1 //===--- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Bitcode writer implementation.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Bitcode/ReaderWriter.h"
15 #include "llvm/Bitcode/BitstreamWriter.h"
16 #include "llvm/Bitcode/LLVMBitCodes.h"
17 #include "ValueEnumerator.h"
18 #include "llvm/Constants.h"
19 #include "llvm/DerivedTypes.h"
20 #include "llvm/InlineAsm.h"
21 #include "llvm/Instructions.h"
22 #include "llvm/Module.h"
23 #include "llvm/Operator.h"
24 #include "llvm/TypeSymbolTable.h"
25 #include "llvm/ValueSymbolTable.h"
26 #include "llvm/Support/ErrorHandling.h"
27 #include "llvm/Support/MathExtras.h"
28 #include "llvm/Support/raw_ostream.h"
29 #include "llvm/System/Program.h"
32 /// These are manifest constants used by the bitcode writer. They do not need to
33 /// be kept in sync with the reader, but need to be consistent within this file.
37 // VALUE_SYMTAB_BLOCK abbrev id's.
38 VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
43 // CONSTANTS_BLOCK abbrev id's.
44 CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
45 CONSTANTS_INTEGER_ABBREV,
46 CONSTANTS_CE_CAST_Abbrev,
47 CONSTANTS_NULL_Abbrev,
49 // FUNCTION_BLOCK abbrev id's.
50 FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
51 FUNCTION_INST_BINOP_ABBREV,
52 FUNCTION_INST_BINOP_FLAGS_ABBREV,
53 FUNCTION_INST_CAST_ABBREV,
54 FUNCTION_INST_RET_VOID_ABBREV,
55 FUNCTION_INST_RET_VAL_ABBREV,
56 FUNCTION_INST_UNREACHABLE_ABBREV
60 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
62 default: llvm_unreachable("Unknown cast instruction!");
63 case Instruction::Trunc : return bitc::CAST_TRUNC;
64 case Instruction::ZExt : return bitc::CAST_ZEXT;
65 case Instruction::SExt : return bitc::CAST_SEXT;
66 case Instruction::FPToUI : return bitc::CAST_FPTOUI;
67 case Instruction::FPToSI : return bitc::CAST_FPTOSI;
68 case Instruction::UIToFP : return bitc::CAST_UITOFP;
69 case Instruction::SIToFP : return bitc::CAST_SITOFP;
70 case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
71 case Instruction::FPExt : return bitc::CAST_FPEXT;
72 case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
73 case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
74 case Instruction::BitCast : return bitc::CAST_BITCAST;
78 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
80 default: llvm_unreachable("Unknown binary instruction!");
81 case Instruction::Add:
82 case Instruction::FAdd: return bitc::BINOP_ADD;
83 case Instruction::Sub:
84 case Instruction::FSub: return bitc::BINOP_SUB;
85 case Instruction::Mul:
86 case Instruction::FMul: return bitc::BINOP_MUL;
87 case Instruction::UDiv: return bitc::BINOP_UDIV;
88 case Instruction::FDiv:
89 case Instruction::SDiv: return bitc::BINOP_SDIV;
90 case Instruction::URem: return bitc::BINOP_UREM;
91 case Instruction::FRem:
92 case Instruction::SRem: return bitc::BINOP_SREM;
93 case Instruction::Shl: return bitc::BINOP_SHL;
94 case Instruction::LShr: return bitc::BINOP_LSHR;
95 case Instruction::AShr: return bitc::BINOP_ASHR;
96 case Instruction::And: return bitc::BINOP_AND;
97 case Instruction::Or: return bitc::BINOP_OR;
98 case Instruction::Xor: return bitc::BINOP_XOR;
104 static void WriteStringRecord(unsigned Code, const std::string &Str,
105 unsigned AbbrevToUse, BitstreamWriter &Stream) {
106 SmallVector<unsigned, 64> Vals;
108 // Code: [strchar x N]
109 for (unsigned i = 0, e = Str.size(); i != e; ++i)
110 Vals.push_back(Str[i]);
112 // Emit the finished record.
113 Stream.EmitRecord(Code, Vals, AbbrevToUse);
116 // Emit information about parameter attributes.
117 static void WriteAttributeTable(const ValueEnumerator &VE,
118 BitstreamWriter &Stream) {
119 const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
120 if (Attrs.empty()) return;
122 Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
124 SmallVector<uint64_t, 64> Record;
125 for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
126 const AttrListPtr &A = Attrs[i];
127 for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
128 const AttributeWithIndex &PAWI = A.getSlot(i);
129 Record.push_back(PAWI.Index);
131 // FIXME: remove in LLVM 3.0
132 // Store the alignment in the bitcode as a 16-bit raw value instead of a
133 // 5-bit log2 encoded value. Shift the bits above the alignment up by
135 uint64_t FauxAttr = PAWI.Attrs & 0xffff;
136 if (PAWI.Attrs & Attribute::Alignment)
137 FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
138 FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
140 Record.push_back(FauxAttr);
143 Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
150 /// WriteTypeTable - Write out the type table for a module.
151 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
152 const ValueEnumerator::TypeList &TypeList = VE.getTypes();
154 Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
155 SmallVector<uint64_t, 64> TypeVals;
157 // Abbrev for TYPE_CODE_POINTER.
158 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
159 Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
160 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
161 Log2_32_Ceil(VE.getTypes().size()+1)));
162 Abbv->Add(BitCodeAbbrevOp(0)); // Addrspace = 0
163 unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
165 // Abbrev for TYPE_CODE_FUNCTION.
166 Abbv = new BitCodeAbbrev();
167 Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
168 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isvararg
169 Abbv->Add(BitCodeAbbrevOp(0)); // FIXME: DEAD value, remove in LLVM 3.0
170 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
171 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
172 Log2_32_Ceil(VE.getTypes().size()+1)));
173 unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
175 // Abbrev for TYPE_CODE_STRUCT.
176 Abbv = new BitCodeAbbrev();
177 Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
178 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ispacked
179 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
180 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
181 Log2_32_Ceil(VE.getTypes().size()+1)));
182 unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
184 // Abbrev for TYPE_CODE_ARRAY.
