140   // descriptors for global variables, and function prototype info.
5141   writeModuleInfo();
5142 
5143   // Emit constants.
5144   writeModuleConstants();
5145 
5146   // Emit metadata kind names.
5147   writeModuleMetadataKinds();
5148 
5149   // Emit metadata.
5150   writeModuleMetadata();
5151 
5152   // Emit module-level use-lists.
5153   if (VE.shouldPreserveUseListOrder())
5154     writeUseListBlock(nullptr);
5155 
5156   writeOperandBundleTags();
5157   writeSyncScopeNames();
5158 
5159   // Emit function bodies.
5160   DenseMap<const Function *, uint64_t> FunctionToBitcodeIndex;
5161   for (const Function &F : M)
5162     if (!F.isDeclaration())
5163       writeFunction(F, FunctionToBitcodeIndex);
5164 
5165   // Need to write after the above call to WriteFunction which populates
5166   // the summary information in the index.
5167   if (Index)
5168     writePerModuleGlobalValueSummary();
5169 
5170   writeGlobalValueSymbolTable(FunctionToBitcodeIndex);
5171 
5172   writeModuleHash(Stream.getMarkedBufferAndResumeFlushing());
5173 
5174   Stream.ExitBlock();
5175 }
5176 
5177 static void writeInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
5178                                uint32_t &Position) {
5179   support::endian::write32le(&Buffer[Position], Value);
5180   Position += 4;
5181 }
5182 
5183 /// If generating a bc file on darwin, we have to emit a
5184 /// header and trailer to make it compatible with the system archiver.  To do
5185 /// this we emit the following header, and then emit a trailer that pads the
5186 /// file out to be a multiple of 16 bytes.
5187 ///
5188 /// struct bc_header {
5189 ///   uint32_t Magic;         // 0x0B17C0DE
5190 ///   uint32_t Version;       // Version, currently always 0.
5191 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
5192 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
5193 ///   uint32_t CPUType;       // CPU specifier.
5194 ///   ... potentially more later ...
5195 /// };
5196 static void emitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
5197                                          const Triple &TT) {
5198   unsigned CPUType = ~0U;
5199 
5200   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
5201   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
5202   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
5203   // specific constants here because they are implicitly part of the Darwin ABI.
5204   enum {
5205     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
5206     DARWIN_CPU_TYPE_X86        = 7,
5207     DARWIN_CPU_TYPE_ARM        = 12,
5208     DARWIN_CPU_TYPE_POWERPC    = 18
5209   };
5210 
5211   Triple::ArchType Arch = TT.getArch();
5212   if (Arch == Triple::x86_64)
5213     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
5214   else if (Arch == Triple::x86)
5215     CPUType = DARWIN_CPU_TYPE_X86;
5216   else if (Arch == Triple::ppc)
5217     CPUType = DARWIN_CPU_TYPE_POWERPC;
5218   else if (Arch == Triple::ppc64)
5219     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
5220   else if (Arch == Triple::arm || Arch == Triple::thumb)
5221     CPUType = DARWIN_CPU_TYPE_ARM;
5222 
5223   // Traditional Bitcode starts after header.
5224   assert(Buffer.size() >= BWH_HeaderSize &&
5225          "Expected header size to be reserved");
5226   unsigned BCOffset = BWH_HeaderSize;
5227   unsigned BCSize = Buffer.size() - BWH_HeaderSize;
5228 
5229   // Write the magic and version.
5230   unsigned Position = 0;
5231   writeInt32ToBuffer(0x0B17C0DE, Buffer, Position);
5232   writeInt32ToBuffer(0, Buffer, Position); // Version.
5233   writeInt32ToBuffer(BCOffset, Buffer, Position);
5234   writeInt32ToBuffer(BCSize, Buffer, Position);
5235   writeInt32ToBuffer(CPUType, Buffer, Position);
5236 
5237   // If the file is not a multiple of 16 bytes, insert dummy padding.
5238   while (Buffer.size() & 15)
5239     Buffer.push_back(0);
5240 }
5241 
5242 /// Helper to write the header common to all bitcode files.
5243 static void writeBitcodeHeader(BitstreamWriter &Stream) {
5244   // Emit the file header.
