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       llvm_unreachable("These should never be used!!!");
1053       break;
1054     case Type::VoidTyID:
1055       Code = bitc::TYPE_CODE_VOID;
1056       break;
1057     case Type::HalfTyID:
1058       Code = bitc::TYPE_CODE_HALF;
1059       break;
1060     case Type::FloatTyID:
1061       Code = bitc::TYPE_CODE_FLOAT;
1062       break;
1063     case Type::DoubleTyID:
1064       Code = bitc::TYPE_CODE_DOUBLE;
1065       break;
1066     case Type::X86_FP80TyID:
1067       Code = bitc::TYPE_CODE_X86_FP80;
1068       break;
1069     case Type::FP128TyID:
1070       Code = bitc::TYPE_CODE_FP128;
1071       break;
1072     case Type::PPC_FP128TyID:
1073       Code = bitc::TYPE_CODE_PPC_FP128;
1074       break;
1075     case Type::LabelTyID:
1076       Code = bitc::TYPE_CODE_LABEL;
1077       break;
1078     case Type::MetadataTyID:
1079       Code = bitc::TYPE_CODE_METADATA;
1080       break;
1081     case Type::X86_MMXTyID:
1082       Code = bitc::TYPE_CODE_X86_MMX;
1083       break;
1084     case Type::IntegerTyID:
1085       // INTEGER: [width]
1086       Code = bitc::TYPE_CODE_INTEGER;
1087       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
1088       break;
1089     case Type::PointerTyID: {
1090       PointerType *PTy = cast<PointerType>(T);
1091       // POINTER: [pointee type, address space]
1092       Code = bitc::TYPE_CODE_POINTER;
1093       TypeVals.push_back(VE.getTypeID(PTy->getNonOpaquePointerElementType()));
1094       unsigned AddressSpace = PTy->getAddressSpace();
1095       TypeVals.push_back(AddressSpace);
1096       if (AddressSpace == 0)
1097         AbbrevToUse = PtrAbbrev;
1098       break;
1099     }
1100     case Type::FunctionTyID: {
1101       FunctionType *FT = cast<FunctionType>(T);
1102       // FUNCTION: [isvararg, retty, paramty x N]
1103       Code = bitc::TYPE_CODE_FUNCTION;
1104       TypeVals.push_back(FT->isVarArg());
1105       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
1106       for (Type *PTy : FT->params())
1107         TypeVals.push_back(VE.getTypeID(PTy));
1108       AbbrevToUse = FunctionAbbrev;
1109       break;
1110     }
1111     case Type::StructTyID: {
1112       StructType *ST = cast<StructType>(T);
1113       // STRUCT: [ispacked, eltty x N]
1114       TypeVals.push_back(ST->isPacked());
1115       // Output all of the element types.
1116       for (Type *ElTy : ST->elements())
1117         TypeVals.push_back(VE.getTypeID(ElTy));
1118 
1119       if (ST->isLiteral()) {
1120         Code = bitc::TYPE_CODE_STRUCT_ANON;
1121         AbbrevToUse = StructAnonAbbrev;
1122       } else {
1123         if (ST->isOpaque()) {
1124           Code = bitc::TYPE_CODE_OPAQUE;
1125         } else {
1126           Code = bitc::TYPE_CODE_STRUCT_NAMED;
1127           AbbrevToUse = StructNamedAbbrev;
1128         }
1129 
1130         // Emit the name if it is present.
1131         if (!ST->getName().empty())
1132           writeStringRecord(Stream, bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
1133                             StructNameAbbrev);
1134       }
1135       break;
1136     }
1137     case Type::ArrayTyID: {
1138       ArrayType *AT = cast<ArrayType>(T);
1139       // ARRAY: [numelts, eltty]
1140       Code = bitc::TYPE_CODE_ARRAY;
1141       TypeVals.push_back(AT->getNumElements());
1142       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
1143       AbbrevToUse = ArrayAbbrev;
1144       break;
1145     }
1146     case Type::FixedVectorTyID:
1147     case Type::ScalableVectorTyID: {
1148       VectorType *VT = cast<VectorType>(T);
1149       // VECTOR [numelts, eltty]
1150       Code = bitc::TYPE_CODE_VECTOR;
1151       TypeVals.push_back(VT->getElementCount().getKnownMinValue());
1152       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
1153       break;
1154     }
1155     }
1156 
1157     // Emit the finished record.
1158     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
1159     TypeVals.clear();
1160   }
1161 
1162   Stream.ExitBlock();
1163 }
1164 
1165 void DXILBitcodeWriter::writeComdats() {
1166   SmallVector<uint16_t, 64> Vals;
1167   for (const Comdat *C : VE.getComdats()) {
1168     // COMDAT: [selection_kind, name]
1169     Vals.push_back(getEncodedComdatSelectionKind(*C));
1170     size_t Size = C->getName().size();
1171     assert(isUInt<16>(Size));
1172     Vals.push_back(Size);
1173     for (char Chr : C->getName())
1174       Vals.push_back((unsigned char)Chr);
1175     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
1176     Vals.clear();
1177   }
1178 }
1179 
1180 void DXILBitcodeWriter::writeValueSymbolTableForwardDecl() {}
1181 
1182 /// Emit top-level description of module, including target triple, inline asm,
1183 /// descriptors for global variables, and function prototype info.
1184 /// Returns the bit offset to backpatch with the location of the real VST.
1185 void DXILBitcodeWriter::writeModuleInfo() {
1186   // Emit various pieces of data attached to a module.
1187   if (!M.getTargetTriple().empty())
1188     writeStringRecord(Stream, bitc::MODULE_CODE_TRIPLE, M.getTargetTriple(),
1189                       0 /*TODO*/);
1190   const std::string &DL = M.getDataLayoutStr();
1191   if (!DL.empty())
1192     writeStringRecord(Stream, bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/);
1193   if (!M.getModuleInlineAsm().empty())
1194     writeStringRecord(Stream, bitc::MODULE_CODE_ASM, M.getModuleInlineAsm(),
1195                       0 /*TODO*/);
1196 
1197   // Emit information about sections and GC, computing how many there are. Also
1198   // compute the maximum alignment value.
1199   std::map<std::string, unsigned> SectionMap;
1200   std::map<std::string, unsigned> GCMap;
1201   MaybeAlign MaxAlignment;
1202   unsigned MaxGlobalType = 0;
1203   const auto UpdateMaxAlignment = [&MaxAlignment](const MaybeAlign A) {
1204     if (A)
1205       MaxAlignment = !MaxAlignment ? *A : std::max(*MaxAlignment, *A);
1206   };
1207   for (const GlobalVariable &GV : M.globals()) {
1208     UpdateMaxAlignment(GV.getAlign());
1209     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
1210     if (GV.hasSection()) {
1211       // Give section names unique ID's.
1212       unsigned &Entry = SectionMap[std::string(GV.getSection())];
1213       if (!Entry) {
1214         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME,
1215                           GV.getSection(), 0 /*TODO*/);
1216         Entry = SectionMap.size();
1217       }
1218     }
1219   }
1220   for (const Function &F : M) {
1221     UpdateMaxAlignment(F.getAlign());
1222     if (F.hasSection()) {
1223       // Give section names unique ID's.
1224       unsigned &Entry = SectionMap[std::string(F.getSection())];
1225       if (!Entry) {
1226         writeStringRecord(Stream, bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
1227                           0 /*TODO*/);
1228         Entry = SectionMap.size();
1229       }
1230     }
1231     if (F.hasGC()) {
1232       // Same for GC names.
1233       unsigned &Entry = GCMap[F.getGC()];
1234       if (!Entry) {
1235         writeStringRecord(Stream, bitc::MODULE_CODE_GCNAME, F.getGC(),
1236                           0 /*TODO*/);
1237         Entry = GCMap.size();
1238       }
1239     }
1240   }
1241 
1242   // Emit abbrev for globals, now that we know # sections and max alignment.
1243   unsigned SimpleGVarAbbrev = 0;
1244   if (!M.global_empty()) {
1245     // Add an abbrev for common globals with no visibility or thread localness.
1246     auto Abbv = std::make_shared<BitCodeAbbrev>();
1247     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
1248     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1249                               Log2_32_Ceil(MaxGlobalType + 1)));
1250     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
1251                                                            //| explicitType << 1
1252                                                            //| constant
1253     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
1254     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
1255     if (MaxAlignment == 0)                                 // Alignment.
1256       Abbv->Add(BitCodeAbbrevOp(0));
1257     else {
1258       unsigned MaxEncAlignment = getEncodedAlign(MaxAlignment);
1259       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1260                                 Log2_32_Ceil(MaxEncAlignment + 1)));
1261     }
1262     if (SectionMap.empty()) // Section.
1263       Abbv->Add(BitCodeAbbrevOp(0));
1264     else
1265       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1266                                 Log2_32_Ceil(SectionMap.size() + 1)));
1267     // Don't bother emitting vis + thread local.
1268     SimpleGVarAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1269   }
1270 
1271   // Emit the global variable information.
