1 //===- Bitcode/Writer/DXILBitcodeWriter.cpp - DXIL Bitcode Writer ---------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Bitcode writer implementation.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "DXILBitcodeWriter.h"
14 #include "DXILValueEnumerator.h"
15 #include "DirectXIRPasses/PointerTypeAnalysis.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/ADT/Triple.h"
18 #include "llvm/Bitcode/BitcodeCommon.h"
19 #include "llvm/Bitcode/BitcodeReader.h"
20 #include "llvm/Bitcode/LLVMBitCodes.h"
21 #include "llvm/Bitstream/BitCodes.h"
22 #include "llvm/Bitstream/BitstreamWriter.h"
23 #include "llvm/IR/Attributes.h"
24 #include "llvm/IR/BasicBlock.h"
25 #include "llvm/IR/Comdat.h"
26 #include "llvm/IR/Constant.h"
27 #include "llvm/IR/Constants.h"
28 #include "llvm/IR/DebugInfoMetadata.h"
29 #include "llvm/IR/DebugLoc.h"
30 #include "llvm/IR/DerivedTypes.h"
31 #include "llvm/IR/Function.h"
32 #include "llvm/IR/GlobalAlias.h"
33 #include "llvm/IR/GlobalIFunc.h"
34 #include "llvm/IR/GlobalObject.h"
35 #include "llvm/IR/GlobalValue.h"
36 #include "llvm/IR/GlobalVariable.h"
37 #include "llvm/IR/InlineAsm.h"
38 #include "llvm/IR/InstrTypes.h"
39 #include "llvm/IR/Instruction.h"
40 #include "llvm/IR/Instructions.h"
41 #include "llvm/IR/LLVMContext.h"
42 #include "llvm/IR/Metadata.h"
43 #include "llvm/IR/Module.h"
44 #include "llvm/IR/ModuleSummaryIndex.h"
45 #include "llvm/IR/Operator.h"
46 #include "llvm/IR/Type.h"
47 #include "llvm/IR/UseListOrder.h"
48 #include "llvm/IR/Value.h"
49 #include "llvm/IR/ValueSymbolTable.h"
50 #include "llvm/Object/IRSymtab.h"
51 #include "llvm/Support/ErrorHandling.h"
52 #include "llvm/Support/ModRef.h"
53 #include "llvm/Support/SHA1.h"
54 
55 namespace llvm {
56 namespace dxil {
57 
58 // Generates an enum to use as an index in the Abbrev array of Metadata record.
59 enum MetadataAbbrev : unsigned {
60 #define HANDLE_MDNODE_LEAF(CLASS) CLASS##AbbrevID,
61 #include "llvm/IR/Metadata.def"
62   LastPlusOne
63 };
64 
65 class DXILBitcodeWriter {
66 
67   /// These are manifest constants used by the bitcode writer. They do not need
68   /// to be kept in sync with the reader, but need to be consistent within this
69   /// file.
70   enum {
71     // VALUE_SYMTAB_BLOCK abbrev id's.
72     VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
73     VST_ENTRY_7_ABBREV,
74     VST_ENTRY_6_ABBREV,
75     VST_BBENTRY_6_ABBREV,
76 
77     // CONSTANTS_BLOCK abbrev id's.
78     CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
79     CONSTANTS_INTEGER_ABBREV,
80     CONSTANTS_CE_CAST_Abbrev,
81     CONSTANTS_NULL_Abbrev,
82 
83     // FUNCTION_BLOCK abbrev id's.
84     FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
85     FUNCTION_INST_BINOP_ABBREV,
86     FUNCTION_INST_BINOP_FLAGS_ABBREV,
87     FUNCTION_INST_CAST_ABBREV,
88     FUNCTION_INST_RET_VOID_ABBREV,
89     FUNCTION_INST_RET_VAL_ABBREV,
90     FUNCTION_INST_UNREACHABLE_ABBREV,
91     FUNCTION_INST_GEP_ABBREV,
92   };
93 
94   // Cache some types
95   Type *I8Ty;
96   Type *I8PtrTy;
97 
98   /// The stream created and owned by the client.
99   BitstreamWriter &Stream;
100 
101   StringTableBuilder &StrtabBuilder;
102 
103   /// The Module to write to bitcode.
104   const Module &M;
105 
106   /// Enumerates ids for all values in the module.
107   ValueEnumerator VE;
108 
109   /// Map that holds the correspondence between GUIDs in the summary index,
110   /// that came from indirect call profiles, and a value id generated by this
111   /// class to use in the VST and summary block records.
112   std::map<GlobalValue::GUID, unsigned> GUIDToValueIdMap;
113 
114   /// Tracks the last value id recorded in the GUIDToValueMap.
115   unsigned GlobalValueId;
116 
117   /// Saves the offset of the VSTOffset record that must eventually be
118   /// backpatched with the offset of the actual VST.
119   uint64_t VSTOffsetPlaceholder = 0;
120 
121   /// Pointer to the buffer allocated by caller for bitcode writing.
122   const SmallVectorImpl<char> &Buffer;
123 
124   /// The start bit of the identification block.
125   uint64_t BitcodeStartBit;
126 
127   /// This maps values to their typed pointers
128   PointerTypeMap PointerMap;
129 
130 public:
131   /// Constructs a ModuleBitcodeWriter object for the given Module,
132   /// writing to the provided \p Buffer.
133   DXILBitcodeWriter(const Module &M, SmallVectorImpl<char> &Buffer,
134                     StringTableBuilder &StrtabBuilder, BitstreamWriter &Stream)
135       : I8Ty(Type::getInt8Ty(M.getContext())),
136         I8PtrTy(TypedPointerType::get(I8Ty, 0)), Stream(Stream),
137         StrtabBuilder(StrtabBuilder), M(M), VE(M, I8PtrTy), Buffer(Buffer),
138         BitcodeStartBit(Stream.GetCurrentBitNo()),
139         PointerMap(PointerTypeAnalysis::run(M)) {
140     GlobalValueId = VE.getValues().size();
141     // Enumerate the typed pointers
142     for (auto El : PointerMap)
143       VE.EnumerateType(El.second);
144   }
145 
146   /// Emit the current module to the bitstream.
147   void write();
148 
149   static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind);
150   static void writeStringRecord(BitstreamWriter &Stream, unsigned Code,
151                                 StringRef Str, unsigned AbbrevToUse);
152   static void writeIdentificationBlock(BitstreamWriter &Stream);
153   static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V);
154   static void emitWideAPInt(SmallVectorImpl<uint64_t> &Vals, const APInt &A);
155 
156   static unsigned getEncodedComdatSelectionKind(const Comdat &C);
157   static unsigned getEncodedLinkage(const GlobalValue::LinkageTypes Linkage);
158   static unsigned getEncodedLinkage(const GlobalValue &GV);
159   static unsigned getEncodedVisibility(const GlobalValue &GV);
160   static unsigned getEncodedThreadLocalMode(const GlobalValue &GV);
161   static unsigned getEncodedDLLStorageClass(const GlobalValue &GV);
162   static unsigned getEncodedCastOpcode(unsigned Opcode);
163   static unsigned getEncodedUnaryOpcode(unsigned Opcode);
164   static unsigned getEncodedBinaryOpcode(unsigned Opcode);
165   static unsigned getEncodedRMWOperation(AtomicRMWInst::BinOp Op);
166   static unsigned getEncodedOrdering(AtomicOrdering Ordering);
167   static uint64_t getOptimizationFlags(const Value *V);
168 
169 private:
170   void writeModuleVersion();
171   void writePerModuleGlobalValueSummary();
172 
173   void writePerModuleFunctionSummaryRecord(SmallVector<uint64_t, 64> &NameVals,
174                                            GlobalValueSummary *Summary,
175                                            unsigned ValueID,
176                                            unsigned FSCallsAbbrev,
177                                            unsigned FSCallsProfileAbbrev,
178                                            const Function &F);
179   void writeModuleLevelReferences(const GlobalVariable &V,
180                                   SmallVector<uint64_t, 64> &NameVals,
181                                   unsigned FSModRefsAbbrev,
182                                   unsigned FSModVTableRefsAbbrev);
183 
184   void assignValueId(GlobalValue::GUID ValGUID) {
185     GUIDToValueIdMap[ValGUID] = ++GlobalValueId;
186   }
187 
188   unsigned getValueId(GlobalValue::GUID ValGUID) {
189     const auto &VMI = GUIDToValueIdMap.find(ValGUID);
190     // Expect that any GUID value had a value Id assigned by an
191     // earlier call to assignValueId.
192     assert(VMI != GUIDToValueIdMap.end() &&
193            "GUID does not have assigned value Id");
194     return VMI->second;
195   }
196 
197   // Helper to get the valueId for the type of value recorded in VI.
198   unsigned getValueId(ValueInfo VI) {
199     if (!VI.haveGVs() || !VI.getValue())
200       return getValueId(VI.getGUID());
201     return VE.getValueID(VI.getValue());
202   }
203 
204   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
205 
206   uint64_t bitcodeStartBit() { return BitcodeStartBit; }
207 
208   size_t addToStrtab(StringRef Str);
209 
210   unsigned createDILocationAbbrev();
211   unsigned createGenericDINodeAbbrev();
212 
213   void writeAttributeGroupTable();
214   void writeAttributeTable();
215   void writeTypeTable();
216   void writeComdats();
217   void writeValueSymbolTableForwardDecl();
218   void writeModuleInfo();
219   void writeValueAsMetadata(const ValueAsMetadata *MD,
220                             SmallVectorImpl<uint64_t> &Record);
221   void writeMDTuple(const MDTuple *N, SmallVectorImpl<uint64_t> &Record,
222                     unsigned Abbrev);
223   void writeDILocation(const DILocation *N, SmallVectorImpl<uint64_t> &Record,
224                        unsigned &Abbrev);
225   void writeGenericDINode(const GenericDINode *N,
226                           SmallVectorImpl<uint64_t> &Record, unsigned &Abbrev) {
227     llvm_unreachable("DXIL cannot contain GenericDI Nodes");
228   }
229   void writeDISubrange(const DISubrange *N, SmallVectorImpl<uint64_t> &Record,
230                        unsigned Abbrev);
231   void writeDIGenericSubrange(const DIGenericSubrange *N,
232                               SmallVectorImpl<uint64_t> &Record,
233                               unsigned Abbrev) {
234     llvm_unreachable("DXIL cannot contain DIGenericSubrange Nodes");
235   }
236   void writeDIEnumerator(const DIEnumerator *N,
237                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
238   void writeDIBasicType(const DIBasicType *N, SmallVectorImpl<uint64_t> &Record,
239                         unsigned Abbrev);
240   void writeDIStringType(const DIStringType *N,
241                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
242     llvm_unreachable("DXIL cannot contain DIStringType Nodes");
243   }
244   void writeDIDerivedType(const DIDerivedType *N,
245                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
246   void writeDICompositeType(const DICompositeType *N,
247                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
248   void writeDISubroutineType(const DISubroutineType *N,
249                              SmallVectorImpl<uint64_t> &Record,
250                              unsigned Abbrev);
251   void writeDIFile(const DIFile *N, SmallVectorImpl<uint64_t> &Record,
252                    unsigned Abbrev);
253   void writeDICompileUnit(const DICompileUnit *N,
254                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
255   void writeDISubprogram(const DISubprogram *N,
256                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
257   void writeDILexicalBlock(const DILexicalBlock *N,
258                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
259   void writeDILexicalBlockFile(const DILexicalBlockFile *N,
260                                SmallVectorImpl<uint64_t> &Record,
261                                unsigned Abbrev);
262   void writeDICommonBlock(const DICommonBlock *N,
263                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
264     llvm_unreachable("DXIL cannot contain DICommonBlock Nodes");
265   }
266   void writeDINamespace(const DINamespace *N, SmallVectorImpl<uint64_t> &Record,
267                         unsigned Abbrev);
268   void writeDIMacro(const DIMacro *N, SmallVectorImpl<uint64_t> &Record,
269                     unsigned Abbrev) {
270     llvm_unreachable("DXIL cannot contain DIMacro Nodes");
271   }
272   void writeDIMacroFile(const DIMacroFile *N, SmallVectorImpl<uint64_t> &Record,
273                         unsigned Abbrev) {
274     llvm_unreachable("DXIL cannot contain DIMacroFile Nodes");
275   }
276   void writeDIArgList(const DIArgList *N, SmallVectorImpl<uint64_t> &Record,
277                       unsigned Abbrev) {
278     llvm_unreachable("DXIL cannot contain DIArgList Nodes");
279   }
280   void writeDIAssignID(const DIAssignID *N, SmallVectorImpl<uint64_t> &Record,
281                        unsigned Abbrev) {
282     // DIAssignID is experimental feature to track variable location in IR..
283     // FIXME: translate DIAssignID to debug info DXIL supports.
