xref: /llvm-project/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp (revision cceae7feda8e33194d1a6c5963bd4114bb8d2b36)
1 //===--- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ----------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // Bitcode writer implementation.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "ValueEnumerator.h"
15 #include "llvm/ADT/StringExtras.h"
16 #include "llvm/ADT/Triple.h"
17 #include "llvm/Bitcode/BitstreamWriter.h"
18 #include "llvm/Bitcode/LLVMBitCodes.h"
19 #include "llvm/Bitcode/ReaderWriter.h"
20 #include "llvm/IR/CallSite.h"
21 #include "llvm/IR/Constants.h"
22 #include "llvm/IR/DebugInfoMetadata.h"
23 #include "llvm/IR/DerivedTypes.h"
24 #include "llvm/IR/InlineAsm.h"
25 #include "llvm/IR/Instructions.h"
26 #include "llvm/IR/LLVMContext.h"
27 #include "llvm/IR/Module.h"
28 #include "llvm/IR/Operator.h"
29 #include "llvm/IR/UseListOrder.h"
30 #include "llvm/IR/ValueSymbolTable.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/MathExtras.h"
33 #include "llvm/Support/Program.h"
34 #include "llvm/Support/SHA1.h"
35 #include "llvm/Support/raw_ostream.h"
36 #include <cctype>
37 #include <map>
38 using namespace llvm;
39 
40 namespace {
41 /// These are manifest constants used by the bitcode writer. They do not need to
42 /// be kept in sync with the reader, but need to be consistent within this file.
43 enum {
44   // VALUE_SYMTAB_BLOCK abbrev id's.
45   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
46   VST_ENTRY_7_ABBREV,
47   VST_ENTRY_6_ABBREV,
48   VST_BBENTRY_6_ABBREV,
49 
50   // CONSTANTS_BLOCK abbrev id's.
51   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
52   CONSTANTS_INTEGER_ABBREV,
53   CONSTANTS_CE_CAST_Abbrev,
54   CONSTANTS_NULL_Abbrev,
55 
56   // FUNCTION_BLOCK abbrev id's.
57   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
58   FUNCTION_INST_BINOP_ABBREV,
59   FUNCTION_INST_BINOP_FLAGS_ABBREV,
60   FUNCTION_INST_CAST_ABBREV,
61   FUNCTION_INST_RET_VOID_ABBREV,
62   FUNCTION_INST_RET_VAL_ABBREV,
63   FUNCTION_INST_UNREACHABLE_ABBREV,
64   FUNCTION_INST_GEP_ABBREV,
65 };
66 
67 /// Abstract class to manage the bitcode writing, subclassed for each bitcode
68 /// file type. Owns the BitstreamWriter, and includes the main entry point for
69 /// writing.
70 class BitcodeWriter {
71 protected:
72   /// Pointer to the buffer allocated by caller for bitcode writing.
73   const SmallVectorImpl<char> &Buffer;
74 
75   /// The stream created and owned by the BitodeWriter.
76   BitstreamWriter Stream;
77 
78   /// Saves the offset of the VSTOffset record that must eventually be
79   /// backpatched with the offset of the actual VST.
80   uint64_t VSTOffsetPlaceholder = 0;
81 
82 public:
83   /// Constructs a BitcodeWriter object, and initializes a BitstreamRecord,
84   /// writing to the provided \p Buffer.
85   BitcodeWriter(SmallVectorImpl<char> &Buffer)
86       : Buffer(Buffer), Stream(Buffer) {}
87 
88   virtual ~BitcodeWriter() = default;
89 
90   /// Main entry point to write the bitcode file, which writes the bitcode
91   /// header and will then invoke the virtual writeBlocks() method.
92   void write();
93 
94 private:
95   /// Derived classes must implement this to write the corresponding blocks for
96   /// that bitcode file type.
97   virtual void writeBlocks() = 0;
98 
99 protected:
100   bool hasVSTOffsetPlaceholder() { return VSTOffsetPlaceholder != 0; }
101   void writeValueSymbolTableForwardDecl();
102   void writeBitcodeHeader();
103 };
104 
105 /// Class to manage the bitcode writing for a module.
106 class ModuleBitcodeWriter : public BitcodeWriter {
107   /// The Module to write to bitcode.
108   const Module &M;
109 
110   /// Enumerates ids for all values in the module.
111   ValueEnumerator VE;
112 
113   /// Optional per-module index to write for ThinLTO.
114   const ModuleSummaryIndex *Index;
115 
116   /// True if a module hash record should be written.
117   bool GenerateHash;
118 
119   /// The start bit of the module block, for use in generating a module hash
120   uint64_t BitcodeStartBit = 0;
121 
122 public:
123   /// Constructs a ModuleBitcodeWriter object for the given Module,
124   /// writing to the provided \p Buffer.
125   ModuleBitcodeWriter(const Module *M, SmallVectorImpl<char> &Buffer,
126                       bool ShouldPreserveUseListOrder,
127                       const ModuleSummaryIndex *Index, bool GenerateHash)
128       : BitcodeWriter(Buffer), M(*M), VE(*M, ShouldPreserveUseListOrder),
129         Index(Index), GenerateHash(GenerateHash) {
130     // Save the start bit of the actual bitcode, in case there is space
131     // saved at the start for the darwin header above. The reader stream
132     // will start at the bitcode, and we need the offset of the VST
133     // to line up.
134     BitcodeStartBit = Stream.GetCurrentBitNo();
135   }
136 
137 private:
138   /// Main entry point for writing a module to bitcode, invoked by
139   /// BitcodeWriter::write() after it writes the header.
140   void writeBlocks() override;
141 
142   /// Create the "IDENTIFICATION_BLOCK_ID" containing a single string with the
143   /// current llvm version, and a record for the epoch number.
144   void writeIdentificationBlock();
145 
146   /// Emit the current module to the bitstream.
147   void writeModule();
148 
149   uint64_t bitcodeStartBit() { return BitcodeStartBit; }
150 
151   void writeStringRecord(unsigned Code, StringRef Str, unsigned AbbrevToUse);
152   void writeAttributeGroupTable();
153   void writeAttributeTable();
154   void writeTypeTable();
155   void writeComdats();
156   void writeModuleInfo();
157   void writeValueAsMetadata(const ValueAsMetadata *MD,
158                             SmallVectorImpl<uint64_t> &Record);
159   void writeMDTuple(const MDTuple *N, SmallVectorImpl<uint64_t> &Record,
160                     unsigned Abbrev);
161   unsigned createDILocationAbbrev();
162   void writeDILocation(const DILocation *N, SmallVectorImpl<uint64_t> &Record,
163                        unsigned &Abbrev);
164   unsigned createGenericDINodeAbbrev();
165   void writeGenericDINode(const GenericDINode *N,
166                           SmallVectorImpl<uint64_t> &Record, unsigned &Abbrev);
167   void writeDISubrange(const DISubrange *N, SmallVectorImpl<uint64_t> &Record,
168                        unsigned Abbrev);
169   void writeDIEnumerator(const DIEnumerator *N,
170                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
171   void writeDIBasicType(const DIBasicType *N, SmallVectorImpl<uint64_t> &Record,
172                         unsigned Abbrev);
173   void writeDIDerivedType(const DIDerivedType *N,
174                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
175   void writeDICompositeType(const DICompositeType *N,
176                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
177   void writeDISubroutineType(const DISubroutineType *N,
178                              SmallVectorImpl<uint64_t> &Record,
179                              unsigned Abbrev);
180   void writeDIFile(const DIFile *N, SmallVectorImpl<uint64_t> &Record,
181                    unsigned Abbrev);
182   void writeDICompileUnit(const DICompileUnit *N,
183                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
184   void writeDISubprogram(const DISubprogram *N,
185                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
186   void writeDILexicalBlock(const DILexicalBlock *N,
187                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
188   void writeDILexicalBlockFile(const DILexicalBlockFile *N,
189                                SmallVectorImpl<uint64_t> &Record,
190                                unsigned Abbrev);
191   void writeDINamespace(const DINamespace *N, SmallVectorImpl<uint64_t> &Record,
192                         unsigned Abbrev);
193   void writeDIMacro(const DIMacro *N, SmallVectorImpl<uint64_t> &Record,
194                     unsigned Abbrev);
195   void writeDIMacroFile(const DIMacroFile *N, SmallVectorImpl<uint64_t> &Record,
196                         unsigned Abbrev);
197   void writeDIModule(const DIModule *N, SmallVectorImpl<uint64_t> &Record,
198                      unsigned Abbrev);
199   void writeDITemplateTypeParameter(const DITemplateTypeParameter *N,
200                                     SmallVectorImpl<uint64_t> &Record,
201                                     unsigned Abbrev);
202   void writeDITemplateValueParameter(const DITemplateValueParameter *N,
203                                      SmallVectorImpl<uint64_t> &Record,
204                                      unsigned Abbrev);
205   void writeDIGlobalVariable(const DIGlobalVariable *N,
206                              SmallVectorImpl<uint64_t> &Record,
207                              unsigned Abbrev);
208   void writeDILocalVariable(const DILocalVariable *N,
209                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
210   void writeDIExpression(const DIExpression *N,
211                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
212   void writeDIObjCProperty(const DIObjCProperty *N,
213                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
214   void writeDIImportedEntity(const DIImportedEntity *N,
215                              SmallVectorImpl<uint64_t> &Record,
216                              unsigned Abbrev);
217   unsigned createNamedMetadataAbbrev();
218   void writeNamedMetadata(SmallVectorImpl<uint64_t> &Record);
219   unsigned createMetadataStringsAbbrev();
220   void writeMetadataStrings(ArrayRef<const Metadata *> Strings,
221                             SmallVectorImpl<uint64_t> &Record);
222   void writeMetadataRecords(ArrayRef<const Metadata *> MDs,
223                             SmallVectorImpl<uint64_t> &Record);
224   void writeModuleMetadata();
225   void writeFunctionMetadata(const Function &F);
226   void writeFunctionMetadataAttachment(const Function &F);
227   void writeGlobalVariableMetadataAttachment(const GlobalVariable &GV);
228   void pushGlobalMetadataAttachment(SmallVectorImpl<uint64_t> &Record,
229                                     const GlobalObject &GO);
230   void writeModuleMetadataStore();
231   void writeOperandBundleTags();
232   void writeConstants(unsigned FirstVal, unsigned LastVal, bool isGlobal);
233   void writeModuleConstants();
234   bool pushValueAndType(const Value *V, unsigned InstID,
235                         SmallVectorImpl<unsigned> &Vals);
236   void writeOperandBundles(ImmutableCallSite CS, unsigned InstID);
237   void pushValue(const Value *V, unsigned InstID,
238                  SmallVectorImpl<unsigned> &Vals);
239   void pushValueSigned(const Value *V, unsigned InstID,
240                        SmallVectorImpl<uint64_t> &Vals);
241   void writeInstruction(const Instruction &I, unsigned InstID,
242                         SmallVectorImpl<unsigned> &Vals);
243   void writeValueSymbolTable(
244       const ValueSymbolTable &VST, bool IsModuleLevel = false,
245       DenseMap<const Function *, uint64_t> *FunctionToBitcodeIndex = nullptr);
246   void writeUseList(UseListOrder &&Order);
247   void writeUseListBlock(const Function *F);
248   void
249   writeFunction(const Function &F,
250                 DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
251   void writeBlockInfo();
252   void writePerModuleFunctionSummaryRecord(SmallVector<uint64_t, 64> &NameVals,
253                                            GlobalValueSummary *Summary,
254                                            unsigned ValueID,
255                                            unsigned FSCallsAbbrev,
256                                            unsigned FSCallsProfileAbbrev,
257                                            const Function &F);
258   void writeModuleLevelReferences(const GlobalVariable &V,
259                                   SmallVector<uint64_t, 64> &NameVals,
260                                   unsigned FSModRefsAbbrev);
261   void writePerModuleGlobalValueSummary();
262   void writeModuleHash(size_t BlockStartPos);
263 };
264 
265 /// Class to manage the bitcode writing for a combined index.
266 class IndexBitcodeWriter : public BitcodeWriter {
267   /// The combined index to write to bitcode.
268   const ModuleSummaryIndex &Index;
269 
270   /// When writing a subset of the index for distributed backends, client
271   /// provides a map of modules to the corresponding GUIDs/summaries to write.
272   std::map<std::string, GVSummaryMapTy> *ModuleToSummariesForIndex;
273 
274   /// Map that holds the correspondence between the GUID used in the combined
275   /// index and a value id generated by this class to use in references.
276   std::map<GlobalValue::GUID, unsigned> GUIDToValueIdMap;
277 
278   /// Tracks the last value id recorded in the GUIDToValueMap.
279   unsigned GlobalValueId = 0;
280 
281 public:
282   /// Constructs a IndexBitcodeWriter object for the given combined index,
283   /// writing to the provided \p Buffer. When writing a subset of the index
284   /// for a distributed backend, provide a \p ModuleToSummariesForIndex map.
285   IndexBitcodeWriter(SmallVectorImpl<char> &Buffer,
286                      const ModuleSummaryIndex &Index,
287                      std::map<std::string, GVSummaryMapTy>
288                          *ModuleToSummariesForIndex = nullptr)
289       : BitcodeWriter(Buffer), Index(Index),
290         ModuleToSummariesForIndex(ModuleToSummariesForIndex) {
291     // Assign unique value ids to all summaries to be written, for use
292     // in writing out the call graph edges. Save the mapping from GUID
293     // to the new global value id to use when writing those edges, which
294     // are currently saved in the index in terms of GUID.
295     for (const auto &I : *this)
296       GUIDToValueIdMap[I.first] = ++GlobalValueId;
297   }
298 
299   /// The below iterator returns the GUID and associated summary.
300   typedef std::pair<GlobalValue::GUID, GlobalValueSummary *> GVInfo;
301 
302   /// Iterator over the value GUID and summaries to be written to bitcode,
303   /// hides the details of whether they are being pulled from the entire
304   /// index or just those in a provided ModuleToSummariesForIndex map.
305   class iterator
306       : public llvm::iterator_facade_base<iterator, std::forward_iterator_tag,
307                                           GVInfo> {
308     /// Enables access to parent class.
309     const IndexBitcodeWriter &Writer;
310 
311     // Iterators used when writing only those summaries in a provided
312     // ModuleToSummariesForIndex map:
313 
314     /// Points to the last element in outer ModuleToSummariesForIndex map.
315     std::map<std::string, GVSummaryMapTy>::iterator ModuleSummariesBack;
316     /// Iterator on outer ModuleToSummariesForIndex map.
317     std::map<std::string, GVSummaryMapTy>::iterator ModuleSummariesIter;
318     /// Iterator on an inner global variable summary map.
319     GVSummaryMapTy::iterator ModuleGVSummariesIter;
320 
321     // Iterators used when writing all summaries in the index:
322 
323     /// Points to the last element in the Index outer GlobalValueMap.
324     const_gvsummary_iterator IndexSummariesBack;
325     /// Iterator on outer GlobalValueMap.
326     const_gvsummary_iterator IndexSummariesIter;
327     /// Iterator on an inner GlobalValueSummaryList.
328     GlobalValueSummaryList::const_iterator IndexGVSummariesIter;
329 
330   public:
331     /// Construct iterator from parent \p Writer and indicate if we are
332     /// constructing the end iterator.
333     iterator(const IndexBitcodeWriter &Writer, bool IsAtEnd) : Writer(Writer) {
334       // Set up the appropriate set of iterators given whether we are writing
335       // the full index or just a subset.
336       // Can't setup the Back or inner iterators if the corresponding map
337       // is empty. This will be handled specially in operator== as well.
338       if (Writer.ModuleToSummariesForIndex &&
339           !Writer.ModuleToSummariesForIndex->empty()) {
340         for (ModuleSummariesBack = Writer.ModuleToSummariesForIndex->begin();
341              std::next(ModuleSummariesBack) !=
342              Writer.ModuleToSummariesForIndex->end();
343              ModuleSummariesBack++)
344           ;
345         ModuleSummariesIter = !IsAtEnd
346                                   ? Writer.ModuleToSummariesForIndex->begin()
347                                   : ModuleSummariesBack;
348         ModuleGVSummariesIter = !IsAtEnd ? ModuleSummariesIter->second.begin()
349                                          : ModuleSummariesBack->second.end();
350       } else if (!Writer.ModuleToSummariesForIndex &&
351                  Writer.Index.begin() != Writer.Index.end()) {
352         for (IndexSummariesBack = Writer.Index.begin();
353              std::next(IndexSummariesBack) != Writer.Index.end();
354              IndexSummariesBack++)
355           ;
356         IndexSummariesIter =
357             !IsAtEnd ? Writer.Index.begin() : IndexSummariesBack;
358         IndexGVSummariesIter = !IsAtEnd ? IndexSummariesIter->second.begin()
359                                         : IndexSummariesBack->second.end();
360       }
361     }
362 
363     /// Increment the appropriate set of iterators.
364     iterator &operator++() {
365       // First the inner iterator is incremented, then if it is at the end
366       // and there are more outer iterations to go, the inner is reset to
367       // the start of the next inner list.
368       if (Writer.ModuleToSummariesForIndex) {
369         ++ModuleGVSummariesIter;
370         if (ModuleGVSummariesIter == ModuleSummariesIter->second.end() &&
371             ModuleSummariesIter != ModuleSummariesBack) {
372           ++ModuleSummariesIter;
373           ModuleGVSummariesIter = ModuleSummariesIter->second.begin();
374         }
375       } else {
376         ++IndexGVSummariesIter;
377         if (IndexGVSummariesIter == IndexSummariesIter->second.end() &&
378             IndexSummariesIter != IndexSummariesBack) {
379           ++IndexSummariesIter;
380           IndexGVSummariesIter = IndexSummariesIter->second.begin();
381         }
382       }
383       return *this;
384     }
385 
386     /// Access the <GUID,GlobalValueSummary*> pair corresponding to the current
387     /// outer and inner iterator positions.
388     GVInfo operator*() {
389       if (Writer.ModuleToSummariesForIndex)
390         return std::make_pair(ModuleGVSummariesIter->first,
391                               ModuleGVSummariesIter->second);
392       return std::make_pair(IndexSummariesIter->first,
393                             IndexGVSummariesIter->get());
394     }
395 
396     /// Checks if the iterators are equal, with special handling for empty
397     /// indexes.
398     bool operator==(const iterator &RHS) const {
399       if (Writer.ModuleToSummariesForIndex) {
400         // First ensure that both are writing the same subset.
