lib/Bitcode/Writer/BitcodeWriter.cpp

   1 //===--- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ----------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Bitcode writer implementation.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Bitcode/ReaderWriter.h"
  15 #include "llvm/Bitcode/BitstreamWriter.h"
  16 #include "llvm/Bitcode/LLVMBitCodes.h"
  17 #include "ValueEnumerator.h"
  18 #include "llvm/Constants.h"
  19 #include "llvm/DerivedTypes.h"
  20 #include "llvm/InlineAsm.h"
  21 #include "llvm/Instructions.h"
  22 #include "llvm/Module.h"
  23 #include "llvm/Operator.h"
  24 #include "llvm/TypeSymbolTable.h"
  25 #include "llvm/ValueSymbolTable.h"
  26 #include "llvm/Support/ErrorHandling.h"
  27 #include "llvm/Support/MathExtras.h"
  28 #include "llvm/Support/raw_ostream.h"
  29 #include "llvm/Support/Program.h"
  30 #include <cctype>
  31 using namespace llvm;
  32
  33 /// These are manifest constants used by the bitcode writer. They do not need to
  34 /// be kept in sync with the reader, but need to be consistent within this file.
  35 enum {
  36   CurVersion = 0,
  37
  38   // VALUE_SYMTAB_BLOCK abbrev id's.
  39   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  40   VST_ENTRY_7_ABBREV,
  41   VST_ENTRY_6_ABBREV,
  42   VST_BBENTRY_6_ABBREV,
  43
  44   // CONSTANTS_BLOCK abbrev id's.
  45   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  46   CONSTANTS_INTEGER_ABBREV,
  47   CONSTANTS_CE_CAST_Abbrev,
  48   CONSTANTS_NULL_Abbrev,
  49
  50   // FUNCTION_BLOCK abbrev id's.
  51   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  52   FUNCTION_INST_BINOP_ABBREV,
  53   FUNCTION_INST_BINOP_FLAGS_ABBREV,
  54   FUNCTION_INST_CAST_ABBREV,
  55   FUNCTION_INST_RET_VOID_ABBREV,
  56   FUNCTION_INST_RET_VAL_ABBREV,
  57   FUNCTION_INST_UNREACHABLE_ABBREV
  58 };
  59
  60
  61 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
  62   switch (Opcode) {
  63   default: llvm_unreachable("Unknown cast instruction!");
  64   case Instruction::Trunc   : return bitc::CAST_TRUNC;
  65   case Instruction::ZExt    : return bitc::CAST_ZEXT;
  66   case Instruction::SExt    : return bitc::CAST_SEXT;
  67   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
  68   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
  69   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
  70   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
  71   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
  72   case Instruction::FPExt   : return bitc::CAST_FPEXT;
  73   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
  74   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
  75   case Instruction::BitCast : return bitc::CAST_BITCAST;
  76   }
  77 }
  78
  79 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
  80   switch (Opcode) {
  81   default: llvm_unreachable("Unknown binary instruction!");
  82   case Instruction::Add:
  83   case Instruction::FAdd: return bitc::BINOP_ADD;
  84   case Instruction::Sub:
  85   case Instruction::FSub: return bitc::BINOP_SUB;
  86   case Instruction::Mul:
  87   case Instruction::FMul: return bitc::BINOP_MUL;
  88   case Instruction::UDiv: return bitc::BINOP_UDIV;
  89   case Instruction::FDiv:
  90   case Instruction::SDiv: return bitc::BINOP_SDIV;
  91   case Instruction::URem: return bitc::BINOP_UREM;
  92   case Instruction::FRem:
  93   case Instruction::SRem: return bitc::BINOP_SREM;
  94   case Instruction::Shl:  return bitc::BINOP_SHL;
  95   case Instruction::LShr: return bitc::BINOP_LSHR;
  96   case Instruction::AShr: return bitc::BINOP_ASHR;
  97   case Instruction::And:  return bitc::BINOP_AND;
  98   case Instruction::Or:   return bitc::BINOP_OR;
  99   case Instruction::Xor:  return bitc::BINOP_XOR;
 100   }
 101 }
 102
 103
 104
 105 static void WriteStringRecord(unsigned Code, const std::string &Str,
 106                               unsigned AbbrevToUse, BitstreamWriter &Stream) {
 107   SmallVector<unsigned, 64> Vals;
 108
 109   // Code: [strchar x N]
 110   for (unsigned i = 0, e = Str.size(); i != e; ++i)
 111     Vals.push_back(Str[i]);
 112
 113   // Emit the finished record.
 114   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 115 }
 116
 117 // Emit information about parameter attributes.
 118 static void WriteAttributeTable(const ValueEnumerator &VE,
 119                                 BitstreamWriter &Stream) {
 120   const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
 121   if (Attrs.empty()) return;
 122
 123   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 124
 125   SmallVector<uint64_t, 64> Record;
 126   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
 127     const AttrListPtr &A = Attrs[i];
 128     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
 129       const AttributeWithIndex &PAWI = A.getSlot(i);
 130       Record.push_back(PAWI.Index);
 131
 132       // FIXME: remove in LLVM 3.0
 133       // Store the alignment in the bitcode as a 16-bit raw value instead of a
 134       // 5-bit log2 encoded value. Shift the bits above the alignment up by
 135       // 11 bits.
 136       uint64_t FauxAttr = PAWI.Attrs & 0xffff;
 137       if (PAWI.Attrs & Attribute::Alignment)
 138         FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
 139       FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
 140
 141       Record.push_back(FauxAttr);
 142     }
 143
 144     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 145     Record.clear();
 146   }
 147
 148   Stream.ExitBlock();
 149 }
 150
 151 /// WriteTypeTable - Write out the type table for a module.
 152 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 153   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 154
 155   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
 156   SmallVector<uint64_t, 64> TypeVals;
 157
 158   // Abbrev for TYPE_CODE_POINTER.
 159   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 160   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
 161   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 162                             Log2_32_Ceil(VE.getTypes().size()+1)));
 163   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
 164   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
 165
 166   // Abbrev for TYPE_CODE_FUNCTION.
 167   Abbv = new BitCodeAbbrev();
 168   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
 169   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
 170   Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
 171   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 172   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 173                             Log2_32_Ceil(VE.getTypes().size()+1)));
 174   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 175
 176   // Abbrev for TYPE_CODE_STRUCT.
 177   Abbv = new BitCodeAbbrev();
 178   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
 179   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 180   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 181   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 182                             Log2_32_Ceil(VE.getTypes().size()+1)));
 183   unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
 184
 185   // Abbrev for TYPE_CODE_ARRAY.
 186   Abbv = new BitCodeAbbrev();
 187   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 188   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 189   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 190                             Log2_32_Ceil(VE.getTypes().size()+1)));
 191   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 192
 193   // Emit an entry count so the reader can reserve space.
 194   TypeVals.push_back(TypeList.size());
 195   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 196   TypeVals.clear();
 197
 198   // Loop over all of the types, emitting each in turn.