284     //   See https://github.com/llvm/llvm-project/issues/58989
285     llvm_unreachable("DXIL cannot contain DIAssignID Nodes");
286   }
287   void writeDIModule(const DIModule *N, SmallVectorImpl<uint64_t> &Record,
288                      unsigned Abbrev);
289   void writeDITemplateTypeParameter(const DITemplateTypeParameter *N,
290                                     SmallVectorImpl<uint64_t> &Record,
291                                     unsigned Abbrev);
292   void writeDITemplateValueParameter(const DITemplateValueParameter *N,
293                                      SmallVectorImpl<uint64_t> &Record,
294                                      unsigned Abbrev);
295   void writeDIGlobalVariable(const DIGlobalVariable *N,
296                              SmallVectorImpl<uint64_t> &Record,
297                              unsigned Abbrev);
298   void writeDILocalVariable(const DILocalVariable *N,
299                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
300   void writeDILabel(const DILabel *N, SmallVectorImpl<uint64_t> &Record,
301                     unsigned Abbrev) {
302     llvm_unreachable("DXIL cannot contain DILabel Nodes");
303   }
304   void writeDIExpression(const DIExpression *N,
305                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
306   void writeDIGlobalVariableExpression(const DIGlobalVariableExpression *N,
307                                        SmallVectorImpl<uint64_t> &Record,
308                                        unsigned Abbrev) {
309     llvm_unreachable("DXIL cannot contain GlobalVariableExpression Nodes");
310   }
311   void writeDIObjCProperty(const DIObjCProperty *N,
312                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
313   void writeDIImportedEntity(const DIImportedEntity *N,
314                              SmallVectorImpl<uint64_t> &Record,
315                              unsigned Abbrev);
316   unsigned createNamedMetadataAbbrev();
317   void writeNamedMetadata(SmallVectorImpl<uint64_t> &Record);
318   unsigned createMetadataStringsAbbrev();
319   void writeMetadataStrings(ArrayRef<const Metadata *> Strings,
320                             SmallVectorImpl<uint64_t> &Record);
321   void writeMetadataRecords(ArrayRef<const Metadata *> MDs,
322                             SmallVectorImpl<uint64_t> &Record,
323                             std::vector<unsigned> *MDAbbrevs = nullptr,
324                             std::vector<uint64_t> *IndexPos = nullptr);
325   void writeModuleMetadata();
326   void writeFunctionMetadata(const Function &F);
327   void writeFunctionMetadataAttachment(const Function &F);
328   void pushGlobalMetadataAttachment(SmallVectorImpl<uint64_t> &Record,
329                                     const GlobalObject &GO);
330   void writeModuleMetadataKinds();
331   void writeOperandBundleTags();
332   void writeSyncScopeNames();
333   void writeConstants(unsigned FirstVal, unsigned LastVal, bool isGlobal);
334   void writeModuleConstants();
335   bool pushValueAndType(const Value *V, unsigned InstID,
336                         SmallVectorImpl<unsigned> &Vals);
337   void writeOperandBundles(const CallBase &CB, unsigned InstID);
338   void pushValue(const Value *V, unsigned InstID,
339                  SmallVectorImpl<unsigned> &Vals);
340   void pushValueSigned(const Value *V, unsigned InstID,
341                        SmallVectorImpl<uint64_t> &Vals);
342   void writeInstruction(const Instruction &I, unsigned InstID,
343                         SmallVectorImpl<unsigned> &Vals);
344   void writeFunctionLevelValueSymbolTable(const ValueSymbolTable &VST);
345   void writeGlobalValueSymbolTable(
346       DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
347   void writeFunction(const Function &F);
348   void writeBlockInfo();
349 
350   unsigned getEncodedSyncScopeID(SyncScope::ID SSID) { return unsigned(SSID); }
351 
352   unsigned getEncodedAlign(MaybeAlign Alignment) { return encode(Alignment); }
353 
354   unsigned getTypeID(Type *T, const Value *V = nullptr);
355   /// getGlobalObjectValueTypeID - returns the element type for a GlobalObject
356   ///
357   /// GlobalObject types are saved by PointerTypeAnalysis as pointers to the
358   /// GlobalObject, but in the bitcode writer we need the pointer element type.
359   unsigned getGlobalObjectValueTypeID(Type *T, const GlobalObject *G);
360 };
361 
362 } // namespace dxil
363 } // namespace llvm
364 
365 using namespace llvm;
366 using namespace llvm::dxil;
367 
368 ////////////////////////////////////////////////////////////////////////////////
369 /// Begin dxil::BitcodeWriter Implementation
370 ////////////////////////////////////////////////////////////////////////////////
371 
372 dxil::BitcodeWriter::BitcodeWriter(SmallVectorImpl<char> &Buffer,
373                                    raw_fd_stream *FS)
374     : Buffer(Buffer), Stream(new BitstreamWriter(Buffer, FS, 512)) {
375   // Emit the file header.
376   Stream->Emit((unsigned)'B', 8);
377   Stream->Emit((unsigned)'C', 8);
378   Stream->Emit(0x0, 4);
379   Stream->Emit(0xC, 4);
380   Stream->Emit(0xE, 4);
381   Stream->Emit(0xD, 4);
382 }
383 
384 dxil::BitcodeWriter::~BitcodeWriter() { }
385 
386 /// Write the specified module to the specified output stream.
387 void dxil::WriteDXILToFile(const Module &M, raw_ostream &Out) {
388   SmallVector<char, 0> Buffer;
389   Buffer.reserve(256 * 1024);
390 
391   // If this is darwin or another generic macho target, reserve space for the
392   // header.
393   Triple TT(M.getTargetTriple());
394   if (TT.isOSDarwin() || TT.isOSBinFormatMachO())
395     Buffer.insert(Buffer.begin(), BWH_HeaderSize, 0);
396 
397   BitcodeWriter Writer(Buffer, dyn_cast<raw_fd_stream>(&Out));
398   Writer.writeModule(M);
399 
400   // Write the generated bitstream to "Out".
401   if (!Buffer.empty())
402     Out.write((char *)&Buffer.front(), Buffer.size());
403 }
404 
405 void BitcodeWriter::writeBlob(unsigned Block, unsigned Record, StringRef Blob) {
406   Stream->EnterSubblock(Block, 3);
407 
408   auto Abbv = std::make_shared<BitCodeAbbrev>();
409   Abbv->Add(BitCodeAbbrevOp(Record));
410   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
411   auto AbbrevNo = Stream->EmitAbbrev(std::move(Abbv));
412 
413   Stream->EmitRecordWithBlob(AbbrevNo, ArrayRef<uint64_t>{Record}, Blob);
414 
415   Stream->ExitBlock();
416 }
417 
418 void BitcodeWriter::writeModule(const Module &M) {
419 
420   // The Mods vector is used by irsymtab::build, which requires non-const
421   // Modules in case it needs to materialize metadata. But the bitcode writer
422   // requires that the module is materialized, so we can cast to non-const here,
423   // after checking that it is in fact materialized.
424   assert(M.isMaterialized());
425   Mods.push_back(const_cast<Module *>(&M));
426 
427   DXILBitcodeWriter ModuleWriter(M, Buffer, StrtabBuilder, *Stream);
428   ModuleWriter.write();
429 }
430 
431 ////////////////////////////////////////////////////////////////////////////////
432 /// Begin dxil::BitcodeWriterBase Implementation
433 ////////////////////////////////////////////////////////////////////////////////
434 
435 unsigned DXILBitcodeWriter::getEncodedCastOpcode(unsigned Opcode) {
436   switch (Opcode) {
437   default:
438     llvm_unreachable("Unknown cast instruction!");
439   case Instruction::Trunc:
440     return bitc::CAST_TRUNC;
441   case Instruction::ZExt:
442     return bitc::CAST_ZEXT;
443   case Instruction::SExt:
444     return bitc::CAST_SEXT;
445   case Instruction::FPToUI:
446     return bitc::CAST_FPTOUI;
447   case Instruction::FPToSI:
448     return bitc::CAST_FPTOSI;
449   case Instruction::UIToFP:
450     return bitc::CAST_UITOFP;
451   case Instruction::SIToFP:
452     return bitc::CAST_SITOFP;
453   case Instruction::FPTrunc:
454     return bitc::CAST_FPTRUNC;
455   case Instruction::FPExt:
456     return bitc::CAST_FPEXT;
457   case Instruction::PtrToInt:
458     return bitc::CAST_PTRTOINT;
459   case Instruction::IntToPtr:
460     return bitc::CAST_INTTOPTR;
461   case Instruction::BitCast:
462     return bitc::CAST_BITCAST;
463   case Instruction::AddrSpaceCast:
464     return bitc::CAST_ADDRSPACECAST;
465   }
466 }
467 
468 unsigned DXILBitcodeWriter::getEncodedUnaryOpcode(unsigned Opcode) {
469   switch (Opcode) {
470   default:
471     llvm_unreachable("Unknown binary instruction!");
472   case Instruction::FNeg:
473     return bitc::UNOP_FNEG;
474   }
475 }
476 
477 unsigned DXILBitcodeWriter::getEncodedBinaryOpcode(unsigned Opcode) {
478   switch (Opcode) {
479   default:
480     llvm_unreachable("Unknown binary instruction!");
481   case Instruction::Add:
482   case Instruction::FAdd:
483     return bitc::BINOP_ADD;
484   case Instruction::Sub:
485   case Instruction::FSub:
486     return bitc::BINOP_SUB;
487   case Instruction::Mul:
488   case Instruction::FMul:
489     return bitc::BINOP_MUL;
490   case Instruction::UDiv:
491     return bitc::BINOP_UDIV;
492   case Instruction::FDiv:
493   case Instruction::SDiv:
494     return bitc::BINOP_SDIV;
495   case Instruction::URem:
496     return bitc::BINOP_UREM;
497   case Instruction::FRem:
498   case Instruction::SRem:
499     return bitc::BINOP_SREM;
500   case Instruction::Shl:
501     return bitc::BINOP_SHL;
502   case Instruction::LShr:
503     return bitc::BINOP_LSHR;
504   case Instruction::AShr:
505     return bitc::BINOP_ASHR;
506   case Instruction::And:
507     return bitc::BINOP_AND;
508   case Instruction::Or:
509     return bitc::BINOP_OR;
510   case Instruction::Xor:
511     return bitc::BINOP_XOR;
512   }
513 }
514 
515 unsigned DXILBitcodeWriter::getTypeID(Type *T, const Value *V) {
516   if (!T->isOpaquePointerTy() &&
517       // For Constant, always check PointerMap to make sure OpaquePointer in
518       // things like constant struct/array works.
519       (!V || !isa<Constant>(V)))
520     return VE.getTypeID(T);
521   auto It = PointerMap.find(V);
522   if (It != PointerMap.end())
523     return VE.getTypeID(It->second);
524   // For Constant, return T when cannot find in PointerMap.
525   // FIXME: support ConstantPointerNull which could map to more than one
526   // TypedPointerType.
527   // See https://github.com/llvm/llvm-project/issues/57942.
528   if (V && isa<Constant>(V) && !isa<ConstantPointerNull>(V))
529     return VE.getTypeID(T);
530   return VE.getTypeID(I8PtrTy);
531 }
532 
533 unsigned DXILBitcodeWriter::getGlobalObjectValueTypeID(Type *T,
534                                                        const GlobalObject *G) {
535   auto It = PointerMap.find(G);
536   if (It != PointerMap.end()) {
537     TypedPointerType *PtrTy = cast<TypedPointerType>(It->second);
538     return VE.getTypeID(PtrTy->getElementType());
539   }
540   return VE.getTypeID(T);
541 }
542 
543 unsigned DXILBitcodeWriter::getEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
544   switch (Op) {
545   default:
546     llvm_unreachable("Unknown RMW operation!");
547   case AtomicRMWInst::Xchg:
548     return bitc::RMW_XCHG;
549   case AtomicRMWInst::Add:
550     return bitc::RMW_ADD;
551   case AtomicRMWInst::Sub:
552     return bitc::RMW_SUB;
553   case AtomicRMWInst::And:
554     return bitc::RMW_AND;
555   case AtomicRMWInst::Nand:
556     return bitc::RMW_NAND;
557   case AtomicRMWInst::Or:
558     return bitc::RMW_OR;
559   case AtomicRMWInst::Xor:
560     return bitc::RMW_XOR;
561   case AtomicRMWInst::Max:
562     return bitc::RMW_MAX;
563   case AtomicRMWInst::Min:
564     return bitc::RMW_MIN;
565   case AtomicRMWInst::UMax:
566     return bitc::RMW_UMAX;
567   case AtomicRMWInst::UMin:
568     return bitc::RMW_UMIN;
569   case AtomicRMWInst::FAdd:
570     return bitc::RMW_FADD;
571   case AtomicRMWInst::FSub:
572     return bitc::RMW_FSUB;
573   case AtomicRMWInst::FMax:
574     return bitc::RMW_FMAX;
575   case AtomicRMWInst::FMin:
576     return bitc::RMW_FMIN;
577   }
578 }
579 
580 unsigned DXILBitcodeWriter::getEncodedOrdering(AtomicOrdering Ordering) {
581   switch (Ordering) {
582   case AtomicOrdering::NotAtomic:
583     return bitc::ORDERING_NOTATOMIC;
584   case AtomicOrdering::Unordered:
585     return bitc::ORDERING_UNORDERED;
586   case AtomicOrdering::Monotonic:
587     return bitc::ORDERING_MONOTONIC;
588   case AtomicOrdering::Acquire:
589     return bitc::ORDERING_ACQUIRE;
590   case AtomicOrdering::Release:
591     return bitc::ORDERING_RELEASE;
592   case AtomicOrdering::AcquireRelease:
593     return bitc::ORDERING_ACQREL;
594   case AtomicOrdering::SequentiallyConsistent:
595     return bitc::ORDERING_SEQCST;
596   }
597   llvm_unreachable("Invalid ordering");
598 }
599 
600 void DXILBitcodeWriter::writeStringRecord(BitstreamWriter &Stream,
601                                           unsigned Code, StringRef Str,
602                                           unsigned AbbrevToUse) {
603   SmallVector<unsigned, 64> Vals;
604 
605   // Code: [strchar x N]
606   for (char C : Str) {
607     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(C))
608       AbbrevToUse = 0;
609     Vals.push_back(C);
610   }
611 
612   // Emit the finished record.
