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].first;
 201     int AbbrevToUse = 0;
 202     unsigned Code = 0;
 203
 204     switch (T->getTypeID()) {
 205     default: llvm_unreachable("Unknown type!");
 206     case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
 207     case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
 208     case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
 209     case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
 210     case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
 211     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 212     case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
 213     case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
 214     case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
 215     case Type::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 SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
 474     if (Div->isExact())
 475       Flags |= 1 << bitc::SDIV_EXACT;
 476   }
 477
 478   return Flags;
 479 }
 480
 481 static void WriteMDNode(const MDNode *N,
 482                         const ValueEnumerator &VE,
 483                         BitstreamWriter &Stream,
 484                         SmallVector<uint64_t, 64> &Record) {
 485   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
 486     if (N->getOperand(i)) {
 487       Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
 488       Record.push_back(VE.getValueID(N->getOperand(i)));
 489     } else {
 490       Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
 491       Record.push_back(0);
 492     }
 493   }
 494   unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE2 :
 495                                            bitc::METADATA_NODE2;
 496   Stream.EmitRecord(MDCode, Record, 0);
 497   Record.clear();
 498 }
 499
 500 static void WriteModuleMetadata(const Module *M,
 501                                 const ValueEnumerator &VE,
 502                                 BitstreamWriter &Stream) {
 503   const ValueEnumerator::ValueList &Vals = VE.getMDValues();
 504   bool StartedMetadataBlock = false;
 505   unsigned MDSAbbrev = 0;
 506   SmallVector<uint64_t, 64> Record;
 507   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 508
 509     if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
 510       if (!N->isFunctionLocal() || !N->getFunction()) {
 511         if (!StartedMetadataBlock) {
 512           Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 513           StartedMetadataBlock = true;
 514         }
 515         WriteMDNode(N, VE, Stream, Record);
 516       }
 517     } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
 518       if (!StartedMetadataBlock)  {
 519         Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 520
 521         // Abbrev for METADATA_STRING.
 522         BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 523         Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
 524         Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 525         Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 526         MDSAbbrev = Stream.EmitAbbrev(Abbv);
 527         StartedMetadataBlock = true;
 528       }
 529
 530       // Code: [strchar x N]
 531       Record.append(MDS->begin(), MDS->end());
 532
 533       // Emit the finished record.
 534       Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
 535       Record.clear();
 536     }
 537   }
 538
 539   // Write named metadata.
 540   for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
 541        E = M->named_metadata_end(); I != E; ++I) {
 542     const NamedMDNode *NMD = I;
 543     if (!StartedMetadataBlock)  {
 544       Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 545       StartedMetadataBlock = true;
 546     }
 547
 548     // Write name.
 549     StringRef Str = NMD->getName();
 550     for (unsigned i = 0, e = Str.size(); i != e; ++i)
 551       Record.push_back(Str[i]);
 552     Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
 553     Record.clear();
 554
 555     // Write named metadata operands.
 556     for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
 557       Record.push_back(VE.getValueID(NMD->getOperand(i)));
 558     Stream.EmitRecord(bitc::METADATA_NAMED_NODE2, Record, 0);
 559     Record.clear();
 560   }
 561
 562   if (StartedMetadataBlock)
 563     Stream.ExitBlock();
 564 }
 565
 566 static void WriteFunctionLocalMetadata(const Function &F,
 567                                        const ValueEnumerator &VE,
 568                                        BitstreamWriter &Stream) {
 569   bool StartedMetadataBlock = false;
 570   SmallVector<uint64_t, 64> Record;
 571   const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
 572   for (unsigned i = 0, e = Vals.size(); i != e; ++i)
 573     if (const MDNode *N = Vals[i])
 574       if (N->isFunctionLocal() && N->getFunction() == &F) {
 575         if (!StartedMetadataBlock) {
 576           Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 577           StartedMetadataBlock = true;
 578         }
 579         WriteMDNode(N, VE, Stream, Record);
 580       }
 581
 582   if (StartedMetadataBlock)
 583     Stream.ExitBlock();
 584 }
 585
 586 static void WriteMetadataAttachment(const Function &F,
 587                                     const ValueEnumerator &VE,
 588                                     BitstreamWriter &Stream) {
 589   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
 590
 591   SmallVector<uint64_t, 64> Record;
 592
 593   // Write metadata attachments
 594   // METADATA_ATTACHMENT2 - [m x [value, [n x [id, mdnode]]]
 595   SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
 596
 597   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
 598     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
 599          I != E; ++I) {
 600       MDs.clear();
 601       I->getAllMetadataOtherThanDebugLoc(MDs);
 602
 603       // If no metadata, ignore instruction.
