BitcodeWriter.cpp revision e8e0213cc3daa2d0457c22e4c12e6973f21fc942 
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/Metadata.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/raw_ostream.h"
30#include "llvm/System/Program.h"
31using namespace llvm;
32
33/// These are manifest constants used by the bitcode writer. They do not need to
34/// be kept in sync with the reader, but need to be consistent within this file.
35enum {
36  CurVersion = 0,
37
38  // VALUE_SYMTAB_BLOCK abbrev id's.
39  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
40  VST_ENTRY_7_ABBREV,
41  VST_ENTRY_6_ABBREV,
42  VST_BBENTRY_6_ABBREV,
43
44  // CONSTANTS_BLOCK abbrev id's.
45  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
46  CONSTANTS_INTEGER_ABBREV,
47  CONSTANTS_CE_CAST_Abbrev,
48  CONSTANTS_NULL_Abbrev,
49
50  // FUNCTION_BLOCK abbrev id's.
51  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
52  FUNCTION_INST_BINOP_ABBREV,
53  FUNCTION_INST_BINOP_FLAGS_ABBREV,
54  FUNCTION_INST_CAST_ABBREV,
55  FUNCTION_INST_RET_VOID_ABBREV,
56  FUNCTION_INST_RET_VAL_ABBREV,
57  FUNCTION_INST_UNREACHABLE_ABBREV
58};
59
60
61static unsigned GetEncodedCastOpcode(unsigned Opcode) {
62  switch (Opcode) {
63  default: llvm_unreachable("Unknown cast instruction!");
64  case Instruction::Trunc   : return bitc::CAST_TRUNC;
65  case Instruction::ZExt    : return bitc::CAST_ZEXT;
66  case Instruction::SExt    : return bitc::CAST_SEXT;
67  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
68  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
69  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
70  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
71  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
72  case Instruction::FPExt   : return bitc::CAST_FPEXT;
73  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
74  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
75  case Instruction::BitCast : return bitc::CAST_BITCAST;
76  }
77}
78
79static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
80  switch (Opcode) {
81  default: llvm_unreachable("Unknown binary instruction!");
82  case Instruction::Add:
83  case Instruction::FAdd: return bitc::BINOP_ADD;
84  case Instruction::Sub:
85  case Instruction::FSub: return bitc::BINOP_SUB;
86  case Instruction::Mul:
87  case Instruction::FMul: return bitc::BINOP_MUL;
88  case Instruction::UDiv: return bitc::BINOP_UDIV;
89  case Instruction::FDiv:
90  case Instruction::SDiv: return bitc::BINOP_SDIV;
91  case Instruction::URem: return bitc::BINOP_UREM;
92  case Instruction::FRem:
93  case Instruction::SRem: return bitc::BINOP_SREM;
94  case Instruction::Shl:  return bitc::BINOP_SHL;
95  case Instruction::LShr: return bitc::BINOP_LSHR;
96  case Instruction::AShr: return bitc::BINOP_ASHR;
97  case Instruction::And:  return bitc::BINOP_AND;
98  case Instruction::Or:   return bitc::BINOP_OR;
99  case Instruction::Xor:  return bitc::BINOP_XOR;
100  }
101}
102
103
104
105static void WriteStringRecord(unsigned Code, const std::string &Str,
106                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
107  SmallVector<unsigned, 64> Vals;
108
109  // Code: [strchar x N]
110  for (unsigned i = 0, e = Str.size(); i != e; ++i)
111    Vals.push_back(Str[i]);
112
113  // Emit the finished record.
114  Stream.EmitRecord(Code, Vals, AbbrevToUse);
115}
116
117// Emit information about parameter attributes.
118static void WriteAttributeTable(const ValueEnumerator &VE,
119                                BitstreamWriter &Stream) {
120  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
121  if (Attrs.empty()) return;
122
123  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
124
125  SmallVector<uint64_t, 64> Record;
126  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
127    const AttrListPtr &A = Attrs[i];
128    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
129      const AttributeWithIndex &PAWI = A.getSlot(i);
130      Record.push_back(PAWI.Index);
131
132      // FIXME: remove in LLVM 3.0
133      // Store the alignment in the bitcode as a 16-bit raw value instead of a
134      // 5-bit log2 encoded value. Shift the bits above the alignment up by
135      // 11 bits.
136      uint64_t FauxAttr = PAWI.Attrs & 0xffff;
137      if (PAWI.Attrs & Attribute::Alignment)
138        FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
139      FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
140
141      Record.push_back(FauxAttr);
142    }
143
144    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
145    Record.clear();
146  }
147
148  Stream.ExitBlock();
149}
150
151/// WriteTypeTable - Write out the type table for a module.
152static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
153  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
154
155  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
156  SmallVector<uint64_t, 64> TypeVals;
157
158  // Abbrev for TYPE_CODE_POINTER.
159  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
160  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
161  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
162                            Log2_32_Ceil(VE.getTypes().size()+1)));
163  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
164  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
165
166  // Abbrev for TYPE_CODE_FUNCTION.
167  Abbv = new BitCodeAbbrev();
168  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
169  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
170  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
171  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
172  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
173                            Log2_32_Ceil(VE.getTypes().size()+1)));
174  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
175
176  // Abbrev for TYPE_CODE_STRUCT.
177  Abbv = new BitCodeAbbrev();
178  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
179  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
180  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
181  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
182                            Log2_32_Ceil(VE.getTypes().size()+1)));
183  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
184
185  // Abbrev for TYPE_CODE_ARRAY.
186  Abbv = new BitCodeAbbrev();
187  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
188  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
189  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
190                            Log2_32_Ceil(VE.getTypes().size()+1)));
191  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
192
193  // Emit an entry count so the reader can reserve space.
194  TypeVals.push_back(TypeList.size());
195  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
196  TypeVals.clear();
197
198  // Loop over all of the types, emitting each in turn.