1272   SmallVector<unsigned, 64> Vals;
1273   for (const GlobalVariable &GV : M.globals()) {
1274     unsigned AbbrevToUse = 0;
1275 
1276     // GLOBALVAR: [type, isconst, initid,
1277     //             linkage, alignment, section, visibility, threadlocal,
1278     //             unnamed_addr, externally_initialized, dllstorageclass,
1279     //             comdat]
1280     Vals.push_back(VE.getTypeID(GV.getValueType()));
1281     Vals.push_back(
1282         GV.getType()->getAddressSpace() << 2 | 2 |
1283         (GV.isConstant() ? 1 : 0)); // HLSL Change - bitwise | was used with
1284                                     // unsigned int and bool
1285     Vals.push_back(
1286         GV.isDeclaration() ? 0 : (VE.getValueID(GV.getInitializer()) + 1));
1287     Vals.push_back(getEncodedLinkage(GV));
1288     Vals.push_back(getEncodedAlign(GV.getAlign()));
1289     Vals.push_back(GV.hasSection() ? SectionMap[std::string(GV.getSection())]
1290                                    : 0);
1291     if (GV.isThreadLocal() ||
1292         GV.getVisibility() != GlobalValue::DefaultVisibility ||
1293         GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None ||
1294         GV.isExternallyInitialized() ||
1295         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
1296         GV.hasComdat()) {
1297       Vals.push_back(getEncodedVisibility(GV));
1298       Vals.push_back(getEncodedThreadLocalMode(GV));
1299       Vals.push_back(GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
1300       Vals.push_back(GV.isExternallyInitialized());
1301       Vals.push_back(getEncodedDLLStorageClass(GV));
1302       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
1303     } else {
1304       AbbrevToUse = SimpleGVarAbbrev;
1305     }
1306 
1307     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
1308     Vals.clear();
1309   }
1310 
1311   // Emit the function proto information.
1312   for (const Function &F : M) {
1313     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
1314     //             section, visibility, gc, unnamed_addr, prologuedata,
1315     //             dllstorageclass, comdat, prefixdata, personalityfn]
1316     Vals.push_back(VE.getTypeID(F.getFunctionType()));
1317     Vals.push_back(F.getCallingConv());
1318     Vals.push_back(F.isDeclaration());
1319     Vals.push_back(getEncodedLinkage(F));
1320     Vals.push_back(VE.getAttributeListID(F.getAttributes()));
1321     Vals.push_back(getEncodedAlign(F.getAlign()));
1322     Vals.push_back(F.hasSection() ? SectionMap[std::string(F.getSection())]
1323                                   : 0);
1324     Vals.push_back(getEncodedVisibility(F));
1325     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
1326     Vals.push_back(F.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
1327     Vals.push_back(
1328         F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1) : 0);
1329     Vals.push_back(getEncodedDLLStorageClass(F));
1330     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
1331     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
1332                                      : 0);
1333     Vals.push_back(
1334         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
1335 
1336     unsigned AbbrevToUse = 0;
1337     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
1338     Vals.clear();
1339   }
1340 
1341   // Emit the alias information.
1342   for (const GlobalAlias &A : M.aliases()) {
1343     // ALIAS: [alias type, aliasee val#, linkage, visibility]
1344     Vals.push_back(VE.getTypeID(A.getValueType()));
1345     Vals.push_back(VE.getValueID(A.getAliasee()));
1346     Vals.push_back(getEncodedLinkage(A));
1347     Vals.push_back(getEncodedVisibility(A));
1348     Vals.push_back(getEncodedDLLStorageClass(A));
1349     Vals.push_back(getEncodedThreadLocalMode(A));
1350     Vals.push_back(A.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
1351     unsigned AbbrevToUse = 0;
1352     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS_OLD, Vals, AbbrevToUse);
1353     Vals.clear();
1354   }
1355 }
1356 
1357 void DXILBitcodeWriter::writeValueAsMetadata(
1358     const ValueAsMetadata *MD, SmallVectorImpl<uint64_t> &Record) {
1359   // Mimic an MDNode with a value as one operand.
1360   Value *V = MD->getValue();
1361   Record.push_back(VE.getTypeID(V->getType()));
1362   Record.push_back(VE.getValueID(V));
1363   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
1364   Record.clear();
1365 }
1366 
1367 void DXILBitcodeWriter::writeMDTuple(const MDTuple *N,
1368                                      SmallVectorImpl<uint64_t> &Record,
1369                                      unsigned Abbrev) {
1370   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
1371     Metadata *MD = N->getOperand(i);
1372     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
1373            "Unexpected function-local metadata");
1374     Record.push_back(VE.getMetadataOrNullID(MD));
1375   }
1376   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
1377                                     : bitc::METADATA_NODE,
1378                     Record, Abbrev);
1379   Record.clear();
1380 }
1381 
1382 void DXILBitcodeWriter::writeDILocation(const DILocation *N,
1383                                         SmallVectorImpl<uint64_t> &Record,
1384                                         unsigned &Abbrev) {
1385   if (!Abbrev)
1386     Abbrev = createDILocationAbbrev();
1387   Record.push_back(N->isDistinct());
1388   Record.push_back(N->getLine());
1389   Record.push_back(N->getColumn());
1390   Record.push_back(VE.getMetadataID(N->getScope()));
1391   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
1392 
1393   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
1394   Record.clear();
1395 }
1396 
1397 static uint64_t rotateSign(APInt Val) {
1398   int64_t I = Val.getSExtValue();
1399   uint64_t U = I;
1400   return I < 0 ? ~(U << 1) : U << 1;
1401 }
1402 
1403 static uint64_t rotateSign(DISubrange::BoundType Val) {
1404   return rotateSign(Val.get<ConstantInt *>()->getValue());
1405 }
1406 
1407 void DXILBitcodeWriter::writeDISubrange(const DISubrange *N,
1408                                         SmallVectorImpl<uint64_t> &Record,
1409                                         unsigned Abbrev) {
1410   Record.push_back(N->isDistinct());
1411   Record.push_back(
1412       N->getCount().get<ConstantInt *>()->getValue().getSExtValue());
1413   Record.push_back(rotateSign(N->getLowerBound()));
1414 
1415   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
1416   Record.clear();
1417 }
1418 
1419 void DXILBitcodeWriter::writeDIEnumerator(const DIEnumerator *N,
1420                                           SmallVectorImpl<uint64_t> &Record,
1421                                           unsigned Abbrev) {
1422   Record.push_back(N->isDistinct());
1423   Record.push_back(rotateSign(N->getValue()));
1424   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1425 
1426   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
1427   Record.clear();
1428 }
1429 
1430 void DXILBitcodeWriter::writeDIBasicType(const DIBasicType *N,
1431                                          SmallVectorImpl<uint64_t> &Record,
1432                                          unsigned Abbrev) {
1433   Record.push_back(N->isDistinct());
1434   Record.push_back(N->getTag());
1435   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1436   Record.push_back(N->getSizeInBits());
1437   Record.push_back(N->getAlignInBits());
1438   Record.push_back(N->getEncoding());
1439 
1440   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
1441   Record.clear();
1442 }
1443 
1444 void DXILBitcodeWriter::writeDIDerivedType(const DIDerivedType *N,
1445                                            SmallVectorImpl<uint64_t> &Record,
1446                                            unsigned Abbrev) {
1447   Record.push_back(N->isDistinct());
1448   Record.push_back(N->getTag());
1449   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1450   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1451   Record.push_back(N->getLine());
1452   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1453   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1454   Record.push_back(N->getSizeInBits());
1455   Record.push_back(N->getAlignInBits());
1456   Record.push_back(N->getOffsetInBits());
1457   Record.push_back(N->getFlags());
1458   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
1459 
1460   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
1461   Record.clear();
1462 }
1463 
1464 void DXILBitcodeWriter::writeDICompositeType(const DICompositeType *N,
1465                                              SmallVectorImpl<uint64_t> &Record,
1466                                              unsigned Abbrev) {
1467   Record.push_back(N->isDistinct());
1468   Record.push_back(N->getTag());
1469   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1470   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1471   Record.push_back(N->getLine());
1472   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1473   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
1474   Record.push_back(N->getSizeInBits());
1475   Record.push_back(N->getAlignInBits());
1476   Record.push_back(N->getOffsetInBits());
1477   Record.push_back(N->getFlags());
1478   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
1479   Record.push_back(N->getRuntimeLang());
1480   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
1481   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1482   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
1483 
1484   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
1485   Record.clear();
1486 }
1487 
1488 void DXILBitcodeWriter::writeDISubroutineType(const DISubroutineType *N,
1489                                               SmallVectorImpl<uint64_t> &Record,
1490                                               unsigned Abbrev) {
1491   Record.push_back(N->isDistinct());
1492   Record.push_back(N->getFlags());
1493   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
1494 
1495   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
1496   Record.clear();
1497 }
1498 
1499 void DXILBitcodeWriter::writeDIFile(const DIFile *N,
1500                                     SmallVectorImpl<uint64_t> &Record,
1501                                     unsigned Abbrev) {
1502   Record.push_back(N->isDistinct());
1503   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
1504   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
1505 
1506   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
1507   Record.clear();
1508 }
1509 
1510 void DXILBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
1511                                            SmallVectorImpl<uint64_t> &Record,
1512                                            unsigned Abbrev) {
1513   Record.push_back(N->isDistinct());
1514   Record.push_back(N->getSourceLanguage());
1515   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1516   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
1517   Record.push_back(N->isOptimized());
1518   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
1519   Record.push_back(N->getRuntimeVersion());
1520   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
1521   Record.push_back(N->getEmissionKind());
1522   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
1523   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
1524   Record.push_back(/* subprograms */ 0);
1525   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
1526   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