613   Stream.EmitRecord(Code, Vals, AbbrevToUse);
614 }
615 
616 uint64_t DXILBitcodeWriter::getAttrKindEncoding(Attribute::AttrKind Kind) {
617   switch (Kind) {
618   case Attribute::Alignment:
619     return bitc::ATTR_KIND_ALIGNMENT;
620   case Attribute::AlwaysInline:
621     return bitc::ATTR_KIND_ALWAYS_INLINE;
622   case Attribute::Builtin:
623     return bitc::ATTR_KIND_BUILTIN;
624   case Attribute::ByVal:
625     return bitc::ATTR_KIND_BY_VAL;
626   case Attribute::Convergent:
627     return bitc::ATTR_KIND_CONVERGENT;
628   case Attribute::InAlloca:
629     return bitc::ATTR_KIND_IN_ALLOCA;
630   case Attribute::Cold:
631     return bitc::ATTR_KIND_COLD;
632   case Attribute::InlineHint:
633     return bitc::ATTR_KIND_INLINE_HINT;
634   case Attribute::InReg:
635     return bitc::ATTR_KIND_IN_REG;
636   case Attribute::JumpTable:
637     return bitc::ATTR_KIND_JUMP_TABLE;
638   case Attribute::MinSize:
639     return bitc::ATTR_KIND_MIN_SIZE;
640   case Attribute::Naked:
641     return bitc::ATTR_KIND_NAKED;
642   case Attribute::Nest:
643     return bitc::ATTR_KIND_NEST;
644   case Attribute::NoAlias:
645     return bitc::ATTR_KIND_NO_ALIAS;
646   case Attribute::NoBuiltin:
647     return bitc::ATTR_KIND_NO_BUILTIN;
648   case Attribute::NoCapture:
649     return bitc::ATTR_KIND_NO_CAPTURE;
650   case Attribute::NoDuplicate:
651     return bitc::ATTR_KIND_NO_DUPLICATE;
652   case Attribute::NoImplicitFloat:
653     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
654   case Attribute::NoInline:
655     return bitc::ATTR_KIND_NO_INLINE;
656   case Attribute::NonLazyBind:
657     return bitc::ATTR_KIND_NON_LAZY_BIND;
658   case Attribute::NonNull:
659     return bitc::ATTR_KIND_NON_NULL;
660   case Attribute::Dereferenceable:
661     return bitc::ATTR_KIND_DEREFERENCEABLE;
662   case Attribute::DereferenceableOrNull:
663     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
664   case Attribute::NoRedZone:
665     return bitc::ATTR_KIND_NO_RED_ZONE;
666   case Attribute::NoReturn:
667     return bitc::ATTR_KIND_NO_RETURN;
668   case Attribute::NoUnwind:
669     return bitc::ATTR_KIND_NO_UNWIND;
670   case Attribute::OptimizeForSize:
671     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
672   case Attribute::OptimizeNone:
673     return bitc::ATTR_KIND_OPTIMIZE_NONE;
674   case Attribute::ReadNone:
675     return bitc::ATTR_KIND_READ_NONE;
676   case Attribute::ReadOnly:
677     return bitc::ATTR_KIND_READ_ONLY;
678   case Attribute::Returned:
679     return bitc::ATTR_KIND_RETURNED;
680   case Attribute::ReturnsTwice:
681     return bitc::ATTR_KIND_RETURNS_TWICE;
682   case Attribute::SExt:
683     return bitc::ATTR_KIND_S_EXT;
684   case Attribute::StackAlignment:
685     return bitc::ATTR_KIND_STACK_ALIGNMENT;
686   case Attribute::StackProtect:
687     return bitc::ATTR_KIND_STACK_PROTECT;
688   case Attribute::StackProtectReq:
689     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
690   case Attribute::StackProtectStrong:
691     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
692   case Attribute::SafeStack:
693     return bitc::ATTR_KIND_SAFESTACK;
694   case Attribute::StructRet:
695     return bitc::ATTR_KIND_STRUCT_RET;
696   case Attribute::SanitizeAddress:
697     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
698   case Attribute::SanitizeThread:
699     return bitc::ATTR_KIND_SANITIZE_THREAD;
700   case Attribute::SanitizeMemory:
701     return bitc::ATTR_KIND_SANITIZE_MEMORY;
702   case Attribute::UWTable:
703     return bitc::ATTR_KIND_UW_TABLE;
704   case Attribute::ZExt:
705     return bitc::ATTR_KIND_Z_EXT;
706   case Attribute::EndAttrKinds:
707     llvm_unreachable("Can not encode end-attribute kinds marker.");
708   case Attribute::None:
709     llvm_unreachable("Can not encode none-attribute.");
710   case Attribute::EmptyKey:
711   case Attribute::TombstoneKey:
712     llvm_unreachable("Trying to encode EmptyKey/TombstoneKey");
713   default:
714     llvm_unreachable("Trying to encode attribute not supported by DXIL. These "
715                      "should be stripped in DXILPrepare");
716   }
717 
718   llvm_unreachable("Trying to encode unknown attribute");
719 }
720 
721 void DXILBitcodeWriter::emitSignedInt64(SmallVectorImpl<uint64_t> &Vals,
722                                         uint64_t V) {
723   if ((int64_t)V >= 0)
724     Vals.push_back(V << 1);
725   else
726     Vals.push_back((-V << 1) | 1);
727 }
728 
729 void DXILBitcodeWriter::emitWideAPInt(SmallVectorImpl<uint64_t> &Vals,
730                                       const APInt &A) {
731   // We have an arbitrary precision integer value to write whose
732   // bit width is > 64. However, in canonical unsigned integer
733   // format it is likely that the high bits are going to be zero.
734   // So, we only write the number of active words.
735   unsigned NumWords = A.getActiveWords();
736   const uint64_t *RawData = A.getRawData();
737   for (unsigned i = 0; i < NumWords; i++)
738     emitSignedInt64(Vals, RawData[i]);
739 }
740 
741 uint64_t DXILBitcodeWriter::getOptimizationFlags(const Value *V) {
742   uint64_t Flags = 0;
743 
744   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
745     if (OBO->hasNoSignedWrap())
746       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
747     if (OBO->hasNoUnsignedWrap())
748       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
749   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
750     if (PEO->isExact())
751       Flags |= 1 << bitc::PEO_EXACT;
752   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
753     if (FPMO->hasAllowReassoc())
754       Flags |= bitc::AllowReassoc;
755     if (FPMO->hasNoNaNs())
756       Flags |= bitc::NoNaNs;
757     if (FPMO->hasNoInfs())
758       Flags |= bitc::NoInfs;
759     if (FPMO->hasNoSignedZeros())
760       Flags |= bitc::NoSignedZeros;
761     if (FPMO->hasAllowReciprocal())
762       Flags |= bitc::AllowReciprocal;
763     if (FPMO->hasAllowContract())
764       Flags |= bitc::AllowContract;
765     if (FPMO->hasApproxFunc())
766       Flags |= bitc::ApproxFunc;
767   }
768 
769   return Flags;
770 }
771 
772 unsigned
773 DXILBitcodeWriter::getEncodedLinkage(const GlobalValue::LinkageTypes Linkage) {
774   switch (Linkage) {
775   case GlobalValue::ExternalLinkage:
776     return 0;
777   case GlobalValue::WeakAnyLinkage:
778     return 16;
779   case GlobalValue::AppendingLinkage:
780     return 2;
781   case GlobalValue::InternalLinkage:
782     return 3;
783   case GlobalValue::LinkOnceAnyLinkage:
784     return 18;
785   case GlobalValue::ExternalWeakLinkage:
786     return 7;
787   case GlobalValue::CommonLinkage:
788     return 8;
789   case GlobalValue::PrivateLinkage:
790     return 9;
791   case GlobalValue::WeakODRLinkage:
792     return 17;
793   case GlobalValue::LinkOnceODRLinkage:
794     return 19;
795   case GlobalValue::AvailableExternallyLinkage:
796     return 12;
797   }
798   llvm_unreachable("Invalid linkage");
799 }
800 
801 unsigned DXILBitcodeWriter::getEncodedLinkage(const GlobalValue &GV) {
802   return getEncodedLinkage(GV.getLinkage());
803 }
804 
805 unsigned DXILBitcodeWriter::getEncodedVisibility(const GlobalValue &GV) {
806   switch (GV.getVisibility()) {
807   case GlobalValue::DefaultVisibility:
808     return 0;
809   case GlobalValue::HiddenVisibility:
810     return 1;
811   case GlobalValue::ProtectedVisibility:
812     return 2;
813   }
814   llvm_unreachable("Invalid visibility");
815 }
816 
817 unsigned DXILBitcodeWriter::getEncodedDLLStorageClass(const GlobalValue &GV) {
818   switch (GV.getDLLStorageClass()) {
819   case GlobalValue::DefaultStorageClass:
820     return 0;
821   case GlobalValue::DLLImportStorageClass:
822     return 1;
823   case GlobalValue::DLLExportStorageClass:
824     return 2;
825   }
826   llvm_unreachable("Invalid DLL storage class");
827 }
828 
829 unsigned DXILBitcodeWriter::getEncodedThreadLocalMode(const GlobalValue &GV) {
830   switch (GV.getThreadLocalMode()) {
831   case GlobalVariable::NotThreadLocal:
832     return 0;
833   case GlobalVariable::GeneralDynamicTLSModel:
834     return 1;
835   case GlobalVariable::LocalDynamicTLSModel:
836     return 2;
837   case GlobalVariable::InitialExecTLSModel:
838     return 3;
839   case GlobalVariable::LocalExecTLSModel:
840     return 4;
841   }
842   llvm_unreachable("Invalid TLS model");
843 }
844 
845 unsigned DXILBitcodeWriter::getEncodedComdatSelectionKind(const Comdat &C) {
846   switch (C.getSelectionKind()) {
847   case Comdat::Any:
848     return bitc::COMDAT_SELECTION_KIND_ANY;
849   case Comdat::ExactMatch:
850     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
851   case Comdat::Largest:
852     return bitc::COMDAT_SELECTION_KIND_LARGEST;
853   case Comdat::NoDeduplicate:
854     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
855   case Comdat::SameSize:
856     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
857   }
858   llvm_unreachable("Invalid selection kind");
859 }
860 
861 ////////////////////////////////////////////////////////////////////////////////
862 /// Begin DXILBitcodeWriter Implementation
863 ////////////////////////////////////////////////////////////////////////////////
864 
865 void DXILBitcodeWriter::writeAttributeGroupTable() {
866   const std::vector<ValueEnumerator::IndexAndAttrSet> &AttrGrps =
867       VE.getAttributeGroups();
868   if (AttrGrps.empty())
869     return;
870 
871   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
872 
873   SmallVector<uint64_t, 64> Record;
874   for (ValueEnumerator::IndexAndAttrSet Pair : AttrGrps) {
875     unsigned AttrListIndex = Pair.first;
876     AttributeSet AS = Pair.second;
877     Record.push_back(VE.getAttributeGroupID(Pair));
878     Record.push_back(AttrListIndex);
879 
880     for (Attribute Attr : AS) {
881       if (Attr.isEnumAttribute()) {
882         uint64_t Val = getAttrKindEncoding(Attr.getKindAsEnum());
883         assert(Val <= bitc::ATTR_KIND_ARGMEMONLY &&
884                "DXIL does not support attributes above ATTR_KIND_ARGMEMONLY");
885         Record.push_back(0);
886         Record.push_back(Val);
887       } else if (Attr.isIntAttribute()) {
888         if (Attr.getKindAsEnum() == Attribute::AttrKind::Memory) {
889           MemoryEffects ME = Attr.getMemoryEffects();
890           if (ME.doesNotAccessMemory()) {
891             Record.push_back(0);
892             Record.push_back(bitc::ATTR_KIND_READ_NONE);
893           } else {
894             if (ME.onlyReadsMemory()) {
895               Record.push_back(0);
896               Record.push_back(bitc::ATTR_KIND_READ_ONLY);
897             }
898             if (ME.onlyAccessesArgPointees()) {
899               Record.push_back(0);
900               Record.push_back(bitc::ATTR_KIND_ARGMEMONLY);
901             }
902           }
903         } else {
904           uint64_t Val = getAttrKindEncoding(Attr.getKindAsEnum());
905           assert(Val <= bitc::ATTR_KIND_ARGMEMONLY &&
906                  "DXIL does not support attributes above ATTR_KIND_ARGMEMONLY");
907           Record.push_back(1);
908           Record.push_back(Val);
909           Record.push_back(Attr.getValueAsInt());
910         }
911       } else {
912         StringRef Kind = Attr.getKindAsString();
913         StringRef Val = Attr.getValueAsString();
914 
915         Record.push_back(Val.empty() ? 3 : 4);
916         Record.append(Kind.begin(), Kind.end());
917         Record.push_back(0);
918         if (!Val.empty()) {
919           Record.append(Val.begin(), Val.end());
920           Record.push_back(0);
921         }
922       }
923     }
924 
925     Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
926     Record.clear();
927   }
928 
929   Stream.ExitBlock();
930 }
931 
932 void DXILBitcodeWriter::writeAttributeTable() {
933   const std::vector<AttributeList> &Attrs = VE.getAttributeLists();
934   if (Attrs.empty())
935     return;
936 
937   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
938 
939   SmallVector<uint64_t, 64> Record;
940   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
941     AttributeList AL = Attrs[i];
942     for (unsigned i : AL.indexes()) {
943       AttributeSet AS = AL.getAttributes(i);
944       if (AS.hasAttributes())
945         Record.push_back(VE.getAttributeGroupID({i, AS}));
946     }
947 
948     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
949     Record.clear();
950   }
951 
952   Stream.ExitBlock();
953 }
954 
955 /// WriteTypeTable - Write out the type table for a module.
956 void DXILBitcodeWriter::writeTypeTable() {
957   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
958 
959   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
960   SmallVector<uint64_t, 64> TypeVals;
961 
962   uint64_t NumBits = VE.computeBitsRequiredForTypeIndicies();
963 
964   // Abbrev for TYPE_CODE_POINTER.
965   auto Abbv = std::make_shared<BitCodeAbbrev>();
966   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
967   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
968   Abbv->Add(BitCodeAbbrevOp(0)); // Addrspace = 0
969   unsigned PtrAbbrev = Stream.EmitAbbrev(std::move(Abbv));
970 
971   // Abbrev for TYPE_CODE_FUNCTION.
972   Abbv = std::make_shared<BitCodeAbbrev>();
973   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
974   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isvararg
975   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
976   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
977   unsigned FunctionAbbrev = Stream.EmitAbbrev(std::move(Abbv));
978 
979   // Abbrev for TYPE_CODE_STRUCT_ANON.
980   Abbv = std::make_shared<BitCodeAbbrev>();
981   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
982   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ispacked
983   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
984   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
985   unsigned StructAnonAbbrev = Stream.EmitAbbrev(std::move(Abbv));
986 
987   // Abbrev for TYPE_CODE_STRUCT_NAME.
988   Abbv = std::make_shared<BitCodeAbbrev>();
989   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
990   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
991   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
992   unsigned StructNameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
993 
994   // Abbrev for TYPE_CODE_STRUCT_NAMED.
995   Abbv = std::make_shared<BitCodeAbbrev>();
996   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
997   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ispacked
998   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
999   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1000   unsigned StructNamedAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1001 
1002   // Abbrev for TYPE_CODE_ARRAY.
1003   Abbv = std::make_shared<BitCodeAbbrev>();
1004   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
1005   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // size
1006   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1007   unsigned ArrayAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1008 
1009   // Emit an entry count so the reader can reserve space.
1010   TypeVals.push_back(TypeList.size());
1011   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
1012   TypeVals.clear();
1013 
1014   // Loop over all of the types, emitting each in turn.