199  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
200    const Type *T = TypeList[i].first;
201    int AbbrevToUse = 0;
202    unsigned Code = 0;
203
204    switch (T->getTypeID()) {
205    default: llvm_unreachable("Unknown type!");
206    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
207    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
208    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
209    case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
210    case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
211    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
212    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
213    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
214    case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
215    case Type::IntegerTyID:
216      // INTEGER: [width]
217      Code = bitc::TYPE_CODE_INTEGER;
218      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
219      break;
220    case Type::PointerTyID: {
221      const PointerType *PTy = cast<PointerType>(T);
222      // POINTER: [pointee type, address space]
223      Code = bitc::TYPE_CODE_POINTER;
224      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
225      unsigned AddressSpace = PTy->getAddressSpace();
226      TypeVals.push_back(AddressSpace);
227      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
228      break;
229    }
230    case Type::FunctionTyID: {
231      const FunctionType *FT = cast<FunctionType>(T);
232      // FUNCTION: [isvararg, attrid, retty, paramty x N]
233      Code = bitc::TYPE_CODE_FUNCTION;
234      TypeVals.push_back(FT->isVarArg());
235      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
236      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
237      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
238        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
239      AbbrevToUse = FunctionAbbrev;
240      break;
241    }
242    case Type::StructTyID: {
243      const StructType *ST = cast<StructType>(T);
244      // STRUCT: [ispacked, eltty x N]
245      Code = bitc::TYPE_CODE_STRUCT;
246      TypeVals.push_back(ST->isPacked());
247      // Output all of the element types.
248      for (StructType::element_iterator I = ST->element_begin(),
249           E = ST->element_end(); I != E; ++I)
250        TypeVals.push_back(VE.getTypeID(*I));
251      AbbrevToUse = StructAbbrev;
252      break;
253    }
254    case Type::ArrayTyID: {
255      const ArrayType *AT = cast<ArrayType>(T);
256      // ARRAY: [numelts, eltty]
257      Code = bitc::TYPE_CODE_ARRAY;
258      TypeVals.push_back(AT->getNumElements());
259      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
260      AbbrevToUse = ArrayAbbrev;
261      break;
262    }
263    case Type::VectorTyID: {
264      const VectorType *VT = cast<VectorType>(T);
265      // VECTOR [numelts, eltty]
266      Code = bitc::TYPE_CODE_VECTOR;
267      TypeVals.push_back(VT->getNumElements());
268      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
269      break;
270    }
271    }
272
273    // Emit the finished record.
274    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
275    TypeVals.clear();
276  }
277
278  Stream.ExitBlock();
279}
280
281static unsigned getEncodedLinkage(const GlobalValue *GV) {
282  switch (GV->getLinkage()) {
283  default: llvm_unreachable("Invalid linkage!");
284  case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
285  case GlobalValue::ExternalLinkage:            return 0;
286  case GlobalValue::WeakAnyLinkage:             return 1;
287  case GlobalValue::AppendingLinkage:           return 2;
288  case GlobalValue::InternalLinkage:            return 3;
289  case GlobalValue::LinkOnceAnyLinkage:         return 4;
290  case GlobalValue::DLLImportLinkage:           return 5;
291  case GlobalValue::DLLExportLinkage:           return 6;
292  case GlobalValue::ExternalWeakLinkage:        return 7;
293  case GlobalValue::CommonLinkage:              return 8;
294  case GlobalValue::PrivateLinkage:             return 9;
295  case GlobalValue::WeakODRLinkage:             return 10;
296  case GlobalValue::LinkOnceODRLinkage:         return 11;
297  case GlobalValue::AvailableExternallyLinkage: return 12;
298  case GlobalValue::LinkerPrivateLinkage:       return 13;
299  }
300}
301
302static unsigned getEncodedVisibility(const GlobalValue *GV) {
303  switch (GV->getVisibility()) {
304  default: llvm_unreachable("Invalid visibility!");
305  case GlobalValue::DefaultVisibility:   return 0;
306  case GlobalValue::HiddenVisibility:    return 1;
307  case GlobalValue::ProtectedVisibility: return 2;
308  }
309}
310
311// Emit top-level description of module, including target triple, inline asm,
312// descriptors for global variables, and function prototype info.
313static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
314                            BitstreamWriter &Stream) {
315  // Emit the list of dependent libraries for the Module.
316  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
317    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
318
319  // Emit various pieces of data attached to a module.
320  if (!M->getTargetTriple().empty())
321    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
322                      0/*TODO*/, Stream);
323  if (!M->getDataLayout().empty())
324    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
325                      0/*TODO*/, Stream);
326  if (!M->getModuleInlineAsm().empty())
327    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
328                      0/*TODO*/, Stream);
329
330  // Emit information about sections and GC, computing how many there are. Also
331  // compute the maximum alignment value.
332  std::map<std::string, unsigned> SectionMap;
333  std::map<std::string, unsigned> GCMap;
334  unsigned MaxAlignment = 0;
335  unsigned MaxGlobalType = 0;
336  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
337       GV != E; ++GV) {
338    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
339    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
340
341    if (!GV->hasSection()) continue;
342    // Give section names unique ID's.
343    unsigned &Entry = SectionMap[GV->getSection()];
344    if (Entry != 0) continue;
345    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
346                      0/*TODO*/, Stream);
347    Entry = SectionMap.size();
348  }
349  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
350    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
351    if (F->hasSection()) {
352      // Give section names unique ID's.
353      unsigned &Entry = SectionMap[F->getSection()];
354      if (!Entry) {
355        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
356                          0/*TODO*/, Stream);
357        Entry = SectionMap.size();
358      }
359    }
360    if (F->hasGC()) {
361      // Same for GC names.
362      unsigned &Entry = GCMap[F->getGC()];
363      if (!Entry) {
364        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
365                          0/*TODO*/, Stream);
366        Entry = GCMap.size();
367      }
368    }
369  }
370
371  // Emit abbrev for globals, now that we know # sections and max alignment.
372  unsigned SimpleGVarAbbrev = 0;
373  if (!M->global_empty()) {
374    // Add an abbrev for common globals with no visibility or thread localness.
375    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
376    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
377    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
378                              Log2_32_Ceil(MaxGlobalType+1)));
379    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
380    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
381    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
382    if (MaxAlignment == 0)                                      // Alignment.
383      Abbv->Add(BitCodeAbbrevOp(0));
384    else {
385      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
386      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
387                               Log2_32_Ceil(MaxEncAlignment+1)));
388    }
389    if (SectionMap.empty())                                    // Section.
390      Abbv->Add(BitCodeAbbrevOp(0));
391    else
392      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
393                               Log2_32_Ceil(SectionMap.size()+1)));
394    // Don't bother emitting vis + thread local.
395    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
396  }
397
398  // Emit the global variable information.
