BitcodeWriter.cpp revision eeb251e8db802b836af7461d0f6eb1252c527ab8 
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::DLLImportLinkage:                return 5;
398  case GlobalValue::DLLExportLinkage:                return 6;
399  case GlobalValue::ExternalWeakLinkage:             return 7;
400  case GlobalValue::CommonLinkage:                   return 8;
401  case GlobalValue::PrivateLinkage:                  return 9;
402  case GlobalValue::WeakODRLinkage:                  return 10;
403  case GlobalValue::LinkOnceODRLinkage:              return 11;
404  case GlobalValue::AvailableExternallyLinkage:      return 12;
405  case GlobalValue::LinkerPrivateLinkage:            return 13;
406  case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
407  }
408  llvm_unreachable("Invalid linkage");
409}
410
411static unsigned getEncodedVisibility(const GlobalValue *GV) {
412  switch (GV->getVisibility()) {
413  default: llvm_unreachable("Invalid visibility!");
414  case GlobalValue::DefaultVisibility:   return 0;
415  case GlobalValue::HiddenVisibility:    return 1;
416  case GlobalValue::ProtectedVisibility: return 2;
417  }
418}
419
420// Emit top-level description of module, including target triple, inline asm,
421// descriptors for global variables, and function prototype info.
422static void WriteModuleInfo(const Module *M,
423                            const llvm_2_9::ValueEnumerator &VE,
424                            BitstreamWriter &Stream) {
425  // Emit various pieces of data attached to a module.
426  if (!M->getTargetTriple().empty())
427    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
428                      0/*TODO*/, Stream);
429  if (!M->getDataLayout().empty())
430    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
431                      0/*TODO*/, Stream);
432  if (!M->getModuleInlineAsm().empty())
433    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
434                      0/*TODO*/, Stream);
435
436  // Emit information about sections and GC, computing how many there are. Also
437  // compute the maximum alignment value.
438  std::map<std::string, unsigned> SectionMap;
439  std::map<std::string, unsigned> GCMap;
440  unsigned MaxAlignment = 0;
441  unsigned MaxGlobalType = 0;
442  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
443       GV != E; ++GV) {
444    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
445    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
446
447    if (!GV->hasSection()) continue;
448    // Give section names unique ID's.
449    unsigned &Entry = SectionMap[GV->getSection()];
450    if (Entry != 0) continue;
451    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
452                      0/*TODO*/, Stream);
453    Entry = SectionMap.size();
454  }
455  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
456    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
457    if (F->hasSection()) {
458      // Give section names unique ID's.
459      unsigned &Entry = SectionMap[F->getSection()];
460      if (!Entry) {
461        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
462                          0/*TODO*/, Stream);
463        Entry = SectionMap.size();
464      }
465    }
466    if (F->hasGC()) {
467      // Same for GC names.
468      unsigned &Entry = GCMap[F->getGC()];
469      if (!Entry) {
470        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
471                          0/*TODO*/, Stream);
472        Entry = GCMap.size();
473      }
474    }
475  }
476
477  // Emit abbrev for globals, now that we know # sections and max alignment.
478  unsigned SimpleGVarAbbrev = 0;
479  if (!M->global_empty()) {
480    // Add an abbrev for common globals with no visibility or thread localness.
481    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
482    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
483    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
484                              Log2_32_Ceil(MaxGlobalType+1)));
485    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
486    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
487    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
488    if (MaxAlignment == 0)                                      // Alignment.
489      Abbv->Add(BitCodeAbbrevOp(0));
490    else {
491      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
492      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
493                               Log2_32_Ceil(MaxEncAlignment+1)));
494    }
495    if (SectionMap.empty())                                    // Section.
496      Abbv->Add(BitCodeAbbrevOp(0));
497    else
498      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
499                               Log2_32_Ceil(SectionMap.size()+1)));
500    // Don't bother emitting vis + thread local.
501    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
502  }
503
504  // Emit the global variable information.
505  SmallVector<unsigned, 64> Vals;
506  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
507       GV != E; ++GV) {
508    unsigned AbbrevToUse = 0;
509
510    // GLOBALVAR: [type, isconst, initid,
511    //             linkage, alignment, section, visibility, threadlocal,
512    //             unnamed_addr]
513    Vals.push_back(VE.getTypeID(GV->getType()));
514    Vals.push_back(GV->isConstant());
515    Vals.push_back(GV->isDeclaration() ? 0 :
516                   (VE.getValueID(GV->getInitializer()) + 1));
517    Vals.push_back(getEncodedLinkage(GV));
518    Vals.push_back(Log2_32(GV->getAlignment())+1);
519    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
520    if (GV->isThreadLocal() ||
521        GV->getVisibility() != GlobalValue::DefaultVisibility ||
522        GV->hasUnnamedAddr()) {
523      Vals.push_back(getEncodedVisibility(GV));
524      Vals.push_back(GV->isThreadLocal());
525      Vals.push_back(GV->hasUnnamedAddr());
526    } else {
527      AbbrevToUse = SimpleGVarAbbrev;
528    }
529
530    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
531    Vals.clear();
532  }
533
534  // Emit the function proto information.
