BitcodeWriter.cpp revision ee4016d1247d3fbe50822de279d3da273d8aef4c 
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 "ReaderWriter_2_9.h"
15#include "legacy_bitcode.h"
16#include "ValueEnumerator.h"
17#include "llvm/ADT/Triple.h"
18#include "llvm/Bitcode/BitstreamWriter.h"
19#include "llvm/Bitcode/LLVMBitCodes.h"
20#include "llvm/IR/Constants.h"
21#include "llvm/IR/DerivedTypes.h"
22#include "llvm/IR/InlineAsm.h"
23#include "llvm/IR/Instructions.h"
24#include "llvm/IR/Module.h"
25#include "llvm/IR/Operator.h"
26#include "llvm/IR/ValueSymbolTable.h"
27#include "llvm/Support/ErrorHandling.h"
28#include "llvm/Support/MathExtras.h"
29#include "llvm/Support/Program.h"
30#include "llvm/Support/raw_ostream.h"
31#include <cctype>
32#include <map>
33using namespace llvm;
34
35// Redefine older bitcode opcodes for use here. Note that these come from
36// LLVM 2.7 (which is what HC shipped with).
37#define METADATA_NODE_2_7             2
38#define METADATA_FN_NODE_2_7          3
39#define METADATA_NAMED_NODE_2_7       5
40#define METADATA_ATTACHMENT_2_7       7
41#define FUNC_CODE_INST_CALL_2_7       22
42#define FUNC_CODE_DEBUG_LOC_2_7       32
43
44// Redefine older bitcode opcodes for use here. Note that these come from
45// LLVM 2.7 - 3.0.
46#define TYPE_BLOCK_ID_OLD_3_0 10
47#define TYPE_SYMTAB_BLOCK_ID_OLD_3_0 13
48#define TYPE_CODE_STRUCT_OLD_3_0 10
49
50/// These are manifest constants used by the bitcode writer. They do not need to
51/// be kept in sync with the reader, but need to be consistent within this file.
52enum {
53  CurVersion = 0,
54
55  // VALUE_SYMTAB_BLOCK abbrev id's.
56  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
57  VST_ENTRY_7_ABBREV,
58  VST_ENTRY_6_ABBREV,
59  VST_BBENTRY_6_ABBREV,
60
61  // CONSTANTS_BLOCK abbrev id's.
62  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
63  CONSTANTS_INTEGER_ABBREV,
64  CONSTANTS_CE_CAST_Abbrev,
65  CONSTANTS_NULL_Abbrev,
66
67  // FUNCTION_BLOCK abbrev id's.
68  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
69  FUNCTION_INST_BINOP_ABBREV,
70  FUNCTION_INST_BINOP_FLAGS_ABBREV,
71  FUNCTION_INST_CAST_ABBREV,
72  FUNCTION_INST_RET_VOID_ABBREV,
73  FUNCTION_INST_RET_VAL_ABBREV,
74  FUNCTION_INST_UNREACHABLE_ABBREV
75};
76
77
78static unsigned GetEncodedCastOpcode(unsigned Opcode) {
79  switch (Opcode) {
80  default: llvm_unreachable("Unknown cast instruction!");
81  case Instruction::Trunc   : return bitc::CAST_TRUNC;
82  case Instruction::ZExt    : return bitc::CAST_ZEXT;
83  case Instruction::SExt    : return bitc::CAST_SEXT;
84  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
85  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
86  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
87  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
88  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
89  case Instruction::FPExt   : return bitc::CAST_FPEXT;
90  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
91  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
92  case Instruction::BitCast : return bitc::CAST_BITCAST;
93  }
94}
95
96static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
97  switch (Opcode) {
98  default: llvm_unreachable("Unknown binary instruction!");
99  case Instruction::Add:
100  case Instruction::FAdd: return bitc::BINOP_ADD;
101  case Instruction::Sub:
102  case Instruction::FSub: return bitc::BINOP_SUB;
103  case Instruction::Mul:
104  case Instruction::FMul: return bitc::BINOP_MUL;
105  case Instruction::UDiv: return bitc::BINOP_UDIV;
106  case Instruction::FDiv:
107  case Instruction::SDiv: return bitc::BINOP_SDIV;
108  case Instruction::URem: return bitc::BINOP_UREM;
109  case Instruction::FRem:
110  case Instruction::SRem: return bitc::BINOP_SREM;
111  case Instruction::Shl:  return bitc::BINOP_SHL;
112  case Instruction::LShr: return bitc::BINOP_LSHR;
113  case Instruction::AShr: return bitc::BINOP_ASHR;
114  case Instruction::And:  return bitc::BINOP_AND;
115  case Instruction::Or:   return bitc::BINOP_OR;
116  case Instruction::Xor:  return bitc::BINOP_XOR;
117  }
118}
119
120static void WriteStringRecord(unsigned Code, StringRef Str,
121                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
122  SmallVector<unsigned, 64> Vals;
123
124  // Code: [strchar x N]
125  for (unsigned i = 0, e = Str.size(); i != e; ++i) {
126    if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
127      AbbrevToUse = 0;
128    Vals.push_back(Str[i]);
129  }
130
131  // Emit the finished record.
132  Stream.EmitRecord(Code, Vals, AbbrevToUse);
133}
134
135// Emit information about parameter attributes.
136static void WriteAttributeTable(const llvm_2_9::ValueEnumerator &VE,
137                                BitstreamWriter &Stream) {
138  const std::vector<AttributeSet> &Attrs = VE.getAttributes();
139  if (Attrs.empty()) return;
140
141  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
142
143  SmallVector<uint64_t, 64> Record;
144  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
145    const AttributeSet &A = Attrs[i];
146    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
147      Record.push_back(A.getSlotIndex(i));
148      Record.push_back(encodeLLVMAttributesForBitcode(A, A.getSlotIndex(i)));
149    }
150
151    // This needs to use the 3.2 entry type
152    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY_OLD, Record);
153    Record.clear();
154  }
155
156  Stream.ExitBlock();
157}
158
159static void WriteTypeSymbolTable(const llvm_2_9::ValueEnumerator &VE,
160                                 BitstreamWriter &Stream) {
161  const llvm_2_9::ValueEnumerator::TypeList &TypeList = VE.getTypes();
162  Stream.EnterSubblock(TYPE_SYMTAB_BLOCK_ID_OLD_3_0, 3);
163
164  // 7-bit fixed width VST_CODE_ENTRY strings.
165  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
166  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
167  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
168                            Log2_32_Ceil(VE.getTypes().size()+1)));
169  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
170  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
171  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
172
173  SmallVector<unsigned, 64> NameVals;
174
175  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
176    Type *T = TypeList[i];
177
178    switch (T->getTypeID()) {
179    case Type::StructTyID: {
180      StructType *ST = cast<StructType>(T);
181      if (ST->isLiteral()) {
182        // Skip anonymous struct definitions in type symbol table
183        // FIXME(srhines)
184        break;
185      }
186
187      // TST_ENTRY: [typeid, namechar x N]
188      NameVals.push_back(i);
189
190      const std::string &Str = ST->getName();
191      bool is7Bit = true;
192      for (unsigned i = 0, e = Str.size(); i != e; ++i) {
193        NameVals.push_back((unsigned char)Str[i]);
194        if (Str[i] & 128)
195          is7Bit = false;
196      }
197
198      // Emit the finished record.
