xref: /llvm-project/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp (revision 1df2338bb62870b7afbb900813570d68d2690a1f)
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 /// These are manifest constants used by the bitcode writer. They do not need to
41 /// be kept in sync with the reader, but need to be consistent within this file.
42 enum {
43   // VALUE_SYMTAB_BLOCK abbrev id's.
44   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
45   VST_ENTRY_7_ABBREV,
46   VST_ENTRY_6_ABBREV,
47   VST_BBENTRY_6_ABBREV,
48 
49   // CONSTANTS_BLOCK abbrev id's.
50   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
51   CONSTANTS_INTEGER_ABBREV,
52   CONSTANTS_CE_CAST_Abbrev,
53   CONSTANTS_NULL_Abbrev,
54 
55   // FUNCTION_BLOCK abbrev id's.
56   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
57   FUNCTION_INST_BINOP_ABBREV,
58   FUNCTION_INST_BINOP_FLAGS_ABBREV,
59   FUNCTION_INST_CAST_ABBREV,
60   FUNCTION_INST_RET_VOID_ABBREV,
61   FUNCTION_INST_RET_VAL_ABBREV,
62   FUNCTION_INST_UNREACHABLE_ABBREV,
63   FUNCTION_INST_GEP_ABBREV,
64 };
65 
66 /// Abstract class to manage the bitcode writing, subclassed for each bitcode
67 /// file type. Owns the BitstreamWriter, and includes the main entry point for
68 /// writing.
69 class BitcodeWriter {
70 protected:
71   /// Pointer to the buffer allocated by caller for bitcode writing.
72   const SmallVectorImpl<char> &Buffer;
73 
74   /// The stream created and owned by the BitodeWriter.
75   BitstreamWriter Stream;
76 
77   /// Saves the offset of the VSTOffset record that must eventually be
78   /// backpatched with the offset of the actual VST.
79   uint64_t VSTOffsetPlaceholder = 0;
80 
81 public:
82   /// Constructs a BitcodeWriter object, and initializes a BitstreamRecord,
83   /// writing to the provided \p Buffer.
84   BitcodeWriter(SmallVectorImpl<char> &Buffer)
85       : Buffer(Buffer), Stream(Buffer) {}
86 
87   virtual ~BitcodeWriter() = default;
88 
89   /// Main entry point to write the bitcode file, which writes the bitcode
90   /// header and will then invoke the virtual writeBlocks() method.
91   void write();
92 
93 private:
94   /// Derived classes must implement this to write the corresponding blocks for
95   /// that bitcode file type.
96   virtual void writeBlocks() = 0;
97 
98 protected:
99   bool hasVSTOffsetPlaceholder() { return VSTOffsetPlaceholder != 0; }
100   void writeValueSymbolTableForwardDecl();
101   void writeBitcodeHeader();
102 };
103 
104 /// Class to manage the bitcode writing for a module.
105 class ModuleBitcodeWriter : public BitcodeWriter {
106   /// The Module to write to bitcode.
107   const Module &M;
108 
109   /// Enumerates ids for all values in the module.
110   ValueEnumerator VE;
111 
112   /// Optional per-module index to write for ThinLTO.
113   const ModuleSummaryIndex *Index;
114 
115   /// True if a module hash record should be written.
116   bool GenerateHash;
117 
118   /// The start bit of the module block, for use in generating a module hash
119   uint64_t BitcodeStartBit = 0;
120 
121 public:
122   /// Constructs a ModuleBitcodeWriter object for the given Module,
123   /// writing to the provided \p Buffer.
124   ModuleBitcodeWriter(const Module *M, SmallVectorImpl<char> &Buffer,
125                       bool ShouldPreserveUseListOrder,
126                       const ModuleSummaryIndex *Index, bool GenerateHash)
127       : BitcodeWriter(Buffer), M(*M), VE(*M, ShouldPreserveUseListOrder),
128         Index(Index), GenerateHash(GenerateHash) {
129     // Save the start bit of the actual bitcode, in case there is space
130     // saved at the start for the darwin header above. The reader stream
131     // will start at the bitcode, and we need the offset of the VST
132     // to line up.
133     BitcodeStartBit = Stream.GetCurrentBitNo();
134   }
135 
136 private:
137   /// Main entry point for writing a module to bitcode, invoked by
138   /// BitcodeWriter::write() after it writes the header.
139   void writeBlocks() override;
140 
141   /// Create the "IDENTIFICATION_BLOCK_ID" containing a single string with the
142   /// current llvm version, and a record for the epoch number.
143   void writeIdentificationBlock();
144 
145   /// Emit the current module to the bitstream.
146   void writeModule();
147 
148   uint64_t bitcodeStartBit() { return BitcodeStartBit; }
149 
150   void writeStringRecord(unsigned Code, StringRef Str, unsigned AbbrevToUse);
151   void writeAttributeGroupTable();
152   void writeAttributeTable();
153   void writeTypeTable();
154   void writeComdats();
155   void writeModuleInfo();
156   void writeValueAsMetadata(const ValueAsMetadata *MD,
157                             SmallVectorImpl<uint64_t> &Record);
158   void writeMDTuple(const MDTuple *N, SmallVectorImpl<uint64_t> &Record,
159                     unsigned Abbrev);
160   unsigned createDILocationAbbrev();
161   void writeDILocation(const DILocation *N, SmallVectorImpl<uint64_t> &Record,
162                        unsigned &Abbrev);
163   unsigned createGenericDINodeAbbrev();
164   void writeGenericDINode(const GenericDINode *N,
165                           SmallVectorImpl<uint64_t> &Record, unsigned &Abbrev);
166   void writeDISubrange(const DISubrange *N, SmallVectorImpl<uint64_t> &Record,
167                        unsigned Abbrev);
168   void writeDIEnumerator(const DIEnumerator *N,
169                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
170   void writeDIBasicType(const DIBasicType *N, SmallVectorImpl<uint64_t> &Record,
171                         unsigned Abbrev);
172   void writeDIDerivedType(const DIDerivedType *N,
173                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
174   void writeDICompositeType(const DICompositeType *N,
175                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
176   void writeDISubroutineType(const DISubroutineType *N,
177                              SmallVectorImpl<uint64_t> &Record,
178                              unsigned Abbrev);
179   void writeDIFile(const DIFile *N, SmallVectorImpl<uint64_t> &Record,
180                    unsigned Abbrev);
181   void writeDICompileUnit(const DICompileUnit *N,
182                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
183   void writeDISubprogram(const DISubprogram *N,
184                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
185   void writeDILexicalBlock(const DILexicalBlock *N,
186                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
187   void writeDILexicalBlockFile(const DILexicalBlockFile *N,
188                                SmallVectorImpl<uint64_t> &Record,
189                                unsigned Abbrev);
190   void writeDINamespace(const DINamespace *N, SmallVectorImpl<uint64_t> &Record,
191                         unsigned Abbrev);
192   void writeDIMacro(const DIMacro *N, SmallVectorImpl<uint64_t> &Record,
193                     unsigned Abbrev);
194   void writeDIMacroFile(const DIMacroFile *N, SmallVectorImpl<uint64_t> &Record,
195                         unsigned Abbrev);
196   void writeDIModule(const DIModule *N, SmallVectorImpl<uint64_t> &Record,
197                      unsigned Abbrev);
198   void writeDITemplateTypeParameter(const DITemplateTypeParameter *N,
199                                     SmallVectorImpl<uint64_t> &Record,
200                                     unsigned Abbrev);
201   void writeDITemplateValueParameter(const DITemplateValueParameter *N,
202                                      SmallVectorImpl<uint64_t> &Record,
203                                      unsigned Abbrev);
204   void writeDIGlobalVariable(const DIGlobalVariable *N,
205                              SmallVectorImpl<uint64_t> &Record,
206                              unsigned Abbrev);
207   void writeDILocalVariable(const DILocalVariable *N,
208                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
209   void writeDIExpression(const DIExpression *N,
210                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
211   void writeDIObjCProperty(const DIObjCProperty *N,
212                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
213   void writeDIImportedEntity(const DIImportedEntity *N,
214                              SmallVectorImpl<uint64_t> &Record,
215                              unsigned Abbrev);
216   unsigned createNamedMetadataAbbrev();
217   void writeNamedMetadata(SmallVectorImpl<uint64_t> &Record);
218   unsigned createMetadataStringsAbbrev();
219   void writeMetadataStrings(ArrayRef<const Metadata *> Strings,
220                             SmallVectorImpl<uint64_t> &Record);
221   void writeMetadataRecords(ArrayRef<const Metadata *> MDs,
222                             SmallVectorImpl<uint64_t> &Record);
223   void writeModuleMetadata();
224   void writeFunctionMetadata(const Function &F);
225   void writeMetadataAttachment(const Function &F);
226   void writeModuleMetadataStore();
227   void writeOperandBundleTags();
228   void writeConstants(unsigned FirstVal, unsigned LastVal, bool isGlobal);
229   void writeModuleConstants();
230   bool pushValueAndType(const Value *V, unsigned InstID,
231                         SmallVectorImpl<unsigned> &Vals);
232   void writeOperandBundles(ImmutableCallSite CS, unsigned InstID);
233   void pushValue(const Value *V, unsigned InstID,
234                  SmallVectorImpl<unsigned> &Vals);
235   void pushValueSigned(const Value *V, unsigned InstID,
236                        SmallVectorImpl<uint64_t> &Vals);
237   void writeInstruction(const Instruction &I, unsigned InstID,
238                         SmallVectorImpl<unsigned> &Vals);
239   void writeValueSymbolTable(
240       const ValueSymbolTable &VST, bool IsModuleLevel = false,
241       DenseMap<const Function *, uint64_t> *FunctionToBitcodeIndex = nullptr);
242   void writeUseList(UseListOrder &&Order);
243   void writeUseListBlock(const Function *F);
244   void
245   writeFunction(const Function &F,
246                 DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
247   void writeBlockInfo();
248   void writePerModuleFunctionSummaryRecord(SmallVector<uint64_t, 64> &NameVals,
249                                            GlobalValueSummary *Summary,
250                                            unsigned ValueID,
251                                            unsigned FSCallsAbbrev,
252                                            unsigned FSCallsProfileAbbrev,
253                                            const Function &F);
254   void writeModuleLevelReferences(const GlobalVariable &V,
255                                   SmallVector<uint64_t, 64> &NameVals,
256                                   unsigned FSModRefsAbbrev);
257   void writePerModuleGlobalValueSummary();
258   void writeModuleHash(size_t BlockStartPos);
259 };
260 
261 /// Class to manage the bitcode writing for a combined index.
262 class IndexBitcodeWriter : public BitcodeWriter {
263   /// The combined index to write to bitcode.
264   const ModuleSummaryIndex &Index;
265 
266   /// Map that holds the correspondence between the GUID used in the combined
267   /// index and a value id generated by this class to use in references.
268   std::map<GlobalValue::GUID, unsigned> GUIDToValueIdMap;
269 
270   /// Tracks the last value id recorded in the GUIDToValueMap.
271   unsigned GlobalValueId = 0;
272 
273 public:
274   /// Constructs a IndexBitcodeWriter object for the given combined index,
275   /// writing to the provided \p Buffer.
276   IndexBitcodeWriter(SmallVectorImpl<char> &Buffer,
277                      const ModuleSummaryIndex &Index)
278       : BitcodeWriter(Buffer), Index(Index) {
279     // Assign unique value ids to all functions in the index for use
280     // in writing out the call graph edges. Save the mapping from GUID
281     // to the new global value id to use when writing those edges, which
282     // are currently saved in the index in terms of GUID.
283     for (auto &II : Index)
284       GUIDToValueIdMap[II.first] = ++GlobalValueId;
285   }
286 
287 private:
288   /// Main entry point for writing a combined index to bitcode, invoked by
289   /// BitcodeWriter::write() after it writes the header.
290   void writeBlocks() override;
291 
292   void writeIndex();
293   void writeModStrings();
294   void writeCombinedValueSymbolTable();
295   void writeCombinedGlobalValueSummary();
296 
297   bool hasValueId(GlobalValue::GUID ValGUID) {
298     const auto &VMI = GUIDToValueIdMap.find(ValGUID);
299     return VMI != GUIDToValueIdMap.end();
300   }
301   unsigned getValueId(GlobalValue::GUID ValGUID) {
302     const auto &VMI = GUIDToValueIdMap.find(ValGUID);
303     // If this GUID doesn't have an entry, assign one.
304     if (VMI == GUIDToValueIdMap.end()) {
305       GUIDToValueIdMap[ValGUID] = ++GlobalValueId;
306       return GlobalValueId;
307     } else {
308       return VMI->second;
309     }
310   }
311   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
312 };
313 
314 static unsigned getEncodedCastOpcode(unsigned Opcode) {
315   switch (Opcode) {
316   default: llvm_unreachable("Unknown cast instruction!");
317   case Instruction::Trunc   : return bitc::CAST_TRUNC;
318   case Instruction::ZExt    : return bitc::CAST_ZEXT;
319   case Instruction::SExt    : return bitc::CAST_SEXT;
320   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
321   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
322   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
323   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
324   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
325   case Instruction::FPExt   : return bitc::CAST_FPEXT;
326   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
327   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
328   case Instruction::BitCast : return bitc::CAST_BITCAST;
329   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
330   }
331 }
332 
333 static unsigned getEncodedBinaryOpcode(unsigned Opcode) {
334   switch (Opcode) {
335   default: llvm_unreachable("Unknown binary instruction!");
336   case Instruction::Add:
337   case Instruction::FAdd: return bitc::BINOP_ADD;
338   case Instruction::Sub:
339   case Instruction::FSub: return bitc::BINOP_SUB;
340   case Instruction::Mul:
341   case Instruction::FMul: return bitc::BINOP_MUL;
342   case Instruction::UDiv: return bitc::BINOP_UDIV;
343   case Instruction::FDiv:
344   case Instruction::SDiv: return bitc::BINOP_SDIV;
345   case Instruction::URem: return bitc::BINOP_UREM;
346   case Instruction::FRem:
347   case Instruction::SRem: return bitc::BINOP_SREM;
348   case Instruction::Shl:  return bitc::BINOP_SHL;
349   case Instruction::LShr: return bitc::BINOP_LSHR;
350   case Instruction::AShr: return bitc::BINOP_ASHR;
351   case Instruction::And:  return bitc::BINOP_AND;
352   case Instruction::Or:   return bitc::BINOP_OR;
353   case Instruction::Xor:  return bitc::BINOP_XOR;
354   }
355 }
356 
357 static unsigned getEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
358   switch (Op) {
359   default: llvm_unreachable("Unknown RMW operation!");
360   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
361   case AtomicRMWInst::Add: return bitc::RMW_ADD;
362   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
363   case AtomicRMWInst::And: return bitc::RMW_AND;
364   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
365   case AtomicRMWInst::Or: return bitc::RMW_OR;
366   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
367   case AtomicRMWInst::Max: return bitc::RMW_MAX;
368   case AtomicRMWInst::Min: return bitc::RMW_MIN;
369   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
370   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
371   }
372 }
373 
374 static unsigned getEncodedOrdering(AtomicOrdering Ordering) {
375   switch (Ordering) {
376   case AtomicOrdering::NotAtomic: return bitc::ORDERING_NOTATOMIC;
377   case AtomicOrdering::Unordered: return bitc::ORDERING_UNORDERED;
378   case AtomicOrdering::Monotonic: return bitc::ORDERING_MONOTONIC;
379   case AtomicOrdering::Acquire: return bitc::ORDERING_ACQUIRE;
380   case AtomicOrdering::Release: return bitc::ORDERING_RELEASE;
381   case AtomicOrdering::AcquireRelease: return bitc::ORDERING_ACQREL;
382   case AtomicOrdering::SequentiallyConsistent: return bitc::ORDERING_SEQCST;
383   }
384   llvm_unreachable("Invalid ordering");
385 }
386 
387 static unsigned getEncodedSynchScope(SynchronizationScope SynchScope) {
388   switch (SynchScope) {
389   case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
390   case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
391   }
392   llvm_unreachable("Invalid synch scope");
393 }
394 
395 void ModuleBitcodeWriter::writeStringRecord(unsigned Code, StringRef Str,
396                                             unsigned AbbrevToUse) {
397   SmallVector<unsigned, 64> Vals;
398 
399   // Code: [strchar x N]
400   for (unsigned i = 0, e = Str.size(); i != e; ++i) {
401     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
402       AbbrevToUse = 0;
403     Vals.push_back(Str[i]);
404   }
405 
406   // Emit the finished record.