 604       if (MDs.empty()) continue;
 605
 606       Record.push_back(VE.getInstructionID(I));
 607
 608       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
 609         Record.push_back(MDs[i].first);
 610         Record.push_back(VE.getValueID(MDs[i].second));
 611       }
 612       Stream.EmitRecord(bitc::METADATA_ATTACHMENT2, Record, 0);
 613       Record.clear();
 614     }
 615
 616   Stream.ExitBlock();
 617 }
 618
 619 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
 620   SmallVector<uint64_t, 64> Record;
 621
 622   // Write metadata kinds
 623   // METADATA_KIND - [n x [id, name]]
 624   SmallVector<StringRef, 4> Names;
 625   M->getMDKindNames(Names);
 626
 627   if (Names.empty()) return;
 628
 629   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 630
 631   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
 632     Record.push_back(MDKindID);
 633     StringRef KName = Names[MDKindID];
 634     Record.append(KName.begin(), KName.end());
 635
 636     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
 637     Record.clear();
 638   }
 639
 640   Stream.ExitBlock();
 641 }
 642
 643 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
 644                            const ValueEnumerator &VE,
 645                            BitstreamWriter &Stream, bool isGlobal) {
 646   if (FirstVal == LastVal) return;
 647
 648   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
 649
 650   unsigned AggregateAbbrev = 0;
 651   unsigned String8Abbrev = 0;
 652   unsigned CString7Abbrev = 0;
 653   unsigned CString6Abbrev = 0;
 654   // If this is a constant pool for the module, emit module-specific abbrevs.
 655   if (isGlobal) {
 656     // Abbrev for CST_CODE_AGGREGATE.
 657     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 658     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
 659     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 660     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
 661     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
 662
 663     // Abbrev for CST_CODE_STRING.
 664     Abbv = new BitCodeAbbrev();
 665     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
 666     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 667     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 668     String8Abbrev = Stream.EmitAbbrev(Abbv);
 669     // Abbrev for CST_CODE_CSTRING.
 670     Abbv = new BitCodeAbbrev();
 671     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 672     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 673     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 674     CString7Abbrev = Stream.EmitAbbrev(Abbv);
 675     // Abbrev for CST_CODE_CSTRING.
 676     Abbv = new BitCodeAbbrev();
 677     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 678     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 679     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 680     CString6Abbrev = Stream.EmitAbbrev(Abbv);
 681   }
 682
 683   SmallVector<uint64_t, 64> Record;
 684
 685   const ValueEnumerator::ValueList &Vals = VE.getValues();
 686   const Type *LastTy = 0;
 687   for (unsigned i = FirstVal; i != LastVal; ++i) {
 688     const Value *V = Vals[i].first;
 689     // If we need to switch types, do so now.
 690     if (V->getType() != LastTy) {
 691       LastTy = V->getType();
 692       Record.push_back(VE.getTypeID(LastTy));
 693       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
 694                         CONSTANTS_SETTYPE_ABBREV);
 695       Record.clear();
 696     }
 697
 698     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
 699       Record.push_back(unsigned(IA->hasSideEffects()) |
 700                        unsigned(IA->isAlignStack()) << 1);
 701
 702       // Add the asm string.
 703       const std::string &AsmStr = IA->getAsmString();
 704       Record.push_back(AsmStr.size());
 705       for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
 706         Record.push_back(AsmStr[i]);
 707
 708       // Add the constraint string.
 709       const std::string &ConstraintStr = IA->getConstraintString();
 710       Record.push_back(ConstraintStr.size());
 711       for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
 712         Record.push_back(ConstraintStr[i]);
 713       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
 714       Record.clear();
 715       continue;
 716     }
 717     const Constant *C = cast<Constant>(V);
 718     unsigned Code = -1U;
 719     unsigned AbbrevToUse = 0;
 720     if (C->isNullValue()) {
 721       Code = bitc::CST_CODE_NULL;
 722     } else if (isa<UndefValue>(C)) {
 723       Code = bitc::CST_CODE_UNDEF;
 724     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
 725       if (IV->getBitWidth() <= 64) {
 726         uint64_t V = IV->getSExtValue();
 727         if ((int64_t)V >= 0)
 728           Record.push_back(V << 1);
 729         else
 730           Record.push_back((-V << 1) | 1);
 731         Code = bitc::CST_CODE_INTEGER;
 732         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
 733       } else {                             // Wide integers, > 64 bits in size.
 734         // We have an arbitrary precision integer value to write whose
 735         // bit width is > 64. However, in canonical unsigned integer
 736         // format it is likely that the high bits are going to be zero.
 737         // So, we only write the number of active words.
 738         unsigned NWords = IV->getValue().getActiveWords();
 739         const uint64_t *RawWords = IV->getValue().getRawData();
 740         for (unsigned i = 0; i != NWords; ++i) {
 741           int64_t V = RawWords[i];
 742           if (V >= 0)
 743             Record.push_back(V << 1);
 744           else
 745             Record.push_back((-V << 1) | 1);
 746         }
 747         Code = bitc::CST_CODE_WIDE_INTEGER;
 748       }
 749     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
 750       Code = bitc::CST_CODE_FLOAT;
 751       const Type *Ty = CFP->getType();
 752       if (Ty->isFloatTy() || Ty->isDoubleTy()) {
 753         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
 754       } else if (Ty->isX86_FP80Ty()) {
 755         // api needed to prevent premature destruction
 756         // bits are not in the same order as a normal i80 APInt, compensate.