199      Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
200      NameVals.clear();
201
202      break;
203    }
204    default: break;
205    }
206  }
207
208#if 0
209  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
210       TI != TE; ++TI) {
211    // TST_ENTRY: [typeid, namechar x N]
212    NameVals.push_back(VE.getTypeID(TI->second));
213
214    const std::string &Str = TI->first;
215    bool is7Bit = true;
216    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
217      NameVals.push_back((unsigned char)Str[i]);
218      if (Str[i] & 128)
219        is7Bit = false;
220    }
221
222    // Emit the finished record.
223    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
224    NameVals.clear();
225  }
226#endif
227
228  Stream.ExitBlock();
229}
230
231/// WriteTypeTable - Write out the type table for a module.
232static void WriteTypeTable(const llvm_2_9::ValueEnumerator &VE,
233                           BitstreamWriter &Stream) {
234  const llvm_2_9::ValueEnumerator::TypeList &TypeList = VE.getTypes();
235
236  Stream.EnterSubblock(TYPE_BLOCK_ID_OLD_3_0, 4 /*count from # abbrevs */);
237  SmallVector<uint64_t, 64> TypeVals;
238
239  // Abbrev for TYPE_CODE_POINTER.
240  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
241  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
242  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
243                            Log2_32_Ceil(VE.getTypes().size()+1)));
244  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
245  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
246
247  // Abbrev for TYPE_CODE_FUNCTION.
248  Abbv = new BitCodeAbbrev();
249  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION_OLD));
250  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
251  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
252  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
253  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
254                            Log2_32_Ceil(VE.getTypes().size()+1)));
255  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
256
257#if 0
258  // Abbrev for TYPE_CODE_STRUCT_ANON.
259  Abbv = new BitCodeAbbrev();
260  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
261  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
262  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
263  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
264                            Log2_32_Ceil(VE.getTypes().size()+1)));
265  unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
266
267  // Abbrev for TYPE_CODE_STRUCT_NAME.
268  Abbv = new BitCodeAbbrev();
269  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
270  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
271  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
272  unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
273
274  // Abbrev for TYPE_CODE_STRUCT_NAMED.
275  Abbv = new BitCodeAbbrev();
276  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
277  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
278  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
279  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
280                            Log2_32_Ceil(VE.getTypes().size()+1)));
281  unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
282#endif
283
284  // Abbrev for TYPE_CODE_STRUCT.
285  Abbv = new BitCodeAbbrev();
286  Abbv->Add(BitCodeAbbrevOp(TYPE_CODE_STRUCT_OLD_3_0));
287  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
288  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
289  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
290                            Log2_32_Ceil(VE.getTypes().size()+1)));
291  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
292
293  // Abbrev for TYPE_CODE_ARRAY.
294  Abbv = new BitCodeAbbrev();
295  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
296  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
297  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
298                            Log2_32_Ceil(VE.getTypes().size()+1)));
299  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
300
301  // Emit an entry count so the reader can reserve space.
302  TypeVals.push_back(TypeList.size());
303  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
304  TypeVals.clear();
305
306  // Loop over all of the types, emitting each in turn.
307  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
308    Type *T = TypeList[i];
309    int AbbrevToUse = 0;
310    unsigned Code = 0;
311
312    switch (T->getTypeID()) {
313    default: llvm_unreachable("Unknown type!");
314    case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;   break;
315    case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;  break;
316    case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE; break;
317    case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80; break;
318    case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128; break;
319    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
320    case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;  break;
321    case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA; break;
322    case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX; break;
323    case Type::IntegerTyID:
324      // INTEGER: [width]
325      Code = bitc::TYPE_CODE_INTEGER;
326      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
327      break;
328    case Type::PointerTyID: {
329      PointerType *PTy = cast<PointerType>(T);
330      // POINTER: [pointee type, address space]
331      Code = bitc::TYPE_CODE_POINTER;
332      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
333      unsigned AddressSpace = PTy->getAddressSpace();
334      TypeVals.push_back(AddressSpace);
335      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
336      break;
337    }
338    case Type::FunctionTyID: {
339      FunctionType *FT = cast<FunctionType>(T);
340      // FUNCTION: [isvararg, attrid, retty, paramty x N]
341      Code = bitc::TYPE_CODE_FUNCTION_OLD;
342      TypeVals.push_back(FT->isVarArg());
343      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
344      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
345      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
346        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
347      AbbrevToUse = FunctionAbbrev;
348      break;
349    }
350    case Type::StructTyID: {
351      StructType *ST = cast<StructType>(T);
352      // STRUCT: [ispacked, eltty x N]
353      TypeVals.push_back(ST->isPacked());
354      // Output all of the element types.
355      for (StructType::element_iterator I = ST->element_begin(),
356           E = ST->element_end(); I != E; ++I)
357        TypeVals.push_back(VE.getTypeID(*I));
358      AbbrevToUse = StructAbbrev;
359      break;
360    }
361    case Type::ArrayTyID: {
362      ArrayType *AT = cast<ArrayType>(T);
363      // ARRAY: [numelts, eltty]
364      Code = bitc::TYPE_CODE_ARRAY;
365      TypeVals.push_back(AT->getNumElements());
366      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
367      AbbrevToUse = ArrayAbbrev;
368      break;
369    }
370    case Type::VectorTyID: {
371      VectorType *VT = cast<VectorType>(T);
372      // VECTOR [numelts, eltty]
373      Code = bitc::TYPE_CODE_VECTOR;
374      TypeVals.push_back(VT->getNumElements());
375      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
376      break;
377    }
378    }
379
380    // Emit the finished record.
381    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
382    TypeVals.clear();
383  }
384
385  Stream.ExitBlock();
386
387  WriteTypeSymbolTable(VE, Stream);
388}
389
390static unsigned getEncodedLinkage(const GlobalValue *GV) {
391  switch (GV->getLinkage()) {
392  case GlobalValue::ExternalLinkage:                 return 0;
393  case GlobalValue::WeakAnyLinkage:                  return 1;
394  case GlobalValue::AppendingLinkage:                return 2;
395  case GlobalValue::InternalLinkage:                 return 3;
396  case GlobalValue::LinkOnceAnyLinkage:              return 4;
397  case GlobalValue::ExternalWeakLinkage:             return 7;
398  case GlobalValue::CommonLinkage:                   return 8;
399  case GlobalValue::PrivateLinkage:                  return 9;
400  case GlobalValue::WeakODRLinkage:                  return 10;
401  case GlobalValue::LinkOnceODRLinkage:              return 11;
402  case GlobalValue::AvailableExternallyLinkage:      return 12;
403  }
404  llvm_unreachable("Invalid linkage");
405}
406
407static unsigned getEncodedVisibility(const GlobalValue *GV) {
408  switch (GV->getVisibility()) {
409  default: llvm_unreachable("Invalid visibility!");
410  case GlobalValue::DefaultVisibility:   return 0;
411  case GlobalValue::HiddenVisibility:    return 1;
412  case GlobalValue::ProtectedVisibility: return 2;
413  }
414}
415
416// Emit top-level description of module, including target triple, inline asm,
417// descriptors for global variables, and function prototype info.