535  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
536    // FUNCTION:  [type, callingconv, isproto, paramattr,
537    //             linkage, alignment, section, visibility, gc, unnamed_addr]
538    Vals.push_back(VE.getTypeID(F->getType()));
539    Vals.push_back(F->getCallingConv());
540    Vals.push_back(F->isDeclaration());
541    Vals.push_back(getEncodedLinkage(F));
542    Vals.push_back(VE.getAttributeID(F->getAttributes()));
543    Vals.push_back(Log2_32(F->getAlignment())+1);
544    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
545    Vals.push_back(getEncodedVisibility(F));
546    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
547    Vals.push_back(F->hasUnnamedAddr());
548
549    unsigned AbbrevToUse = 0;
550    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
551    Vals.clear();
552  }
553
554  // Emit the alias information.
555  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
556       AI != E; ++AI) {
557    Vals.push_back(VE.getTypeID(AI->getType()));
558    Vals.push_back(VE.getValueID(AI->getAliasee()));
559    Vals.push_back(getEncodedLinkage(AI));
560    Vals.push_back(getEncodedVisibility(AI));
561    unsigned AbbrevToUse = 0;
562    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
563    Vals.clear();
564  }
565}
566
567static uint64_t GetOptimizationFlags(const Value *V) {
568  uint64_t Flags = 0;
569
570  if (const OverflowingBinaryOperator *OBO =
571        dyn_cast<OverflowingBinaryOperator>(V)) {
572    if (OBO->hasNoSignedWrap())
573      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
574    if (OBO->hasNoUnsignedWrap())
575      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
576  } else if (const PossiblyExactOperator *PEO =
577               dyn_cast<PossiblyExactOperator>(V)) {
578    if (PEO->isExact())
579      Flags |= 1 << bitc::PEO_EXACT;
580  }
581
582  return Flags;
583}
584
585static void WriteMDNode(const MDNode *N,
586                        const llvm_2_9::ValueEnumerator &VE,
587                        BitstreamWriter &Stream,
588                        SmallVector<uint64_t, 64> &Record) {
589  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
590    if (N->getOperand(i)) {
591      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
592      Record.push_back(VE.getValueID(N->getOperand(i)));
593    } else {
594      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
595      Record.push_back(0);
596    }
597  }
598  unsigned MDCode = N->isFunctionLocal() ? METADATA_FN_NODE_2_7 :
599                                           METADATA_NODE_2_7;
600  Stream.EmitRecord(MDCode, Record, 0);
601  Record.clear();
602}
603
604static void WriteModuleMetadata(const Module *M,
605                                const llvm_2_9::ValueEnumerator &VE,
606                                BitstreamWriter &Stream) {
607  const llvm_2_9::ValueEnumerator::ValueList &Vals = VE.getMDValues();
608  bool StartedMetadataBlock = false;
609  unsigned MDSAbbrev = 0;
610  SmallVector<uint64_t, 64> Record;
611  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
612
613    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
614      if (!N->isFunctionLocal() || !N->getFunction()) {
615        if (!StartedMetadataBlock) {
616          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
617          StartedMetadataBlock = true;
618        }
619        WriteMDNode(N, VE, Stream, Record);
620      }
621    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
622      if (!StartedMetadataBlock)  {
623        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
624
625        // Abbrev for METADATA_STRING.
626        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
627        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
628        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
629        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
630        MDSAbbrev = Stream.EmitAbbrev(Abbv);
631        StartedMetadataBlock = true;
632      }
633
634      // Code: [strchar x N]
635      Record.append(MDS->begin(), MDS->end());
636
637      // Emit the finished record.
638      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
639      Record.clear();
640    }
641  }
642
643  // Write named metadata.
644  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
645       E = M->named_metadata_end(); I != E; ++I) {
646    const NamedMDNode *NMD = I;
647    if (!StartedMetadataBlock)  {
648      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
649      StartedMetadataBlock = true;
650    }
651
652    // Write name.
653    StringRef Str = NMD->getName();
654    for (unsigned i = 0, e = Str.size(); i != e; ++i)
655      Record.push_back(Str[i]);
656    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
657    Record.clear();
658
659    // Write named metadata operands.
660    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
661      Record.push_back(VE.getValueID(NMD->getOperand(i)));
662    Stream.EmitRecord(METADATA_NAMED_NODE_2_7, Record, 0);
663    Record.clear();
664  }
665
666  if (StartedMetadataBlock)
667    Stream.ExitBlock();
668}
669
670static void WriteFunctionLocalMetadata(const Function &F,
671                                       const llvm_2_9::ValueEnumerator &VE,
672                                       BitstreamWriter &Stream) {
673  bool StartedMetadataBlock = false;
674  SmallVector<uint64_t, 64> Record;
675  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
676  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
677    if (const MDNode *N = Vals[i])
678      if (N->isFunctionLocal() && N->getFunction() == &F) {
679        if (!StartedMetadataBlock) {
680          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
681          StartedMetadataBlock = true;
682        }
683        WriteMDNode(N, VE, Stream, Record);
684      }
685
686  if (StartedMetadataBlock)
687    Stream.ExitBlock();
688}
689
690static void WriteMetadataAttachment(const Function &F,
691                                    const llvm_2_9::ValueEnumerator &VE,
692                                    BitstreamWriter &Stream) {
693  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
694
695  SmallVector<uint64_t, 64> Record;
696
697  // Write metadata attachments
698  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
699  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
700
701  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
702    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
703         I != E; ++I) {
704      MDs.clear();
705      I->getAllMetadataOtherThanDebugLoc(MDs);
706
707      // If no metadata, ignore instruction.