 757         APInt api = CFP->getValueAPF().bitcastToAPInt();
 758         const uint64_t *p = api.getRawData();
 759         Record.push_back((p[1] << 48) | (p[0] >> 16));
 760         Record.push_back(p[0] & 0xffffLL);
 761       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
 762         APInt api = CFP->getValueAPF().bitcastToAPInt();
 763         const uint64_t *p = api.getRawData();
 764         Record.push_back(p[0]);
 765         Record.push_back(p[1]);
 766       } else {
 767         assert (0 && "Unknown FP type!");
 768       }
 769     } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
 770       const ConstantArray *CA = cast<ConstantArray>(C);
 771       // Emit constant strings specially.
 772       unsigned NumOps = CA->getNumOperands();
 773       // If this is a null-terminated string, use the denser CSTRING encoding.
 774       if (CA->getOperand(NumOps-1)->isNullValue()) {
 775         Code = bitc::CST_CODE_CSTRING;
 776         --NumOps;  // Don't encode the null, which isn't allowed by char6.
 777       } else {
 778         Code = bitc::CST_CODE_STRING;
 779         AbbrevToUse = String8Abbrev;
 780       }
 781       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
 782       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
 783       for (unsigned i = 0; i != NumOps; ++i) {
 784         unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
 785         Record.push_back(V);
 786         isCStr7 &= (V & 128) == 0;
 787         if (isCStrChar6)
 788           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
 789       }
 790
 791       if (isCStrChar6)
 792         AbbrevToUse = CString6Abbrev;
 793       else if (isCStr7)
 794         AbbrevToUse = CString7Abbrev;
 795     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
 796                isa<ConstantVector>(V)) {
 797       Code = bitc::CST_CODE_AGGREGATE;
 798       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
 799         Record.push_back(VE.getValueID(C->getOperand(i)));
 800       AbbrevToUse = AggregateAbbrev;
 801     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
 802       switch (CE->getOpcode()) {
 803       default:
 804         if (Instruction::isCast(CE->getOpcode())) {
 805           Code = bitc::CST_CODE_CE_CAST;
 806           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
 807           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 808           Record.push_back(VE.getValueID(C->getOperand(0)));
 809           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
 810         } else {
 811           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
 812           Code = bitc::CST_CODE_CE_BINOP;
 813           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
 814           Record.push_back(VE.getValueID(C->getOperand(0)));
 815           Record.push_back(VE.getValueID(C->getOperand(1)));
 816           uint64_t Flags = GetOptimizationFlags(CE);
 817           if (Flags != 0)
 818             Record.push_back(Flags);
 819         }
 820         break;
 821       case Instruction::GetElementPtr:
 822         Code = bitc::CST_CODE_CE_GEP;
 823         if (cast<GEPOperator>(C)->isInBounds())
 824           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
 825         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
 826           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
 827           Record.push_back(VE.getValueID(C->getOperand(i)));
 828         }
 829         break;
 830       case Instruction::Select:
 831         Code = bitc::CST_CODE_CE_SELECT;
 832         Record.push_back(VE.getValueID(C->getOperand(0)));
 833         Record.push_back(VE.getValueID(C->getOperand(1)));
 834         Record.push_back(VE.getValueID(C->getOperand(2)));
 835         break;
 836       case Instruction::ExtractElement:
 837         Code = bitc::CST_CODE_CE_EXTRACTELT;
 838         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 839         Record.push_back(VE.getValueID(C->getOperand(0)));
 840         Record.push_back(VE.getValueID(C->getOperand(1)));
 841         break;
 842       case Instruction::InsertElement:
 843         Code = bitc::CST_CODE_CE_INSERTELT;
 844         Record.push_back(VE.getValueID(C->getOperand(0)));
 845         Record.push_back(VE.getValueID(C->getOperand(1)));
 846         Record.push_back(VE.getValueID(C->getOperand(2)));
 847         break;
 848       case Instruction::ShuffleVector:
 849         // If the return type and argument types are the same, this is a
 850         // standard shufflevector instruction.  If the types are different,
 851         // then the shuffle is widening or truncating the input vectors, and
 852         // the argument type must also be encoded.
 853         if (C->getType() == C->getOperand(0)->getType()) {
 854           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
 855         } else {
 856           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
 857           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 858         }
 859         Record.push_back(VE.getValueID(C->getOperand(0)));
 860         Record.push_back(VE.getValueID(C->getOperand(1)));
 861         Record.push_back(VE.getValueID(C->getOperand(2)));
 862         break;
 863       case Instruction::ICmp:
 864       case Instruction::FCmp:
 865         Code = bitc::CST_CODE_CE_CMP;
 866         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 867         Record.push_back(VE.getValueID(C->getOperand(0)));
 868         Record.push_back(VE.getValueID(C->getOperand(1)));
 869         Record.push_back(CE->getPredicate());
 870         break;
 871       }
 872     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
 873       assert(BA->getFunction() == BA->getBasicBlock()->getParent() &&
 874              "Malformed blockaddress");
 875       Code = bitc::CST_CODE_BLOCKADDRESS;
 876       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
 877       Record.push_back(VE.getValueID(BA->getFunction()));
 878       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
 879     } else {
 880 #ifndef NDEBUG
 881       C->dump();
 882 #endif
 883       llvm_unreachable("Unknown constant!");
 884     }
 885     Stream.EmitRecord(Code, Record, AbbrevToUse);
 886     Record.clear();
 887   }
 888
 889   Stream.ExitBlock();
 890 }
 891
 892 static void WriteModuleConstants(const ValueEnumerator &VE,
 893                                  BitstreamWriter &Stream) {
 894   const ValueEnumerator::ValueList &Vals = VE.getValues();
 895
 896   // Find the first constant to emit, which is the first non-globalvalue value.