185 Abbv = new BitCodeAbbrev();
186 Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
187 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // size
188 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
189 Log2_32_Ceil(VE.getTypes().size()+1)));
190 unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
192 // Emit an entry count so the reader can reserve space.
193 TypeVals.push_back(TypeList.size());
194 Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
197 // Loop over all of the types, emitting each in turn.
198 for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
199 const Type *T = TypeList[i].first;
203 switch (T->getTypeID()) {
204 default: llvm_unreachable("Unknown type!");
205 case Type::VoidTyID: Code = bitc::TYPE_CODE_VOID; break;
206 case Type::FloatTyID: Code = bitc::TYPE_CODE_FLOAT; break;
207 case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
208 case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
209 case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
210 case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
211 case Type::LabelTyID: Code = bitc::TYPE_CODE_LABEL; break;
212 case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
213 case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
214 case Type::IntegerTyID:
216 Code = bitc::TYPE_CODE_INTEGER;
217 TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
219 case Type::PointerTyID: {
220 const PointerType *PTy = cast<PointerType>(T);
221 // POINTER: [pointee type, address space]
222 Code = bitc::TYPE_CODE_POINTER;
223 TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
224 unsigned AddressSpace = PTy->getAddressSpace();
225 TypeVals.push_back(AddressSpace);
226 if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
229 case Type::FunctionTyID: {
230 const FunctionType *FT = cast<FunctionType>(T);
231 // FUNCTION: [isvararg, attrid, retty, paramty x N]
232 Code = bitc::TYPE_CODE_FUNCTION;
233 TypeVals.push_back(FT->isVarArg());
234 TypeVals.push_back(0); // FIXME: DEAD: remove in llvm 3.0
235 TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
236 for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
237 TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
238 AbbrevToUse = FunctionAbbrev;
241 case Type::StructTyID: {
242 const StructType *ST = cast<StructType>(T);
243 // STRUCT: [ispacked, eltty x N]
244 Code = bitc::TYPE_CODE_STRUCT;
245 TypeVals.push_back(ST->isPacked());
246 // Output all of the element types.
247 for (StructType::element_iterator I = ST->element_begin(),
248 E = ST->element_end(); I != E; ++I)
249 TypeVals.push_back(VE.getTypeID(*I));
250 AbbrevToUse = StructAbbrev;
253 case Type::ArrayTyID: {
254 const ArrayType *AT = cast<ArrayType>(T);
255 // ARRAY: [numelts, eltty]
256 Code = bitc::TYPE_CODE_ARRAY;
257 TypeVals.push_back(AT->getNumElements());
258 TypeVals.push_back(VE.getTypeID(AT->getElementType()));
259 AbbrevToUse = ArrayAbbrev;
262 case Type::VectorTyID: {
263 const VectorType *VT = cast<VectorType>(T);
264 // VECTOR [numelts, eltty]
265 Code = bitc::TYPE_CODE_VECTOR;
266 TypeVals.push_back(VT->getNumElements());
267 TypeVals.push_back(VE.getTypeID(VT->getElementType()));
272 // Emit the finished record.
273 Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
280 static unsigned getEncodedLinkage(const GlobalValue *GV) {
281 switch (GV->getLinkage()) {
282 default: llvm_unreachable("Invalid linkage!");
283 case GlobalValue::GhostLinkage: // Map ghost linkage onto external.
284 case GlobalValue::ExternalLinkage: return 0;
285 case GlobalValue::WeakAnyLinkage: return 1;
286 case GlobalValue::AppendingLinkage: return 2;
287 case GlobalValue::InternalLinkage: return 3;
288 case GlobalValue::LinkOnceAnyLinkage: return 4;
289 case GlobalValue::DLLImportLinkage: return 5;
290 case GlobalValue::DLLExportLinkage: return 6;
291 case GlobalValue::ExternalWeakLinkage: return 7;
292 case GlobalValue::CommonLinkage: return 8;
293 case GlobalValue::PrivateLinkage: return 9;
294 case GlobalValue::WeakODRLinkage: return 10;
295 case GlobalValue::LinkOnceODRLinkage: return 11;
296 case GlobalValue::AvailableExternallyLinkage: return 12;
297 case GlobalValue::LinkerPrivateLinkage: return 13;
301 static unsigned getEncodedVisibility(const GlobalValue *GV) {
302 switch (GV->getVisibility()) {
303 default: llvm_unreachable("Invalid visibility!");
304 case GlobalValue::DefaultVisibility: return 0;
305 case GlobalValue::HiddenVisibility: return 1;
306 case GlobalValue::ProtectedVisibility: return 2;
310 // Emit top-level description of module, including target triple, inline asm,
311 // descriptors for global variables, and function prototype info.
312 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
313 BitstreamWriter &Stream) {
314 // Emit the list of dependent libraries for the Module.
315 for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
316 WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
318 // Emit various pieces of data attached to a module.
319 if (!M->getTargetTriple().empty())
320 WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
322 if (!M->getDataLayout().empty())
323 WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
325 if (!M->getModuleInlineAsm().empty())
326 WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
329 // Emit information about sections and GC, computing how many there are. Also
330 // compute the maximum alignment value.
331 std::map<std::string, unsigned> SectionMap;
332 std::map<std::string, unsigned> GCMap;
333 unsigned MaxAlignment = 0;
334 unsigned MaxGlobalType = 0;
335 for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
337 MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
338 MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
340 if (!GV->hasSection()) continue;
341 // Give section names unique ID's.
342 unsigned &Entry = SectionMap[GV->getSection()];
343 if (Entry != 0) continue;
344 WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
346 Entry = SectionMap.size();
348 for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
349 MaxAlignment = std::max(MaxAlignment, F->getAlignment());
350 if (F->hasSection()) {
351 // Give section names unique ID's.
352 unsigned &Entry = SectionMap[F->getSection()];
354 WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
356 Entry = SectionMap.size();
360 // Same for GC names.
361 unsigned &Entry = GCMap[F->getGC()];
363 WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
365 Entry = GCMap.size();
370 // Emit abbrev for globals, now that we know # sections and max alignment.