407   Stream.EmitRecord(Code, Vals, AbbrevToUse);
408 }
409 
410 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
411   switch (Kind) {
412   case Attribute::Alignment:
413     return bitc::ATTR_KIND_ALIGNMENT;
414   case Attribute::AllocSize:
415     return bitc::ATTR_KIND_ALLOC_SIZE;
416   case Attribute::AlwaysInline:
417     return bitc::ATTR_KIND_ALWAYS_INLINE;
418   case Attribute::ArgMemOnly:
419     return bitc::ATTR_KIND_ARGMEMONLY;
420   case Attribute::Builtin:
421     return bitc::ATTR_KIND_BUILTIN;
422   case Attribute::ByVal:
423     return bitc::ATTR_KIND_BY_VAL;
424   case Attribute::Convergent:
425     return bitc::ATTR_KIND_CONVERGENT;
426   case Attribute::InAlloca:
427     return bitc::ATTR_KIND_IN_ALLOCA;
428   case Attribute::Cold:
429     return bitc::ATTR_KIND_COLD;
430   case Attribute::InaccessibleMemOnly:
431     return bitc::ATTR_KIND_INACCESSIBLEMEM_ONLY;
432   case Attribute::InaccessibleMemOrArgMemOnly:
433     return bitc::ATTR_KIND_INACCESSIBLEMEM_OR_ARGMEMONLY;
434   case Attribute::InlineHint:
435     return bitc::ATTR_KIND_INLINE_HINT;
436   case Attribute::InReg:
437     return bitc::ATTR_KIND_IN_REG;
438   case Attribute::JumpTable:
439     return bitc::ATTR_KIND_JUMP_TABLE;
440   case Attribute::MinSize:
441     return bitc::ATTR_KIND_MIN_SIZE;
442   case Attribute::Naked:
443     return bitc::ATTR_KIND_NAKED;
444   case Attribute::Nest:
445     return bitc::ATTR_KIND_NEST;
446   case Attribute::NoAlias:
447     return bitc::ATTR_KIND_NO_ALIAS;
448   case Attribute::NoBuiltin:
449     return bitc::ATTR_KIND_NO_BUILTIN;
450   case Attribute::NoCapture:
451     return bitc::ATTR_KIND_NO_CAPTURE;
452   case Attribute::NoDuplicate:
453     return bitc::ATTR_KIND_NO_DUPLICATE;
454   case Attribute::NoImplicitFloat:
455     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
456   case Attribute::NoInline:
457     return bitc::ATTR_KIND_NO_INLINE;
458   case Attribute::NoRecurse:
459     return bitc::ATTR_KIND_NO_RECURSE;
460   case Attribute::NonLazyBind:
461     return bitc::ATTR_KIND_NON_LAZY_BIND;
462   case Attribute::NonNull:
463     return bitc::ATTR_KIND_NON_NULL;
464   case Attribute::Dereferenceable:
465     return bitc::ATTR_KIND_DEREFERENCEABLE;
466   case Attribute::DereferenceableOrNull:
467     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
468   case Attribute::NoRedZone:
469     return bitc::ATTR_KIND_NO_RED_ZONE;
470   case Attribute::NoReturn:
471     return bitc::ATTR_KIND_NO_RETURN;
472   case Attribute::NoUnwind:
473     return bitc::ATTR_KIND_NO_UNWIND;
474   case Attribute::OptimizeForSize:
475     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
476   case Attribute::OptimizeNone:
477     return bitc::ATTR_KIND_OPTIMIZE_NONE;
478   case Attribute::ReadNone:
479     return bitc::ATTR_KIND_READ_NONE;
480   case Attribute::ReadOnly:
481     return bitc::ATTR_KIND_READ_ONLY;
482   case Attribute::Returned:
483     return bitc::ATTR_KIND_RETURNED;
484   case Attribute::ReturnsTwice:
485     return bitc::ATTR_KIND_RETURNS_TWICE;
486   case Attribute::SExt:
487     return bitc::ATTR_KIND_S_EXT;
488   case Attribute::StackAlignment:
489     return bitc::ATTR_KIND_STACK_ALIGNMENT;
490   case Attribute::StackProtect:
491     return bitc::ATTR_KIND_STACK_PROTECT;
492   case Attribute::StackProtectReq:
493     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
494   case Attribute::StackProtectStrong:
495     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
496   case Attribute::SafeStack:
497     return bitc::ATTR_KIND_SAFESTACK;
498   case Attribute::StructRet:
499     return bitc::ATTR_KIND_STRUCT_RET;
500   case Attribute::SanitizeAddress:
501     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
502   case Attribute::SanitizeThread:
503     return bitc::ATTR_KIND_SANITIZE_THREAD;
504   case Attribute::SanitizeMemory:
505     return bitc::ATTR_KIND_SANITIZE_MEMORY;
506   case Attribute::SwiftError:
507     return bitc::ATTR_KIND_SWIFT_ERROR;
508   case Attribute::SwiftSelf:
509     return bitc::ATTR_KIND_SWIFT_SELF;
510   case Attribute::UWTable:
511     return bitc::ATTR_KIND_UW_TABLE;
512   case Attribute::ZExt:
513     return bitc::ATTR_KIND_Z_EXT;
514   case Attribute::EndAttrKinds:
515     llvm_unreachable("Can not encode end-attribute kinds marker.");
516   case Attribute::None:
517     llvm_unreachable("Can not encode none-attribute.");
518   }
519 
520   llvm_unreachable("Trying to encode unknown attribute");
521 }
522 
523 void ModuleBitcodeWriter::writeAttributeGroupTable() {
524   const std::vector<AttributeSet> &AttrGrps = VE.getAttributeGroups();
525   if (AttrGrps.empty()) return;
526 
527   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
528 
529   SmallVector<uint64_t, 64> Record;
530   for (unsigned i = 0, e = AttrGrps.size(); i != e; ++i) {
531     AttributeSet AS = AttrGrps[i];
532     for (unsigned i = 0, e = AS.getNumSlots(); i != e; ++i) {
533       AttributeSet A = AS.getSlotAttributes(i);
534 
535       Record.push_back(VE.getAttributeGroupID(A));
536       Record.push_back(AS.getSlotIndex(i));
537 
538       for (AttributeSet::iterator I = AS.begin(0), E = AS.end(0);
539            I != E; ++I) {
540         Attribute Attr = *I;
541         if (Attr.isEnumAttribute()) {
542           Record.push_back(0);
543           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
544         } else if (Attr.isIntAttribute()) {
545           Record.push_back(1);
546           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
547           Record.push_back(Attr.getValueAsInt());
548         } else {
549           StringRef Kind = Attr.getKindAsString();
550           StringRef Val = Attr.getValueAsString();
551 
552           Record.push_back(Val.empty() ? 3 : 4);
553           Record.append(Kind.begin(), Kind.end());
554           Record.push_back(0);
555           if (!Val.empty()) {
556             Record.append(Val.begin(), Val.end());
557             Record.push_back(0);
558           }
559         }
560       }
561 
562       Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
563       Record.clear();
564     }
565   }
566 
567   Stream.ExitBlock();
568 }
569 
570 void ModuleBitcodeWriter::writeAttributeTable() {
571   const std::vector<AttributeSet> &Attrs = VE.getAttributes();
572   if (Attrs.empty()) return;
573 
574   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
575 
576   SmallVector<uint64_t, 64> Record;
577   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
578     const AttributeSet &A = Attrs[i];
579     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
580       Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
581 
582     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
583     Record.clear();
584   }
585 
586   Stream.ExitBlock();
587 }
588 
589 /// WriteTypeTable - Write out the type table for a module.
590 void ModuleBitcodeWriter::writeTypeTable() {
591   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
592 
593   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
594   SmallVector<uint64_t, 64> TypeVals;
595 
596   uint64_t NumBits = VE.computeBitsRequiredForTypeIndicies();
597 
598   // Abbrev for TYPE_CODE_POINTER.
599   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
600   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
601   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
602   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
603   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
604 
605   // Abbrev for TYPE_CODE_FUNCTION.
606   Abbv = new BitCodeAbbrev();
607   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
608   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
609   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
610   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
611 
612   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
613 
614   // Abbrev for TYPE_CODE_STRUCT_ANON.
615   Abbv = new BitCodeAbbrev();
616   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
617   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
618   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
619   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
620 
621   unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
622 
623   // Abbrev for TYPE_CODE_STRUCT_NAME.
624   Abbv = new BitCodeAbbrev();
625   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
626   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
627   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
628   unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
629 
630   // Abbrev for TYPE_CODE_STRUCT_NAMED.
631   Abbv = new BitCodeAbbrev();
632   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
633   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
634   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
635   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
636 
637   unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
638 
639   // Abbrev for TYPE_CODE_ARRAY.
640   Abbv = new BitCodeAbbrev();
641   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
642   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
643   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
644 
645   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
646 
647   // Emit an entry count so the reader can reserve space.
648   TypeVals.push_back(TypeList.size());
649   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
650   TypeVals.clear();
651 
652   // Loop over all of the types, emitting each in turn.
653   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
654     Type *T = TypeList[i];
655     int AbbrevToUse = 0;
656     unsigned Code = 0;
657 
658     switch (T->getTypeID()) {
659     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
660     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
661     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
662     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
663     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
664     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
665     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
666     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
667     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
668     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
669     case Type::TokenTyID:     Code = bitc::TYPE_CODE_TOKEN;     break;
670     case Type::IntegerTyID:
671       // INTEGER: [width]
672       Code = bitc::TYPE_CODE_INTEGER;
673       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
674       break;
675     case Type::PointerTyID: {
676       PointerType *PTy = cast<PointerType>(T);
677       // POINTER: [pointee type, address space]
678       Code = bitc::TYPE_CODE_POINTER;
679       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
680       unsigned AddressSpace = PTy->getAddressSpace();
681       TypeVals.push_back(AddressSpace);
682       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
683       break;
684     }
685     case Type::FunctionTyID: {
686       FunctionType *FT = cast<FunctionType>(T);
687       // FUNCTION: [isvararg, retty, paramty x N]
688       Code = bitc::TYPE_CODE_FUNCTION;
689       TypeVals.push_back(FT->isVarArg());
690       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
691       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
692         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
693       AbbrevToUse = FunctionAbbrev;
694       break;
695     }
696     case Type::StructTyID: {
697       StructType *ST = cast<StructType>(T);
698       // STRUCT: [ispacked, eltty x N]
699       TypeVals.push_back(ST->isPacked());
700       // Output all of the element types.
701       for (StructType::element_iterator I = ST->element_begin(),
702            E = ST->element_end(); I != E; ++I)
703         TypeVals.push_back(VE.getTypeID(*I));
704 
705       if (ST->isLiteral()) {
706         Code = bitc::TYPE_CODE_STRUCT_ANON;
707         AbbrevToUse = StructAnonAbbrev;
708       } else {
709         if (ST->isOpaque()) {
710           Code = bitc::TYPE_CODE_OPAQUE;
711         } else {
712           Code = bitc::TYPE_CODE_STRUCT_NAMED;
713           AbbrevToUse = StructNamedAbbrev;
714         }
715 
716         // Emit the name if it is present.
717         if (!ST->getName().empty())
718           writeStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
719                             StructNameAbbrev);
720       }
721       break;
722     }
723     case Type::ArrayTyID: {
724       ArrayType *AT = cast<ArrayType>(T);
725       // ARRAY: [numelts, eltty]
726       Code = bitc::TYPE_CODE_ARRAY;
727       TypeVals.push_back(AT->getNumElements());
728       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
729       AbbrevToUse = ArrayAbbrev;
730       break;
731     }
732     case Type::VectorTyID: {
733       VectorType *VT = cast<VectorType>(T);
734       // VECTOR [numelts, eltty]
735       Code = bitc::TYPE_CODE_VECTOR;
736       TypeVals.push_back(VT->getNumElements());
737       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
738       break;
739     }
740     }
741 
742     // Emit the finished record.
743     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
744     TypeVals.clear();
745   }
746 
747   Stream.ExitBlock();
748 }
749 
750 static unsigned getEncodedLinkage(const GlobalValue::LinkageTypes Linkage) {
751   switch (Linkage) {
752   case GlobalValue::ExternalLinkage:
753     return 0;
754   case GlobalValue::WeakAnyLinkage:
755     return 16;
756   case GlobalValue::AppendingLinkage:
757     return 2;
758   case GlobalValue::InternalLinkage:
759     return 3;
760   case GlobalValue::LinkOnceAnyLinkage:
761     return 18;
762   case GlobalValue::ExternalWeakLinkage:
763     return 7;
764   case GlobalValue::CommonLinkage:
765     return 8;
766   case GlobalValue::PrivateLinkage:
767     return 9;
768   case GlobalValue::WeakODRLinkage:
769     return 17;
770   case GlobalValue::LinkOnceODRLinkage:
771     return 19;
772   case GlobalValue::AvailableExternallyLinkage:
773     return 12;
774   }
775   llvm_unreachable("Invalid linkage");
776 }
777 
778 static unsigned getEncodedLinkage(const GlobalValue &GV) {
779   return getEncodedLinkage(GV.getLinkage());
780 }
781 
782 // Decode the flags for GlobalValue in the summary
783 static uint64_t getEncodedGVSummaryFlags(GlobalValueSummary::GVFlags Flags) {
784   uint64_t RawFlags = 0;
785 
786   RawFlags |= Flags.HasSection; // bool
787 
788   // Linkage don't need to be remapped at that time for the summary. Any future
789   // change to the getEncodedLinkage() function will need to be taken into
790   // account here as well.
791   RawFlags = (RawFlags << 4) | Flags.Linkage; // 4 bits
792 
793   return RawFlags;
794 }
795 
796 static unsigned getEncodedVisibility(const GlobalValue &GV) {
797   switch (GV.getVisibility()) {
798   case GlobalValue::DefaultVisibility:   return 0;
799   case GlobalValue::HiddenVisibility:    return 1;
800   case GlobalValue::ProtectedVisibility: return 2;
801   }
802   llvm_unreachable("Invalid visibility");
803 }
804 
805 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
806   switch (GV.getDLLStorageClass()) {
807   case GlobalValue::DefaultStorageClass:   return 0;
808   case GlobalValue::DLLImportStorageClass: return 1;
809   case GlobalValue::DLLExportStorageClass: return 2;
810   }
811   llvm_unreachable("Invalid DLL storage class");
812 }
813 
814 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
815   switch (GV.getThreadLocalMode()) {
816     case GlobalVariable::NotThreadLocal:         return 0;
817     case GlobalVariable::GeneralDynamicTLSModel: return 1;
818     case GlobalVariable::LocalDynamicTLSModel:   return 2;
819     case GlobalVariable::InitialExecTLSModel:    return 3;
820     case GlobalVariable::LocalExecTLSModel:      return 4;
821   }
822   llvm_unreachable("Invalid TLS model");
823 }
824 
825 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
826   switch (C.getSelectionKind()) {
827   case Comdat::Any:
828     return bitc::COMDAT_SELECTION_KIND_ANY;
829   case Comdat::ExactMatch:
830     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
831   case Comdat::Largest:
832     return bitc::COMDAT_SELECTION_KIND_LARGEST;
833   case Comdat::NoDuplicates:
834     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
835   case Comdat::SameSize:
836     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
837   }
838   llvm_unreachable("Invalid selection kind");
839 }
840 
841 void ModuleBitcodeWriter::writeComdats() {
842   SmallVector<unsigned, 64> Vals;
843   for (const Comdat *C : VE.getComdats()) {
844     // COMDAT: [selection_kind, name]
845     Vals.push_back(getEncodedComdatSelectionKind(*C));
846     size_t Size = C->getName().size();
847     assert(isUInt<32>(Size));
848     Vals.push_back(Size);
849     for (char Chr : C->getName())
850       Vals.push_back((unsigned char)Chr);
851     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
852     Vals.clear();
853   }
854 }
855 
856 /// Write a record that will eventually hold the word offset of the
857 /// module-level VST. For now the offset is 0, which will be backpatched
858 /// after the real VST is written. Saves the bit offset to backpatch.
859 void BitcodeWriter::writeValueSymbolTableForwardDecl() {
860   // Write a placeholder value in for the offset of the real VST,
861   // which is written after the function blocks so that it can include
862   // the offset of each function. The placeholder offset will be
863   // updated when the real VST is written.
864   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
865   Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_VSTOFFSET));
866   // Blocks are 32-bit aligned, so we can use a 32-bit word offset to
867   // hold the real VST offset. Must use fixed instead of VBR as we don't
868   // know how many VBR chunks to reserve ahead of time.
869   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
870   unsigned VSTOffsetAbbrev = Stream.EmitAbbrev(Abbv);
871 
872   // Emit the placeholder
873   uint64_t Vals[] = {bitc::MODULE_CODE_VSTOFFSET, 0};
874   Stream.EmitRecordWithAbbrev(VSTOffsetAbbrev, Vals);
875 
876   // Compute and save the bit offset to the placeholder, which will be
877   // patched when the real VST is written. We can simply subtract the 32-bit
878   // fixed size from the current bit number to get the location to backpatch.
879   VSTOffsetPlaceholder = Stream.GetCurrentBitNo() - 32;
880 }
881 
882 enum StringEncoding { SE_Char6, SE_Fixed7, SE_Fixed8 };
883 
884 /// Determine the encoding to use for the given string name and length.
885 static StringEncoding getStringEncoding(const char *Str, unsigned StrLen) {
886   bool isChar6 = true;
887   for (const char *C = Str, *E = C + StrLen; C != E; ++C) {
888     if (isChar6)
889       isChar6 = BitCodeAbbrevOp::isChar6(*C);
890     if ((unsigned char)*C & 128)
891       // don't bother scanning the rest.
