xref: /llvm-project/llvm/lib/Target/DirectX/DXILWriter/DXILBitcodeWriter.cpp (revision 49b57df16144450331b4f90332d6918168b2a306)
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/Bitcode/BitcodeCommon.h"
18 #include "llvm/Bitcode/BitcodeReader.h"
19 #include "llvm/Bitcode/LLVMBitCodes.h"
20 #include "llvm/Bitstream/BitCodes.h"
21 #include "llvm/Bitstream/BitstreamWriter.h"
22 #include "llvm/IR/Attributes.h"
23 #include "llvm/IR/BasicBlock.h"
24 #include "llvm/IR/Comdat.h"
25 #include "llvm/IR/Constant.h"
26 #include "llvm/IR/Constants.h"
27 #include "llvm/IR/DebugInfoMetadata.h"
28 #include "llvm/IR/DebugLoc.h"
29 #include "llvm/IR/DerivedTypes.h"
30 #include "llvm/IR/Function.h"
31 #include "llvm/IR/GlobalAlias.h"
32 #include "llvm/IR/GlobalIFunc.h"
33 #include "llvm/IR/GlobalObject.h"
34 #include "llvm/IR/GlobalValue.h"
35 #include "llvm/IR/GlobalVariable.h"
36 #include "llvm/IR/InlineAsm.h"
37 #include "llvm/IR/InstrTypes.h"
38 #include "llvm/IR/Instruction.h"
39 #include "llvm/IR/Instructions.h"
40 #include "llvm/IR/LLVMContext.h"
41 #include "llvm/IR/Metadata.h"
42 #include "llvm/IR/Module.h"
43 #include "llvm/IR/ModuleSummaryIndex.h"
44 #include "llvm/IR/Operator.h"
45 #include "llvm/IR/Type.h"
46 #include "llvm/IR/UseListOrder.h"
47 #include "llvm/IR/Value.h"
48 #include "llvm/IR/ValueSymbolTable.h"
49 #include "llvm/Object/IRSymtab.h"
50 #include "llvm/Support/ErrorHandling.h"
51 #include "llvm/Support/ModRef.h"
52 #include "llvm/Support/SHA1.h"
53 #include "llvm/TargetParser/Triple.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     : Buffer(Buffer), Stream(new BitstreamWriter(Buffer)) {
374   // Emit the file header.
375   Stream->Emit((unsigned)'B', 8);
376   Stream->Emit((unsigned)'C', 8);
377   Stream->Emit(0x0, 4);
378   Stream->Emit(0xC, 4);
379   Stream->Emit(0xE, 4);
380   Stream->Emit(0xD, 4);
381 }
382 
383 dxil::BitcodeWriter::~BitcodeWriter() { }
384 
385 /// Write the specified module to the specified output stream.
386 void dxil::WriteDXILToFile(const Module &M, raw_ostream &Out) {
387   SmallVector<char, 0> Buffer;
388   Buffer.reserve(256 * 1024);
389 
390   // If this is darwin or another generic macho target, reserve space for the
391   // header.
392   Triple TT(M.getTargetTriple());
393   if (TT.isOSDarwin() || TT.isOSBinFormatMachO())
394     Buffer.insert(Buffer.begin(), BWH_HeaderSize, 0);
395 
396   BitcodeWriter Writer(Buffer);
397   Writer.writeModule(M);
398 
399   // Write the generated bitstream to "Out".
400   if (!Buffer.empty())
401     Out.write((char *)&Buffer.front(), Buffer.size());
402 }
403 
404 void BitcodeWriter::writeBlob(unsigned Block, unsigned Record, StringRef Blob) {
405   Stream->EnterSubblock(Block, 3);
406 
407   auto Abbv = std::make_shared<BitCodeAbbrev>();
408   Abbv->Add(BitCodeAbbrevOp(Record));
409   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
410   auto AbbrevNo = Stream->EmitAbbrev(std::move(Abbv));
411 
412   Stream->EmitRecordWithBlob(AbbrevNo, ArrayRef<uint64_t>{Record}, Blob);
413 
414   Stream->ExitBlock();
415 }
416 
417 void BitcodeWriter::writeModule(const Module &M) {
418 
419   // The Mods vector is used by irsymtab::build, which requires non-const
420   // Modules in case it needs to materialize metadata. But the bitcode writer
421   // requires that the module is materialized, so we can cast to non-const here,
422   // after checking that it is in fact materialized.
423   assert(M.isMaterialized());
424   Mods.push_back(const_cast<Module *>(&M));
425 
426   DXILBitcodeWriter ModuleWriter(M, Buffer, StrtabBuilder, *Stream);
427   ModuleWriter.write();
428 }
429 
430 ////////////////////////////////////////////////////////////////////////////////
431 /// Begin dxil::BitcodeWriterBase Implementation
432 ////////////////////////////////////////////////////////////////////////////////
433 
434 unsigned DXILBitcodeWriter::getEncodedCastOpcode(unsigned Opcode) {
435   switch (Opcode) {
436   default:
437     llvm_unreachable("Unknown cast instruction!");
438   case Instruction::Trunc:
439     return bitc::CAST_TRUNC;
440   case Instruction::ZExt:
441     return bitc::CAST_ZEXT;
442   case Instruction::SExt:
443     return bitc::CAST_SEXT;
444   case Instruction::FPToUI:
445     return bitc::CAST_FPTOUI;
446   case Instruction::FPToSI:
447     return bitc::CAST_FPTOSI;
448   case Instruction::UIToFP:
449     return bitc::CAST_UITOFP;
450   case Instruction::SIToFP:
451     return bitc::CAST_SITOFP;
452   case Instruction::FPTrunc:
453     return bitc::CAST_FPTRUNC;
454   case Instruction::FPExt:
455     return bitc::CAST_FPEXT;
456   case Instruction::PtrToInt:
457     return bitc::CAST_PTRTOINT;
458   case Instruction::IntToPtr:
459     return bitc::CAST_INTTOPTR;
460   case Instruction::BitCast:
461     return bitc::CAST_BITCAST;
462   case Instruction::AddrSpaceCast:
463     return bitc::CAST_ADDRSPACECAST;
464   }
465 }
466 
467 unsigned DXILBitcodeWriter::getEncodedUnaryOpcode(unsigned Opcode) {
468   switch (Opcode) {
469   default:
470     llvm_unreachable("Unknown binary instruction!");
471   case Instruction::FNeg:
472     return bitc::UNOP_FNEG;
473   }
474 }
475 
476 unsigned DXILBitcodeWriter::getEncodedBinaryOpcode(unsigned Opcode) {
477   switch (Opcode) {
478   default:
479     llvm_unreachable("Unknown binary instruction!");
480   case Instruction::Add:
481   case Instruction::FAdd:
482     return bitc::BINOP_ADD;
483   case Instruction::Sub:
484   case Instruction::FSub:
485     return bitc::BINOP_SUB;
486   case Instruction::Mul:
487   case Instruction::FMul:
488     return bitc::BINOP_MUL;
489   case Instruction::UDiv:
490     return bitc::BINOP_UDIV;
491   case Instruction::FDiv:
492   case Instruction::SDiv:
493     return bitc::BINOP_SDIV;
494   case Instruction::URem:
495     return bitc::BINOP_UREM;
496   case Instruction::FRem:
497   case Instruction::SRem:
498     return bitc::BINOP_SREM;
499   case Instruction::Shl:
500     return bitc::BINOP_SHL;
501   case Instruction::LShr:
502     return bitc::BINOP_LSHR;
503   case Instruction::AShr:
504     return bitc::BINOP_ASHR;
505   case Instruction::And:
506     return bitc::BINOP_AND;
507   case Instruction::Or:
508     return bitc::BINOP_OR;
509   case Instruction::Xor:
510     return bitc::BINOP_XOR;
511   }
512 }
513 
514 unsigned DXILBitcodeWriter::getTypeID(Type *T, const Value *V) {
515   if (!T->isPointerTy() &&
516       // For Constant, always check PointerMap to make sure OpaquePointer in
517       // things like constant struct/array works.
518       (!V || !isa<Constant>(V)))
519     return VE.getTypeID(T);
520   auto It = PointerMap.find(V);
521   if (It != PointerMap.end())
522     return VE.getTypeID(It->second);
523   // For Constant, return T when cannot find in PointerMap.
524   // FIXME: support ConstantPointerNull which could map to more than one
525   // TypedPointerType.
526   // See https://github.com/llvm/llvm-project/issues/57942.
527   if (V && isa<Constant>(V) && !isa<ConstantPointerNull>(V))
528     return VE.getTypeID(T);
529   return VE.getTypeID(I8PtrTy);
530 }
531 
532 unsigned DXILBitcodeWriter::getGlobalObjectValueTypeID(Type *T,
533                                                        const GlobalObject *G) {
534   auto It = PointerMap.find(G);
535   if (It != PointerMap.end()) {
536     TypedPointerType *PtrTy = cast<TypedPointerType>(It->second);
537     return VE.getTypeID(PtrTy->getElementType());
538   }
539   return VE.getTypeID(T);
540 }
541 
542 unsigned DXILBitcodeWriter::getEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
543   switch (Op) {
544   default:
545     llvm_unreachable("Unknown RMW operation!");
546   case AtomicRMWInst::Xchg:
547     return bitc::RMW_XCHG;
548   case AtomicRMWInst::Add:
549     return bitc::RMW_ADD;
550   case AtomicRMWInst::Sub:
551     return bitc::RMW_SUB;
552   case AtomicRMWInst::And:
553     return bitc::RMW_AND;
554   case AtomicRMWInst::Nand:
555     return bitc::RMW_NAND;
556   case AtomicRMWInst::Or:
557     return bitc::RMW_OR;
558   case AtomicRMWInst::Xor:
559     return bitc::RMW_XOR;
560   case AtomicRMWInst::Max:
561     return bitc::RMW_MAX;
562   case AtomicRMWInst::Min:
563     return bitc::RMW_MIN;
564   case AtomicRMWInst::UMax:
565     return bitc::RMW_UMAX;
566   case AtomicRMWInst::UMin:
567     return bitc::RMW_UMIN;
568   case AtomicRMWInst::FAdd:
569     return bitc::RMW_FADD;
570   case AtomicRMWInst::FSub:
571     return bitc::RMW_FSUB;
572   case AtomicRMWInst::FMax:
573     return bitc::RMW_FMAX;
574   case AtomicRMWInst::FMin:
575     return bitc::RMW_FMIN;
576   }
577 }
578 
579 unsigned DXILBitcodeWriter::getEncodedOrdering(AtomicOrdering Ordering) {
580   switch (Ordering) {
581   case AtomicOrdering::NotAtomic:
582     return bitc::ORDERING_NOTATOMIC;
583   case AtomicOrdering::Unordered:
584     return bitc::ORDERING_UNORDERED;
585   case AtomicOrdering::Monotonic:
586     return bitc::ORDERING_MONOTONIC;
587   case AtomicOrdering::Acquire:
588     return bitc::ORDERING_ACQUIRE;
589   case AtomicOrdering::Release:
590     return bitc::ORDERING_RELEASE;
591   case AtomicOrdering::AcquireRelease:
592     return bitc::ORDERING_ACQREL;
593   case AtomicOrdering::SequentiallyConsistent:
594     return bitc::ORDERING_SEQCST;
595   }
596   llvm_unreachable("Invalid ordering");
597 }
598 
599 void DXILBitcodeWriter::writeStringRecord(BitstreamWriter &Stream,
600                                           unsigned Code, StringRef Str,
601                                           unsigned AbbrevToUse) {
602   SmallVector<unsigned, 64> Vals;
603 
604   // Code: [strchar x N]
605   for (char C : Str) {
606     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(C))
607       AbbrevToUse = 0;
608     Vals.push_back(C);
609   }
610 
611   // Emit the finished record.