1015   for (Type *T : TypeList) {
1016     int AbbrevToUse = 0;
1017     unsigned Code = 0;
1018 
1019     switch (T->getTypeID()) {
1020     case Type::BFloatTyID:
1021     case Type::X86_AMXTyID:
1022     case Type::TokenTyID:
1023     case Type::TargetExtTyID:
1024       llvm_unreachable("These should never be used!!!");
1025       break;
1026     case Type::VoidTyID:
1027       Code = bitc::TYPE_CODE_VOID;
1028       break;
1029     case Type::HalfTyID:
1030       Code = bitc::TYPE_CODE_HALF;
1031       break;
1032     case Type::FloatTyID:
1033       Code = bitc::TYPE_CODE_FLOAT;
1034       break;
1035     case Type::DoubleTyID:
1036       Code = bitc::TYPE_CODE_DOUBLE;
1037       break;
1038     case Type::X86_FP80TyID:
1039       Code = bitc::TYPE_CODE_X86_FP80;
1040       break;
1041     case Type::FP128TyID:
1042       Code = bitc::TYPE_CODE_FP128;
1043       break;
1044     case Type::PPC_FP128TyID:
1045       Code = bitc::TYPE_CODE_PPC_FP128;
1046       break;
1047     case Type::LabelTyID:
1048       Code = bitc::TYPE_CODE_LABEL;
1049       break;
1050     case Type::MetadataTyID:
1051       Code = bitc::TYPE_CODE_METADATA;
1052       break;
1053     case Type::X86_MMXTyID:
1054       Code = bitc::TYPE_CODE_X86_MMX;
1055       break;
1056     case Type::IntegerTyID:
1057       // INTEGER: [width]
1058       Code = bitc::TYPE_CODE_INTEGER;
1059       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
1060       break;
1061     case Type::TypedPointerTyID: {
1062       TypedPointerType *PTy = cast<TypedPointerType>(T);
1063       // POINTER: [pointee type, address space]
1064       Code = bitc::TYPE_CODE_POINTER;
1065       TypeVals.push_back(getTypeID(PTy->getElementType()));
1066       unsigned AddressSpace = PTy->getAddressSpace();
1067       TypeVals.push_back(AddressSpace);
1068       if (AddressSpace == 0)
1069         AbbrevToUse = PtrAbbrev;
1070       break;
1071     }
1072     case Type::PointerTyID: {
1073       PointerType *PTy = cast<PointerType>(T);
1074       // POINTER: [pointee type, address space]
1075       Code = bitc::TYPE_CODE_POINTER;
1076       // Emitting an empty struct type for the opaque pointer's type allows
1077       // this to be order-independent. Non-struct types must be emitted in
1078       // bitcode before they can be referenced.
1079       if (PTy->isOpaquePointerTy()) {
1080         TypeVals.push_back(false);
1081         Code = bitc::TYPE_CODE_OPAQUE;
1082         writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME,
1083                           "dxilOpaquePtrReservedName", StructNameAbbrev);
1084       } else {
1085         TypeVals.push_back(getTypeID(PTy->getNonOpaquePointerElementType()));
1086         unsigned AddressSpace = PTy->getAddressSpace();
1087         TypeVals.push_back(AddressSpace);
1088         if (AddressSpace == 0)
1089           AbbrevToUse = PtrAbbrev;
1090       }
1091       break;
1092     }
1093     case Type::FunctionTyID: {
1094       FunctionType *FT = cast<FunctionType>(T);
1095       // FUNCTION: [isvararg, retty, paramty x N]
1096       Code = bitc::TYPE_CODE_FUNCTION;
1097       TypeVals.push_back(FT->isVarArg());
1098       TypeVals.push_back(getTypeID(FT->getReturnType()));
1099       for (Type *PTy : FT->params())
1100         TypeVals.push_back(getTypeID(PTy));
1101       AbbrevToUse = FunctionAbbrev;
1102       break;
1103     }
1104     case Type::StructTyID: {
1105       StructType *ST = cast<StructType>(T);
1106       // STRUCT: [ispacked, eltty x N]
1107       TypeVals.push_back(ST->isPacked());
1108       // Output all of the element types.
1109       for (Type *ElTy : ST->elements())
1110         TypeVals.push_back(getTypeID(ElTy));
1111 
1112       if (ST->isLiteral()) {
1113         Code = bitc::TYPE_CODE_STRUCT_ANON;
1114         AbbrevToUse = StructAnonAbbrev;
1115       } else {
1116         if (ST->isOpaque()) {
1117           Code = bitc::TYPE_CODE_OPAQUE;
1118         } else {
1119           Code = bitc::TYPE_CODE_STRUCT_NAMED;
1120           AbbrevToUse = StructNamedAbbrev;
1121         }
1122 
1123         // Emit the name if it is present.
1124         if (!ST->getName().empty())
1125           writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
1126                             StructNameAbbrev);
1127       }
1128       break;
1129     }
1130     case Type::ArrayTyID: {
1131       ArrayType *AT = cast<ArrayType>(T);
1132       // ARRAY: [numelts, eltty]
1133       Code = bitc::TYPE_CODE_ARRAY;
1134       TypeVals.push_back(AT->getNumElements());
1135       TypeVals.push_back(getTypeID(AT->getElementType()));
1136       AbbrevToUse = ArrayAbbrev;
1137       break;
1138     }
1139     case Type::FixedVectorTyID:
1140     case Type::ScalableVectorTyID: {
1141       VectorType *VT = cast<VectorType>(T);
1142       // VECTOR [numelts, eltty]
1143       Code = bitc::TYPE_CODE_VECTOR;
1144       TypeVals.push_back(VT->getElementCount().getKnownMinValue());
1145       TypeVals.push_back(getTypeID(VT->getElementType()));
1146       break;
1147     }
1148     }
1149 
1150     // Emit the finished record.
1151     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
1152     TypeVals.clear();
1153   }
1154 
1155   Stream.ExitBlock();
1156 }
1157 
1158 void DXILBitcodeWriter::writeComdats() {
1159   SmallVector<uint16_t, 64> Vals;
1160   for (const Comdat *C : VE.getComdats()) {
1161     // COMDAT: [selection_kind, name]
1162     Vals.push_back(getEncodedComdatSelectionKind(*C));
1163     size_t Size = C->getName().size();
1164     assert(isUInt<16>(Size));
1165     Vals.push_back(Size);
1166     for (char Chr : C->getName())
1167       Vals.push_back((unsigned char)Chr);
1168     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
1169     Vals.clear();
1170   }
1171 }
1172 
1173 void DXILBitcodeWriter::writeValueSymbolTableForwardDecl() {}
1174 
1175 /// Emit top-level description of module, including target triple, inline asm,
1176 /// descriptors for global variables, and function prototype info.
1177 /// Returns the bit offset to backpatch with the location of the real VST.
1178 void DXILBitcodeWriter::writeModuleInfo() {
1179   // Emit various pieces of data attached to a module.
1180   if (!M.getTargetTriple().empty())
1181     writeStringRecord(Stream, bitc::MODULE_CODE_TRIPLE, M.getTargetTriple(),
1182                       0 /*TODO*/);
1183   const std::string &DL = M.getDataLayoutStr();
1184   if (!DL.empty())
1185     writeStringRecord(Stream, bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/);
1186   if (!M.getModuleInlineAsm().empty())
1187     writeStringRecord(Stream, bitc::MODULE_CODE_ASM, M.getModuleInlineAsm(),
1188                       0 /*TODO*/);
1189 
1190   // Emit information about sections and GC, computing how many there are. Also
1191   // compute the maximum alignment value.
1192   std::map<std::string, unsigned> SectionMap;
1193   std::map<std::string, unsigned> GCMap;
1194   MaybeAlign MaxAlignment;
1195   unsigned MaxGlobalType = 0;
1196   const auto UpdateMaxAlignment = [&MaxAlignment](const MaybeAlign A) {
1197     if (A)
1198       MaxAlignment = !MaxAlignment ? *A : std::max(*MaxAlignment, *A);
1199   };
1200   for (const GlobalVariable &GV : M.globals()) {
1201     UpdateMaxAlignment(GV.getAlign());
1202     // Use getGlobalObjectValueTypeID to look up the enumerated type ID for
1203     // Global Variable types.
1204     MaxGlobalType = std::max(
1205         MaxGlobalType, getGlobalObjectValueTypeID(GV.getValueType(), &GV));
1206     if (GV.hasSection()) {
1207       // Give section names unique ID's.
1208       unsigned &Entry = SectionMap[std::string(GV.getSection())];
1209       if (!Entry) {
1210         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME,
1211                           GV.getSection(), 0 /*TODO*/);
1212         Entry = SectionMap.size();
1213       }
1214     }
1215   }
1216   for (const Function &F : M) {
1217     UpdateMaxAlignment(F.getAlign());
1218     if (F.hasSection()) {
1219       // Give section names unique ID's.
1220       unsigned &Entry = SectionMap[std::string(F.getSection())];
1221       if (!Entry) {
1222         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
1223                           0 /*TODO*/);
1224         Entry = SectionMap.size();
1225       }
1226     }
1227     if (F.hasGC()) {
1228       // Same for GC names.
1229       unsigned &Entry = GCMap[F.getGC()];
1230       if (!Entry) {
1231         writeStringRecord(Stream, bitc::MODULE_CODE_GCNAME, F.getGC(),
1232                           0 /*TODO*/);
1233         Entry = GCMap.size();
1234       }
1235     }
1236   }
1237 
1238   // Emit abbrev for globals, now that we know # sections and max alignment.
1239   unsigned SimpleGVarAbbrev = 0;
1240   if (!M.global_empty()) {
1241     // Add an abbrev for common globals with no visibility or thread
1242     // localness.
1243     auto Abbv = std::make_shared<BitCodeAbbrev>();
1244     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
1245     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1246                               Log2_32_Ceil(MaxGlobalType + 1)));
1247     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
1248                                                            //| explicitType << 1
1249                                                            //| constant
1250     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
1251     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
1252     if (!MaxAlignment)                                     // Alignment.
1253       Abbv->Add(BitCodeAbbrevOp(0));
1254     else {
1255       unsigned MaxEncAlignment = getEncodedAlign(MaxAlignment);
1256       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1257                                 Log2_32_Ceil(MaxEncAlignment + 1)));
1258     }
1259     if (SectionMap.empty()) // Section.
1260       Abbv->Add(BitCodeAbbrevOp(0));
1261     else
1262       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1263                                 Log2_32_Ceil(SectionMap.size() + 1)));
1264     // Don't bother emitting vis + thread local.
1265     SimpleGVarAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1266   }
1267 
1268   // Emit the global variable information.
1269   SmallVector<unsigned, 64> Vals;
1270   for (const GlobalVariable &GV : M.globals()) {
1271     unsigned AbbrevToUse = 0;
1272 
1273     // GLOBALVAR: [type, isconst, initid,
1274     //             linkage, alignment, section, visibility, threadlocal,
1275     //             unnamed_addr, externally_initialized, dllstorageclass,
1276     //             comdat]
1277     Vals.push_back(getGlobalObjectValueTypeID(GV.getValueType(), &GV));
1278     Vals.push_back(
1279         GV.getType()->getAddressSpace() << 2 | 2 |
1280         (GV.isConstant() ? 1 : 0)); // HLSL Change - bitwise | was used with
1281                                     // unsigned int and bool
1282     Vals.push_back(
1283         GV.isDeclaration() ? 0 : (VE.getValueID(GV.getInitializer()) + 1));
1284     Vals.push_back(getEncodedLinkage(GV));
1285     Vals.push_back(getEncodedAlign(GV.getAlign()));
1286     Vals.push_back(GV.hasSection() ? SectionMap[std::string(GV.getSection())]
1287                                    : 0);
1288     if (GV.isThreadLocal() ||
1289         GV.getVisibility() != GlobalValue::DefaultVisibility ||
1290         GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None ||
1291         GV.isExternallyInitialized() ||
1292         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
1293         GV.hasComdat()) {
1294       Vals.push_back(getEncodedVisibility(GV));
1295       Vals.push_back(getEncodedThreadLocalMode(GV));
1296       Vals.push_back(GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
1297       Vals.push_back(GV.isExternallyInitialized());
1298       Vals.push_back(getEncodedDLLStorageClass(GV));
1299       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
1300     } else {
1301       AbbrevToUse = SimpleGVarAbbrev;
1302     }
1303 
1304     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
1305     Vals.clear();
1306   }
1307 
1308   // Emit the function proto information.
1309   for (const Function &F : M) {
1310     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
1311     //             section, visibility, gc, unnamed_addr, prologuedata,
1312     //             dllstorageclass, comdat, prefixdata, personalityfn]
1313     Vals.push_back(getGlobalObjectValueTypeID(F.getFunctionType(), &F));
1314     Vals.push_back(F.getCallingConv());
1315     Vals.push_back(F.isDeclaration());
1316     Vals.push_back(getEncodedLinkage(F));
1317     Vals.push_back(VE.getAttributeListID(F.getAttributes()));
1318     Vals.push_back(getEncodedAlign(F.getAlign()));
1319     Vals.push_back(F.hasSection() ? SectionMap[std::string(F.getSection())]
1320                                   : 0);
1321     Vals.push_back(getEncodedVisibility(F));
1322     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
1323     Vals.push_back(F.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
1324     Vals.push_back(
1325         F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1) : 0);
1326     Vals.push_back(getEncodedDLLStorageClass(F));
1327     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
1328     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
1329                                      : 0);
1330     Vals.push_back(
1331         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
1332 
1333     unsigned AbbrevToUse = 0;
1334     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
1335     Vals.clear();
1336   }
1337 
1338   // Emit the alias information.
1339   for (const GlobalAlias &A : M.aliases()) {
1340     // ALIAS: [alias type, aliasee val#, linkage, visibility]
1341     Vals.push_back(getTypeID(A.getValueType(), &A));
1342     Vals.push_back(VE.getValueID(A.getAliasee()));
1343     Vals.push_back(getEncodedLinkage(A));
1344     Vals.push_back(getEncodedVisibility(A));
1345     Vals.push_back(getEncodedDLLStorageClass(A));
1346     Vals.push_back(getEncodedThreadLocalMode(A));
1347     Vals.push_back(A.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
1348     unsigned AbbrevToUse = 0;
1349     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS_OLD, Vals, AbbrevToUse);
1350     Vals.clear();
1351   }
1352 }
1353 
1354 void DXILBitcodeWriter::writeValueAsMetadata(
1355     const ValueAsMetadata *MD, SmallVectorImpl<uint64_t> &Record) {
1356   // Mimic an MDNode with a value as one operand.