 199   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 200     const Type *T = TypeList[i];
 201     int AbbrevToUse = 0;
 202     unsigned Code = 0;
 203
 204     switch (T->getTypeID()) {
 205     default: llvm_unreachable("Unknown type!");
 206     case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
 207     case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
 208     case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
 209     case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
 210     case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
 211     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 212     case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
 213     case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
 214     case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
 215     case Type::X86_MMXTyID: Code = bitc::TYPE_CODE_X86_MMX; break;
 216     case Type::IntegerTyID:
 217       // INTEGER: [width]
 218       Code = bitc::TYPE_CODE_INTEGER;
 219       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 220       break;
 221     case Type::PointerTyID: {
 222       const PointerType *PTy = cast<PointerType>(T);
 223       // POINTER: [pointee type, address space]
 224       Code = bitc::TYPE_CODE_POINTER;
 225       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
 226       unsigned AddressSpace = PTy->getAddressSpace();
 227       TypeVals.push_back(AddressSpace);
 228       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
 229       break;
 230     }
 231     case Type::FunctionTyID: {
 232       const FunctionType *FT = cast<FunctionType>(T);
 233       // FUNCTION: [isvararg, attrid, retty, paramty x N]
 234       Code = bitc::TYPE_CODE_FUNCTION;
 235       TypeVals.push_back(FT->isVarArg());
 236       TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
 237       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 238       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 239         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 240       AbbrevToUse = FunctionAbbrev;
 241       break;
 242     }
 243     case Type::StructTyID: {
 244       const StructType *ST = cast<StructType>(T);
 245       // STRUCT: [ispacked, eltty x N]
 246       Code = bitc::TYPE_CODE_STRUCT;
 247       TypeVals.push_back(ST->isPacked());
 248       // Output all of the element types.
 249       for (StructType::element_iterator I = ST->element_begin(),
 250            E = ST->element_end(); I != E; ++I)
 251         TypeVals.push_back(VE.getTypeID(*I));
 252       AbbrevToUse = StructAbbrev;
 253       break;
 254     }
 255     case Type::ArrayTyID: {
 256       const ArrayType *AT = cast<ArrayType>(T);
 257       // ARRAY: [numelts, eltty]
 258       Code = bitc::TYPE_CODE_ARRAY;
 259       TypeVals.push_back(AT->getNumElements());
 260       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 261       AbbrevToUse = ArrayAbbrev;
 262       break;
 263     }
 264     case Type::VectorTyID: {
 265       const VectorType *VT = cast<VectorType>(T);
 266       // VECTOR [numelts, eltty]
 267       Code = bitc::TYPE_CODE_VECTOR;
 268       TypeVals.push_back(VT->getNumElements());
 269       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 270       break;
 271     }
 272     }
 273
 274     // Emit the finished record.
 275     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 276     TypeVals.clear();
 277   }
 278
 279   Stream.ExitBlock();
 280 }
 281
 282 static unsigned getEncodedLinkage(const GlobalValue *GV) {
 283   switch (GV->getLinkage()) {
 284   default: llvm_unreachable("Invalid linkage!");
 285   case GlobalValue::ExternalLinkage:                 return 0;
 286   case GlobalValue::WeakAnyLinkage:                  return 1;
 287   case GlobalValue::AppendingLinkage:                return 2;
 288   case GlobalValue::InternalLinkage:                 return 3;
 289   case GlobalValue::LinkOnceAnyLinkage:              return 4;
 290   case GlobalValue::DLLImportLinkage:                return 5;
 291   case GlobalValue::DLLExportLinkage:                return 6;
 292   case GlobalValue::ExternalWeakLinkage:             return 7;
 293   case GlobalValue::CommonLinkage:                   return 8;
 294   case GlobalValue::PrivateLinkage:                  return 9;
 295   case GlobalValue::WeakODRLinkage:                  return 10;
 296   case GlobalValue::LinkOnceODRLinkage:              return 11;
 297   case GlobalValue::AvailableExternallyLinkage:      return 12;
 298   case GlobalValue::LinkerPrivateLinkage:            return 13;
 299   case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
 300   case GlobalValue::LinkerPrivateWeakDefAutoLinkage: return 15;
 301   }
 302 }
 303
 304 static unsigned getEncodedVisibility(const GlobalValue *GV) {
 305   switch (GV->getVisibility()) {
 306   default: llvm_unreachable("Invalid visibility!");
 307   case GlobalValue::DefaultVisibility:   return 0;
 308   case GlobalValue::HiddenVisibility:    return 1;
 309   case GlobalValue::ProtectedVisibility: return 2;
 310   }
 311 }
 312
 313 // Emit top-level description of module, including target triple, inline asm,
 314 // descriptors for global variables, and function prototype info.
 315 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 316                             BitstreamWriter &Stream) {
 317   // Emit the list of dependent libraries for the Module.
 318   for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
 319     WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
 320
 321   // Emit various pieces of data attached to a module.
 322   if (!M->getTargetTriple().empty())
 323     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 324                       0/*TODO*/, Stream);
 325   if (!M->getDataLayout().empty())
 326     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
 327                       0/*TODO*/, Stream);
 328   if (!M->getModuleInlineAsm().empty())
 329     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 330                       0/*TODO*/, Stream);
 331
 332   // Emit information about sections and GC, computing how many there are. Also
 333   // compute the maximum alignment value.
 334   std::map<std::string, unsigned> SectionMap;
 335   std::map<std::string, unsigned> GCMap;
 336   unsigned MaxAlignment = 0;
 337   unsigned MaxGlobalType = 0;
 338   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 339        GV != E; ++GV) {
 340     MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
 341     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
 342
 343     if (!GV->hasSection()) continue;
 344     // Give section names unique ID's.
 345     unsigned &Entry = SectionMap[GV->getSection()];
 346     if (Entry != 0) continue;
 347     WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
 348                       0/*TODO*/, Stream);
 349     Entry = SectionMap.size();
 350   }
 351   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 352     MaxAlignment = std::max(MaxAlignment, F->getAlignment());
 353     if (F->hasSection()) {
 354       // Give section names unique ID's.
 355       unsigned &Entry = SectionMap[F->getSection()];
 356       if (!Entry) {
 357         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
 358                           0/*TODO*/, Stream);
 359         Entry = SectionMap.size();
 360       }
 361     }
 362     if (F->hasGC()) {
 363       // Same for GC names.
 364       unsigned &Entry = GCMap[F->getGC()];
 365       if (!Entry) {
 366         WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
 367                           0/*TODO*/, Stream);
 368         Entry = GCMap.size();
 369       }
 370     }
 371   }
 372
 373   // Emit abbrev for globals, now that we know # sections and max alignment.
 374   unsigned SimpleGVarAbbrev = 0;
 375   if (!M->global_empty()) {
 376     // Add an abbrev for common globals with no visibility or thread localness.
 377     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 378     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 379     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 380                               Log2_32_Ceil(MaxGlobalType+1)));
 381     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
 382     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
 383     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
 384     if (MaxAlignment == 0)                                      // Alignment.
 385       Abbv->Add(BitCodeAbbrevOp(0));
 386     else {
 387       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 388       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 389                                Log2_32_Ceil(MaxEncAlignment+1)));
 390     }
 391     if (SectionMap.empty())                                    // Section.