1527   Record.push_back(N->getDWOId());
1528 
1529   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
1530   Record.clear();
1531 }
1532 
1533 void DXILBitcodeWriter::writeDISubprogram(const DISubprogram *N,
1534                                           SmallVectorImpl<uint64_t> &Record,
1535                                           unsigned Abbrev) {
1536   Record.push_back(N->isDistinct());
1537   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1538   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1539   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1540   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1541   Record.push_back(N->getLine());
1542   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1543   Record.push_back(N->isLocalToUnit());
1544   Record.push_back(N->isDefinition());
1545   Record.push_back(N->getScopeLine());
1546   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
1547   Record.push_back(N->getVirtuality());
1548   Record.push_back(N->getVirtualIndex());
1549   Record.push_back(N->getFlags());
1550   Record.push_back(N->isOptimized());
1551   Record.push_back(VE.getMetadataOrNullID(N->getRawUnit()));
1552   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1553   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
1554   Record.push_back(VE.getMetadataOrNullID(N->getRetainedNodes().get()));
1555 
1556   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
1557   Record.clear();
1558 }
1559 
1560 void DXILBitcodeWriter::writeDILexicalBlock(const DILexicalBlock *N,
1561                                             SmallVectorImpl<uint64_t> &Record,
1562                                             unsigned Abbrev) {
1563   Record.push_back(N->isDistinct());
1564   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1565   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1566   Record.push_back(N->getLine());
1567   Record.push_back(N->getColumn());
1568 
1569   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
1570   Record.clear();
1571 }
1572 
1573 void DXILBitcodeWriter::writeDILexicalBlockFile(
1574     const DILexicalBlockFile *N, SmallVectorImpl<uint64_t> &Record,
1575     unsigned Abbrev) {
1576   Record.push_back(N->isDistinct());
1577   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1578   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1579   Record.push_back(N->getDiscriminator());
1580 
1581   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
1582   Record.clear();
1583 }
1584 
1585 void DXILBitcodeWriter::writeDINamespace(const DINamespace *N,
1586                                          SmallVectorImpl<uint64_t> &Record,
1587                                          unsigned Abbrev) {
1588   Record.push_back(N->isDistinct());
1589   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1590   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1591   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1592   Record.push_back(/* line number */ 0);
1593 
1594   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
1595   Record.clear();
1596 }
1597 
1598 void DXILBitcodeWriter::writeDIModule(const DIModule *N,
1599                                       SmallVectorImpl<uint64_t> &Record,
1600                                       unsigned Abbrev) {
1601   Record.push_back(N->isDistinct());
1602   for (auto &I : N->operands())
1603     Record.push_back(VE.getMetadataOrNullID(I));
1604 
1605   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
1606   Record.clear();
1607 }
1608 
1609 void DXILBitcodeWriter::writeDITemplateTypeParameter(
1610     const DITemplateTypeParameter *N, SmallVectorImpl<uint64_t> &Record,
1611     unsigned Abbrev) {
1612   Record.push_back(N->isDistinct());
1613   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1614   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1615 
1616   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
1617   Record.clear();
1618 }
1619 
1620 void DXILBitcodeWriter::writeDITemplateValueParameter(
1621     const DITemplateValueParameter *N, SmallVectorImpl<uint64_t> &Record,
1622     unsigned Abbrev) {
1623   Record.push_back(N->isDistinct());
1624   Record.push_back(N->getTag());
1625   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1626   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1627   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
1628 
1629   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
1630   Record.clear();
1631 }
1632 
1633 void DXILBitcodeWriter::writeDIGlobalVariable(const DIGlobalVariable *N,
1634                                               SmallVectorImpl<uint64_t> &Record,
1635                                               unsigned Abbrev) {
1636   Record.push_back(N->isDistinct());
1637   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1638   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1639   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1640   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1641   Record.push_back(N->getLine());
1642   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1643   Record.push_back(N->isLocalToUnit());
1644   Record.push_back(N->isDefinition());
1645   Record.push_back(/* N->getRawVariable() */ 0);
1646   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
1647 
1648   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
1649   Record.clear();
1650 }
1651 
1652 void DXILBitcodeWriter::writeDILocalVariable(const DILocalVariable *N,
1653                                              SmallVectorImpl<uint64_t> &Record,
1654                                              unsigned Abbrev) {
1655   Record.push_back(N->isDistinct());
1656   Record.push_back(N->getTag());
1657   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1658   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1659   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1660   Record.push_back(N->getLine());
1661   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1662   Record.push_back(N->getArg());
1663   Record.push_back(N->getFlags());
1664 
1665   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
1666   Record.clear();
1667 }
1668 
1669 void DXILBitcodeWriter::writeDIExpression(const DIExpression *N,
1670                                           SmallVectorImpl<uint64_t> &Record,
1671                                           unsigned Abbrev) {
1672   Record.reserve(N->getElements().size() + 1);
1673 
1674   Record.push_back(N->isDistinct());
1675   Record.append(N->elements_begin(), N->elements_end());
1676 
1677   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
1678   Record.clear();
1679 }
1680 
1681 void DXILBitcodeWriter::writeDIObjCProperty(const DIObjCProperty *N,
1682                                             SmallVectorImpl<uint64_t> &Record,
1683                                             unsigned Abbrev) {
1684   llvm_unreachable("DXIL does not support objc!!!");
1685 }
1686 
1687 void DXILBitcodeWriter::writeDIImportedEntity(const DIImportedEntity *N,
1688                                               SmallVectorImpl<uint64_t> &Record,
1689                                               unsigned Abbrev) {
1690   Record.push_back(N->isDistinct());
1691   Record.push_back(N->getTag());
1692   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1693   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
1694   Record.push_back(N->getLine());
1695   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1696 
1697   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
1698   Record.clear();
1699 }
1700 
1701 unsigned DXILBitcodeWriter::createDILocationAbbrev() {
1702   // Abbrev for METADATA_LOCATION.
1703   //
1704   // Assume the column is usually under 128, and always output the inlined-at
1705   // location (it's never more expensive than building an array size 1).
1706   std::shared_ptr<BitCodeAbbrev> Abbv = std::make_shared<BitCodeAbbrev>();
1707   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1708   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1709   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1710   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1711   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1712   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1713   return Stream.EmitAbbrev(std::move(Abbv));
1714 }
1715 
1716 unsigned DXILBitcodeWriter::createGenericDINodeAbbrev() {
1717   // Abbrev for METADATA_GENERIC_DEBUG.
1718   //
1719   // Assume the column is usually under 128, and always output the inlined-at
1720   // location (it's never more expensive than building an array size 1).
1721   std::shared_ptr<BitCodeAbbrev> Abbv = std::make_shared<BitCodeAbbrev>();
1722   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1723   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1724   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1725   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1726   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1727   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1728   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1729   return Stream.EmitAbbrev(std::move(Abbv));
1730 }
1731 
1732 void DXILBitcodeWriter::writeMetadataRecords(ArrayRef<const Metadata *> MDs,
1733                                              SmallVectorImpl<uint64_t> &Record,
1734                                              std::vector<unsigned> *MDAbbrevs,
1735                                              std::vector<uint64_t> *IndexPos) {
1736   if (MDs.empty())
1737     return;
1738 
1739     // Initialize MDNode abbreviations.
1740 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
1741 #include "llvm/IR/Metadata.def"
1742 
1743   for (const Metadata *MD : MDs) {
1744     if (IndexPos)
1745       IndexPos->push_back(Stream.GetCurrentBitNo());
1746     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
1747       assert(N->isResolved() && "Expected forward references to be resolved");
1748 
1749       switch (N->getMetadataID()) {
1750       default:
1751         llvm_unreachable("Invalid MDNode subclass");
1752 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
1753   case Metadata::CLASS##Kind:                                                  \
1754     if (MDAbbrevs)                                                             \
1755       write##CLASS(cast<CLASS>(N), Record,                                     \
1756                    (*MDAbbrevs)[MetadataAbbrev::CLASS##AbbrevID]);             \
1757     else                                                                       \
1758       write##CLASS(cast<CLASS>(N), Record, CLASS##Abbrev);                     \
1759     continue;
1760 #include "llvm/IR/Metadata.def"
1761       }
1762     }
1763     writeValueAsMetadata(cast<ValueAsMetadata>(MD), Record);
1764   }
1765 }
1766 
1767 unsigned DXILBitcodeWriter::createMetadataStringsAbbrev() {
1768   auto Abbv = std::make_shared<BitCodeAbbrev>();
1769   Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING_OLD));
1770   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1771   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1772   return Stream.EmitAbbrev(std::move(Abbv));
1773 }
1774 
1775 void DXILBitcodeWriter::writeMetadataStrings(
1776     ArrayRef<const Metadata *> Strings, SmallVectorImpl<uint64_t> &Record) {
1777   for (const Metadata *MD : Strings) {
1778     const MDString *MDS = cast<MDString>(MD);
1779     // Code: [strchar x N]
1780     Record.append(MDS->bytes_begin(), MDS->bytes_end());
1781 
1782     // Emit the finished record.