5245   Stream.Emit((unsigned)'B', 8);
5246   Stream.Emit((unsigned)'C', 8);
5247   Stream.Emit(0x0, 4);
5248   Stream.Emit(0xC, 4);
5249   Stream.Emit(0xE, 4);
5250   Stream.Emit(0xD, 4);
5251 }
5252 
5253 BitcodeWriter::BitcodeWriter(SmallVectorImpl<char> &Buffer)
5254     : Stream(new BitstreamWriter(Buffer)) {
5255   writeBitcodeHeader(*Stream);
5256 }
5257 
5258 BitcodeWriter::BitcodeWriter(raw_ostream &FS)
5259     : Stream(new BitstreamWriter(FS, FlushThreshold)) {
5260   writeBitcodeHeader(*Stream);
5261 }
5262 
5263 BitcodeWriter::~BitcodeWriter() { assert(WroteStrtab); }
5264 
5265 void BitcodeWriter::writeBlob(unsigned Block, unsigned Record, StringRef Blob) {
5266   Stream->EnterSubblock(Block, 3);
5267 
5268   auto Abbv = std::make_shared<BitCodeAbbrev>();
5269   Abbv->Add(BitCodeAbbrevOp(Record));
5270   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
5271   auto AbbrevNo = Stream->EmitAbbrev(std::move(Abbv));
5272 
5273   Stream->EmitRecordWithBlob(AbbrevNo, ArrayRef<uint64_t>{Record}, Blob);
5274 
5275   Stream->ExitBlock();
5276 }
5277 
5278 void BitcodeWriter::writeSymtab() {
5279   assert(!WroteStrtab && !WroteSymtab);
5280 
5281   // If any module has module-level inline asm, we will require a registered asm
5282   // parser for the target so that we can create an accurate symbol table for
5283   // the module.
5284   for (Module *M : Mods) {
5285     if (M->getModuleInlineAsm().empty())
5286       continue;
5287 
5288     std::string Err;
5289     const Triple TT(M->getTargetTriple());
5290     const Target *T = TargetRegistry::lookupTarget(TT.str(), Err);
5291     if (!T || !T->hasMCAsmParser())
5292       return;
5293   }
5294 
5295   WroteSymtab = true;
5296   SmallVector<char, 0> Symtab;
5297   // The irsymtab::build function may be unable to create a symbol table if the
5298   // module is malformed (e.g. it contains an invalid alias). Writing a symbol
5299   // table is not required for correctness, but we still want to be able to
5300   // write malformed modules to bitcode files, so swallow the error.
5301   if (Error E = irsymtab::build(Mods, Symtab, StrtabBuilder, Alloc)) {
5302     consumeError(std::move(E));
5303     return;
5304   }
5305 
5306   writeBlob(bitc::SYMTAB_BLOCK_ID, bitc::SYMTAB_BLOB,
5307             {Symtab.data(), Symtab.size()});
5308 }
5309 
5310 void BitcodeWriter::writeStrtab() {
5311   assert(!WroteStrtab);
5312 
5313   std::vector<char> Strtab;
5314   StrtabBuilder.finalizeInOrder();
5315   Strtab.resize(StrtabBuilder.getSize());
5316   StrtabBuilder.write((uint8_t *)Strtab.data());
5317 
5318   writeBlob(bitc::STRTAB_BLOCK_ID, bitc::STRTAB_BLOB,
5319             {Strtab.data(), Strtab.size()});
5320 
5321   WroteStrtab = true;
5322 }
5323 
5324 void BitcodeWriter::copyStrtab(StringRef Strtab) {
5325   writeBlob(bitc::STRTAB_BLOCK_ID, bitc::STRTAB_BLOB, Strtab);
5326   WroteStrtab = true;
5327 }
5328 
5329 void BitcodeWriter::writeModule(const Module &M,
5330                                 bool ShouldPreserveUseListOrder,
5331                                 const ModuleSummaryIndex *Index,
5332                                 bool GenerateHash, ModuleHash *ModHash) {
5333   assert(!WroteStrtab);
5334 
5335   // The Mods vector is used by irsymtab::build, which requires non-const
5336   // Modules in case it needs to materialize metadata. But the bitcode writer
5337   // requires that the module is materialized, so we can cast to non-const here,
5338   // after checking that it is in fact materialized.
