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 "llvm/ADT/Triple.h"
16 #include "llvm/Bitcode/BitcodeCommon.h"
17 #include "llvm/Bitcode/BitcodeReader.h"
18 #include "llvm/Bitcode/LLVMBitCodes.h"
19 #include "llvm/Bitstream/BitCodes.h"
20 #include "llvm/Bitstream/BitstreamWriter.h"
21 #include "llvm/IR/Attributes.h"
22 #include "llvm/IR/BasicBlock.h"
23 #include "llvm/IR/Comdat.h"
24 #include "llvm/IR/Constant.h"
25 #include "llvm/IR/Constants.h"
26 #include "llvm/IR/DebugInfoMetadata.h"
27 #include "llvm/IR/DebugLoc.h"
28 #include "llvm/IR/DerivedTypes.h"
29 #include "llvm/IR/Function.h"
30 #include "llvm/IR/GlobalAlias.h"
31 #include "llvm/IR/GlobalIFunc.h"
32 #include "llvm/IR/GlobalObject.h"
33 #include "llvm/IR/GlobalValue.h"
34 #include "llvm/IR/GlobalVariable.h"
35 #include "llvm/IR/InlineAsm.h"
36 #include "llvm/IR/InstrTypes.h"
37 #include "llvm/IR/Instruction.h"
38 #include "llvm/IR/Instructions.h"
39 #include "llvm/IR/LLVMContext.h"
40 #include "llvm/IR/Metadata.h"
41 #include "llvm/IR/Module.h"
42 #include "llvm/IR/ModuleSummaryIndex.h"
43 #include "llvm/IR/Operator.h"
44 #include "llvm/IR/Type.h"
45 #include "llvm/IR/UseListOrder.h"
46 #include "llvm/IR/Value.h"
47 #include "llvm/IR/ValueSymbolTable.h"
48 #include "llvm/Object/IRSymtab.h"
49 #include "llvm/Support/ErrorHandling.h"
50 #include "llvm/Support/SHA1.h"
51 
52 namespace llvm {
53 namespace dxil {
54 
55 // Generates an enum to use as an index in the Abbrev array of Metadata record.
56 enum MetadataAbbrev : unsigned {
57 #define HANDLE_MDNODE_LEAF(CLASS) CLASS##AbbrevID,
58 #include "llvm/IR/Metadata.def"
59   LastPlusOne
60 };
61 
62 class DXILBitcodeWriter {
63 
64   /// These are manifest constants used by the bitcode writer. They do not need
65   /// to be kept in sync with the reader, but need to be consistent within this
66   /// file.
67   enum {
68     // VALUE_SYMTAB_BLOCK abbrev id's.
69     VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
70     VST_ENTRY_7_ABBREV,
71     VST_ENTRY_6_ABBREV,
72     VST_BBENTRY_6_ABBREV,
73 
74     // CONSTANTS_BLOCK abbrev id's.
75     CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
76     CONSTANTS_INTEGER_ABBREV,
77     CONSTANTS_CE_CAST_Abbrev,
78     CONSTANTS_NULL_Abbrev,
79 
80     // FUNCTION_BLOCK abbrev id's.
81     FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
82     FUNCTION_INST_BINOP_ABBREV,
83     FUNCTION_INST_BINOP_FLAGS_ABBREV,
84     FUNCTION_INST_CAST_ABBREV,
85     FUNCTION_INST_RET_VOID_ABBREV,
86     FUNCTION_INST_RET_VAL_ABBREV,
87     FUNCTION_INST_UNREACHABLE_ABBREV,
88     FUNCTION_INST_GEP_ABBREV,
89   };
90 
91   /// The stream created and owned by the client.
92   BitstreamWriter &Stream;
93 
94   StringTableBuilder &StrtabBuilder;
95 
96   /// The Module to write to bitcode.
97   const Module &M;
98 
99   /// Enumerates ids for all values in the module.
100   ValueEnumerator VE;
101 
102   /// Map that holds the correspondence between GUIDs in the summary index,
103   /// that came from indirect call profiles, and a value id generated by this
104   /// class to use in the VST and summary block records.
105   std::map<GlobalValue::GUID, unsigned> GUIDToValueIdMap;
106 
107   /// Tracks the last value id recorded in the GUIDToValueMap.
108   unsigned GlobalValueId;
109 
110   /// Saves the offset of the VSTOffset record that must eventually be
111   /// backpatched with the offset of the actual VST.
112   uint64_t VSTOffsetPlaceholder = 0;
113 
114   /// Pointer to the buffer allocated by caller for bitcode writing.
115   const SmallVectorImpl<char> &Buffer;
116 
117   /// The start bit of the identification block.
118   uint64_t BitcodeStartBit;
119 
120 public:
121   /// Constructs a ModuleBitcodeWriter object for the given Module,
122   /// writing to the provided \p Buffer.
123   DXILBitcodeWriter(const Module &M, SmallVectorImpl<char> &Buffer,
124                     StringTableBuilder &StrtabBuilder, BitstreamWriter &Stream)
125       : Stream(Stream), StrtabBuilder(StrtabBuilder), M(M),
126         VE(M, true), Buffer(Buffer),
127         BitcodeStartBit(Stream.GetCurrentBitNo()) {
128     GlobalValueId = VE.getValues().size();
129   }
130 
131   /// Emit the current module to the bitstream.
132   void write();
133 
134   static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind);
135   static void writeStringRecord(BitstreamWriter &Stream, unsigned Code,
136                                 StringRef Str, unsigned AbbrevToUse);
137   static void writeIdentificationBlock(BitstreamWriter &Stream);
138   static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V);
139   static void emitWideAPInt(SmallVectorImpl<uint64_t> &Vals, const APInt &A);
140 
141   static unsigned getEncodedComdatSelectionKind(const Comdat &C);
142   static unsigned getEncodedLinkage(const GlobalValue::LinkageTypes Linkage);
143   static unsigned getEncodedLinkage(const GlobalValue &GV);
144   static unsigned getEncodedVisibility(const GlobalValue &GV);
145   static unsigned getEncodedThreadLocalMode(const GlobalValue &GV);
146   static unsigned getEncodedDLLStorageClass(const GlobalValue &GV);
147   static unsigned getEncodedCastOpcode(unsigned Opcode);
148   static unsigned getEncodedUnaryOpcode(unsigned Opcode);
149   static unsigned getEncodedBinaryOpcode(unsigned Opcode);
150   static unsigned getEncodedRMWOperation(AtomicRMWInst::BinOp Op);
151   static unsigned getEncodedOrdering(AtomicOrdering Ordering);
152   static uint64_t getOptimizationFlags(const Value *V);
153 
154 private:
155   void writeModuleVersion();
156   void writePerModuleGlobalValueSummary();
157 
158   void writePerModuleFunctionSummaryRecord(SmallVector<uint64_t, 64> &NameVals,
159                                            GlobalValueSummary *Summary,
160                                            unsigned ValueID,
161                                            unsigned FSCallsAbbrev,
162                                            unsigned FSCallsProfileAbbrev,
163                                            const Function &F);
164   void writeModuleLevelReferences(const GlobalVariable &V,
165                                   SmallVector<uint64_t, 64> &NameVals,
166                                   unsigned FSModRefsAbbrev,
167                                   unsigned FSModVTableRefsAbbrev);
168 
169   void assignValueId(GlobalValue::GUID ValGUID) {
170     GUIDToValueIdMap[ValGUID] = ++GlobalValueId;
171   }
172 
173   unsigned getValueId(GlobalValue::GUID ValGUID) {
174     const auto &VMI = GUIDToValueIdMap.find(ValGUID);
175     // Expect that any GUID value had a value Id assigned by an
176     // earlier call to assignValueId.
177     assert(VMI != GUIDToValueIdMap.end() &&
178            "GUID does not have assigned value Id");
179     return VMI->second;
180   }
181 
182   // Helper to get the valueId for the type of value recorded in VI.
183   unsigned getValueId(ValueInfo VI) {
184     if (!VI.haveGVs() || !VI.getValue())
185       return getValueId(VI.getGUID());
186     return VE.getValueID(VI.getValue());
187   }
188 
189   std::map<GlobalValue::GUID, unsigned> &valueIds() { return GUIDToValueIdMap; }
190 
191   uint64_t bitcodeStartBit() { return BitcodeStartBit; }
192 
193   size_t addToStrtab(StringRef Str);
194 
195   unsigned createDILocationAbbrev();
196   unsigned createGenericDINodeAbbrev();
197 
198   void writeAttributeGroupTable();
199   void writeAttributeTable();
200   void writeTypeTable();
201   void writeComdats();
202   void writeValueSymbolTableForwardDecl();
203   void writeModuleInfo();
204   void writeValueAsMetadata(const ValueAsMetadata *MD,
205                             SmallVectorImpl<uint64_t> &Record);
206   void writeMDTuple(const MDTuple *N, SmallVectorImpl<uint64_t> &Record,
207                     unsigned Abbrev);
208   void writeDILocation(const DILocation *N, SmallVectorImpl<uint64_t> &Record,
209                        unsigned &Abbrev);
210   void writeGenericDINode(const GenericDINode *N,
211                           SmallVectorImpl<uint64_t> &Record, unsigned &Abbrev) {
212     llvm_unreachable("DXIL cannot contain GenericDI Nodes");
213   }
214   void writeDISubrange(const DISubrange *N, SmallVectorImpl<uint64_t> &Record,
215                        unsigned Abbrev);
216   void writeDIGenericSubrange(const DIGenericSubrange *N,
217                               SmallVectorImpl<uint64_t> &Record,
218                               unsigned Abbrev) {
219     llvm_unreachable("DXIL cannot contain DIGenericSubrange Nodes");
220   }
221   void writeDIEnumerator(const DIEnumerator *N,
222                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
223   void writeDIBasicType(const DIBasicType *N, SmallVectorImpl<uint64_t> &Record,
224                         unsigned Abbrev);
225   void writeDIStringType(const DIStringType *N,
226                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
227     llvm_unreachable("DXIL cannot contain DIStringType Nodes");
228   }
229   void writeDIDerivedType(const DIDerivedType *N,
230                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
231   void writeDICompositeType(const DICompositeType *N,
232                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
233   void writeDISubroutineType(const DISubroutineType *N,
234                              SmallVectorImpl<uint64_t> &Record,
235                              unsigned Abbrev);
236   void writeDIFile(const DIFile *N, SmallVectorImpl<uint64_t> &Record,
237                    unsigned Abbrev);
238   void writeDICompileUnit(const DICompileUnit *N,
239                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
240   void writeDISubprogram(const DISubprogram *N,
241                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
242   void writeDILexicalBlock(const DILexicalBlock *N,
243                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
244   void writeDILexicalBlockFile(const DILexicalBlockFile *N,
245                                SmallVectorImpl<uint64_t> &Record,
246                                unsigned Abbrev);
247   void writeDICommonBlock(const DICommonBlock *N,
248                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
249     llvm_unreachable("DXIL cannot contain DICommonBlock Nodes");
250   }
251   void writeDINamespace(const DINamespace *N, SmallVectorImpl<uint64_t> &Record,
252                         unsigned Abbrev);
253   void writeDIMacro(const DIMacro *N, SmallVectorImpl<uint64_t> &Record,
254                     unsigned Abbrev) {
255     llvm_unreachable("DXIL cannot contain DIMacro Nodes");
256   }
257   void writeDIMacroFile(const DIMacroFile *N, SmallVectorImpl<uint64_t> &Record,
258                         unsigned Abbrev) {
259     llvm_unreachable("DXIL cannot contain DIMacroFile Nodes");
260   }
261   void writeDIArgList(const DIArgList *N, SmallVectorImpl<uint64_t> &Record,
262                       unsigned Abbrev) {
263     llvm_unreachable("DXIL cannot contain DIArgList Nodes");
264   }
265   void writeDIModule(const DIModule *N, SmallVectorImpl<uint64_t> &Record,
266                      unsigned Abbrev);
267   void writeDITemplateTypeParameter(const DITemplateTypeParameter *N,
268                                     SmallVectorImpl<uint64_t> &Record,
269                                     unsigned Abbrev);
270   void writeDITemplateValueParameter(const DITemplateValueParameter *N,
271                                      SmallVectorImpl<uint64_t> &Record,
272                                      unsigned Abbrev);
273   void writeDIGlobalVariable(const DIGlobalVariable *N,
274                              SmallVectorImpl<uint64_t> &Record,
275                              unsigned Abbrev);
276   void writeDILocalVariable(const DILocalVariable *N,
277                             SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
278   void writeDILabel(const DILabel *N, SmallVectorImpl<uint64_t> &Record,
279                     unsigned Abbrev) {
280     llvm_unreachable("DXIL cannot contain DILabel Nodes");
281   }
282   void writeDIExpression(const DIExpression *N,
283                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
284   void writeDIGlobalVariableExpression(const DIGlobalVariableExpression *N,
285                                        SmallVectorImpl<uint64_t> &Record,
286                                        unsigned Abbrev) {
287     llvm_unreachable("DXIL cannot contain GlobalVariableExpression Nodes");
288   }
289   void writeDIObjCProperty(const DIObjCProperty *N,
290                            SmallVectorImpl<uint64_t> &Record, unsigned Abbrev);
291   void writeDIImportedEntity(const DIImportedEntity *N,
292                              SmallVectorImpl<uint64_t> &Record,
293                              unsigned Abbrev);
294   unsigned createNamedMetadataAbbrev();
295   void writeNamedMetadata(SmallVectorImpl<uint64_t> &Record);
296   unsigned createMetadataStringsAbbrev();
297   void writeMetadataStrings(ArrayRef<const Metadata *> Strings,
298                             SmallVectorImpl<uint64_t> &Record);
299   void writeMetadataRecords(ArrayRef<const Metadata *> MDs,
300                             SmallVectorImpl<uint64_t> &Record,
301                             std::vector<unsigned> *MDAbbrevs = nullptr,
302                             std::vector<uint64_t> *IndexPos = nullptr);
303   void writeModuleMetadata();
304   void writeFunctionMetadata(const Function &F);
305   void writeFunctionMetadataAttachment(const Function &F);
306   void pushGlobalMetadataAttachment(SmallVectorImpl<uint64_t> &Record,
307                                     const GlobalObject &GO);
308   void writeModuleMetadataKinds();
309   void writeOperandBundleTags();
310   void writeSyncScopeNames();
311   void writeConstants(unsigned FirstVal, unsigned LastVal, bool isGlobal);
312   void writeModuleConstants();
313   bool pushValueAndType(const Value *V, unsigned InstID,
314                         SmallVectorImpl<unsigned> &Vals);
315   void writeOperandBundles(const CallBase &CB, unsigned InstID);
316   void pushValue(const Value *V, unsigned InstID,
317                  SmallVectorImpl<unsigned> &Vals);
318   void pushValueSigned(const Value *V, unsigned InstID,
319                        SmallVectorImpl<uint64_t> &Vals);
320   void writeInstruction(const Instruction &I, unsigned InstID,
321                         SmallVectorImpl<unsigned> &Vals);
322   void writeFunctionLevelValueSymbolTable(const ValueSymbolTable &VST);
323   void writeGlobalValueSymbolTable(
324       DenseMap<const Function *, uint64_t> &FunctionToBitcodeIndex);
325   void writeUseList(UseListOrder &&Order);
326   void writeUseListBlock(const Function *F);
327   void writeFunction(const Function &F);
328   void writeBlockInfo();
329 
330   unsigned getEncodedSyncScopeID(SyncScope::ID SSID) { return unsigned(SSID); }
331 
332   unsigned getEncodedAlign(MaybeAlign Alignment) { return encode(Alignment); }
333 };
334 
335 } // namespace dxil
336 } // namespace llvm
337 
338 using namespace llvm;
339 using namespace llvm::dxil;
340 
341 ////////////////////////////////////////////////////////////////////////////////
342 /// Begin dxil::BitcodeWriter Implementation
343 ////////////////////////////////////////////////////////////////////////////////
344 
345 dxil::BitcodeWriter::BitcodeWriter(SmallVectorImpl<char> &Buffer, raw_fd_stream *FS)
346     : Buffer(Buffer), Stream(new BitstreamWriter(Buffer, FS, 512)) {
347   // Emit the file header.