1357   Value *V = MD->getValue();
1358   Type *Ty = V->getType();
1359   if (Function *F = dyn_cast<Function>(V))
1360     Ty = TypedPointerType::get(F->getFunctionType(), F->getAddressSpace());
1361   else if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
1362     Ty = TypedPointerType::get(GV->getValueType(), GV->getAddressSpace());
1363   Record.push_back(getTypeID(Ty));
1364   Record.push_back(VE.getValueID(V));
1365   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
1366   Record.clear();
1367 }
1368 
1369 void DXILBitcodeWriter::writeMDTuple(const MDTuple *N,
1370                                      SmallVectorImpl<uint64_t> &Record,
1371                                      unsigned Abbrev) {
1372   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
1373     Metadata *MD = N->getOperand(i);
1374     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
1375            "Unexpected function-local metadata");
1376     Record.push_back(VE.getMetadataOrNullID(MD));
1377   }
1378   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
1379                                     : bitc::METADATA_NODE,
1380                     Record, Abbrev);
1381   Record.clear();
1382 }
1383 
1384 void DXILBitcodeWriter::writeDILocation(const DILocation *N,
1385                                         SmallVectorImpl<uint64_t> &Record,
1386                                         unsigned &Abbrev) {
1387   if (!Abbrev)
1388     Abbrev = createDILocationAbbrev();
1389   Record.push_back(N->isDistinct());
1390   Record.push_back(N->getLine());
1391   Record.push_back(N->getColumn());
1392   Record.push_back(VE.getMetadataID(N->getScope()));
1393   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
1394 
1395   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
1396   Record.clear();
1397 }
1398 
1399 static uint64_t rotateSign(APInt Val) {
1400   int64_t I = Val.getSExtValue();
1401   uint64_t U = I;
1402   return I < 0 ? ~(U << 1) : U << 1;
1403 }
1404 
1405 static uint64_t rotateSign(DISubrange::BoundType Val) {
1406   return rotateSign(Val.get<ConstantInt *>()->getValue());
1407 }
1408 
1409 void DXILBitcodeWriter::writeDISubrange(const DISubrange *N,
1410                                         SmallVectorImpl<uint64_t> &Record,
1411                                         unsigned Abbrev) {
1412   Record.push_back(N->isDistinct());
1413   Record.push_back(
1414       N->getCount().get<ConstantInt *>()->getValue().getSExtValue());
1415   Record.push_back(rotateSign(N->getLowerBound()));
1416 
1417   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
1418   Record.clear();
1419 }
1420 
1421 void DXILBitcodeWriter::writeDIEnumerator(const DIEnumerator *N,
1422                                           SmallVectorImpl<uint64_t> &Record,
1423                                           unsigned Abbrev) {
1424   Record.push_back(N->isDistinct());
1425   Record.push_back(rotateSign(N->getValue()));
1426   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1427 
1428   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
1429   Record.clear();
1430 }
1431 
1432 void DXILBitcodeWriter::writeDIBasicType(const DIBasicType *N,
1433                                          SmallVectorImpl<uint64_t> &Record,
1434                                          unsigned Abbrev) {
1435   Record.push_back(N->isDistinct());
1436   Record.push_back(N->getTag());
1437   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1438   Record.push_back(N->getSizeInBits());
1439   Record.push_back(N->getAlignInBits());
1440   Record.push_back(N->getEncoding());
1441 
1442   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
1443   Record.clear();
1444 }
1445 
1446 void DXILBitcodeWriter::writeDIDerivedType(const DIDerivedType *N,
1447                                            SmallVectorImpl<uint64_t> &Record,
1448                                            unsigned Abbrev) {
1449   Record.push_back(N->isDistinct());
1450   Record.push_back(N->getTag());
1451   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1452   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1453   Record.push_back(N->getLine());
1454   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1455   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1456   Record.push_back(N->getSizeInBits());
1457   Record.push_back(N->getAlignInBits());
1458   Record.push_back(N->getOffsetInBits());
1459   Record.push_back(N->getFlags());
1460   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
1461 
1462   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
1463   Record.clear();
1464 }
1465 
1466 void DXILBitcodeWriter::writeDICompositeType(const DICompositeType *N,
1467                                              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->getFile()));
1473   Record.push_back(N->getLine());
1474   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1475   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1476   Record.push_back(N->getSizeInBits());
1477   Record.push_back(N->getAlignInBits());
1478   Record.push_back(N->getOffsetInBits());
1479   Record.push_back(N->getFlags());
1480   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1481   Record.push_back(N->getRuntimeLang());
1482   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
1483   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1484   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
1485 
1486   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
1487   Record.clear();
1488 }
1489 
1490 void DXILBitcodeWriter::writeDISubroutineType(const DISubroutineType *N,
1491                                               SmallVectorImpl<uint64_t> &Record,
1492                                               unsigned Abbrev) {
1493   Record.push_back(N->isDistinct());
1494   Record.push_back(N->getFlags());
1495   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
1496 
1497   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
1498   Record.clear();
1499 }
1500 
1501 void DXILBitcodeWriter::writeDIFile(const DIFile *N,
1502                                     SmallVectorImpl<uint64_t> &Record,
1503                                     unsigned Abbrev) {
1504   Record.push_back(N->isDistinct());
1505   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
1506   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
1507 
1508   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
1509   Record.clear();
1510 }
1511 
1512 void DXILBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
1513                                            SmallVectorImpl<uint64_t> &Record,
1514                                            unsigned Abbrev) {
1515   Record.push_back(N->isDistinct());
1516   Record.push_back(N->getSourceLanguage());
1517   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1518   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
1519   Record.push_back(N->isOptimized());
1520   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
1521   Record.push_back(N->getRuntimeVersion());
1522   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
1523   Record.push_back(N->getEmissionKind());
1524   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
1525   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
1526   Record.push_back(/* subprograms */ 0);
1527   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
1528   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
1529   Record.push_back(N->getDWOId());
1530 
1531   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
1532   Record.clear();
1533 }
1534 
1535 void DXILBitcodeWriter::writeDISubprogram(const DISubprogram *N,
1536                                           SmallVectorImpl<uint64_t> &Record,
1537                                           unsigned Abbrev) {
1538   Record.push_back(N->isDistinct());
1539   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1540   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1541   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1542   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1543   Record.push_back(N->getLine());
1544   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1545   Record.push_back(N->isLocalToUnit());
1546   Record.push_back(N->isDefinition());
1547   Record.push_back(N->getScopeLine());
1548   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
1549   Record.push_back(N->getVirtuality());
1550   Record.push_back(N->getVirtualIndex());
1551   Record.push_back(N->getFlags());
1552   Record.push_back(N->isOptimized());
1553   Record.push_back(VE.getMetadataOrNullID(N->getRawUnit()));
1554   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1555   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
1556   Record.push_back(VE.getMetadataOrNullID(N->getRetainedNodes().get()));
1557 
1558   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
1559   Record.clear();
1560 }
1561 
1562 void DXILBitcodeWriter::writeDILexicalBlock(const DILexicalBlock *N,
1563                                             SmallVectorImpl<uint64_t> &Record,
1564                                             unsigned Abbrev) {
1565   Record.push_back(N->isDistinct());
1566   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1567   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1568   Record.push_back(N->getLine());
1569   Record.push_back(N->getColumn());
1570 
1571   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
1572   Record.clear();
1573 }
1574 
1575 void DXILBitcodeWriter::writeDILexicalBlockFile(
1576     const DILexicalBlockFile *N, SmallVectorImpl<uint64_t> &Record,
1577     unsigned Abbrev) {
1578   Record.push_back(N->isDistinct());
1579   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1580   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1581   Record.push_back(N->getDiscriminator());
1582 
1583   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
1584   Record.clear();
1585 }
1586 
1587 void DXILBitcodeWriter::writeDINamespace(const DINamespace *N,
1588                                          SmallVectorImpl<uint64_t> &Record,
1589                                          unsigned Abbrev) {
1590   Record.push_back(N->isDistinct());
1591   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1592   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1593   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1594   Record.push_back(/* line number */ 0);
1595 
1596   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
1597   Record.clear();
1598 }
1599 
1600 void DXILBitcodeWriter::writeDIModule(const DIModule *N,
1601                                       SmallVectorImpl<uint64_t> &Record,
1602                                       unsigned Abbrev) {
1603   Record.push_back(N->isDistinct());
1604   for (auto &I : N->operands())
1605     Record.push_back(VE.getMetadataOrNullID(I));
1606 
1607   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
1608   Record.clear();
1609 }
1610 
1611 void DXILBitcodeWriter::writeDITemplateTypeParameter(
1612     const DITemplateTypeParameter *N, SmallVectorImpl<uint64_t> &Record,
1613     unsigned Abbrev) {
1614   Record.push_back(N->isDistinct());
1615   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1616   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1617 
1618   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
1619   Record.clear();
1620 }
1621 
1622 void DXILBitcodeWriter::writeDITemplateValueParameter(
1623     const DITemplateValueParameter *N, SmallVectorImpl<uint64_t> &Record,
1624     unsigned Abbrev) {
1625   Record.push_back(N->isDistinct());
1626   Record.push_back(N->getTag());
1627   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1628   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1629   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
1630 
1631   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
1632   Record.clear();
1633 }
1634 
1635 void DXILBitcodeWriter::writeDIGlobalVariable(const DIGlobalVariable *N,
1636                                               SmallVectorImpl<uint64_t> &Record,
1637                                               unsigned Abbrev) {
1638   Record.push_back(N->isDistinct());
1639   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1640   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1641   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1642   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1643   Record.push_back(N->getLine());
1644   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1645   Record.push_back(N->isLocalToUnit());
1646   Record.push_back(N->isDefinition());
1647   Record.push_back(/* N->getRawVariable() */ 0);
1648   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
1649 
1650   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
1651   Record.clear();
1652 }
1653 
1654 void DXILBitcodeWriter::writeDILocalVariable(const DILocalVariable *N,
1655                                              SmallVectorImpl<uint64_t> &Record,
1656                                              unsigned Abbrev) {
1657   Record.push_back(N->isDistinct());
1658   Record.push_back(N->getTag());
1659   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1660   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1661   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1662   Record.push_back(N->getLine());
1663   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1664   Record.push_back(N->getArg());
1665   Record.push_back(N->getFlags());
1666 
1667   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
1668   Record.clear();
1669 }
1670 
1671 void DXILBitcodeWriter::writeDIExpression(const DIExpression *N,
1672                                           SmallVectorImpl<uint64_t> &Record,
1673                                           unsigned Abbrev) {
1674   Record.reserve(N->getElements().size() + 1);
1675 
1676   Record.push_back(N->isDistinct());
1677   Record.append(N->elements_begin(), N->elements_end());
1678 
1679   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
1680   Record.clear();
1681 }
1682 
1683 void DXILBitcodeWriter::writeDIObjCProperty(const DIObjCProperty *N,
1684                                             SmallVectorImpl<uint64_t> &Record,
1685                                             unsigned Abbrev) {
1686   llvm_unreachable("DXIL does not support objc!!!");
1687 }
1688 
1689 void DXILBitcodeWriter::writeDIImportedEntity(const DIImportedEntity *N,
1690                                               SmallVectorImpl<uint64_t> &Record,
1691                                               unsigned Abbrev) {
1692   Record.push_back(N->isDistinct());
1693   Record.push_back(N->getTag());
1694   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1695   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
1696   Record.push_back(N->getLine());
1697   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1698 
1699   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
1700   Record.clear();
1701 }
1702 
1703 unsigned DXILBitcodeWriter::createDILocationAbbrev() {
1704   // Abbrev for METADATA_LOCATION.
1705   //
1706   // Assume the column is usually under 128, and always output the inlined-at
1707   // location (it's never more expensive than building an array size 1).
1708   std::shared_ptr<BitCodeAbbrev> Abbv = std::make_shared<BitCodeAbbrev>();
1709   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1710   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1711   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1712   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1713   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1714   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1715   return Stream.EmitAbbrev(std::move(Abbv));
1716 }
1717 
1718 unsigned DXILBitcodeWriter::createGenericDINodeAbbrev() {
1719   // Abbrev for METADATA_GENERIC_DEBUG.
1720   //
1721   // Assume the column is usually under 128, and always output the inlined-at
1722   // location (it's never more expensive than building an array size 1).
1723   std::shared_ptr<BitCodeAbbrev> Abbv = std::make_shared<BitCodeAbbrev>();
1724   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1725   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1726   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1727   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1728   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1729   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1730   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1731   return Stream.EmitAbbrev(std::move(Abbv));
1732 }
1733 
1734 void DXILBitcodeWriter::writeMetadataRecords(ArrayRef<const Metadata *> MDs,
1735                                              SmallVectorImpl<uint64_t> &Record,
1736                                              std::vector<unsigned> *MDAbbrevs,
1737                                              std::vector<uint64_t> *IndexPos) {
1738   if (MDs.empty())
1739     return;
1740 
1741     // Initialize MDNode abbreviations.
1742 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
1743 #include "llvm/IR/Metadata.def"
1744 
1745   for (const Metadata *MD : MDs) {
1746     if (IndexPos)
1747       IndexPos->push_back(Stream.GetCurrentBitNo());
1748     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
1749       assert(N->isResolved() && "Expected forward references to be resolved");
1750 
1751       switch (N->getMetadataID()) {
1752       default:
1753         llvm_unreachable("Invalid MDNode subclass");
1754 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
1755   case Metadata::CLASS##Kind:                                                  \
1756     if (MDAbbrevs)                                                             \
1757       write##CLASS(cast<CLASS>(N), Record,                                     \
1758                    (*MDAbbrevs)[MetadataAbbrev::CLASS##AbbrevID]);             \
1759     else                                                                       \
1760       write##CLASS(cast<CLASS>(N), Record, CLASS##Abbrev);                     \
1761     continue;
1762 #include "llvm/IR/Metadata.def"
1763       }
1764     }
1765     writeValueAsMetadata(cast<ValueAsMetadata>(MD), Record);
1766   }
1767 }
1768 
1769 unsigned DXILBitcodeWriter::createMetadataStringsAbbrev() {
1770   auto Abbv = std::make_shared<BitCodeAbbrev>();
1771   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING_OLD));
1772   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1773   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1774   return Stream.EmitAbbrev(std::move(Abbv));
1775 }
1776 
1777 void DXILBitcodeWriter::writeMetadataStrings(
1778     ArrayRef<const Metadata *> Strings, SmallVectorImpl<uint64_t> &Record) {
1779   for (const Metadata *MD : Strings) {
1780     const MDString *MDS = cast<MDString>(MD);
1781     // Code: [strchar x N]
1782     Record.append(MDS->bytes_begin(), MDS->bytes_end());
1783 
1784     // Emit the finished record.
1785     Stream.EmitRecord(bitc::METADATA_STRING_OLD, Record,
1786                       createMetadataStringsAbbrev());
1787     Record.clear();
1788   }
1789 }
1790 
1791 void DXILBitcodeWriter::writeModuleMetadata() {
1792   if (!VE.hasMDs() && M.named_metadata_empty())
1793     return;
1794 
1795   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 5);
1796 
1797   // Emit all abbrevs upfront, so that the reader can jump in the middle of the
1798   // block and load any metadata.
1799   std::vector<unsigned> MDAbbrevs;
1800 
1801   MDAbbrevs.resize(MetadataAbbrev::LastPlusOne);
1802   MDAbbrevs[MetadataAbbrev::DILocationAbbrevID] = createDILocationAbbrev();
1803   MDAbbrevs[MetadataAbbrev::GenericDINodeAbbrevID] =
1804       createGenericDINodeAbbrev();
1805 
1806   unsigned NameAbbrev = 0;
1807   if (!M.named_metadata_empty()) {
1808     // Abbrev for METADATA_NAME.