708      if (MDs.empty()) continue;
709
710      Record.push_back(VE.getInstructionID(I));
711
712      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
713        Record.push_back(MDs[i].first);
714        Record.push_back(VE.getValueID(MDs[i].second));
715      }
716      Stream.EmitRecord(METADATA_ATTACHMENT_2_7, Record, 0);
717      Record.clear();
718    }
719
720  Stream.ExitBlock();
721}
722
723static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
724  SmallVector<uint64_t, 64> Record;
725
726  // Write metadata kinds
727  // METADATA_KIND - [n x [id, name]]
728  SmallVector<StringRef, 4> Names;
729  M->getMDKindNames(Names);
730
731  if (Names.empty()) return;
732
733  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
734
735  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
736    Record.push_back(MDKindID);
737    StringRef KName = Names[MDKindID];
738    Record.append(KName.begin(), KName.end());
739
740    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
741    Record.clear();
742  }
743
744  Stream.ExitBlock();
745}
746
747static void WriteConstants(unsigned FirstVal, unsigned LastVal,
748                           const llvm_2_9::ValueEnumerator &VE,
749                           BitstreamWriter &Stream, bool isGlobal) {
750  if (FirstVal == LastVal) return;
751
752  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
753
754  unsigned AggregateAbbrev = 0;
755  unsigned String8Abbrev = 0;
756  unsigned CString7Abbrev = 0;
757  unsigned CString6Abbrev = 0;
758  // If this is a constant pool for the module, emit module-specific abbrevs.
759  if (isGlobal) {
760    // Abbrev for CST_CODE_AGGREGATE.
761    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
762    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
763    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
764    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
765    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
766
767    // Abbrev for CST_CODE_STRING.
768    Abbv = new BitCodeAbbrev();
769    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
770    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
771    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
772    String8Abbrev = Stream.EmitAbbrev(Abbv);
773    // Abbrev for CST_CODE_CSTRING.
774    Abbv = new BitCodeAbbrev();
775    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
776    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
777    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
778    CString7Abbrev = Stream.EmitAbbrev(Abbv);
779    // Abbrev for CST_CODE_CSTRING.
780    Abbv = new BitCodeAbbrev();
781    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
782    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
783    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
784    CString6Abbrev = Stream.EmitAbbrev(Abbv);
785  }
786
787  SmallVector<uint64_t, 64> Record;
788
789  const llvm_2_9::ValueEnumerator::ValueList &Vals = VE.getValues();
790  Type *LastTy = 0;
791  for (unsigned i = FirstVal; i != LastVal; ++i) {
792    const Value *V = Vals[i].first;
793    // If we need to switch types, do so now.
794    if (V->getType() != LastTy) {
795      LastTy = V->getType();
796      Record.push_back(VE.getTypeID(LastTy));
797      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
798                        CONSTANTS_SETTYPE_ABBREV);
799      Record.clear();
800    }
801
802    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
803      Record.push_back(unsigned(IA->hasSideEffects()) |
804                       unsigned(IA->isAlignStack()) << 1);
805
806      // Add the asm string.
807      const std::string &AsmStr = IA->getAsmString();
808      Record.push_back(AsmStr.size());
809      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
810        Record.push_back(AsmStr[i]);
811
812      // Add the constraint string.
813      const std::string &ConstraintStr = IA->getConstraintString();
814      Record.push_back(ConstraintStr.size());
815      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
816        Record.push_back(ConstraintStr[i]);
817      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
818      Record.clear();
819      continue;
820    }
821    const Constant *C = cast<Constant>(V);
822    unsigned Code = -1U;
823    unsigned AbbrevToUse = 0;
824    if (C->isNullValue()) {
825      Code = bitc::CST_CODE_NULL;
826    } else if (isa<UndefValue>(C)) {
827      Code = bitc::CST_CODE_UNDEF;
828    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
829      if (IV->getBitWidth() <= 64) {
830        uint64_t V = IV->getSExtValue();
831        if ((int64_t)V >= 0)
832          Record.push_back(V << 1);
833        else
834          Record.push_back((-V << 1) | 1);
835        Code = bitc::CST_CODE_INTEGER;
836        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
837      } else {                             // Wide integers, > 64 bits in size.
838        // We have an arbitrary precision integer value to write whose
839        // bit width is > 64. However, in canonical unsigned integer
840        // format it is likely that the high bits are going to be zero.
841        // So, we only write the number of active words.
842        unsigned NWords = IV->getValue().getActiveWords();
843        const uint64_t *RawWords = IV->getValue().getRawData();
844        for (unsigned i = 0; i != NWords; ++i) {
845          int64_t V = RawWords[i];
846          if (V >= 0)
847            Record.push_back(V << 1);
848          else
849            Record.push_back((-V << 1) | 1);
850        }
851        Code = bitc::CST_CODE_WIDE_INTEGER;
852      }
853    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
854      Code = bitc::CST_CODE_FLOAT;
855      Type *Ty = CFP->getType();
856      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
857        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
858      } else if (Ty->isX86_FP80Ty()) {
859        // api needed to prevent premature destruction
860        // bits are not in the same order as a normal i80 APInt, compensate.
861        APInt api = CFP->getValueAPF().bitcastToAPInt();
862        const uint64_t *p = api.getRawData();
863        Record.push_back((p[1] << 48) | (p[0] >> 16));
864        Record.push_back(p[0] & 0xffffLL);
865      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
866        APInt api = CFP->getValueAPF().bitcastToAPInt();
867        const uint64_t *p = api.getRawData();
868        Record.push_back(p[0]);
869        Record.push_back(p[1]);
870      } else {
871        assert (0 && "Unknown FP type!");
872      }
873    } else if (isa<ConstantDataSequential>(C) &&
874               cast<ConstantDataSequential>(C)->isString()) {
875      const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
876      // Emit constant strings specially.