892       return SE_Fixed8;
893   }
894   if (isChar6)
895     return SE_Char6;
896   else
897     return SE_Fixed7;
898 }
899 
900 /// Emit top-level description of module, including target triple, inline asm,
901 /// descriptors for global variables, and function prototype info.
902 /// Returns the bit offset to backpatch with the location of the real VST.
903 void ModuleBitcodeWriter::writeModuleInfo() {
904   // Emit various pieces of data attached to a module.
905   if (!M.getTargetTriple().empty())
906     writeStringRecord(bitc::MODULE_CODE_TRIPLE, M.getTargetTriple(),
907                       0 /*TODO*/);
908   const std::string &DL = M.getDataLayoutStr();
909   if (!DL.empty())
910     writeStringRecord(bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/);
911   if (!M.getModuleInlineAsm().empty())
912     writeStringRecord(bitc::MODULE_CODE_ASM, M.getModuleInlineAsm(),
913                       0 /*TODO*/);
914 
915   // Emit information about sections and GC, computing how many there are. Also
916   // compute the maximum alignment value.
917   std::map<std::string, unsigned> SectionMap;
918   std::map<std::string, unsigned> GCMap;
919   unsigned MaxAlignment = 0;
920   unsigned MaxGlobalType = 0;
921   for (const GlobalValue &GV : M.globals()) {
922     MaxAlignment = std::max(MaxAlignment, GV.getAlignment());
923     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
924     if (GV.hasSection()) {
925       // Give section names unique ID's.
926       unsigned &Entry = SectionMap[GV.getSection()];
927       if (!Entry) {
928         writeStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
929                           0 /*TODO*/);
930         Entry = SectionMap.size();
931       }
932     }
933   }
934   for (const Function &F : M) {
935     MaxAlignment = std::max(MaxAlignment, F.getAlignment());
936     if (F.hasSection()) {
937       // Give section names unique ID's.
938       unsigned &Entry = SectionMap[F.getSection()];
939       if (!Entry) {
940         writeStringRecord(bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
941                           0 /*TODO*/);
942         Entry = SectionMap.size();
943       }
944     }
945     if (F.hasGC()) {
946       // Same for GC names.
947       unsigned &Entry = GCMap[F.getGC()];
948       if (!Entry) {
949         writeStringRecord(bitc::MODULE_CODE_GCNAME, F.getGC(), 0 /*TODO*/);
950         Entry = GCMap.size();
951       }
952     }
953   }
954 
955   // Emit abbrev for globals, now that we know # sections and max alignment.
956   unsigned SimpleGVarAbbrev = 0;
957   if (!M.global_empty()) {
958     // Add an abbrev for common globals with no visibility or thread localness.
959     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
960     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
961     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
962                               Log2_32_Ceil(MaxGlobalType+1)));
963     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
964                                                            //| explicitType << 1
965                                                            //| constant
966     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
967     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
968     if (MaxAlignment == 0)                                 // Alignment.
969       Abbv->Add(BitCodeAbbrevOp(0));
970     else {
971       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
972       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
973                                Log2_32_Ceil(MaxEncAlignment+1)));
974     }
975     if (SectionMap.empty())                                    // Section.
976       Abbv->Add(BitCodeAbbrevOp(0));
977     else
978       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
979                                Log2_32_Ceil(SectionMap.size()+1)));
980     // Don't bother emitting vis + thread local.
981     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
982   }
983 
984   // Emit the global variable information.
985   SmallVector<unsigned, 64> Vals;
986   for (const GlobalVariable &GV : M.globals()) {
987     unsigned AbbrevToUse = 0;
988 
989     // GLOBALVAR: [type, isconst, initid,
990     //             linkage, alignment, section, visibility, threadlocal,
991     //             unnamed_addr, externally_initialized, dllstorageclass,
992     //             comdat]
993     Vals.push_back(VE.getTypeID(GV.getValueType()));
994     Vals.push_back(GV.getType()->getAddressSpace() << 2 | 2 | GV.isConstant());
995     Vals.push_back(GV.isDeclaration() ? 0 :
996                    (VE.getValueID(GV.getInitializer()) + 1));
997     Vals.push_back(getEncodedLinkage(GV));
998     Vals.push_back(Log2_32(GV.getAlignment())+1);
999     Vals.push_back(GV.hasSection() ? SectionMap[GV.getSection()] : 0);
1000     if (GV.isThreadLocal() ||
1001         GV.getVisibility() != GlobalValue::DefaultVisibility ||
1002         GV.hasUnnamedAddr() || GV.isExternallyInitialized() ||
1003         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
1004         GV.hasComdat()) {
1005       Vals.push_back(getEncodedVisibility(GV));
1006       Vals.push_back(getEncodedThreadLocalMode(GV));
1007       Vals.push_back(GV.hasUnnamedAddr());
1008       Vals.push_back(GV.isExternallyInitialized());
1009       Vals.push_back(getEncodedDLLStorageClass(GV));
1010       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
1011     } else {
1012       AbbrevToUse = SimpleGVarAbbrev;
1013     }
1014 
1015     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
1016     Vals.clear();
1017   }
1018 
1019   // Emit the function proto information.
1020   for (const Function &F : M) {
1021     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
1022     //             section, visibility, gc, unnamed_addr, prologuedata,
1023     //             dllstorageclass, comdat, prefixdata, personalityfn]
1024     Vals.push_back(VE.getTypeID(F.getFunctionType()));
1025     Vals.push_back(F.getCallingConv());
1026     Vals.push_back(F.isDeclaration());
1027     Vals.push_back(getEncodedLinkage(F));
1028     Vals.push_back(VE.getAttributeID(F.getAttributes()));
1029     Vals.push_back(Log2_32(F.getAlignment())+1);
1030     Vals.push_back(F.hasSection() ? SectionMap[F.getSection()] : 0);
1031     Vals.push_back(getEncodedVisibility(F));
1032     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
1033     Vals.push_back(F.hasUnnamedAddr());
1034     Vals.push_back(F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1)
1035                                        : 0);
1036     Vals.push_back(getEncodedDLLStorageClass(F));
1037     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
1038     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
1039                                      : 0);
1040     Vals.push_back(
1041         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
1042 
1043     unsigned AbbrevToUse = 0;
1044     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
1045     Vals.clear();
1046   }
1047 
1048   // Emit the alias information.
1049   for (const GlobalAlias &A : M.aliases()) {
1050     // ALIAS: [alias type, aliasee val#, linkage, visibility]
1051     Vals.push_back(VE.getTypeID(A.getValueType()));
1052     Vals.push_back(A.getType()->getAddressSpace());
1053     Vals.push_back(VE.getValueID(A.getAliasee()));
1054     Vals.push_back(getEncodedLinkage(A));
1055     Vals.push_back(getEncodedVisibility(A));
1056     Vals.push_back(getEncodedDLLStorageClass(A));
1057     Vals.push_back(getEncodedThreadLocalMode(A));
1058     Vals.push_back(A.hasUnnamedAddr());
1059     unsigned AbbrevToUse = 0;
1060     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
1061     Vals.clear();
1062   }
1063 
1064   // Emit the ifunc information.
1065   for (const GlobalIFunc &I : M.ifuncs()) {
1066     // IFUNC: [ifunc type, address space, resolver val#, linkage, visibility]
1067     Vals.push_back(VE.getTypeID(I.getValueType()));
1068     Vals.push_back(I.getType()->getAddressSpace());
1069     Vals.push_back(VE.getValueID(I.getResolver()));
1070     Vals.push_back(getEncodedLinkage(I));
1071     Vals.push_back(getEncodedVisibility(I));
1072     Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
1073     Vals.clear();
1074   }
1075 
1076   // Emit the module's source file name.
1077   {
1078     StringEncoding Bits = getStringEncoding(M.getSourceFileName().data(),
1079                                             M.getSourceFileName().size());
1080     BitCodeAbbrevOp AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8);
1081     if (Bits == SE_Char6)
1082       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Char6);
1083     else if (Bits == SE_Fixed7)
1084       AbbrevOpToUse = BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7);
1085 
1086     // MODULE_CODE_SOURCE_FILENAME: [namechar x N]
1087     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1088     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_SOURCE_FILENAME));
1089     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1090     Abbv->Add(AbbrevOpToUse);
1091     unsigned FilenameAbbrev = Stream.EmitAbbrev(Abbv);
1092 
1093     for (const auto P : M.getSourceFileName())
1094       Vals.push_back((unsigned char)P);
1095 
1096     // Emit the finished record.
1097     Stream.EmitRecord(bitc::MODULE_CODE_SOURCE_FILENAME, Vals, FilenameAbbrev);
1098     Vals.clear();
1099   }
1100 
1101   // If we have a VST, write the VSTOFFSET record placeholder.
1102   if (M.getValueSymbolTable().empty())
1103     return;
1104   writeValueSymbolTableForwardDecl();
1105 }
1106 
1107 static uint64_t getOptimizationFlags(const Value *V) {
1108   uint64_t Flags = 0;
1109 
1110   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
1111     if (OBO->hasNoSignedWrap())
1112       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
1113     if (OBO->hasNoUnsignedWrap())
1114       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
1115   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
1116     if (PEO->isExact())
1117       Flags |= 1 << bitc::PEO_EXACT;
1118   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
1119     if (FPMO->hasUnsafeAlgebra())
1120       Flags |= FastMathFlags::UnsafeAlgebra;
1121     if (FPMO->hasNoNaNs())
1122       Flags |= FastMathFlags::NoNaNs;
1123     if (FPMO->hasNoInfs())
1124       Flags |= FastMathFlags::NoInfs;
1125     if (FPMO->hasNoSignedZeros())
1126       Flags |= FastMathFlags::NoSignedZeros;
1127     if (FPMO->hasAllowReciprocal())
1128       Flags |= FastMathFlags::AllowReciprocal;
1129   }
1130 
1131   return Flags;
1132 }
1133 
1134 void ModuleBitcodeWriter::writeValueAsMetadata(
1135     const ValueAsMetadata *MD, SmallVectorImpl<uint64_t> &Record) {
1136   // Mimic an MDNode with a value as one operand.
1137   Value *V = MD->getValue();
1138   Record.push_back(VE.getTypeID(V->getType()));
1139   Record.push_back(VE.getValueID(V));
1140   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
1141   Record.clear();
1142 }
1143 
1144 void ModuleBitcodeWriter::writeMDTuple(const MDTuple *N,
1145                                        SmallVectorImpl<uint64_t> &Record,
1146                                        unsigned Abbrev) {
1147   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
1148     Metadata *MD = N->getOperand(i);
1149     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
1150            "Unexpected function-local metadata");
1151     Record.push_back(VE.getMetadataOrNullID(MD));
1152   }
1153   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
1154                                     : bitc::METADATA_NODE,
1155                     Record, Abbrev);
1156   Record.clear();
1157 }
1158 
1159 unsigned ModuleBitcodeWriter::createDILocationAbbrev() {
1160   // Assume the column is usually under 128, and always output the inlined-at
1161   // location (it's never more expensive than building an array size 1).
1162   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1163   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1164   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1165   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1166   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1167   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1168   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1169   return Stream.EmitAbbrev(Abbv);
1170 }
1171 
1172 void ModuleBitcodeWriter::writeDILocation(const DILocation *N,
1173                                           SmallVectorImpl<uint64_t> &Record,
1174                                           unsigned &Abbrev) {
1175   if (!Abbrev)
1176     Abbrev = createDILocationAbbrev();
1177 
1178   Record.push_back(N->isDistinct());
1179   Record.push_back(N->getLine());
1180   Record.push_back(N->getColumn());
1181   Record.push_back(VE.getMetadataID(N->getScope()));
1182   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
1183 
1184   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
1185   Record.clear();
1186 }
1187 
1188 unsigned ModuleBitcodeWriter::createGenericDINodeAbbrev() {
1189   // Assume the column is usually under 128, and always output the inlined-at
1190   // location (it's never more expensive than building an array size 1).
1191   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1192   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1193   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1194   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1195   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1196   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1197   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1198   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1199   return Stream.EmitAbbrev(Abbv);
1200 }
1201 
1202 void ModuleBitcodeWriter::writeGenericDINode(const GenericDINode *N,
1203                                              SmallVectorImpl<uint64_t> &Record,
1204                                              unsigned &Abbrev) {
1205   if (!Abbrev)
