BitcodeWriter.cpp revision 0386f01e061513094504bc11f8352a40173cada7 
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/Module.h"
23#include "llvm/Operator.h"
24#include "llvm/TypeSymbolTable.h"
25#include "llvm/ValueSymbolTable.h"
26#include "llvm/Support/ErrorHandling.h"
27#include "llvm/Support/MathExtras.h"
28#include "llvm/Support/raw_ostream.h"
29#include "llvm/System/Program.h"
30using namespace llvm;
31
32/// These are manifest constants used by the bitcode writer. They do not need to
33/// be kept in sync with the reader, but need to be consistent within this file.
34enum {
35  CurVersion = 0,
36
37  // VALUE_SYMTAB_BLOCK abbrev id's.
38  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
39  VST_ENTRY_7_ABBREV,
40  VST_ENTRY_6_ABBREV,
41  VST_BBENTRY_6_ABBREV,
42
43  // CONSTANTS_BLOCK abbrev id's.
44  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
45  CONSTANTS_INTEGER_ABBREV,
46  CONSTANTS_CE_CAST_Abbrev,
47  CONSTANTS_NULL_Abbrev,
48
49  // FUNCTION_BLOCK abbrev id's.
50  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
51  FUNCTION_INST_BINOP_ABBREV,
52  FUNCTION_INST_BINOP_FLAGS_ABBREV,
53  FUNCTION_INST_CAST_ABBREV,
54  FUNCTION_INST_RET_VOID_ABBREV,
55  FUNCTION_INST_RET_VAL_ABBREV,
56  FUNCTION_INST_UNREACHABLE_ABBREV
57};
58
59
60static unsigned GetEncodedCastOpcode(unsigned Opcode) {
61  switch (Opcode) {
62  default: llvm_unreachable("Unknown cast instruction!");
63  case Instruction::Trunc   : return bitc::CAST_TRUNC;
64  case Instruction::ZExt    : return bitc::CAST_ZEXT;
65  case Instruction::SExt    : return bitc::CAST_SEXT;
66  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
67  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
68  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
69  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
70  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
71  case Instruction::FPExt   : return bitc::CAST_FPEXT;
72  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
73  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
74  case Instruction::BitCast : return bitc::CAST_BITCAST;
75  }
76}
77
78static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
79  switch (Opcode) {
80  default: llvm_unreachable("Unknown binary instruction!");
81  case Instruction::Add:
82  case Instruction::FAdd: return bitc::BINOP_ADD;
83  case Instruction::Sub:
84  case Instruction::FSub: return bitc::BINOP_SUB;
85  case Instruction::Mul:
86  case Instruction::FMul: return bitc::BINOP_MUL;
87  case Instruction::UDiv: return bitc::BINOP_UDIV;
88  case Instruction::FDiv:
89  case Instruction::SDiv: return bitc::BINOP_SDIV;
90  case Instruction::URem: return bitc::BINOP_UREM;
91  case Instruction::FRem:
92  case Instruction::SRem: return bitc::BINOP_SREM;
93  case Instruction::Shl:  return bitc::BINOP_SHL;
94  case Instruction::LShr: return bitc::BINOP_LSHR;
95  case Instruction::AShr: return bitc::BINOP_ASHR;
96  case Instruction::And:  return bitc::BINOP_AND;
97  case Instruction::Or:   return bitc::BINOP_OR;
98  case Instruction::Xor:  return bitc::BINOP_XOR;
99  }
100}
101
102
103
104static void WriteStringRecord(unsigned Code, const std::string &Str,
105                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
106  SmallVector<unsigned, 64> Vals;
107
108  // Code: [strchar x N]
109  for (unsigned i = 0, e = Str.size(); i != e; ++i)
110    Vals.push_back(Str[i]);
111
112  // Emit the finished record.
113  Stream.EmitRecord(Code, Vals, AbbrevToUse);
114}
115
116// Emit information about parameter attributes.
117static void WriteAttributeTable(const ValueEnumerator &VE,
118                                BitstreamWriter &Stream) {
119  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
120  if (Attrs.empty()) return;
121
122  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
123
124  SmallVector<uint64_t, 64> Record;
125  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
126    const AttrListPtr &A = Attrs[i];
127    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
128      const AttributeWithIndex &PAWI = A.getSlot(i);
129      Record.push_back(PAWI.Index);
130
131      // FIXME: remove in LLVM 3.0
132      // Store the alignment in the bitcode as a 16-bit raw value instead of a
133      // 5-bit log2 encoded value. Shift the bits above the alignment up by
134      // 11 bits.
135      uint64_t FauxAttr = PAWI.Attrs & 0xffff;
136      if (PAWI.Attrs & Attribute::Alignment)
137        FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
138      FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
139
140      Record.push_back(FauxAttr);
141    }
142
143    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
144    Record.clear();
145  }
146
147  Stream.ExitBlock();
148}
149
150/// WriteTypeTable - Write out the type table for a module.
151static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
152  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
153
154  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
155  SmallVector<uint64_t, 64> TypeVals;
156
157  // Abbrev for TYPE_CODE_POINTER.
158  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
159  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
160  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
161                            Log2_32_Ceil(VE.getTypes().size()+1)));
162  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
163  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
164
165  // Abbrev for TYPE_CODE_FUNCTION.
166  Abbv = new BitCodeAbbrev();
167  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
168  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
169  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
170  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
171  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
172                            Log2_32_Ceil(VE.getTypes().size()+1)));
173  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
174
175  // Abbrev for TYPE_CODE_STRUCT.
176  Abbv = new BitCodeAbbrev();
177  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
178  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
179  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
180  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
181                            Log2_32_Ceil(VE.getTypes().size()+1)));
182  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
183
184  // Abbrev for TYPE_CODE_ARRAY.
185  Abbv = new BitCodeAbbrev();
186  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
187  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
188  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
189                            Log2_32_Ceil(VE.getTypes().size()+1)));
190  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
191
192  // Emit an entry count so the reader can reserve space.
193  TypeVals.push_back(TypeList.size());
194  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
195  TypeVals.clear();
196
197  // Loop over all of the types, emitting each in turn.