1809     std::shared_ptr<BitCodeAbbrev> Abbv = std::make_shared<BitCodeAbbrev>();
1810     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
1811     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1812     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1813     NameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1814   }
1815 
1816   SmallVector<uint64_t, 64> Record;
1817   writeMetadataStrings(VE.getMDStrings(), Record);
1818 
1819   std::vector<uint64_t> IndexPos;
1820   IndexPos.reserve(VE.getNonMDStrings().size());
1821   writeMetadataRecords(VE.getNonMDStrings(), Record, &MDAbbrevs, &IndexPos);
1822 
1823   // Write named metadata.
1824   for (const NamedMDNode &NMD : M.named_metadata()) {
1825     // Write name.
1826     StringRef Str = NMD.getName();
1827     Record.append(Str.bytes_begin(), Str.bytes_end());
1828     Stream.EmitRecord(bitc::METADATA_NAME, Record, NameAbbrev);
1829     Record.clear();
1830 
1831     // Write named metadata operands.
1832     for (const MDNode *N : NMD.operands())
1833       Record.push_back(VE.getMetadataID(N));
1834     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
1835     Record.clear();
1836   }
1837 
1838   Stream.ExitBlock();
1839 }
1840 
1841 void DXILBitcodeWriter::writeFunctionMetadata(const Function &F) {
1842   if (!VE.hasMDs())
1843     return;
1844 
1845   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 4);
1846   SmallVector<uint64_t, 64> Record;
1847   writeMetadataStrings(VE.getMDStrings(), Record);
1848   writeMetadataRecords(VE.getNonMDStrings(), Record);
1849   Stream.ExitBlock();
1850 }
1851 
1852 void DXILBitcodeWriter::writeFunctionMetadataAttachment(const Function &F) {
1853   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
1854 
1855   SmallVector<uint64_t, 64> Record;
1856 
1857   // Write metadata attachments
1858   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
1859   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
1860   F.getAllMetadata(MDs);
1861   if (!MDs.empty()) {
1862     for (const auto &I : MDs) {
1863       Record.push_back(I.first);
1864       Record.push_back(VE.getMetadataID(I.second));
1865     }
1866     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1867     Record.clear();
1868   }
1869 
1870   for (const BasicBlock &BB : F)
1871     for (const Instruction &I : BB) {
1872       MDs.clear();
1873       I.getAllMetadataOtherThanDebugLoc(MDs);
1874 
1875       // If no metadata, ignore instruction.
1876       if (MDs.empty())
1877         continue;
1878 
1879       Record.push_back(VE.getInstructionID(&I));
1880 
1881       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1882         Record.push_back(MDs[i].first);
1883         Record.push_back(VE.getMetadataID(MDs[i].second));
1884       }
1885       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1886       Record.clear();
1887     }
1888 
1889   Stream.ExitBlock();
1890 }
1891 
1892 void DXILBitcodeWriter::writeModuleMetadataKinds() {
1893   SmallVector<uint64_t, 64> Record;
1894 
1895   // Write metadata kinds
1896   // METADATA_KIND - [n x [id, name]]
1897   SmallVector<StringRef, 8> Names;
1898   M.getMDKindNames(Names);
1899 
1900   if (Names.empty())
1901     return;
1902 
1903   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1904 
1905   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
1906     Record.push_back(MDKindID);
1907     StringRef KName = Names[MDKindID];
1908     Record.append(KName.begin(), KName.end());
1909 
1910     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
1911     Record.clear();
1912   }
1913 
1914   Stream.ExitBlock();
1915 }
1916 
1917 void DXILBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
1918                                        bool isGlobal) {
1919   if (FirstVal == LastVal)
1920     return;
1921 
1922   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
1923 
1924   unsigned AggregateAbbrev = 0;
1925   unsigned String8Abbrev = 0;
1926   unsigned CString7Abbrev = 0;
1927   unsigned CString6Abbrev = 0;
1928   // If this is a constant pool for the module, emit module-specific abbrevs.
1929   if (isGlobal) {
1930     // Abbrev for CST_CODE_AGGREGATE.
1931     auto Abbv = std::make_shared<BitCodeAbbrev>();
1932     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
1933     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1934     Abbv->Add(
1935         BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal + 1)));
1936     AggregateAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1937 
1938     // Abbrev for CST_CODE_STRING.
1939     Abbv = std::make_shared<BitCodeAbbrev>();
1940     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
1941     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1942     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1943     String8Abbrev = Stream.EmitAbbrev(std::move(Abbv));
1944     // Abbrev for CST_CODE_CSTRING.
1945     Abbv = std::make_shared<BitCodeAbbrev>();
1946     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1947     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1948     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1949     CString7Abbrev = Stream.EmitAbbrev(std::move(Abbv));
1950     // Abbrev for CST_CODE_CSTRING.
1951     Abbv = std::make_shared<BitCodeAbbrev>();
1952     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1953     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1954     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1955     CString6Abbrev = Stream.EmitAbbrev(std::move(Abbv));
1956   }
1957 
1958   SmallVector<uint64_t, 64> Record;
1959 
1960   const ValueEnumerator::ValueList &Vals = VE.getValues();
1961   Type *LastTy = nullptr;
1962   for (unsigned i = FirstVal; i != LastVal; ++i) {
1963     const Value *V = Vals[i].first;
1964     // If we need to switch types, do so now.
1965     if (V->getType() != LastTy) {
1966       LastTy = V->getType();
1967       Record.push_back(getTypeID(LastTy, V));
1968       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
1969                         CONSTANTS_SETTYPE_ABBREV);
1970       Record.clear();
1971     }
1972 
1973     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
1974       Record.push_back(unsigned(IA->hasSideEffects()) |
1975                        unsigned(IA->isAlignStack()) << 1 |
1976                        unsigned(IA->getDialect() & 1) << 2);
1977 
1978       // Add the asm string.
1979       const std::string &AsmStr = IA->getAsmString();
1980       Record.push_back(AsmStr.size());
1981       Record.append(AsmStr.begin(), AsmStr.end());
1982 
1983       // Add the constraint string.
1984       const std::string &ConstraintStr = IA->getConstraintString();
1985       Record.push_back(ConstraintStr.size());
1986       Record.append(ConstraintStr.begin(), ConstraintStr.end());
1987       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
1988       Record.clear();
1989       continue;
1990     }
1991     const Constant *C = cast<Constant>(V);
1992     unsigned Code = -1U;
1993     unsigned AbbrevToUse = 0;
1994     if (C->isNullValue()) {
1995       Code = bitc::CST_CODE_NULL;
1996     } else if (isa<UndefValue>(C)) {
1997       Code = bitc::CST_CODE_UNDEF;
1998     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
1999       if (IV->getBitWidth() <= 64) {
2000         uint64_t V = IV->getSExtValue();
2001         emitSignedInt64(Record, V);
2002         Code = bitc::CST_CODE_INTEGER;
2003         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
2004       } else { // Wide integers, > 64 bits in size.
2005         // We have an arbitrary precision integer value to write whose
2006         // bit width is > 64. However, in canonical unsigned integer
2007         // format it is likely that the high bits are going to be zero.
2008         // So, we only write the number of active words.
2009         unsigned NWords = IV->getValue().getActiveWords();
2010         const uint64_t *RawWords = IV->getValue().getRawData();
2011         for (unsigned i = 0; i != NWords; ++i) {
2012           emitSignedInt64(Record, RawWords[i]);
2013         }
2014         Code = bitc::CST_CODE_WIDE_INTEGER;
2015       }
2016     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
2017       Code = bitc::CST_CODE_FLOAT;
2018       Type *Ty = CFP->getType();
2019       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
2020         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
2021       } else if (Ty->isX86_FP80Ty()) {
2022         // api needed to prevent premature destruction
2023         // bits are not in the same order as a normal i80 APInt, compensate.
2024         APInt api = CFP->getValueAPF().bitcastToAPInt();
2025         const uint64_t *p = api.getRawData();
2026         Record.push_back((p[1] << 48) | (p[0] >> 16));
2027         Record.push_back(p[0] & 0xffffLL);
2028       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
2029         APInt api = CFP->getValueAPF().bitcastToAPInt();
2030         const uint64_t *p = api.getRawData();
2031         Record.push_back(p[0]);
2032         Record.push_back(p[1]);
2033       } else {
2034         assert(0 && "Unknown FP type!");
2035       }
2036     } else if (isa<ConstantDataSequential>(C) &&
2037                cast<ConstantDataSequential>(C)->isString()) {
2038       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
2039       // Emit constant strings specially.
2040       unsigned NumElts = Str->getNumElements();
2041       // If this is a null-terminated string, use the denser CSTRING encoding.
2042       if (Str->isCString()) {
2043         Code = bitc::CST_CODE_CSTRING;
2044         --NumElts; // Don't encode the null, which isn't allowed by char6.
2045       } else {
2046         Code = bitc::CST_CODE_STRING;
2047         AbbrevToUse = String8Abbrev;
2048       }
2049       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
2050       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
2051       for (unsigned i = 0; i != NumElts; ++i) {
2052         unsigned char V = Str->getElementAsInteger(i);
2053         Record.push_back(V);
2054         isCStr7 &= (V & 128) == 0;
2055         if (isCStrChar6)
2056           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
2057       }
2058 
2059       if (isCStrChar6)
2060         AbbrevToUse = CString6Abbrev;
2061       else if (isCStr7)
2062         AbbrevToUse = CString7Abbrev;
2063     } else if (const ConstantDataSequential *CDS =
2064                    dyn_cast<ConstantDataSequential>(C)) {
2065       Code = bitc::CST_CODE_DATA;
2066       Type *EltTy = CDS->getElementType();
2067       if (isa<IntegerType>(EltTy)) {
2068         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2069           Record.push_back(CDS->getElementAsInteger(i));
2070       } else if (EltTy->isFloatTy()) {
2071         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
2072           union {
2073             float F;
2074             uint32_t I;
2075           };
2076           F = CDS->getElementAsFloat(i);
2077           Record.push_back(I);
2078         }
2079       } else {
2080         assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
2081         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
2082           union {
2083             double F;
2084             uint64_t I;
2085           };
2086           F = CDS->getElementAsDouble(i);
2087           Record.push_back(I);
2088         }
2089       }
2090     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
2091                isa<ConstantVector>(C)) {
2092       Code = bitc::CST_CODE_AGGREGATE;
2093       for (const Value *Op : C->operands())
2094         Record.push_back(VE.getValueID(Op));
2095       AbbrevToUse = AggregateAbbrev;
2096     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
2097       switch (CE->getOpcode()) {
2098       default:
2099         if (Instruction::isCast(CE->getOpcode())) {
2100           Code = bitc::CST_CODE_CE_CAST;
2101           Record.push_back(getEncodedCastOpcode(CE->getOpcode()));
2102           Record.push_back(
2103               getTypeID(C->getOperand(0)->getType(), C->getOperand(0)));
2104           Record.push_back(VE.getValueID(C->getOperand(0)));
2105           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
2106         } else {
2107           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
2108           Code = bitc::CST_CODE_CE_BINOP;
2109           Record.push_back(getEncodedBinaryOpcode(CE->getOpcode()));
2110           Record.push_back(VE.getValueID(C->getOperand(0)));
2111           Record.push_back(VE.getValueID(C->getOperand(1)));
2112           uint64_t Flags = getOptimizationFlags(CE);
2113           if (Flags != 0)
2114             Record.push_back(Flags);
2115         }
2116         break;
2117       case Instruction::GetElementPtr: {
2118         Code = bitc::CST_CODE_CE_GEP;
2119         const auto *GO = cast<GEPOperator>(C);
2120         if (GO->isInBounds())
2121           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
2122         Record.push_back(getTypeID(GO->getSourceElementType()));
2123         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
2124           Record.push_back(
2125               getTypeID(C->getOperand(i)->getType(), C->getOperand(i)));
2126           Record.push_back(VE.getValueID(C->getOperand(i)));
2127         }
2128         break;
2129       }
2130       case Instruction::Select:
2131         Code = bitc::CST_CODE_CE_SELECT;
2132         Record.push_back(VE.getValueID(C->getOperand(0)));
2133         Record.push_back(VE.getValueID(C->getOperand(1)));
2134         Record.push_back(VE.getValueID(C->getOperand(2)));
2135         break;
2136       case Instruction::ExtractElement:
2137         Code = bitc::CST_CODE_CE_EXTRACTELT;
2138         Record.push_back(getTypeID(C->getOperand(0)->getType()));
2139         Record.push_back(VE.getValueID(C->getOperand(0)));
2140         Record.push_back(getTypeID(C->getOperand(1)->getType()));
2141         Record.push_back(VE.getValueID(C->getOperand(1)));
2142         break;
2143       case Instruction::InsertElement:
2144         Code = bitc::CST_CODE_CE_INSERTELT;
2145         Record.push_back(VE.getValueID(C->getOperand(0)));
2146         Record.push_back(VE.getValueID(C->getOperand(1)));
2147         Record.push_back(getTypeID(C->getOperand(2)->getType()));
2148         Record.push_back(VE.getValueID(C->getOperand(2)));
2149         break;
2150       case Instruction::ShuffleVector:
2151         // If the return type and argument types are the same, this is a
2152         // standard shufflevector instruction.  If the types are different,
2153         // then the shuffle is widening or truncating the input vectors, and
2154         // the argument type must also be encoded.
2155         if (C->getType() == C->getOperand(0)->getType()) {
2156           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
2157         } else {
2158           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
2159           Record.push_back(getTypeID(C->getOperand(0)->getType()));
2160         }
2161         Record.push_back(VE.getValueID(C->getOperand(0)));
2162         Record.push_back(VE.getValueID(C->getOperand(1)));
2163         Record.push_back(VE.getValueID(C->getOperand(2)));
2164         break;
2165       case Instruction::ICmp:
2166       case Instruction::FCmp:
2167         Code = bitc::CST_CODE_CE_CMP;
2168         Record.push_back(getTypeID(C->getOperand(0)->getType()));
2169         Record.push_back(VE.getValueID(C->getOperand(0)));
2170         Record.push_back(VE.getValueID(C->getOperand(1)));
2171         Record.push_back(CE->getPredicate());
2172         break;
2173       }
2174     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
2175       Code = bitc::CST_CODE_BLOCKADDRESS;
2176       Record.push_back(getTypeID(BA->getFunction()->getType()));
2177       Record.push_back(VE.getValueID(BA->getFunction()));
2178       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
2179     } else {
2180 #ifndef NDEBUG
2181       C->dump();
2182 #endif
2183       llvm_unreachable("Unknown constant!");
2184     }
2185     Stream.EmitRecord(Code, Record, AbbrevToUse);
2186     Record.clear();
2187   }
2188 
2189   Stream.ExitBlock();
2190 }
2191 
2192 void DXILBitcodeWriter::writeModuleConstants() {
2193   const ValueEnumerator::ValueList &Vals = VE.getValues();
2194 
2195   // Find the first constant to emit, which is the first non-globalvalue value.
2196   // We know globalvalues have been emitted by WriteModuleInfo.