1206     Abbrev = createGenericDINodeAbbrev();
1207 
1208   Record.push_back(N->isDistinct());
1209   Record.push_back(N->getTag());
1210   Record.push_back(0); // Per-tag version field; unused for now.
1211 
1212   for (auto &I : N->operands())
1213     Record.push_back(VE.getMetadataOrNullID(I));
1214 
1215   Stream.EmitRecord(bitc::METADATA_GENERIC_DEBUG, Record, Abbrev);
1216   Record.clear();
1217 }
1218 
1219 static uint64_t rotateSign(int64_t I) {
1220   uint64_t U = I;
1221   return I < 0 ? ~(U << 1) : U << 1;
1222 }
1223 
1224 void ModuleBitcodeWriter::writeDISubrange(const DISubrange *N,
1225                                           SmallVectorImpl<uint64_t> &Record,
1226                                           unsigned Abbrev) {
1227   Record.push_back(N->isDistinct());
1228   Record.push_back(N->getCount());
1229   Record.push_back(rotateSign(N->getLowerBound()));
1230 
1231   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
1232   Record.clear();
1233 }
1234 
1235 void ModuleBitcodeWriter::writeDIEnumerator(const DIEnumerator *N,
1236                                             SmallVectorImpl<uint64_t> &Record,
1237                                             unsigned Abbrev) {
1238   Record.push_back(N->isDistinct());
1239   Record.push_back(rotateSign(N->getValue()));
1240   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1241 
1242   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
1243   Record.clear();
1244 }
1245 
1246 void ModuleBitcodeWriter::writeDIBasicType(const DIBasicType *N,
1247                                            SmallVectorImpl<uint64_t> &Record,
1248                                            unsigned Abbrev) {
1249   Record.push_back(N->isDistinct());
1250   Record.push_back(N->getTag());
1251   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1252   Record.push_back(N->getSizeInBits());
1253   Record.push_back(N->getAlignInBits());
1254   Record.push_back(N->getEncoding());
1255 
1256   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
1257   Record.clear();
1258 }
1259 
1260 void ModuleBitcodeWriter::writeDIDerivedType(const DIDerivedType *N,
1261                                              SmallVectorImpl<uint64_t> &Record,
1262                                              unsigned Abbrev) {
1263   Record.push_back(N->isDistinct());
1264   Record.push_back(N->getTag());
1265   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1266   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1267   Record.push_back(N->getLine());
1268   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1269   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1270   Record.push_back(N->getSizeInBits());
1271   Record.push_back(N->getAlignInBits());
1272   Record.push_back(N->getOffsetInBits());
1273   Record.push_back(N->getFlags());
1274   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
1275 
1276   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
1277   Record.clear();
1278 }
1279 
1280 void ModuleBitcodeWriter::writeDICompositeType(
1281     const DICompositeType *N, SmallVectorImpl<uint64_t> &Record,
1282     unsigned Abbrev) {
1283   const unsigned IsNotUsedInOldTypeRef = 0x2;
1284   Record.push_back(IsNotUsedInOldTypeRef | (unsigned)N->isDistinct());
1285   Record.push_back(N->getTag());
1286   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1287   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1288   Record.push_back(N->getLine());
1289   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1290   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1291   Record.push_back(N->getSizeInBits());
1292   Record.push_back(N->getAlignInBits());
1293   Record.push_back(N->getOffsetInBits());
1294   Record.push_back(N->getFlags());
1295   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1296   Record.push_back(N->getRuntimeLang());
1297   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
1298   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1299   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
1300 
1301   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
1302   Record.clear();
1303 }
1304 
1305 void ModuleBitcodeWriter::writeDISubroutineType(
1306     const DISubroutineType *N, SmallVectorImpl<uint64_t> &Record,
1307     unsigned Abbrev) {
1308   const unsigned HasNoOldTypeRefs = 0x2;
1309   Record.push_back(HasNoOldTypeRefs | (unsigned)N->isDistinct());
1310   Record.push_back(N->getFlags());
1311   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
1312 
1313   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
1314   Record.clear();
1315 }
1316 
1317 void ModuleBitcodeWriter::writeDIFile(const DIFile *N,
1318                                       SmallVectorImpl<uint64_t> &Record,
1319                                       unsigned Abbrev) {
1320   Record.push_back(N->isDistinct());
1321   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
1322   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
1323 
1324   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
1325   Record.clear();
1326 }
1327 
1328 void ModuleBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
1329                                              SmallVectorImpl<uint64_t> &Record,
1330                                              unsigned Abbrev) {
1331   assert(N->isDistinct() && "Expected distinct compile units");
1332   Record.push_back(/* IsDistinct */ true);
1333   Record.push_back(N->getSourceLanguage());
1334   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1335   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
1336   Record.push_back(N->isOptimized());
1337   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
1338   Record.push_back(N->getRuntimeVersion());
1339   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
1340   Record.push_back(N->getEmissionKind());
1341   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
1342   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
1343   Record.push_back(/* subprograms */ 0);
1344   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
1345   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
1346   Record.push_back(N->getDWOId());
1347   Record.push_back(VE.getMetadataOrNullID(N->getMacros().get()));
1348 
1349   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
1350   Record.clear();
1351 }
1352 
1353 void ModuleBitcodeWriter::writeDISubprogram(const DISubprogram *N,
1354                                             SmallVectorImpl<uint64_t> &Record,
1355                                             unsigned Abbrev) {
1356   Record.push_back(N->isDistinct());
1357   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1358   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1359   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1360   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1361   Record.push_back(N->getLine());
1362   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1363   Record.push_back(N->isLocalToUnit());
1364   Record.push_back(N->isDefinition());
1365   Record.push_back(N->getScopeLine());
1366   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
1367   Record.push_back(N->getVirtuality());
1368   Record.push_back(N->getVirtualIndex());
1369   Record.push_back(N->getFlags());
1370   Record.push_back(N->isOptimized());
1371   Record.push_back(VE.getMetadataOrNullID(N->getRawUnit()));
1372   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1373   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
1374   Record.push_back(VE.getMetadataOrNullID(N->getVariables().get()));
1375 
1376   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
1377   Record.clear();
1378 }
1379 
1380 void ModuleBitcodeWriter::writeDILexicalBlock(const DILexicalBlock *N,
1381                                               SmallVectorImpl<uint64_t> &Record,
1382                                               unsigned Abbrev) {
1383   Record.push_back(N->isDistinct());
1384   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1385   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1386   Record.push_back(N->getLine());
1387   Record.push_back(N->getColumn());
1388 
1389   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
1390   Record.clear();
1391 }
1392 
1393 void ModuleBitcodeWriter::writeDILexicalBlockFile(
1394     const DILexicalBlockFile *N, SmallVectorImpl<uint64_t> &Record,
1395     unsigned Abbrev) {
1396   Record.push_back(N->isDistinct());
1397   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1398   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1399   Record.push_back(N->getDiscriminator());
1400 
1401   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
1402   Record.clear();
1403 }
1404 
1405 void ModuleBitcodeWriter::writeDINamespace(const DINamespace *N,
1406                                            SmallVectorImpl<uint64_t> &Record,
1407                                            unsigned Abbrev) {
1408   Record.push_back(N->isDistinct());
1409   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1410   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1411   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1412   Record.push_back(N->getLine());
1413 
1414   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
1415   Record.clear();
1416 }
1417 
1418 void ModuleBitcodeWriter::writeDIMacro(const DIMacro *N,
1419                                        SmallVectorImpl<uint64_t> &Record,
1420                                        unsigned Abbrev) {
1421   Record.push_back(N->isDistinct());
1422   Record.push_back(N->getMacinfoType());
1423   Record.push_back(N->getLine());
1424   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1425   Record.push_back(VE.getMetadataOrNullID(N->getRawValue()));
1426 
1427   Stream.EmitRecord(bitc::METADATA_MACRO, Record, Abbrev);
1428   Record.clear();
1429 }
1430 
1431 void ModuleBitcodeWriter::writeDIMacroFile(const DIMacroFile *N,
1432                                            SmallVectorImpl<uint64_t> &Record,
1433                                            unsigned Abbrev) {
1434   Record.push_back(N->isDistinct());
1435   Record.push_back(N->getMacinfoType());
1436   Record.push_back(N->getLine());
1437   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1438   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1439 
1440   Stream.EmitRecord(bitc::METADATA_MACRO_FILE, Record, Abbrev);
1441   Record.clear();
1442 }
1443 
1444 void ModuleBitcodeWriter::writeDIModule(const DIModule *N,
1445                                         SmallVectorImpl<uint64_t> &Record,
1446                                         unsigned Abbrev) {
1447   Record.push_back(N->isDistinct());
1448   for (auto &I : N->operands())
1449     Record.push_back(VE.getMetadataOrNullID(I));
1450 
1451   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
1452   Record.clear();
1453 }
1454 
1455 void ModuleBitcodeWriter::writeDITemplateTypeParameter(
1456     const DITemplateTypeParameter *N, SmallVectorImpl<uint64_t> &Record,
1457     unsigned Abbrev) {
1458   Record.push_back(N->isDistinct());
1459   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1460   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1461 
1462   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
1463   Record.clear();
1464 }
1465 
1466 void ModuleBitcodeWriter::writeDITemplateValueParameter(
1467     const DITemplateValueParameter *N, SmallVectorImpl<uint64_t> &Record,
1468     unsigned Abbrev) {
1469   Record.push_back(N->isDistinct());
1470   Record.push_back(N->getTag());
1471   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1472   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1473   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
1474 
1475   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
1476   Record.clear();
1477 }
1478 
1479 void ModuleBitcodeWriter::writeDIGlobalVariable(
1480     const DIGlobalVariable *N, SmallVectorImpl<uint64_t> &Record,
1481     unsigned Abbrev) {
1482   Record.push_back(N->isDistinct());
1483   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1484   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1485   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1486   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1487   Record.push_back(N->getLine());
1488   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1489   Record.push_back(N->isLocalToUnit());
1490   Record.push_back(N->isDefinition());
1491   Record.push_back(VE.getMetadataOrNullID(N->getRawVariable()));
1492   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
1493 
1494   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
1495   Record.clear();
1496 }
1497 
1498 void ModuleBitcodeWriter::writeDILocalVariable(
1499     const DILocalVariable *N, SmallVectorImpl<uint64_t> &Record,
1500     unsigned Abbrev) {
1501   Record.push_back(N->isDistinct());
1502   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1503   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1504   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1505   Record.push_back(N->getLine());
1506   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1507   Record.push_back(N->getArg());
1508   Record.push_back(N->getFlags());
1509 
1510   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
1511   Record.clear();
1512 }
1513 
1514 void ModuleBitcodeWriter::writeDIExpression(const DIExpression *N,
1515                                             SmallVectorImpl<uint64_t> &Record,
1516                                             unsigned Abbrev) {
1517   Record.reserve(N->getElements().size() + 1);
1518 
1519   Record.push_back(N->isDistinct());
1520   Record.append(N->elements_begin(), N->elements_end());
1521 
1522   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
1523   Record.clear();
1524 }
1525 
1526 void ModuleBitcodeWriter::writeDIObjCProperty(const DIObjCProperty *N,
1527                                               SmallVectorImpl<uint64_t> &Record,
1528                                               unsigned Abbrev) {
1529   Record.push_back(N->isDistinct());
1530   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1531   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1532   Record.push_back(N->getLine());
1533   Record.push_back(VE.getMetadataOrNullID(N->getRawSetterName()));
1534   Record.push_back(VE.getMetadataOrNullID(N->getRawGetterName()));
1535   Record.push_back(N->getAttributes());
1536   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1537 
1538   Stream.EmitRecord(bitc::METADATA_OBJC_PROPERTY, Record, Abbrev);
1539   Record.clear();
1540 }
1541 
1542 void ModuleBitcodeWriter::writeDIImportedEntity(
1543     const DIImportedEntity *N, SmallVectorImpl<uint64_t> &Record,
1544     unsigned Abbrev) {
1545   Record.push_back(N->isDistinct());
1546   Record.push_back(N->getTag());
1547   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1548   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
1549   Record.push_back(N->getLine());
1550   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1551 
1552   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
1553   Record.clear();
1554 }
1555 
1556 unsigned ModuleBitcodeWriter::createNamedMetadataAbbrev() {
1557   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1558   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
1559   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1560   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1561   return Stream.EmitAbbrev(Abbv);
1562 }
1563 
1564 void ModuleBitcodeWriter::writeNamedMetadata(
1565     SmallVectorImpl<uint64_t> &Record) {
1566   if (M.named_metadata_empty())
1567     return;
1568 
1569   unsigned Abbrev = createNamedMetadataAbbrev();
1570   for (const NamedMDNode &NMD : M.named_metadata()) {
1571     // Write name.
1572     StringRef Str = NMD.getName();
1573     Record.append(Str.bytes_begin(), Str.bytes_end());
1574     Stream.EmitRecord(bitc::METADATA_NAME, Record, Abbrev);
1575     Record.clear();
1576 
1577     // Write named metadata operands.
1578     for (const MDNode *N : NMD.operands())
1579       Record.push_back(VE.getMetadataID(N));
1580     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
1581     Record.clear();
1582   }
1583 }
1584 
1585 unsigned ModuleBitcodeWriter::createMetadataStringsAbbrev() {
1586   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1587   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRINGS));
1588   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of strings
1589   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // offset to chars
1590   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1591   return Stream.EmitAbbrev(Abbv);
1592 }
1593 
1594 /// Write out a record for MDString.
1595 ///
1596 /// All the metadata strings in a metadata block are emitted in a single
1597 /// record.  The sizes and strings themselves are shoved into a blob.
1598 void ModuleBitcodeWriter::writeMetadataStrings(
1599     ArrayRef<const Metadata *> Strings, SmallVectorImpl<uint64_t> &Record) {
1600   if (Strings.empty())
1601     return;
1602 
1603   // Start the record with the number of strings.
1604   Record.push_back(bitc::METADATA_STRINGS);
1605   Record.push_back(Strings.size());
1606 
1607   // Emit the sizes of the strings in the blob.
1608   SmallString<256> Blob;
1609   {
1610     BitstreamWriter W(Blob);
1611     for (const Metadata *MD : Strings)
1612       W.EmitVBR(cast<MDString>(MD)->getLength(), 6);
1613     W.FlushToWord();
1614   }
1615 
1616   // Add the offset to the strings to the record.
1617   Record.push_back(Blob.size());
1618 
1619   // Add the strings to the blob.
1620   for (const Metadata *MD : Strings)
1621     Blob.append(cast<MDString>(MD)->getString());
1622 
1623   // Emit the final record.
1624   Stream.EmitRecordWithBlob(createMetadataStringsAbbrev(), Record, Blob);
1625   Record.clear();
1626 }
1627 
1628 void ModuleBitcodeWriter::writeMetadataRecords(
1629     ArrayRef<const Metadata *> MDs, SmallVectorImpl<uint64_t> &Record) {
1630   if (MDs.empty())
1631     return;
1632 
1633   // Initialize MDNode abbreviations.
1634 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
1635 #include "llvm/IR/Metadata.def"
1636 
1637   for (const Metadata *MD : MDs) {
1638     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
1639       assert(N->isResolved() && "Expected forward references to be resolved");
1640 
1641       switch (N->getMetadataID()) {
1642       default:
1643         llvm_unreachable("Invalid MDNode subclass");
1644 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
1645   case Metadata::CLASS##Kind:                                                  \
1646     write##CLASS(cast<CLASS>(N), Record, CLASS##Abbrev);                       \
1647     continue;
1648 #include "llvm/IR/Metadata.def"
1649       }
1650     }
1651     writeValueAsMetadata(cast<ValueAsMetadata>(MD), Record);
1652   }
1653 }
1654 
1655 void ModuleBitcodeWriter::writeModuleMetadata() {
1656   if (!VE.hasMDs() && M.named_metadata_empty())
1657     return;
1658 
1659   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1660   SmallVector<uint64_t, 64> Record;
1661   writeMetadataStrings(VE.getMDStrings(), Record);
1662   writeMetadataRecords(VE.getNonMDStrings(), Record);
1663   writeNamedMetadata(Record);
1664   Stream.ExitBlock();
1665 }
1666 
1667 void ModuleBitcodeWriter::writeFunctionMetadata(const Function &F) {
1668   if (!VE.hasMDs())
1669     return;
1670 
1671   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1672   SmallVector<uint64_t, 64> Record;
1673   writeMetadataStrings(VE.getMDStrings(), Record);
1674   writeMetadataRecords(VE.getNonMDStrings(), Record);
1675   Stream.ExitBlock();
1676 }
1677 
1678 void ModuleBitcodeWriter::writeMetadataAttachment(const Function &F) {
1679   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
1680 
1681   SmallVector<uint64_t, 64> Record;
1682 
1683   // Write metadata attachments
1684   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
1685   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
1686   F.getAllMetadata(MDs);
1687   if (!MDs.empty()) {
1688     for (const auto &I : MDs) {
1689       Record.push_back(I.first);
1690       Record.push_back(VE.getMetadataID(I.second));
1691     }
1692     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1693     Record.clear();
1694   }
1695 
1696   for (const BasicBlock &BB : F)
1697     for (const Instruction &I : BB) {
1698       MDs.clear();
1699       I.getAllMetadataOtherThanDebugLoc(MDs);
1700 
1701       // If no metadata, ignore instruction.
1702       if (MDs.empty()) continue;
1703 
1704       Record.push_back(VE.getInstructionID(&I));
1705 
1706       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1707         Record.push_back(MDs[i].first);
1708         Record.push_back(VE.getMetadataID(MDs[i].second));
1709       }
1710       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1711       Record.clear();
1712     }
1713 
1714   Stream.ExitBlock();
1715 }
1716 
1717 void ModuleBitcodeWriter::writeModuleMetadataStore() {
1718   SmallVector<uint64_t, 64> Record;
1719 
1720   // Write metadata kinds
1721   // METADATA_KIND - [n x [id, name]]
1722   SmallVector<StringRef, 8> Names;
1723   M.getMDKindNames(Names);
1724 
1725   if (Names.empty()) return;
1726 
1727   Stream.EnterSubblock(bitc::METADATA_KIND_BLOCK_ID, 3);
1728 
1729   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
1730     Record.push_back(MDKindID);
1731     StringRef KName = Names[MDKindID];
1732     Record.append(KName.begin(), KName.end());
1733 
1734     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
1735     Record.clear();
1736   }
1737 
1738   Stream.ExitBlock();
1739 }
1740 
1741 void ModuleBitcodeWriter::writeOperandBundleTags() {
1742   // Write metadata kinds
1743   //
1744   // OPERAND_BUNDLE_TAGS_BLOCK_ID : N x OPERAND_BUNDLE_TAG
1745   //
1746   // OPERAND_BUNDLE_TAG - [strchr x N]
1747 
1748   SmallVector<StringRef, 8> Tags;
1749   M.getOperandBundleTags(Tags);
1750 
1751   if (Tags.empty())
1752     return;
1753 
1754   Stream.EnterSubblock(bitc::OPERAND_BUNDLE_TAGS_BLOCK_ID, 3);
1755 
1756   SmallVector<uint64_t, 64> Record;
1757 
1758   for (auto Tag : Tags) {
1759     Record.append(Tag.begin(), Tag.end());
1760 
1761     Stream.EmitRecord(bitc::OPERAND_BUNDLE_TAG, Record, 0);
1762     Record.clear();
1763   }
1764 
1765   Stream.ExitBlock();
1766 }
1767 
1768 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
1769   if ((int64_t)V >= 0)
1770     Vals.push_back(V << 1);
1771   else
1772     Vals.push_back((-V << 1) | 1);
1773 }
1774 
1775 void ModuleBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
1776                                          bool isGlobal) {
1777   if (FirstVal == LastVal) return;
1778 
1779   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
1780 
1781   unsigned AggregateAbbrev = 0;
1782   unsigned String8Abbrev = 0;
1783   unsigned CString7Abbrev = 0;
1784   unsigned CString6Abbrev = 0;
1785   // If this is a constant pool for the module, emit module-specific abbrevs.
1786   if (isGlobal) {
1787     // Abbrev for CST_CODE_AGGREGATE.
1788     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1789     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
1790     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1791     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
1792     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
1793 
1794     // Abbrev for CST_CODE_STRING.
1795     Abbv = new BitCodeAbbrev();
1796     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
1797     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1798     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1799     String8Abbrev = Stream.EmitAbbrev(Abbv);
1800     // Abbrev for CST_CODE_CSTRING.
1801     Abbv = new BitCodeAbbrev();
1802     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1803     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1804     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1805     CString7Abbrev = Stream.EmitAbbrev(Abbv);
1806     // Abbrev for CST_CODE_CSTRING.
1807     Abbv = new BitCodeAbbrev();
1808     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1809     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1810     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1811     CString6Abbrev = Stream.EmitAbbrev(Abbv);
1812   }
1813 
1814   SmallVector<uint64_t, 64> Record;
1815 
1816   const ValueEnumerator::ValueList &Vals = VE.getValues();
1817   Type *LastTy = nullptr;
1818   for (unsigned i = FirstVal; i != LastVal; ++i) {
1819     const Value *V = Vals[i].first;
1820     // If we need to switch types, do so now.
1821     if (V->getType() != LastTy) {
1822       LastTy = V->getType();
1823       Record.push_back(VE.getTypeID(LastTy));
1824       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
1825                         CONSTANTS_SETTYPE_ABBREV);
1826       Record.clear();
1827     }
1828 
1829     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
1830       Record.push_back(unsigned(IA->hasSideEffects()) |
1831                        unsigned(IA->isAlignStack()) << 1 |
1832                        unsigned(IA->getDialect()&1) << 2);
1833 
1834       // Add the asm string.
1835       const std::string &AsmStr = IA->getAsmString();
1836       Record.push_back(AsmStr.size());
1837       Record.append(AsmStr.begin(), AsmStr.end());
1838 
1839       // Add the constraint string.