5339   assert(M.isMaterialized());
5340   Mods.push_back(const_cast<Module *>(&M));
5341 
5342   ModuleBitcodeWriter ModuleWriter(M, StrtabBuilder, *Stream,
5343                                    ShouldPreserveUseListOrder, Index,
5344                                    GenerateHash, ModHash);
5345   ModuleWriter.write();
5346 }
5347 
5348 void BitcodeWriter::writeIndex(
5349     const ModuleSummaryIndex *Index,
5350     const ModuleToSummariesForIndexTy *ModuleToSummariesForIndex,
5351     const GVSummaryPtrSet *DecSummaries) {
5352   IndexBitcodeWriter IndexWriter(*Stream, StrtabBuilder, *Index, DecSummaries,
5353                                  ModuleToSummariesForIndex);
5354   IndexWriter.write();
5355 }
5356 
5357 /// Write the specified module to the specified output stream.
5358 void llvm::WriteBitcodeToFile(const Module &M, raw_ostream &Out,
5359                               bool ShouldPreserveUseListOrder,
5360                               const ModuleSummaryIndex *Index,
5361                               bool GenerateHash, ModuleHash *ModHash) {
5362   auto Write = [&](BitcodeWriter &Writer) {
5363     Writer.writeModule(M, ShouldPreserveUseListOrder, Index, GenerateHash,
5364                        ModHash);
5365     Writer.writeSymtab();
5366     Writer.writeStrtab();
5367   };
5368   Triple TT(M.getTargetTriple());
5369   if (TT.isOSDarwin() || TT.isOSBinFormatMachO()) {
5370     // If this is darwin or another generic macho target, reserve space for the
5371     // header. Note that the header is computed *after* the output is known, so
5372     // we currently explicitly use a buffer, write to it, and then subsequently
5373     // flush to Out.
5374     SmallVector<char, 0> Buffer;
5375     Buffer.reserve(256 * 1024);
5376     Buffer.insert(Buffer.begin(), BWH_HeaderSize, 0);
5377     BitcodeWriter Writer(Buffer);
5378     Write(Writer);
5379     emitDarwinBCHeaderAndTrailer(Buffer, TT);
5380     Out.write(Buffer.data(), Buffer.size());
5381   } else {
5382     BitcodeWriter Writer(Out);
5383     Write(Writer);
5384   }
5385 }
5386 
5387 void IndexBitcodeWriter::write() {
5388   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
5389 
5390   writeModuleVersion();
5391 
5392   // Write the module paths in the combined index.
5393   writeModStrings();
5394 
5395   // Write the summary combined index records.
5396   writeCombinedGlobalValueSummary();
5397 
5398   Stream.ExitBlock();
5399 }
5400 
5401 // Write the specified module summary index to the given raw output stream,
5402 // where it will be written in a new bitcode block. This is used when
5403 // writing the combined index file for ThinLTO. When writing a subset of the
5404 // index for a distributed backend, provide a \p ModuleToSummariesForIndex map.
5405 void llvm::writeIndexToFile(
5406     const ModuleSummaryIndex &Index, raw_ostream &Out,
5407     const ModuleToSummariesForIndexTy *ModuleToSummariesForIndex,
5408     const GVSummaryPtrSet *DecSummaries) {
5409   SmallVector<char, 0> Buffer;
5410   Buffer.reserve(256 * 1024);
5411 
5412   BitcodeWriter Writer(Buffer);
5413   Writer.writeIndex(&Index, ModuleToSummariesForIndex, DecSummaries);
5414   Writer.writeStrtab();
5415 
5416   Out.write((char *)&Buffer.front(), Buffer.size());
5417 }
5418 
5419 namespace {
5420 
5421 /// Class to manage the bitcode writing for a thin link bitcode file.
5422 class ThinLinkBitcodeWriter : public ModuleBitcodeWriterBase {
5423   /// ModHash is for use in ThinLTO incremental build, generated while writing
5424   /// the module bitcode file.