1783     Stream.EmitRecord(bitc::METADATA_STRING_OLD, Record,
1784                       createMetadataStringsAbbrev());
1785     Record.clear();
1786   }
1787 }
1788 
1789 void DXILBitcodeWriter::writeModuleMetadata() {
1790   if (!VE.hasMDs() && M.named_metadata_empty())
1791     return;
1792 
1793   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 5);
1794 
1795   // Emit all abbrevs upfront, so that the reader can jump in the middle of the
1796   // block and load any metadata.
1797   std::vector<unsigned> MDAbbrevs;
1798 
1799   MDAbbrevs.resize(MetadataAbbrev::LastPlusOne);
1800   MDAbbrevs[MetadataAbbrev::DILocationAbbrevID] = createDILocationAbbrev();
1801   MDAbbrevs[MetadataAbbrev::GenericDINodeAbbrevID] =
1802       createGenericDINodeAbbrev();
1803 
1804   unsigned NameAbbrev = 0;
1805   if (!M.named_metadata_empty()) {
1806     // Abbrev for METADATA_NAME.
1807     std::shared_ptr<BitCodeAbbrev> Abbv = std::make_shared<BitCodeAbbrev>();
1808     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
1809     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1810     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1811     NameAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1812   }
1813 
1814   SmallVector<uint64_t, 64> Record;
1815   writeMetadataStrings(VE.getMDStrings(), Record);
1816 
1817   std::vector<uint64_t> IndexPos;
1818   IndexPos.reserve(VE.getNonMDStrings().size());
1819   writeMetadataRecords(VE.getNonMDStrings(), Record, &MDAbbrevs, &IndexPos);
1820 
1821   // Write named metadata.
1822   for (const NamedMDNode &NMD : M.named_metadata()) {
1823     // Write name.
1824     StringRef Str = NMD.getName();
1825     Record.append(Str.bytes_begin(), Str.bytes_end());
1826     Stream.EmitRecord(bitc::METADATA_NAME, Record, NameAbbrev);
1827     Record.clear();
1828 
1829     // Write named metadata operands.
1830     for (const MDNode *N : NMD.operands())
1831       Record.push_back(VE.getMetadataID(N));
1832     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
1833     Record.clear();
1834   }
1835 
1836   Stream.ExitBlock();
1837 }
1838 
1839 void DXILBitcodeWriter::writeFunctionMetadata(const Function &F) {
1840   if (!VE.hasMDs())
1841     return;
1842 
1843   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 4);
1844   SmallVector<uint64_t, 64> Record;
1845   writeMetadataStrings(VE.getMDStrings(), Record);
1846   writeMetadataRecords(VE.getNonMDStrings(), Record);
1847   Stream.ExitBlock();
1848 }
1849 
1850 void DXILBitcodeWriter::writeFunctionMetadataAttachment(const Function &F) {
1851   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
1852 
1853   SmallVector<uint64_t, 64> Record;
1854 
1855   // Write metadata attachments
1856   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
1857   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
1858   F.getAllMetadata(MDs);
1859   if (!MDs.empty()) {
1860     for (const auto &I : MDs) {
1861       Record.push_back(I.first);
1862       Record.push_back(VE.getMetadataID(I.second));
1863     }
1864     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1865     Record.clear();
1866   }
1867 
1868   for (const BasicBlock &BB : F)
1869     for (const Instruction &I : BB) {
1870       MDs.clear();
1871       I.getAllMetadataOtherThanDebugLoc(MDs);
1872 
1873       // If no metadata, ignore instruction.
1874       if (MDs.empty())
1875         continue;
1876 
1877       Record.push_back(VE.getInstructionID(&I));
1878 
1879       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1880         Record.push_back(MDs[i].first);
1881         Record.push_back(VE.getMetadataID(MDs[i].second));
1882       }
1883       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1884       Record.clear();
1885     }
1886 
1887   Stream.ExitBlock();
1888 }
1889 
1890 void DXILBitcodeWriter::writeModuleMetadataKinds() {
1891   SmallVector<uint64_t, 64> Record;
1892 
1893   // Write metadata kinds
1894   // METADATA_KIND - [n x [id, name]]
1895   SmallVector<StringRef, 8> Names;
1896   M.getMDKindNames(Names);
1897 
1898   if (Names.empty())
1899     return;
1900 
1901   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1902 
1903   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
1904     Record.push_back(MDKindID);
1905     StringRef KName = Names[MDKindID];
1906     Record.append(KName.begin(), KName.end());
1907 
1908     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
1909     Record.clear();
1910   }
1911 
1912   Stream.ExitBlock();
1913 }
1914 
1915 void DXILBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
1916                                        bool isGlobal) {
1917   if (FirstVal == LastVal)
1918     return;
1919 
1920   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
1921 
1922   unsigned AggregateAbbrev = 0;
1923   unsigned String8Abbrev = 0;
1924   unsigned CString7Abbrev = 0;
1925   unsigned CString6Abbrev = 0;
1926   // If this is a constant pool for the module, emit module-specific abbrevs.
1927   if (isGlobal) {
1928     // Abbrev for CST_CODE_AGGREGATE.
1929     auto Abbv = std::make_shared<BitCodeAbbrev>();
1930     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
1931     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1932     Abbv->Add(
1933         BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal + 1)));
1934     AggregateAbbrev = Stream.EmitAbbrev(std::move(Abbv));
1935 
1936     // Abbrev for CST_CODE_STRING.
1937     Abbv = std::make_shared<BitCodeAbbrev>();
1938     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
1939     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1940     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1941     String8Abbrev = Stream.EmitAbbrev(std::move(Abbv));
1942     // Abbrev for CST_CODE_CSTRING.
1943     Abbv = std::make_shared<BitCodeAbbrev>();
1944     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1945     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1946     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1947     CString7Abbrev = Stream.EmitAbbrev(std::move(Abbv));
1948     // Abbrev for CST_CODE_CSTRING.
1949     Abbv = std::make_shared<BitCodeAbbrev>();
1950     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1951     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1952     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1953     CString6Abbrev = Stream.EmitAbbrev(std::move(Abbv));
1954   }
1955 
1956   SmallVector<uint64_t, 64> Record;
1957 
1958   const ValueEnumerator::ValueList &Vals = VE.getValues();
1959   Type *LastTy = nullptr;
1960   for (unsigned i = FirstVal; i != LastVal; ++i) {
1961     const Value *V = Vals[i].first;
1962     // If we need to switch types, do so now.
1963     if (V->getType() != LastTy) {
1964       LastTy = V->getType();
1965       Record.push_back(VE.getTypeID(LastTy));
1966       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
1967                         CONSTANTS_SETTYPE_ABBREV);
1968       Record.clear();
1969     }
1970 
1971     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
1972       Record.push_back(unsigned(IA->hasSideEffects()) |
1973                        unsigned(IA->isAlignStack()) << 1 |
1974                        unsigned(IA->getDialect() & 1) << 2);
1975 
1976       // Add the asm string.
1977       const std::string &AsmStr = IA->getAsmString();
1978       Record.push_back(AsmStr.size());
1979       Record.append(AsmStr.begin(), AsmStr.end());
1980 
1981       // Add the constraint string.
1982       const std::string &ConstraintStr = IA->getConstraintString();
1983       Record.push_back(ConstraintStr.size());
1984       Record.append(ConstraintStr.begin(), ConstraintStr.end());
1985       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
1986       Record.clear();
1987       continue;
1988     }
1989     const Constant *C = cast<Constant>(V);
1990     unsigned Code = -1U;
1991     unsigned AbbrevToUse = 0;
1992     if (C->isNullValue()) {
1993       Code = bitc::CST_CODE_NULL;
1994     } else if (isa<UndefValue>(C)) {
1995       Code = bitc::CST_CODE_UNDEF;
1996     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
1997       if (IV->getBitWidth() <= 64) {
1998         uint64_t V = IV->getSExtValue();
1999         emitSignedInt64(Record, V);
2000         Code = bitc::CST_CODE_INTEGER;
2001         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
2002       } else { // Wide integers, > 64 bits in size.
2003         // We have an arbitrary precision integer value to write whose
2004         // bit width is > 64. However, in canonical unsigned integer
2005         // format it is likely that the high bits are going to be zero.
2006         // So, we only write the number of active words.
2007         unsigned NWords = IV->getValue().getActiveWords();
2008         const uint64_t *RawWords = IV->getValue().getRawData();
2009         for (unsigned i = 0; i != NWords; ++i) {
2010           emitSignedInt64(Record, RawWords[i]);
2011         }
2012         Code = bitc::CST_CODE_WIDE_INTEGER;
2013       }
2014     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
2015       Code = bitc::CST_CODE_FLOAT;
2016       Type *Ty = CFP->getType();
2017       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
2018         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
2019       } else if (Ty->isX86_FP80Ty()) {
2020         // api needed to prevent premature destruction
2021         // bits are not in the same order as a normal i80 APInt, compensate.
2022         APInt api = CFP->getValueAPF().bitcastToAPInt();
2023         const uint64_t *p = api.getRawData();
2024         Record.push_back((p[1] << 48) | (p[0] >> 16));
2025         Record.push_back(p[0] & 0xffffLL);
2026       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
2027         APInt api = CFP->getValueAPF().bitcastToAPInt();
2028         const uint64_t *p = api.getRawData();
2029         Record.push_back(p[0]);
2030         Record.push_back(p[1]);
2031       } else {
2032         assert(0 && "Unknown FP type!");
2033       }
2034     } else if (isa<ConstantDataSequential>(C) &&
2035                cast<ConstantDataSequential>(C)->isString()) {
2036       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
2037       // Emit constant strings specially.