1840       const std::string &ConstraintStr = IA->getConstraintString();
1841       Record.push_back(ConstraintStr.size());
1842       Record.append(ConstraintStr.begin(), ConstraintStr.end());
1843       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
1844       Record.clear();
1845       continue;
1846     }
1847     const Constant *C = cast<Constant>(V);
1848     unsigned Code = -1U;
1849     unsigned AbbrevToUse = 0;
1850     if (C->isNullValue()) {
1851       Code = bitc::CST_CODE_NULL;
1852     } else if (isa<UndefValue>(C)) {
1853       Code = bitc::CST_CODE_UNDEF;
1854     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
1855       if (IV->getBitWidth() <= 64) {
1856         uint64_t V = IV->getSExtValue();
1857         emitSignedInt64(Record, V);
1858         Code = bitc::CST_CODE_INTEGER;
1859         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
1860       } else {                             // Wide integers, > 64 bits in size.
1861         // We have an arbitrary precision integer value to write whose
1862         // bit width is > 64. However, in canonical unsigned integer
1863         // format it is likely that the high bits are going to be zero.
1864         // So, we only write the number of active words.
1865         unsigned NWords = IV->getValue().getActiveWords();
1866         const uint64_t *RawWords = IV->getValue().getRawData();
1867         for (unsigned i = 0; i != NWords; ++i) {
1868           emitSignedInt64(Record, RawWords[i]);
1869         }
1870         Code = bitc::CST_CODE_WIDE_INTEGER;
1871       }
1872     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
1873       Code = bitc::CST_CODE_FLOAT;
1874       Type *Ty = CFP->getType();
1875       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
1876         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
1877       } else if (Ty->isX86_FP80Ty()) {
1878         // api needed to prevent premature destruction
1879         // bits are not in the same order as a normal i80 APInt, compensate.
1880         APInt api = CFP->getValueAPF().bitcastToAPInt();
1881         const uint64_t *p = api.getRawData();
1882         Record.push_back((p[1] << 48) | (p[0] >> 16));
1883         Record.push_back(p[0] & 0xffffLL);
1884       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
1885         APInt api = CFP->getValueAPF().bitcastToAPInt();
1886         const uint64_t *p = api.getRawData();
1887         Record.push_back(p[0]);
1888         Record.push_back(p[1]);
1889       } else {
1890         assert (0 && "Unknown FP type!");
1891       }
1892     } else if (isa<ConstantDataSequential>(C) &&
1893                cast<ConstantDataSequential>(C)->isString()) {
1894       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
1895       // Emit constant strings specially.
1896       unsigned NumElts = Str->getNumElements();
1897       // If this is a null-terminated string, use the denser CSTRING encoding.
1898       if (Str->isCString()) {
1899         Code = bitc::CST_CODE_CSTRING;
1900         --NumElts;  // Don't encode the null, which isn't allowed by char6.
1901       } else {
1902         Code = bitc::CST_CODE_STRING;
1903         AbbrevToUse = String8Abbrev;
1904       }
1905       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
1906       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
1907       for (unsigned i = 0; i != NumElts; ++i) {
1908         unsigned char V = Str->getElementAsInteger(i);
1909         Record.push_back(V);
1910         isCStr7 &= (V & 128) == 0;
1911         if (isCStrChar6)
1912           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
1913       }
1914 
1915       if (isCStrChar6)
1916         AbbrevToUse = CString6Abbrev;
1917       else if (isCStr7)
1918         AbbrevToUse = CString7Abbrev;
1919     } else if (const ConstantDataSequential *CDS =
1920                   dyn_cast<ConstantDataSequential>(C)) {
1921       Code = bitc::CST_CODE_DATA;
1922       Type *EltTy = CDS->getType()->getElementType();
1923       if (isa<IntegerType>(EltTy)) {
1924         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
1925           Record.push_back(CDS->getElementAsInteger(i));
1926       } else {
1927         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
1928           Record.push_back(
1929               CDS->getElementAsAPFloat(i).bitcastToAPInt().getLimitedValue());
1930       }
1931     } else if (isa<ConstantAggregate>(C)) {
1932       Code = bitc::CST_CODE_AGGREGATE;
1933       for (const Value *Op : C->operands())
1934         Record.push_back(VE.getValueID(Op));
1935       AbbrevToUse = AggregateAbbrev;
1936     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
1937       switch (CE->getOpcode()) {
1938       default:
1939         if (Instruction::isCast(CE->getOpcode())) {
1940           Code = bitc::CST_CODE_CE_CAST;
1941           Record.push_back(getEncodedCastOpcode(CE->getOpcode()));
1942           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1943           Record.push_back(VE.getValueID(C->getOperand(0)));
1944           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
1945         } else {
1946           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
1947           Code = bitc::CST_CODE_CE_BINOP;
1948           Record.push_back(getEncodedBinaryOpcode(CE->getOpcode()));
1949           Record.push_back(VE.getValueID(C->getOperand(0)));
1950           Record.push_back(VE.getValueID(C->getOperand(1)));
1951           uint64_t Flags = getOptimizationFlags(CE);
1952           if (Flags != 0)
1953             Record.push_back(Flags);
1954         }
1955         break;
1956       case Instruction::GetElementPtr: {
1957         Code = bitc::CST_CODE_CE_GEP;
1958         const auto *GO = cast<GEPOperator>(C);
1959         if (GO->isInBounds())
1960           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
1961         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
1962         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
1963           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
1964           Record.push_back(VE.getValueID(C->getOperand(i)));
1965         }
1966         break;
1967       }
1968       case Instruction::Select:
1969         Code = bitc::CST_CODE_CE_SELECT;
1970         Record.push_back(VE.getValueID(C->getOperand(0)));
1971         Record.push_back(VE.getValueID(C->getOperand(1)));
1972         Record.push_back(VE.getValueID(C->getOperand(2)));
1973         break;
1974       case Instruction::ExtractElement:
1975         Code = bitc::CST_CODE_CE_EXTRACTELT;
1976         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1977         Record.push_back(VE.getValueID(C->getOperand(0)));
1978         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
1979         Record.push_back(VE.getValueID(C->getOperand(1)));
1980         break;
1981       case Instruction::InsertElement:
1982         Code = bitc::CST_CODE_CE_INSERTELT;
1983         Record.push_back(VE.getValueID(C->getOperand(0)));
1984         Record.push_back(VE.getValueID(C->getOperand(1)));
1985         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
1986         Record.push_back(VE.getValueID(C->getOperand(2)));
1987         break;
1988       case Instruction::ShuffleVector:
1989         // If the return type and argument types are the same, this is a
1990         // standard shufflevector instruction.  If the types are different,
1991         // then the shuffle is widening or truncating the input vectors, and
1992         // the argument type must also be encoded.
1993         if (C->getType() == C->getOperand(0)->getType()) {
1994           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
1995         } else {
1996           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
1997           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1998         }
1999         Record.push_back(VE.getValueID(C->getOperand(0)));
2000         Record.push_back(VE.getValueID(C->getOperand(1)));
2001         Record.push_back(VE.getValueID(C->getOperand(2)));
2002         break;
2003       case Instruction::ICmp:
2004       case Instruction::FCmp:
2005         Code = bitc::CST_CODE_CE_CMP;
2006         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2007         Record.push_back(VE.getValueID(C->getOperand(0)));
2008         Record.push_back(VE.getValueID(C->getOperand(1)));
2009         Record.push_back(CE->getPredicate());
2010         break;
2011       }
2012     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
2013       Code = bitc::CST_CODE_BLOCKADDRESS;
2014       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
2015       Record.push_back(VE.getValueID(BA->getFunction()));
2016       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
2017     } else {
2018 #ifndef NDEBUG
2019       C->dump();
2020 #endif
2021       llvm_unreachable("Unknown constant!");
2022     }
2023     Stream.EmitRecord(Code, Record, AbbrevToUse);
2024     Record.clear();
2025   }
2026 
2027   Stream.ExitBlock();
2028 }
2029 
2030 void ModuleBitcodeWriter::writeModuleConstants() {
2031   const ValueEnumerator::ValueList &Vals = VE.getValues();
2032 
2033   // Find the first constant to emit, which is the first non-globalvalue value.
2034   // We know globalvalues have been emitted by WriteModuleInfo.
2035   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
2036     if (!isa<GlobalValue>(Vals[i].first)) {
2037       writeConstants(i, Vals.size(), true);
2038       return;
2039     }
2040   }
2041 }
2042 
2043 /// pushValueAndType - The file has to encode both the value and type id for
2044 /// many values, because we need to know what type to create for forward
2045 /// references.  However, most operands are not forward references, so this type
2046 /// field is not needed.
2047 ///
2048 /// This function adds V's value ID to Vals.  If the value ID is higher than the
2049 /// instruction ID, then it is a forward reference, and it also includes the
2050 /// type ID.  The value ID that is written is encoded relative to the InstID.
2051 bool ModuleBitcodeWriter::pushValueAndType(const Value *V, unsigned InstID,
2052                                            SmallVectorImpl<unsigned> &Vals) {
2053   unsigned ValID = VE.getValueID(V);
2054   // Make encoding relative to the InstID.
2055   Vals.push_back(InstID - ValID);
2056   if (ValID >= InstID) {
2057     Vals.push_back(VE.getTypeID(V->getType()));
2058     return true;
2059   }
2060   return false;
2061 }
2062 
2063 void ModuleBitcodeWriter::writeOperandBundles(ImmutableCallSite CS,
2064                                               unsigned InstID) {
2065   SmallVector<unsigned, 64> Record;
2066   LLVMContext &C = CS.getInstruction()->getContext();
2067 
2068   for (unsigned i = 0, e = CS.getNumOperandBundles(); i != e; ++i) {
2069     const auto &Bundle = CS.getOperandBundleAt(i);
2070     Record.push_back(C.getOperandBundleTagID(Bundle.getTagName()));
2071 
2072     for (auto &Input : Bundle.Inputs)
2073       pushValueAndType(Input, InstID, Record);
2074 
2075     Stream.EmitRecord(bitc::FUNC_CODE_OPERAND_BUNDLE, Record);
2076     Record.clear();
2077   }
2078 }
2079 
2080 /// pushValue - Like pushValueAndType, but where the type of the value is
2081 /// omitted (perhaps it was already encoded in an earlier operand).
2082 void ModuleBitcodeWriter::pushValue(const Value *V, unsigned InstID,
2083                                     SmallVectorImpl<unsigned> &Vals) {
2084   unsigned ValID = VE.getValueID(V);
2085   Vals.push_back(InstID - ValID);
2086 }
2087 
2088 void ModuleBitcodeWriter::pushValueSigned(const Value *V, unsigned InstID,
2089                                           SmallVectorImpl<uint64_t> &Vals) {
2090   unsigned ValID = VE.getValueID(V);
2091   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
2092   emitSignedInt64(Vals, diff);
2093 }
2094 
2095 /// WriteInstruction - Emit an instruction to the specified stream.
2096 void ModuleBitcodeWriter::writeInstruction(const Instruction &I,
2097                                            unsigned InstID,
2098                                            SmallVectorImpl<unsigned> &Vals) {
2099   unsigned Code = 0;
2100   unsigned AbbrevToUse = 0;
2101   VE.setInstructionID(&I);
2102   switch (I.getOpcode()) {
2103   default:
2104     if (Instruction::isCast(I.getOpcode())) {
2105       Code = bitc::FUNC_CODE_INST_CAST;
2106       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2107         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
2108       Vals.push_back(VE.getTypeID(I.getType()));
2109       Vals.push_back(getEncodedCastOpcode(I.getOpcode()));
2110     } else {
2111       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
2112       Code = bitc::FUNC_CODE_INST_BINOP;
2113       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2114         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
2115       pushValue(I.getOperand(1), InstID, Vals);
2116       Vals.push_back(getEncodedBinaryOpcode(I.getOpcode()));
2117       uint64_t Flags = getOptimizationFlags(&I);
2118       if (Flags != 0) {
2119         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
2120           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
2121         Vals.push_back(Flags);
2122       }
2123     }
2124     break;
2125 
2126   case Instruction::GetElementPtr: {
2127     Code = bitc::FUNC_CODE_INST_GEP;
2128     AbbrevToUse = FUNCTION_INST_GEP_ABBREV;
2129     auto &GEPInst = cast<GetElementPtrInst>(I);
2130     Vals.push_back(GEPInst.isInBounds());
2131     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
2132     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
2133       pushValueAndType(I.getOperand(i), InstID, Vals);
2134     break;
2135   }
2136   case Instruction::ExtractValue: {
2137     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
2138     pushValueAndType(I.getOperand(0), InstID, Vals);
2139     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
2140     Vals.append(EVI->idx_begin(), EVI->idx_end());
2141     break;
2142   }
2143   case Instruction::InsertValue: {
2144     Code = bitc::FUNC_CODE_INST_INSERTVAL;
2145     pushValueAndType(I.getOperand(0), InstID, Vals);
2146     pushValueAndType(I.getOperand(1), InstID, Vals);
2147     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
2148     Vals.append(IVI->idx_begin(), IVI->idx_end());
2149     break;
2150   }
2151   case Instruction::Select:
2152     Code = bitc::FUNC_CODE_INST_VSELECT;
2153     pushValueAndType(I.getOperand(1), InstID, Vals);
2154     pushValue(I.getOperand(2), InstID, Vals);
2155     pushValueAndType(I.getOperand(0), InstID, Vals);
2156     break;
2157   case Instruction::ExtractElement:
2158     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
2159     pushValueAndType(I.getOperand(0), InstID, Vals);
2160     pushValueAndType(I.getOperand(1), InstID, Vals);
2161     break;
2162   case Instruction::InsertElement:
2163     Code = bitc::FUNC_CODE_INST_INSERTELT;
2164     pushValueAndType(I.getOperand(0), InstID, Vals);
2165     pushValue(I.getOperand(1), InstID, Vals);
2166     pushValueAndType(I.getOperand(2), InstID, Vals);
2167     break;
2168   case Instruction::ShuffleVector:
2169     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
2170     pushValueAndType(I.getOperand(0), InstID, Vals);
2171     pushValue(I.getOperand(1), InstID, Vals);
2172     pushValue(I.getOperand(2), InstID, Vals);
2173     break;
2174   case Instruction::ICmp:
2175   case Instruction::FCmp: {
2176     // compare returning Int1Ty or vector of Int1Ty
2177     Code = bitc::FUNC_CODE_INST_CMP2;
2178     pushValueAndType(I.getOperand(0), InstID, Vals);
2179     pushValue(I.getOperand(1), InstID, Vals);
2180     Vals.push_back(cast<CmpInst>(I).getPredicate());
2181     uint64_t Flags = getOptimizationFlags(&I);
2182     if (Flags != 0)
2183       Vals.push_back(Flags);
2184     break;
2185   }
2186 
2187   case Instruction::Ret:
2188     {
2189       Code = bitc::FUNC_CODE_INST_RET;
2190       unsigned NumOperands = I.getNumOperands();
2191       if (NumOperands == 0)
2192         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
2193       else if (NumOperands == 1) {
2194         if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2195           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
2196       } else {
2197         for (unsigned i = 0, e = NumOperands; i != e; ++i)
2198           pushValueAndType(I.getOperand(i), InstID, Vals);
2199       }
2200     }
2201     break;
2202   case Instruction::Br:
2203     {
2204       Code = bitc::FUNC_CODE_INST_BR;
2205       const BranchInst &II = cast<BranchInst>(I);
2206       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
2207       if (II.isConditional()) {
2208         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
2209         pushValue(II.getCondition(), InstID, Vals);
2210       }
2211     }
2212     break;
2213   case Instruction::Switch:
2214     {
2215       Code = bitc::FUNC_CODE_INST_SWITCH;
2216       const SwitchInst &SI = cast<SwitchInst>(I);
2217       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
2218       pushValue(SI.getCondition(), InstID, Vals);
2219       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
2220       for (SwitchInst::ConstCaseIt Case : SI.cases()) {
2221         Vals.push_back(VE.getValueID(Case.getCaseValue()));
2222         Vals.push_back(VE.getValueID(Case.getCaseSuccessor()));
2223       }
2224     }
2225     break;
2226   case Instruction::IndirectBr:
2227     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
2228     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
2229     // Encode the address operand as relative, but not the basic blocks.
2230     pushValue(I.getOperand(0), InstID, Vals);
2231     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
2232       Vals.push_back(VE.getValueID(I.getOperand(i)));
2233     break;
2234 
2235   case Instruction::Invoke: {
2236     const InvokeInst *II = cast<InvokeInst>(&I);
2237     const Value *Callee = II->getCalledValue();
2238     FunctionType *FTy = II->getFunctionType();
2239 
2240     if (II->hasOperandBundles())
2241       writeOperandBundles(II, InstID);
2242 
2243     Code = bitc::FUNC_CODE_INST_INVOKE;
2244 
2245     Vals.push_back(VE.getAttributeID(II->getAttributes()));
2246     Vals.push_back(II->getCallingConv() | 1 << 13);
2247     Vals.push_back(VE.getValueID(II->getNormalDest()));
2248     Vals.push_back(VE.getValueID(II->getUnwindDest()));
2249     Vals.push_back(VE.getTypeID(FTy));
2250     pushValueAndType(Callee, InstID, Vals);
2251 
2252     // Emit value #'s for the fixed parameters.