401         if (Writer.ModuleToSummariesForIndex !=
402             RHS.Writer.ModuleToSummariesForIndex)
403           return false;
404         // Already determined above that maps are the same, so if one is
405         // empty, they both are.
406         if (Writer.ModuleToSummariesForIndex->empty())
407           return true;
408         // Ensure the ModuleGVSummariesIter are iterating over the same
409         // container before checking them below.
410         if (ModuleSummariesIter != RHS.ModuleSummariesIter)
411           return false;
412         return ModuleGVSummariesIter == RHS.ModuleGVSummariesIter;
413       }
414       // First ensure RHS also writing the full index, and that both are
415       // writing the same full index.
416       if (RHS.Writer.ModuleToSummariesForIndex ||
417           &Writer.Index != &RHS.Writer.Index)
418         return false;
419       // Already determined above that maps are the same, so if one is
420       // empty, they both are.
421       if (Writer.Index.begin() == Writer.Index.end())
422         return true;
423       // Ensure the IndexGVSummariesIter are iterating over the same
424       // container before checking them below.
425       if (IndexSummariesIter != RHS.IndexSummariesIter)
426         return false;
427       return IndexGVSummariesIter == RHS.IndexGVSummariesIter;
428     }
429   };
430 
431   /// Obtain the start iterator over the summaries to be written.
432   iterator begin() { return iterator(*this, /*IsAtEnd=*/false); }
433   /// Obtain the end iterator over the summaries to be written.
434   iterator end() { return iterator(*this, /*IsAtEnd=*/true); }
435 
436 private:
437   /// Main entry point for writing a combined index to bitcode, invoked by
438   /// BitcodeWriter::write() after it writes the header.
439   void writeBlocks() override;
440 
441   void writeIndex();
442   void writeModStrings();
443   void writeCombinedValueSymbolTable();
444   void writeCombinedGlobalValueSummary();
445 
446   /// Indicates whether the provided \p ModulePath should be written into
447   /// the module string table, e.g. if full index written or if it is in
448   /// the provided subset.
449   bool doIncludeModule(StringRef ModulePath) {
450     return !ModuleToSummariesForIndex ||
451            ModuleToSummariesForIndex->count(ModulePath);
452   }
453 
454   bool hasValueId(GlobalValue::GUID ValGUID) {
455     const auto &VMI = GUIDToValueIdMap.find(ValGUID);
456     return VMI != GUIDToValueIdMap.end();
457   }
458   unsigned getValueId(GlobalValue::GUID ValGUID) {
459     const auto &VMI = GUIDToValueIdMap.find(ValGUID);
460     // If this GUID doesn't have an entry, assign one.
461     if (VMI == GUIDToValueIdMap.end()) {
462       GUIDToValueIdMap[ValGUID] = ++GlobalValueId;
463       return GlobalValueId;
464     } else {
465       return VMI->second;
466     }
467   }
468   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
469 };
470 } // end anonymous namespace
471 
472 static unsigned getEncodedCastOpcode(unsigned Opcode) {
473   switch (Opcode) {
474   default: llvm_unreachable("Unknown cast instruction!");
475   case Instruction::Trunc   : return bitc::CAST_TRUNC;
476   case Instruction::ZExt    : return bitc::CAST_ZEXT;
477   case Instruction::SExt    : return bitc::CAST_SEXT;
478   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
479   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
480   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
481   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
482   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
483   case Instruction::FPExt   : return bitc::CAST_FPEXT;
484   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
485   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
486   case Instruction::BitCast : return bitc::CAST_BITCAST;
487   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
488   }
489 }
490 
491 static unsigned getEncodedBinaryOpcode(unsigned Opcode) {
492   switch (Opcode) {
493   default: llvm_unreachable("Unknown binary instruction!");
494   case Instruction::Add:
495   case Instruction::FAdd: return bitc::BINOP_ADD;
496   case Instruction::Sub:
497   case Instruction::FSub: return bitc::BINOP_SUB;
498   case Instruction::Mul:
499   case Instruction::FMul: return bitc::BINOP_MUL;
500   case Instruction::UDiv: return bitc::BINOP_UDIV;
501   case Instruction::FDiv:
502   case Instruction::SDiv: return bitc::BINOP_SDIV;
503   case Instruction::URem: return bitc::BINOP_UREM;
504   case Instruction::FRem:
505   case Instruction::SRem: return bitc::BINOP_SREM;
506   case Instruction::Shl:  return bitc::BINOP_SHL;
507   case Instruction::LShr: return bitc::BINOP_LSHR;
508   case Instruction::AShr: return bitc::BINOP_ASHR;
509   case Instruction::And:  return bitc::BINOP_AND;
510   case Instruction::Or:   return bitc::BINOP_OR;
511   case Instruction::Xor:  return bitc::BINOP_XOR;
512   }
513 }
514 
515 static unsigned getEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
516   switch (Op) {
517   default: llvm_unreachable("Unknown RMW operation!");
518   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
519   case AtomicRMWInst::Add: return bitc::RMW_ADD;
520   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
521   case AtomicRMWInst::And: return bitc::RMW_AND;
522   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
523   case AtomicRMWInst::Or: return bitc::RMW_OR;
524   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
525   case AtomicRMWInst::Max: return bitc::RMW_MAX;
526   case AtomicRMWInst::Min: return bitc::RMW_MIN;
527   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
528   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
529   }
530 }
531 
532 static unsigned getEncodedOrdering(AtomicOrdering Ordering) {
533   switch (Ordering) {
534   case AtomicOrdering::NotAtomic: return bitc::ORDERING_NOTATOMIC;
535   case AtomicOrdering::Unordered: return bitc::ORDERING_UNORDERED;
536   case AtomicOrdering::Monotonic: return bitc::ORDERING_MONOTONIC;
537   case AtomicOrdering::Acquire: return bitc::ORDERING_ACQUIRE;
538   case AtomicOrdering::Release: return bitc::ORDERING_RELEASE;
539   case AtomicOrdering::AcquireRelease: return bitc::ORDERING_ACQREL;
540   case AtomicOrdering::SequentiallyConsistent: return bitc::ORDERING_SEQCST;
541   }
542   llvm_unreachable("Invalid ordering");
543 }
544 
545 static unsigned getEncodedSynchScope(SynchronizationScope SynchScope) {
546   switch (SynchScope) {
547   case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
548   case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
549   }
550   llvm_unreachable("Invalid synch scope");
551 }
552 
553 void ModuleBitcodeWriter::writeStringRecord(unsigned Code, StringRef Str,
554                                             unsigned AbbrevToUse) {
555   SmallVector<unsigned, 64> Vals;
556 
557   // Code: [strchar x N]
558   for (unsigned i = 0, e = Str.size(); i != e; ++i) {
559     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
560       AbbrevToUse = 0;
561     Vals.push_back(Str[i]);
562   }
563 
564   // Emit the finished record.
565   Stream.EmitRecord(Code, Vals, AbbrevToUse);
566 }
567 
568 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
569   switch (Kind) {
570   case Attribute::Alignment:
571     return bitc::ATTR_KIND_ALIGNMENT;
572   case Attribute::AllocSize:
573     return bitc::ATTR_KIND_ALLOC_SIZE;
574   case Attribute::AlwaysInline:
575     return bitc::ATTR_KIND_ALWAYS_INLINE;
576   case Attribute::ArgMemOnly:
577     return bitc::ATTR_KIND_ARGMEMONLY;
578   case Attribute::Builtin:
579     return bitc::ATTR_KIND_BUILTIN;
580   case Attribute::ByVal:
581     return bitc::ATTR_KIND_BY_VAL;
582   case Attribute::Convergent:
583     return bitc::ATTR_KIND_CONVERGENT;
584   case Attribute::InAlloca:
585     return bitc::ATTR_KIND_IN_ALLOCA;
586   case Attribute::Cold:
587     return bitc::ATTR_KIND_COLD;
588   case Attribute::InaccessibleMemOnly:
589     return bitc::ATTR_KIND_INACCESSIBLEMEM_ONLY;
590   case Attribute::InaccessibleMemOrArgMemOnly:
591     return bitc::ATTR_KIND_INACCESSIBLEMEM_OR_ARGMEMONLY;
592   case Attribute::InlineHint:
593     return bitc::ATTR_KIND_INLINE_HINT;
594   case Attribute::InReg:
595     return bitc::ATTR_KIND_IN_REG;
596   case Attribute::JumpTable:
597     return bitc::ATTR_KIND_JUMP_TABLE;
598   case Attribute::MinSize:
599     return bitc::ATTR_KIND_MIN_SIZE;
600   case Attribute::Naked:
601     return bitc::ATTR_KIND_NAKED;
602   case Attribute::Nest:
603     return bitc::ATTR_KIND_NEST;
604   case Attribute::NoAlias:
605     return bitc::ATTR_KIND_NO_ALIAS;
606   case Attribute::NoBuiltin:
607     return bitc::ATTR_KIND_NO_BUILTIN;
608   case Attribute::NoCapture:
609     return bitc::ATTR_KIND_NO_CAPTURE;
610   case Attribute::NoDuplicate:
611     return bitc::ATTR_KIND_NO_DUPLICATE;
612   case Attribute::NoImplicitFloat:
613     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
614   case Attribute::NoInline:
615     return bitc::ATTR_KIND_NO_INLINE;
616   case Attribute::NoRecurse:
617     return bitc::ATTR_KIND_NO_RECURSE;
618   case Attribute::NonLazyBind:
619     return bitc::ATTR_KIND_NON_LAZY_BIND;
620   case Attribute::NonNull:
621     return bitc::ATTR_KIND_NON_NULL;
622   case Attribute::Dereferenceable:
623     return bitc::ATTR_KIND_DEREFERENCEABLE;
624   case Attribute::DereferenceableOrNull:
625     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
626   case Attribute::NoRedZone:
627     return bitc::ATTR_KIND_NO_RED_ZONE;
628   case Attribute::NoReturn:
629     return bitc::ATTR_KIND_NO_RETURN;
630   case Attribute::NoUnwind:
631     return bitc::ATTR_KIND_NO_UNWIND;
632   case Attribute::OptimizeForSize:
633     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
634   case Attribute::OptimizeNone:
635     return bitc::ATTR_KIND_OPTIMIZE_NONE;
636   case Attribute::ReadNone:
637     return bitc::ATTR_KIND_READ_NONE;
638   case Attribute::ReadOnly:
639     return bitc::ATTR_KIND_READ_ONLY;
640   case Attribute::Returned:
641     return bitc::ATTR_KIND_RETURNED;
642   case Attribute::ReturnsTwice:
643     return bitc::ATTR_KIND_RETURNS_TWICE;
644   case Attribute::SExt:
645     return bitc::ATTR_KIND_S_EXT;
646   case Attribute::StackAlignment:
647     return bitc::ATTR_KIND_STACK_ALIGNMENT;
648   case Attribute::StackProtect:
649     return bitc::ATTR_KIND_STACK_PROTECT;
650   case Attribute::StackProtectReq:
651     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
652   case Attribute::StackProtectStrong:
653     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
654   case Attribute::SafeStack:
655     return bitc::ATTR_KIND_SAFESTACK;
656   case Attribute::StructRet:
657     return bitc::ATTR_KIND_STRUCT_RET;
658   case Attribute::SanitizeAddress:
659     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
660   case Attribute::SanitizeThread:
661     return bitc::ATTR_KIND_SANITIZE_THREAD;
662   case Attribute::SanitizeMemory:
663     return bitc::ATTR_KIND_SANITIZE_MEMORY;
664   case Attribute::SwiftError:
665     return bitc::ATTR_KIND_SWIFT_ERROR;
666   case Attribute::SwiftSelf:
667     return bitc::ATTR_KIND_SWIFT_SELF;
668   case Attribute::UWTable:
669     return bitc::ATTR_KIND_UW_TABLE;
670   case Attribute::ZExt:
671     return bitc::ATTR_KIND_Z_EXT;
672   case Attribute::EndAttrKinds:
673     llvm_unreachable("Can not encode end-attribute kinds marker.");
674   case Attribute::None:
675     llvm_unreachable("Can not encode none-attribute.");
676   }
677 
678   llvm_unreachable("Trying to encode unknown attribute");
679 }
680 
681 void ModuleBitcodeWriter::writeAttributeGroupTable() {
682   const std::vector<AttributeSet> &AttrGrps = VE.getAttributeGroups();
683   if (AttrGrps.empty()) return;
684 
685   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
686 
687   SmallVector<uint64_t, 64> Record;
688   for (unsigned i = 0, e = AttrGrps.size(); i != e; ++i) {
689     AttributeSet AS = AttrGrps[i];
690     for (unsigned i = 0, e = AS.getNumSlots(); i != e; ++i) {
691       AttributeSet A = AS.getSlotAttributes(i);
692 
693       Record.push_back(VE.getAttributeGroupID(A));
694       Record.push_back(AS.getSlotIndex(i));
695 
696       for (AttributeSet::iterator I = AS.begin(0), E = AS.end(0);
697            I != E; ++I) {
698         Attribute Attr = *I;
699         if (Attr.isEnumAttribute()) {
700           Record.push_back(0);
701           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
702         } else if (Attr.isIntAttribute()) {
703           Record.push_back(1);
704           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
705           Record.push_back(Attr.getValueAsInt());
706         } else {
707           StringRef Kind = Attr.getKindAsString();
708           StringRef Val = Attr.getValueAsString();
709 
710           Record.push_back(Val.empty() ? 3 : 4);
711           Record.append(Kind.begin(), Kind.end());
712           Record.push_back(0);
713           if (!Val.empty()) {
714             Record.append(Val.begin(), Val.end());
715             Record.push_back(0);
716           }
717         }
718       }
719 
720       Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
721       Record.clear();
722     }
723   }
724 
725   Stream.ExitBlock();
726 }
727 
728 void ModuleBitcodeWriter::writeAttributeTable() {
729   const std::vector<AttributeSet> &Attrs = VE.getAttributes();
730   if (Attrs.empty()) return;
731 
732   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
733 
734   SmallVector<uint64_t, 64> Record;
735   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
736     const AttributeSet &A = Attrs[i];
737     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
738       Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
739 
740     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
741     Record.clear();
742   }
743 
744   Stream.ExitBlock();
745 }
746 
747 /// WriteTypeTable - Write out the type table for a module.
748 void ModuleBitcodeWriter::writeTypeTable() {
749   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
750 
751   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
752   SmallVector<uint64_t, 64> TypeVals;
753 
754   uint64_t NumBits = VE.computeBitsRequiredForTypeIndicies();
755 
756   // Abbrev for TYPE_CODE_POINTER.
757   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
758   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
759   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
760   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
761   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
762 
763   // Abbrev for TYPE_CODE_FUNCTION.
764   Abbv = new BitCodeAbbrev();
765   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
766   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
767   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
768   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
769 
770   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
771 
772   // Abbrev for TYPE_CODE_STRUCT_ANON.
773   Abbv = new BitCodeAbbrev();
774   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
775   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
776   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
777   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
778 
779   unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
780 
781   // Abbrev for TYPE_CODE_STRUCT_NAME.
782   Abbv = new BitCodeAbbrev();
783   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
784   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
785   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
786   unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
787 
788   // Abbrev for TYPE_CODE_STRUCT_NAMED.
789   Abbv = new BitCodeAbbrev();
790   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
791   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
792   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
793   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
794 
795   unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
796 
797   // Abbrev for TYPE_CODE_ARRAY.
798   Abbv = new BitCodeAbbrev();
799   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
800   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
801   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
802 
803   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
804 
805   // Emit an entry count so the reader can reserve space.
806   TypeVals.push_back(TypeList.size());
807   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
808   TypeVals.clear();
809 
810   // Loop over all of the types, emitting each in turn.
811   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
812     Type *T = TypeList[i];
813     int AbbrevToUse = 0;
814     unsigned Code = 0;
815 
816     switch (T->getTypeID()) {
817     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
818     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
819     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
820     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
821     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
822     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
823     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
824     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
825     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
826     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
827     case Type::TokenTyID:     Code = bitc::TYPE_CODE_TOKEN;     break;
828     case Type::IntegerTyID:
829       // INTEGER: [width]
830       Code = bitc::TYPE_CODE_INTEGER;
831       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
832       break;
833     case Type::PointerTyID: {
834       PointerType *PTy = cast<PointerType>(T);
835       // POINTER: [pointee type, address space]
836       Code = bitc::TYPE_CODE_POINTER;
837       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
838       unsigned AddressSpace = PTy->getAddressSpace();
839       TypeVals.push_back(AddressSpace);
840       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
841       break;
842     }
843     case Type::FunctionTyID: {
844       FunctionType *FT = cast<FunctionType>(T);
845       // FUNCTION: [isvararg, retty, paramty x N]
846       Code = bitc::TYPE_CODE_FUNCTION;
847       TypeVals.push_back(FT->isVarArg());
848       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
849       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
850         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
851       AbbrevToUse = FunctionAbbrev;
852       break;
853     }
854     case Type::StructTyID: {
855       StructType *ST = cast<StructType>(T);
856       // STRUCT: [ispacked, eltty x N]
857       TypeVals.push_back(ST->isPacked());
858       // Output all of the element types.
859       for (StructType::element_iterator I = ST->element_begin(),
860            E = ST->element_end(); I != E; ++I)
861         TypeVals.push_back(VE.getTypeID(*I));
862 
863       if (ST->isLiteral()) {
864         Code = bitc::TYPE_CODE_STRUCT_ANON;
865         AbbrevToUse = StructAnonAbbrev;
866       } else {
867         if (ST->isOpaque()) {
868           Code = bitc::TYPE_CODE_OPAQUE;
869         } else {
870           Code = bitc::TYPE_CODE_STRUCT_NAMED;
871           AbbrevToUse = StructNamedAbbrev;
872         }
873 
874         // Emit the name if it is present.
875         if (!ST->getName().empty())
876           writeStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
877                             StructNameAbbrev);
878       }
879       break;
880     }
881     case Type::ArrayTyID: {
882       ArrayType *AT = cast<ArrayType>(T);
883       // ARRAY: [numelts, eltty]
884       Code = bitc::TYPE_CODE_ARRAY;
885       TypeVals.push_back(AT->getNumElements());
886       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
887       AbbrevToUse = ArrayAbbrev;
888       break;
889     }
890     case Type::VectorTyID: {
891       VectorType *VT = cast<VectorType>(T);
892       // VECTOR [numelts, eltty]
893       Code = bitc::TYPE_CODE_VECTOR;
894       TypeVals.push_back(VT->getNumElements());
895       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
896       break;
897     }
898     }
899 
900     // Emit the finished record.