877      unsigned NumElts = Str->getNumElements();
878      // If this is a null-terminated string, use the denser CSTRING encoding.
879      if (Str->isCString()) {
880        Code = bitc::CST_CODE_CSTRING;
881        --NumElts;  // Don't encode the null, which isn't allowed by char6.
882      } else {
883        Code = bitc::CST_CODE_STRING;
884        AbbrevToUse = String8Abbrev;
885      }
886      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
887      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
888      for (unsigned i = 0; i != NumElts; ++i) {
889        unsigned char V = Str->getElementAsInteger(i);
890        Record.push_back(V);
891        isCStr7 &= (V & 128) == 0;
892        if (isCStrChar6)
893          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
894      }
895
896      if (isCStrChar6)
897        AbbrevToUse = CString6Abbrev;
898      else if (isCStr7)
899        AbbrevToUse = CString7Abbrev;
900    } else if (const ConstantDataSequential *CDS =
901                  dyn_cast<ConstantDataSequential>(C)) {
902      // We must replace ConstantDataSequential's representation with the
903      // legacy ConstantArray/ConstantVector/ConstantStruct version.
904      // ValueEnumerator is similarly modified to mark the appropriate
905      // Constants as used (so they are emitted).
906      Code = bitc::CST_CODE_AGGREGATE;
907      for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
908        Record.push_back(VE.getValueID(CDS->getElementAsConstant(i)));
909      AbbrevToUse = AggregateAbbrev;
910    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
911               isa<ConstantVector>(C)) {
912      Code = bitc::CST_CODE_AGGREGATE;
913      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
914        Record.push_back(VE.getValueID(C->getOperand(i)));
915      AbbrevToUse = AggregateAbbrev;
916    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
917      switch (CE->getOpcode()) {
918      default:
919        if (Instruction::isCast(CE->getOpcode())) {
920          Code = bitc::CST_CODE_CE_CAST;
921          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
922          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
923          Record.push_back(VE.getValueID(C->getOperand(0)));
924          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
925        } else {
926          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
927          Code = bitc::CST_CODE_CE_BINOP;
928          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
929          Record.push_back(VE.getValueID(C->getOperand(0)));
930          Record.push_back(VE.getValueID(C->getOperand(1)));
931          uint64_t Flags = GetOptimizationFlags(CE);
932          if (Flags != 0)
933            Record.push_back(Flags);
934        }
935        break;
936      case Instruction::GetElementPtr:
937        Code = bitc::CST_CODE_CE_GEP;
938        if (cast<GEPOperator>(C)->isInBounds())
939          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
940        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
941          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
942          Record.push_back(VE.getValueID(C->getOperand(i)));
943        }
944        break;
945      case Instruction::Select:
946        Code = bitc::CST_CODE_CE_SELECT;
947        Record.push_back(VE.getValueID(C->getOperand(0)));
948        Record.push_back(VE.getValueID(C->getOperand(1)));
949        Record.push_back(VE.getValueID(C->getOperand(2)));
950        break;
951      case Instruction::ExtractElement:
952        Code = bitc::CST_CODE_CE_EXTRACTELT;
953        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
954        Record.push_back(VE.getValueID(C->getOperand(0)));
955        Record.push_back(VE.getValueID(C->getOperand(1)));
956        break;
957      case Instruction::InsertElement:
958        Code = bitc::CST_CODE_CE_INSERTELT;
959        Record.push_back(VE.getValueID(C->getOperand(0)));
960        Record.push_back(VE.getValueID(C->getOperand(1)));
961        Record.push_back(VE.getValueID(C->getOperand(2)));
962        break;
963      case Instruction::ShuffleVector:
964        // If the return type and argument types are the same, this is a
965        // standard shufflevector instruction.  If the types are different,
966        // then the shuffle is widening or truncating the input vectors, and
967        // the argument type must also be encoded.
968        if (C->getType() == C->getOperand(0)->getType()) {
969          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
970        } else {
971          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
972          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
973        }
974        Record.push_back(VE.getValueID(C->getOperand(0)));
975        Record.push_back(VE.getValueID(C->getOperand(1)));
976        Record.push_back(VE.getValueID(C->getOperand(2)));
977        break;
978      case Instruction::ICmp:
979      case Instruction::FCmp:
980        Code = bitc::CST_CODE_CE_CMP;
981        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
982        Record.push_back(VE.getValueID(C->getOperand(0)));
983        Record.push_back(VE.getValueID(C->getOperand(1)));
984        Record.push_back(CE->getPredicate());
985        break;
986      }
987    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
988      Code = bitc::CST_CODE_BLOCKADDRESS;
989      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
990      Record.push_back(VE.getValueID(BA->getFunction()));
991      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
992    } else {
993#ifndef NDEBUG
994      C->dump();
995#endif
996      llvm_unreachable("Unknown constant!");
997    }
998    Stream.EmitRecord(Code, Record, AbbrevToUse);
999    Record.clear();
1000  }
1001
1002  Stream.ExitBlock();
1003}
1004
1005static void WriteModuleConstants(const llvm_2_9::ValueEnumerator &VE,
1006                                 BitstreamWriter &Stream) {
1007  const llvm_2_9::ValueEnumerator::ValueList &Vals = VE.getValues();
1008
1009  // Find the first constant to emit, which is the first non-globalvalue value.
1010  // We know globalvalues have been emitted by WriteModuleInfo.