418static void WriteModuleInfo(const Module *M,
419                            const llvm_2_9::ValueEnumerator &VE,
420                            BitstreamWriter &Stream) {
421  // Emit various pieces of data attached to a module.
422  if (!M->getTargetTriple().empty())
423    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
424                      0/*TODO*/, Stream);
425  if (M->getDataLayout() != nullptr)
426    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout()->getStringRepresentation(),
427                      0/*TODO*/, Stream);
428  if (!M->getModuleInlineAsm().empty())
429    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
430                      0/*TODO*/, Stream);
431
432  // Emit information about sections and GC, computing how many there are. Also
433  // compute the maximum alignment value.
434  std::map<std::string, unsigned> SectionMap;
435  std::map<std::string, unsigned> GCMap;
436  unsigned MaxAlignment = 0;
437  unsigned MaxGlobalType = 0;
438  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
439       GV != E; ++GV) {
440    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
441    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
442
443    if (!GV->hasSection()) continue;
444    // Give section names unique ID's.
445    unsigned &Entry = SectionMap[GV->getSection()];
446    if (Entry != 0) continue;
447    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
448                      0/*TODO*/, Stream);
449    Entry = SectionMap.size();
450  }
451  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
452    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
453    if (F->hasSection()) {
454      // Give section names unique ID's.
455      unsigned &Entry = SectionMap[F->getSection()];
456      if (!Entry) {
457        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
458                          0/*TODO*/, Stream);
459        Entry = SectionMap.size();
460      }
461    }
462    if (F->hasGC()) {
463      // Same for GC names.
464      unsigned &Entry = GCMap[F->getGC()];
465      if (!Entry) {
466        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
467                          0/*TODO*/, Stream);
468        Entry = GCMap.size();
469      }
470    }
471  }
472
473  // Emit abbrev for globals, now that we know # sections and max alignment.
474  unsigned SimpleGVarAbbrev = 0;
475  if (!M->global_empty()) {
476    // Add an abbrev for common globals with no visibility or thread localness.
477    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
478    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
479    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
480                              Log2_32_Ceil(MaxGlobalType+1)));
481    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
482    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
483    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
484    if (MaxAlignment == 0)                                      // Alignment.
485      Abbv->Add(BitCodeAbbrevOp(0));
486    else {
487      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
488      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
489                               Log2_32_Ceil(MaxEncAlignment+1)));
490    }
491    if (SectionMap.empty())                                    // Section.
492      Abbv->Add(BitCodeAbbrevOp(0));
493    else
494      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
495                               Log2_32_Ceil(SectionMap.size()+1)));
496    // Don't bother emitting vis + thread local.
497    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
498  }
499
500  // Emit the global variable information.
501  SmallVector<unsigned, 64> Vals;
502  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
503       GV != E; ++GV) {
504    unsigned AbbrevToUse = 0;
505
506    // GLOBALVAR: [type, isconst, initid,
507    //             linkage, alignment, section, visibility, threadlocal,
508    //             unnamed_addr]
509    Vals.push_back(VE.getTypeID(GV->getType()));
510    Vals.push_back(GV->isConstant());
511    Vals.push_back(GV->isDeclaration() ? 0 :
512                   (VE.getValueID(GV->getInitializer()) + 1));
513    Vals.push_back(getEncodedLinkage(GV));
514    Vals.push_back(Log2_32(GV->getAlignment())+1);
515    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
516    if (GV->isThreadLocal() ||
517        GV->getVisibility() != GlobalValue::DefaultVisibility ||
518        GV->hasUnnamedAddr()) {
519      Vals.push_back(getEncodedVisibility(GV));
520      Vals.push_back(GV->isThreadLocal());
521      Vals.push_back(GV->hasUnnamedAddr());
522    } else {
523      AbbrevToUse = SimpleGVarAbbrev;
524    }
525
526    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
527    Vals.clear();
528  }
529
530  // Emit the function proto information.
531  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
532    // FUNCTION:  [type, callingconv, isproto, paramattr,
533    //             linkage, alignment, section, visibility, gc, unnamed_addr]
534    Vals.push_back(VE.getTypeID(F->getType()));
535    Vals.push_back(F->getCallingConv());
536    Vals.push_back(F->isDeclaration());
537    Vals.push_back(getEncodedLinkage(F));
538    Vals.push_back(VE.getAttributeID(F->getAttributes()));
539    Vals.push_back(Log2_32(F->getAlignment())+1);
540    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
541    Vals.push_back(getEncodedVisibility(F));
542    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
543    Vals.push_back(F->hasUnnamedAddr());
544
545    unsigned AbbrevToUse = 0;
546    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
547    Vals.clear();
548  }
549
550  // Emit the alias information.
551  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
552       AI != E; ++AI) {
553    Vals.push_back(VE.getTypeID(AI->getType()));
554    Vals.push_back(VE.getValueID(AI->getAliasee()));
555    Vals.push_back(getEncodedLinkage(AI));
556    Vals.push_back(getEncodedVisibility(AI));
557    unsigned AbbrevToUse = 0;
558    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
559    Vals.clear();
560  }
561}
562
563static uint64_t GetOptimizationFlags(const Value *V) {
564  uint64_t Flags = 0;
565
566  if (const OverflowingBinaryOperator *OBO =
567        dyn_cast<OverflowingBinaryOperator>(V)) {
568    if (OBO->hasNoSignedWrap())
569      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
570    if (OBO->hasNoUnsignedWrap())
571      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
572  } else if (const PossiblyExactOperator *PEO =
573               dyn_cast<PossiblyExactOperator>(V)) {
574    if (PEO->isExact())
575      Flags |= 1 << bitc::PEO_EXACT;
576  }
577
578  return Flags;
579}
580
581static void WriteMDNode(const MDNode *N,
582                        const llvm_2_9::ValueEnumerator &VE,
583                        BitstreamWriter &Stream,
584                        SmallVector<uint64_t, 64> &Record) {
585  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
586    if (N->getOperand(i)) {
587      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
588      Record.push_back(VE.getValueID(N->getOperand(i)));
589    } else {
590      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
591      Record.push_back(0);
592    }
593  }
594  unsigned MDCode = N->isFunctionLocal() ? METADATA_FN_NODE_2_7 :
595                                           METADATA_NODE_2_7;
596  Stream.EmitRecord(MDCode, Record, 0);
597  Record.clear();
598}
599
600static void WriteModuleMetadata(const Module *M,
601                                const llvm_2_9::ValueEnumerator &VE,
602                                BitstreamWriter &Stream) {
603  const llvm_2_9::ValueEnumerator::ValueList &Vals = VE.getMDValues();
604  bool StartedMetadataBlock = false;
605  unsigned MDSAbbrev = 0;
606  SmallVector<uint64_t, 64> Record;
607  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
608
609    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
610      if (!N->isFunctionLocal() || !N->getFunction()) {
611        if (!StartedMetadataBlock) {
612          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
613          StartedMetadataBlock = true;
614        }
615        WriteMDNode(N, VE, Stream, Record);
616      }
617    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
618      if (!StartedMetadataBlock)  {
619        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
620
621        // Abbrev for METADATA_STRING.