 392       Abbv->Add(BitCodeAbbrevOp(0));
 393     else
 394       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 395                                Log2_32_Ceil(SectionMap.size()+1)));
 396     // Don't bother emitting vis + thread local.
 397     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 398   }
 399
 400   // Emit the global variable information.
 401   SmallVector<unsigned, 64> Vals;
 402   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 403        GV != E; ++GV) {
 404     unsigned AbbrevToUse = 0;
 405
 406     // GLOBALVAR: [type, isconst, initid,
 407     //             linkage, alignment, section, visibility, threadlocal,
 408     //             unnamed_addr]
 409     Vals.push_back(VE.getTypeID(GV->getType()));
 410     Vals.push_back(GV->isConstant());
 411     Vals.push_back(GV->isDeclaration() ? 0 :
 412                    (VE.getValueID(GV->getInitializer()) + 1));
 413     Vals.push_back(getEncodedLinkage(GV));
 414     Vals.push_back(Log2_32(GV->getAlignment())+1);
 415     Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
 416     if (GV->isThreadLocal() ||
 417         GV->getVisibility() != GlobalValue::DefaultVisibility ||
 418         GV->hasUnnamedAddr()) {
 419       Vals.push_back(getEncodedVisibility(GV));
 420       Vals.push_back(GV->isThreadLocal());
 421       Vals.push_back(GV->hasUnnamedAddr());
 422     } else {
 423       AbbrevToUse = SimpleGVarAbbrev;
 424     }
 425
 426     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 427     Vals.clear();
 428   }
 429
 430   // Emit the function proto information.
 431   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 432     // FUNCTION:  [type, callingconv, isproto, paramattr,
 433     //             linkage, alignment, section, visibility, gc, unnamed_addr]
 434     Vals.push_back(VE.getTypeID(F->getType()));
 435     Vals.push_back(F->getCallingConv());
 436     Vals.push_back(F->isDeclaration());
 437     Vals.push_back(getEncodedLinkage(F));
 438     Vals.push_back(VE.getAttributeID(F->getAttributes()));
 439     Vals.push_back(Log2_32(F->getAlignment())+1);
 440     Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
 441     Vals.push_back(getEncodedVisibility(F));
 442     Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
 443     Vals.push_back(F->hasUnnamedAddr());
 444
 445     unsigned AbbrevToUse = 0;
 446     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 447     Vals.clear();
 448   }
 449
 450
 451   // Emit the alias information.
 452   for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
 453        AI != E; ++AI) {
 454     Vals.push_back(VE.getTypeID(AI->getType()));
 455     Vals.push_back(VE.getValueID(AI->getAliasee()));
 456     Vals.push_back(getEncodedLinkage(AI));
 457     Vals.push_back(getEncodedVisibility(AI));
 458     unsigned AbbrevToUse = 0;
 459     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 460     Vals.clear();
 461   }
 462 }
 463
 464 static uint64_t GetOptimizationFlags(const Value *V) {
 465   uint64_t Flags = 0;
 466
 467   if (const OverflowingBinaryOperator *OBO =
 468         dyn_cast<OverflowingBinaryOperator>(V)) {
 469     if (OBO->hasNoSignedWrap())
 470       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
 471     if (OBO->hasNoUnsignedWrap())
 472       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
 473   } else if (const PossiblyExactOperator *PEO =
 474                dyn_cast<PossiblyExactOperator>(V)) {
 475     if (PEO->isExact())
 476       Flags |= 1 << bitc::PEO_EXACT;
 477   }
 478
 479   return Flags;
 480 }
 481
 482 static void WriteMDNode(const MDNode *N,
 483                         const ValueEnumerator &VE,
 484                         BitstreamWriter &Stream,
 485                         SmallVector<uint64_t, 64> &Record) {
 486   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
 487     if (N->getOperand(i)) {
 488       Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
 489       Record.push_back(VE.getValueID(N->getOperand(i)));
 490     } else {
 491       Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
 492       Record.push_back(0);
 493     }
 494   }
 495   unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE2 :
 496                                            bitc::METADATA_NODE2;
 497   Stream.EmitRecord(MDCode, Record, 0);
 498   Record.clear();
 499 }
 500
 501 static void WriteModuleMetadata(const Module *M,
 502                                 const ValueEnumerator &VE,
 503                                 BitstreamWriter &Stream) {
 504   const ValueEnumerator::ValueList &Vals = VE.getMDValues();
 505   bool StartedMetadataBlock = false;
 506   unsigned MDSAbbrev = 0;
 507   SmallVector<uint64_t, 64> Record;
 508   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 509
 510     if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
 511       if (!N->isFunctionLocal() || !N->getFunction()) {
 512         if (!StartedMetadataBlock) {
 513           Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 514           StartedMetadataBlock = true;
 515         }
 516         WriteMDNode(N, VE, Stream, Record);
 517       }
 518     } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
 519       if (!StartedMetadataBlock)  {
 520         Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 521
 522         // Abbrev for METADATA_STRING.
 523         BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 524         Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
 525         Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 526         Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 527         MDSAbbrev = Stream.EmitAbbrev(Abbv);
 528         StartedMetadataBlock = true;
 529       }
 530
 531       // Code: [strchar x N]
 532       Record.append(MDS->begin(), MDS->end());
 533
 534       // Emit the finished record.
 535       Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
 536       Record.clear();
 537     }
 538   }
 539
 540   // Write named metadata.
 541   for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
 542        E = M->named_metadata_end(); I != E; ++I) {
 543     const NamedMDNode *NMD = I;
 544     if (!StartedMetadataBlock)  {
 545       Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 546       StartedMetadataBlock = true;
 547     }
 548
 549     // Write name.
 550     StringRef Str = NMD->getName();
 551     for (unsigned i = 0, e = Str.size(); i != e; ++i)
 552       Record.push_back(Str[i]);
 553     Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
 554     Record.clear();
 555
 556     // Write named metadata operands.
 557     for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
 558       Record.push_back(VE.getValueID(NMD->getOperand(i)));
 559     Stream.EmitRecord(bitc::METADATA_NAMED_NODE2, Record, 0);
 560     Record.clear();
 561   }
 562
 563   if (StartedMetadataBlock)
 564     Stream.ExitBlock();
 565 }
 566
 567 static void WriteFunctionLocalMetadata(const Function &F,
 568                                        const ValueEnumerator &VE,
 569                                        BitstreamWriter &Stream) {
 570   bool StartedMetadataBlock = false;
 571   SmallVector<uint64_t, 64> Record;
 572   const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
 573   for (unsigned i = 0, e = Vals.size(); i != e; ++i)
 574     if (const MDNode *N = Vals[i])
 575       if (N->isFunctionLocal() && N->getFunction() == &F) {
 576         if (!StartedMetadataBlock) {
 577           Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 578           StartedMetadataBlock = true;
 579         }
 580         WriteMDNode(N, VE, Stream, Record);
 581       }
 582
 583   if (StartedMetadataBlock)
 584     Stream.ExitBlock();
 585 }
 586
 587 static void WriteMetadataAttachment(const Function &F,
 588                                     const ValueEnumerator &VE,
 589                                     BitstreamWriter &Stream) {
 590   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
 591
 592   SmallVector<uint64_t, 64> Record;
 593
 594   // Write metadata attachments
 595   // METADATA_ATTACHMENT2 - [m x [value, [n x [id, mdnode]]]
 596   SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
 597
 598   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
 599     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
 600          I != E; ++I) {
 601       MDs.clear();
 602       I->getAllMetadataOtherThanDebugLoc(MDs);
 603
 604       // If no metadata, ignore instruction.
