BitcodeWriter.cpp revision 2f9c3b002d3cb465fefc5f4b2535ca994c5e9283 
1//===--- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ----------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Bitcode writer implementation.
11//
12//===----------------------------------------------------------------------===//
13
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/MDNode.h"
23#include "llvm/Module.h"
24#include "llvm/Operator.h"
25#include "llvm/TypeSymbolTable.h"
26#include "llvm/ValueSymbolTable.h"
27#include "llvm/Support/ErrorHandling.h"
28#include "llvm/Support/MathExtras.h"
29#include "llvm/Support/Streams.h"
30#include "llvm/Support/raw_ostream.h"
31#include "llvm/System/Program.h"
32using namespace llvm;
33
34/// These are manifest constants used by the bitcode writer. They do not need to
35/// be kept in sync with the reader, but need to be consistent within this file.
36enum {
37  CurVersion = 0,
38
39  // VALUE_SYMTAB_BLOCK abbrev id's.
40  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
41  VST_ENTRY_7_ABBREV,
42  VST_ENTRY_6_ABBREV,
43  VST_BBENTRY_6_ABBREV,
44
45  // CONSTANTS_BLOCK abbrev id's.
46  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
47  CONSTANTS_INTEGER_ABBREV,
48  CONSTANTS_CE_CAST_Abbrev,
49  CONSTANTS_NULL_Abbrev,
50
51  // FUNCTION_BLOCK abbrev id's.
52  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
53  FUNCTION_INST_BINOP_ABBREV,
54  FUNCTION_INST_BINOP_FLAGS_ABBREV,
55  FUNCTION_INST_CAST_ABBREV,
56  FUNCTION_INST_RET_VOID_ABBREV,
57  FUNCTION_INST_RET_VAL_ABBREV,
58  FUNCTION_INST_UNREACHABLE_ABBREV
59};
60
61
62static unsigned GetEncodedCastOpcode(unsigned Opcode) {
63  switch (Opcode) {
64  default: llvm_unreachable("Unknown cast instruction!");
65  case Instruction::Trunc   : return bitc::CAST_TRUNC;
66  case Instruction::ZExt    : return bitc::CAST_ZEXT;
67  case Instruction::SExt    : return bitc::CAST_SEXT;
68  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
69  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
70  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
71  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
72  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
73  case Instruction::FPExt   : return bitc::CAST_FPEXT;
74  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
75  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
76  case Instruction::BitCast : return bitc::CAST_BITCAST;
77  }
78}
79
80static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
81  switch (Opcode) {
82  default: llvm_unreachable("Unknown binary instruction!");
83  case Instruction::Add:
84  case Instruction::FAdd: return bitc::BINOP_ADD;
85  case Instruction::Sub:
86  case Instruction::FSub: return bitc::BINOP_SUB;
87  case Instruction::Mul:
88  case Instruction::FMul: return bitc::BINOP_MUL;
89  case Instruction::UDiv: return bitc::BINOP_UDIV;
90  case Instruction::FDiv:
91  case Instruction::SDiv: return bitc::BINOP_SDIV;
92  case Instruction::URem: return bitc::BINOP_UREM;
93  case Instruction::FRem:
94  case Instruction::SRem: return bitc::BINOP_SREM;
95  case Instruction::Shl:  return bitc::BINOP_SHL;
96  case Instruction::LShr: return bitc::BINOP_LSHR;
97  case Instruction::AShr: return bitc::BINOP_ASHR;
98  case Instruction::And:  return bitc::BINOP_AND;
99  case Instruction::Or:   return bitc::BINOP_OR;
100  case Instruction::Xor:  return bitc::BINOP_XOR;
101  }
102}
103
104
105
106static void WriteStringRecord(unsigned Code, const std::string &Str,
107                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
108  SmallVector<unsigned, 64> Vals;
109
110  // Code: [strchar x N]
111  for (unsigned i = 0, e = Str.size(); i != e; ++i)
112    Vals.push_back(Str[i]);
113
114  // Emit the finished record.
115  Stream.EmitRecord(Code, Vals, AbbrevToUse);
116}
117
118// Emit information about parameter attributes.
119static void WriteAttributeTable(const ValueEnumerator &VE,
120                                BitstreamWriter &Stream) {
121  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
122  if (Attrs.empty()) return;
123
124  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
125
126  SmallVector<uint64_t, 64> Record;
127  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
128    const AttrListPtr &A = Attrs[i];
129    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
130      const AttributeWithIndex &PAWI = A.getSlot(i);
131      Record.push_back(PAWI.Index);
132
133      // FIXME: remove in LLVM 3.0
134      // Store the alignment in the bitcode as a 16-bit raw value instead of a
135      // 5-bit log2 encoded value. Shift the bits above the alignment up by
136      // 11 bits.
137      uint64_t FauxAttr = PAWI.Attrs & 0xffff;
138      if (PAWI.Attrs & Attribute::Alignment)
139        FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
140      FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
141
142      Record.push_back(FauxAttr);
143    }
144
145    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
146    Record.clear();
147  }
148
149  Stream.ExitBlock();
150}
151
152/// WriteTypeTable - Write out the type table for a module.
153static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
154  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
155
156  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
157  SmallVector<uint64_t, 64> TypeVals;
158
159  // Abbrev for TYPE_CODE_POINTER.
160  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
161  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
162  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
163                            Log2_32_Ceil(VE.getTypes().size()+1)));
164  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
165  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
166
167  // Abbrev for TYPE_CODE_FUNCTION.
168  Abbv = new BitCodeAbbrev();
169  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
170  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
171  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
172  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
173  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
174                            Log2_32_Ceil(VE.getTypes().size()+1)));
175  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
176
177  // Abbrev for TYPE_CODE_STRUCT.
178  Abbv = new BitCodeAbbrev();
179  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
180  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
181  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
182  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
183                            Log2_32_Ceil(VE.getTypes().size()+1)));
184  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
185
186  // Abbrev for TYPE_CODE_ARRAY.