2038       unsigned NumElts = Str->getNumElements();
2039       // If this is a null-terminated string, use the denser CSTRING encoding.
2040       if (Str->isCString()) {
2041         Code = bitc::CST_CODE_CSTRING;
2042         --NumElts; // Don't encode the null, which isn't allowed by char6.
2043       } else {
2044         Code = bitc::CST_CODE_STRING;
2045         AbbrevToUse = String8Abbrev;
2046       }
2047       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
2048       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
2049       for (unsigned i = 0; i != NumElts; ++i) {
2050         unsigned char V = Str->getElementAsInteger(i);
2051         Record.push_back(V);
2052         isCStr7 &= (V & 128) == 0;
2053         if (isCStrChar6)
2054           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
2055       }
2056 
2057       if (isCStrChar6)
2058         AbbrevToUse = CString6Abbrev;
2059       else if (isCStr7)
2060         AbbrevToUse = CString7Abbrev;
2061     } else if (const ConstantDataSequential *CDS =
2062                    dyn_cast<ConstantDataSequential>(C)) {
2063       Code = bitc::CST_CODE_DATA;
2064       Type *EltTy = CDS->getType()->getArrayElementType();
2065       if (isa<IntegerType>(EltTy)) {
2066         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
2067           Record.push_back(CDS->getElementAsInteger(i));
2068       } else if (EltTy->isFloatTy()) {
2069         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
2070           union {
2071             float F;
2072             uint32_t I;
2073           };
2074           F = CDS->getElementAsFloat(i);
2075           Record.push_back(I);
2076         }
2077       } else {
2078         assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
2079         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
2080           union {
2081             double F;
2082             uint64_t I;
2083           };
2084           F = CDS->getElementAsDouble(i);
2085           Record.push_back(I);
2086         }
2087       }
2088     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
2089                isa<ConstantVector>(C)) {
2090       Code = bitc::CST_CODE_AGGREGATE;
2091       for (const Value *Op : C->operands())
2092         Record.push_back(VE.getValueID(Op));
2093       AbbrevToUse = AggregateAbbrev;
2094     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
2095       switch (CE->getOpcode()) {
2096       default:
2097         if (Instruction::isCast(CE->getOpcode())) {
2098           Code = bitc::CST_CODE_CE_CAST;
2099           Record.push_back(getEncodedCastOpcode(CE->getOpcode()));
2100           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2101           Record.push_back(VE.getValueID(C->getOperand(0)));
2102           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
2103         } else {
2104           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
2105           Code = bitc::CST_CODE_CE_BINOP;
2106           Record.push_back(getEncodedBinaryOpcode(CE->getOpcode()));
2107           Record.push_back(VE.getValueID(C->getOperand(0)));
2108           Record.push_back(VE.getValueID(C->getOperand(1)));
2109           uint64_t Flags = getOptimizationFlags(CE);
2110           if (Flags != 0)
2111             Record.push_back(Flags);
2112         }
2113         break;
2114       case Instruction::GetElementPtr: {
2115         Code = bitc::CST_CODE_CE_GEP;
2116         const auto *GO = cast<GEPOperator>(C);
2117         if (GO->isInBounds())
2118           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
2119         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
2120         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
2121           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
2122           Record.push_back(VE.getValueID(C->getOperand(i)));
2123         }
2124         break;
2125       }
2126       case Instruction::Select:
2127         Code = bitc::CST_CODE_CE_SELECT;
2128         Record.push_back(VE.getValueID(C->getOperand(0)));
2129         Record.push_back(VE.getValueID(C->getOperand(1)));
2130         Record.push_back(VE.getValueID(C->getOperand(2)));
2131         break;
2132       case Instruction::ExtractElement:
2133         Code = bitc::CST_CODE_CE_EXTRACTELT;
2134         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2135         Record.push_back(VE.getValueID(C->getOperand(0)));
2136         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
2137         Record.push_back(VE.getValueID(C->getOperand(1)));
2138         break;
2139       case Instruction::InsertElement:
2140         Code = bitc::CST_CODE_CE_INSERTELT;
2141         Record.push_back(VE.getValueID(C->getOperand(0)));
2142         Record.push_back(VE.getValueID(C->getOperand(1)));
2143         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
2144         Record.push_back(VE.getValueID(C->getOperand(2)));
2145         break;
2146       case Instruction::ShuffleVector:
2147         // If the return type and argument types are the same, this is a
2148         // standard shufflevector instruction.  If the types are different,
2149         // then the shuffle is widening or truncating the input vectors, and
2150         // the argument type must also be encoded.
2151         if (C->getType() == C->getOperand(0)->getType()) {
2152           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
2153         } else {
2154           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
2155           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2156         }
2157         Record.push_back(VE.getValueID(C->getOperand(0)));
2158         Record.push_back(VE.getValueID(C->getOperand(1)));
2159         Record.push_back(VE.getValueID(C->getOperand(2)));
2160         break;
2161       case Instruction::ICmp:
2162       case Instruction::FCmp:
2163         Code = bitc::CST_CODE_CE_CMP;
2164         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
2165         Record.push_back(VE.getValueID(C->getOperand(0)));
2166         Record.push_back(VE.getValueID(C->getOperand(1)));
2167         Record.push_back(CE->getPredicate());
2168         break;
2169       }
2170     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
2171       Code = bitc::CST_CODE_BLOCKADDRESS;
2172       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
2173       Record.push_back(VE.getValueID(BA->getFunction()));
2174       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
2175     } else {
2176 #ifndef NDEBUG
2177       C->dump();
2178 #endif
2179       llvm_unreachable("Unknown constant!");
2180     }
2181     Stream.EmitRecord(Code, Record, AbbrevToUse);
2182     Record.clear();
2183   }
2184 
2185   Stream.ExitBlock();
2186 }
2187 
2188 void DXILBitcodeWriter::writeModuleConstants() {
2189   const ValueEnumerator::ValueList &Vals = VE.getValues();
2190 
2191   // Find the first constant to emit, which is the first non-globalvalue value.
2192   // We know globalvalues have been emitted by WriteModuleInfo.
2193   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
2194     if (!isa<GlobalValue>(Vals[i].first)) {
2195       writeConstants(i, Vals.size(), true);
2196       return;
2197     }
2198   }
2199 }
2200 
2201 /// pushValueAndType - The file has to encode both the value and type id for
2202 /// many values, because we need to know what type to create for forward
2203 /// references.  However, most operands are not forward references, so this type
2204 /// field is not needed.
2205 ///
2206 /// This function adds V's value ID to Vals.  If the value ID is higher than the
2207 /// instruction ID, then it is a forward reference, and it also includes the
2208 /// type ID.  The value ID that is written is encoded relative to the InstID.
2209 bool DXILBitcodeWriter::pushValueAndType(const Value *V, unsigned InstID,
2210                                          SmallVectorImpl<unsigned> &Vals) {
2211   unsigned ValID = VE.getValueID(V);
2212   // Make encoding relative to the InstID.
2213   Vals.push_back(InstID - ValID);
2214   if (ValID >= InstID) {
2215     Vals.push_back(VE.getTypeID(V->getType()));
2216     return true;
2217   }
2218   return false;
2219 }
2220 
2221 /// pushValue - Like pushValueAndType, but where the type of the value is
2222 /// omitted (perhaps it was already encoded in an earlier operand).