901     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
902     TypeVals.clear();
903   }
904 
905   Stream.ExitBlock();
906 }
907 
908 static unsigned getEncodedLinkage(const GlobalValue::LinkageTypes Linkage) {
909   switch (Linkage) {
910   case GlobalValue::ExternalLinkage:
911     return 0;
912   case GlobalValue::WeakAnyLinkage:
913     return 16;
914   case GlobalValue::AppendingLinkage:
915     return 2;
916   case GlobalValue::InternalLinkage:
917     return 3;
918   case GlobalValue::LinkOnceAnyLinkage:
919     return 18;
920   case GlobalValue::ExternalWeakLinkage:
921     return 7;
922   case GlobalValue::CommonLinkage:
923     return 8;
924   case GlobalValue::PrivateLinkage:
925     return 9;
926   case GlobalValue::WeakODRLinkage:
927     return 17;
928   case GlobalValue::LinkOnceODRLinkage:
929     return 19;
930   case GlobalValue::AvailableExternallyLinkage:
931     return 12;
932   }
933   llvm_unreachable("Invalid linkage");
934 }
935 
936 static unsigned getEncodedLinkage(const GlobalValue &GV) {
937   return getEncodedLinkage(GV.getLinkage());
938 }
939 
940 // Decode the flags for GlobalValue in the summary
941 static uint64_t getEncodedGVSummaryFlags(GlobalValueSummary::GVFlags Flags) {
942   uint64_t RawFlags = 0;
943 
944   RawFlags |= Flags.HasSection; // bool
945 
946   // Linkage don't need to be remapped at that time for the summary. Any future
947   // change to the getEncodedLinkage() function will need to be taken into
948   // account here as well.
949   RawFlags = (RawFlags << 4) | Flags.Linkage; // 4 bits
950 
951   return RawFlags;
952 }
953 
954 static unsigned getEncodedVisibility(const GlobalValue &GV) {
955   switch (GV.getVisibility()) {
956   case GlobalValue::DefaultVisibility:   return 0;
957   case GlobalValue::HiddenVisibility:    return 1;
958   case GlobalValue::ProtectedVisibility: return 2;
959   }
960   llvm_unreachable("Invalid visibility");
961 }
962 
963 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
964   switch (GV.getDLLStorageClass()) {
965   case GlobalValue::DefaultStorageClass:   return 0;
966   case GlobalValue::DLLImportStorageClass: return 1;
967   case GlobalValue::DLLExportStorageClass: return 2;
968   }
969   llvm_unreachable("Invalid DLL storage class");
970 }
971 
972 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
973   switch (GV.getThreadLocalMode()) {
974     case GlobalVariable::NotThreadLocal:         return 0;
975     case GlobalVariable::GeneralDynamicTLSModel: return 1;
976     case GlobalVariable::LocalDynamicTLSModel:   return 2;
977     case GlobalVariable::InitialExecTLSModel:    return 3;
978     case GlobalVariable::LocalExecTLSModel:      return 4;
979   }
980   llvm_unreachable("Invalid TLS model");
981 }
982 
983 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
984   switch (C.getSelectionKind()) {
985   case Comdat::Any:
986     return bitc::COMDAT_SELECTION_KIND_ANY;
987   case Comdat::ExactMatch:
988     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
989   case Comdat::Largest:
990     return bitc::COMDAT_SELECTION_KIND_LARGEST;
991   case Comdat::NoDuplicates:
992     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
993   case Comdat::SameSize:
994     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
995   }
996   llvm_unreachable("Invalid selection kind");
997 }
998 
999 void ModuleBitcodeWriter::writeComdats() {
1000   SmallVector<unsigned, 64> Vals;
1001   for (const Comdat *C : VE.getComdats()) {
1002     // COMDAT: [selection_kind, name]
1003     Vals.push_back(getEncodedComdatSelectionKind(*C));
1004     size_t Size = C->getName().size();
1005     assert(isUInt<32>(Size));
1006     Vals.push_back(Size);
1007     for (char Chr : C->getName())
1008       Vals.push_back((unsigned char)Chr);
1009     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
1010     Vals.clear();
1011   }
1012 }
1013 
1014 /// Write a record that will eventually hold the word offset of the
1015 /// module-level VST. For now the offset is 0, which will be backpatched
1016 /// after the real VST is written. Saves the bit offset to backpatch.
1017 void BitcodeWriter::writeValueSymbolTableForwardDecl() {
1018   // Write a placeholder value in for the offset of the real VST,
1019   // which is written after the function blocks so that it can include
1020   // the offset of each function. The placeholder offset will be
1021   // updated when the real VST is written.
1022   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1023   Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_VSTOFFSET));
1024   // Blocks are 32-bit aligned, so we can use a 32-bit word offset to
1025   // hold the real VST offset. Must use fixed instead of VBR as we don't
1026   // know how many VBR chunks to reserve ahead of time.
1027   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1028   unsigned VSTOffsetAbbrev = Stream.EmitAbbrev(Abbv);
1029 
1030   // Emit the placeholder
1031   uint64_t Vals[] = {bitc::MODULE_CODE_VSTOFFSET, 0};
1032   Stream.EmitRecordWithAbbrev(VSTOffsetAbbrev, Vals);
1033 
1034   // Compute and save the bit offset to the placeholder, which will be
1035   // patched when the real VST is written. We can simply subtract the 32-bit
1036   // fixed size from the current bit number to get the location to backpatch.
1037   VSTOffsetPlaceholder = Stream.GetCurrentBitNo() - 32;
1038 }
1039 
1040 enum StringEncoding { SE_Char6, SE_Fixed7, SE_Fixed8 };
1041 
1042 /// Determine the encoding to use for the given string name and length.
1043 static StringEncoding getStringEncoding(const char *Str, unsigned StrLen) {
1044   bool isChar6 = true;
1045   for (const char *C = Str, *E = C + StrLen; C != E; ++C) {
1046     if (isChar6)
1047       isChar6 = BitCodeAbbrevOp::isChar6(*C);
1048     if ((unsigned char)*C & 128)
1049       // don't bother scanning the rest.
1050       return SE_Fixed8;
1051   }
1052   if (isChar6)
1053     return SE_Char6;
1054   else
1055     return SE_Fixed7;
1056 }
1057 
1058 /// Emit top-level description of module, including target triple, inline asm,
1059 /// descriptors for global variables, and function prototype info.
1060 /// Returns the bit offset to backpatch with the location of the real VST.
1061 void ModuleBitcodeWriter::writeModuleInfo() {
1062   // Emit various pieces of data attached to a module.
1063   if (!M.getTargetTriple().empty())
1064     writeStringRecord(bitc::MODULE_CODE_TRIPLE, M.getTargetTriple(),
1065                       0 /*TODO*/);
1066   const std::string &DL = M.getDataLayoutStr();
1067   if (!DL.empty())
1068     writeStringRecord(bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/);
1069   if (!M.getModuleInlineAsm().empty())
1070     writeStringRecord(bitc::MODULE_CODE_ASM, M.getModuleInlineAsm(),
1071                       0 /*TODO*/);
1072 
1073   // Emit information about sections and GC, computing how many there are. Also
1074   // compute the maximum alignment value.
1075   std::map<std::string, unsigned> SectionMap;
1076   std::map<std::string, unsigned> GCMap;
1077   unsigned MaxAlignment = 0;
1078   unsigned MaxGlobalType = 0;
1079   for (const GlobalValue &GV : M.globals()) {
1080     MaxAlignment = std::max(MaxAlignment, GV.getAlignment());
1081     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
1082     if (GV.hasSection()) {
1083       // Give section names unique ID's.
1084       unsigned &Entry = SectionMap[GV.getSection()];
1085       if (!Entry) {
1086         writeStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
1087                           0 /*TODO*/);
1088         Entry = SectionMap.size();
1089       }
1090     }
1091   }
1092   for (const Function &F : M) {
1093     MaxAlignment = std::max(MaxAlignment, F.getAlignment());
1094     if (F.hasSection()) {
1095       // Give section names unique ID's.
1096       unsigned &Entry = SectionMap[F.getSection()];
1097       if (!Entry) {
1098         writeStringRecord(bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
1099                           0 /*TODO*/);
1100         Entry = SectionMap.size();
1101       }
1102     }
1103     if (F.hasGC()) {
1104       // Same for GC names.
1105       unsigned &Entry = GCMap[F.getGC()];
1106       if (!Entry) {
1107         writeStringRecord(bitc::MODULE_CODE_GCNAME, F.getGC(), 0 /*TODO*/);
1108         Entry = GCMap.size();
1109       }
1110     }
1111   }
1112 
1113   // Emit abbrev for globals, now that we know # sections and max alignment.
1114   unsigned SimpleGVarAbbrev = 0;
1115   if (!M.global_empty()) {
1116     // Add an abbrev for common globals with no visibility or thread localness.
1117     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1118     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
1119     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1120                               Log2_32_Ceil(MaxGlobalType+1)));
1121     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
1122                                                            //| explicitType << 1
1123                                                            //| constant
1124     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
1125     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
1126     if (MaxAlignment == 0)                                 // Alignment.
1127       Abbv->Add(BitCodeAbbrevOp(0));
1128     else {
1129       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
1130       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1131                                Log2_32_Ceil(MaxEncAlignment+1)));
1132     }
1133     if (SectionMap.empty())                                    // Section.
1134       Abbv->Add(BitCodeAbbrevOp(0));
1135     else
1136       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1137                                Log2_32_Ceil(SectionMap.size()+1)));
1138     // Don't bother emitting vis + thread local.
1139     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
1140   }
1141 
1142   // Emit the global variable information.
1143   SmallVector<unsigned, 64> Vals;
1144   for (const GlobalVariable &GV : M.globals()) {
1145     unsigned AbbrevToUse = 0;
1146 
1147     // GLOBALVAR: [type, isconst, initid,
1148     //             linkage, alignment, section, visibility, threadlocal,
1149     //             unnamed_addr, externally_initialized, dllstorageclass,
1150     //             comdat]
1151     Vals.push_back(VE.getTypeID(GV.getValueType()));
1152     Vals.push_back(GV.getType()->getAddressSpace() << 2 | 2 | GV.isConstant());
1153     Vals.push_back(GV.isDeclaration() ? 0 :
1154                    (VE.getValueID(GV.getInitializer()) + 1));
1155     Vals.push_back(getEncodedLinkage(GV));
1156     Vals.push_back(Log2_32(GV.getAlignment())+1);
1157     Vals.push_back(GV.hasSection() ? SectionMap[GV.getSection()] : 0);
1158     if (GV.isThreadLocal() ||
1159         GV.getVisibility() != GlobalValue::DefaultVisibility ||
1160         GV.hasUnnamedAddr() || GV.isExternallyInitialized() ||
1161         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
1162         GV.hasComdat()) {
1163       Vals.push_back(getEncodedVisibility(GV));
1164       Vals.push_back(getEncodedThreadLocalMode(GV));
1165       Vals.push_back(GV.hasUnnamedAddr());
1166       Vals.push_back(GV.isExternallyInitialized());
1167       Vals.push_back(getEncodedDLLStorageClass(GV));
1168       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
1169     } else {
1170       AbbrevToUse = SimpleGVarAbbrev;
1171     }
1172 
1173     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
1174     Vals.clear();
1175   }
1176 
1177   // Emit the function proto information.
1178   for (const Function &F : M) {
1179     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
1180     //             section, visibility, gc, unnamed_addr, prologuedata,
1181     //             dllstorageclass, comdat, prefixdata, personalityfn]
1182     Vals.push_back(VE.getTypeID(F.getFunctionType()));
1183     Vals.push_back(F.getCallingConv());
1184     Vals.push_back(F.isDeclaration());
1185     Vals.push_back(getEncodedLinkage(F));
1186     Vals.push_back(VE.getAttributeID(F.getAttributes()));
1187     Vals.push_back(Log2_32(F.getAlignment())+1);
1188     Vals.push_back(F.hasSection() ? SectionMap[F.getSection()] : 0);
1189     Vals.push_back(getEncodedVisibility(F));
1190     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
1191     Vals.push_back(F.hasUnnamedAddr());
1192     Vals.push_back(F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1)
1193                                        : 0);
1194     Vals.push_back(getEncodedDLLStorageClass(F));
1195     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
1196     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
1197                                      : 0);
1198     Vals.push_back(
1199         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
1200 
1201     unsigned AbbrevToUse = 0;
1202     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
1203     Vals.clear();
1204   }
1205 
1206   // Emit the alias information.
1207   for (const GlobalAlias &A : M.aliases()) {
1208     // ALIAS: [alias type, aliasee val#, linkage, visibility]
1209     Vals.push_back(VE.getTypeID(A.getValueType()));
1210     Vals.push_back(A.getType()->getAddressSpace());
1211     Vals.push_back(VE.getValueID(A.getAliasee()));
1212     Vals.push_back(getEncodedLinkage(A));
1213     Vals.push_back(getEncodedVisibility(A));
1214     Vals.push_back(getEncodedDLLStorageClass(A));
1215     Vals.push_back(getEncodedThreadLocalMode(A));
1216     Vals.push_back(A.hasUnnamedAddr());
1217     unsigned AbbrevToUse = 0;
1218     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
1219     Vals.clear();
1220   }
1221 
1222   // Emit the ifunc information.
1223   for (const GlobalIFunc &I : M.ifuncs()) {
1224     // IFUNC: [ifunc type, address space, resolver val#, linkage, visibility]
1225     Vals.push_back(VE.getTypeID(I.getValueType()));
1226     Vals.push_back(I.getType()->getAddressSpace());
1227     Vals.push_back(VE.getValueID(I.getResolver()));
1228     Vals.push_back(getEncodedLinkage(I));
1229     Vals.push_back(getEncodedVisibility(I));
1230     Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
1231     Vals.clear();
1232   }
1233 
1234   // Emit the module's source file name.
1235   {
1236     StringEncoding Bits = getStringEncoding(M.getSourceFileName().data(),
1237                                             M.getSourceFileName().size());
1238     BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
1239     if (Bits == SE_Char6)
1240       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
1241     else if (Bits == SE_Fixed7)
1242       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
1243 
1244     // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
1245     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1246     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
1247     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1248     Abbv->Add(AbbrevOpToUse);
1249     unsigned FilenameAbbrev = Stream.EmitAbbrev(Abbv);
1250 
1251     for (const auto P : M.getSourceFileName())
1252       Vals.push_back((unsigned char)P);
1253 
1254     // Emit the finished record.
1255     Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
1256     Vals.clear();
1257   }
1258 
1259   // If we have a VST, write the VSTOFFSET record placeholder.
1260   if (M.getValueSymbolTable().empty())
1261     return;
1262   writeValueSymbolTableForwardDecl();
1263 }
1264 
1265 static uint64_t getOptimizationFlags(const Value *V) {
1266   uint64_t Flags = 0;
1267 
1268   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
1269     if (OBO->hasNoSignedWrap())
1270       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
1271     if (OBO->hasNoUnsignedWrap())
1272       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
1273   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
1274     if (PEO->isExact())
1275       Flags |= 1 << bitc::PEO_EXACT;
1276   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
1277     if (FPMO->hasUnsafeAlgebra())
1278       Flags |= FastMathFlags::UnsafeAlgebra;
1279     if (FPMO->hasNoNaNs())
1280       Flags |= FastMathFlags::NoNaNs;
1281     if (FPMO->hasNoInfs())
1282       Flags |= FastMathFlags::NoInfs;
1283     if (FPMO->hasNoSignedZeros())
1284       Flags |= FastMathFlags::NoSignedZeros;
1285     if (FPMO->hasAllowReciprocal())
1286       Flags |= FastMathFlags::AllowReciprocal;
1287   }
1288 
1289   return Flags;
1290 }
1291 
1292 void ModuleBitcodeWriter::writeValueAsMetadata(
1293     const ValueAsMetadata *MD, SmallVectorImpl<uint64_t> &Record) {
1294   // Mimic an MDNode with a value as one operand.
1295   Value *V = MD->getValue();
1296   Record.push_back(VE.getTypeID(V->getType()));
1297   Record.push_back(VE.getValueID(V));
1298   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
1299   Record.clear();
1300 }
1301 
1302 void ModuleBitcodeWriter::writeMDTuple(const MDTuple *N,
1303                                        SmallVectorImpl<uint64_t> &Record,
1304                                        unsigned Abbrev) {
1305   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
1306     Metadata *MD = N->getOperand(i);
1307     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
1308            "Unexpected function-local metadata");
1309     Record.push_back(VE.getMetadataOrNullID(MD));
1310   }
1311   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
1312                                     : bitc::METADATA_NODE,
1313                     Record, Abbrev);
1314   Record.clear();
1315 }
1316 
1317 unsigned ModuleBitcodeWriter::createDILocationAbbrev() {
1318   // Assume the column is usually under 128, and always output the inlined-at
1319   // location (it's never more expensive than building an array size 1).
1320   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1321   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1322   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1323   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1324   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1325   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1326   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1327   return Stream.EmitAbbrev(Abbv);
1328 }
1329 
1330 void ModuleBitcodeWriter::writeDILocation(const DILocation *N,
1331                                           SmallVectorImpl<uint64_t> &Record,
1332                                           unsigned &Abbrev) {
1333   if (!Abbrev)
1334     Abbrev = createDILocationAbbrev();
1335 
1336   Record.push_back(N->isDistinct());
1337   Record.push_back(N->getLine());
1338   Record.push_back(N->getColumn());
1339   Record.push_back(VE.getMetadataID(N->getScope()));
1340   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
1341 
1342   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
1343   Record.clear();
1344 }
1345 
1346 unsigned ModuleBitcodeWriter::createGenericDINodeAbbrev() {
1347   // Assume the column is usually under 128, and always output the inlined-at
1348   // location (it's never more expensive than building an array size 1).