198  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
199    const Type *T = TypeList[i].first;
200    int AbbrevToUse = 0;
201    unsigned Code = 0;
202
203    switch (T->getTypeID()) {
204    default: llvm_unreachable("Unknown type!");
205    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
206    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
207    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
208    case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
209    case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
210    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
211    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
212    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
213    case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
214    case Type::IntegerTyID:
215      // INTEGER: [width]
216      Code = bitc::TYPE_CODE_INTEGER;
217      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
218      break;
219    case Type::PointerTyID: {
220      const PointerType *PTy = cast<PointerType>(T);
221      // POINTER: [pointee type, address space]
222      Code = bitc::TYPE_CODE_POINTER;
223      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
224      unsigned AddressSpace = PTy->getAddressSpace();
225      TypeVals.push_back(AddressSpace);
226      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
227      break;
228    }
229    case Type::FunctionTyID: {
230      const FunctionType *FT = cast<FunctionType>(T);
231      // FUNCTION: [isvararg, attrid, retty, paramty x N]
232      Code = bitc::TYPE_CODE_FUNCTION;
233      TypeVals.push_back(FT->isVarArg());
234      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
235      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
236      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
237        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
238      AbbrevToUse = FunctionAbbrev;
239      break;
240    }
241    case Type::StructTyID: {
242      const StructType *ST = cast<StructType>(T);
243      // STRUCT: [ispacked, eltty x N]
244      Code = bitc::TYPE_CODE_STRUCT;
245      TypeVals.push_back(ST->isPacked());
246      // Output all of the element types.
247      for (StructType::element_iterator I = ST->element_begin(),
248           E = ST->element_end(); I != E; ++I)
249        TypeVals.push_back(VE.getTypeID(*I));
250      AbbrevToUse = StructAbbrev;
251      break;
252    }
253    case Type::ArrayTyID: {
254      const ArrayType *AT = cast<ArrayType>(T);
255      // ARRAY: [numelts, eltty]
256      Code = bitc::TYPE_CODE_ARRAY;
257      TypeVals.push_back(AT->getNumElements());
258      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
259      AbbrevToUse = ArrayAbbrev;
260      break;
261    }
262    case Type::VectorTyID: {
263      const VectorType *VT = cast<VectorType>(T);
264      // VECTOR [numelts, eltty]
265      Code = bitc::TYPE_CODE_VECTOR;
266      TypeVals.push_back(VT->getNumElements());
267      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
268      break;
269    }
270    }
271
272    // Emit the finished record.
273    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
274    TypeVals.clear();
275  }
276
277  Stream.ExitBlock();
278}
279
280static unsigned getEncodedLinkage(const GlobalValue *GV) {
281  switch (GV->getLinkage()) {
282  default: llvm_unreachable("Invalid linkage!");
283  case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
284  case GlobalValue::ExternalLinkage:            return 0;
285  case GlobalValue::WeakAnyLinkage:             return 1;
286  case GlobalValue::AppendingLinkage:           return 2;
287  case GlobalValue::InternalLinkage:            return 3;
288  case GlobalValue::LinkOnceAnyLinkage:         return 4;
289  case GlobalValue::DLLImportLinkage:           return 5;
290  case GlobalValue::DLLExportLinkage:           return 6;
291  case GlobalValue::ExternalWeakLinkage:        return 7;
292  case GlobalValue::CommonLinkage:              return 8;
293  case GlobalValue::PrivateLinkage:             return 9;
294  case GlobalValue::WeakODRLinkage:             return 10;
295  case GlobalValue::LinkOnceODRLinkage:         return 11;
296  case GlobalValue::AvailableExternallyLinkage: return 12;
297  case GlobalValue::LinkerPrivateLinkage:       return 13;
298  }
299}
300
301static unsigned getEncodedVisibility(const GlobalValue *GV) {
302  switch (GV->getVisibility()) {
303  default: llvm_unreachable("Invalid visibility!");
304  case GlobalValue::DefaultVisibility:   return 0;
305  case GlobalValue::HiddenVisibility:    return 1;
306  case GlobalValue::ProtectedVisibility: return 2;
307  }
308}
309
310// Emit top-level description of module, including target triple, inline asm,
311// descriptors for global variables, and function prototype info.
312static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
313                            BitstreamWriter &Stream) {
314  // Emit the list of dependent libraries for the Module.
315  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
316    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
317
318  // Emit various pieces of data attached to a module.
319  if (!M->getTargetTriple().empty())
320    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
321                      0/*TODO*/, Stream);
322  if (!M->getDataLayout().empty())
323    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
324                      0/*TODO*/, Stream);
325  if (!M->getModuleInlineAsm().empty())
326    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
327                      0/*TODO*/, Stream);
328
329  // Emit information about sections and GC, computing how many there are. Also
330  // compute the maximum alignment value.
331  std::map<std::string, unsigned> SectionMap;
332  std::map<std::string, unsigned> GCMap;
333  unsigned MaxAlignment = 0;
334  unsigned MaxGlobalType = 0;
335  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
336       GV != E; ++GV) {
337    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
338    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
339
340    if (!GV->hasSection()) continue;
341    // Give section names unique ID's.
342    unsigned &Entry = SectionMap[GV->getSection()];
343    if (Entry != 0) continue;
344    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
345                      0/*TODO*/, Stream);
346    Entry = SectionMap.size();
347  }
348  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
349    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
350    if (F->hasSection()) {
351      // Give section names unique ID's.
352      unsigned &Entry = SectionMap[F->getSection()];
353      if (!Entry) {
354        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
355                          0/*TODO*/, Stream);
356        Entry = SectionMap.size();
357      }
358    }
359    if (F->hasGC()) {
360      // Same for GC names.
361      unsigned &Entry = GCMap[F->getGC()];
362      if (!Entry) {
363        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
364                          0/*TODO*/, Stream);
365        Entry = GCMap.size();
366      }
367    }
368  }
369
370  // Emit abbrev for globals, now that we know # sections and max alignment.
371  unsigned SimpleGVarAbbrev = 0;
372  if (!M->global_empty()) {
373    // Add an abbrev for common globals with no visibility or thread localness.
374    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
375    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
376    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
377                              Log2_32_Ceil(MaxGlobalType+1)));
378    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
379    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
380    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
381    if (MaxAlignment == 0)                                      // Alignment.