2253     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
2254       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
2255 
2256     // Emit type/value pairs for varargs params.
2257     if (FTy->isVarArg()) {
2258       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
2259            i != e; ++i)
2260         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
2261     }
2262     break;
2263   }
2264   case Instruction::Resume:
2265     Code = bitc::FUNC_CODE_INST_RESUME;
2266     pushValueAndType(I.getOperand(0), InstID, Vals);
2267     break;
2268   case Instruction::CleanupRet: {
2269     Code = bitc::FUNC_CODE_INST_CLEANUPRET;
2270     const auto &CRI = cast<CleanupReturnInst>(I);
2271     pushValue(CRI.getCleanupPad(), InstID, Vals);
2272     if (CRI.hasUnwindDest())
2273       Vals.push_back(VE.getValueID(CRI.getUnwindDest()));
2274     break;
2275   }
2276   case Instruction::CatchRet: {
2277     Code = bitc::FUNC_CODE_INST_CATCHRET;
2278     const auto &CRI = cast<CatchReturnInst>(I);
2279     pushValue(CRI.getCatchPad(), InstID, Vals);
2280     Vals.push_back(VE.getValueID(CRI.getSuccessor()));
2281     break;
2282   }
2283   case Instruction::CleanupPad:
2284   case Instruction::CatchPad: {
2285     const auto &FuncletPad = cast<FuncletPadInst>(I);
2286     Code = isa<CatchPadInst>(FuncletPad) ? bitc::FUNC_CODE_INST_CATCHPAD
2287                                          : bitc::FUNC_CODE_INST_CLEANUPPAD;
2288     pushValue(FuncletPad.getParentPad(), InstID, Vals);
2289 
2290     unsigned NumArgOperands = FuncletPad.getNumArgOperands();
2291     Vals.push_back(NumArgOperands);
2292     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
2293       pushValueAndType(FuncletPad.getArgOperand(Op), InstID, Vals);
2294     break;
2295   }
2296   case Instruction::CatchSwitch: {
2297     Code = bitc::FUNC_CODE_INST_CATCHSWITCH;
2298     const auto &CatchSwitch = cast<CatchSwitchInst>(I);
2299 
2300     pushValue(CatchSwitch.getParentPad(), InstID, Vals);
2301 
2302     unsigned NumHandlers = CatchSwitch.getNumHandlers();
2303     Vals.push_back(NumHandlers);
2304     for (const BasicBlock *CatchPadBB : CatchSwitch.handlers())
2305       Vals.push_back(VE.getValueID(CatchPadBB));
2306 
2307     if (CatchSwitch.hasUnwindDest())
2308       Vals.push_back(VE.getValueID(CatchSwitch.getUnwindDest()));
2309     break;
2310   }
2311   case Instruction::Unreachable:
2312     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
2313     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
2314     break;
2315 
2316   case Instruction::PHI: {
2317     const PHINode &PN = cast<PHINode>(I);
2318     Code = bitc::FUNC_CODE_INST_PHI;
2319     // With the newer instruction encoding, forward references could give
2320     // negative valued IDs.  This is most common for PHIs, so we use
2321     // signed VBRs.
2322     SmallVector<uint64_t, 128> Vals64;
2323     Vals64.push_back(VE.getTypeID(PN.getType()));
2324     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
2325       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64);
2326       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
2327     }
2328     // Emit a Vals64 vector and exit.
2329     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
2330     Vals64.clear();
2331     return;
2332   }
2333 
2334   case Instruction::LandingPad: {
2335     const LandingPadInst &LP = cast<LandingPadInst>(I);
2336     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
2337     Vals.push_back(VE.getTypeID(LP.getType()));
2338     Vals.push_back(LP.isCleanup());
2339     Vals.push_back(LP.getNumClauses());
2340     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
2341       if (LP.isCatch(I))
2342         Vals.push_back(LandingPadInst::Catch);
2343       else
2344         Vals.push_back(LandingPadInst::Filter);
2345       pushValueAndType(LP.getClause(I), InstID, Vals);
2346     }
2347     break;
2348   }
2349 
2350   case Instruction::Alloca: {
2351     Code = bitc::FUNC_CODE_INST_ALLOCA;
2352     const AllocaInst &AI = cast<AllocaInst>(I);
2353     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
2354     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
2355     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
2356     unsigned AlignRecord = Log2_32(AI.getAlignment()) + 1;
2357     assert(Log2_32(Value::MaximumAlignment) + 1 < 1 << 5 &&
2358            "not enough bits for maximum alignment");
2359     assert(AlignRecord < 1 << 5 && "alignment greater than 1 << 64");
2360     AlignRecord |= AI.isUsedWithInAlloca() << 5;
2361     AlignRecord |= 1 << 6;
2362     AlignRecord |= AI.isSwiftError() << 7;
2363     Vals.push_back(AlignRecord);
2364     break;
2365   }
2366 
2367   case Instruction::Load:
2368     if (cast<LoadInst>(I).isAtomic()) {
2369       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
2370       pushValueAndType(I.getOperand(0), InstID, Vals);
2371     } else {
2372       Code = bitc::FUNC_CODE_INST_LOAD;
2373       if (!pushValueAndType(I.getOperand(0), InstID, Vals)) // ptr
2374         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
2375     }
2376     Vals.push_back(VE.getTypeID(I.getType()));
2377     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
2378     Vals.push_back(cast<LoadInst>(I).isVolatile());
2379     if (cast<LoadInst>(I).isAtomic()) {
2380       Vals.push_back(getEncodedOrdering(cast<LoadInst>(I).getOrdering()));
2381       Vals.push_back(getEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
2382     }
2383     break;
2384   case Instruction::Store:
2385     if (cast<StoreInst>(I).isAtomic())
2386       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
2387     else
2388       Code = bitc::FUNC_CODE_INST_STORE;
2389     pushValueAndType(I.getOperand(1), InstID, Vals); // ptrty + ptr
2390     pushValueAndType(I.getOperand(0), InstID, Vals); // valty + val
2391     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
2392     Vals.push_back(cast<StoreInst>(I).isVolatile());
2393     if (cast<StoreInst>(I).isAtomic()) {
2394       Vals.push_back(getEncodedOrdering(cast<StoreInst>(I).getOrdering()));
2395       Vals.push_back(getEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
2396     }
2397     break;
2398   case Instruction::AtomicCmpXchg:
2399     Code = bitc::FUNC_CODE_INST_CMPXCHG;
2400     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
2401     pushValueAndType(I.getOperand(1), InstID, Vals); // cmp.
2402     pushValue(I.getOperand(2), InstID, Vals);        // newval.
2403     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
2404     Vals.push_back(
2405         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
2406     Vals.push_back(
2407         getEncodedSynchScope(cast<AtomicCmpXchgInst>(I).getSynchScope()));
2408     Vals.push_back(
2409         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
2410     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
2411     break;
2412   case Instruction::AtomicRMW:
2413     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
2414     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
2415     pushValue(I.getOperand(1), InstID, Vals);        // val.
2416     Vals.push_back(
2417         getEncodedRMWOperation(cast<AtomicRMWInst>(I).getOperation()));
2418     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
2419     Vals.push_back(getEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
2420     Vals.push_back(
2421         getEncodedSynchScope(cast<AtomicRMWInst>(I).getSynchScope()));
2422     break;
2423   case Instruction::Fence:
2424     Code = bitc::FUNC_CODE_INST_FENCE;
2425     Vals.push_back(getEncodedOrdering(cast<FenceInst>(I).getOrdering()));
2426     Vals.push_back(getEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
2427     break;
2428   case Instruction::Call: {
2429     const CallInst &CI = cast<CallInst>(I);
2430     FunctionType *FTy = CI.getFunctionType();
2431 
2432     if (CI.hasOperandBundles())
2433       writeOperandBundles(&CI, InstID);
2434 
2435     Code = bitc::FUNC_CODE_INST_CALL;
2436 
2437     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
2438 
2439     unsigned Flags = getOptimizationFlags(&I);
2440     Vals.push_back(CI.getCallingConv() << bitc::CALL_CCONV |
2441                    unsigned(CI.isTailCall()) << bitc::CALL_TAIL |
2442                    unsigned(CI.isMustTailCall()) << bitc::CALL_MUSTTAIL |
2443                    1 << bitc::CALL_EXPLICIT_TYPE |
2444                    unsigned(CI.isNoTailCall()) << bitc::CALL_NOTAIL |
2445                    unsigned(Flags != 0) << bitc::CALL_FMF);
2446     if (Flags != 0)
2447       Vals.push_back(Flags);
2448 
2449     Vals.push_back(VE.getTypeID(FTy));
2450     pushValueAndType(CI.getCalledValue(), InstID, Vals); // Callee
2451 
2452     // Emit value #'s for the fixed parameters.
2453     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
2454       // Check for labels (can happen with asm labels).
2455       if (FTy->getParamType(i)->isLabelTy())
2456         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
2457       else
2458         pushValue(CI.getArgOperand(i), InstID, Vals); // fixed param.
2459     }
2460 
2461     // Emit type/value pairs for varargs params.
2462     if (FTy->isVarArg()) {
2463       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
2464            i != e; ++i)
2465         pushValueAndType(CI.getArgOperand(i), InstID, Vals); // varargs
2466     }
2467     break;
2468   }
2469   case Instruction::VAArg:
2470     Code = bitc::FUNC_CODE_INST_VAARG;
2471     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
2472     pushValue(I.getOperand(0), InstID, Vals);                   // valist.
2473     Vals.push_back(VE.getTypeID(I.getType())); // restype.
2474     break;
2475   }
2476 
2477   Stream.EmitRecord(Code, Vals, AbbrevToUse);
2478   Vals.clear();
2479 }
2480 
2481 /// Emit names for globals/functions etc. \p IsModuleLevel is true when
2482 /// we are writing the module-level VST, where we are including a function
2483 /// bitcode index and need to backpatch the VST forward declaration record.
2484 void ModuleBitcodeWriter::writeValueSymbolTable(
2485     const ValueSymbolTable &VST, bool IsModuleLevel,
2486     DenseMap<const Function *, uint64_t> *FunctionToBitcodeIndex) {
2487   if (VST.empty()) {
2488     // writeValueSymbolTableForwardDecl should have returned early as
2489     // well. Ensure this handling remains in sync by asserting that
2490     // the placeholder offset is not set.
2491     assert(!IsModuleLevel || !hasVSTOffsetPlaceholder());
2492     return;
2493   }
2494 
2495   if (IsModuleLevel && hasVSTOffsetPlaceholder()) {
2496     // Get the offset of the VST we are writing, and backpatch it into
2497     // the VST forward declaration record.
2498     uint64_t VSTOffset = Stream.GetCurrentBitNo();
2499     // The BitcodeStartBit was the stream offset of the actual bitcode
2500     // (e.g. excluding any initial darwin header).
2501     VSTOffset -= bitcodeStartBit();
2502     assert((VSTOffset & 31) == 0 && "VST block not 32-bit aligned");
2503     Stream.BackpatchWord(VSTOffsetPlaceholder, VSTOffset / 32);
2504   }
2505 
2506   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
2507 
2508   // For the module-level VST, add abbrev Ids for the VST_CODE_FNENTRY
2509   // records, which are not used in the per-function VSTs.
2510   unsigned FnEntry8BitAbbrev;
2511   unsigned FnEntry7BitAbbrev;
2512   unsigned FnEntry6BitAbbrev;
2513   if (IsModuleLevel && hasVSTOffsetPlaceholder()) {
2514     // 8-bit fixed-width VST_CODE_FNENTRY function strings.
2515     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2516     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
2517     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
2518     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
2519     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2520     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2521     FnEntry8BitAbbrev = Stream.EmitAbbrev(Abbv);
2522 
2523     // 7-bit fixed width VST_CODE_FNENTRY function strings.
2524     Abbv = new BitCodeAbbrev();
2525     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
2526     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
2527     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
2528     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2529     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2530     FnEntry7BitAbbrev = Stream.EmitAbbrev(Abbv);
2531 
2532     // 6-bit char6 VST_CODE_FNENTRY function strings.
2533     Abbv = new BitCodeAbbrev();
2534     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
2535     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
2536     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
2537     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2538     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2539     FnEntry6BitAbbrev = Stream.EmitAbbrev(Abbv);
2540   }
2541 
2542   // FIXME: Set up the abbrev, we know how many values there are!
2543   // FIXME: We know if the type names can use 7-bit ascii.
2544   SmallVector<unsigned, 64> NameVals;
2545 
2546   for (const ValueName &Name : VST) {
2547     // Figure out the encoding to use for the name.
2548     StringEncoding Bits =
2549         getStringEncoding(Name.getKeyData(), Name.getKeyLength());
2550 
2551     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
2552     NameVals.push_back(VE.getValueID(Name.getValue()));
2553 
2554     Function *F = dyn_cast<Function>(Name.getValue());
2555     if (!F) {
2556       // If value is an alias, need to get the aliased base object to
2557       // see if it is a function.
2558       auto *GA = dyn_cast<GlobalAlias>(Name.getValue());
2559       if (GA && GA->getBaseObject())
2560         F = dyn_cast<Function>(GA->getBaseObject());
2561     }
2562 
2563     // VST_CODE_ENTRY:   [valueid, namechar x N]
2564     // VST_CODE_FNENTRY: [valueid, funcoffset, namechar x N]
2565     // VST_CODE_BBENTRY: [bbid, namechar x N]
2566     unsigned Code;
2567     if (isa<BasicBlock>(Name.getValue())) {
2568       Code = bitc::VST_CODE_BBENTRY;
2569       if (Bits == SE_Char6)
2570         AbbrevToUse = VST_BBENTRY_6_ABBREV;
2571     } else if (F && !F->isDeclaration()) {
2572       // Must be the module-level VST, where we pass in the Index and
2573       // have a VSTOffsetPlaceholder. The function-level VST should not
2574       // contain any Function symbols.
2575       assert(FunctionToBitcodeIndex);
2576       assert(hasVSTOffsetPlaceholder());
2577 
2578       // Save the word offset of the function (from the start of the
2579       // actual bitcode written to the stream).
2580       uint64_t BitcodeIndex = (*FunctionToBitcodeIndex)[F] - bitcodeStartBit();
2581       assert((BitcodeIndex & 31) == 0 && "function block not 32-bit aligned");
2582       NameVals.push_back(BitcodeIndex / 32);
2583 
2584       Code = bitc::VST_CODE_FNENTRY;
2585       AbbrevToUse = FnEntry8BitAbbrev;
2586       if (Bits == SE_Char6)
2587         AbbrevToUse = FnEntry6BitAbbrev;
2588       else if (Bits == SE_Fixed7)
2589         AbbrevToUse = FnEntry7BitAbbrev;
2590     } else {
2591       Code = bitc::VST_CODE_ENTRY;
2592       if (Bits == SE_Char6)
2593         AbbrevToUse = VST_ENTRY_6_ABBREV;
2594       else if (Bits == SE_Fixed7)
2595         AbbrevToUse = VST_ENTRY_7_ABBREV;
2596     }
2597 
2598     for (const auto P : Name.getKey())
2599       NameVals.push_back((unsigned char)P);
2600 
2601     // Emit the finished record.
2602     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
2603     NameVals.clear();
2604   }
2605   Stream.ExitBlock();
2606 }
2607 
2608 /// Emit function names and summary offsets for the combined index
2609 /// used by ThinLTO.
2610 void IndexBitcodeWriter::writeCombinedValueSymbolTable() {
2611   assert(hasVSTOffsetPlaceholder() && "Expected non-zero VSTOffsetPlaceholder");
2612   // Get the offset of the VST we are writing, and backpatch it into
2613   // the VST forward declaration record.
2614   uint64_t VSTOffset = Stream.GetCurrentBitNo();
2615   assert((VSTOffset & 31) == 0 && "VST block not 32-bit aligned");
2616   Stream.BackpatchWord(VSTOffsetPlaceholder, VSTOffset / 32);
2617 
2618   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
2619 
2620   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2621   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_COMBINED_ENTRY));
2622   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
2623   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // refguid
2624   unsigned EntryAbbrev = Stream.EmitAbbrev(Abbv);
2625 
2626   SmallVector<uint64_t, 64> NameVals;
2627   for (const auto &GVI : valueIds()) {
2628     // VST_CODE_COMBINED_ENTRY: [valueid, refguid]
2629     NameVals.push_back(GVI.second);
2630     NameVals.push_back(GVI.first);
2631 
2632     // Emit the finished record.
2633     Stream.EmitRecord(bitc::VST_CODE_COMBINED_ENTRY, NameVals, EntryAbbrev);
2634     NameVals.clear();
2635   }
2636   Stream.ExitBlock();
2637 }
2638 
2639 void ModuleBitcodeWriter::writeUseList(UseListOrder &&Order) {
2640   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
2641   unsigned Code;
2642   if (isa<BasicBlock>(Order.V))
2643     Code = bitc::USELIST_CODE_BB;
2644   else
2645     Code = bitc::USELIST_CODE_DEFAULT;
2646 
2647   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
2648   Record.push_back(VE.getValueID(Order.V));
2649   Stream.EmitRecord(Code, Record);
2650 }
2651 
2652 void ModuleBitcodeWriter::writeUseListBlock(const Function *F) {
2653   assert(VE.shouldPreserveUseListOrder() &&
2654          "Expected to be preserving use-list order");
2655 
2656   auto hasMore = [&]() {
2657     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
2658   };
2659   if (!hasMore())
2660     // Nothing to do.