5425   const ModuleHash *ModHash;
5426 
5427 public:
5428   ThinLinkBitcodeWriter(const Module &M, StringTableBuilder &StrtabBuilder,
5429                         BitstreamWriter &Stream,
5430                         const ModuleSummaryIndex &Index,
5431                         const ModuleHash &ModHash)
5432       : ModuleBitcodeWriterBase(M, StrtabBuilder, Stream,
5433                                 /*ShouldPreserveUseListOrder=*/false, &Index),
5434         ModHash(&ModHash) {}
5435 
5436   void write();
5437 
5438 private:
5439   void writeSimplifiedModuleInfo();
5440 };
5441 
5442 } // end anonymous namespace
5443 
5444 // This function writes a simpilified module info for thin link bitcode file.
5445 // It only contains the source file name along with the name(the offset and
5446 // size in strtab) and linkage for global values. For the global value info
5447 // entry, in order to keep linkage at offset 5, there are three zeros used
5448 // as padding.
5449 void ThinLinkBitcodeWriter::writeSimplifiedModuleInfo() {
5450   SmallVector<unsigned, 64> Vals;
5451   // Emit the module's source file name.
5452   {
5453     StringEncoding Bits = getStringEncoding(M.getSourceFileName());
5454     BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
5455     if (Bits == SE_Char6)
5456       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
5457     else if (Bits == SE_Fixed7)
5458       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
5459 
5460     // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
5461     auto Abbv = std::make_shared<BitCodeAbbrev>();
5462     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
5463     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
5464     Abbv->Add(AbbrevOpToUse);
5465     unsigned FilenameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
5466 
5467     for (const auto P : M.getSourceFileName())
5468       Vals.push_back((unsigned char)P);
5469 
5470     Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
5471     Vals.clear();
5472   }
5473 
5474   // Emit the global variable information.
5475   for (const GlobalVariable &GV : M.globals()) {
5476     // GLOBALVAR: [strtab offset, strtab size, 0, 0, 0, linkage]
5477     Vals.push_back(StrtabBuilder.add(GV.getName()));
5478     Vals.push_back(GV.getName().size());
5479     Vals.push_back(0);
5480     Vals.push_back(0);
5481     Vals.push_back(0);
5482     Vals.push_back(getEncodedLinkage(GV));
5483 
5484     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals);
5485     Vals.clear();
5486   }
5487 
5488   // Emit the function proto information.
5489   for (const Function &F : M) {
5490     // FUNCTION:  [strtab offset, strtab size, 0, 0, 0, linkage]
5491     Vals.push_back(StrtabBuilder.add(F.getName()));
5492     Vals.push_back(F.getName().size());
5493     Vals.push_back(0);
5494     Vals.push_back(0);
5495     Vals.push_back(0);
5496     Vals.push_back(getEncodedLinkage(F));
5497 
5498     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals);
5499     Vals.clear();
5500   }
5501 
5502   // Emit the alias information.
5503   for (const GlobalAlias &A : M.aliases()) {
5504     // ALIAS: [strtab offset, strtab size, 0, 0, 0, linkage]
5505     Vals.push_back(StrtabBuilder.add(A.getName()));
5506     Vals.push_back(A.getName().size());
5507     Vals.push_back(0);
5508     Vals.push_back(0);
5509     Vals.push_back(0);
5510     Vals.push_back(getEncodedLinkage(A));
5511 
5512     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals);
5513     Vals.clear();
5514   }
5515 
5516   // Emit the ifunc information.
5517   for (const GlobalIFunc &I : M.ifuncs()) {
5518     // IFUNC: [strtab offset, strtab size, 0, 0, 0, linkage]
5519     Vals.push_back(StrtabBuilder.add(I.getName()));
5520     Vals.push_back(I.getName().size());
5521     Vals.push_back(0);
5522     Vals.push_back(0);
5523     Vals.push_back(0);
5524     Vals.push_back(getEncodedLinkage(I));
5525 
5526     Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
5527     Vals.clear();
5528   }
5529 }
5530 
5531 void ThinLinkBitcodeWriter::write() {
5532   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
5533 
5534   writeModuleVersion();
5535 
5536   writeSimplifiedModuleInfo();
5537 
5538   writePerModuleGlobalValueSummary();
5539 
5540   // Write module hash.