1011  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1012    if (!isa<GlobalValue>(Vals[i].first)) {
1013      WriteConstants(i, Vals.size(), VE, Stream, true);
1014      return;
1015    }
1016  }
1017}
1018
1019/// PushValueAndType - The file has to encode both the value and type id for
1020/// many values, because we need to know what type to create for forward
1021/// references.  However, most operands are not forward references, so this type
1022/// field is not needed.
1023///
1024/// This function adds V's value ID to Vals.  If the value ID is higher than the
1025/// instruction ID, then it is a forward reference, and it also includes the
1026/// type ID.
1027static bool PushValueAndType(const Value *V, unsigned InstID,
1028                             SmallVector<unsigned, 64> &Vals,
1029                             llvm_2_9::ValueEnumerator &VE) {
1030  unsigned ValID = VE.getValueID(V);
1031  Vals.push_back(ValID);
1032  if (ValID >= InstID) {
1033    Vals.push_back(VE.getTypeID(V->getType()));
1034    return true;
1035  }
1036  return false;
1037}
1038
1039/// WriteInstruction - Emit an instruction to the specified stream.
1040static void WriteInstruction(const Instruction &I, unsigned InstID,
1041                             llvm_2_9::ValueEnumerator &VE,
1042                             BitstreamWriter &Stream,
1043                             SmallVector<unsigned, 64> &Vals) {
1044  unsigned Code = 0;
1045  unsigned AbbrevToUse = 0;
1046  VE.setInstructionID(&I);
1047  switch (I.getOpcode()) {
1048  default:
1049    if (Instruction::isCast(I.getOpcode())) {
1050      Code = bitc::FUNC_CODE_INST_CAST;
1051      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1052        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1053      Vals.push_back(VE.getTypeID(I.getType()));
1054      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1055    } else {
1056      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1057      Code = bitc::FUNC_CODE_INST_BINOP;
1058      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1059        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1060      Vals.push_back(VE.getValueID(I.getOperand(1)));
1061      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1062      uint64_t Flags = GetOptimizationFlags(&I);
1063      if (Flags != 0) {
1064        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1065          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1066        Vals.push_back(Flags);
1067      }
1068    }
1069    break;
1070
1071  case Instruction::GetElementPtr:
1072    Code = bitc::FUNC_CODE_INST_GEP;
1073    if (cast<GEPOperator>(&I)->isInBounds())
1074      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
1075    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1076      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1077    break;
1078  case Instruction::ExtractValue: {
1079    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1080    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1081    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1082    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1083      Vals.push_back(*i);
1084    break;
1085  }
1086  case Instruction::InsertValue: {
1087    Code = bitc::FUNC_CODE_INST_INSERTVAL;
1088    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1089    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1090    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1091    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1092      Vals.push_back(*i);
1093    break;
1094  }
1095  case Instruction::Select:
1096    Code = bitc::FUNC_CODE_INST_VSELECT;
1097    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1098    Vals.push_back(VE.getValueID(I.getOperand(2)));
1099    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1100    break;
1101  case Instruction::ExtractElement:
1102    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1103    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1104    Vals.push_back(VE.getValueID(I.getOperand(1)));
1105    break;
1106  case Instruction::InsertElement:
1107    Code = bitc::FUNC_CODE_INST_INSERTELT;
1108    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1109    Vals.push_back(VE.getValueID(I.getOperand(1)));
1110    Vals.push_back(VE.getValueID(I.getOperand(2)));
1111    break;
1112  case Instruction::ShuffleVector:
1113    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1114    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1115    Vals.push_back(VE.getValueID(I.getOperand(1)));
1116    Vals.push_back(VE.getValueID(I.getOperand(2)));
1117    break;
1118  case Instruction::ICmp:
1119  case Instruction::FCmp:
1120    // compare returning Int1Ty or vector of Int1Ty
1121    Code = bitc::FUNC_CODE_INST_CMP2;
1122    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1123    Vals.push_back(VE.getValueID(I.getOperand(1)));
1124    Vals.push_back(cast<CmpInst>(I).getPredicate());
1125    break;
1126
1127  case Instruction::Ret:
1128    {
1129      Code = bitc::FUNC_CODE_INST_RET;
1130      unsigned NumOperands = I.getNumOperands();
1131      if (NumOperands == 0)
1132        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1133      else if (NumOperands == 1) {
1134        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1135          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1136      } else {
1137        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1138          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1139      }
1140    }
1141    break;
1142  case Instruction::Br:
1143    {
1144      Code = bitc::FUNC_CODE_INST_BR;
1145      const BranchInst &II = cast<BranchInst>(I);
1146      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1147      if (II.isConditional()) {
1148        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1149        Vals.push_back(VE.getValueID(II.getCondition()));
1150      }
1151    }
1152    break;
1153  case Instruction::Switch:
1154    {
1155      Code = bitc::FUNC_CODE_INST_SWITCH;
1156      const SwitchInst &SI = cast<SwitchInst>(I);
1157
1158      Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
1159      Vals.push_back(VE.getValueID(SI.getCondition()));
1160      Vals.push_back(VE.getValueID(SI.getDefaultDest()));
1161      for (SwitchInst::ConstCaseIt i = SI.case_begin(), e = SI.case_end();
1162           i != e; ++i) {
1163          Vals.push_back(VE.getValueID(i.getCaseValue()));
1164          Vals.push_back(VE.getValueID(i.getCaseSuccessor()));
1165      }
1166    }
1167    break;
1168  case Instruction::IndirectBr:
1169    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1170    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1171    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1172      Vals.push_back(VE.getValueID(I.getOperand(i)));
1173    break;
1174
1175  case Instruction::Invoke: {
1176    const InvokeInst *II = cast<InvokeInst>(&I);
1177    const Value *Callee(II->getCalledValue());
1178    PointerType *PTy = cast<PointerType>(Callee->getType());
1179    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1180    Code = bitc::FUNC_CODE_INST_INVOKE;
1181
1182    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1183    Vals.push_back(II->getCallingConv());
1184    Vals.push_back(VE.getValueID(II->getNormalDest()));
1185    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1186    PushValueAndType(Callee, InstID, Vals, VE);
1187
1188    // Emit value #'s for the fixed parameters.