612   Stream.EmitRecord(Code, Vals, AbbrevToUse);
613 }
614 
615 uint64_t DXILBitcodeWriter::getAttrKindEncoding(Attribute::AttrKind Kind) {
616   switch (Kind) {
617   case Attribute::Alignment:
618     return bitc::ATTR_KIND_ALIGNMENT;
619   case Attribute::AlwaysInline:
620     return bitc::ATTR_KIND_ALWAYS_INLINE;
621   case Attribute::Builtin:
622     return bitc::ATTR_KIND_BUILTIN;
623   case Attribute::ByVal:
624     return bitc::ATTR_KIND_BY_VAL;
625   case Attribute::Convergent:
626     return bitc::ATTR_KIND_CONVERGENT;
627   case Attribute::InAlloca:
628     return bitc::ATTR_KIND_IN_ALLOCA;
629   case Attribute::Cold:
630     return bitc::ATTR_KIND_COLD;
631   case Attribute::InlineHint:
632     return bitc::ATTR_KIND_INLINE_HINT;
633   case Attribute::InReg:
634     return bitc::ATTR_KIND_IN_REG;
635   case Attribute::JumpTable:
636     return bitc::ATTR_KIND_JUMP_TABLE;
637   case Attribute::MinSize:
638     return bitc::ATTR_KIND_MIN_SIZE;
639   case Attribute::Naked:
640     return bitc::ATTR_KIND_NAKED;
641   case Attribute::Nest:
642     return bitc::ATTR_KIND_NEST;
643   case Attribute::NoAlias:
644     return bitc::ATTR_KIND_NO_ALIAS;
645   case Attribute::NoBuiltin:
646     return bitc::ATTR_KIND_NO_BUILTIN;
647   case Attribute::NoCapture:
648     return bitc::ATTR_KIND_NO_CAPTURE;
649   case Attribute::NoDuplicate:
650     return bitc::ATTR_KIND_NO_DUPLICATE;
651   case Attribute::NoImplicitFloat:
652     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
653   case Attribute::NoInline:
654     return bitc::ATTR_KIND_NO_INLINE;
655   case Attribute::NonLazyBind:
656     return bitc::ATTR_KIND_NON_LAZY_BIND;
657   case Attribute::NonNull:
658     return bitc::ATTR_KIND_NON_NULL;
659   case Attribute::Dereferenceable:
660     return bitc::ATTR_KIND_DEREFERENCEABLE;
661   case Attribute::DereferenceableOrNull:
662     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
663   case Attribute::NoRedZone:
664     return bitc::ATTR_KIND_NO_RED_ZONE;
665   case Attribute::NoReturn:
666     return bitc::ATTR_KIND_NO_RETURN;
667   case Attribute::NoUnwind:
668     return bitc::ATTR_KIND_NO_UNWIND;
669   case Attribute::OptimizeForSize:
670     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
671   case Attribute::OptimizeNone:
672     return bitc::ATTR_KIND_OPTIMIZE_NONE;
673   case Attribute::ReadNone:
674     return bitc::ATTR_KIND_READ_NONE;
675   case Attribute::ReadOnly:
676     return bitc::ATTR_KIND_READ_ONLY;
677   case Attribute::Returned:
678     return bitc::ATTR_KIND_RETURNED;
679   case Attribute::ReturnsTwice:
680     return bitc::ATTR_KIND_RETURNS_TWICE;
681   case Attribute::SExt:
682     return bitc::ATTR_KIND_S_EXT;
683   case Attribute::StackAlignment:
684     return bitc::ATTR_KIND_STACK_ALIGNMENT;
685   case Attribute::StackProtect:
686     return bitc::ATTR_KIND_STACK_PROTECT;
687   case Attribute::StackProtectReq:
688     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
689   case Attribute::StackProtectStrong:
690     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
691   case Attribute::SafeStack:
692     return bitc::ATTR_KIND_SAFESTACK;
693   case Attribute::StructRet:
694     return bitc::ATTR_KIND_STRUCT_RET;
695   case Attribute::SanitizeAddress:
696     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
697   case Attribute::SanitizeThread:
698     return bitc::ATTR_KIND_SANITIZE_THREAD;
699   case Attribute::SanitizeMemory:
700     return bitc::ATTR_KIND_SANITIZE_MEMORY;
701   case Attribute::UWTable:
702     return bitc::ATTR_KIND_UW_TABLE;
703   case Attribute::ZExt:
704     return bitc::ATTR_KIND_Z_EXT;
705   case Attribute::EndAttrKinds:
706     llvm_unreachable("Can not encode end-attribute kinds marker.");
707   case Attribute::None:
708     llvm_unreachable("Can not encode none-attribute.");
709   case Attribute::EmptyKey:
710   case Attribute::TombstoneKey:
711     llvm_unreachable("Trying to encode EmptyKey/TombstoneKey");
712   default:
713     llvm_unreachable("Trying to encode attribute not supported by DXIL. These "
714                      "should be stripped in DXILPrepare");
715   }
716 
717   llvm_unreachable("Trying to encode unknown attribute");
718 }
719 
720 void DXILBitcodeWriter::emitSignedInt64(SmallVectorImpl<uint64_t> &Vals,
721                                         uint64_t V) {
722   if ((int64_t)V >= 0)
723     Vals.push_back(V << 1);
724   else
725     Vals.push_back((-V << 1) | 1);
726 }
727 
728 void DXILBitcodeWriter::emitWideAPInt(SmallVectorImpl<uint64_t> &Vals,
729                                       const APInt &A) {
730   // We have an arbitrary precision integer value to write whose
731   // bit width is > 64. However, in canonical unsigned integer
732   // format it is likely that the high bits are going to be zero.
733   // So, we only write the number of active words.
734   unsigned NumWords = A.getActiveWords();
735   const uint64_t *RawData = A.getRawData();
736   for (unsigned i = 0; i < NumWords; i++)
737     emitSignedInt64(Vals, RawData[i]);
738 }
739 
740 uint64_t DXILBitcodeWriter::getOptimizationFlags(const Value *V) {
741   uint64_t Flags = 0;
742 
743   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
744     if (OBO->hasNoSignedWrap())
745       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
746     if (OBO->hasNoUnsignedWrap())
747       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
748   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
749     if (PEO->isExact())
750       Flags |= 1 << bitc::PEO_EXACT;
751   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
752     if (FPMO->hasAllowReassoc())
753       Flags |= bitc::AllowReassoc;
754     if (FPMO->hasNoNaNs())
755       Flags |= bitc::NoNaNs;
756     if (FPMO->hasNoInfs())
757       Flags |= bitc::NoInfs;
758     if (FPMO->hasNoSignedZeros())
759       Flags |= bitc::NoSignedZeros;
760     if (FPMO->hasAllowReciprocal())
761       Flags |= bitc::AllowReciprocal;
762     if (FPMO->hasAllowContract())
763       Flags |= bitc::AllowContract;
764     if (FPMO->hasApproxFunc())
765       Flags |= bitc::ApproxFunc;
766   }
767 
768   return Flags;
769 }
770 
771 unsigned
772 DXILBitcodeWriter::getEncodedLinkage(const GlobalValue::LinkageTypes Linkage) {
773   switch (Linkage) {
774   case GlobalValue::ExternalLinkage:
775     return 0;
776   case GlobalValue::WeakAnyLinkage:
777     return 16;
778   case GlobalValue::AppendingLinkage:
779     return 2;
780   case GlobalValue::InternalLinkage:
781     return 3;
782   case GlobalValue::LinkOnceAnyLinkage:
783     return 18;
784   case GlobalValue::ExternalWeakLinkage:
785     return 7;
786   case GlobalValue::CommonLinkage:
787     return 8;
788   case GlobalValue::PrivateLinkage:
789     return 9;
790   case GlobalValue::WeakODRLinkage:
791     return 17;
792   case GlobalValue::LinkOnceODRLinkage:
793     return 19;
794   case GlobalValue::AvailableExternallyLinkage:
795     return 12;
796   }
797   llvm_unreachable("Invalid linkage");
798 }
799 
800 unsigned DXILBitcodeWriter::getEncodedLinkage(const GlobalValue &GV) {
801   return getEncodedLinkage(GV.getLinkage());
802 }
803 
804 unsigned DXILBitcodeWriter::getEncodedVisibility(const GlobalValue &GV) {
805   switch (GV.getVisibility()) {
806   case GlobalValue::DefaultVisibility:
807     return 0;
808   case GlobalValue::HiddenVisibility:
809     return 1;
810   case GlobalValue::ProtectedVisibility:
811     return 2;
812   }
813   llvm_unreachable("Invalid visibility");
814 }
815 
816 unsigned DXILBitcodeWriter::getEncodedDLLStorageClass(const GlobalValue &GV) {
817   switch (GV.getDLLStorageClass()) {
818   case GlobalValue::DefaultStorageClass:
819     return 0;
820   case GlobalValue::DLLImportStorageClass:
821     return 1;
822   case GlobalValue::DLLExportStorageClass:
823     return 2;
824   }
825   llvm_unreachable("Invalid DLL storage class");
826 }
827 
828 unsigned DXILBitcodeWriter::getEncodedThreadLocalMode(const GlobalValue &GV) {
829   switch (GV.getThreadLocalMode()) {
830   case GlobalVariable::NotThreadLocal:
831     return 0;
832   case GlobalVariable::GeneralDynamicTLSModel:
833     return 1;
834   case GlobalVariable::LocalDynamicTLSModel:
835     return 2;
836   case GlobalVariable::InitialExecTLSModel:
837     return 3;
838   case GlobalVariable::LocalExecTLSModel:
839     return 4;
840   }
841   llvm_unreachable("Invalid TLS model");
842 }
843 
844 unsigned DXILBitcodeWriter::getEncodedComdatSelectionKind(const Comdat &C) {
845   switch (C.getSelectionKind()) {
846   case Comdat::Any:
847     return bitc::COMDAT_SELECTION_KIND_ANY;
848   case Comdat::ExactMatch:
849     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
850   case Comdat::Largest:
851     return bitc::COMDAT_SELECTION_KIND_LARGEST;
852   case Comdat::NoDeduplicate:
853     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
854   case Comdat::SameSize:
855     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
856   }
857   llvm_unreachable("Invalid selection kind");
858 }
859 
860 ////////////////////////////////////////////////////////////////////////////////
861 /// Begin DXILBitcodeWriter Implementation
862 ////////////////////////////////////////////////////////////////////////////////
863 
864 void DXILBitcodeWriter::writeAttributeGroupTable() {
865   const std::vector<ValueEnumerator::IndexAndAttrSet> &AttrGrps =
866       VE.getAttributeGroups();
867   if (AttrGrps.empty())
868     return;
869 
870   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
871 
872   SmallVector<uint64_t, 64> Record;
873   for (ValueEnumerator::IndexAndAttrSet Pair : AttrGrps) {
874     unsigned AttrListIndex = Pair.first;
875     AttributeSet AS = Pair.second;
876     Record.push_back(VE.getAttributeGroupID(Pair));
877     Record.push_back(AttrListIndex);
878 
879     for (Attribute Attr : AS) {
880       if (Attr.isEnumAttribute()) {
881         uint64_t Val = getAttrKindEncoding(Attr.getKindAsEnum());
882         assert(Val <= bitc::ATTR_KIND_ARGMEMONLY &&
883                "DXIL does not support attributes above ATTR_KIND_ARGMEMONLY");
884         Record.push_back(0);
885         Record.push_back(Val);
886       } else if (Attr.isIntAttribute()) {
887         if (Attr.getKindAsEnum() == Attribute::AttrKind::Memory) {
888           MemoryEffects ME = Attr.getMemoryEffects();
889           if (ME.doesNotAccessMemory()) {
890             Record.push_back(0);
891             Record.push_back(bitc::ATTR_KIND_READ_NONE);
892           } else {
893             if (ME.onlyReadsMemory()) {
894               Record.push_back(0);
895               Record.push_back(bitc::ATTR_KIND_READ_ONLY);
896             }
897             if (ME.onlyAccessesArgPointees()) {
898               Record.push_back(0);
899               Record.push_back(bitc::ATTR_KIND_ARGMEMONLY);
900             }
901           }
902         } else {
903           uint64_t Val = getAttrKindEncoding(Attr.getKindAsEnum());
904           assert(Val <= bitc::ATTR_KIND_ARGMEMONLY &&
905                  "DXIL does not support attributes above ATTR_KIND_ARGMEMONLY");
906           Record.push_back(1);
907           Record.push_back(Val);
908           Record.push_back(Attr.getValueAsInt());
909         }
910       } else {
911         StringRef Kind = Attr.getKindAsString();
912         StringRef Val = Attr.getValueAsString();
913 
914         Record.push_back(Val.empty() ? 3 : 4);
915         Record.append(Kind.begin(), Kind.end());
916         Record.push_back(0);
917         if (!Val.empty()) {
918           Record.append(Val.begin(), Val.end());
919           Record.push_back(0);
920         }
921       }
922     }
923 
924     Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
925     Record.clear();
926   }
927 
928   Stream.ExitBlock();
929 }
930 
931 void DXILBitcodeWriter::writeAttributeTable() {
932   const std::vector<AttributeList> &Attrs = VE.getAttributeLists();
933   if (Attrs.empty())
934     return;
935 
936   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
937 
938   SmallVector<uint64_t, 64> Record;
939   for (AttributeList AL : Attrs) {
940     for (unsigned i : AL.indexes()) {
941       AttributeSet AS = AL.getAttributes(i);
942       if (AS.hasAttributes())
943         Record.push_back(VE.getAttributeGroupID({i, AS}));
944     }
945 
946     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
947     Record.clear();
948   }
949 
950   Stream.ExitBlock();
951 }
952 
953 /// WriteTypeTable - Write out the type table for a module.