 897   // We know globalvalues have been emitted by WriteModuleInfo.
 898   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 899     if (!isa<GlobalValue>(Vals[i].first)) {
 900       WriteConstants(i, Vals.size(), VE, Stream, true);
 901       return;
 902     }
 903   }
 904 }
 905
 906 /// PushValueAndType - The file has to encode both the value and type id for
 907 /// many values, because we need to know what type to create for forward
 908 /// references.  However, most operands are not forward references, so this type
 909 /// field is not needed.
 910 ///
 911 /// This function adds V's value ID to Vals.  If the value ID is higher than the
 912 /// instruction ID, then it is a forward reference, and it also includes the
 913 /// type ID.
 914 static bool PushValueAndType(const Value *V, unsigned InstID,
 915                              SmallVector<unsigned, 64> &Vals,
 916                              ValueEnumerator &VE) {
 917   unsigned ValID = VE.getValueID(V);
 918   Vals.push_back(ValID);
 919   if (ValID >= InstID) {
 920     Vals.push_back(VE.getTypeID(V->getType()));
 921     return true;
 922   }
 923   return false;
 924 }
 925
 926 /// WriteInstruction - Emit an instruction to the specified stream.
 927 static void WriteInstruction(const Instruction &I, unsigned InstID,
 928                              ValueEnumerator &VE, BitstreamWriter &Stream,
 929                              SmallVector<unsigned, 64> &Vals) {
 930   unsigned Code = 0;
 931   unsigned AbbrevToUse = 0;
 932   VE.setInstructionID(&I);
 933   switch (I.getOpcode()) {
 934   default:
 935     if (Instruction::isCast(I.getOpcode())) {
 936       Code = bitc::FUNC_CODE_INST_CAST;
 937       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 938         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
 939       Vals.push_back(VE.getTypeID(I.getType()));
 940       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
 941     } else {
 942       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
 943       Code = bitc::FUNC_CODE_INST_BINOP;
 944       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 945         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
 946       Vals.push_back(VE.getValueID(I.getOperand(1)));
 947       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
 948       uint64_t Flags = GetOptimizationFlags(&I);
 949       if (Flags != 0) {
 950         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
 951           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
 952         Vals.push_back(Flags);
 953       }
 954     }
 955     break;
 956
 957   case Instruction::GetElementPtr:
 958     Code = bitc::FUNC_CODE_INST_GEP;
 959     if (cast<GEPOperator>(&I)->isInBounds())
 960       Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
 961     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 962       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
 963     break;
 964   case Instruction::ExtractValue: {
 965     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
 966     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 967     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
 968     for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
 969       Vals.push_back(*i);
 970     break;
 971   }
 972   case Instruction::InsertValue: {
 973     Code = bitc::FUNC_CODE_INST_INSERTVAL;
 974     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 975     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
 976     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
 977     for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
 978       Vals.push_back(*i);
 979     break;
 980   }
 981   case Instruction::Select:
 982     Code = bitc::FUNC_CODE_INST_VSELECT;
 983     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
 984     Vals.push_back(VE.getValueID(I.getOperand(2)));
 985     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 986     break;
 987   case Instruction::ExtractElement:
 988     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
 989     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 990     Vals.push_back(VE.getValueID(I.getOperand(1)));
 991     break;
 992   case Instruction::InsertElement:
 993     Code = bitc::FUNC_CODE_INST_INSERTELT;
 994     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 995     Vals.push_back(VE.getValueID(I.getOperand(1)));
 996     Vals.push_back(VE.getValueID(I.getOperand(2)));
 997     break;
 998   case Instruction::ShuffleVector:
 999     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1000     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1001     Vals.push_back(VE.getValueID(I.getOperand(1)));
1002     Vals.push_back(VE.getValueID(I.getOperand(2)));
1003     break;
1004   case Instruction::ICmp:
1005   case Instruction::FCmp:
1006     // compare returning Int1Ty or vector of Int1Ty
1007     Code = bitc::FUNC_CODE_INST_CMP2;
1008     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1009     Vals.push_back(VE.getValueID(I.getOperand(1)));
1010     Vals.push_back(cast<CmpInst>(I).getPredicate());
1011     break;
1012
1013   case Instruction::Ret:
1014     {
1015       Code = bitc::FUNC_CODE_INST_RET;
1016       unsigned NumOperands = I.getNumOperands();
1017       if (NumOperands == 0)
1018         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1019       else if (NumOperands == 1) {
1020         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1021           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1022       } else {
1023         for (unsigned i = 0, e = NumOperands; i != e; ++i)
1024           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1025       }
1026     }
1027     break;
1028   case Instruction::Br:
1029     {
1030       Code = bitc::FUNC_CODE_INST_BR;