1349   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1350   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1351   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1352   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1353   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1354   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1355   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1356   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1357   return Stream.EmitAbbrev(Abbv);
1358 }
1359 
1360 void ModuleBitcodeWriter::writeGenericDINode(const GenericDINode *N,
1361                                              SmallVectorImpl<uint64_t> &Record,
1362                                              unsigned &Abbrev) {
1363   if (!Abbrev)
1364     Abbrev = createGenericDINodeAbbrev();
1365 
1366   Record.push_back(N->isDistinct());
1367   Record.push_back(N->getTag());
1368   Record.push_back(0); // Per-tag version field; unused for now.
1369 
1370   for (auto &I : N->operands())
1371     Record.push_back(VE.getMetadataOrNullID(I));
1372 
1373   Stream.EmitRecord(bitc::METADATA_GENERIC_DEBUG, Record, Abbrev);
1374   Record.clear();
1375 }
1376 
1377 static uint64_t rotateSign(int64_t I) {
1378   uint64_t U = I;
1379   return I < 0 ? ~(U << 1) : U << 1;
1380 }
1381 
1382 void ModuleBitcodeWriter::writeDISubrange(const DISubrange *N,
1383                                           SmallVectorImpl<uint64_t> &Record,
1384                                           unsigned Abbrev) {
1385   Record.push_back(N->isDistinct());
1386   Record.push_back(N->getCount());
1387   Record.push_back(rotateSign(N->getLowerBound()));
1388 
1389   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
1390   Record.clear();
1391 }
1392 
1393 void ModuleBitcodeWriter::writeDIEnumerator(const DIEnumerator *N,
1394                                             SmallVectorImpl<uint64_t> &Record,
1395                                             unsigned Abbrev) {
1396   Record.push_back(N->isDistinct());
1397   Record.push_back(rotateSign(N->getValue()));
1398   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1399 
1400   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
1401   Record.clear();
1402 }
1403 
1404 void ModuleBitcodeWriter::writeDIBasicType(const DIBasicType *N,
1405                                            SmallVectorImpl<uint64_t> &Record,
1406                                            unsigned Abbrev) {
1407   Record.push_back(N->isDistinct());
1408   Record.push_back(N->getTag());
1409   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1410   Record.push_back(N->getSizeInBits());
1411   Record.push_back(N->getAlignInBits());
1412   Record.push_back(N->getEncoding());
1413 
1414   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
1415   Record.clear();
1416 }
1417 
1418 void ModuleBitcodeWriter::writeDIDerivedType(const DIDerivedType *N,
1419                                              SmallVectorImpl<uint64_t> &Record,
1420                                              unsigned Abbrev) {
1421   Record.push_back(N->isDistinct());
1422   Record.push_back(N->getTag());
1423   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1424   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1425   Record.push_back(N->getLine());
1426   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1427   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1428   Record.push_back(N->getSizeInBits());
1429   Record.push_back(N->getAlignInBits());
1430   Record.push_back(N->getOffsetInBits());
1431   Record.push_back(N->getFlags());
1432   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
1433 
1434   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
1435   Record.clear();
1436 }
1437 
1438 void ModuleBitcodeWriter::writeDICompositeType(
1439     const DICompositeType *N, SmallVectorImpl<uint64_t> &Record,
1440     unsigned Abbrev) {
1441   const unsigned IsNotUsedInOldTypeRef = 0x2;
1442   Record.push_back(IsNotUsedInOldTypeRef | (unsigned)N->isDistinct());
1443   Record.push_back(N->getTag());
1444   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1445   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1446   Record.push_back(N->getLine());
1447   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1448   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1449   Record.push_back(N->getSizeInBits());
1450   Record.push_back(N->getAlignInBits());
1451   Record.push_back(N->getOffsetInBits());
1452   Record.push_back(N->getFlags());
1453   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1454   Record.push_back(N->getRuntimeLang());
1455   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
1456   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1457   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
1458 
1459   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
1460   Record.clear();
1461 }
1462 
1463 void ModuleBitcodeWriter::writeDISubroutineType(
1464     const DISubroutineType *N, SmallVectorImpl<uint64_t> &Record,
1465     unsigned Abbrev) {
1466   const unsigned HasNoOldTypeRefs = 0x2;
1467   Record.push_back(HasNoOldTypeRefs | (unsigned)N->isDistinct());
1468   Record.push_back(N->getFlags());
1469   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
1470 
1471   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
1472   Record.clear();
1473 }
1474 
1475 void ModuleBitcodeWriter::writeDIFile(const DIFile *N,
1476                                       SmallVectorImpl<uint64_t> &Record,
1477                                       unsigned Abbrev) {
1478   Record.push_back(N->isDistinct());
1479   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
1480   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
1481 
1482   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
1483   Record.clear();
1484 }
1485 
1486 void ModuleBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
1487                                              SmallVectorImpl<uint64_t> &Record,
1488                                              unsigned Abbrev) {
1489   assert(N->isDistinct() && "Expected distinct compile units");
1490   Record.push_back(/* IsDistinct */ true);
1491   Record.push_back(N->getSourceLanguage());
1492   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1493   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
1494   Record.push_back(N->isOptimized());
1495   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
1496   Record.push_back(N->getRuntimeVersion());
1497   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
1498   Record.push_back(N->getEmissionKind());
1499   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
1500   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
1501   Record.push_back(/* subprograms */ 0);
1502   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
1503   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
1504   Record.push_back(N->getDWOId());
1505   Record.push_back(VE.getMetadataOrNullID(N->getMacros().get()));
1506 
1507   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
1508   Record.clear();
1509 }
1510 
1511 void ModuleBitcodeWriter::writeDISubprogram(const DISubprogram *N,
1512                                             SmallVectorImpl<uint64_t> &Record,
1513                                             unsigned Abbrev) {
1514   uint64_t HasUnitFlag = 1 << 1;
1515   Record.push_back(N->isDistinct() | HasUnitFlag);
1516   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1517   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1518   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1519   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1520   Record.push_back(N->getLine());
1521   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1522   Record.push_back(N->isLocalToUnit());
1523   Record.push_back(N->isDefinition());
1524   Record.push_back(N->getScopeLine());
1525   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
1526   Record.push_back(N->getVirtuality());
1527   Record.push_back(N->getVirtualIndex());
1528   Record.push_back(N->getFlags());
1529   Record.push_back(N->isOptimized());
1530   Record.push_back(VE.getMetadataOrNullID(N->getRawUnit()));
1531   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1532   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
1533   Record.push_back(VE.getMetadataOrNullID(N->getVariables().get()));
1534 
1535   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
1536   Record.clear();
1537 }
1538 
1539 void ModuleBitcodeWriter::writeDILexicalBlock(const DILexicalBlock *N,
1540                                               SmallVectorImpl<uint64_t> &Record,
1541                                               unsigned Abbrev) {
1542   Record.push_back(N->isDistinct());
1543   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1544   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1545   Record.push_back(N->getLine());
1546   Record.push_back(N->getColumn());
1547 
1548   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
1549   Record.clear();
1550 }
1551 
1552 void ModuleBitcodeWriter::writeDILexicalBlockFile(
1553     const DILexicalBlockFile *N, SmallVectorImpl<uint64_t> &Record,
1554     unsigned Abbrev) {
1555   Record.push_back(N->isDistinct());
1556   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1557   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1558   Record.push_back(N->getDiscriminator());
1559 
1560   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
1561   Record.clear();
1562 }
1563 
1564 void ModuleBitcodeWriter::writeDINamespace(const DINamespace *N,
1565                                            SmallVectorImpl<uint64_t> &Record,
1566                                            unsigned Abbrev) {
1567   Record.push_back(N->isDistinct());
1568   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1569   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1570   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1571   Record.push_back(N->getLine());
1572 
1573   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
1574   Record.clear();
1575 }
1576 
1577 void ModuleBitcodeWriter::writeDIMacro(const DIMacro *N,
1578                                        SmallVectorImpl<uint64_t> &Record,
1579                                        unsigned Abbrev) {
1580   Record.push_back(N->isDistinct());
1581   Record.push_back(N->getMacinfoType());
1582   Record.push_back(N->getLine());
1583   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1584   Record.push_back(VE.getMetadataOrNullID(N->getRawValue()));
1585 
1586   Stream.EmitRecord(bitc::METADATA_MACRO, Record, Abbrev);
1587   Record.clear();
1588 }
1589 
1590 void ModuleBitcodeWriter::writeDIMacroFile(const DIMacroFile *N,
1591                                            SmallVectorImpl<uint64_t> &Record,
1592                                            unsigned Abbrev) {
1593   Record.push_back(N->isDistinct());
1594   Record.push_back(N->getMacinfoType());
1595   Record.push_back(N->getLine());
1596   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1597   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1598 
1599   Stream.EmitRecord(bitc::METADATA_MACRO_FILE, Record, Abbrev);
1600   Record.clear();
1601 }
1602 
1603 void ModuleBitcodeWriter::writeDIModule(const DIModule *N,
1604                                         SmallVectorImpl<uint64_t> &Record,
1605                                         unsigned Abbrev) {
1606   Record.push_back(N->isDistinct());
1607   for (auto &I : N->operands())
1608     Record.push_back(VE.getMetadataOrNullID(I));
1609 
1610   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
1611   Record.clear();
1612 }
1613 
1614 void ModuleBitcodeWriter::writeDITemplateTypeParameter(
1615     const DITemplateTypeParameter *N, SmallVectorImpl<uint64_t> &Record,
1616     unsigned Abbrev) {
1617   Record.push_back(N->isDistinct());
1618   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1619   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1620 
1621   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
1622   Record.clear();
1623 }
1624 
1625 void ModuleBitcodeWriter::writeDITemplateValueParameter(
1626     const DITemplateValueParameter *N, SmallVectorImpl<uint64_t> &Record,
1627     unsigned Abbrev) {
1628   Record.push_back(N->isDistinct());
1629   Record.push_back(N->getTag());
1630   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1631   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1632   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
1633 
1634   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
1635   Record.clear();
1636 }
1637 
1638 void ModuleBitcodeWriter::writeDIGlobalVariable(
1639     const DIGlobalVariable *N, SmallVectorImpl<uint64_t> &Record,
1640     unsigned Abbrev) {
1641   Record.push_back(N->isDistinct());
1642   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1643   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1644   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1645   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1646   Record.push_back(N->getLine());
1647   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1648   Record.push_back(N->isLocalToUnit());
1649   Record.push_back(N->isDefinition());
1650   Record.push_back(VE.getMetadataOrNullID(N->getRawVariable()));
1651   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
1652 
1653   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
1654   Record.clear();
1655 }
1656 
1657 void ModuleBitcodeWriter::writeDILocalVariable(
1658     const DILocalVariable *N, SmallVectorImpl<uint64_t> &Record,
1659     unsigned Abbrev) {
1660   Record.push_back(N->isDistinct());
1661   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1662   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1663   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1664   Record.push_back(N->getLine());
1665   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1666   Record.push_back(N->getArg());
1667   Record.push_back(N->getFlags());
1668 
1669   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
1670   Record.clear();
1671 }
1672 
1673 void ModuleBitcodeWriter::writeDIExpression(const DIExpression *N,
1674                                             SmallVectorImpl<uint64_t> &Record,
1675                                             unsigned Abbrev) {
1676   Record.reserve(N->getElements().size() + 1);
1677 
1678   Record.push_back(N->isDistinct());
1679   Record.append(N->elements_begin(), N->elements_end());
1680 
1681   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
1682   Record.clear();
1683 }
1684 
1685 void ModuleBitcodeWriter::writeDIObjCProperty(const DIObjCProperty *N,
1686                                               SmallVectorImpl<uint64_t> &Record,
1687                                               unsigned Abbrev) {
1688   Record.push_back(N->isDistinct());
1689   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1690   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1691   Record.push_back(N->getLine());
1692   Record.push_back(VE.getMetadataOrNullID(N->getRawSetterName()));
1693   Record.push_back(VE.getMetadataOrNullID(N->getRawGetterName()));
1694   Record.push_back(N->getAttributes());
1695   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1696 
1697   Stream.EmitRecord(bitc::METADATA_OBJC_PROPERTY, Record, Abbrev);
1698   Record.clear();
1699 }
1700 
1701 void ModuleBitcodeWriter::writeDIImportedEntity(
1702     const DIImportedEntity *N, SmallVectorImpl<uint64_t> &Record,
1703     unsigned Abbrev) {
1704   Record.push_back(N->isDistinct());
1705   Record.push_back(N->getTag());
1706   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1707   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
1708   Record.push_back(N->getLine());
1709   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1710 
1711   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
1712   Record.clear();
1713 }
1714 
1715 unsigned ModuleBitcodeWriter::createNamedMetadataAbbrev() {
1716   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1717   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
1718   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1719   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1720   return Stream.EmitAbbrev(Abbv);
1721 }
1722 
1723 void ModuleBitcodeWriter::writeNamedMetadata(
1724     SmallVectorImpl<uint64_t> &Record) {
1725   if (M.named_metadata_empty())
1726     return;
1727 
1728   unsigned Abbrev = createNamedMetadataAbbrev();
1729   for (const NamedMDNode &NMD : M.named_metadata()) {
1730     // Write name.
1731     StringRef Str = NMD.getName();
1732     Record.append(Str.bytes_begin(), Str.bytes_end());
1733     Stream.EmitRecord(bitc::METADATA_NAME, Record, Abbrev);
1734     Record.clear();
1735 
1736     // Write named metadata operands.
1737     for (const MDNode *N : NMD.operands())
1738       Record.push_back(VE.getMetadataID(N));
1739     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
1740     Record.clear();
1741   }
1742 }
1743 
1744 unsigned ModuleBitcodeWriter::createMetadataStringsAbbrev() {
1745   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1746   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRINGS));
1747   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of strings
1748   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // offset to chars
1749   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1750   return Stream.EmitAbbrev(Abbv);
1751 }
1752 
1753 /// Write out a record for MDString.
1754 ///
1755 /// All the metadata strings in a metadata block are emitted in a single
1756 /// record.  The sizes and strings themselves are shoved into a blob.
1757 void ModuleBitcodeWriter::writeMetadataStrings(
1758     ArrayRef<const Metadata *> Strings, SmallVectorImpl<uint64_t> &Record) {
1759   if (Strings.empty())
1760     return;
1761 
1762   // Start the record with the number of strings.
1763   Record.push_back(bitc::METADATA_STRINGS);
1764   Record.push_back(Strings.size());
1765 
1766   // Emit the sizes of the strings in the blob.
1767   SmallString<256> Blob;
1768   {
1769     BitstreamWriter W(Blob);
1770     for (const Metadata *MD : Strings)
1771       W.EmitVBR(cast<MDString>(MD)->getLength(), 6);
1772     W.FlushToWord();
1773   }
1774 
1775   // Add the offset to the strings to the record.
1776   Record.push_back(Blob.size());
1777 
1778   // Add the strings to the blob.
1779   for (const Metadata *MD : Strings)
1780     Blob.append(cast<MDString>(MD)->getString());
1781 
1782   // Emit the final record.
1783   Stream.EmitRecordWithBlob(createMetadataStringsAbbrev(), Record, Blob);
1784   Record.clear();
1785 }
1786 
1787 void ModuleBitcodeWriter::writeMetadataRecords(
1788     ArrayRef<const Metadata *> MDs, SmallVectorImpl<uint64_t> &Record) {
1789   if (MDs.empty())
1790     return;
1791 
1792   // Initialize MDNode abbreviations.
1793 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
1794 #include "llvm/IR/Metadata.def"
1795 
1796   for (const Metadata *MD : MDs) {
1797     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
1798       assert(N->isResolved() && "Expected forward references to be resolved");
1799 
1800       switch (N->getMetadataID()) {
1801       default:
1802         llvm_unreachable("Invalid MDNode subclass");
1803 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
1804   case Metadata::CLASS##Kind:                                                  \
1805     write##CLASS(cast<CLASS>(N), Record, CLASS##Abbrev);                       \
1806     continue;
1807 #include "llvm/IR/Metadata.def"
1808       }
1809     }
1810     writeValueAsMetadata(cast<ValueAsMetadata>(MD), Record);
1811   }
1812 }
1813 
1814 void ModuleBitcodeWriter::writeModuleMetadata() {
1815   if (!VE.hasMDs() && M.named_metadata_empty())
1816     return;
1817 
1818   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1819   SmallVector<uint64_t, 64> Record;
1820   writeMetadataStrings(VE.getMDStrings(), Record);
1821   writeMetadataRecords(VE.getNonMDStrings(), Record);
1822   writeNamedMetadata(Record);
1823   Stream.ExitBlock();
1824 }
1825 
1826 void ModuleBitcodeWriter::writeFunctionMetadata(const Function &F) {
1827   if (!VE.hasMDs())
1828     return;
1829 
1830   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1831   SmallVector<uint64_t, 64> Record;
1832   writeMetadataStrings(VE.getMDStrings(), Record);
1833   writeMetadataRecords(VE.getNonMDStrings(), Record);
1834   Stream.ExitBlock();
1835 }
1836 
1837 void ModuleBitcodeWriter::pushGlobalMetadataAttachment(
1838     SmallVectorImpl<uint64_t> &Record, const GlobalObject &GO) {
1839   // [n x [id, mdnode]]
1840   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
1841   GO.getAllMetadata(MDs);
1842   for (const auto &I : MDs) {
1843     Record.push_back(I.first);
1844     Record.push_back(VE.getMetadataID(I.second));
1845   }
1846 }
1847 
1848 void ModuleBitcodeWriter::writeFunctionMetadataAttachment(const Function &F) {
1849   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
1850 
1851   SmallVector<uint64_t, 64> Record;
1852 
1853   if (F.hasMetadata()) {
1854     pushGlobalMetadataAttachment(Record, F);
1855     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1856     Record.clear();
1857   }
1858 
1859   // Write metadata attachments
1860   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
1861   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
1862   for (const BasicBlock &BB : F)
1863     for (const Instruction &I : BB) {
1864       MDs.clear();
1865       I.getAllMetadataOtherThanDebugLoc(MDs);
1866 
1867       // If no metadata, ignore instruction.