954 void DXILBitcodeWriter::writeTypeTable() {
955   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
956 
957   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
958   SmallVector<uint64_t, 64> TypeVals;
959 
960   uint64_t NumBits = VE.computeBitsRequiredForTypeIndices();
961 
962   // Abbrev for TYPE_CODE_POINTER.
963   auto Abbv = std::make_shared<BitCodeAbbrev>();
964   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
965   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
966   Abbv->Add(BitCodeAbbrevOp(0)); // Addrspace = 0
967   unsigned PtrAbbrev = Stream.EmitAbbrev(std::move(Abbv));
968 
969   // Abbrev for TYPE_CODE_FUNCTION.
970   Abbv = std::make_shared<BitCodeAbbrev>();
971   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
972   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isvararg
973   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
974   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
975   unsigned FunctionAbbrev = Stream.EmitAbbrev(std::move(Abbv));
976 
977   // Abbrev for TYPE_CODE_STRUCT_ANON.
978   Abbv = std::make_shared<BitCodeAbbrev>();
979   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
980   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ispacked
981   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
982   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
983   unsigned StructAnonAbbrev = Stream.EmitAbbrev(std::move(Abbv));
984 
985   // Abbrev for TYPE_CODE_STRUCT_NAME.
986   Abbv = std::make_shared<BitCodeAbbrev>();
987   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
988   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
989   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
990   unsigned StructNameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
991 
992   // Abbrev for TYPE_CODE_STRUCT_NAMED.
993   Abbv = std::make_shared<BitCodeAbbrev>();
994   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
995   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ispacked
996   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
997   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
998   unsigned StructNamedAbbrev = Stream.EmitAbbrev(std::move(Abbv));
999 
1000   // Abbrev for TYPE_CODE_ARRAY.
1001   Abbv = std::make_shared<BitCodeAbbrev>();
1002   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
1003   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // size
1004   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1005   unsigned ArrayAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1006 
1007   // Emit an entry count so the reader can reserve space.
1008   TypeVals.push_back(TypeList.size());
1009   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
1010   TypeVals.clear();
1011 
1012   // Loop over all of the types, emitting each in turn.
1013   for (Type *T : TypeList) {
1014     int AbbrevToUse = 0;
1015     unsigned Code = 0;
1016 
1017     switch (T->getTypeID()) {
1018     case Type::BFloatTyID:
1019     case Type::X86_AMXTyID:
1020     case Type::TokenTyID:
1021     case Type::TargetExtTyID:
1022       llvm_unreachable("These should never be used!!!");
1023       break;
1024     case Type::VoidTyID:
1025       Code = bitc::TYPE_CODE_VOID;
1026       break;
1027     case Type::HalfTyID:
1028       Code = bitc::TYPE_CODE_HALF;
1029       break;
1030     case Type::FloatTyID:
1031       Code = bitc::TYPE_CODE_FLOAT;
1032       break;
1033     case Type::DoubleTyID:
1034       Code = bitc::TYPE_CODE_DOUBLE;
1035       break;
1036     case Type::X86_FP80TyID:
1037       Code = bitc::TYPE_CODE_X86_FP80;
1038       break;
1039     case Type::FP128TyID:
1040       Code = bitc::TYPE_CODE_FP128;
1041       break;
1042     case Type::PPC_FP128TyID:
1043       Code = bitc::TYPE_CODE_PPC_FP128;
1044       break;
1045     case Type::LabelTyID:
1046       Code = bitc::TYPE_CODE_LABEL;
1047       break;
1048     case Type::MetadataTyID:
1049       Code = bitc::TYPE_CODE_METADATA;
1050       break;
1051     case Type::IntegerTyID:
1052       // INTEGER: [width]
1053       Code = bitc::TYPE_CODE_INTEGER;
1054       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
1055       break;
1056     case Type::TypedPointerTyID: {
1057       TypedPointerType *PTy = cast<TypedPointerType>(T);
1058       // POINTER: [pointee type, address space]
1059       Code = bitc::TYPE_CODE_POINTER;
1060       TypeVals.push_back(getTypeID(PTy->getElementType()));
1061       unsigned AddressSpace = PTy->getAddressSpace();
1062       TypeVals.push_back(AddressSpace);
1063       if (AddressSpace == 0)
1064         AbbrevToUse = PtrAbbrev;
1065       break;
1066     }
1067     case Type::PointerTyID: {
1068       // POINTER: [pointee type, address space]
1069       // Emitting an empty struct type for the pointer's type allows this to be
1070       // order-independent. Non-struct types must be emitted in bitcode before
1071       // they can be referenced.
1072       TypeVals.push_back(false);
1073       Code = bitc::TYPE_CODE_OPAQUE;
1074       writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME,
1075                         "dxilOpaquePtrReservedName", StructNameAbbrev);
1076       break;
1077     }
1078     case Type::FunctionTyID: {
1079       FunctionType *FT = cast<FunctionType>(T);
1080       // FUNCTION: [isvararg, retty, paramty x N]
1081       Code = bitc::TYPE_CODE_FUNCTION;
1082       TypeVals.push_back(FT->isVarArg());
1083       TypeVals.push_back(getTypeID(FT->getReturnType()));
1084       for (Type *PTy : FT->params())
1085         TypeVals.push_back(getTypeID(PTy));
1086       AbbrevToUse = FunctionAbbrev;
1087       break;
1088     }
1089     case Type::StructTyID: {
1090       StructType *ST = cast<StructType>(T);
1091       // STRUCT: [ispacked, eltty x N]
1092       TypeVals.push_back(ST->isPacked());
1093       // Output all of the element types.
1094       for (Type *ElTy : ST->elements())
1095         TypeVals.push_back(getTypeID(ElTy));
1096 
1097       if (ST->isLiteral()) {
1098         Code = bitc::TYPE_CODE_STRUCT_ANON;
1099         AbbrevToUse = StructAnonAbbrev;
1100       } else {
1101         if (ST->isOpaque()) {
1102           Code = bitc::TYPE_CODE_OPAQUE;
1103         } else {
1104           Code = bitc::TYPE_CODE_STRUCT_NAMED;
1105           AbbrevToUse = StructNamedAbbrev;
1106         }
1107 
1108         // Emit the name if it is present.
1109         if (!ST->getName().empty())
1110           writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
1111                             StructNameAbbrev);
1112       }
1113       break;
1114     }
1115     case Type::ArrayTyID: {
1116       ArrayType *AT = cast<ArrayType>(T);
1117       // ARRAY: [numelts, eltty]
1118       Code = bitc::TYPE_CODE_ARRAY;
1119       TypeVals.push_back(AT->getNumElements());
1120       TypeVals.push_back(getTypeID(AT->getElementType()));
1121       AbbrevToUse = ArrayAbbrev;
1122       break;
1123     }
1124     case Type::FixedVectorTyID:
1125     case Type::ScalableVectorTyID: {
1126       VectorType *VT = cast<VectorType>(T);
1127       // VECTOR [numelts, eltty]
1128       Code = bitc::TYPE_CODE_VECTOR;
1129       TypeVals.push_back(VT->getElementCount().getKnownMinValue());
1130       TypeVals.push_back(getTypeID(VT->getElementType()));
1131       break;
1132     }
1133     }
1134 
1135     // Emit the finished record.
1136     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
1137     TypeVals.clear();
1138   }
1139 
1140   Stream.ExitBlock();
1141 }
1142 
1143 void DXILBitcodeWriter::writeComdats() {
1144   SmallVector<uint16_t, 64> Vals;
1145   for (const Comdat *C : VE.getComdats()) {
1146     // COMDAT: [selection_kind, name]
1147     Vals.push_back(getEncodedComdatSelectionKind(*C));
1148     size_t Size = C->getName().size();
1149     assert(isUInt<16>(Size));
1150     Vals.push_back(Size);
1151     for (char Chr : C->getName())
1152       Vals.push_back((unsigned char)Chr);
1153     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
1154     Vals.clear();
1155   }
1156 }
1157 
1158 void DXILBitcodeWriter::writeValueSymbolTableForwardDecl() {}
1159 
1160 /// Emit top-level description of module, including target triple, inline asm,
1161 /// descriptors for global variables, and function prototype info.
1162 /// Returns the bit offset to backpatch with the location of the real VST.
1163 void DXILBitcodeWriter::writeModuleInfo() {
1164   // Emit various pieces of data attached to a module.
1165   if (!M.getTargetTriple().empty())
1166     writeStringRecord(Stream, bitc::MODULE_CODE_TRIPLE, M.getTargetTriple(),
1167                       0 /*TODO*/);
1168   const std::string &DL = M.getDataLayoutStr();
1169   if (!DL.empty())
1170     writeStringRecord(Stream, bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/);
1171   if (!M.getModuleInlineAsm().empty())
1172     writeStringRecord(Stream, bitc::MODULE_CODE_ASM, M.getModuleInlineAsm(),
1173                       0 /*TODO*/);
1174 
1175   // Emit information about sections and GC, computing how many there are. Also
1176   // compute the maximum alignment value.
1177   std::map<std::string, unsigned> SectionMap;
1178   std::map<std::string, unsigned> GCMap;
1179   MaybeAlign MaxAlignment;
1180   unsigned MaxGlobalType = 0;
1181   const auto UpdateMaxAlignment = [&MaxAlignment](const MaybeAlign A) {
1182     if (A)
1183       MaxAlignment = !MaxAlignment ? *A : std::max(*MaxAlignment, *A);
1184   };
1185   for (const GlobalVariable &GV : M.globals()) {
1186     UpdateMaxAlignment(GV.getAlign());
1187     // Use getGlobalObjectValueTypeID to look up the enumerated type ID for
1188     // Global Variable types.
1189     MaxGlobalType = std::max(
1190         MaxGlobalType, getGlobalObjectValueTypeID(GV.getValueType(), &GV));
1191     if (GV.hasSection()) {
1192       // Give section names unique ID's.
1193       unsigned &Entry = SectionMap[std::string(GV.getSection())];
1194       if (!Entry) {
1195         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME,
1196                           GV.getSection(), 0 /*TODO*/);
1197         Entry = SectionMap.size();
1198       }
1199     }
1200   }
1201   for (const Function &F : M) {
1202     UpdateMaxAlignment(F.getAlign());
1203     if (F.hasSection()) {
1204       // Give section names unique ID's.
1205       unsigned &Entry = SectionMap[std::string(F.getSection())];
1206       if (!Entry) {
1207         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
1208                           0 /*TODO*/);
1209         Entry = SectionMap.size();
1210       }
1211     }
1212     if (F.hasGC()) {
1213       // Same for GC names.
1214       unsigned &Entry = GCMap[F.getGC()];
1215       if (!Entry) {
1216         writeStringRecord(Stream, bitc::MODULE_CODE_GCNAME, F.getGC(),
1217                           0 /*TODO*/);
1218         Entry = GCMap.size();
1219       }
1220     }
1221   }
1222 
1223   // Emit abbrev for globals, now that we know # sections and max alignment.
1224   unsigned SimpleGVarAbbrev = 0;
1225   if (!M.global_empty()) {
1226     // Add an abbrev for common globals with no visibility or thread
1227     // localness.
1228     auto Abbv = std::make_shared<BitCodeAbbrev>();
1229     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
1230     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1231                               Log2_32_Ceil(MaxGlobalType + 1)));
1232     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
1233                                                            //| explicitType << 1
1234                                                            //| constant
1235     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
1236     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
1237     if (!MaxAlignment)                                     // Alignment.
1238       Abbv->Add(BitCodeAbbrevOp(0));
1239     else {
1240       unsigned MaxEncAlignment = getEncodedAlign(MaxAlignment);
1241       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1242                                 Log2_32_Ceil(MaxEncAlignment + 1)));
1243     }
1244     if (SectionMap.empty()) // Section.
1245       Abbv->Add(BitCodeAbbrevOp(0));
1246     else
1247       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1248                                 Log2_32_Ceil(SectionMap.size() + 1)));
1249     // Don't bother emitting vis + thread local.
1250     SimpleGVarAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1251   }
1252 
1253   // Emit the global variable information.