399  SmallVector<unsigned, 64> Vals;
400  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
401       GV != E; ++GV) {
402    unsigned AbbrevToUse = 0;
403
404    // GLOBALVAR: [type, isconst, initid,
405    //             linkage, alignment, section, visibility, threadlocal]
406    Vals.push_back(VE.getTypeID(GV->getType()));
407    Vals.push_back(GV->isConstant());
408    Vals.push_back(GV->isDeclaration() ? 0 :
409                   (VE.getValueID(GV->getInitializer()) + 1));
410    Vals.push_back(getEncodedLinkage(GV));
411    Vals.push_back(Log2_32(GV->getAlignment())+1);
412    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
413    if (GV->isThreadLocal() ||
414        GV->getVisibility() != GlobalValue::DefaultVisibility) {
415      Vals.push_back(getEncodedVisibility(GV));
416      Vals.push_back(GV->isThreadLocal());
417    } else {
418      AbbrevToUse = SimpleGVarAbbrev;
419    }
420
421    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
422    Vals.clear();
423  }
424
425  // Emit the function proto information.
426  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
427    // FUNCTION:  [type, callingconv, isproto, paramattr,
428    //             linkage, alignment, section, visibility, gc]
429    Vals.push_back(VE.getTypeID(F->getType()));
430    Vals.push_back(F->getCallingConv());
431    Vals.push_back(F->isDeclaration());
432    Vals.push_back(getEncodedLinkage(F));
433    Vals.push_back(VE.getAttributeID(F->getAttributes()));
434    Vals.push_back(Log2_32(F->getAlignment())+1);
435    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
436    Vals.push_back(getEncodedVisibility(F));
437    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
438
439    unsigned AbbrevToUse = 0;
440    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
441    Vals.clear();
442  }
443
444
445  // Emit the alias information.
446  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
447       AI != E; ++AI) {
448    Vals.push_back(VE.getTypeID(AI->getType()));
449    Vals.push_back(VE.getValueID(AI->getAliasee()));
450    Vals.push_back(getEncodedLinkage(AI));
451    Vals.push_back(getEncodedVisibility(AI));
452    unsigned AbbrevToUse = 0;
453    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
454    Vals.clear();
455  }
456}
457
458static uint64_t GetOptimizationFlags(const Value *V) {
459  uint64_t Flags = 0;
460
461  if (const OverflowingBinaryOperator *OBO =
462        dyn_cast<OverflowingBinaryOperator>(V)) {
463    if (OBO->hasNoSignedWrap())
464      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
465    if (OBO->hasNoUnsignedWrap())
466      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
467  } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
468    if (Div->isExact())
469      Flags |= 1 << bitc::SDIV_EXACT;
470  }
471
472  return Flags;
473}
474
475static void WriteMDNode(const MDNode *N,
476                        const ValueEnumerator &VE,
477                        BitstreamWriter &Stream,
478                        SmallVector<uint64_t, 64> &Record) {
479  for (unsigned i = 0, e = N->getNumElements(); i != e; ++i) {
480    if (N->getElement(i)) {
481      Record.push_back(VE.getTypeID(N->getElement(i)->getType()));
482      Record.push_back(VE.getValueID(N->getElement(i)));
483    } else {
484      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
485      Record.push_back(0);
486    }
487  }
488  Stream.EmitRecord(bitc::METADATA_NODE, Record, 0);
489  Record.clear();
490}
491
492static void WriteModuleMetadata(const ValueEnumerator &VE,
493                                BitstreamWriter &Stream) {
494  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
495  bool StartedMetadataBlock = false;
496  unsigned MDSAbbrev = 0;
497  SmallVector<uint64_t, 64> Record;
498  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
499
500    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
501      if (!StartedMetadataBlock) {
502        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
503        StartedMetadataBlock = true;
504      }
505      WriteMDNode(N, VE, Stream, Record);
506    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
507      if (!StartedMetadataBlock)  {
508        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
509
510        // Abbrev for METADATA_STRING.
511        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
512        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
513        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
514        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
515        MDSAbbrev = Stream.EmitAbbrev(Abbv);
516        StartedMetadataBlock = true;
517      }
518
519      // Code: [strchar x N]
520      const char *StrBegin = MDS->begin();
521      for (unsigned i = 0, e = MDS->length(); i != e; ++i)
522        Record.push_back(StrBegin[i]);
523
524      // Emit the finished record.
525      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
526      Record.clear();
527    } else if (const NamedMDNode *NMD = dyn_cast<NamedMDNode>(Vals[i].first)) {
528      if (!StartedMetadataBlock)  {
529        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
530        StartedMetadataBlock = true;
531      }
532
533      // Write name.
534      std::string Str = NMD->getNameStr();
535      const char *StrBegin = Str.c_str();
536      for (unsigned i = 0, e = Str.length(); i != e; ++i)
537        Record.push_back(StrBegin[i]);
538      Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
539      Record.clear();
540
541      // Write named metadata elements.