1031       BranchInst &II = cast<BranchInst>(I);
1032       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1033       if (II.isConditional()) {
1034         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1035         Vals.push_back(VE.getValueID(II.getCondition()));
1036       }
1037     }
1038     break;
1039   case Instruction::Switch:
1040     Code = bitc::FUNC_CODE_INST_SWITCH;
1041     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1042     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1043       Vals.push_back(VE.getValueID(I.getOperand(i)));
1044     break;
1045   case Instruction::IndirectBr:
1046     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1047     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1048     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1049       Vals.push_back(VE.getValueID(I.getOperand(i)));
1050     break;
1051
1052   case Instruction::Invoke: {
1053     const InvokeInst *II = cast<InvokeInst>(&I);
1054     const Value *Callee(II->getCalledValue());
1055     const PointerType *PTy = cast<PointerType>(Callee->getType());
1056     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1057     Code = bitc::FUNC_CODE_INST_INVOKE;
1058
1059     Vals.push_back(VE.getAttributeID(II->getAttributes()));
1060     Vals.push_back(II->getCallingConv());
1061     Vals.push_back(VE.getValueID(II->getNormalDest()));
1062     Vals.push_back(VE.getValueID(II->getUnwindDest()));
1063     PushValueAndType(Callee, InstID, Vals, VE);
1064
1065     // Emit value #'s for the fixed parameters.
1066     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1067       Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1068
1069     // Emit type/value pairs for varargs params.
1070     if (FTy->isVarArg()) {
1071       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1072            i != e; ++i)
1073         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1074     }
1075     break;
1076   }
1077   case Instruction::Unwind:
1078     Code = bitc::FUNC_CODE_INST_UNWIND;
1079     break;
1080   case Instruction::Unreachable:
1081     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1082     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1083     break;
1084
1085   case Instruction::PHI:
1086     Code = bitc::FUNC_CODE_INST_PHI;
1087     Vals.push_back(VE.getTypeID(I.getType()));
1088     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1089       Vals.push_back(VE.getValueID(I.getOperand(i)));
1090     break;
1091
1092   case Instruction::Alloca:
1093     Code = bitc::FUNC_CODE_INST_ALLOCA;
1094     Vals.push_back(VE.getTypeID(I.getType()));
1095     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1096     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1097     Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1098     break;
1099
1100   case Instruction::Load:
1101     Code = bitc::FUNC_CODE_INST_LOAD;
1102     if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1103       AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1104
1105     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1106     Vals.push_back(cast<LoadInst>(I).isVolatile());
1107     break;
1108   case Instruction::Store:
1109     Code = bitc::FUNC_CODE_INST_STORE2;
1110     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1111     Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1112     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1113     Vals.push_back(cast<StoreInst>(I).isVolatile());
1114     break;
1115   case Instruction::Call: {
1116     const CallInst &CI = cast<CallInst>(I);
1117     const PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1118     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1119
1120     Code = bitc::FUNC_CODE_INST_CALL2;
1121
1122     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1123     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1124     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1125
1126     // Emit value #'s for the fixed parameters.
1127     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1128       Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1129
1130     // Emit type/value pairs for varargs params.
1131     if (FTy->isVarArg()) {
1132       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1133            i != e; ++i)
1134         PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1135     }
1136     break;
1137   }
1138   case Instruction::VAArg:
1139     Code = bitc::FUNC_CODE_INST_VAARG;
1140     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1141     Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1142     Vals.push_back(VE.getTypeID(I.getType())); // restype.
1143     break;
1144   }
1145
1146   Stream.EmitRecord(Code, Vals, AbbrevToUse);
1147   Vals.clear();
1148 }
1149
1150 // Emit names for globals/functions etc.
1151 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1152                                   const ValueEnumerator &VE,
1153                                   BitstreamWriter &Stream) {
1154   if (VST.empty()) return;
1155   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1156
1157   // FIXME: Set up the abbrev, we know how many values there are!
1158   // FIXME: We know if the type names can use 7-bit ascii.
1159   SmallVector<unsigned, 64> NameVals;
1160
1161   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1162        SI != SE; ++SI) {
1163
1164     const ValueName &Name = *SI;
1165
1166     // Figure out the encoding to use for the name.
1167     bool is7Bit = true;
1168     bool isChar6 = true;
1169     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1170          C != E; ++C) {
1171       if (isChar6)
1172         isChar6 = BitCodeAbbrevOp::isChar6(*C);
1173       if ((unsigned char)*C & 128) {
1174         is7Bit = false;
1175         break;  // don't bother scanning the rest.