371 unsigned SimpleGVarAbbrev = 0;
372 if (!M->global_empty()) {
373 // Add an abbrev for common globals with no visibility or thread localness.
374 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
375 Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
376 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
377 Log2_32_Ceil(MaxGlobalType+1)));
378 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Constant.
379 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Initializer.
380 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // Linkage.
381 if (MaxAlignment == 0) // Alignment.
382 Abbv->Add(BitCodeAbbrevOp(0));
384 unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
385 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
386 Log2_32_Ceil(MaxEncAlignment+1)));
388 if (SectionMap.empty()) // Section.
389 Abbv->Add(BitCodeAbbrevOp(0));
391 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
392 Log2_32_Ceil(SectionMap.size()+1)));
393 // Don't bother emitting vis + thread local.
394 SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
397 // Emit the global variable information.
398 SmallVector<unsigned, 64> Vals;
399 for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
401 unsigned AbbrevToUse = 0;
403 // GLOBALVAR: [type, isconst, initid,
404 // linkage, alignment, section, visibility, threadlocal]
405 Vals.push_back(VE.getTypeID(GV->getType()));
406 Vals.push_back(GV->isConstant());
407 Vals.push_back(GV->isDeclaration() ? 0 :
408 (VE.getValueID(GV->getInitializer()) + 1));
409 Vals.push_back(getEncodedLinkage(GV));
410 Vals.push_back(Log2_32(GV->getAlignment())+1);
411 Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
412 if (GV->isThreadLocal() ||
413 GV->getVisibility() != GlobalValue::DefaultVisibility) {
414 Vals.push_back(getEncodedVisibility(GV));
415 Vals.push_back(GV->isThreadLocal());
417 AbbrevToUse = SimpleGVarAbbrev;
420 Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
424 // Emit the function proto information.
425 for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
426 // FUNCTION: [type, callingconv, isproto, paramattr,
427 // linkage, alignment, section, visibility, gc]
428 Vals.push_back(VE.getTypeID(F->getType()));
429 Vals.push_back(F->getCallingConv());
430 Vals.push_back(F->isDeclaration());
431 Vals.push_back(getEncodedLinkage(F));
432 Vals.push_back(VE.getAttributeID(F->getAttributes()));
433 Vals.push_back(Log2_32(F->getAlignment())+1);
434 Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
435 Vals.push_back(getEncodedVisibility(F));
436 Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
438 unsigned AbbrevToUse = 0;
439 Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
444 // Emit the alias information.
445 for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
447 Vals.push_back(VE.getTypeID(AI->getType()));
448 Vals.push_back(VE.getValueID(AI->getAliasee()));
449 Vals.push_back(getEncodedLinkage(AI));
450 Vals.push_back(getEncodedVisibility(AI));
451 unsigned AbbrevToUse = 0;
452 Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
457 static uint64_t GetOptimizationFlags(const Value *V) {
460 if (const OverflowingBinaryOperator *OBO =
461 dyn_cast<OverflowingBinaryOperator>(V)) {
462 if (OBO->hasNoSignedWrap())
463 Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
464 if (OBO->hasNoUnsignedWrap())
465 Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
466 } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
468 Flags |= 1 << bitc::SDIV_EXACT;
474 static void WriteMDNode(const MDNode *N,
475 const ValueEnumerator &VE,
476 BitstreamWriter &Stream,
477 SmallVector<uint64_t, 64> &Record) {
478 for (unsigned i = 0, e = N->getNumElements(); i != e; ++i) {
479 if (N->getElement(i)) {
480 Record.push_back(VE.getTypeID(N->getElement(i)->getType()));
481 Record.push_back(VE.getValueID(N->getElement(i)));
483 Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
487 Stream.EmitRecord(bitc::METADATA_NODE, Record, 0);
491 static void WriteModuleMetadata(const ValueEnumerator &VE,
492 BitstreamWriter &Stream) {
493 const ValueEnumerator::ValueList &Vals = VE.getMDValues();
494 bool StartedMetadataBlock = false;
495 unsigned MDSAbbrev = 0;
496 SmallVector<uint64_t, 64> Record;
497 for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
499 if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
500 if (!StartedMetadataBlock) {
501 Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
502 StartedMetadataBlock = true;
504 WriteMDNode(N, VE, Stream, Record);
505 } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
506 if (!StartedMetadataBlock) {
507 Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
509 // Abbrev for METADATA_STRING.
510 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
511 Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
512 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
513 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
514 MDSAbbrev = Stream.EmitAbbrev(Abbv);
515 StartedMetadataBlock = true;
518 // Code: [strchar x N]
519 Record.append(MDS->begin(), MDS->end());
521 // Emit the finished record.
522 Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
524 } else if (const NamedMDNode *NMD = dyn_cast<NamedMDNode>(Vals[i].first)) {
525 if (!StartedMetadataBlock) {
526 Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
527 StartedMetadataBlock = true;
531 std::string Str = NMD->getNameStr();
532 const char *StrBegin = Str.c_str();
533 for (unsigned i = 0, e = Str.length(); i != e; ++i)
534 Record.push_back(StrBegin[i]);
535 Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
538 // Write named metadata elements.
539 for (unsigned i = 0, e = NMD->getNumElements(); i != e; ++i) {
540 if (NMD->getElement(i))
541 Record.push_back(VE.getValueID(NMD->getElement(i)));
545 Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
550 if (StartedMetadataBlock)
554 static void WriteMetadataAttachment(const Function &F,
555 const ValueEnumerator &VE,
556 BitstreamWriter &Stream) {
557 bool StartedMetadataBlock = false;
558 SmallVector<uint64_t, 64> Record;
560 // Write metadata attachments
561 // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
562 SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
564 for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
565 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
568 I->getAllMetadata(MDs);
570 // If no metadata, ignore instruction.