2223 void DXILBitcodeWriter::pushValue(const Value *V, unsigned InstID,
2224                                   SmallVectorImpl<unsigned> &Vals) {
2225   unsigned ValID = VE.getValueID(V);
2226   Vals.push_back(InstID - ValID);
2227 }
2228 
2229 void DXILBitcodeWriter::pushValueSigned(const Value *V, unsigned InstID,
2230                                         SmallVectorImpl<uint64_t> &Vals) {
2231   unsigned ValID = VE.getValueID(V);
2232   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
2233   emitSignedInt64(Vals, diff);
2234 }
2235 
2236 /// WriteInstruction - Emit an instruction
2237 void DXILBitcodeWriter::writeInstruction(const Instruction &I, unsigned InstID,
2238                                          SmallVectorImpl<unsigned> &Vals) {
2239   unsigned Code = 0;
2240   unsigned AbbrevToUse = 0;
2241   VE.setInstructionID(&I);
2242   switch (I.getOpcode()) {
2243   default:
2244     if (Instruction::isCast(I.getOpcode())) {
2245       Code = bitc::FUNC_CODE_INST_CAST;
2246       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2247         AbbrevToUse = (unsigned)FUNCTION_INST_CAST_ABBREV;
2248       Vals.push_back(VE.getTypeID(I.getType()));
2249       Vals.push_back(getEncodedCastOpcode(I.getOpcode()));
2250     } else {
2251       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
2252       Code = bitc::FUNC_CODE_INST_BINOP;
2253       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2254         AbbrevToUse = (unsigned)FUNCTION_INST_BINOP_ABBREV;
2255       pushValue(I.getOperand(1), InstID, Vals);
2256       Vals.push_back(getEncodedBinaryOpcode(I.getOpcode()));
2257       uint64_t Flags = getOptimizationFlags(&I);
2258       if (Flags != 0) {
2259         if (AbbrevToUse == (unsigned)FUNCTION_INST_BINOP_ABBREV)
2260           AbbrevToUse = (unsigned)FUNCTION_INST_BINOP_FLAGS_ABBREV;
2261         Vals.push_back(Flags);
2262       }
2263     }
2264     break;
2265 
2266   case Instruction::GetElementPtr: {
2267     Code = bitc::FUNC_CODE_INST_GEP;
2268     AbbrevToUse = (unsigned)FUNCTION_INST_GEP_ABBREV;
2269     auto &GEPInst = cast<GetElementPtrInst>(I);
2270     Vals.push_back(GEPInst.isInBounds());
2271     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
2272     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
2273       pushValueAndType(I.getOperand(i), InstID, Vals);
2274     break;
2275   }
2276   case Instruction::ExtractValue: {
2277     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
2278     pushValueAndType(I.getOperand(0), InstID, Vals);
2279     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
2280     Vals.append(EVI->idx_begin(), EVI->idx_end());
2281     break;
2282   }
2283   case Instruction::InsertValue: {
2284     Code = bitc::FUNC_CODE_INST_INSERTVAL;
2285     pushValueAndType(I.getOperand(0), InstID, Vals);
2286     pushValueAndType(I.getOperand(1), InstID, Vals);
2287     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
2288     Vals.append(IVI->idx_begin(), IVI->idx_end());
2289     break;
2290   }
2291   case Instruction::Select:
2292     Code = bitc::FUNC_CODE_INST_VSELECT;
2293     pushValueAndType(I.getOperand(1), InstID, Vals);
2294     pushValue(I.getOperand(2), InstID, Vals);
2295     pushValueAndType(I.getOperand(0), InstID, Vals);
2296     break;
2297   case Instruction::ExtractElement:
2298     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
2299     pushValueAndType(I.getOperand(0), InstID, Vals);
2300     pushValueAndType(I.getOperand(1), InstID, Vals);
2301     break;
2302   case Instruction::InsertElement:
2303     Code = bitc::FUNC_CODE_INST_INSERTELT;
2304     pushValueAndType(I.getOperand(0), InstID, Vals);
2305     pushValue(I.getOperand(1), InstID, Vals);
2306     pushValueAndType(I.getOperand(2), InstID, Vals);
2307     break;
2308   case Instruction::ShuffleVector:
2309     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
2310     pushValueAndType(I.getOperand(0), InstID, Vals);
2311     pushValue(I.getOperand(1), InstID, Vals);
2312     pushValue(I.getOperand(2), InstID, Vals);
2313     break;
2314   case Instruction::ICmp:
2315   case Instruction::FCmp: {
2316     // compare returning Int1Ty or vector of Int1Ty
2317     Code = bitc::FUNC_CODE_INST_CMP2;
2318     pushValueAndType(I.getOperand(0), InstID, Vals);
2319     pushValue(I.getOperand(1), InstID, Vals);
2320     Vals.push_back(cast<CmpInst>(I).getPredicate());
2321     uint64_t Flags = getOptimizationFlags(&I);
2322     if (Flags != 0)
2323       Vals.push_back(Flags);
2324     break;
2325   }
2326 
2327   case Instruction::Ret: {
2328     Code = bitc::FUNC_CODE_INST_RET;
2329     unsigned NumOperands = I.getNumOperands();
2330     if (NumOperands == 0)
2331       AbbrevToUse = (unsigned)FUNCTION_INST_RET_VOID_ABBREV;
2332     else if (NumOperands == 1) {
2333       if (!pushValueAndType(I.getOperand(0), InstID, Vals))
2334         AbbrevToUse = (unsigned)FUNCTION_INST_RET_VAL_ABBREV;
2335     } else {
2336       for (unsigned i = 0, e = NumOperands; i != e; ++i)
2337         pushValueAndType(I.getOperand(i), InstID, Vals);
2338     }
2339   } break;
2340   case Instruction::Br: {
2341     Code = bitc::FUNC_CODE_INST_BR;
2342     const BranchInst &II = cast<BranchInst>(I);
2343     Vals.push_back(VE.getValueID(II.getSuccessor(0)));
2344     if (II.isConditional()) {
2345       Vals.push_back(VE.getValueID(II.getSuccessor(1)));
2346       pushValue(II.getCondition(), InstID, Vals);
2347     }
2348   } break;
2349   case Instruction::Switch: {
2350     Code = bitc::FUNC_CODE_INST_SWITCH;
2351     const SwitchInst &SI = cast<SwitchInst>(I);
2352     Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
2353     pushValue(SI.getCondition(), InstID, Vals);
2354     Vals.push_back(VE.getValueID(SI.getDefaultDest()));
2355     for (auto Case : SI.cases()) {
2356       Vals.push_back(VE.getValueID(Case.getCaseValue()));
2357       Vals.push_back(VE.getValueID(Case.getCaseSuccessor()));
2358     }
2359   } break;
2360   case Instruction::IndirectBr:
2361     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
2362     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
2363     // Encode the address operand as relative, but not the basic blocks.
2364     pushValue(I.getOperand(0), InstID, Vals);
2365     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
2366       Vals.push_back(VE.getValueID(I.getOperand(i)));
2367     break;
2368 
2369   case Instruction::Invoke: {
2370     const InvokeInst *II = cast<InvokeInst>(&I);
2371     const Value *Callee = II->getCalledOperand();
2372     FunctionType *FTy = II->getFunctionType();
2373     Code = bitc::FUNC_CODE_INST_INVOKE;
2374 
2375     Vals.push_back(VE.getAttributeListID(II->getAttributes()));
2376     Vals.push_back(II->getCallingConv() | 1 << 13);
2377     Vals.push_back(VE.getValueID(II->getNormalDest()));
2378     Vals.push_back(VE.getValueID(II->getUnwindDest()));
2379     Vals.push_back(VE.getTypeID(FTy));
2380     pushValueAndType(Callee, InstID, Vals);
2381 
2382     // Emit value #'s for the fixed parameters.
2383     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
2384       pushValue(I.getOperand(i), InstID, Vals); // fixed param.
2385 
2386     // Emit type/value pairs for varargs params.
2387     if (FTy->isVarArg()) {
2388       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands() - 3; i != e;
2389            ++i)
2390         pushValueAndType(I.getOperand(i), InstID, Vals); // vararg
2391     }
2392     break;
2393   }
2394   case Instruction::Resume:
2395     Code = bitc::FUNC_CODE_INST_RESUME;
2396     pushValueAndType(I.getOperand(0), InstID, Vals);
2397     break;
2398   case Instruction::Unreachable:
2399     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
2400     AbbrevToUse = (unsigned)FUNCTION_INST_UNREACHABLE_ABBREV;
2401     break;
2402 
2403   case Instruction::PHI: {
2404     const PHINode &PN = cast<PHINode>(I);
2405     Code = bitc::FUNC_CODE_INST_PHI;
2406     // With the newer instruction encoding, forward references could give
2407     // negative valued IDs.  This is most common for PHIs, so we use
2408     // signed VBRs.
2409     SmallVector<uint64_t, 128> Vals64;
2410     Vals64.push_back(VE.getTypeID(PN.getType()));
2411     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
2412       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64);
2413       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
2414     }
2415     // Emit a Vals64 vector and exit.
2416     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
2417     Vals64.clear();
2418     return;
2419   }
2420 
2421   case Instruction::LandingPad: {
2422     const LandingPadInst &LP = cast<LandingPadInst>(I);
2423     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
2424     Vals.push_back(VE.getTypeID(LP.getType()));
2425     Vals.push_back(LP.isCleanup());
2426     Vals.push_back(LP.getNumClauses());
2427     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
2428       if (LP.isCatch(I))
2429         Vals.push_back(LandingPadInst::Catch);
2430       else
2431         Vals.push_back(LandingPadInst::Filter);
2432       pushValueAndType(LP.getClause(I), InstID, Vals);
2433     }
2434     break;
2435   }
2436 
2437   case Instruction::Alloca: {
2438     Code = bitc::FUNC_CODE_INST_ALLOCA;
2439     const AllocaInst &AI = cast<AllocaInst>(I);
2440     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
2441     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
2442     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
2443     using APV = AllocaPackedValues;
2444     unsigned Record = 0;
2445     unsigned EncodedAlign = getEncodedAlign(AI.getAlign());
2446     Bitfield::set<APV::AlignLower>(
2447         Record, EncodedAlign & ((1 << APV::AlignLower::Bits) - 1));
2448     Bitfield::set<APV::AlignUpper>(Record,
2449                                    EncodedAlign >> APV::AlignLower::Bits);
2450     Bitfield::set<APV::UsedWithInAlloca>(Record, AI.isUsedWithInAlloca());
2451     Vals.push_back(Record);
2452     break;
2453   }
2454 
2455   case Instruction::Load:
2456     if (cast<LoadInst>(I).isAtomic()) {
2457       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
2458       pushValueAndType(I.getOperand(0), InstID, Vals);
2459     } else {
2460       Code = bitc::FUNC_CODE_INST_LOAD;
2461       if (!pushValueAndType(I.getOperand(0), InstID, Vals)) // ptr
2462         AbbrevToUse = (unsigned)FUNCTION_INST_LOAD_ABBREV;
2463     }
2464     Vals.push_back(VE.getTypeID(I.getType()));
2465     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment()) + 1);
2466     Vals.push_back(cast<LoadInst>(I).isVolatile());
2467     if (cast<LoadInst>(I).isAtomic()) {
2468       Vals.push_back(getEncodedOrdering(cast<LoadInst>(I).getOrdering()));
2469       Vals.push_back(getEncodedSyncScopeID(cast<LoadInst>(I).getSyncScopeID()));
2470     }
2471     break;
2472   case Instruction::Store:
2473     if (cast<StoreInst>(I).isAtomic())
2474       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
2475     else
2476       Code = bitc::FUNC_CODE_INST_STORE;
2477     pushValueAndType(I.getOperand(1), InstID, Vals); // ptrty + ptr
2478     pushValueAndType(I.getOperand(0), InstID, Vals); // valty + val
2479     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment()) + 1);
2480     Vals.push_back(cast<StoreInst>(I).isVolatile());
2481     if (cast<StoreInst>(I).isAtomic()) {
2482       Vals.push_back(getEncodedOrdering(cast<StoreInst>(I).getOrdering()));
2483       Vals.push_back(
2484           getEncodedSyncScopeID(cast<StoreInst>(I).getSyncScopeID()));
2485     }
2486     break;
2487   case Instruction::AtomicCmpXchg:
2488     Code = bitc::FUNC_CODE_INST_CMPXCHG;
2489     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
2490     pushValueAndType(I.getOperand(1), InstID, Vals); // cmp.