1176       }
1177     }
1178
1179     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1180
1181     // VST_ENTRY:   [valueid, namechar x N]
1182     // VST_BBENTRY: [bbid, namechar x N]
1183     unsigned Code;
1184     if (isa<BasicBlock>(SI->getValue())) {
1185       Code = bitc::VST_CODE_BBENTRY;
1186       if (isChar6)
1187         AbbrevToUse = VST_BBENTRY_6_ABBREV;
1188     } else {
1189       Code = bitc::VST_CODE_ENTRY;
1190       if (isChar6)
1191         AbbrevToUse = VST_ENTRY_6_ABBREV;
1192       else if (is7Bit)
1193         AbbrevToUse = VST_ENTRY_7_ABBREV;
1194     }
1195
1196     NameVals.push_back(VE.getValueID(SI->getValue()));
1197     for (const char *P = Name.getKeyData(),
1198          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1199       NameVals.push_back((unsigned char)*P);
1200
1201     // Emit the finished record.
1202     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1203     NameVals.clear();
1204   }
1205   Stream.ExitBlock();
1206 }
1207
1208 /// WriteFunction - Emit a function body to the module stream.
1209 static void WriteFunction(const Function &F, ValueEnumerator &VE,
1210                           BitstreamWriter &Stream) {
1211   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1212   VE.incorporateFunction(F);
1213
1214   SmallVector<unsigned, 64> Vals;
1215
1216   // Emit the number of basic blocks, so the reader can create them ahead of
1217   // time.
1218   Vals.push_back(VE.getBasicBlocks().size());
1219   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1220   Vals.clear();
1221
1222   // If there are function-local constants, emit them now.
1223   unsigned CstStart, CstEnd;
1224   VE.getFunctionConstantRange(CstStart, CstEnd);
1225   WriteConstants(CstStart, CstEnd, VE, Stream, false);
1226
1227   // If there is function-local metadata, emit it now.
1228   WriteFunctionLocalMetadata(F, VE, Stream);
1229
1230   // Keep a running idea of what the instruction ID is.
1231   unsigned InstID = CstEnd;
1232
1233   bool NeedsMetadataAttachment = false;
1234
1235   DebugLoc LastDL;
1236
1237   // Finally, emit all the instructions, in order.
1238   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1239     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1240          I != E; ++I) {
1241       WriteInstruction(*I, InstID, VE, Stream, Vals);
1242
1243       if (!I->getType()->isVoidTy())
1244         ++InstID;
1245
1246       // If the instruction has metadata, write a metadata attachment later.
1247       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1248
1249       // If the instruction has a debug location, emit it.
1250       DebugLoc DL = I->getDebugLoc();
1251       if (DL.isUnknown()) {
1252         // nothing todo.
1253       } else if (DL == LastDL) {
1254         // Just repeat the same debug loc as last time.
1255         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1256       } else {
1257         MDNode *Scope, *IA;
1258         DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1259
1260         Vals.push_back(DL.getLine());
1261         Vals.push_back(DL.getCol());
1262         Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1263         Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1264         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC2, Vals);
1265         Vals.clear();
1266
1267         LastDL = DL;
1268       }
1269     }
1270
1271   // Emit names for all the instructions etc.
1272   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1273
1274   if (NeedsMetadataAttachment)
1275     WriteMetadataAttachment(F, VE, Stream);
1276   VE.purgeFunction();
1277   Stream.ExitBlock();
1278 }
1279
1280 /// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1281 static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1282                                  const ValueEnumerator &VE,
1283                                  BitstreamWriter &Stream) {
1284   if (TST.empty()) return;
1285
1286   Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1287
1288   // 7-bit fixed width VST_CODE_ENTRY strings.
1289   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1290   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1291   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1292                             Log2_32_Ceil(VE.getTypes().size()+1)));
1293   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1294   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1295   unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1296
1297   SmallVector<unsigned, 64> NameVals;
1298
1299   for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1300        TI != TE; ++TI) {
1301     // TST_ENTRY: [typeid, namechar x N]
1302     NameVals.push_back(VE.getTypeID(TI->second));
1303
1304     const std::string &Str = TI->first;
1305     bool is7Bit = true;
1306     for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1307       NameVals.push_back((unsigned char)Str[i]);
1308       if (Str[i] & 128)
1309         is7Bit = false;
1310     }
1311
1312     // Emit the finished record.
1313     Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1314     NameVals.clear();
1315   }
1316
1317   Stream.ExitBlock();
1318 }
1319
1320 // Emit blockinfo, which defines the standard abbreviations etc.
1321 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1322   // We only want to emit block info records for blocks that have multiple
1323   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1324   // blocks can defined their abbrevs inline.
1325   Stream.EnterBlockInfoBlock(2);
1326
1327   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1328     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1329     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1330     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1331     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1332     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1333     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1334                                    Abbv) != VST_ENTRY_8_ABBREV)
1335       llvm_unreachable("Unexpected abbrev ordering!");
1336   }
1337
1338   { // 7-bit fixed width VST_ENTRY strings.