348   Stream->Emit((unsigned)'B', 8);
349   Stream->Emit((unsigned)'C', 8);
350   Stream->Emit(0x0, 4);
351   Stream->Emit(0xC, 4);
352   Stream->Emit(0xE, 4);
353   Stream->Emit(0xD, 4);
354 }
355 
356 dxil::BitcodeWriter::~BitcodeWriter() { assert(WroteStrtab); }
357 
358 /// Write the specified module to the specified output stream.
359 void dxil::WriteDXILToFile(const Module &M, raw_ostream &Out) {
360   SmallVector<char, 0> Buffer;
361   Buffer.reserve(256 * 1024);
362 
363   // If this is darwin or another generic macho target, reserve space for the
364   // header.
365   Triple TT(M.getTargetTriple());
366   if (TT.isOSDarwin() || TT.isOSBinFormatMachO())
367     Buffer.insert(Buffer.begin(), BWH_HeaderSize, 0);
368 
369   BitcodeWriter Writer(Buffer, dyn_cast<raw_fd_stream>(&Out));
370   Writer.writeModule(M);
371   Writer.writeSymtab();
372   Writer.writeStrtab();
373 
374   // Write the generated bitstream to "Out".
375   if (!Buffer.empty())
376     Out.write((char *)&Buffer.front(), Buffer.size());
377 }
378 
379 void BitcodeWriter::writeBlob(unsigned Block, unsigned Record, StringRef Blob) {
380   Stream->EnterSubblock(Block, 3);
381 
382   auto Abbv = std::make_shared<BitCodeAbbrev>();
383   Abbv->Add(BitCodeAbbrevOp(Record));
384   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
385   auto AbbrevNo = Stream->EmitAbbrev(std::move(Abbv));
386 
387   Stream->EmitRecordWithBlob(AbbrevNo, ArrayRef<uint64_t>{Record}, Blob);
388 
389   Stream->ExitBlock();
390 }
391 
392 void BitcodeWriter::writeSymtab() {
393   assert(!WroteStrtab && !WroteSymtab);
394 
395   // If any module has module-level inline asm, we will require a registered asm
396   // parser for the target so that we can create an accurate symbol table for
397   // the module.
398   for (Module *M : Mods) {
399     if (M->getModuleInlineAsm().empty())
400       continue;
401   }
402 
403   WroteSymtab = true;
404   SmallVector<char, 0> Symtab;
405   // The irsymtab::build function may be unable to create a symbol table if the
406   // module is malformed (e.g. it contains an invalid alias). Writing a symbol
407   // table is not required for correctness, but we still want to be able to
408   // write malformed modules to bitcode files, so swallow the error.
409   if (Error E = irsymtab::build(Mods, Symtab, StrtabBuilder, Alloc)) {
410     consumeError(std::move(E));
411     return;
412   }
413 
414   writeBlob(bitc::SYMTAB_BLOCK_ID, bitc::SYMTAB_BLOB,
415             {Symtab.data(), Symtab.size()});
416 }
417 
418 void BitcodeWriter::writeStrtab() {
419   assert(!WroteStrtab);
420 
421   std::vector<char> Strtab;
422   StrtabBuilder.finalizeInOrder();
423   Strtab.resize(StrtabBuilder.getSize());
424   StrtabBuilder.write((uint8_t *)Strtab.data());
425 
426   writeBlob(bitc::STRTAB_BLOCK_ID, bitc::STRTAB_BLOB,
427             {Strtab.data(), Strtab.size()});
428 
429   WroteStrtab = true;
430 }
431 
432 void BitcodeWriter::copyStrtab(StringRef Strtab) {
433   writeBlob(bitc::STRTAB_BLOCK_ID, bitc::STRTAB_BLOB, Strtab);
434   WroteStrtab = true;
435 }
436 
437 void BitcodeWriter::writeModule(const Module &M) {
438   assert(!WroteStrtab);
439 
440   // The Mods vector is used by irsymtab::build, which requires non-const
441   // Modules in case it needs to materialize metadata. But the bitcode writer
442   // requires that the module is materialized, so we can cast to non-const here,
443   // after checking that it is in fact materialized.
444   assert(M.isMaterialized());
445   Mods.push_back(const_cast<Module *>(&M));
446 
447   DXILBitcodeWriter ModuleWriter(M, Buffer, StrtabBuilder, *Stream);
448   ModuleWriter.write();
449 }
450 
451 ////////////////////////////////////////////////////////////////////////////////
452 /// Begin dxil::BitcodeWriterBase Implementation
453 ////////////////////////////////////////////////////////////////////////////////
454 
455 unsigned DXILBitcodeWriter::getEncodedCastOpcode(unsigned Opcode) {
456   switch (Opcode) {
457   default:
458     llvm_unreachable("Unknown cast instruction!");
459   case Instruction::Trunc:
460     return bitc::CAST_TRUNC;
461   case Instruction::ZExt:
462     return bitc::CAST_ZEXT;
463   case Instruction::SExt:
464     return bitc::CAST_SEXT;
465   case Instruction::FPToUI:
466     return bitc::CAST_FPTOUI;
467   case Instruction::FPToSI:
468     return bitc::CAST_FPTOSI;
469   case Instruction::UIToFP:
470     return bitc::CAST_UITOFP;
471   case Instruction::SIToFP:
472     return bitc::CAST_SITOFP;
473   case Instruction::FPTrunc:
474     return bitc::CAST_FPTRUNC;
475   case Instruction::FPExt:
476     return bitc::CAST_FPEXT;
477   case Instruction::PtrToInt:
478     return bitc::CAST_PTRTOINT;
479   case Instruction::IntToPtr:
480     return bitc::CAST_INTTOPTR;
481   case Instruction::BitCast:
482     return bitc::CAST_BITCAST;
483   case Instruction::AddrSpaceCast:
484     return bitc::CAST_ADDRSPACECAST;
485   }
486 }
487 
488 unsigned DXILBitcodeWriter::getEncodedUnaryOpcode(unsigned Opcode) {
489   switch (Opcode) {
490   default:
491     llvm_unreachable("Unknown binary instruction!");
492   case Instruction::FNeg:
493     return bitc::UNOP_FNEG;
494   }
495 }
496 
497 unsigned DXILBitcodeWriter::getEncodedBinaryOpcode(unsigned Opcode) {
498   switch (Opcode) {
499   default:
500     llvm_unreachable("Unknown binary instruction!");
501   case Instruction::Add:
502   case Instruction::FAdd:
503     return bitc::BINOP_ADD;
504   case Instruction::Sub:
505   case Instruction::FSub:
506     return bitc::BINOP_SUB;
507   case Instruction::Mul:
508   case Instruction::FMul:
509     return bitc::BINOP_MUL;
510   case Instruction::UDiv:
511     return bitc::BINOP_UDIV;
512   case Instruction::FDiv:
513   case Instruction::SDiv:
514     return bitc::BINOP_SDIV;
515   case Instruction::URem:
516     return bitc::BINOP_UREM;
517   case Instruction::FRem:
518   case Instruction::SRem:
519     return bitc::BINOP_SREM;
520   case Instruction::Shl:
521     return bitc::BINOP_SHL;
522   case Instruction::LShr:
523     return bitc::BINOP_LSHR;
524   case Instruction::AShr:
525     return bitc::BINOP_ASHR;
526   case Instruction::And:
527     return bitc::BINOP_AND;
528   case Instruction::Or:
529     return bitc::BINOP_OR;
530   case Instruction::Xor:
531     return bitc::BINOP_XOR;
532   }
533 }
534 
535 unsigned DXILBitcodeWriter::getEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
536   switch (Op) {
537   default:
538     llvm_unreachable("Unknown RMW operation!");
539   case AtomicRMWInst::Xchg:
540     return bitc::RMW_XCHG;
541   case AtomicRMWInst::Add:
542     return bitc::RMW_ADD;
543   case AtomicRMWInst::Sub:
544     return bitc::RMW_SUB;
545   case AtomicRMWInst::And:
546     return bitc::RMW_AND;
547   case AtomicRMWInst::Nand:
548     return bitc::RMW_NAND;
549   case AtomicRMWInst::Or:
550     return bitc::RMW_OR;
551   case AtomicRMWInst::Xor:
552     return bitc::RMW_XOR;
553   case AtomicRMWInst::Max:
554     return bitc::RMW_MAX;
555   case AtomicRMWInst::Min:
556     return bitc::RMW_MIN;
557   case AtomicRMWInst::UMax:
558     return bitc::RMW_UMAX;
559   case AtomicRMWInst::UMin:
560     return bitc::RMW_UMIN;
561   case AtomicRMWInst::FAdd:
562     return bitc::RMW_FADD;
563   case AtomicRMWInst::FSub:
564     return bitc::RMW_FSUB;
565   }
566 }
567 
568 unsigned DXILBitcodeWriter::getEncodedOrdering(AtomicOrdering Ordering) {
569   switch (Ordering) {
570   case AtomicOrdering::NotAtomic:
571     return bitc::ORDERING_NOTATOMIC;
572   case AtomicOrdering::Unordered:
573     return bitc::ORDERING_UNORDERED;
574   case AtomicOrdering::Monotonic:
575     return bitc::ORDERING_MONOTONIC;
576   case AtomicOrdering::Acquire:
577     return bitc::ORDERING_ACQUIRE;
578   case AtomicOrdering::Release:
579     return bitc::ORDERING_RELEASE;
580   case AtomicOrdering::AcquireRelease:
581     return bitc::ORDERING_ACQREL;
582   case AtomicOrdering::SequentiallyConsistent:
583     return bitc::ORDERING_SEQCST;
584   }
585   llvm_unreachable("Invalid ordering");
586 }
587 
588 void DXILBitcodeWriter::writeStringRecord(BitstreamWriter &Stream,
589                                           unsigned Code, StringRef Str,
590                                           unsigned AbbrevToUse) {
591   SmallVector<unsigned, 64> Vals;
592 
593   // Code: [strchar x N]
594   for (char C : Str) {
595     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(C))
596       AbbrevToUse = 0;
597     Vals.push_back(C);
598   }
599 
600   // Emit the finished record.