382      Abbv->Add(BitCodeAbbrevOp(0));
383    else {
384      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
385      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
386                               Log2_32_Ceil(MaxEncAlignment+1)));
387    }
388    if (SectionMap.empty())                                    // Section.
389      Abbv->Add(BitCodeAbbrevOp(0));
390    else
391      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
392                               Log2_32_Ceil(SectionMap.size()+1)));
393    // Don't bother emitting vis + thread local.
394    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
395  }
396
397  // Emit the global variable information.
398  SmallVector<unsigned, 64> Vals;
399  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
400       GV != E; ++GV) {
401    unsigned AbbrevToUse = 0;
402
403    // GLOBALVAR: [type, isconst, initid,
404    //             linkage, alignment, section, visibility, threadlocal]
405    Vals.push_back(VE.getTypeID(GV->getType()));
406    Vals.push_back(GV->isConstant());
407    Vals.push_back(GV->isDeclaration() ? 0 :
408                   (VE.getValueID(GV->getInitializer()) + 1));
409    Vals.push_back(getEncodedLinkage(GV));
410    Vals.push_back(Log2_32(GV->getAlignment())+1);
411    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
412    if (GV->isThreadLocal() ||
413        GV->getVisibility() != GlobalValue::DefaultVisibility) {
414      Vals.push_back(getEncodedVisibility(GV));
415      Vals.push_back(GV->isThreadLocal());
416    } else {
417      AbbrevToUse = SimpleGVarAbbrev;
418    }
419
420    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
421    Vals.clear();
422  }
423
424  // Emit the function proto information.
425  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
426    // FUNCTION:  [type, callingconv, isproto, paramattr,
427    //             linkage, alignment, section, visibility, gc]
428    Vals.push_back(VE.getTypeID(F->getType()));
429    Vals.push_back(F->getCallingConv());
430    Vals.push_back(F->isDeclaration());
431    Vals.push_back(getEncodedLinkage(F));
432    Vals.push_back(VE.getAttributeID(F->getAttributes()));
433    Vals.push_back(Log2_32(F->getAlignment())+1);
434    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
435    Vals.push_back(getEncodedVisibility(F));
436    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
437
438    unsigned AbbrevToUse = 0;
439    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
440    Vals.clear();
441  }
442
443
444  // Emit the alias information.
445  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
446       AI != E; ++AI) {
447    Vals.push_back(VE.getTypeID(AI->getType()));
448    Vals.push_back(VE.getValueID(AI->getAliasee()));
449    Vals.push_back(getEncodedLinkage(AI));
450    Vals.push_back(getEncodedVisibility(AI));
451    unsigned AbbrevToUse = 0;
452    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
453    Vals.clear();
454  }
455}
456
457static uint64_t GetOptimizationFlags(const Value *V) {
458  uint64_t Flags = 0;
459
460  if (const OverflowingBinaryOperator *OBO =
461        dyn_cast<OverflowingBinaryOperator>(V)) {
462    if (OBO->hasNoSignedWrap())
463      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
464    if (OBO->hasNoUnsignedWrap())
465      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
466  } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
467    if (Div->isExact())
468      Flags |= 1 << bitc::SDIV_EXACT;
469  }
470
471  return Flags;
472}
473
474static void WriteMDNode(const MDNode *N,
475                        const ValueEnumerator &VE,
476                        BitstreamWriter &Stream,
477                        SmallVector<uint64_t, 64> &Record) {
478  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
479    if (N->getOperand(i)) {
480      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
481      Record.push_back(VE.getValueID(N->getOperand(i)));
482    } else {
483      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
484      Record.push_back(0);
485    }
486  }
487  Stream.EmitRecord(bitc::METADATA_NODE, Record, 0);
488  Record.clear();
489}
490
491static void WriteModuleMetadata(const ValueEnumerator &VE,
492                                BitstreamWriter &Stream) {
493  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
494  bool StartedMetadataBlock = false;
495  unsigned MDSAbbrev = 0;
496  SmallVector<uint64_t, 64> Record;
497  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
498
499    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
500      if (!StartedMetadataBlock) {
501        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
502        StartedMetadataBlock = true;
503      }
504      WriteMDNode(N, VE, Stream, Record);
505    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
506      if (!StartedMetadataBlock)  {
507        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
508
509        // Abbrev for METADATA_STRING.
510        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
511        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
512        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
513        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
514        MDSAbbrev = Stream.EmitAbbrev(Abbv);
515        StartedMetadataBlock = true;
516      }
517
518      // Code: [strchar x N]
519      Record.append(MDS->begin(), MDS->end());
520
521      // Emit the finished record.
522      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
523      Record.clear();
524    } else if (const NamedMDNode *NMD = dyn_cast<NamedMDNode>(Vals[i].first)) {
525      if (!StartedMetadataBlock)  {
526        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
527        StartedMetadataBlock = true;
528      }
529
530      // Write name.
531      StringRef Str = NMD->getName();
532      for (unsigned i = 0, e = Str.size(); i != e; ++i)
533        Record.push_back(Str[i]);
534      Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
535      Record.clear();
536
537      // Write named metadata operands.
538      for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
539        if (NMD->getOperand(i))
540          Record.push_back(VE.getValueID(NMD->getOperand(i)));
541        else
542          Record.push_back(~0U);
543      }
544      Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
545      Record.clear();
546    }
547  }
548
549  if (StartedMetadataBlock)
550    Stream.ExitBlock();
551}
552
553static void WriteMetadataAttachment(const Function &F,
554                                    const ValueEnumerator &VE,
555                                    BitstreamWriter &Stream) {
556  bool StartedMetadataBlock = false;
557  SmallVector<uint64_t, 64> Record;
558
559  // Write metadata attachments
560  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
561  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
562
563  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
564    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
565         I != E; ++I) {
566      MDs.clear();
567      I->getAllMetadata(MDs);
568
569      // If no metadata, ignore instruction.