622        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
623        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
624        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
625        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
626        MDSAbbrev = Stream.EmitAbbrev(Abbv);
627        StartedMetadataBlock = true;
628      }
629
630      // Code: [strchar x N]
631      Record.append(MDS->begin(), MDS->end());
632
633      // Emit the finished record.
634      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
635      Record.clear();
636    }
637  }
638
639  // Write named metadata.
640  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
641       E = M->named_metadata_end(); I != E; ++I) {
642    const NamedMDNode *NMD = I;
643    if (!StartedMetadataBlock)  {
644      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
645      StartedMetadataBlock = true;
646    }
647
648    // Write name.
649    StringRef Str = NMD->getName();
650    for (unsigned i = 0, e = Str.size(); i != e; ++i)
651      Record.push_back(Str[i]);
652    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
653    Record.clear();
654
655    // Write named metadata operands.
656    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
657      Record.push_back(VE.getValueID(NMD->getOperand(i)));
658    Stream.EmitRecord(METADATA_NAMED_NODE_2_7, Record, 0);
659    Record.clear();
660  }
661
662  if (StartedMetadataBlock)
663    Stream.ExitBlock();
664}
665
666static void WriteFunctionLocalMetadata(const Function &F,
667                                       const llvm_2_9::ValueEnumerator &VE,
668                                       BitstreamWriter &Stream) {
669  bool StartedMetadataBlock = false;
670  SmallVector<uint64_t, 64> Record;
671  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
672  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
673    if (const MDNode *N = Vals[i])
674      if (N->isFunctionLocal() && N->getFunction() == &F) {
675        if (!StartedMetadataBlock) {
676          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
677          StartedMetadataBlock = true;
678        }
679        WriteMDNode(N, VE, Stream, Record);
680      }
681
682  if (StartedMetadataBlock)
683    Stream.ExitBlock();
684}
685
686static void WriteMetadataAttachment(const Function &F,
687                                    const llvm_2_9::ValueEnumerator &VE,
688                                    BitstreamWriter &Stream) {
689  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
690
691  SmallVector<uint64_t, 64> Record;
692
693  // Write metadata attachments
694  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
695  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
696
697  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
698    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
699         I != E; ++I) {
700      MDs.clear();
701      I->getAllMetadataOtherThanDebugLoc(MDs);
702
703      // If no metadata, ignore instruction.
704      if (MDs.empty()) continue;
705
706      Record.push_back(VE.getInstructionID(I));
707
708      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
709        Record.push_back(MDs[i].first);
710        Record.push_back(VE.getValueID(MDs[i].second));
711      }
712      Stream.EmitRecord(METADATA_ATTACHMENT_2_7, Record, 0);
713      Record.clear();
714    }
715
716  Stream.ExitBlock();
717}
718
719static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
720  SmallVector<uint64_t, 64> Record;
721
722  // Write metadata kinds
723  // METADATA_KIND - [n x [id, name]]
724  SmallVector<StringRef, 4> Names;
725  M->getMDKindNames(Names);
726
727  if (Names.empty()) return;
728
729  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
730
731  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
732    Record.push_back(MDKindID);
733    StringRef KName = Names[MDKindID];
734    Record.append(KName.begin(), KName.end());
735
736    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
737    Record.clear();
738  }
739
740  Stream.ExitBlock();
741}
742
743static void WriteConstants(unsigned FirstVal, unsigned LastVal,
744                           const llvm_2_9::ValueEnumerator &VE,
745                           BitstreamWriter &Stream, bool isGlobal) {
746  if (FirstVal == LastVal) return;
747
748  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
749
750  unsigned AggregateAbbrev = 0;
751  unsigned String8Abbrev = 0;
752  unsigned CString7Abbrev = 0;
753  unsigned CString6Abbrev = 0;
754  // If this is a constant pool for the module, emit module-specific abbrevs.
755  if (isGlobal) {
756    // Abbrev for CST_CODE_AGGREGATE.
757    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
758    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
759    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
760    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
761    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
762
763    // Abbrev for CST_CODE_STRING.
764    Abbv = new BitCodeAbbrev();
765    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
766    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
767    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
768    String8Abbrev = Stream.EmitAbbrev(Abbv);
769    // Abbrev for CST_CODE_CSTRING.
770    Abbv = new BitCodeAbbrev();
771    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
772    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
773    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
774    CString7Abbrev = Stream.EmitAbbrev(Abbv);
775    // Abbrev for CST_CODE_CSTRING.
776    Abbv = new BitCodeAbbrev();
777    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
778    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
779    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
780    CString6Abbrev = Stream.EmitAbbrev(Abbv);
781  }
782
783  SmallVector<uint64_t, 64> Record;
784
785  const llvm_2_9::ValueEnumerator::ValueList &Vals = VE.getValues();
786  Type *LastTy = 0;
787  for (unsigned i = FirstVal; i != LastVal; ++i) {
788    const Value *V = Vals[i].first;
789    // If we need to switch types, do so now.
790    if (V->getType() != LastTy) {
791      LastTy = V->getType();
792      Record.push_back(VE.getTypeID(LastTy));
793      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
794                        CONSTANTS_SETTYPE_ABBREV);
795      Record.clear();
796    }
797
798    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
799      Record.push_back(unsigned(IA->hasSideEffects()) |
800                       unsigned(IA->isAlignStack()) << 1);
801
802      // Add the asm string.
803      const std::string &AsmStr = IA->getAsmString();
804      Record.push_back(AsmStr.size());
805      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
806        Record.push_back(AsmStr[i]);
807
808      // Add the constraint string.
809      const std::string &ConstraintStr = IA->getConstraintString();
810      Record.push_back(ConstraintStr.size());
811      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
812        Record.push_back(ConstraintStr[i]);
813      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
814      Record.clear();
815      continue;
816    }
817    const Constant *C = cast<Constant>(V);
818    unsigned Code = -1U;
819    unsigned AbbrevToUse = 0;
820    if (C->isNullValue()) {
821      Code = bitc::CST_CODE_NULL;
822    } else if (isa<UndefValue>(C)) {
823      Code = bitc::CST_CODE_UNDEF;
824    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
825      if (IV->getBitWidth() <= 64) {
826        uint64_t V = IV->getSExtValue();
827        if ((int64_t)V >= 0)
828          Record.push_back(V << 1);
829        else
830          Record.push_back((-V << 1) | 1);
831        Code = bitc::CST_CODE_INTEGER;
832        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
833      } else {                             // Wide integers, > 64 bits in size.
834        // We have an arbitrary precision integer value to write whose
835        // bit width is > 64. However, in canonical unsigned integer
836        // format it is likely that the high bits are going to be zero.
837        // So, we only write the number of active words.