187  Abbv = new BitCodeAbbrev();
188  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
189  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
190  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
191                            Log2_32_Ceil(VE.getTypes().size()+1)));
192  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
193
194  // Emit an entry count so the reader can reserve space.
195  TypeVals.push_back(TypeList.size());
196  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
197  TypeVals.clear();
198
199  // Loop over all of the types, emitting each in turn.
200  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
201    const Type *T = TypeList[i].first;
202    int AbbrevToUse = 0;
203    unsigned Code = 0;
204
205    switch (T->getTypeID()) {
206    default: llvm_unreachable("Unknown type!");
207    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
208    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
209    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
210    case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
211    case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
212    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
213    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
214    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
215    case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
216    case Type::IntegerTyID:
217      // INTEGER: [width]
218      Code = bitc::TYPE_CODE_INTEGER;
219      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
220      break;
221    case Type::PointerTyID: {
222      const PointerType *PTy = cast<PointerType>(T);
223      // POINTER: [pointee type, address space]
224      Code = bitc::TYPE_CODE_POINTER;
225      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
226      unsigned AddressSpace = PTy->getAddressSpace();
227      TypeVals.push_back(AddressSpace);
228      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
229      break;
230    }
231    case Type::FunctionTyID: {
232      const FunctionType *FT = cast<FunctionType>(T);
233      // FUNCTION: [isvararg, attrid, retty, paramty x N]
234      Code = bitc::TYPE_CODE_FUNCTION;
235      TypeVals.push_back(FT->isVarArg());
236      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
237      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
238      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
239        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
240      AbbrevToUse = FunctionAbbrev;
241      break;
242    }
243    case Type::StructTyID: {
244      const StructType *ST = cast<StructType>(T);
245      // STRUCT: [ispacked, eltty x N]
246      Code = bitc::TYPE_CODE_STRUCT;
247      TypeVals.push_back(ST->isPacked());
248      // Output all of the element types.
249      for (StructType::element_iterator I = ST->element_begin(),
250           E = ST->element_end(); I != E; ++I)
251        TypeVals.push_back(VE.getTypeID(*I));
252      AbbrevToUse = StructAbbrev;
253      break;
254    }
255    case Type::ArrayTyID: {
256      const ArrayType *AT = cast<ArrayType>(T);
257      // ARRAY: [numelts, eltty]
258      Code = bitc::TYPE_CODE_ARRAY;
259      TypeVals.push_back(AT->getNumElements());
260      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
261      AbbrevToUse = ArrayAbbrev;
262      break;
263    }
264    case Type::VectorTyID: {
265      const VectorType *VT = cast<VectorType>(T);
266      // VECTOR [numelts, eltty]
267      Code = bitc::TYPE_CODE_VECTOR;
268      TypeVals.push_back(VT->getNumElements());
269      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
270      break;
271    }
272    }
273
274    // Emit the finished record.
275    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
276    TypeVals.clear();
277  }
278
279  Stream.ExitBlock();
280}
281
282static unsigned getEncodedLinkage(const GlobalValue *GV) {
283  switch (GV->getLinkage()) {
284  default: llvm_unreachable("Invalid linkage!");
285  case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
286  case GlobalValue::ExternalLinkage:            return 0;
287  case GlobalValue::WeakAnyLinkage:             return 1;
288  case GlobalValue::AppendingLinkage:           return 2;
289  case GlobalValue::InternalLinkage:            return 3;
290  case GlobalValue::LinkOnceAnyLinkage:         return 4;
291  case GlobalValue::DLLImportLinkage:           return 5;
292  case GlobalValue::DLLExportLinkage:           return 6;
293  case GlobalValue::ExternalWeakLinkage:        return 7;
294  case GlobalValue::CommonLinkage:              return 8;
295  case GlobalValue::PrivateLinkage:             return 9;
296  case GlobalValue::WeakODRLinkage:             return 10;
297  case GlobalValue::LinkOnceODRLinkage:         return 11;
298  case GlobalValue::AvailableExternallyLinkage: return 12;
299  case GlobalValue::LinkerPrivateLinkage:       return 13;
300  }
301}
302
303static unsigned getEncodedVisibility(const GlobalValue *GV) {
304  switch (GV->getVisibility()) {
305  default: llvm_unreachable("Invalid visibility!");
306  case GlobalValue::DefaultVisibility:   return 0;
307  case GlobalValue::HiddenVisibility:    return 1;
308  case GlobalValue::ProtectedVisibility: return 2;
309  }
310}
311
312// Emit top-level description of module, including target triple, inline asm,
313// descriptors for global variables, and function prototype info.
314static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
315                            BitstreamWriter &Stream) {
316  // Emit the list of dependent libraries for the Module.
317  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
318    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
319
320  // Emit various pieces of data attached to a module.
321  if (!M->getTargetTriple().empty())
322    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
323                      0/*TODO*/, Stream);
324  if (!M->getDataLayout().empty())
325    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
326                      0/*TODO*/, Stream);
327  if (!M->getModuleInlineAsm().empty())
328    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
329                      0/*TODO*/, Stream);
330
331  // Emit information about sections and GC, computing how many there are. Also
332  // compute the maximum alignment value.
333  std::map<std::string, unsigned> SectionMap;
334  std::map<std::string, unsigned> GCMap;
335  unsigned MaxAlignment = 0;
336  unsigned MaxGlobalType = 0;
337  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
338       GV != E; ++GV) {
339    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
340    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
341
342    if (!GV->hasSection()) continue;
343    // Give section names unique ID's.
344    unsigned &Entry = SectionMap[GV->getSection()];
345    if (Entry != 0) continue;
346    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
347                      0/*TODO*/, Stream);
348    Entry = SectionMap.size();
349  }
350  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
351    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
352    if (F->hasSection()) {
353      // Give section names unique ID's.
354      unsigned &Entry = SectionMap[F->getSection()];
355      if (!Entry) {
356        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
357                          0/*TODO*/, Stream);
358        Entry = SectionMap.size();
359      }
360    }
361    if (F->hasGC()) {
362      // Same for GC names.