542      for (unsigned i = 0, e = NMD->getNumElements(); i != e; ++i) {
543        if (NMD->getElement(i))
544          Record.push_back(VE.getValueID(NMD->getElement(i)));
545        else
546          Record.push_back(0);
547      }
548      Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
549      Record.clear();
550    }
551  }
552
553  if (StartedMetadataBlock)
554    Stream.ExitBlock();
555}
556
557static void WriteMetadataAttachment(const Function &F,
558				    const ValueEnumerator &VE,
559				    BitstreamWriter &Stream) {
560  bool StartedMetadataBlock = false;
561  SmallVector<uint64_t, 64> Record;
562
563  // Write metadata attachments
564  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
565  Metadata &TheMetadata = F.getContext().getMetadata();
566  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
567    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
568         I != E; ++I) {
569      const Metadata::MDMapTy *P = TheMetadata.getMDs(I);
570      if (!P) continue;
571      bool RecordedInstruction = false;
572      for (Metadata::MDMapTy::const_iterator PI = P->begin(), PE = P->end();
573	   PI != PE; ++PI) {
574	if (MDNode *ND = dyn_cast_or_null<MDNode>(PI->second)) {
575	  if (RecordedInstruction == false) {
576	    Record.push_back(VE.getInstructionID(I));
577	    RecordedInstruction = true;
578	  }
579	  Record.push_back(PI->first);
580	  Record.push_back(VE.getValueID(ND));
581	}
582      }
583      if (!StartedMetadataBlock)  {
584	Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
585	StartedMetadataBlock = true;
586      }
587      Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
588      Record.clear();
589    }
590
591  if (StartedMetadataBlock)
592    Stream.ExitBlock();
593}
594
595static void WriteModuleMetadataStore(const Module *M,
596				     const ValueEnumerator &VE,
597				     BitstreamWriter &Stream) {
598
599  bool StartedMetadataBlock = false;
600  SmallVector<uint64_t, 64> Record;
601
602  // Write metadata kinds
603  // METADATA_KIND - [n x [id, name]]
604  Metadata &TheMetadata = M->getContext().getMetadata();
605  const StringMap<unsigned> *Kinds = TheMetadata.getHandlerNames();
606  for (StringMap<unsigned>::const_iterator
607	 I = Kinds->begin(), E = Kinds->end(); I != E; ++I) {
608    Record.push_back(I->second);
609    StringRef KName = I->first();
610    for (unsigned i = 0, e = KName.size(); i != e; ++i)
611      Record.push_back(KName[i]);
612    if (!StartedMetadataBlock)  {
613      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
614      StartedMetadataBlock = true;
615    }
616    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
617    Record.clear();
618  }
619
620  if (StartedMetadataBlock)
621    Stream.ExitBlock();
622}
623
624static void WriteConstants(unsigned FirstVal, unsigned LastVal,
625                           const ValueEnumerator &VE,
626                           BitstreamWriter &Stream, bool isGlobal) {
627  if (FirstVal == LastVal) return;
628
629  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
630
631  unsigned AggregateAbbrev = 0;
632  unsigned String8Abbrev = 0;
633  unsigned CString7Abbrev = 0;
634  unsigned CString6Abbrev = 0;
635  // If this is a constant pool for the module, emit module-specific abbrevs.
636  if (isGlobal) {
637    // Abbrev for CST_CODE_AGGREGATE.
638    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
639    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
640    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
641    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
642    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
643
644    // Abbrev for CST_CODE_STRING.
645    Abbv = new BitCodeAbbrev();
646    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
647    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
648    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
649    String8Abbrev = Stream.EmitAbbrev(Abbv);
650    // Abbrev for CST_CODE_CSTRING.
651    Abbv = new BitCodeAbbrev();
652    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
653    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
654    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
655    CString7Abbrev = Stream.EmitAbbrev(Abbv);
656    // Abbrev for CST_CODE_CSTRING.
657    Abbv = new BitCodeAbbrev();
658    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
659    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
660    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
661    CString6Abbrev = Stream.EmitAbbrev(Abbv);
662  }
663
664  SmallVector<uint64_t, 64> Record;
665
666  const ValueEnumerator::ValueList &Vals = VE.getValues();
667  const Type *LastTy = 0;
668  for (unsigned i = FirstVal; i != LastVal; ++i) {
669    const Value *V = Vals[i].first;
670    // If we need to switch types, do so now.
671    if (V->getType() != LastTy) {
672      LastTy = V->getType();
673      Record.push_back(VE.getTypeID(LastTy));
674      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
675                        CONSTANTS_SETTYPE_ABBREV);
676      Record.clear();
677    }
678
679    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
680      Record.push_back(unsigned(IA->hasSideEffects()));
681
682      // Add the asm string.
683      const std::string &AsmStr = IA->getAsmString();
684      Record.push_back(AsmStr.size());
685      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
686        Record.push_back(AsmStr[i]);
687
688      // Add the constraint string.
689      const std::string &ConstraintStr = IA->getConstraintString();
690      Record.push_back(ConstraintStr.size());
691      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
692        Record.push_back(ConstraintStr[i]);
693      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
694      Record.clear();
695      continue;
696    }
697    const Constant *C = cast<Constant>(V);
698    unsigned Code = -1U;
699    unsigned AbbrevToUse = 0;
700    if (C->isNullValue()) {
701      Code = bitc::CST_CODE_NULL;
702    } else if (isa<UndefValue>(C)) {
703      Code = bitc::CST_CODE_UNDEF;
704    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
705      if (IV->getBitWidth() <= 64) {
706        int64_t V = IV->getSExtValue();
707        if (V >= 0)
708          Record.push_back(V << 1);
709        else
710          Record.push_back((-V << 1) | 1);
711        Code = bitc::CST_CODE_INTEGER;
712        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
713      } else {                             // Wide integers, > 64 bits in size.
714        // We have an arbitrary precision integer value to write whose
715        // bit width is > 64. However, in canonical unsigned integer
716        // format it is likely that the high bits are going to be zero.
717        // So, we only write the number of active words.
718        unsigned NWords = IV->getValue().getActiveWords();
719        const uint64_t *RawWords = IV->getValue().getRawData();
720        for (unsigned i = 0; i != NWords; ++i) {
721          int64_t V = RawWords[i];
722          if (V >= 0)
723            Record.push_back(V << 1);
724          else
725            Record.push_back((-V << 1) | 1);
726        }
727        Code = bitc::CST_CODE_WIDE_INTEGER;
728      }
729    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
730      Code = bitc::CST_CODE_FLOAT;
731      const Type *Ty = CFP->getType();
732      if (Ty == Type::getFloatTy(Ty->getContext()) ||
733          Ty == Type::getDoubleTy(Ty->getContext())) {
734        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
735      } else if (Ty == Type::getX86_FP80Ty(Ty->getContext())) {
736        // api needed to prevent premature destruction
737        // bits are not in the same order as a normal i80 APInt, compensate.
738        APInt api = CFP->getValueAPF().bitcastToAPInt();
739        const uint64_t *p = api.getRawData();
740        Record.push_back((p[1] << 48) | (p[0] >> 16));
741        Record.push_back(p[0] & 0xffffLL);
742      } else if (Ty == Type::getFP128Ty(Ty->getContext()) ||
743                 Ty == Type::getPPC_FP128Ty(Ty->getContext())) {
744        APInt api = CFP->getValueAPF().bitcastToAPInt();
745        const uint64_t *p = api.getRawData();
746        Record.push_back(p[0]);
747        Record.push_back(p[1]);
748      } else {
749        assert (0 && "Unknown FP type!");
750      }
751    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
752      // Emit constant strings specially.
753      unsigned NumOps = C->getNumOperands();
754      // If this is a null-terminated string, use the denser CSTRING encoding.