2661     return;
2662 
2663   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
2664   while (hasMore()) {
2665     writeUseList(std::move(VE.UseListOrders.back()));
2666     VE.UseListOrders.pop_back();
2667   }
2668   Stream.ExitBlock();
2669 }
2670 
2671 /// Emit a function body to the module stream.
2672 void ModuleBitcodeWriter::writeFunction(
2673     const Function &F,
2674     DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex) {
2675   // Save the bitcode index of the start of this function block for recording
2676   // in the VST.
2677   FunctionToBitcodeIndex[&F] = Stream.GetCurrentBitNo();
2678 
2679   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
2680   VE.incorporateFunction(F);
2681 
2682   SmallVector<unsigned, 64> Vals;
2683 
2684   // Emit the number of basic blocks, so the reader can create them ahead of
2685   // time.
2686   Vals.push_back(VE.getBasicBlocks().size());
2687   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
2688   Vals.clear();
2689 
2690   // If there are function-local constants, emit them now.
2691   unsigned CstStart, CstEnd;
2692   VE.getFunctionConstantRange(CstStart, CstEnd);
2693   writeConstants(CstStart, CstEnd, false);
2694 
2695   // If there is function-local metadata, emit it now.
2696   writeFunctionMetadata(F);
2697 
2698   // Keep a running idea of what the instruction ID is.
2699   unsigned InstID = CstEnd;
2700 
2701   bool NeedsMetadataAttachment = F.hasMetadata();
2702 
2703   DILocation *LastDL = nullptr;
2704   // Finally, emit all the instructions, in order.
2705   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
2706     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
2707          I != E; ++I) {
2708       writeInstruction(*I, InstID, Vals);
2709 
2710       if (!I->getType()->isVoidTy())
2711         ++InstID;
2712 
2713       // If the instruction has metadata, write a metadata attachment later.
2714       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
2715 
2716       // If the instruction has a debug location, emit it.
2717       DILocation *DL = I->getDebugLoc();
2718       if (!DL)
2719         continue;
2720 
2721       if (DL == LastDL) {
2722         // Just repeat the same debug loc as last time.
2723         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
2724         continue;
2725       }
2726 
2727       Vals.push_back(DL->getLine());
2728       Vals.push_back(DL->getColumn());
2729       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
2730       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
2731       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
2732       Vals.clear();
2733 
2734       LastDL = DL;
2735     }
2736 
2737   // Emit names for all the instructions etc.
2738   writeValueSymbolTable(F.getValueSymbolTable());
2739 
2740   if (NeedsMetadataAttachment)
2741     writeMetadataAttachment(F);
2742   if (VE.shouldPreserveUseListOrder())
2743     writeUseListBlock(&F);
2744   VE.purgeFunction();
2745   Stream.ExitBlock();
2746 }
2747 
2748 // Emit blockinfo, which defines the standard abbreviations etc.
2749 void ModuleBitcodeWriter::writeBlockInfo() {
2750   // We only want to emit block info records for blocks that have multiple
2751   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
2752   // Other blocks can define their abbrevs inline.
2753   Stream.EnterBlockInfoBlock(2);
2754 
2755   { // 8-bit fixed-width VST_CODE_ENTRY/VST_CODE_BBENTRY strings.
2756     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2757     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
2758     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2759     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2760     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2761     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
2762         VST_ENTRY_8_ABBREV)
2763       llvm_unreachable("Unexpected abbrev ordering!");
2764   }
2765 
2766   { // 7-bit fixed width VST_CODE_ENTRY strings.
2767     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2768     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2769     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2770     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2771     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2772     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
2773         VST_ENTRY_7_ABBREV)
2774       llvm_unreachable("Unexpected abbrev ordering!");
2775   }
2776   { // 6-bit char6 VST_CODE_ENTRY strings.
2777     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2778     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2779     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2780     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2781     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2782     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
2783         VST_ENTRY_6_ABBREV)
2784       llvm_unreachable("Unexpected abbrev ordering!");
2785   }
2786   { // 6-bit char6 VST_CODE_BBENTRY strings.
2787     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2788     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
2789     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2790     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2791     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2792     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, Abbv) !=
2793         VST_BBENTRY_6_ABBREV)
2794       llvm_unreachable("Unexpected abbrev ordering!");
2795   }
2796 
2797 
2798 
2799   { // SETTYPE abbrev for CONSTANTS_BLOCK.
2800     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2801     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
2802     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2803                               VE.computeBitsRequiredForTypeIndicies()));
2804     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
2805         CONSTANTS_SETTYPE_ABBREV)
2806       llvm_unreachable("Unexpected abbrev ordering!");
2807   }
2808 
2809   { // INTEGER abbrev for CONSTANTS_BLOCK.
2810     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2811     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
2812     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2813     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
2814         CONSTANTS_INTEGER_ABBREV)
2815       llvm_unreachable("Unexpected abbrev ordering!");
2816   }
2817 
2818   { // CE_CAST abbrev for CONSTANTS_BLOCK.
2819     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2820     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
2821     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
2822     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
2823                               VE.computeBitsRequiredForTypeIndicies()));
2824     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
2825 
2826     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
2827         CONSTANTS_CE_CAST_Abbrev)
2828       llvm_unreachable("Unexpected abbrev ordering!");
2829   }
2830   { // NULL abbrev for CONSTANTS_BLOCK.
2831     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2832     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
2833     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, Abbv) !=
2834         CONSTANTS_NULL_Abbrev)
2835       llvm_unreachable("Unexpected abbrev ordering!");
2836   }
2837 
2838   // FIXME: This should only use space for first class types!
2839 
2840   { // INST_LOAD abbrev for FUNCTION_BLOCK.
2841     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2842     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
2843     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
2844     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2845                               VE.computeBitsRequiredForTypeIndicies()));
2846     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
2847     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
2848     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2849         FUNCTION_INST_LOAD_ABBREV)
2850       llvm_unreachable("Unexpected abbrev ordering!");
2851   }
2852   { // INST_BINOP abbrev for FUNCTION_BLOCK.
2853     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2854     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2855     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2856     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2857     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2858     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2859         FUNCTION_INST_BINOP_ABBREV)
2860       llvm_unreachable("Unexpected abbrev ordering!");
2861   }
2862   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
2863     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2864     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2865     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2866     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2867     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2868     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
2869     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2870         FUNCTION_INST_BINOP_FLAGS_ABBREV)
2871       llvm_unreachable("Unexpected abbrev ordering!");
2872   }
2873   { // INST_CAST abbrev for FUNCTION_BLOCK.
2874     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2875     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
2876     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
2877     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
2878                               VE.computeBitsRequiredForTypeIndicies()));
2879     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
2880     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2881         FUNCTION_INST_CAST_ABBREV)
2882       llvm_unreachable("Unexpected abbrev ordering!");
2883   }
2884 
2885   { // INST_RET abbrev for FUNCTION_BLOCK.
2886     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2887     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2888     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2889         FUNCTION_INST_RET_VOID_ABBREV)
2890       llvm_unreachable("Unexpected abbrev ordering!");
2891   }
2892   { // INST_RET abbrev for FUNCTION_BLOCK.
2893     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2894     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2895     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
2896     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2897         FUNCTION_INST_RET_VAL_ABBREV)
2898       llvm_unreachable("Unexpected abbrev ordering!");
2899   }
2900   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
2901     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2902     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
2903     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2904         FUNCTION_INST_UNREACHABLE_ABBREV)
2905       llvm_unreachable("Unexpected abbrev ordering!");
2906   }
2907   {
2908     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2909     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
2910     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2911     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
2912                               Log2_32_Ceil(VE.getTypes().size() + 1)));
2913     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2914     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2915     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2916         FUNCTION_INST_GEP_ABBREV)
2917       llvm_unreachable("Unexpected abbrev ordering!");
2918   }
2919 
2920   Stream.ExitBlock();
2921 }
2922 
2923 /// Write the module path strings, currently only used when generating
2924 /// a combined index file.
2925 void IndexBitcodeWriter::writeModStrings() {
2926   Stream.EnterSubblock(bitc::MODULE_STRTAB_BLOCK_ID, 3);
2927 
2928   // TODO: See which abbrev sizes we actually need to emit
2929 
2930   // 8-bit fixed-width MST_ENTRY strings.
2931   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2932   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
2933   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2934   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2935   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2936   unsigned Abbrev8Bit = Stream.EmitAbbrev(Abbv);
2937 
2938   // 7-bit fixed width MST_ENTRY strings.
2939   Abbv = new BitCodeAbbrev();
2940   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
2941   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2942   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2943   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2944   unsigned Abbrev7Bit = Stream.EmitAbbrev(Abbv);
2945 
2946   // 6-bit char6 MST_ENTRY strings.
2947   Abbv = new BitCodeAbbrev();
2948   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
2949   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2950   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2951   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2952   unsigned Abbrev6Bit = Stream.EmitAbbrev(Abbv);
2953 
2954   // Module Hash, 160 bits SHA1. Optionally, emitted after each MST_CODE_ENTRY.
2955   Abbv = new BitCodeAbbrev();
2956   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_HASH));
2957   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2958   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2959   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2960   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2961   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2962   unsigned AbbrevHash = Stream.EmitAbbrev(Abbv);
2963 
2964   SmallVector<unsigned, 64> Vals;
2965   for (const auto &MPSE : Index.modulePaths()) {
2966     StringEncoding Bits =
2967         getStringEncoding(MPSE.getKey().data(), MPSE.getKey().size());
2968     unsigned AbbrevToUse = Abbrev8Bit;
2969     if (Bits == SE_Char6)
2970       AbbrevToUse = Abbrev6Bit;
2971     else if (Bits == SE_Fixed7)
2972       AbbrevToUse = Abbrev7Bit;
2973 
2974     Vals.push_back(MPSE.getValue().first);
2975 
2976     for (const auto P : MPSE.getKey())
2977       Vals.push_back((unsigned char)P);
2978 
2979     // Emit the finished record.
2980     Stream.EmitRecord(bitc::MST_CODE_ENTRY, Vals, AbbrevToUse);
2981 
2982     Vals.clear();
2983     // Emit an optional hash for the module now
2984     auto &Hash = MPSE.getValue().second;
2985     bool AllZero = true; // Detect if the hash is empty, and do not generate it
2986     for (auto Val : Hash) {
2987       if (Val)
2988         AllZero = false;
2989       Vals.push_back(Val);
2990     }
2991     if (!AllZero) {
2992       // Emit the hash record.
2993       Stream.EmitRecord(bitc::MST_CODE_HASH, Vals, AbbrevHash);
2994     }
2995 
2996     Vals.clear();
2997   }
2998   Stream.ExitBlock();
2999 }
3000 
3001 // Helper to emit a single function summary record.
3002 void ModuleBitcodeWriter::writePerModuleFunctionSummaryRecord(
3003     SmallVector<uint64_t, 64> &NameVals, GlobalValueSummary *Summary,
3004     unsigned ValueID, unsigned FSCallsAbbrev, unsigned FSCallsProfileAbbrev,
3005     const Function &F) {
3006   NameVals.push_back(ValueID);
3007 
3008   FunctionSummary *FS = cast<FunctionSummary>(Summary);
3009   NameVals.push_back(getEncodedGVSummaryFlags(FS->flags()));
3010   NameVals.push_back(FS->instCount());
3011   NameVals.push_back(FS->refs().size());
3012 
3013   for (auto &RI : FS->refs())
3014     NameVals.push_back(VE.getValueID(RI.getValue()));
3015 
3016   bool HasProfileData = F.getEntryCount().hasValue();
3017   for (auto &ECI : FS->calls()) {
3018     NameVals.push_back(VE.getValueID(ECI.first.getValue()));
3019     assert(ECI.second.CallsiteCount > 0 && "Expected at least one callsite");
3020     NameVals.push_back(ECI.second.CallsiteCount);
3021     if (HasProfileData)
3022       NameVals.push_back(ECI.second.ProfileCount);
3023   }
3024 
3025   unsigned FSAbbrev = (HasProfileData ? FSCallsProfileAbbrev : FSCallsAbbrev);
3026   unsigned Code =
3027       (HasProfileData ? bitc::FS_PERMODULE_PROFILE : bitc::FS_PERMODULE);
3028 
3029   // Emit the finished record.
3030   Stream.EmitRecord(Code, NameVals, FSAbbrev);
3031   NameVals.clear();
3032 }
3033 
3034 // Collect the global value references in the given variable's initializer,
3035 // and emit them in a summary record.
3036 void ModuleBitcodeWriter::writeModuleLevelReferences(
3037     const GlobalVariable &V, SmallVector<uint64_t, 64> &NameVals,
3038     unsigned FSModRefsAbbrev) {
3039   // Only interested in recording variable defs in the summary.
3040   if (V.isDeclaration())
3041     return;
3042   NameVals.push_back(VE.getValueID(&V));
3043   NameVals.push_back(getEncodedGVSummaryFlags(V));
3044   auto *Summary = Index->getGlobalValueSummary(V);
3045   GlobalVarSummary *VS = cast<GlobalVarSummary>(Summary);
3046   for (auto Ref : VS->refs())
3047     NameVals.push_back(VE.getValueID(Ref.getValue()));
3048   Stream.EmitRecord(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS, NameVals,
3049                     FSModRefsAbbrev);
3050   NameVals.clear();
3051 }
3052 
3053 // Current version for the summary.
3054 // This is bumped whenever we introduce changes in the way some record are
3055 // interpreted, like flags for instance.
3056 static const uint64_t INDEX_VERSION = 1;
3057 
3058 /// Emit the per-module summary section alongside the rest of
3059 /// the module's bitcode.
3060 void ModuleBitcodeWriter::writePerModuleGlobalValueSummary() {
3061   if (M.empty())
3062     return;
3063 
3064   if (Index->begin() == Index->end())
3065     return;
3066 
3067   Stream.EnterSubblock(bitc::GLOBALVAL_SUMMARY_BLOCK_ID, 4);
3068 
3069   Stream.EmitRecord(bitc::FS_VERSION, ArrayRef<uint64_t>{INDEX_VERSION});
3070 
3071   // Abbrev for FS_PERMODULE.
3072   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3073   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE));
3074   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3075   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3076   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
3077   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
3078   // numrefs x valueid, n x (valueid, callsitecount)
3079   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3080   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3081   unsigned FSCallsAbbrev = Stream.EmitAbbrev(Abbv);
3082 
3083   // Abbrev for FS_PERMODULE_PROFILE.
3084   Abbv = new BitCodeAbbrev();
3085   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_PROFILE));
3086   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3087   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3088   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
3089   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
3090   // numrefs x valueid, n x (valueid, callsitecount, profilecount)
3091   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3092   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3093   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(Abbv);
3094 
3095   // Abbrev for FS_PERMODULE_GLOBALVAR_INIT_REFS.
3096   Abbv = new BitCodeAbbrev();
3097   Abbv->Add(BitCodeAbbrevOp(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS));
3098   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // valueid
3099   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // flags
3100   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));  // valueids
3101   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3102   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(Abbv);
3103 
3104   // Abbrev for FS_ALIAS.
3105   Abbv = new BitCodeAbbrev();
3106   Abbv->Add(BitCodeAbbrevOp(bitc::FS_ALIAS));
3107   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3108   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3109   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3110   unsigned FSAliasAbbrev = Stream.EmitAbbrev(Abbv);
3111 
3112   SmallVector<uint64_t, 64> NameVals;
3113   // Iterate over the list of functions instead of the Index to
3114   // ensure the ordering is stable.
3115   for (const Function &F : M) {
3116     if (F.isDeclaration())
3117       continue;
3118     // Summary emission does not support anonymous functions, they have to
3119     // renamed using the anonymous function renaming pass.
3120     if (!F.hasName())
3121       report_fatal_error("Unexpected anonymous function when writing summary");
3122 
3123     auto *Summary = Index->getGlobalValueSummary(F);
3124     writePerModuleFunctionSummaryRecord(
3125         NameVals, Summary,
3126         VE.getValueID(M.getValueSymbolTable().lookup(F.getName())),
3127         FSCallsAbbrev, FSCallsProfileAbbrev, F);
3128   }
3129 
3130   // Capture references from GlobalVariable initializers, which are outside
3131   // of a function scope.
3132   for (const GlobalVariable &G : M.globals())
3133     writeModuleLevelReferences(G, NameVals, FSModRefsAbbrev);
3134 
3135   for (const GlobalAlias &A : M.aliases()) {
3136     auto *Aliasee = A.getBaseObject();
3137     if (!Aliasee->hasName())
3138       // Nameless function don't have an entry in the summary, skip it.