571 if (MDs.empty()) continue;
573 Record.push_back(VE.getInstructionID(I));
575 for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
576 Record.push_back(MDs[i].first);
577 Record.push_back(VE.getValueID(MDs[i].second));
579 if (!StartedMetadataBlock) {
580 Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
581 StartedMetadataBlock = true;
583 Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
587 if (StartedMetadataBlock)
591 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
592 SmallVector<uint64_t, 64> Record;
594 // Write metadata kinds
595 // METADATA_KIND - [n x [id, name]]
596 SmallVector<StringRef, 4> Names;
597 M->getMDKindNames(Names);
599 assert(Names[0] == "" && "MDKind #0 is invalid");
600 if (Names.size() == 1) return;
602 Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
604 for (unsigned MDKindID = 1, e = Names.size(); MDKindID != e; ++MDKindID) {
605 Record.push_back(MDKindID);
606 StringRef KName = Names[MDKindID];
607 Record.append(KName.begin(), KName.end());
609 Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
616 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
617 const ValueEnumerator &VE,
618 BitstreamWriter &Stream, bool isGlobal) {
619 if (FirstVal == LastVal) return;
621 Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
623 unsigned AggregateAbbrev = 0;
624 unsigned String8Abbrev = 0;
625 unsigned CString7Abbrev = 0;
626 unsigned CString6Abbrev = 0;
627 // If this is a constant pool for the module, emit module-specific abbrevs.
629 // Abbrev for CST_CODE_AGGREGATE.
630 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
631 Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
632 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
633 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
634 AggregateAbbrev = Stream.EmitAbbrev(Abbv);
636 // Abbrev for CST_CODE_STRING.
637 Abbv = new BitCodeAbbrev();
638 Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
639 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
640 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
641 String8Abbrev = Stream.EmitAbbrev(Abbv);
642 // Abbrev for CST_CODE_CSTRING.
643 Abbv = new BitCodeAbbrev();
644 Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
645 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
646 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
647 CString7Abbrev = Stream.EmitAbbrev(Abbv);
648 // Abbrev for CST_CODE_CSTRING.
649 Abbv = new BitCodeAbbrev();
650 Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
651 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
652 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
653 CString6Abbrev = Stream.EmitAbbrev(Abbv);
656 SmallVector<uint64_t, 64> Record;
658 const ValueEnumerator::ValueList &Vals = VE.getValues();
659 const Type *LastTy = 0;
660 for (unsigned i = FirstVal; i != LastVal; ++i) {
661 const Value *V = Vals[i].first;
662 // If we need to switch types, do so now.
663 if (V->getType() != LastTy) {
664 LastTy = V->getType();
665 Record.push_back(VE.getTypeID(LastTy));
666 Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
667 CONSTANTS_SETTYPE_ABBREV);
671 if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
672 Record.push_back(unsigned(IA->hasSideEffects()) |
673 unsigned(IA->isAlignStack()) << 1);
675 // Add the asm string.
676 const std::string &AsmStr = IA->getAsmString();
677 Record.push_back(AsmStr.size());
678 for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
679 Record.push_back(AsmStr[i]);
681 // Add the constraint string.
682 const std::string &ConstraintStr = IA->getConstraintString();
683 Record.push_back(ConstraintStr.size());
684 for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
685 Record.push_back(ConstraintStr[i]);
686 Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
690 const Constant *C = cast<Constant>(V);
692 unsigned AbbrevToUse = 0;
693 if (C->isNullValue()) {
694 Code = bitc::CST_CODE_NULL;
695 } else if (isa<UndefValue>(C)) {
696 Code = bitc::CST_CODE_UNDEF;
697 } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
698 if (IV->getBitWidth() <= 64) {
699 int64_t V = IV->getSExtValue();
701 Record.push_back(V << 1);
703 Record.push_back((-V << 1) | 1);
704 Code = bitc::CST_CODE_INTEGER;
705 AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
706 } else { // Wide integers, > 64 bits in size.
707 // We have an arbitrary precision integer value to write whose
708 // bit width is > 64. However, in canonical unsigned integer
709 // format it is likely that the high bits are going to be zero.
710 // So, we only write the number of active words.
711 unsigned NWords = IV->getValue().getActiveWords();
712 const uint64_t *RawWords = IV->getValue().getRawData();
713 for (unsigned i = 0; i != NWords; ++i) {
714 int64_t V = RawWords[i];
716 Record.push_back(V << 1);
718 Record.push_back((-V << 1) | 1);
720 Code = bitc::CST_CODE_WIDE_INTEGER;
722 } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
723 Code = bitc::CST_CODE_FLOAT;
724 const Type *Ty = CFP->getType();
725 if (Ty->isFloatTy() || Ty->isDoubleTy()) {
726 Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
727 } else if (Ty->isX86_FP80Ty()) {
728 // api needed to prevent premature destruction
729 // bits are not in the same order as a normal i80 APInt, compensate.
730 APInt api = CFP->getValueAPF().bitcastToAPInt();
731 const uint64_t *p = api.getRawData();
732 Record.push_back((p[1] << 48) | (p[0] >> 16));
733 Record.push_back(p[0] & 0xffffLL);
734 } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
735 APInt api = CFP->getValueAPF().bitcastToAPInt();
736 const uint64_t *p = api.getRawData();
737 Record.push_back(p[0]);
738 Record.push_back(p[1]);
740 assert (0 && "Unknown FP type!");
742 } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
743 const ConstantArray *CA = cast<ConstantArray>(C);
744 // Emit constant strings specially.
745 unsigned NumOps = CA->getNumOperands();
746 // If this is a null-terminated string, use the denser CSTRING encoding.
747 if (CA->getOperand(NumOps-1)->isNullValue()) {
748 Code = bitc::CST_CODE_CSTRING;
749 --NumOps; // Don't encode the null, which isn't allowed by char6.