363      unsigned &Entry = GCMap[F->getGC()];
364      if (!Entry) {
365        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
366                          0/*TODO*/, Stream);
367        Entry = GCMap.size();
368      }
369    }
370  }
371
372  // Emit abbrev for globals, now that we know # sections and max alignment.
373  unsigned SimpleGVarAbbrev = 0;
374  if (!M->global_empty()) {
375    // Add an abbrev for common globals with no visibility or thread localness.
376    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
377    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
378    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
379                              Log2_32_Ceil(MaxGlobalType+1)));
380    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
381    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
382    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
383    if (MaxAlignment == 0)                                      // Alignment.
384      Abbv->Add(BitCodeAbbrevOp(0));
385    else {
386      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
387      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
388                               Log2_32_Ceil(MaxEncAlignment+1)));
389    }
390    if (SectionMap.empty())                                    // Section.
391      Abbv->Add(BitCodeAbbrevOp(0));
392    else
393      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
394                               Log2_32_Ceil(SectionMap.size()+1)));
395    // Don't bother emitting vis + thread local.
396    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
397  }
398
399  // Emit the global variable information.
400  SmallVector<unsigned, 64> Vals;
401  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
402       GV != E; ++GV) {
403    unsigned AbbrevToUse = 0;
404
405    // GLOBALVAR: [type, isconst, initid,
406    //             linkage, alignment, section, visibility, threadlocal]
407    Vals.push_back(VE.getTypeID(GV->getType()));
408    Vals.push_back(GV->isConstant());
409    Vals.push_back(GV->isDeclaration() ? 0 :
410                   (VE.getValueID(GV->getInitializer()) + 1));
411    Vals.push_back(getEncodedLinkage(GV));
412    Vals.push_back(Log2_32(GV->getAlignment())+1);
413    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
414    if (GV->isThreadLocal() ||
415        GV->getVisibility() != GlobalValue::DefaultVisibility) {
416      Vals.push_back(getEncodedVisibility(GV));
417      Vals.push_back(GV->isThreadLocal());
418    } else {
419      AbbrevToUse = SimpleGVarAbbrev;
420    }
421
422    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
423    Vals.clear();
424  }
425
426  // Emit the function proto information.
427  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
428    // FUNCTION:  [type, callingconv, isproto, paramattr,
429    //             linkage, alignment, section, visibility, gc]
430    Vals.push_back(VE.getTypeID(F->getType()));
431    Vals.push_back(F->getCallingConv());
432    Vals.push_back(F->isDeclaration());
433    Vals.push_back(getEncodedLinkage(F));
434    Vals.push_back(VE.getAttributeID(F->getAttributes()));
435    Vals.push_back(Log2_32(F->getAlignment())+1);
436    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
437    Vals.push_back(getEncodedVisibility(F));
438    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
439
440    unsigned AbbrevToUse = 0;
441    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
442    Vals.clear();
443  }
444
445
446  // Emit the alias information.
447  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
448       AI != E; ++AI) {
449    Vals.push_back(VE.getTypeID(AI->getType()));
450    Vals.push_back(VE.getValueID(AI->getAliasee()));
451    Vals.push_back(getEncodedLinkage(AI));
452    Vals.push_back(getEncodedVisibility(AI));
453    unsigned AbbrevToUse = 0;
454    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
455    Vals.clear();
456  }
457}
458
459static uint64_t GetOptimizationFlags(const Value *V) {
460  uint64_t Flags = 0;
461
462  if (const OverflowingBinaryOperator *OBO =
463        dyn_cast<OverflowingBinaryOperator>(V)) {
464    if (OBO->hasNoSignedOverflow())
465      Flags |= 1 << bitc::OBO_NO_SIGNED_OVERFLOW;
466    if (OBO->hasNoUnsignedOverflow())
467      Flags |= 1 << bitc::OBO_NO_UNSIGNED_OVERFLOW;
468  } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
469    if (Div->isExact())
470      Flags |= 1 << bitc::SDIV_EXACT;
471  }
472
473  return Flags;
474}
475
476 static void WriteModuleMetadata(const ValueEnumerator &VE,
477                                 BitstreamWriter &Stream) {
478   const ValueEnumerator::ValueList &Vals = VE.getValues();
479   bool StartedMetadataBlock = false;
480   unsigned MDSAbbrev = 0;
481   SmallVector<uint64_t, 64> Record;
482   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
483
484     if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
485       if (!StartedMetadataBlock) {
486         Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
487         StartedMetadataBlock = true;
488       }
489      for (unsigned i = 0, e = N->getNumElements(); i != e; ++i) {
490        if (N->getElement(i)) {
491          Record.push_back(VE.getTypeID(N->getElement(i)->getType()));
492          Record.push_back(VE.getValueID(N->getElement(i)));
493        } else {
494          Record.push_back(VE.getTypeID(Type::VoidTy));
495          Record.push_back(0);
496        }
497      }
498      Stream.EmitRecord(bitc::METADATA_NODE, Record, 0);
499      Record.clear();
500     } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
501       if (!StartedMetadataBlock)  {
502        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
503
504        // Abbrev for METADATA_STRING.
505        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
506        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
507        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
508        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
509        MDSAbbrev = Stream.EmitAbbrev(Abbv);
510        StartedMetadataBlock = true;
511       }
512
513       // Code: [strchar x N]
514       const char *StrBegin = MDS->begin();
515       for (unsigned i = 0, e = MDS->length(); i != e; ++i)
516        Record.push_back(StrBegin[i]);
517
518       // Emit the finished record.
519      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
520      Record.clear();
521     }
522   }
523
524   if (StartedMetadataBlock)
525     Stream.ExitBlock();
526}
527
528
529static void WriteConstants(unsigned FirstVal, unsigned LastVal,
530                           const ValueEnumerator &VE,
531                           BitstreamWriter &Stream, bool isGlobal) {
532  if (FirstVal == LastVal) return;
533
534  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
535
536  unsigned AggregateAbbrev = 0;
537  unsigned String8Abbrev = 0;
538  unsigned CString7Abbrev = 0;
539  unsigned CString6Abbrev = 0;
540  // If this is a constant pool for the module, emit module-specific abbrevs.