2491     pushValue(I.getOperand(2), InstID, Vals);        // newval.
2492     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
2493     Vals.push_back(
2494         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
2495     Vals.push_back(
2496         getEncodedSyncScopeID(cast<AtomicCmpXchgInst>(I).getSyncScopeID()));
2497     Vals.push_back(
2498         getEncodedOrdering(cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
2499     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
2500     break;
2501   case Instruction::AtomicRMW:
2502     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
2503     pushValueAndType(I.getOperand(0), InstID, Vals); // ptrty + ptr
2504     pushValue(I.getOperand(1), InstID, Vals);        // val.
2505     Vals.push_back(
2506         getEncodedRMWOperation(cast<AtomicRMWInst>(I).getOperation()));
2507     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
2508     Vals.push_back(getEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
2509     Vals.push_back(
2510         getEncodedSyncScopeID(cast<AtomicRMWInst>(I).getSyncScopeID()));
2511     break;
2512   case Instruction::Fence:
2513     Code = bitc::FUNC_CODE_INST_FENCE;
2514     Vals.push_back(getEncodedOrdering(cast<FenceInst>(I).getOrdering()));
2515     Vals.push_back(getEncodedSyncScopeID(cast<FenceInst>(I).getSyncScopeID()));
2516     break;
2517   case Instruction::Call: {
2518     const CallInst &CI = cast<CallInst>(I);
2519     FunctionType *FTy = CI.getFunctionType();
2520 
2521     Code = bitc::FUNC_CODE_INST_CALL;
2522 
2523     Vals.push_back(VE.getAttributeListID(CI.getAttributes()));
2524     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()) |
2525                    unsigned(CI.isMustTailCall()) << 14 | 1 << 15);
2526     Vals.push_back(VE.getTypeID(FTy));
2527     pushValueAndType(CI.getCalledOperand(), InstID, Vals); // Callee
2528 
2529     // Emit value #'s for the fixed parameters.
2530     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
2531       // Check for labels (can happen with asm labels).
2532       if (FTy->getParamType(i)->isLabelTy())
2533         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
2534       else
2535         pushValue(CI.getArgOperand(i), InstID, Vals); // fixed param.
2536     }
2537 
2538     // Emit type/value pairs for varargs params.
2539     if (FTy->isVarArg()) {
2540       for (unsigned i = FTy->getNumParams(), e = CI.arg_size(); i != e; ++i)
2541         pushValueAndType(CI.getArgOperand(i), InstID, Vals); // varargs
2542     }
2543     break;
2544   }
2545   case Instruction::VAArg:
2546     Code = bitc::FUNC_CODE_INST_VAARG;
2547     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType())); // valistty
2548     pushValue(I.getOperand(0), InstID, Vals);                 // valist.
2549     Vals.push_back(VE.getTypeID(I.getType()));                // restype.
2550     break;
2551   }
2552 
2553   Stream.EmitRecord(Code, Vals, AbbrevToUse);
2554   Vals.clear();
2555 }
2556 
2557 // Emit names for globals/functions etc.
2558 void DXILBitcodeWriter::writeFunctionLevelValueSymbolTable(
2559     const ValueSymbolTable &VST) {
2560   if (VST.empty())
2561     return;
2562   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
2563 
2564   SmallVector<unsigned, 64> NameVals;
2565 
2566   // HLSL Change
2567   // Read the named values from a sorted list instead of the original list
2568   // to ensure the binary is the same no matter what values ever existed.
2569   SmallVector<const ValueName *, 16> SortedTable;
2570 
2571   for (auto &VI : VST) {
2572     SortedTable.push_back(VI.second->getValueName());
2573   }
2574   // The keys are unique, so there shouldn't be stability issues.
2575   std::sort(SortedTable.begin(), SortedTable.end(),
2576             [](const ValueName *A, const ValueName *B) {
2577               return A->first() < B->first();
2578             });
2579 
2580   for (const ValueName *SI : SortedTable) {
2581     auto &Name = *SI;
2582 
2583     // Figure out the encoding to use for the name.
2584     bool is7Bit = true;
2585     bool isChar6 = true;
2586     for (const char *C = Name.getKeyData(), *E = C + Name.getKeyLength();
2587          C != E; ++C) {
2588       if (isChar6)
2589         isChar6 = BitCodeAbbrevOp::isChar6(*C);
2590       if ((unsigned char)*C & 128) {
2591         is7Bit = false;
2592         break; // don't bother scanning the rest.
2593       }
2594     }
2595 
2596     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
2597 
2598     // VST_ENTRY:   [valueid, namechar x N]
2599     // VST_BBENTRY: [bbid, namechar x N]
2600     unsigned Code;
2601     if (isa<BasicBlock>(SI->getValue())) {
2602       Code = bitc::VST_CODE_BBENTRY;
2603       if (isChar6)
2604         AbbrevToUse = VST_BBENTRY_6_ABBREV;
2605     } else {
2606       Code = bitc::VST_CODE_ENTRY;
2607       if (isChar6)
2608         AbbrevToUse = VST_ENTRY_6_ABBREV;
2609       else if (is7Bit)
2610         AbbrevToUse = VST_ENTRY_7_ABBREV;
2611     }
2612 
2613     NameVals.push_back(VE.getValueID(SI->getValue()));
2614     for (const char *P = Name.getKeyData(),
2615                     *E = Name.getKeyData() + Name.getKeyLength();
2616          P != E; ++P)
2617       NameVals.push_back((unsigned char)*P);
2618 
2619     // Emit the finished record.
2620     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
2621     NameVals.clear();
2622   }
2623   Stream.ExitBlock();
2624 }
2625 
2626 void DXILBitcodeWriter::writeUseList(UseListOrder &&Order) {
2627   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
2628   unsigned Code;
2629   if (isa<BasicBlock>(Order.V))
2630     Code = bitc::USELIST_CODE_BB;
2631   else
2632     Code = bitc::USELIST_CODE_DEFAULT;
2633 
2634   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
2635   Record.push_back(VE.getValueID(Order.V));
2636   Stream.EmitRecord(Code, Record);
2637 }
2638 
2639 void DXILBitcodeWriter::writeUseListBlock(const Function *F) {
2640   assert(VE.shouldPreserveUseListOrder() &&
2641          "Expected to be preserving use-list order");
2642 
2643   auto hasMore = [&]() {
2644     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
2645   };
2646   if (!hasMore())
2647     // Nothing to do.
2648     return;
2649 
2650   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
2651   while (hasMore()) {
2652     writeUseList(std::move(VE.UseListOrders.back()));
2653     VE.UseListOrders.pop_back();
2654   }
2655   Stream.ExitBlock();
2656 }
2657 
2658 /// Emit a function body to the module stream.
2659 void DXILBitcodeWriter::writeFunction(const Function &F) {
2660   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
2661   VE.incorporateFunction(F);
2662 
2663   SmallVector<unsigned, 64> Vals;
2664 
2665   // Emit the number of basic blocks, so the reader can create them ahead of
2666   // time.
2667   Vals.push_back(VE.getBasicBlocks().size());
2668   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
2669   Vals.clear();
2670 
2671   // If there are function-local constants, emit them now.
2672   unsigned CstStart, CstEnd;
2673   VE.getFunctionConstantRange(CstStart, CstEnd);
2674   writeConstants(CstStart, CstEnd, false);
2675 
2676   // If there is function-local metadata, emit it now.
2677   writeFunctionMetadata(F);
2678 
2679   // Keep a running idea of what the instruction ID is.
2680   unsigned InstID = CstEnd;
2681 
2682   bool NeedsMetadataAttachment = F.hasMetadata();
2683 
2684   DILocation *LastDL = nullptr;
2685 
2686   // Finally, emit all the instructions, in order.
2687   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
2688     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E;
2689          ++I) {
2690       writeInstruction(*I, InstID, Vals);
2691 
2692       if (!I->getType()->isVoidTy())
2693         ++InstID;
2694 
2695       // If the instruction has metadata, write a metadata attachment later.