751 Code = bitc::CST_CODE_STRING;
752 AbbrevToUse = String8Abbrev;
754 bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
755 bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
756 for (unsigned i = 0; i != NumOps; ++i) {
757 unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
759 isCStr7 &= (V & 128) == 0;
761 isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
765 AbbrevToUse = CString6Abbrev;
767 AbbrevToUse = CString7Abbrev;
768 } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
769 isa<ConstantVector>(V)) {
770 Code = bitc::CST_CODE_AGGREGATE;
771 for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
772 Record.push_back(VE.getValueID(C->getOperand(i)));
773 AbbrevToUse = AggregateAbbrev;
774 } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
775 switch (CE->getOpcode()) {
777 if (Instruction::isCast(CE->getOpcode())) {
778 Code = bitc::CST_CODE_CE_CAST;
779 Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
780 Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
781 Record.push_back(VE.getValueID(C->getOperand(0)));
782 AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
784 assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
785 Code = bitc::CST_CODE_CE_BINOP;
786 Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
787 Record.push_back(VE.getValueID(C->getOperand(0)));
788 Record.push_back(VE.getValueID(C->getOperand(1)));
789 uint64_t Flags = GetOptimizationFlags(CE);
791 Record.push_back(Flags);
794 case Instruction::GetElementPtr:
795 Code = bitc::CST_CODE_CE_GEP;
796 if (cast<GEPOperator>(C)->isInBounds())
797 Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
798 for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
799 Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
800 Record.push_back(VE.getValueID(C->getOperand(i)));
803 case Instruction::Select:
804 Code = bitc::CST_CODE_CE_SELECT;
805 Record.push_back(VE.getValueID(C->getOperand(0)));
806 Record.push_back(VE.getValueID(C->getOperand(1)));
807 Record.push_back(VE.getValueID(C->getOperand(2)));
809 case Instruction::ExtractElement:
810 Code = bitc::CST_CODE_CE_EXTRACTELT;
811 Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
812 Record.push_back(VE.getValueID(C->getOperand(0)));
813 Record.push_back(VE.getValueID(C->getOperand(1)));
815 case Instruction::InsertElement:
816 Code = bitc::CST_CODE_CE_INSERTELT;
817 Record.push_back(VE.getValueID(C->getOperand(0)));
818 Record.push_back(VE.getValueID(C->getOperand(1)));
819 Record.push_back(VE.getValueID(C->getOperand(2)));
821 case Instruction::ShuffleVector:
822 // If the return type and argument types are the same, this is a
823 // standard shufflevector instruction. If the types are different,
824 // then the shuffle is widening or truncating the input vectors, and
825 // the argument type must also be encoded.
826 if (C->getType() == C->getOperand(0)->getType()) {
827 Code = bitc::CST_CODE_CE_SHUFFLEVEC;
829 Code = bitc::CST_CODE_CE_SHUFVEC_EX;
830 Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
832 Record.push_back(VE.getValueID(C->getOperand(0)));
833 Record.push_back(VE.getValueID(C->getOperand(1)));
834 Record.push_back(VE.getValueID(C->getOperand(2)));
836 case Instruction::ICmp:
837 case Instruction::FCmp:
838 Code = bitc::CST_CODE_CE_CMP;
839 Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
840 Record.push_back(VE.getValueID(C->getOperand(0)));
841 Record.push_back(VE.getValueID(C->getOperand(1)));
842 Record.push_back(CE->getPredicate());
845 } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
846 assert(BA->getFunction() == BA->getBasicBlock()->getParent() &&
847 "Malformed blockaddress");
848 Code = bitc::CST_CODE_BLOCKADDRESS;
849 Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
850 Record.push_back(VE.getValueID(BA->getFunction()));
851 Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
853 llvm_unreachable("Unknown constant!");
855 Stream.EmitRecord(Code, Record, AbbrevToUse);
862 static void WriteModuleConstants(const ValueEnumerator &VE,
863 BitstreamWriter &Stream) {
864 const ValueEnumerator::ValueList &Vals = VE.getValues();
866 // Find the first constant to emit, which is the first non-globalvalue value.
867 // We know globalvalues have been emitted by WriteModuleInfo.
868 for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
869 if (!isa<GlobalValue>(Vals[i].first)) {
870 WriteConstants(i, Vals.size(), VE, Stream, true);
876 /// PushValueAndType - The file has to encode both the value and type id for
877 /// many values, because we need to know what type to create for forward
878 /// references. However, most operands are not forward references, so this type
879 /// field is not needed.
881 /// This function adds V's value ID to Vals. If the value ID is higher than the
882 /// instruction ID, then it is a forward reference, and it also includes the
884 static bool PushValueAndType(const Value *V, unsigned InstID,
885 SmallVector<unsigned, 64> &Vals,
886 ValueEnumerator &VE) {
887 unsigned ValID = VE.getValueID(V);
888 Vals.push_back(ValID);
889 if (ValID >= InstID) {
890 Vals.push_back(VE.getTypeID(V->getType()));
896 /// WriteInstruction - Emit an instruction to the specified stream.