1868       if (MDs.empty()) continue;
1869 
1870       Record.push_back(VE.getInstructionID(&I));
1871 
1872       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1873         Record.push_back(MDs[i].first);
1874         Record.push_back(VE.getMetadataID(MDs[i].second));
1875       }
1876       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1877       Record.clear();
1878     }
1879 
1880   Stream.ExitBlock();
1881 }
1882 
1883 void ModuleBitcodeWriter::writeModuleMetadataStore() {
1884   SmallVector<uint64_t, 64> Record;
1885 
1886   // Write metadata kinds
1887   // METADATA_KIND - [n x [id, name]]
1888   SmallVector<StringRef, 8> Names;
1889   M.getMDKindNames(Names);
1890 
1891   if (Names.empty()) return;
1892 
1893   Stream.EnterSubblock(bitc::METADATA_KIND_BLOCK_ID, 3);
1894 
1895   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
1896     Record.push_back(MDKindID);
1897     StringRef KName = Names[MDKindID];
1898     Record.append(KName.begin(), KName.end());
1899 
1900     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
1901     Record.clear();
1902   }
1903 
1904   Stream.ExitBlock();
1905 }
1906 
1907 void ModuleBitcodeWriter::writeOperandBundleTags() {
1908   // Write metadata kinds
1909   //
1910   // OPERAND_BUNDLE_TAGS_BLOCK_ID : N x OPERAND_BUNDLE_TAG
1911   //
1912   // OPERAND_BUNDLE_TAG - [strchr x N]
1913 
1914   SmallVector<StringRef, 8> Tags;
1915   M.getOperandBundleTags(Tags);
1916 
1917   if (Tags.empty())
1918     return;
1919 
1920   Stream.EnterSubblock(bitc::OPERAND_BUNDLE_TAGS_BLOCK_ID, 3);
1921 
1922   SmallVector<uint64_t, 64> Record;
1923 
1924   for (auto Tag : Tags) {
1925     Record.append(Tag.begin(), Tag.end());
1926 
1927     Stream.EmitRecord(bitc::OPERAND_BUNDLE_TAG, Record, 0);
1928     Record.clear();
1929   }
1930 
1931   Stream.ExitBlock();
1932 }
1933 
1934 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
1935   if ((int64_t)V >= 0)
1936     Vals.push_back(V << 1);
1937   else
1938     Vals.push_back((-V << 1) | 1);
1939 }
1940 
1941 void ModuleBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
1942                                          bool isGlobal) {
1943   if (FirstVal == LastVal) return;
1944 
1945   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
1946 
1947   unsigned AggregateAbbrev = 0;
1948   unsigned String8Abbrev = 0;
1949   unsigned CString7Abbrev = 0;
1950   unsigned CString6Abbrev = 0;
1951   // If this is a constant pool for the module, emit module-specific abbrevs.
1952   if (isGlobal) {
1953     // Abbrev for CST_CODE_AGGREGATE.
1954     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1955     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
1956     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1957     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
1958     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
1959 
1960     // Abbrev for CST_CODE_STRING.
1961     Abbv = new BitCodeAbbrev();
1962     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
1963     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1964     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1965     String8Abbrev = Stream.EmitAbbrev(Abbv);
1966     // Abbrev for CST_CODE_CSTRING.
1967     Abbv = new BitCodeAbbrev();
1968     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1969     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1970     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1971     CString7Abbrev = Stream.EmitAbbrev(Abbv);
1972     // Abbrev for CST_CODE_CSTRING.
1973     Abbv = new BitCodeAbbrev();
1974     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1975     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1976     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1977     CString6Abbrev = Stream.EmitAbbrev(Abbv);
1978   }
1979 
1980   SmallVector<uint64_t, 64> Record;
1981 
1982   const ValueEnumerator::ValueList &Vals = VE.getValues();
1983   Type *LastTy = nullptr;
1984   for (unsigned i = FirstVal; i != LastVal; ++i) {
1985     const Value *V = Vals[i].first;
1986     // If we need to switch types, do so now.
1987     if (V->getType() != LastTy) {
1988       LastTy = V->getType();
1989       Record.push_back(VE.getTypeID(LastTy));
1990       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
1991                         CONSTANTS_SETTYPE_ABBREV);
1992       Record.clear();
1993     }
1994 
1995     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
1996       Record.push_back(unsigned(IA->hasSideEffects()) |
1997                        unsigned(IA->isAlignStack()) << 1 |
1998                        unsigned(IA->getDialect()&1) << 2);
1999 
2000       // Add the asm string.
2001       const std::string &AsmStr = IA->getAsmString();
2002       Record.push_back(AsmStr.size());
2003       Record.append(AsmStr.begin(), AsmStr.end());
2004 
2005       // Add the constraint string.
2006       const std::string &ConstraintStr = IA->getConstraintString();
2007       Record.push_back(ConstraintStr.size());
2008       Record.append(ConstraintStr.begin(), ConstraintStr.end());
2009       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
2010       Record.clear();
2011       continue;
2012     }
2013     const Constant *C = cast<Constant>(V);
2014     unsigned Code = -1U;
2015     unsigned AbbrevToUse = 0;
2016     if (C->isNullValue()) {
2017       Code = bitc::CST_CODE_NULL;
2018     } else if (isa<UndefValue>(C)) {
2019       Code = bitc::CST_CODE_UNDEF;
2020     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
2021       if (IV->getBitWidth() <= 64) {
2022         uint64_t V = IV->getSExtValue();
2023         emitSignedInt64(Record, V);
2024         Code = bitc::CST_CODE_INTEGER;
2025         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
2026       } else {                             // Wide integers, > 64 bits in size.
2027         // We have an arbitrary precision integer value to write whose
2028         // bit width is > 64. However, in canonical unsigned integer
2029         // format it is likely that the high bits are going to be zero.
2030         // So, we only write the number of active words.
2031         unsigned NWords = IV->getValue().getActiveWords();
2032         const uint64_t *RawWords = IV->getValue().getRawData();
2033         for (unsigned i = 0; i != NWords; ++i) {
2034           emitSignedInt64(Record, RawWords[i]);
2035         }
2036         Code = bitc::CST_CODE_WIDE_INTEGER;
2037       }
2038     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
2039       Code = bitc::CST_CODE_FLOAT;
2040       Type *Ty = CFP->getType();
2041       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
2042         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
2043       } else if (Ty->isX86_FP80Ty()) {
2044         // api needed to prevent premature destruction
2045         // bits are not in the same order as a normal i80 APInt, compensate.
2046         APInt api = CFP->getValueAPF().bitcastToAPInt();
2047         const uint64_t *p = api.getRawData();
2048         Record.push_back((p[1] << 48) | (p[0] >> 16));
2049         Record.push_back(p[0] & 0xffffLL);
2050       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
2051         APInt api = CFP->getValueAPF().bitcastToAPInt();
2052         const uint64_t *p = api.getRawData();
2053         Record.push_back(p[0]);
2054         Record.push_back(p[1]);
2055       } else {
2056         assert (0 && "Unknown FP type!");
2057       }
2058     } else if (isa<ConstantDataSequential>(C) &&
2059                cast<ConstantDataSequential>(C)->isString()) {
2060       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
2061       // Emit constant strings specially.
2062       unsigned NumElts = Str->getNumElements();
2063       // If this is a null-terminated string, use the denser CSTRING encoding.
2064       if (Str->isCString()) {
2065         Code = bitc::CST_CODE_CSTRING;
2066         --NumElts;  // Don't encode the null, which isn't allowed by char6.
2067       } else {
2068         Code = bitc::CST_CODE_STRING;
2069         AbbrevToUse = String8Abbrev;
2070       }
2071       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
2072       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
2073       for (unsigned i = 0; i != NumElts; ++i) {
2074         unsigned char V = Str->getElementAsInteger(i);
2075         Record.push_back(V);
2076         isCStr7 &= (V & 128) == 0;
2077         if (isCStrChar6)
2078           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
2079       }
2080 
2081       if (isCStrChar6)
2082         AbbrevToUse = CString6Abbrev;
2083       else if (isCStr7)
2084         AbbrevToUse = CString7Abbrev;
2085     } else if (const ConstantDataSequential *CDS =
2086                   dyn_cast<ConstantDataSequential>(C)) {
2087       Code = bitc::CST_CODE_DATA;
2088       Type *EltTy = CDS->getType()->getElementType();
2089       if (isa<IntegerType>(EltTy)) {
2090         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2091           Record.push_back(CDS->getElementAsInteger(i));
2092       } else {
2093         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2094           Record.push_back(
2095               CDS->getElementAsAPFloat(i).bitcastToAPInt().getLimitedValue());
2096       }
2097     } else if (isa<ConstantAggregate>(C)) {
2098       Code = bitc::CST_CODE_AGGREGATE;
2099       for (const Value *Op : C->operands())
2100         Record.push_back(VE.getValueID(Op));
2101       AbbrevToUse = AggregateAbbrev;
2102     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
2103       switch (CE->getOpcode()) {
2104       default:
2105         if (Instruction::isCast(CE->getOpcode())) {
2106           Code = bitc::CST_CODE_CE_CAST;
2107           Record.push_back(getEncodedCastOpcode(CE->getOpcode()));
2108           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2109           Record.push_back(VE.getValueID(C->getOperand(0)));
2110           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
2111         } else {
2112           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
2113           Code = bitc::CST_CODE_CE_BINOP;
2114           Record.push_back(getEncodedBinaryOpcode(CE->getOpcode()));
2115           Record.push_back(VE.getValueID(C->getOperand(0)));
2116           Record.push_back(VE.getValueID(C->getOperand(1)));
2117           uint64_t Flags = getOptimizationFlags(CE);
2118           if (Flags != 0)
2119             Record.push_back(Flags);
2120         }
2121         break;
2122       case Instruction::GetElementPtr: {
2123         Code = bitc::CST_CODE_CE_GEP;
2124         const auto *GO = cast<GEPOperator>(C);
2125         if (GO->isInBounds())
2126           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
2127         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
2128         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
2129           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
2130           Record.push_back(VE.getValueID(C->getOperand(i)));
2131         }
2132         break;
2133       }
2134       case Instruction::Select:
2135         Code = bitc::CST_CODE_CE_SELECT;
2136         Record.push_back(VE.getValueID(C->getOperand(0)));
2137         Record.push_back(VE.getValueID(C->getOperand(1)));
2138         Record.push_back(VE.getValueID(C->getOperand(2)));
2139         break;
2140       case Instruction::ExtractElement:
2141         Code = bitc::CST_CODE_CE_EXTRACTELT;
2142         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2143         Record.push_back(VE.getValueID(C->getOperand(0)));
2144         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
2145         Record.push_back(VE.getValueID(C->getOperand(1)));
2146         break;
2147       case Instruction::InsertElement:
2148         Code = bitc::CST_CODE_CE_INSERTELT;
2149         Record.push_back(VE.getValueID(C->getOperand(0)));
2150         Record.push_back(VE.getValueID(C->getOperand(1)));
2151         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
2152         Record.push_back(VE.getValueID(C->getOperand(2)));
2153         break;
2154       case Instruction::ShuffleVector:
2155         // If the return type and argument types are the same, this is a
2156         // standard shufflevector instruction.  If the types are different,
2157         // then the shuffle is widening or truncating the input vectors, and
2158         // the argument type must also be encoded.
2159         if (C->getType() == C->getOperand(0)->getType()) {
2160           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
2161         } else {
2162           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
2163           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2164         }
2165         Record.push_back(VE.getValueID(C->getOperand(0)));
2166         Record.push_back(VE.getValueID(C->getOperand(1)));
2167         Record.push_back(VE.getValueID(C->getOperand(2)));
2168         break;
2169       case Instruction::ICmp:
2170       case Instruction::FCmp:
2171         Code = bitc::CST_CODE_CE_CMP;
2172         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2173         Record.push_back(VE.getValueID(C->getOperand(0)));
2174         Record.push_back(VE.getValueID(C->getOperand(1)));
2175         Record.push_back(CE->getPredicate());
2176         break;
2177       }
2178     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
2179       Code = bitc::CST_CODE_BLOCKADDRESS;
2180       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
2181       Record.push_back(VE.getValueID(BA->getFunction()));
2182       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
2183     } else {
2184 #ifndef NDEBUG
2185       C->dump();
2186 #endif
2187       llvm_unreachable("Unknown constant!");
2188     }
2189     Stream.EmitRecord(Code, Record, AbbrevToUse);
2190     Record.clear();
2191   }
2192 
2193   Stream.ExitBlock();
2194 }
2195 
2196 void ModuleBitcodeWriter::writeModuleConstants() {
2197   const ValueEnumerator::ValueList &Vals = VE.getValues();
2198 
2199   // Find the first constant to emit, which is the first non-globalvalue value.
2200   // We know globalvalues have been emitted by WriteModuleInfo.
2201   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
2202     if (!isa<GlobalValue>(Vals[i].first)) {
2203       writeConstants(i, Vals.size(), true);
2204       return;
2205     }
2206   }
2207 }
2208 
2209 /// pushValueAndType - The file has to encode both the value and type id for
2210 /// many values, because we need to know what type to create for forward
2211 /// references.  However, most operands are not forward references, so this type
2212 /// field is not needed.
2213 ///
2214 /// This function adds V's value ID to Vals.  If the value ID is higher than the
2215 /// instruction ID, then it is a forward reference, and it also includes the
2216 /// type ID.  The value ID that is written is encoded relative to the InstID.
2217 bool ModuleBitcodeWriter::pushValueAndType(const Value *V, unsigned InstID,
2218                                            SmallVectorImpl<unsigned> &Vals) {
2219   unsigned ValID = VE.getValueID(V);
2220   // Make encoding relative to the InstID.
2221   Vals.push_back(InstID - ValID);
2222   if (ValID >= InstID) {
2223     Vals.push_back(VE.getTypeID(V->getType()));
2224     return true;
2225   }
2226   return false;
2227 }
2228 
2229 void ModuleBitcodeWriter::writeOperandBundles(ImmutableCallSite CS,
2230                                               unsigned InstID) {
2231   SmallVector<unsigned, 64> Record;
2232   LLVMContext &C = CS.getInstruction()->getContext();
2233 
2234   for (unsigned i = 0, e = CS.getNumOperandBundles(); i != e; ++i) {
2235     const auto &Bundle = CS.getOperandBundleAt(i);
2236     Record.push_back(C.getOperandBundleTagID(Bundle.getTagName()));
2237 
2238     for (auto &Input : Bundle.Inputs)
2239       pushValueAndType(Input, InstID, Record);
2240 
2241     Stream.EmitRecord(bitc::FUNC_CODE_OPERAND_BUNDLE, Record);
2242     Record.clear();
2243   }
2244 }
2245 
2246 /// pushValue - Like pushValueAndType, but where the type of the value is
2247 /// omitted (perhaps it was already encoded in an earlier operand).
2248 void ModuleBitcodeWriter::pushValue(const Value *V, unsigned InstID,
2249                                     SmallVectorImpl<unsigned> &Vals) {
2250   unsigned ValID = VE.getValueID(V);
2251   Vals.push_back(InstID - ValID);
2252 }
2253 
2254 void ModuleBitcodeWriter::pushValueSigned(const Value *V, unsigned InstID,
2255                                           SmallVectorImpl<uint64_t> &Vals) {
2256   unsigned ValID = VE.getValueID(V);
2257   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
2258   emitSignedInt64(Vals, diff);
2259 }
2260 
2261 /// WriteInstruction - Emit an instruction to the specified stream.
2262 void ModuleBitcodeWriter::writeInstruction(const Instruction &I,
2263                                            unsigned InstID,
2264                                            SmallVectorImpl<unsigned> &Vals) {
2265   unsigned Code = 0;
2266   unsigned AbbrevToUse = 0;
2267   VE.setInstructionID(&I);
2268   switch (I.getOpcode()) {
2269   default:
2270     if (Instruction::isCast(I.getOpcode())) {
2271       Code = bitc::FUNC_CODE_INST_CAST;
2272       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2273         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
2274       Vals.push_back(VE.getTypeID(I.getType()));
2275       Vals.push_back(getEncodedCastOpcode(I.getOpcode()));
2276     } else {
2277       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
2278       Code = bitc::FUNC_CODE_INST_BINOP;
2279       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2280         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
2281       pushValue(I.getOperand(1), InstID, Vals);
2282       Vals.push_back(getEncodedBinaryOpcode(I.getOpcode()));
2283       uint64_t Flags = getOptimizationFlags(&I);
2284       if (Flags != 0) {
2285         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
2286           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
2287         Vals.push_back(Flags);
2288       }
2289     }
2290     break;
2291 
2292   case Instruction::GetElementPtr: {
2293     Code = bitc::FUNC_CODE_INST_GEP;
2294     AbbrevToUse = FUNCTION_INST_GEP_ABBREV;
2295     auto &GEPInst = cast<GetElementPtrInst>(I);
2296     Vals.push_back(GEPInst.isInBounds());
2297     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
2298     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
2299       pushValueAndType(I.getOperand(i), InstID, Vals);
2300     break;
2301   }
2302   case Instruction::ExtractValue: {
2303     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
2304     pushValueAndType(I.getOperand(0), InstID, Vals);
2305     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
2306     Vals.append(EVI->idx_begin(), EVI->idx_end());
2307     break;
2308   }
2309   case Instruction::InsertValue: {
2310     Code = bitc::FUNC_CODE_INST_INSERTVAL;
2311     pushValueAndType(I.getOperand(0), InstID, Vals);
2312     pushValueAndType(I.getOperand(1), InstID, Vals);
2313     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
2314     Vals.append(IVI->idx_begin(), IVI->idx_end());
2315     break;
2316   }
2317   case Instruction::Select:
2318     Code = bitc::FUNC_CODE_INST_VSELECT;
2319     pushValueAndType(I.getOperand(1), InstID, Vals);
2320     pushValue(I.getOperand(2), InstID, Vals);
2321     pushValueAndType(I.getOperand(0), InstID, Vals);
2322     break;
2323   case Instruction::ExtractElement:
2324     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
2325     pushValueAndType(I.getOperand(0), InstID, Vals);
2326     pushValueAndType(I.getOperand(1), InstID, Vals);
2327     break;
2328   case Instruction::InsertElement:
2329     Code = bitc::FUNC_CODE_INST_INSERTELT;
2330     pushValueAndType(I.getOperand(0), InstID, Vals);
2331     pushValue(I.getOperand(1), InstID, Vals);
2332     pushValueAndType(I.getOperand(2), InstID, Vals);
2333     break;
2334   case Instruction::ShuffleVector:
2335     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
2336     pushValueAndType(I.getOperand(0), InstID, Vals);
2337     pushValue(I.getOperand(1), InstID, Vals);
2338     pushValue(I.getOperand(2), InstID, Vals);
2339     break;
2340   case Instruction::ICmp:
2341   case Instruction::FCmp: {
2342     // compare returning Int1Ty or vector of Int1Ty
2343     Code = bitc::FUNC_CODE_INST_CMP2;
2344     pushValueAndType(I.getOperand(0), InstID, Vals);
2345     pushValue(I.getOperand(1), InstID, Vals);
2346     Vals.push_back(cast<CmpInst>(I).getPredicate());
2347     uint64_t Flags = getOptimizationFlags(&I);
2348     if (Flags != 0)
2349       Vals.push_back(Flags);
2350     break;
2351   }
2352 
2353   case Instruction::Ret:
2354     {
2355       Code = bitc::FUNC_CODE_INST_RET;
2356       unsigned NumOperands = I.getNumOperands();
2357       if (NumOperands == 0)
2358         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
2359       else if (NumOperands == 1) {
2360         if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2361           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
2362       } else {
2363         for (unsigned i = 0, e = NumOperands; i != e; ++i)
2364           pushValueAndType(I.getOperand(i), InstID, Vals);
2365       }
2366     }
2367     break;
2368   case Instruction::Br:
2369     {
2370       Code = bitc::FUNC_CODE_INST_BR;
2371       const BranchInst &II = cast<BranchInst>(I);
2372       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
2373       if (II.isConditional()) {
2374         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
2375         pushValue(II.getCondition(), InstID, Vals);
2376       }
2377     }
2378     break;
2379   case Instruction::Switch:
2380     {
2381       Code = bitc::FUNC_CODE_INST_SWITCH;
2382       const SwitchInst &SI = cast<SwitchInst>(I);
2383       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
2384       pushValue(SI.getCondition(), InstID, Vals);
2385       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
2386       for (SwitchInst::ConstCaseIt Case : SI.cases()) {
2387         Vals.push_back(VE.getValueID(Case.getCaseValue()));
2388         Vals.push_back(VE.getValueID(Case.getCaseSuccessor()));
2389       }
2390     }
2391     break;
2392   case Instruction::IndirectBr:
2393     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
2394     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
2395     // Encode the address operand as relative, but not the basic blocks.