570      if (MDs.empty()) continue;
571
572      Record.push_back(VE.getInstructionID(I));
573
574      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
575        Record.push_back(MDs[i].first);
576        Record.push_back(VE.getValueID(MDs[i].second));
577      }
578      if (!StartedMetadataBlock)  {
579        Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
580        StartedMetadataBlock = true;
581      }
582      Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
583      Record.clear();
584    }
585
586  if (StartedMetadataBlock)
587    Stream.ExitBlock();
588}
589
590static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
591  SmallVector<uint64_t, 64> Record;
592
593  // Write metadata kinds
594  // METADATA_KIND - [n x [id, name]]
595  SmallVector<StringRef, 4> Names;
596  M->getMDKindNames(Names);
597
598  assert(Names[0] == "" && "MDKind #0 is invalid");
599  if (Names.size() == 1) return;
600
601  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
602
603  for (unsigned MDKindID = 1, e = Names.size(); MDKindID != e; ++MDKindID) {
604    Record.push_back(MDKindID);
605    StringRef KName = Names[MDKindID];
606    Record.append(KName.begin(), KName.end());
607
608    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
609    Record.clear();
610  }
611
612  Stream.ExitBlock();
613}
614
615static void WriteConstants(unsigned FirstVal, unsigned LastVal,
616                           const ValueEnumerator &VE,
617                           BitstreamWriter &Stream, bool isGlobal) {
618  if (FirstVal == LastVal) return;
619
620  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
621
622  unsigned AggregateAbbrev = 0;
623  unsigned String8Abbrev = 0;
624  unsigned CString7Abbrev = 0;
625  unsigned CString6Abbrev = 0;
626  // If this is a constant pool for the module, emit module-specific abbrevs.
627  if (isGlobal) {
628    // Abbrev for CST_CODE_AGGREGATE.
629    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
630    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
631    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
632    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
633    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
634
635    // Abbrev for CST_CODE_STRING.
636    Abbv = new BitCodeAbbrev();
637    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
638    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
639    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
640    String8Abbrev = Stream.EmitAbbrev(Abbv);
641    // Abbrev for CST_CODE_CSTRING.
642    Abbv = new BitCodeAbbrev();
643    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
644    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
645    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
646    CString7Abbrev = Stream.EmitAbbrev(Abbv);
647    // Abbrev for CST_CODE_CSTRING.
648    Abbv = new BitCodeAbbrev();
649    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
650    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
651    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
652    CString6Abbrev = Stream.EmitAbbrev(Abbv);
653  }
654
655  SmallVector<uint64_t, 64> Record;
656
657  const ValueEnumerator::ValueList &Vals = VE.getValues();
658  const Type *LastTy = 0;
659  for (unsigned i = FirstVal; i != LastVal; ++i) {
660    const Value *V = Vals[i].first;
661    // If we need to switch types, do so now.
662    if (V->getType() != LastTy) {
663      LastTy = V->getType();
664      Record.push_back(VE.getTypeID(LastTy));
665      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
666                        CONSTANTS_SETTYPE_ABBREV);
667      Record.clear();
668    }
669
670    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
671      Record.push_back(unsigned(IA->hasSideEffects()) |
672                       unsigned(IA->isAlignStack()) << 1);
673
674      // Add the asm string.
675      const std::string &AsmStr = IA->getAsmString();
676      Record.push_back(AsmStr.size());
677      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
678        Record.push_back(AsmStr[i]);
679
680      // Add the constraint string.
681      const std::string &ConstraintStr = IA->getConstraintString();
682      Record.push_back(ConstraintStr.size());
683      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
684        Record.push_back(ConstraintStr[i]);
685      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
686      Record.clear();
687      continue;
688    }
689    const Constant *C = cast<Constant>(V);
690    unsigned Code = -1U;
691    unsigned AbbrevToUse = 0;
692    if (C->isNullValue()) {
693      Code = bitc::CST_CODE_NULL;
694    } else if (isa<UndefValue>(C)) {
695      Code = bitc::CST_CODE_UNDEF;
696    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
697      if (IV->getBitWidth() <= 64) {
698        int64_t V = IV->getSExtValue();
699        if (V >= 0)
700          Record.push_back(V << 1);
701        else
702          Record.push_back((-V << 1) | 1);
703        Code = bitc::CST_CODE_INTEGER;
704        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
705      } else {                             // Wide integers, > 64 bits in size.
706        // We have an arbitrary precision integer value to write whose
707        // bit width is > 64. However, in canonical unsigned integer
708        // format it is likely that the high bits are going to be zero.
709        // So, we only write the number of active words.
710        unsigned NWords = IV->getValue().getActiveWords();
711        const uint64_t *RawWords = IV->getValue().getRawData();
712        for (unsigned i = 0; i != NWords; ++i) {
713          int64_t V = RawWords[i];
714          if (V >= 0)
715            Record.push_back(V << 1);
716          else
717            Record.push_back((-V << 1) | 1);
718        }
719        Code = bitc::CST_CODE_WIDE_INTEGER;
720      }
721    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
722      Code = bitc::CST_CODE_FLOAT;
723      const Type *Ty = CFP->getType();
724      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
725        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
726      } else if (Ty->isX86_FP80Ty()) {
727        // api needed to prevent premature destruction
728        // bits are not in the same order as a normal i80 APInt, compensate.
729        APInt api = CFP->getValueAPF().bitcastToAPInt();
730        const uint64_t *p = api.getRawData();
731        Record.push_back((p[1] << 48) | (p[0] >> 16));
732        Record.push_back(p[0] & 0xffffLL);
733      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
734        APInt api = CFP->getValueAPF().bitcastToAPInt();
735        const uint64_t *p = api.getRawData();
736        Record.push_back(p[0]);
737        Record.push_back(p[1]);
738      } else {
739        assert (0 && "Unknown FP type!");
740      }
741    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
742      const ConstantArray *CA = cast<ConstantArray>(C);
743      // Emit constant strings specially.
744      unsigned NumOps = CA->getNumOperands();
745      // If this is a null-terminated string, use the denser CSTRING encoding.
746      if (CA->getOperand(NumOps-1)->isNullValue()) {
747        Code = bitc::CST_CODE_CSTRING;
748        --NumOps;  // Don't encode the null, which isn't allowed by char6.