897 static void WriteInstruction(const Instruction &I, unsigned InstID,
898 ValueEnumerator &VE, BitstreamWriter &Stream,
899 SmallVector<unsigned, 64> &Vals) {
901 unsigned AbbrevToUse = 0;
902 VE.setInstructionID(&I);
903 switch (I.getOpcode()) {
905 if (Instruction::isCast(I.getOpcode())) {
906 Code = bitc::FUNC_CODE_INST_CAST;
907 if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
908 AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
909 Vals.push_back(VE.getTypeID(I.getType()));
910 Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
912 assert(isa<BinaryOperator>(I) && "Unknown instruction!");
913 Code = bitc::FUNC_CODE_INST_BINOP;
914 if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
915 AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
916 Vals.push_back(VE.getValueID(I.getOperand(1)));
917 Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
918 uint64_t Flags = GetOptimizationFlags(&I);
920 if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
921 AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
922 Vals.push_back(Flags);
927 case Instruction::GetElementPtr:
928 Code = bitc::FUNC_CODE_INST_GEP;
929 if (cast<GEPOperator>(&I)->isInBounds())
930 Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
931 for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
932 PushValueAndType(I.getOperand(i), InstID, Vals, VE);
934 case Instruction::ExtractValue: {
935 Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
936 PushValueAndType(I.getOperand(0), InstID, Vals, VE);
937 const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
938 for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
942 case Instruction::InsertValue: {
943 Code = bitc::FUNC_CODE_INST_INSERTVAL;
944 PushValueAndType(I.getOperand(0), InstID, Vals, VE);
945 PushValueAndType(I.getOperand(1), InstID, Vals, VE);
946 const InsertValueInst *IVI = cast<InsertValueInst>(&I);
947 for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
951 case Instruction::Select:
952 Code = bitc::FUNC_CODE_INST_VSELECT;
953 PushValueAndType(I.getOperand(1), InstID, Vals, VE);
954 Vals.push_back(VE.getValueID(I.getOperand(2)));
955 PushValueAndType(I.getOperand(0), InstID, Vals, VE);
957 case Instruction::ExtractElement:
958 Code = bitc::FUNC_CODE_INST_EXTRACTELT;
959 PushValueAndType(I.getOperand(0), InstID, Vals, VE);
960 Vals.push_back(VE.getValueID(I.getOperand(1)));
962 case Instruction::InsertElement:
963 Code = bitc::FUNC_CODE_INST_INSERTELT;
964 PushValueAndType(I.getOperand(0), InstID, Vals, VE);
965 Vals.push_back(VE.getValueID(I.getOperand(1)));
966 Vals.push_back(VE.getValueID(I.getOperand(2)));
968 case Instruction::ShuffleVector:
969 Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
970 PushValueAndType(I.getOperand(0), InstID, Vals, VE);
971 Vals.push_back(VE.getValueID(I.getOperand(1)));
972 Vals.push_back(VE.getValueID(I.getOperand(2)));
974 case Instruction::ICmp:
975 case Instruction::FCmp:
976 // compare returning Int1Ty or vector of Int1Ty
977 Code = bitc::FUNC_CODE_INST_CMP2;
978 PushValueAndType(I.getOperand(0), InstID, Vals, VE);
979 Vals.push_back(VE.getValueID(I.getOperand(1)));
980 Vals.push_back(cast<CmpInst>(I).getPredicate());
983 case Instruction::Ret:
985 Code = bitc::FUNC_CODE_INST_RET;
986 unsigned NumOperands = I.getNumOperands();
987 if (NumOperands == 0)
988 AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
989 else if (NumOperands == 1) {
990 if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
991 AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
993 for (unsigned i = 0, e = NumOperands; i != e; ++i)
994 PushValueAndType(I.getOperand(i), InstID, Vals, VE);
998 case Instruction::Br:
1000 Code = bitc::FUNC_CODE_INST_BR;
1001 BranchInst &II = cast<BranchInst>(I);
1002 Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1003 if (II.isConditional()) {
1004 Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1005 Vals.push_back(VE.getValueID(II.getCondition()));
1009 case Instruction::Switch:
1010 Code = bitc::FUNC_CODE_INST_SWITCH;
1011 Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1012 for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1013 Vals.push_back(VE.getValueID(I.getOperand(i)));
1015 case Instruction::IndirectBr:
1016 Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1017 Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1018 for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1019 Vals.push_back(VE.getValueID(I.getOperand(i)));
1022 case Instruction::Invoke: {
1023 const InvokeInst *II = cast<InvokeInst>(&I);
1024 const Value *Callee(II->getCalledValue());
1025 const PointerType *PTy = cast<PointerType>(Callee->getType());
1026 const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1027 Code = bitc::FUNC_CODE_INST_INVOKE;
1029 Vals.push_back(VE.getAttributeID(II->getAttributes()));
1030 Vals.push_back(II->getCallingConv());
1031 Vals.push_back(VE.getValueID(II->getNormalDest()));
1032 Vals.push_back(VE.getValueID(II->getUnwindDest()));
1033 PushValueAndType(Callee, InstID, Vals, VE);
1035 // Emit value #'s for the fixed parameters.
1036 for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1037 Vals.push_back(VE.getValueID(I.getOperand(i+3))); // fixed param.
1039 // Emit type/value pairs for varargs params.
1040 if (FTy->isVarArg()) {
1041 for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
1043 PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1047 case Instruction::Unwind:
1048 Code = bitc::FUNC_CODE_INST_UNWIND;
1050 case Instruction::Unreachable:
1051 Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1052 AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1055 case Instruction::PHI:
1056 Code = bitc::FUNC_CODE_INST_PHI;
1057 Vals.push_back(VE.getTypeID(I.getType()));
1058 for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1059 Vals.push_back(VE.getValueID(I.getOperand(i)));
1062 case Instruction::Alloca:
1063 Code = bitc::FUNC_CODE_INST_ALLOCA;
1064 Vals.push_back(VE.getTypeID(I.getType()));
1065 Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1066 Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1069 case Instruction::Load:
1070 Code = bitc::FUNC_CODE_INST_LOAD;
1071 if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE)) // ptr
1072 AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1074 Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1075 Vals.push_back(cast<LoadInst>(I).isVolatile());
1077 case Instruction::Store:
1078 Code = bitc::FUNC_CODE_INST_STORE2;
1079 PushValueAndType(I.getOperand(1), InstID, Vals, VE); // ptrty + ptr
1080 Vals.push_back(VE.getValueID(I.getOperand(0))); // val.
1081 Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1082 Vals.push_back(cast<StoreInst>(I).isVolatile());
1084 case Instruction::Call: {
1085 const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
1086 const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1088 Code = bitc::FUNC_CODE_INST_CALL;
1090 const CallInst *CI = cast<CallInst>(&I);
1091 Vals.push_back(VE.getAttributeID(CI->getAttributes()));
1092 Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
1093 PushValueAndType(CI->getOperand(0), InstID, Vals, VE); // Callee
1095 // Emit value #'s for the fixed parameters.
1096 for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1097 Vals.push_back(VE.getValueID(I.getOperand(i+1))); // fixed param.
1099 // Emit type/value pairs for varargs params.
1100 if (FTy->isVarArg()) {
1101 unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
1102 for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
1104 PushValueAndType(I.getOperand(i), InstID, Vals, VE); // varargs
1108 case Instruction::VAArg:
1109 Code = bitc::FUNC_CODE_INST_VAARG;
1110 Vals.push_back(VE.getTypeID(I.getOperand(0)->getType())); // valistty
1111 Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1112 Vals.push_back(VE.getTypeID(I.getType())); // restype.