541  if (isGlobal) {
542    // Abbrev for CST_CODE_AGGREGATE.
543    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
544    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
545    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
546    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
547    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
548
549    // Abbrev for CST_CODE_STRING.
550    Abbv = new BitCodeAbbrev();
551    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
552    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
553    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
554    String8Abbrev = Stream.EmitAbbrev(Abbv);
555    // Abbrev for CST_CODE_CSTRING.
556    Abbv = new BitCodeAbbrev();
557    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
558    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
559    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
560    CString7Abbrev = Stream.EmitAbbrev(Abbv);
561    // Abbrev for CST_CODE_CSTRING.
562    Abbv = new BitCodeAbbrev();
563    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
564    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
565    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
566    CString6Abbrev = Stream.EmitAbbrev(Abbv);
567  }
568
569  SmallVector<uint64_t, 64> Record;
570
571  const ValueEnumerator::ValueList &Vals = VE.getValues();
572  const Type *LastTy = 0;
573  for (unsigned i = FirstVal; i != LastVal; ++i) {
574    const Value *V = Vals[i].first;
575    if (isa<MDString>(V) || isa<MDNode>(V))
576      continue;
577    // If we need to switch types, do so now.
578    if (V->getType() != LastTy) {
579      LastTy = V->getType();
580      Record.push_back(VE.getTypeID(LastTy));
581      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
582                        CONSTANTS_SETTYPE_ABBREV);
583      Record.clear();
584    }
585
586    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
587      Record.push_back(unsigned(IA->hasSideEffects()));
588
589      // Add the asm string.
590      const std::string &AsmStr = IA->getAsmString();
591      Record.push_back(AsmStr.size());
592      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
593        Record.push_back(AsmStr[i]);
594
595      // Add the constraint string.
596      const std::string &ConstraintStr = IA->getConstraintString();
597      Record.push_back(ConstraintStr.size());
598      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
599        Record.push_back(ConstraintStr[i]);
600      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
601      Record.clear();
602      continue;
603    }
604    const Constant *C = cast<Constant>(V);
605    unsigned Code = -1U;
606    unsigned AbbrevToUse = 0;
607    if (C->isNullValue()) {
608      Code = bitc::CST_CODE_NULL;
609    } else if (isa<UndefValue>(C)) {
610      Code = bitc::CST_CODE_UNDEF;
611    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
612      if (IV->getBitWidth() <= 64) {
613        int64_t V = IV->getSExtValue();
614        if (V >= 0)
615          Record.push_back(V << 1);
616        else
617          Record.push_back((-V << 1) | 1);
618        Code = bitc::CST_CODE_INTEGER;
619        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
620      } else {                             // Wide integers, > 64 bits in size.
621        // We have an arbitrary precision integer value to write whose
622        // bit width is > 64. However, in canonical unsigned integer
623        // format it is likely that the high bits are going to be zero.
624        // So, we only write the number of active words.
625        unsigned NWords = IV->getValue().getActiveWords();
626        const uint64_t *RawWords = IV->getValue().getRawData();
627        for (unsigned i = 0; i != NWords; ++i) {
628          int64_t V = RawWords[i];
629          if (V >= 0)
630            Record.push_back(V << 1);
631          else
632            Record.push_back((-V << 1) | 1);
633        }
634        Code = bitc::CST_CODE_WIDE_INTEGER;
635      }
636    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
637      Code = bitc::CST_CODE_FLOAT;
638      const Type *Ty = CFP->getType();
639      if (Ty == Type::FloatTy || Ty == Type::DoubleTy) {
640        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
641      } else if (Ty == Type::X86_FP80Ty) {
642        // api needed to prevent premature destruction
643        // bits are not in the same order as a normal i80 APInt, compensate.
644        APInt api = CFP->getValueAPF().bitcastToAPInt();
645        const uint64_t *p = api.getRawData();
646        Record.push_back((p[1] << 48) | (p[0] >> 16));
647        Record.push_back(p[0] & 0xffffLL);
648      } else if (Ty == Type::FP128Ty || Ty == Type::PPC_FP128Ty) {
649        APInt api = CFP->getValueAPF().bitcastToAPInt();
650        const uint64_t *p = api.getRawData();
651        Record.push_back(p[0]);
652        Record.push_back(p[1]);
653      } else {
654        assert (0 && "Unknown FP type!");
655      }
656    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
657      // Emit constant strings specially.
658      unsigned NumOps = C->getNumOperands();
659      // If this is a null-terminated string, use the denser CSTRING encoding.
660      if (C->getOperand(NumOps-1)->isNullValue()) {
661        Code = bitc::CST_CODE_CSTRING;
662        --NumOps;  // Don't encode the null, which isn't allowed by char6.