755      if (C->getOperand(NumOps-1)->isNullValue()) {
756        Code = bitc::CST_CODE_CSTRING;
757        --NumOps;  // Don't encode the null, which isn't allowed by char6.
758      } else {
759        Code = bitc::CST_CODE_STRING;
760        AbbrevToUse = String8Abbrev;
761      }
762      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
763      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
764      for (unsigned i = 0; i != NumOps; ++i) {
765        unsigned char V = cast<ConstantInt>(C->getOperand(i))->getZExtValue();
766        Record.push_back(V);
767        isCStr7 &= (V & 128) == 0;
768        if (isCStrChar6)
769          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
770      }
771
772      if (isCStrChar6)
773        AbbrevToUse = CString6Abbrev;
774      else if (isCStr7)
775        AbbrevToUse = CString7Abbrev;
776    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
777               isa<ConstantVector>(V)) {
778      Code = bitc::CST_CODE_AGGREGATE;
779      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
780        Record.push_back(VE.getValueID(C->getOperand(i)));
781      AbbrevToUse = AggregateAbbrev;
782    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
783      switch (CE->getOpcode()) {
784      default:
785        if (Instruction::isCast(CE->getOpcode())) {
786          Code = bitc::CST_CODE_CE_CAST;
787          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
788          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
789          Record.push_back(VE.getValueID(C->getOperand(0)));
790          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
791        } else {
792          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
793          Code = bitc::CST_CODE_CE_BINOP;
794          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
795          Record.push_back(VE.getValueID(C->getOperand(0)));
796          Record.push_back(VE.getValueID(C->getOperand(1)));
797          uint64_t Flags = GetOptimizationFlags(CE);
798          if (Flags != 0)
799            Record.push_back(Flags);
800        }
801        break;
802      case Instruction::GetElementPtr:
803        Code = bitc::CST_CODE_CE_GEP;
804        if (cast<GEPOperator>(C)->isInBounds())
805          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
806        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
807          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
808          Record.push_back(VE.getValueID(C->getOperand(i)));
809        }
810        break;
811      case Instruction::Select:
812        Code = bitc::CST_CODE_CE_SELECT;
813        Record.push_back(VE.getValueID(C->getOperand(0)));
814        Record.push_back(VE.getValueID(C->getOperand(1)));
815        Record.push_back(VE.getValueID(C->getOperand(2)));
816        break;
817      case Instruction::ExtractElement:
818        Code = bitc::CST_CODE_CE_EXTRACTELT;
819        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
820        Record.push_back(VE.getValueID(C->getOperand(0)));
821        Record.push_back(VE.getValueID(C->getOperand(1)));
822        break;
823      case Instruction::InsertElement:
824        Code = bitc::CST_CODE_CE_INSERTELT;
825        Record.push_back(VE.getValueID(C->getOperand(0)));
826        Record.push_back(VE.getValueID(C->getOperand(1)));
827        Record.push_back(VE.getValueID(C->getOperand(2)));
828        break;
829      case Instruction::ShuffleVector:
830        // If the return type and argument types are the same, this is a
831        // standard shufflevector instruction.  If the types are different,
832        // then the shuffle is widening or truncating the input vectors, and
833        // the argument type must also be encoded.
834        if (C->getType() == C->getOperand(0)->getType()) {
835          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
836        } else {
837          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
838          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
839        }
840        Record.push_back(VE.getValueID(C->getOperand(0)));
841        Record.push_back(VE.getValueID(C->getOperand(1)));
842        Record.push_back(VE.getValueID(C->getOperand(2)));
843        break;
844      case Instruction::ICmp:
845      case Instruction::FCmp:
846        Code = bitc::CST_CODE_CE_CMP;
847        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
848        Record.push_back(VE.getValueID(C->getOperand(0)));
849        Record.push_back(VE.getValueID(C->getOperand(1)));
850        Record.push_back(CE->getPredicate());
851        break;
852      }
853    } else {
854      llvm_unreachable("Unknown constant!");
855    }
856    Stream.EmitRecord(Code, Record, AbbrevToUse);
857    Record.clear();
858  }
859
860  Stream.ExitBlock();
861}
862
863static void WriteModuleConstants(const ValueEnumerator &VE,
864                                 BitstreamWriter &Stream) {
865  const ValueEnumerator::ValueList &Vals = VE.getValues();
866
867  // Find the first constant to emit, which is the first non-globalvalue value.
868  // We know globalvalues have been emitted by WriteModuleInfo.
869  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
870    if (!isa<GlobalValue>(Vals[i].first)) {
871      WriteConstants(i, Vals.size(), VE, Stream, true);
872      return;
873    }
874  }
875}
876
877/// PushValueAndType - The file has to encode both the value and type id for
878/// many values, because we need to know what type to create for forward
879/// references.  However, most operands are not forward references, so this type
880/// field is not needed.
881///
882/// This function adds V's value ID to Vals.  If the value ID is higher than the
883/// instruction ID, then it is a forward reference, and it also includes the
884/// type ID.
885static bool PushValueAndType(const Value *V, unsigned InstID,
886                             SmallVector<unsigned, 64> &Vals,
887                             ValueEnumerator &VE) {
888  unsigned ValID = VE.getValueID(V);
889  Vals.push_back(ValID);
890  if (ValID >= InstID) {
891    Vals.push_back(VE.getTypeID(V->getType()));
892    return true;
893  }
894  return false;
895}
896
897/// WriteInstruction - Emit an instruction to the specified stream.