601   Stream.EmitRecord(Code, Vals, AbbrevToUse);
602 }
603 
604 uint64_t DXILBitcodeWriter::getAttrKindEncoding(Attribute::AttrKind Kind) {
605   switch (Kind) {
606   case Attribute::Alignment:
607     return bitc::ATTR_KIND_ALIGNMENT;
608   case Attribute::AllocAlign:
609     return bitc::ATTR_KIND_ALLOC_ALIGN;
610   case Attribute::AllocSize:
611     return bitc::ATTR_KIND_ALLOC_SIZE;
612   case Attribute::AlwaysInline:
613     return bitc::ATTR_KIND_ALWAYS_INLINE;
614   case Attribute::ArgMemOnly:
615     return bitc::ATTR_KIND_ARGMEMONLY;
616   case Attribute::Builtin:
617     return bitc::ATTR_KIND_BUILTIN;
618   case Attribute::ByVal:
619     return bitc::ATTR_KIND_BY_VAL;
620   case Attribute::Convergent:
621     return bitc::ATTR_KIND_CONVERGENT;
622   case Attribute::InAlloca:
623     return bitc::ATTR_KIND_IN_ALLOCA;
624   case Attribute::Cold:
625     return bitc::ATTR_KIND_COLD;
626   case Attribute::DisableSanitizerInstrumentation:
627     return bitc::ATTR_KIND_DISABLE_SANITIZER_INSTRUMENTATION;
628   case Attribute::Hot:
629     return bitc::ATTR_KIND_HOT;
630   case Attribute::ElementType:
631     return bitc::ATTR_KIND_ELEMENTTYPE;
632   case Attribute::InaccessibleMemOnly:
633     return bitc::ATTR_KIND_INACCESSIBLEMEM_ONLY;
634   case Attribute::InaccessibleMemOrArgMemOnly:
635     return bitc::ATTR_KIND_INACCESSIBLEMEM_OR_ARGMEMONLY;
636   case Attribute::InlineHint:
637     return bitc::ATTR_KIND_INLINE_HINT;
638   case Attribute::InReg:
639     return bitc::ATTR_KIND_IN_REG;
640   case Attribute::JumpTable:
641     return bitc::ATTR_KIND_JUMP_TABLE;
642   case Attribute::MinSize:
643     return bitc::ATTR_KIND_MIN_SIZE;
644   case Attribute::Naked:
645     return bitc::ATTR_KIND_NAKED;
646   case Attribute::Nest:
647     return bitc::ATTR_KIND_NEST;
648   case Attribute::NoAlias:
649     return bitc::ATTR_KIND_NO_ALIAS;
650   case Attribute::NoBuiltin:
651     return bitc::ATTR_KIND_NO_BUILTIN;
652   case Attribute::NoCallback:
653     return bitc::ATTR_KIND_NO_CALLBACK;
654   case Attribute::NoCapture:
655     return bitc::ATTR_KIND_NO_CAPTURE;
656   case Attribute::NoDuplicate:
657     return bitc::ATTR_KIND_NO_DUPLICATE;
658   case Attribute::NoFree:
659     return bitc::ATTR_KIND_NOFREE;
660   case Attribute::NoImplicitFloat:
661     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
662   case Attribute::NoInline:
663     return bitc::ATTR_KIND_NO_INLINE;
664   case Attribute::NoRecurse:
665     return bitc::ATTR_KIND_NO_RECURSE;
666   case Attribute::NoMerge:
667     return bitc::ATTR_KIND_NO_MERGE;
668   case Attribute::NonLazyBind:
669     return bitc::ATTR_KIND_NON_LAZY_BIND;
670   case Attribute::NonNull:
671     return bitc::ATTR_KIND_NON_NULL;
672   case Attribute::Dereferenceable:
673     return bitc::ATTR_KIND_DEREFERENCEABLE;
674   case Attribute::DereferenceableOrNull:
675     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
676   case Attribute::NoRedZone:
677     return bitc::ATTR_KIND_NO_RED_ZONE;
678   case Attribute::NoReturn:
679     return bitc::ATTR_KIND_NO_RETURN;
680   case Attribute::NoSync:
681     return bitc::ATTR_KIND_NOSYNC;
682   case Attribute::NoCfCheck:
683     return bitc::ATTR_KIND_NOCF_CHECK;
684   case Attribute::NoProfile:
685     return bitc::ATTR_KIND_NO_PROFILE;
686   case Attribute::NoUnwind:
687     return bitc::ATTR_KIND_NO_UNWIND;
688   case Attribute::NoSanitizeBounds:
689     return bitc::ATTR_KIND_NO_SANITIZE_BOUNDS;
690   case Attribute::NoSanitizeCoverage:
691     return bitc::ATTR_KIND_NO_SANITIZE_COVERAGE;
692   case Attribute::NullPointerIsValid:
693     return bitc::ATTR_KIND_NULL_POINTER_IS_VALID;
694   case Attribute::OptForFuzzing:
695     return bitc::ATTR_KIND_OPT_FOR_FUZZING;
696   case Attribute::OptimizeForSize:
697     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
698   case Attribute::OptimizeNone:
699     return bitc::ATTR_KIND_OPTIMIZE_NONE;
700   case Attribute::ReadNone:
701     return bitc::ATTR_KIND_READ_NONE;
702   case Attribute::ReadOnly:
703     return bitc::ATTR_KIND_READ_ONLY;
704   case Attribute::Returned:
705     return bitc::ATTR_KIND_RETURNED;
706   case Attribute::ReturnsTwice:
707     return bitc::ATTR_KIND_RETURNS_TWICE;
708   case Attribute::SExt:
709     return bitc::ATTR_KIND_S_EXT;
710   case Attribute::Speculatable:
711     return bitc::ATTR_KIND_SPECULATABLE;
712   case Attribute::StackAlignment:
713     return bitc::ATTR_KIND_STACK_ALIGNMENT;
714   case Attribute::StackProtect:
715     return bitc::ATTR_KIND_STACK_PROTECT;
716   case Attribute::StackProtectReq:
717     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
718   case Attribute::StackProtectStrong:
719     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
720   case Attribute::SafeStack:
721     return bitc::ATTR_KIND_SAFESTACK;
722   case Attribute::ShadowCallStack:
723     return bitc::ATTR_KIND_SHADOWCALLSTACK;
724   case Attribute::StrictFP:
725     return bitc::ATTR_KIND_STRICT_FP;
726   case Attribute::StructRet:
727     return bitc::ATTR_KIND_STRUCT_RET;
728   case Attribute::SanitizeAddress:
729     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
730   case Attribute::SanitizeHWAddress:
731     return bitc::ATTR_KIND_SANITIZE_HWADDRESS;
732   case Attribute::SanitizeThread:
733     return bitc::ATTR_KIND_SANITIZE_THREAD;
734   case Attribute::SanitizeMemory:
735     return bitc::ATTR_KIND_SANITIZE_MEMORY;
736   case Attribute::SpeculativeLoadHardening:
737     return bitc::ATTR_KIND_SPECULATIVE_LOAD_HARDENING;
738   case Attribute::SwiftError:
739     return bitc::ATTR_KIND_SWIFT_ERROR;
740   case Attribute::SwiftSelf:
741     return bitc::ATTR_KIND_SWIFT_SELF;
742   case Attribute::SwiftAsync:
743     return bitc::ATTR_KIND_SWIFT_ASYNC;
744   case Attribute::UWTable:
745     return bitc::ATTR_KIND_UW_TABLE;
746   case Attribute::VScaleRange:
747     return bitc::ATTR_KIND_VSCALE_RANGE;
748   case Attribute::WillReturn:
749     return bitc::ATTR_KIND_WILLRETURN;
750   case Attribute::WriteOnly:
751     return bitc::ATTR_KIND_WRITEONLY;
752   case Attribute::ZExt:
753     return bitc::ATTR_KIND_Z_EXT;
754   case Attribute::ImmArg:
755     return bitc::ATTR_KIND_IMMARG;
756   case Attribute::SanitizeMemTag:
757     return bitc::ATTR_KIND_SANITIZE_MEMTAG;
758   case Attribute::Preallocated:
759     return bitc::ATTR_KIND_PREALLOCATED;
760   case Attribute::NoUndef:
761     return bitc::ATTR_KIND_NOUNDEF;
762   case Attribute::ByRef:
763     return bitc::ATTR_KIND_BYREF;
764   case Attribute::MustProgress:
765     return bitc::ATTR_KIND_MUSTPROGRESS;
766   case Attribute::EndAttrKinds:
767     llvm_unreachable("Can not encode end-attribute kinds marker.");
768   case Attribute::None:
769     llvm_unreachable("Can not encode none-attribute.");
770   case Attribute::EmptyKey:
771   case Attribute::TombstoneKey:
772     llvm_unreachable("Trying to encode EmptyKey/TombstoneKey");
773   }
774 
775   llvm_unreachable("Trying to encode unknown attribute");
776 }
777 
778 void DXILBitcodeWriter::emitSignedInt64(SmallVectorImpl<uint64_t> &Vals,
779                                         uint64_t V) {
780   if ((int64_t)V >= 0)
781     Vals.push_back(V << 1);
782   else
783     Vals.push_back((-V << 1) | 1);
784 }
785 
786 void DXILBitcodeWriter::emitWideAPInt(SmallVectorImpl<uint64_t> &Vals,
787                                       const APInt &A) {
788   // We have an arbitrary precision integer value to write whose
789   // bit width is > 64. However, in canonical unsigned integer
790   // format it is likely that the high bits are going to be zero.
791   // So, we only write the number of active words.
792   unsigned NumWords = A.getActiveWords();
793   const uint64_t *RawData = A.getRawData();
794   for (unsigned i = 0; i < NumWords; i++)
795     emitSignedInt64(Vals, RawData[i]);
796 }
797 
798 uint64_t DXILBitcodeWriter::getOptimizationFlags(const Value *V) {
799   uint64_t Flags = 0;
800 
801   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
802     if (OBO->hasNoSignedWrap())
803       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
804     if (OBO->hasNoUnsignedWrap())
805       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
806   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
807     if (PEO->isExact())
808       Flags |= 1 << bitc::PEO_EXACT;
809   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
810     if (FPMO->hasAllowReassoc())
811       Flags |= bitc::AllowReassoc;
812     if (FPMO->hasNoNaNs())
813       Flags |= bitc::NoNaNs;
814     if (FPMO->hasNoInfs())
815       Flags |= bitc::NoInfs;
816     if (FPMO->hasNoSignedZeros())
817       Flags |= bitc::NoSignedZeros;
818     if (FPMO->hasAllowReciprocal())
819       Flags |= bitc::AllowReciprocal;
820     if (FPMO->hasAllowContract())
821       Flags |= bitc::AllowContract;
822     if (FPMO->hasApproxFunc())
823       Flags |= bitc::ApproxFunc;
824   }
825 
826   return Flags;
827 }
828 
829 unsigned
830 DXILBitcodeWriter::getEncodedLinkage(const GlobalValue::LinkageTypes Linkage) {
831   switch (Linkage) {
832   case GlobalValue::ExternalLinkage:
833     return 0;
834   case GlobalValue::WeakAnyLinkage:
835     return 16;
836   case GlobalValue::AppendingLinkage:
837     return 2;
838   case GlobalValue::InternalLinkage:
839     return 3;
840   case GlobalValue::LinkOnceAnyLinkage:
841     return 18;
842   case GlobalValue::ExternalWeakLinkage:
843     return 7;
844   case GlobalValue::CommonLinkage:
845     return 8;
846   case GlobalValue::PrivateLinkage:
847     return 9;
848   case GlobalValue::WeakODRLinkage:
849     return 17;
850   case GlobalValue::LinkOnceODRLinkage:
851     return 19;
852   case GlobalValue::AvailableExternallyLinkage:
853     return 12;
854   }
855   llvm_unreachable("Invalid linkage");
856 }
857 
858 unsigned DXILBitcodeWriter::getEncodedLinkage(const GlobalValue &GV) {
859   return getEncodedLinkage(GV.getLinkage());
860 }
861 
862 unsigned DXILBitcodeWriter::getEncodedVisibility(const GlobalValue &GV) {
863   switch (GV.getVisibility()) {
864   case GlobalValue::DefaultVisibility:   return 0;
865   case GlobalValue::HiddenVisibility:    return 1;
866   case GlobalValue::ProtectedVisibility: return 2;
867   }
868   llvm_unreachable("Invalid visibility");
869 }
870 
871 unsigned DXILBitcodeWriter::getEncodedDLLStorageClass(const GlobalValue &GV) {
872   switch (GV.getDLLStorageClass()) {
873   case GlobalValue::DefaultStorageClass:   return 0;
874   case GlobalValue::DLLImportStorageClass: return 1;
875   case GlobalValue::DLLExportStorageClass: return 2;
876   }
877   llvm_unreachable("Invalid DLL storage class");
878 }
879 
880 unsigned DXILBitcodeWriter::getEncodedThreadLocalMode(const GlobalValue &GV) {
881   switch (GV.getThreadLocalMode()) {
882     case GlobalVariable::NotThreadLocal:         return 0;
883     case GlobalVariable::GeneralDynamicTLSModel: return 1;
884     case GlobalVariable::LocalDynamicTLSModel:   return 2;
885     case GlobalVariable::InitialExecTLSModel:    return 3;
886     case GlobalVariable::LocalExecTLSModel:      return 4;
887   }
888   llvm_unreachable("Invalid TLS model");
889 }
890 
891 unsigned DXILBitcodeWriter::getEncodedComdatSelectionKind(const Comdat &C) {
892   switch (C.getSelectionKind()) {
893   case Comdat::Any:
894     return bitc::COMDAT_SELECTION_KIND_ANY;
895   case Comdat::ExactMatch:
896     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
897   case Comdat::Largest:
898     return bitc::COMDAT_SELECTION_KIND_LARGEST;
899   case Comdat::NoDeduplicate:
900     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
901   case Comdat::SameSize:
902     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
903   }
904   llvm_unreachable("Invalid selection kind");
905 }
906 
907 ////////////////////////////////////////////////////////////////////////////////
908 /// Begin DXILBitcodeWriter Implementation
909 ////////////////////////////////////////////////////////////////////////////////
910 
911 void DXILBitcodeWriter::writeAttributeGroupTable() {
912   const std::vector<ValueEnumerator::IndexAndAttrSet> &AttrGrps =
913       VE.getAttributeGroups();
914   if (AttrGrps.empty())
915     return;
916 
917   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
918 
919   SmallVector<uint64_t, 64> Record;
920   for (ValueEnumerator::IndexAndAttrSet Pair : AttrGrps) {
921     unsigned AttrListIndex = Pair.first;
922     AttributeSet AS = Pair.second;
923     Record.push_back(VE.getAttributeGroupID(Pair));
924     Record.push_back(AttrListIndex);
925 
926     for (Attribute Attr : AS) {
927       if (Attr.isEnumAttribute()) {
928         uint64_t Val = getAttrKindEncoding(Attr.getKindAsEnum());
929         assert(Val <= bitc::ATTR_KIND_ARGMEMONLY &&
930                "DXIL does not support attributes above ATTR_KIND_ARGMEMONLY");
931         Record.push_back(0);
932         Record.push_back(Val);
933       } else if (Attr.isIntAttribute()) {
934         uint64_t Val = getAttrKindEncoding(Attr.getKindAsEnum());
935         assert(Val <= bitc::ATTR_KIND_ARGMEMONLY &&
936                "DXIL does not support attributes above ATTR_KIND_ARGMEMONLY");
937         Record.push_back(1);
938         Record.push_back(Val);
939         Record.push_back(Attr.getValueAsInt());
940       } else {
941         StringRef Kind = Attr.getKindAsString();
942         StringRef Val = Attr.getValueAsString();
943 
944         Record.push_back(Val.empty() ? 3 : 4);
945         Record.append(Kind.begin(), Kind.end());
946         Record.push_back(0);
947         if (!Val.empty()) {
948           Record.append(Val.begin(), Val.end());
949           Record.push_back(0);
950         }
951       }
952     }
953 
954     Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
955     Record.clear();
956   }
957 
958   Stream.ExitBlock();
959 }
960 
961 void DXILBitcodeWriter::writeAttributeTable() {
962   const std::vector<AttributeList> &Attrs = VE.getAttributeLists();
963   if (Attrs.empty())
964     return;
965 
966   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
967 
968   SmallVector<uint64_t, 64> Record;
969   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
970     AttributeList AL = Attrs[i];
971     for (unsigned i : AL.indexes()) {
972       AttributeSet AS = AL.getAttributes(i);
973       if (AS.hasAttributes())
974         Record.push_back(VE.getAttributeGroupID({i, AS}));
975     }
976 
977     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
978     Record.clear();
979   }
980 
981   Stream.ExitBlock();
982 }
983 
984 /// WriteTypeTable - Write out the type table for a module.
985 void DXILBitcodeWriter::writeTypeTable() {
986   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
987 
988   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
989   SmallVector<uint64_t, 64> TypeVals;
990 
991   uint64_t NumBits = VE.computeBitsRequiredForTypeIndicies();
992 
993   // Abbrev for TYPE_CODE_POINTER.
994   auto Abbv = std::make_shared<BitCodeAbbrev>();
995   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
996   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
997   Abbv->Add(BitCodeAbbrevOp(0)); // Addrspace = 0
998   unsigned PtrAbbrev = Stream.EmitAbbrev(std::move(Abbv));
999 
1000   // Abbrev for TYPE_CODE_FUNCTION.
1001   Abbv = std::make_shared<BitCodeAbbrev>();
1002   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
1003   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isvararg
1004   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1005   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1006   unsigned FunctionAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1007 
1008   // Abbrev for TYPE_CODE_STRUCT_ANON.
1009   Abbv = std::make_shared<BitCodeAbbrev>();
1010   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
1011   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ispacked
1012   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1013   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1014   unsigned StructAnonAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1015 
1016   // Abbrev for TYPE_CODE_STRUCT_NAME.
1017   Abbv = std::make_shared<BitCodeAbbrev>();
1018   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
1019   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1020   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1021   unsigned StructNameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1022 
1023   // Abbrev for TYPE_CODE_STRUCT_NAMED.