1116 Stream.EmitRecord(Code, Vals, AbbrevToUse);
1120 // Emit names for globals/functions etc.
1121 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1122 const ValueEnumerator &VE,
1123 BitstreamWriter &Stream) {
1124 if (VST.empty()) return;
1125 Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1127 // FIXME: Set up the abbrev, we know how many values there are!
1128 // FIXME: We know if the type names can use 7-bit ascii.
1129 SmallVector<unsigned, 64> NameVals;
1131 for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1134 const ValueName &Name = *SI;
1136 // Figure out the encoding to use for the name.
1138 bool isChar6 = true;
1139 for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1142 isChar6 = BitCodeAbbrevOp::isChar6(*C);
1143 if ((unsigned char)*C & 128) {
1145 break; // don't bother scanning the rest.
1149 unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1151 // VST_ENTRY: [valueid, namechar x N]
1152 // VST_BBENTRY: [bbid, namechar x N]
1154 if (isa<BasicBlock>(SI->getValue())) {
1155 Code = bitc::VST_CODE_BBENTRY;
1157 AbbrevToUse = VST_BBENTRY_6_ABBREV;
1159 Code = bitc::VST_CODE_ENTRY;
1161 AbbrevToUse = VST_ENTRY_6_ABBREV;
1163 AbbrevToUse = VST_ENTRY_7_ABBREV;
1166 NameVals.push_back(VE.getValueID(SI->getValue()));
1167 for (const char *P = Name.getKeyData(),
1168 *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1169 NameVals.push_back((unsigned char)*P);
1171 // Emit the finished record.
1172 Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1178 /// WriteFunction - Emit a function body to the module stream.
1179 static void WriteFunction(const Function &F, ValueEnumerator &VE,
1180 BitstreamWriter &Stream) {
1181 Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1182 VE.incorporateFunction(F);
1184 SmallVector<unsigned, 64> Vals;
1186 // Emit the number of basic blocks, so the reader can create them ahead of
1188 Vals.push_back(VE.getBasicBlocks().size());
1189 Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1192 // If there are function-local constants, emit them now.
1193 unsigned CstStart, CstEnd;
1194 VE.getFunctionConstantRange(CstStart, CstEnd);
1195 WriteConstants(CstStart, CstEnd, VE, Stream, false);
1197 // Keep a running idea of what the instruction ID is.
1198 unsigned InstID = CstEnd;
1200 // Finally, emit all the instructions, in order.
1201 for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1202 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1204 WriteInstruction(*I, InstID, VE, Stream, Vals);
1205 if (!I->getType()->isVoidTy())
1209 // Emit names for all the instructions etc.
1210 WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1212 WriteMetadataAttachment(F, VE, Stream);
1217 /// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1218 static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1219 const ValueEnumerator &VE,
1220 BitstreamWriter &Stream) {
1221 if (TST.empty()) return;
1223 Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1225 // 7-bit fixed width VST_CODE_ENTRY strings.
1226 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1227 Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1228 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1229 Log2_32_Ceil(VE.getTypes().size()+1)));
1230 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1231 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1232 unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1234 SmallVector<unsigned, 64> NameVals;
1236 for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1238 // TST_ENTRY: [typeid, namechar x N]
1239 NameVals.push_back(VE.getTypeID(TI->second));
1241 const std::string &Str = TI->first;
1243 for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1244 NameVals.push_back((unsigned char)Str[i]);
1249 // Emit the finished record.
1250 Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1257 // Emit blockinfo, which defines the standard abbreviations etc.
1258 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1259 // We only want to emit block info records for blocks that have multiple
1260 // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK. Other
1261 // blocks can defined their abbrevs inline.
1262 Stream.EnterBlockInfoBlock(2);
1264 { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1265 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1266 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1267 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1268 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1269 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1270 if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1271 Abbv) != VST_ENTRY_8_ABBREV)
1272 llvm_unreachable("Unexpected abbrev ordering!");
1275 { // 7-bit fixed width VST_ENTRY strings.
1276 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1277 Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1278 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1279 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1280 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1281 if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1282 Abbv) != VST_ENTRY_7_ABBREV)
1283 llvm_unreachable("Unexpected abbrev ordering!");
1285 { // 6-bit char6 VST_ENTRY strings.
1286 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1287 Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1288 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1289 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1290 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1291 if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1292 Abbv) != VST_ENTRY_6_ABBREV)
1293 llvm_unreachable("Unexpected abbrev ordering!");
1295 { // 6-bit char6 VST_BBENTRY strings.
1296 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1297 Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1298 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1299 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1300 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1301 if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1302 Abbv) != VST_BBENTRY_6_ABBREV)
1303 llvm_unreachable("Unexpected abbrev ordering!");
1308 { // SETTYPE abbrev for CONSTANTS_BLOCK.
1309 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1310 Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1311 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1312 Log2_32_Ceil(VE.getTypes().size()+1)));
1313 if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1314 Abbv) != CONSTANTS_SETTYPE_ABBREV)
1315 llvm_unreachable("Unexpected abbrev ordering!");
1318 { // INTEGER abbrev for CONSTANTS_BLOCK.
1319 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1320 Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1321 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1322 if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1323 Abbv) != CONSTANTS_INTEGER_ABBREV)
1324 llvm_unreachable("Unexpected abbrev ordering!");
1327 { // CE_CAST abbrev for CONSTANTS_BLOCK.
1328 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1329 Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1330 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // cast opc
1331 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // typeid
1332 Log2_32_Ceil(VE.getTypes().size()+1)));
1333 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
1335 if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1336 Abbv) != CONSTANTS_CE_CAST_Abbrev)
1337 llvm_unreachable("Unexpected abbrev ordering!");
1339 { // NULL abbrev for CONSTANTS_BLOCK.
1340 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1341 Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1342 if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1343 Abbv) != CONSTANTS_NULL_Abbrev)
1344 llvm_unreachable("Unexpected abbrev ordering!");
1347 // FIXME: This should only use space for first class types!
1349 { // INST_LOAD abbrev for FUNCTION_BLOCK.