 605       if (MDs.empty()) continue;
 606
 607       Record.push_back(VE.getInstructionID(I));
 608
 609       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
 610         Record.push_back(MDs[i].first);
 611         Record.push_back(VE.getValueID(MDs[i].second));
 612       }
 613       Stream.EmitRecord(bitc::METADATA_ATTACHMENT2, Record, 0);
 614       Record.clear();
 615     }
 616
 617   Stream.ExitBlock();
 618 }
 619
 620 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
 621   SmallVector<uint64_t, 64> Record;
 622
 623   // Write metadata kinds
 624   // METADATA_KIND - [n x [id, name]]
 625   SmallVector<StringRef, 4> Names;
 626   M->getMDKindNames(Names);
 627
 628   if (Names.empty()) return;
 629
 630   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 631
 632   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
 633     Record.push_back(MDKindID);
 634     StringRef KName = Names[MDKindID];
 635     Record.append(KName.begin(), KName.end());
 636
 637     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
 638     Record.clear();
 639   }
 640
 641   Stream.ExitBlock();
 642 }
 643
 644 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
 645                            const ValueEnumerator &VE,
 646                            BitstreamWriter &Stream, bool isGlobal) {
 647   if (FirstVal == LastVal) return;
 648
 649   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
 650
 651   unsigned AggregateAbbrev = 0;
 652   unsigned String8Abbrev = 0;
 653   unsigned CString7Abbrev = 0;
 654   unsigned CString6Abbrev = 0;
 655   // If this is a constant pool for the module, emit module-specific abbrevs.
 656   if (isGlobal) {
 657     // Abbrev for CST_CODE_AGGREGATE.
 658     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 659     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
 660     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 661     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
 662     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
 663
 664     // Abbrev for CST_CODE_STRING.
 665     Abbv = new BitCodeAbbrev();
 666     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
 667     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 668     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 669     String8Abbrev = Stream.EmitAbbrev(Abbv);
 670     // Abbrev for CST_CODE_CSTRING.
 671     Abbv = new BitCodeAbbrev();
 672     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 673     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 674     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 675     CString7Abbrev = Stream.EmitAbbrev(Abbv);
 676     // Abbrev for CST_CODE_CSTRING.
 677     Abbv = new BitCodeAbbrev();
 678     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 679     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 680     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 681     CString6Abbrev = Stream.EmitAbbrev(Abbv);
 682   }
 683
 684   SmallVector<uint64_t, 64> Record;
 685
 686   const ValueEnumerator::ValueList &Vals = VE.getValues();
 687   const Type *LastTy = 0;
 688   for (unsigned i = FirstVal; i != LastVal; ++i) {
 689     const Value *V = Vals[i].first;
 690     // If we need to switch types, do so now.
 691     if (V->getType() != LastTy) {
 692       LastTy = V->getType();
 693       Record.push_back(VE.getTypeID(LastTy));
 694       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
 695                         CONSTANTS_SETTYPE_ABBREV);
 696       Record.clear();
 697     }
 698
 699     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
 700       Record.push_back(unsigned(IA->hasSideEffects()) |
 701                        unsigned(IA->isAlignStack()) << 1);
 702
 703       // Add the asm string.
 704       const std::string &AsmStr = IA->getAsmString();
 705       Record.push_back(AsmStr.size());
 706       for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
 707         Record.push_back(AsmStr[i]);
 708
 709       // Add the constraint string.
 710       const std::string &ConstraintStr = IA->getConstraintString();
 711       Record.push_back(ConstraintStr.size());
 712       for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
 713         Record.push_back(ConstraintStr[i]);
 714       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
 715       Record.clear();
 716       continue;
 717     }
 718     const Constant *C = cast<Constant>(V);
 719     unsigned Code = -1U;
 720     unsigned AbbrevToUse = 0;
 721     if (C->isNullValue()) {
 722       Code = bitc::CST_CODE_NULL;
 723     } else if (isa<UndefValue>(C)) {
 724       Code = bitc::CST_CODE_UNDEF;
 725     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
 726       if (IV->getBitWidth() <= 64) {
 727         uint64_t V = IV->getSExtValue();
 728         if ((int64_t)V >= 0)
 729           Record.push_back(V << 1);
 730         else
 731           Record.push_back((-V << 1) | 1);
 732         Code = bitc::CST_CODE_INTEGER;
 733         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
 734       } else {                             // Wide integers, > 64 bits in size.
 735         // We have an arbitrary precision integer value to write whose
 736         // bit width is > 64. However, in canonical unsigned integer
 737         // format it is likely that the high bits are going to be zero.
 738         // So, we only write the number of active words.
 739         unsigned NWords = IV->getValue().getActiveWords();
 740         const uint64_t *RawWords = IV->getValue().getRawData();
 741         for (unsigned i = 0; i != NWords; ++i) {
 742           int64_t V = RawWords[i];
 743           if (V >= 0)
 744             Record.push_back(V << 1);
 745           else
 746             Record.push_back((-V << 1) | 1);
 747         }
 748         Code = bitc::CST_CODE_WIDE_INTEGER;
 749       }
 750     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
 751       Code = bitc::CST_CODE_FLOAT;
 752       const Type *Ty = CFP->getType();
 753       if (Ty->isFloatTy() || Ty->isDoubleTy()) {
 754         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
 755       } else if (Ty->isX86_FP80Ty()) {
 756         // api needed to prevent premature destruction
 757         // bits are not in the same order as a normal i80 APInt, compensate.
 758         APInt api = CFP->getValueAPF().bitcastToAPInt();
 759         const uint64_t *p = api.getRawData();
 760         Record.push_back((p[1] << 48) | (p[0] >> 16));
 761         Record.push_back(p[0] & 0xffffLL);
 762       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
 763         APInt api = CFP->getValueAPF().bitcastToAPInt();
 764         const uint64_t *p = api.getRawData();
 765         Record.push_back(p[0]);
 766         Record.push_back(p[1]);
 767       } else {
 768         assert (0 && "Unknown FP type!");
 769       }
 770     } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
 771       const ConstantArray *CA = cast<ConstantArray>(C);
 772       // Emit constant strings specially.
 773       unsigned NumOps = CA->getNumOperands();
 774       // If this is a null-terminated string, use the denser CSTRING encoding.
 775       if (CA->getOperand(NumOps-1)->isNullValue()) {
 776         Code = bitc::CST_CODE_CSTRING;
 777         --NumOps;  // Don't encode the null, which isn't allowed by char6.