2396     pushValue(I.getOperand(0), InstID, Vals);
2397     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
2398       Vals.push_back(VE.getValueID(I.getOperand(i)));
2399     break;
2400 
2401   case Instruction::Invoke: {
2402     const InvokeInst *II = cast<InvokeInst>(&I);
2403     const Value *Callee = II->getCalledValue();
2404     FunctionType *FTy = II->getFunctionType();
2405 
2406     if (II->hasOperandBundles())
2407       writeOperandBundles(II, InstID);
2408 
2409     Code = bitc::FUNC_CODE_INST_INVOKE;
2410 
2411     Vals.push_back(VE.getAttributeID(II->getAttributes()));
2412     Vals.push_back(II->getCallingConv() | 1 << 13);
2413     Vals.push_back(VE.getValueID(II->getNormalDest()));
2414     Vals.push_back(VE.getValueID(II->getUnwindDest()));
2415     Vals.push_back(VE.getTypeID(FTy));
2416     pushValueAndType(Callee, InstID, Vals);
2417 
2418     // Emit value #'s for the fixed parameters.
2419     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
2420       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
2421 
2422     // Emit type/value pairs for varargs params.
2423     if (FTy->isVarArg()) {
2424       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
2425            i != e; ++i)
2426         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
2427     }
2428     break;
2429   }
2430   case Instruction::Resume:
2431     Code = bitc::FUNC_CODE_INST_RESUME;
2432     pushValueAndType(I.getOperand(0), InstID, Vals);
2433     break;
2434   case Instruction::CleanupRet: {
2435     Code = bitc::FUNC_CODE_INST_CLEANUPRET;
2436     const auto &CRI = cast<CleanupReturnInst>(I);
2437     pushValue(CRI.getCleanupPad(), InstID, Vals);
2438     if (CRI.hasUnwindDest())
2439       Vals.push_back(VE.getValueID(CRI.getUnwindDest()));
2440     break;
2441   }
2442   case Instruction::CatchRet: {
2443     Code = bitc::FUNC_CODE_INST_CATCHRET;
2444     const auto &CRI = cast<CatchReturnInst>(I);
2445     pushValue(CRI.getCatchPad(), InstID, Vals);
2446     Vals.push_back(VE.getValueID(CRI.getSuccessor()));
2447     break;
2448   }
2449   case Instruction::CleanupPad:
2450   case Instruction::CatchPad: {
2451     const auto &FuncletPad = cast<FuncletPadInst>(I);
2452     Code = isa<CatchPadInst>(FuncletPad) ? bitc::FUNC_CODE_INST_CATCHPAD
2453                                          : bitc::FUNC_CODE_INST_CLEANUPPAD;
2454     pushValue(FuncletPad.getParentPad(), InstID, Vals);
2455 
2456     unsigned NumArgOperands = FuncletPad.getNumArgOperands();
2457     Vals.push_back(NumArgOperands);
2458     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
2459       pushValueAndType(FuncletPad.getArgOperand(Op), InstID, Vals);
2460     break;
2461   }
2462   case Instruction::CatchSwitch: {
2463     Code = bitc::FUNC_CODE_INST_CATCHSWITCH;
2464     const auto &CatchSwitch = cast<CatchSwitchInst>(I);
2465 
2466     pushValue(CatchSwitch.getParentPad(), InstID, Vals);
2467 
2468     unsigned NumHandlers = CatchSwitch.getNumHandlers();
2469     Vals.push_back(NumHandlers);
2470     for (const BasicBlock *CatchPadBB : CatchSwitch.handlers())
2471       Vals.push_back(VE.getValueID(CatchPadBB));
2472 
2473     if (CatchSwitch.hasUnwindDest())
2474       Vals.push_back(VE.getValueID(CatchSwitch.getUnwindDest()));
2475     break;
2476   }
2477   case Instruction::Unreachable:
2478     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
2479     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
2480     break;
2481 
2482   case Instruction::PHI: {
2483     const PHINode &PN = cast<PHINode>(I);
2484     Code = bitc::FUNC_CODE_INST_PHI;
2485     // With the newer instruction encoding, forward references could give
2486     // negative valued IDs.  This is most common for PHIs, so we use
2487     // signed VBRs.
2488     SmallVector<uint64_t, 128> Vals64;
2489     Vals64.push_back(VE.getTypeID(PN.getType()));
2490     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
2491       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64);
2492       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
2493     }
2494     // Emit a Vals64 vector and exit.
2495     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
2496     Vals64.clear();
2497     return;
2498   }
2499 
2500   case Instruction::LandingPad: {
2501     const LandingPadInst &LP = cast<LandingPadInst>(I);
2502     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
2503     Vals.push_back(VE.getTypeID(LP.getType()));
2504     Vals.push_back(LP.isCleanup());
2505     Vals.push_back(LP.getNumClauses());
2506     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
2507       if (LP.isCatch(I))
2508         Vals.push_back(LandingPadInst::Catch);
2509       else
2510         Vals.push_back(LandingPadInst::Filter);
2511       pushValueAndType(LP.getClause(I), InstID, Vals);
2512     }
2513     break;
2514   }
2515 
2516   case Instruction::Alloca: {
2517     Code = bitc::FUNC_CODE_INST_ALLOCA;
2518     const AllocaInst &AI = cast<AllocaInst>(I);
2519     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
2520     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
2521     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
2522     unsigned AlignRecord = Log2_32(AI.getAlignment()) + 1;
2523     assert(Log2_32(Value::MaximumAlignment) + 1 < 1 << 5 &&
2524            "not enough bits for maximum alignment");
2525     assert(AlignRecord < 1 << 5 && "alignment greater than 1 << 64");
2526     AlignRecord |= AI.isUsedWithInAlloca() << 5;
2527     AlignRecord |= 1 << 6;
2528     AlignRecord |= AI.isSwiftError() << 7;
2529     Vals.push_back(AlignRecord);
2530     break;
2531   }
2532 
2533   case Instruction::Load:
2534     if (cast<LoadInst>(I).isAtomic()) {
2535       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
2536       pushValueAndType(I.getOperand(0), InstID, Vals);
2537     } else {
2538       Code = bitc::FUNC_CODE_INST_LOAD;
2539       if (!pushValueAndType(I.getOperand(0), InstID, Vals)) // ptr
2540         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
2541     }
2542     Vals.push_back(VE.getTypeID(I.getType()));
2543     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
2544     Vals.push_back(cast<LoadInst>(I).isVolatile());
2545     if (cast<LoadInst>(I).isAtomic()) {
2546       Vals.push_back(getEncodedOrdering(cast<LoadInst>(I).getOrdering()));
2547       Vals.push_back(getEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
2548     }
2549     break;
2550   case Instruction::Store:
2551     if (cast<StoreInst>(I).isAtomic())
2552       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
2553     else
2554       Code = bitc::FUNC_CODE_INST_STORE;
2555     pushValueAndType(I.getOperand(1), InstID, Vals); // ptrty + ptr
2556     pushValueAndType(I.getOperand(0), InstID, Vals); // valty + val
2557     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
2558     Vals.push_back(cast<StoreInst>(I).isVolatile());
2559     if (cast<StoreInst>(I).isAtomic()) {
2560       Vals.push_back(getEncodedOrdering(cast<StoreInst>(I).getOrdering()));
2561       Vals.push_back(getEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
2562     }
2563     break;
2564   case Instruction::AtomicCmpXchg:
2565     Code = bitc::FUNC_CODE_INST_CMPXCHG;
2566     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
2567     pushValueAndType(I.getOperand(1), InstID, Vals); // cmp.
2568     pushValue(I.getOperand(2), InstID, Vals);        // newval.
2569     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
2570     Vals.push_back(
2571         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
2572     Vals.push_back(
2573         getEncodedSynchScope(cast<AtomicCmpXchgInst>(I).getSynchScope()));
2574     Vals.push_back(
2575         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
2576     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
2577     break;
2578   case Instruction::AtomicRMW:
2579     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
2580     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
2581     pushValue(I.getOperand(1), InstID, Vals);        // val.
2582     Vals.push_back(
2583         getEncodedRMWOperation(cast<AtomicRMWInst>(I).getOperation()));
2584     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
2585     Vals.push_back(getEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
2586     Vals.push_back(
2587         getEncodedSynchScope(cast<AtomicRMWInst>(I).getSynchScope()));
2588     break;
2589   case Instruction::Fence:
2590     Code = bitc::FUNC_CODE_INST_FENCE;
2591     Vals.push_back(getEncodedOrdering(cast<FenceInst>(I).getOrdering()));
2592     Vals.push_back(getEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
2593     break;
2594   case Instruction::Call: {
2595     const CallInst &CI = cast<CallInst>(I);
2596     FunctionType *FTy = CI.getFunctionType();
2597 
2598     if (CI.hasOperandBundles())
2599       writeOperandBundles(&CI, InstID);
2600 
2601     Code = bitc::FUNC_CODE_INST_CALL;
2602 
2603     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
2604 
2605     unsigned Flags = getOptimizationFlags(&I);
2606     Vals.push_back(CI.getCallingConv() << bitc::CALL_CCONV |
2607                    unsigned(CI.isTailCall()) << bitc::CALL_TAIL |
2608                    unsigned(CI.isMustTailCall()) << bitc::CALL_MUSTTAIL |
2609                    1 << bitc::CALL_EXPLICIT_TYPE |
2610                    unsigned(CI.isNoTailCall()) << bitc::CALL_NOTAIL |
2611                    unsigned(Flags != 0) << bitc::CALL_FMF);
2612     if (Flags != 0)
2613       Vals.push_back(Flags);
2614 
2615     Vals.push_back(VE.getTypeID(FTy));
2616     pushValueAndType(CI.getCalledValue(), InstID, Vals); // Callee
2617 
2618     // Emit value #'s for the fixed parameters.
2619     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
2620       // Check for labels (can happen with asm labels).
2621       if (FTy->getParamType(i)->isLabelTy())
2622         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
2623       else
2624         pushValue(CI.getArgOperand(i), InstID, Vals); // fixed param.
2625     }
2626 
2627     // Emit type/value pairs for varargs params.
2628     if (FTy->isVarArg()) {
2629       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
2630            i != e; ++i)
2631         pushValueAndType(CI.getArgOperand(i), InstID, Vals); // varargs
2632     }
2633     break;
2634   }
2635   case Instruction::VAArg:
2636     Code = bitc::FUNC_CODE_INST_VAARG;
2637     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
2638     pushValue(I.getOperand(0), InstID, Vals);                   // valist.
2639     Vals.push_back(VE.getTypeID(I.getType())); // restype.
2640     break;
2641   }
2642 
2643   Stream.EmitRecord(Code, Vals, AbbrevToUse);
2644   Vals.clear();
2645 }
2646 
2647 /// Emit names for globals/functions etc. \p IsModuleLevel is true when
2648 /// we are writing the module-level VST, where we are including a function
2649 /// bitcode index and need to backpatch the VST forward declaration record.
2650 void ModuleBitcodeWriter::writeValueSymbolTable(
2651     const ValueSymbolTable &VST, bool IsModuleLevel,
2652     DenseMap<const Function *, uint64_t> *FunctionToBitcodeIndex) {
2653   if (VST.empty()) {
2654     // writeValueSymbolTableForwardDecl should have returned early as
2655     // well. Ensure this handling remains in sync by asserting that
2656     // the placeholder offset is not set.
2657     assert(!IsModuleLevel || !hasVSTOffsetPlaceholder());
2658     return;
2659   }
2660 
2661   if (IsModuleLevel && hasVSTOffsetPlaceholder()) {
2662     // Get the offset of the VST we are writing, and backpatch it into
2663     // the VST forward declaration record.
2664     uint64_t VSTOffset = Stream.GetCurrentBitNo();
2665     // The BitcodeStartBit was the stream offset of the actual bitcode
2666     // (e.g. excluding any initial darwin header).
2667     VSTOffset -= bitcodeStartBit();
2668     assert((VSTOffset & 31) == 0 && "VST block not 32-bit aligned");
2669     Stream.BackpatchWord(VSTOffsetPlaceholder, VSTOffset / 32);
2670   }
2671 
2672   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
2673 
2674   // For the module-level VST, add abbrev Ids for the VST_CODE_FNENTRY
2675   // records, which are not used in the per-function VSTs.
2676   unsigned FnEntry8BitAbbrev;
2677   unsigned FnEntry7BitAbbrev;
2678   unsigned FnEntry6BitAbbrev;
2679   if (IsModuleLevel && hasVSTOffsetPlaceholder()) {
2680     // 8-bit fixed-width VST_CODE_FNENTRY function strings.
2681     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2682     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
2683     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
2684     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
2685     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2686     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2687     FnEntry8BitAbbrev = Stream.EmitAbbrev(Abbv);
2688 
2689     // 7-bit fixed width VST_CODE_FNENTRY function strings.
2690     Abbv = new BitCodeAbbrev();
2691     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
2692     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
2693     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
2694     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2695     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2696     FnEntry7BitAbbrev = Stream.EmitAbbrev(Abbv);
2697 
2698     // 6-bit char6 VST_CODE_FNENTRY function strings.
2699     Abbv = new BitCodeAbbrev();
2700     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
2701     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
2702     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
2703     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2704     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2705     FnEntry6BitAbbrev = Stream.EmitAbbrev(Abbv);
2706   }
2707 
2708   // FIXME: Set up the abbrev, we know how many values there are!
2709   // FIXME: We know if the type names can use 7-bit ascii.
2710   SmallVector<unsigned, 64> NameVals;
2711 
2712   for (const ValueName &Name : VST) {
2713     // Figure out the encoding to use for the name.
2714     StringEncoding Bits =
2715         getStringEncoding(Name.getKeyData(), Name.getKeyLength());
2716 
2717     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
2718     NameVals.push_back(VE.getValueID(Name.getValue()));
2719 
2720     Function *F = dyn_cast<Function>(Name.getValue());
2721     if (!F) {
2722       // If value is an alias, need to get the aliased base object to
2723       // see if it is a function.
2724       auto *GA = dyn_cast<GlobalAlias>(Name.getValue());
2725       if (GA && GA->getBaseObject())
2726         F = dyn_cast<Function>(GA->getBaseObject());
2727     }
2728 
2729     // VST_CODE_ENTRY:   [valueid, namechar x N]
2730     // VST_CODE_FNENTRY: [valueid, funcoffset, namechar x N]
2731     // VST_CODE_BBENTRY: [bbid, namechar x N]
2732     unsigned Code;
2733     if (isa<BasicBlock>(Name.getValue())) {
2734       Code = bitc::VST_CODE_BBENTRY;
2735       if (Bits == SE_Char6)
2736         AbbrevToUse = VST_BBENTRY_6_ABBREV;
2737     } else if (F && !F->isDeclaration()) {
2738       // Must be the module-level VST, where we pass in the Index and
2739       // have a VSTOffsetPlaceholder. The function-level VST should not
2740       // contain any Function symbols.
2741       assert(FunctionToBitcodeIndex);
2742       assert(hasVSTOffsetPlaceholder());
2743 
2744       // Save the word offset of the function (from the start of the
2745       // actual bitcode written to the stream).
2746       uint64_t BitcodeIndex = (*FunctionToBitcodeIndex)[F] - bitcodeStartBit();
2747       assert((BitcodeIndex & 31) == 0 && "function block not 32-bit aligned");
2748       NameVals.push_back(BitcodeIndex / 32);
2749 
2750       Code = bitc::VST_CODE_FNENTRY;
2751       AbbrevToUse = FnEntry8BitAbbrev;
2752       if (Bits == SE_Char6)
2753         AbbrevToUse = FnEntry6BitAbbrev;
2754       else if (Bits == SE_Fixed7)
2755         AbbrevToUse = FnEntry7BitAbbrev;
2756     } else {
2757       Code = bitc::VST_CODE_ENTRY;
2758       if (Bits == SE_Char6)
2759         AbbrevToUse = VST_ENTRY_6_ABBREV;
2760       else if (Bits == SE_Fixed7)
2761         AbbrevToUse = VST_ENTRY_7_ABBREV;
2762     }
2763 
2764     for (const auto P : Name.getKey())
2765       NameVals.push_back((unsigned char)P);
2766 
2767     // Emit the finished record.
2768     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
2769     NameVals.clear();
2770   }
2771   Stream.ExitBlock();
2772 }
2773 
2774 /// Emit function names and summary offsets for the combined index
2775 /// used by ThinLTO.
2776 void IndexBitcodeWriter::writeCombinedValueSymbolTable() {
2777   assert(hasVSTOffsetPlaceholder() && "Expected non-zero VSTOffsetPlaceholder");
2778   // Get the offset of the VST we are writing, and backpatch it into
2779   // the VST forward declaration record.