898static void WriteInstruction(const Instruction &I, unsigned InstID,
899                             ValueEnumerator &VE, BitstreamWriter &Stream,
900                             SmallVector<unsigned, 64> &Vals) {
901  unsigned Code = 0;
902  unsigned AbbrevToUse = 0;
903  VE.setInstructionID(&I);
904  switch (I.getOpcode()) {
905  default:
906    if (Instruction::isCast(I.getOpcode())) {
907      Code = bitc::FUNC_CODE_INST_CAST;
908      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
909        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
910      Vals.push_back(VE.getTypeID(I.getType()));
911      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
912    } else {
913      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
914      Code = bitc::FUNC_CODE_INST_BINOP;
915      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
916        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
917      Vals.push_back(VE.getValueID(I.getOperand(1)));
918      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
919      uint64_t Flags = GetOptimizationFlags(&I);
920      if (Flags != 0) {
921        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
922          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
923        Vals.push_back(Flags);
924      }
925    }
926    break;
927
928  case Instruction::GetElementPtr:
929    Code = bitc::FUNC_CODE_INST_GEP;
930    if (cast<GEPOperator>(&I)->isInBounds())
931      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
932    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
933      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
934    break;
935  case Instruction::ExtractValue: {
936    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
937    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
938    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
939    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
940      Vals.push_back(*i);
941    break;
942  }
943  case Instruction::InsertValue: {
944    Code = bitc::FUNC_CODE_INST_INSERTVAL;
945    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
946    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
947    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
948    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
949      Vals.push_back(*i);
950    break;
951  }
952  case Instruction::Select:
953    Code = bitc::FUNC_CODE_INST_VSELECT;
954    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
955    Vals.push_back(VE.getValueID(I.getOperand(2)));
956    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
957    break;
958  case Instruction::ExtractElement:
959    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
960    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
961    Vals.push_back(VE.getValueID(I.getOperand(1)));
962    break;
963  case Instruction::InsertElement:
964    Code = bitc::FUNC_CODE_INST_INSERTELT;
965    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
966    Vals.push_back(VE.getValueID(I.getOperand(1)));
967    Vals.push_back(VE.getValueID(I.getOperand(2)));
968    break;
969  case Instruction::ShuffleVector:
970    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
971    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
972    Vals.push_back(VE.getValueID(I.getOperand(1)));
973    Vals.push_back(VE.getValueID(I.getOperand(2)));
974    break;
975  case Instruction::ICmp:
976  case Instruction::FCmp:
977    // compare returning Int1Ty or vector of Int1Ty
978    Code = bitc::FUNC_CODE_INST_CMP2;
979    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
980    Vals.push_back(VE.getValueID(I.getOperand(1)));
981    Vals.push_back(cast<CmpInst>(I).getPredicate());
982    break;
983
984  case Instruction::Ret:
985    {
986      Code = bitc::FUNC_CODE_INST_RET;
987      unsigned NumOperands = I.getNumOperands();
988      if (NumOperands == 0)
989        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
990      else if (NumOperands == 1) {
991        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
992          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
993      } else {
994        for (unsigned i = 0, e = NumOperands; i != e; ++i)
995          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
996      }
997    }
998    break;
999  case Instruction::Br:
1000    {
1001      Code = bitc::FUNC_CODE_INST_BR;
1002      BranchInst &II(cast<BranchInst>(I));
1003      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1004      if (II.isConditional()) {
1005        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1006        Vals.push_back(VE.getValueID(II.getCondition()));
1007      }
1008    }
1009    break;
1010  case Instruction::Switch:
1011    Code = bitc::FUNC_CODE_INST_SWITCH;
1012    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1013    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1014      Vals.push_back(VE.getValueID(I.getOperand(i)));
1015    break;
1016  case Instruction::Invoke: {
1017    const InvokeInst *II = cast<InvokeInst>(&I);
1018    const Value *Callee(II->getCalledValue());
1019    const PointerType *PTy = cast<PointerType>(Callee->getType());
1020    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1021    Code = bitc::FUNC_CODE_INST_INVOKE;
1022
1023    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1024    Vals.push_back(II->getCallingConv());
1025    Vals.push_back(VE.getValueID(II->getNormalDest()));
1026    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1027    PushValueAndType(Callee, InstID, Vals, VE);
1028
1029    // Emit value #'s for the fixed parameters.
1030    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1031      Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
1032
1033    // Emit type/value pairs for varargs params.
1034    if (FTy->isVarArg()) {
1035      for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
1036           i != e; ++i)
1037        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1038    }
1039    break;
1040  }
1041  case Instruction::Unwind:
1042    Code = bitc::FUNC_CODE_INST_UNWIND;
1043    break;
1044  case Instruction::Unreachable:
1045    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1046    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1047    break;
1048
1049  case Instruction::PHI:
1050    Code = bitc::FUNC_CODE_INST_PHI;
1051    Vals.push_back(VE.getTypeID(I.getType()));
1052    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1053      Vals.push_back(VE.getValueID(I.getOperand(i)));
1054    break;
1055
1056  case Instruction::Malloc:
1057    Code = bitc::FUNC_CODE_INST_MALLOC;
1058    Vals.push_back(VE.getTypeID(I.getType()));
1059    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1060    Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
1061    break;
1062
1063  case Instruction::Free:
1064    Code = bitc::FUNC_CODE_INST_FREE;
1065    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1066    break;
1067
1068  case Instruction::Alloca:
1069    Code = bitc::FUNC_CODE_INST_ALLOCA;
1070    Vals.push_back(VE.getTypeID(I.getType()));
1071    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1072    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1073    break;
1074
1075  case Instruction::Load:
1076    Code = bitc::FUNC_CODE_INST_LOAD;
1077    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1078      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1079
1080    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1081    Vals.push_back(cast<LoadInst>(I).isVolatile());
1082    break;
1083  case Instruction::Store:
1084    Code = bitc::FUNC_CODE_INST_STORE2;
1085    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1086    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1087    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1088    Vals.push_back(cast<StoreInst>(I).isVolatile());
1089    break;
1090  case Instruction::Call: {
1091    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
1092    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1093
1094    Code = bitc::FUNC_CODE_INST_CALL;
1095
1096    const CallInst *CI = cast<CallInst>(&I);
1097    Vals.push_back(VE.getAttributeID(CI->getAttributes()));
1098    Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
1099    PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
1100
1101    // Emit value #'s for the fixed parameters.
1102    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1103      Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
1104
1105    // Emit type/value pairs for varargs params.
1106    if (FTy->isVarArg()) {
1107      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
1108      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
1109           i != e; ++i)
1110        PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
1111    }
1112    break;
1113  }
1114  case Instruction::VAArg:
1115    Code = bitc::FUNC_CODE_INST_VAARG;
1116    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1117    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1118    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1119    break;
1120  }
1121
1122  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1123  Vals.clear();
1124}
1125
1126// Emit names for globals/functions etc.
1127static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1128                                  const ValueEnumerator &VE,
1129                                  BitstreamWriter &Stream) {
1130  if (VST.empty()) return;
1131  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1132
1133  // FIXME: Set up the abbrev, we know how many values there are!
1134  // FIXME: We know if the type names can use 7-bit ascii.