1189    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1190      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1191
1192    // Emit type/value pairs for varargs params.
1193    if (FTy->isVarArg()) {
1194      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1195           i != e; ++i)
1196        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1197    }
1198    break;
1199  }
1200  case Instruction::Unreachable:
1201    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1202    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1203    break;
1204
1205  case Instruction::PHI: {
1206    const PHINode &PN = cast<PHINode>(I);
1207    Code = bitc::FUNC_CODE_INST_PHI;
1208    Vals.push_back(VE.getTypeID(PN.getType()));
1209    for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1210      Vals.push_back(VE.getValueID(PN.getIncomingValue(i)));
1211      Vals.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1212    }
1213    break;
1214  }
1215
1216  case Instruction::Alloca:
1217    Code = bitc::FUNC_CODE_INST_ALLOCA;
1218    Vals.push_back(VE.getTypeID(I.getType()));
1219    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1220    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1221    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1222    break;
1223
1224  case Instruction::Load:
1225    Code = bitc::FUNC_CODE_INST_LOAD;
1226    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1227      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1228
1229    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1230    Vals.push_back(cast<LoadInst>(I).isVolatile());
1231    break;
1232  case Instruction::Store:
1233    Code = bitc::FUNC_CODE_INST_STORE;
1234    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1235    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1236    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1237    Vals.push_back(cast<StoreInst>(I).isVolatile());
1238    break;
1239  case Instruction::Call: {
1240    const CallInst &CI = cast<CallInst>(I);
1241    PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1242    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1243
1244    Code = FUNC_CODE_INST_CALL_2_7;
1245
1246    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1247    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1248    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1249
1250    // Emit value #'s for the fixed parameters.
1251    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1252      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1253
1254    // Emit type/value pairs for varargs params.
1255    if (FTy->isVarArg()) {
1256      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1257           i != e; ++i)
1258        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1259    }
1260    break;
1261  }
1262  case Instruction::VAArg:
1263    Code = bitc::FUNC_CODE_INST_VAARG;
1264    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1265    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1266    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1267    break;
1268  }
1269
1270  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1271  Vals.clear();
1272}
1273
1274// Emit names for globals/functions etc.
1275static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1276                                  const llvm_2_9::ValueEnumerator &VE,
1277                                  BitstreamWriter &Stream) {
1278  if (VST.empty()) return;
1279  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1280
1281  // FIXME: Set up the abbrev, we know how many values there are!
1282  // FIXME: We know if the type names can use 7-bit ascii.
1283  SmallVector<unsigned, 64> NameVals;
1284
1285  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1286       SI != SE; ++SI) {
1287
1288    const ValueName &Name = *SI;
1289
1290    // Figure out the encoding to use for the name.
1291    bool is7Bit = true;
1292    bool isChar6 = true;
1293    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1294         C != E; ++C) {
1295      if (isChar6)
1296        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1297      if ((unsigned char)*C & 128) {
1298        is7Bit = false;
1299        break;  // don't bother scanning the rest.
1300      }
1301    }
1302
1303    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1304
1305    // VST_ENTRY:   [valueid, namechar x N]
1306    // VST_BBENTRY: [bbid, namechar x N]
1307    unsigned Code;
1308    if (isa<BasicBlock>(SI->getValue())) {
1309      Code = bitc::VST_CODE_BBENTRY;
1310      if (isChar6)
1311        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1312    } else {
1313      Code = bitc::VST_CODE_ENTRY;
1314      if (isChar6)
1315        AbbrevToUse = VST_ENTRY_6_ABBREV;
1316      else if (is7Bit)
1317        AbbrevToUse = VST_ENTRY_7_ABBREV;
1318    }
1319
1320    NameVals.push_back(VE.getValueID(SI->getValue()));
1321    for (const char *P = Name.getKeyData(),
1322         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1323      NameVals.push_back((unsigned char)*P);
1324
1325    // Emit the finished record.
1326    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1327    NameVals.clear();
1328  }
1329  Stream.ExitBlock();
1330}
1331
1332/// WriteFunction - Emit a function body to the module stream.
1333static void WriteFunction(const Function &F, llvm_2_9::ValueEnumerator &VE,
1334                          BitstreamWriter &Stream) {
1335  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1336  VE.incorporateFunction(F);
1337
1338  SmallVector<unsigned, 64> Vals;
1339
1340  // Emit the number of basic blocks, so the reader can create them ahead of
1341  // time.
1342  Vals.push_back(VE.getBasicBlocks().size());
1343  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1344  Vals.clear();
1345
1346  // If there are function-local constants, emit them now.
1347  unsigned CstStart, CstEnd;
1348  VE.getFunctionConstantRange(CstStart, CstEnd);
1349  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1350
1351  // If there is function-local metadata, emit it now.
1352  WriteFunctionLocalMetadata(F, VE, Stream);
1353
1354  // Keep a running idea of what the instruction ID is.