663      } else {
664        Code = bitc::CST_CODE_STRING;
665        AbbrevToUse = String8Abbrev;
666      }
667      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
668      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
669      for (unsigned i = 0; i != NumOps; ++i) {
670        unsigned char V = cast<ConstantInt>(C->getOperand(i))->getZExtValue();
671        Record.push_back(V);
672        isCStr7 &= (V & 128) == 0;
673        if (isCStrChar6)
674          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
675      }
676
677      if (isCStrChar6)
678        AbbrevToUse = CString6Abbrev;
679      else if (isCStr7)
680        AbbrevToUse = CString7Abbrev;
681    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
682               isa<ConstantVector>(V)) {
683      Code = bitc::CST_CODE_AGGREGATE;
684      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
685        Record.push_back(VE.getValueID(C->getOperand(i)));
686      AbbrevToUse = AggregateAbbrev;
687    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
688      switch (CE->getOpcode()) {
689      default:
690        if (Instruction::isCast(CE->getOpcode())) {
691          Code = bitc::CST_CODE_CE_CAST;
692          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
693          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
694          Record.push_back(VE.getValueID(C->getOperand(0)));
695          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
696        } else {
697          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
698          Code = bitc::CST_CODE_CE_BINOP;
699          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
700          Record.push_back(VE.getValueID(C->getOperand(0)));
701          Record.push_back(VE.getValueID(C->getOperand(1)));
702          uint64_t Flags = GetOptimizationFlags(CE);
703          if (Flags != 0)
704            Record.push_back(Flags);
705        }
706        break;
707      case Instruction::GetElementPtr:
708        Code = bitc::CST_CODE_CE_GEP;
709        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
710          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
711          Record.push_back(VE.getValueID(C->getOperand(i)));
712        }
713        break;
714      case Instruction::Select:
715        Code = bitc::CST_CODE_CE_SELECT;
716        Record.push_back(VE.getValueID(C->getOperand(0)));
717        Record.push_back(VE.getValueID(C->getOperand(1)));
718        Record.push_back(VE.getValueID(C->getOperand(2)));
719        break;
720      case Instruction::ExtractElement:
721        Code = bitc::CST_CODE_CE_EXTRACTELT;
722        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
723        Record.push_back(VE.getValueID(C->getOperand(0)));
724        Record.push_back(VE.getValueID(C->getOperand(1)));
725        break;
726      case Instruction::InsertElement:
727        Code = bitc::CST_CODE_CE_INSERTELT;
728        Record.push_back(VE.getValueID(C->getOperand(0)));
729        Record.push_back(VE.getValueID(C->getOperand(1)));
730        Record.push_back(VE.getValueID(C->getOperand(2)));
731        break;
732      case Instruction::ShuffleVector:
733        // If the return type and argument types are the same, this is a
734        // standard shufflevector instruction.  If the types are different,
735        // then the shuffle is widening or truncating the input vectors, and
736        // the argument type must also be encoded.
737        if (C->getType() == C->getOperand(0)->getType()) {
738          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
739        } else {
740          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
741          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
742        }
743        Record.push_back(VE.getValueID(C->getOperand(0)));
744        Record.push_back(VE.getValueID(C->getOperand(1)));
745        Record.push_back(VE.getValueID(C->getOperand(2)));
746        break;
747      case Instruction::ICmp:
748      case Instruction::FCmp:
749        Code = bitc::CST_CODE_CE_CMP;
750        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
751        Record.push_back(VE.getValueID(C->getOperand(0)));
752        Record.push_back(VE.getValueID(C->getOperand(1)));
753        Record.push_back(CE->getPredicate());
754        break;
755      }
756    } else {
757      llvm_unreachable("Unknown constant!");
758    }
759    Stream.EmitRecord(Code, Record, AbbrevToUse);
760    Record.clear();
761  }
762
763  Stream.ExitBlock();
764}
765
766static void WriteModuleConstants(const ValueEnumerator &VE,
767                                 BitstreamWriter &Stream) {
768  const ValueEnumerator::ValueList &Vals = VE.getValues();
769
770  // Find the first constant to emit, which is the first non-globalvalue value.
771  // We know globalvalues have been emitted by WriteModuleInfo.
772  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
773    if (!isa<GlobalValue>(Vals[i].first)) {
774      WriteConstants(i, Vals.size(), VE, Stream, true);
775      return;
776    }
777  }
778}
779
780/// PushValueAndType - The file has to encode both the value and type id for
781/// many values, because we need to know what type to create for forward
782/// references.  However, most operands are not forward references, so this type
783/// field is not needed.
784///
785/// This function adds V's value ID to Vals.  If the value ID is higher than the
786/// instruction ID, then it is a forward reference, and it also includes the
787/// type ID.
788static bool PushValueAndType(const Value *V, unsigned InstID,
789                             SmallVector<unsigned, 64> &Vals,
790                             ValueEnumerator &VE) {
791  unsigned ValID = VE.getValueID(V);
792  Vals.push_back(ValID);
793  if (ValID >= InstID) {
794    Vals.push_back(VE.getTypeID(V->getType()));
795    return true;
796  }
797  return false;
798}
799
800/// WriteInstruction - Emit an instruction to the specified stream.
801static void WriteInstruction(const Instruction &I, unsigned InstID,
802                             ValueEnumerator &VE, BitstreamWriter &Stream,
803                             SmallVector<unsigned, 64> &Vals) {
804  unsigned Code = 0;
805  unsigned AbbrevToUse = 0;
806  switch (I.getOpcode()) {
807  default:
808    if (Instruction::isCast(I.getOpcode())) {
809      Code = bitc::FUNC_CODE_INST_CAST;
810      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
811        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
812      Vals.push_back(VE.getTypeID(I.getType()));
813      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
814    } else {
815      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
816      Code = bitc::FUNC_CODE_INST_BINOP;
817      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
818        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
819      Vals.push_back(VE.getValueID(I.getOperand(1)));
820      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
821      uint64_t Flags = GetOptimizationFlags(&I);
822      if (Flags != 0) {
823        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
824          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
825        Vals.push_back(Flags);
826      }
827    }
828    break;
829
830  case Instruction::GetElementPtr:
831    Code = bitc::FUNC_CODE_INST_GEP;
832    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
833      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
834    break;
835  case Instruction::ExtractValue: {
836    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
837    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
838    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
839    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
840      Vals.push_back(*i);
841    break;
842  }
843  case Instruction::InsertValue: {
844    Code = bitc::FUNC_CODE_INST_INSERTVAL;
845    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
846    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