1024   Abbv = std::make_shared<BitCodeAbbrev>();
1025   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
1026   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ispacked
1027   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1028   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1029   unsigned StructNamedAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1030 
1031   // Abbrev for TYPE_CODE_ARRAY.
1032   Abbv = std::make_shared<BitCodeAbbrev>();
1033   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
1034   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // size
1035   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
1036   unsigned ArrayAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1037 
1038   // Emit an entry count so the reader can reserve space.
1039   TypeVals.push_back(TypeList.size());
1040   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
1041   TypeVals.clear();
1042 
1043   // Loop over all of the types, emitting each in turn.
1044   for (Type *T : TypeList) {
1045     int AbbrevToUse = 0;
1046     unsigned Code = 0;
1047 
1048     switch (T->getTypeID()) {
1049     case Type::BFloatTyID:
1050     case Type::X86_AMXTyID:
1051     case Type::TokenTyID:
1052     case Type::DXILPointerTyID:
1053       llvm_unreachable("These should never be used!!!");
1054       break;
1055     case Type::VoidTyID:
1056       Code = bitc::TYPE_CODE_VOID;
1057       break;
1058     case Type::HalfTyID:
1059       Code = bitc::TYPE_CODE_HALF;
1060       break;
1061     case Type::FloatTyID:
1062       Code = bitc::TYPE_CODE_FLOAT;
1063       break;
1064     case Type::DoubleTyID:
1065       Code = bitc::TYPE_CODE_DOUBLE;
1066       break;
1067     case Type::X86_FP80TyID:
1068       Code = bitc::TYPE_CODE_X86_FP80;
1069       break;
1070     case Type::FP128TyID:
1071       Code = bitc::TYPE_CODE_FP128;
1072       break;
1073     case Type::PPC_FP128TyID:
1074       Code = bitc::TYPE_CODE_PPC_FP128;
1075       break;
1076     case Type::LabelTyID:
1077       Code = bitc::TYPE_CODE_LABEL;
1078       break;
1079     case Type::MetadataTyID:
1080       Code = bitc::TYPE_CODE_METADATA;
1081       break;
1082     case Type::X86_MMXTyID:
1083       Code = bitc::TYPE_CODE_X86_MMX;
1084       break;
1085     case Type::IntegerTyID:
1086       // INTEGER: [width]
1087       Code = bitc::TYPE_CODE_INTEGER;
1088       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
1089       break;
1090     case Type::PointerTyID: {
1091       PointerType *PTy = cast<PointerType>(T);
1092       // POINTER: [pointee type, address space]
1093       Code = bitc::TYPE_CODE_POINTER;
1094       TypeVals.push_back(VE.getTypeID(PTy->getNonOpaquePointerElementType()));
1095       unsigned AddressSpace = PTy->getAddressSpace();
1096       TypeVals.push_back(AddressSpace);
1097       if (AddressSpace == 0)
1098         AbbrevToUse = PtrAbbrev;
1099       break;
1100     }
1101     case Type::FunctionTyID: {
1102       FunctionType *FT = cast<FunctionType>(T);
1103       // FUNCTION: [isvararg, retty, paramty x N]
1104       Code = bitc::TYPE_CODE_FUNCTION;
1105       TypeVals.push_back(FT->isVarArg());
1106       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
1107       for (Type *PTy : FT->params())
1108         TypeVals.push_back(VE.getTypeID(PTy));
1109       AbbrevToUse = FunctionAbbrev;
1110       break;
1111     }
1112     case Type::StructTyID: {
1113       StructType *ST = cast<StructType>(T);
1114       // STRUCT: [ispacked, eltty x N]
1115       TypeVals.push_back(ST->isPacked());
1116       // Output all of the element types.
1117       for (Type *ElTy : ST->elements())
1118         TypeVals.push_back(VE.getTypeID(ElTy));
1119 
1120       if (ST->isLiteral()) {
1121         Code = bitc::TYPE_CODE_STRUCT_ANON;
1122         AbbrevToUse = StructAnonAbbrev;
1123       } else {
1124         if (ST->isOpaque()) {
1125           Code = bitc::TYPE_CODE_OPAQUE;
1126         } else {
1127           Code = bitc::TYPE_CODE_STRUCT_NAMED;
1128           AbbrevToUse = StructNamedAbbrev;
1129         }
1130 
1131         // Emit the name if it is present.
1132         if (!ST->getName().empty())
1133           writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
1134                             StructNameAbbrev);
1135       }
1136       break;
1137     }
1138     case Type::ArrayTyID: {
1139       ArrayType *AT = cast<ArrayType>(T);
1140       // ARRAY: [numelts, eltty]
1141       Code = bitc::TYPE_CODE_ARRAY;
1142       TypeVals.push_back(AT->getNumElements());
1143       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
1144       AbbrevToUse = ArrayAbbrev;
1145       break;
1146     }
1147     case Type::FixedVectorTyID:
1148     case Type::ScalableVectorTyID: {
1149       VectorType *VT = cast<VectorType>(T);
1150       // VECTOR [numelts, eltty]
1151       Code = bitc::TYPE_CODE_VECTOR;
1152       TypeVals.push_back(VT->getElementCount().getKnownMinValue());
1153       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
1154       break;
1155     }
1156     }
1157 
1158     // Emit the finished record.
1159     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
1160     TypeVals.clear();
1161   }
1162 
1163   Stream.ExitBlock();
1164 }
1165 
1166 void DXILBitcodeWriter::writeComdats() {
1167   SmallVector<uint16_t, 64> Vals;
1168   for (const Comdat *C : VE.getComdats()) {
1169     // COMDAT: [selection_kind, name]
1170     Vals.push_back(getEncodedComdatSelectionKind(*C));
1171     size_t Size = C->getName().size();
1172     assert(isUInt<16>(Size));
1173     Vals.push_back(Size);
1174     for (char Chr : C->getName())
1175       Vals.push_back((unsigned char)Chr);
1176     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
1177     Vals.clear();
1178   }
1179 }
1180 
1181 void DXILBitcodeWriter::writeValueSymbolTableForwardDecl() {}
1182 
1183 /// Emit top-level description of module, including target triple, inline asm,
1184 /// descriptors for global variables, and function prototype info.
1185 /// Returns the bit offset to backpatch with the location of the real VST.
1186 void DXILBitcodeWriter::writeModuleInfo() {
1187   // Emit various pieces of data attached to a module.
1188   if (!M.getTargetTriple().empty())
1189     writeStringRecord(Stream, bitc::MODULE_CODE_TRIPLE, M.getTargetTriple(),
1190                       0 /*TODO*/);
1191   const std::string &DL = M.getDataLayoutStr();
1192   if (!DL.empty())
1193     writeStringRecord(Stream, bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/);
1194   if (!M.getModuleInlineAsm().empty())
1195     writeStringRecord(Stream, bitc::MODULE_CODE_ASM, M.getModuleInlineAsm(),
1196                       0 /*TODO*/);
1197 
1198   // Emit information about sections and GC, computing how many there are. Also
1199   // compute the maximum alignment value.
1200   std::map<std::string, unsigned> SectionMap;
1201   std::map<std::string, unsigned> GCMap;
1202   MaybeAlign MaxAlignment;
1203   unsigned MaxGlobalType = 0;
1204   const auto UpdateMaxAlignment = [&MaxAlignment](const MaybeAlign A) {
1205     if (A)
1206       MaxAlignment = !MaxAlignment ? *A : std::max(*MaxAlignment, *A);
1207   };
1208   for (const GlobalVariable &GV : M.globals()) {
1209     UpdateMaxAlignment(GV.getAlign());
1210     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
1211     if (GV.hasSection()) {
1212       // Give section names unique ID's.
1213       unsigned &Entry = SectionMap[std::string(GV.getSection())];
1214       if (!Entry) {
1215         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME,
1216                           GV.getSection(), 0 /*TODO*/);
1217         Entry = SectionMap.size();
1218       }
1219     }
1220   }
1221   for (const Function &F : M) {
1222     UpdateMaxAlignment(F.getAlign());
1223     if (F.hasSection()) {
1224       // Give section names unique ID's.
1225       unsigned &Entry = SectionMap[std::string(F.getSection())];
1226       if (!Entry) {
1227         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
1228                           0 /*TODO*/);
1229         Entry = SectionMap.size();
1230       }
1231     }
1232     if (F.hasGC()) {
1233       // Same for GC names.
1234       unsigned &Entry = GCMap[F.getGC()];
1235       if (!Entry) {
1236         writeStringRecord(Stream, bitc::MODULE_CODE_GCNAME, F.getGC(),
1237                           0 /*TODO*/);
1238         Entry = GCMap.size();
1239       }
1240     }
1241   }
1242 
1243   // Emit abbrev for globals, now that we know # sections and max alignment.
1244   unsigned SimpleGVarAbbrev = 0;
1245   if (!M.global_empty()) {
1246     // Add an abbrev for common globals with no visibility or thread localness.
1247     auto Abbv = std::make_shared<BitCodeAbbrev>();
1248     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
1249     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1250                               Log2_32_Ceil(MaxGlobalType + 1)));
1251     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
1252                                                            //| explicitType << 1
1253                                                            //| constant
1254     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
1255     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
1256     if (MaxAlignment == 0)                                 // Alignment.
1257       Abbv->Add(BitCodeAbbrevOp(0));
1258     else {
1259       unsigned MaxEncAlignment = getEncodedAlign(MaxAlignment);
1260       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1261                                 Log2_32_Ceil(MaxEncAlignment + 1)));
1262     }
1263     if (SectionMap.empty()) // Section.
1264       Abbv->Add(BitCodeAbbrevOp(0));
1265     else
1266       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1267                                 Log2_32_Ceil(SectionMap.size() + 1)));
1268     // Don't bother emitting vis + thread local.
1269     SimpleGVarAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1270   }
1271 
1272   // Emit the global variable information.
1273   SmallVector<unsigned, 64> Vals;
1274   for (const GlobalVariable &GV : M.globals()) {
1275     unsigned AbbrevToUse = 0;
1276 
1277     // GLOBALVAR: [type, isconst, initid,
1278     //             linkage, alignment, section, visibility, threadlocal,
1279     //             unnamed_addr, externally_initialized, dllstorageclass,
1280     //             comdat]
1281     Vals.push_back(VE.getTypeID(GV.getValueType()));
1282     Vals.push_back(
1283         GV.getType()->getAddressSpace() << 2 | 2 |
1284         (GV.isConstant() ? 1 : 0)); // HLSL Change - bitwise | was used with
1285                                     // unsigned int and bool
1286     Vals.push_back(
1287         GV.isDeclaration() ? 0 : (VE.getValueID(GV.getInitializer()) + 1));
1288     Vals.push_back(getEncodedLinkage(GV));
1289     Vals.push_back(getEncodedAlign(GV.getAlign()));
1290     Vals.push_back(GV.hasSection() ? SectionMap[std::string(GV.getSection())]
1291                                    : 0);
1292     if (GV.isThreadLocal() ||
1293         GV.getVisibility() != GlobalValue::DefaultVisibility ||
1294         GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None ||
1295         GV.isExternallyInitialized() ||
1296         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
1297         GV.hasComdat()) {
1298       Vals.push_back(getEncodedVisibility(GV));
1299       Vals.push_back(getEncodedThreadLocalMode(GV));
1300       Vals.push_back(GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
1301       Vals.push_back(GV.isExternallyInitialized());
1302       Vals.push_back(getEncodedDLLStorageClass(GV));
1303       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
1304     } else {
1305       AbbrevToUse = SimpleGVarAbbrev;
1306     }
1307 
1308     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
1309     Vals.clear();
1310   }
1311 
1312   // Emit the function proto information.
1313   for (const Function &F : M) {
1314     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
1315     //             section, visibility, gc, unnamed_addr, prologuedata,
1316     //             dllstorageclass, comdat, prefixdata, personalityfn]
1317     Vals.push_back(VE.getTypeID(F.getFunctionType()));
1318     Vals.push_back(F.getCallingConv());
1319     Vals.push_back(F.isDeclaration());
1320     Vals.push_back(getEncodedLinkage(F));
1321     Vals.push_back(VE.getAttributeListID(F.getAttributes()));
1322     Vals.push_back(getEncodedAlign(F.getAlign()));
1323     Vals.push_back(F.hasSection() ? SectionMap[std::string(F.getSection())]
1324                                   : 0);
1325     Vals.push_back(getEncodedVisibility(F));
1326     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
1327     Vals.push_back(F.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
1328     Vals.push_back(
1329         F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1) : 0);
1330     Vals.push_back(getEncodedDLLStorageClass(F));
1331     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
1332     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
1333                                      : 0);
1334     Vals.push_back(
1335         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
1336 
1337     unsigned AbbrevToUse = 0;
1338     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
1339     Vals.clear();
1340   }
1341 
1342   // Emit the alias information.
1343   for (const GlobalAlias &A : M.aliases()) {
1344     // ALIAS: [alias type, aliasee val#, linkage, visibility]
1345     Vals.push_back(VE.getTypeID(A.getValueType()));
1346     Vals.push_back(VE.getValueID(A.getAliasee()));
1347     Vals.push_back(getEncodedLinkage(A));
1348     Vals.push_back(getEncodedVisibility(A));
1349     Vals.push_back(getEncodedDLLStorageClass(A));
1350     Vals.push_back(getEncodedThreadLocalMode(A));
1351     Vals.push_back(A.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
1352     unsigned AbbrevToUse = 0;
1353     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS_OLD, Vals, AbbrevToUse);
1354     Vals.clear();
1355   }
1356 }
1357 
1358 void DXILBitcodeWriter::writeValueAsMetadata(
1359     const ValueAsMetadata *MD, SmallVectorImpl<uint64_t> &Record) {
1360   // Mimic an MDNode with a value as one operand.