5541   Stream.EmitRecord(bitc::MODULE_CODE_HASH, ArrayRef<uint32_t>(*ModHash));
5542 
5543   Stream.ExitBlock();
5544 }
5545 
5546 void BitcodeWriter::writeThinLinkBitcode(const Module &M,
5547                                          const ModuleSummaryIndex &Index,
5548                                          const ModuleHash &ModHash) {
5549   assert(!WroteStrtab);
5550 
5551   // The Mods vector is used by irsymtab::build, which requires non-const
5552   // Modules in case it needs to materialize metadata. But the bitcode writer
5553   // requires that the module is materialized, so we can cast to non-const here,
5554   // after checking that it is in fact materialized.
5555   assert(M.isMaterialized());
5556   Mods.push_back(const_cast<Module *>(&M));
5557 
5558   ThinLinkBitcodeWriter ThinLinkWriter(M, StrtabBuilder, *Stream, Index,
5559                                        ModHash);
5560   ThinLinkWriter.write();
5561 }
5562 
5563 // Write the specified thin link bitcode file to the given raw output stream,
5564 // where it will be written in a new bitcode block. This is used when
5565 // writing the per-module index file for ThinLTO.
5566 void llvm::writeThinLinkBitcodeToFile(const Module &M, raw_ostream &Out,
5567                                       const ModuleSummaryIndex &Index,
5568                                       const ModuleHash &ModHash) {
5569   SmallVector<char, 0> Buffer;
5570   Buffer.reserve(256 * 1024);
5571 
5572   BitcodeWriter Writer(Buffer);
5573   Writer.writeThinLinkBitcode(M, Index, ModHash);
5574   Writer.writeSymtab();
5575   Writer.writeStrtab();
5576 
5577   Out.write((char *)&Buffer.front(), Buffer.size());
5578 }
5579 
5580 static const char *getSectionNameForBitcode(const Triple &T) {
5581   switch (T.getObjectFormat()) {
5582   case Triple::MachO:
5583     return "__LLVM,__bitcode";
5584   case Triple::COFF:
5585   case Triple::ELF:
5586   case Triple::Wasm:
5587   case Triple::UnknownObjectFormat:
5588     return ".llvmbc";
5589   case Triple::GOFF:
5590     llvm_unreachable("GOFF is not yet implemented");
5591     break;
5592   case Triple::SPIRV:
5593     if (T.getVendor() == Triple::AMD)
5594       return ".llvmbc";
5595     llvm_unreachable("SPIRV is not yet implemented");
5596     break;
5597   case Triple::XCOFF:
5598     llvm_unreachable("XCOFF is not yet implemented");
5599     break;
5600   case Triple::DXContainer:
5601     llvm_unreachable("DXContainer is not yet implemented");
5602     break;
5603   }
5604   llvm_unreachable("Unimplemented ObjectFormatType");
5605 }
5606 
5607 static const char *getSectionNameForCommandline(const Triple &T) {
5608   switch (T.getObjectFormat()) {
5609   case Triple::MachO:
5610     return "__LLVM,__cmdline";
5611   case Triple::COFF:
5612   case Triple::ELF:
5613   case Triple::Wasm:
5614   case Triple::UnknownObjectFormat:
5615     return ".llvmcmd";
5616   case Triple::GOFF:
5617     llvm_unreachable("GOFF is not yet implemented");
5618     break;
5619   case Triple::SPIRV:
5620     if (T.getVendor() == Triple::AMD)
5621       return ".llvmcmd";
5622     llvm_unreachable("SPIRV is not yet implemented");
5623     break;
5624   case Triple::XCOFF:
5625     llvm_unreachable("XCOFF is not yet implemented");
5626     break;
5627   case Triple::DXContainer:
5628     llvm_unreachable("DXC is not yet implemented");
5629     break;
5630   }
5631   llvm_unreachable("Unimplemented ObjectFormatType");
5632 }
5633 
5634 void llvm::embedBitcodeInModule(llvm::Module &M, llvm::MemoryBufferRef Buf,
5635                                 bool EmbedBitcode, bool EmbedCmdline,
5636                                 const std::vector<uint8_t> &CmdArgs) {
5637   // Save llvm.compiler.used and remove it.