838        unsigned NWords = IV->getValue().getActiveWords();
839        const uint64_t *RawWords = IV->getValue().getRawData();
840        for (unsigned i = 0; i != NWords; ++i) {
841          int64_t V = RawWords[i];
842          if (V >= 0)
843            Record.push_back(V << 1);
844          else
845            Record.push_back((-V << 1) | 1);
846        }
847        Code = bitc::CST_CODE_WIDE_INTEGER;
848      }
849    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
850      Code = bitc::CST_CODE_FLOAT;
851      Type *Ty = CFP->getType();
852      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
853        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
854      } else if (Ty->isX86_FP80Ty()) {
855        // api needed to prevent premature destruction
856        // bits are not in the same order as a normal i80 APInt, compensate.
857        APInt api = CFP->getValueAPF().bitcastToAPInt();
858        const uint64_t *p = api.getRawData();
859        Record.push_back((p[1] << 48) | (p[0] >> 16));
860        Record.push_back(p[0] & 0xffffLL);
861      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
862        APInt api = CFP->getValueAPF().bitcastToAPInt();
863        const uint64_t *p = api.getRawData();
864        Record.push_back(p[0]);
865        Record.push_back(p[1]);
866      } else {
867        assert (0 && "Unknown FP type!");
868      }
869    } else if (isa<ConstantDataSequential>(C) &&
870               cast<ConstantDataSequential>(C)->isString()) {
871      const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
872      // Emit constant strings specially.
873      unsigned NumElts = Str->getNumElements();
874      // If this is a null-terminated string, use the denser CSTRING encoding.
875      if (Str->isCString()) {
876        Code = bitc::CST_CODE_CSTRING;
877        --NumElts;  // Don't encode the null, which isn't allowed by char6.
878      } else {
879        Code = bitc::CST_CODE_STRING;
880        AbbrevToUse = String8Abbrev;
881      }
882      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
883      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
884      for (unsigned i = 0; i != NumElts; ++i) {
885        unsigned char V = Str->getElementAsInteger(i);
886        Record.push_back(V);
887        isCStr7 &= (V & 128) == 0;
888        if (isCStrChar6)
889          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
890      }
891
892      if (isCStrChar6)
893        AbbrevToUse = CString6Abbrev;
894      else if (isCStr7)
895        AbbrevToUse = CString7Abbrev;
896    } else if (const ConstantDataSequential *CDS =
897                  dyn_cast<ConstantDataSequential>(C)) {
898      // We must replace ConstantDataSequential's representation with the
899      // legacy ConstantArray/ConstantVector/ConstantStruct version.
900      // ValueEnumerator is similarly modified to mark the appropriate
901      // Constants as used (so they are emitted).
902      Code = bitc::CST_CODE_AGGREGATE;
903      for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
904        Record.push_back(VE.getValueID(CDS->getElementAsConstant(i)));
905      AbbrevToUse = AggregateAbbrev;
906    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
907               isa<ConstantVector>(C)) {
908      Code = bitc::CST_CODE_AGGREGATE;
909      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
910        Record.push_back(VE.getValueID(C->getOperand(i)));
911      AbbrevToUse = AggregateAbbrev;
912    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
913      switch (CE->getOpcode()) {
914      default:
915        if (Instruction::isCast(CE->getOpcode())) {
916          Code = bitc::CST_CODE_CE_CAST;
917          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
918          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
919          Record.push_back(VE.getValueID(C->getOperand(0)));
920          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
921        } else {
922          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
923          Code = bitc::CST_CODE_CE_BINOP;
924          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
925          Record.push_back(VE.getValueID(C->getOperand(0)));
926          Record.push_back(VE.getValueID(C->getOperand(1)));
927          uint64_t Flags = GetOptimizationFlags(CE);
928          if (Flags != 0)
929            Record.push_back(Flags);
930        }
931        break;
932      case Instruction::GetElementPtr:
933        Code = bitc::CST_CODE_CE_GEP;
934        if (cast<GEPOperator>(C)->isInBounds())
935          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
936        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
937          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
938          Record.push_back(VE.getValueID(C->getOperand(i)));
939        }
940        break;
941      case Instruction::Select:
942        Code = bitc::CST_CODE_CE_SELECT;
943        Record.push_back(VE.getValueID(C->getOperand(0)));
944        Record.push_back(VE.getValueID(C->getOperand(1)));
945        Record.push_back(VE.getValueID(C->getOperand(2)));
946        break;
947      case Instruction::ExtractElement:
948        Code = bitc::CST_CODE_CE_EXTRACTELT;
949        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
950        Record.push_back(VE.getValueID(C->getOperand(0)));
951        Record.push_back(VE.getValueID(C->getOperand(1)));
952        break;
953      case Instruction::InsertElement:
954        Code = bitc::CST_CODE_CE_INSERTELT;
955        Record.push_back(VE.getValueID(C->getOperand(0)));
956        Record.push_back(VE.getValueID(C->getOperand(1)));
957        Record.push_back(VE.getValueID(C->getOperand(2)));
958        break;
959      case Instruction::ShuffleVector:
960        // If the return type and argument types are the same, this is a
961        // standard shufflevector instruction.  If the types are different,
962        // then the shuffle is widening or truncating the input vectors, and
963        // the argument type must also be encoded.
964        if (C->getType() == C->getOperand(0)->getType()) {
965          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
966        } else {
967          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
968          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
969        }
970        Record.push_back(VE.getValueID(C->getOperand(0)));
971        Record.push_back(VE.getValueID(C->getOperand(1)));
972        Record.push_back(VE.getValueID(C->getOperand(2)));
973        break;
974      case Instruction::ICmp:
975      case Instruction::FCmp:
976        Code = bitc::CST_CODE_CE_CMP;
977        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
978        Record.push_back(VE.getValueID(C->getOperand(0)));
979        Record.push_back(VE.getValueID(C->getOperand(1)));
980        Record.push_back(CE->getPredicate());
981        break;
982      }
983    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
984      Code = bitc::CST_CODE_BLOCKADDRESS;
985      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
986      Record.push_back(VE.getValueID(BA->getFunction()));
987      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
988    } else {
989#ifndef NDEBUG
990      C->dump();
991#endif
992      llvm_unreachable("Unknown constant!");
993    }
994    Stream.EmitRecord(Code, Record, AbbrevToUse);
995    Record.clear();
996  }
997
998  Stream.ExitBlock();
999}
1000
1001static void WriteModuleConstants(const llvm_2_9::ValueEnumerator &VE,
1002                                 BitstreamWriter &Stream) {
1003  const llvm_2_9::ValueEnumerator::ValueList &Vals = VE.getValues();
1004
1005  // Find the first constant to emit, which is the first non-globalvalue value.
1006  // We know globalvalues have been emitted by WriteModuleInfo.
1007  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1008    if (!isa<GlobalValue>(Vals[i].first)) {
1009      WriteConstants(i, Vals.size(), VE, Stream, true);
1010      return;
1011    }
1012  }
1013}
1014
1015/// PushValueAndType - The file has to encode both the value and type id for
1016/// many values, because we need to know what type to create for forward
1017/// references.  However, most operands are not forward references, so this type
1018/// field is not needed.
1019///
1020/// This function adds V's value ID to Vals.  If the value ID is higher than the
1021/// instruction ID, then it is a forward reference, and it also includes the
1022/// type ID.