749      } else {
750        Code = bitc::CST_CODE_STRING;
751        AbbrevToUse = String8Abbrev;
752      }
753      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
754      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
755      for (unsigned i = 0; i != NumOps; ++i) {
756        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
757        Record.push_back(V);
758        isCStr7 &= (V & 128) == 0;
759        if (isCStrChar6)
760          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
761      }
762
763      if (isCStrChar6)
764        AbbrevToUse = CString6Abbrev;
765      else if (isCStr7)
766        AbbrevToUse = CString7Abbrev;
767    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
768               isa<ConstantVector>(V)) {
769      Code = bitc::CST_CODE_AGGREGATE;
770      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
771        Record.push_back(VE.getValueID(C->getOperand(i)));
772      AbbrevToUse = AggregateAbbrev;
773    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
774      switch (CE->getOpcode()) {
775      default:
776        if (Instruction::isCast(CE->getOpcode())) {
777          Code = bitc::CST_CODE_CE_CAST;
778          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
779          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
780          Record.push_back(VE.getValueID(C->getOperand(0)));
781          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
782        } else {
783          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
784          Code = bitc::CST_CODE_CE_BINOP;
785          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
786          Record.push_back(VE.getValueID(C->getOperand(0)));
787          Record.push_back(VE.getValueID(C->getOperand(1)));
788          uint64_t Flags = GetOptimizationFlags(CE);
789          if (Flags != 0)
790            Record.push_back(Flags);
791        }
792        break;
793      case Instruction::GetElementPtr:
794        Code = bitc::CST_CODE_CE_GEP;
795        if (cast<GEPOperator>(C)->isInBounds())
796          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
797        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
798          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
799          Record.push_back(VE.getValueID(C->getOperand(i)));
800        }
801        break;
802      case Instruction::Select:
803        Code = bitc::CST_CODE_CE_SELECT;
804        Record.push_back(VE.getValueID(C->getOperand(0)));
805        Record.push_back(VE.getValueID(C->getOperand(1)));
806        Record.push_back(VE.getValueID(C->getOperand(2)));
807        break;
808      case Instruction::ExtractElement:
809        Code = bitc::CST_CODE_CE_EXTRACTELT;
810        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
811        Record.push_back(VE.getValueID(C->getOperand(0)));
812        Record.push_back(VE.getValueID(C->getOperand(1)));
813        break;
814      case Instruction::InsertElement:
815        Code = bitc::CST_CODE_CE_INSERTELT;
816        Record.push_back(VE.getValueID(C->getOperand(0)));
817        Record.push_back(VE.getValueID(C->getOperand(1)));
818        Record.push_back(VE.getValueID(C->getOperand(2)));
819        break;
820      case Instruction::ShuffleVector:
821        // If the return type and argument types are the same, this is a
822        // standard shufflevector instruction.  If the types are different,
823        // then the shuffle is widening or truncating the input vectors, and
824        // the argument type must also be encoded.
825        if (C->getType() == C->getOperand(0)->getType()) {
826          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
827        } else {
828          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
829          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
830        }
831        Record.push_back(VE.getValueID(C->getOperand(0)));
832        Record.push_back(VE.getValueID(C->getOperand(1)));
833        Record.push_back(VE.getValueID(C->getOperand(2)));
834        break;
835      case Instruction::ICmp:
836      case Instruction::FCmp:
837        Code = bitc::CST_CODE_CE_CMP;
838        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
839        Record.push_back(VE.getValueID(C->getOperand(0)));
840        Record.push_back(VE.getValueID(C->getOperand(1)));
841        Record.push_back(CE->getPredicate());
842        break;
843      }
844    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
845      assert(BA->getFunction() == BA->getBasicBlock()->getParent() &&
846             "Malformed blockaddress");
847      Code = bitc::CST_CODE_BLOCKADDRESS;
848      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
849      Record.push_back(VE.getValueID(BA->getFunction()));
850      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
851    } else {
852      llvm_unreachable("Unknown constant!");
853    }
854    Stream.EmitRecord(Code, Record, AbbrevToUse);
855    Record.clear();
856  }
857
858  Stream.ExitBlock();
859}
860
861static void WriteModuleConstants(const ValueEnumerator &VE,
862                                 BitstreamWriter &Stream) {
863  const ValueEnumerator::ValueList &Vals = VE.getValues();
864
865  // Find the first constant to emit, which is the first non-globalvalue value.
866  // We know globalvalues have been emitted by WriteModuleInfo.
867  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
868    if (!isa<GlobalValue>(Vals[i].first)) {
869      WriteConstants(i, Vals.size(), VE, Stream, true);
870      return;
871    }
872  }
873}
874
875/// PushValueAndType - The file has to encode both the value and type id for
876/// many values, because we need to know what type to create for forward
877/// references.  However, most operands are not forward references, so this type
878/// field is not needed.
879///
880/// This function adds V's value ID to Vals.  If the value ID is higher than the
881/// instruction ID, then it is a forward reference, and it also includes the
882/// type ID.
883static bool PushValueAndType(const Value *V, unsigned InstID,
884                             SmallVector<unsigned, 64> &Vals,
885                             ValueEnumerator &VE) {
886  unsigned ValID = VE.getValueID(V);
887  Vals.push_back(ValID);
888  if (ValID >= InstID) {
889    Vals.push_back(VE.getTypeID(V->getType()));
890    return true;
891  }
892  return false;
893}
894
895/// WriteInstruction - Emit an instruction to the specified stream.