1135  SmallVector<unsigned, 64> NameVals;
1136
1137  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1138       SI != SE; ++SI) {
1139
1140    const ValueName &Name = *SI;
1141
1142    // Figure out the encoding to use for the name.
1143    bool is7Bit = true;
1144    bool isChar6 = true;
1145    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1146         C != E; ++C) {
1147      if (isChar6)
1148        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1149      if ((unsigned char)*C & 128) {
1150        is7Bit = false;
1151        break;  // don't bother scanning the rest.
1152      }
1153    }
1154
1155    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1156
1157    // VST_ENTRY:   [valueid, namechar x N]
1158    // VST_BBENTRY: [bbid, namechar x N]
1159    unsigned Code;
1160    if (isa<BasicBlock>(SI->getValue())) {
1161      Code = bitc::VST_CODE_BBENTRY;
1162      if (isChar6)
1163        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1164    } else {
1165      Code = bitc::VST_CODE_ENTRY;
1166      if (isChar6)
1167        AbbrevToUse = VST_ENTRY_6_ABBREV;
1168      else if (is7Bit)
1169        AbbrevToUse = VST_ENTRY_7_ABBREV;
1170    }
1171
1172    NameVals.push_back(VE.getValueID(SI->getValue()));
1173    for (const char *P = Name.getKeyData(),
1174         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1175      NameVals.push_back((unsigned char)*P);
1176
1177    // Emit the finished record.
1178    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1179    NameVals.clear();
1180  }
1181  Stream.ExitBlock();
1182}
1183
1184/// WriteFunction - Emit a function body to the module stream.
1185static void WriteFunction(const Function &F, ValueEnumerator &VE,
1186                          BitstreamWriter &Stream) {
1187  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1188  VE.incorporateFunction(F);
1189
1190  SmallVector<unsigned, 64> Vals;
1191
1192  // Emit the number of basic blocks, so the reader can create them ahead of
1193  // time.
1194  Vals.push_back(VE.getBasicBlocks().size());
1195  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1196  Vals.clear();
1197
1198  // If there are function-local constants, emit them now.
1199  unsigned CstStart, CstEnd;
1200  VE.getFunctionConstantRange(CstStart, CstEnd);
1201  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1202
1203  // Keep a running idea of what the instruction ID is.
1204  unsigned InstID = CstEnd;
1205
1206  // Finally, emit all the instructions, in order.
1207  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1208    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1209         I != E; ++I) {
1210      WriteInstruction(*I, InstID, VE, Stream, Vals);
1211      if (I->getType() != Type::getVoidTy(F.getContext()))
1212        ++InstID;
1213    }
1214
1215  // Emit names for all the instructions etc.
1216  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1217
1218  WriteMetadataAttachment(F, VE, Stream);
1219  VE.purgeFunction();
1220  Stream.ExitBlock();
1221}
1222
1223/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1224static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1225                                 const ValueEnumerator &VE,
1226                                 BitstreamWriter &Stream) {
1227  if (TST.empty()) return;
1228
1229  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1230
1231  // 7-bit fixed width VST_CODE_ENTRY strings.
1232  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1233  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1234  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1235                            Log2_32_Ceil(VE.getTypes().size()+1)));
1236  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1237  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1238  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1239
1240  SmallVector<unsigned, 64> NameVals;
1241
1242  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1243       TI != TE; ++TI) {
1244    // TST_ENTRY: [typeid, namechar x N]
1245    NameVals.push_back(VE.getTypeID(TI->second));
1246
1247    const std::string &Str = TI->first;
1248    bool is7Bit = true;
1249    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1250      NameVals.push_back((unsigned char)Str[i]);
1251      if (Str[i] & 128)
1252        is7Bit = false;
1253    }
1254
1255    // Emit the finished record.
1256    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1257    NameVals.clear();
1258  }
1259
1260  Stream.ExitBlock();
1261}
1262
1263// Emit blockinfo, which defines the standard abbreviations etc.
1264static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1265  // We only want to emit block info records for blocks that have multiple
1266  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1267  // blocks can defined their abbrevs inline.
1268  Stream.EnterBlockInfoBlock(2);
1269
1270  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1271    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1272    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1273    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1274    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1275    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1276    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1277                                   Abbv) != VST_ENTRY_8_ABBREV)
1278      llvm_unreachable("Unexpected abbrev ordering!");
1279  }
1280
1281  { // 7-bit fixed width VST_ENTRY strings.
1282    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1283    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1284    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1285    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1286    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1287    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1288                                   Abbv) != VST_ENTRY_7_ABBREV)
1289      llvm_unreachable("Unexpected abbrev ordering!");
1290  }
1291  { // 6-bit char6 VST_ENTRY strings.
1292    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1293    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1294    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1295    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1296    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1297    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1298                                   Abbv) != VST_ENTRY_6_ABBREV)
1299      llvm_unreachable("Unexpected abbrev ordering!");
1300  }
1301  { // 6-bit char6 VST_BBENTRY strings.
1302    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1303    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1304    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1305    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1306    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1307    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1308                                   Abbv) != VST_BBENTRY_6_ABBREV)
1309      llvm_unreachable("Unexpected abbrev ordering!");
1310  }
1311
1312
1313
1314  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1315    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1316    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1317    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1318                              Log2_32_Ceil(VE.getTypes().size()+1)));
1319    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1320                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1321      llvm_unreachable("Unexpected abbrev ordering!");
1322  }
1323
1324  { // INTEGER abbrev for CONSTANTS_BLOCK.
1325    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1326    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1327    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1328    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1329                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1330      llvm_unreachable("Unexpected abbrev ordering!");
1331  }
1332
1333  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1334    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1335    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1336    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1337    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1338                              Log2_32_Ceil(VE.getTypes().size()+1)));
1339    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1340
1341    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1342                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1343      llvm_unreachable("Unexpected abbrev ordering!");
1344  }
1345  { // NULL abbrev for CONSTANTS_BLOCK.
1346    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1347    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1348    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1349                                   Abbv) != CONSTANTS_NULL_Abbrev)
1350      llvm_unreachable("Unexpected abbrev ordering!");
1351  }
1352
1353  // FIXME: This should only use space for first class types!