1023static bool PushValueAndType(const Value *V, unsigned InstID,
1024                             SmallVector<unsigned, 64> &Vals,
1025                             llvm_2_9::ValueEnumerator &VE) {
1026  unsigned ValID = VE.getValueID(V);
1027  Vals.push_back(ValID);
1028  if (ValID >= InstID) {
1029    Vals.push_back(VE.getTypeID(V->getType()));
1030    return true;
1031  }
1032  return false;
1033}
1034
1035/// WriteInstruction - Emit an instruction to the specified stream.
1036static void WriteInstruction(const Instruction &I, unsigned InstID,
1037                             llvm_2_9::ValueEnumerator &VE,
1038                             BitstreamWriter &Stream,
1039                             SmallVector<unsigned, 64> &Vals) {
1040  unsigned Code = 0;
1041  unsigned AbbrevToUse = 0;
1042  VE.setInstructionID(&I);
1043  switch (I.getOpcode()) {
1044  default:
1045    if (Instruction::isCast(I.getOpcode())) {
1046      Code = bitc::FUNC_CODE_INST_CAST;
1047      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1048        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1049      Vals.push_back(VE.getTypeID(I.getType()));
1050      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1051    } else {
1052      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1053      Code = bitc::FUNC_CODE_INST_BINOP;
1054      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1055        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1056      Vals.push_back(VE.getValueID(I.getOperand(1)));
1057      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1058      uint64_t Flags = GetOptimizationFlags(&I);
1059      if (Flags != 0) {
1060        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1061          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1062        Vals.push_back(Flags);
1063      }
1064    }
1065    break;
1066
1067  case Instruction::GetElementPtr:
1068    Code = bitc::FUNC_CODE_INST_GEP;
1069    if (cast<GEPOperator>(&I)->isInBounds())
1070      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
1071    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1072      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1073    break;
1074  case Instruction::ExtractValue: {
1075    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1076    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1077    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1078    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1079      Vals.push_back(*i);
1080    break;
1081  }
1082  case Instruction::InsertValue: {
1083    Code = bitc::FUNC_CODE_INST_INSERTVAL;
1084    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1085    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1086    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1087    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1088      Vals.push_back(*i);
1089    break;
1090  }
1091  case Instruction::Select:
1092    Code = bitc::FUNC_CODE_INST_VSELECT;
1093    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1094    Vals.push_back(VE.getValueID(I.getOperand(2)));
1095    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1096    break;
1097  case Instruction::ExtractElement:
1098    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1099    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1100    Vals.push_back(VE.getValueID(I.getOperand(1)));
1101    break;
1102  case Instruction::InsertElement:
1103    Code = bitc::FUNC_CODE_INST_INSERTELT;
1104    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1105    Vals.push_back(VE.getValueID(I.getOperand(1)));
1106    Vals.push_back(VE.getValueID(I.getOperand(2)));
1107    break;
1108  case Instruction::ShuffleVector:
1109    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1110    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1111    Vals.push_back(VE.getValueID(I.getOperand(1)));
1112    Vals.push_back(VE.getValueID(I.getOperand(2)));
1113    break;
1114  case Instruction::ICmp:
1115  case Instruction::FCmp:
1116    // compare returning Int1Ty or vector of Int1Ty
1117    Code = bitc::FUNC_CODE_INST_CMP2;
1118    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1119    Vals.push_back(VE.getValueID(I.getOperand(1)));
1120    Vals.push_back(cast<CmpInst>(I).getPredicate());
1121    break;
1122
1123  case Instruction::Ret:
1124    {
1125      Code = bitc::FUNC_CODE_INST_RET;
1126      unsigned NumOperands = I.getNumOperands();
1127      if (NumOperands == 0)
1128        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1129      else if (NumOperands == 1) {
1130        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1131          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1132      } else {
1133        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1134          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1135      }
1136    }
1137    break;
1138  case Instruction::Br:
1139    {
1140      Code = bitc::FUNC_CODE_INST_BR;
1141      const BranchInst &II = cast<BranchInst>(I);
1142      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1143      if (II.isConditional()) {
1144        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1145        Vals.push_back(VE.getValueID(II.getCondition()));
1146      }
1147    }
1148    break;
1149  case Instruction::Switch:
1150    {
1151      Code = bitc::FUNC_CODE_INST_SWITCH;
1152      const SwitchInst &SI = cast<SwitchInst>(I);
1153
1154      Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
1155      Vals.push_back(VE.getValueID(SI.getCondition()));
1156      Vals.push_back(VE.getValueID(SI.getDefaultDest()));
1157      for (SwitchInst::ConstCaseIt i = SI.case_begin(), e = SI.case_end();
1158           i != e; ++i) {
1159          Vals.push_back(VE.getValueID(i.getCaseValue()));
1160          Vals.push_back(VE.getValueID(i.getCaseSuccessor()));
1161      }
1162    }
1163    break;
1164  case Instruction::IndirectBr:
1165    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1166    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1167    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1168      Vals.push_back(VE.getValueID(I.getOperand(i)));
1169    break;
1170
1171  case Instruction::Invoke: {
1172    const InvokeInst *II = cast<InvokeInst>(&I);
1173    const Value *Callee(II->getCalledValue());
1174    PointerType *PTy = cast<PointerType>(Callee->getType());
1175    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1176    Code = bitc::FUNC_CODE_INST_INVOKE;
1177
1178    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1179    Vals.push_back(II->getCallingConv());
1180    Vals.push_back(VE.getValueID(II->getNormalDest()));
1181    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1182    PushValueAndType(Callee, InstID, Vals, VE);
1183
1184    // Emit value #'s for the fixed parameters.
1185    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1186      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1187
1188    // Emit type/value pairs for varargs params.
1189    if (FTy->isVarArg()) {
1190      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1191           i != e; ++i)
1192        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1193    }
1194    break;
1195  }
1196  case Instruction::Unreachable:
1197    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1198    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1199    break;
1200
1201  case Instruction::PHI: {
1202    const PHINode &PN = cast<PHINode>(I);
1203    Code = bitc::FUNC_CODE_INST_PHI;
1204    Vals.push_back(VE.getTypeID(PN.getType()));
1205    for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1206      Vals.push_back(VE.getValueID(PN.getIncomingValue(i)));
1207      Vals.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1208    }
1209    break;
1210  }
1211
1212  case Instruction::Alloca:
1213    Code = bitc::FUNC_CODE_INST_ALLOCA;
1214    Vals.push_back(VE.getTypeID(I.getType()));
1215    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1216    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1217    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1218    break;
1219
1220  case Instruction::Load:
1221    Code = bitc::FUNC_CODE_INST_LOAD;
1222    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1223      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1224
1225    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1226    Vals.push_back(cast<LoadInst>(I).isVolatile());
1227    break;
1228  case Instruction::Store:
1229    Code = bitc::FUNC_CODE_INST_STORE;
1230    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1231    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1232    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1233    Vals.push_back(cast<StoreInst>(I).isVolatile());
1234    break;
1235  case Instruction::Call: {
1236    const CallInst &CI = cast<CallInst>(I);
1237    PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1238    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1239
1240    Code = FUNC_CODE_INST_CALL_2_7;
1241
1242    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1243    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1244    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1245
1246    // Emit value #'s for the fixed parameters.