1254   SmallVector<unsigned, 64> Vals;
1255   for (const GlobalVariable &GV : M.globals()) {
1256     unsigned AbbrevToUse = 0;
1257 
1258     // GLOBALVAR: [type, isconst, initid,
1259     //             linkage, alignment, section, visibility, threadlocal,
1260     //             unnamed_addr, externally_initialized, dllstorageclass,
1261     //             comdat]
1262     Vals.push_back(getGlobalObjectValueTypeID(GV.getValueType(), &GV));
1263     Vals.push_back(
1264         GV.getType()->getAddressSpace() << 2 | 2 |
1265         (GV.isConstant() ? 1 : 0)); // HLSL Change - bitwise | was used with
1266                                     // unsigned int and bool
1267     Vals.push_back(
1268         GV.isDeclaration() ? 0 : (VE.getValueID(GV.getInitializer()) + 1));
1269     Vals.push_back(getEncodedLinkage(GV));
1270     Vals.push_back(getEncodedAlign(GV.getAlign()));
1271     Vals.push_back(GV.hasSection() ? SectionMap[std::string(GV.getSection())]
1272                                    : 0);
1273     if (GV.isThreadLocal() ||
1274         GV.getVisibility() != GlobalValue::DefaultVisibility ||
1275         GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None ||
1276         GV.isExternallyInitialized() ||
1277         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
1278         GV.hasComdat()) {
1279       Vals.push_back(getEncodedVisibility(GV));
1280       Vals.push_back(getEncodedThreadLocalMode(GV));
1281       Vals.push_back(GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
1282       Vals.push_back(GV.isExternallyInitialized());
1283       Vals.push_back(getEncodedDLLStorageClass(GV));
1284       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
1285     } else {
1286       AbbrevToUse = SimpleGVarAbbrev;
1287     }
1288 
1289     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
1290     Vals.clear();
1291   }
1292 
1293   // Emit the function proto information.
1294   for (const Function &F : M) {
1295     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
1296     //             section, visibility, gc, unnamed_addr, prologuedata,
1297     //             dllstorageclass, comdat, prefixdata, personalityfn]
1298     Vals.push_back(getGlobalObjectValueTypeID(F.getFunctionType(), &F));
1299     Vals.push_back(F.getCallingConv());
1300     Vals.push_back(F.isDeclaration());
1301     Vals.push_back(getEncodedLinkage(F));
1302     Vals.push_back(VE.getAttributeListID(F.getAttributes()));
1303     Vals.push_back(getEncodedAlign(F.getAlign()));
1304     Vals.push_back(F.hasSection() ? SectionMap[std::string(F.getSection())]
1305                                   : 0);
1306     Vals.push_back(getEncodedVisibility(F));
1307     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
1308     Vals.push_back(F.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
1309     Vals.push_back(
1310         F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1) : 0);
1311     Vals.push_back(getEncodedDLLStorageClass(F));
1312     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
1313     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
1314                                      : 0);
1315     Vals.push_back(
1316         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
1317 
1318     unsigned AbbrevToUse = 0;
1319     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
1320     Vals.clear();
1321   }
1322 
1323   // Emit the alias information.
1324   for (const GlobalAlias &A : M.aliases()) {
1325     // ALIAS: [alias type, aliasee val#, linkage, visibility]
1326     Vals.push_back(getTypeID(A.getValueType(), &A));
1327     Vals.push_back(VE.getValueID(A.getAliasee()));
1328     Vals.push_back(getEncodedLinkage(A));
1329     Vals.push_back(getEncodedVisibility(A));
1330     Vals.push_back(getEncodedDLLStorageClass(A));
1331     Vals.push_back(getEncodedThreadLocalMode(A));
1332     Vals.push_back(A.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
1333     unsigned AbbrevToUse = 0;
1334     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS_OLD, Vals, AbbrevToUse);
1335     Vals.clear();
1336   }
1337 }
1338 
1339 void DXILBitcodeWriter::writeValueAsMetadata(
1340     const ValueAsMetadata *MD, SmallVectorImpl<uint64_t> &Record) {
1341   // Mimic an MDNode with a value as one operand.
1342   Value *V = MD->getValue();
1343   Type *Ty = V->getType();
1344   if (Function *F = dyn_cast<Function>(V))
1345     Ty = TypedPointerType::get(F->getFunctionType(), F->getAddressSpace());
1346   else if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
1347     Ty = TypedPointerType::get(GV->getValueType(), GV->getAddressSpace());
1348   Record.push_back(getTypeID(Ty, V));
1349   Record.push_back(VE.getValueID(V));
1350   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
1351   Record.clear();
1352 }
1353 
1354 void DXILBitcodeWriter::writeMDTuple(const MDTuple *N,
1355                                      SmallVectorImpl<uint64_t> &Record,
1356                                      unsigned Abbrev) {
1357   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
1358     Metadata *MD = N->getOperand(i);
1359     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
1360            "Unexpected function-local metadata");
1361     Record.push_back(VE.getMetadataOrNullID(MD));
1362   }
1363   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
1364                                     : bitc::METADATA_NODE,
1365                     Record, Abbrev);
1366   Record.clear();
1367 }
1368 
1369 void DXILBitcodeWriter::writeDILocation(const DILocation *N,
1370                                         SmallVectorImpl<uint64_t> &Record,
1371                                         unsigned &Abbrev) {
1372   if (!Abbrev)
1373     Abbrev = createDILocationAbbrev();
1374   Record.push_back(N->isDistinct());
1375   Record.push_back(N->getLine());
1376   Record.push_back(N->getColumn());
1377   Record.push_back(VE.getMetadataID(N->getScope()));
1378   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
1379 
1380   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
1381   Record.clear();
1382 }
1383 
1384 static uint64_t rotateSign(APInt Val) {
1385   int64_t I = Val.getSExtValue();
1386   uint64_t U = I;
1387   return I < 0 ? ~(U << 1) : U << 1;
1388 }
1389 
1390 void DXILBitcodeWriter::writeDISubrange(const DISubrange *N,
1391                                         SmallVectorImpl<uint64_t> &Record,
1392                                         unsigned Abbrev) {
1393   Record.push_back(N->isDistinct());
1394 
1395   // TODO: Do we need to handle DIExpression here? What about cases where Count
1396   // isn't specified but UpperBound and such are?
1397   ConstantInt *Count = N->getCount().dyn_cast<ConstantInt *>();
1398   assert(Count && "Count is missing or not ConstantInt");
1399   Record.push_back(Count->getValue().getSExtValue());
1400 
1401   // TODO: Similarly, DIExpression is allowed here now
1402   DISubrange::BoundType LowerBound = N->getLowerBound();
1403   assert((LowerBound.isNull() || LowerBound.is<ConstantInt *>()) &&
1404          "Lower bound provided but not ConstantInt");
1405   Record.push_back(
1406       LowerBound ? rotateSign(LowerBound.get<ConstantInt *>()->getValue()) : 0);
1407 
1408   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
1409   Record.clear();
1410 }
1411 
1412 void DXILBitcodeWriter::writeDIEnumerator(const DIEnumerator *N,
1413                                           SmallVectorImpl<uint64_t> &Record,
1414                                           unsigned Abbrev) {
1415   Record.push_back(N->isDistinct());
1416   Record.push_back(rotateSign(N->getValue()));
1417   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1418 
1419   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
1420   Record.clear();
1421 }
1422 
1423 void DXILBitcodeWriter::writeDIBasicType(const DIBasicType *N,
1424                                          SmallVectorImpl<uint64_t> &Record,
1425                                          unsigned Abbrev) {
1426   Record.push_back(N->isDistinct());
1427   Record.push_back(N->getTag());
1428   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1429   Record.push_back(N->getSizeInBits());
1430   Record.push_back(N->getAlignInBits());
1431   Record.push_back(N->getEncoding());
1432 
1433   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
1434   Record.clear();
1435 }
1436 
1437 void DXILBitcodeWriter::writeDIDerivedType(const DIDerivedType *N,
1438                                            SmallVectorImpl<uint64_t> &Record,
1439                                            unsigned Abbrev) {
1440   Record.push_back(N->isDistinct());
1441   Record.push_back(N->getTag());
1442   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1443   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1444   Record.push_back(N->getLine());
1445   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1446   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1447   Record.push_back(N->getSizeInBits());
1448   Record.push_back(N->getAlignInBits());
1449   Record.push_back(N->getOffsetInBits());
1450   Record.push_back(N->getFlags());
1451   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
1452 
1453   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
1454   Record.clear();
1455 }
1456 
1457 void DXILBitcodeWriter::writeDICompositeType(const DICompositeType *N,
1458                                              SmallVectorImpl<uint64_t> &Record,
1459                                              unsigned Abbrev) {
1460   Record.push_back(N->isDistinct());
1461   Record.push_back(N->getTag());
1462   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1463   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1464   Record.push_back(N->getLine());
1465   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1466   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1467   Record.push_back(N->getSizeInBits());
1468   Record.push_back(N->getAlignInBits());
1469   Record.push_back(N->getOffsetInBits());
1470   Record.push_back(N->getFlags());
1471   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1472   Record.push_back(N->getRuntimeLang());
1473   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
1474   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1475   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
1476 
1477   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
1478   Record.clear();
1479 }
1480 
1481 void DXILBitcodeWriter::writeDISubroutineType(const DISubroutineType *N,
1482                                               SmallVectorImpl<uint64_t> &Record,
1483                                               unsigned Abbrev) {
1484   Record.push_back(N->isDistinct());
1485   Record.push_back(N->getFlags());
1486   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
1487 
1488   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
1489   Record.clear();
1490 }
1491 
1492 void DXILBitcodeWriter::writeDIFile(const DIFile *N,
1493                                     SmallVectorImpl<uint64_t> &Record,
1494                                     unsigned Abbrev) {
1495   Record.push_back(N->isDistinct());
1496   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
1497   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
1498 
1499   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
1500   Record.clear();
1501 }
1502 
1503 void DXILBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
1504                                            SmallVectorImpl<uint64_t> &Record,
1505                                            unsigned Abbrev) {
1506   Record.push_back(N->isDistinct());
1507   Record.push_back(N->getSourceLanguage());
1508   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1509   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
1510   Record.push_back(N->isOptimized());
1511   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
1512   Record.push_back(N->getRuntimeVersion());
1513   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
1514   Record.push_back(N->getEmissionKind());
1515   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
1516   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
1517   Record.push_back(/* subprograms */ 0);
1518   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
1519   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
1520   Record.push_back(N->getDWOId());
1521 
1522   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
1523   Record.clear();
1524 }
1525 
1526 void DXILBitcodeWriter::writeDISubprogram(const DISubprogram *N,
1527                                           SmallVectorImpl<uint64_t> &Record,
1528                                           unsigned Abbrev) {
1529   Record.push_back(N->isDistinct());
1530   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1531   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1532   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1533   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1534   Record.push_back(N->getLine());
1535   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1536   Record.push_back(N->isLocalToUnit());
1537   Record.push_back(N->isDefinition());
1538   Record.push_back(N->getScopeLine());
1539   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
1540   Record.push_back(N->getVirtuality());
1541   Record.push_back(N->getVirtualIndex());
1542   Record.push_back(N->getFlags());
1543   Record.push_back(N->isOptimized());
1544   Record.push_back(VE.getMetadataOrNullID(N->getRawUnit()));
1545   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1546   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
1547   Record.push_back(VE.getMetadataOrNullID(N->getRetainedNodes().get()));
1548 
1549   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
1550   Record.clear();
1551 }
1552 
1553 void DXILBitcodeWriter::writeDILexicalBlock(const DILexicalBlock *N,
1554                                             SmallVectorImpl<uint64_t> &Record,
1555                                             unsigned Abbrev) {
1556   Record.push_back(N->isDistinct());
1557   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1558   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1559   Record.push_back(N->getLine());
1560   Record.push_back(N->getColumn());
1561 
1562   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
1563   Record.clear();
1564 }
1565 
1566 void DXILBitcodeWriter::writeDILexicalBlockFile(
1567     const DILexicalBlockFile *N, SmallVectorImpl<uint64_t> &Record,
1568     unsigned Abbrev) {
1569   Record.push_back(N->isDistinct());
1570   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1571   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1572   Record.push_back(N->getDiscriminator());
1573 
1574   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
1575   Record.clear();
1576 }
1577 
1578 void DXILBitcodeWriter::writeDINamespace(const DINamespace *N,
1579                                          SmallVectorImpl<uint64_t> &Record,
1580                                          unsigned Abbrev) {
1581   Record.push_back(N->isDistinct());
1582   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1583   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1584   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1585   Record.push_back(/* line number */ 0);
1586 
1587   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
1588   Record.clear();
1589 }
1590 
1591 void DXILBitcodeWriter::writeDIModule(const DIModule *N,
1592                                       SmallVectorImpl<uint64_t> &Record,
1593                                       unsigned Abbrev) {
1594   Record.push_back(N->isDistinct());
1595   for (auto &I : N->operands())
1596     Record.push_back(VE.getMetadataOrNullID(I));
1597 
1598   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
1599   Record.clear();
1600 }
1601 
1602 void DXILBitcodeWriter::writeDITemplateTypeParameter(
1603     const DITemplateTypeParameter *N, SmallVectorImpl<uint64_t> &Record,
1604     unsigned Abbrev) {
1605   Record.push_back(N->isDistinct());
1606   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1607   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1608 
1609   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
1610   Record.clear();
1611 }
1612 
1613 void DXILBitcodeWriter::writeDITemplateValueParameter(
1614     const DITemplateValueParameter *N, SmallVectorImpl<uint64_t> &Record,
1615     unsigned Abbrev) {
1616   Record.push_back(N->isDistinct());
1617   Record.push_back(N->getTag());
1618   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1619   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1620   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
1621 
1622   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
1623   Record.clear();
1624 }
1625 
1626 void DXILBitcodeWriter::writeDIGlobalVariable(const DIGlobalVariable *N,
1627                                               SmallVectorImpl<uint64_t> &Record,
1628                                               unsigned Abbrev) {
1629   Record.push_back(N->isDistinct());
1630   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1631   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1632   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1633   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1634   Record.push_back(N->getLine());
1635   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1636   Record.push_back(N->isLocalToUnit());
1637   Record.push_back(N->isDefinition());
1638   Record.push_back(/* N->getRawVariable() */ 0);
1639   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
1640 
1641   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
1642   Record.clear();
1643 }
1644 
1645 void DXILBitcodeWriter::writeDILocalVariable(const DILocalVariable *N,
1646                                              SmallVectorImpl<uint64_t> &Record,
1647                                              unsigned Abbrev) {
1648   Record.push_back(N->isDistinct());
1649   Record.push_back(N->getTag());
1650   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1651   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1652   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1653   Record.push_back(N->getLine());
1654   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1655   Record.push_back(N->getArg());
1656   Record.push_back(N->getFlags());
1657 
1658   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
1659   Record.clear();
1660 }
1661 
1662 void DXILBitcodeWriter::writeDIExpression(const DIExpression *N,
1663                                           SmallVectorImpl<uint64_t> &Record,
1664                                           unsigned Abbrev) {
1665   Record.reserve(N->getElements().size() + 1);
1666 
1667   Record.push_back(N->isDistinct());
1668   Record.append(N->elements_begin(), N->elements_end());
1669 
1670   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
1671   Record.clear();
1672 }
1673 
1674 void DXILBitcodeWriter::writeDIObjCProperty(const DIObjCProperty *N,
1675                                             SmallVectorImpl<uint64_t> &Record,
1676                                             unsigned Abbrev) {
1677   llvm_unreachable("DXIL does not support objc!!!");
1678 }
1679 
1680 void DXILBitcodeWriter::writeDIImportedEntity(const DIImportedEntity *N,
1681                                               SmallVectorImpl<uint64_t> &Record,
1682                                               unsigned Abbrev) {
1683   Record.push_back(N->isDistinct());
1684   Record.push_back(N->getTag());
1685   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1686   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
1687   Record.push_back(N->getLine());
1688   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1689 
1690   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
1691   Record.clear();
1692 }
1693 
1694 unsigned DXILBitcodeWriter::createDILocationAbbrev() {
1695   // Abbrev for METADATA_LOCATION.