1354
1355  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1356    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1357    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1358    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1359    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1360    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1361    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1362                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1363      llvm_unreachable("Unexpected abbrev ordering!");
1364  }
1365  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1366    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1367    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1368    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1369    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1370    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1371    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1372                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1373      llvm_unreachable("Unexpected abbrev ordering!");
1374  }
1375  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1376    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1377    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1378    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1379    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1380    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1381    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1382    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1383                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1384      llvm_unreachable("Unexpected abbrev ordering!");
1385  }
1386  { // INST_CAST abbrev for FUNCTION_BLOCK.
1387    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1388    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1389    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1390    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1391                              Log2_32_Ceil(VE.getTypes().size()+1)));
1392    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1393    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1394                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1395      llvm_unreachable("Unexpected abbrev ordering!");
1396  }
1397
1398  { // INST_RET abbrev for FUNCTION_BLOCK.
1399    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1400    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1401    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1402                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1403      llvm_unreachable("Unexpected abbrev ordering!");
1404  }
1405  { // INST_RET abbrev for FUNCTION_BLOCK.
1406    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1407    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1408    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1409    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1410                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1411      llvm_unreachable("Unexpected abbrev ordering!");
1412  }
1413  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1414    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1415    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1416    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1417                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1418      llvm_unreachable("Unexpected abbrev ordering!");
1419  }
1420
1421  Stream.ExitBlock();
1422}
1423
1424
1425/// WriteModule - Emit the specified module to the bitstream.
1426static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1427  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1428
1429  // Emit the version number if it is non-zero.
1430  if (CurVersion) {
1431    SmallVector<unsigned, 1> Vals;
1432    Vals.push_back(CurVersion);
1433    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1434  }
1435
1436  // Analyze the module, enumerating globals, functions, etc.
1437  ValueEnumerator VE(M);
1438
1439  // Emit blockinfo, which defines the standard abbreviations etc.
1440  WriteBlockInfo(VE, Stream);
1441
1442  // Emit information about parameter attributes.
1443  WriteAttributeTable(VE, Stream);
1444
1445  // Emit information describing all of the types in the module.
1446  WriteTypeTable(VE, Stream);
1447
1448  // Emit top-level description of module, including target triple, inline asm,
1449  // descriptors for global variables, and function prototype info.
1450  WriteModuleInfo(M, VE, Stream);
1451
1452  // Emit constants.
1453  WriteModuleConstants(VE, Stream);
1454
1455  // Emit metadata.
1456  WriteModuleMetadata(VE, Stream);
1457
1458  // Emit function bodies.
1459  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1460    if (!I->isDeclaration())
1461      WriteFunction(*I, VE, Stream);
1462
1463  // Emit metadata.
1464  WriteModuleMetadataStore(M, VE, Stream);
1465
1466  // Emit the type symbol table information.
1467  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1468
1469  // Emit names for globals/functions etc.
1470  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1471
1472  Stream.ExitBlock();
1473}
1474
1475/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1476/// header and trailer to make it compatible with the system archiver.  To do
1477/// this we emit the following header, and then emit a trailer that pads the
1478/// file out to be a multiple of 16 bytes.
1479///
1480/// struct bc_header {
1481///   uint32_t Magic;         // 0x0B17C0DE
1482///   uint32_t Version;       // Version, currently always 0.
1483///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1484///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1485///   uint32_t CPUType;       // CPU specifier.
1486///   ... potentially more later ...
1487/// };
1488enum {
1489  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1490  DarwinBCHeaderSize = 5*4
1491};
1492
1493static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1494                               const std::string &TT) {
1495  unsigned CPUType = ~0U;
1496
1497  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*.  The CPUType is a
1498  // magic number from /usr/include/mach/machine.h.  It is ok to reproduce the
1499  // specific constants here because they are implicitly part of the Darwin ABI.
1500  enum {
1501    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1502    DARWIN_CPU_TYPE_X86        = 7,
1503    DARWIN_CPU_TYPE_POWERPC    = 18
1504  };
1505
1506  if (TT.find("x86_64-") == 0)
1507    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1508  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1509           TT[4] == '-' && TT[1] - '3' < 6)
1510    CPUType = DARWIN_CPU_TYPE_X86;
1511  else if (TT.find("powerpc-") == 0)
1512    CPUType = DARWIN_CPU_TYPE_POWERPC;
1513  else if (TT.find("powerpc64-") == 0)
1514    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1515
1516  // Traditional Bitcode starts after header.
1517  unsigned BCOffset = DarwinBCHeaderSize;
1518
1519  Stream.Emit(0x0B17C0DE, 32);
1520  Stream.Emit(0         , 32);  // Version.
1521  Stream.Emit(BCOffset  , 32);
1522  Stream.Emit(0         , 32);  // Filled in later.
1523  Stream.Emit(CPUType   , 32);
1524}
1525
1526/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1527/// finalize the header.
1528static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1529  // Update the size field in the header.
1530  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1531
1532  // If the file is not a multiple of 16 bytes, insert dummy padding.
1533  while (BufferSize & 15) {
1534    Stream.Emit(0, 8);
1535    ++BufferSize;
1536  }
1537}
1538
1539
1540/// WriteBitcodeToFile - Write the specified module to the specified output
1541/// stream.
1542void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1543  std::vector<unsigned char> Buffer;
1544  BitstreamWriter Stream(Buffer);
1545
1546  Buffer.reserve(256*1024);
1547
1548  WriteBitcodeToStream( M, Stream );
1549
1550  // If writing to stdout, set binary mode.
1551  if (&llvm::outs() == &Out)
1552    sys::Program::ChangeStdoutToBinary();
1553
1554  // Write the generated bitstream to "Out".
1555  Out.write((char*)&Buffer.front(), Buffer.size());
1556
1557  // Make sure it hits disk now.
1558  Out.flush();
1559}
1560
1561/// WriteBitcodeToStream - Write the specified module to the specified output
1562/// stream.
1563void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1564  // If this is darwin, emit a file header and trailer if needed.
1565  bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1566  if (isDarwin)
1567    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1568
1569  // Emit the file header.
1570  Stream.Emit((unsigned)'B', 8);
1571  Stream.Emit((unsigned)'C', 8);
1572  Stream.Emit(0x0, 4);
1573  Stream.Emit(0xC, 4);
1574  Stream.Emit(0xE, 4);
1575  Stream.Emit(0xD, 4);
1576
1577  // Emit the module.
1578  WriteModule(M, Stream);
1579
1580  if (isDarwin)
1581    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1582}
1583