1247    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1248      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1249
1250    // Emit type/value pairs for varargs params.
1251    if (FTy->isVarArg()) {
1252      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1253           i != e; ++i)
1254        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1255    }
1256    break;
1257  }
1258  case Instruction::VAArg:
1259    Code = bitc::FUNC_CODE_INST_VAARG;
1260    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1261    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1262    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1263    break;
1264  }
1265
1266  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1267  Vals.clear();
1268}
1269
1270// Emit names for globals/functions etc.
1271static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1272                                  const llvm_2_9::ValueEnumerator &VE,
1273                                  BitstreamWriter &Stream) {
1274  if (VST.empty()) return;
1275  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1276
1277  // FIXME: Set up the abbrev, we know how many values there are!
1278  // FIXME: We know if the type names can use 7-bit ascii.
1279  SmallVector<unsigned, 64> NameVals;
1280
1281  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1282       SI != SE; ++SI) {
1283
1284    const ValueName &Name = *SI;
1285
1286    // Figure out the encoding to use for the name.
1287    bool is7Bit = true;
1288    bool isChar6 = true;
1289    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1290         C != E; ++C) {
1291      if (isChar6)
1292        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1293      if ((unsigned char)*C & 128) {
1294        is7Bit = false;
1295        break;  // don't bother scanning the rest.
1296      }
1297    }
1298
1299    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1300
1301    // VST_ENTRY:   [valueid, namechar x N]
1302    // VST_BBENTRY: [bbid, namechar x N]
1303    unsigned Code;
1304    if (isa<BasicBlock>(SI->getValue())) {
1305      Code = bitc::VST_CODE_BBENTRY;
1306      if (isChar6)
1307        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1308    } else {
1309      Code = bitc::VST_CODE_ENTRY;
1310      if (isChar6)
1311        AbbrevToUse = VST_ENTRY_6_ABBREV;
1312      else if (is7Bit)
1313        AbbrevToUse = VST_ENTRY_7_ABBREV;
1314    }
1315
1316    NameVals.push_back(VE.getValueID(SI->getValue()));
1317    for (const char *P = Name.getKeyData(),
1318         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1319      NameVals.push_back((unsigned char)*P);
1320
1321    // Emit the finished record.
1322    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1323    NameVals.clear();
1324  }
1325  Stream.ExitBlock();
1326}
1327
1328/// WriteFunction - Emit a function body to the module stream.
1329static void WriteFunction(const Function &F, llvm_2_9::ValueEnumerator &VE,
1330                          BitstreamWriter &Stream) {
1331  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1332  VE.incorporateFunction(F);
1333
1334  SmallVector<unsigned, 64> Vals;
1335
1336  // Emit the number of basic blocks, so the reader can create them ahead of
1337  // time.
1338  Vals.push_back(VE.getBasicBlocks().size());
1339  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1340  Vals.clear();
1341
1342  // If there are function-local constants, emit them now.
1343  unsigned CstStart, CstEnd;
1344  VE.getFunctionConstantRange(CstStart, CstEnd);
1345  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1346
1347  // If there is function-local metadata, emit it now.
1348  WriteFunctionLocalMetadata(F, VE, Stream);
1349
1350  // Keep a running idea of what the instruction ID is.
1351  unsigned InstID = CstEnd;
1352
1353  bool NeedsMetadataAttachment = false;
1354
1355  DebugLoc LastDL;
1356
1357  // Finally, emit all the instructions, in order.
1358  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1359    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1360         I != E; ++I) {
1361      WriteInstruction(*I, InstID, VE, Stream, Vals);
1362
1363      if (!I->getType()->isVoidTy())
1364        ++InstID;
1365
1366      // If the instruction has metadata, write a metadata attachment later.
1367      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1368
1369      // If the instruction has a debug location, emit it.
1370      DebugLoc DL = I->getDebugLoc();
1371      if (DL.isUnknown()) {
1372        // nothing todo.
1373      } else if (DL == LastDL) {
1374        // Just repeat the same debug loc as last time.
1375        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1376      } else {
1377        MDNode *Scope, *IA;
1378        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1379
1380        Vals.push_back(DL.getLine());
1381        Vals.push_back(DL.getCol());
1382        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1383        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1384        Stream.EmitRecord(FUNC_CODE_DEBUG_LOC_2_7, Vals);
1385        Vals.clear();
1386
1387        LastDL = DL;
1388      }
1389    }
1390
1391  // Emit names for all the instructions etc.
1392  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1393
1394  if (NeedsMetadataAttachment)
1395    WriteMetadataAttachment(F, VE, Stream);
1396  VE.purgeFunction();
1397  Stream.ExitBlock();
1398}
1399
1400// Emit blockinfo, which defines the standard abbreviations etc.
1401static void WriteBlockInfo(const llvm_2_9::ValueEnumerator &VE,
1402                           BitstreamWriter &Stream) {
1403  // We only want to emit block info records for blocks that have multiple
1404  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1405  // blocks can defined their abbrevs inline.
1406  Stream.EnterBlockInfoBlock(2);
1407
1408  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1409    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1410    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1411    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1412    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1413    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1414    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1415                                   Abbv) != VST_ENTRY_8_ABBREV)
1416      llvm_unreachable("Unexpected abbrev ordering!");
1417  }
1418
1419  { // 7-bit fixed width VST_ENTRY strings.
1420    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1421    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1422    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1423    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1424    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1425    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1426                                   Abbv) != VST_ENTRY_7_ABBREV)
1427      llvm_unreachable("Unexpected abbrev ordering!");
1428  }
1429  { // 6-bit char6 VST_ENTRY strings.
1430    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1431    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1432    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1433    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1434    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1435    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1436                                   Abbv) != VST_ENTRY_6_ABBREV)
1437      llvm_unreachable("Unexpected abbrev ordering!");
1438  }
1439  { // 6-bit char6 VST_BBENTRY strings.
1440    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1441    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1442    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1443    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1444    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1445    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1446                                   Abbv) != VST_BBENTRY_6_ABBREV)
1447      llvm_unreachable("Unexpected abbrev ordering!");
1448  }
1449
1450
1451
1452  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1453    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1454    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1455    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1456                              Log2_32_Ceil(VE.getTypes().size()+1)));
1457    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1458                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1459      llvm_unreachable("Unexpected abbrev ordering!");
1460  }
1461
1462  { // INTEGER abbrev for CONSTANTS_BLOCK.
1463    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1464    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1465    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1466    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1467                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1468      llvm_unreachable("Unexpected abbrev ordering!");
1469  }
1470
1471  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1472    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1473    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1474    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1475    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1476                              Log2_32_Ceil(VE.getTypes().size()+1)));
1477    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1478
1479    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1480                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1481      llvm_unreachable("Unexpected abbrev ordering!");
1482  }
1483  { // NULL abbrev for CONSTANTS_BLOCK.