2197   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
2198     if (!isa<GlobalValue>(Vals[i].first)) {
2199       writeConstants(i, Vals.size(), true);
2200       return;
2201     }
2202   }
2203 }
2204 
2205 /// pushValueAndType - The file has to encode both the value and type id for
2206 /// many values, because we need to know what type to create for forward
2207 /// references.  However, most operands are not forward references, so this type
2208 /// field is not needed.
2209 ///
2210 /// This function adds V's value ID to Vals.  If the value ID is higher than the
2211 /// instruction ID, then it is a forward reference, and it also includes the
2212 /// type ID.  The value ID that is written is encoded relative to the InstID.
2213 bool DXILBitcodeWriter::pushValueAndType(const Value *V, unsigned InstID,
2214                                          SmallVectorImpl<unsigned> &Vals) {
2215   unsigned ValID = VE.getValueID(V);
2216   // Make encoding relative to the InstID.
2217   Vals.push_back(InstID - ValID);
2218   if (ValID >= InstID) {
2219     Vals.push_back(getTypeID(V->getType(), V));
2220     return true;
2221   }
2222   return false;
2223 }
2224 
2225 /// pushValue - Like pushValueAndType, but where the type of the value is
2226 /// omitted (perhaps it was already encoded in an earlier operand).
2227 void DXILBitcodeWriter::pushValue(const Value *V, unsigned InstID,
2228                                   SmallVectorImpl<unsigned> &Vals) {
2229   unsigned ValID = VE.getValueID(V);
2230   Vals.push_back(InstID - ValID);
2231 }
2232 
2233 void DXILBitcodeWriter::pushValueSigned(const Value *V, unsigned InstID,
2234                                         SmallVectorImpl<uint64_t> &Vals) {
2235   unsigned ValID = VE.getValueID(V);
2236   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
2237   emitSignedInt64(Vals, diff);
2238 }
2239 
2240 /// WriteInstruction - Emit an instruction
2241 void DXILBitcodeWriter::writeInstruction(const Instruction &I, unsigned InstID,
2242                                          SmallVectorImpl<unsigned> &Vals) {
2243   unsigned Code = 0;
2244   unsigned AbbrevToUse = 0;
2245   VE.setInstructionID(&I);
2246   switch (I.getOpcode()) {
2247   default:
2248     if (Instruction::isCast(I.getOpcode())) {
2249       Code = bitc::FUNC_CODE_INST_CAST;
2250       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2251         AbbrevToUse = (unsigned)FUNCTION_INST_CAST_ABBREV;
2252       Vals.push_back(getTypeID(I.getType(), &I));
2253       Vals.push_back(getEncodedCastOpcode(I.getOpcode()));
2254     } else {
2255       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
2256       Code = bitc::FUNC_CODE_INST_BINOP;
2257       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2258         AbbrevToUse = (unsigned)FUNCTION_INST_BINOP_ABBREV;
2259       pushValue(I.getOperand(1), InstID, Vals);
2260       Vals.push_back(getEncodedBinaryOpcode(I.getOpcode()));
2261       uint64_t Flags = getOptimizationFlags(&I);
2262       if (Flags != 0) {
2263         if (AbbrevToUse == (unsigned)FUNCTION_INST_BINOP_ABBREV)
2264           AbbrevToUse = (unsigned)FUNCTION_INST_BINOP_FLAGS_ABBREV;
2265         Vals.push_back(Flags);
2266       }
2267     }
2268     break;
2269 
2270   case Instruction::GetElementPtr: {
2271     Code = bitc::FUNC_CODE_INST_GEP;
2272     AbbrevToUse = (unsigned)FUNCTION_INST_GEP_ABBREV;
2273     auto &GEPInst = cast<GetElementPtrInst>(I);
2274     Vals.push_back(GEPInst.isInBounds());
2275     Vals.push_back(getTypeID(GEPInst.getSourceElementType()));
2276     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
2277       pushValueAndType(I.getOperand(i), InstID, Vals);
2278     break;
2279   }
2280   case Instruction::ExtractValue: {
2281     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
2282     pushValueAndType(I.getOperand(0), InstID, Vals);
2283     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
2284     Vals.append(EVI->idx_begin(), EVI->idx_end());
2285     break;
2286   }
2287   case Instruction::InsertValue: {
2288     Code = bitc::FUNC_CODE_INST_INSERTVAL;
2289     pushValueAndType(I.getOperand(0), InstID, Vals);
2290     pushValueAndType(I.getOperand(1), InstID, Vals);
2291     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
2292     Vals.append(IVI->idx_begin(), IVI->idx_end());
2293     break;
2294   }
2295   case Instruction::Select:
2296     Code = bitc::FUNC_CODE_INST_VSELECT;
2297     pushValueAndType(I.getOperand(1), InstID, Vals);
2298     pushValue(I.getOperand(2), InstID, Vals);
2299     pushValueAndType(I.getOperand(0), InstID, Vals);
2300     break;
2301   case Instruction::ExtractElement:
2302     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
2303     pushValueAndType(I.getOperand(0), InstID, Vals);
2304     pushValueAndType(I.getOperand(1), InstID, Vals);
2305     break;
2306   case Instruction::InsertElement:
2307     Code = bitc::FUNC_CODE_INST_INSERTELT;
2308     pushValueAndType(I.getOperand(0), InstID, Vals);
2309     pushValue(I.getOperand(1), InstID, Vals);
2310     pushValueAndType(I.getOperand(2), InstID, Vals);
2311     break;
2312   case Instruction::ShuffleVector:
2313     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
2314     pushValueAndType(I.getOperand(0), InstID, Vals);
2315     pushValue(I.getOperand(1), InstID, Vals);
2316     pushValue(cast<ShuffleVectorInst>(&I)->getShuffleMaskForBitcode(), InstID,
2317               Vals);
2318     break;
2319   case Instruction::ICmp:
2320   case Instruction::FCmp: {
2321     // compare returning Int1Ty or vector of Int1Ty
2322     Code = bitc::FUNC_CODE_INST_CMP2;
2323     pushValueAndType(I.getOperand(0), InstID, Vals);
2324     pushValue(I.getOperand(1), InstID, Vals);
2325     Vals.push_back(cast<CmpInst>(I).getPredicate());
2326     uint64_t Flags = getOptimizationFlags(&I);
2327     if (Flags != 0)
2328       Vals.push_back(Flags);
2329     break;
2330   }
2331 
2332   case Instruction::Ret: {
2333     Code = bitc::FUNC_CODE_INST_RET;
2334     unsigned NumOperands = I.getNumOperands();
2335     if (NumOperands == 0)
2336       AbbrevToUse = (unsigned)FUNCTION_INST_RET_VOID_ABBREV;
2337     else if (NumOperands == 1) {
2338       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2339         AbbrevToUse = (unsigned)FUNCTION_INST_RET_VAL_ABBREV;
2340     } else {
2341       for (unsigned i = 0, e = NumOperands; i != e; ++i)
2342         pushValueAndType(I.getOperand(i), InstID, Vals);
2343     }
2344   } break;
2345   case Instruction::Br: {
2346     Code = bitc::FUNC_CODE_INST_BR;
2347     const BranchInst &II = cast<BranchInst>(I);
2348     Vals.push_back(VE.getValueID(II.getSuccessor(0)));
2349     if (II.isConditional()) {
2350       Vals.push_back(VE.getValueID(II.getSuccessor(1)));
2351       pushValue(II.getCondition(), InstID, Vals);
2352     }
2353   } break;
2354   case Instruction::Switch: {
2355     Code = bitc::FUNC_CODE_INST_SWITCH;
2356     const SwitchInst &SI = cast<SwitchInst>(I);
2357     Vals.push_back(getTypeID(SI.getCondition()->getType()));
2358     pushValue(SI.getCondition(), InstID, Vals);
2359     Vals.push_back(VE.getValueID(SI.getDefaultDest()));
2360     for (auto Case : SI.cases()) {
2361       Vals.push_back(VE.getValueID(Case.getCaseValue()));
2362       Vals.push_back(VE.getValueID(Case.getCaseSuccessor()));
2363     }
2364   } break;
2365   case Instruction::IndirectBr:
2366     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
2367     Vals.push_back(getTypeID(I.getOperand(0)->getType()));
2368     // Encode the address operand as relative, but not the basic blocks.
2369     pushValue(I.getOperand(0), InstID, Vals);
2370     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
2371       Vals.push_back(VE.getValueID(I.getOperand(i)));
2372     break;
2373 
2374   case Instruction::Invoke: {
2375     const InvokeInst *II = cast<InvokeInst>(&I);
2376     const Value *Callee = II->getCalledOperand();
2377     FunctionType *FTy = II->getFunctionType();
2378     Code = bitc::FUNC_CODE_INST_INVOKE;
2379 
2380     Vals.push_back(VE.getAttributeListID(II->getAttributes()));
2381     Vals.push_back(II->getCallingConv() | 1 << 13);
2382     Vals.push_back(VE.getValueID(II->getNormalDest()));
2383     Vals.push_back(VE.getValueID(II->getUnwindDest()));
2384     Vals.push_back(getTypeID(FTy));
2385     pushValueAndType(Callee, InstID, Vals);
2386 
2387     // Emit value #'s for the fixed parameters.
2388     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
2389       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
2390 
2391     // Emit type/value pairs for varargs params.
2392     if (FTy->isVarArg()) {
2393       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands() - 3; i != e;
2394            ++i)
2395         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
2396     }
2397     break;
2398   }
2399   case Instruction::Resume:
2400     Code = bitc::FUNC_CODE_INST_RESUME;
2401     pushValueAndType(I.getOperand(0), InstID, Vals);
2402     break;
2403   case Instruction::Unreachable:
2404     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
2405     AbbrevToUse = (unsigned)FUNCTION_INST_UNREACHABLE_ABBREV;
2406     break;
2407 
2408   case Instruction::PHI: {
2409     const PHINode &PN = cast<PHINode>(I);
2410     Code = bitc::FUNC_CODE_INST_PHI;
2411     // With the newer instruction encoding, forward references could give
2412     // negative valued IDs.  This is most common for PHIs, so we use
2413     // signed VBRs.
2414     SmallVector<uint64_t, 128> Vals64;
2415     Vals64.push_back(getTypeID(PN.getType()));
2416     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
2417       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64);
2418       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
2419     }
2420     // Emit a Vals64 vector and exit.
2421     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
2422     Vals64.clear();
2423     return;
2424   }
2425 
2426   case Instruction::LandingPad: {
2427     const LandingPadInst &LP = cast<LandingPadInst>(I);
2428     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
2429     Vals.push_back(getTypeID(LP.getType()));
2430     Vals.push_back(LP.isCleanup());
2431     Vals.push_back(LP.getNumClauses());
2432     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
2433       if (LP.isCatch(I))
2434         Vals.push_back(LandingPadInst::Catch);
2435       else
2436         Vals.push_back(LandingPadInst::Filter);
2437       pushValueAndType(LP.getClause(I), InstID, Vals);
2438     }
2439     break;
2440   }
2441 
2442   case Instruction::Alloca: {
2443     Code = bitc::FUNC_CODE_INST_ALLOCA;
2444     const AllocaInst &AI = cast<AllocaInst>(I);
2445     Vals.push_back(getTypeID(AI.getAllocatedType()));
2446     Vals.push_back(getTypeID(I.getOperand(0)->getType()));
2447     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
2448     unsigned AlignRecord = Log2_32(AI.getAlign().value()) + 1;
2449     assert(AlignRecord < 1 << 5 && "alignment greater than 1 << 64");
2450     AlignRecord |= AI.isUsedWithInAlloca() << 5;
2451     AlignRecord |= 1 << 6;
2452     Vals.push_back(AlignRecord);
2453     break;
2454   }
2455 
2456   case Instruction::Load:
2457     if (cast<LoadInst>(I).isAtomic()) {
2458       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
2459       pushValueAndType(I.getOperand(0), InstID, Vals);
2460     } else {
2461       Code = bitc::FUNC_CODE_INST_LOAD;
2462       if (!pushValueAndType(I.getOperand(0), InstID, Vals)) // ptr
2463         AbbrevToUse = (unsigned)FUNCTION_INST_LOAD_ABBREV;
2464     }
2465     Vals.push_back(getTypeID(I.getType()));
2466     Vals.push_back(Log2(cast<LoadInst>(I).getAlign()) + 1);
2467     Vals.push_back(cast<LoadInst>(I).isVolatile());
2468     if (cast<LoadInst>(I).isAtomic()) {
2469       Vals.push_back(getEncodedOrdering(cast<LoadInst>(I).getOrdering()));
2470       Vals.push_back(getEncodedSyncScopeID(cast<LoadInst>(I).getSyncScopeID()));
2471     }
2472     break;
2473   case Instruction::Store:
2474     if (cast<StoreInst>(I).isAtomic())
2475       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
2476     else
2477       Code = bitc::FUNC_CODE_INST_STORE;
2478     pushValueAndType(I.getOperand(1), InstID, Vals); // ptrty + ptr
2479     pushValueAndType(I.getOperand(0), InstID, Vals); // valty + val
2480     Vals.push_back(Log2(cast<StoreInst>(I).getAlign()) + 1);
2481     Vals.push_back(cast<StoreInst>(I).isVolatile());
2482     if (cast<StoreInst>(I).isAtomic()) {
2483       Vals.push_back(getEncodedOrdering(cast<StoreInst>(I).getOrdering()));
2484       Vals.push_back(
2485           getEncodedSyncScopeID(cast<StoreInst>(I).getSyncScopeID()));
2486     }
2487     break;
2488   case Instruction::AtomicCmpXchg:
2489     Code = bitc::FUNC_CODE_INST_CMPXCHG;
2490     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
2491     pushValueAndType(I.getOperand(1), InstID, Vals); // cmp.
2492     pushValue(I.getOperand(2), InstID, Vals);        // newval.
2493     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
2494     Vals.push_back(
2495         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
2496     Vals.push_back(
2497         getEncodedSyncScopeID(cast<AtomicCmpXchgInst>(I).getSyncScopeID()));
2498     Vals.push_back(
2499         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
2500     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
2501     break;
2502   case Instruction::AtomicRMW:
2503     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
2504     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
2505     pushValue(I.getOperand(1), InstID, Vals);        // val.