2780   uint64_t VSTOffset = Stream.GetCurrentBitNo();
2781   assert((VSTOffset & 31) == 0 && "VST block not 32-bit aligned");
2782   Stream.BackpatchWord(VSTOffsetPlaceholder, VSTOffset / 32);
2783 
2784   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
2785 
2786   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2787   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_COMBINED_ENTRY));
2788   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
2789   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // refguid
2790   unsigned EntryAbbrev = Stream.EmitAbbrev(Abbv);
2791 
2792   SmallVector<uint64_t, 64> NameVals;
2793   for (const auto &GVI : valueIds()) {
2794     // VST_CODE_COMBINED_ENTRY: [valueid, refguid]
2795     NameVals.push_back(GVI.second);
2796     NameVals.push_back(GVI.first);
2797 
2798     // Emit the finished record.
2799     Stream.EmitRecord(bitc::VST_CODE_COMBINED_ENTRY, NameVals, EntryAbbrev);
2800     NameVals.clear();
2801   }
2802   Stream.ExitBlock();
2803 }
2804 
2805 void ModuleBitcodeWriter::writeUseList(UseListOrder &&Order) {
2806   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
2807   unsigned Code;
2808   if (isa<BasicBlock>(Order.V))
2809     Code = bitc::USELIST_CODE_BB;
2810   else
2811     Code = bitc::USELIST_CODE_DEFAULT;
2812 
2813   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
2814   Record.push_back(VE.getValueID(Order.V));
2815   Stream.EmitRecord(Code, Record);
2816 }
2817 
2818 void ModuleBitcodeWriter::writeUseListBlock(const Function *F) {
2819   assert(VE.shouldPreserveUseListOrder() &&
2820          "Expected to be preserving use-list order");
2821 
2822   auto hasMore = [&]() {
2823     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
2824   };
2825   if (!hasMore())
2826     // Nothing to do.
2827     return;
2828 
2829   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
2830   while (hasMore()) {
2831     writeUseList(std::move(VE.UseListOrders.back()));
2832     VE.UseListOrders.pop_back();
2833   }
2834   Stream.ExitBlock();
2835 }
2836 
2837 /// Emit a function body to the module stream.
2838 void ModuleBitcodeWriter::writeFunction(
2839     const Function &F,
2840     DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex) {
2841   // Save the bitcode index of the start of this function block for recording
2842   // in the VST.
2843   FunctionToBitcodeIndex[&F] = Stream.GetCurrentBitNo();
2844 
2845   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
2846   VE.incorporateFunction(F);
2847 
2848   SmallVector<unsigned, 64> Vals;
2849 
2850   // Emit the number of basic blocks, so the reader can create them ahead of
2851   // time.
2852   Vals.push_back(VE.getBasicBlocks().size());
2853   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
2854   Vals.clear();
2855 
2856   // If there are function-local constants, emit them now.
2857   unsigned CstStart, CstEnd;
2858   VE.getFunctionConstantRange(CstStart, CstEnd);
2859   writeConstants(CstStart, CstEnd, false);
2860 
2861   // If there is function-local metadata, emit it now.
2862   writeFunctionMetadata(F);
2863 
2864   // Keep a running idea of what the instruction ID is.
2865   unsigned InstID = CstEnd;
2866 
2867   bool NeedsMetadataAttachment = F.hasMetadata();
2868 
2869   DILocation *LastDL = nullptr;
2870   // Finally, emit all the instructions, in order.
2871   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
2872     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
2873          I != E; ++I) {
2874       writeInstruction(*I, InstID, Vals);
2875 
2876       if (!I->getType()->isVoidTy())
2877         ++InstID;
2878 
2879       // If the instruction has metadata, write a metadata attachment later.
2880       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
2881 
2882       // If the instruction has a debug location, emit it.
2883       DILocation *DL = I->getDebugLoc();
2884       if (!DL)
2885         continue;
2886 
2887       if (DL == LastDL) {
2888         // Just repeat the same debug loc as last time.
2889         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
2890         continue;
2891       }
2892 
2893       Vals.push_back(DL->getLine());
2894       Vals.push_back(DL->getColumn());
2895       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
2896       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
2897       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
2898       Vals.clear();
2899 
2900       LastDL = DL;
2901     }
2902 
2903   // Emit names for all the instructions etc.
2904   writeValueSymbolTable(F.getValueSymbolTable());
2905 
2906   if (NeedsMetadataAttachment)
2907     writeFunctionMetadataAttachment(F);
2908   if (VE.shouldPreserveUseListOrder())
2909     writeUseListBlock(&F);
2910   VE.purgeFunction();
2911   Stream.ExitBlock();
2912 }
2913 
2914 // Emit blockinfo, which defines the standard abbreviations etc.
2915 void ModuleBitcodeWriter::writeBlockInfo() {
2916   // We only want to emit block info records for blocks that have multiple
2917   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
2918   // Other blocks can define their abbrevs inline.
2919   Stream.EnterBlockInfoBlock(2);
2920 
2921   { // 8-bit fixed-width VST_CODE_ENTRY/VST_CODE_BBENTRY strings.
2922     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2923     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
2924     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2925     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2926     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2927     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
2928         VST_ENTRY_8_ABBREV)
2929       llvm_unreachable("Unexpected abbrev ordering!");
2930   }
2931 
2932   { // 7-bit fixed width VST_CODE_ENTRY strings.
2933     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2934     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2935     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2936     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2937     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2938     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
2939         VST_ENTRY_7_ABBREV)
2940       llvm_unreachable("Unexpected abbrev ordering!");
2941   }
2942   { // 6-bit char6 VST_CODE_ENTRY strings.
2943     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2944     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2945     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2946     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2947     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2948     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
2949         VST_ENTRY_6_ABBREV)
2950       llvm_unreachable("Unexpected abbrev ordering!");
2951   }
2952   { // 6-bit char6 VST_CODE_BBENTRY strings.
2953     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2954     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
2955     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2956     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2957     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2958     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
2959         VST_BBENTRY_6_ABBREV)
2960       llvm_unreachable("Unexpected abbrev ordering!");
2961   }
2962 
2963 
2964 
2965   { // SETTYPE abbrev for CONSTANTS_BLOCK.
2966     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2967     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
2968     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2969                               VE.computeBitsRequiredForTypeIndicies()));
2970     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
2971         CONSTANTS_SETTYPE_ABBREV)
2972       llvm_unreachable("Unexpected abbrev ordering!");
2973   }
2974 
2975   { // INTEGER abbrev for CONSTANTS_BLOCK.
2976     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2977     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
2978     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2979     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
2980         CONSTANTS_INTEGER_ABBREV)
2981       llvm_unreachable("Unexpected abbrev ordering!");
2982   }
2983 
2984   { // CE_CAST abbrev for CONSTANTS_BLOCK.
2985     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2986     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
2987     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
2988     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
2989                               VE.computeBitsRequiredForTypeIndicies()));
2990     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
2991 
2992     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
2993         CONSTANTS_CE_CAST_Abbrev)
2994       llvm_unreachable("Unexpected abbrev ordering!");
2995   }
2996   { // NULL abbrev for CONSTANTS_BLOCK.
2997     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2998     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
2999     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
3000         CONSTANTS_NULL_Abbrev)
3001       llvm_unreachable("Unexpected abbrev ordering!");
3002   }
3003 
3004   // FIXME: This should only use space for first class types!
3005 
3006   { // INST_LOAD abbrev for FUNCTION_BLOCK.
3007     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3008     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
3009     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
3010     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
3011                               VE.computeBitsRequiredForTypeIndicies()));
3012     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
3013     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
3014     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3015         FUNCTION_INST_LOAD_ABBREV)
3016       llvm_unreachable("Unexpected abbrev ordering!");
3017   }
3018   { // INST_BINOP abbrev for FUNCTION_BLOCK.
3019     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3020     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
3021     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3022     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
3023     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3024     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3025         FUNCTION_INST_BINOP_ABBREV)
3026       llvm_unreachable("Unexpected abbrev ordering!");
3027   }
3028   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
3029     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3030     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
3031     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
3032     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
3033     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
3034     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
3035     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3036         FUNCTION_INST_BINOP_FLAGS_ABBREV)
3037       llvm_unreachable("Unexpected abbrev ordering!");
3038   }
3039   { // INST_CAST abbrev for FUNCTION_BLOCK.
3040     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3041     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
3042     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
3043     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
3044                               VE.computeBitsRequiredForTypeIndicies()));
3045     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
3046     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3047         FUNCTION_INST_CAST_ABBREV)
3048       llvm_unreachable("Unexpected abbrev ordering!");
3049   }
3050 
3051   { // INST_RET abbrev for FUNCTION_BLOCK.
3052     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3053     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
3054     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3055         FUNCTION_INST_RET_VOID_ABBREV)
3056       llvm_unreachable("Unexpected abbrev ordering!");
3057   }
3058   { // INST_RET abbrev for FUNCTION_BLOCK.
3059     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3060     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
3061     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
3062     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3063         FUNCTION_INST_RET_VAL_ABBREV)
3064       llvm_unreachable("Unexpected abbrev ordering!");
3065   }
3066   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
3067     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3068     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
3069     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3070         FUNCTION_INST_UNREACHABLE_ABBREV)
3071       llvm_unreachable("Unexpected abbrev ordering!");
3072   }
3073   {
3074     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3075     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
3076     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
3077     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
3078                               Log2_32_Ceil(VE.getTypes().size() + 1)));
3079     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3080     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
3081     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
3082         FUNCTION_INST_GEP_ABBREV)
3083       llvm_unreachable("Unexpected abbrev ordering!");
3084   }
3085 
3086   Stream.ExitBlock();
3087 }
3088 
3089 /// Write the module path strings, currently only used when generating
3090 /// a combined index file.
3091 void IndexBitcodeWriter::writeModStrings() {
3092   Stream.EnterSubblock(bitc::MODULE_STRTAB_BLOCK_ID, 3);
3093 
3094   // TODO: See which abbrev sizes we actually need to emit
3095 
3096   // 8-bit fixed-width MST_ENTRY strings.
3097   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3098   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3099   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3100   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3101   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
3102   unsigned Abbrev8Bit = Stream.EmitAbbrev(Abbv);
3103 
3104   // 7-bit fixed width MST_ENTRY strings.
3105   Abbv = new BitCodeAbbrev();
3106   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3107   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3108   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3109   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
3110   unsigned Abbrev7Bit = Stream.EmitAbbrev(Abbv);
3111 
3112   // 6-bit char6 MST_ENTRY strings.
3113   Abbv = new BitCodeAbbrev();
3114   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
3115   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3116   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3117   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3118   unsigned Abbrev6Bit = Stream.EmitAbbrev(Abbv);
3119 
3120   // Module Hash, 160 bits SHA1. Optionally, emitted after each MST_CODE_ENTRY.
3121   Abbv = new BitCodeAbbrev();
3122   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_HASH));
3123   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3124   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3125   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3126   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3127   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3128   unsigned AbbrevHash = Stream.EmitAbbrev(Abbv);
3129 
3130   SmallVector<unsigned, 64> Vals;
3131   for (const auto &MPSE : Index.modulePaths()) {
3132     if (!doIncludeModule(MPSE.getKey()))
3133       continue;
3134     StringEncoding Bits =
3135         getStringEncoding(MPSE.getKey().data(), MPSE.getKey().size());
3136     unsigned AbbrevToUse = Abbrev8Bit;
3137     if (Bits == SE_Char6)
3138       AbbrevToUse = Abbrev6Bit;
3139     else if (Bits == SE_Fixed7)
3140       AbbrevToUse = Abbrev7Bit;
3141 
3142     Vals.push_back(MPSE.getValue().first);
3143 
3144     for (const auto P : MPSE.getKey())
3145       Vals.push_back((unsigned char)P);
3146 
3147     // Emit the finished record.
3148     Stream.EmitRecord(bitc::MST_CODE_ENTRY, Vals, AbbrevToUse);
3149 
3150     Vals.clear();
3151     // Emit an optional hash for the module now
3152     auto &Hash = MPSE.getValue().second;
3153     bool AllZero = true; // Detect if the hash is empty, and do not generate it
3154     for (auto Val : Hash) {
3155       if (Val)
3156         AllZero = false;
3157       Vals.push_back(Val);
3158     }
3159     if (!AllZero) {
3160       // Emit the hash record.
3161       Stream.EmitRecord(bitc::MST_CODE_HASH, Vals, AbbrevHash);
3162     }
3163 
3164     Vals.clear();
3165   }
3166   Stream.ExitBlock();
3167 }
3168 
3169 // Helper to emit a single function summary record.
3170 void ModuleBitcodeWriter::writePerModuleFunctionSummaryRecord(
3171     SmallVector<uint64_t, 64> &NameVals, GlobalValueSummary *Summary,
3172     unsigned ValueID, unsigned FSCallsAbbrev, unsigned FSCallsProfileAbbrev,
3173     const Function &F) {
3174   NameVals.push_back(ValueID);
3175 
3176   FunctionSummary *FS = cast<FunctionSummary>(Summary);
3177   NameVals.push_back(getEncodedGVSummaryFlags(FS->flags()));
3178   NameVals.push_back(FS->instCount());
3179   NameVals.push_back(FS->refs().size());
3180 
3181   unsigned SizeBeforeRefs = NameVals.size();
3182   for (auto &RI : FS->refs())
3183     NameVals.push_back(VE.getValueID(RI.getValue()));
3184   // Sort the refs for determinism output, the vector returned by FS->refs() has
3185   // been initialized from a DenseSet.
3186   std::sort(NameVals.begin() + SizeBeforeRefs, NameVals.end());
3187 
3188   std::vector<FunctionSummary::EdgeTy> Calls = FS->calls();
3189   std::sort(Calls.begin(), Calls.end(),
3190             [this](const FunctionSummary::EdgeTy &L,
3191                    const FunctionSummary::EdgeTy &R) {
3192               return VE.getValueID(L.first.getValue()) <
3193                      VE.getValueID(R.first.getValue());
3194             });
3195   bool HasProfileData = F.getEntryCount().hasValue();
3196   for (auto &ECI : Calls) {
3197     NameVals.push_back(VE.getValueID(ECI.first.getValue()));
3198     assert(ECI.second.CallsiteCount > 0 && "Expected at least one callsite");
3199     NameVals.push_back(ECI.second.CallsiteCount);
3200     if (HasProfileData)
3201       NameVals.push_back(ECI.second.ProfileCount);
3202   }
3203 
3204   unsigned FSAbbrev = (HasProfileData ? FSCallsProfileAbbrev : FSCallsAbbrev);
3205   unsigned Code =
3206       (HasProfileData ? bitc::FS_PERMODULE_PROFILE : bitc::FS_PERMODULE);
3207 
3208   // Emit the finished record.
3209   Stream.EmitRecord(Code, NameVals, FSAbbrev);
3210   NameVals.clear();
3211 }
3212 
3213 // Collect the global value references in the given variable's initializer,
3214 // and emit them in a summary record.
3215 void ModuleBitcodeWriter::writeModuleLevelReferences(
3216     const GlobalVariable &V, SmallVector<uint64_t, 64> &NameVals,
3217     unsigned FSModRefsAbbrev) {
3218   // Only interested in recording variable defs in the summary.
3219   if (V.isDeclaration())
3220     return;
3221   NameVals.push_back(VE.getValueID(&V));
3222   NameVals.push_back(getEncodedGVSummaryFlags(V));
3223   auto *Summary = Index->getGlobalValueSummary(V);
3224   GlobalVarSummary *VS = cast<GlobalVarSummary>(Summary);
3225 
3226   unsigned SizeBeforeRefs = NameVals.size();
3227   for (auto &RI : VS->refs())
3228     NameVals.push_back(VE.getValueID(RI.getValue()));
3229   // Sort the refs for determinism output, the vector returned by FS->refs() has
3230   // been initialized from a DenseSet.
3231   std::sort(NameVals.begin() + SizeBeforeRefs, NameVals.end());
3232 
3233   Stream.EmitRecord(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS, NameVals,
3234                     FSModRefsAbbrev);
3235   NameVals.clear();
3236 }
3237 
3238 // Current version for the summary.
3239 // This is bumped whenever we introduce changes in the way some record are
3240 // interpreted, like flags for instance.
3241 static const uint64_t INDEX_VERSION = 1;
3242 
3243 /// Emit the per-module summary section alongside the rest of
3244 /// the module's bitcode.
3245 void ModuleBitcodeWriter::writePerModuleGlobalValueSummary() {
3246   if (M.empty())
3247     return;
3248 
3249   if (Index->begin() == Index->end())
3250     return;
3251 
3252   Stream.EnterSubblock(bitc::GLOBALVAL_SUMMARY_BLOCK_ID, 4);
3253 
3254   Stream.EmitRecord(bitc::FS_VERSION, ArrayRef<uint64_t>{INDEX_VERSION});
3255 
3256   // Abbrev for FS_PERMODULE.
3257   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3258   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE));
3259   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3260   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3261   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
3262   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
3263   // numrefs x valueid, n x (valueid, callsitecount)
3264   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3265   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3266   unsigned FSCallsAbbrev = Stream.EmitAbbrev(Abbv);
3267 
3268   // Abbrev for FS_PERMODULE_PROFILE.
3269   Abbv = new BitCodeAbbrev();
3270   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_PROFILE));
3271   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3272   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3273   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
3274   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
3275   // numrefs x valueid, n x (valueid, callsitecount, profilecount)
3276   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3277   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3278   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(Abbv);
3279 
3280   // Abbrev for FS_PERMODULE_GLOBALVAR_INIT_REFS.
3281   Abbv = new BitCodeAbbrev();
3282   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS));
3283   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
3284   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
3285   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));  // valueids
3286   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3287   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(Abbv);
3288 
3289   // Abbrev for FS_ALIAS.
3290   Abbv = new BitCodeAbbrev();
3291   Abbv->Add(BitCodeAbbrevOp(bitc::FS_ALIAS));
3292   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3293   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3294   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3295   unsigned FSAliasAbbrev = Stream.EmitAbbrev(Abbv);
3296 
3297   SmallVector<uint64_t, 64> NameVals;
3298   // Iterate over the list of functions instead of the Index to
3299   // ensure the ordering is stable.
3300   for (const Function &F : M) {
3301     if (F.isDeclaration())
3302       continue;
3303     // Summary emission does not support anonymous functions, they have to
3304     // renamed using the anonymous function renaming pass.