1696   //
1697   // Assume the column is usually under 128, and always output the inlined-at
1698   // location (it's never more expensive than building an array size 1).
1699   std::shared_ptr<BitCodeAbbrev> Abbv = std::make_shared<BitCodeAbbrev>();
1700   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1701   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1702   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1703   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1704   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1705   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1706   return Stream.EmitAbbrev(std::move(Abbv));
1707 }
1708 
1709 unsigned DXILBitcodeWriter::createGenericDINodeAbbrev() {
1710   // Abbrev for METADATA_GENERIC_DEBUG.
1711   //
1712   // Assume the column is usually under 128, and always output the inlined-at
1713   // location (it's never more expensive than building an array size 1).
1714   std::shared_ptr<BitCodeAbbrev> Abbv = std::make_shared<BitCodeAbbrev>();
1715   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1716   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1717   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1718   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1719   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1720   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1721   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1722   return Stream.EmitAbbrev(std::move(Abbv));
1723 }
1724 
1725 void DXILBitcodeWriter::writeMetadataRecords(ArrayRef<const Metadata *> MDs,
1726                                              SmallVectorImpl<uint64_t> &Record,
1727                                              std::vector<unsigned> *MDAbbrevs,
1728                                              std::vector<uint64_t> *IndexPos) {
1729   if (MDs.empty())
1730     return;
1731 
1732     // Initialize MDNode abbreviations.
1733 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
1734 #include "llvm/IR/Metadata.def"
1735 
1736   for (const Metadata *MD : MDs) {
1737     if (IndexPos)
1738       IndexPos->push_back(Stream.GetCurrentBitNo());
1739     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
1740       assert(N->isResolved() && "Expected forward references to be resolved");
1741 
1742       switch (N->getMetadataID()) {
1743       default:
1744         llvm_unreachable("Invalid MDNode subclass");
1745 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
1746   case Metadata::CLASS##Kind:                                                  \
1747     if (MDAbbrevs)                                                             \
1748       write##CLASS(cast<CLASS>(N), Record,                                     \
1749                    (*MDAbbrevs)[MetadataAbbrev::CLASS##AbbrevID]);             \
1750     else                                                                       \
1751       write##CLASS(cast<CLASS>(N), Record, CLASS##Abbrev);                     \
1752     continue;
1753 #include "llvm/IR/Metadata.def"
1754       }
1755     }
1756     writeValueAsMetadata(cast<ValueAsMetadata>(MD), Record);
1757   }
1758 }
1759 
1760 unsigned DXILBitcodeWriter::createMetadataStringsAbbrev() {
1761   auto Abbv = std::make_shared<BitCodeAbbrev>();
1762   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING_OLD));
1763   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1764   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1765   return Stream.EmitAbbrev(std::move(Abbv));
1766 }
1767 
1768 void DXILBitcodeWriter::writeMetadataStrings(
1769     ArrayRef<const Metadata *> Strings, SmallVectorImpl<uint64_t> &Record) {
1770   if (Strings.empty())
1771     return;
1772 
1773   unsigned MDSAbbrev = createMetadataStringsAbbrev();
1774 
1775   for (const Metadata *MD : Strings) {
1776     const MDString *MDS = cast<MDString>(MD);
1777     // Code: [strchar x N]
1778     Record.append(MDS->bytes_begin(), MDS->bytes_end());
1779 
1780     // Emit the finished record.
1781     Stream.EmitRecord(bitc::METADATA_STRING_OLD, Record, MDSAbbrev);
1782     Record.clear();
1783   }
1784 }
1785 
1786 void DXILBitcodeWriter::writeModuleMetadata() {
1787   if (!VE.hasMDs() && M.named_metadata_empty())
1788     return;
1789 
1790   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 5);
1791 
1792   // Emit all abbrevs upfront, so that the reader can jump in the middle of the
1793   // block and load any metadata.
1794   std::vector<unsigned> MDAbbrevs;
1795 
1796   MDAbbrevs.resize(MetadataAbbrev::LastPlusOne);
1797   MDAbbrevs[MetadataAbbrev::DILocationAbbrevID] = createDILocationAbbrev();
1798   MDAbbrevs[MetadataAbbrev::GenericDINodeAbbrevID] =
1799       createGenericDINodeAbbrev();
1800 
1801   unsigned NameAbbrev = 0;
1802   if (!M.named_metadata_empty()) {
1803     // Abbrev for METADATA_NAME.
1804     std::shared_ptr<BitCodeAbbrev> Abbv = std::make_shared<BitCodeAbbrev>();
1805     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
1806     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1807     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1808     NameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1809   }
1810 
1811   SmallVector<uint64_t, 64> Record;
1812   writeMetadataStrings(VE.getMDStrings(), Record);
1813 
1814   std::vector<uint64_t> IndexPos;
1815   IndexPos.reserve(VE.getNonMDStrings().size());
1816   writeMetadataRecords(VE.getNonMDStrings(), Record, &MDAbbrevs, &IndexPos);
1817 
1818   // Write named metadata.
1819   for (const NamedMDNode &NMD : M.named_metadata()) {
1820     // Write name.
1821     StringRef Str = NMD.getName();
1822     Record.append(Str.bytes_begin(), Str.bytes_end());
1823     Stream.EmitRecord(bitc::METADATA_NAME, Record, NameAbbrev);
1824     Record.clear();
1825 
1826     // Write named metadata operands.
1827     for (const MDNode *N : NMD.operands())
1828       Record.push_back(VE.getMetadataID(N));
1829     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
1830     Record.clear();
1831   }
1832 
1833   Stream.ExitBlock();
1834 }
1835 
1836 void DXILBitcodeWriter::writeFunctionMetadata(const Function &F) {
1837   if (!VE.hasMDs())
1838     return;
1839 
1840   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 4);
1841   SmallVector<uint64_t, 64> Record;
1842   writeMetadataStrings(VE.getMDStrings(), Record);
1843   writeMetadataRecords(VE.getNonMDStrings(), Record);
1844   Stream.ExitBlock();
1845 }
1846 
1847 void DXILBitcodeWriter::writeFunctionMetadataAttachment(const Function &F) {
1848   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
1849 
1850   SmallVector<uint64_t, 64> Record;
1851 
1852   // Write metadata attachments
1853   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
1854   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
1855   F.getAllMetadata(MDs);
1856   if (!MDs.empty()) {
1857     for (const auto &I : MDs) {
1858       Record.push_back(I.first);
1859       Record.push_back(VE.getMetadataID(I.second));
1860     }
1861     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1862     Record.clear();
1863   }
1864 
1865   for (const BasicBlock &BB : F)
1866     for (const Instruction &I : BB) {
1867       MDs.clear();
1868       I.getAllMetadataOtherThanDebugLoc(MDs);
1869 
1870       // If no metadata, ignore instruction.
1871       if (MDs.empty())
1872         continue;
1873 
1874       Record.push_back(VE.getInstructionID(&I));
1875 
1876       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1877         Record.push_back(MDs[i].first);
1878         Record.push_back(VE.getMetadataID(MDs[i].second));
1879       }
1880       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1881       Record.clear();
1882     }
1883 
1884   Stream.ExitBlock();
1885 }
1886 
1887 void DXILBitcodeWriter::writeModuleMetadataKinds() {
1888   SmallVector<uint64_t, 64> Record;
1889 
1890   // Write metadata kinds
1891   // METADATA_KIND - [n x [id, name]]
1892   SmallVector<StringRef, 8> Names;
1893   M.getMDKindNames(Names);
1894 
1895   if (Names.empty())
1896     return;
1897 
1898   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1899 
1900   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
1901     Record.push_back(MDKindID);
1902     StringRef KName = Names[MDKindID];
1903     Record.append(KName.begin(), KName.end());
1904 
1905     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
1906     Record.clear();
1907   }
1908 
1909   Stream.ExitBlock();
1910 }
1911 
1912 void DXILBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
1913                                        bool isGlobal) {
1914   if (FirstVal == LastVal)
1915     return;
1916 
1917   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
1918 
1919   unsigned AggregateAbbrev = 0;
1920   unsigned String8Abbrev = 0;
1921   unsigned CString7Abbrev = 0;
1922   unsigned CString6Abbrev = 0;
1923   // If this is a constant pool for the module, emit module-specific abbrevs.
1924   if (isGlobal) {
1925     // Abbrev for CST_CODE_AGGREGATE.
1926     auto Abbv = std::make_shared<BitCodeAbbrev>();
1927     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
1928     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1929     Abbv->Add(
1930         BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal + 1)));
1931     AggregateAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1932 
1933     // Abbrev for CST_CODE_STRING.
1934     Abbv = std::make_shared<BitCodeAbbrev>();
1935     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
1936     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1937     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1938     String8Abbrev = Stream.EmitAbbrev(std::move(Abbv));
1939     // Abbrev for CST_CODE_CSTRING.
1940     Abbv = std::make_shared<BitCodeAbbrev>();
1941     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1942     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1943     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1944     CString7Abbrev = Stream.EmitAbbrev(std::move(Abbv));
1945     // Abbrev for CST_CODE_CSTRING.
1946     Abbv = std::make_shared<BitCodeAbbrev>();
1947     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1948     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1949     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1950     CString6Abbrev = Stream.EmitAbbrev(std::move(Abbv));
1951   }
1952 
1953   SmallVector<uint64_t, 64> Record;
1954 
1955   const ValueEnumerator::ValueList &Vals = VE.getValues();
1956   Type *LastTy = nullptr;
1957   for (unsigned i = FirstVal; i != LastVal; ++i) {
1958     const Value *V = Vals[i].first;
1959     // If we need to switch types, do so now.
1960     if (V->getType() != LastTy) {
1961       LastTy = V->getType();
1962       Record.push_back(getTypeID(LastTy, V));
1963       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
1964                         CONSTANTS_SETTYPE_ABBREV);
1965       Record.clear();
1966     }
1967 
1968     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
1969       Record.push_back(unsigned(IA->hasSideEffects()) |
1970                        unsigned(IA->isAlignStack()) << 1 |
1971                        unsigned(IA->getDialect() & 1) << 2);
1972 
1973       // Add the asm string.