1484    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1485    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1486    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1487                                   Abbv) != CONSTANTS_NULL_Abbrev)
1488      llvm_unreachable("Unexpected abbrev ordering!");
1489  }
1490
1491  // FIXME: This should only use space for first class types!
1492
1493  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1494    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1495    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1496    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1497    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1498    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1499    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1500                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1501      llvm_unreachable("Unexpected abbrev ordering!");
1502  }
1503  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1504    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1505    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1506    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1507    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1508    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1509    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1510                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1511      llvm_unreachable("Unexpected abbrev ordering!");
1512  }
1513  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1514    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1515    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1516    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1517    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1518    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1519    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1520    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1521                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1522      llvm_unreachable("Unexpected abbrev ordering!");
1523  }
1524  { // INST_CAST abbrev for FUNCTION_BLOCK.
1525    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1526    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1527    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1528    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1529                              Log2_32_Ceil(VE.getTypes().size()+1)));
1530    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1531    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1532                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1533      llvm_unreachable("Unexpected abbrev ordering!");
1534  }
1535
1536  { // INST_RET abbrev for FUNCTION_BLOCK.
1537    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1538    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1539    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1540                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1541      llvm_unreachable("Unexpected abbrev ordering!");
1542  }
1543  { // INST_RET abbrev for FUNCTION_BLOCK.
1544    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1545    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1546    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1547    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1548                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1549      llvm_unreachable("Unexpected abbrev ordering!");
1550  }
1551  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1552    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1553    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1554    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1555                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1556      llvm_unreachable("Unexpected abbrev ordering!");
1557  }
1558
1559  Stream.ExitBlock();
1560}
1561
1562
1563/// WriteModule - Emit the specified module to the bitstream.
1564static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1565  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1566
1567  // Emit the version number if it is non-zero.
1568  if (CurVersion) {
1569    SmallVector<unsigned, 1> Vals;
1570    Vals.push_back(CurVersion);
1571    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1572  }
1573
1574  // Analyze the module, enumerating globals, functions, etc.
1575  llvm_2_9::ValueEnumerator VE(M);
1576
1577  // Emit blockinfo, which defines the standard abbreviations etc.
1578  WriteBlockInfo(VE, Stream);
1579
1580  // Emit information about parameter attributes.
1581  WriteAttributeTable(VE, Stream);
1582
1583  // Emit information describing all of the types in the module.
1584  WriteTypeTable(VE, Stream);
1585
1586  // Emit top-level description of module, including target triple, inline asm,
1587  // descriptors for global variables, and function prototype info.
1588  WriteModuleInfo(M, VE, Stream);
1589
1590  // Emit constants.
1591  WriteModuleConstants(VE, Stream);
1592
1593  // Emit metadata.
1594  WriteModuleMetadata(M, VE, Stream);
1595
1596  // Emit function bodies.
1597  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1598    if (!F->isDeclaration())
1599      WriteFunction(*F, VE, Stream);
1600
1601  // Emit metadata.
1602  WriteModuleMetadataStore(M, Stream);
1603
1604  // Emit names for globals/functions etc.
1605  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1606
1607  Stream.ExitBlock();
1608}
1609
1610/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1611/// header and trailer to make it compatible with the system archiver.  To do
1612/// this we emit the following header, and then emit a trailer that pads the
1613/// file out to be a multiple of 16 bytes.
1614///
1615/// struct bc_header {
1616///   uint32_t Magic;         // 0x0B17C0DE
1617///   uint32_t Version;       // Version, currently always 0.
1618///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1619///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1620///   uint32_t CPUType;       // CPU specifier.
1621///   ... potentially more later ...
1622/// };
1623enum {
1624  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1625  DarwinBCHeaderSize = 5*4
1626};
1627
1628static void WriteInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
1629                               uint32_t &Position) {
1630  Buffer[Position + 0] = (unsigned char) (Value >>  0);
1631  Buffer[Position + 1] = (unsigned char) (Value >>  8);
1632  Buffer[Position + 2] = (unsigned char) (Value >> 16);
1633  Buffer[Position + 3] = (unsigned char) (Value >> 24);
1634  Position += 4;
1635}
1636
1637static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
1638                                         const Triple &TT) {
1639  unsigned CPUType = ~0U;
1640
1641  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1642  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1643  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1644  // specific constants here because they are implicitly part of the Darwin ABI.
1645  enum {
1646    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1647    DARWIN_CPU_TYPE_X86        = 7,
1648    DARWIN_CPU_TYPE_ARM        = 12,
1649    DARWIN_CPU_TYPE_POWERPC    = 18
1650  };
1651
1652  Triple::ArchType Arch = TT.getArch();
1653  if (Arch == Triple::x86_64)
1654    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1655  else if (Arch == Triple::x86)
1656    CPUType = DARWIN_CPU_TYPE_X86;
1657  else if (Arch == Triple::ppc)
1658    CPUType = DARWIN_CPU_TYPE_POWERPC;
1659  else if (Arch == Triple::ppc64)
1660    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1661  else if (Arch == Triple::arm || Arch == Triple::thumb)
1662    CPUType = DARWIN_CPU_TYPE_ARM;
1663
1664  // Traditional Bitcode starts after header.
1665  assert(Buffer.size() >= DarwinBCHeaderSize &&
1666         "Expected header size to be reserved");
1667  unsigned BCOffset = DarwinBCHeaderSize;
1668  unsigned BCSize = Buffer.size()-DarwinBCHeaderSize;
1669
1670  // Write the magic and version.
1671  unsigned Position = 0;
1672  WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position);
1673  WriteInt32ToBuffer(0          , Buffer, Position); // Version.
1674  WriteInt32ToBuffer(BCOffset   , Buffer, Position);
1675  WriteInt32ToBuffer(BCSize     , Buffer, Position);
1676  WriteInt32ToBuffer(CPUType    , Buffer, Position);
1677
1678  // If the file is not a multiple of 16 bytes, insert dummy padding.
1679  while (Buffer.size() & 15)
1680    Buffer.push_back(0);
1681}
1682
1683/// WriteBitcodeToFile - Write the specified module to the specified output
1684/// stream.
1685void llvm_2_9::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1686  SmallVector<char, 1024> Buffer;
1687  Buffer.reserve(256*1024);
1688
1689  // If this is darwin or another generic macho target, reserve space for the
1690  // header.
1691  Triple TT(M->getTargetTriple());
1692  if (TT.isOSDarwin())
1693    Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0);
1694
1695  // Emit the module into the buffer.
1696  {
1697    BitstreamWriter Stream(Buffer);
1698
1699    // Emit the file header.
1700    Stream.Emit((unsigned)'B', 8);
1701    Stream.Emit((unsigned)'C', 8);
1702    Stream.Emit(0x0, 4);
1703    Stream.Emit(0xC, 4);
1704    Stream.Emit(0xE, 4);
1705    Stream.Emit(0xD, 4);
1706
1707    // Emit the module.
1708    WriteModule(M, Stream);
1709  }
1710
1711  if (TT.isOSDarwin())
1712    EmitDarwinBCHeaderAndTrailer(Buffer, TT);
1713
1714  // Write the generated bitstream to "Out".
1715  Out.write((char*)&Buffer.front(), Buffer.size());
1716}
1717