2696       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
2697 
2698       // If the instruction has a debug location, emit it.
2699       DILocation *DL = I->getDebugLoc();
2700       if (!DL)
2701         continue;
2702 
2703       if (DL == LastDL) {
2704         // Just repeat the same debug loc as last time.
2705         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
2706         continue;
2707       }
2708 
2709       Vals.push_back(DL->getLine());
2710       Vals.push_back(DL->getColumn());
2711       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
2712       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
2713       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
2714       Vals.clear();
2715 
2716       LastDL = DL;
2717     }
2718 
2719   // Emit names for all the instructions etc.
2720   if (auto *Symtab = F.getValueSymbolTable())
2721     writeFunctionLevelValueSymbolTable(*Symtab);
2722 
2723   if (NeedsMetadataAttachment)
2724     writeFunctionMetadataAttachment(F);
2725   if (VE.shouldPreserveUseListOrder())
2726     writeUseListBlock(&F);
2727   VE.purgeFunction();
2728   Stream.ExitBlock();
2729 }
2730 
2731 // Emit blockinfo, which defines the standard abbreviations etc.
2732 void DXILBitcodeWriter::writeBlockInfo() {
2733   // We only want to emit block info records for blocks that have multiple
2734   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
2735   // Other blocks can define their abbrevs inline.
2736   Stream.EnterBlockInfoBlock();
2737 
2738   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
2739     auto Abbv = std::make_shared<BitCodeAbbrev>();
2740     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
2741     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2742     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2743     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2744     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2745                                    std::move(Abbv)) != VST_ENTRY_8_ABBREV)
2746       assert(false && "Unexpected abbrev ordering!");
2747   }
2748 
2749   { // 7-bit fixed width VST_ENTRY strings.
2750     auto Abbv = std::make_shared<BitCodeAbbrev>();
2751     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2752     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2753     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2754     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2755     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2756                                    std::move(Abbv)) != VST_ENTRY_7_ABBREV)
2757       assert(false && "Unexpected abbrev ordering!");
2758   }
2759   { // 6-bit char6 VST_ENTRY strings.
2760     auto Abbv = std::make_shared<BitCodeAbbrev>();
2761     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2762     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2763     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2764     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2765     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2766                                    std::move(Abbv)) != VST_ENTRY_6_ABBREV)
2767       assert(false && "Unexpected abbrev ordering!");
2768   }
2769   { // 6-bit char6 VST_BBENTRY strings.
2770     auto Abbv = std::make_shared<BitCodeAbbrev>();
2771     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
2772     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2773     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2774     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2775     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2776                                    std::move(Abbv)) != VST_BBENTRY_6_ABBREV)
2777       assert(false && "Unexpected abbrev ordering!");
2778   }
2779 
2780   { // SETTYPE abbrev for CONSTANTS_BLOCK.
2781     auto Abbv = std::make_shared<BitCodeAbbrev>();
2782     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
2783     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2784                               VE.computeBitsRequiredForTypeIndicies()));
2785     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2786         CONSTANTS_SETTYPE_ABBREV)
2787       assert(false && "Unexpected abbrev ordering!");
2788   }
2789 
2790   { // INTEGER abbrev for CONSTANTS_BLOCK.
2791     auto Abbv = std::make_shared<BitCodeAbbrev>();
2792     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
2793     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2794     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2795         CONSTANTS_INTEGER_ABBREV)
2796       assert(false && "Unexpected abbrev ordering!");
2797   }
2798 
2799   { // CE_CAST abbrev for CONSTANTS_BLOCK.
2800     auto Abbv = std::make_shared<BitCodeAbbrev>();
2801     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
2802     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // cast opc
2803     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,      // typeid
2804                               VE.computeBitsRequiredForTypeIndicies()));
2805     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
2806 
2807     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2808         CONSTANTS_CE_CAST_Abbrev)
2809       assert(false && "Unexpected abbrev ordering!");
2810   }
2811   { // NULL abbrev for CONSTANTS_BLOCK.
2812     auto Abbv = std::make_shared<BitCodeAbbrev>();
2813     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
2814     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID, std::move(Abbv)) !=
2815         CONSTANTS_NULL_Abbrev)
2816       assert(false && "Unexpected abbrev ordering!");
2817   }
2818 
2819   // FIXME: This should only use space for first class types!
2820 
2821   { // INST_LOAD abbrev for FUNCTION_BLOCK.
2822     auto Abbv = std::make_shared<BitCodeAbbrev>();
2823     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
2824     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
2825     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2826                               VE.computeBitsRequiredForTypeIndicies()));
2827     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4));   // Align
2828     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
2829     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2830         (unsigned)FUNCTION_INST_LOAD_ABBREV)
2831       assert(false && "Unexpected abbrev ordering!");
2832   }
2833   { // INST_BINOP abbrev for FUNCTION_BLOCK.
2834     auto Abbv = std::make_shared<BitCodeAbbrev>();
2835     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2836     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LHS
2837     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // RHS
2838     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2839     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2840         (unsigned)FUNCTION_INST_BINOP_ABBREV)
2841       assert(false && "Unexpected abbrev ordering!");
2842   }
2843   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
2844     auto Abbv = std::make_shared<BitCodeAbbrev>();
2845     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2846     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LHS
2847     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // RHS
2848     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2849     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
2850     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2851         (unsigned)FUNCTION_INST_BINOP_FLAGS_ABBREV)
2852       assert(false && "Unexpected abbrev ordering!");
2853   }
2854   { // INST_CAST abbrev for FUNCTION_BLOCK.
2855     auto Abbv = std::make_shared<BitCodeAbbrev>();
2856     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
2857     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // OpVal
2858     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2859                               VE.computeBitsRequiredForTypeIndicies()));
2860     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2861     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2862         (unsigned)FUNCTION_INST_CAST_ABBREV)
2863       assert(false && "Unexpected abbrev ordering!");
2864   }
2865 
2866   { // INST_RET abbrev for FUNCTION_BLOCK.
2867     auto Abbv = std::make_shared<BitCodeAbbrev>();
2868     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2869     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2870         (unsigned)FUNCTION_INST_RET_VOID_ABBREV)
2871       assert(false && "Unexpected abbrev ordering!");
2872   }
2873   { // INST_RET abbrev for FUNCTION_BLOCK.
2874     auto Abbv = std::make_shared<BitCodeAbbrev>();
2875     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2876     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
2877     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2878         (unsigned)FUNCTION_INST_RET_VAL_ABBREV)
2879       assert(false && "Unexpected abbrev ordering!");
2880   }
2881   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
2882     auto Abbv = std::make_shared<BitCodeAbbrev>();
2883     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
2884     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2885         (unsigned)FUNCTION_INST_UNREACHABLE_ABBREV)
2886       assert(false && "Unexpected abbrev ordering!");
2887   }
2888   {
2889     auto Abbv = std::make_shared<BitCodeAbbrev>();
2890     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
2891     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2892     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
2893                               Log2_32_Ceil(VE.getTypes().size() + 1)));
2894     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2895     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2896     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, std::move(Abbv)) !=
2897         (unsigned)FUNCTION_INST_GEP_ABBREV)
2898       assert(false && "Unexpected abbrev ordering!");
2899   }
2900 
2901   Stream.ExitBlock();
2902 }
2903 
2904 void DXILBitcodeWriter::writeModuleVersion() {
2905   // VERSION: [version#]
2906   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, ArrayRef<unsigned>{1});
2907 }
2908 
2909 /// WriteModule - Emit the specified module to the bitstream.
2910 void DXILBitcodeWriter::write() {
2911   // The identification block is new since llvm-3.7, but the old bitcode reader
2912   // will skip it.
2913   // writeIdentificationBlock(Stream);
2914 
2915   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
2916 
2917   // It is redundant to fully-specify this here, but nice to make it explicit
2918   // so that it is clear the DXIL module version is different.
2919   DXILBitcodeWriter::writeModuleVersion();
2920 
2921   // Emit blockinfo, which defines the standard abbreviations etc.
2922   writeBlockInfo();
2923 
2924   // Emit information about attribute groups.
2925   writeAttributeGroupTable();
2926 
2927   // Emit information about parameter attributes.
2928   writeAttributeTable();
2929 
2930   // Emit information describing all of the types in the module.
2931   writeTypeTable();
2932 
2933   writeComdats();
2934 
2935   // Emit top-level description of module, including target triple, inline asm,
2936   // descriptors for global variables, and function prototype info.
2937   writeModuleInfo();
2938 
2939   // Emit constants.
2940   writeModuleConstants();
2941 
2942   // Emit metadata.
2943   writeModuleMetadataKinds();
2944 
2945   // Emit metadata.
2946   writeModuleMetadata();
2947 
2948   // Emit names for globals/functions etc.
2949   // DXIL uses the same format for module-level value symbol table as for the
2950   // function level table.
2951   writeFunctionLevelValueSymbolTable(M.getValueSymbolTable());
2952 
2953   // Emit module-level use-lists.
2954   if (VE.shouldPreserveUseListOrder())
2955     writeUseListBlock(nullptr);
2956 
2957   // Emit function bodies.
2958   for (const Function &F : M)
2959     if (!F.isDeclaration())
2960       writeFunction(F);
2961 
2962   Stream.ExitBlock();
2963 }
2964