3139       continue;
3140     auto AliasId = VE.getValueID(&A);
3141     auto AliaseeId = VE.getValueID(Aliasee);
3142     NameVals.push_back(AliasId);
3143     NameVals.push_back(getEncodedGVSummaryFlags(A));
3144     NameVals.push_back(AliaseeId);
3145     Stream.EmitRecord(bitc::FS_ALIAS, NameVals, FSAliasAbbrev);
3146     NameVals.clear();
3147   }
3148 
3149   Stream.ExitBlock();
3150 }
3151 
3152 /// Emit the combined summary section into the combined index file.
3153 void IndexBitcodeWriter::writeCombinedGlobalValueSummary() {
3154   Stream.EnterSubblock(bitc::GLOBALVAL_SUMMARY_BLOCK_ID, 3);
3155   Stream.EmitRecord(bitc::FS_VERSION, ArrayRef<uint64_t>{INDEX_VERSION});
3156 
3157   // Abbrev for FS_COMBINED.
3158   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3159   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED));
3160   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3161   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
3162   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3163   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
3164   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
3165   // numrefs x valueid, n x (valueid, callsitecount)
3166   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3167   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3168   unsigned FSCallsAbbrev = Stream.EmitAbbrev(Abbv);
3169 
3170   // Abbrev for FS_COMBINED_PROFILE.
3171   Abbv = new BitCodeAbbrev();
3172   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_PROFILE));
3173   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3174   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
3175   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3176   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
3177   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // numrefs
3178   // numrefs x valueid, n x (valueid, callsitecount, profilecount)
3179   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3180   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3181   unsigned FSCallsProfileAbbrev = Stream.EmitAbbrev(Abbv);
3182 
3183   // Abbrev for FS_COMBINED_GLOBALVAR_INIT_REFS.
3184   Abbv = new BitCodeAbbrev();
3185   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS));
3186   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3187   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
3188   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3189   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));    // valueids
3190   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
3191   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(Abbv);
3192 
3193   // Abbrev for FS_COMBINED_ALIAS.
3194   Abbv = new BitCodeAbbrev();
3195   Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_ALIAS));
3196   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3197   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
3198   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // flags
3199   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
3200   unsigned FSAliasAbbrev = Stream.EmitAbbrev(Abbv);
3201 
3202   // The aliases are emitted as a post-pass, and will point to the value
3203   // id of the aliasee. Save them in a vector for post-processing.
3204   SmallVector<AliasSummary *, 64> Aliases;
3205 
3206   // Save the value id for each summary for alias emission.
3207   DenseMap<const GlobalValueSummary *, unsigned> SummaryToValueIdMap;
3208 
3209   SmallVector<uint64_t, 64> NameVals;
3210 
3211   // For local linkage, we also emit the original name separately
3212   // immediately after the record.
3213   auto MaybeEmitOriginalName = [&](GlobalValueSummary &S) {
3214     if (!GlobalValue::isLocalLinkage(S.linkage()))
3215       return;
3216     NameVals.push_back(S.getOriginalName());
3217     Stream.EmitRecord(bitc::FS_COMBINED_ORIGINAL_NAME, NameVals);
3218     NameVals.clear();
3219   };
3220 
3221   for (const auto &GSI : Index) {
3222     for (auto &SI : GSI.second) {
3223       GlobalValueSummary *S = SI.get();
3224       assert(S);
3225 
3226       assert(hasValueId(GSI.first));
3227       unsigned ValueId = getValueId(GSI.first);
3228       SummaryToValueIdMap[S] = ValueId;
3229 
3230       if (auto *AS = dyn_cast<AliasSummary>(S)) {
3231         // Will process aliases as a post-pass because the reader wants all
3232         // global to be loaded first.
3233         Aliases.push_back(AS);
3234         continue;
3235       }
3236 
3237       if (auto *VS = dyn_cast<GlobalVarSummary>(S)) {
3238         NameVals.push_back(ValueId);
3239         NameVals.push_back(Index.getModuleId(VS->modulePath()));
3240         NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
3241         for (auto &RI : VS->refs()) {
3242           NameVals.push_back(getValueId(RI.getGUID()));
3243         }
3244 
3245         // Emit the finished record.
3246         Stream.EmitRecord(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS, NameVals,
3247                           FSModRefsAbbrev);
3248         NameVals.clear();
3249         MaybeEmitOriginalName(*S);
3250         continue;
3251       }
3252 
3253       auto *FS = cast<FunctionSummary>(S);
3254       NameVals.push_back(ValueId);
3255       NameVals.push_back(Index.getModuleId(FS->modulePath()));
3256       NameVals.push_back(getEncodedGVSummaryFlags(FS->flags()));
3257       NameVals.push_back(FS->instCount());
3258       NameVals.push_back(FS->refs().size());
3259 
3260       for (auto &RI : FS->refs()) {
3261         NameVals.push_back(getValueId(RI.getGUID()));
3262       }
3263 
3264       bool HasProfileData = false;
3265       for (auto &EI : FS->calls()) {
3266         HasProfileData |= EI.second.ProfileCount != 0;
3267         if (HasProfileData)
3268           break;
3269       }
3270 
3271       for (auto &EI : FS->calls()) {
3272         // If this GUID doesn't have a value id, it doesn't have a function
3273         // summary and we don't need to record any calls to it.
3274         if (!hasValueId(EI.first.getGUID()))
3275           continue;
3276         NameVals.push_back(getValueId(EI.first.getGUID()));
3277         assert(EI.second.CallsiteCount > 0 && "Expected at least one callsite");
3278         NameVals.push_back(EI.second.CallsiteCount);
3279         if (HasProfileData)
3280           NameVals.push_back(EI.second.ProfileCount);
3281       }
3282 
3283       unsigned FSAbbrev =
3284           (HasProfileData ? FSCallsProfileAbbrev : FSCallsAbbrev);
3285       unsigned Code =
3286           (HasProfileData ? bitc::FS_COMBINED_PROFILE : bitc::FS_COMBINED);
3287 
3288       // Emit the finished record.
3289       Stream.EmitRecord(Code, NameVals, FSAbbrev);
3290       NameVals.clear();
3291       MaybeEmitOriginalName(*S);
3292     }
3293   }
3294 
3295   for (auto *AS : Aliases) {
3296     auto AliasValueId = SummaryToValueIdMap[AS];
3297     assert(AliasValueId);
3298     NameVals.push_back(AliasValueId);
3299     NameVals.push_back(Index.getModuleId(AS->modulePath()));
3300     NameVals.push_back(getEncodedGVSummaryFlags(AS->flags()));
3301     auto AliaseeValueId = SummaryToValueIdMap[&AS->getAliasee()];
3302     assert(AliaseeValueId);
3303     NameVals.push_back(AliaseeValueId);
3304 
3305     // Emit the finished record.
3306     Stream.EmitRecord(bitc::FS_COMBINED_ALIAS, NameVals, FSAliasAbbrev);
3307     NameVals.clear();
3308     MaybeEmitOriginalName(*AS);
3309   }
3310 
3311   Stream.ExitBlock();
3312 }
3313 
3314 void ModuleBitcodeWriter::writeIdentificationBlock() {
3315   Stream.EnterSubblock(bitc::IDENTIFICATION_BLOCK_ID, 5);
3316 
3317   // Write the "user readable" string identifying the bitcode producer
3318   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
3319   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_STRING));
3320   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
3321   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
3322   auto StringAbbrev = Stream.EmitAbbrev(Abbv);
3323   writeStringRecord(bitc::IDENTIFICATION_CODE_STRING,
3324                     "LLVM" LLVM_VERSION_STRING, StringAbbrev);
3325 
3326   // Write the epoch version
3327   Abbv = new BitCodeAbbrev();
3328   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_EPOCH));
3329   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
3330   auto EpochAbbrev = Stream.EmitAbbrev(Abbv);
3331   SmallVector<unsigned, 1> Vals = {bitc::BITCODE_CURRENT_EPOCH};
3332   Stream.EmitRecord(bitc::IDENTIFICATION_CODE_EPOCH, Vals, EpochAbbrev);
3333   Stream.ExitBlock();
3334 }
3335 
3336 void ModuleBitcodeWriter::writeModuleHash(size_t BlockStartPos) {
3337   // Emit the module's hash.
3338   // MODULE_CODE_HASH: [5*i32]
3339   SHA1 Hasher;
3340   Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&(Buffer)[BlockStartPos],
3341                                   Buffer.size() - BlockStartPos));
3342   auto Hash = Hasher.result();
3343   SmallVector<uint64_t, 20> Vals;
3344   auto LShift = [&](unsigned char Val, unsigned Amount)
3345                     -> uint64_t { return ((uint64_t)Val) << Amount; };
3346   for (int Pos = 0; Pos < 20; Pos += 4) {
3347     uint32_t SubHash = LShift(Hash[Pos + 0], 24);
3348     SubHash |= LShift(Hash[Pos + 1], 16) | LShift(Hash[Pos + 2], 8) |
3349                (unsigned)(unsigned char)Hash[Pos + 3];
3350     Vals.push_back(SubHash);
3351   }
3352 
3353   // Emit the finished record.
3354   Stream.EmitRecord(bitc::MODULE_CODE_HASH, Vals);
3355 }
3356 
3357 void BitcodeWriter::write() {
3358   // Emit the file header first.
3359   writeBitcodeHeader();
3360 
3361   writeBlocks();
3362 }
3363 
3364 void ModuleBitcodeWriter::writeBlocks() {
3365   writeIdentificationBlock();
3366   writeModule();
3367 }
3368 
3369 void IndexBitcodeWriter::writeBlocks() {
3370   // Index contains only a single outer (module) block.
3371   writeIndex();
3372 }
3373 
3374 void ModuleBitcodeWriter::writeModule() {
3375   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
3376   size_t BlockStartPos = Buffer.size();
3377 
3378   SmallVector<unsigned, 1> Vals;
3379   unsigned CurVersion = 1;
3380   Vals.push_back(CurVersion);
3381   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
3382 
3383   // Emit blockinfo, which defines the standard abbreviations etc.
3384   writeBlockInfo();
3385 
3386   // Emit information about attribute groups.
3387   writeAttributeGroupTable();
3388 
3389   // Emit information about parameter attributes.
3390   writeAttributeTable();
3391 
3392   // Emit information describing all of the types in the module.
3393   writeTypeTable();
3394 
3395   writeComdats();
3396 
3397   // Emit top-level description of module, including target triple, inline asm,
3398   // descriptors for global variables, and function prototype info.
3399   writeModuleInfo();
3400 
3401   // Emit constants.
3402   writeModuleConstants();
3403 
3404   // Emit metadata.
3405   writeModuleMetadata();
3406 
3407   // Emit metadata.
3408   writeModuleMetadataStore();
3409 
3410   // Emit module-level use-lists.
3411   if (VE.shouldPreserveUseListOrder())
3412     writeUseListBlock(nullptr);
3413 
3414   writeOperandBundleTags();
3415 
3416   // Emit function bodies.
3417   DenseMap<const Function *, uint64_t> FunctionToBitcodeIndex;
3418   for (Module::const_iterator F = M.begin(), E = M.end(); F != E; ++F)
3419     if (!F->isDeclaration())
3420       writeFunction(*F, FunctionToBitcodeIndex);
3421 
3422   // Need to write after the above call to WriteFunction which populates
3423   // the summary information in the index.
3424   if (Index)
3425     writePerModuleGlobalValueSummary();
3426 
3427   writeValueSymbolTable(M.getValueSymbolTable(),
3428                         /* IsModuleLevel */ true, &FunctionToBitcodeIndex);
3429 
3430   if (GenerateHash) {
3431     writeModuleHash(BlockStartPos);
3432   }
3433 
3434   Stream.ExitBlock();
3435 }
3436 
3437 static void writeInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
3438                                uint32_t &Position) {
3439   support::endian::write32le(&Buffer[Position], Value);
3440   Position += 4;
3441 }
3442 
3443 /// If generating a bc file on darwin, we have to emit a
3444 /// header and trailer to make it compatible with the system archiver.  To do
3445 /// this we emit the following header, and then emit a trailer that pads the
3446 /// file out to be a multiple of 16 bytes.
3447 ///
3448 /// struct bc_header {
3449 ///   uint32_t Magic;         // 0x0B17C0DE
3450 ///   uint32_t Version;       // Version, currently always 0.
3451 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
3452 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
3453 ///   uint32_t CPUType;       // CPU specifier.
3454 ///   ... potentially more later ...
3455 /// };
3456 static void emitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
3457                                          const Triple &TT) {
3458   unsigned CPUType = ~0U;
3459 
3460   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
3461   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
3462   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
3463   // specific constants here because they are implicitly part of the Darwin ABI.
3464   enum {
3465     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
3466     DARWIN_CPU_TYPE_X86        = 7,
3467     DARWIN_CPU_TYPE_ARM        = 12,
3468     DARWIN_CPU_TYPE_POWERPC    = 18
3469   };
3470 
3471   Triple::ArchType Arch = TT.getArch();
3472   if (Arch == Triple::x86_64)
3473     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
3474   else if (Arch == Triple::x86)
3475     CPUType = DARWIN_CPU_TYPE_X86;
3476   else if (Arch == Triple::ppc)
3477     CPUType = DARWIN_CPU_TYPE_POWERPC;
3478   else if (Arch == Triple::ppc64)
3479     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
3480   else if (Arch == Triple::arm || Arch == Triple::thumb)
3481     CPUType = DARWIN_CPU_TYPE_ARM;
3482 
3483   // Traditional Bitcode starts after header.
3484   assert(Buffer.size() >= BWH_HeaderSize &&
3485          "Expected header size to be reserved");
3486   unsigned BCOffset = BWH_HeaderSize;
3487   unsigned BCSize = Buffer.size() - BWH_HeaderSize;
3488 
3489   // Write the magic and version.
3490   unsigned Position = 0;
3491   writeInt32ToBuffer(0x0B17C0DE, Buffer, Position);
3492   writeInt32ToBuffer(0, Buffer, Position); // Version.
3493   writeInt32ToBuffer(BCOffset, Buffer, Position);
3494   writeInt32ToBuffer(BCSize, Buffer, Position);
3495   writeInt32ToBuffer(CPUType, Buffer, Position);
3496 
3497   // If the file is not a multiple of 16 bytes, insert dummy padding.
3498   while (Buffer.size() & 15)
3499     Buffer.push_back(0);
3500 }
3501 
3502 /// Helper to write the header common to all bitcode files.
3503 void BitcodeWriter::writeBitcodeHeader() {
3504   // Emit the file header.
3505   Stream.Emit((unsigned)'B', 8);
3506   Stream.Emit((unsigned)'C', 8);
3507   Stream.Emit(0x0, 4);
3508   Stream.Emit(0xC, 4);
3509   Stream.Emit(0xE, 4);
3510   Stream.Emit(0xD, 4);
3511 }
3512 
3513 /// WriteBitcodeToFile - Write the specified module to the specified output
3514 /// stream.
3515 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out,
3516                               bool ShouldPreserveUseListOrder,
3517                               const ModuleSummaryIndex *Index,
3518                               bool GenerateHash) {
3519   SmallVector<char, 0> Buffer;
3520   Buffer.reserve(256*1024);
3521 
3522   // If this is darwin or another generic macho target, reserve space for the
3523   // header.
3524   Triple TT(M->getTargetTriple());
3525   if (TT.isOSDarwin() || TT.isOSBinFormatMachO())
3526     Buffer.insert(Buffer.begin(), BWH_HeaderSize, 0);
3527 
3528   // Emit the module into the buffer.
3529   ModuleBitcodeWriter ModuleWriter(M, Buffer, ShouldPreserveUseListOrder, Index,
3530                                    GenerateHash);
3531   ModuleWriter.write();
3532 
3533   if (TT.isOSDarwin() || TT.isOSBinFormatMachO())
3534     emitDarwinBCHeaderAndTrailer(Buffer, TT);
3535 
3536   // Write the generated bitstream to "Out".
3537   Out.write((char*)&Buffer.front(), Buffer.size());
3538 }
3539 
3540 void IndexBitcodeWriter::writeIndex() {
3541   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
3542 
3543   SmallVector<unsigned, 1> Vals;
3544   unsigned CurVersion = 1;
3545   Vals.push_back(CurVersion);
3546   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
3547 
3548   // If we have a VST, write the VSTOFFSET record placeholder.
3549   writeValueSymbolTableForwardDecl();
3550 
3551   // Write the module paths in the combined index.
3552   writeModStrings();
3553 
3554   // Write the summary combined index records.
3555   writeCombinedGlobalValueSummary();
3556 
3557   // Need a special VST writer for the combined index (we don't have a
3558   // real VST and real values when this is invoked).
3559   writeCombinedValueSymbolTable();
3560 
3561   Stream.ExitBlock();
3562 }
3563 
3564 // Write the specified module summary index to the given raw output stream,
3565 // where it will be written in a new bitcode block. This is used when
3566 // writing the combined index file for ThinLTO.
3567 void llvm::WriteIndexToFile(const ModuleSummaryIndex &Index, raw_ostream &Out) {
3568   SmallVector<char, 0> Buffer;
3569   Buffer.reserve(256 * 1024);
3570 
3571   IndexBitcodeWriter IndexWriter(Buffer, Index);
3572   IndexWriter.write();
3573 
3574   Out.write((char *)&Buffer.front(), Buffer.size());
3575 }
3576