1361   Value *V = MD->getValue();
1362   Record.push_back(VE.getTypeID(V->getType()));
1363   Record.push_back(VE.getValueID(V));
1364   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
1365   Record.clear();
1366 }
1367 
1368 void DXILBitcodeWriter::writeMDTuple(const MDTuple *N,
1369                                      SmallVectorImpl<uint64_t> &Record,
1370                                      unsigned Abbrev) {
1371   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
1372     Metadata *MD = N->getOperand(i);
1373     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
1374            "Unexpected function-local metadata");
1375     Record.push_back(VE.getMetadataOrNullID(MD));
1376   }
1377   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
1378                                     : bitc::METADATA_NODE,
1379                     Record, Abbrev);
1380   Record.clear();
1381 }
1382 
1383 void DXILBitcodeWriter::writeDILocation(const DILocation *N,
1384                                         SmallVectorImpl<uint64_t> &Record,
1385                                         unsigned &Abbrev) {
1386   if (!Abbrev)
1387     Abbrev = createDILocationAbbrev();
1388   Record.push_back(N->isDistinct());
1389   Record.push_back(N->getLine());
1390   Record.push_back(N->getColumn());
1391   Record.push_back(VE.getMetadataID(N->getScope()));
1392   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
1393 
1394   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
1395   Record.clear();
1396 }
1397 
1398 static uint64_t rotateSign(APInt Val) {
1399   int64_t I = Val.getSExtValue();
1400   uint64_t U = I;
1401   return I < 0 ? ~(U << 1) : U << 1;
1402 }
1403 
1404 static uint64_t rotateSign(DISubrange::BoundType Val) {
1405   return rotateSign(Val.get<ConstantInt *>()->getValue());
1406 }
1407 
1408 void DXILBitcodeWriter::writeDISubrange(const DISubrange *N,
1409                                         SmallVectorImpl<uint64_t> &Record,
1410                                         unsigned Abbrev) {
1411   Record.push_back(N->isDistinct());
1412   Record.push_back(
1413       N->getCount().get<ConstantInt *>()->getValue().getSExtValue());
1414   Record.push_back(rotateSign(N->getLowerBound()));
1415 
1416   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
1417   Record.clear();
1418 }
1419 
1420 void DXILBitcodeWriter::writeDIEnumerator(const DIEnumerator *N,
1421                                           SmallVectorImpl<uint64_t> &Record,
1422                                           unsigned Abbrev) {
1423   Record.push_back(N->isDistinct());
1424   Record.push_back(rotateSign(N->getValue()));
1425   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1426 
1427   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
1428   Record.clear();
1429 }
1430 
1431 void DXILBitcodeWriter::writeDIBasicType(const DIBasicType *N,
1432                                          SmallVectorImpl<uint64_t> &Record,
1433                                          unsigned Abbrev) {
1434   Record.push_back(N->isDistinct());
1435   Record.push_back(N->getTag());
1436   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1437   Record.push_back(N->getSizeInBits());
1438   Record.push_back(N->getAlignInBits());
1439   Record.push_back(N->getEncoding());
1440 
1441   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
1442   Record.clear();
1443 }
1444 
1445 void DXILBitcodeWriter::writeDIDerivedType(const DIDerivedType *N,
1446                                            SmallVectorImpl<uint64_t> &Record,
1447                                            unsigned Abbrev) {
1448   Record.push_back(N->isDistinct());
1449   Record.push_back(N->getTag());
1450   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1451   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1452   Record.push_back(N->getLine());
1453   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1454   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1455   Record.push_back(N->getSizeInBits());
1456   Record.push_back(N->getAlignInBits());
1457   Record.push_back(N->getOffsetInBits());
1458   Record.push_back(N->getFlags());
1459   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
1460 
1461   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
1462   Record.clear();
1463 }
1464 
1465 void DXILBitcodeWriter::writeDICompositeType(const DICompositeType *N,
1466                                              SmallVectorImpl<uint64_t> &Record,
1467                                              unsigned Abbrev) {
1468   Record.push_back(N->isDistinct());
1469   Record.push_back(N->getTag());
1470   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1471   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1472   Record.push_back(N->getLine());
1473   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1474   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1475   Record.push_back(N->getSizeInBits());
1476   Record.push_back(N->getAlignInBits());
1477   Record.push_back(N->getOffsetInBits());
1478   Record.push_back(N->getFlags());
1479   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1480   Record.push_back(N->getRuntimeLang());
1481   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
1482   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1483   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
1484 
1485   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
1486   Record.clear();
1487 }
1488 
1489 void DXILBitcodeWriter::writeDISubroutineType(const DISubroutineType *N,
1490                                               SmallVectorImpl<uint64_t> &Record,
1491                                               unsigned Abbrev) {
1492   Record.push_back(N->isDistinct());
1493   Record.push_back(N->getFlags());
1494   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
1495 
1496   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
1497   Record.clear();
1498 }
1499 
1500 void DXILBitcodeWriter::writeDIFile(const DIFile *N,
1501                                     SmallVectorImpl<uint64_t> &Record,
1502                                     unsigned Abbrev) {
1503   Record.push_back(N->isDistinct());
1504   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
1505   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
1506 
1507   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
1508   Record.clear();
1509 }
1510 
1511 void DXILBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
1512                                            SmallVectorImpl<uint64_t> &Record,
1513                                            unsigned Abbrev) {
1514   Record.push_back(N->isDistinct());
1515   Record.push_back(N->getSourceLanguage());
1516   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1517   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
1518   Record.push_back(N->isOptimized());
1519   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
1520   Record.push_back(N->getRuntimeVersion());
1521   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
1522   Record.push_back(N->getEmissionKind());
1523   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
1524   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
1525   Record.push_back(/* subprograms */ 0);
1526   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
1527   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
1528   Record.push_back(N->getDWOId());
1529 
1530   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
1531   Record.clear();
1532 }
1533 
1534 void DXILBitcodeWriter::writeDISubprogram(const DISubprogram *N,
1535                                           SmallVectorImpl<uint64_t> &Record,
1536                                           unsigned Abbrev) {
1537   Record.push_back(N->isDistinct());
1538   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1539   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1540   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1541   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1542   Record.push_back(N->getLine());
1543   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1544   Record.push_back(N->isLocalToUnit());
1545   Record.push_back(N->isDefinition());
1546   Record.push_back(N->getScopeLine());
1547   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
1548   Record.push_back(N->getVirtuality());
1549   Record.push_back(N->getVirtualIndex());
1550   Record.push_back(N->getFlags());
1551   Record.push_back(N->isOptimized());
1552   Record.push_back(VE.getMetadataOrNullID(N->getRawUnit()));
1553   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1554   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
1555   Record.push_back(VE.getMetadataOrNullID(N->getRetainedNodes().get()));
1556 
1557   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
1558   Record.clear();
1559 }
1560 
1561 void DXILBitcodeWriter::writeDILexicalBlock(const DILexicalBlock *N,
1562                                             SmallVectorImpl<uint64_t> &Record,
1563                                             unsigned Abbrev) {
1564   Record.push_back(N->isDistinct());
1565   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1566   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1567   Record.push_back(N->getLine());
1568   Record.push_back(N->getColumn());
1569 
1570   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
1571   Record.clear();
1572 }
1573 
1574 void DXILBitcodeWriter::writeDILexicalBlockFile(
1575     const DILexicalBlockFile *N, SmallVectorImpl<uint64_t> &Record,
1576     unsigned Abbrev) {
1577   Record.push_back(N->isDistinct());
1578   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1579   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1580   Record.push_back(N->getDiscriminator());
1581 
1582   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
1583   Record.clear();
1584 }
1585 
1586 void DXILBitcodeWriter::writeDINamespace(const DINamespace *N,
1587                                          SmallVectorImpl<uint64_t> &Record,
1588                                          unsigned Abbrev) {
1589   Record.push_back(N->isDistinct());
1590   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1591   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1592   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1593   Record.push_back(/* line number */ 0);
1594 
1595   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
1596   Record.clear();
1597 }
1598 
1599 void DXILBitcodeWriter::writeDIModule(const DIModule *N,
1600                                       SmallVectorImpl<uint64_t> &Record,
1601                                       unsigned Abbrev) {
1602   Record.push_back(N->isDistinct());
1603   for (auto &I : N->operands())
1604     Record.push_back(VE.getMetadataOrNullID(I));
1605 
1606   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
1607   Record.clear();
1608 }
1609 
1610 void DXILBitcodeWriter::writeDITemplateTypeParameter(
1611     const DITemplateTypeParameter *N, SmallVectorImpl<uint64_t> &Record,
1612     unsigned Abbrev) {
1613   Record.push_back(N->isDistinct());
1614   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1615   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1616 
1617   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
1618   Record.clear();
1619 }
1620 
1621 void DXILBitcodeWriter::writeDITemplateValueParameter(
1622     const DITemplateValueParameter *N, SmallVectorImpl<uint64_t> &Record,
1623     unsigned Abbrev) {
1624   Record.push_back(N->isDistinct());
1625   Record.push_back(N->getTag());
1626   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1627   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1628   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
1629 
1630   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
1631   Record.clear();
1632 }
1633 
1634 void DXILBitcodeWriter::writeDIGlobalVariable(const DIGlobalVariable *N,
1635                                               SmallVectorImpl<uint64_t> &Record,
1636                                               unsigned Abbrev) {
1637   Record.push_back(N->isDistinct());
1638   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1639   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1640   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1641   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1642   Record.push_back(N->getLine());
1643   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1644   Record.push_back(N->isLocalToUnit());
1645   Record.push_back(N->isDefinition());
1646   Record.push_back(/* N->getRawVariable() */ 0);
1647   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
1648 
1649   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
1650   Record.clear();
1651 }
1652 
1653 void DXILBitcodeWriter::writeDILocalVariable(const DILocalVariable *N,
1654                                              SmallVectorImpl<uint64_t> &Record,
1655                                              unsigned Abbrev) {
1656   Record.push_back(N->isDistinct());
1657   Record.push_back(N->getTag());
1658   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1659   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1660   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1661   Record.push_back(N->getLine());
1662   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1663   Record.push_back(N->getArg());
1664   Record.push_back(N->getFlags());
1665 
1666   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
1667   Record.clear();
1668 }
1669 
1670 void DXILBitcodeWriter::writeDIExpression(const DIExpression *N,
1671                                           SmallVectorImpl<uint64_t> &Record,
1672                                           unsigned Abbrev) {
1673   Record.reserve(N->getElements().size() + 1);
1674 
1675   Record.push_back(N->isDistinct());
1676   Record.append(N->elements_begin(), N->elements_end());
1677 
1678   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
1679   Record.clear();
1680 }
1681 
1682 void DXILBitcodeWriter::writeDIObjCProperty(const DIObjCProperty *N,
1683                                             SmallVectorImpl<uint64_t> &Record,
1684                                             unsigned Abbrev) {
1685   llvm_unreachable("DXIL does not support objc!!!");
1686 }
1687 
1688 void DXILBitcodeWriter::writeDIImportedEntity(const DIImportedEntity *N,
1689                                               SmallVectorImpl<uint64_t> &Record,
1690                                               unsigned Abbrev) {
1691   Record.push_back(N->isDistinct());
1692   Record.push_back(N->getTag());
1693   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1694   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
1695   Record.push_back(N->getLine());
1696   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1697 
1698   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
1699   Record.clear();
1700 }
1701 
1702 unsigned DXILBitcodeWriter::createDILocationAbbrev() {
1703   // Abbrev for METADATA_LOCATION.
1704   //
1705   // Assume the column is usually under 128, and always output the inlined-at
1706   // location (it's never more expensive than building an array size 1).
1707   std::shared_ptr<BitCodeAbbrev> Abbv = std::make_shared<BitCodeAbbrev>();
1708   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1709   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1710   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1711   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1712   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1713   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1714   return Stream.EmitAbbrev(std::move(Abbv));
1715 }
1716 
1717 unsigned DXILBitcodeWriter::createGenericDINodeAbbrev() {
1718   // Abbrev for METADATA_GENERIC_DEBUG.
1719   //
1720   // Assume the column is usually under 128, and always output the inlined-at
1721   // location (it's never more expensive than building an array size 1).
1722   std::shared_ptr<BitCodeAbbrev> Abbv = std::make_shared<BitCodeAbbrev>();
1723   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1724   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1725   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1726   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1727   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1728   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1729   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1730   return Stream.EmitAbbrev(std::move(Abbv));
1731 }
1732 
1733 void DXILBitcodeWriter::writeMetadataRecords(ArrayRef<const Metadata *> MDs,
1734                                              SmallVectorImpl<uint64_t> &Record,
1735                                              std::vector<unsigned> *MDAbbrevs,
1736                                              std::vector<uint64_t> *IndexPos) {
1737   if (MDs.empty())
1738     return;
1739 
1740     // Initialize MDNode abbreviations.
1741 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
1742 #include "llvm/IR/Metadata.def"
1743 
1744   for (const Metadata *MD : MDs) {
1745     if (IndexPos)
1746       IndexPos->push_back(Stream.GetCurrentBitNo());
1747     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
1748       assert(N->isResolved() && "Expected forward references to be resolved");
1749 
1750       switch (N->getMetadataID()) {
1751       default:
1752         llvm_unreachable("Invalid MDNode subclass");
1753 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
1754   case Metadata::CLASS##Kind:                                                  \
1755     if (MDAbbrevs)                                                             \
1756       write##CLASS(cast<CLASS>(N), Record,                                     \
1757                    (*MDAbbrevs)[MetadataAbbrev::CLASS##AbbrevID]);             \
1758     else                                                                       \
1759       write##CLASS(cast<CLASS>(N), Record, CLASS##Abbrev);                     \
1760     continue;
1761 #include "llvm/IR/Metadata.def"
1762       }
1763     }
1764     writeValueAsMetadata(cast<ValueAsMetadata>(MD), Record);
1765   }
1766 }
1767 
1768 unsigned DXILBitcodeWriter::createMetadataStringsAbbrev() {
1769   auto Abbv = std::make_shared<BitCodeAbbrev>();
1770   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING_OLD));
1771   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1772   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1773   return Stream.EmitAbbrev(std::move(Abbv));
1774 }
1775 
1776 void DXILBitcodeWriter::writeMetadataStrings(
1777     ArrayRef<const Metadata *> Strings, SmallVectorImpl<uint64_t> &Record) {
1778   for (const Metadata *MD : Strings) {
1779     const MDString *MDS = cast<MDString>(MD);
1780     // Code: [strchar x N]
1781     Record.append(MDS->bytes_begin(), MDS->bytes_end());
1782 
1783     // Emit the finished record.
1784     Stream.EmitRecord(bitc::METADATA_STRING_OLD, Record,
1785                       createMetadataStringsAbbrev());
1786     Record.clear();
1787   }
1788 }
1789 
1790 void DXILBitcodeWriter::writeModuleMetadata() {
1791   if (!VE.hasMDs() && M.named_metadata_empty())
1792     return;
1793 
1794   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 5);
1795 
1796   // Emit all abbrevs upfront, so that the reader can jump in the middle of the
1797   // block and load any metadata.
1798   std::vector<unsigned> MDAbbrevs;
1799 
1800   MDAbbrevs.resize(MetadataAbbrev::LastPlusOne);
1801   MDAbbrevs[MetadataAbbrev::DILocationAbbrevID] = createDILocationAbbrev();
1802   MDAbbrevs[MetadataAbbrev::GenericDINodeAbbrevID] =
1803       createGenericDINodeAbbrev();
1804 
1805   unsigned NameAbbrev = 0;
1806   if (!M.named_metadata_empty()) {
1807     // Abbrev for METADATA_NAME.