896static void WriteInstruction(const Instruction &I, unsigned InstID,
897                             ValueEnumerator &VE, BitstreamWriter &Stream,
898                             SmallVector<unsigned, 64> &Vals) {
899  unsigned Code = 0;
900  unsigned AbbrevToUse = 0;
901  VE.setInstructionID(&I);
902  switch (I.getOpcode()) {
903  default:
904    if (Instruction::isCast(I.getOpcode())) {
905      Code = bitc::FUNC_CODE_INST_CAST;
906      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
907        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
908      Vals.push_back(VE.getTypeID(I.getType()));
909      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
910    } else {
911      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
912      Code = bitc::FUNC_CODE_INST_BINOP;
913      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
914        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
915      Vals.push_back(VE.getValueID(I.getOperand(1)));
916      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
917      uint64_t Flags = GetOptimizationFlags(&I);
918      if (Flags != 0) {
919        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
920          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
921        Vals.push_back(Flags);
922      }
923    }
924    break;
925
926  case Instruction::GetElementPtr:
927    Code = bitc::FUNC_CODE_INST_GEP;
928    if (cast<GEPOperator>(&I)->isInBounds())
929      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
930    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
931      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
932    break;
933  case Instruction::ExtractValue: {
934    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
935    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
936    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
937    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
938      Vals.push_back(*i);
939    break;
940  }
941  case Instruction::InsertValue: {
942    Code = bitc::FUNC_CODE_INST_INSERTVAL;
943    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
944    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
945    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
946    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
947      Vals.push_back(*i);
948    break;
949  }
950  case Instruction::Select:
951    Code = bitc::FUNC_CODE_INST_VSELECT;
952    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
953    Vals.push_back(VE.getValueID(I.getOperand(2)));
954    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
955    break;
956  case Instruction::ExtractElement:
957    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
958    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
959    Vals.push_back(VE.getValueID(I.getOperand(1)));
960    break;
961  case Instruction::InsertElement:
962    Code = bitc::FUNC_CODE_INST_INSERTELT;
963    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
964    Vals.push_back(VE.getValueID(I.getOperand(1)));
965    Vals.push_back(VE.getValueID(I.getOperand(2)));
966    break;
967  case Instruction::ShuffleVector:
968    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
969    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
970    Vals.push_back(VE.getValueID(I.getOperand(1)));
971    Vals.push_back(VE.getValueID(I.getOperand(2)));
972    break;
973  case Instruction::ICmp:
974  case Instruction::FCmp:
975    // compare returning Int1Ty or vector of Int1Ty
976    Code = bitc::FUNC_CODE_INST_CMP2;
977    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
978    Vals.push_back(VE.getValueID(I.getOperand(1)));
979    Vals.push_back(cast<CmpInst>(I).getPredicate());
980    break;
981
982  case Instruction::Ret:
983    {
984      Code = bitc::FUNC_CODE_INST_RET;
985      unsigned NumOperands = I.getNumOperands();
986      if (NumOperands == 0)
987        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
988      else if (NumOperands == 1) {
989        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
990          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
991      } else {
992        for (unsigned i = 0, e = NumOperands; i != e; ++i)
993          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
994      }
995    }
996    break;
997  case Instruction::Br:
998    {
999      Code = bitc::FUNC_CODE_INST_BR;
1000      BranchInst &II = cast<BranchInst>(I);
1001      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1002      if (II.isConditional()) {
1003        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1004        Vals.push_back(VE.getValueID(II.getCondition()));
1005      }
1006    }
1007    break;
1008  case Instruction::Switch:
1009    Code = bitc::FUNC_CODE_INST_SWITCH;
1010    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1011    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1012      Vals.push_back(VE.getValueID(I.getOperand(i)));
1013    break;
1014  case Instruction::IndirectBr:
1015    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1016    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1017    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1018      Vals.push_back(VE.getValueID(I.getOperand(i)));
1019    break;
1020
1021  case Instruction::Invoke: {
1022    const InvokeInst *II = cast<InvokeInst>(&I);
1023    const Value *Callee(II->getCalledValue());
1024    const PointerType *PTy = cast<PointerType>(Callee->getType());
1025    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1026    Code = bitc::FUNC_CODE_INST_INVOKE;
1027
1028    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1029    Vals.push_back(II->getCallingConv());
1030    Vals.push_back(VE.getValueID(II->getNormalDest()));
1031    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1032    PushValueAndType(Callee, InstID, Vals, VE);
1033
1034    // Emit value #'s for the fixed parameters.
1035    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1036      Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
1037
1038    // Emit type/value pairs for varargs params.
1039    if (FTy->isVarArg()) {
1040      for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
1041           i != e; ++i)
1042        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1043    }
1044    break;
1045  }
1046  case Instruction::Unwind:
1047    Code = bitc::FUNC_CODE_INST_UNWIND;
1048    break;
1049  case Instruction::Unreachable:
1050    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1051    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1052    break;
1053
1054  case Instruction::PHI:
1055    Code = bitc::FUNC_CODE_INST_PHI;
1056    Vals.push_back(VE.getTypeID(I.getType()));
1057    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1058      Vals.push_back(VE.getValueID(I.getOperand(i)));
1059    break;
1060
1061  case Instruction::Alloca:
1062    Code = bitc::FUNC_CODE_INST_ALLOCA;
1063    Vals.push_back(VE.getTypeID(I.getType()));
1064    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1065    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1066    break;
1067
1068  case Instruction::Load:
1069    Code = bitc::FUNC_CODE_INST_LOAD;
1070    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1071      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1072
1073    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1074    Vals.push_back(cast<LoadInst>(I).isVolatile());
1075    break;
1076  case Instruction::Store:
1077    Code = bitc::FUNC_CODE_INST_STORE2;
1078    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1079    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1080    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1081    Vals.push_back(cast<StoreInst>(I).isVolatile());
1082    break;
1083  case Instruction::Call: {
1084    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
1085    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1086
1087    Code = bitc::FUNC_CODE_INST_CALL;
1088
1089    const CallInst *CI = cast<CallInst>(&I);
1090    Vals.push_back(VE.getAttributeID(CI->getAttributes()));
1091    Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
1092    PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
1093
1094    // Emit value #'s for the fixed parameters.
1095    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1096      Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
1097
1098    // Emit type/value pairs for varargs params.
1099    if (FTy->isVarArg()) {
1100      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
1101      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
1102           i != e; ++i)
1103        PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
1104    }
1105    break;
1106  }
1107  case Instruction::VAArg:
1108    Code = bitc::FUNC_CODE_INST_VAARG;
1109    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1110    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1111    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1112    break;
1113  }
1114
1115  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1116  Vals.clear();
1117}
1118
1119// Emit names for globals/functions etc.
1120static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1121                                  const ValueEnumerator &VE,
1122                                  BitstreamWriter &Stream) {
1123  if (VST.empty()) return;
1124  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1125
1126  // FIXME: Set up the abbrev, we know how many values there are!
1127  // FIXME: We know if the type names can use 7-bit ascii.
1128  SmallVector<unsigned, 64> NameVals;
1129
1130  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1131       SI != SE; ++SI) {
1132
1133    const ValueName &Name = *SI;
1134
1135    // Figure out the encoding to use for the name.