847    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
848    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
849      Vals.push_back(*i);
850    break;
851  }
852  case Instruction::Select:
853    Code = bitc::FUNC_CODE_INST_VSELECT;
854    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
855    Vals.push_back(VE.getValueID(I.getOperand(2)));
856    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
857    break;
858  case Instruction::ExtractElement:
859    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
860    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
861    Vals.push_back(VE.getValueID(I.getOperand(1)));
862    break;
863  case Instruction::InsertElement:
864    Code = bitc::FUNC_CODE_INST_INSERTELT;
865    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
866    Vals.push_back(VE.getValueID(I.getOperand(1)));
867    Vals.push_back(VE.getValueID(I.getOperand(2)));
868    break;
869  case Instruction::ShuffleVector:
870    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
871    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
872    Vals.push_back(VE.getValueID(I.getOperand(1)));
873    Vals.push_back(VE.getValueID(I.getOperand(2)));
874    break;
875  case Instruction::ICmp:
876  case Instruction::FCmp:
877    // compare returning Int1Ty or vector of Int1Ty
878    Code = bitc::FUNC_CODE_INST_CMP2;
879    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
880    Vals.push_back(VE.getValueID(I.getOperand(1)));
881    Vals.push_back(cast<CmpInst>(I).getPredicate());
882    break;
883
884  case Instruction::Ret:
885    {
886      Code = bitc::FUNC_CODE_INST_RET;
887      unsigned NumOperands = I.getNumOperands();
888      if (NumOperands == 0)
889        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
890      else if (NumOperands == 1) {
891        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
892          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
893      } else {
894        for (unsigned i = 0, e = NumOperands; i != e; ++i)
895          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
896      }
897    }
898    break;
899  case Instruction::Br:
900    {
901      Code = bitc::FUNC_CODE_INST_BR;
902      BranchInst &II(cast<BranchInst>(I));
903      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
904      if (II.isConditional()) {
905        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
906        Vals.push_back(VE.getValueID(II.getCondition()));
907      }
908    }
909    break;
910  case Instruction::Switch:
911    Code = bitc::FUNC_CODE_INST_SWITCH;
912    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
913    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
914      Vals.push_back(VE.getValueID(I.getOperand(i)));
915    break;
916  case Instruction::Invoke: {
917    const InvokeInst *II = cast<InvokeInst>(&I);
918    const Value *Callee(II->getCalledValue());
919    const PointerType *PTy = cast<PointerType>(Callee->getType());
920    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
921    Code = bitc::FUNC_CODE_INST_INVOKE;
922
923    Vals.push_back(VE.getAttributeID(II->getAttributes()));
924    Vals.push_back(II->getCallingConv());
925    Vals.push_back(VE.getValueID(II->getNormalDest()));
926    Vals.push_back(VE.getValueID(II->getUnwindDest()));
927    PushValueAndType(Callee, InstID, Vals, VE);
928
929    // Emit value #'s for the fixed parameters.
930    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
931      Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
932
933    // Emit type/value pairs for varargs params.
934    if (FTy->isVarArg()) {
935      for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
936           i != e; ++i)
937        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
938    }
939    break;
940  }
941  case Instruction::Unwind:
942    Code = bitc::FUNC_CODE_INST_UNWIND;
943    break;
944  case Instruction::Unreachable:
945    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
946    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
947    break;
948
949  case Instruction::PHI:
950    Code = bitc::FUNC_CODE_INST_PHI;
951    Vals.push_back(VE.getTypeID(I.getType()));
952    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
953      Vals.push_back(VE.getValueID(I.getOperand(i)));
954    break;
955
956  case Instruction::Malloc:
957    Code = bitc::FUNC_CODE_INST_MALLOC;
958    Vals.push_back(VE.getTypeID(I.getType()));
959    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
960    Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
961    break;
962
963  case Instruction::Free:
964    Code = bitc::FUNC_CODE_INST_FREE;
965    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
966    break;
967
968  case Instruction::Alloca:
969    Code = bitc::FUNC_CODE_INST_ALLOCA;
970    Vals.push_back(VE.getTypeID(I.getType()));
971    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
972    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
973    break;
974
975  case Instruction::Load:
976    Code = bitc::FUNC_CODE_INST_LOAD;
977    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
978      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
979
980    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
981    Vals.push_back(cast<LoadInst>(I).isVolatile());
982    break;
983  case Instruction::Store:
984    Code = bitc::FUNC_CODE_INST_STORE2;
985    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
986    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
987    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
988    Vals.push_back(cast<StoreInst>(I).isVolatile());
989    break;
990  case Instruction::Call: {
991    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
992    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
993
994    Code = bitc::FUNC_CODE_INST_CALL;
995
996    const CallInst *CI = cast<CallInst>(&I);
997    Vals.push_back(VE.getAttributeID(CI->getAttributes()));
998    Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
999    PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
1000
1001    // Emit value #'s for the fixed parameters.
1002    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1003      Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
1004
1005    // Emit type/value pairs for varargs params.
1006    if (FTy->isVarArg()) {
1007      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
1008      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
1009           i != e; ++i)
1010        PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
1011    }
1012    break;
1013  }
1014  case Instruction::VAArg:
1015    Code = bitc::FUNC_CODE_INST_VAARG;
1016    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1017    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1018    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1019    break;
1020  }
1021
1022  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1023  Vals.clear();
1024}
1025
1026// Emit names for globals/functions etc.
1027static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1028                                  const ValueEnumerator &VE,
1029                                  BitstreamWriter &Stream) {
1030  if (VST.empty()) return;
1031  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1032
1033  // FIXME: Set up the abbrev, we know how many values there are!
1034  // FIXME: We know if the type names can use 7-bit ascii.
1035  SmallVector<unsigned, 64> NameVals;
1036
1037  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1038       SI != SE; ++SI) {
1039
1040    const ValueName &Name = *SI;
1041
1042    // Figure out the encoding to use for the name.
1043    bool is7Bit = true;
1044    bool isChar6 = true;
1045    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1046         C != E; ++C) {
1047      if (isChar6)
1048        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1049      if ((unsigned char)*C & 128) {
1050        is7Bit = false;
1051        break;  // don't bother scanning the rest.