2506     Vals.push_back(
2507         getEncodedRMWOperation(cast<AtomicRMWInst>(I).getOperation()));
2508     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
2509     Vals.push_back(getEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
2510     Vals.push_back(
2511         getEncodedSyncScopeID(cast<AtomicRMWInst>(I).getSyncScopeID()));
2512     break;
2513   case Instruction::Fence:
2514     Code = bitc::FUNC_CODE_INST_FENCE;
2515     Vals.push_back(getEncodedOrdering(cast<FenceInst>(I).getOrdering()));
2516     Vals.push_back(getEncodedSyncScopeID(cast<FenceInst>(I).getSyncScopeID()));
2517     break;
2518   case Instruction::Call: {
2519     const CallInst &CI = cast<CallInst>(I);
2520     FunctionType *FTy = CI.getFunctionType();
2521 
2522     Code = bitc::FUNC_CODE_INST_CALL;
2523 
2524     Vals.push_back(VE.getAttributeListID(CI.getAttributes()));
2525     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()) |
2526                    unsigned(CI.isMustTailCall()) << 14 | 1 << 15);
2527     Vals.push_back(getGlobalObjectValueTypeID(FTy, CI.getCalledFunction()));
2528     pushValueAndType(CI.getCalledOperand(), InstID, Vals); // Callee
2529 
2530     // Emit value #'s for the fixed parameters.
2531     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
2532       // Check for labels (can happen with asm labels).
2533       if (FTy->getParamType(i)->isLabelTy())
2534         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
2535       else
2536         pushValue(CI.getArgOperand(i), InstID, Vals); // fixed param.
2537     }
2538 
2539     // Emit type/value pairs for varargs params.
2540     if (FTy->isVarArg()) {
2541       for (unsigned i = FTy->getNumParams(), e = CI.arg_size(); i != e; ++i)
2542         pushValueAndType(CI.getArgOperand(i), InstID, Vals); // varargs
2543     }
2544     break;
2545   }
2546   case Instruction::VAArg:
2547     Code = bitc::FUNC_CODE_INST_VAARG;
2548     Vals.push_back(getTypeID(I.getOperand(0)->getType())); // valistty
2549     pushValue(I.getOperand(0), InstID, Vals);              // valist.
2550     Vals.push_back(getTypeID(I.getType()));                // restype.
2551     break;
2552   }
2553 
2554   Stream.EmitRecord(Code, Vals, AbbrevToUse);
2555   Vals.clear();
2556 }
2557 
2558 // Emit names for globals/functions etc.
2559 void DXILBitcodeWriter::writeFunctionLevelValueSymbolTable(
2560     const ValueSymbolTable &VST) {
2561   if (VST.empty())
2562     return;
2563   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
2564 
2565   SmallVector<unsigned, 64> NameVals;
2566 
2567   // HLSL Change
2568   // Read the named values from a sorted list instead of the original list
2569   // to ensure the binary is the same no matter what values ever existed.
2570   SmallVector<const ValueName *, 16> SortedTable;
2571 
2572   for (auto &VI : VST) {
2573     SortedTable.push_back(VI.second->getValueName());
2574   }
2575   // The keys are unique, so there shouldn't be stability issues.
2576   llvm::sort(SortedTable, [](const ValueName *A, const ValueName *B) {
2577     return A->first() < B->first();
2578   });
2579 
2580   for (const ValueName *SI : SortedTable) {
2581     auto &Name = *SI;
2582 
2583     // Figure out the encoding to use for the name.
2584     bool is7Bit = true;
2585     bool isChar6 = true;
2586     for (const char *C = Name.getKeyData(), *E = C + Name.getKeyLength();
2587          C != E; ++C) {
2588       if (isChar6)
2589         isChar6 = BitCodeAbbrevOp::isChar6(*C);
2590       if ((unsigned char)*C & 128) {
2591         is7Bit = false;
2592         break; // don't bother scanning the rest.
2593       }
2594     }
2595 
2596     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
2597 
2598     // VST_ENTRY:   [valueid, namechar x N]
2599     // VST_BBENTRY: [bbid, namechar x N]
2600     unsigned Code;
2601     if (isa<BasicBlock>(SI->getValue())) {
2602       Code = bitc::VST_CODE_BBENTRY;
2603       if (isChar6)
2604         AbbrevToUse = VST_BBENTRY_6_ABBREV;
2605     } else {
2606       Code = bitc::VST_CODE_ENTRY;
2607       if (isChar6)
2608         AbbrevToUse = VST_ENTRY_6_ABBREV;
2609       else if (is7Bit)
2610         AbbrevToUse = VST_ENTRY_7_ABBREV;
2611     }
2612 
2613     NameVals.push_back(VE.getValueID(SI->getValue()));
2614     for (const char *P = Name.getKeyData(),
2615                     *E = Name.getKeyData() + Name.getKeyLength();
2616          P != E; ++P)
2617       NameVals.push_back((unsigned char)*P);
2618 
2619     // Emit the finished record.
2620     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
2621     NameVals.clear();
2622   }
2623   Stream.ExitBlock();
2624 }
2625 
2626 /// Emit a function body to the module stream.
2627 void DXILBitcodeWriter::writeFunction(const Function &F) {
2628   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
2629   VE.incorporateFunction(F);
2630 
2631   SmallVector<unsigned, 64> Vals;
2632 
2633   // Emit the number of basic blocks, so the reader can create them ahead of
2634   // time.
2635   Vals.push_back(VE.getBasicBlocks().size());
2636   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
2637   Vals.clear();
2638 
2639   // If there are function-local constants, emit them now.
2640   unsigned CstStart, CstEnd;
2641   VE.getFunctionConstantRange(CstStart, CstEnd);
2642   writeConstants(CstStart, CstEnd, false);
2643 
2644   // If there is function-local metadata, emit it now.
2645   writeFunctionMetadata(F);
2646 
2647   // Keep a running idea of what the instruction ID is.
2648   unsigned InstID = CstEnd;
2649 
2650   bool NeedsMetadataAttachment = F.hasMetadata();
2651 
2652   DILocation *LastDL = nullptr;
2653 
2654   // Finally, emit all the instructions, in order.
2655   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
2656     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E;
2657          ++I) {
2658       writeInstruction(*I, InstID, Vals);
2659 
2660       if (!I->getType()->isVoidTy())
2661         ++InstID;
2662 
2663       // If the instruction has metadata, write a metadata attachment later.
2664       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
2665 
2666       // If the instruction has a debug location, emit it.
2667       DILocation *DL = I->getDebugLoc();
2668       if (!DL)
2669         continue;
2670 
2671       if (DL == LastDL) {
2672         // Just repeat the same debug loc as last time.
2673         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
2674         continue;
2675       }
2676 
2677       Vals.push_back(DL->getLine());
2678       Vals.push_back(DL->getColumn());
2679       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
2680       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
2681       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
2682       Vals.clear();
2683 
2684       LastDL = DL;
2685     }
2686 
2687   // Emit names for all the instructions etc.
2688   if (auto *Symtab = F.getValueSymbolTable())
2689     writeFunctionLevelValueSymbolTable(*Symtab);
2690 
2691   if (NeedsMetadataAttachment)
2692     writeFunctionMetadataAttachment(F);
2693 
2694   VE.purgeFunction();
2695   Stream.ExitBlock();
2696 }
2697 
2698 // Emit blockinfo, which defines the standard abbreviations etc.
2699 void DXILBitcodeWriter::writeBlockInfo() {
2700   // We only want to emit block info records for blocks that have multiple
2701   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
2702   // Other blocks can define their abbrevs inline.
2703   Stream.EnterBlockInfoBlock();
2704 
2705   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
2706     auto Abbv = std::make_shared<BitCodeAbbrev>();
2707     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
2708     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2709     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2710     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2711     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2712                                    std::move(Abbv)) != VST_ENTRY_8_ABBREV)
2713       assert(false && "Unexpected abbrev ordering!");
2714   }
2715 
2716   { // 7-bit fixed width VST_ENTRY strings.
2717     auto Abbv = std::make_shared<BitCodeAbbrev>();
2718     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2719     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2720     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2721     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2722     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2723                                    std::move(Abbv)) != VST_ENTRY_7_ABBREV)
2724       assert(false && "Unexpected abbrev ordering!");
2725   }
2726   { // 6-bit char6 VST_ENTRY strings.
2727     auto Abbv = std::make_shared<BitCodeAbbrev>();
2728     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2729     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2730     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2731     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2732     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2733                                    std::move(Abbv)) != VST_ENTRY_6_ABBREV)
2734       assert(false && "Unexpected abbrev ordering!");
2735   }
2736   { // 6-bit char6 VST_BBENTRY strings.
2737     auto Abbv = std::make_shared<BitCodeAbbrev>();
2738     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
2739     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2740     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2741     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2742     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2743                                    std::move(Abbv)) != VST_BBENTRY_6_ABBREV)
2744       assert(false && "Unexpected abbrev ordering!");
2745   }
2746 
2747   { // SETTYPE abbrev for CONSTANTS_BLOCK.
2748     auto Abbv = std::make_shared<BitCodeAbbrev>();
2749     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
2750     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2751                               VE.computeBitsRequiredForTypeIndicies()));
2752     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2753         CONSTANTS_SETTYPE_ABBREV)
2754       assert(false && "Unexpected abbrev ordering!");
2755   }
2756 
2757   { // INTEGER abbrev for CONSTANTS_BLOCK.
2758     auto Abbv = std::make_shared<BitCodeAbbrev>();
2759     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
2760     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2761     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2762         CONSTANTS_INTEGER_ABBREV)
2763       assert(false && "Unexpected abbrev ordering!");
2764   }
2765 
2766   { // CE_CAST abbrev for CONSTANTS_BLOCK.
2767     auto Abbv = std::make_shared<BitCodeAbbrev>();
2768     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
2769     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // cast opc
2770     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,      // typeid
2771                               VE.computeBitsRequiredForTypeIndicies()));
2772     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
2773 
2774     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2775         CONSTANTS_CE_CAST_Abbrev)
2776       assert(false && "Unexpected abbrev ordering!");
2777   }
2778   { // NULL abbrev for CONSTANTS_BLOCK.
2779     auto Abbv = std::make_shared<BitCodeAbbrev>();
2780     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
2781     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2782         CONSTANTS_NULL_Abbrev)
2783       assert(false && "Unexpected abbrev ordering!");
2784   }
2785 
2786   // FIXME: This should only use space for first class types!
2787 
2788   { // INST_LOAD abbrev for FUNCTION_BLOCK.
2789     auto Abbv = std::make_shared<BitCodeAbbrev>();
2790     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
2791     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
2792     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2793                               VE.computeBitsRequiredForTypeIndicies()));
2794     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // Align
2795     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
2796     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2797         (unsigned)FUNCTION_INST_LOAD_ABBREV)
2798       assert(false && "Unexpected abbrev ordering!");
2799   }
2800   { // INST_BINOP abbrev for FUNCTION_BLOCK.
2801     auto Abbv = std::make_shared<BitCodeAbbrev>();
2802     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2803     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LHS
2804     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // RHS
2805     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2806     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2807         (unsigned)FUNCTION_INST_BINOP_ABBREV)
2808       assert(false && "Unexpected abbrev ordering!");
2809   }
2810   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
2811     auto Abbv = std::make_shared<BitCodeAbbrev>();
2812     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2813     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LHS
2814     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // RHS
2815     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2816     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
2817     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2818         (unsigned)FUNCTION_INST_BINOP_FLAGS_ABBREV)
2819       assert(false && "Unexpected abbrev ordering!");
2820   }
2821   { // INST_CAST abbrev for FUNCTION_BLOCK.
2822     auto Abbv = std::make_shared<BitCodeAbbrev>();
2823     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
2824     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // OpVal
2825     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2826                               VE.computeBitsRequiredForTypeIndicies()));
2827     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2828     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2829         (unsigned)FUNCTION_INST_CAST_ABBREV)
2830       assert(false && "Unexpected abbrev ordering!");
2831   }
2832 
2833   { // INST_RET abbrev for FUNCTION_BLOCK.
2834     auto Abbv = std::make_shared<BitCodeAbbrev>();
2835     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2836     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2837         (unsigned)FUNCTION_INST_RET_VOID_ABBREV)
2838       assert(false && "Unexpected abbrev ordering!");
2839   }
2840   { // INST_RET abbrev for FUNCTION_BLOCK.
2841     auto Abbv = std::make_shared<BitCodeAbbrev>();
2842     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2843     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
2844     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2845         (unsigned)FUNCTION_INST_RET_VAL_ABBREV)
2846       assert(false && "Unexpected abbrev ordering!");
2847   }
2848   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
2849     auto Abbv = std::make_shared<BitCodeAbbrev>();
2850     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
2851     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2852         (unsigned)FUNCTION_INST_UNREACHABLE_ABBREV)
2853       assert(false && "Unexpected abbrev ordering!");
2854   }
2855   {
2856     auto Abbv = std::make_shared<BitCodeAbbrev>();
2857     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
2858     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2859     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
2860                               Log2_32_Ceil(VE.getTypes().size() + 1)));
2861     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2862     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2863     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2864         (unsigned)FUNCTION_INST_GEP_ABBREV)
2865       assert(false && "Unexpected abbrev ordering!");
2866   }
2867 
2868   Stream.ExitBlock();
2869 }
2870 
2871 void DXILBitcodeWriter::writeModuleVersion() {
2872   // VERSION: [version#]
2873   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, ArrayRef<unsigned>{1});
2874 }
2875 
2876 /// WriteModule - Emit the specified module to the bitstream.
2877 void DXILBitcodeWriter::write() {
2878   // The identification block is new since llvm-3.7, but the old bitcode reader
2879   // will skip it.
2880   // writeIdentificationBlock(Stream);
2881 
2882   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
2883 
2884   // It is redundant to fully-specify this here, but nice to make it explicit
2885   // so that it is clear the DXIL module version is different.
2886   DXILBitcodeWriter::writeModuleVersion();
2887 
2888   // Emit blockinfo, which defines the standard abbreviations etc.
2889   writeBlockInfo();
2890 
2891   // Emit information about attribute groups.
2892   writeAttributeGroupTable();
2893 
2894   // Emit information about parameter attributes.
2895   writeAttributeTable();
2896 
2897   // Emit information describing all of the types in the module.
2898   writeTypeTable();
2899 
2900   writeComdats();
2901 
2902   // Emit top-level description of module, including target triple, inline asm,
2903   // descriptors for global variables, and function prototype info.
2904   writeModuleInfo();
2905 
2906   // Emit constants.
2907   writeModuleConstants();
2908 
2909   // Emit metadata.
2910   writeModuleMetadataKinds();
2911 
2912   // Emit metadata.
2913   writeModuleMetadata();
2914 
2915   // Emit names for globals/functions etc.
2916   // DXIL uses the same format for module-level value symbol table as for the
2917   // function level table.
2918   writeFunctionLevelValueSymbolTable(M.getValueSymbolTable());
2919 
2920   // Emit function bodies.
2921   for (const Function &F : M)
2922     if (!F.isDeclaration())
2923       writeFunction(F);
2924 
2925   Stream.ExitBlock();
2926 }
2927