3305     if (!F.hasName())
3306       report_fatal_error("Unexpected anonymous function when writing summary");
3307 
3308     auto *Summary = Index->getGlobalValueSummary(F);
3309     writePerModuleFunctionSummaryRecord(NameVals, Summary, VE.getValueID(&F),
3310                                         FSCallsAbbrev, FSCallsProfileAbbrev, F);
3311   }
3312 
3313   // Capture references from GlobalVariable initializers, which are outside
3314   // of a function scope.
3315   for (const GlobalVariable &G : M.globals())
3316     writeModuleLevelReferences(G, NameVals, FSModRefsAbbrev);
3317 
3318   for (const GlobalAlias &A : M.aliases()) {
3319     auto *Aliasee = A.getBaseObject();
3320     if (!Aliasee->hasName())
3321       // Nameless function don't have an entry in the summary, skip it.
3322       continue;
3323     auto AliasId = VE.getValueID(&A);
3324     auto AliaseeId = VE.getValueID(Aliasee);
3325     NameVals.push_back(AliasId);
3326     NameVals.push_back(getEncodedGVSummaryFlags(A));
3327     NameVals.push_back(AliaseeId);
3328     Stream.EmitRecord(bitc::FS_ALIAS, NameVals, FSAliasAbbrev);
3329     NameVals.clear();
3330   }
3331 
3332   Stream.ExitBlock();
3333 }
3334 
3335 /// Emit the combined summary section into the combined index file.
3336 void IndexBitcodeWriter::writeCombinedGlobalValueSummary() {
3337   Stream.EnterSubblock(bitc::GLOBALVAL_SUMMARY_BLOCK_ID, 3);
3338   Stream.EmitRecord(bitc::FS_VERSION, ArrayRef<uint64_t>{INDEX_VERSION});
3339 
3340   // Abbrev for FS_COMBINED.
3341   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3342   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED));
3343   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3344   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
3345   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3346   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
3347   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
3348   // numrefs x valueid, n x (valueid, callsitecount)
3349   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3350   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3351   unsigned FSCallsAbbrev = Stream.EmitAbbrev(Abbv);
3352 
3353   // Abbrev for FS_COMBINED_PROFILE.
3354   Abbv = new BitCodeAbbrev();
3355   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_PROFILE));
3356   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3357   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
3358   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3359   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
3360   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
3361   // numrefs x valueid, n x (valueid, callsitecount, profilecount)
3362   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3363   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3364   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(Abbv);
3365 
3366   // Abbrev for FS_COMBINED_GLOBALVAR_INIT_REFS.
3367   Abbv = new BitCodeAbbrev();
3368   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS));
3369   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3370   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
3371   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3372   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));    // valueids
3373   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3374   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(Abbv);
3375 
3376   // Abbrev for FS_COMBINED_ALIAS.
3377   Abbv = new BitCodeAbbrev();
3378   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_ALIAS));
3379   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3380   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
3381   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3382   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3383   unsigned FSAliasAbbrev = Stream.EmitAbbrev(Abbv);
3384 
3385   // The aliases are emitted as a post-pass, and will point to the value
3386   // id of the aliasee. Save them in a vector for post-processing.
3387   SmallVector<AliasSummary *, 64> Aliases;
3388 
3389   // Save the value id for each summary for alias emission.
3390   DenseMap<const GlobalValueSummary *, unsigned> SummaryToValueIdMap;
3391 
3392   SmallVector<uint64_t, 64> NameVals;
3393 
3394   // For local linkage, we also emit the original name separately
3395   // immediately after the record.
3396   auto MaybeEmitOriginalName = [&](GlobalValueSummary &S) {
3397     if (!GlobalValue::isLocalLinkage(S.linkage()))
3398       return;
3399     NameVals.push_back(S.getOriginalName());
3400     Stream.EmitRecord(bitc::FS_COMBINED_ORIGINAL_NAME, NameVals);
3401     NameVals.clear();
3402   };
3403 
3404   for (const auto &I : *this) {
3405     GlobalValueSummary *S = I.second;
3406     assert(S);
3407 
3408     assert(hasValueId(I.first));
3409     unsigned ValueId = getValueId(I.first);
3410     SummaryToValueIdMap[S] = ValueId;
3411 
3412     if (auto *AS = dyn_cast<AliasSummary>(S)) {
3413       // Will process aliases as a post-pass because the reader wants all
3414       // global to be loaded first.
3415       Aliases.push_back(AS);
3416       continue;
3417     }
3418 
3419     if (auto *VS = dyn_cast<GlobalVarSummary>(S)) {
3420       NameVals.push_back(ValueId);
3421       NameVals.push_back(Index.getModuleId(VS->modulePath()));
3422       NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
3423       for (auto &RI : VS->refs()) {
3424         NameVals.push_back(getValueId(RI.getGUID()));
3425       }
3426 
3427       // Emit the finished record.
3428       Stream.EmitRecord(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS, NameVals,
3429                         FSModRefsAbbrev);
3430       NameVals.clear();
3431       MaybeEmitOriginalName(*S);
3432       continue;
3433     }
3434 
3435     auto *FS = cast<FunctionSummary>(S);
3436     NameVals.push_back(ValueId);
3437     NameVals.push_back(Index.getModuleId(FS->modulePath()));
3438     NameVals.push_back(getEncodedGVSummaryFlags(FS->flags()));
3439     NameVals.push_back(FS->instCount());
3440     NameVals.push_back(FS->refs().size());
3441 
3442     for (auto &RI : FS->refs()) {
3443       NameVals.push_back(getValueId(RI.getGUID()));
3444     }
3445 
3446     bool HasProfileData = false;
3447     for (auto &EI : FS->calls()) {
3448       HasProfileData |= EI.second.ProfileCount != 0;
3449       if (HasProfileData)
3450         break;
3451     }
3452 
3453     for (auto &EI : FS->calls()) {
3454       // If this GUID doesn't have a value id, it doesn't have a function
3455       // summary and we don't need to record any calls to it.
3456       if (!hasValueId(EI.first.getGUID()))
3457         continue;
3458       NameVals.push_back(getValueId(EI.first.getGUID()));
3459       assert(EI.second.CallsiteCount > 0 && "Expected at least one callsite");
3460       NameVals.push_back(EI.second.CallsiteCount);
3461       if (HasProfileData)
3462         NameVals.push_back(EI.second.ProfileCount);
3463     }
3464 
3465     unsigned FSAbbrev = (HasProfileData ? FSCallsProfileAbbrev : FSCallsAbbrev);
3466     unsigned Code =
3467         (HasProfileData ? bitc::FS_COMBINED_PROFILE : bitc::FS_COMBINED);
3468 
3469     // Emit the finished record.
3470     Stream.EmitRecord(Code, NameVals, FSAbbrev);
3471     NameVals.clear();
3472     MaybeEmitOriginalName(*S);
3473   }
3474 
3475   for (auto *AS : Aliases) {
3476     auto AliasValueId = SummaryToValueIdMap[AS];
3477     assert(AliasValueId);
3478     NameVals.push_back(AliasValueId);
3479     NameVals.push_back(Index.getModuleId(AS->modulePath()));
3480     NameVals.push_back(getEncodedGVSummaryFlags(AS->flags()));
3481     auto AliaseeValueId = SummaryToValueIdMap[&AS->getAliasee()];
3482     assert(AliaseeValueId);
3483     NameVals.push_back(AliaseeValueId);
3484 
3485     // Emit the finished record.
3486     Stream.EmitRecord(bitc::FS_COMBINED_ALIAS, NameVals, FSAliasAbbrev);
3487     NameVals.clear();
3488     MaybeEmitOriginalName(*AS);
3489   }
3490 
3491   Stream.ExitBlock();
3492 }
3493 
3494 void ModuleBitcodeWriter::writeIdentificationBlock() {
3495   Stream.EnterSubblock(bitc::IDENTIFICATION_BLOCK_ID, 5);
3496 
3497   // Write the "user readable" string identifying the bitcode producer
3498   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3499   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_STRING));
3500   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3501   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3502   auto StringAbbrev = Stream.EmitAbbrev(Abbv);
3503   writeStringRecord(bitc::IDENTIFICATION_CODE_STRING,
3504                     "LLVM" LLVM_VERSION_STRING, StringAbbrev);
3505 
3506   // Write the epoch version
3507   Abbv = new BitCodeAbbrev();
3508   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_EPOCH));
3509   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
3510   auto EpochAbbrev = Stream.EmitAbbrev(Abbv);
3511   SmallVector<unsigned, 1> Vals = {bitc::BITCODE_CURRENT_EPOCH};
3512   Stream.EmitRecord(bitc::IDENTIFICATION_CODE_EPOCH, Vals, EpochAbbrev);
3513   Stream.ExitBlock();
3514 }
3515 
3516 void ModuleBitcodeWriter::writeModuleHash(size_t BlockStartPos) {
3517   // Emit the module's hash.
3518   // MODULE_CODE_HASH: [5*i32]
3519   SHA1 Hasher;
3520   Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&(Buffer)[BlockStartPos],
3521                                   Buffer.size() - BlockStartPos));
3522   auto Hash = Hasher.result();
3523   SmallVector<uint64_t, 20> Vals;
3524   auto LShift = [&](unsigned char Val, unsigned Amount)
3525                     -> uint64_t { return ((uint64_t)Val) << Amount; };
3526   for (int Pos = 0; Pos < 20; Pos += 4) {
3527     uint32_t SubHash = LShift(Hash[Pos + 0], 24);
3528     SubHash |= LShift(Hash[Pos + 1], 16) | LShift(Hash[Pos + 2], 8) |
3529                (unsigned)(unsigned char)Hash[Pos + 3];
3530     Vals.push_back(SubHash);
3531   }
3532 
3533   // Emit the finished record.
3534   Stream.EmitRecord(bitc::MODULE_CODE_HASH, Vals);
3535 }
3536 
3537 void BitcodeWriter::write() {
3538   // Emit the file header first.
3539   writeBitcodeHeader();
3540 
3541   writeBlocks();
3542 }
3543 
3544 void ModuleBitcodeWriter::writeBlocks() {
3545   writeIdentificationBlock();
3546   writeModule();
3547 }
3548 
3549 void IndexBitcodeWriter::writeBlocks() {
3550   // Index contains only a single outer (module) block.
3551   writeIndex();
3552 }
3553 
3554 void ModuleBitcodeWriter::writeModule() {
3555   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
3556   size_t BlockStartPos = Buffer.size();
3557 
3558   SmallVector<unsigned, 1> Vals;
3559   unsigned CurVersion = 1;
3560   Vals.push_back(CurVersion);
3561   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
3562 
3563   // Emit blockinfo, which defines the standard abbreviations etc.
3564   writeBlockInfo();
3565 
3566   // Emit information about attribute groups.
3567   writeAttributeGroupTable();
3568 
3569   // Emit information about parameter attributes.
3570   writeAttributeTable();
3571 
3572   // Emit information describing all of the types in the module.
3573   writeTypeTable();
3574 
3575   writeComdats();
3576 
3577   // Emit top-level description of module, including target triple, inline asm,
3578   // descriptors for global variables, and function prototype info.
3579   writeModuleInfo();
3580 
3581   // Emit constants.
3582   writeModuleConstants();
3583 
3584   // Emit metadata.
3585   writeModuleMetadata();
3586 
3587   // Emit metadata.
3588   writeModuleMetadataStore();
3589 
3590   // Emit module-level use-lists.
3591   if (VE.shouldPreserveUseListOrder())
3592     writeUseListBlock(nullptr);
3593 
3594   writeOperandBundleTags();
3595 
3596   // Emit function bodies.
3597   DenseMap<const Function *, uint64_t> FunctionToBitcodeIndex;
3598   for (Module::const_iterator F = M.begin(), E = M.end(); F != E; ++F)
3599     if (!F->isDeclaration())
3600       writeFunction(*F, FunctionToBitcodeIndex);
3601 
3602   // Need to write after the above call to WriteFunction which populates
3603   // the summary information in the index.
3604   if (Index)
3605     writePerModuleGlobalValueSummary();
3606 
3607   writeValueSymbolTable(M.getValueSymbolTable(),
3608                         /* IsModuleLevel */ true, &FunctionToBitcodeIndex);
3609 
3610   for (const GlobalVariable &GV : M.globals())
3611     if (GV.hasMetadata()) {
3612       SmallVector<uint64_t, 4> Record;
3613       Record.push_back(VE.getValueID(&GV));
3614       pushGlobalMetadataAttachment(Record, GV);
3615       Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR_ATTACHMENT, Record);
3616     }
3617 
3618   if (GenerateHash) {
3619     writeModuleHash(BlockStartPos);
3620   }
3621 
3622   Stream.ExitBlock();
3623 }
3624 
3625 static void writeInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
3626                                uint32_t &Position) {
3627   support::endian::write32le(&Buffer[Position], Value);
3628   Position += 4;
3629 }
3630 
3631 /// If generating a bc file on darwin, we have to emit a
3632 /// header and trailer to make it compatible with the system archiver.  To do
3633 /// this we emit the following header, and then emit a trailer that pads the
3634 /// file out to be a multiple of 16 bytes.
3635 ///
3636 /// struct bc_header {
3637 ///   uint32_t Magic;         // 0x0B17C0DE
3638 ///   uint32_t Version;       // Version, currently always 0.
3639 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
3640 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
3641 ///   uint32_t CPUType;       // CPU specifier.
3642 ///   ... potentially more later ...
3643 /// };
3644 static void emitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
3645                                          const Triple &TT) {
3646   unsigned CPUType = ~0U;
3647 
3648   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
3649   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
3650   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
3651   // specific constants here because they are implicitly part of the Darwin ABI.
3652   enum {
3653     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
3654     DARWIN_CPU_TYPE_X86        = 7,
3655     DARWIN_CPU_TYPE_ARM        = 12,
3656     DARWIN_CPU_TYPE_POWERPC    = 18
3657   };
3658 
3659   Triple::ArchType Arch = TT.getArch();
3660   if (Arch == Triple::x86_64)
3661     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
3662   else if (Arch == Triple::x86)
3663     CPUType = DARWIN_CPU_TYPE_X86;
3664   else if (Arch == Triple::ppc)
3665     CPUType = DARWIN_CPU_TYPE_POWERPC;
3666   else if (Arch == Triple::ppc64)
3667     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
3668   else if (Arch == Triple::arm || Arch == Triple::thumb)
3669     CPUType = DARWIN_CPU_TYPE_ARM;
3670 
3671   // Traditional Bitcode starts after header.
3672   assert(Buffer.size() >= BWH_HeaderSize &&
3673          "Expected header size to be reserved");
3674   unsigned BCOffset = BWH_HeaderSize;
3675   unsigned BCSize = Buffer.size() - BWH_HeaderSize;
3676 
3677   // Write the magic and version.
3678   unsigned Position = 0;
3679   writeInt32ToBuffer(0x0B17C0DE, Buffer, Position);
3680   writeInt32ToBuffer(0, Buffer, Position); // Version.
3681   writeInt32ToBuffer(BCOffset, Buffer, Position);
3682   writeInt32ToBuffer(BCSize, Buffer, Position);
3683   writeInt32ToBuffer(CPUType, Buffer, Position);
3684 
3685   // If the file is not a multiple of 16 bytes, insert dummy padding.
3686   while (Buffer.size() & 15)
3687     Buffer.push_back(0);
3688 }
3689 
3690 /// Helper to write the header common to all bitcode files.
3691 void BitcodeWriter::writeBitcodeHeader() {
3692   // Emit the file header.
3693   Stream.Emit((unsigned)'B', 8);
3694   Stream.Emit((unsigned)'C', 8);
3695   Stream.Emit(0x0, 4);
3696   Stream.Emit(0xC, 4);
3697   Stream.Emit(0xE, 4);
3698   Stream.Emit(0xD, 4);
3699 }
3700 
3701 /// WriteBitcodeToFile - Write the specified module to the specified output
3702 /// stream.
3703 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out,
3704                               bool ShouldPreserveUseListOrder,
3705                               const ModuleSummaryIndex *Index,
3706                               bool GenerateHash) {
3707   SmallVector<char, 0> Buffer;
3708   Buffer.reserve(256*1024);
3709 
3710   // If this is darwin or another generic macho target, reserve space for the
3711   // header.
3712   Triple TT(M->getTargetTriple());
3713   if (TT.isOSDarwin() || TT.isOSBinFormatMachO())
3714     Buffer.insert(Buffer.begin(), BWH_HeaderSize, 0);
3715 
3716   // Emit the module into the buffer.
3717   ModuleBitcodeWriter ModuleWriter(M, Buffer, ShouldPreserveUseListOrder, Index,
3718                                    GenerateHash);
3719   ModuleWriter.write();
3720 
3721   if (TT.isOSDarwin() || TT.isOSBinFormatMachO())
3722     emitDarwinBCHeaderAndTrailer(Buffer, TT);
3723 
3724   // Write the generated bitstream to "Out".
3725   Out.write((char*)&Buffer.front(), Buffer.size());
3726 }
3727 
3728 void IndexBitcodeWriter::writeIndex() {
3729   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
3730 
3731   SmallVector<unsigned, 1> Vals;
3732   unsigned CurVersion = 1;
3733   Vals.push_back(CurVersion);
3734   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
3735 
3736   // If we have a VST, write the VSTOFFSET record placeholder.
3737   writeValueSymbolTableForwardDecl();
3738 
3739   // Write the module paths in the combined index.
3740   writeModStrings();
3741 
3742   // Write the summary combined index records.
3743   writeCombinedGlobalValueSummary();
3744 
3745   // Need a special VST writer for the combined index (we don't have a
3746   // real VST and real values when this is invoked).
3747   writeCombinedValueSymbolTable();
3748 
3749   Stream.ExitBlock();
3750 }
3751 
3752 // Write the specified module summary index to the given raw output stream,
3753 // where it will be written in a new bitcode block. This is used when
3754 // writing the combined index file for ThinLTO. When writing a subset of the
3755 // index for a distributed backend, provide a \p ModuleToSummariesForIndex map.
3756 void llvm::WriteIndexToFile(
3757     const ModuleSummaryIndex &Index, raw_ostream &Out,
3758     std::map<std::string, GVSummaryMapTy> *ModuleToSummariesForIndex) {
3759   SmallVector<char, 0> Buffer;
3760   Buffer.reserve(256 * 1024);
3761 
3762   IndexBitcodeWriter IndexWriter(Buffer, Index, ModuleToSummariesForIndex);
3763   IndexWriter.write();
3764 
3765   Out.write((char *)&Buffer.front(), Buffer.size());
3766 }
3767