1808     std::shared_ptr<BitCodeAbbrev> Abbv = std::make_shared<BitCodeAbbrev>();
1809     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
1810     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1811     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1812     NameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1813   }
1814 
1815   SmallVector<uint64_t, 64> Record;
1816   writeMetadataStrings(VE.getMDStrings(), Record);
1817 
1818   std::vector<uint64_t> IndexPos;
1819   IndexPos.reserve(VE.getNonMDStrings().size());
1820   writeMetadataRecords(VE.getNonMDStrings(), Record, &MDAbbrevs, &IndexPos);
1821 
1822   // Write named metadata.
1823   for (const NamedMDNode &NMD : M.named_metadata()) {
1824     // Write name.
1825     StringRef Str = NMD.getName();
1826     Record.append(Str.bytes_begin(), Str.bytes_end());
1827     Stream.EmitRecord(bitc::METADATA_NAME, Record, NameAbbrev);
1828     Record.clear();
1829 
1830     // Write named metadata operands.
1831     for (const MDNode *N : NMD.operands())
1832       Record.push_back(VE.getMetadataID(N));
1833     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
1834     Record.clear();
1835   }
1836 
1837   Stream.ExitBlock();
1838 }
1839 
1840 void DXILBitcodeWriter::writeFunctionMetadata(const Function &F) {
1841   if (!VE.hasMDs())
1842     return;
1843 
1844   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 4);
1845   SmallVector<uint64_t, 64> Record;
1846   writeMetadataStrings(VE.getMDStrings(), Record);
1847   writeMetadataRecords(VE.getNonMDStrings(), Record);
1848   Stream.ExitBlock();
1849 }
1850 
1851 void DXILBitcodeWriter::writeFunctionMetadataAttachment(const Function &F) {
1852   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
1853 
1854   SmallVector<uint64_t, 64> Record;
1855 
1856   // Write metadata attachments
1857   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
1858   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
1859   F.getAllMetadata(MDs);
1860   if (!MDs.empty()) {
1861     for (const auto &I : MDs) {
1862       Record.push_back(I.first);
1863       Record.push_back(VE.getMetadataID(I.second));
1864     }
1865     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1866     Record.clear();
1867   }
1868 
1869   for (const BasicBlock &BB : F)
1870     for (const Instruction &I : BB) {
1871       MDs.clear();
1872       I.getAllMetadataOtherThanDebugLoc(MDs);
1873 
1874       // If no metadata, ignore instruction.
1875       if (MDs.empty())
1876         continue;
1877 
1878       Record.push_back(VE.getInstructionID(&I));
1879 
1880       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1881         Record.push_back(MDs[i].first);
1882         Record.push_back(VE.getMetadataID(MDs[i].second));
1883       }
1884       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1885       Record.clear();
1886     }
1887 
1888   Stream.ExitBlock();
1889 }
1890 
1891 void DXILBitcodeWriter::writeModuleMetadataKinds() {
1892   SmallVector<uint64_t, 64> Record;
1893 
1894   // Write metadata kinds
1895   // METADATA_KIND - [n x [id, name]]
1896   SmallVector<StringRef, 8> Names;
1897   M.getMDKindNames(Names);
1898 
1899   if (Names.empty())
1900     return;
1901 
1902   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1903 
1904   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
1905     Record.push_back(MDKindID);
1906     StringRef KName = Names[MDKindID];
1907     Record.append(KName.begin(), KName.end());
1908 
1909     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
1910     Record.clear();
1911   }
1912 
1913   Stream.ExitBlock();
1914 }
1915 
1916 void DXILBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
1917                                        bool isGlobal) {
1918   if (FirstVal == LastVal)
1919     return;
1920 
1921   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
1922 
1923   unsigned AggregateAbbrev = 0;
1924   unsigned String8Abbrev = 0;
1925   unsigned CString7Abbrev = 0;
1926   unsigned CString6Abbrev = 0;
1927   // If this is a constant pool for the module, emit module-specific abbrevs.
1928   if (isGlobal) {
1929     // Abbrev for CST_CODE_AGGREGATE.
1930     auto Abbv = std::make_shared<BitCodeAbbrev>();
1931     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
1932     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1933     Abbv->Add(
1934         BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal + 1)));
1935     AggregateAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1936 
1937     // Abbrev for CST_CODE_STRING.
1938     Abbv = std::make_shared<BitCodeAbbrev>();
1939     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
1940     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1941     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1942     String8Abbrev = Stream.EmitAbbrev(std::move(Abbv));
1943     // Abbrev for CST_CODE_CSTRING.
1944     Abbv = std::make_shared<BitCodeAbbrev>();
1945     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1946     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1947     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1948     CString7Abbrev = Stream.EmitAbbrev(std::move(Abbv));
1949     // Abbrev for CST_CODE_CSTRING.
1950     Abbv = std::make_shared<BitCodeAbbrev>();
1951     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1952     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1953     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1954     CString6Abbrev = Stream.EmitAbbrev(std::move(Abbv));
1955   }
1956 
1957   SmallVector<uint64_t, 64> Record;
1958 
1959   const ValueEnumerator::ValueList &Vals = VE.getValues();
1960   Type *LastTy = nullptr;
1961   for (unsigned i = FirstVal; i != LastVal; ++i) {
1962     const Value *V = Vals[i].first;
1963     // If we need to switch types, do so now.
1964     if (V->getType() != LastTy) {
1965       LastTy = V->getType();
1966       Record.push_back(VE.getTypeID(LastTy));
1967       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
1968                         CONSTANTS_SETTYPE_ABBREV);
1969       Record.clear();
1970     }
1971 
1972     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
1973       Record.push_back(unsigned(IA->hasSideEffects()) |
1974                        unsigned(IA->isAlignStack()) << 1 |
1975                        unsigned(IA->getDialect() & 1) << 2);
1976 
1977       // Add the asm string.
1978       const std::string &AsmStr = IA->getAsmString();
1979       Record.push_back(AsmStr.size());
1980       Record.append(AsmStr.begin(), AsmStr.end());
1981 
1982       // Add the constraint string.
1983       const std::string &ConstraintStr = IA->getConstraintString();
1984       Record.push_back(ConstraintStr.size());
1985       Record.append(ConstraintStr.begin(), ConstraintStr.end());
1986       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
1987       Record.clear();
1988       continue;
1989     }
1990     const Constant *C = cast<Constant>(V);
1991     unsigned Code = -1U;
1992     unsigned AbbrevToUse = 0;
1993     if (C->isNullValue()) {
1994       Code = bitc::CST_CODE_NULL;
1995     } else if (isa<UndefValue>(C)) {
1996       Code = bitc::CST_CODE_UNDEF;
1997     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
1998       if (IV->getBitWidth() <= 64) {
1999         uint64_t V = IV->getSExtValue();
2000         emitSignedInt64(Record, V);
2001         Code = bitc::CST_CODE_INTEGER;
2002         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
2003       } else { // Wide integers, > 64 bits in size.
2004         // We have an arbitrary precision integer value to write whose
2005         // bit width is > 64. However, in canonical unsigned integer
2006         // format it is likely that the high bits are going to be zero.
2007         // So, we only write the number of active words.
2008         unsigned NWords = IV->getValue().getActiveWords();
2009         const uint64_t *RawWords = IV->getValue().getRawData();
2010         for (unsigned i = 0; i != NWords; ++i) {
2011           emitSignedInt64(Record, RawWords[i]);
2012         }
2013         Code = bitc::CST_CODE_WIDE_INTEGER;
2014       }
2015     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
2016       Code = bitc::CST_CODE_FLOAT;
2017       Type *Ty = CFP->getType();
2018       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
2019         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
2020       } else if (Ty->isX86_FP80Ty()) {
2021         // api needed to prevent premature destruction
2022         // bits are not in the same order as a normal i80 APInt, compensate.
2023         APInt api = CFP->getValueAPF().bitcastToAPInt();
2024         const uint64_t *p = api.getRawData();
2025         Record.push_back((p[1] << 48) | (p[0] >> 16));
2026         Record.push_back(p[0] & 0xffffLL);
2027       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
2028         APInt api = CFP->getValueAPF().bitcastToAPInt();
2029         const uint64_t *p = api.getRawData();
2030         Record.push_back(p[0]);
2031         Record.push_back(p[1]);
2032       } else {
2033         assert(0 && "Unknown FP type!");
2034       }
2035     } else if (isa<ConstantDataSequential>(C) &&
2036                cast<ConstantDataSequential>(C)->isString()) {
2037       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
2038       // Emit constant strings specially.
2039       unsigned NumElts = Str->getNumElements();
2040       // If this is a null-terminated string, use the denser CSTRING encoding.
2041       if (Str->isCString()) {
2042         Code = bitc::CST_CODE_CSTRING;
2043         --NumElts; // Don't encode the null, which isn't allowed by char6.
2044       } else {
2045         Code = bitc::CST_CODE_STRING;
2046         AbbrevToUse = String8Abbrev;
2047       }
2048       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
2049       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
2050       for (unsigned i = 0; i != NumElts; ++i) {
2051         unsigned char V = Str->getElementAsInteger(i);
2052         Record.push_back(V);
2053         isCStr7 &= (V & 128) == 0;
2054         if (isCStrChar6)
2055           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
2056       }
2057 
2058       if (isCStrChar6)
2059         AbbrevToUse = CString6Abbrev;
2060       else if (isCStr7)
2061         AbbrevToUse = CString7Abbrev;
2062     } else if (const ConstantDataSequential *CDS =
2063                    dyn_cast<ConstantDataSequential>(C)) {
2064       Code = bitc::CST_CODE_DATA;
2065       Type *EltTy = CDS->getType()->getArrayElementType();
2066       if (isa<IntegerType>(EltTy)) {
2067         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2068           Record.push_back(CDS->getElementAsInteger(i));
2069       } else if (EltTy->isFloatTy()) {
2070         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
2071           union {
2072             float F;
2073             uint32_t I;
2074           };
2075           F = CDS->getElementAsFloat(i);
2076           Record.push_back(I);
2077         }
2078       } else {
2079         assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
2080         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
2081           union {
2082             double F;
2083             uint64_t I;
2084           };
2085           F = CDS->getElementAsDouble(i);
2086           Record.push_back(I);
2087         }
2088       }
2089     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
2090                isa<ConstantVector>(C)) {
2091       Code = bitc::CST_CODE_AGGREGATE;
2092       for (const Value *Op : C->operands())
2093         Record.push_back(VE.getValueID(Op));
2094       AbbrevToUse = AggregateAbbrev;
2095     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
2096       switch (CE->getOpcode()) {
2097       default:
2098         if (Instruction::isCast(CE->getOpcode())) {
2099           Code = bitc::CST_CODE_CE_CAST;
2100           Record.push_back(getEncodedCastOpcode(CE->getOpcode()));
2101           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2102           Record.push_back(VE.getValueID(C->getOperand(0)));
2103           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
2104         } else {
2105           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
2106           Code = bitc::CST_CODE_CE_BINOP;
2107           Record.push_back(getEncodedBinaryOpcode(CE->getOpcode()));
2108           Record.push_back(VE.getValueID(C->getOperand(0)));
2109           Record.push_back(VE.getValueID(C->getOperand(1)));
2110           uint64_t Flags = getOptimizationFlags(CE);
2111           if (Flags != 0)
2112             Record.push_back(Flags);
2113         }
2114         break;
2115       case Instruction::GetElementPtr: {
2116         Code = bitc::CST_CODE_CE_GEP;
2117         const auto *GO = cast<GEPOperator>(C);
2118         if (GO->isInBounds())
2119           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
2120         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
2121         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
2122           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
2123           Record.push_back(VE.getValueID(C->getOperand(i)));
2124         }
2125         break;
2126       }
2127       case Instruction::Select:
2128         Code = bitc::CST_CODE_CE_SELECT;
2129         Record.push_back(VE.getValueID(C->getOperand(0)));
2130         Record.push_back(VE.getValueID(C->getOperand(1)));
2131         Record.push_back(VE.getValueID(C->getOperand(2)));
2132         break;
2133       case Instruction::ExtractElement:
2134         Code = bitc::CST_CODE_CE_EXTRACTELT;
2135         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2136         Record.push_back(VE.getValueID(C->getOperand(0)));
2137         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
2138         Record.push_back(VE.getValueID(C->getOperand(1)));
2139         break;
2140       case Instruction::InsertElement:
2141         Code = bitc::CST_CODE_CE_INSERTELT;
2142         Record.push_back(VE.getValueID(C->getOperand(0)));
2143         Record.push_back(VE.getValueID(C->getOperand(1)));
2144         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
2145         Record.push_back(VE.getValueID(C->getOperand(2)));
2146         break;
2147       case Instruction::ShuffleVector:
2148         // If the return type and argument types are the same, this is a
2149         // standard shufflevector instruction.  If the types are different,
2150         // then the shuffle is widening or truncating the input vectors, and
2151         // the argument type must also be encoded.
2152         if (C->getType() == C->getOperand(0)->getType()) {
2153           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
2154         } else {
2155           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
2156           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2157         }
2158         Record.push_back(VE.getValueID(C->getOperand(0)));
2159         Record.push_back(VE.getValueID(C->getOperand(1)));
2160         Record.push_back(VE.getValueID(C->getOperand(2)));
2161         break;
2162       case Instruction::ICmp:
2163       case Instruction::FCmp:
2164         Code = bitc::CST_CODE_CE_CMP;
2165         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2166         Record.push_back(VE.getValueID(C->getOperand(0)));
2167         Record.push_back(VE.getValueID(C->getOperand(1)));
2168         Record.push_back(CE->getPredicate());
2169         break;
2170       }
2171     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
2172       Code = bitc::CST_CODE_BLOCKADDRESS;
2173       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
2174       Record.push_back(VE.getValueID(BA->getFunction()));
2175       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
2176     } else {
2177 #ifndef NDEBUG
2178       C->dump();
2179 #endif
2180       llvm_unreachable("Unknown constant!");
2181     }
2182     Stream.EmitRecord(Code, Record, AbbrevToUse);
2183     Record.clear();
2184   }
2185 
2186   Stream.ExitBlock();
2187 }
2188 
2189 void DXILBitcodeWriter::writeModuleConstants() {
2190   const ValueEnumerator::ValueList &Vals = VE.getValues();
2191 
2192   // Find the first constant to emit, which is the first non-globalvalue value.
2193   // We know globalvalues have been emitted by WriteModuleInfo.
2194   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
2195     if (!isa<GlobalValue>(Vals[i].first)) {
2196       writeConstants(i, Vals.size(), true);
2197       return;
2198     }
2199   }
2200 }
2201 
2202 /// pushValueAndType - The file has to encode both the value and type id for
2203 /// many values, because we need to know what type to create for forward
2204 /// references.  However, most operands are not forward references, so this type
2205 /// field is not needed.
2206 ///
2207 /// This function adds V's value ID to Vals.  If the value ID is higher than the
2208 /// instruction ID, then it is a forward reference, and it also includes the
2209 /// type ID.  The value ID that is written is encoded relative to the InstID.