1974       const std::string &AsmStr = IA->getAsmString();
1975       Record.push_back(AsmStr.size());
1976       Record.append(AsmStr.begin(), AsmStr.end());
1977 
1978       // Add the constraint string.
1979       const std::string &ConstraintStr = IA->getConstraintString();
1980       Record.push_back(ConstraintStr.size());
1981       Record.append(ConstraintStr.begin(), ConstraintStr.end());
1982       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
1983       Record.clear();
1984       continue;
1985     }
1986     const Constant *C = cast<Constant>(V);
1987     unsigned Code = -1U;
1988     unsigned AbbrevToUse = 0;
1989     if (C->isNullValue()) {
1990       Code = bitc::CST_CODE_NULL;
1991     } else if (isa<UndefValue>(C)) {
1992       Code = bitc::CST_CODE_UNDEF;
1993     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
1994       if (IV->getBitWidth() <= 64) {
1995         uint64_t V = IV->getSExtValue();
1996         emitSignedInt64(Record, V);
1997         Code = bitc::CST_CODE_INTEGER;
1998         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
1999       } else { // Wide integers, > 64 bits in size.
2000         // We have an arbitrary precision integer value to write whose
2001         // bit width is > 64. However, in canonical unsigned integer
2002         // format it is likely that the high bits are going to be zero.
2003         // So, we only write the number of active words.
2004         unsigned NWords = IV->getValue().getActiveWords();
2005         const uint64_t *RawWords = IV->getValue().getRawData();
2006         for (unsigned i = 0; i != NWords; ++i) {
2007           emitSignedInt64(Record, RawWords[i]);
2008         }
2009         Code = bitc::CST_CODE_WIDE_INTEGER;
2010       }
2011     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
2012       Code = bitc::CST_CODE_FLOAT;
2013       Type *Ty = CFP->getType();
2014       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
2015         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
2016       } else if (Ty->isX86_FP80Ty()) {
2017         // api needed to prevent premature destruction
2018         // bits are not in the same order as a normal i80 APInt, compensate.
2019         APInt api = CFP->getValueAPF().bitcastToAPInt();
2020         const uint64_t *p = api.getRawData();
2021         Record.push_back((p[1] << 48) | (p[0] >> 16));
2022         Record.push_back(p[0] & 0xffffLL);
2023       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
2024         APInt api = CFP->getValueAPF().bitcastToAPInt();
2025         const uint64_t *p = api.getRawData();
2026         Record.push_back(p[0]);
2027         Record.push_back(p[1]);
2028       } else {
2029         assert(0 && "Unknown FP type!");
2030       }
2031     } else if (isa<ConstantDataSequential>(C) &&
2032                cast<ConstantDataSequential>(C)->isString()) {
2033       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
2034       // Emit constant strings specially.
2035       unsigned NumElts = Str->getNumElements();
2036       // If this is a null-terminated string, use the denser CSTRING encoding.
2037       if (Str->isCString()) {
2038         Code = bitc::CST_CODE_CSTRING;
2039         --NumElts; // Don't encode the null, which isn't allowed by char6.
2040       } else {
2041         Code = bitc::CST_CODE_STRING;
2042         AbbrevToUse = String8Abbrev;
2043       }
2044       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
2045       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
2046       for (unsigned i = 0; i != NumElts; ++i) {
2047         unsigned char V = Str->getElementAsInteger(i);
2048         Record.push_back(V);
2049         isCStr7 &= (V & 128) == 0;
2050         if (isCStrChar6)
2051           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
2052       }
2053 
2054       if (isCStrChar6)
2055         AbbrevToUse = CString6Abbrev;
2056       else if (isCStr7)
2057         AbbrevToUse = CString7Abbrev;
2058     } else if (const ConstantDataSequential *CDS =
2059                    dyn_cast<ConstantDataSequential>(C)) {
2060       Code = bitc::CST_CODE_DATA;
2061       Type *EltTy = CDS->getElementType();
2062       if (isa<IntegerType>(EltTy)) {
2063         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2064           Record.push_back(CDS->getElementAsInteger(i));
2065       } else if (EltTy->isFloatTy()) {
2066         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
2067           union {
2068             float F;
2069             uint32_t I;
2070           };
2071           F = CDS->getElementAsFloat(i);
2072           Record.push_back(I);
2073         }
2074       } else {
2075         assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
2076         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
2077           union {
2078             double F;
2079             uint64_t I;
2080           };
2081           F = CDS->getElementAsDouble(i);
2082           Record.push_back(I);
2083         }
2084       }
2085     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
2086                isa<ConstantVector>(C)) {
2087       Code = bitc::CST_CODE_AGGREGATE;
2088       for (const Value *Op : C->operands())
2089         Record.push_back(VE.getValueID(Op));
2090       AbbrevToUse = AggregateAbbrev;
2091     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
2092       switch (CE->getOpcode()) {
2093       default:
2094         if (Instruction::isCast(CE->getOpcode())) {
2095           Code = bitc::CST_CODE_CE_CAST;
2096           Record.push_back(getEncodedCastOpcode(CE->getOpcode()));
2097           Record.push_back(
2098               getTypeID(C->getOperand(0)->getType(), C->getOperand(0)));
2099           Record.push_back(VE.getValueID(C->getOperand(0)));
2100           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
2101         } else {
2102           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
2103           Code = bitc::CST_CODE_CE_BINOP;
2104           Record.push_back(getEncodedBinaryOpcode(CE->getOpcode()));
2105           Record.push_back(VE.getValueID(C->getOperand(0)));
2106           Record.push_back(VE.getValueID(C->getOperand(1)));
2107           uint64_t Flags = getOptimizationFlags(CE);
2108           if (Flags != 0)
2109             Record.push_back(Flags);
2110         }
2111         break;
2112       case Instruction::GetElementPtr: {
2113         Code = bitc::CST_CODE_CE_GEP;
2114         const auto *GO = cast<GEPOperator>(C);
2115         if (GO->isInBounds())
2116           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
2117         Record.push_back(getTypeID(GO->getSourceElementType()));
2118         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
2119           Record.push_back(
2120               getTypeID(C->getOperand(i)->getType(), C->getOperand(i)));
2121           Record.push_back(VE.getValueID(C->getOperand(i)));
2122         }
2123         break;
2124       }
2125       case Instruction::Select:
2126         Code = bitc::CST_CODE_CE_SELECT;
2127         Record.push_back(VE.getValueID(C->getOperand(0)));
2128         Record.push_back(VE.getValueID(C->getOperand(1)));
2129         Record.push_back(VE.getValueID(C->getOperand(2)));
2130         break;
2131       case Instruction::ExtractElement:
2132         Code = bitc::CST_CODE_CE_EXTRACTELT;
2133         Record.push_back(getTypeID(C->getOperand(0)->getType()));
2134         Record.push_back(VE.getValueID(C->getOperand(0)));
2135         Record.push_back(getTypeID(C->getOperand(1)->getType()));
2136         Record.push_back(VE.getValueID(C->getOperand(1)));
2137         break;
2138       case Instruction::InsertElement:
2139         Code = bitc::CST_CODE_CE_INSERTELT;
2140         Record.push_back(VE.getValueID(C->getOperand(0)));
2141         Record.push_back(VE.getValueID(C->getOperand(1)));
2142         Record.push_back(getTypeID(C->getOperand(2)->getType()));
2143         Record.push_back(VE.getValueID(C->getOperand(2)));
2144         break;
2145       case Instruction::ShuffleVector:
2146         // If the return type and argument types are the same, this is a
2147         // standard shufflevector instruction.  If the types are different,
2148         // then the shuffle is widening or truncating the input vectors, and
2149         // the argument type must also be encoded.
2150         if (C->getType() == C->getOperand(0)->getType()) {
2151           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
2152         } else {
2153           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
2154           Record.push_back(getTypeID(C->getOperand(0)->getType()));
2155         }
2156         Record.push_back(VE.getValueID(C->getOperand(0)));
2157         Record.push_back(VE.getValueID(C->getOperand(1)));
2158         Record.push_back(VE.getValueID(C->getOperand(2)));
2159         break;
2160       }
2161     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
2162       Code = bitc::CST_CODE_BLOCKADDRESS;
2163       Record.push_back(getTypeID(BA->getFunction()->getType()));
2164       Record.push_back(VE.getValueID(BA->getFunction()));
2165       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
2166     } else {
2167 #ifndef NDEBUG
2168       C->dump();
2169 #endif
2170       llvm_unreachable("Unknown constant!");
2171     }
2172     Stream.EmitRecord(Code, Record, AbbrevToUse);
2173     Record.clear();
2174   }
2175 
2176   Stream.ExitBlock();
2177 }
2178 
2179 void DXILBitcodeWriter::writeModuleConstants() {
2180   const ValueEnumerator::ValueList &Vals = VE.getValues();
2181 
2182   // Find the first constant to emit, which is the first non-globalvalue value.
2183   // We know globalvalues have been emitted by WriteModuleInfo.
2184   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
2185     if (!isa<GlobalValue>(Vals[i].first)) {
2186       writeConstants(i, Vals.size(), true);
2187       return;
2188     }
2189   }
2190 }
2191 
2192 /// pushValueAndType - The file has to encode both the value and type id for
2193 /// many values, because we need to know what type to create for forward
2194 /// references.  However, most operands are not forward references, so this type
2195 /// field is not needed.
2196 ///
2197 /// This function adds V's value ID to Vals.  If the value ID is higher than the
2198 /// instruction ID, then it is a forward reference, and it also includes the
2199 /// type ID.  The value ID that is written is encoded relative to the InstID.
2200 bool DXILBitcodeWriter::pushValueAndType(const Value *V, unsigned InstID,
2201                                          SmallVectorImpl<unsigned> &Vals) {
2202   unsigned ValID = VE.getValueID(V);
2203   // Make encoding relative to the InstID.
2204   Vals.push_back(InstID - ValID);
2205   if (ValID >= InstID) {
2206     Vals.push_back(getTypeID(V->getType(), V));
2207     return true;
2208   }
2209   return false;
2210 }
2211 
2212 /// pushValue - Like pushValueAndType, but where the type of the value is
2213 /// omitted (perhaps it was already encoded in an earlier operand).