1136    bool is7Bit = true;
1137    bool isChar6 = true;
1138    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1139         C != E; ++C) {
1140      if (isChar6)
1141        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1142      if ((unsigned char)*C & 128) {
1143        is7Bit = false;
1144        break;  // don't bother scanning the rest.
1145      }
1146    }
1147
1148    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1149
1150    // VST_ENTRY:   [valueid, namechar x N]
1151    // VST_BBENTRY: [bbid, namechar x N]
1152    unsigned Code;
1153    if (isa<BasicBlock>(SI->getValue())) {
1154      Code = bitc::VST_CODE_BBENTRY;
1155      if (isChar6)
1156        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1157    } else {
1158      Code = bitc::VST_CODE_ENTRY;
1159      if (isChar6)
1160        AbbrevToUse = VST_ENTRY_6_ABBREV;
1161      else if (is7Bit)
1162        AbbrevToUse = VST_ENTRY_7_ABBREV;
1163    }
1164
1165    NameVals.push_back(VE.getValueID(SI->getValue()));
1166    for (const char *P = Name.getKeyData(),
1167         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1168      NameVals.push_back((unsigned char)*P);
1169
1170    // Emit the finished record.
1171    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1172    NameVals.clear();
1173  }
1174  Stream.ExitBlock();
1175}
1176
1177/// WriteFunction - Emit a function body to the module stream.
1178static void WriteFunction(const Function &F, ValueEnumerator &VE,
1179                          BitstreamWriter &Stream) {
1180  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1181  VE.incorporateFunction(F);
1182
1183  SmallVector<unsigned, 64> Vals;
1184
1185  // Emit the number of basic blocks, so the reader can create them ahead of
1186  // time.
1187  Vals.push_back(VE.getBasicBlocks().size());
1188  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1189  Vals.clear();
1190
1191  // If there are function-local constants, emit them now.
1192  unsigned CstStart, CstEnd;
1193  VE.getFunctionConstantRange(CstStart, CstEnd);
1194  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1195
1196  // Keep a running idea of what the instruction ID is.
1197  unsigned InstID = CstEnd;
1198
1199  // Finally, emit all the instructions, in order.
1200  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1201    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1202         I != E; ++I) {
1203      WriteInstruction(*I, InstID, VE, Stream, Vals);
1204      if (!I->getType()->isVoidTy())
1205        ++InstID;
1206    }
1207
1208  // Emit names for all the instructions etc.
1209  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1210
1211  WriteMetadataAttachment(F, VE, Stream);
1212  VE.purgeFunction();
1213  Stream.ExitBlock();
1214}
1215
1216/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1217static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1218                                 const ValueEnumerator &VE,
1219                                 BitstreamWriter &Stream) {
1220  if (TST.empty()) return;
1221
1222  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1223
1224  // 7-bit fixed width VST_CODE_ENTRY strings.
1225  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1226  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1227  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1228                            Log2_32_Ceil(VE.getTypes().size()+1)));
1229  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1230  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1231  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1232
1233  SmallVector<unsigned, 64> NameVals;
1234
1235  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1236       TI != TE; ++TI) {
1237    // TST_ENTRY: [typeid, namechar x N]
1238    NameVals.push_back(VE.getTypeID(TI->second));
1239
1240    const std::string &Str = TI->first;
1241    bool is7Bit = true;
1242    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1243      NameVals.push_back((unsigned char)Str[i]);
1244      if (Str[i] & 128)
1245        is7Bit = false;
1246    }
1247
1248    // Emit the finished record.
1249    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1250    NameVals.clear();
1251  }
1252
1253  Stream.ExitBlock();
1254}
1255
1256// Emit blockinfo, which defines the standard abbreviations etc.
1257static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1258  // We only want to emit block info records for blocks that have multiple
1259  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1260  // blocks can defined their abbrevs inline.
1261  Stream.EnterBlockInfoBlock(2);
1262
1263  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1264    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1265    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1266    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1267    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1268    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1269    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1270                                   Abbv) != VST_ENTRY_8_ABBREV)
1271      llvm_unreachable("Unexpected abbrev ordering!");
1272  }
1273
1274  { // 7-bit fixed width VST_ENTRY strings.
1275    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1276    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1277    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1278    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1279    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1280    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1281                                   Abbv) != VST_ENTRY_7_ABBREV)
1282      llvm_unreachable("Unexpected abbrev ordering!");
1283  }
1284  { // 6-bit char6 VST_ENTRY strings.
1285    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1286    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1287    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1288    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1289    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1290    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1291                                   Abbv) != VST_ENTRY_6_ABBREV)
1292      llvm_unreachable("Unexpected abbrev ordering!");
1293  }
1294  { // 6-bit char6 VST_BBENTRY strings.
1295    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1296    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1297    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1298    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1299    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1300    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1301                                   Abbv) != VST_BBENTRY_6_ABBREV)
1302      llvm_unreachable("Unexpected abbrev ordering!");
1303  }
1304
1305
1306
1307  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1308    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1309    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1310    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1311                              Log2_32_Ceil(VE.getTypes().size()+1)));
1312    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1313                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1314      llvm_unreachable("Unexpected abbrev ordering!");
1315  }
1316
1317  { // INTEGER abbrev for CONSTANTS_BLOCK.
1318    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1319    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1320    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1321    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1322                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1323      llvm_unreachable("Unexpected abbrev ordering!");
1324  }
1325
1326  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1327    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1328    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1329    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1330    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1331                              Log2_32_Ceil(VE.getTypes().size()+1)));
1332    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1333
1334    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1335                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1336      llvm_unreachable("Unexpected abbrev ordering!");
1337  }
1338  { // NULL abbrev for CONSTANTS_BLOCK.
1339    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1340    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1341    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1342                                   Abbv) != CONSTANTS_NULL_Abbrev)
1343      llvm_unreachable("Unexpected abbrev ordering!");
1344  }
1345
1346  // FIXME: This should only use space for first class types!
1347
1348  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1349    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1350    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1351    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1352    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1353    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1354    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1355                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1356      llvm_unreachable("Unexpected abbrev ordering!");
1357  }
1358  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1359    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1360    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1361    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1362    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1363    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1364    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1365                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1366      llvm_unreachable("Unexpected abbrev ordering!");
1367  }
1368  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1369    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1370    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1371    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1372    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1373    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1374    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1375    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1376                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1377      llvm_unreachable("Unexpected abbrev ordering!");
1378  }
1379  { // INST_CAST abbrev for FUNCTION_BLOCK.