 778       } else {
 779         Code = bitc::CST_CODE_STRING;
 780         AbbrevToUse = String8Abbrev;
 781       }
 782       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
 783       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
 784       for (unsigned i = 0; i != NumOps; ++i) {
 785         unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
 786         Record.push_back(V);
 787         isCStr7 &= (V & 128) == 0;
 788         if (isCStrChar6)
 789           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
 790       }
 791
 792       if (isCStrChar6)
 793         AbbrevToUse = CString6Abbrev;
 794       else if (isCStr7)
 795         AbbrevToUse = CString7Abbrev;
 796     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
 797                isa<ConstantVector>(V)) {
 798       Code = bitc::CST_CODE_AGGREGATE;
 799       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
 800         Record.push_back(VE.getValueID(C->getOperand(i)));
 801       AbbrevToUse = AggregateAbbrev;
 802     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
 803       switch (CE->getOpcode()) {
 804       default:
 805         if (Instruction::isCast(CE->getOpcode())) {
 806           Code = bitc::CST_CODE_CE_CAST;
 807           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
 808           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 809           Record.push_back(VE.getValueID(C->getOperand(0)));
 810           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
 811         } else {
 812           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
 813           Code = bitc::CST_CODE_CE_BINOP;
 814           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
 815           Record.push_back(VE.getValueID(C->getOperand(0)));
 816           Record.push_back(VE.getValueID(C->getOperand(1)));
 817           uint64_t Flags = GetOptimizationFlags(CE);
 818           if (Flags != 0)
 819             Record.push_back(Flags);
 820         }
 821         break;
 822       case Instruction::GetElementPtr:
 823         Code = bitc::CST_CODE_CE_GEP;
 824         if (cast<GEPOperator>(C)->isInBounds())
 825           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
 826         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
 827           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
 828           Record.push_back(VE.getValueID(C->getOperand(i)));
 829         }
 830         break;
 831       case Instruction::Select:
 832         Code = bitc::CST_CODE_CE_SELECT;
 833         Record.push_back(VE.getValueID(C->getOperand(0)));
 834         Record.push_back(VE.getValueID(C->getOperand(1)));
 835         Record.push_back(VE.getValueID(C->getOperand(2)));
 836         break;
 837       case Instruction::ExtractElement:
 838         Code = bitc::CST_CODE_CE_EXTRACTELT;
 839         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 840         Record.push_back(VE.getValueID(C->getOperand(0)));
 841         Record.push_back(VE.getValueID(C->getOperand(1)));
 842         break;
 843       case Instruction::InsertElement:
 844         Code = bitc::CST_CODE_CE_INSERTELT;
 845         Record.push_back(VE.getValueID(C->getOperand(0)));
 846         Record.push_back(VE.getValueID(C->getOperand(1)));
 847         Record.push_back(VE.getValueID(C->getOperand(2)));
 848         break;
 849       case Instruction::ShuffleVector:
 850         // If the return type and argument types are the same, this is a
 851         // standard shufflevector instruction.  If the types are different,
 852         // then the shuffle is widening or truncating the input vectors, and
 853         // the argument type must also be encoded.
 854         if (C->getType() == C->getOperand(0)->getType()) {
 855           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
 856         } else {
 857           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
 858           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 859         }
 860         Record.push_back(VE.getValueID(C->getOperand(0)));
 861         Record.push_back(VE.getValueID(C->getOperand(1)));
 862         Record.push_back(VE.getValueID(C->getOperand(2)));
 863         break;
 864       case Instruction::ICmp:
 865       case Instruction::FCmp:
 866         Code = bitc::CST_CODE_CE_CMP;
 867         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 868         Record.push_back(VE.getValueID(C->getOperand(0)));
 869         Record.push_back(VE.getValueID(C->getOperand(1)));
 870         Record.push_back(CE->getPredicate());
 871         break;
 872       }
 873     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
 874       assert(BA->getFunction() == BA->getBasicBlock()->getParent() &&
 875              "Malformed blockaddress");
 876       Code = bitc::CST_CODE_BLOCKADDRESS;
 877       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
 878       Record.push_back(VE.getValueID(BA->getFunction()));
 879       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
 880     } else {
 881 #ifndef NDEBUG
 882       C->dump();
 883 #endif
 884       llvm_unreachable("Unknown constant!");
 885     }
 886     Stream.EmitRecord(Code, Record, AbbrevToUse);
 887     Record.clear();
 888   }
 889
 890   Stream.ExitBlock();
 891 }
 892
 893 static void WriteModuleConstants(const ValueEnumerator &VE,
 894                                  BitstreamWriter &Stream) {
 895   const ValueEnumerator::ValueList &Vals = VE.getValues();
 896
 897   // Find the first constant to emit, which is the first non-globalvalue value.
 898   // We know globalvalues have been emitted by WriteModuleInfo.
 899   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 900     if (!isa<GlobalValue>(Vals[i].first)) {
 901       WriteConstants(i, Vals.size(), VE, Stream, true);
 902       return;
 903     }
 904   }
 905 }
 906
 907 /// PushValueAndType - The file has to encode both the value and type id for
 908 /// many values, because we need to know what type to create for forward
 909 /// references.  However, most operands are not forward references, so this type
 910 /// field is not needed.
 911 ///
 912 /// This function adds V's value ID to Vals.  If the value ID is higher than the
 913 /// instruction ID, then it is a forward reference, and it also includes the
 914 /// type ID.
 915 static bool PushValueAndType(const Value *V, unsigned InstID,
 916                              SmallVector<unsigned, 64> &Vals,
 917                              ValueEnumerator &VE) {
 918   unsigned ValID = VE.getValueID(V);
 919   Vals.push_back(ValID);
 920   if (ValID >= InstID) {
 921     Vals.push_back(VE.getTypeID(V->getType()));
 922     return true;
 923   }
 924   return false;
 925 }
 926
 927 /// WriteInstruction - Emit an instruction to the specified stream.