1052      }
1053    }
1054
1055    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1056
1057    // VST_ENTRY:   [valueid, namechar x N]
1058    // VST_BBENTRY: [bbid, namechar x N]
1059    unsigned Code;
1060    if (isa<BasicBlock>(SI->getValue())) {
1061      Code = bitc::VST_CODE_BBENTRY;
1062      if (isChar6)
1063        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1064    } else {
1065      Code = bitc::VST_CODE_ENTRY;
1066      if (isChar6)
1067        AbbrevToUse = VST_ENTRY_6_ABBREV;
1068      else if (is7Bit)
1069        AbbrevToUse = VST_ENTRY_7_ABBREV;
1070    }
1071
1072    NameVals.push_back(VE.getValueID(SI->getValue()));
1073    for (const char *P = Name.getKeyData(),
1074         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1075      NameVals.push_back((unsigned char)*P);
1076
1077    // Emit the finished record.
1078    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1079    NameVals.clear();
1080  }
1081  Stream.ExitBlock();
1082}
1083
1084/// WriteFunction - Emit a function body to the module stream.
1085static void WriteFunction(const Function &F, ValueEnumerator &VE,
1086                          BitstreamWriter &Stream) {
1087  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1088  VE.incorporateFunction(F);
1089
1090  SmallVector<unsigned, 64> Vals;
1091
1092  // Emit the number of basic blocks, so the reader can create them ahead of
1093  // time.
1094  Vals.push_back(VE.getBasicBlocks().size());
1095  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1096  Vals.clear();
1097
1098  // If there are function-local constants, emit them now.
1099  unsigned CstStart, CstEnd;
1100  VE.getFunctionConstantRange(CstStart, CstEnd);
1101  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1102
1103  // Keep a running idea of what the instruction ID is.
1104  unsigned InstID = CstEnd;
1105
1106  // Finally, emit all the instructions, in order.
1107  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1108    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1109         I != E; ++I) {
1110      WriteInstruction(*I, InstID, VE, Stream, Vals);
1111      if (I->getType() != Type::VoidTy)
1112        ++InstID;
1113    }
1114
1115  // Emit names for all the instructions etc.
1116  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1117
1118  VE.purgeFunction();
1119  Stream.ExitBlock();
1120}
1121
1122/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1123static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1124                                 const ValueEnumerator &VE,
1125                                 BitstreamWriter &Stream) {
1126  if (TST.empty()) return;
1127
1128  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1129
1130  // 7-bit fixed width VST_CODE_ENTRY strings.
1131  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1132  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1133  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1134                            Log2_32_Ceil(VE.getTypes().size()+1)));
1135  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1136  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1137  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1138
1139  SmallVector<unsigned, 64> NameVals;
1140
1141  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1142       TI != TE; ++TI) {
1143    // TST_ENTRY: [typeid, namechar x N]
1144    NameVals.push_back(VE.getTypeID(TI->second));
1145
1146    const std::string &Str = TI->first;
1147    bool is7Bit = true;
1148    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1149      NameVals.push_back((unsigned char)Str[i]);
1150      if (Str[i] & 128)
1151        is7Bit = false;
1152    }
1153
1154    // Emit the finished record.
1155    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1156    NameVals.clear();
1157  }
1158
1159  Stream.ExitBlock();
1160}
1161
1162// Emit blockinfo, which defines the standard abbreviations etc.
1163static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1164  // We only want to emit block info records for blocks that have multiple
1165  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1166  // blocks can defined their abbrevs inline.
1167  Stream.EnterBlockInfoBlock(2);
1168
1169  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1170    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1171    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1172    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1173    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1174    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1175    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1176                                   Abbv) != VST_ENTRY_8_ABBREV)
1177      llvm_unreachable("Unexpected abbrev ordering!");
1178  }
1179
1180  { // 7-bit fixed width VST_ENTRY strings.
1181    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1182    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1183    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1184    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1185    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1186    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1187                                   Abbv) != VST_ENTRY_7_ABBREV)
1188      llvm_unreachable("Unexpected abbrev ordering!");
1189  }
1190  { // 6-bit char6 VST_ENTRY strings.
1191    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1192    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1193    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1194    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1195    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1196    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1197                                   Abbv) != VST_ENTRY_6_ABBREV)
1198      llvm_unreachable("Unexpected abbrev ordering!");
1199  }
1200  { // 6-bit char6 VST_BBENTRY strings.
1201    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1202    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1203    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1204    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1205    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1206    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1207                                   Abbv) != VST_BBENTRY_6_ABBREV)
1208      llvm_unreachable("Unexpected abbrev ordering!");
1209  }
1210
1211
1212
1213  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1214    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1215    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1216    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1217                              Log2_32_Ceil(VE.getTypes().size()+1)));
1218    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1219                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1220      llvm_unreachable("Unexpected abbrev ordering!");
1221  }
1222
1223  { // INTEGER abbrev for CONSTANTS_BLOCK.
1224    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1225    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1226    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1227    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1228                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1229      llvm_unreachable("Unexpected abbrev ordering!");
1230  }
1231
1232  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1233    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1234    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1235    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1236    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1237                              Log2_32_Ceil(VE.getTypes().size()+1)));
1238    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1239
1240    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1241                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1242      llvm_unreachable("Unexpected abbrev ordering!");
1243  }
1244  { // NULL abbrev for CONSTANTS_BLOCK.
1245    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1246    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1247    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1248                                   Abbv) != CONSTANTS_NULL_Abbrev)
1249      llvm_unreachable("Unexpected abbrev ordering!");
1250  }
1251
1252  // FIXME: This should only use space for first class types!
1253
1254  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1255    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1256    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1257    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1258    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1259    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1260    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1261                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1262      llvm_unreachable("Unexpected abbrev ordering!");
1263  }
1264  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1265    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1266    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1267    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1268    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1269    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1270    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1271                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1272      llvm_unreachable("Unexpected abbrev ordering!");
1273  }
1274  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1275    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1276    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1277    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1278    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1279    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1280    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1281    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1282                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1283      llvm_unreachable("Unexpected abbrev ordering!");
1284  }
1285  { // INST_CAST abbrev for FUNCTION_BLOCK.
1286    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1287    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1288    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1289    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1290                              Log2_32_Ceil(VE.getTypes().size()+1)));
1291    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1292    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1293                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1294      llvm_unreachable("Unexpected abbrev ordering!");
1295  }
1296
1297  { // INST_RET abbrev for FUNCTION_BLOCK.