2210 bool DXILBitcodeWriter::pushValueAndType(const Value *V, unsigned InstID,
2211                                          SmallVectorImpl<unsigned> &Vals) {
2212   unsigned ValID = VE.getValueID(V);
2213   // Make encoding relative to the InstID.
2214   Vals.push_back(InstID - ValID);
2215   if (ValID >= InstID) {
2216     Vals.push_back(VE.getTypeID(V->getType()));
2217     return true;
2218   }
2219   return false;
2220 }
2221 
2222 /// pushValue - Like pushValueAndType, but where the type of the value is
2223 /// omitted (perhaps it was already encoded in an earlier operand).
2224 void DXILBitcodeWriter::pushValue(const Value *V, unsigned InstID,
2225                                   SmallVectorImpl<unsigned> &Vals) {
2226   unsigned ValID = VE.getValueID(V);
2227   Vals.push_back(InstID - ValID);
2228 }
2229 
2230 void DXILBitcodeWriter::pushValueSigned(const Value *V, unsigned InstID,
2231                                         SmallVectorImpl<uint64_t> &Vals) {
2232   unsigned ValID = VE.getValueID(V);
2233   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
2234   emitSignedInt64(Vals, diff);
2235 }
2236 
2237 /// WriteInstruction - Emit an instruction
2238 void DXILBitcodeWriter::writeInstruction(const Instruction &I, unsigned InstID,
2239                                          SmallVectorImpl<unsigned> &Vals) {
2240   unsigned Code = 0;
2241   unsigned AbbrevToUse = 0;
2242   VE.setInstructionID(&I);
2243   switch (I.getOpcode()) {
2244   default:
2245     if (Instruction::isCast(I.getOpcode())) {
2246       Code = bitc::FUNC_CODE_INST_CAST;
2247       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2248         AbbrevToUse = (unsigned)FUNCTION_INST_CAST_ABBREV;
2249       Vals.push_back(VE.getTypeID(I.getType()));
2250       Vals.push_back(getEncodedCastOpcode(I.getOpcode()));
2251     } else {
2252       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
2253       Code = bitc::FUNC_CODE_INST_BINOP;
2254       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2255         AbbrevToUse = (unsigned)FUNCTION_INST_BINOP_ABBREV;
2256       pushValue(I.getOperand(1), InstID, Vals);
2257       Vals.push_back(getEncodedBinaryOpcode(I.getOpcode()));
2258       uint64_t Flags = getOptimizationFlags(&I);
2259       if (Flags != 0) {
2260         if (AbbrevToUse == (unsigned)FUNCTION_INST_BINOP_ABBREV)
2261           AbbrevToUse = (unsigned)FUNCTION_INST_BINOP_FLAGS_ABBREV;
2262         Vals.push_back(Flags);
2263       }
2264     }
2265     break;
2266 
2267   case Instruction::GetElementPtr: {
2268     Code = bitc::FUNC_CODE_INST_GEP;
2269     AbbrevToUse = (unsigned)FUNCTION_INST_GEP_ABBREV;
2270     auto &GEPInst = cast<GetElementPtrInst>(I);
2271     Vals.push_back(GEPInst.isInBounds());
2272     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
2273     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
2274       pushValueAndType(I.getOperand(i), InstID, Vals);
2275     break;
2276   }
2277   case Instruction::ExtractValue: {
2278     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
2279     pushValueAndType(I.getOperand(0), InstID, Vals);
2280     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
2281     Vals.append(EVI->idx_begin(), EVI->idx_end());
2282     break;
2283   }
2284   case Instruction::InsertValue: {
2285     Code = bitc::FUNC_CODE_INST_INSERTVAL;
2286     pushValueAndType(I.getOperand(0), InstID, Vals);
2287     pushValueAndType(I.getOperand(1), InstID, Vals);
2288     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
2289     Vals.append(IVI->idx_begin(), IVI->idx_end());
2290     break;
2291   }
2292   case Instruction::Select:
2293     Code = bitc::FUNC_CODE_INST_VSELECT;
2294     pushValueAndType(I.getOperand(1), InstID, Vals);
2295     pushValue(I.getOperand(2), InstID, Vals);
2296     pushValueAndType(I.getOperand(0), InstID, Vals);
2297     break;
2298   case Instruction::ExtractElement:
2299     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
2300     pushValueAndType(I.getOperand(0), InstID, Vals);
2301     pushValueAndType(I.getOperand(1), InstID, Vals);
2302     break;
2303   case Instruction::InsertElement:
2304     Code = bitc::FUNC_CODE_INST_INSERTELT;
2305     pushValueAndType(I.getOperand(0), InstID, Vals);
2306     pushValue(I.getOperand(1), InstID, Vals);
2307     pushValueAndType(I.getOperand(2), InstID, Vals);
2308     break;
2309   case Instruction::ShuffleVector:
2310     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
2311     pushValueAndType(I.getOperand(0), InstID, Vals);
2312     pushValue(I.getOperand(1), InstID, Vals);
2313     pushValue(I.getOperand(2), InstID, Vals);
2314     break;
2315   case Instruction::ICmp:
2316   case Instruction::FCmp: {
2317     // compare returning Int1Ty or vector of Int1Ty
2318     Code = bitc::FUNC_CODE_INST_CMP2;
2319     pushValueAndType(I.getOperand(0), InstID, Vals);
2320     pushValue(I.getOperand(1), InstID, Vals);
2321     Vals.push_back(cast<CmpInst>(I).getPredicate());
2322     uint64_t Flags = getOptimizationFlags(&I);
2323     if (Flags != 0)
2324       Vals.push_back(Flags);
2325     break;
2326   }
2327 
2328   case Instruction::Ret: {
2329     Code = bitc::FUNC_CODE_INST_RET;
2330     unsigned NumOperands = I.getNumOperands();
2331     if (NumOperands == 0)
2332       AbbrevToUse = (unsigned)FUNCTION_INST_RET_VOID_ABBREV;
2333     else if (NumOperands == 1) {
2334       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2335         AbbrevToUse = (unsigned)FUNCTION_INST_RET_VAL_ABBREV;
2336     } else {
2337       for (unsigned i = 0, e = NumOperands; i != e; ++i)
2338         pushValueAndType(I.getOperand(i), InstID, Vals);
2339     }
2340   } break;
2341   case Instruction::Br: {
2342     Code = bitc::FUNC_CODE_INST_BR;
2343     const BranchInst &II = cast<BranchInst>(I);
2344     Vals.push_back(VE.getValueID(II.getSuccessor(0)));
2345     if (II.isConditional()) {
2346       Vals.push_back(VE.getValueID(II.getSuccessor(1)));
2347       pushValue(II.getCondition(), InstID, Vals);
2348     }
2349   } break;
2350   case Instruction::Switch: {
2351     Code = bitc::FUNC_CODE_INST_SWITCH;
2352     const SwitchInst &SI = cast<SwitchInst>(I);
2353     Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
2354     pushValue(SI.getCondition(), InstID, Vals);
2355     Vals.push_back(VE.getValueID(SI.getDefaultDest()));
2356     for (auto Case : SI.cases()) {
2357       Vals.push_back(VE.getValueID(Case.getCaseValue()));
2358       Vals.push_back(VE.getValueID(Case.getCaseSuccessor()));
2359     }
2360   } break;
2361   case Instruction::IndirectBr:
2362     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
2363     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
2364     // Encode the address operand as relative, but not the basic blocks.
2365     pushValue(I.getOperand(0), InstID, Vals);
2366     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
2367       Vals.push_back(VE.getValueID(I.getOperand(i)));
2368     break;
2369 
2370   case Instruction::Invoke: {
2371     const InvokeInst *II = cast<InvokeInst>(&I);
2372     const Value *Callee = II->getCalledOperand();
2373     FunctionType *FTy = II->getFunctionType();
2374     Code = bitc::FUNC_CODE_INST_INVOKE;
2375 
2376     Vals.push_back(VE.getAttributeListID(II->getAttributes()));
2377     Vals.push_back(II->getCallingConv() | 1 << 13);
2378     Vals.push_back(VE.getValueID(II->getNormalDest()));
2379     Vals.push_back(VE.getValueID(II->getUnwindDest()));
2380     Vals.push_back(VE.getTypeID(FTy));
2381     pushValueAndType(Callee, InstID, Vals);
2382 
2383     // Emit value #'s for the fixed parameters.
2384     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
2385       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
2386 
2387     // Emit type/value pairs for varargs params.
2388     if (FTy->isVarArg()) {
2389       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands() - 3; i != e;
2390            ++i)
2391         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
2392     }
2393     break;
2394   }
2395   case Instruction::Resume:
2396     Code = bitc::FUNC_CODE_INST_RESUME;
2397     pushValueAndType(I.getOperand(0), InstID, Vals);
2398     break;
2399   case Instruction::Unreachable:
2400     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
2401     AbbrevToUse = (unsigned)FUNCTION_INST_UNREACHABLE_ABBREV;
2402     break;
2403 
2404   case Instruction::PHI: {
2405     const PHINode &PN = cast<PHINode>(I);
2406     Code = bitc::FUNC_CODE_INST_PHI;
2407     // With the newer instruction encoding, forward references could give
2408     // negative valued IDs.  This is most common for PHIs, so we use
2409     // signed VBRs.
2410     SmallVector<uint64_t, 128> Vals64;
2411     Vals64.push_back(VE.getTypeID(PN.getType()));
2412     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
2413       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64);
2414       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
2415     }
2416     // Emit a Vals64 vector and exit.
2417     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
2418     Vals64.clear();
2419     return;
2420   }
2421 
2422   case Instruction::LandingPad: {
2423     const LandingPadInst &LP = cast<LandingPadInst>(I);
2424     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
2425     Vals.push_back(VE.getTypeID(LP.getType()));
2426     Vals.push_back(LP.isCleanup());
2427     Vals.push_back(LP.getNumClauses());
2428     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
2429       if (LP.isCatch(I))
2430         Vals.push_back(LandingPadInst::Catch);
2431       else
2432         Vals.push_back(LandingPadInst::Filter);
2433       pushValueAndType(LP.getClause(I), InstID, Vals);
2434     }
2435     break;
2436   }
2437 
2438   case Instruction::Alloca: {
2439     Code = bitc::FUNC_CODE_INST_ALLOCA;
2440     const AllocaInst &AI = cast<AllocaInst>(I);
2441     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
2442     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
2443     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
2444     using APV = AllocaPackedValues;
2445     unsigned Record = 0;
2446     unsigned EncodedAlign = getEncodedAlign(AI.getAlign());
2447     Bitfield::set<APV::AlignLower>(
2448         Record, EncodedAlign & ((1 << APV::AlignLower::Bits) - 1));
2449     Bitfield::set<APV::AlignUpper>(Record,
2450                                    EncodedAlign >> APV::AlignLower::Bits);
2451     Bitfield::set<APV::UsedWithInAlloca>(Record, AI.isUsedWithInAlloca());
2452     Vals.push_back(Record);
2453     break;
2454   }
2455 
2456   case Instruction::Load:
2457     if (cast<LoadInst>(I).isAtomic()) {
2458       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
2459       pushValueAndType(I.getOperand(0), InstID, Vals);
2460     } else {
2461       Code = bitc::FUNC_CODE_INST_LOAD;
2462       if (!pushValueAndType(I.getOperand(0), InstID, Vals)) // ptr
2463         AbbrevToUse = (unsigned)FUNCTION_INST_LOAD_ABBREV;
2464     }
2465     Vals.push_back(VE.getTypeID(I.getType()));
2466     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment()) + 1);
2467     Vals.push_back(cast<LoadInst>(I).isVolatile());
2468     if (cast<LoadInst>(I).isAtomic()) {
2469       Vals.push_back(getEncodedOrdering(cast<LoadInst>(I).getOrdering()));
2470       Vals.push_back(getEncodedSyncScopeID(cast<LoadInst>(I).getSyncScopeID()));
2471     }
2472     break;
2473   case Instruction::Store:
2474     if (cast<StoreInst>(I).isAtomic())
2475       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
2476     else
2477       Code = bitc::FUNC_CODE_INST_STORE;
2478     pushValueAndType(I.getOperand(1), InstID, Vals); // ptrty + ptr
2479     pushValueAndType(I.getOperand(0), InstID, Vals); // valty + val
2480     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment()) + 1);
2481     Vals.push_back(cast<StoreInst>(I).isVolatile());
2482     if (cast<StoreInst>(I).isAtomic()) {
2483       Vals.push_back(getEncodedOrdering(cast<StoreInst>(I).getOrdering()));
2484       Vals.push_back(
2485           getEncodedSyncScopeID(cast<StoreInst>(I).getSyncScopeID()));
2486     }
2487     break;
2488   case Instruction::AtomicCmpXchg:
2489     Code = bitc::FUNC_CODE_INST_CMPXCHG;
2490     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
2491     pushValueAndType(I.getOperand(1), InstID, Vals); // cmp.
2492     pushValue(I.getOperand(2), InstID, Vals);        // newval.
2493     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
2494     Vals.push_back(
2495         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
2496     Vals.push_back(
2497         getEncodedSyncScopeID(cast<AtomicCmpXchgInst>(I).getSyncScopeID()));
2498     Vals.push_back(
2499         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
2500     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
2501     break;
2502   case Instruction::AtomicRMW:
2503     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
2504     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
2505     pushValue(I.getOperand(1), InstID, Vals);        // val.
2506     Vals.push_back(
2507         getEncodedRMWOperation(cast<AtomicRMWInst>(I).getOperation()));
2508     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
2509     Vals.push_back(getEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
2510     Vals.push_back(
2511         getEncodedSyncScopeID(cast<AtomicRMWInst>(I).getSyncScopeID()));
2512     break;
2513   case Instruction::Fence:
2514     Code = bitc::FUNC_CODE_INST_FENCE;
2515     Vals.push_back(getEncodedOrdering(cast<FenceInst>(I).getOrdering()));
2516     Vals.push_back(getEncodedSyncScopeID(cast<FenceInst>(I).getSyncScopeID()));
2517     break;
2518   case Instruction::Call: {
2519     const CallInst &CI = cast<CallInst>(I);
2520     FunctionType *FTy = CI.getFunctionType();
2521 
2522     Code = bitc::FUNC_CODE_INST_CALL;
2523 
2524     Vals.push_back(VE.getAttributeListID(CI.getAttributes()));
2525     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()) |
2526                    unsigned(CI.isMustTailCall()) << 14 | 1 << 15);
2527     Vals.push_back(VE.getTypeID(FTy));
2528     pushValueAndType(CI.getCalledOperand(), InstID, Vals); // Callee
2529 
2530     // Emit value #'s for the fixed parameters.
2531     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
2532       // Check for labels (can happen with asm labels).
2533       if (FTy->getParamType(i)->isLabelTy())
2534         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
2535       else
2536         pushValue(CI.getArgOperand(i), InstID, Vals); // fixed param.