5638   SmallVector<Constant *, 2> UsedArray;
5639   SmallVector<GlobalValue *, 4> UsedGlobals;
5640   GlobalVariable *Used = collectUsedGlobalVariables(M, UsedGlobals, true);
5641   Type *UsedElementType = Used ? Used->getValueType()->getArrayElementType()
5642                                : PointerType::getUnqual(M.getContext());
5643   for (auto *GV : UsedGlobals) {
5644     if (GV->getName() != "llvm.embedded.module" &&
5645         GV->getName() != "llvm.cmdline")
5646       UsedArray.push_back(
5647           ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
5648   }
5649   if (Used)
5650     Used->eraseFromParent();
5651 
5652   // Embed the bitcode for the llvm module.
5653   std::string Data;
5654   ArrayRef<uint8_t> ModuleData;
5655   Triple T(M.getTargetTriple());
5656 
5657   if (EmbedBitcode) {
5658     if (Buf.getBufferSize() == 0 ||
5659         !isBitcode((const unsigned char *)Buf.getBufferStart(),
5660                    (const unsigned char *)Buf.getBufferEnd())) {
5661       // If the input is LLVM Assembly, bitcode is produced by serializing
5662       // the module. Use-lists order need to be preserved in this case.
5663       llvm::raw_string_ostream OS(Data);
5664       llvm::WriteBitcodeToFile(M, OS, /* ShouldPreserveUseListOrder */ true);
5665       ModuleData =
5666           ArrayRef<uint8_t>((const uint8_t *)OS.str().data(), OS.str().size());
5667     } else
5668       // If the input is LLVM bitcode, write the input byte stream directly.
5669       ModuleData = ArrayRef<uint8_t>((const uint8_t *)Buf.getBufferStart(),
5670                                      Buf.getBufferSize());
5671   }
5672   llvm::Constant *ModuleConstant =
5673       llvm::ConstantDataArray::get(M.getContext(), ModuleData);
5674   llvm::GlobalVariable *GV = new llvm::GlobalVariable(
5675       M, ModuleConstant->getType(), true, llvm::GlobalValue::PrivateLinkage,
5676       ModuleConstant);
5677   GV->setSection(getSectionNameForBitcode(T));
5678   // Set alignment to 1 to prevent padding between two contributions from input
5679   // sections after linking.
5680   GV->setAlignment(Align(1));
5681   UsedArray.push_back(
5682       ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
5683   if (llvm::GlobalVariable *Old =
5684           M.getGlobalVariable("llvm.embedded.module", true)) {
5685     assert(Old->hasZeroLiveUses() &&
5686            "llvm.embedded.module can only be used once in llvm.compiler.used");
5687     GV->takeName(Old);
5688     Old->eraseFromParent();
5689   } else {
5690     GV->setName("llvm.embedded.module");
5691   }
5692 
5693   // Skip if only bitcode needs to be embedded.
5694   if (EmbedCmdline) {
5695     // Embed command-line options.
5696     ArrayRef<uint8_t> CmdData(const_cast<uint8_t *>(CmdArgs.data()),
5697                               CmdArgs.size());
5698     llvm::Constant *CmdConstant =
5699         llvm::ConstantDataArray::get(M.getContext(), CmdData);
5700     GV = new llvm::GlobalVariable(M, CmdConstant->getType(), true,
5701                                   llvm::GlobalValue::PrivateLinkage,
5702                                   CmdConstant);
5703     GV->setSection(getSectionNameForCommandline(T));
5704     GV->setAlignment(Align(1));
5705     UsedArray.push_back(
5706         ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
5707     if (llvm::GlobalVariable *Old = M.getGlobalVariable("llvm.cmdline", true)) {
5708       assert(Old->hasZeroLiveUses() &&
5709              "llvm.cmdline can only be used once in llvm.compiler.used");
5710       GV->takeName(Old);
5711       Old->eraseFromParent();
5712     } else {
5713       GV->setName("llvm.cmdline");
5714     }
5715   }
5716 
5717   if (UsedArray.empty())
5718     return;
5719 
5720   // Recreate llvm.compiler.used.
5721   ArrayType *ATy = ArrayType::get(UsedElementType, UsedArray.size());
5722   auto *NewUsed = new GlobalVariable(
5723       M, ATy, false, llvm::GlobalValue::AppendingLinkage,
5724       llvm::ConstantArray::get(ATy, UsedArray), "llvm.compiler.used");
5725   NewUsed->setSection("llvm.metadata");
5726 }
5727