 928 static void WriteInstruction(const Instruction &I, unsigned InstID,
 929                              ValueEnumerator &VE, BitstreamWriter &Stream,
 930                              SmallVector<unsigned, 64> &Vals) {
 931   unsigned Code = 0;
 932   unsigned AbbrevToUse = 0;
 933   VE.setInstructionID(&I);
 934   switch (I.getOpcode()) {
 935   default:
 936     if (Instruction::isCast(I.getOpcode())) {
 937       Code = bitc::FUNC_CODE_INST_CAST;
 938       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 939         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
 940       Vals.push_back(VE.getTypeID(I.getType()));
 941       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
 942     } else {
 943       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
 944       Code = bitc::FUNC_CODE_INST_BINOP;
 945       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 946         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
 947       Vals.push_back(VE.getValueID(I.getOperand(1)));
 948       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
 949       uint64_t Flags = GetOptimizationFlags(&I);
 950       if (Flags != 0) {
 951         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
 952           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
 953         Vals.push_back(Flags);
 954       }
 955     }
 956     break;
 957
 958   case Instruction::GetElementPtr:
 959     Code = bitc::FUNC_CODE_INST_GEP;
 960     if (cast<GEPOperator>(&I)->isInBounds())
 961       Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
 962     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 963       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
 964     break;
 965   case Instruction::ExtractValue: {
 966     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
 967     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 968     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
 969     for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
 970       Vals.push_back(*i);
 971     break;
 972   }
 973   case Instruction::InsertValue: {
 974     Code = bitc::FUNC_CODE_INST_INSERTVAL;
 975     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 976     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
 977     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
 978     for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
 979       Vals.push_back(*i);
 980     break;
 981   }
 982   case Instruction::Select:
 983     Code = bitc::FUNC_CODE_INST_VSELECT;
 984     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
 985     Vals.push_back(VE.getValueID(I.getOperand(2)));
 986     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 987     break;
 988   case Instruction::ExtractElement:
 989     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
 990     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 991     Vals.push_back(VE.getValueID(I.getOperand(1)));
 992     break;
 993   case Instruction::InsertElement:
 994     Code = bitc::FUNC_CODE_INST_INSERTELT;
 995     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 996     Vals.push_back(VE.getValueID(I.getOperand(1)));
 997     Vals.push_back(VE.getValueID(I.getOperand(2)));
 998     break;
 999   case Instruction::ShuffleVector:
1000     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1001     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1002     Vals.push_back(VE.getValueID(I.getOperand(1)));
1003     Vals.push_back(VE.getValueID(I.getOperand(2)));
1004     break;
1005   case Instruction::ICmp:
1006   case Instruction::FCmp:
1007     // compare returning Int1Ty or vector of Int1Ty
1008     Code = bitc::FUNC_CODE_INST_CMP2;
1009     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1010     Vals.push_back(VE.getValueID(I.getOperand(1)));
1011     Vals.push_back(cast<CmpInst>(I).getPredicate());
1012     break;
1013
1014   case Instruction::Ret:
1015     {
1016       Code = bitc::FUNC_CODE_INST_RET;
1017       unsigned NumOperands = I.getNumOperands();
1018       if (NumOperands == 0)
1019         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1020       else if (NumOperands == 1) {
1021         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1022           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1023       } else {
1024         for (unsigned i = 0, e = NumOperands; i != e; ++i)
1025           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1026       }
1027     }
1028     break;
1029   case Instruction::Br:
1030     {
1031       Code = bitc::FUNC_CODE_INST_BR;
1032       BranchInst &II = cast<BranchInst>(I);
1033       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1034       if (II.isConditional()) {
1035         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1036         Vals.push_back(VE.getValueID(II.getCondition()));
1037       }
1038     }
1039     break;
1040   case Instruction::Switch:
1041     Code = bitc::FUNC_CODE_INST_SWITCH;
1042     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1043     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1044       Vals.push_back(VE.getValueID(I.getOperand(i)));
1045     break;
1046   case Instruction::IndirectBr:
1047     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1048     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1049     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1050       Vals.push_back(VE.getValueID(I.getOperand(i)));
1051     break;
1052
1053   case Instruction::Invoke: {
1054     const InvokeInst *II = cast<InvokeInst>(&I);
1055     const Value *Callee(II->getCalledValue());
1056     const PointerType *PTy = cast<PointerType>(Callee->getType());
1057     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1058     Code = bitc::FUNC_CODE_INST_INVOKE;
1059
1060     Vals.push_back(VE.getAttributeID(II->getAttributes()));
1061     Vals.push_back(II->getCallingConv());
1062     Vals.push_back(VE.getValueID(II->getNormalDest()));
1063     Vals.push_back(VE.getValueID(II->getUnwindDest()));
1064     PushValueAndType(Callee, InstID, Vals, VE);
1065
1066     // Emit value #'s for the fixed parameters.
1067     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1068       Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1069
1070     // Emit type/value pairs for varargs params.
1071     if (FTy->isVarArg()) {
1072       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1073            i != e; ++i)
1074         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1075     }
1076     break;
1077   }
1078   case Instruction::Unwind:
1079     Code = bitc::FUNC_CODE_INST_UNWIND;
1080     break;
1081   case Instruction::Unreachable:
1082     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1083     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1084     break;
1085
1086   case Instruction::PHI:
1087     Code = bitc::FUNC_CODE_INST_PHI;
1088     Vals.push_back(VE.getTypeID(I.getType()));
1089     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1090       Vals.push_back(VE.getValueID(I.getOperand(i)));
1091     break;
1092
1093   case Instruction::Alloca:
1094     Code = bitc::FUNC_CODE_INST_ALLOCA;
1095     Vals.push_back(VE.getTypeID(I.getType()));
1096     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1097     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1098     Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1099     break;
1100
1101   case Instruction::Load:
1102     Code = bitc::FUNC_CODE_INST_LOAD;
1103     if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1104       AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1105
1106     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1107     Vals.push_back(cast<LoadInst>(I).isVolatile());
1108     break;
1109   case Instruction::Store:
1110     Code = bitc::FUNC_CODE_INST_STORE2;
1111     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1112     Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1113     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1114     Vals.push_back(cast<StoreInst>(I).isVolatile());
1115     break;
1116   case Instruction::Call: {
1117     const CallInst &CI = cast<CallInst>(I);
1118     const PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1119     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1120
1121     Code = bitc::FUNC_CODE_INST_CALL2;
1122
1123     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1124     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1125     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1126
1127     // Emit value #'s for the fixed parameters.
1128     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1129       Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1130
1131     // Emit type/value pairs for varargs params.
1132     if (FTy->isVarArg()) {
1133       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1134            i != e; ++i)
1135         PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1136     }
1137     break;
1138   }
1139   case Instruction::VAArg:
1140     Code = bitc::FUNC_CODE_INST_VAARG;
1141     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1142     Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1143     Vals.push_back(VE.getTypeID(I.getType())); // restype.
1144     break;
1145   }
1146
1147   Stream.EmitRecord(Code, Vals, AbbrevToUse);
1148   Vals.clear();
1149 }
1150
1151 // Emit names for globals/functions etc.
1152 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1153                                   const ValueEnumerator &VE,
1154                                   BitstreamWriter &Stream) {
1155   if (VST.empty()) return;
1156   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1157
1158   // FIXME: Set up the abbrev, we know how many values there are!
1159   // FIXME: We know if the type names can use 7-bit ascii.
1160   SmallVector<unsigned, 64> NameVals;
1161
1162   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1163        SI != SE; ++SI) {
1164
1165     const ValueName &Name = *SI;
1166
1167     // Figure out the encoding to use for the name.
1168     bool is7Bit = true;
1169     bool isChar6 = true;
1170     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1171          C != E; ++C) {
1172       if (isChar6)
1173         isChar6 = BitCodeAbbrevOp::isChar6(*C);
1174       if ((unsigned char)*C & 128) {
1175         is7Bit = false;
1176         break;  // don't bother scanning the rest.
1177       }
1178     }
1179
1180     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1181
1182     // VST_ENTRY:   [valueid, namechar x N]
1183     // VST_BBENTRY: [bbid, namechar x N]
1184     unsigned Code;
1185     if (isa<BasicBlock>(SI->getValue())) {
1186       Code = bitc::VST_CODE_BBENTRY;
1187       if (isChar6)
1188         AbbrevToUse = VST_BBENTRY_6_ABBREV;
1189     } else {
1190       Code = bitc::VST_CODE_ENTRY;
1191       if (isChar6)
1192         AbbrevToUse = VST_ENTRY_6_ABBREV;
1193       else if (is7Bit)
1194         AbbrevToUse = VST_ENTRY_7_ABBREV;
1195     }
1196
1197     NameVals.push_back(VE.getValueID(SI->getValue()));
1198     for (const char *P = Name.getKeyData(),
1199          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1200       NameVals.push_back((unsigned char)*P);
1201
1202     // Emit the finished record.