1339     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1340     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1341     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1342     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1343     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1344     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1345                                    Abbv) != VST_ENTRY_7_ABBREV)
1346       llvm_unreachable("Unexpected abbrev ordering!");
1347   }
1348   { // 6-bit char6 VST_ENTRY strings.
1349     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1350     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1351     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1352     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1353     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1354     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1355                                    Abbv) != VST_ENTRY_6_ABBREV)
1356       llvm_unreachable("Unexpected abbrev ordering!");
1357   }
1358   { // 6-bit char6 VST_BBENTRY strings.
1359     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1360     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1361     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1362     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1363     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1364     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1365                                    Abbv) != VST_BBENTRY_6_ABBREV)
1366       llvm_unreachable("Unexpected abbrev ordering!");
1367   }
1368
1369
1370
1371   { // SETTYPE abbrev for CONSTANTS_BLOCK.
1372     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1373     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1374     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1375                               Log2_32_Ceil(VE.getTypes().size()+1)));
1376     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1377                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
1378       llvm_unreachable("Unexpected abbrev ordering!");
1379   }
1380
1381   { // INTEGER abbrev for CONSTANTS_BLOCK.
1382     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1383     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1384     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1385     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1386                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
1387       llvm_unreachable("Unexpected abbrev ordering!");
1388   }
1389
1390   { // CE_CAST abbrev for CONSTANTS_BLOCK.
1391     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1392     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1393     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1394     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1395                               Log2_32_Ceil(VE.getTypes().size()+1)));
1396     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1397
1398     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1399                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
1400       llvm_unreachable("Unexpected abbrev ordering!");
1401   }
1402   { // NULL abbrev for CONSTANTS_BLOCK.
1403     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1404     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1405     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1406                                    Abbv) != CONSTANTS_NULL_Abbrev)
1407       llvm_unreachable("Unexpected abbrev ordering!");
1408   }
1409
1410   // FIXME: This should only use space for first class types!
1411
1412   { // INST_LOAD abbrev for FUNCTION_BLOCK.
1413     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1414     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1415     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1416     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1417     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1418     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1419                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
1420       llvm_unreachable("Unexpected abbrev ordering!");
1421   }
1422   { // INST_BINOP abbrev for FUNCTION_BLOCK.
1423     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1424     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1425     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1426     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1427     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1428     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1429                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
1430       llvm_unreachable("Unexpected abbrev ordering!");
1431   }
1432   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1433     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1434     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1435     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1436     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1437     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1438     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1439     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1440                                    Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1441       llvm_unreachable("Unexpected abbrev ordering!");
1442   }
1443   { // INST_CAST abbrev for FUNCTION_BLOCK.
1444     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1445     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1446     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1447     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1448                               Log2_32_Ceil(VE.getTypes().size()+1)));
1449     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1450     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1451                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
1452       llvm_unreachable("Unexpected abbrev ordering!");
1453   }
1454
1455   { // INST_RET abbrev for FUNCTION_BLOCK.
1456     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1457     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1458     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1459                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1460       llvm_unreachable("Unexpected abbrev ordering!");
1461   }
1462   { // INST_RET abbrev for FUNCTION_BLOCK.
1463     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1464     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1465     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1466     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1467                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1468       llvm_unreachable("Unexpected abbrev ordering!");
1469   }
1470   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1471     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1472     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1473     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1474                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1475       llvm_unreachable("Unexpected abbrev ordering!");
1476   }
1477
1478   Stream.ExitBlock();
1479 }
1480
1481
1482 /// WriteModule - Emit the specified module to the bitstream.
1483 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1484   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1485
1486   // Emit the version number if it is non-zero.
1487   if (CurVersion) {
1488     SmallVector<unsigned, 1> Vals;
1489     Vals.push_back(CurVersion);
1490     Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1491   }
1492
1493   // Analyze the module, enumerating globals, functions, etc.
1494   ValueEnumerator VE(M);
1495
1496   // Emit blockinfo, which defines the standard abbreviations etc.
1497   WriteBlockInfo(VE, Stream);
1498
1499   // Emit information about parameter attributes.
1500   WriteAttributeTable(VE, Stream);
1501
1502   // Emit information describing all of the types in the module.
1503   WriteTypeTable(VE, Stream);
1504
1505   // Emit top-level description of module, including target triple, inline asm,
1506   // descriptors for global variables, and function prototype info.
1507   WriteModuleInfo(M, VE, Stream);
1508
1509   // Emit constants.
1510   WriteModuleConstants(VE, Stream);
1511
1512   // Emit metadata.
1513   WriteModuleMetadata(M, VE, Stream);
1514
1515   // Emit function bodies.
1516   for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1517     if (!I->isDeclaration())
1518       WriteFunction(*I, VE, Stream);
1519
1520   // Emit metadata.
1521   WriteModuleMetadataStore(M, Stream);
1522
1523   // Emit the type symbol table information.
1524   WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1525
1526   // Emit names for globals/functions etc.
1527   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1528
1529   Stream.ExitBlock();
1530 }
1531
1532 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1533 /// header and trailer to make it compatible with the system archiver.  To do
1534 /// this we emit the following header, and then emit a trailer that pads the
1535 /// file out to be a multiple of 16 bytes.