2214 void DXILBitcodeWriter::pushValue(const Value *V, unsigned InstID,
2215                                   SmallVectorImpl<unsigned> &Vals) {
2216   unsigned ValID = VE.getValueID(V);
2217   Vals.push_back(InstID - ValID);
2218 }
2219 
2220 void DXILBitcodeWriter::pushValueSigned(const Value *V, unsigned InstID,
2221                                         SmallVectorImpl<uint64_t> &Vals) {
2222   unsigned ValID = VE.getValueID(V);
2223   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
2224   emitSignedInt64(Vals, diff);
2225 }
2226 
2227 /// WriteInstruction - Emit an instruction
2228 void DXILBitcodeWriter::writeInstruction(const Instruction &I, unsigned InstID,
2229                                          SmallVectorImpl<unsigned> &Vals) {
2230   unsigned Code = 0;
2231   unsigned AbbrevToUse = 0;
2232   VE.setInstructionID(&I);
2233   switch (I.getOpcode()) {
2234   default:
2235     if (Instruction::isCast(I.getOpcode())) {
2236       Code = bitc::FUNC_CODE_INST_CAST;
2237       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2238         AbbrevToUse = (unsigned)FUNCTION_INST_CAST_ABBREV;
2239       Vals.push_back(getTypeID(I.getType(), &I));
2240       Vals.push_back(getEncodedCastOpcode(I.getOpcode()));
2241     } else {
2242       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
2243       Code = bitc::FUNC_CODE_INST_BINOP;
2244       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2245         AbbrevToUse = (unsigned)FUNCTION_INST_BINOP_ABBREV;
2246       pushValue(I.getOperand(1), InstID, Vals);
2247       Vals.push_back(getEncodedBinaryOpcode(I.getOpcode()));
2248       uint64_t Flags = getOptimizationFlags(&I);
2249       if (Flags != 0) {
2250         if (AbbrevToUse == (unsigned)FUNCTION_INST_BINOP_ABBREV)
2251           AbbrevToUse = (unsigned)FUNCTION_INST_BINOP_FLAGS_ABBREV;
2252         Vals.push_back(Flags);
2253       }
2254     }
2255     break;
2256 
2257   case Instruction::GetElementPtr: {
2258     Code = bitc::FUNC_CODE_INST_GEP;
2259     AbbrevToUse = (unsigned)FUNCTION_INST_GEP_ABBREV;
2260     auto &GEPInst = cast<GetElementPtrInst>(I);
2261     Vals.push_back(GEPInst.isInBounds());
2262     Vals.push_back(getTypeID(GEPInst.getSourceElementType()));
2263     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
2264       pushValueAndType(I.getOperand(i), InstID, Vals);
2265     break;
2266   }
2267   case Instruction::ExtractValue: {
2268     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
2269     pushValueAndType(I.getOperand(0), InstID, Vals);
2270     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
2271     Vals.append(EVI->idx_begin(), EVI->idx_end());
2272     break;
2273   }
2274   case Instruction::InsertValue: {
2275     Code = bitc::FUNC_CODE_INST_INSERTVAL;
2276     pushValueAndType(I.getOperand(0), InstID, Vals);
2277     pushValueAndType(I.getOperand(1), InstID, Vals);
2278     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
2279     Vals.append(IVI->idx_begin(), IVI->idx_end());
2280     break;
2281   }
2282   case Instruction::Select:
2283     Code = bitc::FUNC_CODE_INST_VSELECT;
2284     pushValueAndType(I.getOperand(1), InstID, Vals);
2285     pushValue(I.getOperand(2), InstID, Vals);
2286     pushValueAndType(I.getOperand(0), InstID, Vals);
2287     break;
2288   case Instruction::ExtractElement:
2289     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
2290     pushValueAndType(I.getOperand(0), InstID, Vals);
2291     pushValueAndType(I.getOperand(1), InstID, Vals);
2292     break;
2293   case Instruction::InsertElement:
2294     Code = bitc::FUNC_CODE_INST_INSERTELT;
2295     pushValueAndType(I.getOperand(0), InstID, Vals);
2296     pushValue(I.getOperand(1), InstID, Vals);
2297     pushValueAndType(I.getOperand(2), InstID, Vals);
2298     break;
2299   case Instruction::ShuffleVector:
2300     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
2301     pushValueAndType(I.getOperand(0), InstID, Vals);
2302     pushValue(I.getOperand(1), InstID, Vals);
2303     pushValue(cast<ShuffleVectorInst>(&I)->getShuffleMaskForBitcode(), InstID,
2304               Vals);
2305     break;
2306   case Instruction::ICmp:
2307   case Instruction::FCmp: {
2308     // compare returning Int1Ty or vector of Int1Ty
2309     Code = bitc::FUNC_CODE_INST_CMP2;
2310     pushValueAndType(I.getOperand(0), InstID, Vals);
2311     pushValue(I.getOperand(1), InstID, Vals);
2312     Vals.push_back(cast<CmpInst>(I).getPredicate());
2313     uint64_t Flags = getOptimizationFlags(&I);
2314     if (Flags != 0)
2315       Vals.push_back(Flags);
2316     break;
2317   }
2318 
2319   case Instruction::Ret: {
2320     Code = bitc::FUNC_CODE_INST_RET;
2321     unsigned NumOperands = I.getNumOperands();
2322     if (NumOperands == 0)
2323       AbbrevToUse = (unsigned)FUNCTION_INST_RET_VOID_ABBREV;
2324     else if (NumOperands == 1) {
2325       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2326         AbbrevToUse = (unsigned)FUNCTION_INST_RET_VAL_ABBREV;
2327     } else {
2328       for (unsigned i = 0, e = NumOperands; i != e; ++i)
2329         pushValueAndType(I.getOperand(i), InstID, Vals);
2330     }
2331   } break;
2332   case Instruction::Br: {
2333     Code = bitc::FUNC_CODE_INST_BR;
2334     const BranchInst &II = cast<BranchInst>(I);
2335     Vals.push_back(VE.getValueID(II.getSuccessor(0)));
2336     if (II.isConditional()) {
2337       Vals.push_back(VE.getValueID(II.getSuccessor(1)));
2338       pushValue(II.getCondition(), InstID, Vals);
2339     }
2340   } break;
2341   case Instruction::Switch: {
2342     Code = bitc::FUNC_CODE_INST_SWITCH;
2343     const SwitchInst &SI = cast<SwitchInst>(I);
2344     Vals.push_back(getTypeID(SI.getCondition()->getType()));
2345     pushValue(SI.getCondition(), InstID, Vals);
2346     Vals.push_back(VE.getValueID(SI.getDefaultDest()));
2347     for (auto Case : SI.cases()) {
2348       Vals.push_back(VE.getValueID(Case.getCaseValue()));
2349       Vals.push_back(VE.getValueID(Case.getCaseSuccessor()));
2350     }
2351   } break;
2352   case Instruction::IndirectBr:
2353     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
2354     Vals.push_back(getTypeID(I.getOperand(0)->getType()));
2355     // Encode the address operand as relative, but not the basic blocks.
2356     pushValue(I.getOperand(0), InstID, Vals);
2357     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
2358       Vals.push_back(VE.getValueID(I.getOperand(i)));
2359     break;
2360 
2361   case Instruction::Invoke: {
2362     const InvokeInst *II = cast<InvokeInst>(&I);
2363     const Value *Callee = II->getCalledOperand();
2364     FunctionType *FTy = II->getFunctionType();
2365     Code = bitc::FUNC_CODE_INST_INVOKE;
2366 
2367     Vals.push_back(VE.getAttributeListID(II->getAttributes()));
2368     Vals.push_back(II->getCallingConv() | 1 << 13);
2369     Vals.push_back(VE.getValueID(II->getNormalDest()));
2370     Vals.push_back(VE.getValueID(II->getUnwindDest()));
2371     Vals.push_back(getTypeID(FTy));
2372     pushValueAndType(Callee, InstID, Vals);
2373 
2374     // Emit value #'s for the fixed parameters.
2375     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
2376       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
2377 
2378     // Emit type/value pairs for varargs params.
2379     if (FTy->isVarArg()) {
2380       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands() - 3; i != e;
2381            ++i)
2382         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
2383     }
2384     break;
2385   }
2386   case Instruction::Resume:
2387     Code = bitc::FUNC_CODE_INST_RESUME;
2388     pushValueAndType(I.getOperand(0), InstID, Vals);
2389     break;
2390   case Instruction::Unreachable:
2391     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
2392     AbbrevToUse = (unsigned)FUNCTION_INST_UNREACHABLE_ABBREV;
2393     break;
2394 
2395   case Instruction::PHI: {
2396     const PHINode &PN = cast<PHINode>(I);
2397     Code = bitc::FUNC_CODE_INST_PHI;
2398     // With the newer instruction encoding, forward references could give
2399     // negative valued IDs.  This is most common for PHIs, so we use
2400     // signed VBRs.
2401     SmallVector<uint64_t, 128> Vals64;
2402     Vals64.push_back(getTypeID(PN.getType()));
2403     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
2404       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64);
2405       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
2406     }
2407     // Emit a Vals64 vector and exit.
2408     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
2409     Vals64.clear();
2410     return;
2411   }
2412 
2413   case Instruction::LandingPad: {
2414     const LandingPadInst &LP = cast<LandingPadInst>(I);
2415     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
2416     Vals.push_back(getTypeID(LP.getType()));
2417     Vals.push_back(LP.isCleanup());
2418     Vals.push_back(LP.getNumClauses());
2419     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
2420       if (LP.isCatch(I))
2421         Vals.push_back(LandingPadInst::Catch);
2422       else
2423         Vals.push_back(LandingPadInst::Filter);
2424       pushValueAndType(LP.getClause(I), InstID, Vals);
2425     }
2426     break;
2427   }
2428 
2429   case Instruction::Alloca: {
2430     Code = bitc::FUNC_CODE_INST_ALLOCA;
2431     const AllocaInst &AI = cast<AllocaInst>(I);
2432     Vals.push_back(getTypeID(AI.getAllocatedType()));
2433     Vals.push_back(getTypeID(I.getOperand(0)->getType()));
2434     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
2435     unsigned AlignRecord = Log2_32(AI.getAlign().value()) + 1;
2436     assert(AlignRecord < 1 << 5 && "alignment greater than 1 << 64");
2437     AlignRecord |= AI.isUsedWithInAlloca() << 5;
2438     AlignRecord |= 1 << 6;
2439     Vals.push_back(AlignRecord);
2440     break;
2441   }
2442 
2443   case Instruction::Load:
2444     if (cast<LoadInst>(I).isAtomic()) {
2445       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
2446       pushValueAndType(I.getOperand(0), InstID, Vals);
2447     } else {
2448       Code = bitc::FUNC_CODE_INST_LOAD;
2449       if (!pushValueAndType(I.getOperand(0), InstID, Vals)) // ptr
2450         AbbrevToUse = (unsigned)FUNCTION_INST_LOAD_ABBREV;
2451     }
2452     Vals.push_back(getTypeID(I.getType()));
2453     Vals.push_back(Log2(cast<LoadInst>(I).getAlign()) + 1);
2454     Vals.push_back(cast<LoadInst>(I).isVolatile());
2455     if (cast<LoadInst>(I).isAtomic()) {
2456       Vals.push_back(getEncodedOrdering(cast<LoadInst>(I).getOrdering()));
2457       Vals.push_back(getEncodedSyncScopeID(cast<LoadInst>(I).getSyncScopeID()));
2458     }
2459     break;
2460   case Instruction::Store:
2461     if (cast<StoreInst>(I).isAtomic())
2462       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
2463     else
2464       Code = bitc::FUNC_CODE_INST_STORE;
2465     pushValueAndType(I.getOperand(1), InstID, Vals); // ptrty + ptr
2466     pushValueAndType(I.getOperand(0), InstID, Vals); // valty + val
2467     Vals.push_back(Log2(cast<StoreInst>(I).getAlign()) + 1);
2468     Vals.push_back(cast<StoreInst>(I).isVolatile());
2469     if (cast<StoreInst>(I).isAtomic()) {
2470       Vals.push_back(getEncodedOrdering(cast<StoreInst>(I).getOrdering()));
2471       Vals.push_back(
2472           getEncodedSyncScopeID(cast<StoreInst>(I).getSyncScopeID()));
2473     }
2474     break;
2475   case Instruction::AtomicCmpXchg:
2476     Code = bitc::FUNC_CODE_INST_CMPXCHG;
2477     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
2478     pushValueAndType(I.getOperand(1), InstID, Vals); // cmp.
2479     pushValue(I.getOperand(2), InstID, Vals);        // newval.
2480     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
2481     Vals.push_back(
2482         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
2483     Vals.push_back(
2484         getEncodedSyncScopeID(cast<AtomicCmpXchgInst>(I).getSyncScopeID()));
2485     Vals.push_back(
2486         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
2487     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
2488     break;
2489   case Instruction::AtomicRMW:
2490     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
2491     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
2492     pushValue(I.getOperand(1), InstID, Vals);        // val.
2493     Vals.push_back(
2494         getEncodedRMWOperation(cast<AtomicRMWInst>(I).getOperation()));
2495     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
2496     Vals.push_back(getEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
2497     Vals.push_back(
2498         getEncodedSyncScopeID(cast<AtomicRMWInst>(I).getSyncScopeID()));
2499     break;
2500   case Instruction::Fence:
2501     Code = bitc::FUNC_CODE_INST_FENCE;
2502     Vals.push_back(getEncodedOrdering(cast<FenceInst>(I).getOrdering()));
2503     Vals.push_back(getEncodedSyncScopeID(cast<FenceInst>(I).getSyncScopeID()));
2504     break;
2505   case Instruction::Call: {
2506     const CallInst &CI = cast<CallInst>(I);
2507     FunctionType *FTy = CI.getFunctionType();
2508 
2509     Code = bitc::FUNC_CODE_INST_CALL;
2510 
2511     Vals.push_back(VE.getAttributeListID(CI.getAttributes()));
2512     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()) |
2513                    unsigned(CI.isMustTailCall()) << 14 | 1 << 15);
2514     Vals.push_back(getGlobalObjectValueTypeID(FTy, CI.getCalledFunction()));
2515     pushValueAndType(CI.getCalledOperand(), InstID, Vals); // Callee
2516 
2517     // Emit value #'s for the fixed parameters.
2518     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
2519       // Check for labels (can happen with asm labels).
2520       if (FTy->getParamType(i)->isLabelTy())
2521         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
2522       else
2523         pushValue(CI.getArgOperand(i), InstID, Vals); // fixed param.
2524     }
2525 
2526     // Emit type/value pairs for varargs params.
2527     if (FTy->isVarArg()) {
2528       for (unsigned i = FTy->getNumParams(), e = CI.arg_size(); i != e; ++i)
2529         pushValueAndType(CI.getArgOperand(i), InstID, Vals); // varargs
2530     }
2531     break;
2532   }
2533   case Instruction::VAArg:
2534     Code = bitc::FUNC_CODE_INST_VAARG;
2535     Vals.push_back(getTypeID(I.getOperand(0)->getType())); // valistty
2536     pushValue(I.getOperand(0), InstID, Vals);              // valist.
2537     Vals.push_back(getTypeID(I.getType()));                // restype.
2538     break;
2539   }
2540 
2541   Stream.EmitRecord(Code, Vals, AbbrevToUse);
2542   Vals.clear();
2543 }
2544 
2545 // Emit names for globals/functions etc.