1380    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1381    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1382    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1383    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1384                              Log2_32_Ceil(VE.getTypes().size()+1)));
1385    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1386    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1387                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1388      llvm_unreachable("Unexpected abbrev ordering!");
1389  }
1390
1391  { // INST_RET abbrev for FUNCTION_BLOCK.
1392    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1393    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1394    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1395                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1396      llvm_unreachable("Unexpected abbrev ordering!");
1397  }
1398  { // INST_RET abbrev for FUNCTION_BLOCK.
1399    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1400    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1401    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1402    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1403                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1404      llvm_unreachable("Unexpected abbrev ordering!");
1405  }
1406  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1407    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1408    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1409    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1410                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1411      llvm_unreachable("Unexpected abbrev ordering!");
1412  }
1413
1414  Stream.ExitBlock();
1415}
1416
1417
1418/// WriteModule - Emit the specified module to the bitstream.
1419static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1420  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1421
1422  // Emit the version number if it is non-zero.
1423  if (CurVersion) {
1424    SmallVector<unsigned, 1> Vals;
1425    Vals.push_back(CurVersion);
1426    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1427  }
1428
1429  // Analyze the module, enumerating globals, functions, etc.
1430  ValueEnumerator VE(M);
1431
1432  // Emit blockinfo, which defines the standard abbreviations etc.
1433  WriteBlockInfo(VE, Stream);
1434
1435  // Emit information about parameter attributes.
1436  WriteAttributeTable(VE, Stream);
1437
1438  // Emit information describing all of the types in the module.
1439  WriteTypeTable(VE, Stream);
1440
1441  // Emit top-level description of module, including target triple, inline asm,
1442  // descriptors for global variables, and function prototype info.
1443  WriteModuleInfo(M, VE, Stream);
1444
1445  // Emit constants.
1446  WriteModuleConstants(VE, Stream);
1447
1448  // Emit metadata.
1449  WriteModuleMetadata(VE, Stream);
1450
1451  // Emit function bodies.
1452  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1453    if (!I->isDeclaration())
1454      WriteFunction(*I, VE, Stream);
1455
1456  // Emit metadata.
1457  WriteModuleMetadataStore(M, Stream);
1458
1459  // Emit the type symbol table information.
1460  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1461
1462  // Emit names for globals/functions etc.
1463  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1464
1465  Stream.ExitBlock();
1466}
1467
1468/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1469/// header and trailer to make it compatible with the system archiver.  To do
1470/// this we emit the following header, and then emit a trailer that pads the
1471/// file out to be a multiple of 16 bytes.
1472///
1473/// struct bc_header {
1474///   uint32_t Magic;         // 0x0B17C0DE
1475///   uint32_t Version;       // Version, currently always 0.
1476///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1477///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1478///   uint32_t CPUType;       // CPU specifier.
1479///   ... potentially more later ...
1480/// };
1481enum {
1482  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1483  DarwinBCHeaderSize = 5*4
1484};
1485
1486static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1487                               const std::string &TT) {
1488  unsigned CPUType = ~0U;
1489
1490  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*.  The CPUType is a
1491  // magic number from /usr/include/mach/machine.h.  It is ok to reproduce the
1492  // specific constants here because they are implicitly part of the Darwin ABI.
1493  enum {
1494    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1495    DARWIN_CPU_TYPE_X86        = 7,
1496    DARWIN_CPU_TYPE_POWERPC    = 18
1497  };
1498
1499  if (TT.find("x86_64-") == 0)
1500    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1501  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1502           TT[4] == '-' && TT[1] - '3' < 6)
1503    CPUType = DARWIN_CPU_TYPE_X86;
1504  else if (TT.find("powerpc-") == 0)
1505    CPUType = DARWIN_CPU_TYPE_POWERPC;
1506  else if (TT.find("powerpc64-") == 0)
1507    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1508
1509  // Traditional Bitcode starts after header.
1510  unsigned BCOffset = DarwinBCHeaderSize;
1511
1512  Stream.Emit(0x0B17C0DE, 32);
1513  Stream.Emit(0         , 32);  // Version.
1514  Stream.Emit(BCOffset  , 32);
1515  Stream.Emit(0         , 32);  // Filled in later.
1516  Stream.Emit(CPUType   , 32);
1517}
1518
1519/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1520/// finalize the header.
1521static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1522  // Update the size field in the header.
1523  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1524
1525  // If the file is not a multiple of 16 bytes, insert dummy padding.
1526  while (BufferSize & 15) {
1527    Stream.Emit(0, 8);
1528    ++BufferSize;
1529  }
1530}
1531
1532
1533/// WriteBitcodeToFile - Write the specified module to the specified output
1534/// stream.
1535void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1536  std::vector<unsigned char> Buffer;
1537  BitstreamWriter Stream(Buffer);
1538
1539  Buffer.reserve(256*1024);
1540
1541  WriteBitcodeToStream( M, Stream );
1542
1543  // If writing to stdout, set binary mode.
1544  if (&llvm::outs() == &Out)
1545    sys::Program::ChangeStdoutToBinary();
1546
1547  // Write the generated bitstream to "Out".
1548  Out.write((char*)&Buffer.front(), Buffer.size());
1549
1550  // Make sure it hits disk now.
1551  Out.flush();
1552}
1553
1554/// WriteBitcodeToStream - Write the specified module to the specified output
1555/// stream.
1556void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1557  // If this is darwin, emit a file header and trailer if needed.
1558  bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1559  if (isDarwin)
1560    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1561
1562  // Emit the file header.
1563  Stream.Emit((unsigned)'B', 8);
1564  Stream.Emit((unsigned)'C', 8);
1565  Stream.Emit(0x0, 4);
1566  Stream.Emit(0xC, 4);
1567  Stream.Emit(0xE, 4);
1568  Stream.Emit(0xD, 4);
1569
1570  // Emit the module.
1571  WriteModule(M, Stream);
1572
1573  if (isDarwin)
1574    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1575}
1576