1350 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1351 Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1352 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1353 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1354 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1355 if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1356 Abbv) != FUNCTION_INST_LOAD_ABBREV)
1357 llvm_unreachable("Unexpected abbrev ordering!");
1359 { // INST_BINOP abbrev for FUNCTION_BLOCK.
1360 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1361 Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1362 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1363 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1364 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1365 if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1366 Abbv) != FUNCTION_INST_BINOP_ABBREV)
1367 llvm_unreachable("Unexpected abbrev ordering!");
1369 { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1370 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1371 Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1372 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1373 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1374 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1375 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1376 if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1377 Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1378 llvm_unreachable("Unexpected abbrev ordering!");
1380 { // INST_CAST abbrev for FUNCTION_BLOCK.
1381 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1382 Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1383 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // OpVal
1384 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
1385 Log2_32_Ceil(VE.getTypes().size()+1)));
1386 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1387 if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1388 Abbv) != FUNCTION_INST_CAST_ABBREV)
1389 llvm_unreachable("Unexpected abbrev ordering!");
1392 { // INST_RET abbrev for FUNCTION_BLOCK.
1393 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1394 Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1395 if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1396 Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1397 llvm_unreachable("Unexpected abbrev ordering!");
1399 { // INST_RET abbrev for FUNCTION_BLOCK.
1400 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1401 Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1402 Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1403 if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1404 Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1405 llvm_unreachable("Unexpected abbrev ordering!");
1407 { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1408 BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1409 Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1410 if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1411 Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1412 llvm_unreachable("Unexpected abbrev ordering!");
1419 /// WriteModule - Emit the specified module to the bitstream.
1420 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1421 Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1423 // Emit the version number if it is non-zero.
1425 SmallVector<unsigned, 1> Vals;
1426 Vals.push_back(CurVersion);
1427 Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1430 // Analyze the module, enumerating globals, functions, etc.
1431 ValueEnumerator VE(M);
1433 // Emit blockinfo, which defines the standard abbreviations etc.
1434 WriteBlockInfo(VE, Stream);
1436 // Emit information about parameter attributes.
1437 WriteAttributeTable(VE, Stream);
1439 // Emit information describing all of the types in the module.
1440 WriteTypeTable(VE, Stream);
1442 // Emit top-level description of module, including target triple, inline asm,
1443 // descriptors for global variables, and function prototype info.
1444 WriteModuleInfo(M, VE, Stream);
1447 WriteModuleConstants(VE, Stream);
1450 WriteModuleMetadata(VE, Stream);
1452 // Emit function bodies.
1453 for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1454 if (!I->isDeclaration())
1455 WriteFunction(*I, VE, Stream);
1458 WriteModuleMetadataStore(M, Stream);
1460 // Emit the type symbol table information.
1461 WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1463 // Emit names for globals/functions etc.
1464 WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1469 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1470 /// header and trailer to make it compatible with the system archiver. To do
1471 /// this we emit the following header, and then emit a trailer that pads the
1472 /// file out to be a multiple of 16 bytes.
1474 /// struct bc_header {
1475 /// uint32_t Magic; // 0x0B17C0DE
1476 /// uint32_t Version; // Version, currently always 0.
1477 /// uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1478 /// uint32_t BitcodeSize; // Size of traditional bitcode file.
1479 /// uint32_t CPUType; // CPU specifier.
1480 /// ... potentially more later ...
1483 DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1484 DarwinBCHeaderSize = 5*4
1487 static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1488 const std::string &TT) {
1489 unsigned CPUType = ~0U;
1491 // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*. The CPUType is a
1492 // magic number from /usr/include/mach/machine.h. It is ok to reproduce the
1493 // specific constants here because they are implicitly part of the Darwin ABI.
1495 DARWIN_CPU_ARCH_ABI64 = 0x01000000,
1496 DARWIN_CPU_TYPE_X86 = 7,
1497 DARWIN_CPU_TYPE_POWERPC = 18
1500 if (TT.find("x86_64-") == 0)
1501 CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1502 else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1503 TT[4] == '-' && TT[1] - '3' < 6)
1504 CPUType = DARWIN_CPU_TYPE_X86;
1505 else if (TT.find("powerpc-") == 0)
1506 CPUType = DARWIN_CPU_TYPE_POWERPC;
1507 else if (TT.find("powerpc64-") == 0)
1508 CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1510 // Traditional Bitcode starts after header.
1511 unsigned BCOffset = DarwinBCHeaderSize;
1513 Stream.Emit(0x0B17C0DE, 32);
1514 Stream.Emit(0 , 32); // Version.
1515 Stream.Emit(BCOffset , 32);
1516 Stream.Emit(0 , 32); // Filled in later.
1517 Stream.Emit(CPUType , 32);
1520 /// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1521 /// finalize the header.
1522 static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1523 // Update the size field in the header.
1524 Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1526 // If the file is not a multiple of 16 bytes, insert dummy padding.
1527 while (BufferSize & 15) {
1534 /// WriteBitcodeToFile - Write the specified module to the specified output
1536 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1537 std::vector<unsigned char> Buffer;
1538 BitstreamWriter Stream(Buffer);
1540 Buffer.reserve(256*1024);
1542 WriteBitcodeToStream( M, Stream );
1544 // If writing to stdout, set binary mode.
1545 if (&llvm::outs() == &Out)
1546 sys::Program::ChangeStdoutToBinary();
1548 // Write the generated bitstream to "Out".
1549 Out.write((char*)&Buffer.front(), Buffer.size());
1551 // Make sure it hits disk now.
1555 /// WriteBitcodeToStream - Write the specified module to the specified output
1557 void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1558 // If this is darwin, emit a file header and trailer if needed.
1559 bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1561 EmitDarwinBCHeader(Stream, M->getTargetTriple());
1563 // Emit the file header.
1564 Stream.Emit((unsigned)'B', 8);
1565 Stream.Emit((unsigned)'C', 8);
1566 Stream.Emit(0x0, 4);
1567 Stream.Emit(0xC, 4);
1568 Stream.Emit(0xE, 4);
1569 Stream.Emit(0xD, 4);
1572 WriteModule(M, Stream);
1575 EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());