1536 ///
1537 /// struct bc_header {
1538 ///   uint32_t Magic;         // 0x0B17C0DE
1539 ///   uint32_t Version;       // Version, currently always 0.
1540 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1541 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1542 ///   uint32_t CPUType;       // CPU specifier.
1543 ///   ... potentially more later ...
1544 /// };
1545 enum {
1546   DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1547   DarwinBCHeaderSize = 5*4
1548 };
1549
1550 /// isARMTriplet - Return true if the triplet looks like:
1551 /// arm-*, thumb-*, armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*.
1552 static bool isARMTriplet(const std::string &TT) {
1553   size_t Pos = 0;
1554   size_t Size = TT.size();
1555   if (Size >= 6 &&
1556       TT[0] == 't' && TT[1] == 'h' && TT[2] == 'u' &&
1557       TT[3] == 'm' && TT[4] == 'b')
1558     Pos = 5;
1559   else if (Size >= 4 && TT[0] == 'a' && TT[1] == 'r' && TT[2] == 'm')
1560     Pos = 3;
1561   else
1562     return false;
1563
1564   if (TT[Pos] == '-')
1565     return true;
1566   else if (TT[Pos] == 'v') {
1567     if (Size >= Pos+4 &&
1568         TT[Pos+1] == '6' && TT[Pos+2] == 't' && TT[Pos+3] == '2')
1569       return true;
1570     else if (Size >= Pos+4 &&
1571              TT[Pos+1] == '5' && TT[Pos+2] == 't' && TT[Pos+3] == 'e')
1572       return true;
1573   } else
1574     return false;
1575   while (++Pos < Size && TT[Pos] != '-') {
1576     if (!isdigit(TT[Pos]))
1577       return false;
1578   }
1579   return true;
1580 }
1581
1582 static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1583                                const std::string &TT) {
1584   unsigned CPUType = ~0U;
1585
1586   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1587   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1588   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1589   // specific constants here because they are implicitly part of the Darwin ABI.
1590   enum {
1591     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1592     DARWIN_CPU_TYPE_X86        = 7,
1593     DARWIN_CPU_TYPE_ARM        = 12,
1594     DARWIN_CPU_TYPE_POWERPC    = 18
1595   };
1596
1597   if (TT.find("x86_64-") == 0)
1598     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1599   else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1600            TT[4] == '-' && TT[1] - '3' < 6)
1601     CPUType = DARWIN_CPU_TYPE_X86;
1602   else if (TT.find("powerpc-") == 0)
1603     CPUType = DARWIN_CPU_TYPE_POWERPC;
1604   else if (TT.find("powerpc64-") == 0)
1605     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1606   else if (isARMTriplet(TT))
1607     CPUType = DARWIN_CPU_TYPE_ARM;
1608
1609   // Traditional Bitcode starts after header.
1610   unsigned BCOffset = DarwinBCHeaderSize;
1611
1612   Stream.Emit(0x0B17C0DE, 32);
1613   Stream.Emit(0         , 32);  // Version.
1614   Stream.Emit(BCOffset  , 32);
1615   Stream.Emit(0         , 32);  // Filled in later.
1616   Stream.Emit(CPUType   , 32);
1617 }
1618
1619 /// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1620 /// finalize the header.
1621 static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1622   // Update the size field in the header.
1623   Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1624
1625   // If the file is not a multiple of 16 bytes, insert dummy padding.
1626   while (BufferSize & 15) {
1627     Stream.Emit(0, 8);
1628     ++BufferSize;
1629   }
1630 }
1631
1632
1633 /// WriteBitcodeToFile - Write the specified module to the specified output
1634 /// stream.
1635 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1636   std::vector<unsigned char> Buffer;
1637   BitstreamWriter Stream(Buffer);
1638
1639   Buffer.reserve(256*1024);
1640
1641   WriteBitcodeToStream( M, Stream );
1642
1643   // Write the generated bitstream to "Out".
1644   Out.write((char*)&Buffer.front(), Buffer.size());
1645 }
1646
1647 /// WriteBitcodeToStream - Write the specified module to the specified output
1648 /// stream.
1649 void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1650   // If this is darwin or another generic macho target, emit a file header and
1651   // trailer if needed.
1652   bool isMacho =
1653     M->getTargetTriple().find("-darwin") != std::string::npos ||
1654     M->getTargetTriple().find("-macho") != std::string::npos;
1655   if (isMacho)
1656     EmitDarwinBCHeader(Stream, M->getTargetTriple());
1657
1658   // Emit the file header.
1659   Stream.Emit((unsigned)'B', 8);
1660   Stream.Emit((unsigned)'C', 8);
1661   Stream.Emit(0x0, 4);
1662   Stream.Emit(0xC, 4);
1663   Stream.Emit(0xE, 4);
1664   Stream.Emit(0xD, 4);
1665
1666   // Emit the module.
1667   WriteModule(M, Stream);
1668
1669   if (isMacho)
1670     EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1671 }