1203     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1204     NameVals.clear();
1205   }
1206   Stream.ExitBlock();
1207 }
1208
1209 /// WriteFunction - Emit a function body to the module stream.
1210 static void WriteFunction(const Function &F, ValueEnumerator &VE,
1211                           BitstreamWriter &Stream) {
1212   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1213   VE.incorporateFunction(F);
1214
1215   SmallVector<unsigned, 64> Vals;
1216
1217   // Emit the number of basic blocks, so the reader can create them ahead of
1218   // time.
1219   Vals.push_back(VE.getBasicBlocks().size());
1220   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1221   Vals.clear();
1222
1223   // If there are function-local constants, emit them now.
1224   unsigned CstStart, CstEnd;
1225   VE.getFunctionConstantRange(CstStart, CstEnd);
1226   WriteConstants(CstStart, CstEnd, VE, Stream, false);
1227
1228   // If there is function-local metadata, emit it now.
1229   WriteFunctionLocalMetadata(F, VE, Stream);
1230
1231   // Keep a running idea of what the instruction ID is.
1232   unsigned InstID = CstEnd;
1233
1234   bool NeedsMetadataAttachment = false;
1235
1236   DebugLoc LastDL;
1237
1238   // Finally, emit all the instructions, in order.
1239   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1240     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1241          I != E; ++I) {
1242       WriteInstruction(*I, InstID, VE, Stream, Vals);
1243
1244       if (!I->getType()->isVoidTy())
1245         ++InstID;
1246
1247       // If the instruction has metadata, write a metadata attachment later.
1248       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1249
1250       // If the instruction has a debug location, emit it.
1251       DebugLoc DL = I->getDebugLoc();
1252       if (DL.isUnknown()) {
1253         // nothing todo.
1254       } else if (DL == LastDL) {
1255         // Just repeat the same debug loc as last time.
1256         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1257       } else {
1258         MDNode *Scope, *IA;
1259         DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1260
1261         Vals.push_back(DL.getLine());
1262         Vals.push_back(DL.getCol());
1263         Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1264         Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1265         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC2, Vals);
1266         Vals.clear();
1267
1268         LastDL = DL;
1269       }
1270     }
1271
1272   // Emit names for all the instructions etc.
1273   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1274
1275   if (NeedsMetadataAttachment)
1276     WriteMetadataAttachment(F, VE, Stream);
1277   VE.purgeFunction();
1278   Stream.ExitBlock();
1279 }
1280
1281 /// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1282 static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1283                                  const ValueEnumerator &VE,
1284                                  BitstreamWriter &Stream) {
1285   if (TST.empty()) return;
1286
1287   Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1288
1289   // 7-bit fixed width VST_CODE_ENTRY strings.
1290   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1291   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1292   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1293                             Log2_32_Ceil(VE.getTypes().size()+1)));
1294   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1295   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1296   unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1297
1298   SmallVector<unsigned, 64> NameVals;
1299
1300   for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1301        TI != TE; ++TI) {
1302     // TST_ENTRY: [typeid, namechar x N]
1303     NameVals.push_back(VE.getTypeID(TI->second));
1304
1305     const std::string &Str = TI->first;
1306     bool is7Bit = true;
1307     for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1308       NameVals.push_back((unsigned char)Str[i]);
1309       if (Str[i] & 128)
1310         is7Bit = false;
1311     }
1312
1313     // Emit the finished record.
1314     Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1315     NameVals.clear();
1316   }
1317
1318   Stream.ExitBlock();
1319 }
1320
1321 // Emit blockinfo, which defines the standard abbreviations etc.
1322 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1323   // We only want to emit block info records for blocks that have multiple
1324   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1325   // blocks can defined their abbrevs inline.
1326   Stream.EnterBlockInfoBlock(2);
1327
1328   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1329     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1330     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1331     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1332     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1333     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1334     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1335                                    Abbv) != VST_ENTRY_8_ABBREV)
1336       llvm_unreachable("Unexpected abbrev ordering!");
1337   }
1338
1339   { // 7-bit fixed width VST_ENTRY strings.
1340     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1341     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1342     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1343     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1344     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1345     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1346                                    Abbv) != VST_ENTRY_7_ABBREV)
1347       llvm_unreachable("Unexpected abbrev ordering!");
1348   }
1349   { // 6-bit char6 VST_ENTRY strings.
1350     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1351     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1352     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1353     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1354     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1355     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1356                                    Abbv) != VST_ENTRY_6_ABBREV)
1357       llvm_unreachable("Unexpected abbrev ordering!");
1358   }
1359   { // 6-bit char6 VST_BBENTRY strings.
1360     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1361     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1362     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1363     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1364     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1365     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1366                                    Abbv) != VST_BBENTRY_6_ABBREV)
1367       llvm_unreachable("Unexpected abbrev ordering!");
1368   }
1369
1370
1371
1372   { // SETTYPE abbrev for CONSTANTS_BLOCK.
1373     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1374     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1375     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1376                               Log2_32_Ceil(VE.getTypes().size()+1)));
1377     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1378                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
1379       llvm_unreachable("Unexpected abbrev ordering!");
1380   }
1381
1382   { // INTEGER abbrev for CONSTANTS_BLOCK.
1383     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1384     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1385     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1386     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1387                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
1388       llvm_unreachable("Unexpected abbrev ordering!");
1389   }
1390
1391   { // CE_CAST abbrev for CONSTANTS_BLOCK.
1392     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1393     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1394     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1395     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1396                               Log2_32_Ceil(VE.getTypes().size()+1)));
1397     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1398
1399     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1400                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
1401       llvm_unreachable("Unexpected abbrev ordering!");
1402   }
1403   { // NULL abbrev for CONSTANTS_BLOCK.
1404     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1405     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1406     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1407                                    Abbv) != CONSTANTS_NULL_Abbrev)
1408       llvm_unreachable("Unexpected abbrev ordering!");
1409   }
1410
1411   // FIXME: This should only use space for first class types!
1412
1413   { // INST_LOAD abbrev for FUNCTION_BLOCK.
1414     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1415     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1416     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1417     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1418     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1419     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1420                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
1421       llvm_unreachable("Unexpected abbrev ordering!");
1422   }
1423   { // INST_BINOP abbrev for FUNCTION_BLOCK.
1424     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1425     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1426     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1427     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1428     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1429     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1430                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
1431       llvm_unreachable("Unexpected abbrev ordering!");
1432   }
1433   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1434     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1435     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1436     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1437     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1438     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1439     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1440     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1441                                    Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1442       llvm_unreachable("Unexpected abbrev ordering!");
1443   }
1444   { // INST_CAST abbrev for FUNCTION_BLOCK.
1445     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1446     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1447     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1448     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1449                               Log2_32_Ceil(VE.getTypes().size()+1)));
1450     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1451     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1452                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
1453       llvm_unreachable("Unexpected abbrev ordering!");
1454   }
1455
1456   { // INST_RET abbrev for FUNCTION_BLOCK.