2537     }
2538 
2539     // Emit type/value pairs for varargs params.
2540     if (FTy->isVarArg()) {
2541       for (unsigned i = FTy->getNumParams(), e = CI.arg_size(); i != e; ++i)
2542         pushValueAndType(CI.getArgOperand(i), InstID, Vals); // varargs
2543     }
2544     break;
2545   }
2546   case Instruction::VAArg:
2547     Code = bitc::FUNC_CODE_INST_VAARG;
2548     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType())); // valistty
2549     pushValue(I.getOperand(0), InstID, Vals);                 // valist.
2550     Vals.push_back(VE.getTypeID(I.getType()));                // restype.
2551     break;
2552   }
2553 
2554   Stream.EmitRecord(Code, Vals, AbbrevToUse);
2555   Vals.clear();
2556 }
2557 
2558 // Emit names for globals/functions etc.
2559 void DXILBitcodeWriter::writeFunctionLevelValueSymbolTable(
2560     const ValueSymbolTable &VST) {
2561   if (VST.empty())
2562     return;
2563   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
2564 
2565   SmallVector<unsigned, 64> NameVals;
2566 
2567   // HLSL Change
2568   // Read the named values from a sorted list instead of the original list
2569   // to ensure the binary is the same no matter what values ever existed.
2570   SmallVector<const ValueName *, 16> SortedTable;
2571 
2572   for (auto &VI : VST) {
2573     SortedTable.push_back(VI.second->getValueName());
2574   }
2575   // The keys are unique, so there shouldn't be stability issues.
2576   std::sort(SortedTable.begin(), SortedTable.end(),
2577             [](const ValueName *A, const ValueName *B) {
2578               return A->first() < B->first();
2579             });
2580 
2581   for (const ValueName *SI : SortedTable) {
2582     auto &Name = *SI;
2583 
2584     // Figure out the encoding to use for the name.
2585     bool is7Bit = true;
2586     bool isChar6 = true;
2587     for (const char *C = Name.getKeyData(), *E = C + Name.getKeyLength();
2588          C != E; ++C) {
2589       if (isChar6)
2590         isChar6 = BitCodeAbbrevOp::isChar6(*C);
2591       if ((unsigned char)*C & 128) {
2592         is7Bit = false;
2593         break; // don't bother scanning the rest.
2594       }
2595     }
2596 
2597     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
2598 
2599     // VST_ENTRY:   [valueid, namechar x N]
2600     // VST_BBENTRY: [bbid, namechar x N]
2601     unsigned Code;
2602     if (isa<BasicBlock>(SI->getValue())) {
2603       Code = bitc::VST_CODE_BBENTRY;
2604       if (isChar6)
2605         AbbrevToUse = VST_BBENTRY_6_ABBREV;
2606     } else {
2607       Code = bitc::VST_CODE_ENTRY;
2608       if (isChar6)
2609         AbbrevToUse = VST_ENTRY_6_ABBREV;
2610       else if (is7Bit)
2611         AbbrevToUse = VST_ENTRY_7_ABBREV;
2612     }
2613 
2614     NameVals.push_back(VE.getValueID(SI->getValue()));
2615     for (const char *P = Name.getKeyData(),
2616                     *E = Name.getKeyData() + Name.getKeyLength();
2617          P != E; ++P)
2618       NameVals.push_back((unsigned char)*P);
2619 
2620     // Emit the finished record.
2621     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
2622     NameVals.clear();
2623   }
2624   Stream.ExitBlock();
2625 }
2626 
2627 void DXILBitcodeWriter::writeUseList(UseListOrder &&Order) {
2628   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
2629   unsigned Code;
2630   if (isa<BasicBlock>(Order.V))
2631     Code = bitc::USELIST_CODE_BB;
2632   else
2633     Code = bitc::USELIST_CODE_DEFAULT;
2634 
2635   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
2636   Record.push_back(VE.getValueID(Order.V));
2637   Stream.EmitRecord(Code, Record);
2638 }
2639 
2640 void DXILBitcodeWriter::writeUseListBlock(const Function *F) {
2641   assert(VE.shouldPreserveUseListOrder() &&
2642          "Expected to be preserving use-list order");
2643 
2644   auto hasMore = [&]() {
2645     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
2646   };
2647   if (!hasMore())
2648     // Nothing to do.
2649     return;
2650 
2651   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
2652   while (hasMore()) {
2653     writeUseList(std::move(VE.UseListOrders.back()));
2654     VE.UseListOrders.pop_back();
2655   }
2656   Stream.ExitBlock();
2657 }
2658 
2659 /// Emit a function body to the module stream.
2660 void DXILBitcodeWriter::writeFunction(const Function &F) {
2661   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
2662   VE.incorporateFunction(F);
2663 
2664   SmallVector<unsigned, 64> Vals;
2665 
2666   // Emit the number of basic blocks, so the reader can create them ahead of
2667   // time.
2668   Vals.push_back(VE.getBasicBlocks().size());
2669   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
2670   Vals.clear();
2671 
2672   // If there are function-local constants, emit them now.
2673   unsigned CstStart, CstEnd;
2674   VE.getFunctionConstantRange(CstStart, CstEnd);
2675   writeConstants(CstStart, CstEnd, false);
2676 
2677   // If there is function-local metadata, emit it now.
2678   writeFunctionMetadata(F);
2679 
2680   // Keep a running idea of what the instruction ID is.
2681   unsigned InstID = CstEnd;
2682 
2683   bool NeedsMetadataAttachment = F.hasMetadata();
2684 
2685   DILocation *LastDL = nullptr;
2686 
2687   // Finally, emit all the instructions, in order.
2688   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
2689     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E;
2690          ++I) {
2691       writeInstruction(*I, InstID, Vals);
2692 
2693       if (!I->getType()->isVoidTy())
2694         ++InstID;
2695 
2696       // If the instruction has metadata, write a metadata attachment later.
2697       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
2698 
2699       // If the instruction has a debug location, emit it.
2700       DILocation *DL = I->getDebugLoc();
2701       if (!DL)
2702         continue;
2703 
2704       if (DL == LastDL) {
2705         // Just repeat the same debug loc as last time.
2706         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
2707         continue;
2708       }
2709 
2710       Vals.push_back(DL->getLine());
2711       Vals.push_back(DL->getColumn());
2712       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
2713       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
2714       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
2715       Vals.clear();
2716 
2717       LastDL = DL;
2718     }
2719 
2720   // Emit names for all the instructions etc.
2721   if (auto *Symtab = F.getValueSymbolTable())
2722     writeFunctionLevelValueSymbolTable(*Symtab);
2723 
2724   if (NeedsMetadataAttachment)
2725     writeFunctionMetadataAttachment(F);
2726   if (VE.shouldPreserveUseListOrder())
2727     writeUseListBlock(&F);
2728   VE.purgeFunction();
2729   Stream.ExitBlock();
2730 }
2731 
2732 // Emit blockinfo, which defines the standard abbreviations etc.
2733 void DXILBitcodeWriter::writeBlockInfo() {
2734   // We only want to emit block info records for blocks that have multiple
2735   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
2736   // Other blocks can define their abbrevs inline.
2737   Stream.EnterBlockInfoBlock();
2738 
2739   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
2740     auto Abbv = std::make_shared<BitCodeAbbrev>();
2741     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
2742     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2743     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2744     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2745     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2746                                    std::move(Abbv)) != VST_ENTRY_8_ABBREV)
2747       assert(false && "Unexpected abbrev ordering!");
2748   }
2749 
2750   { // 7-bit fixed width VST_ENTRY strings.
2751     auto Abbv = std::make_shared<BitCodeAbbrev>();
2752     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2753     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2754     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2755     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2756     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2757                                    std::move(Abbv)) != VST_ENTRY_7_ABBREV)
2758       assert(false && "Unexpected abbrev ordering!");
2759   }
2760   { // 6-bit char6 VST_ENTRY strings.
2761     auto Abbv = std::make_shared<BitCodeAbbrev>();
2762     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2763     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2764     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2765     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2766     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2767                                    std::move(Abbv)) != VST_ENTRY_6_ABBREV)
2768       assert(false && "Unexpected abbrev ordering!");
2769   }
2770   { // 6-bit char6 VST_BBENTRY strings.
2771     auto Abbv = std::make_shared<BitCodeAbbrev>();
2772     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
2773     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2774     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2775     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2776     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2777                                    std::move(Abbv)) != VST_BBENTRY_6_ABBREV)
2778       assert(false && "Unexpected abbrev ordering!");
2779   }
2780 
2781   { // SETTYPE abbrev for CONSTANTS_BLOCK.
2782     auto Abbv = std::make_shared<BitCodeAbbrev>();
2783     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
2784     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2785                               VE.computeBitsRequiredForTypeIndicies()));
2786     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2787         CONSTANTS_SETTYPE_ABBREV)
2788       assert(false && "Unexpected abbrev ordering!");
2789   }
2790 
2791   { // INTEGER abbrev for CONSTANTS_BLOCK.
2792     auto Abbv = std::make_shared<BitCodeAbbrev>();
2793     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
2794     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2795     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2796         CONSTANTS_INTEGER_ABBREV)
2797       assert(false && "Unexpected abbrev ordering!");
2798   }
2799 
2800   { // CE_CAST abbrev for CONSTANTS_BLOCK.
2801     auto Abbv = std::make_shared<BitCodeAbbrev>();
2802     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
2803     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // cast opc
2804     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,      // typeid
2805                               VE.computeBitsRequiredForTypeIndicies()));
2806     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
2807 
2808     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2809         CONSTANTS_CE_CAST_Abbrev)
2810       assert(false && "Unexpected abbrev ordering!");
2811   }
2812   { // NULL abbrev for CONSTANTS_BLOCK.
2813     auto Abbv = std::make_shared<BitCodeAbbrev>();
2814     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
2815     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2816         CONSTANTS_NULL_Abbrev)
2817       assert(false && "Unexpected abbrev ordering!");
2818   }
2819 
2820   // FIXME: This should only use space for first class types!
2821 
2822   { // INST_LOAD abbrev for FUNCTION_BLOCK.
2823     auto Abbv = std::make_shared<BitCodeAbbrev>();
2824     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
2825     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
2826     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2827                               VE.computeBitsRequiredForTypeIndicies()));
2828     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // Align
2829     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
2830     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2831         (unsigned)FUNCTION_INST_LOAD_ABBREV)
2832       assert(false && "Unexpected abbrev ordering!");
2833   }
2834   { // INST_BINOP abbrev for FUNCTION_BLOCK.
2835     auto Abbv = std::make_shared<BitCodeAbbrev>();
2836     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2837     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LHS
2838     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // RHS
2839     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2840     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2841         (unsigned)FUNCTION_INST_BINOP_ABBREV)
2842       assert(false && "Unexpected abbrev ordering!");
2843   }
2844   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
2845     auto Abbv = std::make_shared<BitCodeAbbrev>();
2846     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2847     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LHS
2848     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // RHS
2849     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2850     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
2851     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2852         (unsigned)FUNCTION_INST_BINOP_FLAGS_ABBREV)
2853       assert(false && "Unexpected abbrev ordering!");
2854   }
2855   { // INST_CAST abbrev for FUNCTION_BLOCK.
2856     auto Abbv = std::make_shared<BitCodeAbbrev>();
2857     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
2858     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // OpVal
2859     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2860                               VE.computeBitsRequiredForTypeIndicies()));
2861     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2862     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2863         (unsigned)FUNCTION_INST_CAST_ABBREV)
2864       assert(false && "Unexpected abbrev ordering!");
2865   }
2866 
2867   { // INST_RET abbrev for FUNCTION_BLOCK.
2868     auto Abbv = std::make_shared<BitCodeAbbrev>();
2869     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2870     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2871         (unsigned)FUNCTION_INST_RET_VOID_ABBREV)
2872       assert(false && "Unexpected abbrev ordering!");
2873   }
2874   { // INST_RET abbrev for FUNCTION_BLOCK.
2875     auto Abbv = std::make_shared<BitCodeAbbrev>();
2876     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2877     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
2878     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2879         (unsigned)FUNCTION_INST_RET_VAL_ABBREV)
2880       assert(false && "Unexpected abbrev ordering!");
2881   }
2882   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
2883     auto Abbv = std::make_shared<BitCodeAbbrev>();
2884     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
2885     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2886         (unsigned)FUNCTION_INST_UNREACHABLE_ABBREV)
2887       assert(false && "Unexpected abbrev ordering!");
2888   }
2889   {
2890     auto Abbv = std::make_shared<BitCodeAbbrev>();
2891     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
2892     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2893     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
2894                               Log2_32_Ceil(VE.getTypes().size() + 1)));
2895     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2896     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2897     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2898         (unsigned)FUNCTION_INST_GEP_ABBREV)
2899       assert(false && "Unexpected abbrev ordering!");
2900   }
2901 
2902   Stream.ExitBlock();
2903 }
2904 
2905 void DXILBitcodeWriter::writeModuleVersion() {
2906   // VERSION: [version#]
2907   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, ArrayRef<unsigned>{1});
2908 }
2909 
2910 /// WriteModule - Emit the specified module to the bitstream.
2911 void DXILBitcodeWriter::write() {
2912   // The identification block is new since llvm-3.7, but the old bitcode reader
2913   // will skip it.
2914   // writeIdentificationBlock(Stream);
2915 
2916   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
2917 
2918   // It is redundant to fully-specify this here, but nice to make it explicit
2919   // so that it is clear the DXIL module version is different.
2920   DXILBitcodeWriter::writeModuleVersion();
2921 
2922   // Emit blockinfo, which defines the standard abbreviations etc.
2923   writeBlockInfo();
2924 
2925   // Emit information about attribute groups.
2926   writeAttributeGroupTable();
2927 
2928   // Emit information about parameter attributes.
2929   writeAttributeTable();
2930 
2931   // Emit information describing all of the types in the module.
2932   writeTypeTable();
2933 
2934   writeComdats();
2935 
2936   // Emit top-level description of module, including target triple, inline asm,
2937   // descriptors for global variables, and function prototype info.
2938   writeModuleInfo();
2939 
2940   // Emit constants.
2941   writeModuleConstants();
2942 
2943   // Emit metadata.
2944   writeModuleMetadataKinds();
2945 
2946   // Emit metadata.
2947   writeModuleMetadata();
2948 
2949   // Emit names for globals/functions etc.
2950   // DXIL uses the same format for module-level value symbol table as for the
2951   // function level table.
2952   writeFunctionLevelValueSymbolTable(M.getValueSymbolTable());
2953 
2954   // Emit module-level use-lists.
2955   if (VE.shouldPreserveUseListOrder())
2956     writeUseListBlock(nullptr);
2957 
2958   // Emit function bodies.
2959   for (const Function &F : M)
2960     if (!F.isDeclaration())
2961       writeFunction(F);
2962 
2963   Stream.ExitBlock();
2964 }
2965