1355  unsigned InstID = CstEnd;
1356
1357  bool NeedsMetadataAttachment = false;
1358
1359  DebugLoc LastDL;
1360
1361  // Finally, emit all the instructions, in order.
1362  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1363    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1364         I != E; ++I) {
1365      WriteInstruction(*I, InstID, VE, Stream, Vals);
1366
1367      if (!I->getType()->isVoidTy())
1368        ++InstID;
1369
1370      // If the instruction has metadata, write a metadata attachment later.
1371      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1372
1373      // If the instruction has a debug location, emit it.
1374      DebugLoc DL = I->getDebugLoc();
1375      if (DL.isUnknown()) {
1376        // nothing todo.
1377      } else if (DL == LastDL) {
1378        // Just repeat the same debug loc as last time.
1379        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1380      } else {
1381        MDNode *Scope, *IA;
1382        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1383
1384        Vals.push_back(DL.getLine());
1385        Vals.push_back(DL.getCol());
1386        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1387        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1388        Stream.EmitRecord(FUNC_CODE_DEBUG_LOC_2_7, Vals);
1389        Vals.clear();
1390
1391        LastDL = DL;
1392      }
1393    }
1394
1395  // Emit names for all the instructions etc.
1396  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1397
1398  if (NeedsMetadataAttachment)
1399    WriteMetadataAttachment(F, VE, Stream);
1400  VE.purgeFunction();
1401  Stream.ExitBlock();
1402}
1403
1404// Emit blockinfo, which defines the standard abbreviations etc.
1405static void WriteBlockInfo(const llvm_2_9::ValueEnumerator &VE,
1406                           BitstreamWriter &Stream) {
1407  // We only want to emit block info records for blocks that have multiple
1408  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1409  // blocks can defined their abbrevs inline.
1410  Stream.EnterBlockInfoBlock(2);
1411
1412  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1413    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1414    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1415    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1416    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1417    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1418    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1419                                   Abbv) != VST_ENTRY_8_ABBREV)
1420      llvm_unreachable("Unexpected abbrev ordering!");
1421  }
1422
1423  { // 7-bit fixed width VST_ENTRY strings.
1424    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1425    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1426    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1427    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1428    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1429    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1430                                   Abbv) != VST_ENTRY_7_ABBREV)
1431      llvm_unreachable("Unexpected abbrev ordering!");
1432  }
1433  { // 6-bit char6 VST_ENTRY strings.
1434    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1435    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1436    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1437    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1438    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1439    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1440                                   Abbv) != VST_ENTRY_6_ABBREV)
1441      llvm_unreachable("Unexpected abbrev ordering!");
1442  }
1443  { // 6-bit char6 VST_BBENTRY strings.
1444    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1445    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1446    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1447    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1448    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1449    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1450                                   Abbv) != VST_BBENTRY_6_ABBREV)
1451      llvm_unreachable("Unexpected abbrev ordering!");
1452  }
1453
1454
1455
1456  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1457    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1458    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1459    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1460                              Log2_32_Ceil(VE.getTypes().size()+1)));
1461    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1462                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1463      llvm_unreachable("Unexpected abbrev ordering!");
1464  }
1465
1466  { // INTEGER abbrev for CONSTANTS_BLOCK.
1467    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1468    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1469    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1470    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1471                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1472      llvm_unreachable("Unexpected abbrev ordering!");
1473  }
1474
1475  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1476    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1477    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1478    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1479    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1480                              Log2_32_Ceil(VE.getTypes().size()+1)));
1481    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1482
1483    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1484                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1485      llvm_unreachable("Unexpected abbrev ordering!");
1486  }
1487  { // NULL abbrev for CONSTANTS_BLOCK.
1488    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1489    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1490    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1491                                   Abbv) != CONSTANTS_NULL_Abbrev)
1492      llvm_unreachable("Unexpected abbrev ordering!");
1493  }
1494
1495  // FIXME: This should only use space for first class types!
1496
1497  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1498    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1499    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1500    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1501    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1502    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1503    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1504                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1505      llvm_unreachable("Unexpected abbrev ordering!");
1506  }
1507  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1508    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1509    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1510    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1511    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1512    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1513    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1514                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1515      llvm_unreachable("Unexpected abbrev ordering!");
1516  }
1517  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1518    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1519    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1520    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1521    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1522    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1523    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1524    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1525                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1526      llvm_unreachable("Unexpected abbrev ordering!");
1527  }
1528  { // INST_CAST abbrev for FUNCTION_BLOCK.
1529    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1530    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1531    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1532    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1533                              Log2_32_Ceil(VE.getTypes().size()+1)));
1534    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1535    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1536                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1537      llvm_unreachable("Unexpected abbrev ordering!");
1538  }
1539
1540  { // INST_RET abbrev for FUNCTION_BLOCK.
1541    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1542    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1543    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1544                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1545      llvm_unreachable("Unexpected abbrev ordering!");
1546  }
1547  { // INST_RET abbrev for FUNCTION_BLOCK.
1548    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1549    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1550    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1551    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1552                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1553      llvm_unreachable("Unexpected abbrev ordering!");
1554  }
1555  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1556    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1557    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1558    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1559                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1560      llvm_unreachable("Unexpected abbrev ordering!");
1561  }
1562
1563  Stream.ExitBlock();
1564}
1565
1566
1567/// WriteModule - Emit the specified module to the bitstream.
1568static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1569  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1570
1571  // Emit the version number if it is non-zero.