1457     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1458     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1459     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1460                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1461       llvm_unreachable("Unexpected abbrev ordering!");
1462   }
1463   { // INST_RET abbrev for FUNCTION_BLOCK.
1464     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1465     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1466     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1467     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1468                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1469       llvm_unreachable("Unexpected abbrev ordering!");
1470   }
1471   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1472     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1473     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1474     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1475                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1476       llvm_unreachable("Unexpected abbrev ordering!");
1477   }
1478
1479   Stream.ExitBlock();
1480 }
1481
1482
1483 /// WriteModule - Emit the specified module to the bitstream.
1484 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1485   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1486
1487   // Emit the version number if it is non-zero.
1488   if (CurVersion) {
1489     SmallVector<unsigned, 1> Vals;
1490     Vals.push_back(CurVersion);
1491     Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1492   }
1493
1494   // Analyze the module, enumerating globals, functions, etc.
1495   ValueEnumerator VE(M);
1496
1497   // Emit blockinfo, which defines the standard abbreviations etc.
1498   WriteBlockInfo(VE, Stream);
1499
1500   // Emit information about parameter attributes.
1501   WriteAttributeTable(VE, Stream);
1502
1503   // Emit information describing all of the types in the module.
1504   WriteTypeTable(VE, Stream);
1505
1506   // Emit top-level description of module, including target triple, inline asm,
1507   // descriptors for global variables, and function prototype info.
1508   WriteModuleInfo(M, VE, Stream);
1509
1510   // Emit constants.
1511   WriteModuleConstants(VE, Stream);
1512
1513   // Emit metadata.
1514   WriteModuleMetadata(M, VE, Stream);
1515
1516   // Emit function bodies.
1517   for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1518     if (!I->isDeclaration())
1519       WriteFunction(*I, VE, Stream);
1520
1521   // Emit metadata.
1522   WriteModuleMetadataStore(M, Stream);
1523
1524   // Emit the type symbol table information.
1525   WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1526
1527   // Emit names for globals/functions etc.
1528   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1529
1530   Stream.ExitBlock();
1531 }
1532
1533 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1534 /// header and trailer to make it compatible with the system archiver.  To do
1535 /// this we emit the following header, and then emit a trailer that pads the
1536 /// file out to be a multiple of 16 bytes.
1537 ///
1538 /// struct bc_header {
1539 ///   uint32_t Magic;         // 0x0B17C0DE
1540 ///   uint32_t Version;       // Version, currently always 0.
1541 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1542 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1543 ///   uint32_t CPUType;       // CPU specifier.
1544 ///   ... potentially more later ...
1545 /// };
1546 enum {
1547   DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1548   DarwinBCHeaderSize = 5*4
1549 };
1550
1551 /// isARMTriplet - Return true if the triplet looks like:
1552 /// arm-*, thumb-*, armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*.
1553 static bool isARMTriplet(const std::string &TT) {
1554   size_t Pos = 0;
1555   size_t Size = TT.size();
1556   if (Size >= 6 &&
1557       TT[0] == 't' && TT[1] == 'h' && TT[2] == 'u' &&
1558       TT[3] == 'm' && TT[4] == 'b')
1559     Pos = 5;
1560   else if (Size >= 4 && TT[0] == 'a' && TT[1] == 'r' && TT[2] == 'm')
1561     Pos = 3;
1562   else
1563     return false;
1564
1565   if (TT[Pos] == '-')
1566     return true;
1567   else if (TT[Pos] == 'v') {
1568     if (Size >= Pos+4 &&
1569         TT[Pos+1] == '6' && TT[Pos+2] == 't' && TT[Pos+3] == '2')
1570       return true;
1571     else if (Size >= Pos+4 &&
1572              TT[Pos+1] == '5' && TT[Pos+2] == 't' && TT[Pos+3] == 'e')
1573       return true;
1574   } else
1575     return false;
1576   while (++Pos < Size && TT[Pos] != '-') {
1577     if (!isdigit(TT[Pos]))
1578       return false;
1579   }
1580   return true;
1581 }
1582
1583 static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1584                                const std::string &TT) {
1585   unsigned CPUType = ~0U;
1586
1587   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1588   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1589   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1590   // specific constants here because they are implicitly part of the Darwin ABI.
1591   enum {
1592     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1593     DARWIN_CPU_TYPE_X86        = 7,
1594     DARWIN_CPU_TYPE_ARM        = 12,
1595     DARWIN_CPU_TYPE_POWERPC    = 18
1596   };
1597
1598   if (TT.find("x86_64-") == 0)
1599     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1600   else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1601            TT[4] == '-' && TT[1] - '3' < 6)
1602     CPUType = DARWIN_CPU_TYPE_X86;
1603   else if (TT.find("powerpc-") == 0)
1604     CPUType = DARWIN_CPU_TYPE_POWERPC;
1605   else if (TT.find("powerpc64-") == 0)
1606     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1607   else if (isARMTriplet(TT))
1608     CPUType = DARWIN_CPU_TYPE_ARM;
1609
1610   // Traditional Bitcode starts after header.
1611   unsigned BCOffset = DarwinBCHeaderSize;
1612
1613   Stream.Emit(0x0B17C0DE, 32);
1614   Stream.Emit(0         , 32);  // Version.
1615   Stream.Emit(BCOffset  , 32);
1616   Stream.Emit(0         , 32);  // Filled in later.
1617   Stream.Emit(CPUType   , 32);
1618 }
1619
1620 /// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1621 /// finalize the header.
1622 static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1623   // Update the size field in the header.
1624   Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1625
1626   // If the file is not a multiple of 16 bytes, insert dummy padding.
1627   while (BufferSize & 15) {
1628     Stream.Emit(0, 8);
1629     ++BufferSize;
1630   }
1631 }
1632
1633
1634 /// WriteBitcodeToFile - Write the specified module to the specified output
1635 /// stream.
1636 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1637   std::vector<unsigned char> Buffer;
1638   BitstreamWriter Stream(Buffer);
1639
1640   Buffer.reserve(256*1024);
1641
1642   WriteBitcodeToStream( M, Stream );
1643
1644   // Write the generated bitstream to "Out".
1645   Out.write((char*)&Buffer.front(), Buffer.size());
1646 }
1647
1648 /// WriteBitcodeToStream - Write the specified module to the specified output
1649 /// stream.
1650 void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1651   // If this is darwin or another generic macho target, emit a file header and
1652   // trailer if needed.
1653   bool isMacho =
1654     M->getTargetTriple().find("-darwin") != std::string::npos ||
1655     M->getTargetTriple().find("-macho") != std::string::npos;
1656   if (isMacho)
1657     EmitDarwinBCHeader(Stream, M->getTargetTriple());
1658
1659   // Emit the file header.
1660   Stream.Emit((unsigned)'B', 8);
1661   Stream.Emit((unsigned)'C', 8);
1662   Stream.Emit(0x0, 4);
1663   Stream.Emit(0xC, 4);
1664   Stream.Emit(0xE, 4);
1665   Stream.Emit(0xD, 4);
1666
1667   // Emit the module.
1668   WriteModule(M, Stream);
1669
1670   if (isMacho)
1671     EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1672 }