2546 void DXILBitcodeWriter::writeFunctionLevelValueSymbolTable(
2547     const ValueSymbolTable &VST) {
2548   if (VST.empty())
2549     return;
2550   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
2551 
2552   SmallVector<unsigned, 64> NameVals;
2553 
2554   // HLSL Change
2555   // Read the named values from a sorted list instead of the original list
2556   // to ensure the binary is the same no matter what values ever existed.
2557   SmallVector<const ValueName *, 16> SortedTable;
2558 
2559   for (auto &VI : VST) {
2560     SortedTable.push_back(VI.second->getValueName());
2561   }
2562   // The keys are unique, so there shouldn't be stability issues.
2563   llvm::sort(SortedTable, [](const ValueName *A, const ValueName *B) {
2564     return A->first() < B->first();
2565   });
2566 
2567   for (const ValueName *SI : SortedTable) {
2568     auto &Name = *SI;
2569 
2570     // Figure out the encoding to use for the name.
2571     bool is7Bit = true;
2572     bool isChar6 = true;
2573     for (const char *C = Name.getKeyData(), *E = C + Name.getKeyLength();
2574          C != E; ++C) {
2575       if (isChar6)
2576         isChar6 = BitCodeAbbrevOp::isChar6(*C);
2577       if ((unsigned char)*C & 128) {
2578         is7Bit = false;
2579         break; // don't bother scanning the rest.
2580       }
2581     }
2582 
2583     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
2584 
2585     // VST_ENTRY:   [valueid, namechar x N]
2586     // VST_BBENTRY: [bbid, namechar x N]
2587     unsigned Code;
2588     if (isa<BasicBlock>(SI->getValue())) {
2589       Code = bitc::VST_CODE_BBENTRY;
2590       if (isChar6)
2591         AbbrevToUse = VST_BBENTRY_6_ABBREV;
2592     } else {
2593       Code = bitc::VST_CODE_ENTRY;
2594       if (isChar6)
2595         AbbrevToUse = VST_ENTRY_6_ABBREV;
2596       else if (is7Bit)
2597         AbbrevToUse = VST_ENTRY_7_ABBREV;
2598     }
2599 
2600     NameVals.push_back(VE.getValueID(SI->getValue()));
2601     for (const char *P = Name.getKeyData(),
2602                     *E = Name.getKeyData() + Name.getKeyLength();
2603          P != E; ++P)
2604       NameVals.push_back((unsigned char)*P);
2605 
2606     // Emit the finished record.
2607     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
2608     NameVals.clear();
2609   }
2610   Stream.ExitBlock();
2611 }
2612 
2613 /// Emit a function body to the module stream.
2614 void DXILBitcodeWriter::writeFunction(const Function &F) {
2615   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
2616   VE.incorporateFunction(F);
2617 
2618   SmallVector<unsigned, 64> Vals;
2619 
2620   // Emit the number of basic blocks, so the reader can create them ahead of
2621   // time.
2622   Vals.push_back(VE.getBasicBlocks().size());
2623   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
2624   Vals.clear();
2625 
2626   // If there are function-local constants, emit them now.
2627   unsigned CstStart, CstEnd;
2628   VE.getFunctionConstantRange(CstStart, CstEnd);
2629   writeConstants(CstStart, CstEnd, false);
2630 
2631   // If there is function-local metadata, emit it now.
2632   writeFunctionMetadata(F);
2633 
2634   // Keep a running idea of what the instruction ID is.
2635   unsigned InstID = CstEnd;
2636 
2637   bool NeedsMetadataAttachment = F.hasMetadata();
2638 
2639   DILocation *LastDL = nullptr;
2640 
2641   // Finally, emit all the instructions, in order.
2642   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
2643     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E;
2644          ++I) {
2645       writeInstruction(*I, InstID, Vals);
2646 
2647       if (!I->getType()->isVoidTy())
2648         ++InstID;
2649 
2650       // If the instruction has metadata, write a metadata attachment later.
2651       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
2652 
2653       // If the instruction has a debug location, emit it.
2654       DILocation *DL = I->getDebugLoc();
2655       if (!DL)
2656         continue;
2657 
2658       if (DL == LastDL) {
2659         // Just repeat the same debug loc as last time.
2660         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
2661         continue;
2662       }
2663 
2664       Vals.push_back(DL->getLine());
2665       Vals.push_back(DL->getColumn());
2666       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
2667       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
2668       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
2669       Vals.clear();
2670 
2671       LastDL = DL;
2672     }
2673 
2674   // Emit names for all the instructions etc.
2675   if (auto *Symtab = F.getValueSymbolTable())
2676     writeFunctionLevelValueSymbolTable(*Symtab);
2677 
2678   if (NeedsMetadataAttachment)
2679     writeFunctionMetadataAttachment(F);
2680 
2681   VE.purgeFunction();
2682   Stream.ExitBlock();
2683 }
2684 
2685 // Emit blockinfo, which defines the standard abbreviations etc.
2686 void DXILBitcodeWriter::writeBlockInfo() {
2687   // We only want to emit block info records for blocks that have multiple
2688   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
2689   // Other blocks can define their abbrevs inline.
2690   Stream.EnterBlockInfoBlock();
2691 
2692   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
2693     auto Abbv = std::make_shared<BitCodeAbbrev>();
2694     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
2695     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2696     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2697     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2698     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2699                                    std::move(Abbv)) != VST_ENTRY_8_ABBREV)
2700       assert(false && "Unexpected abbrev ordering!");
2701   }
2702 
2703   { // 7-bit fixed width VST_ENTRY strings.
2704     auto Abbv = std::make_shared<BitCodeAbbrev>();
2705     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2706     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2707     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2708     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2709     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2710                                    std::move(Abbv)) != VST_ENTRY_7_ABBREV)
2711       assert(false && "Unexpected abbrev ordering!");
2712   }
2713   { // 6-bit char6 VST_ENTRY strings.
2714     auto Abbv = std::make_shared<BitCodeAbbrev>();
2715     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2716     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2717     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2718     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2719     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2720                                    std::move(Abbv)) != VST_ENTRY_6_ABBREV)
2721       assert(false && "Unexpected abbrev ordering!");
2722   }
2723   { // 6-bit char6 VST_BBENTRY strings.
2724     auto Abbv = std::make_shared<BitCodeAbbrev>();
2725     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
2726     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2727     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2728     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2729     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2730                                    std::move(Abbv)) != VST_BBENTRY_6_ABBREV)
2731       assert(false && "Unexpected abbrev ordering!");
2732   }
2733 
2734   { // SETTYPE abbrev for CONSTANTS_BLOCK.
2735     auto Abbv = std::make_shared<BitCodeAbbrev>();
2736     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
2737     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2738                               VE.computeBitsRequiredForTypeIndices()));
2739     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2740         CONSTANTS_SETTYPE_ABBREV)
2741       assert(false && "Unexpected abbrev ordering!");
2742   }
2743 
2744   { // INTEGER abbrev for CONSTANTS_BLOCK.
2745     auto Abbv = std::make_shared<BitCodeAbbrev>();
2746     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
2747     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2748     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2749         CONSTANTS_INTEGER_ABBREV)
2750       assert(false && "Unexpected abbrev ordering!");
2751   }
2752 
2753   { // CE_CAST abbrev for CONSTANTS_BLOCK.
2754     auto Abbv = std::make_shared<BitCodeAbbrev>();
2755     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
2756     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // cast opc
2757     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,      // typeid
2758                               VE.computeBitsRequiredForTypeIndices()));
2759     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
2760 
2761     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2762         CONSTANTS_CE_CAST_Abbrev)
2763       assert(false && "Unexpected abbrev ordering!");
2764   }
2765   { // NULL abbrev for CONSTANTS_BLOCK.
2766     auto Abbv = std::make_shared<BitCodeAbbrev>();
2767     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
2768     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2769         CONSTANTS_NULL_Abbrev)
2770       assert(false && "Unexpected abbrev ordering!");
2771   }
2772 
2773   // FIXME: This should only use space for first class types!
2774 
2775   { // INST_LOAD abbrev for FUNCTION_BLOCK.
2776     auto Abbv = std::make_shared<BitCodeAbbrev>();
2777     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
2778     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
2779     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2780                               VE.computeBitsRequiredForTypeIndices()));
2781     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // Align
2782     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
2783     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2784         (unsigned)FUNCTION_INST_LOAD_ABBREV)
2785       assert(false && "Unexpected abbrev ordering!");
2786   }
2787   { // INST_BINOP abbrev for FUNCTION_BLOCK.
2788     auto Abbv = std::make_shared<BitCodeAbbrev>();
2789     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2790     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LHS
2791     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // RHS
2792     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2793     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2794         (unsigned)FUNCTION_INST_BINOP_ABBREV)
2795       assert(false && "Unexpected abbrev ordering!");
2796   }
2797   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
2798     auto Abbv = std::make_shared<BitCodeAbbrev>();
2799     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2800     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LHS
2801     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // RHS
2802     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2803     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
2804     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2805         (unsigned)FUNCTION_INST_BINOP_FLAGS_ABBREV)
2806       assert(false && "Unexpected abbrev ordering!");
2807   }
2808   { // INST_CAST abbrev for FUNCTION_BLOCK.
2809     auto Abbv = std::make_shared<BitCodeAbbrev>();
2810     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
2811     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // OpVal
2812     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2813                               VE.computeBitsRequiredForTypeIndices()));
2814     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2815     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2816         (unsigned)FUNCTION_INST_CAST_ABBREV)
2817       assert(false && "Unexpected abbrev ordering!");
2818   }
2819 
2820   { // INST_RET abbrev for FUNCTION_BLOCK.
2821     auto Abbv = std::make_shared<BitCodeAbbrev>();
2822     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2823     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2824         (unsigned)FUNCTION_INST_RET_VOID_ABBREV)
2825       assert(false && "Unexpected abbrev ordering!");
2826   }
2827   { // INST_RET abbrev for FUNCTION_BLOCK.
2828     auto Abbv = std::make_shared<BitCodeAbbrev>();
2829     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2830     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
2831     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2832         (unsigned)FUNCTION_INST_RET_VAL_ABBREV)
2833       assert(false && "Unexpected abbrev ordering!");
2834   }
2835   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
2836     auto Abbv = std::make_shared<BitCodeAbbrev>();
2837     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
2838     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2839         (unsigned)FUNCTION_INST_UNREACHABLE_ABBREV)
2840       assert(false && "Unexpected abbrev ordering!");
2841   }
2842   {
2843     auto Abbv = std::make_shared<BitCodeAbbrev>();
2844     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
2845     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2846     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
2847                               Log2_32_Ceil(VE.getTypes().size() + 1)));
2848     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2849     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2850     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2851         (unsigned)FUNCTION_INST_GEP_ABBREV)
2852       assert(false && "Unexpected abbrev ordering!");
2853   }
2854 
2855   Stream.ExitBlock();
2856 }
2857 
2858 void DXILBitcodeWriter::writeModuleVersion() {
2859   // VERSION: [version#]
2860   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, ArrayRef<unsigned>{1});
2861 }
2862 
2863 /// WriteModule - Emit the specified module to the bitstream.
2864 void DXILBitcodeWriter::write() {
2865   // The identification block is new since llvm-3.7, but the old bitcode reader
2866   // will skip it.
2867   // writeIdentificationBlock(Stream);
2868 
2869   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
2870 
2871   // It is redundant to fully-specify this here, but nice to make it explicit
2872   // so that it is clear the DXIL module version is different.
2873   DXILBitcodeWriter::writeModuleVersion();
2874 
2875   // Emit blockinfo, which defines the standard abbreviations etc.
2876   writeBlockInfo();
2877 
2878   // Emit information about attribute groups.
2879   writeAttributeGroupTable();
2880 
2881   // Emit information about parameter attributes.
2882   writeAttributeTable();
2883 
2884   // Emit information describing all of the types in the module.
2885   writeTypeTable();
2886 
2887   writeComdats();
2888 
2889   // Emit top-level description of module, including target triple, inline asm,
2890   // descriptors for global variables, and function prototype info.
2891   writeModuleInfo();
2892 
2893   // Emit constants.
2894   writeModuleConstants();
2895 
2896   // Emit metadata.
2897   writeModuleMetadataKinds();
2898 
2899   // Emit metadata.
2900   writeModuleMetadata();
2901 
2902   // Emit names for globals/functions etc.
2903   // DXIL uses the same format for module-level value symbol table as for the
2904   // function level table.
2905   writeFunctionLevelValueSymbolTable(M.getValueSymbolTable());
2906 
2907   // Emit function bodies.
2908   for (const Function &F : M)
2909     if (!F.isDeclaration())
2910       writeFunction(F);
2911 
2912   Stream.ExitBlock();
2913 }
2914