1572  if (CurVersion) {
1573    SmallVector<unsigned, 1> Vals;
1574    Vals.push_back(CurVersion);
1575    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1576  }
1577
1578  // Analyze the module, enumerating globals, functions, etc.
1579  llvm_2_9::ValueEnumerator VE(M);
1580
1581  // Emit blockinfo, which defines the standard abbreviations etc.
1582  WriteBlockInfo(VE, Stream);
1583
1584  // Emit information about parameter attributes.
1585  WriteAttributeTable(VE, Stream);
1586
1587  // Emit information describing all of the types in the module.
1588  WriteTypeTable(VE, Stream);
1589
1590  // Emit top-level description of module, including target triple, inline asm,
1591  // descriptors for global variables, and function prototype info.
1592  WriteModuleInfo(M, VE, Stream);
1593
1594  // Emit constants.
1595  WriteModuleConstants(VE, Stream);
1596
1597  // Emit metadata.
1598  WriteModuleMetadata(M, VE, Stream);
1599
1600  // Emit function bodies.
1601  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1602    if (!F->isDeclaration())
1603      WriteFunction(*F, VE, Stream);
1604
1605  // Emit metadata.
1606  WriteModuleMetadataStore(M, Stream);
1607
1608  // Emit names for globals/functions etc.
1609  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1610
1611  Stream.ExitBlock();
1612}
1613
1614/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1615/// header and trailer to make it compatible with the system archiver.  To do
1616/// this we emit the following header, and then emit a trailer that pads the
1617/// file out to be a multiple of 16 bytes.
1618///
1619/// struct bc_header {
1620///   uint32_t Magic;         // 0x0B17C0DE
1621///   uint32_t Version;       // Version, currently always 0.
1622///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1623///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1624///   uint32_t CPUType;       // CPU specifier.
1625///   ... potentially more later ...
1626/// };
1627enum {
1628  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1629  DarwinBCHeaderSize = 5*4
1630};
1631
1632static void WriteInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
1633                               uint32_t &Position) {
1634  Buffer[Position + 0] = (unsigned char) (Value >>  0);
1635  Buffer[Position + 1] = (unsigned char) (Value >>  8);
1636  Buffer[Position + 2] = (unsigned char) (Value >> 16);
1637  Buffer[Position + 3] = (unsigned char) (Value >> 24);
1638  Position += 4;
1639}
1640
1641static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
1642                                         const Triple &TT) {
1643  unsigned CPUType = ~0U;
1644
1645  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1646  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1647  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1648  // specific constants here because they are implicitly part of the Darwin ABI.
1649  enum {
1650    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1651    DARWIN_CPU_TYPE_X86        = 7,
1652    DARWIN_CPU_TYPE_ARM        = 12,
1653    DARWIN_CPU_TYPE_POWERPC    = 18
1654  };
1655
1656  Triple::ArchType Arch = TT.getArch();
1657  if (Arch == Triple::x86_64)
1658    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1659  else if (Arch == Triple::x86)
1660    CPUType = DARWIN_CPU_TYPE_X86;
1661  else if (Arch == Triple::ppc)
1662    CPUType = DARWIN_CPU_TYPE_POWERPC;
1663  else if (Arch == Triple::ppc64)
1664    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1665  else if (Arch == Triple::arm || Arch == Triple::thumb)
1666    CPUType = DARWIN_CPU_TYPE_ARM;
1667
1668  // Traditional Bitcode starts after header.
1669  assert(Buffer.size() >= DarwinBCHeaderSize &&
1670         "Expected header size to be reserved");
1671  unsigned BCOffset = DarwinBCHeaderSize;
1672  unsigned BCSize = Buffer.size()-DarwinBCHeaderSize;
1673
1674  // Write the magic and version.
1675  unsigned Position = 0;
1676  WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position);
1677  WriteInt32ToBuffer(0          , Buffer, Position); // Version.
1678  WriteInt32ToBuffer(BCOffset   , Buffer, Position);
1679  WriteInt32ToBuffer(BCSize     , Buffer, Position);
1680  WriteInt32ToBuffer(CPUType    , Buffer, Position);
1681
1682  // If the file is not a multiple of 16 bytes, insert dummy padding.
1683  while (Buffer.size() & 15)
1684    Buffer.push_back(0);
1685}
1686
1687/// WriteBitcodeToFile - Write the specified module to the specified output
1688/// stream.
1689void llvm_2_9::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1690  SmallVector<char, 1024> Buffer;
1691  Buffer.reserve(256*1024);
1692
1693  // If this is darwin or another generic macho target, reserve space for the
1694  // header.
1695  Triple TT(M->getTargetTriple());
1696  if (TT.isOSDarwin())
1697    Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0);
1698
1699  // Emit the module into the buffer.
1700  {
1701    BitstreamWriter Stream(Buffer);
1702
1703    // Emit the file header.
1704    Stream.Emit((unsigned)'B', 8);
1705    Stream.Emit((unsigned)'C', 8);
1706    Stream.Emit(0x0, 4);
1707    Stream.Emit(0xC, 4);
1708    Stream.Emit(0xE, 4);
1709    Stream.Emit(0xD, 4);
1710
1711    // Emit the module.
1712    WriteModule(M, Stream);
1713  }
1714
1715  if (TT.isOSDarwin())
1716    EmitDarwinBCHeaderAndTrailer(Buffer, TT);
1717
1718  // Write the generated bitstream to "Out".
1719  Out.write((char*)&Buffer.front(), Buffer.size());
1720}
1721