1298    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1299    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1300    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1301                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1302      llvm_unreachable("Unexpected abbrev ordering!");
1303  }
1304  { // INST_RET abbrev for FUNCTION_BLOCK.
1305    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1306    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1307    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1308    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1309                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1310      llvm_unreachable("Unexpected abbrev ordering!");
1311  }
1312  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1313    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1314    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1315    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1316                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1317      llvm_unreachable("Unexpected abbrev ordering!");
1318  }
1319
1320  Stream.ExitBlock();
1321}
1322
1323
1324/// WriteModule - Emit the specified module to the bitstream.
1325static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1326  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1327
1328  // Emit the version number if it is non-zero.
1329  if (CurVersion) {
1330    SmallVector<unsigned, 1> Vals;
1331    Vals.push_back(CurVersion);
1332    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1333  }
1334
1335  // Analyze the module, enumerating globals, functions, etc.
1336  ValueEnumerator VE(M);
1337
1338  // Emit blockinfo, which defines the standard abbreviations etc.
1339  WriteBlockInfo(VE, Stream);
1340
1341  // Emit information about parameter attributes.
1342  WriteAttributeTable(VE, Stream);
1343
1344  // Emit information describing all of the types in the module.
1345  WriteTypeTable(VE, Stream);
1346
1347  // Emit top-level description of module, including target triple, inline asm,
1348  // descriptors for global variables, and function prototype info.
1349  WriteModuleInfo(M, VE, Stream);
1350
1351  // Emit constants.
1352  WriteModuleConstants(VE, Stream);
1353
1354  // Emit metadata.
1355  WriteModuleMetadata(VE, Stream);
1356
1357  // Emit function bodies.
1358  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1359    if (!I->isDeclaration())
1360      WriteFunction(*I, VE, Stream);
1361
1362  // Emit the type symbol table information.
1363  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1364
1365  // Emit names for globals/functions etc.
1366  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1367
1368  Stream.ExitBlock();
1369}
1370
1371/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1372/// header and trailer to make it compatible with the system archiver.  To do
1373/// this we emit the following header, and then emit a trailer that pads the
1374/// file out to be a multiple of 16 bytes.
1375///
1376/// struct bc_header {
1377///   uint32_t Magic;         // 0x0B17C0DE
1378///   uint32_t Version;       // Version, currently always 0.
1379///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1380///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1381///   uint32_t CPUType;       // CPU specifier.
1382///   ... potentially more later ...
1383/// };
1384enum {
1385  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1386  DarwinBCHeaderSize = 5*4
1387};
1388
1389static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1390                               const std::string &TT) {
1391  unsigned CPUType = ~0U;
1392
1393  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*.  The CPUType is a
1394  // magic number from /usr/include/mach/machine.h.  It is ok to reproduce the
1395  // specific constants here because they are implicitly part of the Darwin ABI.
1396  enum {
1397    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1398    DARWIN_CPU_TYPE_X86        = 7,
1399    DARWIN_CPU_TYPE_POWERPC    = 18
1400  };
1401
1402  if (TT.find("x86_64-") == 0)
1403    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1404  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1405           TT[4] == '-' && TT[1] - '3' < 6)
1406    CPUType = DARWIN_CPU_TYPE_X86;
1407  else if (TT.find("powerpc-") == 0)
1408    CPUType = DARWIN_CPU_TYPE_POWERPC;
1409  else if (TT.find("powerpc64-") == 0)
1410    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1411
1412  // Traditional Bitcode starts after header.
1413  unsigned BCOffset = DarwinBCHeaderSize;
1414
1415  Stream.Emit(0x0B17C0DE, 32);
1416  Stream.Emit(0         , 32);  // Version.
1417  Stream.Emit(BCOffset  , 32);
1418  Stream.Emit(0         , 32);  // Filled in later.
1419  Stream.Emit(CPUType   , 32);
1420}
1421
1422/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1423/// finalize the header.
1424static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1425  // Update the size field in the header.
1426  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1427
1428  // If the file is not a multiple of 16 bytes, insert dummy padding.
1429  while (BufferSize & 15) {
1430    Stream.Emit(0, 8);
1431    ++BufferSize;
1432  }
1433}
1434
1435
1436/// WriteBitcodeToFile - Write the specified module to the specified output
1437/// stream.
1438void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
1439  raw_os_ostream RawOut(Out);
1440  // If writing to stdout, set binary mode.
1441  if (llvm::cout == Out)
1442    sys::Program::ChangeStdoutToBinary();
1443  WriteBitcodeToFile(M, RawOut);
1444}
1445
1446/// WriteBitcodeToFile - Write the specified module to the specified output
1447/// stream.
1448void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1449  std::vector<unsigned char> Buffer;
1450  BitstreamWriter Stream(Buffer);
1451
1452  Buffer.reserve(256*1024);
1453
1454  WriteBitcodeToStream( M, Stream );
1455
1456  // If writing to stdout, set binary mode.
1457  if (&llvm::outs() == &Out)
1458    sys::Program::ChangeStdoutToBinary();
1459
1460  // Write the generated bitstream to "Out".
1461  Out.write((char*)&Buffer.front(), Buffer.size());
1462
1463  // Make sure it hits disk now.
1464  Out.flush();
1465}
1466
1467/// WriteBitcodeToStream - Write the specified module to the specified output
1468/// stream.
1469void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1470  // If this is darwin, emit a file header and trailer if needed.
1471  bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1472  if (isDarwin)
1473    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1474
1475  // Emit the file header.
1476  Stream.Emit((unsigned)'B', 8);
1477  Stream.Emit((unsigned)'C', 8);
1478  Stream.Emit(0x0, 4);
1479  Stream.Emit(0xC, 4);
1480  Stream.Emit(0xE, 4);
1481  Stream.Emit(0xD, 4);
1482
1483  // Emit the module.
1484  WriteModule(M, Stream);
1485
1486  if (isDarwin)
1487    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1488}
1489